1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
48 * follow IFS rules more precisely, including update semantics
49 * builtins mandated by standards we don't support:
50 * [un]alias, command, fc, getopts, newgrp, readonly, times
51 * make complex ${var%...} constructs support optional
52 * make here documents optional
55 * redirection of stdout+stderr: &> and >&
56 * reserved words: function select
57 * advanced test: [[ ]]
58 * process substitution: <(list) and >(list)
61 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
62 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
63 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
65 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
66 * This is exactly equivalent to let "EXPR".
67 * $[EXPR]: synonym for $((EXPR))
70 * In bash, export builtin is special, its arguments are assignments
71 * and therefore expansion of them should be "one-word" expansion:
72 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
74 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
75 * ls: cannot access i=a: No such file or directory
76 * ls: cannot access b: No such file or directory
77 * Note1: same applies to local builtin.
78 * Note2: bash 3.2.33(1) does this only if export word itself
80 * $ export i=`echo 'aaa bbb'`; echo "$i"
82 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
85 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
86 || defined(__APPLE__) \
88 # include <malloc.h> /* for malloc_trim */
91 /* #include <dmalloc.h> */
95 #include <sys/utsname.h> /* for setting $HOSTNAME */
97 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
99 #include "shell_common.h"
102 #if ENABLE_HUSH_RANDOM_SUPPORT
105 # define CLEAR_RANDOM_T(rnd) ((void)0)
107 #ifndef F_DUPFD_CLOEXEC
108 # define F_DUPFD_CLOEXEC F_DUPFD
111 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
115 //config: bool "hush"
118 //config: hush is a small shell (25k). It handles the normal flow control
119 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
120 //config: case/esac. Redirections, here documents, $((arithmetic))
121 //config: and functions are supported.
123 //config: It will compile and work on no-mmu systems.
125 //config: It does not handle select, aliases, tilde expansion,
126 //config: &>file and >&file redirection of stdout+stderr.
128 //config:config HUSH_BASH_COMPAT
129 //config: bool "bash-compatible extensions"
131 //config: depends on HUSH
133 //config: Enable bash-compatible extensions.
135 //config:config HUSH_BRACE_EXPANSION
136 //config: bool "Brace expansion"
138 //config: depends on HUSH_BASH_COMPAT
140 //config: Enable {abc,def} extension.
142 //config:config HUSH_HELP
143 //config: bool "help builtin"
145 //config: depends on HUSH
147 //config: Enable help builtin in hush. Code size + ~1 kbyte.
149 //config:config HUSH_INTERACTIVE
150 //config: bool "Interactive mode"
152 //config: depends on HUSH
154 //config: Enable interactive mode (prompt and command editing).
155 //config: Without this, hush simply reads and executes commands
156 //config: from stdin just like a shell script from a file.
157 //config: No prompt, no PS1/PS2 magic shell variables.
159 //config:config HUSH_SAVEHISTORY
160 //config: bool "Save command history to .hush_history"
162 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
164 //config: Enable history saving in hush.
166 //config:config HUSH_JOB
167 //config: bool "Job control"
169 //config: depends on HUSH_INTERACTIVE
171 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
172 //config: command (not entire shell), fg/bg builtins work. Without this option,
173 //config: "cmd &" still works by simply spawning a process and immediately
174 //config: prompting for next command (or executing next command in a script),
175 //config: but no separate process group is formed.
177 //config:config HUSH_TICK
178 //config: bool "Process substitution"
180 //config: depends on HUSH
182 //config: Enable process substitution `command` and $(command) in hush.
184 //config:config HUSH_IF
185 //config: bool "Support if/then/elif/else/fi"
187 //config: depends on HUSH
189 //config: Enable if/then/elif/else/fi in hush.
191 //config:config HUSH_LOOPS
192 //config: bool "Support for, while and until loops"
194 //config: depends on HUSH
196 //config: Enable for, while and until loops in hush.
198 //config:config HUSH_CASE
199 //config: bool "Support case ... esac statement"
201 //config: depends on HUSH
203 //config: Enable case ... esac statement in hush. +400 bytes.
205 //config:config HUSH_FUNCTIONS
206 //config: bool "Support funcname() { commands; } syntax"
208 //config: depends on HUSH
210 //config: Enable support for shell functions in hush. +800 bytes.
212 //config:config HUSH_LOCAL
213 //config: bool "Support local builtin"
215 //config: depends on HUSH_FUNCTIONS
217 //config: Enable support for local variables in functions.
219 //config:config HUSH_RANDOM_SUPPORT
220 //config: bool "Pseudorandom generator and $RANDOM variable"
222 //config: depends on HUSH
224 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
225 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
227 //config:config HUSH_EXPORT_N
228 //config: bool "Support 'export -n' option"
230 //config: depends on HUSH
232 //config: export -n unexports variables. It is a bash extension.
234 //config:config HUSH_MODE_X
235 //config: bool "Support 'hush -x' option and 'set -x' command"
237 //config: depends on HUSH
239 //config: This instructs hush to print commands before execution.
240 //config: Adds ~300 bytes.
243 //config: bool "msh (deprecated: aliased to hush)"
245 //config: select HUSH
247 //config: msh is deprecated and will be removed, please migrate to hush.
250 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
251 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
252 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
253 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
255 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
256 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
258 /* -i (interactive) and -s (read stdin) are also accepted,
259 * but currently do nothing, therefore aren't shown in help.
260 * NOMMU-specific options are not meant to be used by users,
261 * therefore we don't show them either.
263 //usage:#define hush_trivial_usage
264 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
265 //usage:#define hush_full_usage "\n\n"
266 //usage: "Unix shell interpreter"
268 //usage:#define msh_trivial_usage hush_trivial_usage
269 //usage:#define msh_full_usage hush_full_usage
271 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
272 //usage:# define sh_trivial_usage hush_trivial_usage
273 //usage:# define sh_full_usage hush_full_usage
275 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
276 //usage:# define bash_trivial_usage hush_trivial_usage
277 //usage:# define bash_full_usage hush_full_usage
282 #define LEAK_HUNTING 0
283 #define BUILD_AS_NOMMU 0
284 /* Enable/disable sanity checks. Ok to enable in production,
285 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
286 * Keeping 1 for now even in released versions.
289 /* Slightly bigger (+200 bytes), but faster hush.
290 * So far it only enables a trick with counting SIGCHLDs and forks,
291 * which allows us to do fewer waitpid's.
292 * (we can detect a case where neither forks were done nor SIGCHLDs happened
293 * and therefore waitpid will return the same result as last time)
295 #define ENABLE_HUSH_FAST 0
296 /* TODO: implement simplified code for users which do not need ${var%...} ops
297 * So far ${var%...} ops are always enabled:
299 #define ENABLE_HUSH_DOLLAR_OPS 1
304 # undef USE_FOR_NOMMU
307 # define USE_FOR_NOMMU(...) __VA_ARGS__
308 # define USE_FOR_MMU(...)
311 #include "NUM_APPLETS.h"
313 /* STANDALONE does not make sense, and won't compile */
314 # undef CONFIG_FEATURE_SH_STANDALONE
315 # undef ENABLE_FEATURE_SH_STANDALONE
316 # undef IF_FEATURE_SH_STANDALONE
317 # undef IF_NOT_FEATURE_SH_STANDALONE
318 # define ENABLE_FEATURE_SH_STANDALONE 0
319 # define IF_FEATURE_SH_STANDALONE(...)
320 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
323 #if !ENABLE_HUSH_INTERACTIVE
324 # undef ENABLE_FEATURE_EDITING
325 # define ENABLE_FEATURE_EDITING 0
326 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
327 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
328 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
329 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
332 /* Do we support ANY keywords? */
333 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
334 # define HAS_KEYWORDS 1
335 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
336 # define IF_HAS_NO_KEYWORDS(...)
338 # define HAS_KEYWORDS 0
339 # define IF_HAS_KEYWORDS(...)
340 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
343 /* If you comment out one of these below, it will be #defined later
344 * to perform debug printfs to stderr: */
345 #define debug_printf(...) do {} while (0)
346 /* Finer-grained debug switches */
347 #define debug_printf_parse(...) do {} while (0)
348 #define debug_print_tree(a, b) do {} while (0)
349 #define debug_printf_exec(...) do {} while (0)
350 #define debug_printf_env(...) do {} while (0)
351 #define debug_printf_jobs(...) do {} while (0)
352 #define debug_printf_expand(...) do {} while (0)
353 #define debug_printf_varexp(...) do {} while (0)
354 #define debug_printf_glob(...) do {} while (0)
355 #define debug_printf_list(...) do {} while (0)
356 #define debug_printf_subst(...) do {} while (0)
357 #define debug_printf_clean(...) do {} while (0)
359 #define ERR_PTR ((void*)(long)1)
361 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
363 #define _SPECIAL_VARS_STR "_*@$!?#"
364 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
365 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
366 #if ENABLE_HUSH_BASH_COMPAT
367 /* Support / and // replace ops */
368 /* Note that // is stored as \ in "encoded" string representation */
369 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
370 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
371 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
373 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
374 # define VAR_SUBST_OPS "%#:-=+?"
375 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
378 #define SPECIAL_VAR_SYMBOL 3
382 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
384 /* This supports saving pointers malloced in vfork child,
385 * to be freed in the parent.
388 typedef struct nommu_save_t {
390 struct variable *old_vars;
392 char **argv_from_re_execing;
405 #if ENABLE_HUSH_LOOPS
412 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
417 /* three pseudo-keywords support contrived "case" syntax: */
418 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
419 RES_MATCH , /* "word)" */
420 RES_CASE_BODY, /* "this command is inside CASE" */
427 typedef struct o_string {
429 int length; /* position where data is appended */
432 /* At least some part of the string was inside '' or "",
433 * possibly empty one: word"", wo''rd etc. */
434 smallint has_quoted_part;
435 smallint has_empty_slot;
436 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
439 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
441 /* Protect newly added chars against globbing
442 * by prepending \ to *, ?, [, \ */
443 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
446 MAYBE_ASSIGNMENT = 0,
447 DEFINITELY_ASSIGNMENT = 1,
449 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
452 /* Used for initialization: o_string foo = NULL_O_STRING; */
453 #define NULL_O_STRING { NULL }
455 #ifndef debug_printf_parse
456 static const char *const assignment_flag[] = {
458 "DEFINITELY_ASSIGNMENT",
464 typedef struct in_str {
466 #if ENABLE_HUSH_INTERACTIVE
467 smallint promptmode; /* 0: PS1, 1: PS2 */
474 /* The descrip member of this structure is only used to make
475 * debugging output pretty */
476 static const struct {
478 signed char default_fd;
481 { O_RDONLY, 0, "<" },
482 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
483 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
484 { O_CREAT|O_RDWR, 1, "<>" },
485 { O_RDONLY, 0, "<<" },
486 /* Should not be needed. Bogus default_fd helps in debugging */
487 /* { O_RDONLY, 77, "<<" }, */
490 struct redir_struct {
491 struct redir_struct *next;
492 char *rd_filename; /* filename */
493 int rd_fd; /* fd to redirect */
494 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
496 smallint rd_type; /* (enum redir_type) */
497 /* note: for heredocs, rd_filename contains heredoc delimiter,
498 * and subsequently heredoc itself; and rd_dup is a bitmask:
499 * bit 0: do we need to trim leading tabs?
500 * bit 1: is heredoc quoted (<<'delim' syntax) ?
503 typedef enum redir_type {
505 REDIRECT_OVERWRITE = 1,
508 REDIRECT_HEREDOC = 4,
509 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
512 REDIRFD_SYNTAX_ERR = -2,
513 REDIRFD_TO_FILE = -1,
514 /* otherwise, rd_fd is redirected to rd_dup */
516 HEREDOC_SKIPTABS = 1,
522 pid_t pid; /* 0 if exited */
523 int assignment_cnt; /* how many argv[i] are assignments? */
524 smallint cmd_type; /* CMD_xxx */
526 #define CMD_SUBSHELL 1
527 #if ENABLE_HUSH_BASH_COMPAT
528 /* used for "[[ EXPR ]]" */
529 # define CMD_SINGLEWORD_NOGLOB 2
531 #if ENABLE_HUSH_FUNCTIONS
532 # define CMD_FUNCDEF 3
535 smalluint cmd_exitcode;
536 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
539 char *group_as_string;
541 #if ENABLE_HUSH_FUNCTIONS
542 struct function *child_func;
543 /* This field is used to prevent a bug here:
544 * while...do f1() {a;}; f1; f1() {b;}; f1; done
545 * When we execute "f1() {a;}" cmd, we create new function and clear
546 * cmd->group, cmd->group_as_string, cmd->argv[0].
547 * When we execute "f1() {b;}", we notice that f1 exists,
548 * and that its "parent cmd" struct is still "alive",
549 * we put those fields back into cmd->xxx
550 * (struct function has ->parent_cmd ptr to facilitate that).
551 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
552 * Without this trick, loop would execute a;b;b;b;...
553 * instead of correct sequence a;b;a;b;...
554 * When command is freed, it severs the link
555 * (sets ->child_func->parent_cmd to NULL).
558 char **argv; /* command name and arguments */
559 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
560 * and on execution these are substituted with their values.
561 * Substitution can make _several_ words out of one argv[n]!
562 * Example: argv[0]=='.^C*^C.' here: echo .$*.
563 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
565 struct redir_struct *redirects; /* I/O redirections */
567 /* Is there anything in this command at all? */
568 #define IS_NULL_CMD(cmd) \
569 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
573 int num_cmds; /* total number of commands in pipe */
574 int alive_cmds; /* number of commands running (not exited) */
575 int stopped_cmds; /* number of commands alive, but stopped */
577 int jobid; /* job number */
578 pid_t pgrp; /* process group ID for the job */
579 char *cmdtext; /* name of job */
581 struct command *cmds; /* array of commands in pipe */
582 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
583 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
584 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
586 typedef enum pipe_style {
592 /* Is there anything in this pipe at all? */
593 #define IS_NULL_PIPE(pi) \
594 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
596 /* This holds pointers to the various results of parsing */
597 struct parse_context {
598 /* linked list of pipes */
599 struct pipe *list_head;
600 /* last pipe (being constructed right now) */
602 /* last command in pipe (being constructed right now) */
603 struct command *command;
604 /* last redirect in command->redirects list */
605 struct redir_struct *pending_redirect;
611 smallint ctx_inverted; /* "! cmd | cmd" */
613 smallint ctx_dsemicolon; /* ";;" seen */
615 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
617 /* group we are enclosed in:
618 * example: "if pipe1; pipe2; then pipe3; fi"
619 * when we see "if" or "then", we malloc and copy current context,
620 * and make ->stack point to it. then we parse pipeN.
621 * when closing "then" / fi" / whatever is found,
622 * we move list_head into ->stack->command->group,
623 * copy ->stack into current context, and delete ->stack.
624 * (parsing of { list } and ( list ) doesn't use this method)
626 struct parse_context *stack;
630 /* On program start, environ points to initial environment.
631 * putenv adds new pointers into it, unsetenv removes them.
632 * Neither of these (de)allocates the strings.
633 * setenv allocates new strings in malloc space and does putenv,
634 * and thus setenv is unusable (leaky) for shell's purposes */
635 #define setenv(...) setenv_is_leaky_dont_use()
637 struct variable *next;
638 char *varstr; /* points to "name=" portion */
639 #if ENABLE_HUSH_LOCAL
640 unsigned func_nest_level;
642 int max_len; /* if > 0, name is part of initial env; else name is malloced */
643 smallint flg_export; /* putenv should be done on this var */
644 smallint flg_read_only;
652 #if ENABLE_HUSH_FUNCTIONS
654 struct function *next;
656 struct command *parent_cmd;
659 char *body_as_string;
665 /* set -/+o OPT support. (TODO: make it optional)
666 * bash supports the following opts:
677 * interactive-comments on
695 static const char o_opt_strings[] ALIGN1 =
698 #if ENABLE_HUSH_MODE_X
705 #if ENABLE_HUSH_MODE_X
713 struct FILE_list *next;
719 /* "Globals" within this file */
720 /* Sorted roughly by size (smaller offsets == smaller code) */
722 /* interactive_fd != 0 means we are an interactive shell.
723 * If we are, then saved_tty_pgrp can also be != 0, meaning
724 * that controlling tty is available. With saved_tty_pgrp == 0,
725 * job control still works, but terminal signals
726 * (^C, ^Z, ^Y, ^\) won't work at all, and background
727 * process groups can only be created with "cmd &".
728 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
729 * to give tty to the foreground process group,
730 * and will take it back when the group is stopped (^Z)
733 #if ENABLE_HUSH_INTERACTIVE
734 /* 'interactive_fd' is a fd# open to ctty, if we have one
735 * _AND_ if we decided to act interactively */
739 # define G_interactive_fd (G.interactive_fd)
741 # define G_interactive_fd 0
743 #if ENABLE_FEATURE_EDITING
744 line_input_t *line_input_state;
749 #if ENABLE_HUSH_RANDOM_SUPPORT
755 pid_t saved_tty_pgrp;
756 struct pipe *job_list;
757 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
759 # define G_saved_tty_pgrp 0
761 char o_opt[NUM_OPT_O];
762 #if ENABLE_HUSH_MODE_X
763 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
767 smallint flag_SIGINT;
768 #if ENABLE_HUSH_LOOPS
769 smallint flag_break_continue;
771 #if ENABLE_HUSH_FUNCTIONS
772 /* 0: outside of a function (or sourced file)
773 * -1: inside of a function, ok to use return builtin
774 * 1: return is invoked, skip all till end of func
776 smallint flag_return_in_progress;
777 # define G_flag_return_in_progress (G.flag_return_in_progress)
779 # define G_flag_return_in_progress 0
781 smallint exiting; /* used to prevent EXIT trap recursion */
782 /* These four support $?, $#, and $1 */
783 smalluint last_exitcode;
784 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
785 smalluint global_args_malloced;
786 /* how many non-NULL argv's we have. NB: $# + 1 */
790 char *argv0_for_re_execing;
792 #if ENABLE_HUSH_LOOPS
793 unsigned depth_break_continue;
794 unsigned depth_of_loop;
798 struct variable *top_var;
799 char **expanded_assignments;
800 #if ENABLE_HUSH_FUNCTIONS
801 struct function *top_func;
802 # if ENABLE_HUSH_LOCAL
803 struct variable **shadowed_vars_pp;
804 unsigned func_nest_level;
807 /* Signal and trap handling */
809 unsigned count_SIGCHLD;
810 unsigned handled_SIGCHLD;
811 smallint we_have_children;
813 struct FILE_list *FILE_list;
814 /* Which signals have non-DFL handler (even with no traps set)?
815 * Set at the start to:
816 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
817 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
818 * The rest is cleared right before execv syscalls.
819 * Other than these two times, never modified.
821 unsigned special_sig_mask;
823 unsigned fatal_sig_mask;
824 # define G_fatal_sig_mask G.fatal_sig_mask
826 # define G_fatal_sig_mask 0
828 char **traps; /* char *traps[NSIG] */
829 sigset_t pending_set;
831 unsigned long memleak_value;
835 #if ENABLE_FEATURE_EDITING
836 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
839 #define G (*ptr_to_globals)
840 /* Not #defining name to G.name - this quickly gets unwieldy
841 * (too many defines). Also, I actually prefer to see when a variable
842 * is global, thus "G." prefix is a useful hint */
843 #define INIT_G() do { \
844 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
845 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
846 sigfillset(&G.sa.sa_mask); \
847 G.sa.sa_flags = SA_RESTART; \
851 /* Function prototypes for builtins */
852 static int builtin_cd(char **argv) FAST_FUNC;
853 static int builtin_echo(char **argv) FAST_FUNC;
854 static int builtin_eval(char **argv) FAST_FUNC;
855 static int builtin_exec(char **argv) FAST_FUNC;
856 static int builtin_exit(char **argv) FAST_FUNC;
857 static int builtin_export(char **argv) FAST_FUNC;
859 static int builtin_fg_bg(char **argv) FAST_FUNC;
860 static int builtin_jobs(char **argv) FAST_FUNC;
863 static int builtin_help(char **argv) FAST_FUNC;
865 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
866 static int builtin_history(char **argv) FAST_FUNC;
868 #if ENABLE_HUSH_LOCAL
869 static int builtin_local(char **argv) FAST_FUNC;
872 static int builtin_memleak(char **argv) FAST_FUNC;
875 static int builtin_printf(char **argv) FAST_FUNC;
877 static int builtin_pwd(char **argv) FAST_FUNC;
878 static int builtin_read(char **argv) FAST_FUNC;
879 static int builtin_set(char **argv) FAST_FUNC;
880 static int builtin_shift(char **argv) FAST_FUNC;
881 static int builtin_source(char **argv) FAST_FUNC;
882 static int builtin_test(char **argv) FAST_FUNC;
883 static int builtin_trap(char **argv) FAST_FUNC;
884 static int builtin_type(char **argv) FAST_FUNC;
885 static int builtin_true(char **argv) FAST_FUNC;
886 static int builtin_umask(char **argv) FAST_FUNC;
887 static int builtin_unset(char **argv) FAST_FUNC;
888 static int builtin_wait(char **argv) FAST_FUNC;
889 #if ENABLE_HUSH_LOOPS
890 static int builtin_break(char **argv) FAST_FUNC;
891 static int builtin_continue(char **argv) FAST_FUNC;
893 #if ENABLE_HUSH_FUNCTIONS
894 static int builtin_return(char **argv) FAST_FUNC;
897 /* Table of built-in functions. They can be forked or not, depending on
898 * context: within pipes, they fork. As simple commands, they do not.
899 * When used in non-forking context, they can change global variables
900 * in the parent shell process. If forked, of course they cannot.
901 * For example, 'unset foo | whatever' will parse and run, but foo will
902 * still be set at the end. */
903 struct built_in_command {
905 int (*b_function)(char **argv) FAST_FUNC;
908 # define BLTIN(cmd, func, help) { cmd, func, help }
910 # define BLTIN(cmd, func, help) { cmd, func }
914 static const struct built_in_command bltins1[] = {
915 BLTIN("." , builtin_source , "Run commands in a file"),
916 BLTIN(":" , builtin_true , NULL),
918 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
920 #if ENABLE_HUSH_LOOPS
921 BLTIN("break" , builtin_break , "Exit from a loop"),
923 BLTIN("cd" , builtin_cd , "Change directory"),
924 #if ENABLE_HUSH_LOOPS
925 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
927 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
928 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
929 BLTIN("exit" , builtin_exit , "Exit"),
930 BLTIN("export" , builtin_export , "Set environment variables"),
932 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
935 BLTIN("help" , builtin_help , NULL),
937 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
938 BLTIN("history" , builtin_history , "Show command history"),
941 BLTIN("jobs" , builtin_jobs , "List jobs"),
943 #if ENABLE_HUSH_LOCAL
944 BLTIN("local" , builtin_local , "Set local variables"),
947 BLTIN("memleak" , builtin_memleak , NULL),
949 BLTIN("read" , builtin_read , "Input into variable"),
950 #if ENABLE_HUSH_FUNCTIONS
951 BLTIN("return" , builtin_return , "Return from a function"),
953 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
954 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
955 #if ENABLE_HUSH_BASH_COMPAT
956 BLTIN("source" , builtin_source , "Run commands in a file"),
958 BLTIN("trap" , builtin_trap , "Trap signals"),
959 BLTIN("true" , builtin_true , NULL),
960 BLTIN("type" , builtin_type , "Show command type"),
961 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
962 BLTIN("umask" , builtin_umask , "Set file creation mask"),
963 BLTIN("unset" , builtin_unset , "Unset variables"),
964 BLTIN("wait" , builtin_wait , "Wait for process"),
966 /* For now, echo and test are unconditionally enabled.
967 * Maybe make it configurable? */
968 static const struct built_in_command bltins2[] = {
969 BLTIN("[" , builtin_test , NULL),
970 BLTIN("echo" , builtin_echo , NULL),
972 BLTIN("printf" , builtin_printf , NULL),
974 BLTIN("pwd" , builtin_pwd , NULL),
975 BLTIN("test" , builtin_test , NULL),
982 /* prevent disasters with G.debug_indent < 0 */
983 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
984 # define debug_enter() (G.debug_indent++)
985 # define debug_leave() (G.debug_indent--)
987 # define indent() ((void)0)
988 # define debug_enter() ((void)0)
989 # define debug_leave() ((void)0)
993 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
996 #ifndef debug_printf_parse
997 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1000 #ifndef debug_printf_exec
1001 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1004 #ifndef debug_printf_env
1005 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1008 #ifndef debug_printf_jobs
1009 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1010 # define DEBUG_JOBS 1
1012 # define DEBUG_JOBS 0
1015 #ifndef debug_printf_expand
1016 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1017 # define DEBUG_EXPAND 1
1019 # define DEBUG_EXPAND 0
1022 #ifndef debug_printf_varexp
1023 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1026 #ifndef debug_printf_glob
1027 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1028 # define DEBUG_GLOB 1
1030 # define DEBUG_GLOB 0
1033 #ifndef debug_printf_list
1034 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1037 #ifndef debug_printf_subst
1038 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1041 #ifndef debug_printf_clean
1042 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1043 # define DEBUG_CLEAN 1
1045 # define DEBUG_CLEAN 0
1049 static void debug_print_strings(const char *prefix, char **vv)
1052 fdprintf(2, "%s:\n", prefix);
1054 fdprintf(2, " '%s'\n", *vv++);
1057 # define debug_print_strings(prefix, vv) ((void)0)
1061 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1064 static void *xxmalloc(int lineno, size_t size)
1066 void *ptr = xmalloc((size + 0xff) & ~0xff);
1067 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1070 static void *xxrealloc(int lineno, void *ptr, size_t size)
1072 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1073 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1076 static char *xxstrdup(int lineno, const char *str)
1078 char *ptr = xstrdup(str);
1079 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1082 static void xxfree(void *ptr)
1084 fdprintf(2, "free %p\n", ptr);
1087 # define xmalloc(s) xxmalloc(__LINE__, s)
1088 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1089 # define xstrdup(s) xxstrdup(__LINE__, s)
1090 # define free(p) xxfree(p)
1094 /* Syntax and runtime errors. They always abort scripts.
1095 * In interactive use they usually discard unparsed and/or unexecuted commands
1096 * and return to the prompt.
1097 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1100 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1101 # define syntax_error(lineno, msg) syntax_error(msg)
1102 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1103 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1104 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1105 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1108 static void die_if_script(unsigned lineno, const char *fmt, ...)
