1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
52 * make trap, read, ulimit builtins optional
55 * redirection of stdout+stderr: &> and >&
56 * reserved words: function select
57 * advanced test: [[ ]]
58 * process substitution: <(list) and >(list)
61 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
62 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
63 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
65 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
66 * This is exactly equivalent to let "EXPR".
67 * $[EXPR]: synonym for $((EXPR))
70 * In bash, export builtin is special, its arguments are assignments
71 * and therefore expansion of them should be "one-word" expansion:
72 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
74 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
75 * ls: cannot access i=a: No such file or directory
76 * ls: cannot access b: No such file or directory
77 * Note1: same applies to local builtin.
78 * Note2: bash 3.2.33(1) does this only if export word itself
80 * $ export i=`echo 'aaa bbb'`; echo "$i"
82 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
89 //config: hush is a small shell (25k). It handles the normal flow control
90 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
91 //config: case/esac. Redirections, here documents, $((arithmetic))
92 //config: and functions are supported.
94 //config: It will compile and work on no-mmu systems.
96 //config: It does not handle select, aliases, tilde expansion,
97 //config: &>file and >&file redirection of stdout+stderr.
99 //config:config HUSH_BASH_COMPAT
100 //config: bool "bash-compatible extensions"
102 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
104 //config: Enable bash-compatible extensions.
106 //config:config HUSH_BRACE_EXPANSION
107 //config: bool "Brace expansion"
109 //config: depends on HUSH_BASH_COMPAT
111 //config: Enable {abc,def} extension.
113 //config:config HUSH_HELP
114 //config: bool "help builtin"
116 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
118 //config: Enable help builtin in hush. Code size + ~1 kbyte.
120 //config:config HUSH_PRINTF
121 //config: bool "printf builtin"
123 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
125 //config: Enable printf builtin in hush.
127 //config:config HUSH_KILL
128 //config: bool "kill builtin (for kill %jobspec)"
130 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
132 //config: Enable kill builtin in hush.
134 //config:config HUSH_WAIT
135 //config: bool "wait builtin"
137 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
139 //config: Enable wait builtin in hush.
141 //config:config HUSH_TYPE
142 //config: bool "type builtin"
144 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
146 //config: Enable type builtin in hush.
148 //config:config HUSH_INTERACTIVE
149 //config: bool "Interactive mode"
151 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
153 //config: Enable interactive mode (prompt and command editing).
154 //config: Without this, hush simply reads and executes commands
155 //config: from stdin just like a shell script from a file.
156 //config: No prompt, no PS1/PS2 magic shell variables.
158 //config:config HUSH_SAVEHISTORY
159 //config: bool "Save command history to .hush_history"
161 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
163 //config: Enable history saving in hush.
165 //config:config HUSH_JOB
166 //config: bool "Job control"
168 //config: depends on HUSH_INTERACTIVE
170 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
171 //config: command (not entire shell), fg/bg builtins work. Without this option,
172 //config: "cmd &" still works by simply spawning a process and immediately
173 //config: prompting for next command (or executing next command in a script),
174 //config: but no separate process group is formed.
176 //config:config HUSH_TICK
177 //config: bool "Process substitution"
179 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
181 //config: Enable process substitution `command` and $(command) in hush.
183 //config:config HUSH_IF
184 //config: bool "Support if/then/elif/else/fi"
186 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
188 //config: Enable if/then/elif/else/fi in hush.
190 //config:config HUSH_LOOPS
191 //config: bool "Support for, while and until loops"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config: Enable for, while and until loops in hush.
197 //config:config HUSH_CASE
198 //config: bool "Support case ... esac statement"
200 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
202 //config: Enable case ... esac statement in hush. +400 bytes.
204 //config:config HUSH_FUNCTIONS
205 //config: bool "Support funcname() { commands; } syntax"
207 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
209 //config: Enable support for shell functions in hush. +800 bytes.
211 //config:config HUSH_LOCAL
212 //config: bool "Support local builtin"
214 //config: depends on HUSH_FUNCTIONS
216 //config: Enable support for local variables in functions.
218 //config:config HUSH_RANDOM_SUPPORT
219 //config: bool "Pseudorandom generator and $RANDOM variable"
221 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
223 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
224 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
226 //config:config HUSH_EXPORT_N
227 //config: bool "Support 'export -n' option"
229 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
231 //config: export -n unexports variables. It is a bash extension.
233 //config:config HUSH_MODE_X
234 //config: bool "Support 'hush -x' option and 'set -x' command"
236 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
238 //config: This instructs hush to print commands before execution.
239 //config: Adds ~300 bytes.
242 //config: bool "msh (deprecated: aliased to hush)"
244 //config: select HUSH
246 //config: msh is deprecated and will be removed, please migrate to hush.
248 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
249 //applet:IF_MSH(APPLET_ODDNAME(msh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
250 //applet:IF_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
251 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
253 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
254 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
255 //kbuild:lib-$(CONFIG_BASH_IS_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 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
269 || defined(__APPLE__) \
271 # include <malloc.h> /* for malloc_trim */
274 /* #include <dmalloc.h> */
276 # include <fnmatch.h>
278 #include <sys/utsname.h> /* for setting $HOSTNAME */
280 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
282 #include "shell_common.h"
285 #if ENABLE_HUSH_RANDOM_SUPPORT
288 # define CLEAR_RANDOM_T(rnd) ((void)0)
290 #ifndef F_DUPFD_CLOEXEC
291 # define F_DUPFD_CLOEXEC F_DUPFD
294 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
299 #define LEAK_HUNTING 0
300 #define BUILD_AS_NOMMU 0
301 /* Enable/disable sanity checks. Ok to enable in production,
302 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
303 * Keeping 1 for now even in released versions.
306 /* Slightly bigger (+200 bytes), but faster hush.
307 * So far it only enables a trick with counting SIGCHLDs and forks,
308 * which allows us to do fewer waitpid's.
309 * (we can detect a case where neither forks were done nor SIGCHLDs happened
310 * and therefore waitpid will return the same result as last time)
312 #define ENABLE_HUSH_FAST 0
313 /* TODO: implement simplified code for users which do not need ${var%...} ops
314 * So far ${var%...} ops are always enabled:
316 #define ENABLE_HUSH_DOLLAR_OPS 1
321 # undef USE_FOR_NOMMU
324 # define USE_FOR_NOMMU(...) __VA_ARGS__
325 # define USE_FOR_MMU(...)
328 #include "NUM_APPLETS.h"
330 /* STANDALONE does not make sense, and won't compile */
331 # undef CONFIG_FEATURE_SH_STANDALONE
332 # undef ENABLE_FEATURE_SH_STANDALONE
333 # undef IF_FEATURE_SH_STANDALONE
334 # undef IF_NOT_FEATURE_SH_STANDALONE
335 # define ENABLE_FEATURE_SH_STANDALONE 0
336 # define IF_FEATURE_SH_STANDALONE(...)
337 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
340 #if !ENABLE_HUSH_INTERACTIVE
341 # undef ENABLE_FEATURE_EDITING
342 # define ENABLE_FEATURE_EDITING 0
343 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
344 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
345 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
346 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
349 /* Do we support ANY keywords? */
350 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
351 # define HAS_KEYWORDS 1
352 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
353 # define IF_HAS_NO_KEYWORDS(...)
355 # define HAS_KEYWORDS 0
356 # define IF_HAS_KEYWORDS(...)
357 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
360 /* If you comment out one of these below, it will be #defined later
361 * to perform debug printfs to stderr: */
362 #define debug_printf(...) do {} while (0)
363 /* Finer-grained debug switches */
364 #define debug_printf_parse(...) do {} while (0)
365 #define debug_print_tree(a, b) do {} while (0)
366 #define debug_printf_exec(...) do {} while (0)
367 #define debug_printf_env(...) do {} while (0)
368 #define debug_printf_jobs(...) do {} while (0)
369 #define debug_printf_expand(...) do {} while (0)
370 #define debug_printf_varexp(...) do {} while (0)
371 #define debug_printf_glob(...) do {} while (0)
372 #define debug_printf_list(...) do {} while (0)
373 #define debug_printf_subst(...) do {} while (0)
374 #define debug_printf_clean(...) do {} while (0)
376 #define ERR_PTR ((void*)(long)1)
378 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
380 #define _SPECIAL_VARS_STR "_*@$!?#"
381 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
382 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
383 #if ENABLE_HUSH_BASH_COMPAT
384 /* Support / and // replace ops */
385 /* Note that // is stored as \ in "encoded" string representation */
386 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
387 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
388 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
390 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
391 # define VAR_SUBST_OPS "%#:-=+?"
392 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
395 #define SPECIAL_VAR_SYMBOL 3
399 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
401 /* This supports saving pointers malloced in vfork child,
402 * to be freed in the parent.
405 typedef struct nommu_save_t {
407 struct variable *old_vars;
409 char **argv_from_re_execing;
422 #if ENABLE_HUSH_LOOPS
429 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
434 /* three pseudo-keywords support contrived "case" syntax: */
435 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
436 RES_MATCH , /* "word)" */
437 RES_CASE_BODY, /* "this command is inside CASE" */
444 typedef struct o_string {
446 int length; /* position where data is appended */
449 /* At least some part of the string was inside '' or "",
450 * possibly empty one: word"", wo''rd etc. */
451 smallint has_quoted_part;
452 smallint has_empty_slot;
453 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
456 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
458 /* Protect newly added chars against globbing
459 * by prepending \ to *, ?, [, \ */
460 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
463 MAYBE_ASSIGNMENT = 0,
464 DEFINITELY_ASSIGNMENT = 1,
466 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
469 /* Used for initialization: o_string foo = NULL_O_STRING; */
470 #define NULL_O_STRING { NULL }
472 #ifndef debug_printf_parse
473 static const char *const assignment_flag[] = {
475 "DEFINITELY_ASSIGNMENT",
481 typedef struct in_str {
483 #if ENABLE_HUSH_INTERACTIVE
484 smallint promptmode; /* 0: PS1, 1: PS2 */
491 /* The descrip member of this structure is only used to make
492 * debugging output pretty */
493 static const struct {
495 signed char default_fd;
498 { O_RDONLY, 0, "<" },
499 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
500 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
501 { O_CREAT|O_RDWR, 1, "<>" },
502 { O_RDONLY, 0, "<<" },
503 /* Should not be needed. Bogus default_fd helps in debugging */
504 /* { O_RDONLY, 77, "<<" }, */
507 struct redir_struct {
508 struct redir_struct *next;
509 char *rd_filename; /* filename */
510 int rd_fd; /* fd to redirect */
511 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
513 smallint rd_type; /* (enum redir_type) */
514 /* note: for heredocs, rd_filename contains heredoc delimiter,
515 * and subsequently heredoc itself; and rd_dup is a bitmask:
516 * bit 0: do we need to trim leading tabs?
517 * bit 1: is heredoc quoted (<<'delim' syntax) ?
520 typedef enum redir_type {
522 REDIRECT_OVERWRITE = 1,
525 REDIRECT_HEREDOC = 4,
526 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
529 REDIRFD_SYNTAX_ERR = -2,
530 REDIRFD_TO_FILE = -1,
531 /* otherwise, rd_fd is redirected to rd_dup */
533 HEREDOC_SKIPTABS = 1,
539 pid_t pid; /* 0 if exited */
540 int assignment_cnt; /* how many argv[i] are assignments? */
541 smallint cmd_type; /* CMD_xxx */
543 #define CMD_SUBSHELL 1
544 #if ENABLE_HUSH_BASH_COMPAT
545 /* used for "[[ EXPR ]]" */
546 # define CMD_SINGLEWORD_NOGLOB 2
548 #if ENABLE_HUSH_FUNCTIONS
549 # define CMD_FUNCDEF 3
552 smalluint cmd_exitcode;
553 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
556 char *group_as_string;
558 #if ENABLE_HUSH_FUNCTIONS
559 struct function *child_func;
560 /* This field is used to prevent a bug here:
561 * while...do f1() {a;}; f1; f1() {b;}; f1; done
562 * When we execute "f1() {a;}" cmd, we create new function and clear
563 * cmd->group, cmd->group_as_string, cmd->argv[0].
564 * When we execute "f1() {b;}", we notice that f1 exists,
565 * and that its "parent cmd" struct is still "alive",
566 * we put those fields back into cmd->xxx
567 * (struct function has ->parent_cmd ptr to facilitate that).
568 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
569 * Without this trick, loop would execute a;b;b;b;...
570 * instead of correct sequence a;b;a;b;...
571 * When command is freed, it severs the link
572 * (sets ->child_func->parent_cmd to NULL).
575 char **argv; /* command name and arguments */
576 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
577 * and on execution these are substituted with their values.
578 * Substitution can make _several_ words out of one argv[n]!
579 * Example: argv[0]=='.^C*^C.' here: echo .$*.
580 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
582 struct redir_struct *redirects; /* I/O redirections */
584 /* Is there anything in this command at all? */
585 #define IS_NULL_CMD(cmd) \
586 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
590 int num_cmds; /* total number of commands in pipe */
591 int alive_cmds; /* number of commands running (not exited) */
592 int stopped_cmds; /* number of commands alive, but stopped */
594 unsigned jobid; /* job number */
595 pid_t pgrp; /* process group ID for the job */
596 char *cmdtext; /* name of job */
598 struct command *cmds; /* array of commands in pipe */
599 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
600 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
601 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
603 typedef enum pipe_style {
609 /* Is there anything in this pipe at all? */
610 #define IS_NULL_PIPE(pi) \
611 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
613 /* This holds pointers to the various results of parsing */
614 struct parse_context {
615 /* linked list of pipes */
616 struct pipe *list_head;
617 /* last pipe (being constructed right now) */
619 /* last command in pipe (being constructed right now) */
620 struct command *command;
621 /* last redirect in command->redirects list */
622 struct redir_struct *pending_redirect;
628 smallint ctx_inverted; /* "! cmd | cmd" */
630 smallint ctx_dsemicolon; /* ";;" seen */
632 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
634 /* group we are enclosed in:
635 * example: "if pipe1; pipe2; then pipe3; fi"
636 * when we see "if" or "then", we malloc and copy current context,
637 * and make ->stack point to it. then we parse pipeN.
638 * when closing "then" / fi" / whatever is found,
639 * we move list_head into ->stack->command->group,
640 * copy ->stack into current context, and delete ->stack.
641 * (parsing of { list } and ( list ) doesn't use this method)
643 struct parse_context *stack;
647 /* On program start, environ points to initial environment.
648 * putenv adds new pointers into it, unsetenv removes them.
649 * Neither of these (de)allocates the strings.
650 * setenv allocates new strings in malloc space and does putenv,
651 * and thus setenv is unusable (leaky) for shell's purposes */
652 #define setenv(...) setenv_is_leaky_dont_use()
654 struct variable *next;
655 char *varstr; /* points to "name=" portion */
656 #if ENABLE_HUSH_LOCAL
657 unsigned func_nest_level;
659 int max_len; /* if > 0, name is part of initial env; else name is malloced */
660 smallint flg_export; /* putenv should be done on this var */
661 smallint flg_read_only;
669 #if ENABLE_HUSH_FUNCTIONS
671 struct function *next;
673 struct command *parent_cmd;
676 char *body_as_string;
682 /* set -/+o OPT support. (TODO: make it optional)
683 * bash supports the following opts:
694 * interactive-comments on
712 static const char o_opt_strings[] ALIGN1 =
715 #if ENABLE_HUSH_MODE_X
722 #if ENABLE_HUSH_MODE_X
730 struct FILE_list *next;
736 /* "Globals" within this file */
737 /* Sorted roughly by size (smaller offsets == smaller code) */
739 /* interactive_fd != 0 means we are an interactive shell.
740 * If we are, then saved_tty_pgrp can also be != 0, meaning
741 * that controlling tty is available. With saved_tty_pgrp == 0,
742 * job control still works, but terminal signals
743 * (^C, ^Z, ^Y, ^\) won't work at all, and background
744 * process groups can only be created with "cmd &".
745 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
746 * to give tty to the foreground process group,
747 * and will take it back when the group is stopped (^Z)
750 #if ENABLE_HUSH_INTERACTIVE
751 /* 'interactive_fd' is a fd# open to ctty, if we have one
752 * _AND_ if we decided to act interactively */
756 # define G_interactive_fd (G.interactive_fd)
758 # define G_interactive_fd 0
760 #if ENABLE_FEATURE_EDITING
761 line_input_t *line_input_state;
766 #if ENABLE_HUSH_RANDOM_SUPPORT
772 pid_t saved_tty_pgrp;
773 struct pipe *job_list;
774 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
776 # define G_saved_tty_pgrp 0
778 char o_opt[NUM_OPT_O];
779 #if ENABLE_HUSH_MODE_X
780 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
784 smallint flag_SIGINT;
785 #if ENABLE_HUSH_LOOPS
786 smallint flag_break_continue;
788 #if ENABLE_HUSH_FUNCTIONS
789 /* 0: outside of a function (or sourced file)
790 * -1: inside of a function, ok to use return builtin
791 * 1: return is invoked, skip all till end of func
793 smallint flag_return_in_progress;
794 # define G_flag_return_in_progress (G.flag_return_in_progress)
796 # define G_flag_return_in_progress 0
798 smallint exiting; /* used to prevent EXIT trap recursion */
799 /* These four support $?, $#, and $1 */
800 smalluint last_exitcode;
801 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
802 smalluint global_args_malloced;
803 /* how many non-NULL argv's we have. NB: $# + 1 */
807 char *argv0_for_re_execing;
809 #if ENABLE_HUSH_LOOPS
810 unsigned depth_break_continue;
811 unsigned depth_of_loop;
815 struct variable *top_var;
816 char **expanded_assignments;
817 #if ENABLE_HUSH_FUNCTIONS
818 struct function *top_func;
819 # if ENABLE_HUSH_LOCAL
820 struct variable **shadowed_vars_pp;
821 unsigned func_nest_level;
824 /* Signal and trap handling */
826 unsigned count_SIGCHLD;
827 unsigned handled_SIGCHLD;
828 smallint we_have_children;
830 struct FILE_list *FILE_list;
831 /* Which signals have non-DFL handler (even with no traps set)?
832 * Set at the start to:
833 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
834 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
835 * The rest is cleared right before execv syscalls.
836 * Other than these two times, never modified.
838 unsigned special_sig_mask;
840 unsigned fatal_sig_mask;
841 # define G_fatal_sig_mask G.fatal_sig_mask
843 # define G_fatal_sig_mask 0
845 char **traps; /* char *traps[NSIG] */
846 sigset_t pending_set;
848 unsigned long memleak_value;
852 #if ENABLE_FEATURE_EDITING
853 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
856 #define G (*ptr_to_globals)
857 /* Not #defining name to G.name - this quickly gets unwieldy
858 * (too many defines). Also, I actually prefer to see when a variable
859 * is global, thus "G." prefix is a useful hint */
860 #define INIT_G() do { \
861 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
862 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
863 sigfillset(&G.sa.sa_mask); \
864 G.sa.sa_flags = SA_RESTART; \
868 /* Function prototypes for builtins */
869 static int builtin_cd(char **argv) FAST_FUNC;
870 static int builtin_echo(char **argv) FAST_FUNC;
871 static int builtin_eval(char **argv) FAST_FUNC;
872 static int builtin_exec(char **argv) FAST_FUNC;
873 static int builtin_exit(char **argv) FAST_FUNC;
874 static int builtin_export(char **argv) FAST_FUNC;
876 static int builtin_fg_bg(char **argv) FAST_FUNC;
877 static int builtin_jobs(char **argv) FAST_FUNC;
880 static int builtin_help(char **argv) FAST_FUNC;
882 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
883 static int builtin_history(char **argv) FAST_FUNC;
885 #if ENABLE_HUSH_LOCAL
886 static int builtin_local(char **argv) FAST_FUNC;
889 static int builtin_memleak(char **argv) FAST_FUNC;
891 #if ENABLE_HUSH_PRINTF
892 static int builtin_printf(char **argv) FAST_FUNC;
894 static int builtin_pwd(char **argv) FAST_FUNC;
895 static int builtin_read(char **argv) FAST_FUNC;
896 static int builtin_set(char **argv) FAST_FUNC;
897 static int builtin_shift(char **argv) FAST_FUNC;
898 static int builtin_source(char **argv) FAST_FUNC;
899 static int builtin_test(char **argv) FAST_FUNC;
900 static int builtin_trap(char **argv) FAST_FUNC;
902 static int builtin_type(char **argv) FAST_FUNC;
904 static int builtin_true(char **argv) FAST_FUNC;
905 static int builtin_umask(char **argv) FAST_FUNC;
906 static int builtin_unset(char **argv) FAST_FUNC;
908 static int builtin_kill(char **argv) FAST_FUNC;
911 static int builtin_wait(char **argv) FAST_FUNC;
913 #if ENABLE_HUSH_LOOPS
914 static int builtin_break(char **argv) FAST_FUNC;
915 static int builtin_continue(char **argv) FAST_FUNC;
917 #if ENABLE_HUSH_FUNCTIONS
918 static int builtin_return(char **argv) FAST_FUNC;
921 /* Table of built-in functions. They can be forked or not, depending on
922 * context: within pipes, they fork. As simple commands, they do not.
923 * When used in non-forking context, they can change global variables
924 * in the parent shell process. If forked, of course they cannot.
925 * For example, 'unset foo | whatever' will parse and run, but foo will
926 * still be set at the end. */
927 struct built_in_command {
929 int (*b_function)(char **argv) FAST_FUNC;
932 # define BLTIN(cmd, func, help) { cmd, func, help }
934 # define BLTIN(cmd, func, help) { cmd, func }
938 static const struct built_in_command bltins1[] = {
939 BLTIN("." , builtin_source , "Run commands in a file"),
940 BLTIN(":" , builtin_true , NULL),
942 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
944 #if ENABLE_HUSH_LOOPS
945 BLTIN("break" , builtin_break , "Exit from a loop"),
947 BLTIN("cd" , builtin_cd , "Change directory"),
948 #if ENABLE_HUSH_LOOPS
949 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
951 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
952 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
953 BLTIN("exit" , builtin_exit , "Exit"),
954 BLTIN("export" , builtin_export , "Set environment variables"),
956 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
959 BLTIN("help" , builtin_help , NULL),
961 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
962 BLTIN("history" , builtin_history , "Show command history"),
965 BLTIN("jobs" , builtin_jobs , "List jobs"),
968 BLTIN("kill" , builtin_kill , "Send signals to processes"),
970 #if ENABLE_HUSH_LOCAL
971 BLTIN("local" , builtin_local , "Set local variables"),
974 BLTIN("memleak" , builtin_memleak , NULL),
976 BLTIN("read" , builtin_read , "Input into variable"),
977 #if ENABLE_HUSH_FUNCTIONS
978 BLTIN("return" , builtin_return , "Return from a function"),
980 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
981 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
982 #if ENABLE_HUSH_BASH_COMPAT
983 BLTIN("source" , builtin_source , "Run commands in a file"),
985 BLTIN("trap" , builtin_trap , "Trap signals"),
986 BLTIN("true" , builtin_true , NULL),
988 BLTIN("type" , builtin_type , "Show command type"),
990 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
991 BLTIN("umask" , builtin_umask , "Set file creation mask"),
992 BLTIN("unset" , builtin_unset , "Unset variables"),
994 BLTIN("wait" , builtin_wait , "Wait for process"),
997 /* For now, echo and test are unconditionally enabled.
998 * Maybe make it configurable? */
999 static const struct built_in_command bltins2[] = {
1000 BLTIN("[" , builtin_test , NULL),
1001 BLTIN("echo" , builtin_echo , NULL),
1002 #if ENABLE_HUSH_PRINTF
1003 BLTIN("printf" , builtin_printf , NULL),
1005 BLTIN("pwd" , builtin_pwd , NULL),
1006 BLTIN("test" , builtin_test , NULL),
1013 /* prevent disasters with G.debug_indent < 0 */
1014 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1015 # define debug_enter() (G.debug_indent++)
1016 # define debug_leave() (G.debug_indent--)
1018 # define indent() ((void)0)
1019 # define debug_enter() ((void)0)
1020 # define debug_leave() ((void)0)
1023 #ifndef debug_printf
1024 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1027 #ifndef debug_printf_parse
1028 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1031 #ifndef debug_printf_exec
1032 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1035 #ifndef debug_printf_env
1036 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1039 #ifndef debug_printf_jobs
1040 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1041 # define DEBUG_JOBS 1
1043 # define DEBUG_JOBS 0
1046 #ifndef debug_printf_expand
1047 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1048 # define DEBUG_EXPAND 1
1050 # define DEBUG_EXPAND 0
1053 #ifndef debug_printf_varexp
1054 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1057 #ifndef debug_printf_glob
1058 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1059 # define DEBUG_GLOB 1
1061 # define DEBUG_GLOB 0
1064 #ifndef debug_printf_list
1065 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1068 #ifndef debug_printf_subst
1069 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1072 #ifndef debug_printf_clean
1073 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1074 # define DEBUG_CLEAN 1
1076 # define DEBUG_CLEAN 0
1080 static void debug_print_strings(const char *prefix, char **vv)
1083 fdprintf(2, "%s:\n", prefix);
1085 fdprintf(2, " '%s'\n", *vv++);
1088 # define debug_print_strings(prefix, vv) ((void)0)
1092 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1095 static void *xxmalloc(int lineno, size_t size)
1097 void *ptr = xmalloc((size + 0xff) & ~0xff);
1098 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1101 static void *xxrealloc(int lineno, void *ptr, size_t size)
1103 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1104 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1107 static char *xxstrdup(int lineno, const char *str)
1109 char *ptr = xstrdup(str);
1110 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1113 static void xxfree(void *ptr)
1115 fdprintf(2, "free %p\n", ptr);
1118 # define xmalloc(s) xxmalloc(__LINE__, s)
1119 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1120 # define xstrdup(s) xxstrdup(__LINE__, s)
1121 # define free(p) xxfree(p)
1125 /* Syntax and runtime errors. They always abort scripts.
1126 * In interactive use they usually discard unparsed and/or unexecuted commands
1127 * and return to the prompt.
1128 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1131 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1132 # define syntax_error(lineno, msg) syntax_error(msg)
1133 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1134 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1135 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1136 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1139 static void die_if_script(unsigned lineno, const char *fmt, ...)
