1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
48 * follow IFS rules more precisely, including update semantics
49 * builtins mandated by standards we don't support:
50 * [un]alias, command, fc, getopts, newgrp, readonly, times
51 * make complex ${var%...} constructs support optional
52 * make here documents optional
55 * redirection of stdout+stderr: &> and >&
56 * reserved words: function select
57 * advanced test: [[ ]]
58 * process substitution: <(list) and >(list)
61 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
62 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
63 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
65 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
66 * This is exactly equivalent to let "EXPR".
67 * $[EXPR]: synonym for $((EXPR))
70 * In bash, export builtin is special, its arguments are assignments
71 * and therefore expansion of them should be "one-word" expansion:
72 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
74 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
75 * ls: cannot access i=a: No such file or directory
76 * ls: cannot access b: No such file or directory
77 * Note1: same applies to local builtin.
78 * Note2: bash 3.2.33(1) does this only if export word itself
80 * $ export i=`echo 'aaa bbb'`; echo "$i"
82 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
89 //config: hush is a small shell (25k). It handles the normal flow control
90 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
91 //config: case/esac. Redirections, here documents, $((arithmetic))
92 //config: and functions are supported.
94 //config: It will compile and work on no-mmu systems.
96 //config: It does not handle select, aliases, tilde expansion,
97 //config: &>file and >&file redirection of stdout+stderr.
99 //config:config HUSH_BASH_COMPAT
100 //config: bool "bash-compatible extensions"
102 //config: depends on HUSH
104 //config: Enable bash-compatible extensions.
106 //config:config HUSH_BRACE_EXPANSION
107 //config: bool "Brace expansion"
109 //config: depends on HUSH_BASH_COMPAT
111 //config: Enable {abc,def} extension.
113 //config:config HUSH_HELP
114 //config: bool "help builtin"
116 //config: depends on HUSH
118 //config: Enable help builtin in hush. Code size + ~1 kbyte.
120 //config:config HUSH_INTERACTIVE
121 //config: bool "Interactive mode"
123 //config: depends on HUSH
125 //config: Enable interactive mode (prompt and command editing).
126 //config: Without this, hush simply reads and executes commands
127 //config: from stdin just like a shell script from a file.
128 //config: No prompt, no PS1/PS2 magic shell variables.
130 //config:config HUSH_SAVEHISTORY
131 //config: bool "Save command history to .hush_history"
133 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
135 //config: Enable history saving in hush.
137 //config:config HUSH_JOB
138 //config: bool "Job control"
140 //config: depends on HUSH_INTERACTIVE
142 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
143 //config: command (not entire shell), fg/bg builtins work. Without this option,
144 //config: "cmd &" still works by simply spawning a process and immediately
145 //config: prompting for next command (or executing next command in a script),
146 //config: but no separate process group is formed.
148 //config:config HUSH_TICK
149 //config: bool "Process substitution"
151 //config: depends on HUSH
153 //config: Enable process substitution `command` and $(command) in hush.
155 //config:config HUSH_IF
156 //config: bool "Support if/then/elif/else/fi"
158 //config: depends on HUSH
160 //config: Enable if/then/elif/else/fi in hush.
162 //config:config HUSH_LOOPS
163 //config: bool "Support for, while and until loops"
165 //config: depends on HUSH
167 //config: Enable for, while and until loops in hush.
169 //config:config HUSH_CASE
170 //config: bool "Support case ... esac statement"
172 //config: depends on HUSH
174 //config: Enable case ... esac statement in hush. +400 bytes.
176 //config:config HUSH_FUNCTIONS
177 //config: bool "Support funcname() { commands; } syntax"
179 //config: depends on HUSH
181 //config: Enable support for shell functions in hush. +800 bytes.
183 //config:config HUSH_LOCAL
184 //config: bool "Support local builtin"
186 //config: depends on HUSH_FUNCTIONS
188 //config: Enable support for local variables in functions.
190 //config:config HUSH_RANDOM_SUPPORT
191 //config: bool "Pseudorandom generator and $RANDOM variable"
193 //config: depends on HUSH
195 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
196 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
198 //config:config HUSH_EXPORT_N
199 //config: bool "Support 'export -n' option"
201 //config: depends on HUSH
203 //config: export -n unexports variables. It is a bash extension.
205 //config:config HUSH_MODE_X
206 //config: bool "Support 'hush -x' option and 'set -x' command"
208 //config: depends on HUSH
210 //config: This instructs hush to print commands before execution.
211 //config: Adds ~300 bytes.
214 //config: bool "msh (deprecated: aliased to hush)"
216 //config: select HUSH
218 //config: msh is deprecated and will be removed, please migrate to hush.
221 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
222 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
223 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
224 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
226 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
227 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
229 /* -i (interactive) and -s (read stdin) are also accepted,
230 * but currently do nothing, therefore aren't shown in help.
231 * NOMMU-specific options are not meant to be used by users,
232 * therefore we don't show them either.
234 //usage:#define hush_trivial_usage
235 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
236 //usage:#define hush_full_usage "\n\n"
237 //usage: "Unix shell interpreter"
239 //usage:#define msh_trivial_usage hush_trivial_usage
240 //usage:#define msh_full_usage hush_full_usage
242 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
243 //usage:# define sh_trivial_usage hush_trivial_usage
244 //usage:# define sh_full_usage hush_full_usage
246 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
247 //usage:# define bash_trivial_usage hush_trivial_usage
248 //usage:# define bash_full_usage hush_full_usage
251 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
252 || defined(__APPLE__) \
254 # include <malloc.h> /* for malloc_trim */
257 /* #include <dmalloc.h> */
259 # include <fnmatch.h>
261 #include <sys/utsname.h> /* for setting $HOSTNAME */
263 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
265 #include "shell_common.h"
268 #if ENABLE_HUSH_RANDOM_SUPPORT
271 # define CLEAR_RANDOM_T(rnd) ((void)0)
273 #ifndef F_DUPFD_CLOEXEC
274 # define F_DUPFD_CLOEXEC F_DUPFD
277 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
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;
1578 static void restore_ttypgrp_and__exit(void) NORETURN;
1579 static void restore_ttypgrp_and__exit(void)
1581 /* xfunc has failed! die die die */
1582 /* no EXIT traps, this is an escape hatch! */
1584 hush_exit(xfunc_error_retval);
1589 /* Needed only on some libc:
1590 * It was observed that on exit(), fgetc'ed buffered data
1591 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1592 * With the net effect that even after fork(), not vfork(),
1593 * exit() in NOEXECed applet in "sh SCRIPT":
1594 * noexec_applet_here
1595 * echo END_OF_SCRIPT
1596 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1597 * This makes "echo END_OF_SCRIPT" executed twice.
1598 * Similar problems can be seen with die_if_script() -> xfunc_die()
1599 * and in `cmd` handling.
1600 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1602 static void fflush_and__exit(void) NORETURN;
1603 static void fflush_and__exit(void)
1606 _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 //FIXME: shouldn't it be set to 128 + sig instead?
1750 G.last_exitcode = save_rcode;
1752 } /* else: "" trap, ignoring signal */
1755 /* not a trap: special action */
1758 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1765 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1766 /* bash is observed to signal whole process groups,
1767 * not individual processes */
1768 for (job = G.job_list; job; job = job->next) {
1771 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1772 if (kill(- job->pgrp, SIGHUP) == 0)
1773 kill(- job->pgrp, SIGCONT);
1778 #if ENABLE_HUSH_FAST
1780 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1782 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1784 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1785 * This simplifies wait builtin a bit.
1789 default: /* ignored: */
1790 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1791 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1793 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1794 * Example: wait is not interrupted by TERM
1795 * in interactive shell, because TERM is ignored.
1804 static const char *get_cwd(int force)
1806 if (force || G.cwd == NULL) {
1807 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1808 * we must not try to free(bb_msg_unknown) */
1809 if (G.cwd == bb_msg_unknown)
1811 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1813 G.cwd = bb_msg_unknown;
1820 * Shell and environment variable support
1822 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1824 struct variable **pp;
1825 struct variable *cur;
1828 while ((cur = *pp) != NULL) {
1829 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1836 static const char* FAST_FUNC get_local_var_value(const char *name)
1838 struct variable **vpp;
1839 unsigned len = strlen(name);
1841 if (G.expanded_assignments) {
1842 char **cpp = G.expanded_assignments;
1845 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1846 return cp + len + 1;
1851 vpp = get_ptr_to_local_var(name, len);
1853 return (*vpp)->varstr + len + 1;
1855 if (strcmp(name, "PPID") == 0)
1856 return utoa(G.root_ppid);
1857 // bash compat: UID? EUID?
1858 #if ENABLE_HUSH_RANDOM_SUPPORT
1859 if (strcmp(name, "RANDOM") == 0)
1860 return utoa(next_random(&G.random_gen));
1865 /* str holds "NAME=VAL" and is expected to be malloced.
1866 * We take ownership of it.
1868 * 0: do not change export flag
1869 * (if creating new variable, flag will be 0)
1870 * 1: set export flag and putenv the variable
1871 * -1: clear export flag and unsetenv the variable
1872 * flg_read_only is set only when we handle -R var=val
1874 #if !BB_MMU && ENABLE_HUSH_LOCAL
1875 /* all params are used */
1876 #elif BB_MMU && ENABLE_HUSH_LOCAL
1877 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1878 set_local_var(str, flg_export, local_lvl)
1879 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1880 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1881 set_local_var(str, flg_export)
1882 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1883 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1884 set_local_var(str, flg_export, flg_read_only)
1886 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1888 struct variable **var_pp;
1889 struct variable *cur;
1890 char *free_me = NULL;
1894 eq_sign = strchr(str, '=');
1895 if (!eq_sign) { /* not expected to ever happen? */
1900 name_len = eq_sign - str + 1; /* including '=' */
1901 var_pp = &G.top_var;
1902 while ((cur = *var_pp) != NULL) {
1903 if (strncmp(cur->varstr, str, name_len) != 0) {
1904 var_pp = &cur->next;
1908 /* We found an existing var with this name */
1909 if (cur->flg_read_only) {
1913 bb_error_msg("%s: readonly variable", str);
1917 if (flg_export == -1) { // "&& cur->flg_export" ?
1918 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1923 #if ENABLE_HUSH_LOCAL
1924 if (cur->func_nest_level < local_lvl) {
1925 /* New variable is declared as local,
1926 * and existing one is global, or local
1927 * from enclosing function.
1928 * Remove and save old one: */
1929 *var_pp = cur->next;
1930 cur->next = *G.shadowed_vars_pp;
1931 *G.shadowed_vars_pp = cur;
1932 /* bash 3.2.33(1) and exported vars:
1934 * # f() { local z=a; env | grep ^z; }
1940 if (cur->flg_export)
1945 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1950 if (cur->max_len != 0) {
1951 if (cur->max_len >= strlen(str)) {
1952 /* This one is from startup env, reuse space */
1953 strcpy(cur->varstr, str);
1958 goto set_str_and_exp;
1960 /* max_len == 0 signifies "malloced" var, which we can
1961 * (and have to) free. But we can't free(cur->varstr) here:
1962 * if cur->flg_export is 1, it is in the environment.
1963 * We should either unsetenv+free, or wait until putenv,
1964 * then putenv(new)+free(old).
