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)
1141 bb_error_msg("hush.c:%u", lineno);
1143 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1147 # undef die_if_script
1148 # undef syntax_error
1149 # undef syntax_error_at
1150 # undef syntax_error_unterm_ch
1151 # undef syntax_error_unterm_str
1152 # undef syntax_error_unexpected_ch
1154 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1155 # define syntax_error(msg) syntax_error(__LINE__, msg)
1156 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1157 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1158 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1159 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1163 #if ENABLE_HUSH_INTERACTIVE
1164 static void cmdedit_update_prompt(void);
1166 # define cmdedit_update_prompt() ((void)0)
1170 /* Utility functions
1172 /* Replace each \x with x in place, return ptr past NUL. */
1173 static char *unbackslash(char *src)
1175 char *dst = src = strchrnul(src, '\\');
1179 if ((*dst++ = *src++) == '\0')
1185 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1206 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1207 v[count1 + count2] = NULL;
1210 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1214 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1216 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1217 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1220 #define add_strings_to_strings(strings, add, need_to_dup) \
1221 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1224 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1225 static char **add_string_to_strings(char **strings, char *add)
1230 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1233 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1235 char **ptr = add_string_to_strings(strings, add);
1236 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1239 #define add_string_to_strings(strings, add) \
1240 xx_add_string_to_strings(__LINE__, strings, add)
1243 static void free_strings(char **strings)
1258 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1260 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1261 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1263 /* fd was not open? */
1273 /* Manipulating the list of open FILEs */
1274 static FILE *remember_FILE(FILE *fp)
1277 struct FILE_list *n = xmalloc(sizeof(*n));
1278 n->next = G.FILE_list;
1282 close_on_exec_on(n->fd);
1286 static void fclose_and_forget(FILE *fp)
1288 struct FILE_list **pp = &G.FILE_list;
1290 struct FILE_list *cur = *pp;
1291 if (cur->fp == fp) {
1300 static int save_FILEs_on_redirect(int fd)
1302 struct FILE_list *fl = G.FILE_list;
1305 /* We use it only on script files, they are all CLOEXEC */
1306 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1313 static void restore_redirected_FILEs(void)
1315 struct FILE_list *fl = G.FILE_list;
1317 int should_be = fileno(fl->fp);
1318 if (fl->fd != should_be) {
1319 xmove_fd(fl->fd, should_be);
1325 #if ENABLE_FEATURE_SH_STANDALONE
1326 static void close_all_FILE_list(void)
1328 struct FILE_list *fl = G.FILE_list;
1330 /* fclose would also free FILE object.
1331 * It is disastrous if we share memory with a vforked parent.
1332 * I'm not sure we never come here after vfork.
1333 * Therefore just close fd, nothing more.
1335 /*fclose(fl->fp); - unsafe */
1343 /* Helpers for setting new $n and restoring them back
1345 typedef struct save_arg_t {
1349 smallint sv_g_malloced;
1352 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1356 sv->sv_argv0 = argv[0];
1357 sv->sv_g_argv = G.global_argv;
1358 sv->sv_g_argc = G.global_argc;
1359 sv->sv_g_malloced = G.global_args_malloced;
1361 argv[0] = G.global_argv[0]; /* retain $0 */
1362 G.global_argv = argv;
1363 G.global_args_malloced = 0;
1371 static void restore_G_args(save_arg_t *sv, char **argv)
1375 if (G.global_args_malloced) {
1376 /* someone ran "set -- arg1 arg2 ...", undo */
1378 while (*++pp) /* note: does not free $0 */
1380 free(G.global_argv);
1382 argv[0] = sv->sv_argv0;
1383 G.global_argv = sv->sv_g_argv;
1384 G.global_argc = sv->sv_g_argc;
1385 G.global_args_malloced = sv->sv_g_malloced;
1389 /* Basic theory of signal handling in shell
1390 * ========================================
1391 * This does not describe what hush does, rather, it is current understanding
1392 * what it _should_ do. If it doesn't, it's a bug.
1393 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1395 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1396 * is finished or backgrounded. It is the same in interactive and
1397 * non-interactive shells, and is the same regardless of whether
1398 * a user trap handler is installed or a shell special one is in effect.
1399 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1400 * backgrounds (i.e. stops) or kills all members of currently running
1403 * Wait builtin is interruptible by signals for which user trap is set
1404 * or by SIGINT in interactive shell.
1406 * Trap handlers will execute even within trap handlers. (right?)
1408 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1409 * except for handlers set to '' (empty string).
1411 * If job control is off, backgrounded commands ("cmd &")
1412 * have SIGINT, SIGQUIT set to SIG_IGN.
1414 * Commands which are run in command substitution ("`cmd`")
1415 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1417 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1418 * by the shell from its parent.
1420 * Signals which differ from SIG_DFL action
1421 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1424 * SIGTERM (interactive): ignore
1425 * SIGHUP (interactive):
1426 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1427 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1428 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1429 * that all pipe members are stopped. Try this in bash:
1430 * while :; do :; done - ^Z does not background it
1431 * (while :; do :; done) - ^Z backgrounds it
1432 * SIGINT (interactive): wait for last pipe, ignore the rest
1433 * of the command line, show prompt. NB: ^C does not send SIGINT
1434 * to interactive shell while shell is waiting for a pipe,
1435 * since shell is bg'ed (is not in foreground process group).
1436 * Example 1: this waits 5 sec, but does not execute ls:
1437 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1438 * Example 2: this does not wait and does not execute ls:
1439 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1440 * Example 3: this does not wait 5 sec, but executes ls:
1441 * "sleep 5; ls -l" + press ^C
1442 * Example 4: this does not wait and does not execute ls:
1443 * "sleep 5 & wait; ls -l" + press ^C
1445 * (What happens to signals which are IGN on shell start?)
1446 * (What happens with signal mask on shell start?)
1448 * Old implementation
1449 * ==================
1450 * We use in-kernel pending signal mask to determine which signals were sent.
1451 * We block all signals which we don't want to take action immediately,
1452 * i.e. we block all signals which need to have special handling as described
1453 * above, and all signals which have traps set.
1454 * After each pipe execution, we extract any pending signals via sigtimedwait()
1457 * unsigned special_sig_mask: a mask of such "special" signals
1458 * sigset_t blocked_set: current blocked signal set
1461 * clear bit in blocked_set unless it is also in special_sig_mask
1462 * "trap 'cmd' SIGxxx":
1463 * set bit in blocked_set (even if 'cmd' is '')
1464 * after [v]fork, if we plan to be a shell:
1465 * unblock signals with special interactive handling
1466 * (child shell is not interactive),
1467 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1468 * after [v]fork, if we plan to exec:
1469 * POSIX says fork clears pending signal mask in child - no need to clear it.
1470 * Restore blocked signal set to one inherited by shell just prior to exec.
1472 * Note: as a result, we do not use signal handlers much. The only uses
1473 * are to count SIGCHLDs
1474 * and to restore tty pgrp on signal-induced exit.
1477 * Standard says "When a subshell is entered, traps that are not being ignored
1478 * are set to the default actions". bash interprets it so that traps which
1479 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1481 * Problem: the above approach makes it unwieldy to catch signals while
1482 * we are in read builtin, or while we read commands from stdin:
1483 * masked signals are not visible!
1485 * New implementation
1486 * ==================
1487 * We record each signal we are interested in by installing signal handler
1488 * for them - a bit like emulating kernel pending signal mask in userspace.
1489 * We are interested in: signals which need to have special handling
1490 * as described above, and all signals which have traps set.
1491 * Signals are recorded in pending_set.
1492 * After each pipe execution, we extract any pending signals
1495 * unsigned special_sig_mask: a mask of shell-special signals.
1496 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1497 * char *traps[sig] if trap for sig is set (even if it's '').
1498 * sigset_t pending_set: set of sigs we received.
1501 * if sig is in special_sig_mask, set handler back to:
1502 * record_pending_signo, or to IGN if it's a tty stop signal
1503 * if sig is in fatal_sig_mask, set handler back to sigexit.
1504 * else: set handler back to SIG_DFL
1505 * "trap 'cmd' SIGxxx":
1506 * set handler to record_pending_signo.
1508 * set handler to SIG_IGN.
1509 * after [v]fork, if we plan to be a shell:
1510 * set signals with special interactive handling to SIG_DFL
1511 * (because child shell is not interactive),
1512 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1513 * after [v]fork, if we plan to exec:
1514 * POSIX says fork clears pending signal mask in child - no need to clear it.
1516 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1517 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1520 * Standard says "When a subshell is entered, traps that are not being ignored
1521 * are set to the default actions". bash interprets it so that traps which
1522 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1525 SPECIAL_INTERACTIVE_SIGS = 0
1530 SPECIAL_JOBSTOP_SIGS = 0
1539 static void record_pending_signo(int sig)
1541 sigaddset(&G.pending_set, sig);
1542 #if ENABLE_HUSH_FAST
1543 if (sig == SIGCHLD) {
1545 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1550 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1552 struct sigaction old_sa;
1554 /* We could use signal() to install handlers... almost:
1555 * except that we need to mask ALL signals while handlers run.
1556 * I saw signal nesting in strace, race window isn't small.
1557 * SA_RESTART is also needed, but in Linux, signal()
1558 * sets SA_RESTART too.
1560 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1561 /* sigfillset(&G.sa.sa_mask); - already done */
1562 /* G.sa.sa_flags = SA_RESTART; - already done */
1563 G.sa.sa_handler = handler;
1564 sigaction(sig, &G.sa, &old_sa);
1565 return old_sa.sa_handler;
1568 static void hush_exit(int exitcode) NORETURN;
1570 static void restore_ttypgrp_and__exit(void) NORETURN;
1571 static void restore_ttypgrp_and__exit(void)
1573 /* xfunc has failed! die die die */
1574 /* no EXIT traps, this is an escape hatch! */
1576 hush_exit(xfunc_error_retval);
1581 /* Needed only on some libc:
1582 * It was observed that on exit(), fgetc'ed buffered data
1583 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1584 * With the net effect that even after fork(), not vfork(),
1585 * exit() in NOEXECed applet in "sh SCRIPT":
1586 * noexec_applet_here
1587 * echo END_OF_SCRIPT
1588 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1589 * This makes "echo END_OF_SCRIPT" executed twice.
1590 * Similar problems can be seen with die_if_script() -> xfunc_die()
1591 * and in `cmd` handling.
1592 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1594 static void fflush_and__exit(void) NORETURN;
1595 static void fflush_and__exit(void)
1598 _exit(xfunc_error_retval);
1601 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1602 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1603 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1604 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1606 /* Restores tty foreground process group, and exits.
1607 * May be called as signal handler for fatal signal
1608 * (will resend signal to itself, producing correct exit state)
1609 * or called directly with -EXITCODE.
1610 * We also call it if xfunc is exiting.
1612 static void sigexit(int sig) NORETURN;
1613 static void sigexit(int sig)
1615 /* Careful: we can end up here after [v]fork. Do not restore
1616 * tty pgrp then, only top-level shell process does that */
1617 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1618 /* Disable all signals: job control, SIGPIPE, etc.
1619 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1621 sigprocmask_allsigs(SIG_BLOCK);
1622 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1625 /* Not a signal, just exit */
1629 kill_myself_with_sig(sig); /* does not return */
1633 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1634 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1638 static sighandler_t pick_sighandler(unsigned sig)
1640 sighandler_t handler = SIG_DFL;
1641 if (sig < sizeof(unsigned)*8) {
1642 unsigned sigmask = (1 << sig);
1646 if (G_fatal_sig_mask & sigmask)
1650 /* sig has special handling? */
1651 if (G.special_sig_mask & sigmask) {
1652 handler = record_pending_signo;
1653 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1654 * in order to ignore them: they will be raised
1655 * in an endless loop when we try to do some
1656 * terminal ioctls! We do have to _ignore_ these.
1658 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1665 /* Restores tty foreground process group, and exits. */
1666 static void hush_exit(int exitcode)
1668 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1669 save_history(G.line_input_state);
1673 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1675 /* argv[0] is unused */
1676 argv[1] = G.traps[0];
1678 G.exiting = 1; /* prevent EXIT trap recursion */
1679 /* Note: G.traps[0] is not cleared!
1680 * "trap" will still show it, if executed
1685 #if ENABLE_FEATURE_CLEAN_UP
1687 struct variable *cur_var;
1688 if (G.cwd != bb_msg_unknown)
1690 cur_var = G.top_var;
1692 struct variable *tmp = cur_var;
1693 if (!cur_var->max_len)
1694 free(cur_var->varstr);
1695 cur_var = cur_var->next;
1703 sigexit(- (exitcode & 0xff));
1710 //TODO: return a mask of ALL handled sigs?
1711 static int check_and_run_traps(void)
1718 if (sigisemptyset(&G.pending_set))
1723 if (sigismember(&G.pending_set, sig)) {
1724 sigdelset(&G.pending_set, sig);
1727 } while (sig < NSIG);
1730 if (G.traps && G.traps[sig]) {
1731 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1732 if (G.traps[sig][0]) {
1733 /* We have user-defined handler */
1734 smalluint save_rcode;
1736 /* argv[0] is unused */
1737 argv[1] = G.traps[sig];
1739 save_rcode = G.last_exitcode;
1741 //FIXME: shouldn't it be set to 128 + sig instead?
1742 G.last_exitcode = save_rcode;
1744 } /* else: "" trap, ignoring signal */
1747 /* not a trap: special action */
1750 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1757 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1758 /* bash is observed to signal whole process groups,
1759 * not individual processes */
1760 for (job = G.job_list; job; job = job->next) {
1763 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1764 if (kill(- job->pgrp, SIGHUP) == 0)
1765 kill(- job->pgrp, SIGCONT);
1770 #if ENABLE_HUSH_FAST
1772 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1774 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1776 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1777 * This simplifies wait builtin a bit.
1781 default: /* ignored: */
1782 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1783 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1785 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1786 * Example: wait is not interrupted by TERM
1787 * in interactive shell, because TERM is ignored.
1796 static const char *get_cwd(int force)
1798 if (force || G.cwd == NULL) {
1799 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1800 * we must not try to free(bb_msg_unknown) */
1801 if (G.cwd == bb_msg_unknown)
1803 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1805 G.cwd = bb_msg_unknown;
1812 * Shell and environment variable support
1814 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1816 struct variable **pp;
1817 struct variable *cur;
1820 while ((cur = *pp) != NULL) {
1821 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1828 static const char* FAST_FUNC get_local_var_value(const char *name)
1830 struct variable **vpp;
1831 unsigned len = strlen(name);
1833 if (G.expanded_assignments) {
1834 char **cpp = G.expanded_assignments;
1837 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1838 return cp + len + 1;
1843 vpp = get_ptr_to_local_var(name, len);
1845 return (*vpp)->varstr + len + 1;
1847 if (strcmp(name, "PPID") == 0)
1848 return utoa(G.root_ppid);
1849 // bash compat: UID? EUID?
1850 #if ENABLE_HUSH_RANDOM_SUPPORT
1851 if (strcmp(name, "RANDOM") == 0)
1852 return utoa(next_random(&G.random_gen));
1857 /* str holds "NAME=VAL" and is expected to be malloced.
1858 * We take ownership of it.
1860 * 0: do not change export flag
1861 * (if creating new variable, flag will be 0)
1862 * 1: set export flag and putenv the variable
1863 * -1: clear export flag and unsetenv the variable
1864 * flg_read_only is set only when we handle -R var=val
1866 #if !BB_MMU && ENABLE_HUSH_LOCAL
1867 /* all params are used */
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, local_lvl)
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)
1874 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1875 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1876 set_local_var(str, flg_export, flg_read_only)
1878 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1880 struct variable **var_pp;
1881 struct variable *cur;
1882 char *free_me = NULL;
1886 eq_sign = strchr(str, '=');
1887 if (!eq_sign) { /* not expected to ever happen? */
1892 name_len = eq_sign - str + 1; /* including '=' */
1893 var_pp = &G.top_var;
1894 while ((cur = *var_pp) != NULL) {
1895 if (strncmp(cur->varstr, str, name_len) != 0) {
1896 var_pp = &cur->next;
1900 /* We found an existing var with this name */
1901 if (cur->flg_read_only) {
1905 bb_error_msg("%s: readonly variable", str);
1909 if (flg_export == -1) { // "&& cur->flg_export" ?
1910 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1915 #if ENABLE_HUSH_LOCAL
1916 if (cur->func_nest_level < local_lvl) {
1917 /* New variable is declared as local,
1918 * and existing one is global, or local
1919 * from enclosing function.
1920 * Remove and save old one: */
1921 *var_pp = cur->next;
1922 cur->next = *G.shadowed_vars_pp;
1923 *G.shadowed_vars_pp = cur;
1924 /* bash 3.2.33(1) and exported vars:
1926 * # f() { local z=a; env | grep ^z; }
1932 if (cur->flg_export)
1937 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1942 if (cur->max_len != 0) {
1943 if (cur->max_len >= strlen(str)) {
1944 /* This one is from startup env, reuse space */
1945 strcpy(cur->varstr, str);
1950 goto set_str_and_exp;
1952 /* max_len == 0 signifies "malloced" var, which we can
1953 * (and have to) free. But we can't free(cur->varstr) here:
1954 * if cur->flg_export is 1, it is in the environment.
1955 * We should either unsetenv+free, or wait until putenv,
1956 * then putenv(new)+free(old).
1958 free_me = cur->varstr;
1959 goto set_str_and_exp;
1962 /* Not found - create new variable struct */
1963 cur = xzalloc(sizeof(*cur));
1964 #if ENABLE_HUSH_LOCAL
1965 cur->func_nest_level = local_lvl;
1967 cur->next = *var_pp;
1973 cur->flg_read_only = flg_read_only;
1976 if (flg_export == 1)
1977 cur->flg_export = 1;
1978 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1979 cmdedit_update_prompt();
1980 if (cur->flg_export) {
1981 if (flg_export == -1) {
1982 cur->flg_export = 0;
1983 /* unsetenv was already done */
1986 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1987 i = putenv(cur->varstr);
1988 /* only now we can free old exported malloced string */
1997 /* Used at startup and after each cd */
1998 static void set_pwd_var(int exp)
2000 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2001 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2004 static int unset_local_var_len(const char *name, int name_len)
2006 struct variable *cur;
2007 struct variable **var_pp;
2010 return EXIT_SUCCESS;
2011 var_pp = &G.top_var;
2012 while ((cur = *var_pp) != NULL) {
2013 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2014 if (cur->flg_read_only) {
2015 bb_error_msg("%s: readonly variable", name);
2016 return EXIT_FAILURE;
2018 *var_pp = cur->next;
2019 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2020 bb_unsetenv(cur->varstr);
2021 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2022 cmdedit_update_prompt();
2026 return EXIT_SUCCESS;
2028 var_pp = &cur->next;
2030 return EXIT_SUCCESS;
2033 static int unset_local_var(const char *name)
2035 return unset_local_var_len(name, strlen(name));
2038 static void unset_vars(char **strings)
2046 const char *eq = strchrnul(*v, '=');
2047 unset_local_var_len(*v, (int)(eq - *v));
2053 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2055 char *var = xasprintf("%s=%s", name, val);
2056 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2061 * Helpers for "var1=val1 var2=val2 cmd" feature
2063 static void add_vars(struct variable *var)
2065 struct variable *next;
2069 var->next = G.top_var;
2071 if (var->flg_export) {
2072 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2073 putenv(var->varstr);
2075 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2081 static struct variable *set_vars_and_save_old(char **strings)
2084 struct variable *old = NULL;
2090 struct variable *var_p;
2091 struct variable **var_pp;
2094 eq = strchr(*s, '=');
2096 var_pp = get_ptr_to_local_var(*s, eq - *s);
2098 /* Remove variable from global linked list */
2100 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2101 *var_pp = var_p->next;
2102 /* Add it to returned list */
2106 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2117 static void reinit_unicode_for_hush(void)
2119 /* Unicode support should be activated even if LANG is set
2120 * _during_ shell execution, not only if it was set when
2121 * shell was started. Therefore, re-check LANG every time:
2123 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2124 || ENABLE_UNICODE_USING_LOCALE
2126 const char *s = get_local_var_value("LC_ALL");
2127 if (!s) s = get_local_var_value("LC_CTYPE");
2128 if (!s) s = get_local_var_value("LANG");
2134 * in_str support (strings, and "strings" read from files).
2137 #if ENABLE_HUSH_INTERACTIVE
2138 /* To test correct lineedit/interactive behavior, type from command line:
2144 * It excercises a lot of corner cases.
2146 static void cmdedit_update_prompt(void)
2148 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2149 G.PS1 = get_local_var_value("PS1");
2152 G.PS2 = get_local_var_value("PS2");
2159 static const char *setup_prompt_string(int promptmode)
2161 const char *prompt_str;
2162 debug_printf("setup_prompt_string %d ", promptmode);
2163 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2164 /* Set up the prompt */
2165 if (promptmode == 0) { /* PS1 */
2167 /* bash uses $PWD value, even if it is set by user.
2168 * It uses current dir only if PWD is unset.
2169 * We always use current dir. */
2170 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2175 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2176 debug_printf("prompt_str '%s'\n", prompt_str);
2179 static int get_user_input(struct in_str *i)
2182 const char *prompt_str;
2184 prompt_str = setup_prompt_string(i->promptmode);
2185 # if ENABLE_FEATURE_EDITING
2187 reinit_unicode_for_hush();
2188 if (G.flag_SIGINT) {
2189 /* There was ^C'ed, make it look prettier: */
2193 /* buglet: SIGINT will not make new prompt to appear _at once_,
2194 * only after <Enter>. (^C works immediately) */
2195 r = read_line_input(G.line_input_state, prompt_str,
2196 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2199 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2201 write(STDOUT_FILENO, "^C", 2);
2204 check_and_run_traps();
2205 if (r != 0 && !G.flag_SIGINT)
2207 /* ^C or SIGINT: repeat */
2208 G.last_exitcode = 128 + SIGINT;
2211 /* EOF/error detected */
2213 i->peek_buf[0] = r = EOF;
2216 i->p = G.user_input_buf;
2217 return (unsigned char)*i->p++;
2221 if (i->last_char == '\0' || i->last_char == '\n') {
2222 /* Why check_and_run_traps here? Try this interactively:
2223 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2224 * $ <[enter], repeatedly...>
2225 * Without check_and_run_traps, handler never runs.
2227 check_and_run_traps();
2228 fputs(prompt_str, stdout);
2231 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2233 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2234 * no ^C masking happens during fgetc, no special code for ^C:
2235 * it generates SIGINT as usual.
2237 check_and_run_traps();
2239 G.last_exitcode = 128 + SIGINT;
2246 /* This is the magic location that prints prompts
2247 * and gets data back from the user */
2248 static int fgetc_interactive(struct in_str *i)
2251 /* If it's interactive stdin, get new line. */
2252 if (G_interactive_fd && i->file == stdin) {
2253 /* Returns first char (or EOF), the rest is in i->p[] */
2254 ch = get_user_input(i);
2255 i->promptmode = 1; /* PS2 */
2257 /* Not stdin: script file, sourced file, etc */
2258 do ch = fgetc(i->file); while (ch == '\0');
2263 static inline int fgetc_interactive(struct in_str *i)
2266 do ch = fgetc(i->file); while (ch == '\0');
2269 #endif /* INTERACTIVE */
2271 static int i_getch(struct in_str *i)
2276 /* string-based in_str */
2277 ch = (unsigned char)*i->p;
2286 /* FILE-based in_str */
2288 #if ENABLE_FEATURE_EDITING
2289 /* This can be stdin, check line editing char[] buffer */
2290 if (i->p && *i->p != '\0') {
2291 ch = (unsigned char)*i->p++;
2295 /* peek_buf[] is an int array, not char. Can contain EOF. */
2296 ch = i->peek_buf[0];
2298 int ch2 = i->peek_buf[1];
2299 i->peek_buf[0] = ch2;
2300 if (ch2 == 0) /* very likely, avoid redundant write */
2306 ch = fgetc_interactive(i);
2308 debug_printf("file_get: got '%c' %d\n", ch, ch);
2313 static int i_peek(struct in_str *i)
2318 /* string-based in_str */
2319 /* Doesn't report EOF on NUL. None of the callers care. */
2320 return (unsigned char)*i->p;
2323 /* FILE-based in_str */
2325 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2326 /* This can be stdin, check line editing char[] buffer */
2327 if (i->p && *i->p != '\0')
2328 return (unsigned char)*i->p;
2330 /* peek_buf[] is an int array, not char. Can contain EOF. */
2331 ch = i->peek_buf[0];
2335 /* Need to get a new char */
2336 ch = fgetc_interactive(i);
2337 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2339 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2340 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2346 i->peek_buf[0] = ch;
2347 /*i->peek_buf[1] = 0; - already is */
2351 /* Only ever called if i_peek() was called, and did not return EOF.