1113 bb_error_msg("hush.c:%u", lineno);
1116 bb_verror_msg(fmt, p, NULL);
1118 if (!G_interactive_fd)
1122 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1125 bb_error_msg("syntax error: %s", msg);
1127 bb_error_msg("syntax error");
1130 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1132 bb_error_msg("syntax error at '%s'", msg);
1135 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1137 bb_error_msg("syntax error: unterminated %s", s);
1140 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1142 char msg[2] = { ch, '\0' };
1143 syntax_error_unterm_str(lineno, msg);
1146 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1151 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1155 # undef die_if_script
1156 # undef syntax_error
1157 # undef syntax_error_at
1158 # undef syntax_error_unterm_ch
1159 # undef syntax_error_unterm_str
1160 # undef syntax_error_unexpected_ch
1162 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1163 # define syntax_error(msg) syntax_error(__LINE__, msg)
1164 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1165 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1166 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1167 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1171 #if ENABLE_HUSH_INTERACTIVE
1172 static void cmdedit_update_prompt(void);
1174 # define cmdedit_update_prompt() ((void)0)
1178 /* Utility functions
1180 /* Replace each \x with x in place, return ptr past NUL. */
1181 static char *unbackslash(char *src)
1183 char *dst = src = strchrnul(src, '\\');
1187 if ((*dst++ = *src++) == '\0')
1193 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1214 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1215 v[count1 + count2] = NULL;
1218 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1222 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1224 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1225 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1228 #define add_strings_to_strings(strings, add, need_to_dup) \
1229 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1232 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1233 static char **add_string_to_strings(char **strings, char *add)
1238 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1241 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1243 char **ptr = add_string_to_strings(strings, add);
1244 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1247 #define add_string_to_strings(strings, add) \
1248 xx_add_string_to_strings(__LINE__, strings, add)
1251 static void free_strings(char **strings)
1266 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1268 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1269 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1271 /* fd was not open? */
1281 /* Manipulating the list of open FILEs */
1282 static FILE *remember_FILE(FILE *fp)
1285 struct FILE_list *n = xmalloc(sizeof(*n));
1286 n->next = G.FILE_list;
1290 close_on_exec_on(n->fd);
1294 static void fclose_and_forget(FILE *fp)
1296 struct FILE_list **pp = &G.FILE_list;
1298 struct FILE_list *cur = *pp;
1299 if (cur->fp == fp) {
1308 static int save_FILEs_on_redirect(int fd)
1310 struct FILE_list *fl = G.FILE_list;
1313 /* We use it only on script files, they are all CLOEXEC */
1314 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1321 static void restore_redirected_FILEs(void)
1323 struct FILE_list *fl = G.FILE_list;
1325 int should_be = fileno(fl->fp);
1326 if (fl->fd != should_be) {
1327 xmove_fd(fl->fd, should_be);
1333 #if ENABLE_FEATURE_SH_STANDALONE
1334 static void close_all_FILE_list(void)
1336 struct FILE_list *fl = G.FILE_list;
1338 /* fclose would also free FILE object.
1339 * It is disastrous if we share memory with a vforked parent.
1340 * I'm not sure we never come here after vfork.
1341 * Therefore just close fd, nothing more.
1343 /*fclose(fl->fp); - unsafe */
1351 /* Helpers for setting new $n and restoring them back
1353 typedef struct save_arg_t {
1357 smallint sv_g_malloced;
1360 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1364 sv->sv_argv0 = argv[0];
1365 sv->sv_g_argv = G.global_argv;
1366 sv->sv_g_argc = G.global_argc;
1367 sv->sv_g_malloced = G.global_args_malloced;
1369 argv[0] = G.global_argv[0]; /* retain $0 */
1370 G.global_argv = argv;
1371 G.global_args_malloced = 0;
1379 static void restore_G_args(save_arg_t *sv, char **argv)
1383 if (G.global_args_malloced) {
1384 /* someone ran "set -- arg1 arg2 ...", undo */
1386 while (*++pp) /* note: does not free $0 */
1388 free(G.global_argv);
1390 argv[0] = sv->sv_argv0;
1391 G.global_argv = sv->sv_g_argv;
1392 G.global_argc = sv->sv_g_argc;
1393 G.global_args_malloced = sv->sv_g_malloced;
1397 /* Basic theory of signal handling in shell
1398 * ========================================
1399 * This does not describe what hush does, rather, it is current understanding
1400 * what it _should_ do. If it doesn't, it's a bug.
1401 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1403 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1404 * is finished or backgrounded. It is the same in interactive and
1405 * non-interactive shells, and is the same regardless of whether
1406 * a user trap handler is installed or a shell special one is in effect.
1407 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1408 * backgrounds (i.e. stops) or kills all members of currently running
1411 * Wait builtin is interruptible by signals for which user trap is set
1412 * or by SIGINT in interactive shell.
1414 * Trap handlers will execute even within trap handlers. (right?)
1416 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1417 * except for handlers set to '' (empty string).
1419 * If job control is off, backgrounded commands ("cmd &")
1420 * have SIGINT, SIGQUIT set to SIG_IGN.
1422 * Commands which are run in command substitution ("`cmd`")
1423 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1425 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1426 * by the shell from its parent.
1428 * Signals which differ from SIG_DFL action
1429 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1432 * SIGTERM (interactive): ignore
1433 * SIGHUP (interactive):
1434 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1435 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1436 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1437 * that all pipe members are stopped. Try this in bash:
1438 * while :; do :; done - ^Z does not background it
1439 * (while :; do :; done) - ^Z backgrounds it
1440 * SIGINT (interactive): wait for last pipe, ignore the rest
1441 * of the command line, show prompt. NB: ^C does not send SIGINT
1442 * to interactive shell while shell is waiting for a pipe,
1443 * since shell is bg'ed (is not in foreground process group).
1444 * Example 1: this waits 5 sec, but does not execute ls:
1445 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1446 * Example 2: this does not wait and does not execute ls:
1447 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1448 * Example 3: this does not wait 5 sec, but executes ls:
1449 * "sleep 5; ls -l" + press ^C
1450 * Example 4: this does not wait and does not execute ls:
1451 * "sleep 5 & wait; ls -l" + press ^C
1453 * (What happens to signals which are IGN on shell start?)
1454 * (What happens with signal mask on shell start?)
1456 * Old implementation
1457 * ==================
1458 * We use in-kernel pending signal mask to determine which signals were sent.
1459 * We block all signals which we don't want to take action immediately,
1460 * i.e. we block all signals which need to have special handling as described
1461 * above, and all signals which have traps set.
1462 * After each pipe execution, we extract any pending signals via sigtimedwait()
1465 * unsigned special_sig_mask: a mask of such "special" signals
1466 * sigset_t blocked_set: current blocked signal set
1469 * clear bit in blocked_set unless it is also in special_sig_mask
1470 * "trap 'cmd' SIGxxx":
1471 * set bit in blocked_set (even if 'cmd' is '')
1472 * after [v]fork, if we plan to be a shell:
1473 * unblock signals with special interactive handling
1474 * (child shell is not interactive),
1475 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1476 * after [v]fork, if we plan to exec:
1477 * POSIX says fork clears pending signal mask in child - no need to clear it.
1478 * Restore blocked signal set to one inherited by shell just prior to exec.
1480 * Note: as a result, we do not use signal handlers much. The only uses
1481 * are to count SIGCHLDs
1482 * and to restore tty pgrp on signal-induced exit.
1485 * Standard says "When a subshell is entered, traps that are not being ignored
1486 * are set to the default actions". bash interprets it so that traps which
1487 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1489 * Problem: the above approach makes it unwieldy to catch signals while
1490 * we are in read builtin, or while we read commands from stdin:
1491 * masked signals are not visible!
1493 * New implementation
1494 * ==================
1495 * We record each signal we are interested in by installing signal handler
1496 * for them - a bit like emulating kernel pending signal mask in userspace.
1497 * We are interested in: signals which need to have special handling
1498 * as described above, and all signals which have traps set.
1499 * Signals are recorded in pending_set.
1500 * After each pipe execution, we extract any pending signals
1503 * unsigned special_sig_mask: a mask of shell-special signals.
1504 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1505 * char *traps[sig] if trap for sig is set (even if it's '').
1506 * sigset_t pending_set: set of sigs we received.
1509 * if sig is in special_sig_mask, set handler back to:
1510 * record_pending_signo, or to IGN if it's a tty stop signal
1511 * if sig is in fatal_sig_mask, set handler back to sigexit.
1512 * else: set handler back to SIG_DFL
1513 * "trap 'cmd' SIGxxx":
1514 * set handler to record_pending_signo.
1516 * set handler to SIG_IGN.
1517 * after [v]fork, if we plan to be a shell:
1518 * set signals with special interactive handling to SIG_DFL
1519 * (because child shell is not interactive),
1520 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1521 * after [v]fork, if we plan to exec:
1522 * POSIX says fork clears pending signal mask in child - no need to clear it.
1524 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1525 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1528 * Standard says "When a subshell is entered, traps that are not being ignored
1529 * are set to the default actions". bash interprets it so that traps which
1530 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1533 SPECIAL_INTERACTIVE_SIGS = 0
1538 SPECIAL_JOBSTOP_SIGS = 0
1547 static void record_pending_signo(int sig)
1549 sigaddset(&G.pending_set, sig);
1550 #if ENABLE_HUSH_FAST
1551 if (sig == SIGCHLD) {
1553 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1558 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1560 struct sigaction old_sa;
1562 /* We could use signal() to install handlers... almost:
1563 * except that we need to mask ALL signals while handlers run.
1564 * I saw signal nesting in strace, race window isn't small.
1565 * SA_RESTART is also needed, but in Linux, signal()
1566 * sets SA_RESTART too.
1568 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1569 /* sigfillset(&G.sa.sa_mask); - already done */
1570 /* G.sa.sa_flags = SA_RESTART; - already done */
1571 G.sa.sa_handler = handler;
1572 sigaction(sig, &G.sa, &old_sa);
1573 return old_sa.sa_handler;
1576 static void hush_exit(int exitcode) NORETURN;
1577 static void fflush_and__exit(void) NORETURN;
1578 static void restore_ttypgrp_and__exit(void) NORETURN;
1580 static void restore_ttypgrp_and__exit(void)
1582 /* xfunc has failed! die die die */
1583 /* no EXIT traps, this is an escape hatch! */
1585 hush_exit(xfunc_error_retval);
1588 /* Needed only on some libc:
1589 * It was observed that on exit(), fgetc'ed buffered data
1590 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1591 * With the net effect that even after fork(), not vfork(),
1592 * exit() in NOEXECed applet in "sh SCRIPT":
1593 * noexec_applet_here
1594 * echo END_OF_SCRIPT
1595 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1596 * This makes "echo END_OF_SCRIPT" executed twice.
1597 * Similar problems can be seen with die_if_script() -> xfunc_die()
1598 * and in `cmd` handling.
1599 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1601 static void fflush_and__exit(void)
1604 _exit(xfunc_error_retval);
1609 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1610 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1611 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1612 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1614 /* Restores tty foreground process group, and exits.
1615 * May be called as signal handler for fatal signal
1616 * (will resend signal to itself, producing correct exit state)
1617 * or called directly with -EXITCODE.
1618 * We also call it if xfunc is exiting.
1620 static void sigexit(int sig) NORETURN;
1621 static void sigexit(int sig)
1623 /* Careful: we can end up here after [v]fork. Do not restore
1624 * tty pgrp then, only top-level shell process does that */
1625 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1626 /* Disable all signals: job control, SIGPIPE, etc.
1627 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1629 sigprocmask_allsigs(SIG_BLOCK);
1630 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1633 /* Not a signal, just exit */
1637 kill_myself_with_sig(sig); /* does not return */
1641 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1642 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1646 static sighandler_t pick_sighandler(unsigned sig)
1648 sighandler_t handler = SIG_DFL;
1649 if (sig < sizeof(unsigned)*8) {
1650 unsigned sigmask = (1 << sig);
1654 if (G_fatal_sig_mask & sigmask)
1658 /* sig has special handling? */
1659 if (G.special_sig_mask & sigmask) {
1660 handler = record_pending_signo;
1661 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1662 * in order to ignore them: they will be raised
1663 * in an endless loop when we try to do some
1664 * terminal ioctls! We do have to _ignore_ these.
1666 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1673 /* Restores tty foreground process group, and exits. */
1674 static void hush_exit(int exitcode)
1676 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1677 save_history(G.line_input_state);
1681 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1683 /* argv[0] is unused */
1684 argv[1] = G.traps[0];
1686 G.exiting = 1; /* prevent EXIT trap recursion */
1687 /* Note: G.traps[0] is not cleared!
1688 * "trap" will still show it, if executed
1693 #if ENABLE_FEATURE_CLEAN_UP
1695 struct variable *cur_var;
1696 if (G.cwd != bb_msg_unknown)
1698 cur_var = G.top_var;
1700 struct variable *tmp = cur_var;
1701 if (!cur_var->max_len)
1702 free(cur_var->varstr);
1703 cur_var = cur_var->next;
1711 sigexit(- (exitcode & 0xff));
1718 //TODO: return a mask of ALL handled sigs?
1719 static int check_and_run_traps(void)
1726 if (sigisemptyset(&G.pending_set))
1731 if (sigismember(&G.pending_set, sig)) {
1732 sigdelset(&G.pending_set, sig);
1735 } while (sig < NSIG);
1738 if (G.traps && G.traps[sig]) {
1739 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1740 if (G.traps[sig][0]) {
1741 /* We have user-defined handler */
1742 smalluint save_rcode;
1744 /* argv[0] is unused */
1745 argv[1] = G.traps[sig];
1747 save_rcode = G.last_exitcode;
1749 G.last_exitcode = save_rcode;
1751 } /* else: "" trap, ignoring signal */
1754 /* not a trap: special action */
1757 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1758 /* Builtin was ^C'ed, make it look prettier: */
1766 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1767 /* bash is observed to signal whole process groups,
1768 * not individual processes */
1769 for (job = G.job_list; job; job = job->next) {
1772 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1773 if (kill(- job->pgrp, SIGHUP) == 0)
1774 kill(- job->pgrp, SIGCONT);
1779 #if ENABLE_HUSH_FAST
1781 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1783 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1785 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1786 * This simplifies wait builtin a bit.
1790 default: /* ignored: */
1791 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1792 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1794 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1795 * Example: wait is not interrupted by TERM
1796 * in interactive shell, because TERM is ignored.
1805 static const char *get_cwd(int force)
1807 if (force || G.cwd == NULL) {
1808 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1809 * we must not try to free(bb_msg_unknown) */
1810 if (G.cwd == bb_msg_unknown)
1812 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1814 G.cwd = bb_msg_unknown;
1821 * Shell and environment variable support
1823 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1825 struct variable **pp;
1826 struct variable *cur;
1829 while ((cur = *pp) != NULL) {
1830 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1837 static const char* FAST_FUNC get_local_var_value(const char *name)
1839 struct variable **vpp;
1840 unsigned len = strlen(name);
1842 if (G.expanded_assignments) {
1843 char **cpp = G.expanded_assignments;
1846 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1847 return cp + len + 1;
1852 vpp = get_ptr_to_local_var(name, len);
1854 return (*vpp)->varstr + len + 1;
1856 if (strcmp(name, "PPID") == 0)
1857 return utoa(G.root_ppid);
1858 // bash compat: UID? EUID?
1859 #if ENABLE_HUSH_RANDOM_SUPPORT
1860 if (strcmp(name, "RANDOM") == 0)
1861 return utoa(next_random(&G.random_gen));
1866 /* str holds "NAME=VAL" and is expected to be malloced.
1867 * We take ownership of it.
1869 * 0: do not change export flag
1870 * (if creating new variable, flag will be 0)
1871 * 1: set export flag and putenv the variable
1872 * -1: clear export flag and unsetenv the variable
1873 * flg_read_only is set only when we handle -R var=val
1875 #if !BB_MMU && ENABLE_HUSH_LOCAL
1876 /* all params are used */
1877 #elif BB_MMU && ENABLE_HUSH_LOCAL
1878 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1879 set_local_var(str, flg_export, local_lvl)
1880 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1881 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1882 set_local_var(str, flg_export)
1883 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1884 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1885 set_local_var(str, flg_export, flg_read_only)
1887 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1889 struct variable **var_pp;
1890 struct variable *cur;
1891 char *free_me = NULL;
1895 eq_sign = strchr(str, '=');
1896 if (!eq_sign) { /* not expected to ever happen? */
1901 name_len = eq_sign - str + 1; /* including '=' */
1902 var_pp = &G.top_var;
1903 while ((cur = *var_pp) != NULL) {
1904 if (strncmp(cur->varstr, str, name_len) != 0) {
1905 var_pp = &cur->next;
1909 /* We found an existing var with this name */
1910 if (cur->flg_read_only) {
1914 bb_error_msg("%s: readonly variable", str);
1918 if (flg_export == -1) { // "&& cur->flg_export" ?
1919 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1924 #if ENABLE_HUSH_LOCAL
1925 if (cur->func_nest_level < local_lvl) {
1926 /* New variable is declared as local,
1927 * and existing one is global, or local
1928 * from enclosing function.
1929 * Remove and save old one: */
1930 *var_pp = cur->next;
1931 cur->next = *G.shadowed_vars_pp;
1932 *G.shadowed_vars_pp = cur;
1933 /* bash 3.2.33(1) and exported vars:
1935 * # f() { local z=a; env | grep ^z; }
1941 if (cur->flg_export)
1946 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1951 if (cur->max_len != 0) {
1952 if (cur->max_len >= strlen(str)) {
1953 /* This one is from startup env, reuse space */
1954 strcpy(cur->varstr, str);
1959 goto set_str_and_exp;
1961 /* max_len == 0 signifies "malloced" var, which we can
1962 * (and have to) free. But we can't free(cur->varstr) here:
1963 * if cur->flg_export is 1, it is in the environment.
1964 * We should either unsetenv+free, or wait until putenv,
1965 * then putenv(new)+free(old).
1967 free_me = cur->varstr;
1968 goto set_str_and_exp;
1971 /* Not found - create new variable struct */
1972 cur = xzalloc(sizeof(*cur));
1973 #if ENABLE_HUSH_LOCAL
1974 cur->func_nest_level = local_lvl;
1976 cur->next = *var_pp;
1982 cur->flg_read_only = flg_read_only;
1985 if (flg_export == 1)
1986 cur->flg_export = 1;
1987 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1988 cmdedit_update_prompt();
1989 if (cur->flg_export) {
1990 if (flg_export == -1) {
1991 cur->flg_export = 0;
1992 /* unsetenv was already done */
1995 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1996 i = putenv(cur->varstr);
1997 /* only now we can free old exported malloced string */
2006 /* Used at startup and after each cd */
2007 static void set_pwd_var(int exp)
2009 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2010 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2013 static int unset_local_var_len(const char *name, int name_len)
2015 struct variable *cur;
2016 struct variable **var_pp;
2019 return EXIT_SUCCESS;
2020 var_pp = &G.top_var;
2021 while ((cur = *var_pp) != NULL) {
2022 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2023 if (cur->flg_read_only) {
2024 bb_error_msg("%s: readonly variable", name);
2025 return EXIT_FAILURE;
2027 *var_pp = cur->next;
2028 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2029 bb_unsetenv(cur->varstr);
2030 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2031 cmdedit_update_prompt();
2035 return EXIT_SUCCESS;
2037 var_pp = &cur->next;
2039 return EXIT_SUCCESS;
2042 static int unset_local_var(const char *name)
2044 return unset_local_var_len(name, strlen(name));
2047 static void unset_vars(char **strings)
2055 const char *eq = strchrnul(*v, '=');
2056 unset_local_var_len(*v, (int)(eq - *v));
2062 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2064 char *var = xasprintf("%s=%s", name, val);
2065 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2070 * Helpers for "var1=val1 var2=val2 cmd" feature
2072 static void add_vars(struct variable *var)
2074 struct variable *next;
2078 var->next = G.top_var;
2080 if (var->flg_export) {
2081 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2082 putenv(var->varstr);
2084 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2090 static struct variable *set_vars_and_save_old(char **strings)
2093 struct variable *old = NULL;
2099 struct variable *var_p;
2100 struct variable **var_pp;
2103 eq = strchr(*s, '=');
2105 var_pp = get_ptr_to_local_var(*s, eq - *s);
2107 /* Remove variable from global linked list */
2109 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2110 *var_pp = var_p->next;
2111 /* Add it to returned list */
2115 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2126 static void reinit_unicode_for_hush(void)
2128 /* Unicode support should be activated even if LANG is set
2129 * _during_ shell execution, not only if it was set when
2130 * shell was started. Therefore, re-check LANG every time:
2132 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2133 || ENABLE_UNICODE_USING_LOCALE
2135 const char *s = get_local_var_value("LC_ALL");
2136 if (!s) s = get_local_var_value("LC_CTYPE");
2137 if (!s) s = get_local_var_value("LANG");
2143 * in_str support (strings, and "strings" read from files).
2146 #if ENABLE_HUSH_INTERACTIVE
2147 /* To test correct lineedit/interactive behavior, type from command line:
2153 * It excercises a lot of corner cases.
2155 static void cmdedit_update_prompt(void)
2157 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2158 G.PS1 = get_local_var_value("PS1");
2161 G.PS2 = get_local_var_value("PS2");
2168 static const char *setup_prompt_string(int promptmode)
2170 const char *prompt_str;
2171 debug_printf("setup_prompt_string %d ", promptmode);
2172 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2173 /* Set up the prompt */
2174 if (promptmode == 0) { /* PS1 */
2176 /* bash uses $PWD value, even if it is set by user.
2177 * It uses current dir only if PWD is unset.
2178 * We always use current dir. */
2179 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2184 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2185 debug_printf("prompt_str '%s'\n", prompt_str);
2188 static int get_user_input(struct in_str *i)
2191 const char *prompt_str;
2193 prompt_str = setup_prompt_string(i->promptmode);
2194 # if ENABLE_FEATURE_EDITING
2196 reinit_unicode_for_hush();
2198 /* buglet: SIGINT will not make new prompt to appear _at once_,
2199 * only after <Enter>. (^C will work) */
2200 r = read_line_input(G.line_input_state, prompt_str,
2201 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2204 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2205 check_and_run_traps();
2206 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2208 /* EOF/error detected */
2210 i->peek_buf[0] = r = EOF;
2213 i->p = G.user_input_buf;
2214 return (unsigned char)*i->p++;
2218 if (i->last_char == '\0' || i->last_char == '\n') {
2219 /* Why check_and_run_traps here? Try this interactively:
2220 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2221 * $ <[enter], repeatedly...>
2222 * Without check_and_run_traps, handler never runs.
2224 check_and_run_traps();
2225 fputs(prompt_str, stdout);
2229 } while (G.flag_SIGINT || r == '\0');
2233 /* This is the magic location that prints prompts
2234 * and gets data back from the user */
2235 static int fgetc_interactive(struct in_str *i)
2238 /* If it's interactive stdin, get new line. */
2239 if (G_interactive_fd && i->file == stdin) {
2240 /* Returns first char (or EOF), the rest is in i->p[] */
2241 ch = get_user_input(i);
2242 i->promptmode = 1; /* PS2 */
2244 /* Not stdin: script file, sourced file, etc */
2245 do ch = fgetc(i->file); while (ch == '\0');
2250 static inline int fgetc_interactive(struct in_str *i)
2253 do ch = fgetc(i->file); while (ch == '\0');
2256 #endif /* INTERACTIVE */
2258 static int i_getch(struct in_str *i)
2263 /* string-based in_str */
2264 ch = (unsigned char)*i->p;
2273 /* FILE-based in_str */
2275 #if ENABLE_FEATURE_EDITING
2276 /* This can be stdin, check line editing char[] buffer */
2277 if (i->p && *i->p != '\0') {
2278 ch = (unsigned char)*i->p++;
2282 /* peek_buf[] is an int array, not char. Can contain EOF. */
2283 ch = i->peek_buf[0];
2285 int ch2 = i->peek_buf[1];
2286 i->peek_buf[0] = ch2;
2287 if (ch2 == 0) /* very likely, avoid redundant write */
2293 ch = fgetc_interactive(i);
2295 debug_printf("file_get: got '%c' %d\n", ch, ch);
2300 static int i_peek(struct in_str *i)
2305 /* string-based in_str */
2306 /* Doesn't report EOF on NUL. None of the callers care. */
2307 return (unsigned char)*i->p;
2310 /* FILE-based in_str */
2312 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2313 /* This can be stdin, check line editing char[] buffer */
2314 if (i->p && *i->p != '\0')
2315 return (unsigned char)*i->p;
2317 /* peek_buf[] is an int array, not char. Can contain EOF. */
2318 ch = i->peek_buf[0];
2322 /* Need to get a new char */
2323 ch = fgetc_interactive(i);
2324 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2326 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2327 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2333 i->peek_buf[0] = ch;
2334 /*i->peek_buf[1] = 0; - already is */
2338 /* Only ever called if i_peek() was called, and did not return EOF.
2339 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2340 * not end-of-line. Therefore we never need to read a new editing line here.
2342 static int i_peek2(struct in_str *i)
2346 /* There are two cases when i->p[] buffer exists.
2347 * (1) it's a string in_str.
2348 * (2) It's a file, and we have a saved line editing buffer.
2349 * In both cases, we know that i->p[0] exists and not NUL, and
2350 * the peek2 result is in i->p[1].
2353 return (unsigned char)i->p[1];
2355 /* Now we know it is a file-based in_str. */
2357 /* peek_buf[] is an int array, not char. Can contain EOF. */
2358 /* Is there 2nd char? */
2359 ch = i->peek_buf[1];
2361 /* We did not read it yet, get it now */
2362 do ch = fgetc(i->file); while (ch == '\0');
2363 i->peek_buf[1] = ch;
2366 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2370 static void setup_file_in_str(struct in_str *i, FILE *f)
2372 memset(i, 0, sizeof(*i));
2373 /* i->promptmode = 0; - PS1 (memset did it) */
2378 static void setup_string_in_str(struct in_str *i, const char *s)
2380 memset(i, 0, sizeof(*i));
2381 /* i->promptmode = 0; - PS1 (memset did it) */
2382 /*i->file = NULL */;
2390 #define B_CHUNK (32 * sizeof(char*))
2392 static void o_reset_to_empty_unquoted(o_string *o)
2395 o->has_quoted_part = 0;
2400 static void o_free(o_string *o)
2403 memset(o, 0, sizeof(*o));
2406 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2411 static void o_grow_by(o_string *o, int len)
2413 if (o->length + len > o->maxlen) {
2414 o->maxlen += (2 * len) | (B_CHUNK-1);
2415 o->data = xrealloc(o->data, 1 + o->maxlen);
2419 static void o_addchr(o_string *o, int ch)
2421 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2422 if (o->length < o->maxlen) {
2423 /* likely. avoid o_grow_by() call */
2425 o->data[o->length] = ch;
2427 o->data[o->length] = '\0';
2435 /* Valid only if we know o_string is not empty */
2436 static void o_delchr(o_string *o)
2439 o->data[o->length] = '\0';
2443 static void o_addblock(o_string *o, const char *str, int len)
2446 memcpy(&o->data[o->length], str, len);
2448 o->data[o->length] = '\0';
2451 static void o_addstr(o_string *o, const char *str)
2453 o_addblock(o, str, strlen(str));
2457 static void nommu_addchr(o_string *o, int ch)
2463 # define nommu_addchr(o, str) ((void)0)
2466 static void o_addstr_with_NUL(o_string *o, const char *str)
2468 o_addblock(o, str, strlen(str) + 1);
2472 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2473 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2474 * Apparently, on unquoted $v bash still does globbing
2475 * ("v='*.txt'; echo $v" prints all .txt files),
2476 * but NOT brace expansion! Thus, there should be TWO independent
2477 * quoting mechanisms on $v expansion side: one protects
2478 * $v from brace expansion, and other additionally protects "$v" against globbing.
2479 * We have only second one.
2482 #if ENABLE_HUSH_BRACE_EXPANSION
2483 # define MAYBE_BRACES "{}"
2485 # define MAYBE_BRACES ""
2488 /* My analysis of quoting semantics tells me that state information
2489 * is associated with a destination, not a source.