1966 free_me = cur->varstr;
1967 goto set_str_and_exp;
1970 /* Not found - create new variable struct */
1971 cur = xzalloc(sizeof(*cur));
1972 #if ENABLE_HUSH_LOCAL
1973 cur->func_nest_level = local_lvl;
1975 cur->next = *var_pp;
1981 cur->flg_read_only = flg_read_only;
1984 if (flg_export == 1)
1985 cur->flg_export = 1;
1986 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1987 cmdedit_update_prompt();
1988 if (cur->flg_export) {
1989 if (flg_export == -1) {
1990 cur->flg_export = 0;
1991 /* unsetenv was already done */
1994 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1995 i = putenv(cur->varstr);
1996 /* only now we can free old exported malloced string */
2005 /* Used at startup and after each cd */
2006 static void set_pwd_var(int exp)
2008 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2009 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2012 static int unset_local_var_len(const char *name, int name_len)
2014 struct variable *cur;
2015 struct variable **var_pp;
2018 return EXIT_SUCCESS;
2019 var_pp = &G.top_var;
2020 while ((cur = *var_pp) != NULL) {
2021 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2022 if (cur->flg_read_only) {
2023 bb_error_msg("%s: readonly variable", name);
2024 return EXIT_FAILURE;
2026 *var_pp = cur->next;
2027 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2028 bb_unsetenv(cur->varstr);
2029 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2030 cmdedit_update_prompt();
2034 return EXIT_SUCCESS;
2036 var_pp = &cur->next;
2038 return EXIT_SUCCESS;
2041 static int unset_local_var(const char *name)
2043 return unset_local_var_len(name, strlen(name));
2046 static void unset_vars(char **strings)
2054 const char *eq = strchrnul(*v, '=');
2055 unset_local_var_len(*v, (int)(eq - *v));
2061 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2063 char *var = xasprintf("%s=%s", name, val);
2064 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2069 * Helpers for "var1=val1 var2=val2 cmd" feature
2071 static void add_vars(struct variable *var)
2073 struct variable *next;
2077 var->next = G.top_var;
2079 if (var->flg_export) {
2080 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2081 putenv(var->varstr);
2083 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2089 static struct variable *set_vars_and_save_old(char **strings)
2092 struct variable *old = NULL;
2098 struct variable *var_p;
2099 struct variable **var_pp;
2102 eq = strchr(*s, '=');
2104 var_pp = get_ptr_to_local_var(*s, eq - *s);
2106 /* Remove variable from global linked list */
2108 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2109 *var_pp = var_p->next;
2110 /* Add it to returned list */
2114 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2125 static void reinit_unicode_for_hush(void)
2127 /* Unicode support should be activated even if LANG is set
2128 * _during_ shell execution, not only if it was set when
2129 * shell was started. Therefore, re-check LANG every time:
2131 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2132 || ENABLE_UNICODE_USING_LOCALE
2134 const char *s = get_local_var_value("LC_ALL");
2135 if (!s) s = get_local_var_value("LC_CTYPE");
2136 if (!s) s = get_local_var_value("LANG");
2142 * in_str support (strings, and "strings" read from files).
2145 #if ENABLE_HUSH_INTERACTIVE
2146 /* To test correct lineedit/interactive behavior, type from command line:
2152 * It excercises a lot of corner cases.
2154 static void cmdedit_update_prompt(void)
2156 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2157 G.PS1 = get_local_var_value("PS1");
2160 G.PS2 = get_local_var_value("PS2");
2167 static const char *setup_prompt_string(int promptmode)
2169 const char *prompt_str;
2170 debug_printf("setup_prompt_string %d ", promptmode);
2171 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2172 /* Set up the prompt */
2173 if (promptmode == 0) { /* PS1 */
2175 /* bash uses $PWD value, even if it is set by user.
2176 * It uses current dir only if PWD is unset.
2177 * We always use current dir. */
2178 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2183 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2184 debug_printf("prompt_str '%s'\n", prompt_str);
2187 static int get_user_input(struct in_str *i)
2190 const char *prompt_str;
2192 prompt_str = setup_prompt_string(i->promptmode);
2193 # if ENABLE_FEATURE_EDITING
2195 reinit_unicode_for_hush();
2196 if (G.flag_SIGINT) {
2197 /* There was ^C'ed, make it look prettier: */
2201 /* buglet: SIGINT will not make new prompt to appear _at once_,
2202 * only after <Enter>. (^C works immediately) */
2203 r = read_line_input(G.line_input_state, prompt_str,
2204 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2207 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2209 write(STDOUT_FILENO, "^C", 2);
2212 check_and_run_traps();
2213 if (r != 0 && !G.flag_SIGINT)
2215 /* ^C or SIGINT: repeat */
2216 G.last_exitcode = 128 + SIGINT;
2219 /* EOF/error detected */
2221 i->peek_buf[0] = r = EOF;
2224 i->p = G.user_input_buf;
2225 return (unsigned char)*i->p++;
2229 if (i->last_char == '\0' || i->last_char == '\n') {
2230 /* Why check_and_run_traps here? Try this interactively:
2231 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2232 * $ <[enter], repeatedly...>
2233 * Without check_and_run_traps, handler never runs.
2235 check_and_run_traps();
2236 fputs(prompt_str, stdout);
2239 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2241 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2242 * no ^C masking happens during fgetc, no special code for ^C:
2243 * it generates SIGINT as usual.
2245 check_and_run_traps();
2247 G.last_exitcode = 128 + SIGINT;
2254 /* This is the magic location that prints prompts
2255 * and gets data back from the user */
2256 static int fgetc_interactive(struct in_str *i)
2259 /* If it's interactive stdin, get new line. */
2260 if (G_interactive_fd && i->file == stdin) {
2261 /* Returns first char (or EOF), the rest is in i->p[] */
2262 ch = get_user_input(i);
2263 i->promptmode = 1; /* PS2 */
2265 /* Not stdin: script file, sourced file, etc */
2266 do ch = fgetc(i->file); while (ch == '\0');
2271 static inline int fgetc_interactive(struct in_str *i)
2274 do ch = fgetc(i->file); while (ch == '\0');
2277 #endif /* INTERACTIVE */
2279 static int i_getch(struct in_str *i)
2284 /* string-based in_str */
2285 ch = (unsigned char)*i->p;
2294 /* FILE-based in_str */
2296 #if ENABLE_FEATURE_EDITING
2297 /* This can be stdin, check line editing char[] buffer */
2298 if (i->p && *i->p != '\0') {
2299 ch = (unsigned char)*i->p++;
2303 /* peek_buf[] is an int array, not char. Can contain EOF. */
2304 ch = i->peek_buf[0];
2306 int ch2 = i->peek_buf[1];
2307 i->peek_buf[0] = ch2;
2308 if (ch2 == 0) /* very likely, avoid redundant write */
2314 ch = fgetc_interactive(i);
2316 debug_printf("file_get: got '%c' %d\n", ch, ch);
2321 static int i_peek(struct in_str *i)
2326 /* string-based in_str */
2327 /* Doesn't report EOF on NUL. None of the callers care. */
2328 return (unsigned char)*i->p;
2331 /* FILE-based in_str */
2333 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2334 /* This can be stdin, check line editing char[] buffer */
2335 if (i->p && *i->p != '\0')
2336 return (unsigned char)*i->p;
2338 /* peek_buf[] is an int array, not char. Can contain EOF. */
2339 ch = i->peek_buf[0];
2343 /* Need to get a new char */
2344 ch = fgetc_interactive(i);
2345 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2347 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2348 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2354 i->peek_buf[0] = ch;
2355 /*i->peek_buf[1] = 0; - already is */
2359 /* Only ever called if i_peek() was called, and did not return EOF.
2360 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2361 * not end-of-line. Therefore we never need to read a new editing line here.
2363 static int i_peek2(struct in_str *i)
2367 /* There are two cases when i->p[] buffer exists.
2368 * (1) it's a string in_str.
2369 * (2) It's a file, and we have a saved line editing buffer.
2370 * In both cases, we know that i->p[0] exists and not NUL, and
2371 * the peek2 result is in i->p[1].
2374 return (unsigned char)i->p[1];
2376 /* Now we know it is a file-based in_str. */
2378 /* peek_buf[] is an int array, not char. Can contain EOF. */
2379 /* Is there 2nd char? */
2380 ch = i->peek_buf[1];
2382 /* We did not read it yet, get it now */
2383 do ch = fgetc(i->file); while (ch == '\0');
2384 i->peek_buf[1] = ch;
2387 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2391 static void setup_file_in_str(struct in_str *i, FILE *f)
2393 memset(i, 0, sizeof(*i));
2394 /* i->promptmode = 0; - PS1 (memset did it) */
2399 static void setup_string_in_str(struct in_str *i, const char *s)
2401 memset(i, 0, sizeof(*i));
2402 /* i->promptmode = 0; - PS1 (memset did it) */
2403 /*i->file = NULL */;
2411 #define B_CHUNK (32 * sizeof(char*))
2413 static void o_reset_to_empty_unquoted(o_string *o)
2416 o->has_quoted_part = 0;
2421 static void o_free(o_string *o)
2424 memset(o, 0, sizeof(*o));
2427 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2432 static void o_grow_by(o_string *o, int len)
2434 if (o->length + len > o->maxlen) {
2435 o->maxlen += (2 * len) | (B_CHUNK-1);
2436 o->data = xrealloc(o->data, 1 + o->maxlen);
2440 static void o_addchr(o_string *o, int ch)
2442 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2443 if (o->length < o->maxlen) {
2444 /* likely. avoid o_grow_by() call */
2446 o->data[o->length] = ch;
2448 o->data[o->length] = '\0';
2456 /* Valid only if we know o_string is not empty */
2457 static void o_delchr(o_string *o)
2460 o->data[o->length] = '\0';
2464 static void o_addblock(o_string *o, const char *str, int len)
2467 memcpy(&o->data[o->length], str, len);
2469 o->data[o->length] = '\0';
2472 static void o_addstr(o_string *o, const char *str)
2474 o_addblock(o, str, strlen(str));
2478 static void nommu_addchr(o_string *o, int ch)
2484 # define nommu_addchr(o, str) ((void)0)
2487 static void o_addstr_with_NUL(o_string *o, const char *str)
2489 o_addblock(o, str, strlen(str) + 1);
2493 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2494 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2495 * Apparently, on unquoted $v bash still does globbing
2496 * ("v='*.txt'; echo $v" prints all .txt files),
2497 * but NOT brace expansion! Thus, there should be TWO independent
2498 * quoting mechanisms on $v expansion side: one protects
2499 * $v from brace expansion, and other additionally protects "$v" against globbing.
2500 * We have only second one.
2503 #if ENABLE_HUSH_BRACE_EXPANSION
2504 # define MAYBE_BRACES "{}"
2506 # define MAYBE_BRACES ""
2509 /* My analysis of quoting semantics tells me that state information
2510 * is associated with a destination, not a source.
2512 static void o_addqchr(o_string *o, int ch)
2515 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2520 o->data[o->length] = '\\';
2523 o->data[o->length] = ch;
2525 o->data[o->length] = '\0';
2528 static void o_addQchr(o_string *o, int ch)
2531 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2532 && strchr("*?[\\" MAYBE_BRACES, ch)
2535 o->data[o->length] = '\\';
2539 o->data[o->length] = ch;
2541 o->data[o->length] = '\0';
2544 static void o_addqblock(o_string *o, const char *str, int len)
2549 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2550 if (ordinary_cnt > len) /* paranoia */
2552 o_addblock(o, str, ordinary_cnt);
2553 if (ordinary_cnt == len)
2554 return; /* NUL is already added by o_addblock */
2555 str += ordinary_cnt;
2556 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2560 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2562 o->data[o->length] = '\\';
2566 o->data[o->length] = ch;
2569 o->data[o->length] = '\0';
2572 static void o_addQblock(o_string *o, const char *str, int len)
2574 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2575 o_addblock(o, str, len);
2578 o_addqblock(o, str, len);
2581 static void o_addQstr(o_string *o, const char *str)
2583 o_addQblock(o, str, strlen(str));
2586 /* A special kind of o_string for $VAR and `cmd` expansion.