2352 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2353 * not end-of-line. Therefore we never need to read a new editing line here.
2355 static int i_peek2(struct in_str *i)
2359 /* There are two cases when i->p[] buffer exists.
2360 * (1) it's a string in_str.
2361 * (2) It's a file, and we have a saved line editing buffer.
2362 * In both cases, we know that i->p[0] exists and not NUL, and
2363 * the peek2 result is in i->p[1].
2366 return (unsigned char)i->p[1];
2368 /* Now we know it is a file-based in_str. */
2370 /* peek_buf[] is an int array, not char. Can contain EOF. */
2371 /* Is there 2nd char? */
2372 ch = i->peek_buf[1];
2374 /* We did not read it yet, get it now */
2375 do ch = fgetc(i->file); while (ch == '\0');
2376 i->peek_buf[1] = ch;
2379 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2383 static void setup_file_in_str(struct in_str *i, FILE *f)
2385 memset(i, 0, sizeof(*i));
2386 /* i->promptmode = 0; - PS1 (memset did it) */
2391 static void setup_string_in_str(struct in_str *i, const char *s)
2393 memset(i, 0, sizeof(*i));
2394 /* i->promptmode = 0; - PS1 (memset did it) */
2395 /*i->file = NULL */;
2403 #define B_CHUNK (32 * sizeof(char*))
2405 static void o_reset_to_empty_unquoted(o_string *o)
2408 o->has_quoted_part = 0;
2413 static void o_free(o_string *o)
2416 memset(o, 0, sizeof(*o));
2419 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2424 static void o_grow_by(o_string *o, int len)
2426 if (o->length + len > o->maxlen) {
2427 o->maxlen += (2 * len) | (B_CHUNK-1);
2428 o->data = xrealloc(o->data, 1 + o->maxlen);
2432 static void o_addchr(o_string *o, int ch)
2434 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2435 if (o->length < o->maxlen) {
2436 /* likely. avoid o_grow_by() call */
2438 o->data[o->length] = ch;
2440 o->data[o->length] = '\0';
2448 /* Valid only if we know o_string is not empty */
2449 static void o_delchr(o_string *o)
2452 o->data[o->length] = '\0';
2456 static void o_addblock(o_string *o, const char *str, int len)
2459 memcpy(&o->data[o->length], str, len);
2461 o->data[o->length] = '\0';
2464 static void o_addstr(o_string *o, const char *str)
2466 o_addblock(o, str, strlen(str));
2470 static void nommu_addchr(o_string *o, int ch)
2476 # define nommu_addchr(o, str) ((void)0)
2479 static void o_addstr_with_NUL(o_string *o, const char *str)
2481 o_addblock(o, str, strlen(str) + 1);
2485 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2486 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2487 * Apparently, on unquoted $v bash still does globbing
2488 * ("v='*.txt'; echo $v" prints all .txt files),
2489 * but NOT brace expansion! Thus, there should be TWO independent
2490 * quoting mechanisms on $v expansion side: one protects
2491 * $v from brace expansion, and other additionally protects "$v" against globbing.
2492 * We have only second one.
2495 #if ENABLE_HUSH_BRACE_EXPANSION
2496 # define MAYBE_BRACES "{}"
2498 # define MAYBE_BRACES ""
2501 /* My analysis of quoting semantics tells me that state information
2502 * is associated with a destination, not a source.
2504 static void o_addqchr(o_string *o, int ch)
2507 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2512 o->data[o->length] = '\\';
2515 o->data[o->length] = ch;
2517 o->data[o->length] = '\0';
2520 static void o_addQchr(o_string *o, int ch)
2523 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2524 && strchr("*?[\\" MAYBE_BRACES, ch)
2527 o->data[o->length] = '\\';
2531 o->data[o->length] = ch;
2533 o->data[o->length] = '\0';
2536 static void o_addqblock(o_string *o, const char *str, int len)
2541 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2542 if (ordinary_cnt > len) /* paranoia */
2544 o_addblock(o, str, ordinary_cnt);
2545 if (ordinary_cnt == len)
2546 return; /* NUL is already added by o_addblock */
2547 str += ordinary_cnt;
2548 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2552 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2554 o->data[o->length] = '\\';
2558 o->data[o->length] = ch;
2561 o->data[o->length] = '\0';
2564 static void o_addQblock(o_string *o, const char *str, int len)
2566 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2567 o_addblock(o, str, len);
2570 o_addqblock(o, str, len);
2573 static void o_addQstr(o_string *o, const char *str)
2575 o_addQblock(o, str, strlen(str));
2578 /* A special kind of o_string for $VAR and `cmd` expansion.
2579 * It contains char* list[] at the beginning, which is grown in 16 element
2580 * increments. Actual string data starts at the next multiple of 16 * (char*).
2581 * list[i] contains an INDEX (int!) into this string data.
2582 * It means that if list[] needs to grow, data needs to be moved higher up
2583 * but list[i]'s need not be modified.
2584 * NB: remembering how many list[i]'s you have there is crucial.
2585 * o_finalize_list() operation post-processes this structure - calculates
2586 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2588 #if DEBUG_EXPAND || DEBUG_GLOB
2589 static void debug_print_list(const char *prefix, o_string *o, int n)
2591 char **list = (char**)o->data;
2592 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2596 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2597 prefix, list, n, string_start, o->length, o->maxlen,
2598 !!(o->o_expflags & EXP_FLAG_GLOB),
2600 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2603 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2604 o->data + (int)(uintptr_t)list[i] + string_start,
2605 o->data + (int)(uintptr_t)list[i] + string_start);
2609 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2611 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2615 # define debug_print_list(prefix, o, n) ((void)0)
2618 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2619 * in list[n] so that it points past last stored byte so far.
2620 * It returns n+1. */
2621 static int o_save_ptr_helper(o_string *o, int n)
2623 char **list = (char**)o->data;
2627 if (!o->has_empty_slot) {
2628 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2629 string_len = o->length - string_start;
2630 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2631 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2632 /* list[n] points to string_start, make space for 16 more pointers */
2633 o->maxlen += 0x10 * sizeof(list[0]);
2634 o->data = xrealloc(o->data, o->maxlen + 1);
2635 list = (char**)o->data;
2636 memmove(list + n + 0x10, list + n, string_len);
2637 o->length += 0x10 * sizeof(list[0]);
2639 debug_printf_list("list[%d]=%d string_start=%d\n",
2640 n, string_len, string_start);
2643 /* We have empty slot at list[n], reuse without growth */
2644 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2645 string_len = o->length - string_start;
2646 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2647 n, string_len, string_start);
2648 o->has_empty_slot = 0;
2650 o->has_quoted_part = 0;
2651 list[n] = (char*)(uintptr_t)string_len;
2655 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2656 static int o_get_last_ptr(o_string *o, int n)
2658 char **list = (char**)o->data;
2659 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2661 return ((int)(uintptr_t)list[n-1]) + string_start;
2664 #if ENABLE_HUSH_BRACE_EXPANSION
2665 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2666 * first, it processes even {a} (no commas), second,
2667 * I didn't manage to make it return strings when they don't match
2668 * existing files. Need to re-implement it.
2672 static int glob_needed(const char *s)
2681 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2687 /* Return pointer to next closing brace or to comma */
2688 static const char *next_brace_sub(const char *cp)
2692 while (*cp != '\0') {
2699 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2705 return *cp != '\0' ? cp : NULL;
2707 /* Recursive brace globber. Note: may garble pattern[]. */
2708 static int glob_brace(char *pattern, o_string *o, int n)
2710 char *new_pattern_buf;
2717 debug_printf_glob("glob_brace('%s')\n", pattern);
2723 if (*begin == '{') {
2724 /* Find the first sub-pattern and at the same time
2725 * find the rest after the closing brace */
2726 next = next_brace_sub(begin);
2728 /* An illegal expression */
2732 /* "{abc}" with no commas - illegal
2733 * brace expr, disregard and skip it */
2739 if (*begin == '\\' && begin[1] != '\0')
2743 debug_printf_glob("begin:%s\n", begin);
2744 debug_printf_glob("next:%s\n", next);
2746 /* Now find the end of the whole brace expression */
2748 while (*rest != '}') {
2749 rest = next_brace_sub(rest);
2751 /* An illegal expression */
2754 debug_printf_glob("rest:%s\n", rest);
2756 rest_len = strlen(++rest) + 1;
2758 /* We are sure the brace expression is well-formed */
2760 /* Allocate working buffer large enough for our work */
2761 new_pattern_buf = xmalloc(strlen(pattern));
2763 /* We have a brace expression. BEGIN points to the opening {,
2764 * NEXT points past the terminator of the first element, and REST
2765 * points past the final }. We will accumulate result names from
2766 * recursive runs for each brace alternative in the buffer using
2771 /* Construct the new glob expression */
2774 mempcpy(new_pattern_buf,
2775 /* We know the prefix for all sub-patterns */
2776 pattern, begin - pattern),
2780 /* Note: glob_brace() may garble new_pattern_buf[].
2781 * That's why we re-copy prefix every time (1st memcpy above).
2783 n = glob_brace(new_pattern_buf, o, n);
2785 /* We saw the last entry */
2789 next = next_brace_sub(next);
2791 free(new_pattern_buf);
2799 memset(&globdata, 0, sizeof(globdata));
2800 gr = glob(pattern, 0, NULL, &globdata);
2801 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2803 if (gr == GLOB_NOMATCH) {
2804 globfree(&globdata);
2805 /* NB: garbles parameter */
2806 unbackslash(pattern);
2807 o_addstr_with_NUL(o, pattern);
2808 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2809 return o_save_ptr_helper(o, n);
2811 if (gr == GLOB_NOSPACE)
2812 bb_error_msg_and_die(bb_msg_memory_exhausted);
2813 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2814 * but we didn't specify it. Paranoia again. */
2815 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2817 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2818 char **argv = globdata.gl_pathv;
2820 o_addstr_with_NUL(o, *argv);
2821 n = o_save_ptr_helper(o, n);
2827 globfree(&globdata);
2831 /* Performs globbing on last list[],
2832 * saving each result as a new list[].
2834 static int perform_glob(o_string *o, int n)
2836 char *pattern, *copy;
2838 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2840 return o_save_ptr_helper(o, n);
2841 pattern = o->data + o_get_last_ptr(o, n);
2842 debug_printf_glob("glob pattern '%s'\n", pattern);
2843 if (!glob_needed(pattern)) {
2844 /* unbackslash last string in o in place, fix length */
2845 o->length = unbackslash(pattern) - o->data;
2846 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2847 return o_save_ptr_helper(o, n);
2850 copy = xstrdup(pattern);
2851 /* "forget" pattern in o */
2852 o->length = pattern - o->data;
2853 n = glob_brace(copy, o, n);
2856 debug_print_list("perform_glob returning", o, n);
2860 #else /* !HUSH_BRACE_EXPANSION */
2863 static int glob_needed(const char *s)
2872 if (*s == '*' || *s == '[' || *s == '?')
2878 /* Performs globbing on last list[],
2879 * saving each result as a new list[].
2881 static int perform_glob(o_string *o, int n)
2887 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2889 return o_save_ptr_helper(o, n);
2890 pattern = o->data + o_get_last_ptr(o, n);
2891 debug_printf_glob("glob pattern '%s'\n", pattern);
2892 if (!glob_needed(pattern)) {
2894 /* unbackslash last string in o in place, fix length */
2895 o->length = unbackslash(pattern) - o->data;
2896 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2897 return o_save_ptr_helper(o, n);
2900 memset(&globdata, 0, sizeof(globdata));
2901 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2902 * If we glob "*.\*" and don't find anything, we need
2903 * to fall back to using literal "*.*", but GLOB_NOCHECK
2904 * will return "*.\*"!
2906 gr = glob(pattern, 0, NULL, &globdata);
2907 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2909 if (gr == GLOB_NOMATCH) {
2910 globfree(&globdata);
2913 if (gr == GLOB_NOSPACE)
2914 bb_error_msg_and_die(bb_msg_memory_exhausted);
2915 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2916 * but we didn't specify it. Paranoia again. */
2917 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2919 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2920 char **argv = globdata.gl_pathv;
2921 /* "forget" pattern in o */
2922 o->length = pattern - o->data;
2924 o_addstr_with_NUL(o, *argv);
2925 n = o_save_ptr_helper(o, n);
2931 globfree(&globdata);
2933 debug_print_list("perform_glob returning", o, n);
2937 #endif /* !HUSH_BRACE_EXPANSION */
2939 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2940 * Otherwise, just finish current list[] and start new */
2941 static int o_save_ptr(o_string *o, int n)
2943 if (o->o_expflags & EXP_FLAG_GLOB) {
2944 /* If o->has_empty_slot, list[n] was already globbed
2945 * (if it was requested back then when it was filled)
2946 * so don't do that again! */
2947 if (!o->has_empty_slot)
2948 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2950 return o_save_ptr_helper(o, n);
2953 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2954 static char **o_finalize_list(o_string *o, int n)
2959 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2961 debug_print_list("finalized", o, n);
2962 debug_printf_expand("finalized n:%d\n", n);
2963 list = (char**)o->data;
2964 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2968 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2973 static void free_pipe_list(struct pipe *pi);
2975 /* Returns pi->next - next pipe in the list */
2976 static struct pipe *free_pipe(struct pipe *pi)
2981 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2982 for (i = 0; i < pi->num_cmds; i++) {
2983 struct command *command;
2984 struct redir_struct *r, *rnext;
2986 command = &pi->cmds[i];
2987 debug_printf_clean(" command %d:\n", i);
2988 if (command->argv) {
2992 for (a = 0, p = command->argv; *p; a++, p++) {
2993 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2996 free_strings(command->argv);
2997 //command->argv = NULL;
2999 /* not "else if": on syntax error, we may have both! */
3000 if (command->group) {
3001 debug_printf_clean(" begin group (cmd_type:%d)\n",
3003 free_pipe_list(command->group);
3004 debug_printf_clean(" end group\n");
3005 //command->group = NULL;
3007 /* else is crucial here.
3008 * If group != NULL, child_func is meaningless */
3009 #if ENABLE_HUSH_FUNCTIONS
3010 else if (command->child_func) {
3011 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3012 command->child_func->parent_cmd = NULL;
3016 free(command->group_as_string);
3017 //command->group_as_string = NULL;
3019 for (r = command->redirects; r; r = rnext) {
3020 debug_printf_clean(" redirect %d%s",
3021 r->rd_fd, redir_table[r->rd_type].descrip);
3022 /* guard against the case >$FOO, where foo is unset or blank */
3023 if (r->rd_filename) {
3024 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3025 free(r->rd_filename);
3026 //r->rd_filename = NULL;
3028 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3032 //command->redirects = NULL;
3034 free(pi->cmds); /* children are an array, they get freed all at once */
3038 //pi->cmdtext = NULL;
3046 static void free_pipe_list(struct pipe *pi)
3050 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3052 debug_printf_clean("pipe followup code %d\n", pi->followup);
3058 /*** Parsing routines ***/
3060 #ifndef debug_print_tree
3061 static void debug_print_tree(struct pipe *pi, int lvl)
3063 static const char *const PIPE[] = {
3069 static const char *RES[] = {
3070 [RES_NONE ] = "NONE" ,
3073 [RES_THEN ] = "THEN" ,
3074 [RES_ELIF ] = "ELIF" ,
3075 [RES_ELSE ] = "ELSE" ,
3078 # if ENABLE_HUSH_LOOPS
3079 [RES_FOR ] = "FOR" ,
3080 [RES_WHILE] = "WHILE",
3081 [RES_UNTIL] = "UNTIL",
3083 [RES_DONE ] = "DONE" ,
3085 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3088 # if ENABLE_HUSH_CASE
3089 [RES_CASE ] = "CASE" ,
3090 [RES_CASE_IN ] = "CASE_IN" ,
3091 [RES_MATCH] = "MATCH",
3092 [RES_CASE_BODY] = "CASE_BODY",
3093 [RES_ESAC ] = "ESAC" ,
3095 [RES_XXXX ] = "XXXX" ,
3096 [RES_SNTX ] = "SNTX" ,
3098 static const char *const CMDTYPE[] = {
3102 # if ENABLE_HUSH_FUNCTIONS
3111 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3112 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3114 while (prn < pi->num_cmds) {
3115 struct command *command = &pi->cmds[prn];
3116 char **argv = command->argv;
3118 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3120 command->assignment_cnt);
3121 if (command->group) {
3122 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3123 CMDTYPE[command->cmd_type],
3126 , " group_as_string:", command->group_as_string
3131 debug_print_tree(command->group, lvl+1);
3135 if (argv) while (*argv) {
3136 fdprintf(2, " '%s'", *argv);
3146 #endif /* debug_print_tree */
3148 static struct pipe *new_pipe(void)
3151 pi = xzalloc(sizeof(struct pipe));
3152 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3156 /* Command (member of a pipe) is complete, or we start a new pipe
3157 * if ctx->command is NULL.
3158 * No errors possible here.
3160 static int done_command(struct parse_context *ctx)
3162 /* The command is really already in the pipe structure, so
3163 * advance the pipe counter and make a new, null command. */
3164 struct pipe *pi = ctx->pipe;
3165 struct command *command = ctx->command;
3167 #if 0 /* Instead we emit error message at run time */
3168 if (ctx->pending_redirect) {
3169 /* For example, "cmd >" (no filename to redirect to) */
3170 die_if_script("syntax error: %s", "invalid redirect");
3171 ctx->pending_redirect = NULL;
3176 if (IS_NULL_CMD(command)) {
3177 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3181 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3182 //debug_print_tree(ctx->list_head, 20);
3184 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3187 /* Only real trickiness here is that the uncommitted
3188 * command structure is not counted in pi->num_cmds. */
3189 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3190 ctx->command = command = &pi->cmds[pi->num_cmds];
3192 memset(command, 0, sizeof(*command));
3193 return pi->num_cmds; /* used only for 0/nonzero check */
3196 static void done_pipe(struct parse_context *ctx, pipe_style type)
3200 debug_printf_parse("done_pipe entered, followup %d\n", type);
3201 /* Close previous command */
3202 not_null = done_command(ctx);
3203 ctx->pipe->followup = type;
3205 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3206 ctx->ctx_inverted = 0;
3207 ctx->pipe->res_word = ctx->ctx_res_w;
3210 /* Without this check, even just <enter> on command line generates
3211 * tree of three NOPs (!). Which is harmless but annoying.
3212 * IOW: it is safe to do it unconditionally. */
3215 || ctx->ctx_res_w == RES_FI
3217 #if ENABLE_HUSH_LOOPS
3218 || ctx->ctx_res_w == RES_DONE
3219 || ctx->ctx_res_w == RES_FOR
3220 || ctx->ctx_res_w == RES_IN
3222 #if ENABLE_HUSH_CASE
3223 || ctx->ctx_res_w == RES_ESAC
3227 debug_printf_parse("done_pipe: adding new pipe: "
3228 "not_null:%d ctx->ctx_res_w:%d\n",
3229 not_null, ctx->ctx_res_w);
3231 ctx->pipe->next = new_p;
3233 /* RES_THEN, RES_DO etc are "sticky" -
3234 * they remain set for pipes inside if/while.
3235 * This is used to control execution.
3236 * RES_FOR and RES_IN are NOT sticky (needed to support
3237 * cases where variable or value happens to match a keyword):
3239 #if ENABLE_HUSH_LOOPS
3240 if (ctx->ctx_res_w == RES_FOR
3241 || ctx->ctx_res_w == RES_IN)
3242 ctx->ctx_res_w = RES_NONE;
3244 #if ENABLE_HUSH_CASE
3245 if (ctx->ctx_res_w == RES_MATCH)
3246 ctx->ctx_res_w = RES_CASE_BODY;
3247 if (ctx->ctx_res_w == RES_CASE)
3248 ctx->ctx_res_w = RES_CASE_IN;
3250 ctx->command = NULL; /* trick done_command below */
3251 /* Create the memory for command, roughly:
3252 * ctx->pipe->cmds = new struct command;
3253 * ctx->command = &ctx->pipe->cmds[0];
3256 //debug_print_tree(ctx->list_head, 10);
3258 debug_printf_parse("done_pipe return\n");
3261 static void initialize_context(struct parse_context *ctx)
3263 memset(ctx, 0, sizeof(*ctx));
3264 ctx->pipe = ctx->list_head = new_pipe();
3265 /* Create the memory for command, roughly:
3266 * ctx->pipe->cmds = new struct command;
3267 * ctx->command = &ctx->pipe->cmds[0];
3272 /* If a reserved word is found and processed, parse context is modified
3273 * and 1 is returned.
3276 struct reserved_combo {
3279 unsigned char assignment_flag;
3283 FLAG_END = (1 << RES_NONE ),
3285 FLAG_IF = (1 << RES_IF ),
3286 FLAG_THEN = (1 << RES_THEN ),
3287 FLAG_ELIF = (1 << RES_ELIF ),
3288 FLAG_ELSE = (1 << RES_ELSE ),
3289 FLAG_FI = (1 << RES_FI ),
3291 # if ENABLE_HUSH_LOOPS
3292 FLAG_FOR = (1 << RES_FOR ),
3293 FLAG_WHILE = (1 << RES_WHILE),
3294 FLAG_UNTIL = (1 << RES_UNTIL),
3295 FLAG_DO = (1 << RES_DO ),
3296 FLAG_DONE = (1 << RES_DONE ),
3297 FLAG_IN = (1 << RES_IN ),
3299 # if ENABLE_HUSH_CASE
3300 FLAG_MATCH = (1 << RES_MATCH),
3301 FLAG_ESAC = (1 << RES_ESAC ),
3303 FLAG_START = (1 << RES_XXXX ),
3306 static const struct reserved_combo* match_reserved_word(o_string *word)
3308 /* Mostly a list of accepted follow-up reserved words.
3309 * FLAG_END means we are done with the sequence, and are ready
3310 * to turn the compound list into a command.
3311 * FLAG_START means the word must start a new compound list.
3313 static const struct reserved_combo reserved_list[] = {
3315 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3316 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3317 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3318 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3319 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3320 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3322 # if ENABLE_HUSH_LOOPS
3323 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3324 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3325 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3326 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3327 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3328 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3330 # if ENABLE_HUSH_CASE
3331 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3332 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3335 const struct reserved_combo *r;
3337 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3338 if (strcmp(word->data, r->literal) == 0)
3343 /* Return 0: not a keyword, 1: keyword
3345 static int reserved_word(o_string *word, struct parse_context *ctx)
3347 # if ENABLE_HUSH_CASE
3348 static const struct reserved_combo reserved_match = {
3349 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3352 const struct reserved_combo *r;
3354 if (word->has_quoted_part)
3356 r = match_reserved_word(word);
3360 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3361 # if ENABLE_HUSH_CASE
3362 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3363 /* "case word IN ..." - IN part starts first MATCH part */
3364 r = &reserved_match;
3367 if (r->flag == 0) { /* '!' */
3368 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3369 syntax_error("! ! command");
3370 ctx->ctx_res_w = RES_SNTX;
3372 ctx->ctx_inverted = 1;
3375 if (r->flag & FLAG_START) {
3376 struct parse_context *old;
3378 old = xmalloc(sizeof(*old));
3379 debug_printf_parse("push stack %p\n", old);
3380 *old = *ctx; /* physical copy */
3381 initialize_context(ctx);
3383 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3384 syntax_error_at(word->data);
3385 ctx->ctx_res_w = RES_SNTX;
3388 /* "{...} fi" is ok. "{...} if" is not
3390 * if { echo foo; } then { echo bar; } fi */
3391 if (ctx->command->group)
3392 done_pipe(ctx, PIPE_SEQ);
3395 ctx->ctx_res_w = r->res;
3396 ctx->old_flag = r->flag;
3397 word->o_assignment = r->assignment_flag;
3398 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3400 if (ctx->old_flag & FLAG_END) {
3401 struct parse_context *old;
3403 done_pipe(ctx, PIPE_SEQ);
3404 debug_printf_parse("pop stack %p\n", ctx->stack);
3406 old->command->group = ctx->list_head;
3407 old->command->cmd_type = CMD_NORMAL;
3409 /* At this point, the compound command's string is in
3410 * ctx->as_string... except for the leading keyword!