1144 bb_error_msg("hush.c:%u", lineno);
1147 bb_verror_msg(fmt, p, NULL);
1149 if (!G_interactive_fd)
1153 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1156 bb_error_msg("syntax error: %s", msg);
1158 bb_error_msg("syntax error");
1161 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1163 bb_error_msg("syntax error at '%s'", msg);
1166 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1168 bb_error_msg("syntax error: unterminated %s", s);
1171 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1173 char msg[2] = { ch, '\0' };
1174 syntax_error_unterm_str(lineno, msg);
1177 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1183 bb_error_msg("hush.c:%u", lineno);
1185 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1189 # undef die_if_script
1190 # undef syntax_error
1191 # undef syntax_error_at
1192 # undef syntax_error_unterm_ch
1193 # undef syntax_error_unterm_str
1194 # undef syntax_error_unexpected_ch
1196 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1197 # define syntax_error(msg) syntax_error(__LINE__, msg)
1198 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1199 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1200 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1201 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1205 #if ENABLE_HUSH_INTERACTIVE
1206 static void cmdedit_update_prompt(void);
1208 # define cmdedit_update_prompt() ((void)0)
1212 /* Utility functions
1214 /* Replace each \x with x in place, return ptr past NUL. */
1215 static char *unbackslash(char *src)
1217 char *dst = src = strchrnul(src, '\\');
1221 if ((*dst++ = *src++) == '\0')
1227 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1248 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1249 v[count1 + count2] = NULL;
1252 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1256 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1258 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1259 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1262 #define add_strings_to_strings(strings, add, need_to_dup) \
1263 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1266 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1267 static char **add_string_to_strings(char **strings, char *add)
1272 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1275 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1277 char **ptr = add_string_to_strings(strings, add);
1278 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1281 #define add_string_to_strings(strings, add) \
1282 xx_add_string_to_strings(__LINE__, strings, add)
1285 static void free_strings(char **strings)
1300 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1302 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1303 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1305 /* fd was not open? */
1315 /* Manipulating the list of open FILEs */
1316 static FILE *remember_FILE(FILE *fp)
1319 struct FILE_list *n = xmalloc(sizeof(*n));
1320 n->next = G.FILE_list;
1324 close_on_exec_on(n->fd);
1328 static void fclose_and_forget(FILE *fp)
1330 struct FILE_list **pp = &G.FILE_list;
1332 struct FILE_list *cur = *pp;
1333 if (cur->fp == fp) {
1342 static int save_FILEs_on_redirect(int fd)
1344 struct FILE_list *fl = G.FILE_list;
1347 /* We use it only on script files, they are all CLOEXEC */
1348 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1355 static void restore_redirected_FILEs(void)
1357 struct FILE_list *fl = G.FILE_list;
1359 int should_be = fileno(fl->fp);
1360 if (fl->fd != should_be) {
1361 xmove_fd(fl->fd, should_be);
1367 #if ENABLE_FEATURE_SH_STANDALONE
1368 static void close_all_FILE_list(void)
1370 struct FILE_list *fl = G.FILE_list;
1372 /* fclose would also free FILE object.
1373 * It is disastrous if we share memory with a vforked parent.
1374 * I'm not sure we never come here after vfork.
1375 * Therefore just close fd, nothing more.
1377 /*fclose(fl->fp); - unsafe */
1385 /* Helpers for setting new $n and restoring them back
1387 typedef struct save_arg_t {
1391 smallint sv_g_malloced;
1394 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1398 sv->sv_argv0 = argv[0];
1399 sv->sv_g_argv = G.global_argv;
1400 sv->sv_g_argc = G.global_argc;
1401 sv->sv_g_malloced = G.global_args_malloced;
1403 argv[0] = G.global_argv[0]; /* retain $0 */
1404 G.global_argv = argv;
1405 G.global_args_malloced = 0;
1413 static void restore_G_args(save_arg_t *sv, char **argv)
1417 if (G.global_args_malloced) {
1418 /* someone ran "set -- arg1 arg2 ...", undo */
1420 while (*++pp) /* note: does not free $0 */
1422 free(G.global_argv);
1424 argv[0] = sv->sv_argv0;
1425 G.global_argv = sv->sv_g_argv;
1426 G.global_argc = sv->sv_g_argc;
1427 G.global_args_malloced = sv->sv_g_malloced;
1431 /* Basic theory of signal handling in shell
1432 * ========================================
1433 * This does not describe what hush does, rather, it is current understanding
1434 * what it _should_ do. If it doesn't, it's a bug.
1435 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1437 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1438 * is finished or backgrounded. It is the same in interactive and
1439 * non-interactive shells, and is the same regardless of whether
1440 * a user trap handler is installed or a shell special one is in effect.
1441 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1442 * backgrounds (i.e. stops) or kills all members of currently running
1445 * Wait builtin is interruptible by signals for which user trap is set
1446 * or by SIGINT in interactive shell.
1448 * Trap handlers will execute even within trap handlers. (right?)
1450 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1451 * except for handlers set to '' (empty string).
1453 * If job control is off, backgrounded commands ("cmd &")
1454 * have SIGINT, SIGQUIT set to SIG_IGN.
1456 * Commands which are run in command substitution ("`cmd`")
1457 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1459 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1460 * by the shell from its parent.
1462 * Signals which differ from SIG_DFL action
1463 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1466 * SIGTERM (interactive): ignore
1467 * SIGHUP (interactive):
1468 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1469 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1470 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1471 * that all pipe members are stopped. Try this in bash:
1472 * while :; do :; done - ^Z does not background it
1473 * (while :; do :; done) - ^Z backgrounds it
1474 * SIGINT (interactive): wait for last pipe, ignore the rest
1475 * of the command line, show prompt. NB: ^C does not send SIGINT
1476 * to interactive shell while shell is waiting for a pipe,
1477 * since shell is bg'ed (is not in foreground process group).
1478 * Example 1: this waits 5 sec, but does not execute ls:
1479 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1480 * Example 2: this does not wait and does not execute ls:
1481 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1482 * Example 3: this does not wait 5 sec, but executes ls:
1483 * "sleep 5; ls -l" + press ^C
1484 * Example 4: this does not wait and does not execute ls:
1485 * "sleep 5 & wait; ls -l" + press ^C
1487 * (What happens to signals which are IGN on shell start?)
1488 * (What happens with signal mask on shell start?)
1490 * Old implementation
1491 * ==================
1492 * We use in-kernel pending signal mask to determine which signals were sent.
1493 * We block all signals which we don't want to take action immediately,
1494 * i.e. we block all signals which need to have special handling as described
1495 * above, and all signals which have traps set.
1496 * After each pipe execution, we extract any pending signals via sigtimedwait()
1499 * unsigned special_sig_mask: a mask of such "special" signals
1500 * sigset_t blocked_set: current blocked signal set
1503 * clear bit in blocked_set unless it is also in special_sig_mask
1504 * "trap 'cmd' SIGxxx":
1505 * set bit in blocked_set (even if 'cmd' is '')
1506 * after [v]fork, if we plan to be a shell:
1507 * unblock signals with special interactive handling
1508 * (child shell is not interactive),
1509 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1510 * after [v]fork, if we plan to exec:
1511 * POSIX says fork clears pending signal mask in child - no need to clear it.
1512 * Restore blocked signal set to one inherited by shell just prior to exec.
1514 * Note: as a result, we do not use signal handlers much. The only uses
1515 * are to count SIGCHLDs
1516 * and to restore tty pgrp on signal-induced exit.
1519 * Standard says "When a subshell is entered, traps that are not being ignored
1520 * are set to the default actions". bash interprets it so that traps which
1521 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1523 * Problem: the above approach makes it unwieldy to catch signals while
1524 * we are in read builtin, or while we read commands from stdin:
1525 * masked signals are not visible!
1527 * New implementation
1528 * ==================
1529 * We record each signal we are interested in by installing signal handler
1530 * for them - a bit like emulating kernel pending signal mask in userspace.
1531 * We are interested in: signals which need to have special handling
1532 * as described above, and all signals which have traps set.
1533 * Signals are recorded in pending_set.
1534 * After each pipe execution, we extract any pending signals
1537 * unsigned special_sig_mask: a mask of shell-special signals.
1538 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1539 * char *traps[sig] if trap for sig is set (even if it's '').
1540 * sigset_t pending_set: set of sigs we received.
1543 * if sig is in special_sig_mask, set handler back to:
1544 * record_pending_signo, or to IGN if it's a tty stop signal
1545 * if sig is in fatal_sig_mask, set handler back to sigexit.
1546 * else: set handler back to SIG_DFL
1547 * "trap 'cmd' SIGxxx":
1548 * set handler to record_pending_signo.
1550 * set handler to SIG_IGN.
1551 * after [v]fork, if we plan to be a shell:
1552 * set signals with special interactive handling to SIG_DFL
1553 * (because child shell is not interactive),
1554 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1555 * after [v]fork, if we plan to exec:
1556 * POSIX says fork clears pending signal mask in child - no need to clear it.
1558 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1559 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1562 * Standard says "When a subshell is entered, traps that are not being ignored
1563 * are set to the default actions". bash interprets it so that traps which
1564 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1567 SPECIAL_INTERACTIVE_SIGS = 0
1572 SPECIAL_JOBSTOP_SIGS = 0
1581 static void record_pending_signo(int sig)
1583 sigaddset(&G.pending_set, sig);
1584 #if ENABLE_HUSH_FAST
1585 if (sig == SIGCHLD) {
1587 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1592 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1594 struct sigaction old_sa;
1596 /* We could use signal() to install handlers... almost:
1597 * except that we need to mask ALL signals while handlers run.
1598 * I saw signal nesting in strace, race window isn't small.
1599 * SA_RESTART is also needed, but in Linux, signal()
1600 * sets SA_RESTART too.
1602 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1603 /* sigfillset(&G.sa.sa_mask); - already done */
1604 /* G.sa.sa_flags = SA_RESTART; - already done */
1605 G.sa.sa_handler = handler;
1606 sigaction(sig, &G.sa, &old_sa);
1607 return old_sa.sa_handler;
1610 static void hush_exit(int exitcode) NORETURN;
1612 static void restore_ttypgrp_and__exit(void) NORETURN;
1613 static void restore_ttypgrp_and__exit(void)
1615 /* xfunc has failed! die die die */
1616 /* no EXIT traps, this is an escape hatch! */
1618 hush_exit(xfunc_error_retval);
1623 /* Needed only on some libc:
1624 * It was observed that on exit(), fgetc'ed buffered data
1625 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1626 * With the net effect that even after fork(), not vfork(),
1627 * exit() in NOEXECed applet in "sh SCRIPT":
1628 * noexec_applet_here
1629 * echo END_OF_SCRIPT
1630 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1631 * This makes "echo END_OF_SCRIPT" executed twice.
1632 * Similar problems can be seen with die_if_script() -> xfunc_die()
1633 * and in `cmd` handling.
1634 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1636 static void fflush_and__exit(void) NORETURN;
1637 static void fflush_and__exit(void)
1640 _exit(xfunc_error_retval);
1643 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1644 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1645 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1646 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1648 /* Restores tty foreground process group, and exits.
1649 * May be called as signal handler for fatal signal
1650 * (will resend signal to itself, producing correct exit state)
1651 * or called directly with -EXITCODE.
1652 * We also call it if xfunc is exiting.
1654 static void sigexit(int sig) NORETURN;
1655 static void sigexit(int sig)
1657 /* Careful: we can end up here after [v]fork. Do not restore
1658 * tty pgrp then, only top-level shell process does that */
1659 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1660 /* Disable all signals: job control, SIGPIPE, etc.
1661 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1663 sigprocmask_allsigs(SIG_BLOCK);
1664 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1667 /* Not a signal, just exit */
1671 kill_myself_with_sig(sig); /* does not return */
1675 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1676 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1680 static sighandler_t pick_sighandler(unsigned sig)
1682 sighandler_t handler = SIG_DFL;
1683 if (sig < sizeof(unsigned)*8) {
1684 unsigned sigmask = (1 << sig);
1688 if (G_fatal_sig_mask & sigmask)
1692 /* sig has special handling? */
1693 if (G.special_sig_mask & sigmask) {
1694 handler = record_pending_signo;
1695 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1696 * in order to ignore them: they will be raised
1697 * in an endless loop when we try to do some
1698 * terminal ioctls! We do have to _ignore_ these.
1700 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1707 /* Restores tty foreground process group, and exits. */
1708 static void hush_exit(int exitcode)
1710 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1711 save_history(G.line_input_state);
1715 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1717 /* argv[0] is unused */
1718 argv[1] = G.traps[0];
1720 G.exiting = 1; /* prevent EXIT trap recursion */
1721 /* Note: G.traps[0] is not cleared!
1722 * "trap" will still show it, if executed
1727 #if ENABLE_FEATURE_CLEAN_UP
1729 struct variable *cur_var;
1730 if (G.cwd != bb_msg_unknown)
1732 cur_var = G.top_var;
1734 struct variable *tmp = cur_var;
1735 if (!cur_var->max_len)
1736 free(cur_var->varstr);
1737 cur_var = cur_var->next;
1745 sigexit(- (exitcode & 0xff));
1752 //TODO: return a mask of ALL handled sigs?
1753 static int check_and_run_traps(void)
1760 if (sigisemptyset(&G.pending_set))
1765 if (sigismember(&G.pending_set, sig)) {
1766 sigdelset(&G.pending_set, sig);
1769 } while (sig < NSIG);
1772 if (G.traps && G.traps[sig]) {
1773 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1774 if (G.traps[sig][0]) {
1775 /* We have user-defined handler */
1776 smalluint save_rcode;
1778 /* argv[0] is unused */
1779 argv[1] = G.traps[sig];
1781 save_rcode = G.last_exitcode;
1783 //FIXME: shouldn't it be set to 128 + sig instead?
1784 G.last_exitcode = save_rcode;
1786 } /* else: "" trap, ignoring signal */
1789 /* not a trap: special action */
1792 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1799 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1800 /* bash is observed to signal whole process groups,
1801 * not individual processes */
1802 for (job = G.job_list; job; job = job->next) {
1805 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1806 if (kill(- job->pgrp, SIGHUP) == 0)
1807 kill(- job->pgrp, SIGCONT);
1812 #if ENABLE_HUSH_FAST
1814 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1816 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1818 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1819 * This simplifies wait builtin a bit.
1823 default: /* ignored: */
1824 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1825 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1827 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1828 * Example: wait is not interrupted by TERM
1829 * in interactive shell, because TERM is ignored.
1838 static const char *get_cwd(int force)
1840 if (force || G.cwd == NULL) {
1841 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1842 * we must not try to free(bb_msg_unknown) */
1843 if (G.cwd == bb_msg_unknown)
1845 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1847 G.cwd = bb_msg_unknown;
1854 * Shell and environment variable support
1856 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1858 struct variable **pp;
1859 struct variable *cur;
1862 while ((cur = *pp) != NULL) {
1863 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1870 static const char* FAST_FUNC get_local_var_value(const char *name)
1872 struct variable **vpp;
1873 unsigned len = strlen(name);
1875 if (G.expanded_assignments) {
1876 char **cpp = G.expanded_assignments;
1879 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1880 return cp + len + 1;
1885 vpp = get_ptr_to_local_var(name, len);
1887 return (*vpp)->varstr + len + 1;
1889 if (strcmp(name, "PPID") == 0)
1890 return utoa(G.root_ppid);
1891 // bash compat: UID? EUID?
1892 #if ENABLE_HUSH_RANDOM_SUPPORT
1893 if (strcmp(name, "RANDOM") == 0)
1894 return utoa(next_random(&G.random_gen));
1899 /* str holds "NAME=VAL" and is expected to be malloced.
1900 * We take ownership of it.
1902 * 0: do not change export flag
1903 * (if creating new variable, flag will be 0)
1904 * 1: set export flag and putenv the variable
1905 * -1: clear export flag and unsetenv the variable
1906 * flg_read_only is set only when we handle -R var=val
1908 #if !BB_MMU && ENABLE_HUSH_LOCAL
1909 /* all params are used */
1910 #elif BB_MMU && ENABLE_HUSH_LOCAL
1911 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1912 set_local_var(str, flg_export, local_lvl)
1913 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1914 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1915 set_local_var(str, flg_export)
1916 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1917 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1918 set_local_var(str, flg_export, flg_read_only)
1920 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1922 struct variable **var_pp;
1923 struct variable *cur;
1924 char *free_me = NULL;
1928 eq_sign = strchr(str, '=');
1929 if (!eq_sign) { /* not expected to ever happen? */
1934 name_len = eq_sign - str + 1; /* including '=' */
1935 var_pp = &G.top_var;
1936 while ((cur = *var_pp) != NULL) {
1937 if (strncmp(cur->varstr, str, name_len) != 0) {
1938 var_pp = &cur->next;
1942 /* We found an existing var with this name */
1943 if (cur->flg_read_only) {
1947 bb_error_msg("%s: readonly variable", str);
1951 if (flg_export == -1) { // "&& cur->flg_export" ?
1952 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1957 #if ENABLE_HUSH_LOCAL
1958 if (cur->func_nest_level < local_lvl) {
1959 /* New variable is declared as local,
1960 * and existing one is global, or local
1961 * from enclosing function.
1962 * Remove and save old one: */
1963 *var_pp = cur->next;
1964 cur->next = *G.shadowed_vars_pp;
1965 *G.shadowed_vars_pp = cur;
1966 /* bash 3.2.33(1) and exported vars:
1968 * # f() { local z=a; env | grep ^z; }
1974 if (cur->flg_export)
1979 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1984 if (cur->max_len != 0) {
1985 if (cur->max_len >= strlen(str)) {
1986 /* This one is from startup env, reuse space */
1987 strcpy(cur->varstr, str);
1992 goto set_str_and_exp;
1994 /* max_len == 0 signifies "malloced" var, which we can
1995 * (and have to) free. But we can't free(cur->varstr) here:
1996 * if cur->flg_export is 1, it is in the environment.
1997 * We should either unsetenv+free, or wait until putenv,
1998 * then putenv(new)+free(old).
2000 free_me = cur->varstr;
2001 goto set_str_and_exp;
2004 /* Not found - create new variable struct */
2005 cur = xzalloc(sizeof(*cur));
2006 #if ENABLE_HUSH_LOCAL
2007 cur->func_nest_level = local_lvl;
2009 cur->next = *var_pp;
2015 cur->flg_read_only = flg_read_only;
2018 if (flg_export == 1)
2019 cur->flg_export = 1;
2020 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2021 cmdedit_update_prompt();
2022 if (cur->flg_export) {
2023 if (flg_export == -1) {
2024 cur->flg_export = 0;
2025 /* unsetenv was already done */
2028 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2029 i = putenv(cur->varstr);
2030 /* only now we can free old exported malloced string */
2039 /* Used at startup and after each cd */
2040 static void set_pwd_var(int exp)
2042 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2043 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2046 static int unset_local_var_len(const char *name, int name_len)
2048 struct variable *cur;
2049 struct variable **var_pp;
2052 return EXIT_SUCCESS;
2053 var_pp = &G.top_var;
2054 while ((cur = *var_pp) != NULL) {
2055 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2056 if (cur->flg_read_only) {
2057 bb_error_msg("%s: readonly variable", name);
2058 return EXIT_FAILURE;
2060 *var_pp = cur->next;
2061 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2062 bb_unsetenv(cur->varstr);
2063 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2064 cmdedit_update_prompt();
2068 return EXIT_SUCCESS;
2070 var_pp = &cur->next;
2072 return EXIT_SUCCESS;
2075 static int unset_local_var(const char *name)
2077 return unset_local_var_len(name, strlen(name));
2080 static void unset_vars(char **strings)
2088 const char *eq = strchrnul(*v, '=');
2089 unset_local_var_len(*v, (int)(eq - *v));
2095 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2097 char *var = xasprintf("%s=%s", name, val);
2098 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2103 * Helpers for "var1=val1 var2=val2 cmd" feature
2105 static void add_vars(struct variable *var)
2107 struct variable *next;
2111 var->next = G.top_var;
2113 if (var->flg_export) {
2114 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2115 putenv(var->varstr);
2117 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2123 static struct variable *set_vars_and_save_old(char **strings)
2126 struct variable *old = NULL;
2132 struct variable *var_p;
2133 struct variable **var_pp;
2136 eq = strchr(*s, '=');
2138 var_pp = get_ptr_to_local_var(*s, eq - *s);
2140 /* Remove variable from global linked list */
2142 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2143 *var_pp = var_p->next;
2144 /* Add it to returned list */
2148 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2159 static void reinit_unicode_for_hush(void)
2161 /* Unicode support should be activated even if LANG is set
2162 * _during_ shell execution, not only if it was set when
2163 * shell was started. Therefore, re-check LANG every time:
2165 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2166 || ENABLE_UNICODE_USING_LOCALE
2168 const char *s = get_local_var_value("LC_ALL");
2169 if (!s) s = get_local_var_value("LC_CTYPE");
2170 if (!s) s = get_local_var_value("LANG");
2176 * in_str support (strings, and "strings" read from files).
2179 #if ENABLE_HUSH_INTERACTIVE
2180 /* To test correct lineedit/interactive behavior, type from command line:
2186 * It excercises a lot of corner cases.
2188 static void cmdedit_update_prompt(void)
2190 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2191 G.PS1 = get_local_var_value("PS1");
2194 G.PS2 = get_local_var_value("PS2");
2201 static const char *setup_prompt_string(int promptmode)
2203 const char *prompt_str;
2204 debug_printf("setup_prompt_string %d ", promptmode);
2205 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2206 /* Set up the prompt */
2207 if (promptmode == 0) { /* PS1 */
2209 /* bash uses $PWD value, even if it is set by user.
2210 * It uses current dir only if PWD is unset.
2211 * We always use current dir. */
2212 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2217 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2218 debug_printf("prompt_str '%s'\n", prompt_str);
2221 static int get_user_input(struct in_str *i)
2224 const char *prompt_str;
2226 prompt_str = setup_prompt_string(i->promptmode);
2227 # if ENABLE_FEATURE_EDITING
2229 reinit_unicode_for_hush();
2230 if (G.flag_SIGINT) {
2231 /* There was ^C'ed, make it look prettier: */
2235 /* buglet: SIGINT will not make new prompt to appear _at once_,
2236 * only after <Enter>. (^C works immediately) */
2237 r = read_line_input(G.line_input_state, prompt_str,
2238 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2241 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2243 write(STDOUT_FILENO, "^C", 2);
2246 check_and_run_traps();
2247 if (r != 0 && !G.flag_SIGINT)
2249 /* ^C or SIGINT: repeat */
2250 G.last_exitcode = 128 + SIGINT;
2253 /* EOF/error detected */
2255 i->peek_buf[0] = r = EOF;
2258 i->p = G.user_input_buf;
2259 return (unsigned char)*i->p++;
2263 if (i->last_char == '\0' || i->last_char == '\n') {
2264 /* Why check_and_run_traps here? Try this interactively:
2265 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2266 * $ <[enter], repeatedly...>
2267 * Without check_and_run_traps, handler never runs.
2269 check_and_run_traps();
2270 fputs(prompt_str, stdout);
2273 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2275 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2276 * no ^C masking happens during fgetc, no special code for ^C:
2277 * it generates SIGINT as usual.
2279 check_and_run_traps();
2281 G.last_exitcode = 128 + SIGINT;
2288 /* This is the magic location that prints prompts
2289 * and gets data back from the user */
2290 static int fgetc_interactive(struct in_str *i)
2293 /* If it's interactive stdin, get new line. */
2294 if (G_interactive_fd && i->file == stdin) {
2295 /* Returns first char (or EOF), the rest is in i->p[] */
2296 ch = get_user_input(i);
2297 i->promptmode = 1; /* PS2 */
2299 /* Not stdin: script file, sourced file, etc */
2300 do ch = fgetc(i->file); while (ch == '\0');
2305 static inline int fgetc_interactive(struct in_str *i)
2308 do ch = fgetc(i->file); while (ch == '\0');
2311 #endif /* INTERACTIVE */
2313 static int i_getch(struct in_str *i)
2318 /* string-based in_str */
2319 ch = (unsigned char)*i->p;
2328 /* FILE-based in_str */
2330 #if ENABLE_FEATURE_EDITING
2331 /* This can be stdin, check line editing char[] buffer */
2332 if (i->p && *i->p != '\0') {
2333 ch = (unsigned char)*i->p++;
2337 /* peek_buf[] is an int array, not char. Can contain EOF. */
2338 ch = i->peek_buf[0];
2340 int ch2 = i->peek_buf[1];
2341 i->peek_buf[0] = ch2;
2342 if (ch2 == 0) /* very likely, avoid redundant write */
2348 ch = fgetc_interactive(i);
2350 debug_printf("file_get: got '%c' %d\n", ch, ch);
2355 static int i_peek(struct in_str *i)
2360 /* string-based in_str */
2361 /* Doesn't report EOF on NUL. None of the callers care. */
2362 return (unsigned char)*i->p;
2365 /* FILE-based in_str */
2367 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2368 /* This can be stdin, check line editing char[] buffer */
2369 if (i->p && *i->p != '\0')
2370 return (unsigned char)*i->p;
2372 /* peek_buf[] is an int array, not char. Can contain EOF. */
2373 ch = i->peek_buf[0];
2377 /* Need to get a new char */
2378 ch = fgetc_interactive(i);
2379 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2381 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2382 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2388 i->peek_buf[0] = ch;
2389 /*i->peek_buf[1] = 0; - already is */
2393 /* Only ever called if i_peek() was called, and did not return EOF.
2394 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2395 * not end-of-line. Therefore we never need to read a new editing line here.
2397 static int i_peek2(struct in_str *i)
2401 /* There are two cases when i->p[] buffer exists.
2402 * (1) it's a string in_str.
2403 * (2) It's a file, and we have a saved line editing buffer.
2404 * In both cases, we know that i->p[0] exists and not NUL, and
2405 * the peek2 result is in i->p[1].
2408 return (unsigned char)i->p[1];
2410 /* Now we know it is a file-based in_str. */
2412 /* peek_buf[] is an int array, not char. Can contain EOF. */
2413 /* Is there 2nd char? */
2414 ch = i->peek_buf[1];
2416 /* We did not read it yet, get it now */
2417 do ch = fgetc(i->file); while (ch == '\0');
2418 i->peek_buf[1] = ch;
2421 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2425 static void setup_file_in_str(struct in_str *i, FILE *f)
2427 memset(i, 0, sizeof(*i));
2428 /* i->promptmode = 0; - PS1 (memset did it) */
2433 static void setup_string_in_str(struct in_str *i, const char *s)
2435 memset(i, 0, sizeof(*i));
2436 /* i->promptmode = 0; - PS1 (memset did it) */
2437 /*i->file = NULL */;
2445 #define B_CHUNK (32 * sizeof(char*))
2447 static void o_reset_to_empty_unquoted(o_string *o)
2450 o->has_quoted_part = 0;
2455 static void o_free(o_string *o)
2458 memset(o, 0, sizeof(*o));
2461 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2466 static void o_grow_by(o_string *o, int len)
2468 if (o->length + len > o->maxlen) {
2469 o->maxlen += (2 * len) | (B_CHUNK-1);
2470 o->data = xrealloc(o->data, 1 + o->maxlen);
2474 static void o_addchr(o_string *o, int ch)
2476 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2477 if (o->length < o->maxlen) {
2478 /* likely. avoid o_grow_by() call */
2480 o->data[o->length] = ch;
2482 o->data[o->length] = '\0';
2490 /* Valid only if we know o_string is not empty */
2491 static void o_delchr(o_string *o)
2494 o->data[o->length] = '\0';
2498 static void o_addblock(o_string *o, const char *str, int len)
2501 memcpy(&o->data[o->length], str, len);
2503 o->data[o->length] = '\0';
2506 static void o_addstr(o_string *o, const char *str)
2508 o_addblock(o, str, strlen(str));
2512 static void nommu_addchr(o_string *o, int ch)
2518 # define nommu_addchr(o, str) ((void)0)
2521 static void o_addstr_with_NUL(o_string *o, const char *str)
2523 o_addblock(o, str, strlen(str) + 1);
2527 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2528 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2529 * Apparently, on unquoted $v bash still does globbing
2530 * ("v='*.txt'; echo $v" prints all .txt files),
2531 * but NOT brace expansion! Thus, there should be TWO independent
2532 * quoting mechanisms on $v expansion side: one protects
2533 * $v from brace expansion, and other additionally protects "$v" against globbing.
2534 * We have only second one.
2537 #if ENABLE_HUSH_BRACE_EXPANSION
2538 # define MAYBE_BRACES "{}"
2540 # define MAYBE_BRACES ""
2543 /* My analysis of quoting semantics tells me that state information
2544 * is associated with a destination, not a source.
