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"
85 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
86 || defined(__APPLE__) \
88 # include <malloc.h> /* for malloc_trim */
91 /* #include <dmalloc.h> */
95 #include <sys/utsname.h> /* for setting $HOSTNAME */
97 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
99 #include "shell_common.h"
102 #if ENABLE_HUSH_RANDOM_SUPPORT
105 # define CLEAR_RANDOM_T(rnd) ((void)0)
107 #ifndef F_DUPFD_CLOEXEC
108 # define F_DUPFD_CLOEXEC F_DUPFD
111 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
115 //config: bool "hush"
118 //config: hush is a small shell (25k). It handles the normal flow control
119 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
120 //config: case/esac. Redirections, here documents, $((arithmetic))
121 //config: and functions are supported.
123 //config: It will compile and work on no-mmu systems.
125 //config: It does not handle select, aliases, tilde expansion,
126 //config: &>file and >&file redirection of stdout+stderr.
128 //config:config HUSH_BASH_COMPAT
129 //config: bool "bash-compatible extensions"
131 //config: depends on HUSH
133 //config: Enable bash-compatible extensions.
135 //config:config HUSH_BRACE_EXPANSION
136 //config: bool "Brace expansion"
138 //config: depends on HUSH_BASH_COMPAT
140 //config: Enable {abc,def} extension.
142 //config:config HUSH_HELP
143 //config: bool "help builtin"
145 //config: depends on HUSH
147 //config: Enable help builtin in hush. Code size + ~1 kbyte.
149 //config:config HUSH_INTERACTIVE
150 //config: bool "Interactive mode"
152 //config: depends on HUSH
154 //config: Enable interactive mode (prompt and command editing).
155 //config: Without this, hush simply reads and executes commands
156 //config: from stdin just like a shell script from a file.
157 //config: No prompt, no PS1/PS2 magic shell variables.
159 //config:config HUSH_SAVEHISTORY
160 //config: bool "Save command history to .hush_history"
162 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
164 //config: Enable history saving in hush.
166 //config:config HUSH_JOB
167 //config: bool "Job control"
169 //config: depends on HUSH_INTERACTIVE
171 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
172 //config: command (not entire shell), fg/bg builtins work. Without this option,
173 //config: "cmd &" still works by simply spawning a process and immediately
174 //config: prompting for next command (or executing next command in a script),
175 //config: but no separate process group is formed.
177 //config:config HUSH_TICK
178 //config: bool "Process substitution"
180 //config: depends on HUSH
182 //config: Enable process substitution `command` and $(command) in hush.
184 //config:config HUSH_IF
185 //config: bool "Support if/then/elif/else/fi"
187 //config: depends on HUSH
189 //config: Enable if/then/elif/else/fi in hush.
191 //config:config HUSH_LOOPS
192 //config: bool "Support for, while and until loops"
194 //config: depends on HUSH
196 //config: Enable for, while and until loops in hush.
198 //config:config HUSH_CASE
199 //config: bool "Support case ... esac statement"
201 //config: depends on HUSH
203 //config: Enable case ... esac statement in hush. +400 bytes.
205 //config:config HUSH_FUNCTIONS
206 //config: bool "Support funcname() { commands; } syntax"
208 //config: depends on HUSH
210 //config: Enable support for shell functions in hush. +800 bytes.
212 //config:config HUSH_LOCAL
213 //config: bool "Support local builtin"
215 //config: depends on HUSH_FUNCTIONS
217 //config: Enable support for local variables in functions.
219 //config:config HUSH_RANDOM_SUPPORT
220 //config: bool "Pseudorandom generator and $RANDOM variable"
222 //config: depends on HUSH
224 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
225 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
227 //config:config HUSH_EXPORT_N
228 //config: bool "Support 'export -n' option"
230 //config: depends on HUSH
232 //config: export -n unexports variables. It is a bash extension.
234 //config:config HUSH_MODE_X
235 //config: bool "Support 'hush -x' option and 'set -x' command"
237 //config: depends on HUSH
239 //config: This instructs hush to print commands before execution.
240 //config: Adds ~300 bytes.
243 //config: bool "msh (deprecated: aliased to hush)"
245 //config: select HUSH
247 //config: msh is deprecated and will be removed, please migrate to hush.
250 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
251 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
252 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
253 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
255 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
256 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
258 /* -i (interactive) and -s (read stdin) are also accepted,
259 * but currently do nothing, therefore aren't shown in help.
260 * NOMMU-specific options are not meant to be used by users,
261 * therefore we don't show them either.
263 //usage:#define hush_trivial_usage
264 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
265 //usage:#define hush_full_usage "\n\n"
266 //usage: "Unix shell interpreter"
268 //usage:#define msh_trivial_usage hush_trivial_usage
269 //usage:#define msh_full_usage hush_full_usage
271 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
272 //usage:# define sh_trivial_usage hush_trivial_usage
273 //usage:# define sh_full_usage hush_full_usage
275 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
276 //usage:# define bash_trivial_usage hush_trivial_usage
277 //usage:# define bash_full_usage hush_full_usage
282 #define LEAK_HUNTING 0
283 #define BUILD_AS_NOMMU 0
284 /* Enable/disable sanity checks. Ok to enable in production,
285 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
286 * Keeping 1 for now even in released versions.
289 /* Slightly bigger (+200 bytes), but faster hush.
290 * So far it only enables a trick with counting SIGCHLDs and forks,
291 * which allows us to do fewer waitpid's.
292 * (we can detect a case where neither forks were done nor SIGCHLDs happened
293 * and therefore waitpid will return the same result as last time)
295 #define ENABLE_HUSH_FAST 0
296 /* TODO: implement simplified code for users which do not need ${var%...} ops
297 * So far ${var%...} ops are always enabled:
299 #define ENABLE_HUSH_DOLLAR_OPS 1
304 # undef USE_FOR_NOMMU
307 # define USE_FOR_NOMMU(...) __VA_ARGS__
308 # define USE_FOR_MMU(...)
311 #include "NUM_APPLETS.h"
313 /* STANDALONE does not make sense, and won't compile */
314 # undef CONFIG_FEATURE_SH_STANDALONE
315 # undef ENABLE_FEATURE_SH_STANDALONE
316 # undef IF_FEATURE_SH_STANDALONE
317 # undef IF_NOT_FEATURE_SH_STANDALONE
318 # define ENABLE_FEATURE_SH_STANDALONE 0
319 # define IF_FEATURE_SH_STANDALONE(...)
320 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
323 #if !ENABLE_HUSH_INTERACTIVE
324 # undef ENABLE_FEATURE_EDITING
325 # define ENABLE_FEATURE_EDITING 0
326 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
327 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
328 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
329 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
332 /* Do we support ANY keywords? */
333 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
334 # define HAS_KEYWORDS 1
335 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
336 # define IF_HAS_NO_KEYWORDS(...)
338 # define HAS_KEYWORDS 0
339 # define IF_HAS_KEYWORDS(...)
340 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
343 /* If you comment out one of these below, it will be #defined later
344 * to perform debug printfs to stderr: */
345 #define debug_printf(...) do {} while (0)
346 /* Finer-grained debug switches */
347 #define debug_printf_parse(...) do {} while (0)
348 #define debug_print_tree(a, b) do {} while (0)
349 #define debug_printf_exec(...) do {} while (0)
350 #define debug_printf_env(...) do {} while (0)
351 #define debug_printf_jobs(...) do {} while (0)
352 #define debug_printf_expand(...) do {} while (0)
353 #define debug_printf_varexp(...) do {} while (0)
354 #define debug_printf_glob(...) do {} while (0)
355 #define debug_printf_list(...) do {} while (0)
356 #define debug_printf_subst(...) do {} while (0)
357 #define debug_printf_clean(...) do {} while (0)
359 #define ERR_PTR ((void*)(long)1)
361 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
363 #define _SPECIAL_VARS_STR "_*@$!?#"
364 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
365 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
366 #if ENABLE_HUSH_BASH_COMPAT
367 /* Support / and // replace ops */
368 /* Note that // is stored as \ in "encoded" string representation */
369 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
370 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
371 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
373 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
374 # define VAR_SUBST_OPS "%#:-=+?"
375 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
378 #define SPECIAL_VAR_SYMBOL 3
382 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
384 /* This supports saving pointers malloced in vfork child,
385 * to be freed in the parent.
388 typedef struct nommu_save_t {
390 struct variable *old_vars;
392 char **argv_from_re_execing;
405 #if ENABLE_HUSH_LOOPS
412 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
417 /* three pseudo-keywords support contrived "case" syntax: */
418 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
419 RES_MATCH , /* "word)" */
420 RES_CASE_BODY, /* "this command is inside CASE" */
427 typedef struct o_string {
429 int length; /* position where data is appended */
432 /* At least some part of the string was inside '' or "",
433 * possibly empty one: word"", wo''rd etc. */
434 smallint has_quoted_part;
435 smallint has_empty_slot;
436 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
439 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
441 /* Protect newly added chars against globbing
442 * by prepending \ to *, ?, [, \ */
443 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
446 MAYBE_ASSIGNMENT = 0,
447 DEFINITELY_ASSIGNMENT = 1,
449 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
452 /* Used for initialization: o_string foo = NULL_O_STRING; */
453 #define NULL_O_STRING { NULL }
455 #ifndef debug_printf_parse
456 static const char *const assignment_flag[] = {
458 "DEFINITELY_ASSIGNMENT",
464 typedef struct in_str {
466 #if ENABLE_HUSH_INTERACTIVE
467 smallint promptmode; /* 0: PS1, 1: PS2 */
472 int (*get) (struct in_str *) FAST_FUNC;
473 int (*peek) (struct in_str *) FAST_FUNC;
475 #define i_getch(input) ((input)->get(input))
476 #define i_peek(input) ((input)->peek(input))
478 /* The descrip member of this structure is only used to make
479 * debugging output pretty */
480 static const struct {
482 signed char default_fd;
485 { O_RDONLY, 0, "<" },
486 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
487 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
488 { O_CREAT|O_RDWR, 1, "<>" },
489 { O_RDONLY, 0, "<<" },
490 /* Should not be needed. Bogus default_fd helps in debugging */
491 /* { O_RDONLY, 77, "<<" }, */
494 struct redir_struct {
495 struct redir_struct *next;
496 char *rd_filename; /* filename */
497 int rd_fd; /* fd to redirect */
498 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
500 smallint rd_type; /* (enum redir_type) */
501 /* note: for heredocs, rd_filename contains heredoc delimiter,
502 * and subsequently heredoc itself; and rd_dup is a bitmask:
503 * bit 0: do we need to trim leading tabs?
504 * bit 1: is heredoc quoted (<<'delim' syntax) ?
507 typedef enum redir_type {
509 REDIRECT_OVERWRITE = 1,
512 REDIRECT_HEREDOC = 4,
513 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
516 REDIRFD_SYNTAX_ERR = -2,
517 REDIRFD_TO_FILE = -1,
518 /* otherwise, rd_fd is redirected to rd_dup */
520 HEREDOC_SKIPTABS = 1,
526 pid_t pid; /* 0 if exited */
527 int assignment_cnt; /* how many argv[i] are assignments? */
528 smallint cmd_type; /* CMD_xxx */
530 #define CMD_SUBSHELL 1
531 #if ENABLE_HUSH_BASH_COMPAT
532 /* used for "[[ EXPR ]]" */
533 # define CMD_SINGLEWORD_NOGLOB 2
535 #if ENABLE_HUSH_FUNCTIONS
536 # define CMD_FUNCDEF 3
539 smalluint cmd_exitcode;
540 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
543 char *group_as_string;
545 #if ENABLE_HUSH_FUNCTIONS
546 struct function *child_func;
547 /* This field is used to prevent a bug here:
548 * while...do f1() {a;}; f1; f1() {b;}; f1; done
549 * When we execute "f1() {a;}" cmd, we create new function and clear
550 * cmd->group, cmd->group_as_string, cmd->argv[0].
551 * When we execute "f1() {b;}", we notice that f1 exists,
552 * and that its "parent cmd" struct is still "alive",
553 * we put those fields back into cmd->xxx
554 * (struct function has ->parent_cmd ptr to facilitate that).
555 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
556 * Without this trick, loop would execute a;b;b;b;...
557 * instead of correct sequence a;b;a;b;...
558 * When command is freed, it severs the link
559 * (sets ->child_func->parent_cmd to NULL).
562 char **argv; /* command name and arguments */
563 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
564 * and on execution these are substituted with their values.
565 * Substitution can make _several_ words out of one argv[n]!
566 * Example: argv[0]=='.^C*^C.' here: echo .$*.
567 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
569 struct redir_struct *redirects; /* I/O redirections */
571 /* Is there anything in this command at all? */
572 #define IS_NULL_CMD(cmd) \
573 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
577 int num_cmds; /* total number of commands in pipe */
578 int alive_cmds; /* number of commands running (not exited) */
579 int stopped_cmds; /* number of commands alive, but stopped */
581 int jobid; /* job number */
582 pid_t pgrp; /* process group ID for the job */
583 char *cmdtext; /* name of job */
585 struct command *cmds; /* array of commands in pipe */
586 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
587 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
588 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
590 typedef enum pipe_style {
596 /* Is there anything in this pipe at all? */
597 #define IS_NULL_PIPE(pi) \
598 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
600 /* This holds pointers to the various results of parsing */
601 struct parse_context {
602 /* linked list of pipes */
603 struct pipe *list_head;
604 /* last pipe (being constructed right now) */
606 /* last command in pipe (being constructed right now) */
607 struct command *command;
608 /* last redirect in command->redirects list */
609 struct redir_struct *pending_redirect;
615 smallint ctx_inverted; /* "! cmd | cmd" */
617 smallint ctx_dsemicolon; /* ";;" seen */
619 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
621 /* group we are enclosed in:
622 * example: "if pipe1; pipe2; then pipe3; fi"
623 * when we see "if" or "then", we malloc and copy current context,
624 * and make ->stack point to it. then we parse pipeN.
625 * when closing "then" / fi" / whatever is found,
626 * we move list_head into ->stack->command->group,
627 * copy ->stack into current context, and delete ->stack.
628 * (parsing of { list } and ( list ) doesn't use this method)
630 struct parse_context *stack;
634 /* On program start, environ points to initial environment.
635 * putenv adds new pointers into it, unsetenv removes them.
636 * Neither of these (de)allocates the strings.
637 * setenv allocates new strings in malloc space and does putenv,
638 * and thus setenv is unusable (leaky) for shell's purposes */
639 #define setenv(...) setenv_is_leaky_dont_use()
641 struct variable *next;
642 char *varstr; /* points to "name=" portion */
643 #if ENABLE_HUSH_LOCAL
644 unsigned func_nest_level;
646 int max_len; /* if > 0, name is part of initial env; else name is malloced */
647 smallint flg_export; /* putenv should be done on this var */
648 smallint flg_read_only;
656 #if ENABLE_HUSH_FUNCTIONS
658 struct function *next;
660 struct command *parent_cmd;
663 char *body_as_string;
669 /* set -/+o OPT support. (TODO: make it optional)
670 * bash supports the following opts:
681 * interactive-comments on
699 static const char o_opt_strings[] ALIGN1 =
702 #if ENABLE_HUSH_MODE_X
709 #if ENABLE_HUSH_MODE_X
717 struct FILE_list *next;
723 /* "Globals" within this file */
724 /* Sorted roughly by size (smaller offsets == smaller code) */
726 /* interactive_fd != 0 means we are an interactive shell.
727 * If we are, then saved_tty_pgrp can also be != 0, meaning
728 * that controlling tty is available. With saved_tty_pgrp == 0,
729 * job control still works, but terminal signals
730 * (^C, ^Z, ^Y, ^\) won't work at all, and background
731 * process groups can only be created with "cmd &".
732 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
733 * to give tty to the foreground process group,
734 * and will take it back when the group is stopped (^Z)
737 #if ENABLE_HUSH_INTERACTIVE
738 /* 'interactive_fd' is a fd# open to ctty, if we have one
739 * _AND_ if we decided to act interactively */
743 # define G_interactive_fd (G.interactive_fd)
745 # define G_interactive_fd 0
747 #if ENABLE_FEATURE_EDITING
748 line_input_t *line_input_state;
753 #if ENABLE_HUSH_RANDOM_SUPPORT
759 pid_t saved_tty_pgrp;
760 struct pipe *job_list;
761 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
763 # define G_saved_tty_pgrp 0
765 char o_opt[NUM_OPT_O];
766 #if ENABLE_HUSH_MODE_X
767 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
771 smallint flag_SIGINT;
772 #if ENABLE_HUSH_LOOPS
773 smallint flag_break_continue;
775 #if ENABLE_HUSH_FUNCTIONS
776 /* 0: outside of a function (or sourced file)
777 * -1: inside of a function, ok to use return builtin
778 * 1: return is invoked, skip all till end of func
780 smallint flag_return_in_progress;
781 # define G_flag_return_in_progress (G.flag_return_in_progress)
783 # define G_flag_return_in_progress 0
785 smallint exiting; /* used to prevent EXIT trap recursion */
786 /* These four support $?, $#, and $1 */
787 smalluint last_exitcode;
788 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
789 smalluint global_args_malloced;
790 /* how many non-NULL argv's we have. NB: $# + 1 */
794 char *argv0_for_re_execing;
796 #if ENABLE_HUSH_LOOPS
797 unsigned depth_break_continue;
798 unsigned depth_of_loop;
802 struct variable *top_var;
803 char **expanded_assignments;
804 #if ENABLE_HUSH_FUNCTIONS
805 struct function *top_func;
806 # if ENABLE_HUSH_LOCAL
807 struct variable **shadowed_vars_pp;
808 unsigned func_nest_level;
811 /* Signal and trap handling */
813 unsigned count_SIGCHLD;
814 unsigned handled_SIGCHLD;
815 smallint we_have_children;
817 struct FILE_list *FILE_list;
818 /* Which signals have non-DFL handler (even with no traps set)?
819 * Set at the start to:
820 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
821 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
822 * The rest is cleared right before execv syscalls.
823 * Other than these two times, never modified.
825 unsigned special_sig_mask;
827 unsigned fatal_sig_mask;
828 # define G_fatal_sig_mask G.fatal_sig_mask
830 # define G_fatal_sig_mask 0
832 char **traps; /* char *traps[NSIG] */
833 sigset_t pending_set;
835 unsigned long memleak_value;
839 #if ENABLE_FEATURE_EDITING
840 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
843 #define G (*ptr_to_globals)
844 /* Not #defining name to G.name - this quickly gets unwieldy
845 * (too many defines). Also, I actually prefer to see when a variable
846 * is global, thus "G." prefix is a useful hint */
847 #define INIT_G() do { \
848 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
849 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
850 sigfillset(&G.sa.sa_mask); \
851 G.sa.sa_flags = SA_RESTART; \
855 /* Function prototypes for builtins */
856 static int builtin_cd(char **argv) FAST_FUNC;
857 static int builtin_echo(char **argv) FAST_FUNC;
858 static int builtin_eval(char **argv) FAST_FUNC;
859 static int builtin_exec(char **argv) FAST_FUNC;
860 static int builtin_exit(char **argv) FAST_FUNC;
861 static int builtin_export(char **argv) FAST_FUNC;
863 static int builtin_fg_bg(char **argv) FAST_FUNC;
864 static int builtin_jobs(char **argv) FAST_FUNC;
867 static int builtin_help(char **argv) FAST_FUNC;
869 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
870 static int builtin_history(char **argv) FAST_FUNC;
872 #if ENABLE_HUSH_LOCAL
873 static int builtin_local(char **argv) FAST_FUNC;
876 static int builtin_memleak(char **argv) FAST_FUNC;
879 static int builtin_printf(char **argv) FAST_FUNC;
881 static int builtin_pwd(char **argv) FAST_FUNC;
882 static int builtin_read(char **argv) FAST_FUNC;
883 static int builtin_set(char **argv) FAST_FUNC;
884 static int builtin_shift(char **argv) FAST_FUNC;
885 static int builtin_source(char **argv) FAST_FUNC;
886 static int builtin_test(char **argv) FAST_FUNC;
887 static int builtin_trap(char **argv) FAST_FUNC;
888 static int builtin_type(char **argv) FAST_FUNC;
889 static int builtin_true(char **argv) FAST_FUNC;
890 static int builtin_umask(char **argv) FAST_FUNC;
891 static int builtin_unset(char **argv) FAST_FUNC;
892 static int builtin_wait(char **argv) FAST_FUNC;
893 #if ENABLE_HUSH_LOOPS
894 static int builtin_break(char **argv) FAST_FUNC;
895 static int builtin_continue(char **argv) FAST_FUNC;
897 #if ENABLE_HUSH_FUNCTIONS
898 static int builtin_return(char **argv) FAST_FUNC;
901 /* Table of built-in functions. They can be forked or not, depending on
902 * context: within pipes, they fork. As simple commands, they do not.
903 * When used in non-forking context, they can change global variables
904 * in the parent shell process. If forked, of course they cannot.
905 * For example, 'unset foo | whatever' will parse and run, but foo will
906 * still be set at the end. */
907 struct built_in_command {
909 int (*b_function)(char **argv) FAST_FUNC;
912 # define BLTIN(cmd, func, help) { cmd, func, help }
914 # define BLTIN(cmd, func, help) { cmd, func }
918 static const struct built_in_command bltins1[] = {
919 BLTIN("." , builtin_source , "Run commands in a file"),
920 BLTIN(":" , builtin_true , NULL),
922 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
924 #if ENABLE_HUSH_LOOPS
925 BLTIN("break" , builtin_break , "Exit from a loop"),
927 BLTIN("cd" , builtin_cd , "Change directory"),
928 #if ENABLE_HUSH_LOOPS
929 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
931 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
932 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
933 BLTIN("exit" , builtin_exit , "Exit"),
934 BLTIN("export" , builtin_export , "Set environment variables"),
936 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
939 BLTIN("help" , builtin_help , NULL),
941 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
942 BLTIN("history" , builtin_history , "Show command history"),
945 BLTIN("jobs" , builtin_jobs , "List jobs"),
947 #if ENABLE_HUSH_LOCAL
948 BLTIN("local" , builtin_local , "Set local variables"),
951 BLTIN("memleak" , builtin_memleak , NULL),
953 BLTIN("read" , builtin_read , "Input into variable"),
954 #if ENABLE_HUSH_FUNCTIONS
955 BLTIN("return" , builtin_return , "Return from a function"),
957 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
958 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
959 #if ENABLE_HUSH_BASH_COMPAT
960 BLTIN("source" , builtin_source , "Run commands in a file"),
962 BLTIN("trap" , builtin_trap , "Trap signals"),
963 BLTIN("true" , builtin_true , NULL),
964 BLTIN("type" , builtin_type , "Show command type"),
965 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
966 BLTIN("umask" , builtin_umask , "Set file creation mask"),
967 BLTIN("unset" , builtin_unset , "Unset variables"),
968 BLTIN("wait" , builtin_wait , "Wait for process"),
970 /* For now, echo and test are unconditionally enabled.
971 * Maybe make it configurable? */
972 static const struct built_in_command bltins2[] = {
973 BLTIN("[" , builtin_test , NULL),
974 BLTIN("echo" , builtin_echo , NULL),
976 BLTIN("printf" , builtin_printf , NULL),
978 BLTIN("pwd" , builtin_pwd , NULL),
979 BLTIN("test" , builtin_test , NULL),
986 /* prevent disasters with G.debug_indent < 0 */
987 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
988 # define debug_enter() (G.debug_indent++)
989 # define debug_leave() (G.debug_indent--)
991 # define indent() ((void)0)
992 # define debug_enter() ((void)0)
993 # define debug_leave() ((void)0)
997 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1000 #ifndef debug_printf_parse
1001 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1004 #ifndef debug_printf_exec
1005 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1008 #ifndef debug_printf_env
1009 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1012 #ifndef debug_printf_jobs
1013 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1014 # define DEBUG_JOBS 1
1016 # define DEBUG_JOBS 0
1019 #ifndef debug_printf_expand
1020 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1021 # define DEBUG_EXPAND 1
1023 # define DEBUG_EXPAND 0
1026 #ifndef debug_printf_varexp
1027 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1030 #ifndef debug_printf_glob
1031 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1032 # define DEBUG_GLOB 1
1034 # define DEBUG_GLOB 0
1037 #ifndef debug_printf_list
1038 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1041 #ifndef debug_printf_subst
1042 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1045 #ifndef debug_printf_clean
1046 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1047 # define DEBUG_CLEAN 1
1049 # define DEBUG_CLEAN 0
1053 static void debug_print_strings(const char *prefix, char **vv)
1056 fdprintf(2, "%s:\n", prefix);
1058 fdprintf(2, " '%s'\n", *vv++);
1061 # define debug_print_strings(prefix, vv) ((void)0)
1065 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1068 static void *xxmalloc(int lineno, size_t size)
1070 void *ptr = xmalloc((size + 0xff) & ~0xff);
1071 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1074 static void *xxrealloc(int lineno, void *ptr, size_t size)
1076 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1077 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1080 static char *xxstrdup(int lineno, const char *str)
1082 char *ptr = xstrdup(str);
1083 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1086 static void xxfree(void *ptr)
1088 fdprintf(2, "free %p\n", ptr);
1091 # define xmalloc(s) xxmalloc(__LINE__, s)
1092 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1093 # define xstrdup(s) xxstrdup(__LINE__, s)
1094 # define free(p) xxfree(p)
1098 /* Syntax and runtime errors. They always abort scripts.
1099 * In interactive use they usually discard unparsed and/or unexecuted commands
1100 * and return to the prompt.
1101 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1104 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1105 # define syntax_error(lineno, msg) syntax_error(msg)
1106 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1107 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1108 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1109 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1112 static void die_if_script(unsigned lineno, const char *fmt, ...)
1117 bb_error_msg("hush.c:%u", lineno);
1120 bb_verror_msg(fmt, p, NULL);
1122 if (!G_interactive_fd)
1126 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1129 bb_error_msg("syntax error: %s", msg);
1131 bb_error_msg("syntax error");
1134 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1136 bb_error_msg("syntax error at '%s'", msg);
1139 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1141 bb_error_msg("syntax error: unterminated %s", s);
1144 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1146 char msg[2] = { ch, '\0' };
1147 syntax_error_unterm_str(lineno, msg);
1150 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1155 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1159 # undef die_if_script
1160 # undef syntax_error
1161 # undef syntax_error_at
1162 # undef syntax_error_unterm_ch
1163 # undef syntax_error_unterm_str
1164 # undef syntax_error_unexpected_ch
1166 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1167 # define syntax_error(msg) syntax_error(__LINE__, msg)
1168 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1169 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1170 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1171 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1175 #if ENABLE_HUSH_INTERACTIVE
1176 static void cmdedit_update_prompt(void);
1178 # define cmdedit_update_prompt() ((void)0)
1182 /* Utility functions
1184 /* Replace each \x with x in place, return ptr past NUL. */
1185 static char *unbackslash(char *src)
1187 char *dst = src = strchrnul(src, '\\');
1191 if ((*dst++ = *src++) == '\0')
1197 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1218 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1219 v[count1 + count2] = NULL;
1222 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1226 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1228 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1229 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1232 #define add_strings_to_strings(strings, add, need_to_dup) \
1233 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1236 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1237 static char **add_string_to_strings(char **strings, char *add)
1242 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1245 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1247 char **ptr = add_string_to_strings(strings, add);
1248 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1251 #define add_string_to_strings(strings, add) \
1252 xx_add_string_to_strings(__LINE__, strings, add)
1255 static void free_strings(char **strings)
1270 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1272 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1273 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1275 /* fd was not open? */
1285 /* Manipulating the list of open FILEs */
1286 static FILE *remember_FILE(FILE *fp)
1289 struct FILE_list *n = xmalloc(sizeof(*n));
1290 n->next = G.FILE_list;
1294 close_on_exec_on(n->fd);
1298 static void fclose_and_forget(FILE *fp)
1300 struct FILE_list **pp = &G.FILE_list;
1302 struct FILE_list *cur = *pp;
1303 if (cur->fp == fp) {
1312 static int save_FILEs_on_redirect(int fd)
1314 struct FILE_list *fl = G.FILE_list;
1317 /* We use it only on script files, they are all CLOEXEC */
1318 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1325 static void restore_redirected_FILEs(void)
1327 struct FILE_list *fl = G.FILE_list;
1329 int should_be = fileno(fl->fp);
1330 if (fl->fd != should_be) {
1331 xmove_fd(fl->fd, should_be);
1337 #if ENABLE_FEATURE_SH_STANDALONE
1338 static void close_all_FILE_list(void)
1340 struct FILE_list *fl = G.FILE_list;
1342 /* fclose would also free FILE object.