2587 * It contains char* list[] at the beginning, which is grown in 16 element
2588 * increments. Actual string data starts at the next multiple of 16 * (char*).
2589 * list[i] contains an INDEX (int!) into this string data.
2590 * It means that if list[] needs to grow, data needs to be moved higher up
2591 * but list[i]'s need not be modified.
2592 * NB: remembering how many list[i]'s you have there is crucial.
2593 * o_finalize_list() operation post-processes this structure - calculates
2594 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2596 #if DEBUG_EXPAND || DEBUG_GLOB
2597 static void debug_print_list(const char *prefix, o_string *o, int n)
2599 char **list = (char**)o->data;
2600 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2604 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2605 prefix, list, n, string_start, o->length, o->maxlen,
2606 !!(o->o_expflags & EXP_FLAG_GLOB),
2608 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2611 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2612 o->data + (int)(uintptr_t)list[i] + string_start,
2613 o->data + (int)(uintptr_t)list[i] + string_start);
2617 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2619 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2623 # define debug_print_list(prefix, o, n) ((void)0)
2626 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2627 * in list[n] so that it points past last stored byte so far.
2628 * It returns n+1. */
2629 static int o_save_ptr_helper(o_string *o, int n)
2631 char **list = (char**)o->data;
2635 if (!o->has_empty_slot) {
2636 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2637 string_len = o->length - string_start;
2638 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2639 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2640 /* list[n] points to string_start, make space for 16 more pointers */
2641 o->maxlen += 0x10 * sizeof(list[0]);
2642 o->data = xrealloc(o->data, o->maxlen + 1);
2643 list = (char**)o->data;
2644 memmove(list + n + 0x10, list + n, string_len);
2645 o->length += 0x10 * sizeof(list[0]);
2647 debug_printf_list("list[%d]=%d string_start=%d\n",
2648 n, string_len, string_start);
2651 /* We have empty slot at list[n], reuse without growth */
2652 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2653 string_len = o->length - string_start;
2654 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2655 n, string_len, string_start);
2656 o->has_empty_slot = 0;
2658 o->has_quoted_part = 0;
2659 list[n] = (char*)(uintptr_t)string_len;
2663 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2664 static int o_get_last_ptr(o_string *o, int n)
2666 char **list = (char**)o->data;
2667 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2669 return ((int)(uintptr_t)list[n-1]) + string_start;
2672 #if ENABLE_HUSH_BRACE_EXPANSION
2673 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2674 * first, it processes even {a} (no commas), second,
2675 * I didn't manage to make it return strings when they don't match
2676 * existing files. Need to re-implement it.
2680 static int glob_needed(const char *s)
2689 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2695 /* Return pointer to next closing brace or to comma */
2696 static const char *next_brace_sub(const char *cp)
2700 while (*cp != '\0') {
2707 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2713 return *cp != '\0' ? cp : NULL;
2715 /* Recursive brace globber. Note: may garble pattern[]. */
2716 static int glob_brace(char *pattern, o_string *o, int n)
2718 char *new_pattern_buf;
2725 debug_printf_glob("glob_brace('%s')\n", pattern);
2731 if (*begin == '{') {
2732 /* Find the first sub-pattern and at the same time
2733 * find the rest after the closing brace */
2734 next = next_brace_sub(begin);
2736 /* An illegal expression */
2740 /* "{abc}" with no commas - illegal
2741 * brace expr, disregard and skip it */
2747 if (*begin == '\\' && begin[1] != '\0')
2751 debug_printf_glob("begin:%s\n", begin);
2752 debug_printf_glob("next:%s\n", next);
2754 /* Now find the end of the whole brace expression */
2756 while (*rest != '}') {
2757 rest = next_brace_sub(rest);
2759 /* An illegal expression */
2762 debug_printf_glob("rest:%s\n", rest);
2764 rest_len = strlen(++rest) + 1;
2766 /* We are sure the brace expression is well-formed */
2768 /* Allocate working buffer large enough for our work */
2769 new_pattern_buf = xmalloc(strlen(pattern));
2771 /* We have a brace expression. BEGIN points to the opening {,
2772 * NEXT points past the terminator of the first element, and REST
2773 * points past the final }. We will accumulate result names from
2774 * recursive runs for each brace alternative in the buffer using
2779 /* Construct the new glob expression */
2782 mempcpy(new_pattern_buf,
2783 /* We know the prefix for all sub-patterns */
2784 pattern, begin - pattern),
2788 /* Note: glob_brace() may garble new_pattern_buf[].
2789 * That's why we re-copy prefix every time (1st memcpy above).
2791 n = glob_brace(new_pattern_buf, o, n);
2793 /* We saw the last entry */
2797 next = next_brace_sub(next);
2799 free(new_pattern_buf);
2807 memset(&globdata, 0, sizeof(globdata));
2808 gr = glob(pattern, 0, NULL, &globdata);
2809 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2811 if (gr == GLOB_NOMATCH) {
2812 globfree(&globdata);
2813 /* NB: garbles parameter */
2814 unbackslash(pattern);
2815 o_addstr_with_NUL(o, pattern);
2816 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2817 return o_save_ptr_helper(o, n);
2819 if (gr == GLOB_NOSPACE)
2820 bb_error_msg_and_die(bb_msg_memory_exhausted);
2821 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2822 * but we didn't specify it. Paranoia again. */
2823 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2825 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2826 char **argv = globdata.gl_pathv;
2828 o_addstr_with_NUL(o, *argv);
2829 n = o_save_ptr_helper(o, n);
2835 globfree(&globdata);
2839 /* Performs globbing on last list[],
2840 * saving each result as a new list[].
2842 static int perform_glob(o_string *o, int n)
2844 char *pattern, *copy;
2846 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2848 return o_save_ptr_helper(o, n);
2849 pattern = o->data + o_get_last_ptr(o, n);
2850 debug_printf_glob("glob pattern '%s'\n", pattern);
2851 if (!glob_needed(pattern)) {
2852 /* unbackslash last string in o in place, fix length */
2853 o->length = unbackslash(pattern) - o->data;
2854 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2855 return o_save_ptr_helper(o, n);
2858 copy = xstrdup(pattern);
2859 /* "forget" pattern in o */
2860 o->length = pattern - o->data;
2861 n = glob_brace(copy, o, n);
2864 debug_print_list("perform_glob returning", o, n);
2868 #else /* !HUSH_BRACE_EXPANSION */
2871 static int glob_needed(const char *s)
2880 if (*s == '*' || *s == '[' || *s == '?')
2886 /* Performs globbing on last list[],
2887 * saving each result as a new list[].
2889 static int perform_glob(o_string *o, int n)
2895 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2897 return o_save_ptr_helper(o, n);
2898 pattern = o->data + o_get_last_ptr(o, n);
2899 debug_printf_glob("glob pattern '%s'\n", pattern);
2900 if (!glob_needed(pattern)) {
2902 /* unbackslash last string in o in place, fix length */
2903 o->length = unbackslash(pattern) - o->data;
2904 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2905 return o_save_ptr_helper(o, n);
2908 memset(&globdata, 0, sizeof(globdata));
2909 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2910 * If we glob "*.\*" and don't find anything, we need
2911 * to fall back to using literal "*.*", but GLOB_NOCHECK
2912 * will return "*.\*"!
2914 gr = glob(pattern, 0, NULL, &globdata);
2915 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2917 if (gr == GLOB_NOMATCH) {
2918 globfree(&globdata);
2921 if (gr == GLOB_NOSPACE)
2922 bb_error_msg_and_die(bb_msg_memory_exhausted);
2923 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2924 * but we didn't specify it. Paranoia again. */
2925 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2927 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2928 char **argv = globdata.gl_pathv;
2929 /* "forget" pattern in o */
2930 o->length = pattern - o->data;
2932 o_addstr_with_NUL(o, *argv);
2933 n = o_save_ptr_helper(o, n);
2939 globfree(&globdata);
2941 debug_print_list("perform_glob returning", o, n);
2945 #endif /* !HUSH_BRACE_EXPANSION */
2947 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2948 * Otherwise, just finish current list[] and start new */
2949 static int o_save_ptr(o_string *o, int n)
2951 if (o->o_expflags & EXP_FLAG_GLOB) {
2952 /* If o->has_empty_slot, list[n] was already globbed
2953 * (if it was requested back then when it was filled)
2954 * so don't do that again! */
2955 if (!o->has_empty_slot)
2956 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2958 return o_save_ptr_helper(o, n);
2961 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2962 static char **o_finalize_list(o_string *o, int n)
2967 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2969 debug_print_list("finalized", o, n);
2970 debug_printf_expand("finalized n:%d\n", n);
2971 list = (char**)o->data;
2972 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2976 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2981 static void free_pipe_list(struct pipe *pi);
2983 /* Returns pi->next - next pipe in the list */
2984 static struct pipe *free_pipe(struct pipe *pi)
2989 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2990 for (i = 0; i < pi->num_cmds; i++) {
2991 struct command *command;
2992 struct redir_struct *r, *rnext;
2994 command = &pi->cmds[i];
2995 debug_printf_clean(" command %d:\n", i);
2996 if (command->argv) {
3000 for (a = 0, p = command->argv; *p; a++, p++) {
3001 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3004 free_strings(command->argv);
3005 //command->argv = NULL;
3007 /* not "else if": on syntax error, we may have both! */
3008 if (command->group) {
3009 debug_printf_clean(" begin group (cmd_type:%d)\n",
3011 free_pipe_list(command->group);
3012 debug_printf_clean(" end group\n");
3013 //command->group = NULL;
3015 /* else is crucial here.
3016 * If group != NULL, child_func is meaningless */
3017 #if ENABLE_HUSH_FUNCTIONS
3018 else if (command->child_func) {
3019 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3020 command->child_func->parent_cmd = NULL;
3024 free(command->group_as_string);
3025 //command->group_as_string = NULL;
3027 for (r = command->redirects; r; r = rnext) {
3028 debug_printf_clean(" redirect %d%s",
3029 r->rd_fd, redir_table[r->rd_type].descrip);
3030 /* guard against the case >$FOO, where foo is unset or blank */
3031 if (r->rd_filename) {
3032 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3033 free(r->rd_filename);
3034 //r->rd_filename = NULL;
3036 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3040 //command->redirects = NULL;
3042 free(pi->cmds); /* children are an array, they get freed all at once */
3046 //pi->cmdtext = NULL;
3054 static void free_pipe_list(struct pipe *pi)
3058 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3060 debug_printf_clean("pipe followup code %d\n", pi->followup);
3066 /*** Parsing routines ***/
3068 #ifndef debug_print_tree
3069 static void debug_print_tree(struct pipe *pi, int lvl)
3071 static const char *const PIPE[] = {
3077 static const char *RES[] = {
3078 [RES_NONE ] = "NONE" ,
3081 [RES_THEN ] = "THEN" ,
3082 [RES_ELIF ] = "ELIF" ,
3083 [RES_ELSE ] = "ELSE" ,
3086 # if ENABLE_HUSH_LOOPS
3087 [RES_FOR ] = "FOR" ,
3088 [RES_WHILE] = "WHILE",
3089 [RES_UNTIL] = "UNTIL",
3091 [RES_DONE ] = "DONE" ,
3093 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3096 # if ENABLE_HUSH_CASE
3097 [RES_CASE ] = "CASE" ,
3098 [RES_CASE_IN ] = "CASE_IN" ,
3099 [RES_MATCH] = "MATCH",
3100 [RES_CASE_BODY] = "CASE_BODY",
3101 [RES_ESAC ] = "ESAC" ,
3103 [RES_XXXX ] = "XXXX" ,
3104 [RES_SNTX ] = "SNTX" ,
3106 static const char *const CMDTYPE[] = {
3110 # if ENABLE_HUSH_FUNCTIONS
3119 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3120 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3122 while (prn < pi->num_cmds) {
3123 struct command *command = &pi->cmds[prn];
3124 char **argv = command->argv;
3126 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3128 command->assignment_cnt);
3129 if (command->group) {
3130 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3131 CMDTYPE[command->cmd_type],
3134 , " group_as_string:", command->group_as_string
3139 debug_print_tree(command->group, lvl+1);
3143 if (argv) while (*argv) {
3144 fdprintf(2, " '%s'", *argv);
3154 #endif /* debug_print_tree */
3156 static struct pipe *new_pipe(void)
3159 pi = xzalloc(sizeof(struct pipe));
3160 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3164 /* Command (member of a pipe) is complete, or we start a new pipe
3165 * if ctx->command is NULL.