2546 static void o_addqchr(o_string *o, int ch)
2549 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2554 o->data[o->length] = '\\';
2557 o->data[o->length] = ch;
2559 o->data[o->length] = '\0';
2562 static void o_addQchr(o_string *o, int ch)
2565 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2566 && strchr("*?[\\" MAYBE_BRACES, ch)
2569 o->data[o->length] = '\\';
2573 o->data[o->length] = ch;
2575 o->data[o->length] = '\0';
2578 static void o_addqblock(o_string *o, const char *str, int len)
2583 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2584 if (ordinary_cnt > len) /* paranoia */
2586 o_addblock(o, str, ordinary_cnt);
2587 if (ordinary_cnt == len)
2588 return; /* NUL is already added by o_addblock */
2589 str += ordinary_cnt;
2590 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2594 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2596 o->data[o->length] = '\\';
2600 o->data[o->length] = ch;
2603 o->data[o->length] = '\0';
2606 static void o_addQblock(o_string *o, const char *str, int len)
2608 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2609 o_addblock(o, str, len);
2612 o_addqblock(o, str, len);
2615 static void o_addQstr(o_string *o, const char *str)
2617 o_addQblock(o, str, strlen(str));
2620 /* A special kind of o_string for $VAR and `cmd` expansion.
2621 * It contains char* list[] at the beginning, which is grown in 16 element
2622 * increments. Actual string data starts at the next multiple of 16 * (char*).
2623 * list[i] contains an INDEX (int!) into this string data.
2624 * It means that if list[] needs to grow, data needs to be moved higher up
2625 * but list[i]'s need not be modified.
2626 * NB: remembering how many list[i]'s you have there is crucial.
2627 * o_finalize_list() operation post-processes this structure - calculates
2628 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2630 #if DEBUG_EXPAND || DEBUG_GLOB
2631 static void debug_print_list(const char *prefix, o_string *o, int n)
2633 char **list = (char**)o->data;
2634 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2638 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2639 prefix, list, n, string_start, o->length, o->maxlen,
2640 !!(o->o_expflags & EXP_FLAG_GLOB),
2642 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2645 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2646 o->data + (int)(uintptr_t)list[i] + string_start,
2647 o->data + (int)(uintptr_t)list[i] + string_start);
2651 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2653 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2657 # define debug_print_list(prefix, o, n) ((void)0)
2660 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2661 * in list[n] so that it points past last stored byte so far.
2662 * It returns n+1. */
2663 static int o_save_ptr_helper(o_string *o, int n)
2665 char **list = (char**)o->data;
2669 if (!o->has_empty_slot) {
2670 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2671 string_len = o->length - string_start;
2672 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2673 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2674 /* list[n] points to string_start, make space for 16 more pointers */
2675 o->maxlen += 0x10 * sizeof(list[0]);
2676 o->data = xrealloc(o->data, o->maxlen + 1);
2677 list = (char**)o->data;
2678 memmove(list + n + 0x10, list + n, string_len);
2679 o->length += 0x10 * sizeof(list[0]);
2681 debug_printf_list("list[%d]=%d string_start=%d\n",
2682 n, string_len, string_start);
2685 /* We have empty slot at list[n], reuse without growth */
2686 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2687 string_len = o->length - string_start;
2688 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2689 n, string_len, string_start);
2690 o->has_empty_slot = 0;
2692 o->has_quoted_part = 0;
2693 list[n] = (char*)(uintptr_t)string_len;
2697 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2698 static int o_get_last_ptr(o_string *o, int n)
2700 char **list = (char**)o->data;
2701 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2703 return ((int)(uintptr_t)list[n-1]) + string_start;
2706 #if ENABLE_HUSH_BRACE_EXPANSION
2707 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2708 * first, it processes even {a} (no commas), second,
2709 * I didn't manage to make it return strings when they don't match
2710 * existing files. Need to re-implement it.
2714 static int glob_needed(const char *s)
2723 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2729 /* Return pointer to next closing brace or to comma */
2730 static const char *next_brace_sub(const char *cp)
2734 while (*cp != '\0') {
2741 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2747 return *cp != '\0' ? cp : NULL;
2749 /* Recursive brace globber. Note: may garble pattern[]. */
2750 static int glob_brace(char *pattern, o_string *o, int n)
2752 char *new_pattern_buf;
2759 debug_printf_glob("glob_brace('%s')\n", pattern);
2765 if (*begin == '{') {
2766 /* Find the first sub-pattern and at the same time
2767 * find the rest after the closing brace */
2768 next = next_brace_sub(begin);
2770 /* An illegal expression */
2774 /* "{abc}" with no commas - illegal
2775 * brace expr, disregard and skip it */
2781 if (*begin == '\\' && begin[1] != '\0')
2785 debug_printf_glob("begin:%s\n", begin);
2786 debug_printf_glob("next:%s\n", next);
2788 /* Now find the end of the whole brace expression */
2790 while (*rest != '}') {
2791 rest = next_brace_sub(rest);
2793 /* An illegal expression */
2796 debug_printf_glob("rest:%s\n", rest);
2798 rest_len = strlen(++rest) + 1;
2800 /* We are sure the brace expression is well-formed */
2802 /* Allocate working buffer large enough for our work */
2803 new_pattern_buf = xmalloc(strlen(pattern));
2805 /* We have a brace expression. BEGIN points to the opening {,
2806 * NEXT points past the terminator of the first element, and REST
2807 * points past the final }. We will accumulate result names from
2808 * recursive runs for each brace alternative in the buffer using
2813 /* Construct the new glob expression */
2816 mempcpy(new_pattern_buf,
2817 /* We know the prefix for all sub-patterns */
2818 pattern, begin - pattern),
2822 /* Note: glob_brace() may garble new_pattern_buf[].
2823 * That's why we re-copy prefix every time (1st memcpy above).
2825 n = glob_brace(new_pattern_buf, o, n);
2827 /* We saw the last entry */
2831 next = next_brace_sub(next);
2833 free(new_pattern_buf);
2841 memset(&globdata, 0, sizeof(globdata));
2842 gr = glob(pattern, 0, NULL, &globdata);
2843 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2845 if (gr == GLOB_NOMATCH) {
2846 globfree(&globdata);
2847 /* NB: garbles parameter */
2848 unbackslash(pattern);
2849 o_addstr_with_NUL(o, pattern);
2850 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2851 return o_save_ptr_helper(o, n);
2853 if (gr == GLOB_NOSPACE)
2854 bb_error_msg_and_die(bb_msg_memory_exhausted);
2855 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2856 * but we didn't specify it. Paranoia again. */
2857 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2859 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2860 char **argv = globdata.gl_pathv;
2862 o_addstr_with_NUL(o, *argv);
2863 n = o_save_ptr_helper(o, n);
2869 globfree(&globdata);
2873 /* Performs globbing on last list[],
2874 * saving each result as a new list[].
2876 static int perform_glob(o_string *o, int n)
2878 char *pattern, *copy;
2880 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2882 return o_save_ptr_helper(o, n);
2883 pattern = o->data + o_get_last_ptr(o, n);
2884 debug_printf_glob("glob pattern '%s'\n", pattern);
2885 if (!glob_needed(pattern)) {
2886 /* unbackslash last string in o in place, fix length */
2887 o->length = unbackslash(pattern) - o->data;
2888 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2889 return o_save_ptr_helper(o, n);
2892 copy = xstrdup(pattern);
2893 /* "forget" pattern in o */
2894 o->length = pattern - o->data;
2895 n = glob_brace(copy, o, n);
2898 debug_print_list("perform_glob returning", o, n);
2902 #else /* !HUSH_BRACE_EXPANSION */
2905 static int glob_needed(const char *s)
2914 if (*s == '*' || *s == '[' || *s == '?')
2920 /* Performs globbing on last list[],
2921 * saving each result as a new list[].
2923 static int perform_glob(o_string *o, int n)
2929 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2931 return o_save_ptr_helper(o, n);
2932 pattern = o->data + o_get_last_ptr(o, n);
2933 debug_printf_glob("glob pattern '%s'\n", pattern);
2934 if (!glob_needed(pattern)) {
2936 /* unbackslash last string in o in place, fix length */
2937 o->length = unbackslash(pattern) - o->data;
2938 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2939 return o_save_ptr_helper(o, n);
2942 memset(&globdata, 0, sizeof(globdata));
2943 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2944 * If we glob "*.\*" and don't find anything, we need
2945 * to fall back to using literal "*.*", but GLOB_NOCHECK
2946 * will return "*.\*"!
2948 gr = glob(pattern, 0, NULL, &globdata);
2949 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2951 if (gr == GLOB_NOMATCH) {
2952 globfree(&globdata);
2955 if (gr == GLOB_NOSPACE)
2956 bb_error_msg_and_die(bb_msg_memory_exhausted);
2957 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2958 * but we didn't specify it. Paranoia again. */
2959 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2961 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2962 char **argv = globdata.gl_pathv;
2963 /* "forget" pattern in o */
2964 o->length = pattern - o->data;
2966 o_addstr_with_NUL(o, *argv);
2967 n = o_save_ptr_helper(o, n);
2973 globfree(&globdata);
2975 debug_print_list("perform_glob returning", o, n);
2979 #endif /* !HUSH_BRACE_EXPANSION */
2981 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2982 * Otherwise, just finish current list[] and start new */
2983 static int o_save_ptr(o_string *o, int n)
2985 if (o->o_expflags & EXP_FLAG_GLOB) {
2986 /* If o->has_empty_slot, list[n] was already globbed
2987 * (if it was requested back then when it was filled)
2988 * so don't do that again! */
2989 if (!o->has_empty_slot)
2990 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2992 return o_save_ptr_helper(o, n);
2995 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2996 static char **o_finalize_list(o_string *o, int n)
3001 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3003 debug_print_list("finalized", o, n);
3004 debug_printf_expand("finalized n:%d\n", n);
3005 list = (char**)o->data;
3006 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3010 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3015 static void free_pipe_list(struct pipe *pi);
3017 /* Returns pi->next - next pipe in the list */
3018 static struct pipe *free_pipe(struct pipe *pi)
3023 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3024 for (i = 0; i < pi->num_cmds; i++) {
3025 struct command *command;
3026 struct redir_struct *r, *rnext;
3028 command = &pi->cmds[i];
3029 debug_printf_clean(" command %d:\n", i);
3030 if (command->argv) {
3034 for (a = 0, p = command->argv; *p; a++, p++) {
3035 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3038 free_strings(command->argv);
3039 //command->argv = NULL;
3041 /* not "else if": on syntax error, we may have both! */
3042 if (command->group) {
3043 debug_printf_clean(" begin group (cmd_type:%d)\n",
3045 free_pipe_list(command->group);
3046 debug_printf_clean(" end group\n");
3047 //command->group = NULL;
3049 /* else is crucial here.
3050 * If group != NULL, child_func is meaningless */
3051 #if ENABLE_HUSH_FUNCTIONS
3052 else if (command->child_func) {
3053 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3054 command->child_func->parent_cmd = NULL;
3058 free(command->group_as_string);
3059 //command->group_as_string = NULL;
3061 for (r = command->redirects; r; r = rnext) {
3062 debug_printf_clean(" redirect %d%s",
3063 r->rd_fd, redir_table[r->rd_type].descrip);
3064 /* guard against the case >$FOO, where foo is unset or blank */
3065 if (r->rd_filename) {
3066 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3067 free(r->rd_filename);
3068 //r->rd_filename = NULL;
3070 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3074 //command->redirects = NULL;
3076 free(pi->cmds); /* children are an array, they get freed all at once */
3080 //pi->cmdtext = NULL;
3088 static void free_pipe_list(struct pipe *pi)
3092 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3094 debug_printf_clean("pipe followup code %d\n", pi->followup);
3100 /*** Parsing routines ***/
3102 #ifndef debug_print_tree
3103 static void debug_print_tree(struct pipe *pi, int lvl)
3105 static const char *const PIPE[] = {
3111 static const char *RES[] = {
3112 [RES_NONE ] = "NONE" ,
3115 [RES_THEN ] = "THEN" ,
3116 [RES_ELIF ] = "ELIF" ,
3117 [RES_ELSE ] = "ELSE" ,
3120 # if ENABLE_HUSH_LOOPS
3121 [RES_FOR ] = "FOR" ,
3122 [RES_WHILE] = "WHILE",
3123 [RES_UNTIL] = "UNTIL",
3125 [RES_DONE ] = "DONE" ,
3127 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3130 # if ENABLE_HUSH_CASE
3131 [RES_CASE ] = "CASE" ,
3132 [RES_CASE_IN ] = "CASE_IN" ,
3133 [RES_MATCH] = "MATCH",
3134 [RES_CASE_BODY] = "CASE_BODY",
3135 [RES_ESAC ] = "ESAC" ,
3137 [RES_XXXX ] = "XXXX" ,
3138 [RES_SNTX ] = "SNTX" ,
3140 static const char *const CMDTYPE[] = {
3144 # if ENABLE_HUSH_FUNCTIONS
3153 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3154 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3156 while (prn < pi->num_cmds) {
3157 struct command *command = &pi->cmds[prn];
3158 char **argv = command->argv;
3160 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3162 command->assignment_cnt);
3163 if (command->group) {
3164 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3165 CMDTYPE[command->cmd_type],
3168 , " group_as_string:", command->group_as_string
3173 debug_print_tree(command->group, lvl+1);
3177 if (argv) while (*argv) {
3178 fdprintf(2, " '%s'", *argv);
3188 #endif /* debug_print_tree */
3190 static struct pipe *new_pipe(void)
3193 pi = xzalloc(sizeof(struct pipe));
3194 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3198 /* Command (member of a pipe) is complete, or we start a new pipe
3199 * if ctx->command is NULL.
3200 * No errors possible here.
3202 static int done_command(struct parse_context *ctx)
3204 /* The command is really already in the pipe structure, so
3205 * advance the pipe counter and make a new, null command. */
3206 struct pipe *pi = ctx->pipe;
3207 struct command *command = ctx->command;
3209 #if 0 /* Instead we emit error message at run time */
3210 if (ctx->pending_redirect) {
3211 /* For example, "cmd >" (no filename to redirect to) */
3212 die_if_script("syntax error: %s", "invalid redirect");
3213 ctx->pending_redirect = NULL;
3218 if (IS_NULL_CMD(command)) {
3219 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3223 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3224 //debug_print_tree(ctx->list_head, 20);
3226 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3229 /* Only real trickiness here is that the uncommitted
3230 * command structure is not counted in pi->num_cmds. */
3231 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3232 ctx->command = command = &pi->cmds[pi->num_cmds];
3234 memset(command, 0, sizeof(*command));
3235 return pi->num_cmds; /* used only for 0/nonzero check */
3238 static void done_pipe(struct parse_context *ctx, pipe_style type)
3242 debug_printf_parse("done_pipe entered, followup %d\n", type);
3243 /* Close previous command */
3244 not_null = done_command(ctx);
3245 ctx->pipe->followup = type;
3247 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3248 ctx->ctx_inverted = 0;
3249 ctx->pipe->res_word = ctx->ctx_res_w;
3252 /* Without this check, even just <enter> on command line generates
3253 * tree of three NOPs (!). Which is harmless but annoying.
3254 * IOW: it is safe to do it unconditionally. */
3257 || ctx->ctx_res_w == RES_FI
3259 #if ENABLE_HUSH_LOOPS
3260 || ctx->ctx_res_w == RES_DONE
3261 || ctx->ctx_res_w == RES_FOR
3262 || ctx->ctx_res_w == RES_IN
3264 #if ENABLE_HUSH_CASE
3265 || ctx->ctx_res_w == RES_ESAC
3269 debug_printf_parse("done_pipe: adding new pipe: "
3270 "not_null:%d ctx->ctx_res_w:%d\n",
3271 not_null, ctx->ctx_res_w);
3273 ctx->pipe->next = new_p;
3275 /* RES_THEN, RES_DO etc are "sticky" -
3276 * they remain set for pipes inside if/while.
3277 * This is used to control execution.
3278 * RES_FOR and RES_IN are NOT sticky (needed to support
3279 * cases where variable or value happens to match a keyword):
3281 #if ENABLE_HUSH_LOOPS
3282 if (ctx->ctx_res_w == RES_FOR
3283 || ctx->ctx_res_w == RES_IN)
3284 ctx->ctx_res_w = RES_NONE;
3286 #if ENABLE_HUSH_CASE
3287 if (ctx->ctx_res_w == RES_MATCH)
3288 ctx->ctx_res_w = RES_CASE_BODY;
3289 if (ctx->ctx_res_w == RES_CASE)
3290 ctx->ctx_res_w = RES_CASE_IN;
3292 ctx->command = NULL; /* trick done_command below */
3293 /* Create the memory for command, roughly:
3294 * ctx->pipe->cmds = new struct command;
3295 * ctx->command = &ctx->pipe->cmds[0];
3298 //debug_print_tree(ctx->list_head, 10);
3300 debug_printf_parse("done_pipe return\n");
3303 static void initialize_context(struct parse_context *ctx)
3305 memset(ctx, 0, sizeof(*ctx));
3306 ctx->pipe = ctx->list_head = new_pipe();
3307 /* Create the memory for command, roughly:
3308 * ctx->pipe->cmds = new struct command;
3309 * ctx->command = &ctx->pipe->cmds[0];
3314 /* If a reserved word is found and processed, parse context is modified
3315 * and 1 is returned.
3318 struct reserved_combo {
3321 unsigned char assignment_flag;
3325 FLAG_END = (1 << RES_NONE ),
3327 FLAG_IF = (1 << RES_IF ),
3328 FLAG_THEN = (1 << RES_THEN ),
3329 FLAG_ELIF = (1 << RES_ELIF ),
3330 FLAG_ELSE = (1 << RES_ELSE ),
3331 FLAG_FI = (1 << RES_FI ),
3333 # if ENABLE_HUSH_LOOPS
3334 FLAG_FOR = (1 << RES_FOR ),
3335 FLAG_WHILE = (1 << RES_WHILE),
3336 FLAG_UNTIL = (1 << RES_UNTIL),
3337 FLAG_DO = (1 << RES_DO ),
3338 FLAG_DONE = (1 << RES_DONE ),
3339 FLAG_IN = (1 << RES_IN ),
3341 # if ENABLE_HUSH_CASE
3342 FLAG_MATCH = (1 << RES_MATCH),
3343 FLAG_ESAC = (1 << RES_ESAC ),
3345 FLAG_START = (1 << RES_XXXX ),
3348 static const struct reserved_combo* match_reserved_word(o_string *word)
3350 /* Mostly a list of accepted follow-up reserved words.
3351 * FLAG_END means we are done with the sequence, and are ready
3352 * to turn the compound list into a command.
3353 * FLAG_START means the word must start a new compound list.
3355 static const struct reserved_combo reserved_list[] = {
3357 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3358 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3359 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3360 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3361 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3362 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3364 # if ENABLE_HUSH_LOOPS
3365 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3366 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3367 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3368 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3369 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3370 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3372 # if ENABLE_HUSH_CASE
3373 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3374 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3377 const struct reserved_combo *r;
3379 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3380 if (strcmp(word->data, r->literal) == 0)
3385 /* Return 0: not a keyword, 1: keyword
3387 static int reserved_word(o_string *word, struct parse_context *ctx)
3389 # if ENABLE_HUSH_CASE
3390 static const struct reserved_combo reserved_match = {
3391 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3394 const struct reserved_combo *r;
3396 if (word->has_quoted_part)
3398 r = match_reserved_word(word);
3402 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3403 # if ENABLE_HUSH_CASE
3404 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3405 /* "case word IN ..." - IN part starts first MATCH part */
3406 r = &reserved_match;
3409 if (r->flag == 0) { /* '!' */
3410 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3411 syntax_error("! ! command");
3412 ctx->ctx_res_w = RES_SNTX;
3414 ctx->ctx_inverted = 1;
3417 if (r->flag & FLAG_START) {
3418 struct parse_context *old;
3420 old = xmalloc(sizeof(*old));
3421 debug_printf_parse("push stack %p\n", old);
3422 *old = *ctx; /* physical copy */
3423 initialize_context(ctx);
3425 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3426 syntax_error_at(word->data);
3427 ctx->ctx_res_w = RES_SNTX;
3430 /* "{...} fi" is ok. "{...} if" is not
3432 * if { echo foo; } then { echo bar; } fi */
3433 if (ctx->command->group)
3434 done_pipe(ctx, PIPE_SEQ);
3437 ctx->ctx_res_w = r->res;
3438 ctx->old_flag = r->flag;
3439 word->o_assignment = r->assignment_flag;
3440 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3442 if (ctx->old_flag & FLAG_END) {
3443 struct parse_context *old;
3445 done_pipe(ctx, PIPE_SEQ);
3446 debug_printf_parse("pop stack %p\n", ctx->stack);
3448 old->command->group = ctx->list_head;
3449 old->command->cmd_type = CMD_NORMAL;
3451 /* At this point, the compound command's string is in
3452 * ctx->as_string... except for the leading keyword!
3453 * Consider this example: "echo a | if true; then echo a; fi"
3454 * ctx->as_string will contain "true; then echo a; fi",
3455 * with "if " remaining in old->as_string!
3459 int len = old->as_string.length;
3460 /* Concatenate halves */
3461 o_addstr(&old->as_string, ctx->as_string.data);
3462 o_free_unsafe(&ctx->as_string);
3463 /* Find where leading keyword starts in first half */
3464 str = old->as_string.data + len;
3465 if (str > old->as_string.data)
3466 str--; /* skip whitespace after keyword */
3467 while (str > old->as_string.data && isalpha(str[-1]))
3469 /* Ugh, we're done with this horrid hack */
3470 old->command->group_as_string = xstrdup(str);
3471 debug_printf_parse("pop, remembering as:'%s'\n",
3472 old->command->group_as_string);
3475 *ctx = *old; /* physical copy */
3480 #endif /* HAS_KEYWORDS */
3482 /* Word is complete, look at it and update parsing context.
3483 * Normal return is 0. Syntax errors return 1.
3484 * Note: on return, word is reset, but not o_free'd!
3486 static int done_word(o_string *word, struct parse_context *ctx)
3488 struct command *command = ctx->command;
3490 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3491 if (word->length == 0 && !word->has_quoted_part) {
3492 debug_printf_parse("done_word return 0: true null, ignored\n");
3496 if (ctx->pending_redirect) {
3497 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3498 * only if run as "bash", not "sh" */
3499 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3501 * ...the word that follows the redirection operator
3502 * shall be subjected to tilde expansion, parameter expansion,
3503 * command substitution, arithmetic expansion, and quote
3504 * removal. Pathname expansion shall not be performed
3505 * on the word by a non-interactive shell; an interactive
3506 * shell may perform it, but shall do so only when
3507 * the expansion would result in one word."
3509 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3510 /* Cater for >\file case:
3511 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3512 * Same with heredocs:
3513 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3515 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3516 unbackslash(ctx->pending_redirect->rd_filename);
3517 /* Is it <<"HEREDOC"? */
3518 if (word->has_quoted_part) {
3519 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3522 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3523 ctx->pending_redirect = NULL;
3526 # if ENABLE_HUSH_CASE
3527 if (ctx->ctx_dsemicolon
3528 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3530 /* already done when ctx_dsemicolon was set to 1: */
3531 /* ctx->ctx_res_w = RES_MATCH; */
3532 ctx->ctx_dsemicolon = 0;
3535 if (!command->argv /* if it's the first word... */
3536 # if ENABLE_HUSH_LOOPS
3537 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3538 && ctx->ctx_res_w != RES_IN
3540 # if ENABLE_HUSH_CASE
3541 && ctx->ctx_res_w != RES_CASE
3544 int reserved = reserved_word(word, ctx);
3545 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3547 o_reset_to_empty_unquoted(word);
3548 debug_printf_parse("done_word return %d\n",
3549 (ctx->ctx_res_w == RES_SNTX));
3550 return (ctx->ctx_res_w == RES_SNTX);
3552 # if ENABLE_HUSH_BASH_COMPAT
3553 if (strcmp(word->data, "[[") == 0) {
3554 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3560 if (command->group) {
3561 /* "{ echo foo; } echo bar" - bad */
3562 syntax_error_at(word->data);
3563 debug_printf_parse("done_word return 1: syntax error, "
3564 "groups and arglists don't mix\n");
3568 /* If this word wasn't an assignment, next ones definitely
3569 * can't be assignments. Even if they look like ones. */
3570 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3571 && word->o_assignment != WORD_IS_KEYWORD
3573 word->o_assignment = NOT_ASSIGNMENT;
3575 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3576 command->assignment_cnt++;
3577 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3579 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3580 word->o_assignment = MAYBE_ASSIGNMENT;
3582 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3584 if (word->has_quoted_part
3585 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3586 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3587 /* (otherwise it's known to be not empty and is already safe) */
3589 /* exclude "$@" - it can expand to no word despite "" */
3590 char *p = word->data;
3591 while (p[0] == SPECIAL_VAR_SYMBOL
3592 && (p[1] & 0x7f) == '@'
3593 && p[2] == SPECIAL_VAR_SYMBOL
3598 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3599 debug_print_strings("word appended to argv", command->argv);
3602 #if ENABLE_HUSH_LOOPS
3603 if (ctx->ctx_res_w == RES_FOR) {
3604 if (word->has_quoted_part
3605 || !is_well_formed_var_name(command->argv[0], '\0')
3607 /* bash says just "not a valid identifier" */
3608 syntax_error("not a valid identifier in for");
3611 /* Force FOR to have just one word (variable name) */
3612 /* NB: basically, this makes hush see "for v in ..."
3613 * syntax as if it is "for v; in ...". FOR and IN become
3614 * two pipe structs in parse tree. */
3615 done_pipe(ctx, PIPE_SEQ);
3618 #if ENABLE_HUSH_CASE
3619 /* Force CASE to have just one word */
3620 if (ctx->ctx_res_w == RES_CASE) {
3621 done_pipe(ctx, PIPE_SEQ);
3625 o_reset_to_empty_unquoted(word);
3627 debug_printf_parse("done_word return 0\n");
3632 /* Peek ahead in the input to find out if we have a "&n" construct,
3633 * as in "2>&1", that represents duplicating a file descriptor.
3635 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3636 * REDIRFD_SYNTAX_ERR if syntax error,
3637 * REDIRFD_TO_FILE if no & was seen,
3638 * or the number found.
3641 #define parse_redir_right_fd(as_string, input) \
3642 parse_redir_right_fd(input)
3644 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3650 return REDIRFD_TO_FILE;
3652 ch = i_getch(input); /* get the & */
3653 nommu_addchr(as_string, ch);
3656 ch = i_getch(input);
3657 nommu_addchr(as_string, ch);
3658 return REDIRFD_CLOSE;
3662 while (ch != EOF && isdigit(ch)) {
3663 d = d*10 + (ch-'0');
3665 ch = i_getch(input);
3666 nommu_addchr(as_string, ch);
3671 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3673 bb_error_msg("ambiguous redirect");
3674 return REDIRFD_SYNTAX_ERR;
3677 /* Return code is 0 normal, 1 if a syntax error is detected
3679 static int parse_redirect(struct parse_context *ctx,
3682 struct in_str *input)
3684 struct command *command = ctx->command;
3685 struct redir_struct *redir;
3686 struct redir_struct **redirp;
3689 dup_num = REDIRFD_TO_FILE;
3690 if (style != REDIRECT_HEREDOC) {
3691 /* Check for a '>&1' type redirect */
3692 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3693 if (dup_num == REDIRFD_SYNTAX_ERR)
3696 int ch = i_peek(input);
3697 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3698 if (dup_num) { /* <<-... */
3699 ch = i_getch(input);
3700 nommu_addchr(&ctx->as_string, ch);
3705 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3706 int ch = i_peek(input);
3708 /* >|FILE redirect ("clobbering" >).
3709 * Since we do not support "set -o noclobber" yet,
3710 * >| and > are the same for now. Just eat |.