3411 * Consider this example: "echo a | if true; then echo a; fi"
3412 * ctx->as_string will contain "true; then echo a; fi",
3413 * with "if " remaining in old->as_string!
3417 int len = old->as_string.length;
3418 /* Concatenate halves */
3419 o_addstr(&old->as_string, ctx->as_string.data);
3420 o_free_unsafe(&ctx->as_string);
3421 /* Find where leading keyword starts in first half */
3422 str = old->as_string.data + len;
3423 if (str > old->as_string.data)
3424 str--; /* skip whitespace after keyword */
3425 while (str > old->as_string.data && isalpha(str[-1]))
3427 /* Ugh, we're done with this horrid hack */
3428 old->command->group_as_string = xstrdup(str);
3429 debug_printf_parse("pop, remembering as:'%s'\n",
3430 old->command->group_as_string);
3433 *ctx = *old; /* physical copy */
3438 #endif /* HAS_KEYWORDS */
3440 /* Word is complete, look at it and update parsing context.
3441 * Normal return is 0. Syntax errors return 1.
3442 * Note: on return, word is reset, but not o_free'd!
3444 static int done_word(o_string *word, struct parse_context *ctx)
3446 struct command *command = ctx->command;
3448 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3449 if (word->length == 0 && !word->has_quoted_part) {
3450 debug_printf_parse("done_word return 0: true null, ignored\n");
3454 if (ctx->pending_redirect) {
3455 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3456 * only if run as "bash", not "sh" */
3457 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3459 * ...the word that follows the redirection operator
3460 * shall be subjected to tilde expansion, parameter expansion,
3461 * command substitution, arithmetic expansion, and quote
3462 * removal. Pathname expansion shall not be performed
3463 * on the word by a non-interactive shell; an interactive
3464 * shell may perform it, but shall do so only when
3465 * the expansion would result in one word."
3467 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3468 /* Cater for >\file case:
3469 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3470 * Same with heredocs:
3471 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3473 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3474 unbackslash(ctx->pending_redirect->rd_filename);
3475 /* Is it <<"HEREDOC"? */
3476 if (word->has_quoted_part) {
3477 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3480 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3481 ctx->pending_redirect = NULL;
3484 # if ENABLE_HUSH_CASE
3485 if (ctx->ctx_dsemicolon
3486 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3488 /* already done when ctx_dsemicolon was set to 1: */
3489 /* ctx->ctx_res_w = RES_MATCH; */
3490 ctx->ctx_dsemicolon = 0;
3493 if (!command->argv /* if it's the first word... */
3494 # if ENABLE_HUSH_LOOPS
3495 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3496 && ctx->ctx_res_w != RES_IN
3498 # if ENABLE_HUSH_CASE
3499 && ctx->ctx_res_w != RES_CASE
3502 int reserved = reserved_word(word, ctx);
3503 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3505 o_reset_to_empty_unquoted(word);
3506 debug_printf_parse("done_word return %d\n",
3507 (ctx->ctx_res_w == RES_SNTX));
3508 return (ctx->ctx_res_w == RES_SNTX);
3510 # if ENABLE_HUSH_BASH_COMPAT
3511 if (strcmp(word->data, "[[") == 0) {
3512 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3518 if (command->group) {
3519 /* "{ echo foo; } echo bar" - bad */
3520 syntax_error_at(word->data);
3521 debug_printf_parse("done_word return 1: syntax error, "
3522 "groups and arglists don't mix\n");
3526 /* If this word wasn't an assignment, next ones definitely
3527 * can't be assignments. Even if they look like ones. */
3528 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3529 && word->o_assignment != WORD_IS_KEYWORD
3531 word->o_assignment = NOT_ASSIGNMENT;
3533 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3534 command->assignment_cnt++;
3535 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3537 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3538 word->o_assignment = MAYBE_ASSIGNMENT;
3540 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3542 if (word->has_quoted_part
3543 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3544 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3545 /* (otherwise it's known to be not empty and is already safe) */
3547 /* exclude "$@" - it can expand to no word despite "" */
3548 char *p = word->data;
3549 while (p[0] == SPECIAL_VAR_SYMBOL
3550 && (p[1] & 0x7f) == '@'
3551 && p[2] == SPECIAL_VAR_SYMBOL
3556 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3557 debug_print_strings("word appended to argv", command->argv);
3560 #if ENABLE_HUSH_LOOPS
3561 if (ctx->ctx_res_w == RES_FOR) {
3562 if (word->has_quoted_part
3563 || !is_well_formed_var_name(command->argv[0], '\0')
3565 /* bash says just "not a valid identifier" */
3566 syntax_error("not a valid identifier in for");
3569 /* Force FOR to have just one word (variable name) */
3570 /* NB: basically, this makes hush see "for v in ..."
3571 * syntax as if it is "for v; in ...". FOR and IN become
3572 * two pipe structs in parse tree. */
3573 done_pipe(ctx, PIPE_SEQ);
3576 #if ENABLE_HUSH_CASE
3577 /* Force CASE to have just one word */
3578 if (ctx->ctx_res_w == RES_CASE) {
3579 done_pipe(ctx, PIPE_SEQ);
3583 o_reset_to_empty_unquoted(word);
3585 debug_printf_parse("done_word return 0\n");
3590 /* Peek ahead in the input to find out if we have a "&n" construct,
3591 * as in "2>&1", that represents duplicating a file descriptor.
3593 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3594 * REDIRFD_SYNTAX_ERR if syntax error,
3595 * REDIRFD_TO_FILE if no & was seen,
3596 * or the number found.
3599 #define parse_redir_right_fd(as_string, input) \
3600 parse_redir_right_fd(input)
3602 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3608 return REDIRFD_TO_FILE;
3610 ch = i_getch(input); /* get the & */
3611 nommu_addchr(as_string, ch);
3614 ch = i_getch(input);
3615 nommu_addchr(as_string, ch);
3616 return REDIRFD_CLOSE;
3620 while (ch != EOF && isdigit(ch)) {
3621 d = d*10 + (ch-'0');
3623 ch = i_getch(input);
3624 nommu_addchr(as_string, ch);
3629 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3631 bb_error_msg("ambiguous redirect");
3632 return REDIRFD_SYNTAX_ERR;
3635 /* Return code is 0 normal, 1 if a syntax error is detected
3637 static int parse_redirect(struct parse_context *ctx,
3640 struct in_str *input)
3642 struct command *command = ctx->command;
3643 struct redir_struct *redir;
3644 struct redir_struct **redirp;
3647 dup_num = REDIRFD_TO_FILE;
3648 if (style != REDIRECT_HEREDOC) {
3649 /* Check for a '>&1' type redirect */
3650 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3651 if (dup_num == REDIRFD_SYNTAX_ERR)
3654 int ch = i_peek(input);
3655 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3656 if (dup_num) { /* <<-... */
3657 ch = i_getch(input);
3658 nommu_addchr(&ctx->as_string, ch);
3663 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3664 int ch = i_peek(input);
3666 /* >|FILE redirect ("clobbering" >).
3667 * Since we do not support "set -o noclobber" yet,
3668 * >| and > are the same for now. Just eat |.
3670 ch = i_getch(input);
3671 nommu_addchr(&ctx->as_string, ch);
3675 /* Create a new redir_struct and append it to the linked list */
3676 redirp = &command->redirects;
3677 while ((redir = *redirp) != NULL) {
3678 redirp = &(redir->next);
3680 *redirp = redir = xzalloc(sizeof(*redir));
3681 /* redir->next = NULL; */
3682 /* redir->rd_filename = NULL; */
3683 redir->rd_type = style;
3684 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3686 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3687 redir_table[style].descrip);
3689 redir->rd_dup = dup_num;
3690 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3691 /* Erik had a check here that the file descriptor in question
3692 * is legit; I postpone that to "run time"
3693 * A "-" representation of "close me" shows up as a -3 here */
3694 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3695 redir->rd_fd, redir->rd_dup);
3697 #if 0 /* Instead we emit error message at run time */
3698 if (ctx->pending_redirect) {
3699 /* For example, "cmd > <file" */
3700 die_if_script("syntax error: %s", "invalid redirect");
3703 /* Set ctx->pending_redirect, so we know what to do at the
3704 * end of the next parsed word. */
3705 ctx->pending_redirect = redir;
3710 /* If a redirect is immediately preceded by a number, that number is
3711 * supposed to tell which file descriptor to redirect. This routine
3712 * looks for such preceding numbers. In an ideal world this routine
3713 * needs to handle all the following classes of redirects...
3714 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3715 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3716 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3717 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3719 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3721 * ... If n is quoted, the number shall not be recognized as part of
3722 * the redirection expression. For example:
3724 * writes the character 2 into file a"
3725 * We are getting it right by setting ->has_quoted_part on any \<char>
3727 * A -1 return means no valid number was found,
3728 * the caller should use the appropriate default for this redirection.
3730 static int redirect_opt_num(o_string *o)
3734 if (o->data == NULL)
3736 num = bb_strtou(o->data, NULL, 10);
3737 if (errno || num < 0)
3739 o_reset_to_empty_unquoted(o);
3744 #define fetch_till_str(as_string, input, word, skip_tabs) \
3745 fetch_till_str(input, word, skip_tabs)
3747 static char *fetch_till_str(o_string *as_string,
3748 struct in_str *input,
3752 o_string heredoc = NULL_O_STRING;
3754 int prev = 0; /* not \ */
3760 ch = i_getch(input);
3762 nommu_addchr(as_string, ch);
3763 if ((ch == '\n' || ch == EOF)
3764 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3766 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3767 heredoc.data[past_EOL] = '\0';
3768 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3769 return heredoc.data;
3771 while (ch == '\n') {
3772 o_addchr(&heredoc, ch);
3775 past_EOL = heredoc.length;
3777 ch = i_getch(input);
3779 nommu_addchr(as_string, ch);
3780 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3784 o_free_unsafe(&heredoc);
3787 o_addchr(&heredoc, ch);
3788 nommu_addchr(as_string, ch);
3789 if (prev == '\\' && ch == '\\')
3790 /* Correctly handle foo\\<eol> (not a line cont.) */
3791 prev = 0; /* not \ */
3797 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3798 * and load them all. There should be exactly heredoc_cnt of them.
3800 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3802 struct pipe *pi = ctx->list_head;
3804 while (pi && heredoc_cnt) {
3806 struct command *cmd = pi->cmds;
3808 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3810 cmd->argv ? cmd->argv[0] : "NONE");
3811 for (i = 0; i < pi->num_cmds; i++) {
3812 struct redir_struct *redir = cmd->redirects;
3814 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3815 i, cmd->argv ? cmd->argv[0] : "NONE");
3817 if (redir->rd_type == REDIRECT_HEREDOC) {
3820 redir->rd_type = REDIRECT_HEREDOC2;
3821 /* redir->rd_dup is (ab)used to indicate <<- */
3822 p = fetch_till_str(&ctx->as_string, input,
3823 redir->rd_filename, redir->rd_dup);
3825 syntax_error("unexpected EOF in here document");
3828 free(redir->rd_filename);
3829 redir->rd_filename = p;
3832 redir = redir->next;
3839 /* Should be 0. If it isn't, it's a parse error */
3841 bb_error_msg_and_die("heredoc BUG 2");
3847 static int run_list(struct pipe *pi);
3849 #define parse_stream(pstring, input, end_trigger) \
3850 parse_stream(input, end_trigger)
3852 static struct pipe *parse_stream(char **pstring,
3853 struct in_str *input,
3857 #if !ENABLE_HUSH_FUNCTIONS
3858 #define parse_group(dest, ctx, input, ch) \
3859 parse_group(ctx, input, ch)
3861 static int parse_group(o_string *dest, struct parse_context *ctx,
3862 struct in_str *input, int ch)
3864 /* dest contains characters seen prior to ( or {.
3865 * Typically it's empty, but for function defs,
3866 * it contains function name (without '()'). */
3867 struct pipe *pipe_list;
3869 struct command *command = ctx->command;
3871 debug_printf_parse("parse_group entered\n");
3872 #if ENABLE_HUSH_FUNCTIONS
3873 if (ch == '(' && !dest->has_quoted_part) {
3875 if (done_word(dest, ctx))
3878 goto skip; /* (... */
3879 if (command->argv[1]) { /* word word ... (... */
3880 syntax_error_unexpected_ch('(');
3883 /* it is "word(..." or "word (..." */
3885 ch = i_getch(input);
3886 while (ch == ' ' || ch == '\t');
3888 syntax_error_unexpected_ch(ch);
3891 nommu_addchr(&ctx->as_string, ch);
3893 ch = i_getch(input);
3894 while (ch == ' ' || ch == '\t' || ch == '\n');
3896 syntax_error_unexpected_ch(ch);
3899 nommu_addchr(&ctx->as_string, ch);
3900 command->cmd_type = CMD_FUNCDEF;
3905 #if 0 /* Prevented by caller */
3906 if (command->argv /* word [word]{... */
3907 || dest->length /* word{... */
3908 || dest->has_quoted_part /* ""{... */
3911 debug_printf_parse("parse_group return 1: "
3912 "syntax error, groups and arglists don't mix\n");
3917 #if ENABLE_HUSH_FUNCTIONS
3923 command->cmd_type = CMD_SUBSHELL;
3925 /* bash does not allow "{echo...", requires whitespace */
3927 if (ch != ' ' && ch != '\t' && ch != '\n'
3928 && ch != '(' /* but "{(..." is allowed (without whitespace) */
3930 syntax_error_unexpected_ch(ch);
3934 ch = i_getch(input);
3935 nommu_addchr(&ctx->as_string, ch);
3941 # define as_string NULL
3943 char *as_string = NULL;
3945 pipe_list = parse_stream(&as_string, input, endch);
3948 o_addstr(&ctx->as_string, as_string);
3950 /* empty ()/{} or parse error? */
3951 if (!pipe_list || pipe_list == ERR_PTR) {
3952 /* parse_stream already emitted error msg */
3955 debug_printf_parse("parse_group return 1: "
3956 "parse_stream returned %p\n", pipe_list);
3959 command->group = pipe_list;
3961 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3962 command->group_as_string = as_string;
3963 debug_printf_parse("end of group, remembering as:'%s'\n",
3964 command->group_as_string);
3968 debug_printf_parse("parse_group return 0\n");
3970 /* command remains "open", available for possible redirects */
3973 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3978 ch = i_getch(input);
3981 ch2 = i_peek(input);
3984 /* backslash+newline, skip it */
3989 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3997 ch2 = i_peek2(input);
4000 /* backslash+newline, skip it */
4006 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4007 /* Subroutines for copying $(...) and `...` things */
4008 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4010 static int add_till_single_quote(o_string *dest, struct in_str *input)
4013 int ch = i_getch(input);
4015 syntax_error_unterm_ch('\'');
4023 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4024 static int add_till_double_quote(o_string *dest, struct in_str *input)
4027 int ch = i_getch(input);
4029 syntax_error_unterm_ch('"');
4034 if (ch == '\\') { /* \x. Copy both chars. */
4036 ch = i_getch(input);
4040 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4045 //if (ch == '$') ...
4048 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4050 * "Within the backquoted style of command substitution, backslash
4051 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4052 * The search for the matching backquote shall be satisfied by the first
4053 * backquote found without a preceding backslash; during this search,
4054 * if a non-escaped backquote is encountered within a shell comment,
4055 * a here-document, an embedded command substitution of the $(command)
4056 * form, or a quoted string, undefined results occur. A single-quoted
4057 * or double-quoted string that begins, but does not end, within the
4058 * "`...`" sequence produces undefined results."
4060 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4062 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4065 int ch = i_getch(input);
4069 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4070 ch = i_getch(input);
4074 && (!in_dquote || ch != '"')
4076 o_addchr(dest, '\\');
4080 syntax_error_unterm_ch('`');
4086 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4087 * quoting and nested ()s.
4088 * "With the $(command) style of command substitution, all characters
4089 * following the open parenthesis to the matching closing parenthesis
4090 * constitute the command. Any valid shell script can be used for command,
4091 * except a script consisting solely of redirections which produces
4092 * unspecified results."
4094 * echo $(echo '(TEST)' BEST) (TEST) BEST
4095 * echo $(echo 'TEST)' BEST) TEST) BEST
4096 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4098 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4099 * can contain arbitrary constructs, just like $(cmd).
4100 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4101 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4103 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4104 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4107 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4108 # if ENABLE_HUSH_BASH_COMPAT
4109 char end_char2 = end_ch >> 8;
4111 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4114 ch = i_getch(input);
4116 syntax_error_unterm_ch(end_ch);
4119 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4122 /* we look for closing )) of $((EXPR)) */
4123 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4124 i_getch(input); /* eat second ')' */
4129 if (ch == '(' || ch == '{') {
4130 ch = (ch == '(' ? ')' : '}');
4131 if (!add_till_closing_bracket(dest, input, ch))
4137 if (!add_till_single_quote(dest, input))
4143 if (!add_till_double_quote(dest, input))
4149 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4155 /* \x. Copy verbatim. Important for \(, \) */
4156 ch = i_getch(input);
4158 syntax_error_unterm_ch(')');
4163 /* "backslash+newline", ignore both */
4164 o_delchr(dest); /* undo insertion of '\' */
4174 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4176 /* Return code: 0 for OK, 1 for syntax error */
4178 #define parse_dollar(as_string, dest, input, quote_mask) \
4179 parse_dollar(dest, input, quote_mask)
4180 #define as_string NULL
4182 static int parse_dollar(o_string *as_string,
4184 struct in_str *input, unsigned char quote_mask)
4186 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4188 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4190 ch = i_getch(input);
4191 nommu_addchr(as_string, ch);
4193 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4195 debug_printf_parse(": '%c'\n", ch);
4196 o_addchr(dest, ch | quote_mask);
4198 ch = i_peek_and_eat_bkslash_nl(input);
4199 if (!isalnum(ch) && ch != '_') {
4200 /* End of variable name reached */
4203 ch = i_getch(input);
4204 nommu_addchr(as_string, ch);
4206 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4207 } else if (isdigit(ch)) {
4209 ch = i_getch(input);
4210 nommu_addchr(as_string, ch);
4211 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4212 debug_printf_parse(": '%c'\n", ch);
4213 o_addchr(dest, ch | quote_mask);
4214 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4215 } else switch (ch) {
4217 case '!': /* last bg pid */
4218 case '?': /* last exit code */
4219 case '#': /* number of args */
4220 case '*': /* args */
4221 case '@': /* args */
4222 goto make_one_char_var;
4224 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4226 ch = i_getch(input); /* eat '{' */
4227 nommu_addchr(as_string, ch);
4229 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4230 /* It should be ${?}, or ${#var},
4231 * or even ${?+subst} - operator acting on a special variable,
4232 * or the beginning of variable name.
4235 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4238 syntax_error_unterm_str("${name}");
4239 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4242 nommu_addchr(as_string, ch);
4245 /* It's possible to just call add_till_closing_bracket() at this point.
4246 * However, this regresses some of our testsuite cases
4247 * which check invalid constructs like ${%}.
4248 * Oh well... let's check that the var name part is fine... */
4254 debug_printf_parse(": '%c'\n", ch);
4256 ch = i_getch(input);
4257 nommu_addchr(as_string, ch);
4261 if (!isalnum(ch) && ch != '_') {
4263 unsigned char last_ch;
4264 /* handle parameter expansions
4265 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4267 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4268 goto bad_dollar_syntax;
4270 /* Eat everything until closing '}' (or ':') */
4272 if (ENABLE_HUSH_BASH_COMPAT
4274 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4276 /* It's ${var:N[:M]} thing */
4277 end_ch = '}' * 0x100 + ':';
4279 if (ENABLE_HUSH_BASH_COMPAT
4282 /* It's ${var/[/]pattern[/repl]} thing */
4283 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4285 nommu_addchr(as_string, '/');
4288 end_ch = '}' * 0x100 + '/';
4294 #if ENABLE_HUSH_DOLLAR_OPS
4295 last_ch = add_till_closing_bracket(dest, input, end_ch);
4296 if (last_ch == 0) /* error? */
4299 #error Simple code to only allow ${var} is not implemented
4302 o_addstr(as_string, dest->data + pos);
4303 o_addchr(as_string, last_ch);
4306 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4307 /* close the first block: */
4308 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4309 /* while parsing N from ${var:N[:M]}
4310 * or pattern from ${var/[/]pattern[/repl]} */
4311 if ((end_ch & 0xff) == last_ch) {
4312 /* got ':' or '/'- parse the rest */
4317 if (end_ch == '}' * 0x100 + ':') {
4318 /* it's ${var:N} - emulate :999999999 */
4319 o_addstr(dest, "999999999");
4320 } /* else: it's ${var/[/]pattern} */
4325 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4328 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4332 ch = i_getch(input);
4333 nommu_addchr(as_string, ch);
4334 # if ENABLE_FEATURE_SH_MATH
4335 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4336 ch = i_getch(input);
4337 nommu_addchr(as_string, ch);
4338 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4339 o_addchr(dest, /*quote_mask |*/ '+');
4342 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4343 return 0; /* error */
4345 o_addstr(as_string, dest->data + pos);
4346 o_addchr(as_string, ')');
4347 o_addchr(as_string, ')');
4349 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4353 # if ENABLE_HUSH_TICK
4354 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4355 o_addchr(dest, quote_mask | '`');
4358 if (!add_till_closing_bracket(dest, input, ')'))
4359 return 0; /* error */
4361 o_addstr(as_string, dest->data + pos);
4362 o_addchr(as_string, ')');
4364 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4370 ch = i_getch(input);
4371 nommu_addchr(as_string, ch);
4372 ch = i_peek_and_eat_bkslash_nl(input);
4373 if (isalnum(ch)) { /* it's $_name or $_123 */
4378 /* TODO: $_ and $-: */
4379 /* $_ Shell or shell script name; or last argument of last command
4380 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4381 * but in command's env, set to full pathname used to invoke it */
4382 /* $- Option flags set by set builtin or shell options (-i etc) */
4384 o_addQchr(dest, '$');
4386 debug_printf_parse("parse_dollar return 1 (ok)\n");
4392 # if ENABLE_HUSH_BASH_COMPAT
4393 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4394 encode_string(dest, input, dquote_end, process_bkslash)
4396 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4397 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4398 encode_string(dest, input, dquote_end)
4400 #define as_string NULL
4404 # if ENABLE_HUSH_BASH_COMPAT
4405 /* all parameters are needed, no macro tricks */
4407 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4408 encode_string(as_string, dest, input, dquote_end)
4411 static int encode_string(o_string *as_string,
4413 struct in_str *input,
4415 int process_bkslash)
4417 #if !ENABLE_HUSH_BASH_COMPAT
4418 const int process_bkslash = 1;
4424 ch = i_getch(input);
4426 nommu_addchr(as_string, ch);
4427 if (ch == dquote_end) { /* may be only '"' or EOF */
4428 debug_printf_parse("encode_string return 1 (ok)\n");
4431 /* note: can't move it above ch == dquote_end check! */
4433 syntax_error_unterm_ch('"');
4434 return 0; /* error */
4438 next = i_peek(input);
4440 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4441 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4442 if (process_bkslash && ch == '\\') {
4444 syntax_error("\\<eof>");
4448 * "The backslash retains its special meaning [in "..."]