2491 static void o_addqchr(o_string *o, int ch)
2494 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2499 o->data[o->length] = '\\';
2502 o->data[o->length] = ch;
2504 o->data[o->length] = '\0';
2507 static void o_addQchr(o_string *o, int ch)
2510 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2511 && strchr("*?[\\" MAYBE_BRACES, ch)
2514 o->data[o->length] = '\\';
2518 o->data[o->length] = ch;
2520 o->data[o->length] = '\0';
2523 static void o_addqblock(o_string *o, const char *str, int len)
2528 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2529 if (ordinary_cnt > len) /* paranoia */
2531 o_addblock(o, str, ordinary_cnt);
2532 if (ordinary_cnt == len)
2533 return; /* NUL is already added by o_addblock */
2534 str += ordinary_cnt;
2535 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2539 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2541 o->data[o->length] = '\\';
2545 o->data[o->length] = ch;
2548 o->data[o->length] = '\0';
2551 static void o_addQblock(o_string *o, const char *str, int len)
2553 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2554 o_addblock(o, str, len);
2557 o_addqblock(o, str, len);
2560 static void o_addQstr(o_string *o, const char *str)
2562 o_addQblock(o, str, strlen(str));
2565 /* A special kind of o_string for $VAR and `cmd` expansion.
2566 * It contains char* list[] at the beginning, which is grown in 16 element
2567 * increments. Actual string data starts at the next multiple of 16 * (char*).
2568 * list[i] contains an INDEX (int!) into this string data.
2569 * It means that if list[] needs to grow, data needs to be moved higher up
2570 * but list[i]'s need not be modified.
2571 * NB: remembering how many list[i]'s you have there is crucial.
2572 * o_finalize_list() operation post-processes this structure - calculates
2573 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2575 #if DEBUG_EXPAND || DEBUG_GLOB
2576 static void debug_print_list(const char *prefix, o_string *o, int n)
2578 char **list = (char**)o->data;
2579 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2583 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2584 prefix, list, n, string_start, o->length, o->maxlen,
2585 !!(o->o_expflags & EXP_FLAG_GLOB),
2587 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2590 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2591 o->data + (int)(uintptr_t)list[i] + string_start,
2592 o->data + (int)(uintptr_t)list[i] + string_start);
2596 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2598 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2602 # define debug_print_list(prefix, o, n) ((void)0)
2605 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2606 * in list[n] so that it points past last stored byte so far.
2607 * It returns n+1. */
2608 static int o_save_ptr_helper(o_string *o, int n)
2610 char **list = (char**)o->data;
2614 if (!o->has_empty_slot) {
2615 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2616 string_len = o->length - string_start;
2617 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2618 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2619 /* list[n] points to string_start, make space for 16 more pointers */
2620 o->maxlen += 0x10 * sizeof(list[0]);
2621 o->data = xrealloc(o->data, o->maxlen + 1);
2622 list = (char**)o->data;
2623 memmove(list + n + 0x10, list + n, string_len);
2624 o->length += 0x10 * sizeof(list[0]);
2626 debug_printf_list("list[%d]=%d string_start=%d\n",
2627 n, string_len, string_start);
2630 /* We have empty slot at list[n], reuse without growth */
2631 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2632 string_len = o->length - string_start;
2633 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2634 n, string_len, string_start);
2635 o->has_empty_slot = 0;
2637 o->has_quoted_part = 0;
2638 list[n] = (char*)(uintptr_t)string_len;
2642 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2643 static int o_get_last_ptr(o_string *o, int n)
2645 char **list = (char**)o->data;
2646 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2648 return ((int)(uintptr_t)list[n-1]) + string_start;
2651 #if ENABLE_HUSH_BRACE_EXPANSION
2652 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2653 * first, it processes even {a} (no commas), second,
2654 * I didn't manage to make it return strings when they don't match
2655 * existing files. Need to re-implement it.
2659 static int glob_needed(const char *s)
2668 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2674 /* Return pointer to next closing brace or to comma */
2675 static const char *next_brace_sub(const char *cp)
2679 while (*cp != '\0') {
2686 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2692 return *cp != '\0' ? cp : NULL;
2694 /* Recursive brace globber. Note: may garble pattern[]. */
2695 static int glob_brace(char *pattern, o_string *o, int n)
2697 char *new_pattern_buf;
2704 debug_printf_glob("glob_brace('%s')\n", pattern);
2710 if (*begin == '{') {
2711 /* Find the first sub-pattern and at the same time
2712 * find the rest after the closing brace */
2713 next = next_brace_sub(begin);
2715 /* An illegal expression */
2719 /* "{abc}" with no commas - illegal
2720 * brace expr, disregard and skip it */
2726 if (*begin == '\\' && begin[1] != '\0')
2730 debug_printf_glob("begin:%s\n", begin);
2731 debug_printf_glob("next:%s\n", next);
2733 /* Now find the end of the whole brace expression */
2735 while (*rest != '}') {
2736 rest = next_brace_sub(rest);
2738 /* An illegal expression */
2741 debug_printf_glob("rest:%s\n", rest);
2743 rest_len = strlen(++rest) + 1;
2745 /* We are sure the brace expression is well-formed */
2747 /* Allocate working buffer large enough for our work */
2748 new_pattern_buf = xmalloc(strlen(pattern));
2750 /* We have a brace expression. BEGIN points to the opening {,
2751 * NEXT points past the terminator of the first element, and REST
2752 * points past the final }. We will accumulate result names from
2753 * recursive runs for each brace alternative in the buffer using
2758 /* Construct the new glob expression */
2761 mempcpy(new_pattern_buf,
2762 /* We know the prefix for all sub-patterns */
2763 pattern, begin - pattern),
2767 /* Note: glob_brace() may garble new_pattern_buf[].
2768 * That's why we re-copy prefix every time (1st memcpy above).
2770 n = glob_brace(new_pattern_buf, o, n);
2772 /* We saw the last entry */
2776 next = next_brace_sub(next);
2778 free(new_pattern_buf);
2786 memset(&globdata, 0, sizeof(globdata));
2787 gr = glob(pattern, 0, NULL, &globdata);
2788 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2790 if (gr == GLOB_NOMATCH) {
2791 globfree(&globdata);
2792 /* NB: garbles parameter */
2793 unbackslash(pattern);
2794 o_addstr_with_NUL(o, pattern);
2795 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2796 return o_save_ptr_helper(o, n);
2798 if (gr == GLOB_NOSPACE)
2799 bb_error_msg_and_die(bb_msg_memory_exhausted);
2800 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2801 * but we didn't specify it. Paranoia again. */
2802 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2804 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2805 char **argv = globdata.gl_pathv;
2807 o_addstr_with_NUL(o, *argv);
2808 n = o_save_ptr_helper(o, n);
2814 globfree(&globdata);
2818 /* Performs globbing on last list[],
2819 * saving each result as a new list[].
2821 static int perform_glob(o_string *o, int n)
2823 char *pattern, *copy;
2825 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2827 return o_save_ptr_helper(o, n);
2828 pattern = o->data + o_get_last_ptr(o, n);
2829 debug_printf_glob("glob pattern '%s'\n", pattern);
2830 if (!glob_needed(pattern)) {
2831 /* unbackslash last string in o in place, fix length */
2832 o->length = unbackslash(pattern) - o->data;
2833 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2834 return o_save_ptr_helper(o, n);
2837 copy = xstrdup(pattern);
2838 /* "forget" pattern in o */
2839 o->length = pattern - o->data;
2840 n = glob_brace(copy, o, n);
2843 debug_print_list("perform_glob returning", o, n);
2847 #else /* !HUSH_BRACE_EXPANSION */
2850 static int glob_needed(const char *s)
2859 if (*s == '*' || *s == '[' || *s == '?')
2865 /* Performs globbing on last list[],
2866 * saving each result as a new list[].
2868 static int perform_glob(o_string *o, int n)
2874 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2876 return o_save_ptr_helper(o, n);
2877 pattern = o->data + o_get_last_ptr(o, n);
2878 debug_printf_glob("glob pattern '%s'\n", pattern);
2879 if (!glob_needed(pattern)) {
2881 /* unbackslash last string in o in place, fix length */
2882 o->length = unbackslash(pattern) - o->data;
2883 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2884 return o_save_ptr_helper(o, n);
2887 memset(&globdata, 0, sizeof(globdata));
2888 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2889 * If we glob "*.\*" and don't find anything, we need
2890 * to fall back to using literal "*.*", but GLOB_NOCHECK
2891 * will return "*.\*"!
2893 gr = glob(pattern, 0, NULL, &globdata);
2894 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2896 if (gr == GLOB_NOMATCH) {
2897 globfree(&globdata);
2900 if (gr == GLOB_NOSPACE)
2901 bb_error_msg_and_die(bb_msg_memory_exhausted);
2902 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2903 * but we didn't specify it. Paranoia again. */
2904 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2906 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2907 char **argv = globdata.gl_pathv;
2908 /* "forget" pattern in o */
2909 o->length = pattern - o->data;
2911 o_addstr_with_NUL(o, *argv);
2912 n = o_save_ptr_helper(o, n);
2918 globfree(&globdata);
2920 debug_print_list("perform_glob returning", o, n);
2924 #endif /* !HUSH_BRACE_EXPANSION */
2926 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2927 * Otherwise, just finish current list[] and start new */
2928 static int o_save_ptr(o_string *o, int n)
2930 if (o->o_expflags & EXP_FLAG_GLOB) {
2931 /* If o->has_empty_slot, list[n] was already globbed
2932 * (if it was requested back then when it was filled)
2933 * so don't do that again! */
2934 if (!o->has_empty_slot)
2935 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2937 return o_save_ptr_helper(o, n);
2940 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2941 static char **o_finalize_list(o_string *o, int n)
2946 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2948 debug_print_list("finalized", o, n);
2949 debug_printf_expand("finalized n:%d\n", n);
2950 list = (char**)o->data;
2951 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2955 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2960 static void free_pipe_list(struct pipe *pi);
2962 /* Returns pi->next - next pipe in the list */
2963 static struct pipe *free_pipe(struct pipe *pi)
2968 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2969 for (i = 0; i < pi->num_cmds; i++) {
2970 struct command *command;
2971 struct redir_struct *r, *rnext;
2973 command = &pi->cmds[i];
2974 debug_printf_clean(" command %d:\n", i);
2975 if (command->argv) {
2979 for (a = 0, p = command->argv; *p; a++, p++) {
2980 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2983 free_strings(command->argv);
2984 //command->argv = NULL;
2986 /* not "else if": on syntax error, we may have both! */
2987 if (command->group) {
2988 debug_printf_clean(" begin group (cmd_type:%d)\n",
2990 free_pipe_list(command->group);
2991 debug_printf_clean(" end group\n");
2992 //command->group = NULL;
2994 /* else is crucial here.
2995 * If group != NULL, child_func is meaningless */
2996 #if ENABLE_HUSH_FUNCTIONS
2997 else if (command->child_func) {
2998 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2999 command->child_func->parent_cmd = NULL;
3003 free(command->group_as_string);
3004 //command->group_as_string = NULL;
3006 for (r = command->redirects; r; r = rnext) {
3007 debug_printf_clean(" redirect %d%s",
3008 r->rd_fd, redir_table[r->rd_type].descrip);
3009 /* guard against the case >$FOO, where foo is unset or blank */
3010 if (r->rd_filename) {
3011 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3012 free(r->rd_filename);
3013 //r->rd_filename = NULL;
3015 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3019 //command->redirects = NULL;
3021 free(pi->cmds); /* children are an array, they get freed all at once */
3025 //pi->cmdtext = NULL;
3033 static void free_pipe_list(struct pipe *pi)
3037 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3039 debug_printf_clean("pipe followup code %d\n", pi->followup);
3045 /*** Parsing routines ***/
3047 #ifndef debug_print_tree
3048 static void debug_print_tree(struct pipe *pi, int lvl)
3050 static const char *const PIPE[] = {
3056 static const char *RES[] = {
3057 [RES_NONE ] = "NONE" ,
3060 [RES_THEN ] = "THEN" ,
3061 [RES_ELIF ] = "ELIF" ,
3062 [RES_ELSE ] = "ELSE" ,
3065 # if ENABLE_HUSH_LOOPS
3066 [RES_FOR ] = "FOR" ,
3067 [RES_WHILE] = "WHILE",
3068 [RES_UNTIL] = "UNTIL",
3070 [RES_DONE ] = "DONE" ,
3072 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3075 # if ENABLE_HUSH_CASE
3076 [RES_CASE ] = "CASE" ,
3077 [RES_CASE_IN ] = "CASE_IN" ,
3078 [RES_MATCH] = "MATCH",
3079 [RES_CASE_BODY] = "CASE_BODY",
3080 [RES_ESAC ] = "ESAC" ,
3082 [RES_XXXX ] = "XXXX" ,
3083 [RES_SNTX ] = "SNTX" ,
3085 static const char *const CMDTYPE[] = {
3089 # if ENABLE_HUSH_FUNCTIONS
3098 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3099 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3101 while (prn < pi->num_cmds) {
3102 struct command *command = &pi->cmds[prn];
3103 char **argv = command->argv;
3105 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3107 command->assignment_cnt);
3108 if (command->group) {
3109 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3110 CMDTYPE[command->cmd_type],
3113 , " group_as_string:", command->group_as_string
3118 debug_print_tree(command->group, lvl+1);
3122 if (argv) while (*argv) {
3123 fdprintf(2, " '%s'", *argv);
3133 #endif /* debug_print_tree */
3135 static struct pipe *new_pipe(void)
3138 pi = xzalloc(sizeof(struct pipe));
3139 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3143 /* Command (member of a pipe) is complete, or we start a new pipe
3144 * if ctx->command is NULL.
3145 * No errors possible here.
3147 static int done_command(struct parse_context *ctx)
3149 /* The command is really already in the pipe structure, so
3150 * advance the pipe counter and make a new, null command. */
3151 struct pipe *pi = ctx->pipe;
3152 struct command *command = ctx->command;
3154 #if 0 /* Instead we emit error message at run time */
3155 if (ctx->pending_redirect) {
3156 /* For example, "cmd >" (no filename to redirect to) */
3157 die_if_script("syntax error: %s", "invalid redirect");
3158 ctx->pending_redirect = NULL;
3163 if (IS_NULL_CMD(command)) {
3164 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3168 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3169 //debug_print_tree(ctx->list_head, 20);
3171 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3174 /* Only real trickiness here is that the uncommitted
3175 * command structure is not counted in pi->num_cmds. */
3176 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3177 ctx->command = command = &pi->cmds[pi->num_cmds];
3179 memset(command, 0, sizeof(*command));
3180 return pi->num_cmds; /* used only for 0/nonzero check */
3183 static void done_pipe(struct parse_context *ctx, pipe_style type)
3187 debug_printf_parse("done_pipe entered, followup %d\n", type);
3188 /* Close previous command */
3189 not_null = done_command(ctx);
3190 ctx->pipe->followup = type;
3192 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3193 ctx->ctx_inverted = 0;
3194 ctx->pipe->res_word = ctx->ctx_res_w;
3197 /* Without this check, even just <enter> on command line generates
3198 * tree of three NOPs (!). Which is harmless but annoying.
3199 * IOW: it is safe to do it unconditionally. */
3202 || ctx->ctx_res_w == RES_FI
3204 #if ENABLE_HUSH_LOOPS
3205 || ctx->ctx_res_w == RES_DONE
3206 || ctx->ctx_res_w == RES_FOR
3207 || ctx->ctx_res_w == RES_IN
3209 #if ENABLE_HUSH_CASE
3210 || ctx->ctx_res_w == RES_ESAC
3214 debug_printf_parse("done_pipe: adding new pipe: "
3215 "not_null:%d ctx->ctx_res_w:%d\n",
3216 not_null, ctx->ctx_res_w);
3218 ctx->pipe->next = new_p;
3220 /* RES_THEN, RES_DO etc are "sticky" -
3221 * they remain set for pipes inside if/while.
3222 * This is used to control execution.
3223 * RES_FOR and RES_IN are NOT sticky (needed to support
3224 * cases where variable or value happens to match a keyword):
3226 #if ENABLE_HUSH_LOOPS
3227 if (ctx->ctx_res_w == RES_FOR
3228 || ctx->ctx_res_w == RES_IN)
3229 ctx->ctx_res_w = RES_NONE;
3231 #if ENABLE_HUSH_CASE
3232 if (ctx->ctx_res_w == RES_MATCH)
3233 ctx->ctx_res_w = RES_CASE_BODY;
3234 if (ctx->ctx_res_w == RES_CASE)
3235 ctx->ctx_res_w = RES_CASE_IN;
3237 ctx->command = NULL; /* trick done_command below */
3238 /* Create the memory for command, roughly:
3239 * ctx->pipe->cmds = new struct command;
3240 * ctx->command = &ctx->pipe->cmds[0];
3243 //debug_print_tree(ctx->list_head, 10);
3245 debug_printf_parse("done_pipe return\n");
3248 static void initialize_context(struct parse_context *ctx)
3250 memset(ctx, 0, sizeof(*ctx));
3251 ctx->pipe = ctx->list_head = new_pipe();
3252 /* Create the memory for command, roughly:
3253 * ctx->pipe->cmds = new struct command;
3254 * ctx->command = &ctx->pipe->cmds[0];
3259 /* If a reserved word is found and processed, parse context is modified
3260 * and 1 is returned.
3263 struct reserved_combo {
3266 unsigned char assignment_flag;
3270 FLAG_END = (1 << RES_NONE ),
3272 FLAG_IF = (1 << RES_IF ),
3273 FLAG_THEN = (1 << RES_THEN ),
3274 FLAG_ELIF = (1 << RES_ELIF ),
3275 FLAG_ELSE = (1 << RES_ELSE ),
3276 FLAG_FI = (1 << RES_FI ),
3278 # if ENABLE_HUSH_LOOPS
3279 FLAG_FOR = (1 << RES_FOR ),
3280 FLAG_WHILE = (1 << RES_WHILE),
3281 FLAG_UNTIL = (1 << RES_UNTIL),
3282 FLAG_DO = (1 << RES_DO ),
3283 FLAG_DONE = (1 << RES_DONE ),
3284 FLAG_IN = (1 << RES_IN ),
3286 # if ENABLE_HUSH_CASE
3287 FLAG_MATCH = (1 << RES_MATCH),
3288 FLAG_ESAC = (1 << RES_ESAC ),
3290 FLAG_START = (1 << RES_XXXX ),
3293 static const struct reserved_combo* match_reserved_word(o_string *word)
3295 /* Mostly a list of accepted follow-up reserved words.
3296 * FLAG_END means we are done with the sequence, and are ready
3297 * to turn the compound list into a command.
3298 * FLAG_START means the word must start a new compound list.
3300 static const struct reserved_combo reserved_list[] = {
3302 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3303 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3304 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3305 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3306 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3307 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3309 # if ENABLE_HUSH_LOOPS
3310 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3311 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3312 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3313 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3314 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3315 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3317 # if ENABLE_HUSH_CASE
3318 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3319 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3322 const struct reserved_combo *r;
3324 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3325 if (strcmp(word->data, r->literal) == 0)
3330 /* Return 0: not a keyword, 1: keyword
3332 static int reserved_word(o_string *word, struct parse_context *ctx)
3334 # if ENABLE_HUSH_CASE
3335 static const struct reserved_combo reserved_match = {
3336 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3339 const struct reserved_combo *r;
3341 if (word->has_quoted_part)
3343 r = match_reserved_word(word);
3347 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3348 # if ENABLE_HUSH_CASE
3349 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3350 /* "case word IN ..." - IN part starts first MATCH part */
3351 r = &reserved_match;
3354 if (r->flag == 0) { /* '!' */
3355 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3356 syntax_error("! ! command");
3357 ctx->ctx_res_w = RES_SNTX;
3359 ctx->ctx_inverted = 1;
3362 if (r->flag & FLAG_START) {
3363 struct parse_context *old;
3365 old = xmalloc(sizeof(*old));
3366 debug_printf_parse("push stack %p\n", old);
3367 *old = *ctx; /* physical copy */
3368 initialize_context(ctx);
3370 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3371 syntax_error_at(word->data);
3372 ctx->ctx_res_w = RES_SNTX;
3375 /* "{...} fi" is ok. "{...} if" is not
3377 * if { echo foo; } then { echo bar; } fi */
3378 if (ctx->command->group)
3379 done_pipe(ctx, PIPE_SEQ);
3382 ctx->ctx_res_w = r->res;
3383 ctx->old_flag = r->flag;
3384 word->o_assignment = r->assignment_flag;
3385 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3387 if (ctx->old_flag & FLAG_END) {
3388 struct parse_context *old;
3390 done_pipe(ctx, PIPE_SEQ);
3391 debug_printf_parse("pop stack %p\n", ctx->stack);
3393 old->command->group = ctx->list_head;
3394 old->command->cmd_type = CMD_NORMAL;
3396 /* At this point, the compound command's string is in
3397 * ctx->as_string... except for the leading keyword!
3398 * Consider this example: "echo a | if true; then echo a; fi"
3399 * ctx->as_string will contain "true; then echo a; fi",
3400 * with "if " remaining in old->as_string!
3404 int len = old->as_string.length;
3405 /* Concatenate halves */
3406 o_addstr(&old->as_string, ctx->as_string.data);
3407 o_free_unsafe(&ctx->as_string);
3408 /* Find where leading keyword starts in first half */
3409 str = old->as_string.data + len;
3410 if (str > old->as_string.data)
3411 str--; /* skip whitespace after keyword */
3412 while (str > old->as_string.data && isalpha(str[-1]))
3414 /* Ugh, we're done with this horrid hack */
3415 old->command->group_as_string = xstrdup(str);
3416 debug_printf_parse("pop, remembering as:'%s'\n",
3417 old->command->group_as_string);
3420 *ctx = *old; /* physical copy */
3425 #endif /* HAS_KEYWORDS */
3427 /* Word is complete, look at it and update parsing context.
3428 * Normal return is 0. Syntax errors return 1.
3429 * Note: on return, word is reset, but not o_free'd!
3431 static int done_word(o_string *word, struct parse_context *ctx)
3433 struct command *command = ctx->command;
3435 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3436 if (word->length == 0 && !word->has_quoted_part) {
3437 debug_printf_parse("done_word return 0: true null, ignored\n");
3441 if (ctx->pending_redirect) {
3442 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3443 * only if run as "bash", not "sh" */
3444 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3446 * ...the word that follows the redirection operator
3447 * shall be subjected to tilde expansion, parameter expansion,
3448 * command substitution, arithmetic expansion, and quote
3449 * removal. Pathname expansion shall not be performed
3450 * on the word by a non-interactive shell; an interactive
3451 * shell may perform it, but shall do so only when
3452 * the expansion would result in one word."
3454 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3455 /* Cater for >\file case:
3456 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3457 * Same with heredocs:
3458 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3460 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3461 unbackslash(ctx->pending_redirect->rd_filename);
3462 /* Is it <<"HEREDOC"? */
3463 if (word->has_quoted_part) {
3464 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3467 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3468 ctx->pending_redirect = NULL;
3471 # if ENABLE_HUSH_CASE
3472 if (ctx->ctx_dsemicolon
3473 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3475 /* already done when ctx_dsemicolon was set to 1: */
3476 /* ctx->ctx_res_w = RES_MATCH; */
3477 ctx->ctx_dsemicolon = 0;
3480 if (!command->argv /* if it's the first word... */
3481 # if ENABLE_HUSH_LOOPS
3482 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3483 && ctx->ctx_res_w != RES_IN
3485 # if ENABLE_HUSH_CASE
3486 && ctx->ctx_res_w != RES_CASE
3489 int reserved = reserved_word(word, ctx);
3490 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3492 o_reset_to_empty_unquoted(word);
3493 debug_printf_parse("done_word return %d\n",
3494 (ctx->ctx_res_w == RES_SNTX));
3495 return (ctx->ctx_res_w == RES_SNTX);
3497 # if ENABLE_HUSH_BASH_COMPAT
3498 if (strcmp(word->data, "[[") == 0) {
3499 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3505 if (command->group) {
3506 /* "{ echo foo; } echo bar" - bad */
3507 syntax_error_at(word->data);
3508 debug_printf_parse("done_word return 1: syntax error, "
3509 "groups and arglists don't mix\n");
3513 /* If this word wasn't an assignment, next ones definitely
3514 * can't be assignments. Even if they look like ones. */
3515 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3516 && word->o_assignment != WORD_IS_KEYWORD
3518 word->o_assignment = NOT_ASSIGNMENT;
3520 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3521 command->assignment_cnt++;
3522 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3524 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3525 word->o_assignment = MAYBE_ASSIGNMENT;
3527 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3529 if (word->has_quoted_part
3530 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3531 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3532 /* (otherwise it's known to be not empty and is already safe) */
3534 /* exclude "$@" - it can expand to no word despite "" */
3535 char *p = word->data;
3536 while (p[0] == SPECIAL_VAR_SYMBOL
3537 && (p[1] & 0x7f) == '@'
3538 && p[2] == SPECIAL_VAR_SYMBOL
3543 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3544 debug_print_strings("word appended to argv", command->argv);
3547 #if ENABLE_HUSH_LOOPS
3548 if (ctx->ctx_res_w == RES_FOR) {
3549 if (word->has_quoted_part
3550 || !is_well_formed_var_name(command->argv[0], '\0')
3552 /* bash says just "not a valid identifier" */
3553 syntax_error("not a valid identifier in for");
3556 /* Force FOR to have just one word (variable name) */
3557 /* NB: basically, this makes hush see "for v in ..."
3558 * syntax as if it is "for v; in ...". FOR and IN become
3559 * two pipe structs in parse tree. */
3560 done_pipe(ctx, PIPE_SEQ);
3563 #if ENABLE_HUSH_CASE
3564 /* Force CASE to have just one word */
3565 if (ctx->ctx_res_w == RES_CASE) {
3566 done_pipe(ctx, PIPE_SEQ);
3570 o_reset_to_empty_unquoted(word);
3572 debug_printf_parse("done_word return 0\n");
3577 /* Peek ahead in the input to find out if we have a "&n" construct,
3578 * as in "2>&1", that represents duplicating a file descriptor.
3580 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3581 * REDIRFD_SYNTAX_ERR if syntax error,
3582 * REDIRFD_TO_FILE if no & was seen,
3583 * or the number found.
3586 #define parse_redir_right_fd(as_string, input) \
3587 parse_redir_right_fd(input)
3589 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3595 return REDIRFD_TO_FILE;
3597 ch = i_getch(input); /* get the & */
3598 nommu_addchr(as_string, ch);
3601 ch = i_getch(input);
3602 nommu_addchr(as_string, ch);
3603 return REDIRFD_CLOSE;
3607 while (ch != EOF && isdigit(ch)) {
3608 d = d*10 + (ch-'0');
3610 ch = i_getch(input);
3611 nommu_addchr(as_string, ch);
3616 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3618 bb_error_msg("ambiguous redirect");
3619 return REDIRFD_SYNTAX_ERR;
3622 /* Return code is 0 normal, 1 if a syntax error is detected
3624 static int parse_redirect(struct parse_context *ctx,
3627 struct in_str *input)
3629 struct command *command = ctx->command;
3630 struct redir_struct *redir;
3631 struct redir_struct **redirp;
3634 dup_num = REDIRFD_TO_FILE;
3635 if (style != REDIRECT_HEREDOC) {
3636 /* Check for a '>&1' type redirect */
3637 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3638 if (dup_num == REDIRFD_SYNTAX_ERR)
3641 int ch = i_peek(input);
3642 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3643 if (dup_num) { /* <<-... */
3644 ch = i_getch(input);
3645 nommu_addchr(&ctx->as_string, ch);
3650 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3651 int ch = i_peek(input);
3653 /* >|FILE redirect ("clobbering" >).