3712 ch = i_getch(input);
3713 nommu_addchr(&ctx->as_string, ch);
3717 /* Create a new redir_struct and append it to the linked list */
3718 redirp = &command->redirects;
3719 while ((redir = *redirp) != NULL) {
3720 redirp = &(redir->next);
3722 *redirp = redir = xzalloc(sizeof(*redir));
3723 /* redir->next = NULL; */
3724 /* redir->rd_filename = NULL; */
3725 redir->rd_type = style;
3726 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3728 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3729 redir_table[style].descrip);
3731 redir->rd_dup = dup_num;
3732 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3733 /* Erik had a check here that the file descriptor in question
3734 * is legit; I postpone that to "run time"
3735 * A "-" representation of "close me" shows up as a -3 here */
3736 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3737 redir->rd_fd, redir->rd_dup);
3739 #if 0 /* Instead we emit error message at run time */
3740 if (ctx->pending_redirect) {
3741 /* For example, "cmd > <file" */
3742 die_if_script("syntax error: %s", "invalid redirect");
3745 /* Set ctx->pending_redirect, so we know what to do at the
3746 * end of the next parsed word. */
3747 ctx->pending_redirect = redir;
3752 /* If a redirect is immediately preceded by a number, that number is
3753 * supposed to tell which file descriptor to redirect. This routine
3754 * looks for such preceding numbers. In an ideal world this routine
3755 * needs to handle all the following classes of redirects...
3756 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3757 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3758 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3759 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3761 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3763 * ... If n is quoted, the number shall not be recognized as part of
3764 * the redirection expression. For example:
3766 * writes the character 2 into file a"
3767 * We are getting it right by setting ->has_quoted_part on any \<char>
3769 * A -1 return means no valid number was found,
3770 * the caller should use the appropriate default for this redirection.
3772 static int redirect_opt_num(o_string *o)
3776 if (o->data == NULL)
3778 num = bb_strtou(o->data, NULL, 10);
3779 if (errno || num < 0)
3781 o_reset_to_empty_unquoted(o);
3786 #define fetch_till_str(as_string, input, word, skip_tabs) \
3787 fetch_till_str(input, word, skip_tabs)
3789 static char *fetch_till_str(o_string *as_string,
3790 struct in_str *input,
3794 o_string heredoc = NULL_O_STRING;
3796 int prev = 0; /* not \ */
3802 ch = i_getch(input);
3804 nommu_addchr(as_string, ch);
3805 if ((ch == '\n' || ch == EOF)
3806 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3808 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3809 heredoc.data[past_EOL] = '\0';
3810 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3811 return heredoc.data;
3813 while (ch == '\n') {
3814 o_addchr(&heredoc, ch);
3817 past_EOL = heredoc.length;
3819 ch = i_getch(input);
3821 nommu_addchr(as_string, ch);
3822 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3826 o_free_unsafe(&heredoc);
3829 o_addchr(&heredoc, ch);
3830 nommu_addchr(as_string, ch);
3831 if (prev == '\\' && ch == '\\')
3832 /* Correctly handle foo\\<eol> (not a line cont.) */
3833 prev = 0; /* not \ */
3839 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3840 * and load them all. There should be exactly heredoc_cnt of them.
3842 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3844 struct pipe *pi = ctx->list_head;
3846 while (pi && heredoc_cnt) {
3848 struct command *cmd = pi->cmds;
3850 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3852 cmd->argv ? cmd->argv[0] : "NONE");
3853 for (i = 0; i < pi->num_cmds; i++) {
3854 struct redir_struct *redir = cmd->redirects;
3856 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3857 i, cmd->argv ? cmd->argv[0] : "NONE");
3859 if (redir->rd_type == REDIRECT_HEREDOC) {
3862 redir->rd_type = REDIRECT_HEREDOC2;
3863 /* redir->rd_dup is (ab)used to indicate <<- */
3864 p = fetch_till_str(&ctx->as_string, input,
3865 redir->rd_filename, redir->rd_dup);
3867 syntax_error("unexpected EOF in here document");
3870 free(redir->rd_filename);
3871 redir->rd_filename = p;
3874 redir = redir->next;
3881 /* Should be 0. If it isn't, it's a parse error */
3883 bb_error_msg_and_die("heredoc BUG 2");
3889 static int run_list(struct pipe *pi);
3891 #define parse_stream(pstring, input, end_trigger) \
3892 parse_stream(input, end_trigger)
3894 static struct pipe *parse_stream(char **pstring,
3895 struct in_str *input,
3899 #if !ENABLE_HUSH_FUNCTIONS
3900 #define parse_group(dest, ctx, input, ch) \
3901 parse_group(ctx, input, ch)
3903 static int parse_group(o_string *dest, struct parse_context *ctx,
3904 struct in_str *input, int ch)
3906 /* dest contains characters seen prior to ( or {.
3907 * Typically it's empty, but for function defs,
3908 * it contains function name (without '()'). */
3909 struct pipe *pipe_list;
3911 struct command *command = ctx->command;
3913 debug_printf_parse("parse_group entered\n");
3914 #if ENABLE_HUSH_FUNCTIONS
3915 if (ch == '(' && !dest->has_quoted_part) {
3917 if (done_word(dest, ctx))
3920 goto skip; /* (... */
3921 if (command->argv[1]) { /* word word ... (... */
3922 syntax_error_unexpected_ch('(');
3925 /* it is "word(..." or "word (..." */
3927 ch = i_getch(input);
3928 while (ch == ' ' || ch == '\t');
3930 syntax_error_unexpected_ch(ch);
3933 nommu_addchr(&ctx->as_string, ch);
3935 ch = i_getch(input);
3936 while (ch == ' ' || ch == '\t' || ch == '\n');
3938 syntax_error_unexpected_ch(ch);
3941 nommu_addchr(&ctx->as_string, ch);
3942 command->cmd_type = CMD_FUNCDEF;
3947 #if 0 /* Prevented by caller */
3948 if (command->argv /* word [word]{... */
3949 || dest->length /* word{... */
3950 || dest->has_quoted_part /* ""{... */
3953 debug_printf_parse("parse_group return 1: "
3954 "syntax error, groups and arglists don't mix\n");
3959 #if ENABLE_HUSH_FUNCTIONS
3965 command->cmd_type = CMD_SUBSHELL;
3967 /* bash does not allow "{echo...", requires whitespace */
3969 if (ch != ' ' && ch != '\t' && ch != '\n'
3970 && ch != '(' /* but "{(..." is allowed (without whitespace) */
3972 syntax_error_unexpected_ch(ch);
3976 ch = i_getch(input);
3977 nommu_addchr(&ctx->as_string, ch);
3983 # define as_string NULL
3985 char *as_string = NULL;
3987 pipe_list = parse_stream(&as_string, input, endch);
3990 o_addstr(&ctx->as_string, as_string);
3992 /* empty ()/{} or parse error? */
3993 if (!pipe_list || pipe_list == ERR_PTR) {
3994 /* parse_stream already emitted error msg */
3997 debug_printf_parse("parse_group return 1: "
3998 "parse_stream returned %p\n", pipe_list);
4001 command->group = pipe_list;
4003 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4004 command->group_as_string = as_string;
4005 debug_printf_parse("end of group, remembering as:'%s'\n",
4006 command->group_as_string);
4010 debug_printf_parse("parse_group return 0\n");
4012 /* command remains "open", available for possible redirects */
4015 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4020 ch = i_getch(input);
4023 ch2 = i_peek(input);
4026 /* backslash+newline, skip it */
4031 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4039 ch2 = i_peek2(input);
4042 /* backslash+newline, skip it */
4048 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4049 /* Subroutines for copying $(...) and `...` things */
4050 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4052 static int add_till_single_quote(o_string *dest, struct in_str *input)
4055 int ch = i_getch(input);
4057 syntax_error_unterm_ch('\'');
4065 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4066 static int add_till_double_quote(o_string *dest, struct in_str *input)
4069 int ch = i_getch(input);
4071 syntax_error_unterm_ch('"');
4076 if (ch == '\\') { /* \x. Copy both chars. */
4078 ch = i_getch(input);
4082 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4087 //if (ch == '$') ...
4090 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4092 * "Within the backquoted style of command substitution, backslash
4093 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4094 * The search for the matching backquote shall be satisfied by the first
4095 * backquote found without a preceding backslash; during this search,
4096 * if a non-escaped backquote is encountered within a shell comment,
4097 * a here-document, an embedded command substitution of the $(command)
4098 * form, or a quoted string, undefined results occur. A single-quoted
4099 * or double-quoted string that begins, but does not end, within the
4100 * "`...`" sequence produces undefined results."
4102 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4104 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4107 int ch = i_getch(input);
4111 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4112 ch = i_getch(input);
4116 && (!in_dquote || ch != '"')
4118 o_addchr(dest, '\\');
4122 syntax_error_unterm_ch('`');
4128 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4129 * quoting and nested ()s.
4130 * "With the $(command) style of command substitution, all characters
4131 * following the open parenthesis to the matching closing parenthesis
4132 * constitute the command. Any valid shell script can be used for command,
4133 * except a script consisting solely of redirections which produces
4134 * unspecified results."
4136 * echo $(echo '(TEST)' BEST) (TEST) BEST
4137 * echo $(echo 'TEST)' BEST) TEST) BEST
4138 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4140 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4141 * can contain arbitrary constructs, just like $(cmd).
4142 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4143 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4145 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4146 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4149 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4150 # if ENABLE_HUSH_BASH_COMPAT
4151 char end_char2 = end_ch >> 8;
4153 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4156 ch = i_getch(input);
4158 syntax_error_unterm_ch(end_ch);
4161 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4164 /* we look for closing )) of $((EXPR)) */
4165 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4166 i_getch(input); /* eat second ')' */
4171 if (ch == '(' || ch == '{') {
4172 ch = (ch == '(' ? ')' : '}');
4173 if (!add_till_closing_bracket(dest, input, ch))
4179 if (!add_till_single_quote(dest, input))
4185 if (!add_till_double_quote(dest, input))
4191 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4197 /* \x. Copy verbatim. Important for \(, \) */
4198 ch = i_getch(input);
4200 syntax_error_unterm_ch(')');
4205 /* "backslash+newline", ignore both */
4206 o_delchr(dest); /* undo insertion of '\' */
4216 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4218 /* Return code: 0 for OK, 1 for syntax error */
4220 #define parse_dollar(as_string, dest, input, quote_mask) \
4221 parse_dollar(dest, input, quote_mask)
4222 #define as_string NULL
4224 static int parse_dollar(o_string *as_string,
4226 struct in_str *input, unsigned char quote_mask)
4228 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4230 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4232 ch = i_getch(input);
4233 nommu_addchr(as_string, ch);
4235 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4237 debug_printf_parse(": '%c'\n", ch);
4238 o_addchr(dest, ch | quote_mask);
4240 ch = i_peek_and_eat_bkslash_nl(input);
4241 if (!isalnum(ch) && ch != '_') {
4242 /* End of variable name reached */
4245 ch = i_getch(input);
4246 nommu_addchr(as_string, ch);
4248 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4249 } else if (isdigit(ch)) {
4251 ch = i_getch(input);
4252 nommu_addchr(as_string, ch);
4253 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4254 debug_printf_parse(": '%c'\n", ch);
4255 o_addchr(dest, ch | quote_mask);
4256 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4257 } else switch (ch) {
4259 case '!': /* last bg pid */
4260 case '?': /* last exit code */
4261 case '#': /* number of args */
4262 case '*': /* args */
4263 case '@': /* args */
4264 goto make_one_char_var;
4266 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4268 ch = i_getch(input); /* eat '{' */
4269 nommu_addchr(as_string, ch);
4271 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4272 /* It should be ${?}, or ${#var},
4273 * or even ${?+subst} - operator acting on a special variable,
4274 * or the beginning of variable name.
4277 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4280 syntax_error_unterm_str("${name}");
4281 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4284 nommu_addchr(as_string, ch);
4287 /* It's possible to just call add_till_closing_bracket() at this point.
4288 * However, this regresses some of our testsuite cases
4289 * which check invalid constructs like ${%}.
4290 * Oh well... let's check that the var name part is fine... */
4296 debug_printf_parse(": '%c'\n", ch);
4298 ch = i_getch(input);
4299 nommu_addchr(as_string, ch);
4303 if (!isalnum(ch) && ch != '_') {
4305 unsigned char last_ch;
4306 /* handle parameter expansions
4307 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4309 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4310 goto bad_dollar_syntax;
4312 /* Eat everything until closing '}' (or ':') */
4314 if (ENABLE_HUSH_BASH_COMPAT
4316 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4318 /* It's ${var:N[:M]} thing */
4319 end_ch = '}' * 0x100 + ':';
4321 if (ENABLE_HUSH_BASH_COMPAT
4324 /* It's ${var/[/]pattern[/repl]} thing */
4325 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4327 nommu_addchr(as_string, '/');
4330 end_ch = '}' * 0x100 + '/';
4336 #if ENABLE_HUSH_DOLLAR_OPS
4337 last_ch = add_till_closing_bracket(dest, input, end_ch);
4338 if (last_ch == 0) /* error? */
4341 #error Simple code to only allow ${var} is not implemented
4344 o_addstr(as_string, dest->data + pos);
4345 o_addchr(as_string, last_ch);
4348 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4349 /* close the first block: */
4350 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4351 /* while parsing N from ${var:N[:M]}
4352 * or pattern from ${var/[/]pattern[/repl]} */
4353 if ((end_ch & 0xff) == last_ch) {
4354 /* got ':' or '/'- parse the rest */
4359 if (end_ch == '}' * 0x100 + ':') {
4360 /* it's ${var:N} - emulate :999999999 */
4361 o_addstr(dest, "999999999");
4362 } /* else: it's ${var/[/]pattern} */
4367 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4370 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4374 ch = i_getch(input);
4375 nommu_addchr(as_string, ch);
4376 # if ENABLE_FEATURE_SH_MATH
4377 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4378 ch = i_getch(input);
4379 nommu_addchr(as_string, ch);
4380 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4381 o_addchr(dest, /*quote_mask |*/ '+');
4384 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4385 return 0; /* error */
4387 o_addstr(as_string, dest->data + pos);
4388 o_addchr(as_string, ')');
4389 o_addchr(as_string, ')');
4391 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4395 # if ENABLE_HUSH_TICK
4396 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4397 o_addchr(dest, quote_mask | '`');
4400 if (!add_till_closing_bracket(dest, input, ')'))
4401 return 0; /* error */
4403 o_addstr(as_string, dest->data + pos);
4404 o_addchr(as_string, ')');
4406 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4412 ch = i_getch(input);
4413 nommu_addchr(as_string, ch);
4414 ch = i_peek_and_eat_bkslash_nl(input);
4415 if (isalnum(ch)) { /* it's $_name or $_123 */
4420 /* TODO: $_ and $-: */
4421 /* $_ Shell or shell script name; or last argument of last command
4422 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4423 * but in command's env, set to full pathname used to invoke it */
4424 /* $- Option flags set by set builtin or shell options (-i etc) */
4426 o_addQchr(dest, '$');
4428 debug_printf_parse("parse_dollar return 1 (ok)\n");
4434 # if ENABLE_HUSH_BASH_COMPAT
4435 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4436 encode_string(dest, input, dquote_end, process_bkslash)
4438 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4439 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4440 encode_string(dest, input, dquote_end)
4442 #define as_string NULL
4446 # if ENABLE_HUSH_BASH_COMPAT
4447 /* all parameters are needed, no macro tricks */
4449 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4450 encode_string(as_string, dest, input, dquote_end)
4453 static int encode_string(o_string *as_string,
4455 struct in_str *input,
4457 int process_bkslash)
4459 #if !ENABLE_HUSH_BASH_COMPAT
4460 const int process_bkslash = 1;
4466 ch = i_getch(input);
4468 nommu_addchr(as_string, ch);
4469 if (ch == dquote_end) { /* may be only '"' or EOF */
4470 debug_printf_parse("encode_string return 1 (ok)\n");
4473 /* note: can't move it above ch == dquote_end check! */
4475 syntax_error_unterm_ch('"');
4476 return 0; /* error */
4480 next = i_peek(input);
4482 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4483 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4484 if (process_bkslash && ch == '\\') {
4486 syntax_error("\\<eof>");
4490 * "The backslash retains its special meaning [in "..."]
4491 * only when followed by one of the following characters:
4492 * $, `, ", \, or <newline>. A double quote may be quoted
4493 * within double quotes by preceding it with a backslash."
4494 * NB: in (unquoted) heredoc, above does not apply to ",
4495 * therefore we check for it by "next == dquote_end" cond.
4497 if (next == dquote_end || strchr("$`\\\n", next)) {
4498 ch = i_getch(input); /* eat next */
4500 goto again; /* skip \<newline> */
4501 } /* else: ch remains == '\\', and we double it below: */
4502 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4503 nommu_addchr(as_string, ch);
4507 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4508 debug_printf_parse("encode_string return 0: "
4509 "parse_dollar returned 0 (error)\n");
4514 #if ENABLE_HUSH_TICK
4516 //unsigned pos = dest->length;
4517 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4518 o_addchr(dest, 0x80 | '`');
4519 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4520 return 0; /* error */
4521 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4522 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4526 o_addQchr(dest, ch);
4532 * Scan input until EOF or end_trigger char.
4533 * Return a list of pipes to execute, or NULL on EOF
4534 * or if end_trigger character is met.
4535 * On syntax error, exit if shell is not interactive,
4536 * reset parsing machinery and start parsing anew,
4537 * or return ERR_PTR.
4539 static struct pipe *parse_stream(char **pstring,
4540 struct in_str *input,
4543 struct parse_context ctx;
4544 o_string dest = NULL_O_STRING;
4547 /* Single-quote triggers a bypass of the main loop until its mate is
4548 * found. When recursing, quote state is passed in via dest->o_expflags.
4550 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4551 end_trigger ? end_trigger : 'X');
4554 /* If very first arg is "" or '', dest.data may end up NULL.
4555 * Preventing this: */
4556 o_addchr(&dest, '\0');
4559 /* We used to separate words on $IFS here. This was wrong.
4560 * $IFS is used only for word splitting when $var is expanded,
4561 * here we should use blank chars as separators, not $IFS
4564 if (MAYBE_ASSIGNMENT != 0)
4565 dest.o_assignment = MAYBE_ASSIGNMENT;
4566 initialize_context(&ctx);
4569 const char *is_blank;
4570 const char *is_special;
4574 redir_type redir_style;
4576 ch = i_getch(input);
4577 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4578 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4583 syntax_error_unterm_str("here document");
4586 if (end_trigger == ')') {
4587 syntax_error_unterm_ch('(');
4590 if (end_trigger == '}') {
4591 syntax_error_unterm_ch('{');
4595 if (done_word(&dest, &ctx)) {
4599 done_pipe(&ctx, PIPE_SEQ);
4601 /* If we got nothing... */
4602 /* (this makes bare "&" cmd a no-op.
4603 * bash says: "syntax error near unexpected token '&'") */
4604 if (pi->num_cmds == 0
4605 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4611 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4613 *pstring = ctx.as_string.data;
4615 o_free_unsafe(&ctx.as_string);
4618 debug_printf_parse("parse_stream return %p\n", pi);
4621 nommu_addchr(&ctx.as_string, ch);
4625 next = i_peek(input);
4627 is_special = "{}<>;&|()#'" /* special outside of "str" */
4628 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4629 /* Are { and } special here? */
4630 if (ctx.command->argv /* word [word]{... - non-special */
4631 || dest.length /* word{... - non-special */
4632 || dest.has_quoted_part /* ""{... - non-special */
4633 || (next != ';' /* }; - special */
4634 && next != ')' /* }) - special */
4635 && next != '(' /* {( - special */
4636 && next != '&' /* }& and }&& ... - special */
4637 && next != '|' /* }|| ... - special */
4638 && !strchr(defifs, next) /* {word - non-special */
4641 /* They are not special, skip "{}" */
4644 is_special = strchr(is_special, ch);
4645 is_blank = strchr(defifs, ch);
4647 if (!is_special && !is_blank) { /* ordinary char */
4649 o_addQchr(&dest, ch);
4650 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4651 || dest.o_assignment == WORD_IS_KEYWORD)
4653 && is_well_formed_var_name(dest.data, '=')
4655 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4656 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4662 if (done_word(&dest, &ctx)) {
4666 /* Is this a case when newline is simply ignored?
4668 * "cmd | <newline> cmd ..."
4669 * "case ... in <newline> word) ..."
4671 if (IS_NULL_CMD(ctx.command)
4672 && dest.length == 0 && !dest.has_quoted_part
4674 /* This newline can be ignored. But...
4675 * Without check #1, interactive shell
4676 * ignores even bare <newline>,
4677 * and shows the continuation prompt:
4678 * ps1_prompt$ <enter>
4679 * ps2> _ <=== wrong, should be ps1
4680 * Without check #2, "cmd & <newline>"
4681 * is similarly mistreated.
4682 * (BTW, this makes "cmd & cmd"
4683 * and "cmd && cmd" non-orthogonal.
4684 * Really, ask yourself, why
4685 * "cmd && <newline>" doesn't start
4686 * cmd but waits for more input?
4689 struct pipe *pi = ctx.list_head;
4690 if (pi->num_cmds != 0 /* check #1 */
4691 && pi->followup != PIPE_BG /* check #2 */
4696 /* Treat newline as a command separator. */
4697 done_pipe(&ctx, PIPE_SEQ);
4698 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4700 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4705 dest.o_assignment = MAYBE_ASSIGNMENT;
4706 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4708 /* note: if (is_blank) continue;
4709 * will still trigger for us */
4713 /* "cmd}" or "cmd }..." without semicolon or &:
4714 * } is an ordinary char in this case, even inside { cmd; }
4715 * Pathological example: { ""}; } should exec "}" cmd
4718 if (dest.length != 0 /* word} */
4719 || dest.has_quoted_part /* ""} */
4723 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4724 /* Generally, there should be semicolon: "cmd; }"
4725 * However, bash allows to omit it if "cmd" is
4726 * a group. Examples:
4729 * { echo 0 >&2 | { echo 1; } }
4730 * { while false; do :; done }
4731 * { case a in b) ;; esac }
4733 if (ctx.command->group)
4737 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4738 /* Can't be an end of {cmd}, skip the check */
4739 goto skip_end_trigger;
4740 /* else: } does terminate a group */
4743 if (end_trigger && end_trigger == ch
4744 && (ch != ';' || heredoc_cnt == 0)
4745 #if ENABLE_HUSH_CASE
4747 || ctx.ctx_res_w != RES_MATCH
4748 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4753 /* This is technically valid:
4754 * { cat <<HERE; }; echo Ok
4758 * but we don't support this.
4759 * We require heredoc to be in enclosing {}/(),
4762 syntax_error_unterm_str("here document");
4765 if (done_word(&dest, &ctx)) {
4768 done_pipe(&ctx, PIPE_SEQ);
4769 dest.o_assignment = MAYBE_ASSIGNMENT;
4770 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4771 /* Do we sit outside of any if's, loops or case's? */
4773 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4777 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4779 *pstring = ctx.as_string.data;
4781 o_free_unsafe(&ctx.as_string);
4784 debug_printf_parse("parse_stream return %p: "
4785 "end_trigger char found\n",
4787 return ctx.list_head;
4794 /* Catch <, > before deciding whether this word is
4795 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4798 redir_fd = redirect_opt_num(&dest);
4799 if (done_word(&dest, &ctx)) {
4802 redir_style = REDIRECT_OVERWRITE;
4804 redir_style = REDIRECT_APPEND;
4805 ch = i_getch(input);
4806 nommu_addchr(&ctx.as_string, ch);
4809 else if (next == '(') {
4810 syntax_error(">(process) not supported");
4814 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4816 continue; /* back to top of while (1) */
4818 redir_fd = redirect_opt_num(&dest);
4819 if (done_word(&dest, &ctx)) {
4822 redir_style = REDIRECT_INPUT;
4824 redir_style = REDIRECT_HEREDOC;
4826 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4827 ch = i_getch(input);
4828 nommu_addchr(&ctx.as_string, ch);
4829 } else if (next == '>') {
4830 redir_style = REDIRECT_IO;
4831 ch = i_getch(input);
4832 nommu_addchr(&ctx.as_string, ch);
4835 else if (next == '(') {
4836 syntax_error("<(process) not supported");
4840 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4842 continue; /* back to top of while (1) */
4844 if (dest.length == 0 && !dest.has_quoted_part) {
4845 /* skip "#comment" */
4848 if (ch == EOF || ch == '\n')
4851 /* note: we do not add it to &ctx.as_string */
4853 nommu_addchr(&ctx.as_string, '\n');
4854 continue; /* back to top of while (1) */
4859 /* It's "\<newline>" */
4861 /* Remove trailing '\' from ctx.as_string */
4862 ctx.as_string.data[--ctx.as_string.length] = '\0';
4864 ch = i_getch(input); /* eat it */
4865 continue; /* back to top of while (1) */
4870 if (dest.o_assignment == MAYBE_ASSIGNMENT
4871 /* check that we are not in word in "a=1 2>word b=1": */
4872 && !ctx.pending_redirect
4874 /* ch is a special char and thus this word
4875 * cannot be an assignment */
4876 dest.o_assignment = NOT_ASSIGNMENT;
4877 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4880 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4883 case '#': /* non-comment #: "echo a#b" etc */
4884 o_addQchr(&dest, ch);
4888 syntax_error("\\<eof>");
4891 ch = i_getch(input);
4892 /* note: ch != '\n' (that case does not reach this place) */
4893 o_addchr(&dest, '\\');
4894 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4895 o_addchr(&dest, ch);
4896 nommu_addchr(&ctx.as_string, ch);
4897 /* Example: echo Hello \2>file
4898 * we need to know that word 2 is quoted */
4899 dest.has_quoted_part = 1;
4902 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4903 debug_printf_parse("parse_stream parse error: "
4904 "parse_dollar returned 0 (error)\n");
4909 dest.has_quoted_part = 1;
4910 if (next == '\'' && !ctx.pending_redirect) {
4911 insert_empty_quoted_str_marker:
4912 nommu_addchr(&ctx.as_string, next);
4913 i_getch(input); /* eat second ' */
4914 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4915 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4918 ch = i_getch(input);
4920 syntax_error_unterm_ch('\'');
4923 nommu_addchr(&ctx.as_string, ch);
4926 o_addqchr(&dest, ch);
4931 dest.has_quoted_part = 1;
4932 if (next == '"' && !ctx.pending_redirect)
4933 goto insert_empty_quoted_str_marker;
4934 if (dest.o_assignment == NOT_ASSIGNMENT)
4935 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4936 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4938 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4940 #if ENABLE_HUSH_TICK
4942 USE_FOR_NOMMU(unsigned pos;)
4944 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4945 o_addchr(&dest, '`');
4946 USE_FOR_NOMMU(pos = dest.length;)
4947 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4950 o_addstr(&ctx.as_string, dest.data + pos);
4951 o_addchr(&ctx.as_string, '`');
4953 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4954 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4959 #if ENABLE_HUSH_CASE
4962 if (done_word(&dest, &ctx)) {
4965 done_pipe(&ctx, PIPE_SEQ);
4966 #if ENABLE_HUSH_CASE
4967 /* Eat multiple semicolons, detect
4968 * whether it means something special */
4973 ch = i_getch(input);
4974 nommu_addchr(&ctx.as_string, ch);
4975 if (ctx.ctx_res_w == RES_CASE_BODY) {
4976 ctx.ctx_dsemicolon = 1;
4977 ctx.ctx_res_w = RES_MATCH;
4983 /* We just finished a cmd. New one may start
4984 * with an assignment */
4985 dest.o_assignment = MAYBE_ASSIGNMENT;
4986 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4989 if (done_word(&dest, &ctx)) {
4993 ch = i_getch(input);
4994 nommu_addchr(&ctx.as_string, ch);
4995 done_pipe(&ctx, PIPE_AND);
4997 done_pipe(&ctx, PIPE_BG);
5001 if (done_word(&dest, &ctx)) {
5004 #if ENABLE_HUSH_CASE
5005 if (ctx.ctx_res_w == RES_MATCH)
5006 break; /* we are in case's "word | word)" */
5008 if (next == '|') { /* || */
5009 ch = i_getch(input);
5010 nommu_addchr(&ctx.as_string, ch);
5011 done_pipe(&ctx, PIPE_OR);
5013 /* we could pick up a file descriptor choice here
5014 * with redirect_opt_num(), but bash doesn't do it.