3166 * No errors possible here.
3168 static int done_command(struct parse_context *ctx)
3170 /* The command is really already in the pipe structure, so
3171 * advance the pipe counter and make a new, null command. */
3172 struct pipe *pi = ctx->pipe;
3173 struct command *command = ctx->command;
3175 #if 0 /* Instead we emit error message at run time */
3176 if (ctx->pending_redirect) {
3177 /* For example, "cmd >" (no filename to redirect to) */
3178 die_if_script("syntax error: %s", "invalid redirect");
3179 ctx->pending_redirect = NULL;
3184 if (IS_NULL_CMD(command)) {
3185 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3189 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3190 //debug_print_tree(ctx->list_head, 20);
3192 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3195 /* Only real trickiness here is that the uncommitted
3196 * command structure is not counted in pi->num_cmds. */
3197 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3198 ctx->command = command = &pi->cmds[pi->num_cmds];
3200 memset(command, 0, sizeof(*command));
3201 return pi->num_cmds; /* used only for 0/nonzero check */
3204 static void done_pipe(struct parse_context *ctx, pipe_style type)
3208 debug_printf_parse("done_pipe entered, followup %d\n", type);
3209 /* Close previous command */
3210 not_null = done_command(ctx);
3211 ctx->pipe->followup = type;
3213 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3214 ctx->ctx_inverted = 0;
3215 ctx->pipe->res_word = ctx->ctx_res_w;
3218 /* Without this check, even just <enter> on command line generates
3219 * tree of three NOPs (!). Which is harmless but annoying.
3220 * IOW: it is safe to do it unconditionally. */
3223 || ctx->ctx_res_w == RES_FI
3225 #if ENABLE_HUSH_LOOPS
3226 || ctx->ctx_res_w == RES_DONE
3227 || ctx->ctx_res_w == RES_FOR
3228 || ctx->ctx_res_w == RES_IN
3230 #if ENABLE_HUSH_CASE
3231 || ctx->ctx_res_w == RES_ESAC
3235 debug_printf_parse("done_pipe: adding new pipe: "
3236 "not_null:%d ctx->ctx_res_w:%d\n",
3237 not_null, ctx->ctx_res_w);
3239 ctx->pipe->next = new_p;
3241 /* RES_THEN, RES_DO etc are "sticky" -
3242 * they remain set for pipes inside if/while.
3243 * This is used to control execution.
3244 * RES_FOR and RES_IN are NOT sticky (needed to support
3245 * cases where variable or value happens to match a keyword):
3247 #if ENABLE_HUSH_LOOPS
3248 if (ctx->ctx_res_w == RES_FOR
3249 || ctx->ctx_res_w == RES_IN)
3250 ctx->ctx_res_w = RES_NONE;
3252 #if ENABLE_HUSH_CASE
3253 if (ctx->ctx_res_w == RES_MATCH)
3254 ctx->ctx_res_w = RES_CASE_BODY;
3255 if (ctx->ctx_res_w == RES_CASE)
3256 ctx->ctx_res_w = RES_CASE_IN;
3258 ctx->command = NULL; /* trick done_command below */
3259 /* Create the memory for command, roughly:
3260 * ctx->pipe->cmds = new struct command;
3261 * ctx->command = &ctx->pipe->cmds[0];
3264 //debug_print_tree(ctx->list_head, 10);
3266 debug_printf_parse("done_pipe return\n");
3269 static void initialize_context(struct parse_context *ctx)
3271 memset(ctx, 0, sizeof(*ctx));
3272 ctx->pipe = ctx->list_head = new_pipe();
3273 /* Create the memory for command, roughly:
3274 * ctx->pipe->cmds = new struct command;
3275 * ctx->command = &ctx->pipe->cmds[0];
3280 /* If a reserved word is found and processed, parse context is modified
3281 * and 1 is returned.
3284 struct reserved_combo {
3287 unsigned char assignment_flag;
3291 FLAG_END = (1 << RES_NONE ),
3293 FLAG_IF = (1 << RES_IF ),
3294 FLAG_THEN = (1 << RES_THEN ),
3295 FLAG_ELIF = (1 << RES_ELIF ),
3296 FLAG_ELSE = (1 << RES_ELSE ),
3297 FLAG_FI = (1 << RES_FI ),
3299 # if ENABLE_HUSH_LOOPS
3300 FLAG_FOR = (1 << RES_FOR ),
3301 FLAG_WHILE = (1 << RES_WHILE),
3302 FLAG_UNTIL = (1 << RES_UNTIL),
3303 FLAG_DO = (1 << RES_DO ),
3304 FLAG_DONE = (1 << RES_DONE ),
3305 FLAG_IN = (1 << RES_IN ),
3307 # if ENABLE_HUSH_CASE
3308 FLAG_MATCH = (1 << RES_MATCH),
3309 FLAG_ESAC = (1 << RES_ESAC ),
3311 FLAG_START = (1 << RES_XXXX ),
3314 static const struct reserved_combo* match_reserved_word(o_string *word)
3316 /* Mostly a list of accepted follow-up reserved words.
3317 * FLAG_END means we are done with the sequence, and are ready
3318 * to turn the compound list into a command.
3319 * FLAG_START means the word must start a new compound list.
3321 static const struct reserved_combo reserved_list[] = {
3323 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3324 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3325 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3326 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3327 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3328 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3330 # if ENABLE_HUSH_LOOPS
3331 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3332 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3333 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3334 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3335 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3336 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3338 # if ENABLE_HUSH_CASE
3339 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3340 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3343 const struct reserved_combo *r;
3345 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3346 if (strcmp(word->data, r->literal) == 0)
3351 /* Return 0: not a keyword, 1: keyword
3353 static int reserved_word(o_string *word, struct parse_context *ctx)
3355 # if ENABLE_HUSH_CASE
3356 static const struct reserved_combo reserved_match = {
3357 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3360 const struct reserved_combo *r;
3362 if (word->has_quoted_part)
3364 r = match_reserved_word(word);
3368 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3369 # if ENABLE_HUSH_CASE
3370 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3371 /* "case word IN ..." - IN part starts first MATCH part */
3372 r = &reserved_match;
3375 if (r->flag == 0) { /* '!' */
3376 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3377 syntax_error("! ! command");
3378 ctx->ctx_res_w = RES_SNTX;
3380 ctx->ctx_inverted = 1;
3383 if (r->flag & FLAG_START) {
3384 struct parse_context *old;
3386 old = xmalloc(sizeof(*old));
3387 debug_printf_parse("push stack %p\n", old);
3388 *old = *ctx; /* physical copy */
3389 initialize_context(ctx);
3391 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3392 syntax_error_at(word->data);
3393 ctx->ctx_res_w = RES_SNTX;
3396 /* "{...} fi" is ok. "{...} if" is not
3398 * if { echo foo; } then { echo bar; } fi */
3399 if (ctx->command->group)
3400 done_pipe(ctx, PIPE_SEQ);
3403 ctx->ctx_res_w = r->res;
3404 ctx->old_flag = r->flag;
3405 word->o_assignment = r->assignment_flag;
3406 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3408 if (ctx->old_flag & FLAG_END) {
3409 struct parse_context *old;
3411 done_pipe(ctx, PIPE_SEQ);
3412 debug_printf_parse("pop stack %p\n", ctx->stack);
3414 old->command->group = ctx->list_head;
3415 old->command->cmd_type = CMD_NORMAL;
3417 /* At this point, the compound command's string is in
3418 * ctx->as_string... except for the leading keyword!
3419 * Consider this example: "echo a | if true; then echo a; fi"
3420 * ctx->as_string will contain "true; then echo a; fi",
3421 * with "if " remaining in old->as_string!
3425 int len = old->as_string.length;
3426 /* Concatenate halves */
3427 o_addstr(&old->as_string, ctx->as_string.data);
3428 o_free_unsafe(&ctx->as_string);
3429 /* Find where leading keyword starts in first half */
3430 str = old->as_string.data + len;
3431 if (str > old->as_string.data)
3432 str--; /* skip whitespace after keyword */
3433 while (str > old->as_string.data && isalpha(str[-1]))
3435 /* Ugh, we're done with this horrid hack */
3436 old->command->group_as_string = xstrdup(str);
3437 debug_printf_parse("pop, remembering as:'%s'\n",
3438 old->command->group_as_string);
3441 *ctx = *old; /* physical copy */
3446 #endif /* HAS_KEYWORDS */
3448 /* Word is complete, look at it and update parsing context.
3449 * Normal return is 0. Syntax errors return 1.
3450 * Note: on return, word is reset, but not o_free'd!
3452 static int done_word(o_string *word, struct parse_context *ctx)
3454 struct command *command = ctx->command;
3456 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3457 if (word->length == 0 && !word->has_quoted_part) {
3458 debug_printf_parse("done_word return 0: true null, ignored\n");
3462 if (ctx->pending_redirect) {
3463 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3464 * only if run as "bash", not "sh" */
3465 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3467 * ...the word that follows the redirection operator
3468 * shall be subjected to tilde expansion, parameter expansion,
3469 * command substitution, arithmetic expansion, and quote
3470 * removal. Pathname expansion shall not be performed
3471 * on the word by a non-interactive shell; an interactive
3472 * shell may perform it, but shall do so only when
3473 * the expansion would result in one word."