4449 * only when followed by one of the following characters:
4450 * $, `, ", \, or <newline>. A double quote may be quoted
4451 * within double quotes by preceding it with a backslash."
4452 * NB: in (unquoted) heredoc, above does not apply to ",
4453 * therefore we check for it by "next == dquote_end" cond.
4455 if (next == dquote_end || strchr("$`\\\n", next)) {
4456 ch = i_getch(input); /* eat next */
4458 goto again; /* skip \<newline> */
4459 } /* else: ch remains == '\\', and we double it below: */
4460 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4461 nommu_addchr(as_string, ch);
4465 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4466 debug_printf_parse("encode_string return 0: "
4467 "parse_dollar returned 0 (error)\n");
4472 #if ENABLE_HUSH_TICK
4474 //unsigned pos = dest->length;
4475 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4476 o_addchr(dest, 0x80 | '`');
4477 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4478 return 0; /* error */
4479 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4480 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4484 o_addQchr(dest, ch);
4490 * Scan input until EOF or end_trigger char.
4491 * Return a list of pipes to execute, or NULL on EOF
4492 * or if end_trigger character is met.
4493 * On syntax error, exit if shell is not interactive,
4494 * reset parsing machinery and start parsing anew,
4495 * or return ERR_PTR.
4497 static struct pipe *parse_stream(char **pstring,
4498 struct in_str *input,
4501 struct parse_context ctx;
4502 o_string dest = NULL_O_STRING;
4505 /* Single-quote triggers a bypass of the main loop until its mate is
4506 * found. When recursing, quote state is passed in via dest->o_expflags.
4508 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4509 end_trigger ? end_trigger : 'X');
4512 /* If very first arg is "" or '', dest.data may end up NULL.
4513 * Preventing this: */
4514 o_addchr(&dest, '\0');
4517 /* We used to separate words on $IFS here. This was wrong.
4518 * $IFS is used only for word splitting when $var is expanded,
4519 * here we should use blank chars as separators, not $IFS
4522 if (MAYBE_ASSIGNMENT != 0)
4523 dest.o_assignment = MAYBE_ASSIGNMENT;
4524 initialize_context(&ctx);
4527 const char *is_blank;
4528 const char *is_special;
4532 redir_type redir_style;
4534 ch = i_getch(input);
4535 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4536 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4541 syntax_error_unterm_str("here document");
4544 if (end_trigger == ')') {
4545 syntax_error_unterm_ch('(');
4548 if (end_trigger == '}') {
4549 syntax_error_unterm_ch('{');
4553 if (done_word(&dest, &ctx)) {
4557 done_pipe(&ctx, PIPE_SEQ);
4559 /* If we got nothing... */
4560 /* (this makes bare "&" cmd a no-op.
4561 * bash says: "syntax error near unexpected token '&'") */
4562 if (pi->num_cmds == 0
4563 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4569 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4571 *pstring = ctx.as_string.data;
4573 o_free_unsafe(&ctx.as_string);
4576 debug_printf_parse("parse_stream return %p\n", pi);
4579 nommu_addchr(&ctx.as_string, ch);
4583 next = i_peek(input);
4585 is_special = "{}<>;&|()#'" /* special outside of "str" */
4586 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4587 /* Are { and } special here? */
4588 if (ctx.command->argv /* word [word]{... - non-special */
4589 || dest.length /* word{... - non-special */
4590 || dest.has_quoted_part /* ""{... - non-special */
4591 || (next != ';' /* }; - special */
4592 && next != ')' /* }) - special */
4593 && next != '(' /* {( - special */
4594 && next != '&' /* }& and }&& ... - special */
4595 && next != '|' /* }|| ... - special */
4596 && !strchr(defifs, next) /* {word - non-special */
4599 /* They are not special, skip "{}" */
4602 is_special = strchr(is_special, ch);
4603 is_blank = strchr(defifs, ch);
4605 if (!is_special && !is_blank) { /* ordinary char */
4607 o_addQchr(&dest, ch);
4608 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4609 || dest.o_assignment == WORD_IS_KEYWORD)
4611 && is_well_formed_var_name(dest.data, '=')
4613 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4614 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4620 if (done_word(&dest, &ctx)) {
4624 /* Is this a case when newline is simply ignored?
4626 * "cmd | <newline> cmd ..."
4627 * "case ... in <newline> word) ..."
4629 if (IS_NULL_CMD(ctx.command)
4630 && dest.length == 0 && !dest.has_quoted_part
4632 /* This newline can be ignored. But...
4633 * Without check #1, interactive shell
4634 * ignores even bare <newline>,
4635 * and shows the continuation prompt:
4636 * ps1_prompt$ <enter>
4637 * ps2> _ <=== wrong, should be ps1
4638 * Without check #2, "cmd & <newline>"
4639 * is similarly mistreated.
4640 * (BTW, this makes "cmd & cmd"
4641 * and "cmd && cmd" non-orthogonal.
4642 * Really, ask yourself, why
4643 * "cmd && <newline>" doesn't start
4644 * cmd but waits for more input?
4647 struct pipe *pi = ctx.list_head;
4648 if (pi->num_cmds != 0 /* check #1 */
4649 && pi->followup != PIPE_BG /* check #2 */
4654 /* Treat newline as a command separator. */
4655 done_pipe(&ctx, PIPE_SEQ);
4656 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4658 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4663 dest.o_assignment = MAYBE_ASSIGNMENT;
4664 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4666 /* note: if (is_blank) continue;
4667 * will still trigger for us */
4671 /* "cmd}" or "cmd }..." without semicolon or &:
4672 * } is an ordinary char in this case, even inside { cmd; }
4673 * Pathological example: { ""}; } should exec "}" cmd
4676 if (dest.length != 0 /* word} */
4677 || dest.has_quoted_part /* ""} */
4681 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4682 /* Generally, there should be semicolon: "cmd; }"
4683 * However, bash allows to omit it if "cmd" is
4684 * a group. Examples:
4687 * { echo 0 >&2 | { echo 1; } }
4688 * { while false; do :; done }
4689 * { case a in b) ;; esac }
4691 if (ctx.command->group)
4695 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4696 /* Can't be an end of {cmd}, skip the check */
4697 goto skip_end_trigger;
4698 /* else: } does terminate a group */
4701 if (end_trigger && end_trigger == ch
4702 && (ch != ';' || heredoc_cnt == 0)
4703 #if ENABLE_HUSH_CASE
4705 || ctx.ctx_res_w != RES_MATCH
4706 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4711 /* This is technically valid:
4712 * { cat <<HERE; }; echo Ok
4716 * but we don't support this.
4717 * We require heredoc to be in enclosing {}/(),
4720 syntax_error_unterm_str("here document");
4723 if (done_word(&dest, &ctx)) {
4726 done_pipe(&ctx, PIPE_SEQ);
4727 dest.o_assignment = MAYBE_ASSIGNMENT;
4728 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4729 /* Do we sit outside of any if's, loops or case's? */
4731 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4735 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4737 *pstring = ctx.as_string.data;
4739 o_free_unsafe(&ctx.as_string);
4742 debug_printf_parse("parse_stream return %p: "
4743 "end_trigger char found\n",
4745 return ctx.list_head;
4752 /* Catch <, > before deciding whether this word is
4753 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4756 redir_fd = redirect_opt_num(&dest);
4757 if (done_word(&dest, &ctx)) {
4760 redir_style = REDIRECT_OVERWRITE;
4762 redir_style = REDIRECT_APPEND;
4763 ch = i_getch(input);
4764 nommu_addchr(&ctx.as_string, ch);
4767 else if (next == '(') {
4768 syntax_error(">(process) not supported");
4772 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4774 continue; /* back to top of while (1) */
4776 redir_fd = redirect_opt_num(&dest);
4777 if (done_word(&dest, &ctx)) {
4780 redir_style = REDIRECT_INPUT;
4782 redir_style = REDIRECT_HEREDOC;
4784 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4785 ch = i_getch(input);
4786 nommu_addchr(&ctx.as_string, ch);
4787 } else if (next == '>') {
4788 redir_style = REDIRECT_IO;
4789 ch = i_getch(input);
4790 nommu_addchr(&ctx.as_string, ch);
4793 else if (next == '(') {
4794 syntax_error("<(process) not supported");
4798 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4800 continue; /* back to top of while (1) */
4802 if (dest.length == 0 && !dest.has_quoted_part) {
4803 /* skip "#comment" */
4806 if (ch == EOF || ch == '\n')
4809 /* note: we do not add it to &ctx.as_string */
4811 nommu_addchr(&ctx.as_string, '\n');
4812 continue; /* back to top of while (1) */
4817 /* It's "\<newline>" */
4819 /* Remove trailing '\' from ctx.as_string */
4820 ctx.as_string.data[--ctx.as_string.length] = '\0';
4822 ch = i_getch(input); /* eat it */
4823 continue; /* back to top of while (1) */
4828 if (dest.o_assignment == MAYBE_ASSIGNMENT
4829 /* check that we are not in word in "a=1 2>word b=1": */
4830 && !ctx.pending_redirect
4832 /* ch is a special char and thus this word
4833 * cannot be an assignment */
4834 dest.o_assignment = NOT_ASSIGNMENT;
4835 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4838 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4841 case '#': /* non-comment #: "echo a#b" etc */
4842 o_addQchr(&dest, ch);
4846 syntax_error("\\<eof>");
4849 ch = i_getch(input);
4850 /* note: ch != '\n' (that case does not reach this place) */
4851 o_addchr(&dest, '\\');
4852 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4853 o_addchr(&dest, ch);
4854 nommu_addchr(&ctx.as_string, ch);
4855 /* Example: echo Hello \2>file
4856 * we need to know that word 2 is quoted */
4857 dest.has_quoted_part = 1;
4860 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4861 debug_printf_parse("parse_stream parse error: "
4862 "parse_dollar returned 0 (error)\n");
4867 dest.has_quoted_part = 1;
4868 if (next == '\'' && !ctx.pending_redirect) {
4869 insert_empty_quoted_str_marker:
4870 nommu_addchr(&ctx.as_string, next);
4871 i_getch(input); /* eat second ' */
4872 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4873 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4876 ch = i_getch(input);
4878 syntax_error_unterm_ch('\'');
4881 nommu_addchr(&ctx.as_string, ch);
4884 o_addqchr(&dest, ch);
4889 dest.has_quoted_part = 1;
4890 if (next == '"' && !ctx.pending_redirect)
4891 goto insert_empty_quoted_str_marker;
4892 if (dest.o_assignment == NOT_ASSIGNMENT)
4893 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4894 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4896 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4898 #if ENABLE_HUSH_TICK
4900 USE_FOR_NOMMU(unsigned pos;)
4902 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4903 o_addchr(&dest, '`');
4904 USE_FOR_NOMMU(pos = dest.length;)
4905 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4908 o_addstr(&ctx.as_string, dest.data + pos);
4909 o_addchr(&ctx.as_string, '`');
4911 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4912 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4917 #if ENABLE_HUSH_CASE
4920 if (done_word(&dest, &ctx)) {
4923 done_pipe(&ctx, PIPE_SEQ);
4924 #if ENABLE_HUSH_CASE
4925 /* Eat multiple semicolons, detect
4926 * whether it means something special */
4931 ch = i_getch(input);
4932 nommu_addchr(&ctx.as_string, ch);
4933 if (ctx.ctx_res_w == RES_CASE_BODY) {
4934 ctx.ctx_dsemicolon = 1;
4935 ctx.ctx_res_w = RES_MATCH;
4941 /* We just finished a cmd. New one may start
4942 * with an assignment */
4943 dest.o_assignment = MAYBE_ASSIGNMENT;
4944 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4947 if (done_word(&dest, &ctx)) {
4951 ch = i_getch(input);
4952 nommu_addchr(&ctx.as_string, ch);
4953 done_pipe(&ctx, PIPE_AND);
4955 done_pipe(&ctx, PIPE_BG);
4959 if (done_word(&dest, &ctx)) {
4962 #if ENABLE_HUSH_CASE
4963 if (ctx.ctx_res_w == RES_MATCH)
4964 break; /* we are in case's "word | word)" */
4966 if (next == '|') { /* || */
4967 ch = i_getch(input);
4968 nommu_addchr(&ctx.as_string, ch);
4969 done_pipe(&ctx, PIPE_OR);
4971 /* we could pick up a file descriptor choice here
4972 * with redirect_opt_num(), but bash doesn't do it.
4973 * "echo foo 2| cat" yields "foo 2". */
4978 #if ENABLE_HUSH_CASE
4979 /* "case... in [(]word)..." - skip '(' */
4980 if (ctx.ctx_res_w == RES_MATCH
4981 && ctx.command->argv == NULL /* not (word|(... */
4982 && dest.length == 0 /* not word(... */
4983 && dest.has_quoted_part == 0 /* not ""(... */
4989 if (parse_group(&dest, &ctx, input, ch) != 0) {
4994 #if ENABLE_HUSH_CASE
4995 if (ctx.ctx_res_w == RES_MATCH)
4999 /* proper use of this character is caught by end_trigger:
5000 * if we see {, we call parse_group(..., end_trigger='}')
5001 * and it will match } earlier (not here). */
5002 syntax_error_unexpected_ch(ch);
5003 G.last_exitcode = 2;
5007 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5012 G.last_exitcode = 1;
5015 struct parse_context *pctx;
5016 IF_HAS_KEYWORDS(struct parse_context *p2;)
5018 /* Clean up allocated tree.
5019 * Sample for finding leaks on syntax error recovery path.
5020 * Run it from interactive shell, watch pmap `pidof hush`.
5021 * while if false; then false; fi; do break; fi
5022 * Samples to catch leaks at execution:
5023 * while if (true | { true;}); then echo ok; fi; do break; done
5024 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5028 /* Update pipe/command counts,
5029 * otherwise freeing may miss some */
5030 done_pipe(pctx, PIPE_SEQ);
5031 debug_printf_clean("freeing list %p from ctx %p\n",
5032 pctx->list_head, pctx);
5033 debug_print_tree(pctx->list_head, 0);
5034 free_pipe_list(pctx->list_head);
5035 debug_printf_clean("freed list %p\n", pctx->list_head);
5037 o_free_unsafe(&pctx->as_string);
5039 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5043 IF_HAS_KEYWORDS(pctx = p2;)
5044 } while (HAS_KEYWORDS && pctx);
5057 /*** Execution routines ***/
5059 /* Expansion can recurse, need forward decls: */
5060 #if !ENABLE_HUSH_BASH_COMPAT
5061 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5062 #define expand_string_to_string(str, do_unbackslash) \
5063 expand_string_to_string(str)
5065 static char *expand_string_to_string(const char *str, int do_unbackslash);
5066 #if ENABLE_HUSH_TICK
5067 static int process_command_subs(o_string *dest, const char *s);
5070 /* expand_strvec_to_strvec() takes a list of strings, expands
5071 * all variable references within and returns a pointer to
5072 * a list of expanded strings, possibly with larger number
5073 * of strings. (Think VAR="a b"; echo $VAR).
5074 * This new list is allocated as a single malloc block.
5075 * NULL-terminated list of char* pointers is at the beginning of it,
5076 * followed by strings themselves.
5077 * Caller can deallocate entire list by single free(list). */
5079 /* A horde of its helpers come first: */
5081 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5083 while (--len >= 0) {
5086 #if ENABLE_HUSH_BRACE_EXPANSION
5087 if (c == '{' || c == '}') {
5088 /* { -> \{, } -> \} */
5090 /* And now we want to add { or } and continue:
5093 * luckily, just falling throught achieves this.
5099 /* \z -> \\\z; \<eol> -> \\<eol> */
5104 o_addchr(o, *str++);
5110 /* Store given string, finalizing the word and starting new one whenever
5111 * we encounter IFS char(s). This is used for expanding variable values.
5112 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5113 * Return in *ended_with_ifs:
5114 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5116 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5118 int last_is_ifs = 0;
5123 if (!*str) /* EOL - do not finalize word */
5125 word_len = strcspn(str, G.ifs);
5127 /* We have WORD_LEN leading non-IFS chars */
5128 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5129 o_addblock(output, str, word_len);
5131 /* Protect backslashes against globbing up :)
5132 * Example: "v='\*'; echo b$v" prints "b\*"
5133 * (and does not try to glob on "*")
5135 o_addblock_duplicate_backslash(output, str, word_len);
5136 /*/ Why can't we do it easier? */
5137 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5138 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5142 if (!*str) /* EOL - do not finalize word */
5146 /* We know str here points to at least one IFS char */
5148 str += strspn(str, G.ifs); /* skip IFS chars */
5149 if (!*str) /* EOL - do not finalize word */
5152 /* Start new word... but not always! */
5153 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5154 if (output->has_quoted_part
5155 /* Case "v=' a'; echo $v":
5156 * here nothing precedes the space in $v expansion,
5157 * therefore we should not finish the word
5158 * (IOW: if there *is* word to finalize, only then do it):
5160 || (n > 0 && output->data[output->length - 1])
5162 o_addchr(output, '\0');
5163 debug_print_list("expand_on_ifs", output, n);
5164 n = o_save_ptr(output, n);
5169 *ended_with_ifs = last_is_ifs;
5170 debug_print_list("expand_on_ifs[1]", output, n);
5174 /* Helper to expand $((...)) and heredoc body. These act as if
5175 * they are in double quotes, with the exception that they are not :).
5176 * Just the rules are similar: "expand only $var and `cmd`"
5178 * Returns malloced string.
5179 * As an optimization, we return NULL if expansion is not needed.
5181 #if !ENABLE_HUSH_BASH_COMPAT
5182 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5183 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5184 encode_then_expand_string(str)
5186 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5189 struct in_str input;
5190 o_string dest = NULL_O_STRING;
5192 if (!strchr(str, '$')
5193 && !strchr(str, '\\')
5194 #if ENABLE_HUSH_TICK
5195 && !strchr(str, '`')
5201 /* We need to expand. Example:
5202 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5204 setup_string_in_str(&input, str);
5205 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5206 //TODO: error check (encode_string returns 0 on error)?
5207 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5208 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5209 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5210 o_free_unsafe(&dest);
5214 #if ENABLE_FEATURE_SH_MATH
5215 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5217 arith_state_t math_state;
5221 math_state.lookupvar = get_local_var_value;
5222 math_state.setvar = set_local_var_from_halves;
5223 //math_state.endofname = endofname;
5224 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5225 res = arith(&math_state, exp_str ? exp_str : arg);
5228 *errmsg_p = math_state.errmsg;
5229 if (math_state.errmsg)
5230 die_if_script(math_state.errmsg);
5235 #if ENABLE_HUSH_BASH_COMPAT
5236 /* ${var/[/]pattern[/repl]} helpers */
5237 static char *strstr_pattern(char *val, const char *pattern, int *size)
5240 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5241 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5248 /* Optimization: if "*pat" did not match the start of "string",
5249 * we know that "tring", "ring" etc will not match too:
5251 if (pattern[0] == '*')
5256 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5258 char *result = NULL;
5259 unsigned res_len = 0;
5260 unsigned repl_len = strlen(repl);
5264 char *s = strstr_pattern(val, pattern, &size);
5268 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5269 memcpy(result + res_len, val, s - val);
5271 strcpy(result + res_len, repl);
5272 res_len += repl_len;
5273 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5279 if (val[0] && result) {
5280 result = xrealloc(result, res_len + strlen(val) + 1);
5281 strcpy(result + res_len, val);
5282 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5284 debug_printf_varexp("result:'%s'\n", result);
5290 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5292 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5294 const char *val = NULL;
5295 char *to_be_freed = NULL;
5300 char exp_save = exp_save; /* for compiler */
5301 char *exp_saveptr; /* points to expansion operator */
5302 char *exp_word = exp_word; /* for compiler */
5305 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5307 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5309 first_char = arg[0] = arg0 & 0x7f;
5312 if (first_char == '#' /* ${#... */
5313 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5315 /* It must be length operator: ${#var} */
5319 /* Maybe handle parameter expansion */
5320 if (exp_saveptr /* if 2nd char is one of expansion operators */
5321 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5323 /* ${?:0}, ${#[:]%0} etc */
5324 exp_saveptr = var + 1;
5326 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5327 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5329 exp_op = exp_save = *exp_saveptr;
5331 exp_word = exp_saveptr + 1;
5332 if (exp_op == ':') {
5333 exp_op = *exp_word++;
5334 //TODO: try ${var:} and ${var:bogus} in non-bash config
5335 if (ENABLE_HUSH_BASH_COMPAT
5336 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5338 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5343 *exp_saveptr = '\0';
5344 } /* else: it's not an expansion op, but bare ${var} */
5347 /* Look up the variable in question */
5348 if (isdigit(var[0])) {
5349 /* parse_dollar should have vetted var for us */
5350 int n = xatoi_positive(var);
5351 if (n < G.global_argc)
5352 val = G.global_argv[n];
5353 /* else val remains NULL: $N with too big N */
5357 val = utoa(G.root_pid);
5359 case '!': /* bg pid */
5360 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5362 case '?': /* exitcode */
5363 val = utoa(G.last_exitcode);
5365 case '#': /* argc */
5366 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5369 val = get_local_var_value(var);
5373 /* Handle any expansions */
5374 if (exp_op == 'L') {
5375 reinit_unicode_for_hush();
5376 debug_printf_expand("expand: length(%s)=", val);
5377 val = utoa(val ? unicode_strlen(val) : 0);
5378 debug_printf_expand("%s\n", val);
5379 } else if (exp_op) {
5380 if (exp_op == '%' || exp_op == '#') {
5381 /* Standard-mandated substring removal ops:
5382 * ${parameter%word} - remove smallest suffix pattern
5383 * ${parameter%%word} - remove largest suffix pattern
5384 * ${parameter#word} - remove smallest prefix pattern
5385 * ${parameter##word} - remove largest prefix pattern
5387 * Word is expanded to produce a glob pattern.
5388 * Then var's value is matched to it and matching part removed.
5390 if (val && val[0]) {
5394 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5395 if (exp_op == *exp_word) /* ## or %% */
5397 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5399 exp_word = exp_exp_word;
5400 /* HACK ALERT. We depend here on the fact that
5401 * G.global_argv and results of utoa and get_local_var_value
5402 * are actually in writable memory:
5403 * scan_and_match momentarily stores NULs there. */
5405 loc = scan_and_match(t, exp_word, scan_flags);
5406 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5407 // exp_op, t, exp_word, loc);
5409 if (loc) { /* match was found */
5410 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5411 val = loc; /* take right part */
5413 val = to_be_freed = xstrndup(val, loc - val); /* left */
5417 #if ENABLE_HUSH_BASH_COMPAT
5418 else if (exp_op == '/' || exp_op == '\\') {
5419 /* It's ${var/[/]pattern[/repl]} thing.
5420 * Note that in encoded form it has TWO parts:
5421 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5422 * and if // is used, it is encoded as \:
5423 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5425 /* Empty variable always gives nothing: */
5426 // "v=''; echo ${v/*/w}" prints "", not "w"
5427 if (val && val[0]) {
5428 /* pattern uses non-standard expansion.
5429 * repl should be unbackslashed and globbed
5430 * by the usual expansion rules:
5432 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5433 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5434 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5435 * v='a bz'; echo ${v/a*z/\z} prints "z"
5436 * (note that a*z _pattern_ is never globbed!)
5438 char *pattern, *repl, *t;
5439 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5441 pattern = xstrdup(exp_word);
5442 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5443 *p++ = SPECIAL_VAR_SYMBOL;
5445 p = strchr(p, SPECIAL_VAR_SYMBOL);
5447 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5448 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5449 /* HACK ALERT. We depend here on the fact that
5450 * G.global_argv and results of utoa and get_local_var_value
5451 * are actually in writable memory:
5452 * replace_pattern momentarily stores NULs there. */
5454 to_be_freed = replace_pattern(t,
5456 (repl ? repl : exp_word),
5458 if (to_be_freed) /* at least one replace happened */
5465 else if (exp_op == ':') {
5466 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_FEATURE_SH_MATH
5467 /* It's ${var:N[:M]} bashism.