1343 * It is disastrous if we share memory with a vforked parent.
1344 * I'm not sure we never come here after vfork.
1345 * Therefore just close fd, nothing more.
1347 /*fclose(fl->fp); - unsafe */
1355 /* Helpers for setting new $n and restoring them back
1357 typedef struct save_arg_t {
1361 smallint sv_g_malloced;
1364 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1368 sv->sv_argv0 = argv[0];
1369 sv->sv_g_argv = G.global_argv;
1370 sv->sv_g_argc = G.global_argc;
1371 sv->sv_g_malloced = G.global_args_malloced;
1373 argv[0] = G.global_argv[0]; /* retain $0 */
1374 G.global_argv = argv;
1375 G.global_args_malloced = 0;
1383 static void restore_G_args(save_arg_t *sv, char **argv)
1387 if (G.global_args_malloced) {
1388 /* someone ran "set -- arg1 arg2 ...", undo */
1390 while (*++pp) /* note: does not free $0 */
1392 free(G.global_argv);
1394 argv[0] = sv->sv_argv0;
1395 G.global_argv = sv->sv_g_argv;
1396 G.global_argc = sv->sv_g_argc;
1397 G.global_args_malloced = sv->sv_g_malloced;
1401 /* Basic theory of signal handling in shell
1402 * ========================================
1403 * This does not describe what hush does, rather, it is current understanding
1404 * what it _should_ do. If it doesn't, it's a bug.
1405 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1407 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1408 * is finished or backgrounded. It is the same in interactive and
1409 * non-interactive shells, and is the same regardless of whether
1410 * a user trap handler is installed or a shell special one is in effect.
1411 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1412 * backgrounds (i.e. stops) or kills all members of currently running
1415 * Wait builtin is interruptible by signals for which user trap is set
1416 * or by SIGINT in interactive shell.
1418 * Trap handlers will execute even within trap handlers. (right?)
1420 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1421 * except for handlers set to '' (empty string).
1423 * If job control is off, backgrounded commands ("cmd &")
1424 * have SIGINT, SIGQUIT set to SIG_IGN.
1426 * Commands which are run in command substitution ("`cmd`")
1427 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1429 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1430 * by the shell from its parent.
1432 * Signals which differ from SIG_DFL action
1433 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1436 * SIGTERM (interactive): ignore
1437 * SIGHUP (interactive):
1438 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1439 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1440 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1441 * that all pipe members are stopped. Try this in bash:
1442 * while :; do :; done - ^Z does not background it
1443 * (while :; do :; done) - ^Z backgrounds it
1444 * SIGINT (interactive): wait for last pipe, ignore the rest
1445 * of the command line, show prompt. NB: ^C does not send SIGINT
1446 * to interactive shell while shell is waiting for a pipe,
1447 * since shell is bg'ed (is not in foreground process group).
1448 * Example 1: this waits 5 sec, but does not execute ls:
1449 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1450 * Example 2: this does not wait and does not execute ls:
1451 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1452 * Example 3: this does not wait 5 sec, but executes ls:
1453 * "sleep 5; ls -l" + press ^C
1454 * Example 4: this does not wait and does not execute ls:
1455 * "sleep 5 & wait; ls -l" + press ^C
1457 * (What happens to signals which are IGN on shell start?)
1458 * (What happens with signal mask on shell start?)
1460 * Old implementation
1461 * ==================
1462 * We use in-kernel pending signal mask to determine which signals were sent.
1463 * We block all signals which we don't want to take action immediately,
1464 * i.e. we block all signals which need to have special handling as described
1465 * above, and all signals which have traps set.
1466 * After each pipe execution, we extract any pending signals via sigtimedwait()
1469 * unsigned special_sig_mask: a mask of such "special" signals
1470 * sigset_t blocked_set: current blocked signal set
1473 * clear bit in blocked_set unless it is also in special_sig_mask
1474 * "trap 'cmd' SIGxxx":
1475 * set bit in blocked_set (even if 'cmd' is '')
1476 * after [v]fork, if we plan to be a shell:
1477 * unblock signals with special interactive handling
1478 * (child shell is not interactive),
1479 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1480 * after [v]fork, if we plan to exec:
1481 * POSIX says fork clears pending signal mask in child - no need to clear it.
1482 * Restore blocked signal set to one inherited by shell just prior to exec.
1484 * Note: as a result, we do not use signal handlers much. The only uses
1485 * are to count SIGCHLDs
1486 * and to restore tty pgrp on signal-induced exit.
1489 * Standard says "When a subshell is entered, traps that are not being ignored
1490 * are set to the default actions". bash interprets it so that traps which
1491 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1493 * Problem: the above approach makes it unwieldy to catch signals while
1494 * we are in read builtin, or while we read commands from stdin:
1495 * masked signals are not visible!
1497 * New implementation
1498 * ==================
1499 * We record each signal we are interested in by installing signal handler
1500 * for them - a bit like emulating kernel pending signal mask in userspace.
1501 * We are interested in: signals which need to have special handling
1502 * as described above, and all signals which have traps set.
1503 * Signals are recorded in pending_set.
1504 * After each pipe execution, we extract any pending signals
1507 * unsigned special_sig_mask: a mask of shell-special signals.
1508 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1509 * char *traps[sig] if trap for sig is set (even if it's '').
1510 * sigset_t pending_set: set of sigs we received.
1513 * if sig is in special_sig_mask, set handler back to:
1514 * record_pending_signo, or to IGN if it's a tty stop signal
1515 * if sig is in fatal_sig_mask, set handler back to sigexit.
1516 * else: set handler back to SIG_DFL
1517 * "trap 'cmd' SIGxxx":
1518 * set handler to record_pending_signo.
1520 * set handler to SIG_IGN.
1521 * after [v]fork, if we plan to be a shell:
1522 * set signals with special interactive handling to SIG_DFL
1523 * (because child shell is not interactive),
1524 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1525 * after [v]fork, if we plan to exec:
1526 * POSIX says fork clears pending signal mask in child - no need to clear it.
1528 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1529 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1532 * Standard says "When a subshell is entered, traps that are not being ignored
1533 * are set to the default actions". bash interprets it so that traps which
1534 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1537 SPECIAL_INTERACTIVE_SIGS = 0
1542 SPECIAL_JOBSTOP_SIGS = 0
1551 static void record_pending_signo(int sig)
1553 sigaddset(&G.pending_set, sig);
1554 #if ENABLE_HUSH_FAST
1555 if (sig == SIGCHLD) {
1557 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1562 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1564 struct sigaction old_sa;
1566 /* We could use signal() to install handlers... almost:
1567 * except that we need to mask ALL signals while handlers run.
1568 * I saw signal nesting in strace, race window isn't small.
1569 * SA_RESTART is also needed, but in Linux, signal()
1570 * sets SA_RESTART too.
1572 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1573 /* sigfillset(&G.sa.sa_mask); - already done */
1574 /* G.sa.sa_flags = SA_RESTART; - already done */
1575 G.sa.sa_handler = handler;
1576 sigaction(sig, &G.sa, &old_sa);
1577 return old_sa.sa_handler;
1580 static void hush_exit(int exitcode) NORETURN;
1581 static void fflush_and__exit(void) NORETURN;
1582 static void restore_ttypgrp_and__exit(void) NORETURN;
1584 static void restore_ttypgrp_and__exit(void)
1586 /* xfunc has failed! die die die */
1587 /* no EXIT traps, this is an escape hatch! */
1589 hush_exit(xfunc_error_retval);
1592 /* Needed only on some libc:
1593 * It was observed that on exit(), fgetc'ed buffered data
1594 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1595 * With the net effect that even after fork(), not vfork(),
1596 * exit() in NOEXECed applet in "sh SCRIPT":
1597 * noexec_applet_here
1598 * echo END_OF_SCRIPT
1599 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1600 * This makes "echo END_OF_SCRIPT" executed twice.
1601 * Similar problems can be seen with die_if_script() -> xfunc_die()
1602 * and in `cmd` handling.
1603 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1605 static void fflush_and__exit(void)
1608 _exit(xfunc_error_retval);
1613 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1614 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1615 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1616 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1618 /* Restores tty foreground process group, and exits.
1619 * May be called as signal handler for fatal signal
1620 * (will resend signal to itself, producing correct exit state)
1621 * or called directly with -EXITCODE.
1622 * We also call it if xfunc is exiting.
1624 static void sigexit(int sig) NORETURN;
1625 static void sigexit(int sig)
1627 /* Careful: we can end up here after [v]fork. Do not restore
1628 * tty pgrp then, only top-level shell process does that */
1629 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1630 /* Disable all signals: job control, SIGPIPE, etc.
1631 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1633 sigprocmask_allsigs(SIG_BLOCK);
1634 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1637 /* Not a signal, just exit */
1641 kill_myself_with_sig(sig); /* does not return */
1645 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1646 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1650 static sighandler_t pick_sighandler(unsigned sig)
1652 sighandler_t handler = SIG_DFL;
1653 if (sig < sizeof(unsigned)*8) {
1654 unsigned sigmask = (1 << sig);
1658 if (G_fatal_sig_mask & sigmask)
1662 /* sig has special handling? */
1663 if (G.special_sig_mask & sigmask) {
1664 handler = record_pending_signo;
1665 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1666 * in order to ignore them: they will be raised
1667 * in an endless loop when we try to do some
1668 * terminal ioctls! We do have to _ignore_ these.
1670 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1677 /* Restores tty foreground process group, and exits. */
1678 static void hush_exit(int exitcode)
1680 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1681 save_history(G.line_input_state);
1685 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1687 /* argv[0] is unused */
1688 argv[1] = G.traps[0];
1690 G.exiting = 1; /* prevent EXIT trap recursion */
1691 /* Note: G.traps[0] is not cleared!
1692 * "trap" will still show it, if executed
1697 #if ENABLE_FEATURE_CLEAN_UP
1699 struct variable *cur_var;
1700 if (G.cwd != bb_msg_unknown)
1702 cur_var = G.top_var;
1704 struct variable *tmp = cur_var;
1705 if (!cur_var->max_len)
1706 free(cur_var->varstr);
1707 cur_var = cur_var->next;
1715 sigexit(- (exitcode & 0xff));
1722 //TODO: return a mask of ALL handled sigs?
1723 static int check_and_run_traps(void)
1730 if (sigisemptyset(&G.pending_set))
1735 if (sigismember(&G.pending_set, sig)) {
1736 sigdelset(&G.pending_set, sig);
1739 } while (sig < NSIG);
1742 if (G.traps && G.traps[sig]) {
1743 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1744 if (G.traps[sig][0]) {
1745 /* We have user-defined handler */
1746 smalluint save_rcode;
1748 /* argv[0] is unused */
1749 argv[1] = G.traps[sig];
1751 save_rcode = G.last_exitcode;
1753 G.last_exitcode = save_rcode;
1755 } /* else: "" trap, ignoring signal */
1758 /* not a trap: special action */
1761 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1762 /* Builtin was ^C'ed, make it look prettier: */
1770 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1771 /* bash is observed to signal whole process groups,
1772 * not individual processes */
1773 for (job = G.job_list; job; job = job->next) {
1776 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1777 if (kill(- job->pgrp, SIGHUP) == 0)
1778 kill(- job->pgrp, SIGCONT);
1783 #if ENABLE_HUSH_FAST
1785 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1787 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1789 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1790 * This simplifies wait builtin a bit.
1794 default: /* ignored: */
1795 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1796 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1798 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1799 * Example: wait is not interrupted by TERM
1800 * in interactive shell, because TERM is ignored.
1809 static const char *get_cwd(int force)
1811 if (force || G.cwd == NULL) {
1812 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1813 * we must not try to free(bb_msg_unknown) */
1814 if (G.cwd == bb_msg_unknown)
1816 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1818 G.cwd = bb_msg_unknown;
1825 * Shell and environment variable support
1827 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1829 struct variable **pp;
1830 struct variable *cur;
1833 while ((cur = *pp) != NULL) {
1834 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1841 static const char* FAST_FUNC get_local_var_value(const char *name)
1843 struct variable **vpp;
1844 unsigned len = strlen(name);
1846 if (G.expanded_assignments) {
1847 char **cpp = G.expanded_assignments;
1850 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1851 return cp + len + 1;
1856 vpp = get_ptr_to_local_var(name, len);
1858 return (*vpp)->varstr + len + 1;
1860 if (strcmp(name, "PPID") == 0)
1861 return utoa(G.root_ppid);
1862 // bash compat: UID? EUID?
1863 #if ENABLE_HUSH_RANDOM_SUPPORT
1864 if (strcmp(name, "RANDOM") == 0)
1865 return utoa(next_random(&G.random_gen));
1870 /* str holds "NAME=VAL" and is expected to be malloced.
1871 * We take ownership of it.
1873 * 0: do not change export flag
1874 * (if creating new variable, flag will be 0)
1875 * 1: set export flag and putenv the variable
1876 * -1: clear export flag and unsetenv the variable
1877 * flg_read_only is set only when we handle -R var=val
1879 #if !BB_MMU && ENABLE_HUSH_LOCAL
1880 /* all params are used */
1881 #elif BB_MMU && ENABLE_HUSH_LOCAL
1882 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1883 set_local_var(str, flg_export, local_lvl)
1884 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1885 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1886 set_local_var(str, flg_export)
1887 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1888 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1889 set_local_var(str, flg_export, flg_read_only)
1891 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1893 struct variable **var_pp;
1894 struct variable *cur;
1895 char *free_me = NULL;
1899 eq_sign = strchr(str, '=');
1900 if (!eq_sign) { /* not expected to ever happen? */
1905 name_len = eq_sign - str + 1; /* including '=' */
1906 var_pp = &G.top_var;
1907 while ((cur = *var_pp) != NULL) {
1908 if (strncmp(cur->varstr, str, name_len) != 0) {
1909 var_pp = &cur->next;
1913 /* We found an existing var with this name */
1914 if (cur->flg_read_only) {
1918 bb_error_msg("%s: readonly variable", str);
1922 if (flg_export == -1) { // "&& cur->flg_export" ?
1923 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1928 #if ENABLE_HUSH_LOCAL
1929 if (cur->func_nest_level < local_lvl) {
1930 /* New variable is declared as local,
1931 * and existing one is global, or local
1932 * from enclosing function.
1933 * Remove and save old one: */
1934 *var_pp = cur->next;
1935 cur->next = *G.shadowed_vars_pp;
1936 *G.shadowed_vars_pp = cur;
1937 /* bash 3.2.33(1) and exported vars:
1939 * # f() { local z=a; env | grep ^z; }
1945 if (cur->flg_export)
1950 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1955 if (cur->max_len != 0) {
1956 if (cur->max_len >= strlen(str)) {
1957 /* This one is from startup env, reuse space */
1958 strcpy(cur->varstr, str);
1963 goto set_str_and_exp;
1965 /* max_len == 0 signifies "malloced" var, which we can
1966 * (and have to) free. But we can't free(cur->varstr) here:
1967 * if cur->flg_export is 1, it is in the environment.
1968 * We should either unsetenv+free, or wait until putenv,
1969 * then putenv(new)+free(old).
1971 free_me = cur->varstr;
1972 goto set_str_and_exp;
1975 /* Not found - create new variable struct */
1976 cur = xzalloc(sizeof(*cur));
1977 #if ENABLE_HUSH_LOCAL
1978 cur->func_nest_level = local_lvl;
1980 cur->next = *var_pp;
1986 cur->flg_read_only = flg_read_only;
1989 if (flg_export == 1)
1990 cur->flg_export = 1;
1991 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1992 cmdedit_update_prompt();
1993 if (cur->flg_export) {
1994 if (flg_export == -1) {
1995 cur->flg_export = 0;
1996 /* unsetenv was already done */
1999 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2000 i = putenv(cur->varstr);
2001 /* only now we can free old exported malloced string */
2010 /* Used at startup and after each cd */
2011 static void set_pwd_var(int exp)
2013 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2014 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2017 static int unset_local_var_len(const char *name, int name_len)
2019 struct variable *cur;
2020 struct variable **var_pp;
2023 return EXIT_SUCCESS;
2024 var_pp = &G.top_var;
2025 while ((cur = *var_pp) != NULL) {
2026 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2027 if (cur->flg_read_only) {
2028 bb_error_msg("%s: readonly variable", name);
2029 return EXIT_FAILURE;
2031 *var_pp = cur->next;
2032 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2033 bb_unsetenv(cur->varstr);
2034 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2035 cmdedit_update_prompt();
2039 return EXIT_SUCCESS;
2041 var_pp = &cur->next;
2043 return EXIT_SUCCESS;
2046 static int unset_local_var(const char *name)
2048 return unset_local_var_len(name, strlen(name));
2051 static void unset_vars(char **strings)
2059 const char *eq = strchrnul(*v, '=');
2060 unset_local_var_len(*v, (int)(eq - *v));
2066 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2068 char *var = xasprintf("%s=%s", name, val);
2069 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2074 * Helpers for "var1=val1 var2=val2 cmd" feature
2076 static void add_vars(struct variable *var)
2078 struct variable *next;
2082 var->next = G.top_var;
2084 if (var->flg_export) {
2085 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2086 putenv(var->varstr);
2088 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2094 static struct variable *set_vars_and_save_old(char **strings)
2097 struct variable *old = NULL;
2103 struct variable *var_p;
2104 struct variable **var_pp;
2107 eq = strchr(*s, '=');
2109 var_pp = get_ptr_to_local_var(*s, eq - *s);
2111 /* Remove variable from global linked list */
2113 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2114 *var_pp = var_p->next;
2115 /* Add it to returned list */
2119 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2130 static void reinit_unicode_for_hush(void)
2132 /* Unicode support should be activated even if LANG is set
2133 * _during_ shell execution, not only if it was set when
2134 * shell was started. Therefore, re-check LANG every time:
2136 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2137 || ENABLE_UNICODE_USING_LOCALE
2139 const char *s = get_local_var_value("LC_ALL");
2140 if (!s) s = get_local_var_value("LC_CTYPE");
2141 if (!s) s = get_local_var_value("LANG");
2147 * in_str support (strings, and "strings" read from files).
2150 #if ENABLE_HUSH_INTERACTIVE
2151 /* To test correct lineedit/interactive behavior, type from command line:
2157 * It excercises a lot of corner cases.
2159 static void cmdedit_update_prompt(void)
2161 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2162 G.PS1 = get_local_var_value("PS1");
2165 G.PS2 = get_local_var_value("PS2");
2172 static const char *setup_prompt_string(int promptmode)
2174 const char *prompt_str;
2175 debug_printf("setup_prompt_string %d ", promptmode);
2176 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2177 /* Set up the prompt */
2178 if (promptmode == 0) { /* PS1 */
2180 /* bash uses $PWD value, even if it is set by user.
2181 * It uses current dir only if PWD is unset.
2182 * We always use current dir. */
2183 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2188 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2189 debug_printf("prompt_str '%s'\n", prompt_str);
2192 static int get_user_input(struct in_str *i)
2195 const char *prompt_str;
2197 prompt_str = setup_prompt_string(i->promptmode);
2198 # if ENABLE_FEATURE_EDITING
2200 reinit_unicode_for_hush();
2202 /* buglet: SIGINT will not make new prompt to appear _at once_,
2203 * only after <Enter>. (^C will work) */
2204 r = read_line_input(G.line_input_state, prompt_str,
2205 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2208 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2209 check_and_run_traps();
2210 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2212 /* EOF/error detected */
2214 i->peek_buf[0] = r = EOF;
2217 i->p = G.user_input_buf;
2218 return (unsigned char)*i->p++;
2222 if (i->last_char == '\0' || i->last_char == '\n') {
2223 /* Why check_and_run_traps here? Try this interactively:
2224 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2225 * $ <[enter], repeatedly...>
2226 * Without check_and_run_traps, handler never runs.
2228 check_and_run_traps();
2229 fputs(prompt_str, stdout);
2233 } while (G.flag_SIGINT || r == '\0');
2237 /* This is the magic location that prints prompts
2238 * and gets data back from the user */
2239 static int fgetc_interactive(struct in_str *i)
2242 /* If it's interactive stdin, get new line. */
2243 if (G_interactive_fd && i->file == stdin) {
2244 /* Returns first char (or EOF), the rest is in i->p[] */
2245 ch = get_user_input(i);
2246 i->promptmode = 1; /* PS2 */
2248 /* Not stdin: script file, sourced file, etc */
2249 do ch = fgetc(i->file); while (ch == '\0');
2254 static inline int fgetc_interactive(struct in_str *i)
2257 do ch = fgetc(i->file); while (ch == '\0');
2260 #endif /* INTERACTIVE */
2262 static int FAST_FUNC file_get(struct in_str *i)
2266 #if ENABLE_FEATURE_EDITING
2267 /* This can be stdin, check line editing char[] buffer */
2268 if (i->p && *i->p != '\0') {
2269 ch = (unsigned char)*i->p++;
2273 /* peek_buf[] is an int array, not char. Can contain EOF. */
2274 ch = i->peek_buf[0];
2276 int ch2 = i->peek_buf[1];
2277 i->peek_buf[0] = ch2;
2278 if (ch2 == 0) /* very likely, avoid redundant write */
2284 ch = fgetc_interactive(i);
2286 debug_printf("file_get: got '%c' %d\n", ch, ch);
2291 static int FAST_FUNC file_peek(struct in_str *i)
2295 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2296 /* This can be stdin, check line editing char[] buffer */
2297 if (i->p && *i->p != '\0')
2298 return (unsigned char)*i->p;
2300 /* peek_buf[] is an int array, not char. Can contain EOF. */
2301 ch = i->peek_buf[0];
2305 /* Need to get a new char */
2306 ch = fgetc_interactive(i);
2307 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2309 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2310 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2316 i->peek_buf[0] = ch;
2317 /*i->peek_buf[1] = 0; - already is */
2321 static int FAST_FUNC static_get(struct in_str *i)
2323 int ch = (unsigned char)*i->p;
2332 static int FAST_FUNC static_peek(struct in_str *i)
2334 /* Doesn't report EOF on NUL. None of the callers care. */
2335 return (unsigned char)*i->p;
2338 /* Only ever called if i_peek() was called, and did not return EOF.
2339 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2340 * not end-of-line. Therefore we never need to read a new editing line here.
2342 static int i_peek2(struct in_str *i)
2346 /* There are two cases when i->p[] buffer exists.
2347 * (1) it's a string in_str.
2348 * (2) It's a file, and we have a saved line editing buffer.
2349 * In both cases, we know that i->p[0] exists and not NUL, and
2350 * the peek2 result is in i->p[1].
2353 return (unsigned char)i->p[1];
2355 /* Now we know it is a file-based in_str. */
2357 /* peek_buf[] is an int array, not char. Can contain EOF. */
2358 /* Is there 2nd char? */
2359 ch = i->peek_buf[1];
2361 /* We did not read it yet, get it now */
2362 do ch = fgetc(i->file); while (ch == '\0');
2363 i->peek_buf[1] = ch;
2366 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2370 static void setup_file_in_str(struct in_str *i, FILE *f)
2372 memset(i, 0, sizeof(*i));
2374 i->peek = file_peek;
2375 /* i->promptmode = 0; - PS1 (memset did it) */
2380 static void setup_string_in_str(struct in_str *i, const char *s)
2382 memset(i, 0, sizeof(*i));
2383 i->get = static_get;
2384 i->peek = static_peek;
2385 /* i->promptmode = 0; - PS1 (memset did it) */
2393 #define B_CHUNK (32 * sizeof(char*))
2395 static void o_reset_to_empty_unquoted(o_string *o)
2398 o->has_quoted_part = 0;
2403 static void o_free(o_string *o)
2406 memset(o, 0, sizeof(*o));
2409 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2414 static void o_grow_by(o_string *o, int len)
2416 if (o->length + len > o->maxlen) {
2417 o->maxlen += (2 * len) | (B_CHUNK-1);
2418 o->data = xrealloc(o->data, 1 + o->maxlen);
2422 static void o_addchr(o_string *o, int ch)
2424 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2425 if (o->length < o->maxlen) {
2426 /* likely. avoid o_grow_by() call */
2428 o->data[o->length] = ch;
2430 o->data[o->length] = '\0';
2438 /* Valid only if we know o_string is not empty */
2439 static void o_delchr(o_string *o)
2442 o->data[o->length] = '\0';
2446 static void o_addblock(o_string *o, const char *str, int len)
2449 memcpy(&o->data[o->length], str, len);
2451 o->data[o->length] = '\0';
2454 static void o_addstr(o_string *o, const char *str)
2456 o_addblock(o, str, strlen(str));
2460 static void nommu_addchr(o_string *o, int ch)
2466 # define nommu_addchr(o, str) ((void)0)
2469 static void o_addstr_with_NUL(o_string *o, const char *str)
2471 o_addblock(o, str, strlen(str) + 1);
2475 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2476 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2477 * Apparently, on unquoted $v bash still does globbing
2478 * ("v='*.txt'; echo $v" prints all .txt files),
2479 * but NOT brace expansion! Thus, there should be TWO independent
2480 * quoting mechanisms on $v expansion side: one protects
2481 * $v from brace expansion, and other additionally protects "$v" against globbing.
2482 * We have only second one.
2485 #if ENABLE_HUSH_BRACE_EXPANSION
2486 # define MAYBE_BRACES "{}"
2488 # define MAYBE_BRACES ""
2491 /* My analysis of quoting semantics tells me that state information
2492 * is associated with a destination, not a source.