3475 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3476 /* Cater for >\file case:
3477 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3478 * Same with heredocs:
3479 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3481 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3482 unbackslash(ctx->pending_redirect->rd_filename);
3483 /* Is it <<"HEREDOC"? */
3484 if (word->has_quoted_part) {
3485 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3488 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3489 ctx->pending_redirect = NULL;
3492 # if ENABLE_HUSH_CASE
3493 if (ctx->ctx_dsemicolon
3494 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3496 /* already done when ctx_dsemicolon was set to 1: */
3497 /* ctx->ctx_res_w = RES_MATCH; */
3498 ctx->ctx_dsemicolon = 0;
3501 if (!command->argv /* if it's the first word... */
3502 # if ENABLE_HUSH_LOOPS
3503 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3504 && ctx->ctx_res_w != RES_IN
3506 # if ENABLE_HUSH_CASE
3507 && ctx->ctx_res_w != RES_CASE
3510 int reserved = reserved_word(word, ctx);
3511 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3513 o_reset_to_empty_unquoted(word);
3514 debug_printf_parse("done_word return %d\n",
3515 (ctx->ctx_res_w == RES_SNTX));
3516 return (ctx->ctx_res_w == RES_SNTX);
3518 # if ENABLE_HUSH_BASH_COMPAT
3519 if (strcmp(word->data, "[[") == 0) {
3520 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3526 if (command->group) {
3527 /* "{ echo foo; } echo bar" - bad */
3528 syntax_error_at(word->data);
3529 debug_printf_parse("done_word return 1: syntax error, "
3530 "groups and arglists don't mix\n");
3534 /* If this word wasn't an assignment, next ones definitely
3535 * can't be assignments. Even if they look like ones. */
3536 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3537 && word->o_assignment != WORD_IS_KEYWORD
3539 word->o_assignment = NOT_ASSIGNMENT;
3541 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3542 command->assignment_cnt++;
3543 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3545 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3546 word->o_assignment = MAYBE_ASSIGNMENT;
3548 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3550 if (word->has_quoted_part
3551 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3552 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3553 /* (otherwise it's known to be not empty and is already safe) */
3555 /* exclude "$@" - it can expand to no word despite "" */
3556 char *p = word->data;
3557 while (p[0] == SPECIAL_VAR_SYMBOL
3558 && (p[1] & 0x7f) == '@'
3559 && p[2] == SPECIAL_VAR_SYMBOL
3564 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3565 debug_print_strings("word appended to argv", command->argv);
3568 #if ENABLE_HUSH_LOOPS
3569 if (ctx->ctx_res_w == RES_FOR) {
3570 if (word->has_quoted_part
3571 || !is_well_formed_var_name(command->argv[0], '\0')
3573 /* bash says just "not a valid identifier" */
3574 syntax_error("not a valid identifier in for");
3577 /* Force FOR to have just one word (variable name) */
3578 /* NB: basically, this makes hush see "for v in ..."
3579 * syntax as if it is "for v; in ...". FOR and IN become
3580 * two pipe structs in parse tree. */
3581 done_pipe(ctx, PIPE_SEQ);
3584 #if ENABLE_HUSH_CASE
3585 /* Force CASE to have just one word */
3586 if (ctx->ctx_res_w == RES_CASE) {
3587 done_pipe(ctx, PIPE_SEQ);
3591 o_reset_to_empty_unquoted(word);
3593 debug_printf_parse("done_word return 0\n");
3598 /* Peek ahead in the input to find out if we have a "&n" construct,
3599 * as in "2>&1", that represents duplicating a file descriptor.
3601 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3602 * REDIRFD_SYNTAX_ERR if syntax error,
3603 * REDIRFD_TO_FILE if no & was seen,
3604 * or the number found.
3607 #define parse_redir_right_fd(as_string, input) \
3608 parse_redir_right_fd(input)
3610 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3616 return REDIRFD_TO_FILE;
3618 ch = i_getch(input); /* get the & */
3619 nommu_addchr(as_string, ch);
3622 ch = i_getch(input);
3623 nommu_addchr(as_string, ch);
3624 return REDIRFD_CLOSE;
3628 while (ch != EOF && isdigit(ch)) {
3629 d = d*10 + (ch-'0');
3631 ch = i_getch(input);
3632 nommu_addchr(as_string, ch);
3637 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3639 bb_error_msg("ambiguous redirect");
3640 return REDIRFD_SYNTAX_ERR;
3643 /* Return code is 0 normal, 1 if a syntax error is detected
3645 static int parse_redirect(struct parse_context *ctx,
3648 struct in_str *input)
3650 struct command *command = ctx->command;
3651 struct redir_struct *redir;
3652 struct redir_struct **redirp;
3655 dup_num = REDIRFD_TO_FILE;
3656 if (style != REDIRECT_HEREDOC) {
3657 /* Check for a '>&1' type redirect */
3658 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3659 if (dup_num == REDIRFD_SYNTAX_ERR)
3662 int ch = i_peek(input);
3663 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3664 if (dup_num) { /* <<-... */
3665 ch = i_getch(input);
3666 nommu_addchr(&ctx->as_string, ch);
3671 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3672 int ch = i_peek(input);
3674 /* >|FILE redirect ("clobbering" >).
3675 * Since we do not support "set -o noclobber" yet,
3676 * >| and > are the same for now. Just eat |.
3678 ch = i_getch(input);
3679 nommu_addchr(&ctx->as_string, ch);
3683 /* Create a new redir_struct and append it to the linked list */
3684 redirp = &command->redirects;
3685 while ((redir = *redirp) != NULL) {
3686 redirp = &(redir->next);
3688 *redirp = redir = xzalloc(sizeof(*redir));
3689 /* redir->next = NULL; */
3690 /* redir->rd_filename = NULL; */
3691 redir->rd_type = style;
3692 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3694 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3695 redir_table[style].descrip);
3697 redir->rd_dup = dup_num;
3698 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3699 /* Erik had a check here that the file descriptor in question
3700 * is legit; I postpone that to "run time"
3701 * A "-" representation of "close me" shows up as a -3 here */
3702 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3703 redir->rd_fd, redir->rd_dup);
3705 #if 0 /* Instead we emit error message at run time */
3706 if (ctx->pending_redirect) {
3707 /* For example, "cmd > <file" */
3708 die_if_script("syntax error: %s", "invalid redirect");
3711 /* Set ctx->pending_redirect, so we know what to do at the
3712 * end of the next parsed word. */
3713 ctx->pending_redirect = redir;
3718 /* If a redirect is immediately preceded by a number, that number is
3719 * supposed to tell which file descriptor to redirect. This routine
3720 * looks for such preceding numbers. In an ideal world this routine
3721 * needs to handle all the following classes of redirects...
3722 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3723 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3724 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3725 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3727 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3729 * ... If n is quoted, the number shall not be recognized as part of
3730 * the redirection expression. For example:
3732 * writes the character 2 into file a"
3733 * We are getting it right by setting ->has_quoted_part on any \<char>
3735 * A -1 return means no valid number was found,
3736 * the caller should use the appropriate default for this redirection.
3738 static int redirect_opt_num(o_string *o)
3742 if (o->data == NULL)
3744 num = bb_strtou(o->data, NULL, 10);
3745 if (errno || num < 0)
3747 o_reset_to_empty_unquoted(o);
3752 #define fetch_till_str(as_string, input, word, skip_tabs) \
3753 fetch_till_str(input, word, skip_tabs)
3755 static char *fetch_till_str(o_string *as_string,
3756 struct in_str *input,
3760 o_string heredoc = NULL_O_STRING;
3762 int prev = 0; /* not \ */
3768 ch = i_getch(input);
3770 nommu_addchr(as_string, ch);
3771 if ((ch == '\n' || ch == EOF)
3772 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3774 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3775 heredoc.data[past_EOL] = '\0';
3776 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3777 return heredoc.data;
3779 while (ch == '\n') {
3780 o_addchr(&heredoc, ch);
3783 past_EOL = heredoc.length;
3785 ch = i_getch(input);
3787 nommu_addchr(as_string, ch);
3788 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3792 o_free_unsafe(&heredoc);
3795 o_addchr(&heredoc, ch);
3796 nommu_addchr(as_string, ch);
3797 if (prev == '\\' && ch == '\\')
3798 /* Correctly handle foo\\<eol> (not a line cont.) */
3799 prev = 0; /* not \ */
3805 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3806 * and load them all. There should be exactly heredoc_cnt of them.
3808 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3810 struct pipe *pi = ctx->list_head;
3812 while (pi && heredoc_cnt) {
3814 struct command *cmd = pi->cmds;
3816 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3818 cmd->argv ? cmd->argv[0] : "NONE");
3819 for (i = 0; i < pi->num_cmds; i++) {
3820 struct redir_struct *redir = cmd->redirects;
3822 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3823 i, cmd->argv ? cmd->argv[0] : "NONE");
3825 if (redir->rd_type == REDIRECT_HEREDOC) {
3828 redir->rd_type = REDIRECT_HEREDOC2;
3829 /* redir->rd_dup is (ab)used to indicate <<- */
3830 p = fetch_till_str(&ctx->as_string, input,
3831 redir->rd_filename, redir->rd_dup);
3833 syntax_error("unexpected EOF in here document");
3836 free(redir->rd_filename);
3837 redir->rd_filename = p;
3840 redir = redir->next;
3847 /* Should be 0. If it isn't, it's a parse error */
3849 bb_error_msg_and_die("heredoc BUG 2");
3855 static int run_list(struct pipe *pi);
3857 #define parse_stream(pstring, input, end_trigger) \
3858 parse_stream(input, end_trigger)
3860 static struct pipe *parse_stream(char **pstring,
3861 struct in_str *input,
3865 #if !ENABLE_HUSH_FUNCTIONS
3866 #define parse_group(dest, ctx, input, ch) \
3867 parse_group(ctx, input, ch)
3869 static int parse_group(o_string *dest, struct parse_context *ctx,
3870 struct in_str *input, int ch)
3872 /* dest contains characters seen prior to ( or {.
3873 * Typically it's empty, but for function defs,
3874 * it contains function name (without '()'). */
3875 struct pipe *pipe_list;
3877 struct command *command = ctx->command;
3879 debug_printf_parse("parse_group entered\n");
3880 #if ENABLE_HUSH_FUNCTIONS
3881 if (ch == '(' && !dest->has_quoted_part) {
3883 if (done_word(dest, ctx))
3886 goto skip; /* (... */
3887 if (command->argv[1]) { /* word word ... (... */
3888 syntax_error_unexpected_ch('(');
3891 /* it is "word(..." or "word (..." */
3893 ch = i_getch(input);
3894 while (ch == ' ' || ch == '\t');
3896 syntax_error_unexpected_ch(ch);
3899 nommu_addchr(&ctx->as_string, ch);
3901 ch = i_getch(input);
3902 while (ch == ' ' || ch == '\t' || ch == '\n');
3904 syntax_error_unexpected_ch(ch);
3907 nommu_addchr(&ctx->as_string, ch);
3908 command->cmd_type = CMD_FUNCDEF;
3913 #if 0 /* Prevented by caller */
3914 if (command->argv /* word [word]{... */
3915 || dest->length /* word{... */
3916 || dest->has_quoted_part /* ""{... */
3919 debug_printf_parse("parse_group return 1: "
3920 "syntax error, groups and arglists don't mix\n");
3925 #if ENABLE_HUSH_FUNCTIONS
3931 command->cmd_type = CMD_SUBSHELL;
3933 /* bash does not allow "{echo...", requires whitespace */
3935 if (ch != ' ' && ch != '\t' && ch != '\n'
3936 && ch != '(' /* but "{(..." is allowed (without whitespace) */
3938 syntax_error_unexpected_ch(ch);
3942 ch = i_getch(input);
3943 nommu_addchr(&ctx->as_string, ch);
3949 # define as_string NULL
3951 char *as_string = NULL;
3953 pipe_list = parse_stream(&as_string, input, endch);
3956 o_addstr(&ctx->as_string, as_string);
3958 /* empty ()/{} or parse error? */
3959 if (!pipe_list || pipe_list == ERR_PTR) {
3960 /* parse_stream already emitted error msg */
3963 debug_printf_parse("parse_group return 1: "
3964 "parse_stream returned %p\n", pipe_list);
3967 command->group = pipe_list;
3969 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3970 command->group_as_string = as_string;
3971 debug_printf_parse("end of group, remembering as:'%s'\n",
3972 command->group_as_string);
3976 debug_printf_parse("parse_group return 0\n");
3978 /* command remains "open", available for possible redirects */
3981 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3986 ch = i_getch(input);
3989 ch2 = i_peek(input);
3992 /* backslash+newline, skip it */
3997 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4005 ch2 = i_peek2(input);
4008 /* backslash+newline, skip it */
4014 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
4015 /* Subroutines for copying $(...) and `...` things */
4016 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4018 static int add_till_single_quote(o_string *dest, struct in_str *input)
4021 int ch = i_getch(input);
4023 syntax_error_unterm_ch('\'');
4031 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4032 static int add_till_double_quote(o_string *dest, struct in_str *input)
4035 int ch = i_getch(input);
4037 syntax_error_unterm_ch('"');
4042 if (ch == '\\') { /* \x. Copy both chars. */
4044 ch = i_getch(input);
4048 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4053 //if (ch == '$') ...