5468 * Note that in encoded form it has TWO parts:
5469 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5474 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5477 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5478 *p++ = SPECIAL_VAR_SYMBOL;
5480 p = strchr(p, SPECIAL_VAR_SYMBOL);
5482 len = expand_and_evaluate_arith(exp_word, &errmsg);
5485 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5486 if (len >= 0) { /* bash compat: len < 0 is illegal */
5487 if (beg < 0) /* bash compat */
5489 debug_printf_varexp("from val:'%s'\n", val);
5490 if (len == 0 || !val || beg >= strlen(val)) {
5494 /* Paranoia. What if user entered 9999999999999
5495 * which fits in arith_t but not int? */
5498 val = to_be_freed = xstrndup(val + beg, len);
5500 debug_printf_varexp("val:'%s'\n", val);
5504 die_if_script("malformed ${%s:...}", var);
5507 } else { /* one of "-=+?" */
5508 /* Standard-mandated substitution ops:
5509 * ${var?word} - indicate error if unset
5510 * If var is unset, word (or a message indicating it is unset
5511 * if word is null) is written to standard error
5512 * and the shell exits with a non-zero exit status.
5513 * Otherwise, the value of var is substituted.
5514 * ${var-word} - use default value
5515 * If var is unset, word is substituted.
5516 * ${var=word} - assign and use default value
5517 * If var is unset, word is assigned to var.
5518 * In all cases, final value of var is substituted.
5519 * ${var+word} - use alternative value
5520 * If var is unset, null is substituted.
5521 * Otherwise, word is substituted.
5523 * Word is subjected to tilde expansion, parameter expansion,
5524 * command substitution, and arithmetic expansion.
5525 * If word is not needed, it is not expanded.
5527 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5528 * but also treat null var as if it is unset.
5530 int use_word = (!val || ((exp_save == ':') && !val[0]));
5532 use_word = !use_word;
5533 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5534 (exp_save == ':') ? "true" : "false", use_word);
5536 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5538 exp_word = to_be_freed;
5539 if (exp_op == '?') {
5540 /* mimic bash message */
5541 die_if_script("%s: %s",
5543 exp_word[0] ? exp_word : "parameter null or not set"
5545 //TODO: how interactive bash aborts expansion mid-command?
5550 if (exp_op == '=') {
5551 /* ${var=[word]} or ${var:=[word]} */
5552 if (isdigit(var[0]) || var[0] == '#') {
5553 /* mimic bash message */
5554 die_if_script("$%s: cannot assign in this way", var);
5557 char *new_var = xasprintf("%s=%s", var, val);
5558 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5562 } /* one of "-=+?" */
5564 *exp_saveptr = exp_save;
5570 *to_be_freed_pp = to_be_freed;
5574 /* Expand all variable references in given string, adding words to list[]
5575 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5576 * to be filled). This routine is extremely tricky: has to deal with
5577 * variables/parameters with whitespace, $* and $@, and constructs like
5578 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5579 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5581 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5582 * expansion of right-hand side of assignment == 1-element expand.
5584 char cant_be_null = 0; /* only bit 0x80 matters */
5585 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5588 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5589 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5590 debug_print_list("expand_vars_to_list", output, n);
5591 n = o_save_ptr(output, n);
5592 debug_print_list("expand_vars_to_list[0]", output, n);
5594 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5596 char *to_be_freed = NULL;
5597 const char *val = NULL;
5598 #if ENABLE_HUSH_TICK
5599 o_string subst_result = NULL_O_STRING;
5601 #if ENABLE_FEATURE_SH_MATH
5602 char arith_buf[sizeof(arith_t)*3 + 2];
5606 o_addchr(output, '\0');
5607 n = o_save_ptr(output, n);
5611 o_addblock(output, arg, p - arg);
5612 debug_print_list("expand_vars_to_list[1]", output, n);
5614 p = strchr(p, SPECIAL_VAR_SYMBOL);
5616 /* Fetch special var name (if it is indeed one of them)
5617 * and quote bit, force the bit on if singleword expansion -
5618 * important for not getting v=$@ expand to many words. */
5619 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5621 /* Is this variable quoted and thus expansion can't be null?
5622 * "$@" is special. Even if quoted, it can still
5623 * expand to nothing (not even an empty string),
5624 * thus it is excluded. */
5625 if ((first_ch & 0x7f) != '@')
5626 cant_be_null |= first_ch;
5628 switch (first_ch & 0x7f) {
5629 /* Highest bit in first_ch indicates that var is double-quoted */
5633 if (!G.global_argv[1])
5636 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5637 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5638 while (G.global_argv[i]) {
5639 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5640 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5641 if (G.global_argv[i++][0] && G.global_argv[i]) {
5642 /* this argv[] is not empty and not last:
5643 * put terminating NUL, start new word */
5644 o_addchr(output, '\0');
5645 debug_print_list("expand_vars_to_list[2]", output, n);
5646 n = o_save_ptr(output, n);
5647 debug_print_list("expand_vars_to_list[3]", output, n);
5651 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5652 * and in this case should treat it like '$*' - see 'else...' below */
5653 if (first_ch == ('@'|0x80) /* quoted $@ */
5654 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5657 o_addQstr(output, G.global_argv[i]);
5658 if (++i >= G.global_argc)
5660 o_addchr(output, '\0');
5661 debug_print_list("expand_vars_to_list[4]", output, n);
5662 n = o_save_ptr(output, n);
5664 } else { /* quoted $* (or v="$@" case): add as one word */
5666 o_addQstr(output, G.global_argv[i]);
5667 if (!G.global_argv[++i])
5670 o_addchr(output, G.ifs[0]);
5672 output->has_quoted_part = 1;
5676 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5677 /* "Empty variable", used to make "" etc to not disappear */
5678 output->has_quoted_part = 1;
5680 cant_be_null = 0x80;
5682 #if ENABLE_HUSH_TICK
5683 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5684 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5686 /* Can't just stuff it into output o_string,
5687 * expanded result may need to be globbed
5688 * and $IFS-splitted */
5689 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5690 G.last_exitcode = process_command_subs(&subst_result, arg);
5691 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5692 val = subst_result.data;
5695 #if ENABLE_FEATURE_SH_MATH
5696 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5699 arg++; /* skip '+' */
5700 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5701 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5702 res = expand_and_evaluate_arith(arg, NULL);
5703 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5704 sprintf(arith_buf, ARITH_FMT, res);
5710 val = expand_one_var(&to_be_freed, arg, &p);
5711 IF_HUSH_TICK(store_val:)
5712 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5713 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5714 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5715 if (val && val[0]) {
5716 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5719 } else { /* quoted $VAR, val will be appended below */
5720 output->has_quoted_part = 1;
5721 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5722 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5725 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5727 if (val && val[0]) {
5728 o_addQstr(output, val);
5732 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5733 * Do the check to avoid writing to a const string. */
5734 if (*p != SPECIAL_VAR_SYMBOL)
5735 *p = SPECIAL_VAR_SYMBOL;
5737 #if ENABLE_HUSH_TICK
5738 o_free(&subst_result);
5741 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5745 o_addchr(output, '\0');
5746 n = o_save_ptr(output, n);
5748 debug_print_list("expand_vars_to_list[a]", output, n);
5749 /* this part is literal, and it was already pre-quoted
5750 * if needed (much earlier), do not use o_addQstr here! */
5751 o_addstr_with_NUL(output, arg);
5752 debug_print_list("expand_vars_to_list[b]", output, n);
5753 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5754 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5757 /* allow to reuse list[n] later without re-growth */
5758 output->has_empty_slot = 1;
5760 o_addchr(output, '\0');
5766 static char **expand_variables(char **argv, unsigned expflags)
5770 o_string output = NULL_O_STRING;
5772 output.o_expflags = expflags;
5776 n = expand_vars_to_list(&output, n, *argv);
5779 debug_print_list("expand_variables", &output, n);
5781 /* output.data (malloced in one block) gets returned in "list" */
5782 list = o_finalize_list(&output, n);
5783 debug_print_strings("expand_variables[1]", list);
5787 static char **expand_strvec_to_strvec(char **argv)
5789 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5792 #if ENABLE_HUSH_BASH_COMPAT
5793 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5795 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5799 /* Used for expansion of right hand of assignments,
5800 * $((...)), heredocs, variable espansion parts.
5802 * NB: should NOT do globbing!
5803 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5805 static char *expand_string_to_string(const char *str, int do_unbackslash)
5807 #if !ENABLE_HUSH_BASH_COMPAT
5808 const int do_unbackslash = 1;
5810 char *argv[2], **list;
5812 debug_printf_expand("string_to_string<='%s'\n", str);
5813 /* This is generally an optimization, but it also
5814 * handles "", which otherwise trips over !list[0] check below.
5815 * (is this ever happens that we actually get str="" here?)
5817 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5818 //TODO: Can use on strings with \ too, just unbackslash() them?
5819 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5820 return xstrdup(str);
5823 argv[0] = (char*)str;
5825 list = expand_variables(argv, do_unbackslash
5826 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5827 : EXP_FLAG_SINGLEWORD
5830 if (!list[0] || list[1])
5831 bb_error_msg_and_die("BUG in varexp2");
5832 /* actually, just move string 2*sizeof(char*) bytes back */
5833 overlapping_strcpy((char*)list, list[0]);
5835 unbackslash((char*)list);
5836 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5840 /* Used for "eval" builtin */
5841 static char* expand_strvec_to_string(char **argv)
5845 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5846 /* Convert all NULs to spaces */
5851 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5852 bb_error_msg_and_die("BUG in varexp3");
5853 /* bash uses ' ' regardless of $IFS contents */
5858 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5859 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5863 static char **expand_assignments(char **argv, int count)
5868 G.expanded_assignments = p = NULL;
5869 /* Expand assignments into one string each */
5870 for (i = 0; i < count; i++) {
5871 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5873 G.expanded_assignments = NULL;
5878 static void switch_off_special_sigs(unsigned mask)
5881 while ((mask >>= 1) != 0) {
5886 if (G.traps[sig] && !G.traps[sig][0])
5887 /* trap is '', has to remain SIG_IGN */
5890 G.traps[sig] = NULL;
5892 /* We are here only if no trap or trap was not '' */
5893 install_sighandler(sig, SIG_DFL);
5899 void re_execute_shell(char ***to_free, const char *s,
5900 char *g_argv0, char **g_argv,
5901 char **builtin_argv) NORETURN;
5903 static void reset_traps_to_defaults(void)
5905 /* This function is always called in a child shell
5906 * after fork (not vfork, NOMMU doesn't use this function).
5911 /* Child shells are not interactive.
5912 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5913 * Testcase: (while :; do :; done) + ^Z should background.
5914 * Same goes for SIGTERM, SIGHUP, SIGINT.
5916 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5917 if (!G.traps && !mask)
5918 return; /* already no traps and no special sigs */
5920 /* Switch off special sigs */
5921 switch_off_special_sigs(mask);
5923 G_fatal_sig_mask = 0;
5925 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5926 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5927 * remain set in G.special_sig_mask */
5932 /* Reset all sigs to default except ones with empty traps */
5933 for (sig = 0; sig < NSIG; sig++) {
5935 continue; /* no trap: nothing to do */
5936 if (!G.traps[sig][0])
5937 continue; /* empty trap: has to remain SIG_IGN */
5938 /* sig has non-empty trap, reset it: */
5940 G.traps[sig] = NULL;
5941 /* There is no signal for trap 0 (EXIT) */
5944 install_sighandler(sig, pick_sighandler(sig));
5950 static void re_execute_shell(char ***to_free, const char *s,
5951 char *g_argv0, char **g_argv,
5952 char **builtin_argv) NORETURN;
5953 static void re_execute_shell(char ***to_free, const char *s,
5954 char *g_argv0, char **g_argv,
5955 char **builtin_argv)
5957 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5958 /* delims + 2 * (number of bytes in printed hex numbers) */
5959 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5960 char *heredoc_argv[4];
5961 struct variable *cur;
5962 # if ENABLE_HUSH_FUNCTIONS
5963 struct function *funcp;
5967 unsigned long long empty_trap_mask;
5969 if (!g_argv0) { /* heredoc */
5970 argv = heredoc_argv;
5971 argv[0] = (char *) G.argv0_for_re_execing;
5972 argv[1] = (char *) "-<";
5973 argv[2] = (char *) s;
5975 pp = &argv[3]; /* used as pointer to empty environment */
5981 if (pp) while (*pp++)
5984 empty_trap_mask = 0;
5987 for (sig = 1; sig < NSIG; sig++) {
5988 if (G.traps[sig] && !G.traps[sig][0])
5989 empty_trap_mask |= 1LL << sig;
5993 sprintf(param_buf, NOMMU_HACK_FMT
5994 , (unsigned) G.root_pid
5995 , (unsigned) G.root_ppid
5996 , (unsigned) G.last_bg_pid
5997 , (unsigned) G.last_exitcode
6000 IF_HUSH_LOOPS(, G.depth_of_loop)
6002 # undef NOMMU_HACK_FMT
6003 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6004 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6007 for (cur = G.top_var; cur; cur = cur->next) {
6008 if (!cur->flg_export || cur->flg_read_only)
6011 # if ENABLE_HUSH_FUNCTIONS
6012 for (funcp = G.top_func; funcp; funcp = funcp->next)
6018 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6019 *pp++ = (char *) G.argv0_for_re_execing;
6021 for (cur = G.top_var; cur; cur = cur->next) {
6022 if (strcmp(cur->varstr, hush_version_str) == 0)
6024 if (cur->flg_read_only) {
6025 *pp++ = (char *) "-R";
6026 *pp++ = cur->varstr;
6027 } else if (!cur->flg_export) {
6028 *pp++ = (char *) "-V";
6029 *pp++ = cur->varstr;
6032 # if ENABLE_HUSH_FUNCTIONS
6033 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6034 *pp++ = (char *) "-F";
6035 *pp++ = funcp->name;
6036 *pp++ = funcp->body_as_string;
6039 /* We can pass activated traps here. Say, -Tnn:trap_string
6041 * However, POSIX says that subshells reset signals with traps
6043 * I tested bash-3.2 and it not only does that with true subshells
6044 * of the form ( list ), but with any forked children shells.
6045 * I set trap "echo W" WINCH; and then tried:
6047 * { echo 1; sleep 20; echo 2; } &
6048 * while true; do echo 1; sleep 20; echo 2; break; done &
6049 * true | { echo 1; sleep 20; echo 2; } | cat
6051 * In all these cases sending SIGWINCH to the child shell
6052 * did not run the trap. If I add trap "echo V" WINCH;
6053 * _inside_ group (just before echo 1), it works.
6055 * I conclude it means we don't need to pass active traps here.
6057 *pp++ = (char *) "-c";
6060 while (*++builtin_argv)
6061 *pp++ = *builtin_argv;
6062 *pp++ = (char *) "";
6067 /* *pp = NULL; - is already there */
6071 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6072 /* Don't propagate SIG_IGN to the child */
6073 if (SPECIAL_JOBSTOP_SIGS != 0)
6074 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6075 execve(bb_busybox_exec_path, argv, pp);
6076 /* Fallback. Useful for init=/bin/hush usage etc */
6077 if (argv[0][0] == '/')
6078 execve(argv[0], argv, pp);
6079 xfunc_error_retval = 127;
6080 bb_error_msg_and_die("can't re-execute the shell");
6082 #endif /* !BB_MMU */
6085 static int run_and_free_list(struct pipe *pi);
6087 /* Executing from string: eval, sh -c '...'
6088 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6089 * end_trigger controls how often we stop parsing
6090 * NUL: parse all, execute, return
6091 * ';': parse till ';' or newline, execute, repeat till EOF
6093 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6095 /* Why we need empty flag?
6096 * An obscure corner case "false; ``; echo $?":
6097 * empty command in `` should still set $? to 0.
6098 * But we can't just set $? to 0 at the start,
6099 * this breaks "false; echo `echo $?`" case.
6103 struct pipe *pipe_list;
6105 #if ENABLE_HUSH_INTERACTIVE
6106 if (end_trigger == ';')
6107 inp->promptmode = 0; /* PS1 */
6109 pipe_list = parse_stream(NULL, inp, end_trigger);
6110 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6111 /* If we are in "big" script
6112 * (not in `cmd` or something similar)...
6114 if (pipe_list == ERR_PTR && end_trigger == ';') {
6115 /* Discard cached input (rest of line) */
6116 int ch = inp->last_char;
6117 while (ch != EOF && ch != '\n') {
6118 //bb_error_msg("Discarded:'%c'", ch);
6123 /* This stream isn't empty */
6127 if (!pipe_list && empty)
6128 G.last_exitcode = 0;
6131 debug_print_tree(pipe_list, 0);
6132 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6133 run_and_free_list(pipe_list);
6135 if (G_flag_return_in_progress == 1)
6140 static void parse_and_run_string(const char *s)
6142 struct in_str input;
6143 setup_string_in_str(&input, s);
6144 parse_and_run_stream(&input, '\0');
6147 static void parse_and_run_file(FILE *f)
6149 struct in_str input;
6150 setup_file_in_str(&input, f);
6151 parse_and_run_stream(&input, ';');
6154 #if ENABLE_HUSH_TICK
6155 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6160 char **to_free = NULL;
6164 pid = BB_MMU ? xfork() : xvfork();
6165 if (pid == 0) { /* child */
6166 disable_restore_tty_pgrp_on_exit();
6167 /* Process substitution is not considered to be usual
6168 * 'command execution'.
6169 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6176 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6177 close(channel[0]); /* NB: close _first_, then move fd! */
6178 xmove_fd(channel[1], 1);
6179 /* Prevent it from trying to handle ctrl-z etc */
6180 IF_HUSH_JOB(G.run_list_level = 1;)
6181 /* Awful hack for `trap` or $(trap).
6183 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6184 * contains an example where "trap" is executed in a subshell:
6186 * save_traps=$(trap)
6188 * eval "$save_traps"
6190 * Standard does not say that "trap" in subshell shall print
6191 * parent shell's traps. It only says that its output
6192 * must have suitable form, but then, in the above example
6193 * (which is not supposed to be normative), it implies that.
6195 * bash (and probably other shell) does implement it
6196 * (traps are reset to defaults, but "trap" still shows them),
6197 * but as a result, "trap" logic is hopelessly messed up:
6200 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6201 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6202 * # true | trap <--- trap is in subshell - no output (ditto)
6203 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6204 * trap -- 'echo Ho' SIGWINCH
6205 * # echo `(trap)` <--- in subshell in subshell - output
6206 * trap -- 'echo Ho' SIGWINCH
6207 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6208 * trap -- 'echo Ho' SIGWINCH
6210 * The rules when to forget and when to not forget traps
6211 * get really complex and nonsensical.
6213 * Our solution: ONLY bare $(trap) or `trap` is special.
6215 s = skip_whitespace(s);
6216 if (is_prefixed_with(s, "trap")
6217 && skip_whitespace(s + 4)[0] == '\0'
6219 static const char *const argv[] = { NULL, NULL };
6220 builtin_trap((char**)argv);
6221 fflush_all(); /* important */
6225 reset_traps_to_defaults();
6226 parse_and_run_string(s);
6227 _exit(G.last_exitcode);
6229 /* We re-execute after vfork on NOMMU. This makes this script safe:
6230 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6231 * huge=`cat BIG` # was blocking here forever
6234 re_execute_shell(&to_free,
6244 # if ENABLE_HUSH_FAST
6246 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6247 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6248 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6250 enable_restore_tty_pgrp_on_exit();
6255 return remember_FILE(xfdopen_for_read(channel[0]));
6258 /* Return code is exit status of the process that is run. */
6259 static int process_command_subs(o_string *dest, const char *s)
6262 struct in_str pipe_str;
6264 int status, ch, eol_cnt;
6266 fp = generate_stream_from_string(s, &pid);
6268 /* Now send results of command back into original context */
6269 setup_file_in_str(&pipe_str, fp);
6271 while ((ch = i_getch(&pipe_str)) != EOF) {
6277 o_addchr(dest, '\n');
6280 o_addQchr(dest, ch);
6283 debug_printf("done reading from `cmd` pipe, closing it\n");
6284 fclose_and_forget(fp);
6285 /* We need to extract exitcode. Test case
6286 * "true; echo `sleep 1; false` $?"
6288 safe_waitpid(pid, &status, 0);
6289 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6290 return WEXITSTATUS(status);
6292 #endif /* ENABLE_HUSH_TICK */
6295 static void setup_heredoc(struct redir_struct *redir)
6297 struct fd_pair pair;
6300 /* the _body_ of heredoc (misleading field name) */
6301 const char *heredoc = redir->rd_filename;
6308 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6309 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6313 len = strlen(heredoc);
6315 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6317 xmove_fd(pair.rd, redir->rd_fd);
6319 /* Try writing without forking. Newer kernels have
6320 * dynamically growing pipes. Must use non-blocking write! */
6323 written = write(pair.wr, heredoc, len);
6334 ndelay_off(pair.wr);
6336 /* Okay, pipe buffer was not big enough */
6337 /* Note: we must not create a stray child (bastard? :)
6338 * for the unsuspecting parent process. Child creates a grandchild
6339 * and exits before parent execs the process which consumes heredoc
6340 * (that exec happens after we return from this function) */
6347 disable_restore_tty_pgrp_on_exit();
6348 pid = BB_MMU ? xfork() : xvfork();
6352 close(redir->rd_fd); /* read side of the pipe */
6354 full_write(pair.wr, heredoc, len); /* may loop or block */
6357 /* Delegate blocking writes to another process */
6358 xmove_fd(pair.wr, STDOUT_FILENO);
6359 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6363 #if ENABLE_HUSH_FAST
6365 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6367 enable_restore_tty_pgrp_on_exit();
6373 wait(NULL); /* wait till child has died */
6376 /* fd: redirect wants this fd to be used (e.g. 3>file).
6377 * Move all conflicting internally used fds,
6378 * and remember them so that we can restore them later.
6380 static int save_fds_on_redirect(int fd, int squirrel[3])
6383 /* Handle redirects of fds 0,1,2 */
6385 /* If we collide with an already moved stdio fd... */
6386 if (fd == squirrel[0]) {
6387 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6390 if (fd == squirrel[1]) {
6391 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6394 if (fd == squirrel[2]) {
6395 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6398 /* If we are about to redirect stdio fd, and did not yet move it... */
6399 if (fd <= 2 && squirrel[fd] < 0) {
6400 /* We avoid taking stdio fds */
6401 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6402 if (squirrel[fd] < 0 && errno != EBADF)
6404 return 0; /* "we did not close fd" */
6408 #if ENABLE_HUSH_INTERACTIVE
6409 if (fd != 0 && fd == G.interactive_fd) {
6410 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6415 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6416 * (1) Redirect in a forked child. No need to save FILEs' fds,
6417 * we aren't going to use them anymore, ok to trash.
6418 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6419 * but how are we doing to use them?
6420 * "fileno(fd) = new_fd" can't be done.
6425 return save_FILEs_on_redirect(fd);
6428 static void restore_redirects(int squirrel[3])
6431 for (i = 0; i <= 2; i++) {
6434 /* We simply die on error */
6439 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6441 restore_redirected_FILEs();
6444 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6445 * and stderr if they are redirected. */
6446 static int setup_redirects(struct command *prog, int squirrel[])
6449 struct redir_struct *redir;
6451 for (redir = prog->redirects; redir; redir = redir->next) {
6452 if (redir->rd_type == REDIRECT_HEREDOC2) {
6453 /* "rd_fd<<HERE" case */
6454 save_fds_on_redirect(redir->rd_fd, squirrel);
6455 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6457 debug_printf_parse("set heredoc '%s'\n",
6458 redir->rd_filename);
6459 setup_heredoc(redir);
6463 if (redir->rd_dup == REDIRFD_TO_FILE) {
6464 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6466 if (redir->rd_filename == NULL) {
6469 * "cmd >" (no filename)
6470 * "cmd > <file" (2nd redirect starts too early)
6472 die_if_script("syntax error: %s", "invalid redirect");
6475 mode = redir_table[redir->rd_type].mode;
6476 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6477 openfd = open_or_warn(p, mode);
6480 /* Error message from open_or_warn can be lost
6481 * if stderr has been redirected, but bash
6482 * and ash both lose it as well
6483 * (though zsh doesn't!)