5015 * "echo foo 2| cat" yields "foo 2". */
5020 #if ENABLE_HUSH_CASE
5021 /* "case... in [(]word)..." - skip '(' */
5022 if (ctx.ctx_res_w == RES_MATCH
5023 && ctx.command->argv == NULL /* not (word|(... */
5024 && dest.length == 0 /* not word(... */
5025 && dest.has_quoted_part == 0 /* not ""(... */
5031 if (parse_group(&dest, &ctx, input, ch) != 0) {
5036 #if ENABLE_HUSH_CASE
5037 if (ctx.ctx_res_w == RES_MATCH)
5041 /* proper use of this character is caught by end_trigger:
5042 * if we see {, we call parse_group(..., end_trigger='}')
5043 * and it will match } earlier (not here). */
5044 syntax_error_unexpected_ch(ch);
5045 G.last_exitcode = 2;
5049 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5054 G.last_exitcode = 1;
5057 struct parse_context *pctx;
5058 IF_HAS_KEYWORDS(struct parse_context *p2;)
5060 /* Clean up allocated tree.
5061 * Sample for finding leaks on syntax error recovery path.
5062 * Run it from interactive shell, watch pmap `pidof hush`.
5063 * while if false; then false; fi; do break; fi
5064 * Samples to catch leaks at execution:
5065 * while if (true | { true;}); then echo ok; fi; do break; done
5066 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5070 /* Update pipe/command counts,
5071 * otherwise freeing may miss some */
5072 done_pipe(pctx, PIPE_SEQ);
5073 debug_printf_clean("freeing list %p from ctx %p\n",
5074 pctx->list_head, pctx);
5075 debug_print_tree(pctx->list_head, 0);
5076 free_pipe_list(pctx->list_head);
5077 debug_printf_clean("freed list %p\n", pctx->list_head);
5079 o_free_unsafe(&pctx->as_string);
5081 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5085 IF_HAS_KEYWORDS(pctx = p2;)
5086 } while (HAS_KEYWORDS && pctx);
5099 /*** Execution routines ***/
5101 /* Expansion can recurse, need forward decls: */
5102 #if !ENABLE_HUSH_BASH_COMPAT
5103 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5104 #define expand_string_to_string(str, do_unbackslash) \
5105 expand_string_to_string(str)
5107 static char *expand_string_to_string(const char *str, int do_unbackslash);
5108 #if ENABLE_HUSH_TICK
5109 static int process_command_subs(o_string *dest, const char *s);
5112 /* expand_strvec_to_strvec() takes a list of strings, expands
5113 * all variable references within and returns a pointer to
5114 * a list of expanded strings, possibly with larger number
5115 * of strings. (Think VAR="a b"; echo $VAR).
5116 * This new list is allocated as a single malloc block.
5117 * NULL-terminated list of char* pointers is at the beginning of it,
5118 * followed by strings themselves.
5119 * Caller can deallocate entire list by single free(list). */
5121 /* A horde of its helpers come first: */
5123 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5125 while (--len >= 0) {
5128 #if ENABLE_HUSH_BRACE_EXPANSION
5129 if (c == '{' || c == '}') {
5130 /* { -> \{, } -> \} */
5132 /* And now we want to add { or } and continue:
5135 * luckily, just falling throught achieves this.
5141 /* \z -> \\\z; \<eol> -> \\<eol> */
5146 o_addchr(o, *str++);
5152 /* Store given string, finalizing the word and starting new one whenever
5153 * we encounter IFS char(s). This is used for expanding variable values.
5154 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5155 * Return in *ended_with_ifs:
5156 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5158 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5160 int last_is_ifs = 0;
5165 if (!*str) /* EOL - do not finalize word */
5167 word_len = strcspn(str, G.ifs);
5169 /* We have WORD_LEN leading non-IFS chars */
5170 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5171 o_addblock(output, str, word_len);
5173 /* Protect backslashes against globbing up :)
5174 * Example: "v='\*'; echo b$v" prints "b\*"
5175 * (and does not try to glob on "*")
5177 o_addblock_duplicate_backslash(output, str, word_len);
5178 /*/ Why can't we do it easier? */
5179 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5180 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5184 if (!*str) /* EOL - do not finalize word */
5188 /* We know str here points to at least one IFS char */
5190 str += strspn(str, G.ifs); /* skip IFS chars */
5191 if (!*str) /* EOL - do not finalize word */
5194 /* Start new word... but not always! */
5195 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5196 if (output->has_quoted_part
5197 /* Case "v=' a'; echo $v":
5198 * here nothing precedes the space in $v expansion,
5199 * therefore we should not finish the word
5200 * (IOW: if there *is* word to finalize, only then do it):
5202 || (n > 0 && output->data[output->length - 1])
5204 o_addchr(output, '\0');
5205 debug_print_list("expand_on_ifs", output, n);
5206 n = o_save_ptr(output, n);
5211 *ended_with_ifs = last_is_ifs;
5212 debug_print_list("expand_on_ifs[1]", output, n);
5216 /* Helper to expand $((...)) and heredoc body. These act as if
5217 * they are in double quotes, with the exception that they are not :).
5218 * Just the rules are similar: "expand only $var and `cmd`"
5220 * Returns malloced string.
5221 * As an optimization, we return NULL if expansion is not needed.
5223 #if !ENABLE_HUSH_BASH_COMPAT
5224 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5225 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5226 encode_then_expand_string(str)
5228 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5231 struct in_str input;
5232 o_string dest = NULL_O_STRING;
5234 if (!strchr(str, '$')
5235 && !strchr(str, '\\')
5236 #if ENABLE_HUSH_TICK
5237 && !strchr(str, '`')
5243 /* We need to expand. Example:
5244 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5246 setup_string_in_str(&input, str);
5247 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5248 //TODO: error check (encode_string returns 0 on error)?
5249 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5250 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5251 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5252 o_free_unsafe(&dest);
5256 #if ENABLE_FEATURE_SH_MATH
5257 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5259 arith_state_t math_state;
5263 math_state.lookupvar = get_local_var_value;
5264 math_state.setvar = set_local_var_from_halves;
5265 //math_state.endofname = endofname;
5266 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5267 res = arith(&math_state, exp_str ? exp_str : arg);
5270 *errmsg_p = math_state.errmsg;
5271 if (math_state.errmsg)
5272 die_if_script(math_state.errmsg);
5277 #if ENABLE_HUSH_BASH_COMPAT
5278 /* ${var/[/]pattern[/repl]} helpers */
5279 static char *strstr_pattern(char *val, const char *pattern, int *size)
5282 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5283 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5290 /* Optimization: if "*pat" did not match the start of "string",
5291 * we know that "tring", "ring" etc will not match too:
5293 if (pattern[0] == '*')
5298 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5300 char *result = NULL;
5301 unsigned res_len = 0;
5302 unsigned repl_len = strlen(repl);
5306 char *s = strstr_pattern(val, pattern, &size);
5310 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5311 memcpy(result + res_len, val, s - val);
5313 strcpy(result + res_len, repl);
5314 res_len += repl_len;
5315 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5321 if (val[0] && result) {
5322 result = xrealloc(result, res_len + strlen(val) + 1);
5323 strcpy(result + res_len, val);
5324 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5326 debug_printf_varexp("result:'%s'\n", result);
5332 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5334 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5336 const char *val = NULL;
5337 char *to_be_freed = NULL;
5342 char exp_save = exp_save; /* for compiler */
5343 char *exp_saveptr; /* points to expansion operator */
5344 char *exp_word = exp_word; /* for compiler */
5347 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5349 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5351 first_char = arg[0] = arg0 & 0x7f;
5354 if (first_char == '#' /* ${#... */
5355 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5357 /* It must be length operator: ${#var} */
5361 /* Maybe handle parameter expansion */
5362 if (exp_saveptr /* if 2nd char is one of expansion operators */
5363 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5365 /* ${?:0}, ${#[:]%0} etc */
5366 exp_saveptr = var + 1;
5368 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5369 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5371 exp_op = exp_save = *exp_saveptr;
5373 exp_word = exp_saveptr + 1;
5374 if (exp_op == ':') {
5375 exp_op = *exp_word++;
5376 //TODO: try ${var:} and ${var:bogus} in non-bash config
5377 if (ENABLE_HUSH_BASH_COMPAT
5378 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5380 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5385 *exp_saveptr = '\0';
5386 } /* else: it's not an expansion op, but bare ${var} */
5389 /* Look up the variable in question */
5390 if (isdigit(var[0])) {
5391 /* parse_dollar should have vetted var for us */
5392 int n = xatoi_positive(var);
5393 if (n < G.global_argc)
5394 val = G.global_argv[n];
5395 /* else val remains NULL: $N with too big N */
5399 val = utoa(G.root_pid);
5401 case '!': /* bg pid */
5402 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5404 case '?': /* exitcode */
5405 val = utoa(G.last_exitcode);
5407 case '#': /* argc */
5408 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5411 val = get_local_var_value(var);
5415 /* Handle any expansions */
5416 if (exp_op == 'L') {
5417 reinit_unicode_for_hush();
5418 debug_printf_expand("expand: length(%s)=", val);
5419 val = utoa(val ? unicode_strlen(val) : 0);
5420 debug_printf_expand("%s\n", val);
5421 } else if (exp_op) {
5422 if (exp_op == '%' || exp_op == '#') {
5423 /* Standard-mandated substring removal ops:
5424 * ${parameter%word} - remove smallest suffix pattern
5425 * ${parameter%%word} - remove largest suffix pattern
5426 * ${parameter#word} - remove smallest prefix pattern
5427 * ${parameter##word} - remove largest prefix pattern
5429 * Word is expanded to produce a glob pattern.
5430 * Then var's value is matched to it and matching part removed.
5432 if (val && val[0]) {
5436 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5437 if (exp_op == *exp_word) /* ## or %% */
5439 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5441 exp_word = exp_exp_word;
5442 /* HACK ALERT. We depend here on the fact that
5443 * G.global_argv and results of utoa and get_local_var_value
5444 * are actually in writable memory:
5445 * scan_and_match momentarily stores NULs there. */
5447 loc = scan_and_match(t, exp_word, scan_flags);
5448 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5449 // exp_op, t, exp_word, loc);
5451 if (loc) { /* match was found */
5452 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5453 val = loc; /* take right part */
5455 val = to_be_freed = xstrndup(val, loc - val); /* left */
5459 #if ENABLE_HUSH_BASH_COMPAT
5460 else if (exp_op == '/' || exp_op == '\\') {
5461 /* It's ${var/[/]pattern[/repl]} thing.
5462 * Note that in encoded form it has TWO parts:
5463 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5464 * and if // is used, it is encoded as \:
5465 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5467 /* Empty variable always gives nothing: */
5468 // "v=''; echo ${v/*/w}" prints "", not "w"
5469 if (val && val[0]) {
5470 /* pattern uses non-standard expansion.
5471 * repl should be unbackslashed and globbed
5472 * by the usual expansion rules:
5474 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5475 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5476 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5477 * v='a bz'; echo ${v/a*z/\z} prints "z"
5478 * (note that a*z _pattern_ is never globbed!)
5480 char *pattern, *repl, *t;
5481 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5483 pattern = xstrdup(exp_word);
5484 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5485 *p++ = SPECIAL_VAR_SYMBOL;
5487 p = strchr(p, SPECIAL_VAR_SYMBOL);
5489 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5490 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5491 /* HACK ALERT. We depend here on the fact that
5492 * G.global_argv and results of utoa and get_local_var_value
5493 * are actually in writable memory:
5494 * replace_pattern momentarily stores NULs there. */
5496 to_be_freed = replace_pattern(t,
5498 (repl ? repl : exp_word),
5500 if (to_be_freed) /* at least one replace happened */
5507 else if (exp_op == ':') {
5508 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_FEATURE_SH_MATH
5509 /* It's ${var:N[:M]} bashism.
5510 * Note that in encoded form it has TWO parts:
5511 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5516 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5519 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5520 *p++ = SPECIAL_VAR_SYMBOL;
5522 p = strchr(p, SPECIAL_VAR_SYMBOL);
5524 len = expand_and_evaluate_arith(exp_word, &errmsg);
5527 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5528 if (len >= 0) { /* bash compat: len < 0 is illegal */
5529 if (beg < 0) /* bash compat */
5531 debug_printf_varexp("from val:'%s'\n", val);
5532 if (len == 0 || !val || beg >= strlen(val)) {
5536 /* Paranoia. What if user entered 9999999999999
5537 * which fits in arith_t but not int? */
5540 val = to_be_freed = xstrndup(val + beg, len);
5542 debug_printf_varexp("val:'%s'\n", val);
5546 die_if_script("malformed ${%s:...}", var);
5549 } else { /* one of "-=+?" */
5550 /* Standard-mandated substitution ops:
5551 * ${var?word} - indicate error if unset
5552 * If var is unset, word (or a message indicating it is unset
5553 * if word is null) is written to standard error
5554 * and the shell exits with a non-zero exit status.
5555 * Otherwise, the value of var is substituted.
5556 * ${var-word} - use default value
5557 * If var is unset, word is substituted.
5558 * ${var=word} - assign and use default value
5559 * If var is unset, word is assigned to var.
5560 * In all cases, final value of var is substituted.
5561 * ${var+word} - use alternative value
5562 * If var is unset, null is substituted.
5563 * Otherwise, word is substituted.
5565 * Word is subjected to tilde expansion, parameter expansion,
5566 * command substitution, and arithmetic expansion.
5567 * If word is not needed, it is not expanded.
5569 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5570 * but also treat null var as if it is unset.
5572 int use_word = (!val || ((exp_save == ':') && !val[0]));
5574 use_word = !use_word;
5575 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5576 (exp_save == ':') ? "true" : "false", use_word);
5578 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5580 exp_word = to_be_freed;
5581 if (exp_op == '?') {
5582 /* mimic bash message */
5583 die_if_script("%s: %s",
5585 exp_word[0] ? exp_word : "parameter null or not set"
5587 //TODO: how interactive bash aborts expansion mid-command?
5592 if (exp_op == '=') {
5593 /* ${var=[word]} or ${var:=[word]} */
5594 if (isdigit(var[0]) || var[0] == '#') {
5595 /* mimic bash message */
5596 die_if_script("$%s: cannot assign in this way", var);
5599 char *new_var = xasprintf("%s=%s", var, val);
5600 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5604 } /* one of "-=+?" */
5606 *exp_saveptr = exp_save;
5612 *to_be_freed_pp = to_be_freed;
5616 /* Expand all variable references in given string, adding words to list[]
5617 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5618 * to be filled). This routine is extremely tricky: has to deal with
5619 * variables/parameters with whitespace, $* and $@, and constructs like
5620 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5621 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5623 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5624 * expansion of right-hand side of assignment == 1-element expand.
5626 char cant_be_null = 0; /* only bit 0x80 matters */
5627 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5630 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5631 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5632 debug_print_list("expand_vars_to_list", output, n);
5633 n = o_save_ptr(output, n);
5634 debug_print_list("expand_vars_to_list[0]", output, n);
5636 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5638 char *to_be_freed = NULL;
5639 const char *val = NULL;
5640 #if ENABLE_HUSH_TICK
5641 o_string subst_result = NULL_O_STRING;
5643 #if ENABLE_FEATURE_SH_MATH
5644 char arith_buf[sizeof(arith_t)*3 + 2];
5648 o_addchr(output, '\0');
5649 n = o_save_ptr(output, n);
5653 o_addblock(output, arg, p - arg);
5654 debug_print_list("expand_vars_to_list[1]", output, n);
5656 p = strchr(p, SPECIAL_VAR_SYMBOL);
5658 /* Fetch special var name (if it is indeed one of them)
5659 * and quote bit, force the bit on if singleword expansion -
5660 * important for not getting v=$@ expand to many words. */
5661 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5663 /* Is this variable quoted and thus expansion can't be null?
5664 * "$@" is special. Even if quoted, it can still
5665 * expand to nothing (not even an empty string),
5666 * thus it is excluded. */
5667 if ((first_ch & 0x7f) != '@')
5668 cant_be_null |= first_ch;
5670 switch (first_ch & 0x7f) {
5671 /* Highest bit in first_ch indicates that var is double-quoted */
5675 if (!G.global_argv[1])
5678 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5679 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5680 while (G.global_argv[i]) {
5681 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5682 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5683 if (G.global_argv[i++][0] && G.global_argv[i]) {
5684 /* this argv[] is not empty and not last:
5685 * put terminating NUL, start new word */
5686 o_addchr(output, '\0');
5687 debug_print_list("expand_vars_to_list[2]", output, n);
5688 n = o_save_ptr(output, n);
5689 debug_print_list("expand_vars_to_list[3]", output, n);
5693 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5694 * and in this case should treat it like '$*' - see 'else...' below */
5695 if (first_ch == ('@'|0x80) /* quoted $@ */
5696 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5699 o_addQstr(output, G.global_argv[i]);
5700 if (++i >= G.global_argc)
5702 o_addchr(output, '\0');
5703 debug_print_list("expand_vars_to_list[4]", output, n);
5704 n = o_save_ptr(output, n);
5706 } else { /* quoted $* (or v="$@" case): add as one word */
5708 o_addQstr(output, G.global_argv[i]);
5709 if (!G.global_argv[++i])
5712 o_addchr(output, G.ifs[0]);
5714 output->has_quoted_part = 1;
5718 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5719 /* "Empty variable", used to make "" etc to not disappear */
5720 output->has_quoted_part = 1;
5722 cant_be_null = 0x80;
5724 #if ENABLE_HUSH_TICK
5725 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5726 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5728 /* Can't just stuff it into output o_string,
5729 * expanded result may need to be globbed
5730 * and $IFS-splitted */
5731 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5732 G.last_exitcode = process_command_subs(&subst_result, arg);
5733 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5734 val = subst_result.data;
5737 #if ENABLE_FEATURE_SH_MATH
5738 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5741 arg++; /* skip '+' */
5742 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5743 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5744 res = expand_and_evaluate_arith(arg, NULL);
5745 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5746 sprintf(arith_buf, ARITH_FMT, res);
5752 val = expand_one_var(&to_be_freed, arg, &p);
5753 IF_HUSH_TICK(store_val:)
5754 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5755 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5756 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5757 if (val && val[0]) {
5758 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5761 } else { /* quoted $VAR, val will be appended below */
5762 output->has_quoted_part = 1;
5763 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5764 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5767 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5769 if (val && val[0]) {
5770 o_addQstr(output, val);
5774 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5775 * Do the check to avoid writing to a const string. */
5776 if (*p != SPECIAL_VAR_SYMBOL)
5777 *p = SPECIAL_VAR_SYMBOL;
5779 #if ENABLE_HUSH_TICK
5780 o_free(&subst_result);
5783 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5787 o_addchr(output, '\0');
5788 n = o_save_ptr(output, n);
5790 debug_print_list("expand_vars_to_list[a]", output, n);
5791 /* this part is literal, and it was already pre-quoted
5792 * if needed (much earlier), do not use o_addQstr here! */
5793 o_addstr_with_NUL(output, arg);
5794 debug_print_list("expand_vars_to_list[b]", output, n);
5795 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5796 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5799 /* allow to reuse list[n] later without re-growth */
5800 output->has_empty_slot = 1;
5802 o_addchr(output, '\0');
5808 static char **expand_variables(char **argv, unsigned expflags)
5812 o_string output = NULL_O_STRING;
5814 output.o_expflags = expflags;
5818 n = expand_vars_to_list(&output, n, *argv);
5821 debug_print_list("expand_variables", &output, n);
5823 /* output.data (malloced in one block) gets returned in "list" */
5824 list = o_finalize_list(&output, n);
5825 debug_print_strings("expand_variables[1]", list);
5829 static char **expand_strvec_to_strvec(char **argv)
5831 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5834 #if ENABLE_HUSH_BASH_COMPAT
5835 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5837 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5841 /* Used for expansion of right hand of assignments,
5842 * $((...)), heredocs, variable espansion parts.
5844 * NB: should NOT do globbing!
5845 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5847 static char *expand_string_to_string(const char *str, int do_unbackslash)
5849 #if !ENABLE_HUSH_BASH_COMPAT
5850 const int do_unbackslash = 1;
5852 char *argv[2], **list;
5854 debug_printf_expand("string_to_string<='%s'\n", str);
5855 /* This is generally an optimization, but it also
5856 * handles "", which otherwise trips over !list[0] check below.
5857 * (is this ever happens that we actually get str="" here?)
5859 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5860 //TODO: Can use on strings with \ too, just unbackslash() them?
5861 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5862 return xstrdup(str);
5865 argv[0] = (char*)str;
5867 list = expand_variables(argv, do_unbackslash
5868 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5869 : EXP_FLAG_SINGLEWORD
5872 if (!list[0] || list[1])
5873 bb_error_msg_and_die("BUG in varexp2");
5874 /* actually, just move string 2*sizeof(char*) bytes back */
5875 overlapping_strcpy((char*)list, list[0]);
5877 unbackslash((char*)list);
5878 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5882 /* Used for "eval" builtin */
5883 static char* expand_strvec_to_string(char **argv)
5887 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5888 /* Convert all NULs to spaces */
5893 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5894 bb_error_msg_and_die("BUG in varexp3");
5895 /* bash uses ' ' regardless of $IFS contents */
5900 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5901 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5905 static char **expand_assignments(char **argv, int count)
5910 G.expanded_assignments = p = NULL;
5911 /* Expand assignments into one string each */
5912 for (i = 0; i < count; i++) {
5913 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5915 G.expanded_assignments = NULL;
5920 static void switch_off_special_sigs(unsigned mask)
5923 while ((mask >>= 1) != 0) {
5928 if (G.traps[sig] && !G.traps[sig][0])
5929 /* trap is '', has to remain SIG_IGN */
5932 G.traps[sig] = NULL;
5934 /* We are here only if no trap or trap was not '' */
5935 install_sighandler(sig, SIG_DFL);
5941 void re_execute_shell(char ***to_free, const char *s,
5942 char *g_argv0, char **g_argv,
5943 char **builtin_argv) NORETURN;
5945 static void reset_traps_to_defaults(void)
5947 /* This function is always called in a child shell
5948 * after fork (not vfork, NOMMU doesn't use this function).
5953 /* Child shells are not interactive.
5954 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5955 * Testcase: (while :; do :; done) + ^Z should background.
5956 * Same goes for SIGTERM, SIGHUP, SIGINT.
5958 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5959 if (!G.traps && !mask)
5960 return; /* already no traps and no special sigs */
5962 /* Switch off special sigs */
5963 switch_off_special_sigs(mask);
5965 G_fatal_sig_mask = 0;
5967 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5968 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5969 * remain set in G.special_sig_mask */
5974 /* Reset all sigs to default except ones with empty traps */
5975 for (sig = 0; sig < NSIG; sig++) {
5977 continue; /* no trap: nothing to do */
5978 if (!G.traps[sig][0])
5979 continue; /* empty trap: has to remain SIG_IGN */
5980 /* sig has non-empty trap, reset it: */
5982 G.traps[sig] = NULL;
5983 /* There is no signal for trap 0 (EXIT) */
5986 install_sighandler(sig, pick_sighandler(sig));
5992 static void re_execute_shell(char ***to_free, const char *s,
5993 char *g_argv0, char **g_argv,
5994 char **builtin_argv) NORETURN;
5995 static void re_execute_shell(char ***to_free, const char *s,
5996 char *g_argv0, char **g_argv,
5997 char **builtin_argv)
5999 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6000 /* delims + 2 * (number of bytes in printed hex numbers) */
6001 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6002 char *heredoc_argv[4];
6003 struct variable *cur;
6004 # if ENABLE_HUSH_FUNCTIONS
6005 struct function *funcp;
6009 unsigned long long empty_trap_mask;
6011 if (!g_argv0) { /* heredoc */
6012 argv = heredoc_argv;
6013 argv[0] = (char *) G.argv0_for_re_execing;
6014 argv[1] = (char *) "-<";
6015 argv[2] = (char *) s;
6017 pp = &argv[3]; /* used as pointer to empty environment */
6023 if (pp) while (*pp++)
6026 empty_trap_mask = 0;
6029 for (sig = 1; sig < NSIG; sig++) {
6030 if (G.traps[sig] && !G.traps[sig][0])
6031 empty_trap_mask |= 1LL << sig;
6035 sprintf(param_buf, NOMMU_HACK_FMT
6036 , (unsigned) G.root_pid
6037 , (unsigned) G.root_ppid
6038 , (unsigned) G.last_bg_pid
6039 , (unsigned) G.last_exitcode
6042 IF_HUSH_LOOPS(, G.depth_of_loop)
6044 # undef NOMMU_HACK_FMT
6045 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6046 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6049 for (cur = G.top_var; cur; cur = cur->next) {
6050 if (!cur->flg_export || cur->flg_read_only)
6053 # if ENABLE_HUSH_FUNCTIONS
6054 for (funcp = G.top_func; funcp; funcp = funcp->next)
6060 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6061 *pp++ = (char *) G.argv0_for_re_execing;
6063 for (cur = G.top_var; cur; cur = cur->next) {
6064 if (strcmp(cur->varstr, hush_version_str) == 0)
6066 if (cur->flg_read_only) {
6067 *pp++ = (char *) "-R";
6068 *pp++ = cur->varstr;
6069 } else if (!cur->flg_export) {
6070 *pp++ = (char *) "-V";
6071 *pp++ = cur->varstr;
6074 # if ENABLE_HUSH_FUNCTIONS
6075 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6076 *pp++ = (char *) "-F";
6077 *pp++ = funcp->name;
6078 *pp++ = funcp->body_as_string;
6081 /* We can pass activated traps here. Say, -Tnn:trap_string
6083 * However, POSIX says that subshells reset signals with traps
6085 * I tested bash-3.2 and it not only does that with true subshells
6086 * of the form ( list ), but with any forked children shells.
6087 * I set trap "echo W" WINCH; and then tried:
6089 * { echo 1; sleep 20; echo 2; } &
6090 * while true; do echo 1; sleep 20; echo 2; break; done &
6091 * true | { echo 1; sleep 20; echo 2; } | cat
6093 * In all these cases sending SIGWINCH to the child shell
6094 * did not run the trap. If I add trap "echo V" WINCH;
6095 * _inside_ group (just before echo 1), it works.
6097 * I conclude it means we don't need to pass active traps here.
6099 *pp++ = (char *) "-c";
6102 while (*++builtin_argv)
6103 *pp++ = *builtin_argv;
6104 *pp++ = (char *) "";
6109 /* *pp = NULL; - is already there */
6113 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6114 /* Don't propagate SIG_IGN to the child */
6115 if (SPECIAL_JOBSTOP_SIGS != 0)
6116 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6117 execve(bb_busybox_exec_path, argv, pp);
6118 /* Fallback. Useful for init=/bin/hush usage etc */
6119 if (argv[0][0] == '/')
6120 execve(argv[0], argv, pp);
6121 xfunc_error_retval = 127;
6122 bb_error_msg_and_die("can't re-execute the shell");
6124 #endif /* !BB_MMU */
6127 static int run_and_free_list(struct pipe *pi);
6129 /* Executing from string: eval, sh -c '...'