4056 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4058 * "Within the backquoted style of command substitution, backslash
4059 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4060 * The search for the matching backquote shall be satisfied by the first
4061 * backquote found without a preceding backslash; during this search,
4062 * if a non-escaped backquote is encountered within a shell comment,
4063 * a here-document, an embedded command substitution of the $(command)
4064 * form, or a quoted string, undefined results occur. A single-quoted
4065 * or double-quoted string that begins, but does not end, within the
4066 * "`...`" sequence produces undefined results."
4068 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4070 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4073 int ch = i_getch(input);
4077 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4078 ch = i_getch(input);
4082 && (!in_dquote || ch != '"')
4084 o_addchr(dest, '\\');
4088 syntax_error_unterm_ch('`');
4094 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4095 * quoting and nested ()s.
4096 * "With the $(command) style of command substitution, all characters
4097 * following the open parenthesis to the matching closing parenthesis
4098 * constitute the command. Any valid shell script can be used for command,
4099 * except a script consisting solely of redirections which produces
4100 * unspecified results."
4102 * echo $(echo '(TEST)' BEST) (TEST) BEST
4103 * echo $(echo 'TEST)' BEST) TEST) BEST
4104 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4106 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4107 * can contain arbitrary constructs, just like $(cmd).
4108 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4109 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4111 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4112 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4115 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4116 # if ENABLE_HUSH_BASH_COMPAT
4117 char end_char2 = end_ch >> 8;
4119 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4122 ch = i_getch(input);
4124 syntax_error_unterm_ch(end_ch);
4127 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4130 /* we look for closing )) of $((EXPR)) */
4131 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4132 i_getch(input); /* eat second ')' */
4137 if (ch == '(' || ch == '{') {
4138 ch = (ch == '(' ? ')' : '}');
4139 if (!add_till_closing_bracket(dest, input, ch))
4145 if (!add_till_single_quote(dest, input))
4151 if (!add_till_double_quote(dest, input))
4157 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4163 /* \x. Copy verbatim. Important for \(, \) */
4164 ch = i_getch(input);
4166 syntax_error_unterm_ch(')');
4171 /* "backslash+newline", ignore both */
4172 o_delchr(dest); /* undo insertion of '\' */
4182 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4184 /* Return code: 0 for OK, 1 for syntax error */
4186 #define parse_dollar(as_string, dest, input, quote_mask) \
4187 parse_dollar(dest, input, quote_mask)
4188 #define as_string NULL
4190 static int parse_dollar(o_string *as_string,
4192 struct in_str *input, unsigned char quote_mask)
4194 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4196 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4198 ch = i_getch(input);
4199 nommu_addchr(as_string, ch);
4201 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4203 debug_printf_parse(": '%c'\n", ch);
4204 o_addchr(dest, ch | quote_mask);
4206 ch = i_peek_and_eat_bkslash_nl(input);
4207 if (!isalnum(ch) && ch != '_') {
4208 /* End of variable name reached */
4211 ch = i_getch(input);
4212 nommu_addchr(as_string, ch);
4214 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4215 } else if (isdigit(ch)) {
4217 ch = i_getch(input);
4218 nommu_addchr(as_string, ch);
4219 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4220 debug_printf_parse(": '%c'\n", ch);
4221 o_addchr(dest, ch | quote_mask);
4222 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4223 } else switch (ch) {
4225 case '!': /* last bg pid */
4226 case '?': /* last exit code */
4227 case '#': /* number of args */
4228 case '*': /* args */
4229 case '@': /* args */
4230 goto make_one_char_var;
4232 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4234 ch = i_getch(input); /* eat '{' */
4235 nommu_addchr(as_string, ch);
4237 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4238 /* It should be ${?}, or ${#var},
4239 * or even ${?+subst} - operator acting on a special variable,
4240 * or the beginning of variable name.
4243 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4246 syntax_error_unterm_str("${name}");
4247 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4250 nommu_addchr(as_string, ch);
4253 /* It's possible to just call add_till_closing_bracket() at this point.
4254 * However, this regresses some of our testsuite cases
4255 * which check invalid constructs like ${%}.
4256 * Oh well... let's check that the var name part is fine... */
4262 debug_printf_parse(": '%c'\n", ch);
4264 ch = i_getch(input);
4265 nommu_addchr(as_string, ch);
4269 if (!isalnum(ch) && ch != '_') {
4271 unsigned char last_ch;
4272 /* handle parameter expansions
4273 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4275 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4276 goto bad_dollar_syntax;
4278 /* Eat everything until closing '}' (or ':') */
4280 if (ENABLE_HUSH_BASH_COMPAT
4282 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4284 /* It's ${var:N[:M]} thing */
4285 end_ch = '}' * 0x100 + ':';
4287 if (ENABLE_HUSH_BASH_COMPAT
4290 /* It's ${var/[/]pattern[/repl]} thing */
4291 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4293 nommu_addchr(as_string, '/');
4296 end_ch = '}' * 0x100 + '/';
4302 #if ENABLE_HUSH_DOLLAR_OPS
4303 last_ch = add_till_closing_bracket(dest, input, end_ch);
4304 if (last_ch == 0) /* error? */
4307 #error Simple code to only allow ${var} is not implemented
4310 o_addstr(as_string, dest->data + pos);
4311 o_addchr(as_string, last_ch);
4314 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4315 /* close the first block: */
4316 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4317 /* while parsing N from ${var:N[:M]}
4318 * or pattern from ${var/[/]pattern[/repl]} */
4319 if ((end_ch & 0xff) == last_ch) {
4320 /* got ':' or '/'- parse the rest */
4325 if (end_ch == '}' * 0x100 + ':') {
4326 /* it's ${var:N} - emulate :999999999 */
4327 o_addstr(dest, "999999999");
4328 } /* else: it's ${var/[/]pattern} */
4333 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4336 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4340 ch = i_getch(input);
4341 nommu_addchr(as_string, ch);
4342 # if ENABLE_SH_MATH_SUPPORT
4343 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4344 ch = i_getch(input);
4345 nommu_addchr(as_string, ch);
4346 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4347 o_addchr(dest, /*quote_mask |*/ '+');
4350 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4351 return 0; /* error */
4353 o_addstr(as_string, dest->data + pos);
4354 o_addchr(as_string, ')');
4355 o_addchr(as_string, ')');
4357 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4361 # if ENABLE_HUSH_TICK
4362 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4363 o_addchr(dest, quote_mask | '`');
4366 if (!add_till_closing_bracket(dest, input, ')'))
4367 return 0; /* error */
4369 o_addstr(as_string, dest->data + pos);
4370 o_addchr(as_string, ')');
4372 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4378 ch = i_getch(input);
4379 nommu_addchr(as_string, ch);
4380 ch = i_peek_and_eat_bkslash_nl(input);
4381 if (isalnum(ch)) { /* it's $_name or $_123 */
4386 /* TODO: $_ and $-: */
4387 /* $_ Shell or shell script name; or last argument of last command
4388 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4389 * but in command's env, set to full pathname used to invoke it */
4390 /* $- Option flags set by set builtin or shell options (-i etc) */
4392 o_addQchr(dest, '$');
4394 debug_printf_parse("parse_dollar return 1 (ok)\n");
4400 # if ENABLE_HUSH_BASH_COMPAT
4401 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4402 encode_string(dest, input, dquote_end, process_bkslash)
4404 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4405 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4406 encode_string(dest, input, dquote_end)
4408 #define as_string NULL
4412 # if ENABLE_HUSH_BASH_COMPAT
4413 /* all parameters are needed, no macro tricks */
4415 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4416 encode_string(as_string, dest, input, dquote_end)
4419 static int encode_string(o_string *as_string,
4421 struct in_str *input,
4423 int process_bkslash)
4425 #if !ENABLE_HUSH_BASH_COMPAT
4426 const int process_bkslash = 1;
4432 ch = i_getch(input);
4434 nommu_addchr(as_string, ch);
4435 if (ch == dquote_end) { /* may be only '"' or EOF */
4436 debug_printf_parse("encode_string return 1 (ok)\n");
4439 /* note: can't move it above ch == dquote_end check! */
4441 syntax_error_unterm_ch('"');
4442 return 0; /* error */
4446 next = i_peek(input);
4448 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4449 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4450 if (process_bkslash && ch == '\\') {
4452 syntax_error("\\<eof>");
4456 * "The backslash retains its special meaning [in "..."]
4457 * only when followed by one of the following characters:
4458 * $, `, ", \, or <newline>. A double quote may be quoted
4459 * within double quotes by preceding it with a backslash."
4460 * NB: in (unquoted) heredoc, above does not apply to ",
4461 * therefore we check for it by "next == dquote_end" cond.
4463 if (next == dquote_end || strchr("$`\\\n", next)) {
4464 ch = i_getch(input); /* eat next */
4466 goto again; /* skip \<newline> */
4467 } /* else: ch remains == '\\', and we double it below: */
4468 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4469 nommu_addchr(as_string, ch);
4473 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4474 debug_printf_parse("encode_string return 0: "
4475 "parse_dollar returned 0 (error)\n");
4480 #if ENABLE_HUSH_TICK
4482 //unsigned pos = dest->length;
4483 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4484 o_addchr(dest, 0x80 | '`');
4485 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4486 return 0; /* error */
4487 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4488 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4492 o_addQchr(dest, ch);
4498 * Scan input until EOF or end_trigger char.
4499 * Return a list of pipes to execute, or NULL on EOF
4500 * or if end_trigger character is met.
4501 * On syntax error, exit if shell is not interactive,
4502 * reset parsing machinery and start parsing anew,
4503 * or return ERR_PTR.
4505 static struct pipe *parse_stream(char **pstring,
4506 struct in_str *input,
4509 struct parse_context ctx;
4510 o_string dest = NULL_O_STRING;
4513 /* Single-quote triggers a bypass of the main loop until its mate is
4514 * found. When recursing, quote state is passed in via dest->o_expflags.
4516 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4517 end_trigger ? end_trigger : 'X');
4520 /* If very first arg is "" or '', dest.data may end up NULL.
4521 * Preventing this: */
4522 o_addchr(&dest, '\0');
4525 /* We used to separate words on $IFS here. This was wrong.
4526 * $IFS is used only for word splitting when $var is expanded,
4527 * here we should use blank chars as separators, not $IFS
4530 if (MAYBE_ASSIGNMENT != 0)
4531 dest.o_assignment = MAYBE_ASSIGNMENT;
4532 initialize_context(&ctx);
4535 const char *is_blank;
4536 const char *is_special;
4540 redir_type redir_style;
4542 ch = i_getch(input);
4543 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4544 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4549 syntax_error_unterm_str("here document");
4552 if (end_trigger == ')') {
4553 syntax_error_unterm_ch('(');
4556 if (end_trigger == '}') {
4557 syntax_error_unterm_ch('{');
4561 if (done_word(&dest, &ctx)) {
4565 done_pipe(&ctx, PIPE_SEQ);
4567 /* If we got nothing... */
4568 /* (this makes bare "&" cmd a no-op.