3654 * Since we do not support "set -o noclobber" yet,
3655 * >| and > are the same for now. Just eat |.
3657 ch = i_getch(input);
3658 nommu_addchr(&ctx->as_string, ch);
3662 /* Create a new redir_struct and append it to the linked list */
3663 redirp = &command->redirects;
3664 while ((redir = *redirp) != NULL) {
3665 redirp = &(redir->next);
3667 *redirp = redir = xzalloc(sizeof(*redir));
3668 /* redir->next = NULL; */
3669 /* redir->rd_filename = NULL; */
3670 redir->rd_type = style;
3671 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3673 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3674 redir_table[style].descrip);
3676 redir->rd_dup = dup_num;
3677 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3678 /* Erik had a check here that the file descriptor in question
3679 * is legit; I postpone that to "run time"
3680 * A "-" representation of "close me" shows up as a -3 here */
3681 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3682 redir->rd_fd, redir->rd_dup);
3684 #if 0 /* Instead we emit error message at run time */
3685 if (ctx->pending_redirect) {
3686 /* For example, "cmd > <file" */
3687 die_if_script("syntax error: %s", "invalid redirect");
3690 /* Set ctx->pending_redirect, so we know what to do at the
3691 * end of the next parsed word. */
3692 ctx->pending_redirect = redir;
3697 /* If a redirect is immediately preceded by a number, that number is
3698 * supposed to tell which file descriptor to redirect. This routine
3699 * looks for such preceding numbers. In an ideal world this routine
3700 * needs to handle all the following classes of redirects...
3701 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3702 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3703 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3704 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3706 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3708 * ... If n is quoted, the number shall not be recognized as part of
3709 * the redirection expression. For example:
3711 * writes the character 2 into file a"
3712 * We are getting it right by setting ->has_quoted_part on any \<char>
3714 * A -1 return means no valid number was found,
3715 * the caller should use the appropriate default for this redirection.
3717 static int redirect_opt_num(o_string *o)
3721 if (o->data == NULL)
3723 num = bb_strtou(o->data, NULL, 10);
3724 if (errno || num < 0)
3726 o_reset_to_empty_unquoted(o);
3731 #define fetch_till_str(as_string, input, word, skip_tabs) \
3732 fetch_till_str(input, word, skip_tabs)
3734 static char *fetch_till_str(o_string *as_string,
3735 struct in_str *input,
3739 o_string heredoc = NULL_O_STRING;
3741 int prev = 0; /* not \ */
3747 ch = i_getch(input);
3749 nommu_addchr(as_string, ch);
3750 if ((ch == '\n' || ch == EOF)
3751 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3753 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3754 heredoc.data[past_EOL] = '\0';
3755 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3756 return heredoc.data;
3758 while (ch == '\n') {
3759 o_addchr(&heredoc, ch);
3762 past_EOL = heredoc.length;
3764 ch = i_getch(input);
3766 nommu_addchr(as_string, ch);
3767 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3771 o_free_unsafe(&heredoc);
3774 o_addchr(&heredoc, ch);
3775 nommu_addchr(as_string, ch);
3776 if (prev == '\\' && ch == '\\')
3777 /* Correctly handle foo\\<eol> (not a line cont.) */
3778 prev = 0; /* not \ */
3784 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3785 * and load them all. There should be exactly heredoc_cnt of them.
3787 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3789 struct pipe *pi = ctx->list_head;
3791 while (pi && heredoc_cnt) {
3793 struct command *cmd = pi->cmds;
3795 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3797 cmd->argv ? cmd->argv[0] : "NONE");
3798 for (i = 0; i < pi->num_cmds; i++) {
3799 struct redir_struct *redir = cmd->redirects;
3801 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3802 i, cmd->argv ? cmd->argv[0] : "NONE");
3804 if (redir->rd_type == REDIRECT_HEREDOC) {
3807 redir->rd_type = REDIRECT_HEREDOC2;
3808 /* redir->rd_dup is (ab)used to indicate <<- */
3809 p = fetch_till_str(&ctx->as_string, input,
3810 redir->rd_filename, redir->rd_dup);
3812 syntax_error("unexpected EOF in here document");
3815 free(redir->rd_filename);
3816 redir->rd_filename = p;
3819 redir = redir->next;
3826 /* Should be 0. If it isn't, it's a parse error */
3828 bb_error_msg_and_die("heredoc BUG 2");
3834 static int run_list(struct pipe *pi);
3836 #define parse_stream(pstring, input, end_trigger) \
3837 parse_stream(input, end_trigger)
3839 static struct pipe *parse_stream(char **pstring,
3840 struct in_str *input,
3844 #if !ENABLE_HUSH_FUNCTIONS
3845 #define parse_group(dest, ctx, input, ch) \
3846 parse_group(ctx, input, ch)
3848 static int parse_group(o_string *dest, struct parse_context *ctx,
3849 struct in_str *input, int ch)
3851 /* dest contains characters seen prior to ( or {.
3852 * Typically it's empty, but for function defs,
3853 * it contains function name (without '()'). */
3854 struct pipe *pipe_list;
3856 struct command *command = ctx->command;
3858 debug_printf_parse("parse_group entered\n");
3859 #if ENABLE_HUSH_FUNCTIONS
3860 if (ch == '(' && !dest->has_quoted_part) {
3862 if (done_word(dest, ctx))
3865 goto skip; /* (... */
3866 if (command->argv[1]) { /* word word ... (... */
3867 syntax_error_unexpected_ch('(');
3870 /* it is "word(..." or "word (..." */
3872 ch = i_getch(input);
3873 while (ch == ' ' || ch == '\t');
3875 syntax_error_unexpected_ch(ch);
3878 nommu_addchr(&ctx->as_string, ch);
3880 ch = i_getch(input);
3881 while (ch == ' ' || ch == '\t' || ch == '\n');
3883 syntax_error_unexpected_ch(ch);
3886 nommu_addchr(&ctx->as_string, ch);
3887 command->cmd_type = CMD_FUNCDEF;
3892 #if 0 /* Prevented by caller */
3893 if (command->argv /* word [word]{... */
3894 || dest->length /* word{... */
3895 || dest->has_quoted_part /* ""{... */
3898 debug_printf_parse("parse_group return 1: "
3899 "syntax error, groups and arglists don't mix\n");
3904 #if ENABLE_HUSH_FUNCTIONS
3910 command->cmd_type = CMD_SUBSHELL;
3912 /* bash does not allow "{echo...", requires whitespace */
3914 if (ch != ' ' && ch != '\t' && ch != '\n'
3915 && ch != '(' /* but "{(..." is allowed (without whitespace) */
3917 syntax_error_unexpected_ch(ch);
3921 ch = i_getch(input);
3922 nommu_addchr(&ctx->as_string, ch);
3928 # define as_string NULL
3930 char *as_string = NULL;
3932 pipe_list = parse_stream(&as_string, input, endch);
3935 o_addstr(&ctx->as_string, as_string);
3937 /* empty ()/{} or parse error? */
3938 if (!pipe_list || pipe_list == ERR_PTR) {
3939 /* parse_stream already emitted error msg */
3942 debug_printf_parse("parse_group return 1: "
3943 "parse_stream returned %p\n", pipe_list);
3946 command->group = pipe_list;
3948 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3949 command->group_as_string = as_string;
3950 debug_printf_parse("end of group, remembering as:'%s'\n",
3951 command->group_as_string);
3955 debug_printf_parse("parse_group return 0\n");
3957 /* command remains "open", available for possible redirects */
3960 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3965 ch = i_getch(input);
3968 ch2 = i_peek(input);
3971 /* backslash+newline, skip it */
3976 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3984 ch2 = i_peek2(input);
3987 /* backslash+newline, skip it */
3993 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3994 /* Subroutines for copying $(...) and `...` things */
3995 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3997 static int add_till_single_quote(o_string *dest, struct in_str *input)
4000 int ch = i_getch(input);
4002 syntax_error_unterm_ch('\'');
4010 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4011 static int add_till_double_quote(o_string *dest, struct in_str *input)
4014 int ch = i_getch(input);
4016 syntax_error_unterm_ch('"');
4021 if (ch == '\\') { /* \x. Copy both chars. */
4023 ch = i_getch(input);
4027 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4032 //if (ch == '$') ...
4035 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4037 * "Within the backquoted style of command substitution, backslash
4038 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4039 * The search for the matching backquote shall be satisfied by the first
4040 * backquote found without a preceding backslash; during this search,
4041 * if a non-escaped backquote is encountered within a shell comment,
4042 * a here-document, an embedded command substitution of the $(command)
4043 * form, or a quoted string, undefined results occur. A single-quoted
4044 * or double-quoted string that begins, but does not end, within the
4045 * "`...`" sequence produces undefined results."
4047 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4049 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4052 int ch = i_getch(input);
4056 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4057 ch = i_getch(input);
4061 && (!in_dquote || ch != '"')
4063 o_addchr(dest, '\\');
4067 syntax_error_unterm_ch('`');
4073 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4074 * quoting and nested ()s.
4075 * "With the $(command) style of command substitution, all characters
4076 * following the open parenthesis to the matching closing parenthesis
4077 * constitute the command. Any valid shell script can be used for command,
4078 * except a script consisting solely of redirections which produces
4079 * unspecified results."
4081 * echo $(echo '(TEST)' BEST) (TEST) BEST
4082 * echo $(echo 'TEST)' BEST) TEST) BEST
4083 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4085 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4086 * can contain arbitrary constructs, just like $(cmd).
4087 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4088 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4090 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4091 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4094 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4095 # if ENABLE_HUSH_BASH_COMPAT
4096 char end_char2 = end_ch >> 8;
4098 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4101 ch = i_getch(input);
4103 syntax_error_unterm_ch(end_ch);
4106 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4109 /* we look for closing )) of $((EXPR)) */
4110 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4111 i_getch(input); /* eat second ')' */
4116 if (ch == '(' || ch == '{') {
4117 ch = (ch == '(' ? ')' : '}');
4118 if (!add_till_closing_bracket(dest, input, ch))
4124 if (!add_till_single_quote(dest, input))
4130 if (!add_till_double_quote(dest, input))
4136 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4142 /* \x. Copy verbatim. Important for \(, \) */
4143 ch = i_getch(input);
4145 syntax_error_unterm_ch(')');
4150 /* "backslash+newline", ignore both */
4151 o_delchr(dest); /* undo insertion of '\' */
4161 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4163 /* Return code: 0 for OK, 1 for syntax error */
4165 #define parse_dollar(as_string, dest, input, quote_mask) \
4166 parse_dollar(dest, input, quote_mask)
4167 #define as_string NULL
4169 static int parse_dollar(o_string *as_string,
4171 struct in_str *input, unsigned char quote_mask)
4173 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4175 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4177 ch = i_getch(input);
4178 nommu_addchr(as_string, ch);
4180 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4182 debug_printf_parse(": '%c'\n", ch);
4183 o_addchr(dest, ch | quote_mask);
4185 ch = i_peek_and_eat_bkslash_nl(input);
4186 if (!isalnum(ch) && ch != '_') {
4187 /* End of variable name reached */
4190 ch = i_getch(input);
4191 nommu_addchr(as_string, ch);
4193 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4194 } else if (isdigit(ch)) {
4196 ch = i_getch(input);
4197 nommu_addchr(as_string, ch);
4198 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4199 debug_printf_parse(": '%c'\n", ch);
4200 o_addchr(dest, ch | quote_mask);
4201 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4202 } else switch (ch) {
4204 case '!': /* last bg pid */
4205 case '?': /* last exit code */
4206 case '#': /* number of args */
4207 case '*': /* args */
4208 case '@': /* args */
4209 goto make_one_char_var;
4211 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4213 ch = i_getch(input); /* eat '{' */
4214 nommu_addchr(as_string, ch);
4216 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4217 /* It should be ${?}, or ${#var},
4218 * or even ${?+subst} - operator acting on a special variable,
4219 * or the beginning of variable name.
4222 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4225 syntax_error_unterm_str("${name}");
4226 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4229 nommu_addchr(as_string, ch);
4232 /* It's possible to just call add_till_closing_bracket() at this point.
4233 * However, this regresses some of our testsuite cases
4234 * which check invalid constructs like ${%}.
4235 * Oh well... let's check that the var name part is fine... */
4241 debug_printf_parse(": '%c'\n", ch);
4243 ch = i_getch(input);
4244 nommu_addchr(as_string, ch);
4248 if (!isalnum(ch) && ch != '_') {
4250 unsigned char last_ch;
4251 /* handle parameter expansions
4252 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4254 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4255 goto bad_dollar_syntax;
4257 /* Eat everything until closing '}' (or ':') */
4259 if (ENABLE_HUSH_BASH_COMPAT
4261 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4263 /* It's ${var:N[:M]} thing */
4264 end_ch = '}' * 0x100 + ':';
4266 if (ENABLE_HUSH_BASH_COMPAT
4269 /* It's ${var/[/]pattern[/repl]} thing */
4270 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4272 nommu_addchr(as_string, '/');
4275 end_ch = '}' * 0x100 + '/';
4281 #if ENABLE_HUSH_DOLLAR_OPS
4282 last_ch = add_till_closing_bracket(dest, input, end_ch);
4283 if (last_ch == 0) /* error? */
4286 #error Simple code to only allow ${var} is not implemented
4289 o_addstr(as_string, dest->data + pos);
4290 o_addchr(as_string, last_ch);
4293 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4294 /* close the first block: */
4295 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4296 /* while parsing N from ${var:N[:M]}
4297 * or pattern from ${var/[/]pattern[/repl]} */
4298 if ((end_ch & 0xff) == last_ch) {
4299 /* got ':' or '/'- parse the rest */
4304 if (end_ch == '}' * 0x100 + ':') {
4305 /* it's ${var:N} - emulate :999999999 */
4306 o_addstr(dest, "999999999");
4307 } /* else: it's ${var/[/]pattern} */
4312 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4315 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4319 ch = i_getch(input);
4320 nommu_addchr(as_string, ch);
4321 # if ENABLE_SH_MATH_SUPPORT
4322 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4323 ch = i_getch(input);
4324 nommu_addchr(as_string, ch);
4325 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4326 o_addchr(dest, /*quote_mask |*/ '+');
4329 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4330 return 0; /* error */
4332 o_addstr(as_string, dest->data + pos);
4333 o_addchr(as_string, ')');
4334 o_addchr(as_string, ')');
4336 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4340 # if ENABLE_HUSH_TICK
4341 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4342 o_addchr(dest, quote_mask | '`');
4345 if (!add_till_closing_bracket(dest, input, ')'))
4346 return 0; /* error */
4348 o_addstr(as_string, dest->data + pos);
4349 o_addchr(as_string, ')');
4351 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4357 ch = i_getch(input);
4358 nommu_addchr(as_string, ch);
4359 ch = i_peek_and_eat_bkslash_nl(input);
4360 if (isalnum(ch)) { /* it's $_name or $_123 */
4365 /* TODO: $_ and $-: */
4366 /* $_ Shell or shell script name; or last argument of last command
4367 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4368 * but in command's env, set to full pathname used to invoke it */
4369 /* $- Option flags set by set builtin or shell options (-i etc) */
4371 o_addQchr(dest, '$');
4373 debug_printf_parse("parse_dollar return 1 (ok)\n");
4379 # if ENABLE_HUSH_BASH_COMPAT
4380 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4381 encode_string(dest, input, dquote_end, process_bkslash)
4383 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4384 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4385 encode_string(dest, input, dquote_end)
4387 #define as_string NULL
4391 # if ENABLE_HUSH_BASH_COMPAT
4392 /* all parameters are needed, no macro tricks */
4394 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4395 encode_string(as_string, dest, input, dquote_end)
4398 static int encode_string(o_string *as_string,
4400 struct in_str *input,
4402 int process_bkslash)
4404 #if !ENABLE_HUSH_BASH_COMPAT
4405 const int process_bkslash = 1;
4411 ch = i_getch(input);
4413 nommu_addchr(as_string, ch);
4414 if (ch == dquote_end) { /* may be only '"' or EOF */
4415 debug_printf_parse("encode_string return 1 (ok)\n");
4418 /* note: can't move it above ch == dquote_end check! */
4420 syntax_error_unterm_ch('"');
4421 return 0; /* error */
4425 next = i_peek(input);
4427 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4428 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4429 if (process_bkslash && ch == '\\') {
4431 syntax_error("\\<eof>");
4435 * "The backslash retains its special meaning [in "..."]
4436 * only when followed by one of the following characters:
4437 * $, `, ", \, or <newline>. A double quote may be quoted
4438 * within double quotes by preceding it with a backslash."
4439 * NB: in (unquoted) heredoc, above does not apply to ",
4440 * therefore we check for it by "next == dquote_end" cond.
4442 if (next == dquote_end || strchr("$`\\\n", next)) {
4443 ch = i_getch(input); /* eat next */
4445 goto again; /* skip \<newline> */
4446 } /* else: ch remains == '\\', and we double it below: */
4447 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4448 nommu_addchr(as_string, ch);
4452 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4453 debug_printf_parse("encode_string return 0: "
4454 "parse_dollar returned 0 (error)\n");
4459 #if ENABLE_HUSH_TICK
4461 //unsigned pos = dest->length;
4462 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4463 o_addchr(dest, 0x80 | '`');
4464 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4465 return 0; /* error */
4466 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4467 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4471 o_addQchr(dest, ch);
4477 * Scan input until EOF or end_trigger char.
4478 * Return a list of pipes to execute, or NULL on EOF
4479 * or if end_trigger character is met.
4480 * On syntax error, exit if shell is not interactive,
4481 * reset parsing machinery and start parsing anew,
4482 * or return ERR_PTR.
4484 static struct pipe *parse_stream(char **pstring,
4485 struct in_str *input,
4488 struct parse_context ctx;
4489 o_string dest = NULL_O_STRING;
4492 /* Single-quote triggers a bypass of the main loop until its mate is
4493 * found. When recursing, quote state is passed in via dest->o_expflags.
4495 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4496 end_trigger ? end_trigger : 'X');
4499 /* If very first arg is "" or '', dest.data may end up NULL.
4500 * Preventing this: */
4501 o_addchr(&dest, '\0');
4504 /* We used to separate words on $IFS here. This was wrong.
4505 * $IFS is used only for word splitting when $var is expanded,
4506 * here we should use blank chars as separators, not $IFS
4509 if (MAYBE_ASSIGNMENT != 0)
4510 dest.o_assignment = MAYBE_ASSIGNMENT;
4511 initialize_context(&ctx);
4514 const char *is_blank;
4515 const char *is_special;
4519 redir_type redir_style;
4521 ch = i_getch(input);
4522 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4523 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4528 syntax_error_unterm_str("here document");
4531 if (end_trigger == ')') {
4532 syntax_error_unterm_ch('(');
4535 if (end_trigger == '}') {
4536 syntax_error_unterm_ch('{');
4540 if (done_word(&dest, &ctx)) {
4544 done_pipe(&ctx, PIPE_SEQ);
4546 /* If we got nothing... */
4547 /* (this makes bare "&" cmd a no-op.
4548 * bash says: "syntax error near unexpected token '&'") */
4549 if (pi->num_cmds == 0
4550 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4556 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4558 *pstring = ctx.as_string.data;
4560 o_free_unsafe(&ctx.as_string);
4563 debug_printf_parse("parse_stream return %p\n", pi);
4566 nommu_addchr(&ctx.as_string, ch);
4570 next = i_peek(input);
4572 is_special = "{}<>;&|()#'" /* special outside of "str" */
4573 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4574 /* Are { and } special here? */
4575 if (ctx.command->argv /* word [word]{... - non-special */
4576 || dest.length /* word{... - non-special */
4577 || dest.has_quoted_part /* ""{... - non-special */
4578 || (next != ';' /* }; - special */
4579 && next != ')' /* }) - special */
4580 && next != '(' /* {( - special */
4581 && next != '&' /* }& and }&& ... - special */
4582 && next != '|' /* }|| ... - special */
4583 && !strchr(defifs, next) /* {word - non-special */
4586 /* They are not special, skip "{}" */
4589 is_special = strchr(is_special, ch);
4590 is_blank = strchr(defifs, ch);
4592 if (!is_special && !is_blank) { /* ordinary char */
4594 o_addQchr(&dest, ch);
4595 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4596 || dest.o_assignment == WORD_IS_KEYWORD)
4598 && is_well_formed_var_name(dest.data, '=')
4600 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4601 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4607 if (done_word(&dest, &ctx)) {
4611 /* Is this a case when newline is simply ignored?
4613 * "cmd | <newline> cmd ..."
4614 * "case ... in <newline> word) ..."
4616 if (IS_NULL_CMD(ctx.command)
4617 && dest.length == 0 && !dest.has_quoted_part
4619 /* This newline can be ignored. But...
4620 * Without check #1, interactive shell
4621 * ignores even bare <newline>,
4622 * and shows the continuation prompt:
4623 * ps1_prompt$ <enter>
4624 * ps2> _ <=== wrong, should be ps1
4625 * Without check #2, "cmd & <newline>"
4626 * is similarly mistreated.
4627 * (BTW, this makes "cmd & cmd"
4628 * and "cmd && cmd" non-orthogonal.
4629 * Really, ask yourself, why
4630 * "cmd && <newline>" doesn't start
4631 * cmd but waits for more input?
4634 struct pipe *pi = ctx.list_head;
4635 if (pi->num_cmds != 0 /* check #1 */
4636 && pi->followup != PIPE_BG /* check #2 */
4641 /* Treat newline as a command separator. */
4642 done_pipe(&ctx, PIPE_SEQ);
4643 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4645 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4650 dest.o_assignment = MAYBE_ASSIGNMENT;
4651 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4653 /* note: if (is_blank) continue;
4654 * will still trigger for us */
4658 /* "cmd}" or "cmd }..." without semicolon or &:
4659 * } is an ordinary char in this case, even inside { cmd; }
4660 * Pathological example: { ""}; } should exec "}" cmd
4663 if (dest.length != 0 /* word} */
4664 || dest.has_quoted_part /* ""} */
4668 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4669 /* Generally, there should be semicolon: "cmd; }"
4670 * However, bash allows to omit it if "cmd" is
4671 * a group. Examples:
4674 * { echo 0 >&2 | { echo 1; } }
4675 * { while false; do :; done }
4676 * { case a in b) ;; esac }
4678 if (ctx.command->group)
4682 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4683 /* Can't be an end of {cmd}, skip the check */
4684 goto skip_end_trigger;
4685 /* else: } does terminate a group */
4688 if (end_trigger && end_trigger == ch
4689 && (ch != ';' || heredoc_cnt == 0)
4690 #if ENABLE_HUSH_CASE
4692 || ctx.ctx_res_w != RES_MATCH
4693 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4698 /* This is technically valid:
4699 * { cat <<HERE; }; echo Ok
4703 * but we don't support this.
4704 * We require heredoc to be in enclosing {}/(),
4707 syntax_error_unterm_str("here document");
4710 if (done_word(&dest, &ctx)) {
4713 done_pipe(&ctx, PIPE_SEQ);
4714 dest.o_assignment = MAYBE_ASSIGNMENT;
4715 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4716 /* Do we sit outside of any if's, loops or case's? */
4718 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4722 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4724 *pstring = ctx.as_string.data;
4726 o_free_unsafe(&ctx.as_string);
4729 debug_printf_parse("parse_stream return %p: "
4730 "end_trigger char found\n",
4732 return ctx.list_head;
4739 /* Catch <, > before deciding whether this word is
4740 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4743 redir_fd = redirect_opt_num(&dest);
4744 if (done_word(&dest, &ctx)) {
4747 redir_style = REDIRECT_OVERWRITE;
4749 redir_style = REDIRECT_APPEND;
4750 ch = i_getch(input);
4751 nommu_addchr(&ctx.as_string, ch);
4754 else if (next == '(') {
4755 syntax_error(">(process) not supported");
4759 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4761 continue; /* back to top of while (1) */
4763 redir_fd = redirect_opt_num(&dest);
4764 if (done_word(&dest, &ctx)) {
4767 redir_style = REDIRECT_INPUT;
4769 redir_style = REDIRECT_HEREDOC;
4771 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4772 ch = i_getch(input);
4773 nommu_addchr(&ctx.as_string, ch);
4774 } else if (next == '>') {
4775 redir_style = REDIRECT_IO;
4776 ch = i_getch(input);
4777 nommu_addchr(&ctx.as_string, ch);
4780 else if (next == '(') {
4781 syntax_error("<(process) not supported");
4785 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4787 continue; /* back to top of while (1) */
4789 if (dest.length == 0 && !dest.has_quoted_part) {
4790 /* skip "#comment" */
4793 if (ch == EOF || ch == '\n')
4796 /* note: we do not add it to &ctx.as_string */
4798 nommu_addchr(&ctx.as_string, '\n');
4799 continue; /* back to top of while (1) */
4804 /* It's "\<newline>" */
4806 /* Remove trailing '\' from ctx.as_string */
4807 ctx.as_string.data[--ctx.as_string.length] = '\0';
4809 ch = i_getch(input); /* eat it */
4810 continue; /* back to top of while (1) */
4815 if (dest.o_assignment == MAYBE_ASSIGNMENT
4816 /* check that we are not in word in "a=1 2>word b=1": */
4817 && !ctx.pending_redirect
4819 /* ch is a special char and thus this word
4820 * cannot be an assignment */
4821 dest.o_assignment = NOT_ASSIGNMENT;
4822 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4825 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4828 case '#': /* non-comment #: "echo a#b" etc */
4829 o_addQchr(&dest, ch);
4833 syntax_error("\\<eof>");
4836 ch = i_getch(input);
4837 /* note: ch != '\n' (that case does not reach this place) */
4838 o_addchr(&dest, '\\');
4839 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4840 o_addchr(&dest, ch);
4841 nommu_addchr(&ctx.as_string, ch);
4842 /* Example: echo Hello \2>file
4843 * we need to know that word 2 is quoted */
4844 dest.has_quoted_part = 1;
4847 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4848 debug_printf_parse("parse_stream parse error: "
4849 "parse_dollar returned 0 (error)\n");
4854 dest.has_quoted_part = 1;
4855 if (next == '\'' && !ctx.pending_redirect) {
4856 insert_empty_quoted_str_marker:
4857 nommu_addchr(&ctx.as_string, next);
4858 i_getch(input); /* eat second ' */
4859 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4860 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4863 ch = i_getch(input);
4865 syntax_error_unterm_ch('\'');
4868 nommu_addchr(&ctx.as_string, ch);
4871 o_addqchr(&dest, ch);
4876 dest.has_quoted_part = 1;
4877 if (next == '"' && !ctx.pending_redirect)
4878 goto insert_empty_quoted_str_marker;
4879 if (dest.o_assignment == NOT_ASSIGNMENT)
4880 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4881 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4883 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4885 #if ENABLE_HUSH_TICK
4887 USE_FOR_NOMMU(unsigned pos;)
4889 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4890 o_addchr(&dest, '`');
4891 USE_FOR_NOMMU(pos = dest.length;)
4892 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4895 o_addstr(&ctx.as_string, dest.data + pos);
4896 o_addchr(&ctx.as_string, '`');
4898 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4899 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4904 #if ENABLE_HUSH_CASE
4907 if (done_word(&dest, &ctx)) {
4910 done_pipe(&ctx, PIPE_SEQ);
4911 #if ENABLE_HUSH_CASE
4912 /* Eat multiple semicolons, detect
4913 * whether it means something special */
4918 ch = i_getch(input);
4919 nommu_addchr(&ctx.as_string, ch);
4920 if (ctx.ctx_res_w == RES_CASE_BODY) {
4921 ctx.ctx_dsemicolon = 1;
4922 ctx.ctx_res_w = RES_MATCH;
4928 /* We just finished a cmd. New one may start
4929 * with an assignment */
4930 dest.o_assignment = MAYBE_ASSIGNMENT;
4931 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4934 if (done_word(&dest, &ctx)) {
4938 ch = i_getch(input);
4939 nommu_addchr(&ctx.as_string, ch);
4940 done_pipe(&ctx, PIPE_AND);
4942 done_pipe(&ctx, PIPE_BG);
4946 if (done_word(&dest, &ctx)) {
4949 #if ENABLE_HUSH_CASE
4950 if (ctx.ctx_res_w == RES_MATCH)
4951 break; /* we are in case's "word | word)" */
4953 if (next == '|') { /* || */
4954 ch = i_getch(input);
4955 nommu_addchr(&ctx.as_string, ch);
4956 done_pipe(&ctx, PIPE_OR);
4958 /* we could pick up a file descriptor choice here
4959 * with redirect_opt_num(), but bash doesn't do it.