6130 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6131 * end_trigger controls how often we stop parsing
6132 * NUL: parse all, execute, return
6133 * ';': parse till ';' or newline, execute, repeat till EOF
6135 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6137 /* Why we need empty flag?
6138 * An obscure corner case "false; ``; echo $?":
6139 * empty command in `` should still set $? to 0.
6140 * But we can't just set $? to 0 at the start,
6141 * this breaks "false; echo `echo $?`" case.
6145 struct pipe *pipe_list;
6147 #if ENABLE_HUSH_INTERACTIVE
6148 if (end_trigger == ';')
6149 inp->promptmode = 0; /* PS1 */
6151 pipe_list = parse_stream(NULL, inp, end_trigger);
6152 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6153 /* If we are in "big" script
6154 * (not in `cmd` or something similar)...
6156 if (pipe_list == ERR_PTR && end_trigger == ';') {
6157 /* Discard cached input (rest of line) */
6158 int ch = inp->last_char;
6159 while (ch != EOF && ch != '\n') {
6160 //bb_error_msg("Discarded:'%c'", ch);
6165 /* This stream isn't empty */
6169 if (!pipe_list && empty)
6170 G.last_exitcode = 0;
6173 debug_print_tree(pipe_list, 0);
6174 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6175 run_and_free_list(pipe_list);
6177 if (G_flag_return_in_progress == 1)
6182 static void parse_and_run_string(const char *s)
6184 struct in_str input;
6185 setup_string_in_str(&input, s);
6186 parse_and_run_stream(&input, '\0');
6189 static void parse_and_run_file(FILE *f)
6191 struct in_str input;
6192 setup_file_in_str(&input, f);
6193 parse_and_run_stream(&input, ';');
6196 #if ENABLE_HUSH_TICK
6197 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6202 char **to_free = NULL;
6206 pid = BB_MMU ? xfork() : xvfork();
6207 if (pid == 0) { /* child */
6208 disable_restore_tty_pgrp_on_exit();
6209 /* Process substitution is not considered to be usual
6210 * 'command execution'.
6211 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6218 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6219 close(channel[0]); /* NB: close _first_, then move fd! */
6220 xmove_fd(channel[1], 1);
6221 /* Prevent it from trying to handle ctrl-z etc */
6222 IF_HUSH_JOB(G.run_list_level = 1;)
6223 /* Awful hack for `trap` or $(trap).
6225 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6226 * contains an example where "trap" is executed in a subshell:
6228 * save_traps=$(trap)
6230 * eval "$save_traps"
6232 * Standard does not say that "trap" in subshell shall print
6233 * parent shell's traps. It only says that its output
6234 * must have suitable form, but then, in the above example
6235 * (which is not supposed to be normative), it implies that.
6237 * bash (and probably other shell) does implement it
6238 * (traps are reset to defaults, but "trap" still shows them),
6239 * but as a result, "trap" logic is hopelessly messed up:
6242 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6243 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6244 * # true | trap <--- trap is in subshell - no output (ditto)
6245 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6246 * trap -- 'echo Ho' SIGWINCH
6247 * # echo `(trap)` <--- in subshell in subshell - output
6248 * trap -- 'echo Ho' SIGWINCH
6249 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6250 * trap -- 'echo Ho' SIGWINCH
6252 * The rules when to forget and when to not forget traps
6253 * get really complex and nonsensical.
6255 * Our solution: ONLY bare $(trap) or `trap` is special.
6257 s = skip_whitespace(s);
6258 if (is_prefixed_with(s, "trap")
6259 && skip_whitespace(s + 4)[0] == '\0'
6261 static const char *const argv[] = { NULL, NULL };
6262 builtin_trap((char**)argv);
6263 fflush_all(); /* important */
6267 reset_traps_to_defaults();
6268 parse_and_run_string(s);
6269 _exit(G.last_exitcode);
6271 /* We re-execute after vfork on NOMMU. This makes this script safe:
6272 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6273 * huge=`cat BIG` # was blocking here forever
6276 re_execute_shell(&to_free,
6286 # if ENABLE_HUSH_FAST
6288 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6289 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6290 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6292 enable_restore_tty_pgrp_on_exit();
6297 return remember_FILE(xfdopen_for_read(channel[0]));
6300 /* Return code is exit status of the process that is run. */
6301 static int process_command_subs(o_string *dest, const char *s)
6304 struct in_str pipe_str;
6306 int status, ch, eol_cnt;
6308 fp = generate_stream_from_string(s, &pid);
6310 /* Now send results of command back into original context */
6311 setup_file_in_str(&pipe_str, fp);
6313 while ((ch = i_getch(&pipe_str)) != EOF) {
6319 o_addchr(dest, '\n');
6322 o_addQchr(dest, ch);
6325 debug_printf("done reading from `cmd` pipe, closing it\n");
6326 fclose_and_forget(fp);
6327 /* We need to extract exitcode. Test case
6328 * "true; echo `sleep 1; false` $?"
6330 safe_waitpid(pid, &status, 0);
6331 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6332 return WEXITSTATUS(status);
6334 #endif /* ENABLE_HUSH_TICK */
6337 static void setup_heredoc(struct redir_struct *redir)
6339 struct fd_pair pair;
6342 /* the _body_ of heredoc (misleading field name) */
6343 const char *heredoc = redir->rd_filename;
6350 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6351 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6355 len = strlen(heredoc);
6357 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6359 xmove_fd(pair.rd, redir->rd_fd);
6361 /* Try writing without forking. Newer kernels have
6362 * dynamically growing pipes. Must use non-blocking write! */
6365 written = write(pair.wr, heredoc, len);
6376 ndelay_off(pair.wr);
6378 /* Okay, pipe buffer was not big enough */
6379 /* Note: we must not create a stray child (bastard? :)
6380 * for the unsuspecting parent process. Child creates a grandchild
6381 * and exits before parent execs the process which consumes heredoc
6382 * (that exec happens after we return from this function) */
6389 disable_restore_tty_pgrp_on_exit();
6390 pid = BB_MMU ? xfork() : xvfork();
6394 close(redir->rd_fd); /* read side of the pipe */
6396 full_write(pair.wr, heredoc, len); /* may loop or block */
6399 /* Delegate blocking writes to another process */
6400 xmove_fd(pair.wr, STDOUT_FILENO);
6401 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6405 #if ENABLE_HUSH_FAST
6407 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6409 enable_restore_tty_pgrp_on_exit();
6415 wait(NULL); /* wait till child has died */
6418 /* fd: redirect wants this fd to be used (e.g. 3>file).
6419 * Move all conflicting internally used fds,
6420 * and remember them so that we can restore them later.
6422 static int save_fds_on_redirect(int fd, int squirrel[3])
6425 /* Handle redirects of fds 0,1,2 */
6427 /* If we collide with an already moved stdio fd... */
6428 if (fd == squirrel[0]) {
6429 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6432 if (fd == squirrel[1]) {
6433 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6436 if (fd == squirrel[2]) {
6437 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6440 /* If we are about to redirect stdio fd, and did not yet move it... */
6441 if (fd <= 2 && squirrel[fd] < 0) {
6442 /* We avoid taking stdio fds */
6443 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6444 if (squirrel[fd] < 0 && errno != EBADF)
6446 return 0; /* "we did not close fd" */
6450 #if ENABLE_HUSH_INTERACTIVE
6451 if (fd != 0 && fd == G.interactive_fd) {
6452 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6457 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6458 * (1) Redirect in a forked child. No need to save FILEs' fds,
6459 * we aren't going to use them anymore, ok to trash.
6460 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6461 * but how are we doing to use them?
6462 * "fileno(fd) = new_fd" can't be done.
6467 return save_FILEs_on_redirect(fd);
6470 static void restore_redirects(int squirrel[3])
6473 for (i = 0; i <= 2; i++) {
6476 /* We simply die on error */
6481 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6483 restore_redirected_FILEs();
6486 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6487 * and stderr if they are redirected. */
6488 static int setup_redirects(struct command *prog, int squirrel[])
6491 struct redir_struct *redir;
6493 for (redir = prog->redirects; redir; redir = redir->next) {
6494 if (redir->rd_type == REDIRECT_HEREDOC2) {
6495 /* "rd_fd<<HERE" case */
6496 save_fds_on_redirect(redir->rd_fd, squirrel);
6497 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6499 debug_printf_parse("set heredoc '%s'\n",
6500 redir->rd_filename);
6501 setup_heredoc(redir);
6505 if (redir->rd_dup == REDIRFD_TO_FILE) {
6506 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6508 if (redir->rd_filename == NULL) {
6511 * "cmd >" (no filename)
6512 * "cmd > <file" (2nd redirect starts too early)
6514 die_if_script("syntax error: %s", "invalid redirect");
6517 mode = redir_table[redir->rd_type].mode;
6518 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6519 openfd = open_or_warn(p, mode);
6522 /* Error message from open_or_warn can be lost
6523 * if stderr has been redirected, but bash
6524 * and ash both lose it as well
6525 * (though zsh doesn't!)
6530 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6531 openfd = redir->rd_dup;
6534 if (openfd != redir->rd_fd) {
6535 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6536 if (openfd == REDIRFD_CLOSE) {
6537 /* "rd_fd >&-" means "close me" */
6539 /* ^^^ optimization: saving may already
6540 * have closed it. If not... */
6541 close(redir->rd_fd);
6544 xdup2(openfd, redir->rd_fd);
6545 if (redir->rd_dup == REDIRFD_TO_FILE)
6546 /* "rd_fd > FILE" */
6548 /* else: "rd_fd > rd_dup" */
6555 static char *find_in_path(const char *arg)
6558 const char *PATH = get_local_var_value("PATH");
6564 const char *end = strchrnul(PATH, ':');
6565 int sz = end - PATH; /* must be int! */
6569 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6571 /* We have xxx::yyyy in $PATH,
6572 * it means "use current dir" */
6575 if (access(ret, F_OK) == 0)
6588 static const struct built_in_command *find_builtin_helper(const char *name,
6589 const struct built_in_command *x,
6590 const struct built_in_command *end)
6593 if (strcmp(name, x->b_cmd) != 0) {
6597 debug_printf_exec("found builtin '%s'\n", name);
6602 static const struct built_in_command *find_builtin1(const char *name)
6604 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6606 static const struct built_in_command *find_builtin(const char *name)
6608 const struct built_in_command *x = find_builtin1(name);
6611 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6614 #if ENABLE_HUSH_FUNCTIONS
6615 static struct function **find_function_slot(const char *name)
6617 struct function **funcpp = &G.top_func;
6619 if (strcmp(name, (*funcpp)->name) == 0) {
6622 funcpp = &(*funcpp)->next;
6627 static const struct function *find_function(const char *name)
6629 const struct function *funcp = *find_function_slot(name);
6631 debug_printf_exec("found function '%s'\n", name);
6635 /* Note: takes ownership on name ptr */
6636 static struct function *new_function(char *name)
6638 struct function **funcpp = find_function_slot(name);
6639 struct function *funcp = *funcpp;
6641 if (funcp != NULL) {
6642 struct command *cmd = funcp->parent_cmd;
6643 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6645 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6647 /* Note: if !funcp->body, do not free body_as_string!
6648 * This is a special case of "-F name body" function:
6649 * body_as_string was not malloced! */
6651 free_pipe_list(funcp->body);
6653 free(funcp->body_as_string);
6657 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6658 cmd->argv[0] = funcp->name;
6659 cmd->group = funcp->body;
6661 cmd->group_as_string = funcp->body_as_string;
6665 debug_printf_exec("remembering new function '%s'\n", name);
6666 funcp = *funcpp = xzalloc(sizeof(*funcp));
6667 /*funcp->next = NULL;*/
6674 static void unset_func(const char *name)
6676 struct function **funcpp = find_function_slot(name);
6677 struct function *funcp = *funcpp;
6679 if (funcp != NULL) {
6680 debug_printf_exec("freeing function '%s'\n", funcp->name);
6681 *funcpp = funcp->next;
6682 /* funcp is unlinked now, deleting it.
6683 * Note: if !funcp->body, the function was created by
6684 * "-F name body", do not free ->body_as_string
6685 * and ->name as they were not malloced. */
6687 free_pipe_list(funcp->body);
6690 free(funcp->body_as_string);
6698 #define exec_function(to_free, funcp, argv) \
6699 exec_function(funcp, argv)
6701 static void exec_function(char ***to_free,
6702 const struct function *funcp,
6703 char **argv) NORETURN;
6704 static void exec_function(char ***to_free,
6705 const struct function *funcp,
6711 argv[0] = G.global_argv[0];
6712 G.global_argv = argv;
6716 /* On MMU, funcp->body is always non-NULL */
6717 n = run_list(funcp->body);
6721 re_execute_shell(to_free,
6722 funcp->body_as_string,
6729 static int run_function(const struct function *funcp, char **argv)
6735 save_and_replace_G_args(&sv, argv);
6737 /* "we are in function, ok to use return" */
6738 sv_flg = G_flag_return_in_progress;
6739 G_flag_return_in_progress = -1;
6740 # if ENABLE_HUSH_LOCAL
6741 G.func_nest_level++;
6744 /* On MMU, funcp->body is always non-NULL */
6747 /* Function defined by -F */
6748 parse_and_run_string(funcp->body_as_string);
6749 rc = G.last_exitcode;
6753 rc = run_list(funcp->body);
6756 # if ENABLE_HUSH_LOCAL
6758 struct variable *var;
6759 struct variable **var_pp;
6761 var_pp = &G.top_var;
6762 while ((var = *var_pp) != NULL) {
6763 if (var->func_nest_level < G.func_nest_level) {
6764 var_pp = &var->next;
6768 if (var->flg_export)
6769 bb_unsetenv(var->varstr);
6770 /* Remove from global list */
6771 *var_pp = var->next;
6777 G.func_nest_level--;
6780 G_flag_return_in_progress = sv_flg;
6782 restore_G_args(&sv, argv);
6786 #endif /* ENABLE_HUSH_FUNCTIONS */
6790 #define exec_builtin(to_free, x, argv) \
6791 exec_builtin(x, argv)
6793 #define exec_builtin(to_free, x, argv) \
6794 exec_builtin(to_free, argv)
6796 static void exec_builtin(char ***to_free,
6797 const struct built_in_command *x,
6798 char **argv) NORETURN;
6799 static void exec_builtin(char ***to_free,
6800 const struct built_in_command *x,
6806 rcode = x->b_function(argv);
6811 /* On NOMMU, we must never block!
6812 * Example: { sleep 99 | read line; } & echo Ok
6814 re_execute_shell(to_free,
6823 static void execvp_or_die(char **argv) NORETURN;
6824 static void execvp_or_die(char **argv)
6827 debug_printf_exec("execing '%s'\n", argv[0]);
6828 /* Don't propagate SIG_IGN to the child */
6829 if (SPECIAL_JOBSTOP_SIGS != 0)
6830 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6831 execvp(argv[0], argv);
6833 if (errno == EACCES) e = 126;
6834 if (errno == ENOENT) e = 127;
6835 bb_perror_msg("can't execute '%s'", argv[0]);
6839 #if ENABLE_HUSH_MODE_X
6840 static void dump_cmd_in_x_mode(char **argv)
6842 if (G_x_mode && argv) {
6843 /* We want to output the line in one write op */
6851 len += strlen(argv[n++]) + 1;
6857 p += sprintf(p, " %s", argv[n++]);
6865 # define dump_cmd_in_x_mode(argv) ((void)0)
6869 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6870 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6871 #define pseudo_exec(nommu_save, command, argv_expanded) \
6872 pseudo_exec(command, argv_expanded)
6875 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6877 * Don't exit() here. If you don't exec, use _exit instead.
6878 * The at_exit handlers apparently confuse the calling process,
6879 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6881 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6882 char **argv, int assignment_cnt,
6883 char **argv_expanded) NORETURN;
6884 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6885 char **argv, int assignment_cnt,
6886 char **argv_expanded)
6890 new_env = expand_assignments(argv, assignment_cnt);
6891 dump_cmd_in_x_mode(new_env);
6893 if (!argv[assignment_cnt]) {
6894 /* Case when we are here: ... | var=val | ...
6895 * (note that we do not exit early, i.e., do not optimize out
6896 * expand_assignments(): think about ... | var=`sleep 1` | ...
6898 free_strings(new_env);
6899 _exit(EXIT_SUCCESS);
6903 set_vars_and_save_old(new_env);
6904 free(new_env); /* optional */
6905 /* we can also destroy set_vars_and_save_old's return value,
6908 nommu_save->new_env = new_env;
6909 nommu_save->old_vars = set_vars_and_save_old(new_env);
6912 if (argv_expanded) {
6913 argv = argv_expanded;
6915 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6917 nommu_save->argv = argv;
6920 dump_cmd_in_x_mode(argv);
6922 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6923 if (strchr(argv[0], '/') != NULL)
6927 /* Check if the command matches any of the builtins.
6928 * Depending on context, this might be redundant. But it's
6929 * easier to waste a few CPU cycles than it is to figure out
6930 * if this is one of those cases.
6933 /* On NOMMU, it is more expensive to re-execute shell
6934 * just in order to run echo or test builtin.
6935 * It's better to skip it here and run corresponding
6936 * non-builtin later. */
6937 const struct built_in_command *x;
6938 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6940 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6943 #if ENABLE_HUSH_FUNCTIONS
6944 /* Check if the command matches any functions */
6946 const struct function *funcp = find_function(argv[0]);
6948 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6953 #if ENABLE_FEATURE_SH_STANDALONE
6954 /* Check if the command matches any busybox applets */
6956 int a = find_applet_by_name(argv[0]);
6958 # if BB_MMU /* see above why on NOMMU it is not allowed */
6959 if (APPLET_IS_NOEXEC(a)) {
6960 /* Do not leak open fds from opened script files etc */
6961 close_all_FILE_list();
6962 debug_printf_exec("running applet '%s'\n", argv[0]);
6963 run_applet_no_and_exit(a, argv);
6966 /* Re-exec ourselves */
6967 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6968 /* Don't propagate SIG_IGN to the child */
6969 if (SPECIAL_JOBSTOP_SIGS != 0)
6970 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6971 execv(bb_busybox_exec_path, argv);
6972 /* If they called chroot or otherwise made the binary no longer
6973 * executable, fall through */
6978 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6981 execvp_or_die(argv);
6984 /* Called after [v]fork() in run_pipe
6986 static void pseudo_exec(nommu_save_t *nommu_save,
6987 struct command *command,
6988 char **argv_expanded) NORETURN;
6989 static void pseudo_exec(nommu_save_t *nommu_save,
6990 struct command *command,
6991 char **argv_expanded)
6993 if (command->argv) {
6994 pseudo_exec_argv(nommu_save, command->argv,
6995 command->assignment_cnt, argv_expanded);
6998 if (command->group) {
6999 /* Cases when we are here:
7002 * ... | ( list ) | ...
7003 * ... | { list } | ...
7007 debug_printf_exec("pseudo_exec: run_list\n");
7008 reset_traps_to_defaults();
7009 rcode = run_list(command->group);
7010 /* OK to leak memory by not calling free_pipe_list,
7011 * since this process is about to exit */
7014 re_execute_shell(&nommu_save->argv_from_re_execing,
7015 command->group_as_string,
7022 /* Case when we are here: ... | >file */
7023 debug_printf_exec("pseudo_exec'ed null command\n");
7024 _exit(EXIT_SUCCESS);
7028 static const char *get_cmdtext(struct pipe *pi)
7034 /* This is subtle. ->cmdtext is created only on first backgrounding.
7035 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7036 * On subsequent bg argv is trashed, but we won't use it */
7040 argv = pi->cmds[0].argv;
7042 pi->cmdtext = xzalloc(1);
7047 len += strlen(*argv) + 1;
7051 argv = pi->cmds[0].argv;
7053 p = stpcpy(p, *argv);
7060 static void insert_bg_job(struct pipe *pi)
7062 struct pipe *job, **jobp;
7065 /* Linear search for the ID of the job to use */
7067 for (job = G.job_list; job; job = job->next)
7068 if (job->jobid >= pi->jobid)
7069 pi->jobid = job->jobid + 1;
7071 /* Add job to the list of running jobs */
7073 while ((job = *jobp) != NULL)
7075 job = *jobp = xmalloc(sizeof(*job));
7077 *job = *pi; /* physical copy */
7079 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7080 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7081 for (i = 0; i < pi->num_cmds; i++) {
7082 job->cmds[i].pid = pi->cmds[i].pid;
7083 /* all other fields are not used and stay zero */
7085 job->cmdtext = xstrdup(get_cmdtext(pi));
7087 if (G_interactive_fd)
7088 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7089 G.last_jobid = job->jobid;
7092 static void remove_bg_job(struct pipe *pi)
7094 struct pipe *prev_pipe;
7096 if (pi == G.job_list) {
7097 G.job_list = pi->next;
7099 prev_pipe = G.job_list;
7100 while (prev_pipe->next != pi)
7101 prev_pipe = prev_pipe->next;
7102 prev_pipe->next = pi->next;
7105 G.last_jobid = G.job_list->jobid;
7110 /* Remove a backgrounded job */
7111 static void delete_finished_bg_job(struct pipe *pi)
7118 static int job_exited_or_stopped(struct pipe *pi)
7122 if (pi->alive_cmds != pi->stopped_cmds)
7125 /* All processes in fg pipe have exited or stopped */
7129 rcode = pi->cmds[i].cmd_exitcode;
7130 /* usually last process gives overall exitstatus,
7131 * but with "set -o pipefail", last *failed* process does */
7132 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7135 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7139 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7146 dead = WIFEXITED(status) || WIFSIGNALED(status);
7149 if (WIFSTOPPED(status))
7150 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7151 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7152 if (WIFSIGNALED(status))
7153 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7154 childpid, WTERMSIG(status), WEXITSTATUS(status));
7155 if (WIFEXITED(status))
7156 debug_printf_jobs("pid %d exited, exitcode %d\n",
7157 childpid, WEXITSTATUS(status));
7159 /* Were we asked to wait for a fg pipe? */
7161 i = fg_pipe->num_cmds;
7166 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7167 if (fg_pipe->cmds[i].pid != childpid)
7171 fg_pipe->cmds[i].pid = 0;
7172 fg_pipe->alive_cmds--;
7173 ex = WEXITSTATUS(status);
7174 /* bash prints killer signal's name for *last*
7175 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7176 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7178 if (WIFSIGNALED(status)) {
7179 int sig = WTERMSIG(status);
7180 if (i == fg_pipe->num_cmds-1)
7181 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7182 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7183 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7184 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7185 * Maybe we need to use sig | 128? */
7188 fg_pipe->cmds[i].cmd_exitcode = ex;
7190 fg_pipe->stopped_cmds++;
7192 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7193 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7194 rcode = job_exited_or_stopped(fg_pipe);
7196 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7197 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7198 * and "killall -STOP cat" */
7199 if (G_interactive_fd) {
7201 if (fg_pipe->alive_cmds != 0)
7202 insert_bg_job(fg_pipe);
7206 if (fg_pipe->alive_cmds == 0)
7209 /* There are still running processes in the fg_pipe */
7212 /* It wasnt in fg_pipe, look for process in bg pipes */
7216 /* We were asked to wait for bg or orphaned children */
7217 /* No need to remember exitcode in this case */
7218 for (pi = G.job_list; pi; pi = pi->next) {
7219 for (i = 0; i < pi->num_cmds; i++) {
7220 if (pi->cmds[i].pid == childpid)
7221 goto found_pi_and_prognum;
7224 /* Happens when shell is used as init process (init=/bin/sh) */
7225 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7226 return -1; /* this wasn't a process from fg_pipe */
7228 found_pi_and_prognum:
7231 pi->cmds[i].pid = 0;
7232 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7233 if (WIFSIGNALED(status))
7234 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7236 if (!pi->alive_cmds) {
7237 if (G_interactive_fd)
7238 printf(JOB_STATUS_FORMAT, pi->jobid,
7239 "Done", pi->cmdtext);
7240 delete_finished_bg_job(pi);
7247 return -1; /* this wasn't a process from fg_pipe */
7250 /* Check to see if any processes have exited -- if they have,
7251 * figure out why and see if a job has completed.
7253 * If non-NULL fg_pipe: wait for its completion or stop.
7254 * Return its exitcode or zero if stopped.
7256 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7257 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7258 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7259 * or 0 if no children changed status.
7261 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7262 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7263 * or 0 if no children changed status.
7265 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7271 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7273 attributes = WUNTRACED;
7274 if (fg_pipe == NULL)
7275 attributes |= WNOHANG;
7278 #if ENABLE_HUSH_FAST
7279 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7280 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7281 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7282 /* There was neither fork nor SIGCHLD since last waitpid */
7283 /* Avoid doing waitpid syscall if possible */
7284 if (!G.we_have_children) {
7288 if (fg_pipe == NULL) { /* is WNOHANG set? */
7289 /* We have children, but they did not exit
7290 * or stop yet (we saw no SIGCHLD) */
7293 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7297 /* Do we do this right?
7298 * bash-3.00# sleep 20 | false
7300 * [3]+ Stopped sleep 20 | false
7301 * bash-3.00# echo $?
7302 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7303 * [hush 1.14.0: yes we do it right]
7307 #if ENABLE_HUSH_FAST
7309 i = G.count_SIGCHLD;
7311 childpid = waitpid(-1, &status, attributes);
7312 if (childpid <= 0) {
7313 if (childpid && errno != ECHILD)
7314 bb_perror_msg("waitpid");
7315 #if ENABLE_HUSH_FAST
7316 else { /* Until next SIGCHLD, waitpid's are useless */
7317 G.we_have_children = (childpid == 0);
7318 G.handled_SIGCHLD = i;
7319 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7322 /* ECHILD (no children), or 0 (no change in children status) */
7326 rcode = process_wait_result(fg_pipe, childpid, status);
7328 /* fg_pipe exited or stopped */
7331 if (childpid == waitfor_pid) {
7332 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7333 rcode = WEXITSTATUS(status);
7334 if (WIFSIGNALED(status))
7335 rcode = 128 + WTERMSIG(status);
7336 if (WIFSTOPPED(status))
7337 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7338 rcode = 128 + WSTOPSIG(status);
7340 break; /* "wait PID" called us, give it exitcode+1 */
7342 /* This wasn't one of our processes, or */
7343 /* fg_pipe still has running processes, do waitpid again */
7344 } /* while (waitpid succeeds)... */
7350 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7353 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7354 if (G_saved_tty_pgrp) {
7355 /* Job finished, move the shell to the foreground */
7356 p = getpgrp(); /* our process group id */
7357 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7358 tcsetpgrp(G_interactive_fd, p);
7364 /* Start all the jobs, but don't wait for anything to finish.
7367 * Return code is normally -1, when the caller has to wait for children
7368 * to finish to determine the exit status of the pipe. If the pipe
7369 * is a simple builtin command, however, the action is done by the
7370 * time run_pipe returns, and the exit code is provided as the
7373 * Returns -1 only if started some children. IOW: we have to
7374 * mask out retvals of builtins etc with 0xff!
7376 * The only case when we do not need to [v]fork is when the pipe
7377 * is single, non-backgrounded, non-subshell command. Examples:
7378 * cmd ; ... { list } ; ...
7379 * cmd && ... { list } && ...
7380 * cmd || ... { list } || ...
7381 * If it is, then we can run cmd as a builtin, NOFORK,
7382 * or (if SH_STANDALONE) an applet, and we can run the { list }
7383 * with run_list. If it isn't one of these, we fork and exec cmd.