4569 * bash says: "syntax error near unexpected token '&'") */
4570 if (pi->num_cmds == 0
4571 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4577 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4579 *pstring = ctx.as_string.data;
4581 o_free_unsafe(&ctx.as_string);
4584 debug_printf_parse("parse_stream return %p\n", pi);
4587 nommu_addchr(&ctx.as_string, ch);
4591 next = i_peek(input);
4593 is_special = "{}<>;&|()#'" /* special outside of "str" */
4594 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4595 /* Are { and } special here? */
4596 if (ctx.command->argv /* word [word]{... - non-special */
4597 || dest.length /* word{... - non-special */
4598 || dest.has_quoted_part /* ""{... - non-special */
4599 || (next != ';' /* }; - special */
4600 && next != ')' /* }) - special */
4601 && next != '(' /* {( - special */
4602 && next != '&' /* }& and }&& ... - special */
4603 && next != '|' /* }|| ... - special */
4604 && !strchr(defifs, next) /* {word - non-special */
4607 /* They are not special, skip "{}" */
4610 is_special = strchr(is_special, ch);
4611 is_blank = strchr(defifs, ch);
4613 if (!is_special && !is_blank) { /* ordinary char */
4615 o_addQchr(&dest, ch);
4616 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4617 || dest.o_assignment == WORD_IS_KEYWORD)
4619 && is_well_formed_var_name(dest.data, '=')
4621 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4622 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4628 if (done_word(&dest, &ctx)) {
4632 /* Is this a case when newline is simply ignored?
4634 * "cmd | <newline> cmd ..."
4635 * "case ... in <newline> word) ..."
4637 if (IS_NULL_CMD(ctx.command)
4638 && dest.length == 0 && !dest.has_quoted_part
4640 /* This newline can be ignored. But...
4641 * Without check #1, interactive shell
4642 * ignores even bare <newline>,
4643 * and shows the continuation prompt:
4644 * ps1_prompt$ <enter>
4645 * ps2> _ <=== wrong, should be ps1
4646 * Without check #2, "cmd & <newline>"
4647 * is similarly mistreated.
4648 * (BTW, this makes "cmd & cmd"
4649 * and "cmd && cmd" non-orthogonal.
4650 * Really, ask yourself, why
4651 * "cmd && <newline>" doesn't start
4652 * cmd but waits for more input?
4655 struct pipe *pi = ctx.list_head;
4656 if (pi->num_cmds != 0 /* check #1 */
4657 && pi->followup != PIPE_BG /* check #2 */
4662 /* Treat newline as a command separator. */
4663 done_pipe(&ctx, PIPE_SEQ);
4664 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4666 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4671 dest.o_assignment = MAYBE_ASSIGNMENT;
4672 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4674 /* note: if (is_blank) continue;
4675 * will still trigger for us */
4679 /* "cmd}" or "cmd }..." without semicolon or &:
4680 * } is an ordinary char in this case, even inside { cmd; }
4681 * Pathological example: { ""}; } should exec "}" cmd
4684 if (dest.length != 0 /* word} */
4685 || dest.has_quoted_part /* ""} */
4689 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4690 /* Generally, there should be semicolon: "cmd; }"
4691 * However, bash allows to omit it if "cmd" is
4692 * a group. Examples:
4695 * { echo 0 >&2 | { echo 1; } }
4696 * { while false; do :; done }
4697 * { case a in b) ;; esac }
4699 if (ctx.command->group)
4703 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4704 /* Can't be an end of {cmd}, skip the check */
4705 goto skip_end_trigger;
4706 /* else: } does terminate a group */
4709 if (end_trigger && end_trigger == ch
4710 && (ch != ';' || heredoc_cnt == 0)
4711 #if ENABLE_HUSH_CASE
4713 || ctx.ctx_res_w != RES_MATCH
4714 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4719 /* This is technically valid:
4720 * { cat <<HERE; }; echo Ok
4724 * but we don't support this.
4725 * We require heredoc to be in enclosing {}/(),
4728 syntax_error_unterm_str("here document");
4731 if (done_word(&dest, &ctx)) {
4734 done_pipe(&ctx, PIPE_SEQ);
4735 dest.o_assignment = MAYBE_ASSIGNMENT;
4736 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4737 /* Do we sit outside of any if's, loops or case's? */
4739 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4743 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4745 *pstring = ctx.as_string.data;
4747 o_free_unsafe(&ctx.as_string);
4750 debug_printf_parse("parse_stream return %p: "
4751 "end_trigger char found\n",
4753 return ctx.list_head;
4760 /* Catch <, > before deciding whether this word is
4761 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4764 redir_fd = redirect_opt_num(&dest);
4765 if (done_word(&dest, &ctx)) {
4768 redir_style = REDIRECT_OVERWRITE;
4770 redir_style = REDIRECT_APPEND;
4771 ch = i_getch(input);
4772 nommu_addchr(&ctx.as_string, ch);
4775 else if (next == '(') {
4776 syntax_error(">(process) not supported");
4780 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4782 continue; /* back to top of while (1) */
4784 redir_fd = redirect_opt_num(&dest);
4785 if (done_word(&dest, &ctx)) {
4788 redir_style = REDIRECT_INPUT;
4790 redir_style = REDIRECT_HEREDOC;
4792 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4793 ch = i_getch(input);
4794 nommu_addchr(&ctx.as_string, ch);
4795 } else if (next == '>') {
4796 redir_style = REDIRECT_IO;
4797 ch = i_getch(input);
4798 nommu_addchr(&ctx.as_string, ch);
4801 else if (next == '(') {
4802 syntax_error("<(process) not supported");
4806 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4808 continue; /* back to top of while (1) */
4810 if (dest.length == 0 && !dest.has_quoted_part) {
4811 /* skip "#comment" */
4814 if (ch == EOF || ch == '\n')
4817 /* note: we do not add it to &ctx.as_string */
4819 nommu_addchr(&ctx.as_string, '\n');
4820 continue; /* back to top of while (1) */
4825 /* It's "\<newline>" */
4827 /* Remove trailing '\' from ctx.as_string */
4828 ctx.as_string.data[--ctx.as_string.length] = '\0';
4830 ch = i_getch(input); /* eat it */
4831 continue; /* back to top of while (1) */
4836 if (dest.o_assignment == MAYBE_ASSIGNMENT
4837 /* check that we are not in word in "a=1 2>word b=1": */
4838 && !ctx.pending_redirect
4840 /* ch is a special char and thus this word
4841 * cannot be an assignment */
4842 dest.o_assignment = NOT_ASSIGNMENT;
4843 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4846 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4849 case '#': /* non-comment #: "echo a#b" etc */
4850 o_addQchr(&dest, ch);
4854 syntax_error("\\<eof>");
4857 ch = i_getch(input);
4858 /* note: ch != '\n' (that case does not reach this place) */
4859 o_addchr(&dest, '\\');
4860 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4861 o_addchr(&dest, ch);
4862 nommu_addchr(&ctx.as_string, ch);
4863 /* Example: echo Hello \2>file
4864 * we need to know that word 2 is quoted */
4865 dest.has_quoted_part = 1;
4868 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4869 debug_printf_parse("parse_stream parse error: "
4870 "parse_dollar returned 0 (error)\n");
4875 dest.has_quoted_part = 1;
4876 if (next == '\'' && !ctx.pending_redirect) {
4877 insert_empty_quoted_str_marker:
4878 nommu_addchr(&ctx.as_string, next);
4879 i_getch(input); /* eat second ' */
4880 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4881 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4884 ch = i_getch(input);
4886 syntax_error_unterm_ch('\'');
4889 nommu_addchr(&ctx.as_string, ch);
4892 o_addqchr(&dest, ch);
4897 dest.has_quoted_part = 1;
4898 if (next == '"' && !ctx.pending_redirect)
4899 goto insert_empty_quoted_str_marker;
4900 if (dest.o_assignment == NOT_ASSIGNMENT)
4901 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4902 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4904 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4906 #if ENABLE_HUSH_TICK
4908 USE_FOR_NOMMU(unsigned pos;)
4910 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4911 o_addchr(&dest, '`');
4912 USE_FOR_NOMMU(pos = dest.length;)
4913 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4916 o_addstr(&ctx.as_string, dest.data + pos);
4917 o_addchr(&ctx.as_string, '`');
4919 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4920 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4925 #if ENABLE_HUSH_CASE
4928 if (done_word(&dest, &ctx)) {
4931 done_pipe(&ctx, PIPE_SEQ);
4932 #if ENABLE_HUSH_CASE
4933 /* Eat multiple semicolons, detect
4934 * whether it means something special */
4939 ch = i_getch(input);
4940 nommu_addchr(&ctx.as_string, ch);
4941 if (ctx.ctx_res_w == RES_CASE_BODY) {
4942 ctx.ctx_dsemicolon = 1;
4943 ctx.ctx_res_w = RES_MATCH;
4949 /* We just finished a cmd. New one may start
4950 * with an assignment */
4951 dest.o_assignment = MAYBE_ASSIGNMENT;
4952 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4955 if (done_word(&dest, &ctx)) {
4959 ch = i_getch(input);
4960 nommu_addchr(&ctx.as_string, ch);
4961 done_pipe(&ctx, PIPE_AND);
4963 done_pipe(&ctx, PIPE_BG);
4967 if (done_word(&dest, &ctx)) {
4970 #if ENABLE_HUSH_CASE
4971 if (ctx.ctx_res_w == RES_MATCH)
4972 break; /* we are in case's "word | word)" */
4974 if (next == '|') { /* || */
4975 ch = i_getch(input);
4976 nommu_addchr(&ctx.as_string, ch);
4977 done_pipe(&ctx, PIPE_OR);
4979 /* we could pick up a file descriptor choice here
4980 * with redirect_opt_num(), but bash doesn't do it.
4981 * "echo foo 2| cat" yields "foo 2". */
4986 #if ENABLE_HUSH_CASE
4987 /* "case... in [(]word)..." - skip '(' */
4988 if (ctx.ctx_res_w == RES_MATCH
4989 && ctx.command->argv == NULL /* not (word|(... */
4990 && dest.length == 0 /* not word(... */
4991 && dest.has_quoted_part == 0 /* not ""(... */
4997 if (parse_group(&dest, &ctx, input, ch) != 0) {
5002 #if ENABLE_HUSH_CASE
5003 if (ctx.ctx_res_w == RES_MATCH)
5007 /* proper use of this character is caught by end_trigger:
5008 * if we see {, we call parse_group(..., end_trigger='}')
5009 * and it will match } earlier (not here). */
5010 syntax_error_unexpected_ch(ch);
5014 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5020 struct parse_context *pctx;
5021 IF_HAS_KEYWORDS(struct parse_context *p2;)
5023 /* Clean up allocated tree.
5024 * Sample for finding leaks on syntax error recovery path.
5025 * Run it from interactive shell, watch pmap `pidof hush`.
5026 * while if false; then false; fi; do break; fi
5027 * Samples to catch leaks at execution:
5028 * while if (true | { true;}); then echo ok; fi; do break; done
5029 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5033 /* Update pipe/command counts,
5034 * otherwise freeing may miss some */
5035 done_pipe(pctx, PIPE_SEQ);
5036 debug_printf_clean("freeing list %p from ctx %p\n",
5037 pctx->list_head, pctx);
5038 debug_print_tree(pctx->list_head, 0);
5039 free_pipe_list(pctx->list_head);
5040 debug_printf_clean("freed list %p\n", pctx->list_head);
5042 o_free_unsafe(&pctx->as_string);
5044 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5048 IF_HAS_KEYWORDS(pctx = p2;)
5049 } while (HAS_KEYWORDS && pctx);
5052 G.last_exitcode = 1;
5063 /*** Execution routines ***/
5065 /* Expansion can recurse, need forward decls: */
5066 #if !ENABLE_HUSH_BASH_COMPAT
5067 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5068 #define expand_string_to_string(str, do_unbackslash) \
5069 expand_string_to_string(str)
5071 static char *expand_string_to_string(const char *str, int do_unbackslash);
5072 #if ENABLE_HUSH_TICK
5073 static int process_command_subs(o_string *dest, const char *s);
5076 /* expand_strvec_to_strvec() takes a list of strings, expands
5077 * all variable references within and returns a pointer to
5078 * a list of expanded strings, possibly with larger number
5079 * of strings. (Think VAR="a b"; echo $VAR).