2494 static void o_addqchr(o_string *o, int ch)
2497 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2502 o->data[o->length] = '\\';
2505 o->data[o->length] = ch;
2507 o->data[o->length] = '\0';
2510 static void o_addQchr(o_string *o, int ch)
2513 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2514 && strchr("*?[\\" MAYBE_BRACES, ch)
2517 o->data[o->length] = '\\';
2521 o->data[o->length] = ch;
2523 o->data[o->length] = '\0';
2526 static void o_addqblock(o_string *o, const char *str, int len)
2531 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2532 if (ordinary_cnt > len) /* paranoia */
2534 o_addblock(o, str, ordinary_cnt);
2535 if (ordinary_cnt == len)
2536 return; /* NUL is already added by o_addblock */
2537 str += ordinary_cnt;
2538 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2542 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2544 o->data[o->length] = '\\';
2548 o->data[o->length] = ch;
2551 o->data[o->length] = '\0';
2554 static void o_addQblock(o_string *o, const char *str, int len)
2556 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2557 o_addblock(o, str, len);
2560 o_addqblock(o, str, len);
2563 static void o_addQstr(o_string *o, const char *str)
2565 o_addQblock(o, str, strlen(str));
2568 /* A special kind of o_string for $VAR and `cmd` expansion.
2569 * It contains char* list[] at the beginning, which is grown in 16 element
2570 * increments. Actual string data starts at the next multiple of 16 * (char*).
2571 * list[i] contains an INDEX (int!) into this string data.
2572 * It means that if list[] needs to grow, data needs to be moved higher up
2573 * but list[i]'s need not be modified.
2574 * NB: remembering how many list[i]'s you have there is crucial.
2575 * o_finalize_list() operation post-processes this structure - calculates
2576 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2578 #if DEBUG_EXPAND || DEBUG_GLOB
2579 static void debug_print_list(const char *prefix, o_string *o, int n)
2581 char **list = (char**)o->data;
2582 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2586 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2587 prefix, list, n, string_start, o->length, o->maxlen,
2588 !!(o->o_expflags & EXP_FLAG_GLOB),
2590 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2593 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2594 o->data + (int)(uintptr_t)list[i] + string_start,
2595 o->data + (int)(uintptr_t)list[i] + string_start);
2599 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2601 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2605 # define debug_print_list(prefix, o, n) ((void)0)
2608 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2609 * in list[n] so that it points past last stored byte so far.
2610 * It returns n+1. */
2611 static int o_save_ptr_helper(o_string *o, int n)
2613 char **list = (char**)o->data;
2617 if (!o->has_empty_slot) {
2618 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2619 string_len = o->length - string_start;
2620 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2621 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2622 /* list[n] points to string_start, make space for 16 more pointers */
2623 o->maxlen += 0x10 * sizeof(list[0]);
2624 o->data = xrealloc(o->data, o->maxlen + 1);
2625 list = (char**)o->data;
2626 memmove(list + n + 0x10, list + n, string_len);
2627 o->length += 0x10 * sizeof(list[0]);
2629 debug_printf_list("list[%d]=%d string_start=%d\n",
2630 n, string_len, string_start);
2633 /* We have empty slot at list[n], reuse without growth */
2634 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2635 string_len = o->length - string_start;
2636 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2637 n, string_len, string_start);
2638 o->has_empty_slot = 0;
2640 o->has_quoted_part = 0;
2641 list[n] = (char*)(uintptr_t)string_len;
2645 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2646 static int o_get_last_ptr(o_string *o, int n)
2648 char **list = (char**)o->data;
2649 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2651 return ((int)(uintptr_t)list[n-1]) + string_start;
2654 #if ENABLE_HUSH_BRACE_EXPANSION
2655 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2656 * first, it processes even {a} (no commas), second,
2657 * I didn't manage to make it return strings when they don't match
2658 * existing files. Need to re-implement it.
2662 static int glob_needed(const char *s)
2671 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2677 /* Return pointer to next closing brace or to comma */
2678 static const char *next_brace_sub(const char *cp)
2682 while (*cp != '\0') {
2689 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2695 return *cp != '\0' ? cp : NULL;
2697 /* Recursive brace globber. Note: may garble pattern[]. */
2698 static int glob_brace(char *pattern, o_string *o, int n)
2700 char *new_pattern_buf;
2707 debug_printf_glob("glob_brace('%s')\n", pattern);
2713 if (*begin == '{') {
2714 /* Find the first sub-pattern and at the same time
2715 * find the rest after the closing brace */
2716 next = next_brace_sub(begin);
2718 /* An illegal expression */
2722 /* "{abc}" with no commas - illegal
2723 * brace expr, disregard and skip it */
2729 if (*begin == '\\' && begin[1] != '\0')
2733 debug_printf_glob("begin:%s\n", begin);
2734 debug_printf_glob("next:%s\n", next);
2736 /* Now find the end of the whole brace expression */
2738 while (*rest != '}') {
2739 rest = next_brace_sub(rest);
2741 /* An illegal expression */
2744 debug_printf_glob("rest:%s\n", rest);
2746 rest_len = strlen(++rest) + 1;
2748 /* We are sure the brace expression is well-formed */
2750 /* Allocate working buffer large enough for our work */
2751 new_pattern_buf = xmalloc(strlen(pattern));
2753 /* We have a brace expression. BEGIN points to the opening {,
2754 * NEXT points past the terminator of the first element, and REST
2755 * points past the final }. We will accumulate result names from
2756 * recursive runs for each brace alternative in the buffer using
2761 /* Construct the new glob expression */
2764 mempcpy(new_pattern_buf,
2765 /* We know the prefix for all sub-patterns */
2766 pattern, begin - pattern),
2770 /* Note: glob_brace() may garble new_pattern_buf[].
2771 * That's why we re-copy prefix every time (1st memcpy above).
2773 n = glob_brace(new_pattern_buf, o, n);
2775 /* We saw the last entry */
2779 next = next_brace_sub(next);
2781 free(new_pattern_buf);
2789 memset(&globdata, 0, sizeof(globdata));
2790 gr = glob(pattern, 0, NULL, &globdata);
2791 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2793 if (gr == GLOB_NOMATCH) {
2794 globfree(&globdata);
2795 /* NB: garbles parameter */
2796 unbackslash(pattern);
2797 o_addstr_with_NUL(o, pattern);
2798 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2799 return o_save_ptr_helper(o, n);
2801 if (gr == GLOB_NOSPACE)
2802 bb_error_msg_and_die(bb_msg_memory_exhausted);
2803 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2804 * but we didn't specify it. Paranoia again. */
2805 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2807 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2808 char **argv = globdata.gl_pathv;
2810 o_addstr_with_NUL(o, *argv);
2811 n = o_save_ptr_helper(o, n);
2817 globfree(&globdata);
2821 /* Performs globbing on last list[],
2822 * saving each result as a new list[].
2824 static int perform_glob(o_string *o, int n)
2826 char *pattern, *copy;
2828 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2830 return o_save_ptr_helper(o, n);
2831 pattern = o->data + o_get_last_ptr(o, n);
2832 debug_printf_glob("glob pattern '%s'\n", pattern);
2833 if (!glob_needed(pattern)) {
2834 /* unbackslash last string in o in place, fix length */
2835 o->length = unbackslash(pattern) - o->data;
2836 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2837 return o_save_ptr_helper(o, n);
2840 copy = xstrdup(pattern);
2841 /* "forget" pattern in o */
2842 o->length = pattern - o->data;
2843 n = glob_brace(copy, o, n);
2846 debug_print_list("perform_glob returning", o, n);
2850 #else /* !HUSH_BRACE_EXPANSION */
2853 static int glob_needed(const char *s)
2862 if (*s == '*' || *s == '[' || *s == '?')
2868 /* Performs globbing on last list[],
2869 * saving each result as a new list[].
2871 static int perform_glob(o_string *o, int n)
2877 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2879 return o_save_ptr_helper(o, n);
2880 pattern = o->data + o_get_last_ptr(o, n);
2881 debug_printf_glob("glob pattern '%s'\n", pattern);
2882 if (!glob_needed(pattern)) {
2884 /* unbackslash last string in o in place, fix length */
2885 o->length = unbackslash(pattern) - o->data;
2886 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2887 return o_save_ptr_helper(o, n);
2890 memset(&globdata, 0, sizeof(globdata));
2891 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2892 * If we glob "*.\*" and don't find anything, we need
2893 * to fall back to using literal "*.*", but GLOB_NOCHECK
2894 * will return "*.\*"!
2896 gr = glob(pattern, 0, NULL, &globdata);
2897 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2899 if (gr == GLOB_NOMATCH) {
2900 globfree(&globdata);
2903 if (gr == GLOB_NOSPACE)
2904 bb_error_msg_and_die(bb_msg_memory_exhausted);
2905 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2906 * but we didn't specify it. Paranoia again. */
2907 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2909 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2910 char **argv = globdata.gl_pathv;
2911 /* "forget" pattern in o */
2912 o->length = pattern - o->data;
2914 o_addstr_with_NUL(o, *argv);
2915 n = o_save_ptr_helper(o, n);
2921 globfree(&globdata);
2923 debug_print_list("perform_glob returning", o, n);
2927 #endif /* !HUSH_BRACE_EXPANSION */
2929 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2930 * Otherwise, just finish current list[] and start new */
2931 static int o_save_ptr(o_string *o, int n)
2933 if (o->o_expflags & EXP_FLAG_GLOB) {
2934 /* If o->has_empty_slot, list[n] was already globbed
2935 * (if it was requested back then when it was filled)
2936 * so don't do that again! */
2937 if (!o->has_empty_slot)
2938 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2940 return o_save_ptr_helper(o, n);
2943 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2944 static char **o_finalize_list(o_string *o, int n)
2949 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2951 debug_print_list("finalized", o, n);
2952 debug_printf_expand("finalized n:%d\n", n);
2953 list = (char**)o->data;
2954 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2958 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2963 static void free_pipe_list(struct pipe *pi);
2965 /* Returns pi->next - next pipe in the list */
2966 static struct pipe *free_pipe(struct pipe *pi)
2971 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2972 for (i = 0; i < pi->num_cmds; i++) {
2973 struct command *command;
2974 struct redir_struct *r, *rnext;
2976 command = &pi->cmds[i];
2977 debug_printf_clean(" command %d:\n", i);
2978 if (command->argv) {
2982 for (a = 0, p = command->argv; *p; a++, p++) {
2983 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2986 free_strings(command->argv);
2987 //command->argv = NULL;
2989 /* not "else if": on syntax error, we may have both! */
2990 if (command->group) {
2991 debug_printf_clean(" begin group (cmd_type:%d)\n",
2993 free_pipe_list(command->group);
2994 debug_printf_clean(" end group\n");
2995 //command->group = NULL;
2997 /* else is crucial here.
2998 * If group != NULL, child_func is meaningless */
2999 #if ENABLE_HUSH_FUNCTIONS
3000 else if (command->child_func) {
3001 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3002 command->child_func->parent_cmd = NULL;
3006 free(command->group_as_string);
3007 //command->group_as_string = NULL;
3009 for (r = command->redirects; r; r = rnext) {
3010 debug_printf_clean(" redirect %d%s",
3011 r->rd_fd, redir_table[r->rd_type].descrip);
3012 /* guard against the case >$FOO, where foo is unset or blank */
3013 if (r->rd_filename) {
3014 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3015 free(r->rd_filename);
3016 //r->rd_filename = NULL;
3018 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3022 //command->redirects = NULL;
3024 free(pi->cmds); /* children are an array, they get freed all at once */
3028 //pi->cmdtext = NULL;
3036 static void free_pipe_list(struct pipe *pi)
3040 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3042 debug_printf_clean("pipe followup code %d\n", pi->followup);
3048 /*** Parsing routines ***/
3050 #ifndef debug_print_tree
3051 static void debug_print_tree(struct pipe *pi, int lvl)
3053 static const char *const PIPE[] = {
3059 static const char *RES[] = {
3060 [RES_NONE ] = "NONE" ,
3063 [RES_THEN ] = "THEN" ,
3064 [RES_ELIF ] = "ELIF" ,
3065 [RES_ELSE ] = "ELSE" ,
3068 # if ENABLE_HUSH_LOOPS
3069 [RES_FOR ] = "FOR" ,
3070 [RES_WHILE] = "WHILE",
3071 [RES_UNTIL] = "UNTIL",
3073 [RES_DONE ] = "DONE" ,
3075 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3078 # if ENABLE_HUSH_CASE
3079 [RES_CASE ] = "CASE" ,
3080 [RES_CASE_IN ] = "CASE_IN" ,
3081 [RES_MATCH] = "MATCH",
3082 [RES_CASE_BODY] = "CASE_BODY",
3083 [RES_ESAC ] = "ESAC" ,
3085 [RES_XXXX ] = "XXXX" ,
3086 [RES_SNTX ] = "SNTX" ,
3088 static const char *const CMDTYPE[] = {
3092 # if ENABLE_HUSH_FUNCTIONS
3101 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3102 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3104 while (prn < pi->num_cmds) {
3105 struct command *command = &pi->cmds[prn];
3106 char **argv = command->argv;
3108 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3110 command->assignment_cnt);
3111 if (command->group) {
3112 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3113 CMDTYPE[command->cmd_type],
3116 , " group_as_string:", command->group_as_string
3121 debug_print_tree(command->group, lvl+1);
3125 if (argv) while (*argv) {
3126 fdprintf(2, " '%s'", *argv);
3136 #endif /* debug_print_tree */
3138 static struct pipe *new_pipe(void)
3141 pi = xzalloc(sizeof(struct pipe));
3142 /*pi->followup = 0; - deliberately invalid value */
3143 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3147 /* Command (member of a pipe) is complete, or we start a new pipe
3148 * if ctx->command is NULL.
3149 * No errors possible here.
3151 static int done_command(struct parse_context *ctx)
3153 /* The command is really already in the pipe structure, so
3154 * advance the pipe counter and make a new, null command. */
3155 struct pipe *pi = ctx->pipe;
3156 struct command *command = ctx->command;
3158 #if 0 /* Instead we emit error message at run time */
3159 if (ctx->pending_redirect) {
3160 /* For example, "cmd >" (no filename to redirect to) */
3161 die_if_script("syntax error: %s", "invalid redirect");
3162 ctx->pending_redirect = NULL;
3167 if (IS_NULL_CMD(command)) {
3168 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3172 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3173 //debug_print_tree(ctx->list_head, 20);
3175 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3178 /* Only real trickiness here is that the uncommitted
3179 * command structure is not counted in pi->num_cmds. */
3180 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3181 ctx->command = command = &pi->cmds[pi->num_cmds];
3183 memset(command, 0, sizeof(*command));
3184 return pi->num_cmds; /* used only for 0/nonzero check */
3187 static void done_pipe(struct parse_context *ctx, pipe_style type)
3191 debug_printf_parse("done_pipe entered, followup %d\n", type);
3192 /* Close previous command */
3193 not_null = done_command(ctx);
3194 ctx->pipe->followup = type;
3196 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3197 ctx->ctx_inverted = 0;
3198 ctx->pipe->res_word = ctx->ctx_res_w;
3201 /* Without this check, even just <enter> on command line generates
3202 * tree of three NOPs (!). Which is harmless but annoying.
3203 * IOW: it is safe to do it unconditionally. */
3206 || ctx->ctx_res_w == RES_FI
3208 #if ENABLE_HUSH_LOOPS
3209 || ctx->ctx_res_w == RES_DONE
3210 || ctx->ctx_res_w == RES_FOR
3211 || ctx->ctx_res_w == RES_IN
3213 #if ENABLE_HUSH_CASE
3214 || ctx->ctx_res_w == RES_ESAC
3218 debug_printf_parse("done_pipe: adding new pipe: "
3219 "not_null:%d ctx->ctx_res_w:%d\n",
3220 not_null, ctx->ctx_res_w);
3222 ctx->pipe->next = new_p;
3224 /* RES_THEN, RES_DO etc are "sticky" -
3225 * they remain set for pipes inside if/while.
3226 * This is used to control execution.
3227 * RES_FOR and RES_IN are NOT sticky (needed to support
3228 * cases where variable or value happens to match a keyword):
3230 #if ENABLE_HUSH_LOOPS
3231 if (ctx->ctx_res_w == RES_FOR
3232 || ctx->ctx_res_w == RES_IN)
3233 ctx->ctx_res_w = RES_NONE;
3235 #if ENABLE_HUSH_CASE
3236 if (ctx->ctx_res_w == RES_MATCH)
3237 ctx->ctx_res_w = RES_CASE_BODY;
3238 if (ctx->ctx_res_w == RES_CASE)
3239 ctx->ctx_res_w = RES_CASE_IN;
3241 ctx->command = NULL; /* trick done_command below */
3242 /* Create the memory for command, roughly:
3243 * ctx->pipe->cmds = new struct command;
3244 * ctx->command = &ctx->pipe->cmds[0];
3247 //debug_print_tree(ctx->list_head, 10);
3249 debug_printf_parse("done_pipe return\n");
3252 static void initialize_context(struct parse_context *ctx)
3254 memset(ctx, 0, sizeof(*ctx));
3255 ctx->pipe = ctx->list_head = new_pipe();
3256 /* Create the memory for command, roughly:
3257 * ctx->pipe->cmds = new struct command;
3258 * ctx->command = &ctx->pipe->cmds[0];
3263 /* If a reserved word is found and processed, parse context is modified
3264 * and 1 is returned.
3267 struct reserved_combo {
3270 unsigned char assignment_flag;
3274 FLAG_END = (1 << RES_NONE ),
3276 FLAG_IF = (1 << RES_IF ),
3277 FLAG_THEN = (1 << RES_THEN ),
3278 FLAG_ELIF = (1 << RES_ELIF ),
3279 FLAG_ELSE = (1 << RES_ELSE ),
3280 FLAG_FI = (1 << RES_FI ),
3282 # if ENABLE_HUSH_LOOPS
3283 FLAG_FOR = (1 << RES_FOR ),
3284 FLAG_WHILE = (1 << RES_WHILE),
3285 FLAG_UNTIL = (1 << RES_UNTIL),
3286 FLAG_DO = (1 << RES_DO ),
3287 FLAG_DONE = (1 << RES_DONE ),
3288 FLAG_IN = (1 << RES_IN ),
3290 # if ENABLE_HUSH_CASE
3291 FLAG_MATCH = (1 << RES_MATCH),
3292 FLAG_ESAC = (1 << RES_ESAC ),
3294 FLAG_START = (1 << RES_XXXX ),
3297 static const struct reserved_combo* match_reserved_word(o_string *word)
3299 /* Mostly a list of accepted follow-up reserved words.
3300 * FLAG_END means we are done with the sequence, and are ready
3301 * to turn the compound list into a command.
3302 * FLAG_START means the word must start a new compound list.
3304 static const struct reserved_combo reserved_list[] = {
3306 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3307 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3308 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3309 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3310 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3311 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3313 # if ENABLE_HUSH_LOOPS
3314 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3315 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3316 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3317 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3318 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3319 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3321 # if ENABLE_HUSH_CASE
3322 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3323 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3326 const struct reserved_combo *r;
3328 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3329 if (strcmp(word->data, r->literal) == 0)
3334 /* Return 0: not a keyword, 1: keyword
3336 static int reserved_word(o_string *word, struct parse_context *ctx)
3338 # if ENABLE_HUSH_CASE
3339 static const struct reserved_combo reserved_match = {
3340 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3343 const struct reserved_combo *r;
3345 if (word->has_quoted_part)
3347 r = match_reserved_word(word);
3351 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3352 # if ENABLE_HUSH_CASE
3353 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3354 /* "case word IN ..." - IN part starts first MATCH part */
3355 r = &reserved_match;
3358 if (r->flag == 0) { /* '!' */
3359 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3360 syntax_error("! ! command");
3361 ctx->ctx_res_w = RES_SNTX;
3363 ctx->ctx_inverted = 1;
3366 if (r->flag & FLAG_START) {
3367 struct parse_context *old;
3369 old = xmalloc(sizeof(*old));
3370 debug_printf_parse("push stack %p\n", old);
3371 *old = *ctx; /* physical copy */
3372 initialize_context(ctx);
3374 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3375 syntax_error_at(word->data);
3376 ctx->ctx_res_w = RES_SNTX;
3379 /* "{...} fi" is ok. "{...} if" is not
3381 * if { echo foo; } then { echo bar; } fi */
3382 if (ctx->command->group)
3383 done_pipe(ctx, PIPE_SEQ);
3386 ctx->ctx_res_w = r->res;
3387 ctx->old_flag = r->flag;
3388 word->o_assignment = r->assignment_flag;
3389 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3391 if (ctx->old_flag & FLAG_END) {
3392 struct parse_context *old;
3394 done_pipe(ctx, PIPE_SEQ);
3395 debug_printf_parse("pop stack %p\n", ctx->stack);
3397 old->command->group = ctx->list_head;
3398 old->command->cmd_type = CMD_NORMAL;
3400 /* At this point, the compound command's string is in
3401 * ctx->as_string... except for the leading keyword!
3402 * Consider this example: "echo a | if true; then echo a; fi"
3403 * ctx->as_string will contain "true; then echo a; fi",
3404 * with "if " remaining in old->as_string!
3408 int len = old->as_string.length;
3409 /* Concatenate halves */
3410 o_addstr(&old->as_string, ctx->as_string.data);
3411 o_free_unsafe(&ctx->as_string);
3412 /* Find where leading keyword starts in first half */
3413 str = old->as_string.data + len;
3414 if (str > old->as_string.data)
3415 str--; /* skip whitespace after keyword */
3416 while (str > old->as_string.data && isalpha(str[-1]))
3418 /* Ugh, we're done with this horrid hack */
3419 old->command->group_as_string = xstrdup(str);
3420 debug_printf_parse("pop, remembering as:'%s'\n",
3421 old->command->group_as_string);
3424 *ctx = *old; /* physical copy */
3429 #endif /* HAS_KEYWORDS */
3431 /* Word is complete, look at it and update parsing context.
3432 * Normal return is 0. Syntax errors return 1.
3433 * Note: on return, word is reset, but not o_free'd!
3435 static int done_word(o_string *word, struct parse_context *ctx)
3437 struct command *command = ctx->command;
3439 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3440 if (word->length == 0 && !word->has_quoted_part) {
3441 debug_printf_parse("done_word return 0: true null, ignored\n");
3445 if (ctx->pending_redirect) {
3446 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3447 * only if run as "bash", not "sh" */
3448 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3450 * ...the word that follows the redirection operator
3451 * shall be subjected to tilde expansion, parameter expansion,
3452 * command substitution, arithmetic expansion, and quote
3453 * removal. Pathname expansion shall not be performed
3454 * on the word by a non-interactive shell; an interactive
3455 * shell may perform it, but shall do so only when
3456 * the expansion would result in one word."
3458 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3459 /* Cater for >\file case:
3460 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3461 * Same with heredocs:
3462 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3464 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3465 unbackslash(ctx->pending_redirect->rd_filename);
3466 /* Is it <<"HEREDOC"? */
3467 if (word->has_quoted_part) {
3468 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3471 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3472 ctx->pending_redirect = NULL;
3475 # if ENABLE_HUSH_CASE
3476 if (ctx->ctx_dsemicolon
3477 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3479 /* already done when ctx_dsemicolon was set to 1: */
3480 /* ctx->ctx_res_w = RES_MATCH; */
3481 ctx->ctx_dsemicolon = 0;
3484 if (!command->argv /* if it's the first word... */
3485 # if ENABLE_HUSH_LOOPS
3486 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3487 && ctx->ctx_res_w != RES_IN
3489 # if ENABLE_HUSH_CASE
3490 && ctx->ctx_res_w != RES_CASE
3493 int reserved = reserved_word(word, ctx);
3494 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3496 o_reset_to_empty_unquoted(word);
3497 debug_printf_parse("done_word return %d\n",
3498 (ctx->ctx_res_w == RES_SNTX));
3499 return (ctx->ctx_res_w == RES_SNTX);
3501 # if ENABLE_HUSH_BASH_COMPAT
3502 if (strcmp(word->data, "[[") == 0) {
3503 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3509 if (command->group) {
3510 /* "{ echo foo; } echo bar" - bad */
3511 syntax_error_at(word->data);
3512 debug_printf_parse("done_word return 1: syntax error, "
3513 "groups and arglists don't mix\n");
3517 /* If this word wasn't an assignment, next ones definitely
3518 * can't be assignments. Even if they look like ones. */
3519 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3520 && word->o_assignment != WORD_IS_KEYWORD
3522 word->o_assignment = NOT_ASSIGNMENT;
3524 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3525 command->assignment_cnt++;
3526 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3528 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3529 word->o_assignment = MAYBE_ASSIGNMENT;
3531 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3533 if (word->has_quoted_part
3534 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3535 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3536 /* (otherwise it's known to be not empty and is already safe) */
3538 /* exclude "$@" - it can expand to no word despite "" */
3539 char *p = word->data;
3540 while (p[0] == SPECIAL_VAR_SYMBOL
3541 && (p[1] & 0x7f) == '@'
3542 && p[2] == SPECIAL_VAR_SYMBOL
3547 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3548 debug_print_strings("word appended to argv", command->argv);
3551 #if ENABLE_HUSH_LOOPS
3552 if (ctx->ctx_res_w == RES_FOR) {
3553 if (word->has_quoted_part
3554 || !is_well_formed_var_name(command->argv[0], '\0')
3556 /* bash says just "not a valid identifier" */
3557 syntax_error("not a valid identifier in for");
3560 /* Force FOR to have just one word (variable name) */
3561 /* NB: basically, this makes hush see "for v in ..."
3562 * syntax as if it is "for v; in ...". FOR and IN become
3563 * two pipe structs in parse tree. */
3564 done_pipe(ctx, PIPE_SEQ);
3567 #if ENABLE_HUSH_CASE
3568 /* Force CASE to have just one word */
3569 if (ctx->ctx_res_w == RES_CASE) {
3570 done_pipe(ctx, PIPE_SEQ);
3574 o_reset_to_empty_unquoted(word);
3576 debug_printf_parse("done_word return 0\n");
3581 /* Peek ahead in the input to find out if we have a "&n" construct,
3582 * as in "2>&1", that represents duplicating a file descriptor.
3584 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3585 * REDIRFD_SYNTAX_ERR if syntax error,
3586 * REDIRFD_TO_FILE if no & was seen,
3587 * or the number found.
3590 #define parse_redir_right_fd(as_string, input) \
3591 parse_redir_right_fd(input)
3593 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3599 return REDIRFD_TO_FILE;
3601 ch = i_getch(input); /* get the & */
3602 nommu_addchr(as_string, ch);
3605 ch = i_getch(input);
3606 nommu_addchr(as_string, ch);
3607 return REDIRFD_CLOSE;
3611 while (ch != EOF && isdigit(ch)) {
3612 d = d*10 + (ch-'0');
3614 ch = i_getch(input);
3615 nommu_addchr(as_string, ch);
3620 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3622 bb_error_msg("ambiguous redirect");
3623 return REDIRFD_SYNTAX_ERR;
3626 /* Return code is 0 normal, 1 if a syntax error is detected
3628 static int parse_redirect(struct parse_context *ctx,
3631 struct in_str *input)
3633 struct command *command = ctx->command;
3634 struct redir_struct *redir;
3635 struct redir_struct **redirp;
3638 dup_num = REDIRFD_TO_FILE;
3639 if (style != REDIRECT_HEREDOC) {
3640 /* Check for a '>&1' type redirect */
3641 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3642 if (dup_num == REDIRFD_SYNTAX_ERR)
3645 int ch = i_peek(input);
3646 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3647 if (dup_num) { /* <<-... */
3648 ch = i_getch(input);
3649 nommu_addchr(&ctx->as_string, ch);
3654 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3655 int ch = i_peek(input);
3657 /* >|FILE redirect ("clobbering" >).