7385 * Cases when we must fork:
7386 * non-single: cmd | cmd
7387 * backgrounded: cmd & { list } &
7388 * subshell: ( list ) [&]
7390 #if !ENABLE_HUSH_MODE_X
7391 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7392 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7394 static int redirect_and_varexp_helper(char ***new_env_p,
7395 struct variable **old_vars_p,
7396 struct command *command,
7398 char **argv_expanded)
7400 /* setup_redirects acts on file descriptors, not FILEs.
7401 * This is perfect for work that comes after exec().
7402 * Is it really safe for inline use? Experimentally,
7403 * things seem to work. */
7404 int rcode = setup_redirects(command, squirrel);
7406 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7407 *new_env_p = new_env;
7408 dump_cmd_in_x_mode(new_env);
7409 dump_cmd_in_x_mode(argv_expanded);
7411 *old_vars_p = set_vars_and_save_old(new_env);
7415 static NOINLINE int run_pipe(struct pipe *pi)
7417 static const char *const null_ptr = NULL;
7421 struct command *command;
7422 char **argv_expanded;
7424 /* it is not always needed, but we aim to smaller code */
7425 int squirrel[] = { -1, -1, -1 };
7428 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7431 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7432 * Result should be 3 lines: q w e, qwe, q w e
7434 G.ifs = get_local_var_value("IFS");
7438 IF_HUSH_JOB(pi->pgrp = -1;)
7439 pi->stopped_cmds = 0;
7440 command = &pi->cmds[0];
7441 argv_expanded = NULL;
7443 if (pi->num_cmds != 1
7444 || pi->followup == PIPE_BG
7445 || command->cmd_type == CMD_SUBSHELL
7452 debug_printf_exec(": group:%p argv:'%s'\n",
7453 command->group, command->argv ? command->argv[0] : "NONE");
7455 if (command->group) {
7456 #if ENABLE_HUSH_FUNCTIONS
7457 if (command->cmd_type == CMD_FUNCDEF) {
7458 /* "executing" func () { list } */
7459 struct function *funcp;
7461 funcp = new_function(command->argv[0]);
7462 /* funcp->name is already set to argv[0] */
7463 funcp->body = command->group;
7465 funcp->body_as_string = command->group_as_string;
7466 command->group_as_string = NULL;
7468 command->group = NULL;
7469 command->argv[0] = NULL;
7470 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7471 funcp->parent_cmd = command;
7472 command->child_func = funcp;
7474 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7476 return EXIT_SUCCESS;
7480 debug_printf("non-subshell group\n");
7481 rcode = 1; /* exitcode if redir failed */
7482 if (setup_redirects(command, squirrel) == 0) {
7483 debug_printf_exec(": run_list\n");
7484 rcode = run_list(command->group) & 0xff;
7486 restore_redirects(squirrel);
7487 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7489 debug_printf_exec("run_pipe: return %d\n", rcode);
7493 argv = command->argv ? command->argv : (char **) &null_ptr;
7495 const struct built_in_command *x;
7496 #if ENABLE_HUSH_FUNCTIONS
7497 const struct function *funcp;
7501 char **new_env = NULL;
7502 struct variable *old_vars = NULL;
7504 if (argv[command->assignment_cnt] == NULL) {
7505 /* Assignments, but no command */
7506 /* Ensure redirects take effect (that is, create files).
7507 * Try "a=t >file" */
7508 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7509 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7510 /* Set shell variables */
7514 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7515 /* Do we need to flag set_local_var() errors?
7516 * "assignment to readonly var" and "putenv error"
7521 /* Redirect error sets $? to 1. Otherwise,
7522 * if evaluating assignment value set $?, retain it.
7523 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7525 rcode = G.last_exitcode;
7526 /* Exit, _skipping_ variable restoring code: */
7527 goto clean_up_and_ret0;
7529 #else /* Older, bigger, but more correct code */
7531 rcode = setup_redirects(command, squirrel);
7532 restore_redirects(squirrel);
7533 /* Set shell variables */
7535 bb_putchar_stderr('+');
7537 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7539 fprintf(stderr, " %s", p);
7540 debug_printf_exec("set shell var:'%s'->'%s'\n",
7542 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7543 /* Do we need to flag set_local_var() errors?
7544 * "assignment to readonly var" and "putenv error"
7549 bb_putchar_stderr('\n');
7550 /* Redirect error sets $? to 1. Otherwise,
7551 * if evaluating assignment value set $?, retain it.
7552 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7554 rcode = G.last_exitcode;
7555 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7557 debug_printf_exec("run_pipe: return %d\n", rcode);
7562 /* Expand the rest into (possibly) many strings each */
7563 #if ENABLE_HUSH_BASH_COMPAT
7564 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7565 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7569 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7572 /* if someone gives us an empty string: `cmd with empty output` */
7573 if (!argv_expanded[0]) {
7574 free(argv_expanded);
7576 return G.last_exitcode;
7579 x = find_builtin(argv_expanded[0]);
7580 #if ENABLE_HUSH_FUNCTIONS
7583 funcp = find_function(argv_expanded[0]);
7587 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7588 debug_printf("exec with redirects only\n");
7589 rcode = setup_redirects(command, NULL);
7590 /* rcode=1 can be if redir file can't be opened */
7591 goto clean_up_and_ret1;
7594 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7597 debug_printf_exec(": builtin '%s' '%s'...\n",
7598 x->b_cmd, argv_expanded[1]);
7600 rcode = x->b_function(argv_expanded) & 0xff;
7603 #if ENABLE_HUSH_FUNCTIONS
7605 # if ENABLE_HUSH_LOCAL
7606 struct variable **sv;
7607 sv = G.shadowed_vars_pp;
7608 G.shadowed_vars_pp = &old_vars;
7610 debug_printf_exec(": function '%s' '%s'...\n",
7611 funcp->name, argv_expanded[1]);
7612 rcode = run_function(funcp, argv_expanded) & 0xff;
7613 # if ENABLE_HUSH_LOCAL
7614 G.shadowed_vars_pp = sv;
7620 unset_vars(new_env);
7622 /* clean_up_and_ret0: */
7623 restore_redirects(squirrel);
7625 free(argv_expanded);
7626 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7628 debug_printf_exec("run_pipe return %d\n", rcode);
7632 if (ENABLE_FEATURE_SH_NOFORK) {
7633 int n = find_applet_by_name(argv_expanded[0]);
7634 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7635 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7637 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7638 argv_expanded[0], argv_expanded[1]);
7639 rcode = run_nofork_applet(n, argv_expanded);
7641 goto clean_up_and_ret;
7644 /* It is neither builtin nor applet. We must fork. */
7648 /* NB: argv_expanded may already be created, and that
7649 * might include `cmd` runs! Do not rerun it! We *must*
7650 * use argv_expanded if it's non-NULL */
7652 /* Going to fork a child per each pipe member */
7657 while (cmd_no < pi->num_cmds) {
7658 struct fd_pair pipefds;
7660 volatile nommu_save_t nommu_save;
7661 nommu_save.new_env = NULL;
7662 nommu_save.old_vars = NULL;
7663 nommu_save.argv = NULL;
7664 nommu_save.argv_from_re_execing = NULL;
7666 command = &pi->cmds[cmd_no];
7668 if (command->argv) {
7669 debug_printf_exec(": pipe member '%s' '%s'...\n",
7670 command->argv[0], command->argv[1]);
7672 debug_printf_exec(": pipe member with no argv\n");
7675 /* pipes are inserted between pairs of commands */
7678 if (cmd_no < pi->num_cmds)
7679 xpiped_pair(pipefds);
7681 command->pid = BB_MMU ? fork() : vfork();
7682 if (!command->pid) { /* child */
7684 disable_restore_tty_pgrp_on_exit();
7685 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7687 /* Every child adds itself to new process group
7688 * with pgid == pid_of_first_child_in_pipe */
7689 if (G.run_list_level == 1 && G_interactive_fd) {
7692 if (pgrp < 0) /* true for 1st process only */
7694 if (setpgid(0, pgrp) == 0
7695 && pi->followup != PIPE_BG
7696 && G_saved_tty_pgrp /* we have ctty */
7698 /* We do it in *every* child, not just first,
7700 tcsetpgrp(G_interactive_fd, pgrp);
7704 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7705 /* 1st cmd in backgrounded pipe
7706 * should have its stdin /dev/null'ed */
7708 if (open(bb_dev_null, O_RDONLY))
7709 xopen("/", O_RDONLY);
7711 xmove_fd(next_infd, 0);
7713 xmove_fd(pipefds.wr, 1);
7716 /* Like bash, explicit redirects override pipes,
7717 * and the pipe fd (fd#1) is available for dup'ing:
7718 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7719 * of cmd1 goes into pipe.
7721 if (setup_redirects(command, NULL)) {
7722 /* Happens when redir file can't be opened:
7723 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7725 * hush: can't open '/qwe/rty': No such file or directory
7727 * (echo BAR is not executed, it hits _exit(1) below)
7732 /* Stores to nommu_save list of env vars putenv'ed
7733 * (NOMMU, on MMU we don't need that) */
7734 /* cast away volatility... */
7735 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7736 /* pseudo_exec() does not return */
7739 /* parent or error */
7740 #if ENABLE_HUSH_FAST
7742 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7744 enable_restore_tty_pgrp_on_exit();
7746 /* Clean up after vforked child */
7747 free(nommu_save.argv);
7748 free(nommu_save.argv_from_re_execing);
7749 unset_vars(nommu_save.new_env);
7750 add_vars(nommu_save.old_vars);
7752 free(argv_expanded);
7753 argv_expanded = NULL;
7754 if (command->pid < 0) { /* [v]fork failed */
7755 /* Clearly indicate, was it fork or vfork */
7756 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7760 /* Second and next children need to know pid of first one */
7762 pi->pgrp = command->pid;
7768 if (cmd_no < pi->num_cmds)
7770 /* Pass read (output) pipe end to next iteration */
7771 next_infd = pipefds.rd;
7774 if (!pi->alive_cmds) {
7776 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7781 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7785 /* NB: called by pseudo_exec, and therefore must not modify any
7786 * global data until exec/_exit (we can be a child after vfork!) */
7787 static int run_list(struct pipe *pi)
7789 #if ENABLE_HUSH_CASE
7790 char *case_word = NULL;
7792 #if ENABLE_HUSH_LOOPS
7793 struct pipe *loop_top = NULL;
7794 char **for_lcur = NULL;
7795 char **for_list = NULL;
7797 smallint last_followup;
7799 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7800 smalluint cond_code = 0;
7802 enum { cond_code = 0 };
7805 smallint rword; /* RES_foo */
7806 smallint last_rword; /* ditto */
7809 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7812 #if ENABLE_HUSH_LOOPS
7813 /* Check syntax for "for" */
7816 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7817 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7819 /* current word is FOR or IN (BOLD in comments below) */
7820 if (cpipe->next == NULL) {
7821 syntax_error("malformed for");
7823 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7826 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7827 if (cpipe->next->res_word == RES_DO)
7829 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7830 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7831 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7833 syntax_error("malformed for");
7835 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7842 /* Past this point, all code paths should jump to ret: label
7843 * in order to return, no direct "return" statements please.
7844 * This helps to ensure that no memory is leaked. */
7852 last_rword = RES_XXXX;
7854 last_followup = PIPE_SEQ;
7855 rcode = G.last_exitcode;
7857 /* Go through list of pipes, (maybe) executing them. */
7858 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7863 if (G_flag_return_in_progress == 1)
7866 IF_HAS_KEYWORDS(rword = pi->res_word;)
7867 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7868 rword, cond_code, last_rword);
7869 #if ENABLE_HUSH_LOOPS
7870 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7871 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7873 /* start of a loop: remember where loop starts */
7878 /* Still in the same "if...", "then..." or "do..." branch? */
7879 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7880 if ((rcode == 0 && last_followup == PIPE_OR)
7881 || (rcode != 0 && last_followup == PIPE_AND)
7883 /* It is "<true> || CMD" or "<false> && CMD"
7884 * and we should not execute CMD */
7885 debug_printf_exec("skipped cmd because of || or &&\n");
7886 last_followup = pi->followup;
7887 goto dont_check_jobs_but_continue;
7890 last_followup = pi->followup;
7891 IF_HAS_KEYWORDS(last_rword = rword;)
7894 if (rword == RES_THEN) {
7895 /* if false; then ... fi has exitcode 0! */
7896 G.last_exitcode = rcode = EXIT_SUCCESS;
7897 /* "if <false> THEN cmd": skip cmd */
7901 if (rword == RES_ELSE || rword == RES_ELIF) {
7902 /* "if <true> then ... ELSE/ELIF cmd":
7903 * skip cmd and all following ones */
7908 #if ENABLE_HUSH_LOOPS
7909 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7911 /* first loop through for */
7913 static const char encoded_dollar_at[] ALIGN1 = {
7914 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7915 }; /* encoded representation of "$@" */
7916 static const char *const encoded_dollar_at_argv[] = {
7917 encoded_dollar_at, NULL
7918 }; /* argv list with one element: "$@" */
7921 vals = (char**)encoded_dollar_at_argv;
7922 if (pi->next->res_word == RES_IN) {
7923 /* if no variable values after "in" we skip "for" */
7924 if (!pi->next->cmds[0].argv) {
7925 G.last_exitcode = rcode = EXIT_SUCCESS;
7926 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7929 vals = pi->next->cmds[0].argv;
7930 } /* else: "for var; do..." -> assume "$@" list */
7931 /* create list of variable values */
7932 debug_print_strings("for_list made from", vals);
7933 for_list = expand_strvec_to_strvec(vals);
7934 for_lcur = for_list;
7935 debug_print_strings("for_list", for_list);
7938 /* "for" loop is over, clean up */
7944 /* Insert next value from for_lcur */
7945 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7946 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7949 if (rword == RES_IN) {
7950 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7952 if (rword == RES_DONE) {
7953 continue; /* "done" has no cmds too */
7956 #if ENABLE_HUSH_CASE
7957 if (rword == RES_CASE) {
7958 debug_printf_exec("CASE cond_code:%d\n", cond_code);
7959 case_word = expand_strvec_to_string(pi->cmds->argv);
7962 if (rword == RES_MATCH) {
7965 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
7966 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7968 /* all prev words didn't match, does this one match? */
7969 argv = pi->cmds->argv;
7971 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7972 /* TODO: which FNM_xxx flags to use? */
7973 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7975 if (cond_code == 0) { /* match! we will execute this branch */
7977 case_word = NULL; /* make future "word)" stop */
7984 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7985 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
7987 continue; /* not matched yet, skip this pipe */
7989 if (rword == RES_ESAC) {
7990 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
7992 /* "case" did not match anything: still set $? (to 0) */
7993 G.last_exitcode = rcode = EXIT_SUCCESS;
7997 /* Just pressing <enter> in shell should check for jobs.
7998 * OTOH, in non-interactive shell this is useless
7999 * and only leads to extra job checks */
8000 if (pi->num_cmds == 0) {
8001 if (G_interactive_fd)
8002 goto check_jobs_and_continue;
8006 /* After analyzing all keywords and conditions, we decided
8007 * to execute this pipe. NB: have to do checkjobs(NULL)
8008 * after run_pipe to collect any background children,
8009 * even if list execution is to be stopped. */
8010 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8011 #if ENABLE_HUSH_LOOPS
8012 G.flag_break_continue = 0;
8014 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8016 /* We ran a builtin, function, or group.
8017 * rcode is already known
8018 * and we don't need to wait for anything. */
8019 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8020 G.last_exitcode = rcode;
8021 check_and_run_traps();
8022 #if ENABLE_HUSH_LOOPS
8023 /* Was it "break" or "continue"? */
8024 if (G.flag_break_continue) {
8025 smallint fbc = G.flag_break_continue;
8026 /* We might fall into outer *loop*,
8027 * don't want to break it too */
8029 G.depth_break_continue--;
8030 if (G.depth_break_continue == 0)
8031 G.flag_break_continue = 0;
8032 /* else: e.g. "continue 2" should *break* once, *then* continue */
8033 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8034 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8035 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8038 /* "continue": simulate end of loop */
8043 if (G_flag_return_in_progress == 1) {
8044 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8047 } else if (pi->followup == PIPE_BG) {
8048 /* What does bash do with attempts to background builtins? */
8049 /* even bash 3.2 doesn't do that well with nested bg:
8050 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8051 * I'm NOT treating inner &'s as jobs */
8053 if (G.run_list_level == 1)
8056 /* Last command's pid goes to $! */
8057 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8058 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8059 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8060 rcode = EXIT_SUCCESS;
8064 if (G.run_list_level == 1 && G_interactive_fd) {
8065 /* Waits for completion, then fg's main shell */
8066 rcode = checkjobs_and_fg_shell(pi);
8067 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8071 /* This one just waits for completion */
8072 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8073 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8075 G.last_exitcode = rcode;
8076 check_and_run_traps();
8079 /* Analyze how result affects subsequent commands */
8081 if (rword == RES_IF || rword == RES_ELIF)
8084 check_jobs_and_continue:
8085 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8086 dont_check_jobs_but_continue: ;
8087 #if ENABLE_HUSH_LOOPS
8088 /* Beware of "while false; true; do ..."! */
8090 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8091 /* check for RES_DONE is needed for "while ...; do \n done" case */
8093 if (rword == RES_WHILE) {
8095 /* "while false; do...done" - exitcode 0 */
8096 G.last_exitcode = rcode = EXIT_SUCCESS;
8097 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8101 if (rword == RES_UNTIL) {
8103 debug_printf_exec(": until expr is true: breaking\n");
8114 #if ENABLE_HUSH_LOOPS
8119 #if ENABLE_HUSH_CASE
8123 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8127 /* Select which version we will use */
8128 static int run_and_free_list(struct pipe *pi)
8131 debug_printf_exec("run_and_free_list entered\n");
8132 if (!G.o_opt[OPT_O_NOEXEC]) {
8133 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8134 rcode = run_list(pi);
8136 /* free_pipe_list has the side effect of clearing memory.
8137 * In the long run that function can be merged with run_list,
8138 * but doing that now would hobble the debugging effort. */
8140 debug_printf_exec("run_and_free_list return %d\n", rcode);
8145 static void install_sighandlers(unsigned mask)
8147 sighandler_t old_handler;
8149 while ((mask >>= 1) != 0) {
8153 old_handler = install_sighandler(sig, pick_sighandler(sig));
8154 /* POSIX allows shell to re-enable SIGCHLD
8155 * even if it was SIG_IGN on entry.
8156 * Therefore we skip IGN check for it:
8160 if (old_handler == SIG_IGN) {
8161 /* oops... restore back to IGN, and record this fact */
8162 install_sighandler(sig, old_handler);
8164 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8166 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8171 /* Called a few times only (or even once if "sh -c") */
8172 static void install_special_sighandlers(void)
8176 /* Which signals are shell-special? */
8177 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8178 if (G_interactive_fd) {
8179 mask |= SPECIAL_INTERACTIVE_SIGS;
8180 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8181 mask |= SPECIAL_JOBSTOP_SIGS;
8183 /* Careful, do not re-install handlers we already installed */
8184 if (G.special_sig_mask != mask) {
8185 unsigned diff = mask & ~G.special_sig_mask;
8186 G.special_sig_mask = mask;
8187 install_sighandlers(diff);
8193 /* Set handlers to restore tty pgrp and exit */
8194 static void install_fatal_sighandlers(void)
8198 /* We will restore tty pgrp on these signals */
8200 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8201 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8202 + (1 << SIGBUS ) * HUSH_DEBUG
8203 + (1 << SIGSEGV) * HUSH_DEBUG
8204 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8206 /* bash 3.2 seems to handle these just like 'fatal' ones */
8209 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8210 * if we aren't interactive... but in this case
8211 * we never want to restore pgrp on exit, and this fn is not called
8213 /*+ (1 << SIGHUP )*/
8214 /*+ (1 << SIGTERM)*/
8215 /*+ (1 << SIGINT )*/
8217 G_fatal_sig_mask = mask;
8219 install_sighandlers(mask);
8223 static int set_mode(int state, char mode, const char *o_opt)
8228 G.o_opt[OPT_O_NOEXEC] = state;
8231 IF_HUSH_MODE_X(G_x_mode = state;)
8235 /* "set -+o" without parameter.
8236 * in bash, set -o produces this output:
8240 * We always use the second form.
8242 const char *p = o_opt_strings;
8245 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8251 idx = index_in_strings(o_opt_strings, o_opt);
8253 G.o_opt[idx] = state;
8257 return EXIT_FAILURE;
8259 return EXIT_SUCCESS;
8262 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8263 int hush_main(int argc, char **argv)
8266 OPT_login = (1 << 0),
8270 unsigned builtin_argc;
8272 struct variable *cur_var;
8273 struct variable *shell_ver;
8276 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8277 G.last_exitcode = EXIT_SUCCESS;
8279 #if ENABLE_HUSH_FAST
8280 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8283 G.argv0_for_re_execing = argv[0];
8285 /* Deal with HUSH_VERSION */
8286 shell_ver = xzalloc(sizeof(*shell_ver));
8287 shell_ver->flg_export = 1;
8288 shell_ver->flg_read_only = 1;
8289 /* Code which handles ${var<op>...} needs writable values for all variables,
8290 * therefore we xstrdup: */
8291 shell_ver->varstr = xstrdup(hush_version_str);
8292 /* Create shell local variables from the values
8293 * currently living in the environment */
8294 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8295 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8296 G.top_var = shell_ver;
8297 cur_var = G.top_var;
8300 char *value = strchr(*e, '=');
8301 if (value) { /* paranoia */
8302 cur_var->next = xzalloc(sizeof(*cur_var));
8303 cur_var = cur_var->next;
8304 cur_var->varstr = *e;
8305 cur_var->max_len = strlen(*e);
8306 cur_var->flg_export = 1;
8310 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8311 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8312 putenv(shell_ver->varstr);
8315 set_pwd_var(/*exp:*/ 1);
8317 #if ENABLE_HUSH_BASH_COMPAT
8318 /* Set (but not export) HOSTNAME unless already set */
8319 if (!get_local_var_value("HOSTNAME")) {
8322 set_local_var_from_halves("HOSTNAME", uts.nodename);
8324 /* bash also exports SHLVL and _,
8325 * and sets (but doesn't export) the following variables:
8327 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8328 * BASH_VERSION='3.2.0(1)-release'
8330 * MACHTYPE=i386-pc-linux-gnu
8332 * PPID=<NNNNN> - we also do it elsewhere
8343 * PIPESTATUS=([0]="0")
8344 * HISTFILE=/<xxx>/.bash_history
8348 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8350 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8361 #if ENABLE_FEATURE_EDITING
8362 G.line_input_state = new_line_input_t(FOR_SHELL);
8365 /* Initialize some more globals to non-zero values */
8366 cmdedit_update_prompt();
8368 die_func = restore_ttypgrp_and__exit;
8370 /* Shell is non-interactive at first. We need to call
8371 * install_special_sighandlers() if we are going to execute "sh <script>",
8372 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8373 * If we later decide that we are interactive, we run install_special_sighandlers()
8374 * in order to intercept (more) signals.
8378 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8379 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8382 opt = getopt(argc, argv, "+c:xinsl"
8385 # if ENABLE_HUSH_FUNCTIONS
8395 * sh ... -c 'script'
8396 * sh ... -c 'script' ARG0 [ARG1...]
8397 * On NOMMU, if builtin_argc != 0,
8398 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8399 * "" needs to be replaced with NULL
8400 * and BARGV vector fed to builtin function.
8401 * Note: the form without ARG0 never happens:
8402 * sh ... -c 'builtin' BARGV... ""
8405 G.root_pid = getpid();
8406 G.root_ppid = getppid();
8408 G.global_argv = argv + optind;
8409 G.global_argc = argc - optind;
8411 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8412 const struct built_in_command *x;
8414 install_special_sighandlers();
8415 x = find_builtin(optarg);
8416 if (x) { /* paranoia */
8417 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8418 G.global_argv += builtin_argc;
8419 G.global_argv[-1] = NULL; /* replace "" */
8421 G.last_exitcode = x->b_function(argv + optind - 1);
8425 if (!G.global_argv[0]) {
8426 /* -c 'script' (no params): prevent empty $0 */
8427 G.global_argv--; /* points to argv[i] of 'script' */
8428 G.global_argv[0] = argv[0];
8430 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8431 install_special_sighandlers();
8432 parse_and_run_string(optarg);
8435 /* Well, we cannot just declare interactiveness,
8436 * we have to have some stuff (ctty, etc) */
8437 /* G_interactive_fd++; */
8440 /* "-s" means "read from stdin", but this is how we always
8441 * operate, so simply do nothing here. */
8447 case '<': /* "big heredoc" support */
8448 full_write1_str(optarg);
8451 unsigned long long empty_trap_mask;
8453 G.root_pid = bb_strtou(optarg, &optarg, 16);
8455 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8457 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8459 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8461 builtin_argc = bb_strtou(optarg, &optarg, 16);
8463 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8464 if (empty_trap_mask != 0) {
8466 install_special_sighandlers();
8467 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8468 for (sig = 1; sig < NSIG; sig++) {
8469 if (empty_trap_mask & (1LL << sig)) {
8470 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8471 install_sighandler(sig, SIG_IGN);
8475 # if ENABLE_HUSH_LOOPS
8477 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8483 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8485 # if ENABLE_HUSH_FUNCTIONS
8487 struct function *funcp = new_function(optarg);
8488 /* funcp->name is already set to optarg */
8489 /* funcp->body is set to NULL. It's a special case. */
8490 funcp->body_as_string = argv[optind];
8498 if (set_mode(1, opt, NULL) == 0) /* no error */
8502 fprintf(stderr, "Usage: sh [FILE]...\n"
8503 " or: sh -c command [args]...\n\n");
8509 } /* option parsing loop */
8511 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8512 G.global_argc = argc - (optind - 1);
8513 G.global_argv = argv + (optind - 1);
8514 G.global_argv[0] = argv[0];
8517 G.root_pid = getpid();
8518 G.root_ppid = getppid();
8521 /* If we are login shell... */
8522 if (flags & OPT_login) {
8524 debug_printf("sourcing /etc/profile\n");
8525 input = fopen_for_read("/etc/profile");
8526 if (input != NULL) {
8527 remember_FILE(input);
8528 install_special_sighandlers();
8529 parse_and_run_file(input);
8530 fclose_and_forget(input);
8532 /* bash: after sourcing /etc/profile,
8533 * tries to source (in the given order):
8534 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8535 * stopping on first found. --noprofile turns this off.
8536 * bash also sources ~/.bash_logout on exit.
8537 * If called as sh, skips .bash_XXX files.
8541 if (G.global_argv[1]) {
8544 * "bash <script>" (which is never interactive (unless -i?))
8545 * sources $BASH_ENV here (without scanning $PATH).
8546 * If called as sh, does the same but with $ENV.
8547 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8551 debug_printf("running script '%s'\n", G.global_argv[0]);
8552 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8553 input = xfopen_for_read(G.global_argv[0]);
8554 xfunc_error_retval = 1;
8555 remember_FILE(input);
8556 install_special_sighandlers();
8557 parse_and_run_file(input);
8558 #if ENABLE_FEATURE_CLEAN_UP
8559 fclose_and_forget(input);
8564 /* Up to here, shell was non-interactive. Now it may become one.
8565 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8568 /* A shell is interactive if the '-i' flag was given,
8569 * or if all of the following conditions are met:
8571 * no arguments remaining or the -s flag given
8572 * standard input is a terminal
8573 * standard output is a terminal
8574 * Refer to Posix.2, the description of the 'sh' utility.