6488 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6489 openfd = redir->rd_dup;
6492 if (openfd != redir->rd_fd) {
6493 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6494 if (openfd == REDIRFD_CLOSE) {
6495 /* "rd_fd >&-" means "close me" */
6497 /* ^^^ optimization: saving may already
6498 * have closed it. If not... */
6499 close(redir->rd_fd);
6502 xdup2(openfd, redir->rd_fd);
6503 if (redir->rd_dup == REDIRFD_TO_FILE)
6504 /* "rd_fd > FILE" */
6506 /* else: "rd_fd > rd_dup" */
6513 static char *find_in_path(const char *arg)
6516 const char *PATH = get_local_var_value("PATH");
6522 const char *end = strchrnul(PATH, ':');
6523 int sz = end - PATH; /* must be int! */
6527 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6529 /* We have xxx::yyyy in $PATH,
6530 * it means "use current dir" */
6533 if (access(ret, F_OK) == 0)
6546 static const struct built_in_command *find_builtin_helper(const char *name,
6547 const struct built_in_command *x,
6548 const struct built_in_command *end)
6551 if (strcmp(name, x->b_cmd) != 0) {
6555 debug_printf_exec("found builtin '%s'\n", name);
6560 static const struct built_in_command *find_builtin1(const char *name)
6562 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6564 static const struct built_in_command *find_builtin(const char *name)
6566 const struct built_in_command *x = find_builtin1(name);
6569 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6572 #if ENABLE_HUSH_FUNCTIONS
6573 static struct function **find_function_slot(const char *name)
6575 struct function **funcpp = &G.top_func;
6577 if (strcmp(name, (*funcpp)->name) == 0) {
6580 funcpp = &(*funcpp)->next;
6585 static const struct function *find_function(const char *name)
6587 const struct function *funcp = *find_function_slot(name);
6589 debug_printf_exec("found function '%s'\n", name);
6593 /* Note: takes ownership on name ptr */
6594 static struct function *new_function(char *name)
6596 struct function **funcpp = find_function_slot(name);
6597 struct function *funcp = *funcpp;
6599 if (funcp != NULL) {
6600 struct command *cmd = funcp->parent_cmd;
6601 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6603 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6605 /* Note: if !funcp->body, do not free body_as_string!
6606 * This is a special case of "-F name body" function:
6607 * body_as_string was not malloced! */
6609 free_pipe_list(funcp->body);
6611 free(funcp->body_as_string);
6615 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6616 cmd->argv[0] = funcp->name;
6617 cmd->group = funcp->body;
6619 cmd->group_as_string = funcp->body_as_string;
6623 debug_printf_exec("remembering new function '%s'\n", name);
6624 funcp = *funcpp = xzalloc(sizeof(*funcp));
6625 /*funcp->next = NULL;*/
6632 static void unset_func(const char *name)
6634 struct function **funcpp = find_function_slot(name);
6635 struct function *funcp = *funcpp;
6637 if (funcp != NULL) {
6638 debug_printf_exec("freeing function '%s'\n", funcp->name);
6639 *funcpp = funcp->next;
6640 /* funcp is unlinked now, deleting it.
6641 * Note: if !funcp->body, the function was created by
6642 * "-F name body", do not free ->body_as_string
6643 * and ->name as they were not malloced. */
6645 free_pipe_list(funcp->body);
6648 free(funcp->body_as_string);
6656 #define exec_function(to_free, funcp, argv) \
6657 exec_function(funcp, argv)
6659 static void exec_function(char ***to_free,
6660 const struct function *funcp,
6661 char **argv) NORETURN;
6662 static void exec_function(char ***to_free,
6663 const struct function *funcp,
6669 argv[0] = G.global_argv[0];
6670 G.global_argv = argv;
6674 /* On MMU, funcp->body is always non-NULL */
6675 n = run_list(funcp->body);
6679 re_execute_shell(to_free,
6680 funcp->body_as_string,
6687 static int run_function(const struct function *funcp, char **argv)
6693 save_and_replace_G_args(&sv, argv);
6695 /* "we are in function, ok to use return" */
6696 sv_flg = G_flag_return_in_progress;
6697 G_flag_return_in_progress = -1;
6698 # if ENABLE_HUSH_LOCAL
6699 G.func_nest_level++;
6702 /* On MMU, funcp->body is always non-NULL */
6705 /* Function defined by -F */
6706 parse_and_run_string(funcp->body_as_string);
6707 rc = G.last_exitcode;
6711 rc = run_list(funcp->body);
6714 # if ENABLE_HUSH_LOCAL
6716 struct variable *var;
6717 struct variable **var_pp;
6719 var_pp = &G.top_var;
6720 while ((var = *var_pp) != NULL) {
6721 if (var->func_nest_level < G.func_nest_level) {
6722 var_pp = &var->next;
6726 if (var->flg_export)
6727 bb_unsetenv(var->varstr);
6728 /* Remove from global list */
6729 *var_pp = var->next;
6735 G.func_nest_level--;
6738 G_flag_return_in_progress = sv_flg;
6740 restore_G_args(&sv, argv);
6744 #endif /* ENABLE_HUSH_FUNCTIONS */
6748 #define exec_builtin(to_free, x, argv) \
6749 exec_builtin(x, argv)
6751 #define exec_builtin(to_free, x, argv) \
6752 exec_builtin(to_free, argv)
6754 static void exec_builtin(char ***to_free,
6755 const struct built_in_command *x,
6756 char **argv) NORETURN;
6757 static void exec_builtin(char ***to_free,
6758 const struct built_in_command *x,
6764 rcode = x->b_function(argv);
6769 /* On NOMMU, we must never block!
6770 * Example: { sleep 99 | read line; } & echo Ok
6772 re_execute_shell(to_free,
6781 static void execvp_or_die(char **argv) NORETURN;
6782 static void execvp_or_die(char **argv)
6785 debug_printf_exec("execing '%s'\n", argv[0]);
6786 /* Don't propagate SIG_IGN to the child */
6787 if (SPECIAL_JOBSTOP_SIGS != 0)
6788 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6789 execvp(argv[0], argv);
6791 if (errno == EACCES) e = 126;
6792 if (errno == ENOENT) e = 127;
6793 bb_perror_msg("can't execute '%s'", argv[0]);
6797 #if ENABLE_HUSH_MODE_X
6798 static void dump_cmd_in_x_mode(char **argv)
6800 if (G_x_mode && argv) {
6801 /* We want to output the line in one write op */
6809 len += strlen(argv[n++]) + 1;
6815 p += sprintf(p, " %s", argv[n++]);
6823 # define dump_cmd_in_x_mode(argv) ((void)0)
6827 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6828 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6829 #define pseudo_exec(nommu_save, command, argv_expanded) \
6830 pseudo_exec(command, argv_expanded)
6833 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6835 * Don't exit() here. If you don't exec, use _exit instead.
6836 * The at_exit handlers apparently confuse the calling process,
6837 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6839 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6840 char **argv, int assignment_cnt,
6841 char **argv_expanded) NORETURN;
6842 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6843 char **argv, int assignment_cnt,
6844 char **argv_expanded)
6848 new_env = expand_assignments(argv, assignment_cnt);
6849 dump_cmd_in_x_mode(new_env);
6851 if (!argv[assignment_cnt]) {
6852 /* Case when we are here: ... | var=val | ...
6853 * (note that we do not exit early, i.e., do not optimize out
6854 * expand_assignments(): think about ... | var=`sleep 1` | ...
6856 free_strings(new_env);
6857 _exit(EXIT_SUCCESS);
6861 set_vars_and_save_old(new_env);
6862 free(new_env); /* optional */
6863 /* we can also destroy set_vars_and_save_old's return value,
6866 nommu_save->new_env = new_env;
6867 nommu_save->old_vars = set_vars_and_save_old(new_env);
6870 if (argv_expanded) {
6871 argv = argv_expanded;
6873 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6875 nommu_save->argv = argv;
6878 dump_cmd_in_x_mode(argv);
6880 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6881 if (strchr(argv[0], '/') != NULL)
6885 /* Check if the command matches any of the builtins.
6886 * Depending on context, this might be redundant. But it's
6887 * easier to waste a few CPU cycles than it is to figure out
6888 * if this is one of those cases.
6891 /* On NOMMU, it is more expensive to re-execute shell
6892 * just in order to run echo or test builtin.
6893 * It's better to skip it here and run corresponding
6894 * non-builtin later. */
6895 const struct built_in_command *x;
6896 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6898 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6901 #if ENABLE_HUSH_FUNCTIONS
6902 /* Check if the command matches any functions */
6904 const struct function *funcp = find_function(argv[0]);
6906 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6911 #if ENABLE_FEATURE_SH_STANDALONE
6912 /* Check if the command matches any busybox applets */
6914 int a = find_applet_by_name(argv[0]);
6916 # if BB_MMU /* see above why on NOMMU it is not allowed */
6917 if (APPLET_IS_NOEXEC(a)) {
6918 /* Do not leak open fds from opened script files etc */
6919 close_all_FILE_list();
6920 debug_printf_exec("running applet '%s'\n", argv[0]);
6921 run_applet_no_and_exit(a, argv);
6924 /* Re-exec ourselves */
6925 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6926 /* Don't propagate SIG_IGN to the child */
6927 if (SPECIAL_JOBSTOP_SIGS != 0)
6928 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6929 execv(bb_busybox_exec_path, argv);
6930 /* If they called chroot or otherwise made the binary no longer
6931 * executable, fall through */
6936 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6939 execvp_or_die(argv);
6942 /* Called after [v]fork() in run_pipe
6944 static void pseudo_exec(nommu_save_t *nommu_save,
6945 struct command *command,
6946 char **argv_expanded) NORETURN;
6947 static void pseudo_exec(nommu_save_t *nommu_save,
6948 struct command *command,
6949 char **argv_expanded)
6951 if (command->argv) {
6952 pseudo_exec_argv(nommu_save, command->argv,
6953 command->assignment_cnt, argv_expanded);
6956 if (command->group) {
6957 /* Cases when we are here:
6960 * ... | ( list ) | ...
6961 * ... | { list } | ...
6965 debug_printf_exec("pseudo_exec: run_list\n");
6966 reset_traps_to_defaults();
6967 rcode = run_list(command->group);
6968 /* OK to leak memory by not calling free_pipe_list,
6969 * since this process is about to exit */
6972 re_execute_shell(&nommu_save->argv_from_re_execing,
6973 command->group_as_string,
6980 /* Case when we are here: ... | >file */
6981 debug_printf_exec("pseudo_exec'ed null command\n");
6982 _exit(EXIT_SUCCESS);
6986 static const char *get_cmdtext(struct pipe *pi)
6992 /* This is subtle. ->cmdtext is created only on first backgrounding.
6993 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6994 * On subsequent bg argv is trashed, but we won't use it */
6998 argv = pi->cmds[0].argv;
7000 pi->cmdtext = xzalloc(1);
7005 len += strlen(*argv) + 1;
7009 argv = pi->cmds[0].argv;
7011 p = stpcpy(p, *argv);
7018 static void insert_bg_job(struct pipe *pi)
7020 struct pipe *job, **jobp;
7023 /* Linear search for the ID of the job to use */
7025 for (job = G.job_list; job; job = job->next)
7026 if (job->jobid >= pi->jobid)
7027 pi->jobid = job->jobid + 1;
7029 /* Add job to the list of running jobs */
7031 while ((job = *jobp) != NULL)
7033 job = *jobp = xmalloc(sizeof(*job));
7035 *job = *pi; /* physical copy */
7037 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7038 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7039 for (i = 0; i < pi->num_cmds; i++) {
7040 job->cmds[i].pid = pi->cmds[i].pid;
7041 /* all other fields are not used and stay zero */
7043 job->cmdtext = xstrdup(get_cmdtext(pi));
7045 if (G_interactive_fd)
7046 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7047 G.last_jobid = job->jobid;
7050 static void remove_bg_job(struct pipe *pi)
7052 struct pipe *prev_pipe;
7054 if (pi == G.job_list) {
7055 G.job_list = pi->next;
7057 prev_pipe = G.job_list;
7058 while (prev_pipe->next != pi)
7059 prev_pipe = prev_pipe->next;
7060 prev_pipe->next = pi->next;
7063 G.last_jobid = G.job_list->jobid;
7068 /* Remove a backgrounded job */
7069 static void delete_finished_bg_job(struct pipe *pi)
7076 static int job_exited_or_stopped(struct pipe *pi)
7080 if (pi->alive_cmds != pi->stopped_cmds)
7083 /* All processes in fg pipe have exited or stopped */
7087 rcode = pi->cmds[i].cmd_exitcode;
7088 /* usually last process gives overall exitstatus,
7089 * but with "set -o pipefail", last *failed* process does */
7090 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7093 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7097 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7104 dead = WIFEXITED(status) || WIFSIGNALED(status);
7107 if (WIFSTOPPED(status))
7108 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7109 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7110 if (WIFSIGNALED(status))
7111 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7112 childpid, WTERMSIG(status), WEXITSTATUS(status));
7113 if (WIFEXITED(status))
7114 debug_printf_jobs("pid %d exited, exitcode %d\n",
7115 childpid, WEXITSTATUS(status));
7117 /* Were we asked to wait for a fg pipe? */
7119 i = fg_pipe->num_cmds;
7124 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7125 if (fg_pipe->cmds[i].pid != childpid)
7129 fg_pipe->cmds[i].pid = 0;
7130 fg_pipe->alive_cmds--;
7131 ex = WEXITSTATUS(status);
7132 /* bash prints killer signal's name for *last*
7133 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7134 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7136 if (WIFSIGNALED(status)) {
7137 int sig = WTERMSIG(status);
7138 if (i == fg_pipe->num_cmds-1)
7139 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7140 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7141 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7142 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7143 * Maybe we need to use sig | 128? */
7146 fg_pipe->cmds[i].cmd_exitcode = ex;
7148 fg_pipe->stopped_cmds++;
7150 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7151 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7152 rcode = job_exited_or_stopped(fg_pipe);
7154 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7155 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7156 * and "killall -STOP cat" */
7157 if (G_interactive_fd) {
7159 if (fg_pipe->alive_cmds != 0)
7160 insert_bg_job(fg_pipe);
7164 if (fg_pipe->alive_cmds == 0)
7167 /* There are still running processes in the fg_pipe */
7170 /* It wasnt in fg_pipe, look for process in bg pipes */
7174 /* We were asked to wait for bg or orphaned children */
7175 /* No need to remember exitcode in this case */
7176 for (pi = G.job_list; pi; pi = pi->next) {
7177 for (i = 0; i < pi->num_cmds; i++) {
7178 if (pi->cmds[i].pid == childpid)
7179 goto found_pi_and_prognum;
7182 /* Happens when shell is used as init process (init=/bin/sh) */
7183 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7184 return -1; /* this wasn't a process from fg_pipe */
7186 found_pi_and_prognum:
7189 pi->cmds[i].pid = 0;
7190 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7191 if (WIFSIGNALED(status))
7192 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7194 if (!pi->alive_cmds) {
7195 if (G_interactive_fd)
7196 printf(JOB_STATUS_FORMAT, pi->jobid,
7197 "Done", pi->cmdtext);
7198 delete_finished_bg_job(pi);
7205 return -1; /* this wasn't a process from fg_pipe */
7208 /* Check to see if any processes have exited -- if they have,
7209 * figure out why and see if a job has completed.
7211 * If non-NULL fg_pipe: wait for its completion or stop.
7212 * Return its exitcode or zero if stopped.
7214 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7215 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7216 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7217 * or 0 if no children changed status.
7219 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7220 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7221 * or 0 if no children changed status.
7223 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7229 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7231 attributes = WUNTRACED;
7232 if (fg_pipe == NULL)
7233 attributes |= WNOHANG;
7236 #if ENABLE_HUSH_FAST
7237 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7238 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7239 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7240 /* There was neither fork nor SIGCHLD since last waitpid */
7241 /* Avoid doing waitpid syscall if possible */
7242 if (!G.we_have_children) {
7246 if (fg_pipe == NULL) { /* is WNOHANG set? */
7247 /* We have children, but they did not exit
7248 * or stop yet (we saw no SIGCHLD) */
7251 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7255 /* Do we do this right?
7256 * bash-3.00# sleep 20 | false
7258 * [3]+ Stopped sleep 20 | false
7259 * bash-3.00# echo $?
7260 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7261 * [hush 1.14.0: yes we do it right]
7265 #if ENABLE_HUSH_FAST
7267 i = G.count_SIGCHLD;
7269 childpid = waitpid(-1, &status, attributes);
7270 if (childpid <= 0) {
7271 if (childpid && errno != ECHILD)
7272 bb_perror_msg("waitpid");
7273 #if ENABLE_HUSH_FAST
7274 else { /* Until next SIGCHLD, waitpid's are useless */
7275 G.we_have_children = (childpid == 0);
7276 G.handled_SIGCHLD = i;
7277 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7280 /* ECHILD (no children), or 0 (no change in children status) */
7284 rcode = process_wait_result(fg_pipe, childpid, status);
7286 /* fg_pipe exited or stopped */
7289 if (childpid == waitfor_pid) {
7290 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7291 rcode = WEXITSTATUS(status);
7292 if (WIFSIGNALED(status))
7293 rcode = 128 + WTERMSIG(status);
7294 if (WIFSTOPPED(status))
7295 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7296 rcode = 128 + WSTOPSIG(status);
7298 break; /* "wait PID" called us, give it exitcode+1 */
7300 /* This wasn't one of our processes, or */
7301 /* fg_pipe still has running processes, do waitpid again */
7302 } /* while (waitpid succeeds)... */
7308 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7311 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7312 if (G_saved_tty_pgrp) {
7313 /* Job finished, move the shell to the foreground */
7314 p = getpgrp(); /* our process group id */
7315 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7316 tcsetpgrp(G_interactive_fd, p);
7322 /* Start all the jobs, but don't wait for anything to finish.
7325 * Return code is normally -1, when the caller has to wait for children
7326 * to finish to determine the exit status of the pipe. If the pipe
7327 * is a simple builtin command, however, the action is done by the
7328 * time run_pipe returns, and the exit code is provided as the
7331 * Returns -1 only if started some children. IOW: we have to
7332 * mask out retvals of builtins etc with 0xff!
7334 * The only case when we do not need to [v]fork is when the pipe
7335 * is single, non-backgrounded, non-subshell command. Examples:
7336 * cmd ; ... { list } ; ...
7337 * cmd && ... { list } && ...
7338 * cmd || ... { list } || ...
7339 * If it is, then we can run cmd as a builtin, NOFORK,
7340 * or (if SH_STANDALONE) an applet, and we can run the { list }
7341 * with run_list. If it isn't one of these, we fork and exec cmd.
7343 * Cases when we must fork:
7344 * non-single: cmd | cmd
7345 * backgrounded: cmd & { list } &
7346 * subshell: ( list ) [&]
7348 #if !ENABLE_HUSH_MODE_X
7349 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7350 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7352 static int redirect_and_varexp_helper(char ***new_env_p,
7353 struct variable **old_vars_p,
7354 struct command *command,
7356 char **argv_expanded)
7358 /* setup_redirects acts on file descriptors, not FILEs.
7359 * This is perfect for work that comes after exec().
7360 * Is it really safe for inline use? Experimentally,
7361 * things seem to work. */
7362 int rcode = setup_redirects(command, squirrel);
7364 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7365 *new_env_p = new_env;
7366 dump_cmd_in_x_mode(new_env);
7367 dump_cmd_in_x_mode(argv_expanded);
7369 *old_vars_p = set_vars_and_save_old(new_env);
7373 static NOINLINE int run_pipe(struct pipe *pi)
7375 static const char *const null_ptr = NULL;
7379 struct command *command;
7380 char **argv_expanded;
7382 /* it is not always needed, but we aim to smaller code */
7383 int squirrel[] = { -1, -1, -1 };
7386 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7389 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7390 * Result should be 3 lines: q w e, qwe, q w e
7392 G.ifs = get_local_var_value("IFS");
7396 IF_HUSH_JOB(pi->pgrp = -1;)
7397 pi->stopped_cmds = 0;
7398 command = &pi->cmds[0];
7399 argv_expanded = NULL;
7401 if (pi->num_cmds != 1
7402 || pi->followup == PIPE_BG
7403 || command->cmd_type == CMD_SUBSHELL
7410 debug_printf_exec(": group:%p argv:'%s'\n",
7411 command->group, command->argv ? command->argv[0] : "NONE");
7413 if (command->group) {
7414 #if ENABLE_HUSH_FUNCTIONS
7415 if (command->cmd_type == CMD_FUNCDEF) {
7416 /* "executing" func () { list } */
7417 struct function *funcp;
7419 funcp = new_function(command->argv[0]);
7420 /* funcp->name is already set to argv[0] */
7421 funcp->body = command->group;
7423 funcp->body_as_string = command->group_as_string;
7424 command->group_as_string = NULL;
7426 command->group = NULL;
7427 command->argv[0] = NULL;
7428 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7429 funcp->parent_cmd = command;
7430 command->child_func = funcp;
7432 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7434 return EXIT_SUCCESS;
7438 debug_printf("non-subshell group\n");
7439 rcode = 1; /* exitcode if redir failed */
7440 if (setup_redirects(command, squirrel) == 0) {
7441 debug_printf_exec(": run_list\n");
7442 rcode = run_list(command->group) & 0xff;
7444 restore_redirects(squirrel);
7445 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7447 debug_printf_exec("run_pipe: return %d\n", rcode);
7451 argv = command->argv ? command->argv : (char **) &null_ptr;
7453 const struct built_in_command *x;
7454 #if ENABLE_HUSH_FUNCTIONS
7455 const struct function *funcp;
7459 char **new_env = NULL;
7460 struct variable *old_vars = NULL;
7462 if (argv[command->assignment_cnt] == NULL) {
7463 /* Assignments, but no command */
7464 /* Ensure redirects take effect (that is, create files).
7465 * Try "a=t >file" */
7466 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7467 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7468 /* Set shell variables */
7472 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7473 /* Do we need to flag set_local_var() errors?
7474 * "assignment to readonly var" and "putenv error"
7479 /* Redirect error sets $? to 1. Otherwise,
7480 * if evaluating assignment value set $?, retain it.
7481 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7483 rcode = G.last_exitcode;
7484 /* Exit, _skipping_ variable restoring code: */
7485 goto clean_up_and_ret0;
7487 #else /* Older, bigger, but more correct code */
7489 rcode = setup_redirects(command, squirrel);
7490 restore_redirects(squirrel);
7491 /* Set shell variables */
7493 bb_putchar_stderr('+');
7495 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7497 fprintf(stderr, " %s", p);
7498 debug_printf_exec("set shell var:'%s'->'%s'\n",
7500 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7501 /* Do we need to flag set_local_var() errors?
7502 * "assignment to readonly var" and "putenv error"
7507 bb_putchar_stderr('\n');
7508 /* Redirect error sets $? to 1. Otherwise,
7509 * if evaluating assignment value set $?, retain it.