3658 * Since we do not support "set -o noclobber" yet,
3659 * >| and > are the same for now. Just eat |.
3661 ch = i_getch(input);
3662 nommu_addchr(&ctx->as_string, ch);
3666 /* Create a new redir_struct and append it to the linked list */
3667 redirp = &command->redirects;
3668 while ((redir = *redirp) != NULL) {
3669 redirp = &(redir->next);
3671 *redirp = redir = xzalloc(sizeof(*redir));
3672 /* redir->next = NULL; */
3673 /* redir->rd_filename = NULL; */
3674 redir->rd_type = style;
3675 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3677 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3678 redir_table[style].descrip);
3680 redir->rd_dup = dup_num;
3681 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3682 /* Erik had a check here that the file descriptor in question
3683 * is legit; I postpone that to "run time"
3684 * A "-" representation of "close me" shows up as a -3 here */
3685 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3686 redir->rd_fd, redir->rd_dup);
3688 #if 0 /* Instead we emit error message at run time */
3689 if (ctx->pending_redirect) {
3690 /* For example, "cmd > <file" */
3691 die_if_script("syntax error: %s", "invalid redirect");
3694 /* Set ctx->pending_redirect, so we know what to do at the
3695 * end of the next parsed word. */
3696 ctx->pending_redirect = redir;
3701 /* If a redirect is immediately preceded by a number, that number is
3702 * supposed to tell which file descriptor to redirect. This routine
3703 * looks for such preceding numbers. In an ideal world this routine
3704 * needs to handle all the following classes of redirects...
3705 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3706 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3707 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3708 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3710 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3712 * ... If n is quoted, the number shall not be recognized as part of
3713 * the redirection expression. For example:
3715 * writes the character 2 into file a"
3716 * We are getting it right by setting ->has_quoted_part on any \<char>
3718 * A -1 return means no valid number was found,
3719 * the caller should use the appropriate default for this redirection.
3721 static int redirect_opt_num(o_string *o)
3725 if (o->data == NULL)
3727 num = bb_strtou(o->data, NULL, 10);
3728 if (errno || num < 0)
3730 o_reset_to_empty_unquoted(o);
3735 #define fetch_till_str(as_string, input, word, skip_tabs) \
3736 fetch_till_str(input, word, skip_tabs)
3738 static char *fetch_till_str(o_string *as_string,
3739 struct in_str *input,
3743 o_string heredoc = NULL_O_STRING;
3745 int prev = 0; /* not \ */
3751 ch = i_getch(input);
3753 nommu_addchr(as_string, ch);
3754 if ((ch == '\n' || ch == EOF)
3755 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3757 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3758 heredoc.data[past_EOL] = '\0';
3759 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3760 return heredoc.data;
3762 while (ch == '\n') {
3763 o_addchr(&heredoc, ch);
3766 past_EOL = heredoc.length;
3768 ch = i_getch(input);
3770 nommu_addchr(as_string, ch);
3771 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3775 o_free_unsafe(&heredoc);
3778 o_addchr(&heredoc, ch);
3779 nommu_addchr(as_string, ch);
3780 if (prev == '\\' && ch == '\\')
3781 /* Correctly handle foo\\<eol> (not a line cont.) */
3782 prev = 0; /* not \ */
3788 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3789 * and load them all. There should be exactly heredoc_cnt of them.
3791 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3793 struct pipe *pi = ctx->list_head;
3795 while (pi && heredoc_cnt) {
3797 struct command *cmd = pi->cmds;
3799 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3801 cmd->argv ? cmd->argv[0] : "NONE");
3802 for (i = 0; i < pi->num_cmds; i++) {
3803 struct redir_struct *redir = cmd->redirects;
3805 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3806 i, cmd->argv ? cmd->argv[0] : "NONE");
3808 if (redir->rd_type == REDIRECT_HEREDOC) {
3811 redir->rd_type = REDIRECT_HEREDOC2;
3812 /* redir->rd_dup is (ab)used to indicate <<- */
3813 p = fetch_till_str(&ctx->as_string, input,
3814 redir->rd_filename, redir->rd_dup);
3816 syntax_error("unexpected EOF in here document");
3819 free(redir->rd_filename);
3820 redir->rd_filename = p;
3823 redir = redir->next;
3830 /* Should be 0. If it isn't, it's a parse error */
3832 bb_error_msg_and_die("heredoc BUG 2");
3838 static int run_list(struct pipe *pi);
3840 #define parse_stream(pstring, input, end_trigger) \
3841 parse_stream(input, end_trigger)
3843 static struct pipe *parse_stream(char **pstring,
3844 struct in_str *input,
3848 #if !ENABLE_HUSH_FUNCTIONS
3849 #define parse_group(dest, ctx, input, ch) \
3850 parse_group(ctx, input, ch)
3852 static int parse_group(o_string *dest, struct parse_context *ctx,
3853 struct in_str *input, int ch)
3855 /* dest contains characters seen prior to ( or {.
3856 * Typically it's empty, but for function defs,
3857 * it contains function name (without '()'). */
3858 struct pipe *pipe_list;
3860 struct command *command = ctx->command;
3862 debug_printf_parse("parse_group entered\n");
3863 #if ENABLE_HUSH_FUNCTIONS
3864 if (ch == '(' && !dest->has_quoted_part) {
3866 if (done_word(dest, ctx))
3869 goto skip; /* (... */
3870 if (command->argv[1]) { /* word word ... (... */
3871 syntax_error_unexpected_ch('(');
3874 /* it is "word(..." or "word (..." */
3876 ch = i_getch(input);
3877 while (ch == ' ' || ch == '\t');
3879 syntax_error_unexpected_ch(ch);
3882 nommu_addchr(&ctx->as_string, ch);
3884 ch = i_getch(input);
3885 while (ch == ' ' || ch == '\t' || ch == '\n');
3887 syntax_error_unexpected_ch(ch);
3890 nommu_addchr(&ctx->as_string, ch);
3891 command->cmd_type = CMD_FUNCDEF;
3896 #if 0 /* Prevented by caller */
3897 if (command->argv /* word [word]{... */
3898 || dest->length /* word{... */
3899 || dest->has_quoted_part /* ""{... */
3902 debug_printf_parse("parse_group return 1: "
3903 "syntax error, groups and arglists don't mix\n");
3908 #if ENABLE_HUSH_FUNCTIONS
3914 command->cmd_type = CMD_SUBSHELL;
3916 /* bash does not allow "{echo...", requires whitespace */
3918 if (ch != ' ' && ch != '\t' && ch != '\n'
3919 && ch != '(' /* but "{(..." is allowed (without whitespace) */
3921 syntax_error_unexpected_ch(ch);
3925 ch = i_getch(input);
3926 nommu_addchr(&ctx->as_string, ch);
3932 # define as_string NULL
3934 char *as_string = NULL;
3936 pipe_list = parse_stream(&as_string, input, endch);
3939 o_addstr(&ctx->as_string, as_string);
3941 /* empty ()/{} or parse error? */
3942 if (!pipe_list || pipe_list == ERR_PTR) {
3943 /* parse_stream already emitted error msg */
3946 debug_printf_parse("parse_group return 1: "
3947 "parse_stream returned %p\n", pipe_list);
3950 command->group = pipe_list;
3952 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3953 command->group_as_string = as_string;
3954 debug_printf_parse("end of group, remembering as:'%s'\n",
3955 command->group_as_string);
3959 debug_printf_parse("parse_group return 0\n");
3961 /* command remains "open", available for possible redirects */
3964 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3969 ch = i_getch(input);
3972 ch2 = i_peek(input);
3975 /* backslash+newline, skip it */
3980 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3988 ch2 = i_peek2(input);
3991 /* backslash+newline, skip it */
3997 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3998 /* Subroutines for copying $(...) and `...` things */
3999 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4001 static int add_till_single_quote(o_string *dest, struct in_str *input)
4004 int ch = i_getch(input);
4006 syntax_error_unterm_ch('\'');
4014 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4015 static int add_till_double_quote(o_string *dest, struct in_str *input)
4018 int ch = i_getch(input);
4020 syntax_error_unterm_ch('"');
4025 if (ch == '\\') { /* \x. Copy both chars. */
4027 ch = i_getch(input);
4031 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4036 //if (ch == '$') ...
4039 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4041 * "Within the backquoted style of command substitution, backslash
4042 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4043 * The search for the matching backquote shall be satisfied by the first
4044 * backquote found without a preceding backslash; during this search,
4045 * if a non-escaped backquote is encountered within a shell comment,
4046 * a here-document, an embedded command substitution of the $(command)
4047 * form, or a quoted string, undefined results occur. A single-quoted
4048 * or double-quoted string that begins, but does not end, within the
4049 * "`...`" sequence produces undefined results."
4051 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4053 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4056 int ch = i_getch(input);
4060 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4061 ch = i_getch(input);
4065 && (!in_dquote || ch != '"')
4067 o_addchr(dest, '\\');
4071 syntax_error_unterm_ch('`');
4077 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4078 * quoting and nested ()s.
4079 * "With the $(command) style of command substitution, all characters
4080 * following the open parenthesis to the matching closing parenthesis
4081 * constitute the command. Any valid shell script can be used for command,
4082 * except a script consisting solely of redirections which produces
4083 * unspecified results."
4085 * echo $(echo '(TEST)' BEST) (TEST) BEST
4086 * echo $(echo 'TEST)' BEST) TEST) BEST
4087 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4089 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4090 * can contain arbitrary constructs, just like $(cmd).
4091 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4092 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4094 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4095 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4098 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4099 # if ENABLE_HUSH_BASH_COMPAT
4100 char end_char2 = end_ch >> 8;
4102 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4105 ch = i_getch(input);
4107 syntax_error_unterm_ch(end_ch);
4110 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4113 /* we look for closing )) of $((EXPR)) */
4114 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4115 i_getch(input); /* eat second ')' */
4120 if (ch == '(' || ch == '{') {
4121 ch = (ch == '(' ? ')' : '}');
4122 if (!add_till_closing_bracket(dest, input, ch))
4128 if (!add_till_single_quote(dest, input))
4134 if (!add_till_double_quote(dest, input))
4140 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4146 /* \x. Copy verbatim. Important for \(, \) */
4147 ch = i_getch(input);
4149 syntax_error_unterm_ch(')');
4154 /* "backslash+newline", ignore both */
4155 o_delchr(dest); /* undo insertion of '\' */
4165 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4167 /* Return code: 0 for OK, 1 for syntax error */
4169 #define parse_dollar(as_string, dest, input, quote_mask) \
4170 parse_dollar(dest, input, quote_mask)
4171 #define as_string NULL
4173 static int parse_dollar(o_string *as_string,
4175 struct in_str *input, unsigned char quote_mask)
4177 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4179 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4181 ch = i_getch(input);
4182 nommu_addchr(as_string, ch);
4184 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4186 debug_printf_parse(": '%c'\n", ch);
4187 o_addchr(dest, ch | quote_mask);
4189 ch = i_peek_and_eat_bkslash_nl(input);
4190 if (!isalnum(ch) && ch != '_') {
4191 /* End of variable name reached */
4194 ch = i_getch(input);
4195 nommu_addchr(as_string, ch);
4197 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4198 } else if (isdigit(ch)) {
4200 ch = i_getch(input);
4201 nommu_addchr(as_string, ch);
4202 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4203 debug_printf_parse(": '%c'\n", ch);
4204 o_addchr(dest, ch | quote_mask);
4205 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4206 } else switch (ch) {
4208 case '!': /* last bg pid */
4209 case '?': /* last exit code */
4210 case '#': /* number of args */
4211 case '*': /* args */
4212 case '@': /* args */
4213 goto make_one_char_var;
4215 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4217 ch = i_getch(input); /* eat '{' */
4218 nommu_addchr(as_string, ch);
4220 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4221 /* It should be ${?}, or ${#var},
4222 * or even ${?+subst} - operator acting on a special variable,
4223 * or the beginning of variable name.
4226 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4229 syntax_error_unterm_str("${name}");
4230 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4233 nommu_addchr(as_string, ch);
4236 /* It's possible to just call add_till_closing_bracket() at this point.
4237 * However, this regresses some of our testsuite cases
4238 * which check invalid constructs like ${%}.
4239 * Oh well... let's check that the var name part is fine... */
4245 debug_printf_parse(": '%c'\n", ch);
4247 ch = i_getch(input);
4248 nommu_addchr(as_string, ch);
4252 if (!isalnum(ch) && ch != '_') {
4254 unsigned char last_ch;
4255 /* handle parameter expansions
4256 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4258 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4259 goto bad_dollar_syntax;
4261 /* Eat everything until closing '}' (or ':') */
4263 if (ENABLE_HUSH_BASH_COMPAT
4265 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4267 /* It's ${var:N[:M]} thing */
4268 end_ch = '}' * 0x100 + ':';
4270 if (ENABLE_HUSH_BASH_COMPAT
4273 /* It's ${var/[/]pattern[/repl]} thing */
4274 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4276 nommu_addchr(as_string, '/');
4279 end_ch = '}' * 0x100 + '/';
4285 #if ENABLE_HUSH_DOLLAR_OPS
4286 last_ch = add_till_closing_bracket(dest, input, end_ch);
4287 if (last_ch == 0) /* error? */
4290 #error Simple code to only allow ${var} is not implemented
4293 o_addstr(as_string, dest->data + pos);
4294 o_addchr(as_string, last_ch);
4297 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4298 /* close the first block: */
4299 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4300 /* while parsing N from ${var:N[:M]}
4301 * or pattern from ${var/[/]pattern[/repl]} */
4302 if ((end_ch & 0xff) == last_ch) {
4303 /* got ':' or '/'- parse the rest */
4308 if (end_ch == '}' * 0x100 + ':') {
4309 /* it's ${var:N} - emulate :999999999 */
4310 o_addstr(dest, "999999999");
4311 } /* else: it's ${var/[/]pattern} */
4316 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4319 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4323 ch = i_getch(input);
4324 nommu_addchr(as_string, ch);
4325 # if ENABLE_SH_MATH_SUPPORT
4326 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4327 ch = i_getch(input);
4328 nommu_addchr(as_string, ch);
4329 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4330 o_addchr(dest, /*quote_mask |*/ '+');
4333 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4334 return 0; /* error */
4336 o_addstr(as_string, dest->data + pos);
4337 o_addchr(as_string, ')');
4338 o_addchr(as_string, ')');
4340 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4344 # if ENABLE_HUSH_TICK
4345 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4346 o_addchr(dest, quote_mask | '`');
4349 if (!add_till_closing_bracket(dest, input, ')'))
4350 return 0; /* error */
4352 o_addstr(as_string, dest->data + pos);
4353 o_addchr(as_string, ')');
4355 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4361 ch = i_getch(input);
4362 nommu_addchr(as_string, ch);
4363 ch = i_peek_and_eat_bkslash_nl(input);
4364 if (isalnum(ch)) { /* it's $_name or $_123 */
4369 /* TODO: $_ and $-: */
4370 /* $_ Shell or shell script name; or last argument of last command
4371 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4372 * but in command's env, set to full pathname used to invoke it */
4373 /* $- Option flags set by set builtin or shell options (-i etc) */
4375 o_addQchr(dest, '$');
4377 debug_printf_parse("parse_dollar return 1 (ok)\n");
4383 # if ENABLE_HUSH_BASH_COMPAT
4384 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4385 encode_string(dest, input, dquote_end, process_bkslash)
4387 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4388 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4389 encode_string(dest, input, dquote_end)
4391 #define as_string NULL
4395 # if ENABLE_HUSH_BASH_COMPAT
4396 /* all parameters are needed, no macro tricks */
4398 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4399 encode_string(as_string, dest, input, dquote_end)
4402 static int encode_string(o_string *as_string,
4404 struct in_str *input,
4406 int process_bkslash)
4408 #if !ENABLE_HUSH_BASH_COMPAT
4409 const int process_bkslash = 1;
4415 ch = i_getch(input);
4417 nommu_addchr(as_string, ch);
4418 if (ch == dquote_end) { /* may be only '"' or EOF */
4419 debug_printf_parse("encode_string return 1 (ok)\n");
4422 /* note: can't move it above ch == dquote_end check! */
4424 syntax_error_unterm_ch('"');
4425 return 0; /* error */
4429 next = i_peek(input);
4431 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4432 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4433 if (process_bkslash && ch == '\\') {
4435 syntax_error("\\<eof>");
4439 * "The backslash retains its special meaning [in "..."]
4440 * only when followed by one of the following characters:
4441 * $, `, ", \, or <newline>. A double quote may be quoted
4442 * within double quotes by preceding it with a backslash."
4443 * NB: in (unquoted) heredoc, above does not apply to ",
4444 * therefore we check for it by "next == dquote_end" cond.
4446 if (next == dquote_end || strchr("$`\\\n", next)) {
4447 ch = i_getch(input); /* eat next */
4449 goto again; /* skip \<newline> */
4450 } /* else: ch remains == '\\', and we double it below: */
4451 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4452 nommu_addchr(as_string, ch);
4456 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4457 debug_printf_parse("encode_string return 0: "
4458 "parse_dollar returned 0 (error)\n");
4463 #if ENABLE_HUSH_TICK
4465 //unsigned pos = dest->length;
4466 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4467 o_addchr(dest, 0x80 | '`');
4468 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4469 return 0; /* error */
4470 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4471 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4475 o_addQchr(dest, ch);
4481 * Scan input until EOF or end_trigger char.
4482 * Return a list of pipes to execute, or NULL on EOF
4483 * or if end_trigger character is met.
4484 * On syntax error, exit if shell is not interactive,
4485 * reset parsing machinery and start parsing anew,
4486 * or return ERR_PTR.
4488 static struct pipe *parse_stream(char **pstring,
4489 struct in_str *input,
4492 struct parse_context ctx;
4493 o_string dest = NULL_O_STRING;
4496 /* Single-quote triggers a bypass of the main loop until its mate is
4497 * found. When recursing, quote state is passed in via dest->o_expflags.
4499 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4500 end_trigger ? end_trigger : 'X');
4503 /* If very first arg is "" or '', dest.data may end up NULL.
4504 * Preventing this: */
4505 o_addchr(&dest, '\0');
4508 /* We used to separate words on $IFS here. This was wrong.
4509 * $IFS is used only for word splitting when $var is expanded,
4510 * here we should use blank chars as separators, not $IFS
4513 if (MAYBE_ASSIGNMENT != 0)
4514 dest.o_assignment = MAYBE_ASSIGNMENT;
4515 initialize_context(&ctx);
4518 const char *is_blank;
4519 const char *is_special;
4523 redir_type redir_style;
4525 ch = i_getch(input);
4526 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4527 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4532 syntax_error_unterm_str("here document");
4535 if (end_trigger == ')') {
4536 syntax_error_unterm_ch('(');
4539 if (end_trigger == '}') {
4540 syntax_error_unterm_ch('{');
4544 if (done_word(&dest, &ctx)) {
4548 done_pipe(&ctx, PIPE_SEQ);
4550 /* If we got nothing... */
4551 /* (this makes bare "&" cmd a no-op.
4552 * bash says: "syntax error near unexpected token '&'") */
4553 if (pi->num_cmds == 0
4554 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4560 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4562 *pstring = ctx.as_string.data;
4564 o_free_unsafe(&ctx.as_string);
4567 debug_printf_parse("parse_stream return %p\n", pi);
4570 nommu_addchr(&ctx.as_string, ch);
4574 next = i_peek(input);
4576 is_special = "{}<>;&|()#'" /* special outside of "str" */
4577 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4578 /* Are { and } special here? */
4579 if (ctx.command->argv /* word [word]{... - non-special */
4580 || dest.length /* word{... - non-special */
4581 || dest.has_quoted_part /* ""{... - non-special */
4582 || (next != ';' /* }; - special */
4583 && next != ')' /* }) - special */
4584 && next != '(' /* {( - special */
4585 && next != '&' /* }& and }&& ... - special */
4586 && next != '|' /* }|| ... - special */
4587 && !strchr(defifs, next) /* {word - non-special */
4590 /* They are not special, skip "{}" */
4593 is_special = strchr(is_special, ch);
4594 is_blank = strchr(defifs, ch);
4596 if (!is_special && !is_blank) { /* ordinary char */
4598 o_addQchr(&dest, ch);
4599 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4600 || dest.o_assignment == WORD_IS_KEYWORD)
4602 && is_well_formed_var_name(dest.data, '=')
4604 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4605 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4611 if (done_word(&dest, &ctx)) {
4615 /* Is this a case when newline is simply ignored?
4617 * "cmd | <newline> cmd ..."
4618 * "case ... in <newline> word) ..."
4620 if (IS_NULL_CMD(ctx.command)
4621 && dest.length == 0 && !dest.has_quoted_part
4623 /* This newline can be ignored. But...
4624 * Without check #1, interactive shell
4625 * ignores even bare <newline>,
4626 * and shows the continuation prompt:
4627 * ps1_prompt$ <enter>
4628 * ps2> _ <=== wrong, should be ps1
4629 * Without check #2, "cmd & <newline>"
4630 * is similarly mistreated.
4631 * (BTW, this makes "cmd & cmd"
4632 * and "cmd && cmd" non-orthogonal.
4633 * Really, ask yourself, why
4634 * "cmd && <newline>" doesn't start
4635 * cmd but waits for more input?
4638 struct pipe *pi = ctx.list_head;
4639 if (pi->num_cmds != 0 /* check #1 */
4640 && pi->followup != PIPE_BG /* check #2 */
4645 /* Treat newline as a command separator. */
4646 done_pipe(&ctx, PIPE_SEQ);
4647 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4649 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4654 dest.o_assignment = MAYBE_ASSIGNMENT;
4655 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4657 /* note: if (is_blank) continue;
4658 * will still trigger for us */
4662 /* "cmd}" or "cmd }..." without semicolon or &:
4663 * } is an ordinary char in this case, even inside { cmd; }
4664 * Pathological example: { ""}; } should exec "}" cmd
4667 if (dest.length != 0 /* word} */
4668 || dest.has_quoted_part /* ""} */
4672 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4673 /* Generally, there should be semicolon: "cmd; }"
4674 * However, bash allows to omit it if "cmd" is
4675 * a group. Examples:
4678 * { echo 0 >&2 | { echo 1; } }
4679 * { while false; do :; done }
4680 * { case a in b) ;; esac }
4682 if (ctx.command->group)
4686 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4687 /* Can't be an end of {cmd}, skip the check */
4688 goto skip_end_trigger;
4689 /* else: } does terminate a group */
4692 if (end_trigger && end_trigger == ch
4693 && (ch != ';' || heredoc_cnt == 0)
4694 #if ENABLE_HUSH_CASE
4696 || ctx.ctx_res_w != RES_MATCH
4697 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4702 /* This is technically valid:
4703 * { cat <<HERE; }; echo Ok
4707 * but we don't support this.
4708 * We require heredoc to be in enclosing {}/(),
4711 syntax_error_unterm_str("here document");
4714 if (done_word(&dest, &ctx)) {
4717 done_pipe(&ctx, PIPE_SEQ);
4718 dest.o_assignment = MAYBE_ASSIGNMENT;
4719 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4720 /* Do we sit outside of any if's, loops or case's? */
4722 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4726 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4728 *pstring = ctx.as_string.data;
4730 o_free_unsafe(&ctx.as_string);
4733 debug_printf_parse("parse_stream return %p: "
4734 "end_trigger char found\n",
4736 return ctx.list_head;
4743 /* Catch <, > before deciding whether this word is
4744 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4747 redir_fd = redirect_opt_num(&dest);
4748 if (done_word(&dest, &ctx)) {
4751 redir_style = REDIRECT_OVERWRITE;
4753 redir_style = REDIRECT_APPEND;
4754 ch = i_getch(input);
4755 nommu_addchr(&ctx.as_string, ch);
4758 else if (next == '(') {
4759 syntax_error(">(process) not supported");
4763 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4765 continue; /* back to top of while (1) */
4767 redir_fd = redirect_opt_num(&dest);
4768 if (done_word(&dest, &ctx)) {
4771 redir_style = REDIRECT_INPUT;
4773 redir_style = REDIRECT_HEREDOC;
4775 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4776 ch = i_getch(input);
4777 nommu_addchr(&ctx.as_string, ch);
4778 } else if (next == '>') {
4779 redir_style = REDIRECT_IO;
4780 ch = i_getch(input);
4781 nommu_addchr(&ctx.as_string, ch);
4784 else if (next == '(') {
4785 syntax_error("<(process) not supported");
4789 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4791 continue; /* back to top of while (1) */
4793 if (dest.length == 0 && !dest.has_quoted_part) {
4794 /* skip "#comment" */
4797 if (ch == EOF || ch == '\n')
4800 /* note: we do not add it to &ctx.as_string */
4802 nommu_addchr(&ctx.as_string, '\n');
4803 continue; /* back to top of while (1) */
4808 /* It's "\<newline>" */
4810 /* Remove trailing '\' from ctx.as_string */
4811 ctx.as_string.data[--ctx.as_string.length] = '\0';
4813 ch = i_getch(input); /* eat it */
4814 continue; /* back to top of while (1) */
4819 if (dest.o_assignment == MAYBE_ASSIGNMENT
4820 /* check that we are not in word in "a=1 2>word b=1": */
4821 && !ctx.pending_redirect
4823 /* ch is a special char and thus this word
4824 * cannot be an assignment */
4825 dest.o_assignment = NOT_ASSIGNMENT;
4826 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4829 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4832 case '#': /* non-comment #: "echo a#b" etc */
4833 o_addQchr(&dest, ch);
4837 syntax_error("\\<eof>");
4840 ch = i_getch(input);
4841 /* note: ch != '\n' (that case does not reach this place) */
4842 o_addchr(&dest, '\\');
4843 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4844 o_addchr(&dest, ch);
4845 nommu_addchr(&ctx.as_string, ch);
4846 /* Example: echo Hello \2>file
4847 * we need to know that word 2 is quoted */
4848 dest.has_quoted_part = 1;
4851 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4852 debug_printf_parse("parse_stream parse error: "
4853 "parse_dollar returned 0 (error)\n");
4858 dest.has_quoted_part = 1;
4859 if (next == '\'' && !ctx.pending_redirect) {
4860 insert_empty_quoted_str_marker:
4861 nommu_addchr(&ctx.as_string, next);
4862 i_getch(input); /* eat second ' */
4863 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4864 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4867 ch = i_getch(input);
4869 syntax_error_unterm_ch('\'');
4872 nommu_addchr(&ctx.as_string, ch);
4875 o_addqchr(&dest, ch);
4880 dest.has_quoted_part = 1;
4881 if (next == '"' && !ctx.pending_redirect)
4882 goto insert_empty_quoted_str_marker;
4883 if (dest.o_assignment == NOT_ASSIGNMENT)
4884 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4885 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4887 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4889 #if ENABLE_HUSH_TICK
4891 USE_FOR_NOMMU(unsigned pos;)
4893 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4894 o_addchr(&dest, '`');
4895 USE_FOR_NOMMU(pos = dest.length;)
4896 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4899 o_addstr(&ctx.as_string, dest.data + pos);
4900 o_addchr(&ctx.as_string, '`');
4902 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4903 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4908 #if ENABLE_HUSH_CASE
4911 if (done_word(&dest, &ctx)) {
4914 done_pipe(&ctx, PIPE_SEQ);
4915 #if ENABLE_HUSH_CASE
4916 /* Eat multiple semicolons, detect
4917 * whether it means something special */
4922 ch = i_getch(input);
4923 nommu_addchr(&ctx.as_string, ch);
4924 if (ctx.ctx_res_w == RES_CASE_BODY) {
4925 ctx.ctx_dsemicolon = 1;
4926 ctx.ctx_res_w = RES_MATCH;
4932 /* We just finished a cmd. New one may start
4933 * with an assignment */
4934 dest.o_assignment = MAYBE_ASSIGNMENT;
4935 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4938 if (done_word(&dest, &ctx)) {
4942 ch = i_getch(input);
4943 nommu_addchr(&ctx.as_string, ch);
4944 done_pipe(&ctx, PIPE_AND);
4946 done_pipe(&ctx, PIPE_BG);
4950 if (done_word(&dest, &ctx)) {
4953 #if ENABLE_HUSH_CASE
4954 if (ctx.ctx_res_w == RES_MATCH)
4955 break; /* we are in case's "word | word)" */
4957 if (next == '|') { /* || */
4958 ch = i_getch(input);
4959 nommu_addchr(&ctx.as_string, ch);
4960 done_pipe(&ctx, PIPE_OR);
4962 /* we could pick up a file descriptor choice here
4963 * with redirect_opt_num(), but bash doesn't do it.