8577 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8578 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8579 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8580 if (G_saved_tty_pgrp < 0)
8581 G_saved_tty_pgrp = 0;
8583 /* try to dup stdin to high fd#, >= 255 */
8584 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8585 if (G_interactive_fd < 0) {
8586 /* try to dup to any fd */
8587 G_interactive_fd = dup(STDIN_FILENO);
8588 if (G_interactive_fd < 0) {
8590 G_interactive_fd = 0;
8591 G_saved_tty_pgrp = 0;
8594 // TODO: track & disallow any attempts of user
8595 // to (inadvertently) close/redirect G_interactive_fd
8597 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8598 if (G_interactive_fd) {
8599 close_on_exec_on(G_interactive_fd);
8601 if (G_saved_tty_pgrp) {
8602 /* If we were run as 'hush &', sleep until we are
8603 * in the foreground (tty pgrp == our pgrp).
8604 * If we get started under a job aware app (like bash),
8605 * make sure we are now in charge so we don't fight over
8606 * who gets the foreground */
8608 pid_t shell_pgrp = getpgrp();
8609 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8610 if (G_saved_tty_pgrp == shell_pgrp)
8612 /* send TTIN to ourself (should stop us) */
8613 kill(- shell_pgrp, SIGTTIN);
8617 /* Install more signal handlers */
8618 install_special_sighandlers();
8620 if (G_saved_tty_pgrp) {
8621 /* Set other signals to restore saved_tty_pgrp */
8622 install_fatal_sighandlers();
8623 /* Put ourselves in our own process group
8624 * (bash, too, does this only if ctty is available) */
8625 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8626 /* Grab control of the terminal */
8627 tcsetpgrp(G_interactive_fd, getpid());
8629 enable_restore_tty_pgrp_on_exit();
8631 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8633 const char *hp = get_local_var_value("HISTFILE");
8635 hp = get_local_var_value("HOME");
8637 hp = concat_path_file(hp, ".hush_history");
8642 G.line_input_state->hist_file = hp;
8643 //set_local_var(xasprintf("HISTFILE=%s", ...));
8645 # if ENABLE_FEATURE_SH_HISTFILESIZE
8646 hp = get_local_var_value("HISTFILESIZE");
8647 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8652 install_special_sighandlers();
8654 #elif ENABLE_HUSH_INTERACTIVE
8655 /* No job control compiled in, only prompt/line editing */
8656 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8657 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8658 if (G_interactive_fd < 0) {
8659 /* try to dup to any fd */
8660 G_interactive_fd = dup(STDIN_FILENO);
8661 if (G_interactive_fd < 0)
8663 G_interactive_fd = 0;
8666 if (G_interactive_fd) {
8667 close_on_exec_on(G_interactive_fd);
8669 install_special_sighandlers();
8671 /* We have interactiveness code disabled */
8672 install_special_sighandlers();
8675 * if interactive but not a login shell, sources ~/.bashrc
8676 * (--norc turns this off, --rcfile <file> overrides)
8679 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8680 /* note: ash and hush share this string */
8681 printf("\n\n%s %s\n"
8682 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8685 "hush - the humble shell"
8689 parse_and_run_file(stdin);
8692 hush_exit(G.last_exitcode);
8697 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8698 int msh_main(int argc, char **argv)
8700 bb_error_msg("msh is deprecated, please use hush instead");
8701 return hush_main(argc, argv);
8709 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8714 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8721 return applet_main_func(argc, argv - argc);
8724 static int FAST_FUNC builtin_test(char **argv)
8726 return run_applet_main(argv, test_main);
8729 static int FAST_FUNC builtin_echo(char **argv)
8731 return run_applet_main(argv, echo_main);
8734 #if ENABLE_HUSH_PRINTF
8735 static int FAST_FUNC builtin_printf(char **argv)
8737 return run_applet_main(argv, printf_main);
8741 static char **skip_dash_dash(char **argv)
8744 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8749 static int FAST_FUNC builtin_eval(char **argv)
8751 int rcode = EXIT_SUCCESS;
8753 argv = skip_dash_dash(argv);
8755 char *str = expand_strvec_to_string(argv);
8757 * eval "echo Hi; done" ("done" is syntax error):
8758 * "echo Hi" will not execute too.
8760 parse_and_run_string(str);
8762 rcode = G.last_exitcode;
8767 static int FAST_FUNC builtin_cd(char **argv)
8771 argv = skip_dash_dash(argv);
8773 if (newdir == NULL) {
8774 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8775 * bash says "bash: cd: HOME not set" and does nothing
8778 const char *home = get_local_var_value("HOME");
8779 newdir = home ? home : "/";
8781 if (chdir(newdir)) {
8782 /* Mimic bash message exactly */
8783 bb_perror_msg("cd: %s", newdir);
8784 return EXIT_FAILURE;
8786 /* Read current dir (get_cwd(1) is inside) and set PWD.
8787 * Note: do not enforce exporting. If PWD was unset or unexported,
8788 * set it again, but do not export. bash does the same.
8790 set_pwd_var(/*exp:*/ 0);
8791 return EXIT_SUCCESS;
8794 static int FAST_FUNC builtin_exec(char **argv)
8796 argv = skip_dash_dash(argv);
8797 if (argv[0] == NULL)
8798 return EXIT_SUCCESS; /* bash does this */
8800 /* Careful: we can end up here after [v]fork. Do not restore
8801 * tty pgrp then, only top-level shell process does that */
8802 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8803 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8805 /* TODO: if exec fails, bash does NOT exit! We do.
8806 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8807 * and tcsetpgrp, and this is inherently racy.
8809 execvp_or_die(argv);
8812 static int FAST_FUNC builtin_exit(char **argv)
8814 debug_printf_exec("%s()\n", __func__);
8816 /* interactive bash:
8817 * # trap "echo EEE" EXIT
8820 * There are stopped jobs.
8821 * (if there are _stopped_ jobs, running ones don't count)
8824 * EEE (then bash exits)
8826 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8829 /* note: EXIT trap is run by hush_exit */
8830 argv = skip_dash_dash(argv);
8831 if (argv[0] == NULL)
8832 hush_exit(G.last_exitcode);
8833 /* mimic bash: exit 123abc == exit 255 + error msg */
8834 xfunc_error_retval = 255;
8835 /* bash: exit -2 == exit 254, no error msg */
8836 hush_exit(xatoi(argv[0]) & 0xff);
8839 static void print_escaped(const char *s)
8844 const char *p = strchrnul(s, '\'');
8845 /* print 'xxxx', possibly just '' */
8846 printf("'%.*s'", (int)(p - s), s);
8851 /* s points to '; print "'''...'''" */
8853 do putchar('\''); while (*++s == '\'');
8858 #if !ENABLE_HUSH_LOCAL
8859 #define helper_export_local(argv, exp, lvl) \
8860 helper_export_local(argv, exp)
8862 static void helper_export_local(char **argv, int exp, int lvl)
8866 char *name_end = strchrnul(name, '=');
8868 /* So far we do not check that name is valid (TODO?) */
8870 if (*name_end == '\0') {
8871 struct variable *var, **vpp;
8873 vpp = get_ptr_to_local_var(name, name_end - name);
8874 var = vpp ? *vpp : NULL;
8876 if (exp == -1) { /* unexporting? */
8877 /* export -n NAME (without =VALUE) */
8879 var->flg_export = 0;
8880 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8882 } /* else: export -n NOT_EXISTING_VAR: no-op */
8885 if (exp == 1) { /* exporting? */
8886 /* export NAME (without =VALUE) */
8888 var->flg_export = 1;
8889 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8890 putenv(var->varstr);
8894 #if ENABLE_HUSH_LOCAL
8895 if (exp == 0 /* local? */
8896 && var && var->func_nest_level == lvl
8898 /* "local x=abc; ...; local x" - ignore second local decl */
8902 /* Exporting non-existing variable.
8903 * bash does not put it in environment,
8904 * but remembers that it is exported,
8905 * and does put it in env when it is set later.
8906 * We just set it to "" and export. */
8907 /* Or, it's "local NAME" (without =VALUE).
8908 * bash sets the value to "". */
8909 name = xasprintf("%s=", name);
8911 /* (Un)exporting/making local NAME=VALUE */
8912 name = xstrdup(name);
8914 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8918 static int FAST_FUNC builtin_export(char **argv)
8920 unsigned opt_unexport;
8922 #if ENABLE_HUSH_EXPORT_N
8923 /* "!": do not abort on errors */
8924 opt_unexport = getopt32(argv, "!n");
8925 if (opt_unexport == (uint32_t)-1)
8926 return EXIT_FAILURE;
8933 if (argv[0] == NULL) {
8940 /* ash emits: export VAR='VAL'
8941 * bash: declare -x VAR="VAL"
8942 * we follow ash example */
8943 const char *s = *e++;
8944 const char *p = strchr(s, '=');
8946 if (!p) /* wtf? take next variable */
8949 printf("export %.*s", (int)(p - s) + 1, s);
8950 print_escaped(p + 1);
8954 /*fflush_all(); - done after each builtin anyway */
8956 return EXIT_SUCCESS;
8959 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8961 return EXIT_SUCCESS;
8964 #if ENABLE_HUSH_LOCAL
8965 static int FAST_FUNC builtin_local(char **argv)
8967 if (G.func_nest_level == 0) {
8968 bb_error_msg("%s: not in a function", argv[0]);
8969 return EXIT_FAILURE; /* bash compat */
8971 helper_export_local(argv, 0, G.func_nest_level);
8972 return EXIT_SUCCESS;
8976 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8977 static int FAST_FUNC builtin_unset(char **argv)
8982 /* "!": do not abort on errors */
8983 /* "+": stop at 1st non-option */
8984 opts = getopt32(argv, "!+vf");
8985 if (opts == (unsigned)-1)
8986 return EXIT_FAILURE;
8988 bb_error_msg("unset: -v and -f are exclusive");
8989 return EXIT_FAILURE;
8995 if (!(opts & 2)) { /* not -f */
8996 if (unset_local_var(*argv)) {
8997 /* unset <nonexistent_var> doesn't fail.
8998 * Error is when one tries to unset RO var.
8999 * Message was printed by unset_local_var. */
9003 #if ENABLE_HUSH_FUNCTIONS
9013 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9014 * built-in 'set' handler
9016 * set [-abCefhmnuvx] [-o option] [argument...]
9017 * set [+abCefhmnuvx] [+o option] [argument...]
9018 * set -- [argument...]
9021 * Implementations shall support the options in both their hyphen and
9022 * plus-sign forms. These options can also be specified as options to sh.
9024 * Write out all variables and their values: set
9025 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9026 * Turn on the -x and -v options: set -xv
9027 * Unset all positional parameters: set --
9028 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9029 * Set the positional parameters to the expansion of x, even if x expands
9030 * with a leading '-' or '+': set -- $x
9032 * So far, we only support "set -- [argument...]" and some of the short names.
9034 static int FAST_FUNC builtin_set(char **argv)
9037 char **pp, **g_argv;
9038 char *arg = *++argv;
9042 for (e = G.top_var; e; e = e->next)
9044 return EXIT_SUCCESS;
9048 if (strcmp(arg, "--") == 0) {
9052 if (arg[0] != '+' && arg[0] != '-')
9054 for (n = 1; arg[n]; ++n) {
9055 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9057 if (arg[n] == 'o' && argv[1])
9060 } while ((arg = *++argv) != NULL);
9061 /* Now argv[0] is 1st argument */
9064 return EXIT_SUCCESS;
9067 /* NB: G.global_argv[0] ($0) is never freed/changed */
9068 g_argv = G.global_argv;
9069 if (G.global_args_malloced) {
9075 G.global_args_malloced = 1;
9076 pp = xzalloc(sizeof(pp[0]) * 2);
9077 pp[0] = g_argv[0]; /* retain $0 */
9080 /* This realloc's G.global_argv */
9081 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9088 return EXIT_SUCCESS;
9090 /* Nothing known, so abort */
9092 bb_error_msg("set: %s: invalid option", arg);
9093 return EXIT_FAILURE;
9096 static int FAST_FUNC builtin_shift(char **argv)
9099 argv = skip_dash_dash(argv);
9103 if (n >= 0 && n < G.global_argc) {
9104 if (G.global_args_malloced) {
9107 free(G.global_argv[m++]);
9110 memmove(&G.global_argv[1], &G.global_argv[n+1],
9111 G.global_argc * sizeof(G.global_argv[0]));
9112 return EXIT_SUCCESS;
9114 return EXIT_FAILURE;
9117 /* Interruptibility of read builtin in bash
9118 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9120 * Empty trap makes read ignore corresponding signal, for any signal.
9123 * - terminates non-interactive shell;
9124 * - interrupts read in interactive shell;
9125 * if it has non-empty trap:
9126 * - executes trap and returns to command prompt in interactive shell;
9127 * - executes trap and returns to read in non-interactive shell;
9129 * - is ignored (does not interrupt) read in interactive shell;
9130 * - terminates non-interactive shell;
9131 * if it has non-empty trap:
9132 * - executes trap and returns to read;
9134 * - terminates shell (regardless of interactivity);
9135 * if it has non-empty trap:
9136 * - executes trap and returns to read;
9138 static int FAST_FUNC builtin_read(char **argv)
9148 /* "!": do not abort on errors.
9149 * Option string must start with "sr" to match BUILTIN_READ_xxx
9151 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9152 if (read_flags == (uint32_t)-1)
9153 return EXIT_FAILURE;
9155 ifs = get_local_var_value("IFS"); /* can be NULL */
9158 r = shell_builtin_read(set_local_var_from_halves,
9168 if ((uintptr_t)r == 1 && errno == EINTR) {
9169 unsigned sig = check_and_run_traps();
9170 if (sig && sig != SIGINT)
9174 if ((uintptr_t)r > 1) {
9175 bb_error_msg("%s", r);
9176 r = (char*)(uintptr_t)1;
9179 return (uintptr_t)r;
9182 static int FAST_FUNC builtin_trap(char **argv)
9188 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9193 /* No args: print all trapped */
9194 for (i = 0; i < NSIG; ++i) {
9197 print_escaped(G.traps[i]);
9198 /* note: bash adds "SIG", but only if invoked
9199 * as "bash". If called as "sh", or if set -o posix,
9200 * then it prints short signal names.
9201 * We are printing short names: */
9202 printf(" %s\n", get_signame(i));
9205 /*fflush_all(); - done after each builtin anyway */
9206 return EXIT_SUCCESS;
9210 /* If first arg is a number: reset all specified signals */
9211 sig = bb_strtou(*argv, NULL, 10);
9217 sighandler_t handler;
9219 sig = get_signum(*argv++);
9220 if (sig < 0 || sig >= NSIG) {
9222 /* Mimic bash message exactly */
9223 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9228 G.traps[sig] = xstrdup(new_cmd);
9230 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9231 get_signame(sig), sig, G.traps[sig]);
9233 /* There is no signal for 0 (EXIT) */
9238 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9240 /* We are removing trap handler */
9241 handler = pick_sighandler(sig);
9242 install_sighandler(sig, handler);
9247 if (!argv[1]) { /* no second arg */
9248 bb_error_msg("trap: invalid arguments");
9249 return EXIT_FAILURE;
9252 /* First arg is "-": reset all specified to default */
9253 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9254 /* Everything else: set arg as signal handler
9255 * (includes "" case, which ignores signal) */
9256 if (argv[0][0] == '-') {
9257 if (argv[0][1] == '\0') { /* "-" */
9258 /* new_cmd remains NULL: "reset these sigs" */
9261 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9264 /* else: "-something", no special meaning */
9269 goto process_sig_list;
9272 #if ENABLE_HUSH_TYPE
9273 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9274 static int FAST_FUNC builtin_type(char **argv)
9276 int ret = EXIT_SUCCESS;
9282 if (0) {} /* make conditional compile easier below */
9283 /*else if (find_alias(*argv))
9284 type = "an alias";*/
9285 #if ENABLE_HUSH_FUNCTIONS
9286 else if (find_function(*argv))
9287 type = "a function";
9289 else if (find_builtin(*argv))
9290 type = "a shell builtin";
9291 else if ((path = find_in_path(*argv)) != NULL)
9294 bb_error_msg("type: %s: not found", *argv);
9299 printf("%s is %s\n", *argv, type);
9308 static struct pipe *parse_jobspec(const char *str)
9313 if (sscanf(str, "%%%u", &jobnum) != 1) {
9315 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9317 bb_error_msg("bad argument '%s'", str);
9320 /* It is "%%", "%+" or "%" - current job */
9321 jobnum = G.last_jobid;
9323 bb_error_msg("no current job");
9327 for (pi = G.job_list; pi; pi = pi->next) {
9328 if (pi->jobid == jobnum) {
9332 bb_error_msg("%d: no such job", jobnum);
9336 /* built-in 'fg' and 'bg' handler */
9337 static int FAST_FUNC builtin_fg_bg(char **argv)
9342 if (!G_interactive_fd)
9343 return EXIT_FAILURE;
9345 /* If they gave us no args, assume they want the last backgrounded task */
9347 for (pi = G.job_list; pi; pi = pi->next) {
9348 if (pi->jobid == G.last_jobid) {
9352 bb_error_msg("%s: no current job", argv[0]);
9353 return EXIT_FAILURE;
9356 pi = parse_jobspec(argv[1]);
9358 return EXIT_FAILURE;
9360 /* TODO: bash prints a string representation
9361 * of job being foregrounded (like "sleep 1 | cat") */
9362 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9363 /* Put the job into the foreground. */
9364 tcsetpgrp(G_interactive_fd, pi->pgrp);
9367 /* Restart the processes in the job */
9368 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9369 for (i = 0; i < pi->num_cmds; i++) {
9370 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9372 pi->stopped_cmds = 0;
9374 i = kill(- pi->pgrp, SIGCONT);
9376 if (errno == ESRCH) {
9377 delete_finished_bg_job(pi);
9378 return EXIT_SUCCESS;
9380 bb_perror_msg("kill (SIGCONT)");
9383 if (argv[0][0] == 'f') {
9385 return checkjobs_and_fg_shell(pi);
9387 return EXIT_SUCCESS;
9391 #if ENABLE_HUSH_HELP
9392 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9394 const struct built_in_command *x;
9397 "Built-in commands:\n"
9398 "------------------\n");
9399 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9401 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9403 return EXIT_SUCCESS;
9407 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9408 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9410 show_history(G.line_input_state);
9411 return EXIT_SUCCESS;
9416 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9419 const char *status_string;
9421 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9422 for (job = G.job_list; job; job = job->next) {
9423 if (job->alive_cmds == job->stopped_cmds)
9424 status_string = "Stopped";
9426 status_string = "Running";
9428 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9430 return EXIT_SUCCESS;
9435 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9440 # ifdef M_TRIM_THRESHOLD
9441 /* Optional. Reduces probability of false positives */
9444 /* Crude attempt to find where "free memory" starts,
9445 * sans fragmentation. */
9447 l = (unsigned long)p;
9450 if (l < (unsigned long)p) l = (unsigned long)p;
9456 struct mallinfo mi = mallinfo();
9457 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9458 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9462 if (!G.memleak_value)
9463 G.memleak_value = l;
9465 l -= G.memleak_value;
9472 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9477 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9480 return EXIT_SUCCESS;
9483 static int FAST_FUNC builtin_source(char **argv)
9485 char *arg_path, *filename;
9488 #if ENABLE_HUSH_FUNCTIONS
9492 argv = skip_dash_dash(argv);
9495 /* bash says: "bash: .: filename argument required" */
9496 return 2; /* bash compat */
9499 if (!strchr(filename, '/')) {
9500 arg_path = find_in_path(filename);
9502 filename = arg_path;
9504 input = remember_FILE(fopen_or_warn(filename, "r"));
9507 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9508 /* POSIX: non-interactive shell should abort here,
9509 * not merely fail. So far no one complained :)
9511 return EXIT_FAILURE;
9514 #if ENABLE_HUSH_FUNCTIONS
9515 sv_flg = G_flag_return_in_progress;
9516 /* "we are inside sourced file, ok to use return" */
9517 G_flag_return_in_progress = -1;
9520 save_and_replace_G_args(&sv, argv);
9522 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9523 G.last_exitcode = 0;
9524 parse_and_run_file(input);
9525 fclose_and_forget(input);
9528 restore_G_args(&sv, argv);
9529 #if ENABLE_HUSH_FUNCTIONS
9530 G_flag_return_in_progress = sv_flg;
9533 return G.last_exitcode;
9536 static int FAST_FUNC builtin_umask(char **argv)
9543 argv = skip_dash_dash(argv);
9545 mode_t old_mask = mask;
9547 /* numeric umasks are taken as-is */
9548 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9549 if (!isdigit(argv[0][0]))
9551 mask = bb_parse_mode(argv[0], mask);
9552 if (!isdigit(argv[0][0]))
9554 if ((unsigned)mask > 0777) {
9557 * bash: umask: 'q': invalid symbolic mode operator
9558 * bash: umask: 999: octal number out of range
9560 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9565 printf("%04o\n", (unsigned) mask);
9566 /* fall through and restore mask which we set to 0 */
9570 return !rc; /* rc != 0 - success */
9573 #if ENABLE_HUSH_KILL
9574 static int FAST_FUNC builtin_kill(char **argv)
9578 argv = skip_dash_dash(argv);
9579 if (argv[0] && strcmp(argv[0], "-l") != 0) {
9587 if (argv[i][0] != '%')
9590 * "kill %N" - job kill
9591 * Converting to pgrp / pid kill
9593 pi = parse_jobspec(argv[i]);
9595 /* Eat bad jobspec */
9599 argv[j - 1] = argv[j];
9606 * In jobs started under job control, we signal
9607 * entire process group by kill -PGRP_ID.
9608 * This happens, f.e., in interactive shell.
9610 * Otherwise, we signal each child via
9611 * kill PID1 PID2 PID3.
9613 * sh -c 'sleep 1|sleep 1 & kill %1'
9614 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9615 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9618 if (ENABLE_HUSH_JOB && G_interactive_fd)
9620 dst = alloca(n * sizeof(int)*4);
9623 if (G_interactive_fd)
9624 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9627 for (j = 0; j < n; j++) {
9628 struct command *cmd = &pi->cmds[j];
9629 /* Skip exited members of the job */
9633 * kill_main has matching code to expect
9634 * leading space. Needed to not confuse
9635 * negative pids with "kill -SIGNAL_NO" syntax
9637 dst += sprintf(dst, " %u", (int)cmd->pid);
9640 } while (argv[++i]);
9643 if (argv[0] || ret == 0) {
9645 argv[0] = (char*)"kill"; /* why? think about "kill -- PID" */
9646 /* kill_main also handles "killall" etc, so it does look at argv[0]! */
9647 ret = run_applet_main(argv, kill_main);
9653 #if ENABLE_HUSH_WAIT
9654 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9655 #if !ENABLE_HUSH_JOB
9656 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9658 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9665 if (!sigisemptyset(&G.pending_set))
9668 /* waitpid is not interruptible by SA_RESTARTed
9669 * signals which we use. Thus, this ugly dance:
9672 /* Make sure possible SIGCHLD is stored in kernel's
9673 * pending signal mask before we call waitpid.
9674 * Or else we may race with SIGCHLD, lose it,
9675 * and get stuck in sigsuspend...
9677 sigfillset(&oldset); /* block all signals, remember old set */
9678 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9680 if (!sigisemptyset(&G.pending_set)) {
9681 /* Crap! we raced with some signal! */
9685 /*errno = 0; - checkjobs does this */
9686 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9687 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9688 debug_printf_exec("checkjobs:%d\n", ret);
9691 int rcode = job_exited_or_stopped(waitfor_pipe);
9692 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9695 sigprocmask(SIG_SETMASK, &oldset, NULL);
9700 /* if ECHILD, there are no children (ret is -1 or 0) */
9701 /* if ret == 0, no children changed state */
9702 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9703 if (errno == ECHILD || ret) {
9705 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9707 sigprocmask(SIG_SETMASK, &oldset, NULL);
9710 /* Wait for SIGCHLD or any other signal */
9711 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9712 /* Note: sigsuspend invokes signal handler */
9713 sigsuspend(&oldset);
9715 sigprocmask(SIG_SETMASK, &oldset, NULL);
9717 /* So, did we get a signal? */
9718 sig = check_and_run_traps();
9719 if (sig /*&& sig != SIGCHLD - always true */) {
9723 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9728 static int FAST_FUNC builtin_wait(char **argv)
9733 argv = skip_dash_dash(argv);
9734 if (argv[0] == NULL) {
9735 /* Don't care about wait results */
9736 /* Note 1: must wait until there are no more children */
9737 /* Note 2: must be interruptible */
9739 * $ sleep 3 & sleep 6 & wait
9744 * $ sleep 3 & sleep 6 & wait
9748 * ^C <-- after ~4 sec from keyboard
9751 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9755 pid_t pid = bb_strtou(*argv, NULL, 10);
9756 if (errno || pid <= 0) {
9758 if (argv[0][0] == '%') {
9759 struct pipe *wait_pipe;
9760 ret = 127; /* bash compat for bad jobspecs */
9761 wait_pipe = parse_jobspec(*argv);
9763 ret = job_exited_or_stopped(wait_pipe);
9765 ret = wait_for_child_or_signal(wait_pipe, 0);
9767 /* else: parse_jobspec() already emitted error msg */
9771 /* mimic bash message */
9772 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9774 continue; /* bash checks all argv[] */
9777 /* Do we have such child? */
9778 ret = waitpid(pid, &status, WNOHANG);
9781 if (errno == ECHILD) {
9782 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9783 /* "wait $!" but last bg task has already exited. Try:
9784 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9785 * In bash it prints exitcode 0, then 3.
9786 * In dash, it is 127.
9788 /* ret = G.last_bg_pid_exitstatus - FIXME */
9790 /* Example: "wait 1". mimic bash message */
9791 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9795 bb_perror_msg("wait %s", *argv);
9798 continue; /* bash checks all argv[] */
9801 /* Yes, and it still runs */
9802 ret = wait_for_child_or_signal(NULL, pid);
9804 /* Yes, and it just exited */
9805 process_wait_result(NULL, pid, status);
9806 ret = WEXITSTATUS(status);
9807 if (WIFSIGNALED(status))
9808 ret = 128 + WTERMSIG(status);
9816 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9817 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9820 def = bb_strtou(argv[1], NULL, 10);
9821 if (errno || def < def_min || argv[2]) {
9822 bb_error_msg("%s: bad arguments", argv[0]);
9830 #if ENABLE_HUSH_LOOPS
9831 static int FAST_FUNC builtin_break(char **argv)
9834 if (G.depth_of_loop == 0) {
9835 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9836 /* if we came from builtin_continue(), need to undo "= 1" */
9837 G.flag_break_continue = 0;
9838 return EXIT_SUCCESS; /* bash compat */
9840 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9842 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9843 if (depth == UINT_MAX)
9844 G.flag_break_continue = BC_BREAK;
9845 if (G.depth_of_loop < depth)
9846 G.depth_break_continue = G.depth_of_loop;
9848 return EXIT_SUCCESS;
9851 static int FAST_FUNC builtin_continue(char **argv)
9853 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9854 return builtin_break(argv);
9858 #if ENABLE_HUSH_FUNCTIONS
9859 static int FAST_FUNC builtin_return(char **argv)
9863 if (G_flag_return_in_progress != -1) {
9864 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9865 return EXIT_FAILURE; /* bash compat */
9868 G_flag_return_in_progress = 1;
9871 * out of range: wraps around at 256, does not error out
9872 * non-numeric param:
9873 * f() { false; return qwe; }; f; echo $?
9874 * bash: return: qwe: numeric argument required <== we do this
9875 * 255 <== we also do this
9877 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);