4960 * "echo foo 2| cat" yields "foo 2". */
4965 #if ENABLE_HUSH_CASE
4966 /* "case... in [(]word)..." - skip '(' */
4967 if (ctx.ctx_res_w == RES_MATCH
4968 && ctx.command->argv == NULL /* not (word|(... */
4969 && dest.length == 0 /* not word(... */
4970 && dest.has_quoted_part == 0 /* not ""(... */
4976 if (parse_group(&dest, &ctx, input, ch) != 0) {
4981 #if ENABLE_HUSH_CASE
4982 if (ctx.ctx_res_w == RES_MATCH)
4986 /* proper use of this character is caught by end_trigger:
4987 * if we see {, we call parse_group(..., end_trigger='}')
4988 * and it will match } earlier (not here). */
4989 syntax_error_unexpected_ch(ch);
4993 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4999 struct parse_context *pctx;
5000 IF_HAS_KEYWORDS(struct parse_context *p2;)
5002 /* Clean up allocated tree.
5003 * Sample for finding leaks on syntax error recovery path.
5004 * Run it from interactive shell, watch pmap `pidof hush`.
5005 * while if false; then false; fi; do break; fi
5006 * Samples to catch leaks at execution:
5007 * while if (true | { true;}); then echo ok; fi; do break; done
5008 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5012 /* Update pipe/command counts,
5013 * otherwise freeing may miss some */
5014 done_pipe(pctx, PIPE_SEQ);
5015 debug_printf_clean("freeing list %p from ctx %p\n",
5016 pctx->list_head, pctx);
5017 debug_print_tree(pctx->list_head, 0);
5018 free_pipe_list(pctx->list_head);
5019 debug_printf_clean("freed list %p\n", pctx->list_head);
5021 o_free_unsafe(&pctx->as_string);
5023 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5027 IF_HAS_KEYWORDS(pctx = p2;)
5028 } while (HAS_KEYWORDS && pctx);
5031 G.last_exitcode = 1;
5042 /*** Execution routines ***/
5044 /* Expansion can recurse, need forward decls: */
5045 #if !ENABLE_HUSH_BASH_COMPAT
5046 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5047 #define expand_string_to_string(str, do_unbackslash) \
5048 expand_string_to_string(str)
5050 static char *expand_string_to_string(const char *str, int do_unbackslash);
5051 #if ENABLE_HUSH_TICK
5052 static int process_command_subs(o_string *dest, const char *s);
5055 /* expand_strvec_to_strvec() takes a list of strings, expands
5056 * all variable references within and returns a pointer to
5057 * a list of expanded strings, possibly with larger number
5058 * of strings. (Think VAR="a b"; echo $VAR).
5059 * This new list is allocated as a single malloc block.
5060 * NULL-terminated list of char* pointers is at the beginning of it,
5061 * followed by strings themselves.
5062 * Caller can deallocate entire list by single free(list). */
5064 /* A horde of its helpers come first: */
5066 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5068 while (--len >= 0) {
5071 #if ENABLE_HUSH_BRACE_EXPANSION
5072 if (c == '{' || c == '}') {
5073 /* { -> \{, } -> \} */
5075 /* And now we want to add { or } and continue:
5078 * luckily, just falling throught achieves this.
5084 /* \z -> \\\z; \<eol> -> \\<eol> */
5089 o_addchr(o, *str++);
5095 /* Store given string, finalizing the word and starting new one whenever
5096 * we encounter IFS char(s). This is used for expanding variable values.
5097 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5098 * Return in *ended_with_ifs:
5099 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5101 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5103 int last_is_ifs = 0;
5108 if (!*str) /* EOL - do not finalize word */
5110 word_len = strcspn(str, G.ifs);
5112 /* We have WORD_LEN leading non-IFS chars */
5113 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5114 o_addblock(output, str, word_len);
5116 /* Protect backslashes against globbing up :)
5117 * Example: "v='\*'; echo b$v" prints "b\*"
5118 * (and does not try to glob on "*")
5120 o_addblock_duplicate_backslash(output, str, word_len);
5121 /*/ Why can't we do it easier? */
5122 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5123 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5127 if (!*str) /* EOL - do not finalize word */
5131 /* We know str here points to at least one IFS char */
5133 str += strspn(str, G.ifs); /* skip IFS chars */
5134 if (!*str) /* EOL - do not finalize word */
5137 /* Start new word... but not always! */
5138 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5139 if (output->has_quoted_part
5140 /* Case "v=' a'; echo $v":
5141 * here nothing precedes the space in $v expansion,
5142 * therefore we should not finish the word
5143 * (IOW: if there *is* word to finalize, only then do it):
5145 || (n > 0 && output->data[output->length - 1])
5147 o_addchr(output, '\0');
5148 debug_print_list("expand_on_ifs", output, n);
5149 n = o_save_ptr(output, n);
5154 *ended_with_ifs = last_is_ifs;
5155 debug_print_list("expand_on_ifs[1]", output, n);
5159 /* Helper to expand $((...)) and heredoc body. These act as if
5160 * they are in double quotes, with the exception that they are not :).
5161 * Just the rules are similar: "expand only $var and `cmd`"
5163 * Returns malloced string.
5164 * As an optimization, we return NULL if expansion is not needed.
5166 #if !ENABLE_HUSH_BASH_COMPAT
5167 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5168 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5169 encode_then_expand_string(str)
5171 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5174 struct in_str input;
5175 o_string dest = NULL_O_STRING;
5177 if (!strchr(str, '$')
5178 && !strchr(str, '\\')
5179 #if ENABLE_HUSH_TICK
5180 && !strchr(str, '`')
5186 /* We need to expand. Example:
5187 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5189 setup_string_in_str(&input, str);
5190 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5191 //TODO: error check (encode_string returns 0 on error)?
5192 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5193 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5194 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5195 o_free_unsafe(&dest);
5199 #if ENABLE_SH_MATH_SUPPORT
5200 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5202 arith_state_t math_state;
5206 math_state.lookupvar = get_local_var_value;
5207 math_state.setvar = set_local_var_from_halves;
5208 //math_state.endofname = endofname;
5209 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5210 res = arith(&math_state, exp_str ? exp_str : arg);
5213 *errmsg_p = math_state.errmsg;
5214 if (math_state.errmsg)
5215 die_if_script(math_state.errmsg);
5220 #if ENABLE_HUSH_BASH_COMPAT
5221 /* ${var/[/]pattern[/repl]} helpers */
5222 static char *strstr_pattern(char *val, const char *pattern, int *size)
5225 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5226 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5233 /* Optimization: if "*pat" did not match the start of "string",
5234 * we know that "tring", "ring" etc will not match too:
5236 if (pattern[0] == '*')
5241 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5243 char *result = NULL;
5244 unsigned res_len = 0;
5245 unsigned repl_len = strlen(repl);
5249 char *s = strstr_pattern(val, pattern, &size);
5253 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5254 memcpy(result + res_len, val, s - val);
5256 strcpy(result + res_len, repl);
5257 res_len += repl_len;
5258 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5264 if (val[0] && result) {
5265 result = xrealloc(result, res_len + strlen(val) + 1);
5266 strcpy(result + res_len, val);
5267 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5269 debug_printf_varexp("result:'%s'\n", result);
5275 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5277 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5279 const char *val = NULL;
5280 char *to_be_freed = NULL;
5285 char exp_save = exp_save; /* for compiler */
5286 char *exp_saveptr; /* points to expansion operator */
5287 char *exp_word = exp_word; /* for compiler */
5290 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5292 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5294 first_char = arg[0] = arg0 & 0x7f;
5297 if (first_char == '#' /* ${#... */
5298 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5300 /* It must be length operator: ${#var} */
5304 /* Maybe handle parameter expansion */
5305 if (exp_saveptr /* if 2nd char is one of expansion operators */
5306 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5308 /* ${?:0}, ${#[:]%0} etc */
5309 exp_saveptr = var + 1;
5311 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5312 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5314 exp_op = exp_save = *exp_saveptr;
5316 exp_word = exp_saveptr + 1;
5317 if (exp_op == ':') {
5318 exp_op = *exp_word++;
5319 //TODO: try ${var:} and ${var:bogus} in non-bash config
5320 if (ENABLE_HUSH_BASH_COMPAT
5321 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5323 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5328 *exp_saveptr = '\0';
5329 } /* else: it's not an expansion op, but bare ${var} */
5332 /* Look up the variable in question */
5333 if (isdigit(var[0])) {
5334 /* parse_dollar should have vetted var for us */
5335 int n = xatoi_positive(var);
5336 if (n < G.global_argc)
5337 val = G.global_argv[n];
5338 /* else val remains NULL: $N with too big N */
5342 val = utoa(G.root_pid);
5344 case '!': /* bg pid */
5345 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5347 case '?': /* exitcode */
5348 val = utoa(G.last_exitcode);
5350 case '#': /* argc */
5351 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5354 val = get_local_var_value(var);
5358 /* Handle any expansions */
5359 if (exp_op == 'L') {
5360 reinit_unicode_for_hush();
5361 debug_printf_expand("expand: length(%s)=", val);
5362 val = utoa(val ? unicode_strlen(val) : 0);
5363 debug_printf_expand("%s\n", val);
5364 } else if (exp_op) {
5365 if (exp_op == '%' || exp_op == '#') {
5366 /* Standard-mandated substring removal ops:
5367 * ${parameter%word} - remove smallest suffix pattern
5368 * ${parameter%%word} - remove largest suffix pattern
5369 * ${parameter#word} - remove smallest prefix pattern
5370 * ${parameter##word} - remove largest prefix pattern
5372 * Word is expanded to produce a glob pattern.
5373 * Then var's value is matched to it and matching part removed.
5375 if (val && val[0]) {
5379 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5380 if (exp_op == *exp_word) /* ## or %% */
5382 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5384 exp_word = exp_exp_word;
5385 /* HACK ALERT. We depend here on the fact that
5386 * G.global_argv and results of utoa and get_local_var_value
5387 * are actually in writable memory:
5388 * scan_and_match momentarily stores NULs there. */
5390 loc = scan_and_match(t, exp_word, scan_flags);
5391 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5392 // exp_op, t, exp_word, loc);
5394 if (loc) { /* match was found */
5395 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5396 val = loc; /* take right part */
5398 val = to_be_freed = xstrndup(val, loc - val); /* left */
5402 #if ENABLE_HUSH_BASH_COMPAT
5403 else if (exp_op == '/' || exp_op == '\\') {
5404 /* It's ${var/[/]pattern[/repl]} thing.
5405 * Note that in encoded form it has TWO parts:
5406 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5407 * and if // is used, it is encoded as \:
5408 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5410 /* Empty variable always gives nothing: */
5411 // "v=''; echo ${v/*/w}" prints "", not "w"
5412 if (val && val[0]) {
5413 /* pattern uses non-standard expansion.
5414 * repl should be unbackslashed and globbed
5415 * by the usual expansion rules:
5417 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5418 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5419 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5420 * v='a bz'; echo ${v/a*z/\z} prints "z"
5421 * (note that a*z _pattern_ is never globbed!)
5423 char *pattern, *repl, *t;
5424 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5426 pattern = xstrdup(exp_word);
5427 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5428 *p++ = SPECIAL_VAR_SYMBOL;
5430 p = strchr(p, SPECIAL_VAR_SYMBOL);
5432 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5433 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5434 /* HACK ALERT. We depend here on the fact that
5435 * G.global_argv and results of utoa and get_local_var_value
5436 * are actually in writable memory:
5437 * replace_pattern momentarily stores NULs there. */
5439 to_be_freed = replace_pattern(t,
5441 (repl ? repl : exp_word),
5443 if (to_be_freed) /* at least one replace happened */
5450 else if (exp_op == ':') {
5451 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5452 /* It's ${var:N[:M]} bashism.
5453 * Note that in encoded form it has TWO parts:
5454 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5459 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5462 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5463 *p++ = SPECIAL_VAR_SYMBOL;
5465 p = strchr(p, SPECIAL_VAR_SYMBOL);
5467 len = expand_and_evaluate_arith(exp_word, &errmsg);
5470 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5471 if (len >= 0) { /* bash compat: len < 0 is illegal */
5472 if (beg < 0) /* bash compat */
5474 debug_printf_varexp("from val:'%s'\n", val);
5475 if (len == 0 || !val || beg >= strlen(val)) {
5479 /* Paranoia. What if user entered 9999999999999
5480 * which fits in arith_t but not int? */
5483 val = to_be_freed = xstrndup(val + beg, len);
5485 debug_printf_varexp("val:'%s'\n", val);
5489 die_if_script("malformed ${%s:...}", var);
5492 } else { /* one of "-=+?" */
5493 /* Standard-mandated substitution ops:
5494 * ${var?word} - indicate error if unset
5495 * If var is unset, word (or a message indicating it is unset
5496 * if word is null) is written to standard error
5497 * and the shell exits with a non-zero exit status.
5498 * Otherwise, the value of var is substituted.
5499 * ${var-word} - use default value
5500 * If var is unset, word is substituted.
5501 * ${var=word} - assign and use default value
5502 * If var is unset, word is assigned to var.
5503 * In all cases, final value of var is substituted.
5504 * ${var+word} - use alternative value
5505 * If var is unset, null is substituted.
5506 * Otherwise, word is substituted.
5508 * Word is subjected to tilde expansion, parameter expansion,
5509 * command substitution, and arithmetic expansion.
5510 * If word is not needed, it is not expanded.
5512 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5513 * but also treat null var as if it is unset.
5515 int use_word = (!val || ((exp_save == ':') && !val[0]));
5517 use_word = !use_word;
5518 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5519 (exp_save == ':') ? "true" : "false", use_word);
5521 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5523 exp_word = to_be_freed;
5524 if (exp_op == '?') {
5525 /* mimic bash message */
5526 die_if_script("%s: %s",
5528 exp_word[0] ? exp_word : "parameter null or not set"
5530 //TODO: how interactive bash aborts expansion mid-command?
5535 if (exp_op == '=') {
5536 /* ${var=[word]} or ${var:=[word]} */
5537 if (isdigit(var[0]) || var[0] == '#') {
5538 /* mimic bash message */
5539 die_if_script("$%s: cannot assign in this way", var);
5542 char *new_var = xasprintf("%s=%s", var, val);
5543 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5547 } /* one of "-=+?" */
5549 *exp_saveptr = exp_save;
5555 *to_be_freed_pp = to_be_freed;
5559 /* Expand all variable references in given string, adding words to list[]
5560 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5561 * to be filled). This routine is extremely tricky: has to deal with
5562 * variables/parameters with whitespace, $* and $@, and constructs like
5563 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5564 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5566 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5567 * expansion of right-hand side of assignment == 1-element expand.
5569 char cant_be_null = 0; /* only bit 0x80 matters */
5570 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5573 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5574 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5575 debug_print_list("expand_vars_to_list", output, n);
5576 n = o_save_ptr(output, n);
5577 debug_print_list("expand_vars_to_list[0]", output, n);
5579 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5581 char *to_be_freed = NULL;
5582 const char *val = NULL;
5583 #if ENABLE_HUSH_TICK
5584 o_string subst_result = NULL_O_STRING;
5586 #if ENABLE_SH_MATH_SUPPORT
5587 char arith_buf[sizeof(arith_t)*3 + 2];
5591 o_addchr(output, '\0');
5592 n = o_save_ptr(output, n);
5596 o_addblock(output, arg, p - arg);
5597 debug_print_list("expand_vars_to_list[1]", output, n);
5599 p = strchr(p, SPECIAL_VAR_SYMBOL);
5601 /* Fetch special var name (if it is indeed one of them)
5602 * and quote bit, force the bit on if singleword expansion -
5603 * important for not getting v=$@ expand to many words. */
5604 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5606 /* Is this variable quoted and thus expansion can't be null?
5607 * "$@" is special. Even if quoted, it can still
5608 * expand to nothing (not even an empty string),
5609 * thus it is excluded. */
5610 if ((first_ch & 0x7f) != '@')
5611 cant_be_null |= first_ch;
5613 switch (first_ch & 0x7f) {
5614 /* Highest bit in first_ch indicates that var is double-quoted */
5618 if (!G.global_argv[1])
5621 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5622 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5623 while (G.global_argv[i]) {
5624 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5625 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5626 if (G.global_argv[i++][0] && G.global_argv[i]) {
5627 /* this argv[] is not empty and not last:
5628 * put terminating NUL, start new word */
5629 o_addchr(output, '\0');
5630 debug_print_list("expand_vars_to_list[2]", output, n);
5631 n = o_save_ptr(output, n);
5632 debug_print_list("expand_vars_to_list[3]", output, n);
5636 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5637 * and in this case should treat it like '$*' - see 'else...' below */
5638 if (first_ch == ('@'|0x80) /* quoted $@ */
5639 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5642 o_addQstr(output, G.global_argv[i]);
5643 if (++i >= G.global_argc)
5645 o_addchr(output, '\0');
5646 debug_print_list("expand_vars_to_list[4]", output, n);
5647 n = o_save_ptr(output, n);
5649 } else { /* quoted $* (or v="$@" case): add as one word */
5651 o_addQstr(output, G.global_argv[i]);
5652 if (!G.global_argv[++i])
5655 o_addchr(output, G.ifs[0]);
5657 output->has_quoted_part = 1;
5661 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5662 /* "Empty variable", used to make "" etc to not disappear */
5663 output->has_quoted_part = 1;
5665 cant_be_null = 0x80;
5667 #if ENABLE_HUSH_TICK
5668 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5669 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5671 /* Can't just stuff it into output o_string,
5672 * expanded result may need to be globbed
5673 * and $IFS-splitted */
5674 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5675 G.last_exitcode = process_command_subs(&subst_result, arg);
5676 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5677 val = subst_result.data;
5680 #if ENABLE_SH_MATH_SUPPORT
5681 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5684 arg++; /* skip '+' */
5685 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5686 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5687 res = expand_and_evaluate_arith(arg, NULL);
5688 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5689 sprintf(arith_buf, ARITH_FMT, res);
5695 val = expand_one_var(&to_be_freed, arg, &p);
5696 IF_HUSH_TICK(store_val:)
5697 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5698 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5699 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5700 if (val && val[0]) {
5701 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5704 } else { /* quoted $VAR, val will be appended below */
5705 output->has_quoted_part = 1;
5706 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5707 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5710 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5712 if (val && val[0]) {
5713 o_addQstr(output, val);
5717 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5718 * Do the check to avoid writing to a const string. */
5719 if (*p != SPECIAL_VAR_SYMBOL)
5720 *p = SPECIAL_VAR_SYMBOL;
5722 #if ENABLE_HUSH_TICK
5723 o_free(&subst_result);
5726 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5730 o_addchr(output, '\0');
5731 n = o_save_ptr(output, n);
5733 debug_print_list("expand_vars_to_list[a]", output, n);
5734 /* this part is literal, and it was already pre-quoted
5735 * if needed (much earlier), do not use o_addQstr here! */
5736 o_addstr_with_NUL(output, arg);
5737 debug_print_list("expand_vars_to_list[b]", output, n);
5738 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5739 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5742 /* allow to reuse list[n] later without re-growth */
5743 output->has_empty_slot = 1;
5745 o_addchr(output, '\0');
5751 static char **expand_variables(char **argv, unsigned expflags)
5755 o_string output = NULL_O_STRING;
5757 output.o_expflags = expflags;
5761 n = expand_vars_to_list(&output, n, *argv);
5764 debug_print_list("expand_variables", &output, n);
5766 /* output.data (malloced in one block) gets returned in "list" */
5767 list = o_finalize_list(&output, n);
5768 debug_print_strings("expand_variables[1]", list);
5772 static char **expand_strvec_to_strvec(char **argv)
5774 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5777 #if ENABLE_HUSH_BASH_COMPAT
5778 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5780 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5784 /* Used for expansion of right hand of assignments,
5785 * $((...)), heredocs, variable espansion parts.
5787 * NB: should NOT do globbing!
5788 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5790 static char *expand_string_to_string(const char *str, int do_unbackslash)
5792 #if !ENABLE_HUSH_BASH_COMPAT
5793 const int do_unbackslash = 1;
5795 char *argv[2], **list;
5797 debug_printf_expand("string_to_string<='%s'\n", str);
5798 /* This is generally an optimization, but it also
5799 * handles "", which otherwise trips over !list[0] check below.
5800 * (is this ever happens that we actually get str="" here?)
5802 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5803 //TODO: Can use on strings with \ too, just unbackslash() them?
5804 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5805 return xstrdup(str);
5808 argv[0] = (char*)str;
5810 list = expand_variables(argv, do_unbackslash
5811 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5812 : EXP_FLAG_SINGLEWORD
5815 if (!list[0] || list[1])
5816 bb_error_msg_and_die("BUG in varexp2");
5817 /* actually, just move string 2*sizeof(char*) bytes back */
5818 overlapping_strcpy((char*)list, list[0]);
5820 unbackslash((char*)list);
5821 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5825 /* Used for "eval" builtin */
5826 static char* expand_strvec_to_string(char **argv)
5830 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5831 /* Convert all NULs to spaces */
5836 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5837 bb_error_msg_and_die("BUG in varexp3");
5838 /* bash uses ' ' regardless of $IFS contents */
5843 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5844 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5848 static char **expand_assignments(char **argv, int count)
5853 G.expanded_assignments = p = NULL;
5854 /* Expand assignments into one string each */
5855 for (i = 0; i < count; i++) {
5856 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5858 G.expanded_assignments = NULL;
5863 static void switch_off_special_sigs(unsigned mask)
5866 while ((mask >>= 1) != 0) {
5871 if (G.traps[sig] && !G.traps[sig][0])
5872 /* trap is '', has to remain SIG_IGN */
5875 G.traps[sig] = NULL;
5877 /* We are here only if no trap or trap was not '' */
5878 install_sighandler(sig, SIG_DFL);
5884 void re_execute_shell(char ***to_free, const char *s,
5885 char *g_argv0, char **g_argv,
5886 char **builtin_argv) NORETURN;
5888 static void reset_traps_to_defaults(void)
5890 /* This function is always called in a child shell
5891 * after fork (not vfork, NOMMU doesn't use this function).
5896 /* Child shells are not interactive.
5897 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5898 * Testcase: (while :; do :; done) + ^Z should background.
5899 * Same goes for SIGTERM, SIGHUP, SIGINT.
5901 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5902 if (!G.traps && !mask)
5903 return; /* already no traps and no special sigs */
5905 /* Switch off special sigs */
5906 switch_off_special_sigs(mask);
5908 G_fatal_sig_mask = 0;
5910 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5911 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5912 * remain set in G.special_sig_mask */
5917 /* Reset all sigs to default except ones with empty traps */
5918 for (sig = 0; sig < NSIG; sig++) {
5920 continue; /* no trap: nothing to do */
5921 if (!G.traps[sig][0])
5922 continue; /* empty trap: has to remain SIG_IGN */
5923 /* sig has non-empty trap, reset it: */
5925 G.traps[sig] = NULL;
5926 /* There is no signal for trap 0 (EXIT) */
5929 install_sighandler(sig, pick_sighandler(sig));
5935 static void re_execute_shell(char ***to_free, const char *s,
5936 char *g_argv0, char **g_argv,
5937 char **builtin_argv) NORETURN;
5938 static void re_execute_shell(char ***to_free, const char *s,
5939 char *g_argv0, char **g_argv,
5940 char **builtin_argv)
5942 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5943 /* delims + 2 * (number of bytes in printed hex numbers) */
5944 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5945 char *heredoc_argv[4];
5946 struct variable *cur;
5947 # if ENABLE_HUSH_FUNCTIONS
5948 struct function *funcp;
5952 unsigned long long empty_trap_mask;
5954 if (!g_argv0) { /* heredoc */
5955 argv = heredoc_argv;
5956 argv[0] = (char *) G.argv0_for_re_execing;
5957 argv[1] = (char *) "-<";
5958 argv[2] = (char *) s;
5960 pp = &argv[3]; /* used as pointer to empty environment */
5966 if (pp) while (*pp++)
5969 empty_trap_mask = 0;
5972 for (sig = 1; sig < NSIG; sig++) {
5973 if (G.traps[sig] && !G.traps[sig][0])
5974 empty_trap_mask |= 1LL << sig;
5978 sprintf(param_buf, NOMMU_HACK_FMT
5979 , (unsigned) G.root_pid
5980 , (unsigned) G.root_ppid
5981 , (unsigned) G.last_bg_pid
5982 , (unsigned) G.last_exitcode
5985 IF_HUSH_LOOPS(, G.depth_of_loop)
5987 # undef NOMMU_HACK_FMT
5988 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5989 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5992 for (cur = G.top_var; cur; cur = cur->next) {
5993 if (!cur->flg_export || cur->flg_read_only)
5996 # if ENABLE_HUSH_FUNCTIONS
5997 for (funcp = G.top_func; funcp; funcp = funcp->next)
6003 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6004 *pp++ = (char *) G.argv0_for_re_execing;
6006 for (cur = G.top_var; cur; cur = cur->next) {
6007 if (strcmp(cur->varstr, hush_version_str) == 0)
6009 if (cur->flg_read_only) {
6010 *pp++ = (char *) "-R";
6011 *pp++ = cur->varstr;
6012 } else if (!cur->flg_export) {
6013 *pp++ = (char *) "-V";
6014 *pp++ = cur->varstr;
6017 # if ENABLE_HUSH_FUNCTIONS
6018 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6019 *pp++ = (char *) "-F";
6020 *pp++ = funcp->name;
6021 *pp++ = funcp->body_as_string;
6024 /* We can pass activated traps here. Say, -Tnn:trap_string
6026 * However, POSIX says that subshells reset signals with traps
6028 * I tested bash-3.2 and it not only does that with true subshells
6029 * of the form ( list ), but with any forked children shells.