4964 * "echo foo 2| cat" yields "foo 2". */
4969 #if ENABLE_HUSH_CASE
4970 /* "case... in [(]word)..." - skip '(' */
4971 if (ctx.ctx_res_w == RES_MATCH
4972 && ctx.command->argv == NULL /* not (word|(... */
4973 && dest.length == 0 /* not word(... */
4974 && dest.has_quoted_part == 0 /* not ""(... */
4980 if (parse_group(&dest, &ctx, input, ch) != 0) {
4985 #if ENABLE_HUSH_CASE
4986 if (ctx.ctx_res_w == RES_MATCH)
4990 /* proper use of this character is caught by end_trigger:
4991 * if we see {, we call parse_group(..., end_trigger='}')
4992 * and it will match } earlier (not here). */
4993 syntax_error_unexpected_ch(ch);
4997 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5003 struct parse_context *pctx;
5004 IF_HAS_KEYWORDS(struct parse_context *p2;)
5006 /* Clean up allocated tree.
5007 * Sample for finding leaks on syntax error recovery path.
5008 * Run it from interactive shell, watch pmap `pidof hush`.
5009 * while if false; then false; fi; do break; fi
5010 * Samples to catch leaks at execution:
5011 * while if (true | { true;}); then echo ok; fi; do break; done
5012 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5016 /* Update pipe/command counts,
5017 * otherwise freeing may miss some */
5018 done_pipe(pctx, PIPE_SEQ);
5019 debug_printf_clean("freeing list %p from ctx %p\n",
5020 pctx->list_head, pctx);
5021 debug_print_tree(pctx->list_head, 0);
5022 free_pipe_list(pctx->list_head);
5023 debug_printf_clean("freed list %p\n", pctx->list_head);
5025 o_free_unsafe(&pctx->as_string);
5027 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5031 IF_HAS_KEYWORDS(pctx = p2;)
5032 } while (HAS_KEYWORDS && pctx);
5035 G.last_exitcode = 1;
5046 /*** Execution routines ***/
5048 /* Expansion can recurse, need forward decls: */
5049 #if !ENABLE_HUSH_BASH_COMPAT
5050 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5051 #define expand_string_to_string(str, do_unbackslash) \
5052 expand_string_to_string(str)
5054 static char *expand_string_to_string(const char *str, int do_unbackslash);
5055 #if ENABLE_HUSH_TICK
5056 static int process_command_subs(o_string *dest, const char *s);
5059 /* expand_strvec_to_strvec() takes a list of strings, expands
5060 * all variable references within and returns a pointer to
5061 * a list of expanded strings, possibly with larger number
5062 * of strings. (Think VAR="a b"; echo $VAR).
5063 * This new list is allocated as a single malloc block.
5064 * NULL-terminated list of char* pointers is at the beginning of it,
5065 * followed by strings themselves.
5066 * Caller can deallocate entire list by single free(list). */
5068 /* A horde of its helpers come first: */
5070 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5072 while (--len >= 0) {
5075 #if ENABLE_HUSH_BRACE_EXPANSION
5076 if (c == '{' || c == '}') {
5077 /* { -> \{, } -> \} */
5079 /* And now we want to add { or } and continue:
5082 * luckily, just falling throught achieves this.
5088 /* \z -> \\\z; \<eol> -> \\<eol> */
5093 o_addchr(o, *str++);
5099 /* Store given string, finalizing the word and starting new one whenever
5100 * we encounter IFS char(s). This is used for expanding variable values.
5101 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5102 * Return in *ended_with_ifs:
5103 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5105 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5107 int last_is_ifs = 0;
5112 if (!*str) /* EOL - do not finalize word */
5114 word_len = strcspn(str, G.ifs);
5116 /* We have WORD_LEN leading non-IFS chars */
5117 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5118 o_addblock(output, str, word_len);
5120 /* Protect backslashes against globbing up :)
5121 * Example: "v='\*'; echo b$v" prints "b\*"
5122 * (and does not try to glob on "*")
5124 o_addblock_duplicate_backslash(output, str, word_len);
5125 /*/ Why can't we do it easier? */
5126 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5127 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5131 if (!*str) /* EOL - do not finalize word */
5135 /* We know str here points to at least one IFS char */
5137 str += strspn(str, G.ifs); /* skip IFS chars */
5138 if (!*str) /* EOL - do not finalize word */
5141 /* Start new word... but not always! */
5142 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5143 if (output->has_quoted_part
5144 /* Case "v=' a'; echo $v":
5145 * here nothing precedes the space in $v expansion,
5146 * therefore we should not finish the word
5147 * (IOW: if there *is* word to finalize, only then do it):
5149 || (n > 0 && output->data[output->length - 1])
5151 o_addchr(output, '\0');
5152 debug_print_list("expand_on_ifs", output, n);
5153 n = o_save_ptr(output, n);
5158 *ended_with_ifs = last_is_ifs;
5159 debug_print_list("expand_on_ifs[1]", output, n);
5163 /* Helper to expand $((...)) and heredoc body. These act as if
5164 * they are in double quotes, with the exception that they are not :).
5165 * Just the rules are similar: "expand only $var and `cmd`"
5167 * Returns malloced string.
5168 * As an optimization, we return NULL if expansion is not needed.
5170 #if !ENABLE_HUSH_BASH_COMPAT
5171 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5172 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5173 encode_then_expand_string(str)
5175 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5178 struct in_str input;
5179 o_string dest = NULL_O_STRING;
5181 if (!strchr(str, '$')
5182 && !strchr(str, '\\')
5183 #if ENABLE_HUSH_TICK
5184 && !strchr(str, '`')
5190 /* We need to expand. Example:
5191 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5193 setup_string_in_str(&input, str);
5194 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5195 //TODO: error check (encode_string returns 0 on error)?
5196 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5197 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5198 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5199 o_free_unsafe(&dest);
5203 #if ENABLE_SH_MATH_SUPPORT
5204 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5206 arith_state_t math_state;
5210 math_state.lookupvar = get_local_var_value;
5211 math_state.setvar = set_local_var_from_halves;
5212 //math_state.endofname = endofname;
5213 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5214 res = arith(&math_state, exp_str ? exp_str : arg);
5217 *errmsg_p = math_state.errmsg;
5218 if (math_state.errmsg)
5219 die_if_script(math_state.errmsg);
5224 #if ENABLE_HUSH_BASH_COMPAT
5225 /* ${var/[/]pattern[/repl]} helpers */
5226 static char *strstr_pattern(char *val, const char *pattern, int *size)
5229 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5230 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5237 /* Optimization: if "*pat" did not match the start of "string",
5238 * we know that "tring", "ring" etc will not match too:
5240 if (pattern[0] == '*')
5245 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5247 char *result = NULL;
5248 unsigned res_len = 0;
5249 unsigned repl_len = strlen(repl);
5253 char *s = strstr_pattern(val, pattern, &size);
5257 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5258 memcpy(result + res_len, val, s - val);
5260 strcpy(result + res_len, repl);
5261 res_len += repl_len;
5262 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5268 if (val[0] && result) {
5269 result = xrealloc(result, res_len + strlen(val) + 1);
5270 strcpy(result + res_len, val);
5271 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5273 debug_printf_varexp("result:'%s'\n", result);
5279 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5281 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5283 const char *val = NULL;
5284 char *to_be_freed = NULL;
5289 char exp_save = exp_save; /* for compiler */
5290 char *exp_saveptr; /* points to expansion operator */
5291 char *exp_word = exp_word; /* for compiler */
5294 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5296 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5298 first_char = arg[0] = arg0 & 0x7f;
5301 if (first_char == '#' /* ${#... */
5302 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5304 /* It must be length operator: ${#var} */
5308 /* Maybe handle parameter expansion */
5309 if (exp_saveptr /* if 2nd char is one of expansion operators */
5310 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5312 /* ${?:0}, ${#[:]%0} etc */
5313 exp_saveptr = var + 1;
5315 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5316 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5318 exp_op = exp_save = *exp_saveptr;
5320 exp_word = exp_saveptr + 1;
5321 if (exp_op == ':') {
5322 exp_op = *exp_word++;
5323 //TODO: try ${var:} and ${var:bogus} in non-bash config
5324 if (ENABLE_HUSH_BASH_COMPAT
5325 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5327 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5332 *exp_saveptr = '\0';
5333 } /* else: it's not an expansion op, but bare ${var} */
5336 /* Look up the variable in question */
5337 if (isdigit(var[0])) {
5338 /* parse_dollar should have vetted var for us */
5339 int n = xatoi_positive(var);
5340 if (n < G.global_argc)
5341 val = G.global_argv[n];
5342 /* else val remains NULL: $N with too big N */
5346 val = utoa(G.root_pid);
5348 case '!': /* bg pid */
5349 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5351 case '?': /* exitcode */
5352 val = utoa(G.last_exitcode);
5354 case '#': /* argc */
5355 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5358 val = get_local_var_value(var);
5362 /* Handle any expansions */
5363 if (exp_op == 'L') {
5364 reinit_unicode_for_hush();
5365 debug_printf_expand("expand: length(%s)=", val);
5366 val = utoa(val ? unicode_strlen(val) : 0);
5367 debug_printf_expand("%s\n", val);
5368 } else if (exp_op) {
5369 if (exp_op == '%' || exp_op == '#') {
5370 /* Standard-mandated substring removal ops:
5371 * ${parameter%word} - remove smallest suffix pattern
5372 * ${parameter%%word} - remove largest suffix pattern
5373 * ${parameter#word} - remove smallest prefix pattern
5374 * ${parameter##word} - remove largest prefix pattern
5376 * Word is expanded to produce a glob pattern.
5377 * Then var's value is matched to it and matching part removed.
5379 if (val && val[0]) {
5383 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5384 if (exp_op == *exp_word) /* ## or %% */
5386 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5388 exp_word = exp_exp_word;
5389 /* HACK ALERT. We depend here on the fact that
5390 * G.global_argv and results of utoa and get_local_var_value
5391 * are actually in writable memory:
5392 * scan_and_match momentarily stores NULs there. */
5394 loc = scan_and_match(t, exp_word, scan_flags);
5395 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5396 // exp_op, t, exp_word, loc);
5398 if (loc) { /* match was found */
5399 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5400 val = loc; /* take right part */
5402 val = to_be_freed = xstrndup(val, loc - val); /* left */
5406 #if ENABLE_HUSH_BASH_COMPAT
5407 else if (exp_op == '/' || exp_op == '\\') {
5408 /* It's ${var/[/]pattern[/repl]} thing.
5409 * Note that in encoded form it has TWO parts:
5410 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5411 * and if // is used, it is encoded as \:
5412 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5414 /* Empty variable always gives nothing: */
5415 // "v=''; echo ${v/*/w}" prints "", not "w"
5416 if (val && val[0]) {
5417 /* pattern uses non-standard expansion.
5418 * repl should be unbackslashed and globbed
5419 * by the usual expansion rules:
5421 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5422 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5423 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5424 * v='a bz'; echo ${v/a*z/\z} prints "z"
5425 * (note that a*z _pattern_ is never globbed!)
5427 char *pattern, *repl, *t;
5428 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5430 pattern = xstrdup(exp_word);
5431 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5432 *p++ = SPECIAL_VAR_SYMBOL;
5434 p = strchr(p, SPECIAL_VAR_SYMBOL);
5436 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5437 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5438 /* HACK ALERT. We depend here on the fact that
5439 * G.global_argv and results of utoa and get_local_var_value
5440 * are actually in writable memory:
5441 * replace_pattern momentarily stores NULs there. */
5443 to_be_freed = replace_pattern(t,
5445 (repl ? repl : exp_word),
5447 if (to_be_freed) /* at least one replace happened */
5454 else if (exp_op == ':') {
5455 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5456 /* It's ${var:N[:M]} bashism.
5457 * Note that in encoded form it has TWO parts:
5458 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5463 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5466 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5467 *p++ = SPECIAL_VAR_SYMBOL;
5469 p = strchr(p, SPECIAL_VAR_SYMBOL);
5471 len = expand_and_evaluate_arith(exp_word, &errmsg);
5474 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5475 if (len >= 0) { /* bash compat: len < 0 is illegal */
5476 if (beg < 0) /* bash compat */
5478 debug_printf_varexp("from val:'%s'\n", val);
5479 if (len == 0 || !val || beg >= strlen(val)) {
5483 /* Paranoia. What if user entered 9999999999999
5484 * which fits in arith_t but not int? */
5487 val = to_be_freed = xstrndup(val + beg, len);
5489 debug_printf_varexp("val:'%s'\n", val);
5493 die_if_script("malformed ${%s:...}", var);
5496 } else { /* one of "-=+?" */
5497 /* Standard-mandated substitution ops:
5498 * ${var?word} - indicate error if unset
5499 * If var is unset, word (or a message indicating it is unset
5500 * if word is null) is written to standard error
5501 * and the shell exits with a non-zero exit status.
5502 * Otherwise, the value of var is substituted.
5503 * ${var-word} - use default value
5504 * If var is unset, word is substituted.
5505 * ${var=word} - assign and use default value
5506 * If var is unset, word is assigned to var.
5507 * In all cases, final value of var is substituted.
5508 * ${var+word} - use alternative value
5509 * If var is unset, null is substituted.
5510 * Otherwise, word is substituted.
5512 * Word is subjected to tilde expansion, parameter expansion,
5513 * command substitution, and arithmetic expansion.
5514 * If word is not needed, it is not expanded.
5516 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5517 * but also treat null var as if it is unset.
5519 int use_word = (!val || ((exp_save == ':') && !val[0]));
5521 use_word = !use_word;
5522 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5523 (exp_save == ':') ? "true" : "false", use_word);
5525 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5527 exp_word = to_be_freed;
5528 if (exp_op == '?') {
5529 /* mimic bash message */
5530 die_if_script("%s: %s",
5532 exp_word[0] ? exp_word : "parameter null or not set"
5534 //TODO: how interactive bash aborts expansion mid-command?
5539 if (exp_op == '=') {
5540 /* ${var=[word]} or ${var:=[word]} */
5541 if (isdigit(var[0]) || var[0] == '#') {
5542 /* mimic bash message */
5543 die_if_script("$%s: cannot assign in this way", var);
5546 char *new_var = xasprintf("%s=%s", var, val);
5547 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5551 } /* one of "-=+?" */
5553 *exp_saveptr = exp_save;
5559 *to_be_freed_pp = to_be_freed;
5563 /* Expand all variable references in given string, adding words to list[]
5564 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5565 * to be filled). This routine is extremely tricky: has to deal with
5566 * variables/parameters with whitespace, $* and $@, and constructs like
5567 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5568 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5570 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5571 * expansion of right-hand side of assignment == 1-element expand.
5573 char cant_be_null = 0; /* only bit 0x80 matters */
5574 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5577 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5578 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5579 debug_print_list("expand_vars_to_list", output, n);
5580 n = o_save_ptr(output, n);
5581 debug_print_list("expand_vars_to_list[0]", output, n);
5583 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5585 char *to_be_freed = NULL;
5586 const char *val = NULL;
5587 #if ENABLE_HUSH_TICK
5588 o_string subst_result = NULL_O_STRING;
5590 #if ENABLE_SH_MATH_SUPPORT
5591 char arith_buf[sizeof(arith_t)*3 + 2];
5595 o_addchr(output, '\0');
5596 n = o_save_ptr(output, n);
5600 o_addblock(output, arg, p - arg);
5601 debug_print_list("expand_vars_to_list[1]", output, n);
5603 p = strchr(p, SPECIAL_VAR_SYMBOL);
5605 /* Fetch special var name (if it is indeed one of them)
5606 * and quote bit, force the bit on if singleword expansion -
5607 * important for not getting v=$@ expand to many words. */
5608 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5610 /* Is this variable quoted and thus expansion can't be null?
5611 * "$@" is special. Even if quoted, it can still
5612 * expand to nothing (not even an empty string),
5613 * thus it is excluded. */
5614 if ((first_ch & 0x7f) != '@')
5615 cant_be_null |= first_ch;
5617 switch (first_ch & 0x7f) {
5618 /* Highest bit in first_ch indicates that var is double-quoted */
5622 if (!G.global_argv[1])
5625 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5626 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5627 while (G.global_argv[i]) {
5628 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5629 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5630 if (G.global_argv[i++][0] && G.global_argv[i]) {
5631 /* this argv[] is not empty and not last:
5632 * put terminating NUL, start new word */
5633 o_addchr(output, '\0');
5634 debug_print_list("expand_vars_to_list[2]", output, n);
5635 n = o_save_ptr(output, n);
5636 debug_print_list("expand_vars_to_list[3]", output, n);
5640 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5641 * and in this case should treat it like '$*' - see 'else...' below */
5642 if (first_ch == ('@'|0x80) /* quoted $@ */
5643 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5646 o_addQstr(output, G.global_argv[i]);
5647 if (++i >= G.global_argc)
5649 o_addchr(output, '\0');
5650 debug_print_list("expand_vars_to_list[4]", output, n);
5651 n = o_save_ptr(output, n);
5653 } else { /* quoted $* (or v="$@" case): add as one word */
5655 o_addQstr(output, G.global_argv[i]);
5656 if (!G.global_argv[++i])
5659 o_addchr(output, G.ifs[0]);
5661 output->has_quoted_part = 1;
5665 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5666 /* "Empty variable", used to make "" etc to not disappear */
5667 output->has_quoted_part = 1;
5669 cant_be_null = 0x80;
5671 #if ENABLE_HUSH_TICK
5672 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5673 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5675 /* Can't just stuff it into output o_string,
5676 * expanded result may need to be globbed
5677 * and $IFS-splitted */
5678 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5679 G.last_exitcode = process_command_subs(&subst_result, arg);
5680 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5681 val = subst_result.data;
5684 #if ENABLE_SH_MATH_SUPPORT
5685 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5688 arg++; /* skip '+' */
5689 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5690 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5691 res = expand_and_evaluate_arith(arg, NULL);
5692 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5693 sprintf(arith_buf, ARITH_FMT, res);
5699 val = expand_one_var(&to_be_freed, arg, &p);
5700 IF_HUSH_TICK(store_val:)
5701 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5702 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5703 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5704 if (val && val[0]) {
5705 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5708 } else { /* quoted $VAR, val will be appended below */
5709 output->has_quoted_part = 1;
5710 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5711 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5714 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5716 if (val && val[0]) {
5717 o_addQstr(output, val);
5721 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5722 * Do the check to avoid writing to a const string. */
5723 if (*p != SPECIAL_VAR_SYMBOL)
5724 *p = SPECIAL_VAR_SYMBOL;
5726 #if ENABLE_HUSH_TICK
5727 o_free(&subst_result);
5730 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5734 o_addchr(output, '\0');
5735 n = o_save_ptr(output, n);
5737 debug_print_list("expand_vars_to_list[a]", output, n);
5738 /* this part is literal, and it was already pre-quoted
5739 * if needed (much earlier), do not use o_addQstr here! */
5740 o_addstr_with_NUL(output, arg);
5741 debug_print_list("expand_vars_to_list[b]", output, n);
5742 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5743 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5746 /* allow to reuse list[n] later without re-growth */
5747 output->has_empty_slot = 1;
5749 o_addchr(output, '\0');
5755 static char **expand_variables(char **argv, unsigned expflags)
5759 o_string output = NULL_O_STRING;
5761 output.o_expflags = expflags;
5765 n = expand_vars_to_list(&output, n, *argv);
5768 debug_print_list("expand_variables", &output, n);
5770 /* output.data (malloced in one block) gets returned in "list" */
5771 list = o_finalize_list(&output, n);
5772 debug_print_strings("expand_variables[1]", list);
5776 static char **expand_strvec_to_strvec(char **argv)
5778 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5781 #if ENABLE_HUSH_BASH_COMPAT
5782 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5784 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5788 /* Used for expansion of right hand of assignments,
5789 * $((...)), heredocs, variable espansion parts.
5791 * NB: should NOT do globbing!
5792 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5794 static char *expand_string_to_string(const char *str, int do_unbackslash)
5796 #if !ENABLE_HUSH_BASH_COMPAT
5797 const int do_unbackslash = 1;
5799 char *argv[2], **list;
5801 debug_printf_expand("string_to_string<='%s'\n", str);
5802 /* This is generally an optimization, but it also
5803 * handles "", which otherwise trips over !list[0] check below.
5804 * (is this ever happens that we actually get str="" here?)
5806 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5807 //TODO: Can use on strings with \ too, just unbackslash() them?
5808 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5809 return xstrdup(str);
5812 argv[0] = (char*)str;
5814 list = expand_variables(argv, do_unbackslash
5815 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5816 : EXP_FLAG_SINGLEWORD
5819 if (!list[0] || list[1])
5820 bb_error_msg_and_die("BUG in varexp2");
5821 /* actually, just move string 2*sizeof(char*) bytes back */
5822 overlapping_strcpy((char*)list, list[0]);
5824 unbackslash((char*)list);
5825 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5829 /* Used for "eval" builtin */
5830 static char* expand_strvec_to_string(char **argv)
5834 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5835 /* Convert all NULs to spaces */
5840 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5841 bb_error_msg_and_die("BUG in varexp3");
5842 /* bash uses ' ' regardless of $IFS contents */
5847 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5848 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5852 static char **expand_assignments(char **argv, int count)
5857 G.expanded_assignments = p = NULL;
5858 /* Expand assignments into one string each */
5859 for (i = 0; i < count; i++) {
5860 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5862 G.expanded_assignments = NULL;
5867 static void switch_off_special_sigs(unsigned mask)
5870 while ((mask >>= 1) != 0) {
5875 if (G.traps[sig] && !G.traps[sig][0])
5876 /* trap is '', has to remain SIG_IGN */
5879 G.traps[sig] = NULL;
5881 /* We are here only if no trap or trap was not '' */
5882 install_sighandler(sig, SIG_DFL);
5888 void re_execute_shell(char ***to_free, const char *s,
5889 char *g_argv0, char **g_argv,
5890 char **builtin_argv) NORETURN;
5892 static void reset_traps_to_defaults(void)
5894 /* This function is always called in a child shell
5895 * after fork (not vfork, NOMMU doesn't use this function).
5900 /* Child shells are not interactive.
5901 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5902 * Testcase: (while :; do :; done) + ^Z should background.
5903 * Same goes for SIGTERM, SIGHUP, SIGINT.
5905 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5906 if (!G.traps && !mask)
5907 return; /* already no traps and no special sigs */
5909 /* Switch off special sigs */
5910 switch_off_special_sigs(mask);
5912 G_fatal_sig_mask = 0;
5914 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5915 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5916 * remain set in G.special_sig_mask */
5921 /* Reset all sigs to default except ones with empty traps */
5922 for (sig = 0; sig < NSIG; sig++) {
5924 continue; /* no trap: nothing to do */
5925 if (!G.traps[sig][0])
5926 continue; /* empty trap: has to remain SIG_IGN */
5927 /* sig has non-empty trap, reset it: */
5929 G.traps[sig] = NULL;
5930 /* There is no signal for trap 0 (EXIT) */
5933 install_sighandler(sig, pick_sighandler(sig));
5939 static void re_execute_shell(char ***to_free, const char *s,
5940 char *g_argv0, char **g_argv,
5941 char **builtin_argv) NORETURN;
5942 static void re_execute_shell(char ***to_free, const char *s,
5943 char *g_argv0, char **g_argv,
5944 char **builtin_argv)
5946 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5947 /* delims + 2 * (number of bytes in printed hex numbers) */
5948 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5949 char *heredoc_argv[4];
5950 struct variable *cur;
5951 # if ENABLE_HUSH_FUNCTIONS
5952 struct function *funcp;
5956 unsigned long long empty_trap_mask;
5958 if (!g_argv0) { /* heredoc */
5959 argv = heredoc_argv;
5960 argv[0] = (char *) G.argv0_for_re_execing;
5961 argv[1] = (char *) "-<";
5962 argv[2] = (char *) s;
5964 pp = &argv[3]; /* used as pointer to empty environment */
5970 if (pp) while (*pp++)
5973 empty_trap_mask = 0;
5976 for (sig = 1; sig < NSIG; sig++) {
5977 if (G.traps[sig] && !G.traps[sig][0])
5978 empty_trap_mask |= 1LL << sig;
5982 sprintf(param_buf, NOMMU_HACK_FMT
5983 , (unsigned) G.root_pid
5984 , (unsigned) G.root_ppid
5985 , (unsigned) G.last_bg_pid
5986 , (unsigned) G.last_exitcode
5989 IF_HUSH_LOOPS(, G.depth_of_loop)
5991 # undef NOMMU_HACK_FMT
5992 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5993 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5996 for (cur = G.top_var; cur; cur = cur->next) {
5997 if (!cur->flg_export || cur->flg_read_only)
6000 # if ENABLE_HUSH_FUNCTIONS
6001 for (funcp = G.top_func; funcp; funcp = funcp->next)
6007 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6008 *pp++ = (char *) G.argv0_for_re_execing;
6010 for (cur = G.top_var; cur; cur = cur->next) {
6011 if (strcmp(cur->varstr, hush_version_str) == 0)
6013 if (cur->flg_read_only) {
6014 *pp++ = (char *) "-R";
6015 *pp++ = cur->varstr;
6016 } else if (!cur->flg_export) {
6017 *pp++ = (char *) "-V";
6018 *pp++ = cur->varstr;
6021 # if ENABLE_HUSH_FUNCTIONS
6022 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6023 *pp++ = (char *) "-F";
6024 *pp++ = funcp->name;
6025 *pp++ = funcp->body_as_string;
6028 /* We can pass activated traps here. Say, -Tnn:trap_string
6030 * However, POSIX says that subshells reset signals with traps
6032 * I tested bash-3.2 and it not only does that with true subshells
6033 * of the form ( list ), but with any forked children shells.