7510 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7512 rcode = G.last_exitcode;
7513 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7515 debug_printf_exec("run_pipe: return %d\n", rcode);
7520 /* Expand the rest into (possibly) many strings each */
7521 #if ENABLE_HUSH_BASH_COMPAT
7522 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7523 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7527 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7530 /* if someone gives us an empty string: `cmd with empty output` */
7531 if (!argv_expanded[0]) {
7532 free(argv_expanded);
7534 return G.last_exitcode;
7537 x = find_builtin(argv_expanded[0]);
7538 #if ENABLE_HUSH_FUNCTIONS
7541 funcp = find_function(argv_expanded[0]);
7545 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7546 debug_printf("exec with redirects only\n");
7547 rcode = setup_redirects(command, NULL);
7548 /* rcode=1 can be if redir file can't be opened */
7549 goto clean_up_and_ret1;
7552 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7555 debug_printf_exec(": builtin '%s' '%s'...\n",
7556 x->b_cmd, argv_expanded[1]);
7558 rcode = x->b_function(argv_expanded) & 0xff;
7561 #if ENABLE_HUSH_FUNCTIONS
7563 # if ENABLE_HUSH_LOCAL
7564 struct variable **sv;
7565 sv = G.shadowed_vars_pp;
7566 G.shadowed_vars_pp = &old_vars;
7568 debug_printf_exec(": function '%s' '%s'...\n",
7569 funcp->name, argv_expanded[1]);
7570 rcode = run_function(funcp, argv_expanded) & 0xff;
7571 # if ENABLE_HUSH_LOCAL
7572 G.shadowed_vars_pp = sv;
7578 unset_vars(new_env);
7580 /* clean_up_and_ret0: */
7581 restore_redirects(squirrel);
7583 free(argv_expanded);
7584 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7586 debug_printf_exec("run_pipe return %d\n", rcode);
7590 if (ENABLE_FEATURE_SH_NOFORK) {
7591 int n = find_applet_by_name(argv_expanded[0]);
7592 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7593 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7595 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7596 argv_expanded[0], argv_expanded[1]);
7597 rcode = run_nofork_applet(n, argv_expanded);
7599 goto clean_up_and_ret;
7602 /* It is neither builtin nor applet. We must fork. */
7606 /* NB: argv_expanded may already be created, and that
7607 * might include `cmd` runs! Do not rerun it! We *must*
7608 * use argv_expanded if it's non-NULL */
7610 /* Going to fork a child per each pipe member */
7615 while (cmd_no < pi->num_cmds) {
7616 struct fd_pair pipefds;
7618 volatile nommu_save_t nommu_save;
7619 nommu_save.new_env = NULL;
7620 nommu_save.old_vars = NULL;
7621 nommu_save.argv = NULL;
7622 nommu_save.argv_from_re_execing = NULL;
7624 command = &pi->cmds[cmd_no];
7626 if (command->argv) {
7627 debug_printf_exec(": pipe member '%s' '%s'...\n",
7628 command->argv[0], command->argv[1]);
7630 debug_printf_exec(": pipe member with no argv\n");
7633 /* pipes are inserted between pairs of commands */
7636 if (cmd_no < pi->num_cmds)
7637 xpiped_pair(pipefds);
7639 command->pid = BB_MMU ? fork() : vfork();
7640 if (!command->pid) { /* child */
7642 disable_restore_tty_pgrp_on_exit();
7643 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7645 /* Every child adds itself to new process group
7646 * with pgid == pid_of_first_child_in_pipe */
7647 if (G.run_list_level == 1 && G_interactive_fd) {
7650 if (pgrp < 0) /* true for 1st process only */
7652 if (setpgid(0, pgrp) == 0
7653 && pi->followup != PIPE_BG
7654 && G_saved_tty_pgrp /* we have ctty */
7656 /* We do it in *every* child, not just first,
7658 tcsetpgrp(G_interactive_fd, pgrp);
7662 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7663 /* 1st cmd in backgrounded pipe
7664 * should have its stdin /dev/null'ed */
7666 if (open(bb_dev_null, O_RDONLY))
7667 xopen("/", O_RDONLY);
7669 xmove_fd(next_infd, 0);
7671 xmove_fd(pipefds.wr, 1);
7674 /* Like bash, explicit redirects override pipes,
7675 * and the pipe fd (fd#1) is available for dup'ing:
7676 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7677 * of cmd1 goes into pipe.
7679 if (setup_redirects(command, NULL)) {
7680 /* Happens when redir file can't be opened:
7681 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7683 * hush: can't open '/qwe/rty': No such file or directory
7685 * (echo BAR is not executed, it hits _exit(1) below)
7690 /* Stores to nommu_save list of env vars putenv'ed
7691 * (NOMMU, on MMU we don't need that) */
7692 /* cast away volatility... */
7693 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7694 /* pseudo_exec() does not return */
7697 /* parent or error */
7698 #if ENABLE_HUSH_FAST
7700 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7702 enable_restore_tty_pgrp_on_exit();
7704 /* Clean up after vforked child */
7705 free(nommu_save.argv);
7706 free(nommu_save.argv_from_re_execing);
7707 unset_vars(nommu_save.new_env);
7708 add_vars(nommu_save.old_vars);
7710 free(argv_expanded);
7711 argv_expanded = NULL;
7712 if (command->pid < 0) { /* [v]fork failed */
7713 /* Clearly indicate, was it fork or vfork */
7714 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7718 /* Second and next children need to know pid of first one */
7720 pi->pgrp = command->pid;
7726 if (cmd_no < pi->num_cmds)
7728 /* Pass read (output) pipe end to next iteration */
7729 next_infd = pipefds.rd;
7732 if (!pi->alive_cmds) {
7734 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7739 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7743 /* NB: called by pseudo_exec, and therefore must not modify any
7744 * global data until exec/_exit (we can be a child after vfork!) */
7745 static int run_list(struct pipe *pi)
7747 #if ENABLE_HUSH_CASE
7748 char *case_word = NULL;
7750 #if ENABLE_HUSH_LOOPS
7751 struct pipe *loop_top = NULL;
7752 char **for_lcur = NULL;
7753 char **for_list = NULL;
7755 smallint last_followup;
7757 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7758 smalluint cond_code = 0;
7760 enum { cond_code = 0 };
7763 smallint rword; /* RES_foo */
7764 smallint last_rword; /* ditto */
7767 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7770 #if ENABLE_HUSH_LOOPS
7771 /* Check syntax for "for" */
7774 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7775 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7777 /* current word is FOR or IN (BOLD in comments below) */
7778 if (cpipe->next == NULL) {
7779 syntax_error("malformed for");
7781 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7784 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7785 if (cpipe->next->res_word == RES_DO)
7787 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7788 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7789 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7791 syntax_error("malformed for");
7793 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7800 /* Past this point, all code paths should jump to ret: label
7801 * in order to return, no direct "return" statements please.
7802 * This helps to ensure that no memory is leaked. */
7810 last_rword = RES_XXXX;
7812 last_followup = PIPE_SEQ;
7813 rcode = G.last_exitcode;
7815 /* Go through list of pipes, (maybe) executing them. */
7816 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7821 if (G_flag_return_in_progress == 1)
7824 IF_HAS_KEYWORDS(rword = pi->res_word;)
7825 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7826 rword, cond_code, last_rword);
7827 #if ENABLE_HUSH_LOOPS
7828 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7829 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7831 /* start of a loop: remember where loop starts */
7836 /* Still in the same "if...", "then..." or "do..." branch? */
7837 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7838 if ((rcode == 0 && last_followup == PIPE_OR)
7839 || (rcode != 0 && last_followup == PIPE_AND)
7841 /* It is "<true> || CMD" or "<false> && CMD"
7842 * and we should not execute CMD */
7843 debug_printf_exec("skipped cmd because of || or &&\n");
7844 last_followup = pi->followup;
7845 goto dont_check_jobs_but_continue;
7848 last_followup = pi->followup;
7849 IF_HAS_KEYWORDS(last_rword = rword;)
7852 if (rword == RES_THEN) {
7853 /* if false; then ... fi has exitcode 0! */
7854 G.last_exitcode = rcode = EXIT_SUCCESS;
7855 /* "if <false> THEN cmd": skip cmd */
7859 if (rword == RES_ELSE || rword == RES_ELIF) {
7860 /* "if <true> then ... ELSE/ELIF cmd":
7861 * skip cmd and all following ones */
7866 #if ENABLE_HUSH_LOOPS
7867 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7869 /* first loop through for */
7871 static const char encoded_dollar_at[] ALIGN1 = {
7872 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7873 }; /* encoded representation of "$@" */
7874 static const char *const encoded_dollar_at_argv[] = {
7875 encoded_dollar_at, NULL
7876 }; /* argv list with one element: "$@" */
7879 vals = (char**)encoded_dollar_at_argv;
7880 if (pi->next->res_word == RES_IN) {
7881 /* if no variable values after "in" we skip "for" */
7882 if (!pi->next->cmds[0].argv) {
7883 G.last_exitcode = rcode = EXIT_SUCCESS;
7884 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7887 vals = pi->next->cmds[0].argv;
7888 } /* else: "for var; do..." -> assume "$@" list */
7889 /* create list of variable values */
7890 debug_print_strings("for_list made from", vals);
7891 for_list = expand_strvec_to_strvec(vals);
7892 for_lcur = for_list;
7893 debug_print_strings("for_list", for_list);
7896 /* "for" loop is over, clean up */
7902 /* Insert next value from for_lcur */
7903 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7904 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7907 if (rword == RES_IN) {
7908 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7910 if (rword == RES_DONE) {
7911 continue; /* "done" has no cmds too */
7914 #if ENABLE_HUSH_CASE
7915 if (rword == RES_CASE) {
7916 debug_printf_exec("CASE cond_code:%d\n", cond_code);
7917 case_word = expand_strvec_to_string(pi->cmds->argv);
7920 if (rword == RES_MATCH) {
7923 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
7924 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7926 /* all prev words didn't match, does this one match? */
7927 argv = pi->cmds->argv;
7929 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7930 /* TODO: which FNM_xxx flags to use? */
7931 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7933 if (cond_code == 0) { /* match! we will execute this branch */
7935 case_word = NULL; /* make future "word)" stop */
7942 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7943 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
7945 continue; /* not matched yet, skip this pipe */
7947 if (rword == RES_ESAC) {
7948 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
7950 /* "case" did not match anything: still set $? (to 0) */
7951 G.last_exitcode = rcode = EXIT_SUCCESS;
7955 /* Just pressing <enter> in shell should check for jobs.
7956 * OTOH, in non-interactive shell this is useless
7957 * and only leads to extra job checks */
7958 if (pi->num_cmds == 0) {
7959 if (G_interactive_fd)
7960 goto check_jobs_and_continue;
7964 /* After analyzing all keywords and conditions, we decided
7965 * to execute this pipe. NB: have to do checkjobs(NULL)
7966 * after run_pipe to collect any background children,
7967 * even if list execution is to be stopped. */
7968 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7969 #if ENABLE_HUSH_LOOPS
7970 G.flag_break_continue = 0;
7972 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
7974 /* We ran a builtin, function, or group.
7975 * rcode is already known
7976 * and we don't need to wait for anything. */
7977 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7978 G.last_exitcode = rcode;
7979 check_and_run_traps();
7980 #if ENABLE_HUSH_LOOPS
7981 /* Was it "break" or "continue"? */
7982 if (G.flag_break_continue) {
7983 smallint fbc = G.flag_break_continue;
7984 /* We might fall into outer *loop*,
7985 * don't want to break it too */
7987 G.depth_break_continue--;
7988 if (G.depth_break_continue == 0)
7989 G.flag_break_continue = 0;
7990 /* else: e.g. "continue 2" should *break* once, *then* continue */
7991 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7992 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7993 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7996 /* "continue": simulate end of loop */
8001 if (G_flag_return_in_progress == 1) {
8002 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8005 } else if (pi->followup == PIPE_BG) {
8006 /* What does bash do with attempts to background builtins? */
8007 /* even bash 3.2 doesn't do that well with nested bg:
8008 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8009 * I'm NOT treating inner &'s as jobs */
8011 if (G.run_list_level == 1)
8014 /* Last command's pid goes to $! */
8015 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8016 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8017 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8018 rcode = EXIT_SUCCESS;
8022 if (G.run_list_level == 1 && G_interactive_fd) {
8023 /* Waits for completion, then fg's main shell */
8024 rcode = checkjobs_and_fg_shell(pi);
8025 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8029 /* This one just waits for completion */
8030 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8031 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8033 G.last_exitcode = rcode;
8034 check_and_run_traps();
8037 /* Analyze how result affects subsequent commands */
8039 if (rword == RES_IF || rword == RES_ELIF)
8042 check_jobs_and_continue:
8043 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8044 dont_check_jobs_but_continue: ;
8045 #if ENABLE_HUSH_LOOPS
8046 /* Beware of "while false; true; do ..."! */
8048 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8049 /* check for RES_DONE is needed for "while ...; do \n done" case */
8051 if (rword == RES_WHILE) {
8053 /* "while false; do...done" - exitcode 0 */
8054 G.last_exitcode = rcode = EXIT_SUCCESS;
8055 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8059 if (rword == RES_UNTIL) {
8061 debug_printf_exec(": until expr is true: breaking\n");
8072 #if ENABLE_HUSH_LOOPS
8077 #if ENABLE_HUSH_CASE
8081 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8085 /* Select which version we will use */
8086 static int run_and_free_list(struct pipe *pi)
8089 debug_printf_exec("run_and_free_list entered\n");
8090 if (!G.o_opt[OPT_O_NOEXEC]) {
8091 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8092 rcode = run_list(pi);
8094 /* free_pipe_list has the side effect of clearing memory.
8095 * In the long run that function can be merged with run_list,
8096 * but doing that now would hobble the debugging effort. */
8098 debug_printf_exec("run_and_free_list return %d\n", rcode);
8103 static void install_sighandlers(unsigned mask)
8105 sighandler_t old_handler;
8107 while ((mask >>= 1) != 0) {
8111 old_handler = install_sighandler(sig, pick_sighandler(sig));
8112 /* POSIX allows shell to re-enable SIGCHLD
8113 * even if it was SIG_IGN on entry.
8114 * Therefore we skip IGN check for it:
8118 if (old_handler == SIG_IGN) {
8119 /* oops... restore back to IGN, and record this fact */
8120 install_sighandler(sig, old_handler);
8122 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8124 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8129 /* Called a few times only (or even once if "sh -c") */
8130 static void install_special_sighandlers(void)
8134 /* Which signals are shell-special? */
8135 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8136 if (G_interactive_fd) {
8137 mask |= SPECIAL_INTERACTIVE_SIGS;
8138 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8139 mask |= SPECIAL_JOBSTOP_SIGS;
8141 /* Careful, do not re-install handlers we already installed */
8142 if (G.special_sig_mask != mask) {
8143 unsigned diff = mask & ~G.special_sig_mask;
8144 G.special_sig_mask = mask;
8145 install_sighandlers(diff);
8151 /* Set handlers to restore tty pgrp and exit */
8152 static void install_fatal_sighandlers(void)
8156 /* We will restore tty pgrp on these signals */
8158 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8159 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8160 + (1 << SIGBUS ) * HUSH_DEBUG
8161 + (1 << SIGSEGV) * HUSH_DEBUG
8162 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8164 /* bash 3.2 seems to handle these just like 'fatal' ones */
8167 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8168 * if we aren't interactive... but in this case
8169 * we never want to restore pgrp on exit, and this fn is not called
8171 /*+ (1 << SIGHUP )*/
8172 /*+ (1 << SIGTERM)*/
8173 /*+ (1 << SIGINT )*/
8175 G_fatal_sig_mask = mask;
8177 install_sighandlers(mask);
8181 static int set_mode(int state, char mode, const char *o_opt)
8186 G.o_opt[OPT_O_NOEXEC] = state;
8189 IF_HUSH_MODE_X(G_x_mode = state;)
8193 /* "set -+o" without parameter.
8194 * in bash, set -o produces this output:
8198 * We always use the second form.
8200 const char *p = o_opt_strings;
8203 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8209 idx = index_in_strings(o_opt_strings, o_opt);
8211 G.o_opt[idx] = state;
8215 return EXIT_FAILURE;
8217 return EXIT_SUCCESS;
8220 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8221 int hush_main(int argc, char **argv)
8224 OPT_login = (1 << 0),
8228 unsigned builtin_argc;
8230 struct variable *cur_var;
8231 struct variable *shell_ver;
8234 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8235 G.last_exitcode = EXIT_SUCCESS;
8237 #if ENABLE_HUSH_FAST
8238 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8241 G.argv0_for_re_execing = argv[0];
8243 /* Deal with HUSH_VERSION */
8244 shell_ver = xzalloc(sizeof(*shell_ver));
8245 shell_ver->flg_export = 1;
8246 shell_ver->flg_read_only = 1;
8247 /* Code which handles ${var<op>...} needs writable values for all variables,
8248 * therefore we xstrdup: */
8249 shell_ver->varstr = xstrdup(hush_version_str);
8250 /* Create shell local variables from the values
8251 * currently living in the environment */
8252 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8253 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8254 G.top_var = shell_ver;
8255 cur_var = G.top_var;
8258 char *value = strchr(*e, '=');
8259 if (value) { /* paranoia */
8260 cur_var->next = xzalloc(sizeof(*cur_var));
8261 cur_var = cur_var->next;
8262 cur_var->varstr = *e;
8263 cur_var->max_len = strlen(*e);
8264 cur_var->flg_export = 1;
8268 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8269 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8270 putenv(shell_ver->varstr);
8273 set_pwd_var(/*exp:*/ 1);
8275 #if ENABLE_HUSH_BASH_COMPAT
8276 /* Set (but not export) HOSTNAME unless already set */
8277 if (!get_local_var_value("HOSTNAME")) {
8280 set_local_var_from_halves("HOSTNAME", uts.nodename);
8282 /* bash also exports SHLVL and _,
8283 * and sets (but doesn't export) the following variables:
8285 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8286 * BASH_VERSION='3.2.0(1)-release'
8288 * MACHTYPE=i386-pc-linux-gnu
8290 * PPID=<NNNNN> - we also do it elsewhere
8301 * PIPESTATUS=([0]="0")
8302 * HISTFILE=/<xxx>/.bash_history
8306 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8308 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8319 #if ENABLE_FEATURE_EDITING
8320 G.line_input_state = new_line_input_t(FOR_SHELL);
8323 /* Initialize some more globals to non-zero values */
8324 cmdedit_update_prompt();
8326 die_func = restore_ttypgrp_and__exit;
8328 /* Shell is non-interactive at first. We need to call
8329 * install_special_sighandlers() if we are going to execute "sh <script>",
8330 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8331 * If we later decide that we are interactive, we run install_special_sighandlers()
8332 * in order to intercept (more) signals.
8336 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8337 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8340 opt = getopt(argc, argv, "+c:xinsl"
8343 # if ENABLE_HUSH_FUNCTIONS
8353 * sh ... -c 'script'
8354 * sh ... -c 'script' ARG0 [ARG1...]
8355 * On NOMMU, if builtin_argc != 0,
8356 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8357 * "" needs to be replaced with NULL
8358 * and BARGV vector fed to builtin function.
8359 * Note: the form without ARG0 never happens:
8360 * sh ... -c 'builtin' BARGV... ""
8363 G.root_pid = getpid();
8364 G.root_ppid = getppid();
8366 G.global_argv = argv + optind;
8367 G.global_argc = argc - optind;
8369 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8370 const struct built_in_command *x;
8372 install_special_sighandlers();
8373 x = find_builtin(optarg);
8374 if (x) { /* paranoia */
8375 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8376 G.global_argv += builtin_argc;
8377 G.global_argv[-1] = NULL; /* replace "" */
8379 G.last_exitcode = x->b_function(argv + optind - 1);
8383 if (!G.global_argv[0]) {
8384 /* -c 'script' (no params): prevent empty $0 */
8385 G.global_argv--; /* points to argv[i] of 'script' */
8386 G.global_argv[0] = argv[0];
8388 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8389 install_special_sighandlers();
8390 parse_and_run_string(optarg);
8393 /* Well, we cannot just declare interactiveness,
8394 * we have to have some stuff (ctty, etc) */
8395 /* G_interactive_fd++; */
8398 /* "-s" means "read from stdin", but this is how we always
8399 * operate, so simply do nothing here. */
8405 case '<': /* "big heredoc" support */
8406 full_write1_str(optarg);
8409 unsigned long long empty_trap_mask;
8411 G.root_pid = bb_strtou(optarg, &optarg, 16);
8413 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8415 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8417 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8419 builtin_argc = bb_strtou(optarg, &optarg, 16);
8421 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8422 if (empty_trap_mask != 0) {
8424 install_special_sighandlers();
8425 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8426 for (sig = 1; sig < NSIG; sig++) {
8427 if (empty_trap_mask & (1LL << sig)) {
8428 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8429 install_sighandler(sig, SIG_IGN);
8433 # if ENABLE_HUSH_LOOPS
8435 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8441 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8443 # if ENABLE_HUSH_FUNCTIONS
8445 struct function *funcp = new_function(optarg);
8446 /* funcp->name is already set to optarg */
8447 /* funcp->body is set to NULL. It's a special case. */
8448 funcp->body_as_string = argv[optind];
8456 if (set_mode(1, opt, NULL) == 0) /* no error */
8460 fprintf(stderr, "Usage: sh [FILE]...\n"
8461 " or: sh -c command [args]...\n\n");
8467 } /* option parsing loop */
8469 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8470 G.global_argc = argc - (optind - 1);
8471 G.global_argv = argv + (optind - 1);
8472 G.global_argv[0] = argv[0];
8475 G.root_pid = getpid();
8476 G.root_ppid = getppid();
8479 /* If we are login shell... */
8480 if (flags & OPT_login) {
8482 debug_printf("sourcing /etc/profile\n");
8483 input = fopen_for_read("/etc/profile");
8484 if (input != NULL) {
8485 remember_FILE(input);
8486 install_special_sighandlers();
8487 parse_and_run_file(input);
8488 fclose_and_forget(input);
8490 /* bash: after sourcing /etc/profile,
8491 * tries to source (in the given order):
8492 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8493 * stopping on first found. --noprofile turns this off.
8494 * bash also sources ~/.bash_logout on exit.
8495 * If called as sh, skips .bash_XXX files.
8499 if (G.global_argv[1]) {
8502 * "bash <script>" (which is never interactive (unless -i?))
8503 * sources $BASH_ENV here (without scanning $PATH).
8504 * If called as sh, does the same but with $ENV.
8505 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8509 debug_printf("running script '%s'\n", G.global_argv[0]);
8510 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8511 input = xfopen_for_read(G.global_argv[0]);
8512 xfunc_error_retval = 1;
8513 remember_FILE(input);
8514 install_special_sighandlers();
8515 parse_and_run_file(input);
8516 #if ENABLE_FEATURE_CLEAN_UP
8517 fclose_and_forget(input);
8522 /* Up to here, shell was non-interactive. Now it may become one.
8523 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8526 /* A shell is interactive if the '-i' flag was given,
8527 * or if all of the following conditions are met:
8529 * no arguments remaining or the -s flag given
8530 * standard input is a terminal
8531 * standard output is a terminal
8532 * Refer to Posix.2, the description of the 'sh' utility.
8535 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8536 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8537 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8538 if (G_saved_tty_pgrp < 0)
8539 G_saved_tty_pgrp = 0;
8541 /* try to dup stdin to high fd#, >= 255 */
8542 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8543 if (G_interactive_fd < 0) {
8544 /* try to dup to any fd */
8545 G_interactive_fd = dup(STDIN_FILENO);
8546 if (G_interactive_fd < 0) {
8548 G_interactive_fd = 0;
8549 G_saved_tty_pgrp = 0;
8552 // TODO: track & disallow any attempts of user
8553 // to (inadvertently) close/redirect G_interactive_fd
8555 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8556 if (G_interactive_fd) {
8557 close_on_exec_on(G_interactive_fd);
8559 if (G_saved_tty_pgrp) {
8560 /* If we were run as 'hush &', sleep until we are
8561 * in the foreground (tty pgrp == our pgrp).