6030 * I set trap "echo W" WINCH; and then tried:
6032 * { echo 1; sleep 20; echo 2; } &
6033 * while true; do echo 1; sleep 20; echo 2; break; done &
6034 * true | { echo 1; sleep 20; echo 2; } | cat
6036 * In all these cases sending SIGWINCH to the child shell
6037 * did not run the trap. If I add trap "echo V" WINCH;
6038 * _inside_ group (just before echo 1), it works.
6040 * I conclude it means we don't need to pass active traps here.
6042 *pp++ = (char *) "-c";
6045 while (*++builtin_argv)
6046 *pp++ = *builtin_argv;
6047 *pp++ = (char *) "";
6052 /* *pp = NULL; - is already there */
6056 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6057 /* Don't propagate SIG_IGN to the child */
6058 if (SPECIAL_JOBSTOP_SIGS != 0)
6059 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6060 execve(bb_busybox_exec_path, argv, pp);
6061 /* Fallback. Useful for init=/bin/hush usage etc */
6062 if (argv[0][0] == '/')
6063 execve(argv[0], argv, pp);
6064 xfunc_error_retval = 127;
6065 bb_error_msg_and_die("can't re-execute the shell");
6067 #endif /* !BB_MMU */
6070 static int run_and_free_list(struct pipe *pi);
6072 /* Executing from string: eval, sh -c '...'
6073 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6074 * end_trigger controls how often we stop parsing
6075 * NUL: parse all, execute, return
6076 * ';': parse till ';' or newline, execute, repeat till EOF
6078 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6080 /* Why we need empty flag?
6081 * An obscure corner case "false; ``; echo $?":
6082 * empty command in `` should still set $? to 0.
6083 * But we can't just set $? to 0 at the start,
6084 * this breaks "false; echo `echo $?`" case.
6088 struct pipe *pipe_list;
6090 #if ENABLE_HUSH_INTERACTIVE
6091 if (end_trigger == ';')
6092 inp->promptmode = 0; /* PS1 */
6094 pipe_list = parse_stream(NULL, inp, end_trigger);
6095 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6096 /* If we are in "big" script
6097 * (not in `cmd` or something similar)...
6099 if (pipe_list == ERR_PTR && end_trigger == ';') {
6100 /* Discard cached input (rest of line) */
6101 int ch = inp->last_char;
6102 while (ch != EOF && ch != '\n') {
6103 //bb_error_msg("Discarded:'%c'", ch);
6108 /* This stream isn't empty */
6112 if (!pipe_list && empty)
6113 G.last_exitcode = 0;
6116 debug_print_tree(pipe_list, 0);
6117 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6118 run_and_free_list(pipe_list);
6120 if (G_flag_return_in_progress == 1)
6125 static void parse_and_run_string(const char *s)
6127 struct in_str input;
6128 setup_string_in_str(&input, s);
6129 parse_and_run_stream(&input, '\0');
6132 static void parse_and_run_file(FILE *f)
6134 struct in_str input;
6135 setup_file_in_str(&input, f);
6136 parse_and_run_stream(&input, ';');
6139 #if ENABLE_HUSH_TICK
6140 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6145 char **to_free = NULL;
6149 pid = BB_MMU ? xfork() : xvfork();
6150 if (pid == 0) { /* child */
6151 disable_restore_tty_pgrp_on_exit();
6152 /* Process substitution is not considered to be usual
6153 * 'command execution'.
6154 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6161 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6162 close(channel[0]); /* NB: close _first_, then move fd! */
6163 xmove_fd(channel[1], 1);
6164 /* Prevent it from trying to handle ctrl-z etc */
6165 IF_HUSH_JOB(G.run_list_level = 1;)
6166 /* Awful hack for `trap` or $(trap).
6168 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6169 * contains an example where "trap" is executed in a subshell:
6171 * save_traps=$(trap)
6173 * eval "$save_traps"
6175 * Standard does not say that "trap" in subshell shall print
6176 * parent shell's traps. It only says that its output
6177 * must have suitable form, but then, in the above example
6178 * (which is not supposed to be normative), it implies that.
6180 * bash (and probably other shell) does implement it
6181 * (traps are reset to defaults, but "trap" still shows them),
6182 * but as a result, "trap" logic is hopelessly messed up:
6185 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6186 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6187 * # true | trap <--- trap is in subshell - no output (ditto)
6188 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6189 * trap -- 'echo Ho' SIGWINCH
6190 * # echo `(trap)` <--- in subshell in subshell - output
6191 * trap -- 'echo Ho' SIGWINCH
6192 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6193 * trap -- 'echo Ho' SIGWINCH
6195 * The rules when to forget and when to not forget traps
6196 * get really complex and nonsensical.
6198 * Our solution: ONLY bare $(trap) or `trap` is special.
6200 s = skip_whitespace(s);
6201 if (is_prefixed_with(s, "trap")
6202 && skip_whitespace(s + 4)[0] == '\0'
6204 static const char *const argv[] = { NULL, NULL };
6205 builtin_trap((char**)argv);
6206 fflush_all(); /* important */
6210 reset_traps_to_defaults();
6211 parse_and_run_string(s);
6212 _exit(G.last_exitcode);
6214 /* We re-execute after vfork on NOMMU. This makes this script safe:
6215 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6216 * huge=`cat BIG` # was blocking here forever
6219 re_execute_shell(&to_free,
6229 # if ENABLE_HUSH_FAST
6231 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6232 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6233 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6235 enable_restore_tty_pgrp_on_exit();
6240 return remember_FILE(xfdopen_for_read(channel[0]));
6243 /* Return code is exit status of the process that is run. */
6244 static int process_command_subs(o_string *dest, const char *s)
6247 struct in_str pipe_str;
6249 int status, ch, eol_cnt;
6251 fp = generate_stream_from_string(s, &pid);
6253 /* Now send results of command back into original context */
6254 setup_file_in_str(&pipe_str, fp);
6256 while ((ch = i_getch(&pipe_str)) != EOF) {
6262 o_addchr(dest, '\n');
6265 o_addQchr(dest, ch);
6268 debug_printf("done reading from `cmd` pipe, closing it\n");
6269 fclose_and_forget(fp);
6270 /* We need to extract exitcode. Test case
6271 * "true; echo `sleep 1; false` $?"
6273 safe_waitpid(pid, &status, 0);
6274 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6275 return WEXITSTATUS(status);
6277 #endif /* ENABLE_HUSH_TICK */
6280 static void setup_heredoc(struct redir_struct *redir)
6282 struct fd_pair pair;
6285 /* the _body_ of heredoc (misleading field name) */
6286 const char *heredoc = redir->rd_filename;
6293 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6294 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6298 len = strlen(heredoc);
6300 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6302 xmove_fd(pair.rd, redir->rd_fd);
6304 /* Try writing without forking. Newer kernels have
6305 * dynamically growing pipes. Must use non-blocking write! */
6308 written = write(pair.wr, heredoc, len);
6319 ndelay_off(pair.wr);
6321 /* Okay, pipe buffer was not big enough */
6322 /* Note: we must not create a stray child (bastard? :)
6323 * for the unsuspecting parent process. Child creates a grandchild
6324 * and exits before parent execs the process which consumes heredoc
6325 * (that exec happens after we return from this function) */
6332 disable_restore_tty_pgrp_on_exit();
6333 pid = BB_MMU ? xfork() : xvfork();
6337 close(redir->rd_fd); /* read side of the pipe */
6339 full_write(pair.wr, heredoc, len); /* may loop or block */
6342 /* Delegate blocking writes to another process */
6343 xmove_fd(pair.wr, STDOUT_FILENO);
6344 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6348 #if ENABLE_HUSH_FAST
6350 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6352 enable_restore_tty_pgrp_on_exit();
6358 wait(NULL); /* wait till child has died */
6361 /* fd: redirect wants this fd to be used (e.g. 3>file).
6362 * Move all conflicting internally used fds,
6363 * and remember them so that we can restore them later.
6365 static int save_fds_on_redirect(int fd, int squirrel[3])
6368 /* Handle redirects of fds 0,1,2 */
6370 /* If we collide with an already moved stdio fd... */
6371 if (fd == squirrel[0]) {
6372 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6375 if (fd == squirrel[1]) {
6376 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6379 if (fd == squirrel[2]) {
6380 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6383 /* If we are about to redirect stdio fd, and did not yet move it... */
6384 if (fd <= 2 && squirrel[fd] < 0) {
6385 /* We avoid taking stdio fds */
6386 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6387 if (squirrel[fd] < 0 && errno != EBADF)
6389 return 0; /* "we did not close fd" */
6393 #if ENABLE_HUSH_INTERACTIVE
6394 if (fd != 0 && fd == G.interactive_fd) {
6395 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6400 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6401 * (1) Redirect in a forked child. No need to save FILEs' fds,
6402 * we aren't going to use them anymore, ok to trash.
6403 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6404 * but how are we doing to use them?
6405 * "fileno(fd) = new_fd" can't be done.
6410 return save_FILEs_on_redirect(fd);
6413 static void restore_redirects(int squirrel[3])
6416 for (i = 0; i <= 2; i++) {
6419 /* We simply die on error */
6424 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6426 restore_redirected_FILEs();
6429 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6430 * and stderr if they are redirected. */
6431 static int setup_redirects(struct command *prog, int squirrel[])
6434 struct redir_struct *redir;
6436 for (redir = prog->redirects; redir; redir = redir->next) {
6437 if (redir->rd_type == REDIRECT_HEREDOC2) {
6438 /* "rd_fd<<HERE" case */
6439 save_fds_on_redirect(redir->rd_fd, squirrel);
6440 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6442 debug_printf_parse("set heredoc '%s'\n",
6443 redir->rd_filename);
6444 setup_heredoc(redir);
6448 if (redir->rd_dup == REDIRFD_TO_FILE) {
6449 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6451 if (redir->rd_filename == NULL) {
6454 * "cmd >" (no filename)
6455 * "cmd > <file" (2nd redirect starts too early)
6457 die_if_script("syntax error: %s", "invalid redirect");
6460 mode = redir_table[redir->rd_type].mode;
6461 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6462 openfd = open_or_warn(p, mode);
6465 /* Error message from open_or_warn can be lost
6466 * if stderr has been redirected, but bash
6467 * and ash both lose it as well
6468 * (though zsh doesn't!)
6473 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6474 openfd = redir->rd_dup;
6477 if (openfd != redir->rd_fd) {
6478 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6479 if (openfd == REDIRFD_CLOSE) {
6480 /* "rd_fd >&-" means "close me" */
6482 /* ^^^ optimization: saving may already
6483 * have closed it. If not... */
6484 close(redir->rd_fd);
6487 xdup2(openfd, redir->rd_fd);
6488 if (redir->rd_dup == REDIRFD_TO_FILE)
6489 /* "rd_fd > FILE" */
6491 /* else: "rd_fd > rd_dup" */
6498 static char *find_in_path(const char *arg)
6501 const char *PATH = get_local_var_value("PATH");
6507 const char *end = strchrnul(PATH, ':');
6508 int sz = end - PATH; /* must be int! */
6512 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6514 /* We have xxx::yyyy in $PATH,
6515 * it means "use current dir" */
6518 if (access(ret, F_OK) == 0)
6531 static const struct built_in_command *find_builtin_helper(const char *name,
6532 const struct built_in_command *x,
6533 const struct built_in_command *end)
6536 if (strcmp(name, x->b_cmd) != 0) {
6540 debug_printf_exec("found builtin '%s'\n", name);
6545 static const struct built_in_command *find_builtin1(const char *name)
6547 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6549 static const struct built_in_command *find_builtin(const char *name)
6551 const struct built_in_command *x = find_builtin1(name);
6554 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6557 #if ENABLE_HUSH_FUNCTIONS
6558 static struct function **find_function_slot(const char *name)
6560 struct function **funcpp = &G.top_func;
6562 if (strcmp(name, (*funcpp)->name) == 0) {
6565 funcpp = &(*funcpp)->next;
6570 static const struct function *find_function(const char *name)
6572 const struct function *funcp = *find_function_slot(name);
6574 debug_printf_exec("found function '%s'\n", name);
6578 /* Note: takes ownership on name ptr */
6579 static struct function *new_function(char *name)
6581 struct function **funcpp = find_function_slot(name);
6582 struct function *funcp = *funcpp;
6584 if (funcp != NULL) {
6585 struct command *cmd = funcp->parent_cmd;
6586 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6588 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6590 /* Note: if !funcp->body, do not free body_as_string!
6591 * This is a special case of "-F name body" function:
6592 * body_as_string was not malloced! */
6594 free_pipe_list(funcp->body);
6596 free(funcp->body_as_string);
6600 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6601 cmd->argv[0] = funcp->name;
6602 cmd->group = funcp->body;
6604 cmd->group_as_string = funcp->body_as_string;
6608 debug_printf_exec("remembering new function '%s'\n", name);
6609 funcp = *funcpp = xzalloc(sizeof(*funcp));
6610 /*funcp->next = NULL;*/
6617 static void unset_func(const char *name)
6619 struct function **funcpp = find_function_slot(name);
6620 struct function *funcp = *funcpp;
6622 if (funcp != NULL) {
6623 debug_printf_exec("freeing function '%s'\n", funcp->name);
6624 *funcpp = funcp->next;
6625 /* funcp is unlinked now, deleting it.
6626 * Note: if !funcp->body, the function was created by
6627 * "-F name body", do not free ->body_as_string
6628 * and ->name as they were not malloced. */
6630 free_pipe_list(funcp->body);
6633 free(funcp->body_as_string);
6641 #define exec_function(to_free, funcp, argv) \
6642 exec_function(funcp, argv)
6644 static void exec_function(char ***to_free,
6645 const struct function *funcp,
6646 char **argv) NORETURN;
6647 static void exec_function(char ***to_free,
6648 const struct function *funcp,
6654 argv[0] = G.global_argv[0];
6655 G.global_argv = argv;
6659 /* On MMU, funcp->body is always non-NULL */
6660 n = run_list(funcp->body);
6664 re_execute_shell(to_free,
6665 funcp->body_as_string,
6672 static int run_function(const struct function *funcp, char **argv)
6678 save_and_replace_G_args(&sv, argv);
6680 /* "we are in function, ok to use return" */
6681 sv_flg = G_flag_return_in_progress;
6682 G_flag_return_in_progress = -1;
6683 # if ENABLE_HUSH_LOCAL
6684 G.func_nest_level++;
6687 /* On MMU, funcp->body is always non-NULL */
6690 /* Function defined by -F */
6691 parse_and_run_string(funcp->body_as_string);
6692 rc = G.last_exitcode;
6696 rc = run_list(funcp->body);
6699 # if ENABLE_HUSH_LOCAL
6701 struct variable *var;
6702 struct variable **var_pp;
6704 var_pp = &G.top_var;
6705 while ((var = *var_pp) != NULL) {
6706 if (var->func_nest_level < G.func_nest_level) {
6707 var_pp = &var->next;
6711 if (var->flg_export)
6712 bb_unsetenv(var->varstr);
6713 /* Remove from global list */
6714 *var_pp = var->next;
6720 G.func_nest_level--;
6723 G_flag_return_in_progress = sv_flg;
6725 restore_G_args(&sv, argv);
6729 #endif /* ENABLE_HUSH_FUNCTIONS */
6733 #define exec_builtin(to_free, x, argv) \
6734 exec_builtin(x, argv)
6736 #define exec_builtin(to_free, x, argv) \
6737 exec_builtin(to_free, argv)
6739 static void exec_builtin(char ***to_free,
6740 const struct built_in_command *x,
6741 char **argv) NORETURN;
6742 static void exec_builtin(char ***to_free,
6743 const struct built_in_command *x,
6749 rcode = x->b_function(argv);
6754 /* On NOMMU, we must never block!
6755 * Example: { sleep 99 | read line; } & echo Ok
6757 re_execute_shell(to_free,
6766 static void execvp_or_die(char **argv) NORETURN;
6767 static void execvp_or_die(char **argv)
6770 debug_printf_exec("execing '%s'\n", argv[0]);
6771 /* Don't propagate SIG_IGN to the child */
6772 if (SPECIAL_JOBSTOP_SIGS != 0)
6773 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6774 execvp(argv[0], argv);
6776 if (errno == EACCES) e = 126;
6777 if (errno == ENOENT) e = 127;
6778 bb_perror_msg("can't execute '%s'", argv[0]);
6782 #if ENABLE_HUSH_MODE_X
6783 static void dump_cmd_in_x_mode(char **argv)
6785 if (G_x_mode && argv) {
6786 /* We want to output the line in one write op */
6794 len += strlen(argv[n++]) + 1;
6800 p += sprintf(p, " %s", argv[n++]);
6808 # define dump_cmd_in_x_mode(argv) ((void)0)
6812 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6813 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6814 #define pseudo_exec(nommu_save, command, argv_expanded) \
6815 pseudo_exec(command, argv_expanded)
6818 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6820 * Don't exit() here. If you don't exec, use _exit instead.
6821 * The at_exit handlers apparently confuse the calling process,
6822 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6824 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6825 char **argv, int assignment_cnt,
6826 char **argv_expanded) NORETURN;
6827 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6828 char **argv, int assignment_cnt,
6829 char **argv_expanded)
6833 new_env = expand_assignments(argv, assignment_cnt);
6834 dump_cmd_in_x_mode(new_env);
6836 if (!argv[assignment_cnt]) {
6837 /* Case when we are here: ... | var=val | ...
6838 * (note that we do not exit early, i.e., do not optimize out
6839 * expand_assignments(): think about ... | var=`sleep 1` | ...
6841 free_strings(new_env);
6842 _exit(EXIT_SUCCESS);
6846 set_vars_and_save_old(new_env);
6847 free(new_env); /* optional */
6848 /* we can also destroy set_vars_and_save_old's return value,
6851 nommu_save->new_env = new_env;
6852 nommu_save->old_vars = set_vars_and_save_old(new_env);
6855 if (argv_expanded) {
6856 argv = argv_expanded;
6858 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6860 nommu_save->argv = argv;
6863 dump_cmd_in_x_mode(argv);
6865 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6866 if (strchr(argv[0], '/') != NULL)
6870 /* Check if the command matches any of the builtins.
6871 * Depending on context, this might be redundant. But it's
6872 * easier to waste a few CPU cycles than it is to figure out
6873 * if this is one of those cases.
6876 /* On NOMMU, it is more expensive to re-execute shell
6877 * just in order to run echo or test builtin.
6878 * It's better to skip it here and run corresponding
6879 * non-builtin later. */
6880 const struct built_in_command *x;
6881 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6883 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6886 #if ENABLE_HUSH_FUNCTIONS
6887 /* Check if the command matches any functions */
6889 const struct function *funcp = find_function(argv[0]);
6891 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6896 #if ENABLE_FEATURE_SH_STANDALONE
6897 /* Check if the command matches any busybox applets */
6899 int a = find_applet_by_name(argv[0]);
6901 # if BB_MMU /* see above why on NOMMU it is not allowed */
6902 if (APPLET_IS_NOEXEC(a)) {
6903 /* Do not leak open fds from opened script files etc */
6904 close_all_FILE_list();
6905 debug_printf_exec("running applet '%s'\n", argv[0]);
6906 run_applet_no_and_exit(a, argv);
6909 /* Re-exec ourselves */
6910 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6911 /* Don't propagate SIG_IGN to the child */
6912 if (SPECIAL_JOBSTOP_SIGS != 0)
6913 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6914 execv(bb_busybox_exec_path, argv);
6915 /* If they called chroot or otherwise made the binary no longer
6916 * executable, fall through */
6921 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6924 execvp_or_die(argv);
6927 /* Called after [v]fork() in run_pipe
6929 static void pseudo_exec(nommu_save_t *nommu_save,
6930 struct command *command,
6931 char **argv_expanded) NORETURN;
6932 static void pseudo_exec(nommu_save_t *nommu_save,
6933 struct command *command,
6934 char **argv_expanded)
6936 if (command->argv) {
6937 pseudo_exec_argv(nommu_save, command->argv,
6938 command->assignment_cnt, argv_expanded);
6941 if (command->group) {
6942 /* Cases when we are here:
6945 * ... | ( list ) | ...
6946 * ... | { list } | ...
6950 debug_printf_exec("pseudo_exec: run_list\n");
6951 reset_traps_to_defaults();
6952 rcode = run_list(command->group);
6953 /* OK to leak memory by not calling free_pipe_list,
6954 * since this process is about to exit */
6957 re_execute_shell(&nommu_save->argv_from_re_execing,
6958 command->group_as_string,
6965 /* Case when we are here: ... | >file */
6966 debug_printf_exec("pseudo_exec'ed null command\n");
6967 _exit(EXIT_SUCCESS);
6971 static const char *get_cmdtext(struct pipe *pi)
6977 /* This is subtle. ->cmdtext is created only on first backgrounding.
6978 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6979 * On subsequent bg argv is trashed, but we won't use it */
6983 argv = pi->cmds[0].argv;
6985 pi->cmdtext = xzalloc(1);
6990 len += strlen(*argv) + 1;
6994 argv = pi->cmds[0].argv;
6996 p = stpcpy(p, *argv);
7003 static void insert_bg_job(struct pipe *pi)
7005 struct pipe *job, **jobp;
7008 /* Linear search for the ID of the job to use */
7010 for (job = G.job_list; job; job = job->next)
7011 if (job->jobid >= pi->jobid)
7012 pi->jobid = job->jobid + 1;
7014 /* Add job to the list of running jobs */
7016 while ((job = *jobp) != NULL)
7018 job = *jobp = xmalloc(sizeof(*job));
7020 *job = *pi; /* physical copy */
7022 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7023 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7024 for (i = 0; i < pi->num_cmds; i++) {
7025 job->cmds[i].pid = pi->cmds[i].pid;
7026 /* all other fields are not used and stay zero */
7028 job->cmdtext = xstrdup(get_cmdtext(pi));
7030 if (G_interactive_fd)
7031 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7032 G.last_jobid = job->jobid;
7035 static void remove_bg_job(struct pipe *pi)
7037 struct pipe *prev_pipe;
7039 if (pi == G.job_list) {
7040 G.job_list = pi->next;
7042 prev_pipe = G.job_list;
7043 while (prev_pipe->next != pi)
7044 prev_pipe = prev_pipe->next;
7045 prev_pipe->next = pi->next;
7048 G.last_jobid = G.job_list->jobid;
7053 /* Remove a backgrounded job */
7054 static void delete_finished_bg_job(struct pipe *pi)
7061 static int job_exited_or_stopped(struct pipe *pi)
7065 if (pi->alive_cmds != pi->stopped_cmds)
7068 /* All processes in fg pipe have exited or stopped */
7072 rcode = pi->cmds[i].cmd_exitcode;
7073 /* usually last process gives overall exitstatus,
7074 * but with "set -o pipefail", last *failed* process does */
7075 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7078 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7082 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7089 dead = WIFEXITED(status) || WIFSIGNALED(status);
7092 if (WIFSTOPPED(status))
7093 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7094 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7095 if (WIFSIGNALED(status))
7096 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7097 childpid, WTERMSIG(status), WEXITSTATUS(status));
7098 if (WIFEXITED(status))
7099 debug_printf_jobs("pid %d exited, exitcode %d\n",
7100 childpid, WEXITSTATUS(status));
7102 /* Were we asked to wait for a fg pipe? */
7104 i = fg_pipe->num_cmds;
7109 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7110 if (fg_pipe->cmds[i].pid != childpid)
7114 fg_pipe->cmds[i].pid = 0;
7115 fg_pipe->alive_cmds--;
7116 ex = WEXITSTATUS(status);
7117 /* bash prints killer signal's name for *last*
7118 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7119 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7121 if (WIFSIGNALED(status)) {
7122 int sig = WTERMSIG(status);
7123 if (i == fg_pipe->num_cmds-1)
7124 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7125 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7126 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7127 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7128 * Maybe we need to use sig | 128? */
7131 fg_pipe->cmds[i].cmd_exitcode = ex;
7133 fg_pipe->stopped_cmds++;
7135 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7136 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7137 rcode = job_exited_or_stopped(fg_pipe);
7139 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7140 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7141 * and "killall -STOP cat" */
7142 if (G_interactive_fd) {
7144 if (fg_pipe->alive_cmds != 0)
7145 insert_bg_job(fg_pipe);
7149 if (fg_pipe->alive_cmds == 0)
7152 /* There are still running processes in the fg_pipe */
7155 /* It wasnt in fg_pipe, look for process in bg pipes */
7159 /* We were asked to wait for bg or orphaned children */
7160 /* No need to remember exitcode in this case */
7161 for (pi = G.job_list; pi; pi = pi->next) {
7162 for (i = 0; i < pi->num_cmds; i++) {
7163 if (pi->cmds[i].pid == childpid)
7164 goto found_pi_and_prognum;
7167 /* Happens when shell is used as init process (init=/bin/sh) */
7168 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7169 return -1; /* this wasn't a process from fg_pipe */
7171 found_pi_and_prognum:
7174 pi->cmds[i].pid = 0;
7175 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7176 if (WIFSIGNALED(status))
7177 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7179 if (!pi->alive_cmds) {
7180 if (G_interactive_fd)
7181 printf(JOB_STATUS_FORMAT, pi->jobid,
7182 "Done", pi->cmdtext);
7183 delete_finished_bg_job(pi);
7190 return -1; /* this wasn't a process from fg_pipe */
7193 /* Check to see if any processes have exited -- if they have,
7194 * figure out why and see if a job has completed.
7196 * If non-NULL fg_pipe: wait for its completion or stop.
7197 * Return its exitcode or zero if stopped.
7199 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7200 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7201 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7202 * or 0 if no children changed status.
7204 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7205 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7206 * or 0 if no children changed status.
7208 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7214 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7216 attributes = WUNTRACED;
7217 if (fg_pipe == NULL)
7218 attributes |= WNOHANG;
7221 #if ENABLE_HUSH_FAST
7222 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7223 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7224 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7225 /* There was neither fork nor SIGCHLD since last waitpid */
7226 /* Avoid doing waitpid syscall if possible */
7227 if (!G.we_have_children) {
7231 if (fg_pipe == NULL) { /* is WNOHANG set? */
7232 /* We have children, but they did not exit
7233 * or stop yet (we saw no SIGCHLD) */
7236 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7240 /* Do we do this right?
7241 * bash-3.00# sleep 20 | false
7243 * [3]+ Stopped sleep 20 | false
7244 * bash-3.00# echo $?
7245 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7246 * [hush 1.14.0: yes we do it right]
7250 #if ENABLE_HUSH_FAST
7252 i = G.count_SIGCHLD;
7254 childpid = waitpid(-1, &status, attributes);
7255 if (childpid <= 0) {
7256 if (childpid && errno != ECHILD)
7257 bb_perror_msg("waitpid");
7258 #if ENABLE_HUSH_FAST
7259 else { /* Until next SIGCHLD, waitpid's are useless */
7260 G.we_have_children = (childpid == 0);
7261 G.handled_SIGCHLD = i;
7262 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7265 /* ECHILD (no children), or 0 (no change in children status) */
7269 rcode = process_wait_result(fg_pipe, childpid, status);
7271 /* fg_pipe exited or stopped */
7274 if (childpid == waitfor_pid) {
7275 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7276 rcode = WEXITSTATUS(status);
7277 if (WIFSIGNALED(status))
7278 rcode = 128 + WTERMSIG(status);
7279 if (WIFSTOPPED(status))
7280 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7281 rcode = 128 + WSTOPSIG(status);
7283 break; /* "wait PID" called us, give it exitcode+1 */
7285 /* This wasn't one of our processes, or */
7286 /* fg_pipe still has running processes, do waitpid again */
7287 } /* while (waitpid succeeds)... */
7293 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7296 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7297 if (G_saved_tty_pgrp) {
7298 /* Job finished, move the shell to the foreground */
7299 p = getpgrp(); /* our process group id */
7300 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7301 tcsetpgrp(G_interactive_fd, p);
7307 /* Start all the jobs, but don't wait for anything to finish.