6034 * I set trap "echo W" WINCH; and then tried:
6036 * { echo 1; sleep 20; echo 2; } &
6037 * while true; do echo 1; sleep 20; echo 2; break; done &
6038 * true | { echo 1; sleep 20; echo 2; } | cat
6040 * In all these cases sending SIGWINCH to the child shell
6041 * did not run the trap. If I add trap "echo V" WINCH;
6042 * _inside_ group (just before echo 1), it works.
6044 * I conclude it means we don't need to pass active traps here.
6046 *pp++ = (char *) "-c";
6049 while (*++builtin_argv)
6050 *pp++ = *builtin_argv;
6051 *pp++ = (char *) "";
6056 /* *pp = NULL; - is already there */
6060 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6061 /* Don't propagate SIG_IGN to the child */
6062 if (SPECIAL_JOBSTOP_SIGS != 0)
6063 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6064 execve(bb_busybox_exec_path, argv, pp);
6065 /* Fallback. Useful for init=/bin/hush usage etc */
6066 if (argv[0][0] == '/')
6067 execve(argv[0], argv, pp);
6068 xfunc_error_retval = 127;
6069 bb_error_msg_and_die("can't re-execute the shell");
6071 #endif /* !BB_MMU */
6074 static int run_and_free_list(struct pipe *pi);
6076 /* Executing from string: eval, sh -c '...'
6077 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6078 * end_trigger controls how often we stop parsing
6079 * NUL: parse all, execute, return
6080 * ';': parse till ';' or newline, execute, repeat till EOF
6082 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6084 /* Why we need empty flag?
6085 * An obscure corner case "false; ``; echo $?":
6086 * empty command in `` should still set $? to 0.
6087 * But we can't just set $? to 0 at the start,
6088 * this breaks "false; echo `echo $?`" case.
6092 struct pipe *pipe_list;
6094 #if ENABLE_HUSH_INTERACTIVE
6095 if (end_trigger == ';')
6096 inp->promptmode = 0; /* PS1 */
6098 pipe_list = parse_stream(NULL, inp, end_trigger);
6099 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6100 /* If we are in "big" script
6101 * (not in `cmd` or something similar)...
6103 if (pipe_list == ERR_PTR && end_trigger == ';') {
6104 /* Discard cached input (rest of line) */
6105 int ch = inp->last_char;
6106 while (ch != EOF && ch != '\n') {
6107 //bb_error_msg("Discarded:'%c'", ch);
6112 /* This stream isn't empty */
6116 if (!pipe_list && empty)
6117 G.last_exitcode = 0;
6120 debug_print_tree(pipe_list, 0);
6121 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6122 run_and_free_list(pipe_list);
6124 if (G_flag_return_in_progress == 1)
6129 static void parse_and_run_string(const char *s)
6131 struct in_str input;
6132 setup_string_in_str(&input, s);
6133 parse_and_run_stream(&input, '\0');
6136 static void parse_and_run_file(FILE *f)
6138 struct in_str input;
6139 setup_file_in_str(&input, f);
6140 parse_and_run_stream(&input, ';');
6143 #if ENABLE_HUSH_TICK
6144 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6149 char **to_free = NULL;
6153 pid = BB_MMU ? xfork() : xvfork();
6154 if (pid == 0) { /* child */
6155 disable_restore_tty_pgrp_on_exit();
6156 /* Process substitution is not considered to be usual
6157 * 'command execution'.
6158 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6165 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6166 close(channel[0]); /* NB: close _first_, then move fd! */
6167 xmove_fd(channel[1], 1);
6168 /* Prevent it from trying to handle ctrl-z etc */
6169 IF_HUSH_JOB(G.run_list_level = 1;)
6170 /* Awful hack for `trap` or $(trap).
6172 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6173 * contains an example where "trap" is executed in a subshell:
6175 * save_traps=$(trap)
6177 * eval "$save_traps"
6179 * Standard does not say that "trap" in subshell shall print
6180 * parent shell's traps. It only says that its output
6181 * must have suitable form, but then, in the above example
6182 * (which is not supposed to be normative), it implies that.
6184 * bash (and probably other shell) does implement it
6185 * (traps are reset to defaults, but "trap" still shows them),
6186 * but as a result, "trap" logic is hopelessly messed up:
6189 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6190 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6191 * # true | trap <--- trap is in subshell - no output (ditto)
6192 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6193 * trap -- 'echo Ho' SIGWINCH
6194 * # echo `(trap)` <--- in subshell in subshell - output
6195 * trap -- 'echo Ho' SIGWINCH
6196 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6197 * trap -- 'echo Ho' SIGWINCH
6199 * The rules when to forget and when to not forget traps
6200 * get really complex and nonsensical.
6202 * Our solution: ONLY bare $(trap) or `trap` is special.
6204 s = skip_whitespace(s);
6205 if (is_prefixed_with(s, "trap")
6206 && skip_whitespace(s + 4)[0] == '\0'
6208 static const char *const argv[] = { NULL, NULL };
6209 builtin_trap((char**)argv);
6210 fflush_all(); /* important */
6214 reset_traps_to_defaults();
6215 parse_and_run_string(s);
6216 _exit(G.last_exitcode);
6218 /* We re-execute after vfork on NOMMU. This makes this script safe:
6219 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6220 * huge=`cat BIG` # was blocking here forever
6223 re_execute_shell(&to_free,
6233 # if ENABLE_HUSH_FAST
6235 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6236 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6237 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6239 enable_restore_tty_pgrp_on_exit();
6244 return remember_FILE(xfdopen_for_read(channel[0]));
6247 /* Return code is exit status of the process that is run. */
6248 static int process_command_subs(o_string *dest, const char *s)
6251 struct in_str pipe_str;
6253 int status, ch, eol_cnt;
6255 fp = generate_stream_from_string(s, &pid);
6257 /* Now send results of command back into original context */
6258 setup_file_in_str(&pipe_str, fp);
6260 while ((ch = i_getch(&pipe_str)) != EOF) {
6266 o_addchr(dest, '\n');
6269 o_addQchr(dest, ch);
6272 debug_printf("done reading from `cmd` pipe, closing it\n");
6273 fclose_and_forget(fp);
6274 /* We need to extract exitcode. Test case
6275 * "true; echo `sleep 1; false` $?"
6277 safe_waitpid(pid, &status, 0);
6278 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6279 return WEXITSTATUS(status);
6281 #endif /* ENABLE_HUSH_TICK */
6284 static void setup_heredoc(struct redir_struct *redir)
6286 struct fd_pair pair;
6289 /* the _body_ of heredoc (misleading field name) */
6290 const char *heredoc = redir->rd_filename;
6297 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6298 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6302 len = strlen(heredoc);
6304 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6306 xmove_fd(pair.rd, redir->rd_fd);
6308 /* Try writing without forking. Newer kernels have
6309 * dynamically growing pipes. Must use non-blocking write! */
6312 written = write(pair.wr, heredoc, len);
6323 ndelay_off(pair.wr);
6325 /* Okay, pipe buffer was not big enough */
6326 /* Note: we must not create a stray child (bastard? :)
6327 * for the unsuspecting parent process. Child creates a grandchild
6328 * and exits before parent execs the process which consumes heredoc
6329 * (that exec happens after we return from this function) */
6336 disable_restore_tty_pgrp_on_exit();
6337 pid = BB_MMU ? xfork() : xvfork();
6341 close(redir->rd_fd); /* read side of the pipe */
6343 full_write(pair.wr, heredoc, len); /* may loop or block */
6346 /* Delegate blocking writes to another process */
6347 xmove_fd(pair.wr, STDOUT_FILENO);
6348 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6352 #if ENABLE_HUSH_FAST
6354 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6356 enable_restore_tty_pgrp_on_exit();
6362 wait(NULL); /* wait till child has died */
6365 /* fd: redirect wants this fd to be used (e.g. 3>file).
6366 * Move all conflicting internally used fds,
6367 * and remember them so that we can restore them later.
6369 static int save_fds_on_redirect(int fd, int squirrel[3])
6372 /* Handle redirects of fds 0,1,2 */
6374 /* If we collide with an already moved stdio fd... */
6375 if (fd == squirrel[0]) {
6376 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6379 if (fd == squirrel[1]) {
6380 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6383 if (fd == squirrel[2]) {
6384 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6387 /* If we are about to redirect stdio fd, and did not yet move it... */
6388 if (fd <= 2 && squirrel[fd] < 0) {
6389 /* We avoid taking stdio fds */
6390 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6391 if (squirrel[fd] < 0 && errno != EBADF)
6393 return 0; /* "we did not close fd" */
6397 #if ENABLE_HUSH_INTERACTIVE
6398 if (fd != 0 && fd == G.interactive_fd) {
6399 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6404 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6405 * (1) Redirect in a forked child. No need to save FILEs' fds,
6406 * we aren't going to use them anymore, ok to trash.
6407 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6408 * but how are we doing to use them?
6409 * "fileno(fd) = new_fd" can't be done.
6414 return save_FILEs_on_redirect(fd);
6417 static void restore_redirects(int squirrel[3])
6420 for (i = 0; i <= 2; i++) {
6423 /* We simply die on error */
6428 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6430 restore_redirected_FILEs();
6433 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6434 * and stderr if they are redirected. */
6435 static int setup_redirects(struct command *prog, int squirrel[])
6438 struct redir_struct *redir;
6440 for (redir = prog->redirects; redir; redir = redir->next) {
6441 if (redir->rd_type == REDIRECT_HEREDOC2) {
6442 /* "rd_fd<<HERE" case */
6443 save_fds_on_redirect(redir->rd_fd, squirrel);
6444 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6446 debug_printf_parse("set heredoc '%s'\n",
6447 redir->rd_filename);
6448 setup_heredoc(redir);
6452 if (redir->rd_dup == REDIRFD_TO_FILE) {
6453 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6455 if (redir->rd_filename == NULL) {
6458 * "cmd >" (no filename)
6459 * "cmd > <file" (2nd redirect starts too early)
6461 die_if_script("syntax error: %s", "invalid redirect");
6464 mode = redir_table[redir->rd_type].mode;
6465 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6466 openfd = open_or_warn(p, mode);
6469 /* Error message from open_or_warn can be lost
6470 * if stderr has been redirected, but bash
6471 * and ash both lose it as well
6472 * (though zsh doesn't!)
6477 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6478 openfd = redir->rd_dup;
6481 if (openfd != redir->rd_fd) {
6482 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6483 if (openfd == REDIRFD_CLOSE) {
6484 /* "rd_fd >&-" means "close me" */
6486 /* ^^^ optimization: saving may already
6487 * have closed it. If not... */
6488 close(redir->rd_fd);
6491 xdup2(openfd, redir->rd_fd);
6492 if (redir->rd_dup == REDIRFD_TO_FILE)
6493 /* "rd_fd > FILE" */
6495 /* else: "rd_fd > rd_dup" */
6502 static char *find_in_path(const char *arg)
6505 const char *PATH = get_local_var_value("PATH");
6511 const char *end = strchrnul(PATH, ':');
6512 int sz = end - PATH; /* must be int! */
6516 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6518 /* We have xxx::yyyy in $PATH,
6519 * it means "use current dir" */
6522 if (access(ret, F_OK) == 0)
6535 static const struct built_in_command *find_builtin_helper(const char *name,
6536 const struct built_in_command *x,
6537 const struct built_in_command *end)
6540 if (strcmp(name, x->b_cmd) != 0) {
6544 debug_printf_exec("found builtin '%s'\n", name);
6549 static const struct built_in_command *find_builtin1(const char *name)
6551 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6553 static const struct built_in_command *find_builtin(const char *name)
6555 const struct built_in_command *x = find_builtin1(name);
6558 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6561 #if ENABLE_HUSH_FUNCTIONS
6562 static struct function **find_function_slot(const char *name)
6564 struct function **funcpp = &G.top_func;
6566 if (strcmp(name, (*funcpp)->name) == 0) {
6569 funcpp = &(*funcpp)->next;
6574 static const struct function *find_function(const char *name)
6576 const struct function *funcp = *find_function_slot(name);
6578 debug_printf_exec("found function '%s'\n", name);
6582 /* Note: takes ownership on name ptr */
6583 static struct function *new_function(char *name)
6585 struct function **funcpp = find_function_slot(name);
6586 struct function *funcp = *funcpp;
6588 if (funcp != NULL) {
6589 struct command *cmd = funcp->parent_cmd;
6590 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6592 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6594 /* Note: if !funcp->body, do not free body_as_string!
6595 * This is a special case of "-F name body" function:
6596 * body_as_string was not malloced! */
6598 free_pipe_list(funcp->body);
6600 free(funcp->body_as_string);
6604 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6605 cmd->argv[0] = funcp->name;
6606 cmd->group = funcp->body;
6608 cmd->group_as_string = funcp->body_as_string;
6612 debug_printf_exec("remembering new function '%s'\n", name);
6613 funcp = *funcpp = xzalloc(sizeof(*funcp));
6614 /*funcp->next = NULL;*/
6621 static void unset_func(const char *name)
6623 struct function **funcpp = find_function_slot(name);
6624 struct function *funcp = *funcpp;
6626 if (funcp != NULL) {
6627 debug_printf_exec("freeing function '%s'\n", funcp->name);
6628 *funcpp = funcp->next;
6629 /* funcp is unlinked now, deleting it.
6630 * Note: if !funcp->body, the function was created by
6631 * "-F name body", do not free ->body_as_string
6632 * and ->name as they were not malloced. */
6634 free_pipe_list(funcp->body);
6637 free(funcp->body_as_string);
6645 #define exec_function(to_free, funcp, argv) \
6646 exec_function(funcp, argv)
6648 static void exec_function(char ***to_free,
6649 const struct function *funcp,
6650 char **argv) NORETURN;
6651 static void exec_function(char ***to_free,
6652 const struct function *funcp,
6658 argv[0] = G.global_argv[0];
6659 G.global_argv = argv;
6663 /* On MMU, funcp->body is always non-NULL */
6664 n = run_list(funcp->body);
6668 re_execute_shell(to_free,
6669 funcp->body_as_string,
6676 static int run_function(const struct function *funcp, char **argv)
6682 save_and_replace_G_args(&sv, argv);
6684 /* "we are in function, ok to use return" */
6685 sv_flg = G_flag_return_in_progress;
6686 G_flag_return_in_progress = -1;
6687 # if ENABLE_HUSH_LOCAL
6688 G.func_nest_level++;
6691 /* On MMU, funcp->body is always non-NULL */
6694 /* Function defined by -F */
6695 parse_and_run_string(funcp->body_as_string);
6696 rc = G.last_exitcode;
6700 rc = run_list(funcp->body);
6703 # if ENABLE_HUSH_LOCAL
6705 struct variable *var;
6706 struct variable **var_pp;
6708 var_pp = &G.top_var;
6709 while ((var = *var_pp) != NULL) {
6710 if (var->func_nest_level < G.func_nest_level) {
6711 var_pp = &var->next;
6715 if (var->flg_export)
6716 bb_unsetenv(var->varstr);
6717 /* Remove from global list */
6718 *var_pp = var->next;
6724 G.func_nest_level--;
6727 G_flag_return_in_progress = sv_flg;
6729 restore_G_args(&sv, argv);
6733 #endif /* ENABLE_HUSH_FUNCTIONS */
6737 #define exec_builtin(to_free, x, argv) \
6738 exec_builtin(x, argv)
6740 #define exec_builtin(to_free, x, argv) \
6741 exec_builtin(to_free, argv)
6743 static void exec_builtin(char ***to_free,
6744 const struct built_in_command *x,
6745 char **argv) NORETURN;
6746 static void exec_builtin(char ***to_free,
6747 const struct built_in_command *x,
6753 rcode = x->b_function(argv);
6758 /* On NOMMU, we must never block!
6759 * Example: { sleep 99 | read line; } & echo Ok
6761 re_execute_shell(to_free,
6770 static void execvp_or_die(char **argv) NORETURN;
6771 static void execvp_or_die(char **argv)
6774 debug_printf_exec("execing '%s'\n", argv[0]);
6775 /* Don't propagate SIG_IGN to the child */
6776 if (SPECIAL_JOBSTOP_SIGS != 0)
6777 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6778 execvp(argv[0], argv);
6780 if (errno == EACCES) e = 126;
6781 if (errno == ENOENT) e = 127;
6782 bb_perror_msg("can't execute '%s'", argv[0]);
6786 #if ENABLE_HUSH_MODE_X
6787 static void dump_cmd_in_x_mode(char **argv)
6789 if (G_x_mode && argv) {
6790 /* We want to output the line in one write op */
6798 len += strlen(argv[n++]) + 1;
6804 p += sprintf(p, " %s", argv[n++]);
6812 # define dump_cmd_in_x_mode(argv) ((void)0)
6816 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6817 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6818 #define pseudo_exec(nommu_save, command, argv_expanded) \
6819 pseudo_exec(command, argv_expanded)
6822 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6824 * Don't exit() here. If you don't exec, use _exit instead.
6825 * The at_exit handlers apparently confuse the calling process,
6826 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6828 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6829 char **argv, int assignment_cnt,
6830 char **argv_expanded) NORETURN;
6831 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6832 char **argv, int assignment_cnt,
6833 char **argv_expanded)
6837 new_env = expand_assignments(argv, assignment_cnt);
6838 dump_cmd_in_x_mode(new_env);
6840 if (!argv[assignment_cnt]) {
6841 /* Case when we are here: ... | var=val | ...
6842 * (note that we do not exit early, i.e., do not optimize out
6843 * expand_assignments(): think about ... | var=`sleep 1` | ...
6845 free_strings(new_env);
6846 _exit(EXIT_SUCCESS);
6850 set_vars_and_save_old(new_env);
6851 free(new_env); /* optional */
6852 /* we can also destroy set_vars_and_save_old's return value,
6855 nommu_save->new_env = new_env;
6856 nommu_save->old_vars = set_vars_and_save_old(new_env);
6859 if (argv_expanded) {
6860 argv = argv_expanded;
6862 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6864 nommu_save->argv = argv;
6867 dump_cmd_in_x_mode(argv);
6869 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6870 if (strchr(argv[0], '/') != NULL)
6874 /* Check if the command matches any of the builtins.
6875 * Depending on context, this might be redundant. But it's
6876 * easier to waste a few CPU cycles than it is to figure out
6877 * if this is one of those cases.
6880 /* On NOMMU, it is more expensive to re-execute shell
6881 * just in order to run echo or test builtin.
6882 * It's better to skip it here and run corresponding
6883 * non-builtin later. */
6884 const struct built_in_command *x;
6885 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6887 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6890 #if ENABLE_HUSH_FUNCTIONS
6891 /* Check if the command matches any functions */
6893 const struct function *funcp = find_function(argv[0]);
6895 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6900 #if ENABLE_FEATURE_SH_STANDALONE
6901 /* Check if the command matches any busybox applets */
6903 int a = find_applet_by_name(argv[0]);
6905 # if BB_MMU /* see above why on NOMMU it is not allowed */
6906 if (APPLET_IS_NOEXEC(a)) {
6907 /* Do not leak open fds from opened script files etc */
6908 close_all_FILE_list();
6909 debug_printf_exec("running applet '%s'\n", argv[0]);
6910 run_applet_no_and_exit(a, argv);
6913 /* Re-exec ourselves */
6914 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6915 /* Don't propagate SIG_IGN to the child */
6916 if (SPECIAL_JOBSTOP_SIGS != 0)
6917 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6918 execv(bb_busybox_exec_path, argv);
6919 /* If they called chroot or otherwise made the binary no longer
6920 * executable, fall through */
6925 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6928 execvp_or_die(argv);
6931 /* Called after [v]fork() in run_pipe
6933 static void pseudo_exec(nommu_save_t *nommu_save,
6934 struct command *command,
6935 char **argv_expanded) NORETURN;
6936 static void pseudo_exec(nommu_save_t *nommu_save,
6937 struct command *command,
6938 char **argv_expanded)
6940 if (command->argv) {
6941 pseudo_exec_argv(nommu_save, command->argv,
6942 command->assignment_cnt, argv_expanded);
6945 if (command->group) {
6946 /* Cases when we are here:
6949 * ... | ( list ) | ...
6950 * ... | { list } | ...
6954 debug_printf_exec("pseudo_exec: run_list\n");
6955 reset_traps_to_defaults();
6956 rcode = run_list(command->group);
6957 /* OK to leak memory by not calling free_pipe_list,
6958 * since this process is about to exit */
6961 re_execute_shell(&nommu_save->argv_from_re_execing,
6962 command->group_as_string,
6969 /* Case when we are here: ... | >file */
6970 debug_printf_exec("pseudo_exec'ed null command\n");
6971 _exit(EXIT_SUCCESS);
6975 static const char *get_cmdtext(struct pipe *pi)
6981 /* This is subtle. ->cmdtext is created only on first backgrounding.
6982 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6983 * On subsequent bg argv is trashed, but we won't use it */
6987 argv = pi->cmds[0].argv;
6989 pi->cmdtext = xzalloc(1);
6994 len += strlen(*argv) + 1;
6998 argv = pi->cmds[0].argv;
7000 p = stpcpy(p, *argv);
7007 static void insert_bg_job(struct pipe *pi)
7009 struct pipe *job, **jobp;
7012 /* Linear search for the ID of the job to use */
7014 for (job = G.job_list; job; job = job->next)
7015 if (job->jobid >= pi->jobid)
7016 pi->jobid = job->jobid + 1;
7018 /* Add job to the list of running jobs */
7020 while ((job = *jobp) != NULL)
7022 job = *jobp = xmalloc(sizeof(*job));
7024 *job = *pi; /* physical copy */
7026 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7027 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7028 for (i = 0; i < pi->num_cmds; i++) {
7029 job->cmds[i].pid = pi->cmds[i].pid;
7030 /* all other fields are not used and stay zero */
7032 job->cmdtext = xstrdup(get_cmdtext(pi));
7034 if (G_interactive_fd)
7035 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7036 G.last_jobid = job->jobid;
7039 static void remove_bg_job(struct pipe *pi)
7041 struct pipe *prev_pipe;
7043 if (pi == G.job_list) {
7044 G.job_list = pi->next;
7046 prev_pipe = G.job_list;
7047 while (prev_pipe->next != pi)
7048 prev_pipe = prev_pipe->next;
7049 prev_pipe->next = pi->next;
7052 G.last_jobid = G.job_list->jobid;
7057 /* Remove a backgrounded job */
7058 static void delete_finished_bg_job(struct pipe *pi)
7065 static int job_exited_or_stopped(struct pipe *pi)
7069 if (pi->alive_cmds != pi->stopped_cmds)
7072 /* All processes in fg pipe have exited or stopped */
7076 rcode = pi->cmds[i].cmd_exitcode;
7077 /* usually last process gives overall exitstatus,
7078 * but with "set -o pipefail", last *failed* process does */
7079 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7082 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7086 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7093 dead = WIFEXITED(status) || WIFSIGNALED(status);
7096 if (WIFSTOPPED(status))
7097 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7098 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7099 if (WIFSIGNALED(status))
7100 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7101 childpid, WTERMSIG(status), WEXITSTATUS(status));
7102 if (WIFEXITED(status))
7103 debug_printf_jobs("pid %d exited, exitcode %d\n",
7104 childpid, WEXITSTATUS(status));
7106 /* Were we asked to wait for a fg pipe? */
7108 i = fg_pipe->num_cmds;
7113 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7114 if (fg_pipe->cmds[i].pid != childpid)
7118 fg_pipe->cmds[i].pid = 0;
7119 fg_pipe->alive_cmds--;
7120 ex = WEXITSTATUS(status);
7121 /* bash prints killer signal's name for *last*
7122 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7123 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7125 if (WIFSIGNALED(status)) {
7126 int sig = WTERMSIG(status);
7127 if (i == fg_pipe->num_cmds-1)
7128 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7129 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7130 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7131 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7132 * Maybe we need to use sig | 128? */
7135 fg_pipe->cmds[i].cmd_exitcode = ex;
7137 fg_pipe->stopped_cmds++;
7139 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7140 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7141 rcode = job_exited_or_stopped(fg_pipe);
7143 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7144 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7145 * and "killall -STOP cat" */
7146 if (G_interactive_fd) {
7148 if (fg_pipe->alive_cmds != 0)
7149 insert_bg_job(fg_pipe);
7153 if (fg_pipe->alive_cmds == 0)
7156 /* There are still running processes in the fg_pipe */
7159 /* It wasnt in fg_pipe, look for process in bg pipes */
7163 /* We were asked to wait for bg or orphaned children */
7164 /* No need to remember exitcode in this case */
7165 for (pi = G.job_list; pi; pi = pi->next) {
7166 for (i = 0; i < pi->num_cmds; i++) {
7167 if (pi->cmds[i].pid == childpid)
7168 goto found_pi_and_prognum;
7171 /* Happens when shell is used as init process (init=/bin/sh) */
7172 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7173 return -1; /* this wasn't a process from fg_pipe */
7175 found_pi_and_prognum:
7178 pi->cmds[i].pid = 0;
7179 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7180 if (WIFSIGNALED(status))
7181 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7183 if (!pi->alive_cmds) {
7184 if (G_interactive_fd)
7185 printf(JOB_STATUS_FORMAT, pi->jobid,
7186 "Done", pi->cmdtext);
7187 delete_finished_bg_job(pi);
7194 return -1; /* this wasn't a process from fg_pipe */
7197 /* Check to see if any processes have exited -- if they have,
7198 * figure out why and see if a job has completed.
7200 * If non-NULL fg_pipe: wait for its completion or stop.
7201 * Return its exitcode or zero if stopped.
7203 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7204 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7205 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7206 * or 0 if no children changed status.
7208 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7209 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7210 * or 0 if no children changed status.
7212 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7218 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7220 attributes = WUNTRACED;
7221 if (fg_pipe == NULL)
7222 attributes |= WNOHANG;
7225 #if ENABLE_HUSH_FAST
7226 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7227 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7228 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7229 /* There was neither fork nor SIGCHLD since last waitpid */
7230 /* Avoid doing waitpid syscall if possible */
7231 if (!G.we_have_children) {
7235 if (fg_pipe == NULL) { /* is WNOHANG set? */
7236 /* We have children, but they did not exit
7237 * or stop yet (we saw no SIGCHLD) */
7240 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7244 /* Do we do this right?
7245 * bash-3.00# sleep 20 | false
7247 * [3]+ Stopped sleep 20 | false
7248 * bash-3.00# echo $?
7249 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7250 * [hush 1.14.0: yes we do it right]
7254 #if ENABLE_HUSH_FAST
7256 i = G.count_SIGCHLD;
7258 childpid = waitpid(-1, &status, attributes);
7259 if (childpid <= 0) {
7260 if (childpid && errno != ECHILD)
7261 bb_perror_msg("waitpid");
7262 #if ENABLE_HUSH_FAST
7263 else { /* Until next SIGCHLD, waitpid's are useless */
7264 G.we_have_children = (childpid == 0);
7265 G.handled_SIGCHLD = i;
7266 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7269 /* ECHILD (no children), or 0 (no change in children status) */
7273 rcode = process_wait_result(fg_pipe, childpid, status);
7275 /* fg_pipe exited or stopped */
7278 if (childpid == waitfor_pid) {
7279 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7280 rcode = WEXITSTATUS(status);
7281 if (WIFSIGNALED(status))
7282 rcode = 128 + WTERMSIG(status);
7283 if (WIFSTOPPED(status))
7284 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7285 rcode = 128 + WSTOPSIG(status);
7287 break; /* "wait PID" called us, give it exitcode+1 */
7289 /* This wasn't one of our processes, or */
7290 /* fg_pipe still has running processes, do waitpid again */
7291 } /* while (waitpid succeeds)... */
7297 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7300 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7301 if (G_saved_tty_pgrp) {
7302 /* Job finished, move the shell to the foreground */
7303 p = getpgrp(); /* our process group id */
7304 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7305 tcsetpgrp(G_interactive_fd, p);
7311 /* Start all the jobs, but don't wait for anything to finish.