8562 * If we get started under a job aware app (like bash),
8563 * make sure we are now in charge so we don't fight over
8564 * who gets the foreground */
8566 pid_t shell_pgrp = getpgrp();
8567 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8568 if (G_saved_tty_pgrp == shell_pgrp)
8570 /* send TTIN to ourself (should stop us) */
8571 kill(- shell_pgrp, SIGTTIN);
8575 /* Install more signal handlers */
8576 install_special_sighandlers();
8578 if (G_saved_tty_pgrp) {
8579 /* Set other signals to restore saved_tty_pgrp */
8580 install_fatal_sighandlers();
8581 /* Put ourselves in our own process group
8582 * (bash, too, does this only if ctty is available) */
8583 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8584 /* Grab control of the terminal */
8585 tcsetpgrp(G_interactive_fd, getpid());
8587 enable_restore_tty_pgrp_on_exit();
8589 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8591 const char *hp = get_local_var_value("HISTFILE");
8593 hp = get_local_var_value("HOME");
8595 hp = concat_path_file(hp, ".hush_history");
8600 G.line_input_state->hist_file = hp;
8601 //set_local_var(xasprintf("HISTFILE=%s", ...));
8603 # if ENABLE_FEATURE_SH_HISTFILESIZE
8604 hp = get_local_var_value("HISTFILESIZE");
8605 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8610 install_special_sighandlers();
8612 #elif ENABLE_HUSH_INTERACTIVE
8613 /* No job control compiled in, only prompt/line editing */
8614 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8615 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8616 if (G_interactive_fd < 0) {
8617 /* try to dup to any fd */
8618 G_interactive_fd = dup(STDIN_FILENO);
8619 if (G_interactive_fd < 0)
8621 G_interactive_fd = 0;
8624 if (G_interactive_fd) {
8625 close_on_exec_on(G_interactive_fd);
8627 install_special_sighandlers();
8629 /* We have interactiveness code disabled */
8630 install_special_sighandlers();
8633 * if interactive but not a login shell, sources ~/.bashrc
8634 * (--norc turns this off, --rcfile <file> overrides)
8637 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8638 /* note: ash and hush share this string */
8639 printf("\n\n%s %s\n"
8640 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8643 "hush - the humble shell"
8647 parse_and_run_file(stdin);
8650 hush_exit(G.last_exitcode);
8655 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8656 int msh_main(int argc, char **argv)
8658 bb_error_msg("msh is deprecated, please use hush instead");
8659 return hush_main(argc, argv);
8667 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8672 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8679 return applet_main_func(argc, argv - argc);
8682 static int FAST_FUNC builtin_test(char **argv)
8684 return run_applet_main(argv, test_main);
8687 static int FAST_FUNC builtin_echo(char **argv)
8689 return run_applet_main(argv, echo_main);
8693 static int FAST_FUNC builtin_printf(char **argv)
8695 return run_applet_main(argv, printf_main);
8699 static char **skip_dash_dash(char **argv)
8702 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8707 static int FAST_FUNC builtin_eval(char **argv)
8709 int rcode = EXIT_SUCCESS;
8711 argv = skip_dash_dash(argv);
8713 char *str = expand_strvec_to_string(argv);
8715 * eval "echo Hi; done" ("done" is syntax error):
8716 * "echo Hi" will not execute too.
8718 parse_and_run_string(str);
8720 rcode = G.last_exitcode;
8725 static int FAST_FUNC builtin_cd(char **argv)
8729 argv = skip_dash_dash(argv);
8731 if (newdir == NULL) {
8732 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8733 * bash says "bash: cd: HOME not set" and does nothing
8736 const char *home = get_local_var_value("HOME");
8737 newdir = home ? home : "/";
8739 if (chdir(newdir)) {
8740 /* Mimic bash message exactly */
8741 bb_perror_msg("cd: %s", newdir);
8742 return EXIT_FAILURE;
8744 /* Read current dir (get_cwd(1) is inside) and set PWD.
8745 * Note: do not enforce exporting. If PWD was unset or unexported,
8746 * set it again, but do not export. bash does the same.
8748 set_pwd_var(/*exp:*/ 0);
8749 return EXIT_SUCCESS;
8752 static int FAST_FUNC builtin_exec(char **argv)
8754 argv = skip_dash_dash(argv);
8755 if (argv[0] == NULL)
8756 return EXIT_SUCCESS; /* bash does this */
8758 /* Careful: we can end up here after [v]fork. Do not restore
8759 * tty pgrp then, only top-level shell process does that */
8760 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8761 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8763 /* TODO: if exec fails, bash does NOT exit! We do.
8764 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8765 * and tcsetpgrp, and this is inherently racy.
8767 execvp_or_die(argv);
8770 static int FAST_FUNC builtin_exit(char **argv)
8772 debug_printf_exec("%s()\n", __func__);
8774 /* interactive bash:
8775 * # trap "echo EEE" EXIT
8778 * There are stopped jobs.
8779 * (if there are _stopped_ jobs, running ones don't count)
8782 * EEE (then bash exits)
8784 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8787 /* note: EXIT trap is run by hush_exit */
8788 argv = skip_dash_dash(argv);
8789 if (argv[0] == NULL)
8790 hush_exit(G.last_exitcode);
8791 /* mimic bash: exit 123abc == exit 255 + error msg */
8792 xfunc_error_retval = 255;
8793 /* bash: exit -2 == exit 254, no error msg */
8794 hush_exit(xatoi(argv[0]) & 0xff);
8797 static void print_escaped(const char *s)
8802 const char *p = strchrnul(s, '\'');
8803 /* print 'xxxx', possibly just '' */
8804 printf("'%.*s'", (int)(p - s), s);
8809 /* s points to '; print "'''...'''" */
8811 do putchar('\''); while (*++s == '\'');
8816 #if !ENABLE_HUSH_LOCAL
8817 #define helper_export_local(argv, exp, lvl) \
8818 helper_export_local(argv, exp)
8820 static void helper_export_local(char **argv, int exp, int lvl)
8824 char *name_end = strchrnul(name, '=');
8826 /* So far we do not check that name is valid (TODO?) */
8828 if (*name_end == '\0') {
8829 struct variable *var, **vpp;
8831 vpp = get_ptr_to_local_var(name, name_end - name);
8832 var = vpp ? *vpp : NULL;
8834 if (exp == -1) { /* unexporting? */
8835 /* export -n NAME (without =VALUE) */
8837 var->flg_export = 0;
8838 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8840 } /* else: export -n NOT_EXISTING_VAR: no-op */
8843 if (exp == 1) { /* exporting? */
8844 /* export NAME (without =VALUE) */
8846 var->flg_export = 1;
8847 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8848 putenv(var->varstr);
8852 #if ENABLE_HUSH_LOCAL
8853 if (exp == 0 /* local? */
8854 && var && var->func_nest_level == lvl
8856 /* "local x=abc; ...; local x" - ignore second local decl */
8860 /* Exporting non-existing variable.
8861 * bash does not put it in environment,
8862 * but remembers that it is exported,
8863 * and does put it in env when it is set later.
8864 * We just set it to "" and export. */
8865 /* Or, it's "local NAME" (without =VALUE).
8866 * bash sets the value to "". */
8867 name = xasprintf("%s=", name);
8869 /* (Un)exporting/making local NAME=VALUE */
8870 name = xstrdup(name);
8872 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8876 static int FAST_FUNC builtin_export(char **argv)
8878 unsigned opt_unexport;
8880 #if ENABLE_HUSH_EXPORT_N
8881 /* "!": do not abort on errors */
8882 opt_unexport = getopt32(argv, "!n");
8883 if (opt_unexport == (uint32_t)-1)
8884 return EXIT_FAILURE;
8891 if (argv[0] == NULL) {
8898 /* ash emits: export VAR='VAL'
8899 * bash: declare -x VAR="VAL"
8900 * we follow ash example */
8901 const char *s = *e++;
8902 const char *p = strchr(s, '=');
8904 if (!p) /* wtf? take next variable */
8907 printf("export %.*s", (int)(p - s) + 1, s);
8908 print_escaped(p + 1);
8912 /*fflush_all(); - done after each builtin anyway */
8914 return EXIT_SUCCESS;
8917 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8919 return EXIT_SUCCESS;
8922 #if ENABLE_HUSH_LOCAL
8923 static int FAST_FUNC builtin_local(char **argv)
8925 if (G.func_nest_level == 0) {
8926 bb_error_msg("%s: not in a function", argv[0]);
8927 return EXIT_FAILURE; /* bash compat */
8929 helper_export_local(argv, 0, G.func_nest_level);
8930 return EXIT_SUCCESS;
8934 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8935 static int FAST_FUNC builtin_unset(char **argv)
8940 /* "!": do not abort on errors */
8941 /* "+": stop at 1st non-option */
8942 opts = getopt32(argv, "!+vf");
8943 if (opts == (unsigned)-1)
8944 return EXIT_FAILURE;
8946 bb_error_msg("unset: -v and -f are exclusive");
8947 return EXIT_FAILURE;
8953 if (!(opts & 2)) { /* not -f */
8954 if (unset_local_var(*argv)) {
8955 /* unset <nonexistent_var> doesn't fail.
8956 * Error is when one tries to unset RO var.
8957 * Message was printed by unset_local_var. */
8961 #if ENABLE_HUSH_FUNCTIONS
8971 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8972 * built-in 'set' handler
8974 * set [-abCefhmnuvx] [-o option] [argument...]
8975 * set [+abCefhmnuvx] [+o option] [argument...]
8976 * set -- [argument...]
8979 * Implementations shall support the options in both their hyphen and
8980 * plus-sign forms. These options can also be specified as options to sh.
8982 * Write out all variables and their values: set
8983 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8984 * Turn on the -x and -v options: set -xv
8985 * Unset all positional parameters: set --
8986 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8987 * Set the positional parameters to the expansion of x, even if x expands
8988 * with a leading '-' or '+': set -- $x
8990 * So far, we only support "set -- [argument...]" and some of the short names.
8992 static int FAST_FUNC builtin_set(char **argv)
8995 char **pp, **g_argv;
8996 char *arg = *++argv;
9000 for (e = G.top_var; e; e = e->next)
9002 return EXIT_SUCCESS;
9006 if (strcmp(arg, "--") == 0) {
9010 if (arg[0] != '+' && arg[0] != '-')
9012 for (n = 1; arg[n]; ++n) {
9013 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9015 if (arg[n] == 'o' && argv[1])
9018 } while ((arg = *++argv) != NULL);
9019 /* Now argv[0] is 1st argument */
9022 return EXIT_SUCCESS;
9025 /* NB: G.global_argv[0] ($0) is never freed/changed */
9026 g_argv = G.global_argv;
9027 if (G.global_args_malloced) {
9033 G.global_args_malloced = 1;
9034 pp = xzalloc(sizeof(pp[0]) * 2);
9035 pp[0] = g_argv[0]; /* retain $0 */
9038 /* This realloc's G.global_argv */
9039 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9046 return EXIT_SUCCESS;
9048 /* Nothing known, so abort */
9050 bb_error_msg("set: %s: invalid option", arg);
9051 return EXIT_FAILURE;
9054 static int FAST_FUNC builtin_shift(char **argv)
9057 argv = skip_dash_dash(argv);
9061 if (n >= 0 && n < G.global_argc) {
9062 if (G.global_args_malloced) {
9065 free(G.global_argv[m++]);
9068 memmove(&G.global_argv[1], &G.global_argv[n+1],
9069 G.global_argc * sizeof(G.global_argv[0]));
9070 return EXIT_SUCCESS;
9072 return EXIT_FAILURE;
9075 /* Interruptibility of read builtin in bash
9076 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9078 * Empty trap makes read ignore corresponding signal, for any signal.
9081 * - terminates non-interactive shell;
9082 * - interrupts read in interactive shell;
9083 * if it has non-empty trap:
9084 * - executes trap and returns to command prompt in interactive shell;
9085 * - executes trap and returns to read in non-interactive shell;
9087 * - is ignored (does not interrupt) read in interactive shell;
9088 * - terminates non-interactive shell;
9089 * if it has non-empty trap:
9090 * - executes trap and returns to read;
9092 * - terminates shell (regardless of interactivity);
9093 * if it has non-empty trap:
9094 * - executes trap and returns to read;
9096 static int FAST_FUNC builtin_read(char **argv)
9106 /* "!": do not abort on errors.
9107 * Option string must start with "sr" to match BUILTIN_READ_xxx
9109 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9110 if (read_flags == (uint32_t)-1)
9111 return EXIT_FAILURE;
9113 ifs = get_local_var_value("IFS"); /* can be NULL */
9116 r = shell_builtin_read(set_local_var_from_halves,
9126 if ((uintptr_t)r == 1 && errno == EINTR) {
9127 unsigned sig = check_and_run_traps();
9128 if (sig && sig != SIGINT)
9132 if ((uintptr_t)r > 1) {
9133 bb_error_msg("%s", r);
9134 r = (char*)(uintptr_t)1;
9137 return (uintptr_t)r;
9140 static int FAST_FUNC builtin_trap(char **argv)
9146 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9151 /* No args: print all trapped */
9152 for (i = 0; i < NSIG; ++i) {
9155 print_escaped(G.traps[i]);
9156 /* note: bash adds "SIG", but only if invoked
9157 * as "bash". If called as "sh", or if set -o posix,
9158 * then it prints short signal names.
9159 * We are printing short names: */
9160 printf(" %s\n", get_signame(i));
9163 /*fflush_all(); - done after each builtin anyway */
9164 return EXIT_SUCCESS;
9168 /* If first arg is a number: reset all specified signals */
9169 sig = bb_strtou(*argv, NULL, 10);
9175 sighandler_t handler;
9177 sig = get_signum(*argv++);
9178 if (sig < 0 || sig >= NSIG) {
9180 /* Mimic bash message exactly */
9181 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9186 G.traps[sig] = xstrdup(new_cmd);
9188 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9189 get_signame(sig), sig, G.traps[sig]);
9191 /* There is no signal for 0 (EXIT) */
9196 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9198 /* We are removing trap handler */
9199 handler = pick_sighandler(sig);
9200 install_sighandler(sig, handler);
9205 if (!argv[1]) { /* no second arg */
9206 bb_error_msg("trap: invalid arguments");
9207 return EXIT_FAILURE;
9210 /* First arg is "-": reset all specified to default */
9211 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9212 /* Everything else: set arg as signal handler
9213 * (includes "" case, which ignores signal) */
9214 if (argv[0][0] == '-') {
9215 if (argv[0][1] == '\0') { /* "-" */
9216 /* new_cmd remains NULL: "reset these sigs" */
9219 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9222 /* else: "-something", no special meaning */
9227 goto process_sig_list;
9230 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9231 static int FAST_FUNC builtin_type(char **argv)
9233 int ret = EXIT_SUCCESS;
9239 if (0) {} /* make conditional compile easier below */
9240 /*else if (find_alias(*argv))
9241 type = "an alias";*/
9242 #if ENABLE_HUSH_FUNCTIONS
9243 else if (find_function(*argv))
9244 type = "a function";
9246 else if (find_builtin(*argv))
9247 type = "a shell builtin";
9248 else if ((path = find_in_path(*argv)) != NULL)
9251 bb_error_msg("type: %s: not found", *argv);
9256 printf("%s is %s\n", *argv, type);
9264 static struct pipe *parse_jobspec(const char *str)
9269 if (sscanf(str, "%%%d", &jobnum) != 1) {
9270 bb_error_msg("bad argument '%s'", str);
9273 for (pi = G.job_list; pi; pi = pi->next) {
9274 if (pi->jobid == jobnum) {
9278 bb_error_msg("%d: no such job", jobnum);
9282 /* built-in 'fg' and 'bg' handler */
9283 static int FAST_FUNC builtin_fg_bg(char **argv)
9288 if (!G_interactive_fd)
9289 return EXIT_FAILURE;
9291 /* If they gave us no args, assume they want the last backgrounded task */
9293 for (pi = G.job_list; pi; pi = pi->next) {
9294 if (pi->jobid == G.last_jobid) {
9298 bb_error_msg("%s: no current job", argv[0]);
9299 return EXIT_FAILURE;
9302 pi = parse_jobspec(argv[1]);
9304 return EXIT_FAILURE;
9306 /* TODO: bash prints a string representation
9307 * of job being foregrounded (like "sleep 1 | cat") */
9308 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9309 /* Put the job into the foreground. */
9310 tcsetpgrp(G_interactive_fd, pi->pgrp);
9313 /* Restart the processes in the job */
9314 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9315 for (i = 0; i < pi->num_cmds; i++) {
9316 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9318 pi->stopped_cmds = 0;
9320 i = kill(- pi->pgrp, SIGCONT);
9322 if (errno == ESRCH) {
9323 delete_finished_bg_job(pi);
9324 return EXIT_SUCCESS;
9326 bb_perror_msg("kill (SIGCONT)");
9329 if (argv[0][0] == 'f') {
9331 return checkjobs_and_fg_shell(pi);
9333 return EXIT_SUCCESS;
9337 #if ENABLE_HUSH_HELP
9338 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9340 const struct built_in_command *x;
9343 "Built-in commands:\n"
9344 "------------------\n");
9345 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9347 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9349 return EXIT_SUCCESS;
9353 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9354 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9356 show_history(G.line_input_state);
9357 return EXIT_SUCCESS;
9362 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9365 const char *status_string;
9367 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9368 for (job = G.job_list; job; job = job->next) {
9369 if (job->alive_cmds == job->stopped_cmds)
9370 status_string = "Stopped";
9372 status_string = "Running";
9374 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9376 return EXIT_SUCCESS;
9381 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9386 # ifdef M_TRIM_THRESHOLD
9387 /* Optional. Reduces probability of false positives */
9390 /* Crude attempt to find where "free memory" starts,
9391 * sans fragmentation. */
9393 l = (unsigned long)p;
9396 if (l < (unsigned long)p) l = (unsigned long)p;
9402 struct mallinfo mi = mallinfo();
9403 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9404 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9408 if (!G.memleak_value)
9409 G.memleak_value = l;
9411 l -= G.memleak_value;
9418 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9423 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9426 return EXIT_SUCCESS;
9429 static int FAST_FUNC builtin_source(char **argv)
9431 char *arg_path, *filename;
9434 #if ENABLE_HUSH_FUNCTIONS
9438 argv = skip_dash_dash(argv);
9441 /* bash says: "bash: .: filename argument required" */
9442 return 2; /* bash compat */
9445 if (!strchr(filename, '/')) {
9446 arg_path = find_in_path(filename);
9448 filename = arg_path;
9450 input = remember_FILE(fopen_or_warn(filename, "r"));
9453 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9454 /* POSIX: non-interactive shell should abort here,
9455 * not merely fail. So far no one complained :)
9457 return EXIT_FAILURE;
9460 #if ENABLE_HUSH_FUNCTIONS
9461 sv_flg = G_flag_return_in_progress;
9462 /* "we are inside sourced file, ok to use return" */
9463 G_flag_return_in_progress = -1;
9466 save_and_replace_G_args(&sv, argv);
9468 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9469 G.last_exitcode = 0;
9470 parse_and_run_file(input);
9471 fclose_and_forget(input);
9474 restore_G_args(&sv, argv);
9475 #if ENABLE_HUSH_FUNCTIONS
9476 G_flag_return_in_progress = sv_flg;
9479 return G.last_exitcode;
9482 static int FAST_FUNC builtin_umask(char **argv)
9489 argv = skip_dash_dash(argv);
9491 mode_t old_mask = mask;
9493 /* numeric umasks are taken as-is */
9494 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9495 if (!isdigit(argv[0][0]))
9497 mask = bb_parse_mode(argv[0], mask);
9498 if (!isdigit(argv[0][0]))
9500 if ((unsigned)mask > 0777) {
9503 * bash: umask: 'q': invalid symbolic mode operator
9504 * bash: umask: 999: octal number out of range
9506 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9511 printf("%04o\n", (unsigned) mask);
9512 /* fall through and restore mask which we set to 0 */
9516 return !rc; /* rc != 0 - success */
9519 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9520 #if !ENABLE_HUSH_JOB
9521 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9523 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9530 if (!sigisemptyset(&G.pending_set))
9533 /* waitpid is not interruptible by SA_RESTARTed
9534 * signals which we use. Thus, this ugly dance:
9537 /* Make sure possible SIGCHLD is stored in kernel's
9538 * pending signal mask before we call waitpid.
9539 * Or else we may race with SIGCHLD, lose it,
9540 * and get stuck in sigsuspend...
9542 sigfillset(&oldset); /* block all signals, remember old set */
9543 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9545 if (!sigisemptyset(&G.pending_set)) {
9546 /* Crap! we raced with some signal! */
9550 /*errno = 0; - checkjobs does this */
9551 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9552 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9553 debug_printf_exec("checkjobs:%d\n", ret);
9556 int rcode = job_exited_or_stopped(waitfor_pipe);
9557 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9560 sigprocmask(SIG_SETMASK, &oldset, NULL);
9565 /* if ECHILD, there are no children (ret is -1 or 0) */
9566 /* if ret == 0, no children changed state */
9567 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9568 if (errno == ECHILD || ret) {
9570 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9572 sigprocmask(SIG_SETMASK, &oldset, NULL);
9575 /* Wait for SIGCHLD or any other signal */
9576 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9577 /* Note: sigsuspend invokes signal handler */
9578 sigsuspend(&oldset);
9580 sigprocmask(SIG_SETMASK, &oldset, NULL);
9582 /* So, did we get a signal? */
9583 sig = check_and_run_traps();
9584 if (sig /*&& sig != SIGCHLD - always true */) {
9588 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9593 static int FAST_FUNC builtin_wait(char **argv)
9598 argv = skip_dash_dash(argv);
9599 if (argv[0] == NULL) {
9600 /* Don't care about wait results */
9601 /* Note 1: must wait until there are no more children */
9602 /* Note 2: must be interruptible */
9604 * $ sleep 3 & sleep 6 & wait
9609 * $ sleep 3 & sleep 6 & wait
9613 * ^C <-- after ~4 sec from keyboard
9616 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9620 pid_t pid = bb_strtou(*argv, NULL, 10);
9621 if (errno || pid <= 0) {
9623 if (argv[0][0] == '%') {
9624 struct pipe *wait_pipe;
9625 wait_pipe = parse_jobspec(*argv);
9627 ret = job_exited_or_stopped(wait_pipe);
9629 ret = wait_for_child_or_signal(wait_pipe, 0);
9634 /* mimic bash message */
9635 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9637 continue; /* bash checks all argv[] */
9640 /* Do we have such child? */
9641 ret = waitpid(pid, &status, WNOHANG);
9644 if (errno == ECHILD) {
9645 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9646 /* "wait $!" but last bg task has already exited. Try:
9647 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9648 * In bash it prints exitcode 0, then 3.
9649 * In dash, it is 127.
9651 /* ret = G.last_bg_pid_exitstatus - FIXME */
9653 /* Example: "wait 1". mimic bash message */
9654 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9658 bb_perror_msg("wait %s", *argv);
9661 continue; /* bash checks all argv[] */
9664 /* Yes, and it still runs */
9665 ret = wait_for_child_or_signal(NULL, pid);
9667 /* Yes, and it just exited */
9668 process_wait_result(NULL, pid, status);
9669 ret = WEXITSTATUS(status);
9670 if (WIFSIGNALED(status))
9671 ret = 128 + WTERMSIG(status);
9678 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9679 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9682 def = bb_strtou(argv[1], NULL, 10);
9683 if (errno || def < def_min || argv[2]) {
9684 bb_error_msg("%s: bad arguments", argv[0]);
9692 #if ENABLE_HUSH_LOOPS
9693 static int FAST_FUNC builtin_break(char **argv)
9696 if (G.depth_of_loop == 0) {
9697 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9698 /* if we came from builtin_continue(), need to undo "= 1" */
9699 G.flag_break_continue = 0;
9700 return EXIT_SUCCESS; /* bash compat */
9702 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9704 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9705 if (depth == UINT_MAX)
9706 G.flag_break_continue = BC_BREAK;
9707 if (G.depth_of_loop < depth)
9708 G.depth_break_continue = G.depth_of_loop;
9710 return EXIT_SUCCESS;
9713 static int FAST_FUNC builtin_continue(char **argv)
9715 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9716 return builtin_break(argv);
9720 #if ENABLE_HUSH_FUNCTIONS
9721 static int FAST_FUNC builtin_return(char **argv)
9725 if (G_flag_return_in_progress != -1) {
9726 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9727 return EXIT_FAILURE; /* bash compat */
9730 G_flag_return_in_progress = 1;
9733 * out of range: wraps around at 256, does not error out
9734 * non-numeric param:
9735 * f() { false; return qwe; }; f; echo $?
9736 * bash: return: qwe: numeric argument required <== we do this
9737 * 255 <== we also do this
9739 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);