7310 * Return code is normally -1, when the caller has to wait for children
7311 * to finish to determine the exit status of the pipe. If the pipe
7312 * is a simple builtin command, however, the action is done by the
7313 * time run_pipe returns, and the exit code is provided as the
7316 * Returns -1 only if started some children. IOW: we have to
7317 * mask out retvals of builtins etc with 0xff!
7319 * The only case when we do not need to [v]fork is when the pipe
7320 * is single, non-backgrounded, non-subshell command. Examples:
7321 * cmd ; ... { list } ; ...
7322 * cmd && ... { list } && ...
7323 * cmd || ... { list } || ...
7324 * If it is, then we can run cmd as a builtin, NOFORK,
7325 * or (if SH_STANDALONE) an applet, and we can run the { list }
7326 * with run_list. If it isn't one of these, we fork and exec cmd.
7328 * Cases when we must fork:
7329 * non-single: cmd | cmd
7330 * backgrounded: cmd & { list } &
7331 * subshell: ( list ) [&]
7333 #if !ENABLE_HUSH_MODE_X
7334 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7335 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7337 static int redirect_and_varexp_helper(char ***new_env_p,
7338 struct variable **old_vars_p,
7339 struct command *command,
7341 char **argv_expanded)
7343 /* setup_redirects acts on file descriptors, not FILEs.
7344 * This is perfect for work that comes after exec().
7345 * Is it really safe for inline use? Experimentally,
7346 * things seem to work. */
7347 int rcode = setup_redirects(command, squirrel);
7349 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7350 *new_env_p = new_env;
7351 dump_cmd_in_x_mode(new_env);
7352 dump_cmd_in_x_mode(argv_expanded);
7354 *old_vars_p = set_vars_and_save_old(new_env);
7358 static NOINLINE int run_pipe(struct pipe *pi)
7360 static const char *const null_ptr = NULL;
7364 struct command *command;
7365 char **argv_expanded;
7367 /* it is not always needed, but we aim to smaller code */
7368 int squirrel[] = { -1, -1, -1 };
7371 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7374 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7375 * Result should be 3 lines: q w e, qwe, q w e
7377 G.ifs = get_local_var_value("IFS");
7381 IF_HUSH_JOB(pi->pgrp = -1;)
7382 pi->stopped_cmds = 0;
7383 command = &pi->cmds[0];
7384 argv_expanded = NULL;
7386 if (pi->num_cmds != 1
7387 || pi->followup == PIPE_BG
7388 || command->cmd_type == CMD_SUBSHELL
7395 debug_printf_exec(": group:%p argv:'%s'\n",
7396 command->group, command->argv ? command->argv[0] : "NONE");
7398 if (command->group) {
7399 #if ENABLE_HUSH_FUNCTIONS
7400 if (command->cmd_type == CMD_FUNCDEF) {
7401 /* "executing" func () { list } */
7402 struct function *funcp;
7404 funcp = new_function(command->argv[0]);
7405 /* funcp->name is already set to argv[0] */
7406 funcp->body = command->group;
7408 funcp->body_as_string = command->group_as_string;
7409 command->group_as_string = NULL;
7411 command->group = NULL;
7412 command->argv[0] = NULL;
7413 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7414 funcp->parent_cmd = command;
7415 command->child_func = funcp;
7417 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7419 return EXIT_SUCCESS;
7423 debug_printf("non-subshell group\n");
7424 rcode = 1; /* exitcode if redir failed */
7425 if (setup_redirects(command, squirrel) == 0) {
7426 debug_printf_exec(": run_list\n");
7427 rcode = run_list(command->group) & 0xff;
7429 restore_redirects(squirrel);
7430 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7432 debug_printf_exec("run_pipe: return %d\n", rcode);
7436 argv = command->argv ? command->argv : (char **) &null_ptr;
7438 const struct built_in_command *x;
7439 #if ENABLE_HUSH_FUNCTIONS
7440 const struct function *funcp;
7444 char **new_env = NULL;
7445 struct variable *old_vars = NULL;
7447 if (argv[command->assignment_cnt] == NULL) {
7448 /* Assignments, but no command */
7449 /* Ensure redirects take effect (that is, create files).
7450 * Try "a=t >file" */
7451 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7452 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7453 /* Set shell variables */
7457 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7458 /* Do we need to flag set_local_var() errors?
7459 * "assignment to readonly var" and "putenv error"
7464 /* Redirect error sets $? to 1. Otherwise,
7465 * if evaluating assignment value set $?, retain it.
7466 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7468 rcode = G.last_exitcode;
7469 /* Exit, _skipping_ variable restoring code: */
7470 goto clean_up_and_ret0;
7472 #else /* Older, bigger, but more correct code */
7474 rcode = setup_redirects(command, squirrel);
7475 restore_redirects(squirrel);
7476 /* Set shell variables */
7478 bb_putchar_stderr('+');
7480 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7482 fprintf(stderr, " %s", p);
7483 debug_printf_exec("set shell var:'%s'->'%s'\n",
7485 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7486 /* Do we need to flag set_local_var() errors?
7487 * "assignment to readonly var" and "putenv error"
7492 bb_putchar_stderr('\n');
7493 /* Redirect error sets $? to 1. Otherwise,
7494 * if evaluating assignment value set $?, retain it.
7495 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7497 rcode = G.last_exitcode;
7498 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7500 debug_printf_exec("run_pipe: return %d\n", rcode);
7505 /* Expand the rest into (possibly) many strings each */
7506 #if ENABLE_HUSH_BASH_COMPAT
7507 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7508 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7512 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7515 /* if someone gives us an empty string: `cmd with empty output` */
7516 if (!argv_expanded[0]) {
7517 free(argv_expanded);
7519 return G.last_exitcode;
7522 x = find_builtin(argv_expanded[0]);
7523 #if ENABLE_HUSH_FUNCTIONS
7526 funcp = find_function(argv_expanded[0]);
7530 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7531 debug_printf("exec with redirects only\n");
7532 rcode = setup_redirects(command, NULL);
7533 /* rcode=1 can be if redir file can't be opened */
7534 goto clean_up_and_ret1;
7537 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7540 debug_printf_exec(": builtin '%s' '%s'...\n",
7541 x->b_cmd, argv_expanded[1]);
7543 rcode = x->b_function(argv_expanded) & 0xff;
7546 #if ENABLE_HUSH_FUNCTIONS
7548 # if ENABLE_HUSH_LOCAL
7549 struct variable **sv;
7550 sv = G.shadowed_vars_pp;
7551 G.shadowed_vars_pp = &old_vars;
7553 debug_printf_exec(": function '%s' '%s'...\n",
7554 funcp->name, argv_expanded[1]);
7555 rcode = run_function(funcp, argv_expanded) & 0xff;
7556 # if ENABLE_HUSH_LOCAL
7557 G.shadowed_vars_pp = sv;
7563 unset_vars(new_env);
7565 /* clean_up_and_ret0: */
7566 restore_redirects(squirrel);
7568 free(argv_expanded);
7569 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7571 debug_printf_exec("run_pipe return %d\n", rcode);
7575 if (ENABLE_FEATURE_SH_NOFORK) {
7576 int n = find_applet_by_name(argv_expanded[0]);
7577 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7578 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7580 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7581 argv_expanded[0], argv_expanded[1]);
7582 rcode = run_nofork_applet(n, argv_expanded);
7584 goto clean_up_and_ret;
7587 /* It is neither builtin nor applet. We must fork. */
7591 /* NB: argv_expanded may already be created, and that
7592 * might include `cmd` runs! Do not rerun it! We *must*
7593 * use argv_expanded if it's non-NULL */
7595 /* Going to fork a child per each pipe member */
7600 while (cmd_no < pi->num_cmds) {
7601 struct fd_pair pipefds;
7603 volatile nommu_save_t nommu_save;
7604 nommu_save.new_env = NULL;
7605 nommu_save.old_vars = NULL;
7606 nommu_save.argv = NULL;
7607 nommu_save.argv_from_re_execing = NULL;
7609 command = &pi->cmds[cmd_no];
7611 if (command->argv) {
7612 debug_printf_exec(": pipe member '%s' '%s'...\n",
7613 command->argv[0], command->argv[1]);
7615 debug_printf_exec(": pipe member with no argv\n");
7618 /* pipes are inserted between pairs of commands */
7621 if (cmd_no < pi->num_cmds)
7622 xpiped_pair(pipefds);
7624 command->pid = BB_MMU ? fork() : vfork();
7625 if (!command->pid) { /* child */
7627 disable_restore_tty_pgrp_on_exit();
7628 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7630 /* Every child adds itself to new process group
7631 * with pgid == pid_of_first_child_in_pipe */
7632 if (G.run_list_level == 1 && G_interactive_fd) {
7635 if (pgrp < 0) /* true for 1st process only */
7637 if (setpgid(0, pgrp) == 0
7638 && pi->followup != PIPE_BG
7639 && G_saved_tty_pgrp /* we have ctty */
7641 /* We do it in *every* child, not just first,
7643 tcsetpgrp(G_interactive_fd, pgrp);
7647 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7648 /* 1st cmd in backgrounded pipe
7649 * should have its stdin /dev/null'ed */
7651 if (open(bb_dev_null, O_RDONLY))
7652 xopen("/", O_RDONLY);
7654 xmove_fd(next_infd, 0);
7656 xmove_fd(pipefds.wr, 1);
7659 /* Like bash, explicit redirects override pipes,
7660 * and the pipe fd (fd#1) is available for dup'ing:
7661 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7662 * of cmd1 goes into pipe.
7664 if (setup_redirects(command, NULL)) {
7665 /* Happens when redir file can't be opened:
7666 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7668 * hush: can't open '/qwe/rty': No such file or directory
7670 * (echo BAR is not executed, it hits _exit(1) below)
7675 /* Stores to nommu_save list of env vars putenv'ed
7676 * (NOMMU, on MMU we don't need that) */
7677 /* cast away volatility... */
7678 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7679 /* pseudo_exec() does not return */
7682 /* parent or error */
7683 #if ENABLE_HUSH_FAST
7685 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7687 enable_restore_tty_pgrp_on_exit();
7689 /* Clean up after vforked child */
7690 free(nommu_save.argv);
7691 free(nommu_save.argv_from_re_execing);
7692 unset_vars(nommu_save.new_env);
7693 add_vars(nommu_save.old_vars);
7695 free(argv_expanded);
7696 argv_expanded = NULL;
7697 if (command->pid < 0) { /* [v]fork failed */
7698 /* Clearly indicate, was it fork or vfork */
7699 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7703 /* Second and next children need to know pid of first one */
7705 pi->pgrp = command->pid;
7711 if (cmd_no < pi->num_cmds)
7713 /* Pass read (output) pipe end to next iteration */
7714 next_infd = pipefds.rd;
7717 if (!pi->alive_cmds) {
7719 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7724 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7728 /* NB: called by pseudo_exec, and therefore must not modify any
7729 * global data until exec/_exit (we can be a child after vfork!) */
7730 static int run_list(struct pipe *pi)
7732 #if ENABLE_HUSH_CASE
7733 char *case_word = NULL;
7735 #if ENABLE_HUSH_LOOPS
7736 struct pipe *loop_top = NULL;
7737 char **for_lcur = NULL;
7738 char **for_list = NULL;
7740 smallint last_followup;
7742 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7743 smalluint cond_code = 0;
7745 enum { cond_code = 0 };
7748 smallint rword; /* RES_foo */
7749 smallint last_rword; /* ditto */
7752 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7755 #if ENABLE_HUSH_LOOPS
7756 /* Check syntax for "for" */
7759 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7760 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7762 /* current word is FOR or IN (BOLD in comments below) */
7763 if (cpipe->next == NULL) {
7764 syntax_error("malformed for");
7766 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7769 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7770 if (cpipe->next->res_word == RES_DO)
7772 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7773 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7774 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7776 syntax_error("malformed for");
7778 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7785 /* Past this point, all code paths should jump to ret: label
7786 * in order to return, no direct "return" statements please.
7787 * This helps to ensure that no memory is leaked. */
7795 last_rword = RES_XXXX;
7797 last_followup = PIPE_SEQ;
7798 rcode = G.last_exitcode;
7800 /* Go through list of pipes, (maybe) executing them. */
7801 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7806 if (G_flag_return_in_progress == 1)
7809 IF_HAS_KEYWORDS(rword = pi->res_word;)
7810 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7811 rword, cond_code, last_rword);
7812 #if ENABLE_HUSH_LOOPS
7813 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7814 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7816 /* start of a loop: remember where loop starts */
7821 /* Still in the same "if...", "then..." or "do..." branch? */
7822 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7823 if ((rcode == 0 && last_followup == PIPE_OR)
7824 || (rcode != 0 && last_followup == PIPE_AND)
7826 /* It is "<true> || CMD" or "<false> && CMD"
7827 * and we should not execute CMD */
7828 debug_printf_exec("skipped cmd because of || or &&\n");
7829 last_followup = pi->followup;
7830 goto dont_check_jobs_but_continue;
7833 last_followup = pi->followup;
7834 IF_HAS_KEYWORDS(last_rword = rword;)
7837 if (rword == RES_THEN) {
7838 /* if false; then ... fi has exitcode 0! */
7839 G.last_exitcode = rcode = EXIT_SUCCESS;
7840 /* "if <false> THEN cmd": skip cmd */
7844 if (rword == RES_ELSE || rword == RES_ELIF) {
7845 /* "if <true> then ... ELSE/ELIF cmd":
7846 * skip cmd and all following ones */
7851 #if ENABLE_HUSH_LOOPS
7852 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7854 /* first loop through for */
7856 static const char encoded_dollar_at[] ALIGN1 = {
7857 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7858 }; /* encoded representation of "$@" */
7859 static const char *const encoded_dollar_at_argv[] = {
7860 encoded_dollar_at, NULL
7861 }; /* argv list with one element: "$@" */
7864 vals = (char**)encoded_dollar_at_argv;
7865 if (pi->next->res_word == RES_IN) {
7866 /* if no variable values after "in" we skip "for" */
7867 if (!pi->next->cmds[0].argv) {
7868 G.last_exitcode = rcode = EXIT_SUCCESS;
7869 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7872 vals = pi->next->cmds[0].argv;
7873 } /* else: "for var; do..." -> assume "$@" list */
7874 /* create list of variable values */
7875 debug_print_strings("for_list made from", vals);
7876 for_list = expand_strvec_to_strvec(vals);
7877 for_lcur = for_list;
7878 debug_print_strings("for_list", for_list);
7881 /* "for" loop is over, clean up */
7887 /* Insert next value from for_lcur */
7888 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7889 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7892 if (rword == RES_IN) {
7893 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7895 if (rword == RES_DONE) {
7896 continue; /* "done" has no cmds too */
7899 #if ENABLE_HUSH_CASE
7900 if (rword == RES_CASE) {
7901 debug_printf_exec("CASE cond_code:%d\n", cond_code);
7902 case_word = expand_strvec_to_string(pi->cmds->argv);
7905 if (rword == RES_MATCH) {
7908 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
7909 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7911 /* all prev words didn't match, does this one match? */
7912 argv = pi->cmds->argv;
7914 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7915 /* TODO: which FNM_xxx flags to use? */
7916 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7918 if (cond_code == 0) { /* match! we will execute this branch */
7920 case_word = NULL; /* make future "word)" stop */
7927 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7928 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
7930 continue; /* not matched yet, skip this pipe */
7932 if (rword == RES_ESAC) {
7933 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
7935 /* "case" did not match anything: still set $? (to 0) */
7936 G.last_exitcode = rcode = EXIT_SUCCESS;
7940 /* Just pressing <enter> in shell should check for jobs.
7941 * OTOH, in non-interactive shell this is useless
7942 * and only leads to extra job checks */
7943 if (pi->num_cmds == 0) {
7944 if (G_interactive_fd)
7945 goto check_jobs_and_continue;
7949 /* After analyzing all keywords and conditions, we decided
7950 * to execute this pipe. NB: have to do checkjobs(NULL)
7951 * after run_pipe to collect any background children,
7952 * even if list execution is to be stopped. */
7953 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7954 #if ENABLE_HUSH_LOOPS
7955 G.flag_break_continue = 0;
7957 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
7959 /* We ran a builtin, function, or group.
7960 * rcode is already known
7961 * and we don't need to wait for anything. */
7962 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7963 G.last_exitcode = rcode;
7964 check_and_run_traps();
7965 #if ENABLE_HUSH_LOOPS
7966 /* Was it "break" or "continue"? */
7967 if (G.flag_break_continue) {
7968 smallint fbc = G.flag_break_continue;
7969 /* We might fall into outer *loop*,
7970 * don't want to break it too */
7972 G.depth_break_continue--;
7973 if (G.depth_break_continue == 0)
7974 G.flag_break_continue = 0;
7975 /* else: e.g. "continue 2" should *break* once, *then* continue */
7976 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7977 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7978 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7981 /* "continue": simulate end of loop */
7986 if (G_flag_return_in_progress == 1) {
7987 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7990 } else if (pi->followup == PIPE_BG) {
7991 /* What does bash do with attempts to background builtins? */
7992 /* even bash 3.2 doesn't do that well with nested bg:
7993 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7994 * I'm NOT treating inner &'s as jobs */
7996 if (G.run_list_level == 1)
7999 /* Last command's pid goes to $! */
8000 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8001 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8002 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8003 rcode = EXIT_SUCCESS;
8007 if (G.run_list_level == 1 && G_interactive_fd) {
8008 /* Waits for completion, then fg's main shell */
8009 rcode = checkjobs_and_fg_shell(pi);
8010 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8014 /* This one just waits for completion */
8015 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8016 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8018 G.last_exitcode = rcode;
8019 check_and_run_traps();
8022 /* Analyze how result affects subsequent commands */
8024 if (rword == RES_IF || rword == RES_ELIF)
8027 check_jobs_and_continue:
8028 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8029 dont_check_jobs_but_continue: ;
8030 #if ENABLE_HUSH_LOOPS
8031 /* Beware of "while false; true; do ..."! */
8033 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8034 /* check for RES_DONE is needed for "while ...; do \n done" case */
8036 if (rword == RES_WHILE) {
8038 /* "while false; do...done" - exitcode 0 */
8039 G.last_exitcode = rcode = EXIT_SUCCESS;
8040 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8044 if (rword == RES_UNTIL) {
8046 debug_printf_exec(": until expr is true: breaking\n");
8057 #if ENABLE_HUSH_LOOPS
8062 #if ENABLE_HUSH_CASE
8066 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8070 /* Select which version we will use */
8071 static int run_and_free_list(struct pipe *pi)
8074 debug_printf_exec("run_and_free_list entered\n");
8075 if (!G.o_opt[OPT_O_NOEXEC]) {
8076 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8077 rcode = run_list(pi);
8079 /* free_pipe_list has the side effect of clearing memory.
8080 * In the long run that function can be merged with run_list,
8081 * but doing that now would hobble the debugging effort. */
8083 debug_printf_exec("run_and_free_list return %d\n", rcode);
8088 static void install_sighandlers(unsigned mask)
8090 sighandler_t old_handler;
8092 while ((mask >>= 1) != 0) {
8096 old_handler = install_sighandler(sig, pick_sighandler(sig));
8097 /* POSIX allows shell to re-enable SIGCHLD
8098 * even if it was SIG_IGN on entry.
8099 * Therefore we skip IGN check for it:
8103 if (old_handler == SIG_IGN) {
8104 /* oops... restore back to IGN, and record this fact */
8105 install_sighandler(sig, old_handler);
8107 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8109 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8114 /* Called a few times only (or even once if "sh -c") */
8115 static void install_special_sighandlers(void)
8119 /* Which signals are shell-special? */
8120 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8121 if (G_interactive_fd) {
8122 mask |= SPECIAL_INTERACTIVE_SIGS;
8123 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8124 mask |= SPECIAL_JOBSTOP_SIGS;
8126 /* Careful, do not re-install handlers we already installed */
8127 if (G.special_sig_mask != mask) {
8128 unsigned diff = mask & ~G.special_sig_mask;
8129 G.special_sig_mask = mask;
8130 install_sighandlers(diff);
8136 /* Set handlers to restore tty pgrp and exit */
8137 static void install_fatal_sighandlers(void)
8141 /* We will restore tty pgrp on these signals */
8143 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8144 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8145 + (1 << SIGBUS ) * HUSH_DEBUG
8146 + (1 << SIGSEGV) * HUSH_DEBUG
8147 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8149 /* bash 3.2 seems to handle these just like 'fatal' ones */
8152 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8153 * if we aren't interactive... but in this case
8154 * we never want to restore pgrp on exit, and this fn is not called
8156 /*+ (1 << SIGHUP )*/
8157 /*+ (1 << SIGTERM)*/
8158 /*+ (1 << SIGINT )*/
8160 G_fatal_sig_mask = mask;
8162 install_sighandlers(mask);
8166 static int set_mode(int state, char mode, const char *o_opt)
8171 G.o_opt[OPT_O_NOEXEC] = state;
8174 IF_HUSH_MODE_X(G_x_mode = state;)
8178 /* "set -+o" without parameter.
8179 * in bash, set -o produces this output:
8183 * We always use the second form.
8185 const char *p = o_opt_strings;
8188 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8194 idx = index_in_strings(o_opt_strings, o_opt);
8196 G.o_opt[idx] = state;
8200 return EXIT_FAILURE;
8202 return EXIT_SUCCESS;
8205 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8206 int hush_main(int argc, char **argv)
8209 OPT_login = (1 << 0),
8213 unsigned builtin_argc;
8215 struct variable *cur_var;
8216 struct variable *shell_ver;
8219 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8220 G.last_exitcode = EXIT_SUCCESS;
8222 #if ENABLE_HUSH_FAST
8223 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8226 G.argv0_for_re_execing = argv[0];
8228 /* Deal with HUSH_VERSION */
8229 shell_ver = xzalloc(sizeof(*shell_ver));
8230 shell_ver->flg_export = 1;
8231 shell_ver->flg_read_only = 1;
8232 /* Code which handles ${var<op>...} needs writable values for all variables,
8233 * therefore we xstrdup: */
8234 shell_ver->varstr = xstrdup(hush_version_str);
8235 /* Create shell local variables from the values
8236 * currently living in the environment */
8237 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8238 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8239 G.top_var = shell_ver;
8240 cur_var = G.top_var;
8243 char *value = strchr(*e, '=');
8244 if (value) { /* paranoia */
8245 cur_var->next = xzalloc(sizeof(*cur_var));
8246 cur_var = cur_var->next;
8247 cur_var->varstr = *e;
8248 cur_var->max_len = strlen(*e);
8249 cur_var->flg_export = 1;
8253 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8254 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8255 putenv(shell_ver->varstr);
8258 set_pwd_var(/*exp:*/ 1);
8260 #if ENABLE_HUSH_BASH_COMPAT
8261 /* Set (but not export) HOSTNAME unless already set */
8262 if (!get_local_var_value("HOSTNAME")) {
8265 set_local_var_from_halves("HOSTNAME", uts.nodename);
8267 /* bash also exports SHLVL and _,
8268 * and sets (but doesn't export) the following variables:
8270 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8271 * BASH_VERSION='3.2.0(1)-release'
8273 * MACHTYPE=i386-pc-linux-gnu
8275 * PPID=<NNNNN> - we also do it elsewhere
8286 * PIPESTATUS=([0]="0")
8287 * HISTFILE=/<xxx>/.bash_history
8291 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8293 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8304 #if ENABLE_FEATURE_EDITING
8305 G.line_input_state = new_line_input_t(FOR_SHELL);
8308 /* Initialize some more globals to non-zero values */
8309 cmdedit_update_prompt();
8311 die_func = restore_ttypgrp_and__exit;
8313 /* Shell is non-interactive at first. We need to call
8314 * install_special_sighandlers() if we are going to execute "sh <script>",
8315 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8316 * If we later decide that we are interactive, we run install_special_sighandlers()
8317 * in order to intercept (more) signals.
8321 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8322 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8325 opt = getopt(argc, argv, "+c:xinsl"
8328 # if ENABLE_HUSH_FUNCTIONS
8338 * sh ... -c 'script'
8339 * sh ... -c 'script' ARG0 [ARG1...]
8340 * On NOMMU, if builtin_argc != 0,
8341 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8342 * "" needs to be replaced with NULL
8343 * and BARGV vector fed to builtin function.
8344 * Note: the form without ARG0 never happens:
8345 * sh ... -c 'builtin' BARGV... ""
8348 G.root_pid = getpid();
8349 G.root_ppid = getppid();
8351 G.global_argv = argv + optind;
8352 G.global_argc = argc - optind;
8354 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8355 const struct built_in_command *x;
8357 install_special_sighandlers();
8358 x = find_builtin(optarg);
8359 if (x) { /* paranoia */
8360 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8361 G.global_argv += builtin_argc;
8362 G.global_argv[-1] = NULL; /* replace "" */
8364 G.last_exitcode = x->b_function(argv + optind - 1);
8368 if (!G.global_argv[0]) {
8369 /* -c 'script' (no params): prevent empty $0 */
8370 G.global_argv--; /* points to argv[i] of 'script' */
8371 G.global_argv[0] = argv[0];
8373 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8374 install_special_sighandlers();
8375 parse_and_run_string(optarg);
8378 /* Well, we cannot just declare interactiveness,
8379 * we have to have some stuff (ctty, etc) */
8380 /* G_interactive_fd++; */
8383 /* "-s" means "read from stdin", but this is how we always
8384 * operate, so simply do nothing here. */
8390 case '<': /* "big heredoc" support */
8391 full_write1_str(optarg);
8394 unsigned long long empty_trap_mask;
8396 G.root_pid = bb_strtou(optarg, &optarg, 16);
8398 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8400 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8402 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8404 builtin_argc = bb_strtou(optarg, &optarg, 16);
8406 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8407 if (empty_trap_mask != 0) {
8409 install_special_sighandlers();
8410 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8411 for (sig = 1; sig < NSIG; sig++) {
8412 if (empty_trap_mask & (1LL << sig)) {
8413 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8414 install_sighandler(sig, SIG_IGN);
8418 # if ENABLE_HUSH_LOOPS
8420 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8426 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8428 # if ENABLE_HUSH_FUNCTIONS
8430 struct function *funcp = new_function(optarg);
8431 /* funcp->name is already set to optarg */
8432 /* funcp->body is set to NULL. It's a special case. */
8433 funcp->body_as_string = argv[optind];
8441 if (set_mode(1, opt, NULL) == 0) /* no error */
8445 fprintf(stderr, "Usage: sh [FILE]...\n"
8446 " or: sh -c command [args]...\n\n");
8452 } /* option parsing loop */
8454 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8455 G.global_argc = argc - (optind - 1);
8456 G.global_argv = argv + (optind - 1);
8457 G.global_argv[0] = argv[0];
8460 G.root_pid = getpid();
8461 G.root_ppid = getppid();
8464 /* If we are login shell... */
8465 if (flags & OPT_login) {
8467 debug_printf("sourcing /etc/profile\n");
8468 input = fopen_for_read("/etc/profile");
8469 if (input != NULL) {
8470 remember_FILE(input);
8471 install_special_sighandlers();
8472 parse_and_run_file(input);
8473 fclose_and_forget(input);
8475 /* bash: after sourcing /etc/profile,
8476 * tries to source (in the given order):
8477 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8478 * stopping on first found. --noprofile turns this off.