7314 * Return code is normally -1, when the caller has to wait for children
7315 * to finish to determine the exit status of the pipe. If the pipe
7316 * is a simple builtin command, however, the action is done by the
7317 * time run_pipe returns, and the exit code is provided as the
7320 * Returns -1 only if started some children. IOW: we have to
7321 * mask out retvals of builtins etc with 0xff!
7323 * The only case when we do not need to [v]fork is when the pipe
7324 * is single, non-backgrounded, non-subshell command. Examples:
7325 * cmd ; ... { list } ; ...
7326 * cmd && ... { list } && ...
7327 * cmd || ... { list } || ...
7328 * If it is, then we can run cmd as a builtin, NOFORK,
7329 * or (if SH_STANDALONE) an applet, and we can run the { list }
7330 * with run_list. If it isn't one of these, we fork and exec cmd.
7332 * Cases when we must fork:
7333 * non-single: cmd | cmd
7334 * backgrounded: cmd & { list } &
7335 * subshell: ( list ) [&]
7337 #if !ENABLE_HUSH_MODE_X
7338 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7339 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7341 static int redirect_and_varexp_helper(char ***new_env_p,
7342 struct variable **old_vars_p,
7343 struct command *command,
7345 char **argv_expanded)
7347 /* setup_redirects acts on file descriptors, not FILEs.
7348 * This is perfect for work that comes after exec().
7349 * Is it really safe for inline use? Experimentally,
7350 * things seem to work. */
7351 int rcode = setup_redirects(command, squirrel);
7353 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7354 *new_env_p = new_env;
7355 dump_cmd_in_x_mode(new_env);
7356 dump_cmd_in_x_mode(argv_expanded);
7358 *old_vars_p = set_vars_and_save_old(new_env);
7362 static NOINLINE int run_pipe(struct pipe *pi)
7364 static const char *const null_ptr = NULL;
7368 struct command *command;
7369 char **argv_expanded;
7371 /* it is not always needed, but we aim to smaller code */
7372 int squirrel[] = { -1, -1, -1 };
7375 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7378 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7379 * Result should be 3 lines: q w e, qwe, q w e
7381 G.ifs = get_local_var_value("IFS");
7385 IF_HUSH_JOB(pi->pgrp = -1;)
7386 pi->stopped_cmds = 0;
7387 command = &pi->cmds[0];
7388 argv_expanded = NULL;
7390 if (pi->num_cmds != 1
7391 || pi->followup == PIPE_BG
7392 || command->cmd_type == CMD_SUBSHELL
7399 debug_printf_exec(": group:%p argv:'%s'\n",
7400 command->group, command->argv ? command->argv[0] : "NONE");
7402 if (command->group) {
7403 #if ENABLE_HUSH_FUNCTIONS
7404 if (command->cmd_type == CMD_FUNCDEF) {
7405 /* "executing" func () { list } */
7406 struct function *funcp;
7408 funcp = new_function(command->argv[0]);
7409 /* funcp->name is already set to argv[0] */
7410 funcp->body = command->group;
7412 funcp->body_as_string = command->group_as_string;
7413 command->group_as_string = NULL;
7415 command->group = NULL;
7416 command->argv[0] = NULL;
7417 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7418 funcp->parent_cmd = command;
7419 command->child_func = funcp;
7421 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7423 return EXIT_SUCCESS;
7427 debug_printf("non-subshell group\n");
7428 rcode = 1; /* exitcode if redir failed */
7429 if (setup_redirects(command, squirrel) == 0) {
7430 debug_printf_exec(": run_list\n");
7431 rcode = run_list(command->group) & 0xff;
7433 restore_redirects(squirrel);
7434 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7436 debug_printf_exec("run_pipe: return %d\n", rcode);
7440 argv = command->argv ? command->argv : (char **) &null_ptr;
7442 const struct built_in_command *x;
7443 #if ENABLE_HUSH_FUNCTIONS
7444 const struct function *funcp;
7448 char **new_env = NULL;
7449 struct variable *old_vars = NULL;
7451 if (argv[command->assignment_cnt] == NULL) {
7452 /* Assignments, but no command */
7453 /* Ensure redirects take effect (that is, create files).
7454 * Try "a=t >file" */
7455 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7456 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7457 /* Set shell variables */
7461 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7462 /* Do we need to flag set_local_var() errors?
7463 * "assignment to readonly var" and "putenv error"
7468 /* Redirect error sets $? to 1. Otherwise,
7469 * if evaluating assignment value set $?, retain it.
7470 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7472 rcode = G.last_exitcode;
7473 /* Exit, _skipping_ variable restoring code: */
7474 goto clean_up_and_ret0;
7476 #else /* Older, bigger, but more correct code */
7478 rcode = setup_redirects(command, squirrel);
7479 restore_redirects(squirrel);
7480 /* Set shell variables */
7482 bb_putchar_stderr('+');
7484 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7486 fprintf(stderr, " %s", p);
7487 debug_printf_exec("set shell var:'%s'->'%s'\n",
7489 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7490 /* Do we need to flag set_local_var() errors?
7491 * "assignment to readonly var" and "putenv error"
7496 bb_putchar_stderr('\n');
7497 /* Redirect error sets $? to 1. Otherwise,
7498 * if evaluating assignment value set $?, retain it.
7499 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7501 rcode = G.last_exitcode;
7502 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7504 debug_printf_exec("run_pipe: return %d\n", rcode);
7509 /* Expand the rest into (possibly) many strings each */
7510 #if ENABLE_HUSH_BASH_COMPAT
7511 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7512 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7516 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7519 /* if someone gives us an empty string: `cmd with empty output` */
7520 if (!argv_expanded[0]) {
7521 free(argv_expanded);
7523 return G.last_exitcode;
7526 x = find_builtin(argv_expanded[0]);
7527 #if ENABLE_HUSH_FUNCTIONS
7530 funcp = find_function(argv_expanded[0]);
7534 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7535 debug_printf("exec with redirects only\n");
7536 rcode = setup_redirects(command, NULL);
7537 /* rcode=1 can be if redir file can't be opened */
7538 goto clean_up_and_ret1;
7541 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7544 debug_printf_exec(": builtin '%s' '%s'...\n",
7545 x->b_cmd, argv_expanded[1]);
7547 rcode = x->b_function(argv_expanded) & 0xff;
7550 #if ENABLE_HUSH_FUNCTIONS
7552 # if ENABLE_HUSH_LOCAL
7553 struct variable **sv;
7554 sv = G.shadowed_vars_pp;
7555 G.shadowed_vars_pp = &old_vars;
7557 debug_printf_exec(": function '%s' '%s'...\n",
7558 funcp->name, argv_expanded[1]);
7559 rcode = run_function(funcp, argv_expanded) & 0xff;
7560 # if ENABLE_HUSH_LOCAL
7561 G.shadowed_vars_pp = sv;
7567 unset_vars(new_env);
7569 /* clean_up_and_ret0: */
7570 restore_redirects(squirrel);
7572 free(argv_expanded);
7573 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7575 debug_printf_exec("run_pipe return %d\n", rcode);
7579 if (ENABLE_FEATURE_SH_NOFORK) {
7580 int n = find_applet_by_name(argv_expanded[0]);
7581 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7582 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7584 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7585 argv_expanded[0], argv_expanded[1]);
7586 rcode = run_nofork_applet(n, argv_expanded);
7588 goto clean_up_and_ret;
7591 /* It is neither builtin nor applet. We must fork. */
7595 /* NB: argv_expanded may already be created, and that
7596 * might include `cmd` runs! Do not rerun it! We *must*
7597 * use argv_expanded if it's non-NULL */
7599 /* Going to fork a child per each pipe member */
7604 while (cmd_no < pi->num_cmds) {
7605 struct fd_pair pipefds;
7607 volatile nommu_save_t nommu_save;
7608 nommu_save.new_env = NULL;
7609 nommu_save.old_vars = NULL;
7610 nommu_save.argv = NULL;
7611 nommu_save.argv_from_re_execing = NULL;
7613 command = &pi->cmds[cmd_no];
7615 if (command->argv) {
7616 debug_printf_exec(": pipe member '%s' '%s'...\n",
7617 command->argv[0], command->argv[1]);
7619 debug_printf_exec(": pipe member with no argv\n");
7622 /* pipes are inserted between pairs of commands */
7625 if (cmd_no < pi->num_cmds)
7626 xpiped_pair(pipefds);
7628 command->pid = BB_MMU ? fork() : vfork();
7629 if (!command->pid) { /* child */
7631 disable_restore_tty_pgrp_on_exit();
7632 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7634 /* Every child adds itself to new process group
7635 * with pgid == pid_of_first_child_in_pipe */
7636 if (G.run_list_level == 1 && G_interactive_fd) {
7639 if (pgrp < 0) /* true for 1st process only */
7641 if (setpgid(0, pgrp) == 0
7642 && pi->followup != PIPE_BG
7643 && G_saved_tty_pgrp /* we have ctty */
7645 /* We do it in *every* child, not just first,
7647 tcsetpgrp(G_interactive_fd, pgrp);
7651 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7652 /* 1st cmd in backgrounded pipe
7653 * should have its stdin /dev/null'ed */
7655 if (open(bb_dev_null, O_RDONLY))
7656 xopen("/", O_RDONLY);
7658 xmove_fd(next_infd, 0);
7660 xmove_fd(pipefds.wr, 1);
7663 /* Like bash, explicit redirects override pipes,
7664 * and the pipe fd (fd#1) is available for dup'ing:
7665 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7666 * of cmd1 goes into pipe.
7668 if (setup_redirects(command, NULL)) {
7669 /* Happens when redir file can't be opened:
7670 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7672 * hush: can't open '/qwe/rty': No such file or directory
7674 * (echo BAR is not executed, it hits _exit(1) below)
7679 /* Stores to nommu_save list of env vars putenv'ed
7680 * (NOMMU, on MMU we don't need that) */
7681 /* cast away volatility... */
7682 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7683 /* pseudo_exec() does not return */
7686 /* parent or error */
7687 #if ENABLE_HUSH_FAST
7689 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7691 enable_restore_tty_pgrp_on_exit();
7693 /* Clean up after vforked child */
7694 free(nommu_save.argv);
7695 free(nommu_save.argv_from_re_execing);
7696 unset_vars(nommu_save.new_env);
7697 add_vars(nommu_save.old_vars);
7699 free(argv_expanded);
7700 argv_expanded = NULL;
7701 if (command->pid < 0) { /* [v]fork failed */
7702 /* Clearly indicate, was it fork or vfork */
7703 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7707 /* Second and next children need to know pid of first one */
7709 pi->pgrp = command->pid;
7715 if (cmd_no < pi->num_cmds)
7717 /* Pass read (output) pipe end to next iteration */
7718 next_infd = pipefds.rd;
7721 if (!pi->alive_cmds) {
7723 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7728 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7732 /* NB: called by pseudo_exec, and therefore must not modify any
7733 * global data until exec/_exit (we can be a child after vfork!) */
7734 static int run_list(struct pipe *pi)
7736 #if ENABLE_HUSH_CASE
7737 char *case_word = NULL;
7739 #if ENABLE_HUSH_LOOPS
7740 struct pipe *loop_top = NULL;
7741 char **for_lcur = NULL;
7742 char **for_list = NULL;
7744 smallint last_followup;
7746 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7747 smalluint cond_code = 0;
7749 enum { cond_code = 0 };
7752 smallint rword; /* RES_foo */
7753 smallint last_rword; /* ditto */
7756 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7759 #if ENABLE_HUSH_LOOPS
7760 /* Check syntax for "for" */
7763 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7764 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7766 /* current word is FOR or IN (BOLD in comments below) */
7767 if (cpipe->next == NULL) {
7768 syntax_error("malformed for");
7770 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7773 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7774 if (cpipe->next->res_word == RES_DO)
7776 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7777 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7778 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7780 syntax_error("malformed for");
7782 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7789 /* Past this point, all code paths should jump to ret: label
7790 * in order to return, no direct "return" statements please.
7791 * This helps to ensure that no memory is leaked. */
7799 last_rword = RES_XXXX;
7801 last_followup = PIPE_SEQ;
7802 rcode = G.last_exitcode;
7804 /* Go through list of pipes, (maybe) executing them. */
7805 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7810 if (G_flag_return_in_progress == 1)
7813 IF_HAS_KEYWORDS(rword = pi->res_word;)
7814 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7815 rword, cond_code, last_rword);
7816 #if ENABLE_HUSH_LOOPS
7817 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7818 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7820 /* start of a loop: remember where loop starts */
7825 /* Still in the same "if...", "then..." or "do..." branch? */
7826 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7827 if ((rcode == 0 && last_followup == PIPE_OR)
7828 || (rcode != 0 && last_followup == PIPE_AND)
7830 /* It is "<true> || CMD" or "<false> && CMD"
7831 * and we should not execute CMD */
7832 debug_printf_exec("skipped cmd because of || or &&\n");
7833 last_followup = pi->followup;
7834 goto dont_check_jobs_but_continue;
7837 last_followup = pi->followup;
7838 IF_HAS_KEYWORDS(last_rword = rword;)
7841 if (rword == RES_THEN) {
7842 /* if false; then ... fi has exitcode 0! */
7843 G.last_exitcode = rcode = EXIT_SUCCESS;
7844 /* "if <false> THEN cmd": skip cmd */
7848 if (rword == RES_ELSE || rword == RES_ELIF) {
7849 /* "if <true> then ... ELSE/ELIF cmd":
7850 * skip cmd and all following ones */
7855 #if ENABLE_HUSH_LOOPS
7856 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7858 /* first loop through for */
7860 static const char encoded_dollar_at[] ALIGN1 = {
7861 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7862 }; /* encoded representation of "$@" */
7863 static const char *const encoded_dollar_at_argv[] = {
7864 encoded_dollar_at, NULL
7865 }; /* argv list with one element: "$@" */
7868 vals = (char**)encoded_dollar_at_argv;
7869 if (pi->next->res_word == RES_IN) {
7870 /* if no variable values after "in" we skip "for" */
7871 if (!pi->next->cmds[0].argv) {
7872 G.last_exitcode = rcode = EXIT_SUCCESS;
7873 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7876 vals = pi->next->cmds[0].argv;
7877 } /* else: "for var; do..." -> assume "$@" list */
7878 /* create list of variable values */
7879 debug_print_strings("for_list made from", vals);
7880 for_list = expand_strvec_to_strvec(vals);
7881 for_lcur = for_list;
7882 debug_print_strings("for_list", for_list);
7885 /* "for" loop is over, clean up */
7891 /* Insert next value from for_lcur */
7892 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7893 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7896 if (rword == RES_IN) {
7897 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7899 if (rword == RES_DONE) {
7900 continue; /* "done" has no cmds too */
7903 #if ENABLE_HUSH_CASE
7904 if (rword == RES_CASE) {
7905 debug_printf_exec("CASE cond_code:%d\n", cond_code);
7906 case_word = expand_strvec_to_string(pi->cmds->argv);
7909 if (rword == RES_MATCH) {
7912 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
7913 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7915 /* all prev words didn't match, does this one match? */
7916 argv = pi->cmds->argv;
7918 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7919 /* TODO: which FNM_xxx flags to use? */
7920 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7922 if (cond_code == 0) { /* match! we will execute this branch */
7924 case_word = NULL; /* make future "word)" stop */
7931 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7932 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
7934 continue; /* not matched yet, skip this pipe */
7936 if (rword == RES_ESAC) {
7937 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
7939 /* "case" did not match anything: still set $? (to 0) */
7940 G.last_exitcode = rcode = EXIT_SUCCESS;
7944 /* Just pressing <enter> in shell should check for jobs.
7945 * OTOH, in non-interactive shell this is useless
7946 * and only leads to extra job checks */
7947 if (pi->num_cmds == 0) {
7948 if (G_interactive_fd)
7949 goto check_jobs_and_continue;
7953 /* After analyzing all keywords and conditions, we decided
7954 * to execute this pipe. NB: have to do checkjobs(NULL)
7955 * after run_pipe to collect any background children,
7956 * even if list execution is to be stopped. */
7957 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7958 #if ENABLE_HUSH_LOOPS
7959 G.flag_break_continue = 0;
7961 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
7963 /* We ran a builtin, function, or group.
7964 * rcode is already known
7965 * and we don't need to wait for anything. */
7966 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7967 G.last_exitcode = rcode;
7968 check_and_run_traps();
7969 #if ENABLE_HUSH_LOOPS
7970 /* Was it "break" or "continue"? */
7971 if (G.flag_break_continue) {
7972 smallint fbc = G.flag_break_continue;
7973 /* We might fall into outer *loop*,
7974 * don't want to break it too */
7976 G.depth_break_continue--;
7977 if (G.depth_break_continue == 0)
7978 G.flag_break_continue = 0;
7979 /* else: e.g. "continue 2" should *break* once, *then* continue */
7980 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7981 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7982 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7985 /* "continue": simulate end of loop */
7990 if (G_flag_return_in_progress == 1) {
7991 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7994 } else if (pi->followup == PIPE_BG) {
7995 /* What does bash do with attempts to background builtins? */
7996 /* even bash 3.2 doesn't do that well with nested bg:
7997 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7998 * I'm NOT treating inner &'s as jobs */
8000 if (G.run_list_level == 1)
8003 /* Last command's pid goes to $! */
8004 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8005 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8006 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8007 G.last_exitcode = rcode = EXIT_SUCCESS;
8008 check_and_run_traps();
8011 if (G.run_list_level == 1 && G_interactive_fd) {
8012 /* Waits for completion, then fg's main shell */
8013 rcode = checkjobs_and_fg_shell(pi);
8014 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8017 { /* This one just waits for completion */
8018 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8019 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8021 G.last_exitcode = rcode;
8022 check_and_run_traps();
8025 /* Analyze how result affects subsequent commands */
8027 if (rword == RES_IF || rword == RES_ELIF)
8030 check_jobs_and_continue:
8031 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8032 dont_check_jobs_but_continue: ;
8033 #if ENABLE_HUSH_LOOPS
8034 /* Beware of "while false; true; do ..."! */
8036 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8037 /* check for RES_DONE is needed for "while ...; do \n done" case */
8039 if (rword == RES_WHILE) {
8041 /* "while false; do...done" - exitcode 0 */
8042 G.last_exitcode = rcode = EXIT_SUCCESS;
8043 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8047 if (rword == RES_UNTIL) {
8049 debug_printf_exec(": until expr is true: breaking\n");
8060 #if ENABLE_HUSH_LOOPS
8065 #if ENABLE_HUSH_CASE
8069 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8073 /* Select which version we will use */
8074 static int run_and_free_list(struct pipe *pi)
8077 debug_printf_exec("run_and_free_list entered\n");
8078 if (!G.o_opt[OPT_O_NOEXEC]) {
8079 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8080 rcode = run_list(pi);
8082 /* free_pipe_list has the side effect of clearing memory.
8083 * In the long run that function can be merged with run_list,
8084 * but doing that now would hobble the debugging effort. */
8086 debug_printf_exec("run_and_free_list return %d\n", rcode);
8091 static void install_sighandlers(unsigned mask)
8093 sighandler_t old_handler;
8095 while ((mask >>= 1) != 0) {
8099 old_handler = install_sighandler(sig, pick_sighandler(sig));
8100 /* POSIX allows shell to re-enable SIGCHLD
8101 * even if it was SIG_IGN on entry.
8102 * Therefore we skip IGN check for it:
8106 if (old_handler == SIG_IGN) {
8107 /* oops... restore back to IGN, and record this fact */
8108 install_sighandler(sig, old_handler);
8110 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8112 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8117 /* Called a few times only (or even once if "sh -c") */
8118 static void install_special_sighandlers(void)
8122 /* Which signals are shell-special? */
8123 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8124 if (G_interactive_fd) {
8125 mask |= SPECIAL_INTERACTIVE_SIGS;
8126 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8127 mask |= SPECIAL_JOBSTOP_SIGS;
8129 /* Careful, do not re-install handlers we already installed */
8130 if (G.special_sig_mask != mask) {
8131 unsigned diff = mask & ~G.special_sig_mask;
8132 G.special_sig_mask = mask;
8133 install_sighandlers(diff);
8139 /* Set handlers to restore tty pgrp and exit */
8140 static void install_fatal_sighandlers(void)
8144 /* We will restore tty pgrp on these signals */
8146 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8147 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8148 + (1 << SIGBUS ) * HUSH_DEBUG
8149 + (1 << SIGSEGV) * HUSH_DEBUG
8150 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8152 /* bash 3.2 seems to handle these just like 'fatal' ones */
8155 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8156 * if we aren't interactive... but in this case
8157 * we never want to restore pgrp on exit, and this fn is not called
8159 /*+ (1 << SIGHUP )*/
8160 /*+ (1 << SIGTERM)*/
8161 /*+ (1 << SIGINT )*/
8163 G_fatal_sig_mask = mask;
8165 install_sighandlers(mask);
8169 static int set_mode(int state, char mode, const char *o_opt)
8174 G.o_opt[OPT_O_NOEXEC] = state;
8177 IF_HUSH_MODE_X(G_x_mode = state;)
8181 /* "set -+o" without parameter.
8182 * in bash, set -o produces this output:
8186 * We always use the second form.
8188 const char *p = o_opt_strings;
8191 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8197 idx = index_in_strings(o_opt_strings, o_opt);
8199 G.o_opt[idx] = state;
8203 return EXIT_FAILURE;
8205 return EXIT_SUCCESS;
8208 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8209 int hush_main(int argc, char **argv)
8212 OPT_login = (1 << 0),
8216 unsigned builtin_argc;
8218 struct variable *cur_var;
8219 struct variable *shell_ver;
8222 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8223 G.last_exitcode = EXIT_SUCCESS;
8225 #if ENABLE_HUSH_FAST
8226 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8229 G.argv0_for_re_execing = argv[0];
8231 /* Deal with HUSH_VERSION */
8232 shell_ver = xzalloc(sizeof(*shell_ver));
8233 shell_ver->flg_export = 1;
8234 shell_ver->flg_read_only = 1;
8235 /* Code which handles ${var<op>...} needs writable values for all variables,
8236 * therefore we xstrdup: */
8237 shell_ver->varstr = xstrdup(hush_version_str);
8238 /* Create shell local variables from the values
8239 * currently living in the environment */
8240 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8241 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8242 G.top_var = shell_ver;
8243 cur_var = G.top_var;
8246 char *value = strchr(*e, '=');
8247 if (value) { /* paranoia */
8248 cur_var->next = xzalloc(sizeof(*cur_var));
8249 cur_var = cur_var->next;
8250 cur_var->varstr = *e;
8251 cur_var->max_len = strlen(*e);
8252 cur_var->flg_export = 1;
8256 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8257 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8258 putenv(shell_ver->varstr);
8261 set_pwd_var(/*exp:*/ 1);
8263 #if ENABLE_HUSH_BASH_COMPAT
8264 /* Set (but not export) HOSTNAME unless already set */
8265 if (!get_local_var_value("HOSTNAME")) {
8268 set_local_var_from_halves("HOSTNAME", uts.nodename);
8270 /* bash also exports SHLVL and _,
8271 * and sets (but doesn't export) the following variables:
8273 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8274 * BASH_VERSION='3.2.0(1)-release'
8276 * MACHTYPE=i386-pc-linux-gnu
8278 * PPID=<NNNNN> - we also do it elsewhere
8289 * PIPESTATUS=([0]="0")
8290 * HISTFILE=/<xxx>/.bash_history
8294 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8296 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8307 #if ENABLE_FEATURE_EDITING
8308 G.line_input_state = new_line_input_t(FOR_SHELL);
8311 /* Initialize some more globals to non-zero values */
8312 cmdedit_update_prompt();
8314 die_func = restore_ttypgrp_and__exit;
8316 /* Shell is non-interactive at first. We need to call
8317 * install_special_sighandlers() if we are going to execute "sh <script>",
8318 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8319 * If we later decide that we are interactive, we run install_special_sighandlers()
8320 * in order to intercept (more) signals.
8324 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8325 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8328 opt = getopt(argc, argv, "+c:xinsl"
8331 # if ENABLE_HUSH_FUNCTIONS
8341 * sh ... -c 'script'
8342 * sh ... -c 'script' ARG0 [ARG1...]
8343 * On NOMMU, if builtin_argc != 0,
8344 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8345 * "" needs to be replaced with NULL
8346 * and BARGV vector fed to builtin function.
8347 * Note: the form without ARG0 never happens:
8348 * sh ... -c 'builtin' BARGV... ""
8351 G.root_pid = getpid();
8352 G.root_ppid = getppid();
8354 G.global_argv = argv + optind;
8355 G.global_argc = argc - optind;
8357 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8358 const struct built_in_command *x;
8360 install_special_sighandlers();
8361 x = find_builtin(optarg);
8362 if (x) { /* paranoia */
8363 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8364 G.global_argv += builtin_argc;
8365 G.global_argv[-1] = NULL; /* replace "" */
8367 G.last_exitcode = x->b_function(argv + optind - 1);
8371 if (!G.global_argv[0]) {
8372 /* -c 'script' (no params): prevent empty $0 */
8373 G.global_argv--; /* points to argv[i] of 'script' */
8374 G.global_argv[0] = argv[0];
8376 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8377 install_special_sighandlers();
8378 parse_and_run_string(optarg);
8381 /* Well, we cannot just declare interactiveness,
8382 * we have to have some stuff (ctty, etc) */
8383 /* G_interactive_fd++; */
8386 /* "-s" means "read from stdin", but this is how we always
8387 * operate, so simply do nothing here. */
8393 case '<': /* "big heredoc" support */
8394 full_write1_str(optarg);
8397 unsigned long long empty_trap_mask;
8399 G.root_pid = bb_strtou(optarg, &optarg, 16);
8401 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8403 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8405 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8407 builtin_argc = bb_strtou(optarg, &optarg, 16);
8409 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8410 if (empty_trap_mask != 0) {
8412 install_special_sighandlers();
8413 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8414 for (sig = 1; sig < NSIG; sig++) {
8415 if (empty_trap_mask & (1LL << sig)) {
8416 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8417 install_sighandler(sig, SIG_IGN);
8421 # if ENABLE_HUSH_LOOPS
8423 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8429 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8431 # if ENABLE_HUSH_FUNCTIONS
8433 struct function *funcp = new_function(optarg);
8434 /* funcp->name is already set to optarg */
8435 /* funcp->body is set to NULL. It's a special case. */
8436 funcp->body_as_string = argv[optind];
8444 if (set_mode(1, opt, NULL) == 0) /* no error */
8448 fprintf(stderr, "Usage: sh [FILE]...\n"
8449 " or: sh -c command [args]...\n\n");
8455 } /* option parsing loop */
8457 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8458 G.global_argc = argc - (optind - 1);
8459 G.global_argv = argv + (optind - 1);
8460 G.global_argv[0] = argv[0];
8463 G.root_pid = getpid();
8464 G.root_ppid = getppid();
8467 /* If we are login shell... */
8468 if (flags & OPT_login) {
8470 debug_printf("sourcing /etc/profile\n");
8471 input = fopen_for_read("/etc/profile");
8472 if (input != NULL) {
8473 remember_FILE(input);
8474 install_special_sighandlers();
8475 parse_and_run_file(input);
8476 fclose_and_forget(input);
8478 /* bash: after sourcing /etc/profile,
8479 * tries to source (in the given order):
8480 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8481 * stopping on first found. --noprofile turns this off.