8479 * bash also sources ~/.bash_logout on exit.
8480 * If called as sh, skips .bash_XXX files.
8484 if (G.global_argv[1]) {
8487 * "bash <script>" (which is never interactive (unless -i?))
8488 * sources $BASH_ENV here (without scanning $PATH).
8489 * If called as sh, does the same but with $ENV.
8490 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8494 debug_printf("running script '%s'\n", G.global_argv[0]);
8495 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8496 input = xfopen_for_read(G.global_argv[0]);
8497 xfunc_error_retval = 1;
8498 remember_FILE(input);
8499 install_special_sighandlers();
8500 parse_and_run_file(input);
8501 #if ENABLE_FEATURE_CLEAN_UP
8502 fclose_and_forget(input);
8507 /* Up to here, shell was non-interactive. Now it may become one.
8508 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8511 /* A shell is interactive if the '-i' flag was given,
8512 * or if all of the following conditions are met:
8514 * no arguments remaining or the -s flag given
8515 * standard input is a terminal
8516 * standard output is a terminal
8517 * Refer to Posix.2, the description of the 'sh' utility.
8520 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8521 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8522 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8523 if (G_saved_tty_pgrp < 0)
8524 G_saved_tty_pgrp = 0;
8526 /* try to dup stdin to high fd#, >= 255 */
8527 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8528 if (G_interactive_fd < 0) {
8529 /* try to dup to any fd */
8530 G_interactive_fd = dup(STDIN_FILENO);
8531 if (G_interactive_fd < 0) {
8533 G_interactive_fd = 0;
8534 G_saved_tty_pgrp = 0;
8537 // TODO: track & disallow any attempts of user
8538 // to (inadvertently) close/redirect G_interactive_fd
8540 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8541 if (G_interactive_fd) {
8542 close_on_exec_on(G_interactive_fd);
8544 if (G_saved_tty_pgrp) {
8545 /* If we were run as 'hush &', sleep until we are
8546 * in the foreground (tty pgrp == our pgrp).
8547 * If we get started under a job aware app (like bash),
8548 * make sure we are now in charge so we don't fight over
8549 * who gets the foreground */
8551 pid_t shell_pgrp = getpgrp();
8552 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8553 if (G_saved_tty_pgrp == shell_pgrp)
8555 /* send TTIN to ourself (should stop us) */
8556 kill(- shell_pgrp, SIGTTIN);
8560 /* Install more signal handlers */
8561 install_special_sighandlers();
8563 if (G_saved_tty_pgrp) {
8564 /* Set other signals to restore saved_tty_pgrp */
8565 install_fatal_sighandlers();
8566 /* Put ourselves in our own process group
8567 * (bash, too, does this only if ctty is available) */
8568 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8569 /* Grab control of the terminal */
8570 tcsetpgrp(G_interactive_fd, getpid());
8572 enable_restore_tty_pgrp_on_exit();
8574 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8576 const char *hp = get_local_var_value("HISTFILE");
8578 hp = get_local_var_value("HOME");
8580 hp = concat_path_file(hp, ".hush_history");
8585 G.line_input_state->hist_file = hp;
8586 //set_local_var(xasprintf("HISTFILE=%s", ...));
8588 # if ENABLE_FEATURE_SH_HISTFILESIZE
8589 hp = get_local_var_value("HISTFILESIZE");
8590 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8595 install_special_sighandlers();
8597 #elif ENABLE_HUSH_INTERACTIVE
8598 /* No job control compiled in, only prompt/line editing */
8599 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8600 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8601 if (G_interactive_fd < 0) {
8602 /* try to dup to any fd */
8603 G_interactive_fd = dup(STDIN_FILENO);
8604 if (G_interactive_fd < 0)
8606 G_interactive_fd = 0;
8609 if (G_interactive_fd) {
8610 close_on_exec_on(G_interactive_fd);
8612 install_special_sighandlers();
8614 /* We have interactiveness code disabled */
8615 install_special_sighandlers();
8618 * if interactive but not a login shell, sources ~/.bashrc
8619 * (--norc turns this off, --rcfile <file> overrides)
8622 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8623 /* note: ash and hush share this string */
8624 printf("\n\n%s %s\n"
8625 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8628 "hush - the humble shell"
8632 parse_and_run_file(stdin);
8635 hush_exit(G.last_exitcode);
8640 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8641 int msh_main(int argc, char **argv)
8643 bb_error_msg("msh is deprecated, please use hush instead");
8644 return hush_main(argc, argv);
8652 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8657 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8664 return applet_main_func(argc, argv - argc);
8667 static int FAST_FUNC builtin_test(char **argv)
8669 return run_applet_main(argv, test_main);
8672 static int FAST_FUNC builtin_echo(char **argv)
8674 return run_applet_main(argv, echo_main);
8678 static int FAST_FUNC builtin_printf(char **argv)
8680 return run_applet_main(argv, printf_main);
8684 static char **skip_dash_dash(char **argv)
8687 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8692 static int FAST_FUNC builtin_eval(char **argv)
8694 int rcode = EXIT_SUCCESS;
8696 argv = skip_dash_dash(argv);
8698 char *str = expand_strvec_to_string(argv);
8700 * eval "echo Hi; done" ("done" is syntax error):
8701 * "echo Hi" will not execute too.
8703 parse_and_run_string(str);
8705 rcode = G.last_exitcode;
8710 static int FAST_FUNC builtin_cd(char **argv)
8714 argv = skip_dash_dash(argv);
8716 if (newdir == NULL) {
8717 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8718 * bash says "bash: cd: HOME not set" and does nothing
8721 const char *home = get_local_var_value("HOME");
8722 newdir = home ? home : "/";
8724 if (chdir(newdir)) {
8725 /* Mimic bash message exactly */
8726 bb_perror_msg("cd: %s", newdir);
8727 return EXIT_FAILURE;
8729 /* Read current dir (get_cwd(1) is inside) and set PWD.
8730 * Note: do not enforce exporting. If PWD was unset or unexported,
8731 * set it again, but do not export. bash does the same.
8733 set_pwd_var(/*exp:*/ 0);
8734 return EXIT_SUCCESS;
8737 static int FAST_FUNC builtin_exec(char **argv)
8739 argv = skip_dash_dash(argv);
8740 if (argv[0] == NULL)
8741 return EXIT_SUCCESS; /* bash does this */
8743 /* Careful: we can end up here after [v]fork. Do not restore
8744 * tty pgrp then, only top-level shell process does that */
8745 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8746 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8748 /* TODO: if exec fails, bash does NOT exit! We do.
8749 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8750 * and tcsetpgrp, and this is inherently racy.
8752 execvp_or_die(argv);
8755 static int FAST_FUNC builtin_exit(char **argv)
8757 debug_printf_exec("%s()\n", __func__);
8759 /* interactive bash:
8760 * # trap "echo EEE" EXIT
8763 * There are stopped jobs.
8764 * (if there are _stopped_ jobs, running ones don't count)
8767 * EEE (then bash exits)
8769 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8772 /* note: EXIT trap is run by hush_exit */
8773 argv = skip_dash_dash(argv);
8774 if (argv[0] == NULL)
8775 hush_exit(G.last_exitcode);
8776 /* mimic bash: exit 123abc == exit 255 + error msg */
8777 xfunc_error_retval = 255;
8778 /* bash: exit -2 == exit 254, no error msg */
8779 hush_exit(xatoi(argv[0]) & 0xff);
8782 static void print_escaped(const char *s)
8787 const char *p = strchrnul(s, '\'');
8788 /* print 'xxxx', possibly just '' */
8789 printf("'%.*s'", (int)(p - s), s);
8794 /* s points to '; print "'''...'''" */
8796 do putchar('\''); while (*++s == '\'');
8801 #if !ENABLE_HUSH_LOCAL
8802 #define helper_export_local(argv, exp, lvl) \
8803 helper_export_local(argv, exp)
8805 static void helper_export_local(char **argv, int exp, int lvl)
8809 char *name_end = strchrnul(name, '=');
8811 /* So far we do not check that name is valid (TODO?) */
8813 if (*name_end == '\0') {
8814 struct variable *var, **vpp;
8816 vpp = get_ptr_to_local_var(name, name_end - name);
8817 var = vpp ? *vpp : NULL;
8819 if (exp == -1) { /* unexporting? */
8820 /* export -n NAME (without =VALUE) */
8822 var->flg_export = 0;
8823 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8825 } /* else: export -n NOT_EXISTING_VAR: no-op */
8828 if (exp == 1) { /* exporting? */
8829 /* export NAME (without =VALUE) */
8831 var->flg_export = 1;
8832 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8833 putenv(var->varstr);
8837 #if ENABLE_HUSH_LOCAL
8838 if (exp == 0 /* local? */
8839 && var && var->func_nest_level == lvl
8841 /* "local x=abc; ...; local x" - ignore second local decl */
8845 /* Exporting non-existing variable.
8846 * bash does not put it in environment,
8847 * but remembers that it is exported,
8848 * and does put it in env when it is set later.
8849 * We just set it to "" and export. */
8850 /* Or, it's "local NAME" (without =VALUE).
8851 * bash sets the value to "". */
8852 name = xasprintf("%s=", name);
8854 /* (Un)exporting/making local NAME=VALUE */
8855 name = xstrdup(name);
8857 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8861 static int FAST_FUNC builtin_export(char **argv)
8863 unsigned opt_unexport;
8865 #if ENABLE_HUSH_EXPORT_N
8866 /* "!": do not abort on errors */
8867 opt_unexport = getopt32(argv, "!n");
8868 if (opt_unexport == (uint32_t)-1)
8869 return EXIT_FAILURE;
8876 if (argv[0] == NULL) {
8883 /* ash emits: export VAR='VAL'
8884 * bash: declare -x VAR="VAL"
8885 * we follow ash example */
8886 const char *s = *e++;
8887 const char *p = strchr(s, '=');
8889 if (!p) /* wtf? take next variable */
8892 printf("export %.*s", (int)(p - s) + 1, s);
8893 print_escaped(p + 1);
8897 /*fflush_all(); - done after each builtin anyway */
8899 return EXIT_SUCCESS;
8902 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8904 return EXIT_SUCCESS;
8907 #if ENABLE_HUSH_LOCAL
8908 static int FAST_FUNC builtin_local(char **argv)
8910 if (G.func_nest_level == 0) {
8911 bb_error_msg("%s: not in a function", argv[0]);
8912 return EXIT_FAILURE; /* bash compat */
8914 helper_export_local(argv, 0, G.func_nest_level);
8915 return EXIT_SUCCESS;
8919 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8920 static int FAST_FUNC builtin_unset(char **argv)
8925 /* "!": do not abort on errors */
8926 /* "+": stop at 1st non-option */
8927 opts = getopt32(argv, "!+vf");
8928 if (opts == (unsigned)-1)
8929 return EXIT_FAILURE;
8931 bb_error_msg("unset: -v and -f are exclusive");
8932 return EXIT_FAILURE;
8938 if (!(opts & 2)) { /* not -f */
8939 if (unset_local_var(*argv)) {
8940 /* unset <nonexistent_var> doesn't fail.
8941 * Error is when one tries to unset RO var.
8942 * Message was printed by unset_local_var. */
8946 #if ENABLE_HUSH_FUNCTIONS
8956 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8957 * built-in 'set' handler
8959 * set [-abCefhmnuvx] [-o option] [argument...]
8960 * set [+abCefhmnuvx] [+o option] [argument...]
8961 * set -- [argument...]
8964 * Implementations shall support the options in both their hyphen and
8965 * plus-sign forms. These options can also be specified as options to sh.
8967 * Write out all variables and their values: set
8968 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8969 * Turn on the -x and -v options: set -xv
8970 * Unset all positional parameters: set --
8971 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8972 * Set the positional parameters to the expansion of x, even if x expands
8973 * with a leading '-' or '+': set -- $x
8975 * So far, we only support "set -- [argument...]" and some of the short names.
8977 static int FAST_FUNC builtin_set(char **argv)
8980 char **pp, **g_argv;
8981 char *arg = *++argv;
8985 for (e = G.top_var; e; e = e->next)
8987 return EXIT_SUCCESS;
8991 if (strcmp(arg, "--") == 0) {
8995 if (arg[0] != '+' && arg[0] != '-')
8997 for (n = 1; arg[n]; ++n) {
8998 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9000 if (arg[n] == 'o' && argv[1])
9003 } while ((arg = *++argv) != NULL);
9004 /* Now argv[0] is 1st argument */
9007 return EXIT_SUCCESS;
9010 /* NB: G.global_argv[0] ($0) is never freed/changed */
9011 g_argv = G.global_argv;
9012 if (G.global_args_malloced) {
9018 G.global_args_malloced = 1;
9019 pp = xzalloc(sizeof(pp[0]) * 2);
9020 pp[0] = g_argv[0]; /* retain $0 */
9023 /* This realloc's G.global_argv */
9024 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9031 return EXIT_SUCCESS;
9033 /* Nothing known, so abort */
9035 bb_error_msg("set: %s: invalid option", arg);
9036 return EXIT_FAILURE;
9039 static int FAST_FUNC builtin_shift(char **argv)
9042 argv = skip_dash_dash(argv);
9046 if (n >= 0 && n < G.global_argc) {
9047 if (G.global_args_malloced) {
9050 free(G.global_argv[m++]);
9053 memmove(&G.global_argv[1], &G.global_argv[n+1],
9054 G.global_argc * sizeof(G.global_argv[0]));
9055 return EXIT_SUCCESS;
9057 return EXIT_FAILURE;
9060 /* Interruptibility of read builtin in bash
9061 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9063 * Empty trap makes read ignore corresponding signal, for any signal.
9066 * - terminates non-interactive shell;
9067 * - interrupts read in interactive shell;
9068 * if it has non-empty trap:
9069 * - executes trap and returns to command prompt in interactive shell;
9070 * - executes trap and returns to read in non-interactive shell;
9072 * - is ignored (does not interrupt) read in interactive shell;
9073 * - terminates non-interactive shell;
9074 * if it has non-empty trap:
9075 * - executes trap and returns to read;
9077 * - terminates shell (regardless of interactivity);
9078 * if it has non-empty trap:
9079 * - executes trap and returns to read;
9081 static int FAST_FUNC builtin_read(char **argv)
9091 /* "!": do not abort on errors.
9092 * Option string must start with "sr" to match BUILTIN_READ_xxx
9094 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9095 if (read_flags == (uint32_t)-1)
9096 return EXIT_FAILURE;
9098 ifs = get_local_var_value("IFS"); /* can be NULL */
9101 r = shell_builtin_read(set_local_var_from_halves,
9111 if ((uintptr_t)r == 1 && errno == EINTR) {
9112 unsigned sig = check_and_run_traps();
9113 if (sig && sig != SIGINT)
9117 if ((uintptr_t)r > 1) {
9118 bb_error_msg("%s", r);
9119 r = (char*)(uintptr_t)1;
9122 return (uintptr_t)r;
9125 static int FAST_FUNC builtin_trap(char **argv)
9131 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9136 /* No args: print all trapped */
9137 for (i = 0; i < NSIG; ++i) {
9140 print_escaped(G.traps[i]);
9141 /* note: bash adds "SIG", but only if invoked
9142 * as "bash". If called as "sh", or if set -o posix,
9143 * then it prints short signal names.
9144 * We are printing short names: */
9145 printf(" %s\n", get_signame(i));
9148 /*fflush_all(); - done after each builtin anyway */
9149 return EXIT_SUCCESS;
9153 /* If first arg is a number: reset all specified signals */
9154 sig = bb_strtou(*argv, NULL, 10);
9160 sighandler_t handler;
9162 sig = get_signum(*argv++);
9163 if (sig < 0 || sig >= NSIG) {
9165 /* Mimic bash message exactly */
9166 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9171 G.traps[sig] = xstrdup(new_cmd);
9173 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9174 get_signame(sig), sig, G.traps[sig]);
9176 /* There is no signal for 0 (EXIT) */
9181 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9183 /* We are removing trap handler */
9184 handler = pick_sighandler(sig);
9185 install_sighandler(sig, handler);
9190 if (!argv[1]) { /* no second arg */
9191 bb_error_msg("trap: invalid arguments");
9192 return EXIT_FAILURE;
9195 /* First arg is "-": reset all specified to default */
9196 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9197 /* Everything else: set arg as signal handler
9198 * (includes "" case, which ignores signal) */
9199 if (argv[0][0] == '-') {
9200 if (argv[0][1] == '\0') { /* "-" */
9201 /* new_cmd remains NULL: "reset these sigs" */
9204 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9207 /* else: "-something", no special meaning */
9212 goto process_sig_list;
9215 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9216 static int FAST_FUNC builtin_type(char **argv)
9218 int ret = EXIT_SUCCESS;
9224 if (0) {} /* make conditional compile easier below */
9225 /*else if (find_alias(*argv))
9226 type = "an alias";*/
9227 #if ENABLE_HUSH_FUNCTIONS
9228 else if (find_function(*argv))
9229 type = "a function";
9231 else if (find_builtin(*argv))
9232 type = "a shell builtin";
9233 else if ((path = find_in_path(*argv)) != NULL)
9236 bb_error_msg("type: %s: not found", *argv);
9241 printf("%s is %s\n", *argv, type);
9249 static struct pipe *parse_jobspec(const char *str)
9254 if (sscanf(str, "%%%d", &jobnum) != 1) {
9255 bb_error_msg("bad argument '%s'", str);
9258 for (pi = G.job_list; pi; pi = pi->next) {
9259 if (pi->jobid == jobnum) {
9263 bb_error_msg("%d: no such job", jobnum);
9267 /* built-in 'fg' and 'bg' handler */
9268 static int FAST_FUNC builtin_fg_bg(char **argv)
9273 if (!G_interactive_fd)
9274 return EXIT_FAILURE;
9276 /* If they gave us no args, assume they want the last backgrounded task */
9278 for (pi = G.job_list; pi; pi = pi->next) {
9279 if (pi->jobid == G.last_jobid) {
9283 bb_error_msg("%s: no current job", argv[0]);
9284 return EXIT_FAILURE;
9287 pi = parse_jobspec(argv[1]);
9289 return EXIT_FAILURE;
9291 /* TODO: bash prints a string representation
9292 * of job being foregrounded (like "sleep 1 | cat") */
9293 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9294 /* Put the job into the foreground. */
9295 tcsetpgrp(G_interactive_fd, pi->pgrp);
9298 /* Restart the processes in the job */
9299 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9300 for (i = 0; i < pi->num_cmds; i++) {
9301 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9303 pi->stopped_cmds = 0;
9305 i = kill(- pi->pgrp, SIGCONT);
9307 if (errno == ESRCH) {
9308 delete_finished_bg_job(pi);
9309 return EXIT_SUCCESS;
9311 bb_perror_msg("kill (SIGCONT)");
9314 if (argv[0][0] == 'f') {
9316 return checkjobs_and_fg_shell(pi);
9318 return EXIT_SUCCESS;
9322 #if ENABLE_HUSH_HELP
9323 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9325 const struct built_in_command *x;
9328 "Built-in commands:\n"
9329 "------------------\n");
9330 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9332 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9334 return EXIT_SUCCESS;
9338 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9339 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9341 show_history(G.line_input_state);
9342 return EXIT_SUCCESS;
9347 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9350 const char *status_string;
9352 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9353 for (job = G.job_list; job; job = job->next) {
9354 if (job->alive_cmds == job->stopped_cmds)
9355 status_string = "Stopped";
9357 status_string = "Running";
9359 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9361 return EXIT_SUCCESS;
9366 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9371 # ifdef M_TRIM_THRESHOLD
9372 /* Optional. Reduces probability of false positives */
9375 /* Crude attempt to find where "free memory" starts,
9376 * sans fragmentation. */
9378 l = (unsigned long)p;
9381 if (l < (unsigned long)p) l = (unsigned long)p;
9387 struct mallinfo mi = mallinfo();
9388 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9389 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9393 if (!G.memleak_value)
9394 G.memleak_value = l;
9396 l -= G.memleak_value;
9403 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9408 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9411 return EXIT_SUCCESS;
9414 static int FAST_FUNC builtin_source(char **argv)
9416 char *arg_path, *filename;
9419 #if ENABLE_HUSH_FUNCTIONS
9423 argv = skip_dash_dash(argv);
9426 /* bash says: "bash: .: filename argument required" */
9427 return 2; /* bash compat */
9430 if (!strchr(filename, '/')) {
9431 arg_path = find_in_path(filename);
9433 filename = arg_path;
9435 input = remember_FILE(fopen_or_warn(filename, "r"));
9438 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9439 /* POSIX: non-interactive shell should abort here,
9440 * not merely fail. So far no one complained :)
9442 return EXIT_FAILURE;
9445 #if ENABLE_HUSH_FUNCTIONS
9446 sv_flg = G_flag_return_in_progress;
9447 /* "we are inside sourced file, ok to use return" */
9448 G_flag_return_in_progress = -1;
9451 save_and_replace_G_args(&sv, argv);
9453 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9454 G.last_exitcode = 0;
9455 parse_and_run_file(input);
9456 fclose_and_forget(input);
9459 restore_G_args(&sv, argv);
9460 #if ENABLE_HUSH_FUNCTIONS
9461 G_flag_return_in_progress = sv_flg;
9464 return G.last_exitcode;
9467 static int FAST_FUNC builtin_umask(char **argv)
9474 argv = skip_dash_dash(argv);
9476 mode_t old_mask = mask;
9478 /* numeric umasks are taken as-is */
9479 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9480 if (!isdigit(argv[0][0]))
9482 mask = bb_parse_mode(argv[0], mask);
9483 if (!isdigit(argv[0][0]))
9485 if ((unsigned)mask > 0777) {
9488 * bash: umask: 'q': invalid symbolic mode operator
9489 * bash: umask: 999: octal number out of range
9491 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9496 printf("%04o\n", (unsigned) mask);
9497 /* fall through and restore mask which we set to 0 */
9501 return !rc; /* rc != 0 - success */
9504 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9505 #if !ENABLE_HUSH_JOB
9506 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9508 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9515 if (!sigisemptyset(&G.pending_set))
9518 /* waitpid is not interruptible by SA_RESTARTed
9519 * signals which we use. Thus, this ugly dance:
9522 /* Make sure possible SIGCHLD is stored in kernel's
9523 * pending signal mask before we call waitpid.
9524 * Or else we may race with SIGCHLD, lose it,
9525 * and get stuck in sigsuspend...
9527 sigfillset(&oldset); /* block all signals, remember old set */
9528 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9530 if (!sigisemptyset(&G.pending_set)) {
9531 /* Crap! we raced with some signal! */
9535 /*errno = 0; - checkjobs does this */
9536 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9537 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9538 debug_printf_exec("checkjobs:%d\n", ret);
9541 int rcode = job_exited_or_stopped(waitfor_pipe);
9542 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9545 sigprocmask(SIG_SETMASK, &oldset, NULL);
9550 /* if ECHILD, there are no children (ret is -1 or 0) */
9551 /* if ret == 0, no children changed state */
9552 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9553 if (errno == ECHILD || ret) {
9555 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9557 sigprocmask(SIG_SETMASK, &oldset, NULL);
9560 /* Wait for SIGCHLD or any other signal */
9561 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9562 /* Note: sigsuspend invokes signal handler */
9563 sigsuspend(&oldset);
9565 sigprocmask(SIG_SETMASK, &oldset, NULL);
9567 /* So, did we get a signal? */
9568 sig = check_and_run_traps();
9569 if (sig /*&& sig != SIGCHLD - always true */) {
9573 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9578 static int FAST_FUNC builtin_wait(char **argv)
9583 argv = skip_dash_dash(argv);
9584 if (argv[0] == NULL) {
9585 /* Don't care about wait results */
9586 /* Note 1: must wait until there are no more children */
9587 /* Note 2: must be interruptible */
9589 * $ sleep 3 & sleep 6 & wait
9594 * $ sleep 3 & sleep 6 & wait
9598 * ^C <-- after ~4 sec from keyboard
9601 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9605 pid_t pid = bb_strtou(*argv, NULL, 10);
9606 if (errno || pid <= 0) {
9608 if (argv[0][0] == '%') {
9609 struct pipe *wait_pipe;
9610 wait_pipe = parse_jobspec(*argv);
9612 ret = job_exited_or_stopped(wait_pipe);
9614 ret = wait_for_child_or_signal(wait_pipe, 0);
9619 /* mimic bash message */
9620 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9622 continue; /* bash checks all argv[] */
9625 /* Do we have such child? */
9626 ret = waitpid(pid, &status, WNOHANG);
9629 if (errno == ECHILD) {
9630 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9631 /* "wait $!" but last bg task has already exited. Try:
9632 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9633 * In bash it prints exitcode 0, then 3.
9634 * In dash, it is 127.
9636 /* ret = G.last_bg_pid_exitstatus - FIXME */
9638 /* Example: "wait 1". mimic bash message */
9639 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9643 bb_perror_msg("wait %s", *argv);
9646 continue; /* bash checks all argv[] */
9649 /* Yes, and it still runs */
9650 ret = wait_for_child_or_signal(NULL, pid);
9652 /* Yes, and it just exited */
9653 process_wait_result(NULL, pid, status);
9654 ret = WEXITSTATUS(status);
9655 if (WIFSIGNALED(status))
9656 ret = 128 + WTERMSIG(status);
9663 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9664 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9667 def = bb_strtou(argv[1], NULL, 10);
9668 if (errno || def < def_min || argv[2]) {
9669 bb_error_msg("%s: bad arguments", argv[0]);
9677 #if ENABLE_HUSH_LOOPS
9678 static int FAST_FUNC builtin_break(char **argv)
9681 if (G.depth_of_loop == 0) {
9682 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9683 /* if we came from builtin_continue(), need to undo "= 1" */
9684 G.flag_break_continue = 0;
9685 return EXIT_SUCCESS; /* bash compat */
9687 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9689 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9690 if (depth == UINT_MAX)
9691 G.flag_break_continue = BC_BREAK;
9692 if (G.depth_of_loop < depth)
9693 G.depth_break_continue = G.depth_of_loop;
9695 return EXIT_SUCCESS;
9698 static int FAST_FUNC builtin_continue(char **argv)
9700 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9701 return builtin_break(argv);
9705 #if ENABLE_HUSH_FUNCTIONS
9706 static int FAST_FUNC builtin_return(char **argv)
9710 if (G_flag_return_in_progress != -1) {
9711 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9712 return EXIT_FAILURE; /* bash compat */
9715 G_flag_return_in_progress = 1;
9718 * out of range: wraps around at 256, does not error out
9719 * non-numeric param:
9720 * f() { false; return qwe; }; f; echo $?
9721 * bash: return: qwe: numeric argument required <== we do this
9722 * 255 <== we also do this
9724 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);