8482 * bash also sources ~/.bash_logout on exit.
8483 * If called as sh, skips .bash_XXX files.
8487 if (G.global_argv[1]) {
8490 * "bash <script>" (which is never interactive (unless -i?))
8491 * sources $BASH_ENV here (without scanning $PATH).
8492 * If called as sh, does the same but with $ENV.
8493 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8497 debug_printf("running script '%s'\n", G.global_argv[0]);
8498 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8499 input = xfopen_for_read(G.global_argv[0]);
8500 xfunc_error_retval = 1;
8501 remember_FILE(input);
8502 install_special_sighandlers();
8503 parse_and_run_file(input);
8504 #if ENABLE_FEATURE_CLEAN_UP
8505 fclose_and_forget(input);
8510 /* Up to here, shell was non-interactive. Now it may become one.
8511 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8514 /* A shell is interactive if the '-i' flag was given,
8515 * or if all of the following conditions are met:
8517 * no arguments remaining or the -s flag given
8518 * standard input is a terminal
8519 * standard output is a terminal
8520 * Refer to Posix.2, the description of the 'sh' utility.
8523 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8524 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8525 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8526 if (G_saved_tty_pgrp < 0)
8527 G_saved_tty_pgrp = 0;
8529 /* try to dup stdin to high fd#, >= 255 */
8530 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8531 if (G_interactive_fd < 0) {
8532 /* try to dup to any fd */
8533 G_interactive_fd = dup(STDIN_FILENO);
8534 if (G_interactive_fd < 0) {
8536 G_interactive_fd = 0;
8537 G_saved_tty_pgrp = 0;
8540 // TODO: track & disallow any attempts of user
8541 // to (inadvertently) close/redirect G_interactive_fd
8543 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8544 if (G_interactive_fd) {
8545 close_on_exec_on(G_interactive_fd);
8547 if (G_saved_tty_pgrp) {
8548 /* If we were run as 'hush &', sleep until we are
8549 * in the foreground (tty pgrp == our pgrp).
8550 * If we get started under a job aware app (like bash),
8551 * make sure we are now in charge so we don't fight over
8552 * who gets the foreground */
8554 pid_t shell_pgrp = getpgrp();
8555 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8556 if (G_saved_tty_pgrp == shell_pgrp)
8558 /* send TTIN to ourself (should stop us) */
8559 kill(- shell_pgrp, SIGTTIN);
8563 /* Install more signal handlers */
8564 install_special_sighandlers();
8566 if (G_saved_tty_pgrp) {
8567 /* Set other signals to restore saved_tty_pgrp */
8568 install_fatal_sighandlers();
8569 /* Put ourselves in our own process group
8570 * (bash, too, does this only if ctty is available) */
8571 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8572 /* Grab control of the terminal */
8573 tcsetpgrp(G_interactive_fd, getpid());
8575 enable_restore_tty_pgrp_on_exit();
8577 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8579 const char *hp = get_local_var_value("HISTFILE");
8581 hp = get_local_var_value("HOME");
8583 hp = concat_path_file(hp, ".hush_history");
8588 G.line_input_state->hist_file = hp;
8589 //set_local_var(xasprintf("HISTFILE=%s", ...));
8591 # if ENABLE_FEATURE_SH_HISTFILESIZE
8592 hp = get_local_var_value("HISTFILESIZE");
8593 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8598 install_special_sighandlers();
8600 #elif ENABLE_HUSH_INTERACTIVE
8601 /* No job control compiled in, only prompt/line editing */
8602 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8603 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8604 if (G_interactive_fd < 0) {
8605 /* try to dup to any fd */
8606 G_interactive_fd = dup(STDIN_FILENO);
8607 if (G_interactive_fd < 0)
8609 G_interactive_fd = 0;
8612 if (G_interactive_fd) {
8613 close_on_exec_on(G_interactive_fd);
8615 install_special_sighandlers();
8617 /* We have interactiveness code disabled */
8618 install_special_sighandlers();
8621 * if interactive but not a login shell, sources ~/.bashrc
8622 * (--norc turns this off, --rcfile <file> overrides)
8625 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8626 /* note: ash and hush share this string */
8627 printf("\n\n%s %s\n"
8628 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8631 "hush - the humble shell"
8635 parse_and_run_file(stdin);
8638 hush_exit(G.last_exitcode);
8643 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8644 int msh_main(int argc, char **argv)
8646 bb_error_msg("msh is deprecated, please use hush instead");
8647 return hush_main(argc, argv);
8655 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8660 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8667 return applet_main_func(argc, argv - argc);
8670 static int FAST_FUNC builtin_test(char **argv)
8672 return run_applet_main(argv, test_main);
8675 static int FAST_FUNC builtin_echo(char **argv)
8677 return run_applet_main(argv, echo_main);
8681 static int FAST_FUNC builtin_printf(char **argv)
8683 return run_applet_main(argv, printf_main);
8687 static char **skip_dash_dash(char **argv)
8690 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8695 static int FAST_FUNC builtin_eval(char **argv)
8697 int rcode = EXIT_SUCCESS;
8699 argv = skip_dash_dash(argv);
8701 char *str = expand_strvec_to_string(argv);
8703 * eval "echo Hi; done" ("done" is syntax error):
8704 * "echo Hi" will not execute too.
8706 parse_and_run_string(str);
8708 rcode = G.last_exitcode;
8713 static int FAST_FUNC builtin_cd(char **argv)
8717 argv = skip_dash_dash(argv);
8719 if (newdir == NULL) {
8720 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8721 * bash says "bash: cd: HOME not set" and does nothing
8724 const char *home = get_local_var_value("HOME");
8725 newdir = home ? home : "/";
8727 if (chdir(newdir)) {
8728 /* Mimic bash message exactly */
8729 bb_perror_msg("cd: %s", newdir);
8730 return EXIT_FAILURE;
8732 /* Read current dir (get_cwd(1) is inside) and set PWD.
8733 * Note: do not enforce exporting. If PWD was unset or unexported,
8734 * set it again, but do not export. bash does the same.
8736 set_pwd_var(/*exp:*/ 0);
8737 return EXIT_SUCCESS;
8740 static int FAST_FUNC builtin_exec(char **argv)
8742 argv = skip_dash_dash(argv);
8743 if (argv[0] == NULL)
8744 return EXIT_SUCCESS; /* bash does this */
8746 /* Careful: we can end up here after [v]fork. Do not restore
8747 * tty pgrp then, only top-level shell process does that */
8748 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8749 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8751 /* TODO: if exec fails, bash does NOT exit! We do.
8752 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8753 * and tcsetpgrp, and this is inherently racy.
8755 execvp_or_die(argv);
8758 static int FAST_FUNC builtin_exit(char **argv)
8760 debug_printf_exec("%s()\n", __func__);
8762 /* interactive bash:
8763 * # trap "echo EEE" EXIT
8766 * There are stopped jobs.
8767 * (if there are _stopped_ jobs, running ones don't count)
8770 * EEE (then bash exits)
8772 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8775 /* note: EXIT trap is run by hush_exit */
8776 argv = skip_dash_dash(argv);
8777 if (argv[0] == NULL)
8778 hush_exit(G.last_exitcode);
8779 /* mimic bash: exit 123abc == exit 255 + error msg */
8780 xfunc_error_retval = 255;
8781 /* bash: exit -2 == exit 254, no error msg */
8782 hush_exit(xatoi(argv[0]) & 0xff);
8785 static void print_escaped(const char *s)
8790 const char *p = strchrnul(s, '\'');
8791 /* print 'xxxx', possibly just '' */
8792 printf("'%.*s'", (int)(p - s), s);
8797 /* s points to '; print "'''...'''" */
8799 do putchar('\''); while (*++s == '\'');
8804 #if !ENABLE_HUSH_LOCAL
8805 #define helper_export_local(argv, exp, lvl) \
8806 helper_export_local(argv, exp)
8808 static void helper_export_local(char **argv, int exp, int lvl)
8812 char *name_end = strchrnul(name, '=');
8814 /* So far we do not check that name is valid (TODO?) */
8816 if (*name_end == '\0') {
8817 struct variable *var, **vpp;
8819 vpp = get_ptr_to_local_var(name, name_end - name);
8820 var = vpp ? *vpp : NULL;
8822 if (exp == -1) { /* unexporting? */
8823 /* export -n NAME (without =VALUE) */
8825 var->flg_export = 0;
8826 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8828 } /* else: export -n NOT_EXISTING_VAR: no-op */
8831 if (exp == 1) { /* exporting? */
8832 /* export NAME (without =VALUE) */
8834 var->flg_export = 1;
8835 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8836 putenv(var->varstr);
8840 #if ENABLE_HUSH_LOCAL
8841 if (exp == 0 /* local? */
8842 && var && var->func_nest_level == lvl
8844 /* "local x=abc; ...; local x" - ignore second local decl */
8848 /* Exporting non-existing variable.
8849 * bash does not put it in environment,
8850 * but remembers that it is exported,
8851 * and does put it in env when it is set later.
8852 * We just set it to "" and export. */
8853 /* Or, it's "local NAME" (without =VALUE).
8854 * bash sets the value to "". */
8855 name = xasprintf("%s=", name);
8857 /* (Un)exporting/making local NAME=VALUE */
8858 name = xstrdup(name);
8860 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8864 static int FAST_FUNC builtin_export(char **argv)
8866 unsigned opt_unexport;
8868 #if ENABLE_HUSH_EXPORT_N
8869 /* "!": do not abort on errors */
8870 opt_unexport = getopt32(argv, "!n");
8871 if (opt_unexport == (uint32_t)-1)
8872 return EXIT_FAILURE;
8879 if (argv[0] == NULL) {
8886 /* ash emits: export VAR='VAL'
8887 * bash: declare -x VAR="VAL"
8888 * we follow ash example */
8889 const char *s = *e++;
8890 const char *p = strchr(s, '=');
8892 if (!p) /* wtf? take next variable */
8895 printf("export %.*s", (int)(p - s) + 1, s);
8896 print_escaped(p + 1);
8900 /*fflush_all(); - done after each builtin anyway */
8902 return EXIT_SUCCESS;
8905 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8907 return EXIT_SUCCESS;
8910 #if ENABLE_HUSH_LOCAL
8911 static int FAST_FUNC builtin_local(char **argv)
8913 if (G.func_nest_level == 0) {
8914 bb_error_msg("%s: not in a function", argv[0]);
8915 return EXIT_FAILURE; /* bash compat */
8917 helper_export_local(argv, 0, G.func_nest_level);
8918 return EXIT_SUCCESS;
8922 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8923 static int FAST_FUNC builtin_unset(char **argv)
8928 /* "!": do not abort on errors */
8929 /* "+": stop at 1st non-option */
8930 opts = getopt32(argv, "!+vf");
8931 if (opts == (unsigned)-1)
8932 return EXIT_FAILURE;
8934 bb_error_msg("unset: -v and -f are exclusive");
8935 return EXIT_FAILURE;
8941 if (!(opts & 2)) { /* not -f */
8942 if (unset_local_var(*argv)) {
8943 /* unset <nonexistent_var> doesn't fail.
8944 * Error is when one tries to unset RO var.
8945 * Message was printed by unset_local_var. */
8949 #if ENABLE_HUSH_FUNCTIONS
8959 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8960 * built-in 'set' handler
8962 * set [-abCefhmnuvx] [-o option] [argument...]
8963 * set [+abCefhmnuvx] [+o option] [argument...]
8964 * set -- [argument...]
8967 * Implementations shall support the options in both their hyphen and
8968 * plus-sign forms. These options can also be specified as options to sh.
8970 * Write out all variables and their values: set
8971 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8972 * Turn on the -x and -v options: set -xv
8973 * Unset all positional parameters: set --
8974 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8975 * Set the positional parameters to the expansion of x, even if x expands
8976 * with a leading '-' or '+': set -- $x
8978 * So far, we only support "set -- [argument...]" and some of the short names.
8980 static int FAST_FUNC builtin_set(char **argv)
8983 char **pp, **g_argv;
8984 char *arg = *++argv;
8988 for (e = G.top_var; e; e = e->next)
8990 return EXIT_SUCCESS;
8994 if (strcmp(arg, "--") == 0) {
8998 if (arg[0] != '+' && arg[0] != '-')
9000 for (n = 1; arg[n]; ++n) {
9001 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9003 if (arg[n] == 'o' && argv[1])
9006 } while ((arg = *++argv) != NULL);
9007 /* Now argv[0] is 1st argument */
9010 return EXIT_SUCCESS;
9013 /* NB: G.global_argv[0] ($0) is never freed/changed */
9014 g_argv = G.global_argv;
9015 if (G.global_args_malloced) {
9021 G.global_args_malloced = 1;
9022 pp = xzalloc(sizeof(pp[0]) * 2);
9023 pp[0] = g_argv[0]; /* retain $0 */
9026 /* This realloc's G.global_argv */
9027 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9034 return EXIT_SUCCESS;
9036 /* Nothing known, so abort */
9038 bb_error_msg("set: %s: invalid option", arg);
9039 return EXIT_FAILURE;
9042 static int FAST_FUNC builtin_shift(char **argv)
9045 argv = skip_dash_dash(argv);
9049 if (n >= 0 && n < G.global_argc) {
9050 if (G.global_args_malloced) {
9053 free(G.global_argv[m++]);
9056 memmove(&G.global_argv[1], &G.global_argv[n+1],
9057 G.global_argc * sizeof(G.global_argv[0]));
9058 return EXIT_SUCCESS;
9060 return EXIT_FAILURE;
9063 /* Interruptibility of read builtin in bash
9064 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9066 * Empty trap makes read ignore corresponding signal, for any signal.
9069 * - terminates non-interactive shell;
9070 * - interrupts read in interactive shell;
9071 * if it has non-empty trap:
9072 * - executes trap and returns to command prompt in interactive shell;
9073 * - executes trap and returns to read in non-interactive shell;
9075 * - is ignored (does not interrupt) read in interactive shell;
9076 * - terminates non-interactive shell;
9077 * if it has non-empty trap:
9078 * - executes trap and returns to read;
9080 * - terminates shell (regardless of interactivity);
9081 * if it has non-empty trap:
9082 * - executes trap and returns to read;
9084 static int FAST_FUNC builtin_read(char **argv)
9094 /* "!": do not abort on errors.
9095 * Option string must start with "sr" to match BUILTIN_READ_xxx
9097 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9098 if (read_flags == (uint32_t)-1)
9099 return EXIT_FAILURE;
9101 ifs = get_local_var_value("IFS"); /* can be NULL */
9104 r = shell_builtin_read(set_local_var_from_halves,
9114 if ((uintptr_t)r == 1 && errno == EINTR) {
9115 unsigned sig = check_and_run_traps();
9116 if (sig && sig != SIGINT)
9120 if ((uintptr_t)r > 1) {
9121 bb_error_msg("%s", r);
9122 r = (char*)(uintptr_t)1;
9125 return (uintptr_t)r;
9128 static int FAST_FUNC builtin_trap(char **argv)
9134 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9139 /* No args: print all trapped */
9140 for (i = 0; i < NSIG; ++i) {
9143 print_escaped(G.traps[i]);
9144 /* note: bash adds "SIG", but only if invoked
9145 * as "bash". If called as "sh", or if set -o posix,
9146 * then it prints short signal names.
9147 * We are printing short names: */
9148 printf(" %s\n", get_signame(i));
9151 /*fflush_all(); - done after each builtin anyway */
9152 return EXIT_SUCCESS;
9156 /* If first arg is a number: reset all specified signals */
9157 sig = bb_strtou(*argv, NULL, 10);
9163 sighandler_t handler;
9165 sig = get_signum(*argv++);
9166 if (sig < 0 || sig >= NSIG) {
9168 /* Mimic bash message exactly */
9169 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9174 G.traps[sig] = xstrdup(new_cmd);
9176 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9177 get_signame(sig), sig, G.traps[sig]);
9179 /* There is no signal for 0 (EXIT) */
9184 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9186 /* We are removing trap handler */
9187 handler = pick_sighandler(sig);
9188 install_sighandler(sig, handler);
9193 if (!argv[1]) { /* no second arg */
9194 bb_error_msg("trap: invalid arguments");
9195 return EXIT_FAILURE;
9198 /* First arg is "-": reset all specified to default */
9199 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9200 /* Everything else: set arg as signal handler
9201 * (includes "" case, which ignores signal) */
9202 if (argv[0][0] == '-') {
9203 if (argv[0][1] == '\0') { /* "-" */
9204 /* new_cmd remains NULL: "reset these sigs" */
9207 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9210 /* else: "-something", no special meaning */
9215 goto process_sig_list;
9218 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9219 static int FAST_FUNC builtin_type(char **argv)
9221 int ret = EXIT_SUCCESS;
9227 if (0) {} /* make conditional compile easier below */
9228 /*else if (find_alias(*argv))
9229 type = "an alias";*/
9230 #if ENABLE_HUSH_FUNCTIONS
9231 else if (find_function(*argv))
9232 type = "a function";
9234 else if (find_builtin(*argv))
9235 type = "a shell builtin";
9236 else if ((path = find_in_path(*argv)) != NULL)
9239 bb_error_msg("type: %s: not found", *argv);
9244 printf("%s is %s\n", *argv, type);
9252 static struct pipe *parse_jobspec(const char *str)
9257 if (sscanf(str, "%%%d", &jobnum) != 1) {
9258 bb_error_msg("bad argument '%s'", str);
9261 for (pi = G.job_list; pi; pi = pi->next) {
9262 if (pi->jobid == jobnum) {
9266 bb_error_msg("%d: no such job", jobnum);
9270 /* built-in 'fg' and 'bg' handler */
9271 static int FAST_FUNC builtin_fg_bg(char **argv)
9276 if (!G_interactive_fd)
9277 return EXIT_FAILURE;
9279 /* If they gave us no args, assume they want the last backgrounded task */
9281 for (pi = G.job_list; pi; pi = pi->next) {
9282 if (pi->jobid == G.last_jobid) {
9286 bb_error_msg("%s: no current job", argv[0]);
9287 return EXIT_FAILURE;
9290 pi = parse_jobspec(argv[1]);
9292 return EXIT_FAILURE;
9294 /* TODO: bash prints a string representation
9295 * of job being foregrounded (like "sleep 1 | cat") */
9296 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9297 /* Put the job into the foreground. */
9298 tcsetpgrp(G_interactive_fd, pi->pgrp);
9301 /* Restart the processes in the job */
9302 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9303 for (i = 0; i < pi->num_cmds; i++) {
9304 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9306 pi->stopped_cmds = 0;
9308 i = kill(- pi->pgrp, SIGCONT);
9310 if (errno == ESRCH) {
9311 delete_finished_bg_job(pi);
9312 return EXIT_SUCCESS;
9314 bb_perror_msg("kill (SIGCONT)");
9317 if (argv[0][0] == 'f') {
9319 return checkjobs_and_fg_shell(pi);
9321 return EXIT_SUCCESS;
9325 #if ENABLE_HUSH_HELP
9326 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9328 const struct built_in_command *x;
9331 "Built-in commands:\n"
9332 "------------------\n");
9333 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9335 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9337 return EXIT_SUCCESS;
9341 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9342 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9344 show_history(G.line_input_state);
9345 return EXIT_SUCCESS;
9350 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9353 const char *status_string;
9355 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9356 for (job = G.job_list; job; job = job->next) {
9357 if (job->alive_cmds == job->stopped_cmds)
9358 status_string = "Stopped";
9360 status_string = "Running";
9362 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9364 return EXIT_SUCCESS;
9369 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9374 # ifdef M_TRIM_THRESHOLD
9375 /* Optional. Reduces probability of false positives */
9378 /* Crude attempt to find where "free memory" starts,
9379 * sans fragmentation. */
9381 l = (unsigned long)p;
9384 if (l < (unsigned long)p) l = (unsigned long)p;
9390 struct mallinfo mi = mallinfo();
9391 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9392 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9396 if (!G.memleak_value)
9397 G.memleak_value = l;
9399 l -= G.memleak_value;
9406 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9411 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9414 return EXIT_SUCCESS;
9417 static int FAST_FUNC builtin_source(char **argv)
9419 char *arg_path, *filename;
9422 #if ENABLE_HUSH_FUNCTIONS
9426 argv = skip_dash_dash(argv);
9429 /* bash says: "bash: .: filename argument required" */
9430 return 2; /* bash compat */
9433 if (!strchr(filename, '/')) {
9434 arg_path = find_in_path(filename);
9436 filename = arg_path;
9438 input = remember_FILE(fopen_or_warn(filename, "r"));
9441 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9442 /* POSIX: non-interactive shell should abort here,
9443 * not merely fail. So far no one complained :)
9445 return EXIT_FAILURE;
9448 #if ENABLE_HUSH_FUNCTIONS
9449 sv_flg = G_flag_return_in_progress;
9450 /* "we are inside sourced file, ok to use return" */
9451 G_flag_return_in_progress = -1;
9454 save_and_replace_G_args(&sv, argv);
9456 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9457 G.last_exitcode = 0;
9458 parse_and_run_file(input);
9459 fclose_and_forget(input);
9462 restore_G_args(&sv, argv);
9463 #if ENABLE_HUSH_FUNCTIONS
9464 G_flag_return_in_progress = sv_flg;
9467 return G.last_exitcode;
9470 static int FAST_FUNC builtin_umask(char **argv)
9477 argv = skip_dash_dash(argv);
9479 mode_t old_mask = mask;
9481 /* numeric umasks are taken as-is */
9482 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9483 if (!isdigit(argv[0][0]))
9485 mask = bb_parse_mode(argv[0], mask);
9486 if (!isdigit(argv[0][0]))
9488 if ((unsigned)mask > 0777) {
9491 * bash: umask: 'q': invalid symbolic mode operator
9492 * bash: umask: 999: octal number out of range
9494 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9499 printf("%04o\n", (unsigned) mask);
9500 /* fall through and restore mask which we set to 0 */
9504 return !rc; /* rc != 0 - success */
9507 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9508 #if !ENABLE_HUSH_JOB
9509 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9511 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9518 if (!sigisemptyset(&G.pending_set))
9521 /* waitpid is not interruptible by SA_RESTARTed
9522 * signals which we use. Thus, this ugly dance:
9525 /* Make sure possible SIGCHLD is stored in kernel's
9526 * pending signal mask before we call waitpid.
9527 * Or else we may race with SIGCHLD, lose it,
9528 * and get stuck in sigsuspend...
9530 sigfillset(&oldset); /* block all signals, remember old set */
9531 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9533 if (!sigisemptyset(&G.pending_set)) {
9534 /* Crap! we raced with some signal! */
9538 /*errno = 0; - checkjobs does this */
9539 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9540 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9541 debug_printf_exec("checkjobs:%d\n", ret);
9544 int rcode = job_exited_or_stopped(waitfor_pipe);
9545 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9548 sigprocmask(SIG_SETMASK, &oldset, NULL);
9553 /* if ECHILD, there are no children (ret is -1 or 0) */
9554 /* if ret == 0, no children changed state */
9555 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9556 if (errno == ECHILD || ret) {
9558 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9560 sigprocmask(SIG_SETMASK, &oldset, NULL);
9563 /* Wait for SIGCHLD or any other signal */
9564 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9565 /* Note: sigsuspend invokes signal handler */
9566 sigsuspend(&oldset);
9568 sigprocmask(SIG_SETMASK, &oldset, NULL);
9570 /* So, did we get a signal? */
9571 sig = check_and_run_traps();
9572 if (sig /*&& sig != SIGCHLD - always true */) {
9576 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9581 static int FAST_FUNC builtin_wait(char **argv)
9586 argv = skip_dash_dash(argv);
9587 if (argv[0] == NULL) {
9588 /* Don't care about wait results */
9589 /* Note 1: must wait until there are no more children */
9590 /* Note 2: must be interruptible */
9592 * $ sleep 3 & sleep 6 & wait
9597 * $ sleep 3 & sleep 6 & wait
9601 * ^C <-- after ~4 sec from keyboard
9604 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9608 pid_t pid = bb_strtou(*argv, NULL, 10);
9609 if (errno || pid <= 0) {
9611 if (argv[0][0] == '%') {
9612 struct pipe *wait_pipe;
9613 wait_pipe = parse_jobspec(*argv);
9615 ret = job_exited_or_stopped(wait_pipe);
9617 ret = wait_for_child_or_signal(wait_pipe, 0);
9622 /* mimic bash message */
9623 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9625 continue; /* bash checks all argv[] */
9628 /* Do we have such child? */
9629 ret = waitpid(pid, &status, WNOHANG);
9632 if (errno == ECHILD) {
9633 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9634 /* "wait $!" but last bg task has already exited. Try:
9635 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9636 * In bash it prints exitcode 0, then 3.
9637 * In dash, it is 127.
9639 /* ret = G.last_bg_pid_exitstatus - FIXME */
9641 /* Example: "wait 1". mimic bash message */
9642 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9646 bb_perror_msg("wait %s", *argv);
9649 continue; /* bash checks all argv[] */
9652 /* Yes, and it still runs */
9653 ret = wait_for_child_or_signal(NULL, pid);
9655 /* Yes, and it just exited */
9656 process_wait_result(NULL, pid, status);
9657 ret = WEXITSTATUS(status);
9658 if (WIFSIGNALED(status))
9659 ret = 128 + WTERMSIG(status);
9666 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9667 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9670 def = bb_strtou(argv[1], NULL, 10);
9671 if (errno || def < def_min || argv[2]) {
9672 bb_error_msg("%s: bad arguments", argv[0]);
9680 #if ENABLE_HUSH_LOOPS
9681 static int FAST_FUNC builtin_break(char **argv)
9684 if (G.depth_of_loop == 0) {
9685 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9686 /* if we came from builtin_continue(), need to undo "= 1" */
9687 G.flag_break_continue = 0;
9688 return EXIT_SUCCESS; /* bash compat */
9690 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9692 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9693 if (depth == UINT_MAX)
9694 G.flag_break_continue = BC_BREAK;
9695 if (G.depth_of_loop < depth)
9696 G.depth_break_continue = G.depth_of_loop;
9698 return EXIT_SUCCESS;
9701 static int FAST_FUNC builtin_continue(char **argv)
9703 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9704 return builtin_break(argv);
9708 #if ENABLE_HUSH_FUNCTIONS
9709 static int FAST_FUNC builtin_return(char **argv)
9713 if (G_flag_return_in_progress != -1) {
9714 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9715 return EXIT_FAILURE; /* bash compat */
9718 G_flag_return_in_progress = 1;
9721 * out of range: wraps around at 256, does not error out
9722 * non-numeric param:
9723 * f() { false; return qwe; }; f; echo $?
9724 * bash: return: qwe: numeric argument required <== we do this
9725 * 255 <== we also do this
9727 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);