5080 * This new list is allocated as a single malloc block.
5081 * NULL-terminated list of char* pointers is at the beginning of it,
5082 * followed by strings themselves.
5083 * Caller can deallocate entire list by single free(list). */
5085 /* A horde of its helpers come first: */
5087 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5089 while (--len >= 0) {
5092 #if ENABLE_HUSH_BRACE_EXPANSION
5093 if (c == '{' || c == '}') {
5094 /* { -> \{, } -> \} */
5096 /* And now we want to add { or } and continue:
5099 * luckily, just falling throught achieves this.
5105 /* \z -> \\\z; \<eol> -> \\<eol> */
5110 o_addchr(o, *str++);
5116 /* Store given string, finalizing the word and starting new one whenever
5117 * we encounter IFS char(s). This is used for expanding variable values.
5118 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5119 * Return in *ended_with_ifs:
5120 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5122 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5124 int last_is_ifs = 0;
5129 if (!*str) /* EOL - do not finalize word */
5131 word_len = strcspn(str, G.ifs);
5133 /* We have WORD_LEN leading non-IFS chars */
5134 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5135 o_addblock(output, str, word_len);
5137 /* Protect backslashes against globbing up :)
5138 * Example: "v='\*'; echo b$v" prints "b\*"
5139 * (and does not try to glob on "*")
5141 o_addblock_duplicate_backslash(output, str, word_len);
5142 /*/ Why can't we do it easier? */
5143 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5144 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5148 if (!*str) /* EOL - do not finalize word */
5152 /* We know str here points to at least one IFS char */
5154 str += strspn(str, G.ifs); /* skip IFS chars */
5155 if (!*str) /* EOL - do not finalize word */
5158 /* Start new word... but not always! */
5159 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5160 if (output->has_quoted_part
5161 /* Case "v=' a'; echo $v":
5162 * here nothing precedes the space in $v expansion,
5163 * therefore we should not finish the word
5164 * (IOW: if there *is* word to finalize, only then do it):
5166 || (n > 0 && output->data[output->length - 1])
5168 o_addchr(output, '\0');
5169 debug_print_list("expand_on_ifs", output, n);
5170 n = o_save_ptr(output, n);
5175 *ended_with_ifs = last_is_ifs;
5176 debug_print_list("expand_on_ifs[1]", output, n);
5180 /* Helper to expand $((...)) and heredoc body. These act as if
5181 * they are in double quotes, with the exception that they are not :).
5182 * Just the rules are similar: "expand only $var and `cmd`"
5184 * Returns malloced string.
5185 * As an optimization, we return NULL if expansion is not needed.
5187 #if !ENABLE_HUSH_BASH_COMPAT
5188 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5189 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5190 encode_then_expand_string(str)
5192 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5195 struct in_str input;
5196 o_string dest = NULL_O_STRING;
5198 if (!strchr(str, '$')
5199 && !strchr(str, '\\')
5200 #if ENABLE_HUSH_TICK
5201 && !strchr(str, '`')
5207 /* We need to expand. Example:
5208 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5210 setup_string_in_str(&input, str);
5211 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5212 //TODO: error check (encode_string returns 0 on error)?
5213 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5214 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5215 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5216 o_free_unsafe(&dest);
5220 #if ENABLE_SH_MATH_SUPPORT
5221 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5223 arith_state_t math_state;
5227 math_state.lookupvar = get_local_var_value;
5228 math_state.setvar = set_local_var_from_halves;
5229 //math_state.endofname = endofname;
5230 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5231 res = arith(&math_state, exp_str ? exp_str : arg);
5234 *errmsg_p = math_state.errmsg;
5235 if (math_state.errmsg)
5236 die_if_script(math_state.errmsg);
5241 #if ENABLE_HUSH_BASH_COMPAT
5242 /* ${var/[/]pattern[/repl]} helpers */
5243 static char *strstr_pattern(char *val, const char *pattern, int *size)
5246 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5247 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5254 /* Optimization: if "*pat" did not match the start of "string",
5255 * we know that "tring", "ring" etc will not match too:
5257 if (pattern[0] == '*')
5262 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5264 char *result = NULL;
5265 unsigned res_len = 0;
5266 unsigned repl_len = strlen(repl);
5270 char *s = strstr_pattern(val, pattern, &size);
5274 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5275 memcpy(result + res_len, val, s - val);
5277 strcpy(result + res_len, repl);
5278 res_len += repl_len;
5279 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5285 if (val[0] && result) {
5286 result = xrealloc(result, res_len + strlen(val) + 1);
5287 strcpy(result + res_len, val);
5288 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5290 debug_printf_varexp("result:'%s'\n", result);
5296 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5298 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5300 const char *val = NULL;
5301 char *to_be_freed = NULL;
5306 char exp_save = exp_save; /* for compiler */
5307 char *exp_saveptr; /* points to expansion operator */
5308 char *exp_word = exp_word; /* for compiler */
5311 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5313 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5315 first_char = arg[0] = arg0 & 0x7f;
5318 if (first_char == '#' /* ${#... */
5319 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5321 /* It must be length operator: ${#var} */
5325 /* Maybe handle parameter expansion */
5326 if (exp_saveptr /* if 2nd char is one of expansion operators */
5327 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5329 /* ${?:0}, ${#[:]%0} etc */
5330 exp_saveptr = var + 1;
5332 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5333 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5335 exp_op = exp_save = *exp_saveptr;
5337 exp_word = exp_saveptr + 1;
5338 if (exp_op == ':') {
5339 exp_op = *exp_word++;
5340 //TODO: try ${var:} and ${var:bogus} in non-bash config
5341 if (ENABLE_HUSH_BASH_COMPAT
5342 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5344 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5349 *exp_saveptr = '\0';
5350 } /* else: it's not an expansion op, but bare ${var} */
5353 /* Look up the variable in question */
5354 if (isdigit(var[0])) {
5355 /* parse_dollar should have vetted var for us */
5356 int n = xatoi_positive(var);
5357 if (n < G.global_argc)
5358 val = G.global_argv[n];
5359 /* else val remains NULL: $N with too big N */
5363 val = utoa(G.root_pid);
5365 case '!': /* bg pid */
5366 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5368 case '?': /* exitcode */
5369 val = utoa(G.last_exitcode);
5371 case '#': /* argc */
5372 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5375 val = get_local_var_value(var);
5379 /* Handle any expansions */
5380 if (exp_op == 'L') {
5381 reinit_unicode_for_hush();
5382 debug_printf_expand("expand: length(%s)=", val);
5383 val = utoa(val ? unicode_strlen(val) : 0);
5384 debug_printf_expand("%s\n", val);
5385 } else if (exp_op) {
5386 if (exp_op == '%' || exp_op == '#') {
5387 /* Standard-mandated substring removal ops:
5388 * ${parameter%word} - remove smallest suffix pattern
5389 * ${parameter%%word} - remove largest suffix pattern
5390 * ${parameter#word} - remove smallest prefix pattern
5391 * ${parameter##word} - remove largest prefix pattern
5393 * Word is expanded to produce a glob pattern.
5394 * Then var's value is matched to it and matching part removed.
5396 if (val && val[0]) {
5400 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5401 if (exp_op == *exp_word) /* ## or %% */
5403 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5405 exp_word = exp_exp_word;
5406 /* HACK ALERT. We depend here on the fact that
5407 * G.global_argv and results of utoa and get_local_var_value
5408 * are actually in writable memory:
5409 * scan_and_match momentarily stores NULs there. */
5411 loc = scan_and_match(t, exp_word, scan_flags);
5412 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5413 // exp_op, t, exp_word, loc);
5415 if (loc) { /* match was found */
5416 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5417 val = loc; /* take right part */
5419 val = to_be_freed = xstrndup(val, loc - val); /* left */
5423 #if ENABLE_HUSH_BASH_COMPAT
5424 else if (exp_op == '/' || exp_op == '\\') {
5425 /* It's ${var/[/]pattern[/repl]} thing.
5426 * Note that in encoded form it has TWO parts:
5427 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5428 * and if // is used, it is encoded as \:
5429 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5431 /* Empty variable always gives nothing: */
5432 // "v=''; echo ${v/*/w}" prints "", not "w"
5433 if (val && val[0]) {
5434 /* pattern uses non-standard expansion.
5435 * repl should be unbackslashed and globbed
5436 * by the usual expansion rules:
5438 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5439 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5440 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5441 * v='a bz'; echo ${v/a*z/\z} prints "z"
5442 * (note that a*z _pattern_ is never globbed!)
5444 char *pattern, *repl, *t;
5445 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5447 pattern = xstrdup(exp_word);
5448 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5449 *p++ = SPECIAL_VAR_SYMBOL;
5451 p = strchr(p, SPECIAL_VAR_SYMBOL);
5453 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5454 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5455 /* HACK ALERT. We depend here on the fact that
5456 * G.global_argv and results of utoa and get_local_var_value
5457 * are actually in writable memory:
5458 * replace_pattern momentarily stores NULs there. */
5460 to_be_freed = replace_pattern(t,
5462 (repl ? repl : exp_word),
5464 if (to_be_freed) /* at least one replace happened */
5471 else if (exp_op == ':') {
5472 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5473 /* It's ${var:N[:M]} bashism.
5474 * Note that in encoded form it has TWO parts:
5475 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5480 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5483 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5484 *p++ = SPECIAL_VAR_SYMBOL;
5486 p = strchr(p, SPECIAL_VAR_SYMBOL);
5488 len = expand_and_evaluate_arith(exp_word, &errmsg);
5491 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5492 if (len >= 0) { /* bash compat: len < 0 is illegal */
5493 if (beg < 0) /* bash compat */
5495 debug_printf_varexp("from val:'%s'\n", val);
5496 if (len == 0 || !val || beg >= strlen(val)) {
5500 /* Paranoia. What if user entered 9999999999999
5501 * which fits in arith_t but not int? */
5504 val = to_be_freed = xstrndup(val + beg, len);
5506 debug_printf_varexp("val:'%s'\n", val);
5510 die_if_script("malformed ${%s:...}", var);
5513 } else { /* one of "-=+?" */
5514 /* Standard-mandated substitution ops:
5515 * ${var?word} - indicate error if unset
5516 * If var is unset, word (or a message indicating it is unset
5517 * if word is null) is written to standard error
5518 * and the shell exits with a non-zero exit status.
5519 * Otherwise, the value of var is substituted.
5520 * ${var-word} - use default value
5521 * If var is unset, word is substituted.
5522 * ${var=word} - assign and use default value
5523 * If var is unset, word is assigned to var.
5524 * In all cases, final value of var is substituted.
5525 * ${var+word} - use alternative value
5526 * If var is unset, null is substituted.
5527 * Otherwise, word is substituted.
5529 * Word is subjected to tilde expansion, parameter expansion,
5530 * command substitution, and arithmetic expansion.
5531 * If word is not needed, it is not expanded.
5533 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5534 * but also treat null var as if it is unset.
5536 int use_word = (!val || ((exp_save == ':') && !val[0]));
5538 use_word = !use_word;
5539 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5540 (exp_save == ':') ? "true" : "false", use_word);
5542 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5544 exp_word = to_be_freed;
5545 if (exp_op == '?') {
5546 /* mimic bash message */
5547 die_if_script("%s: %s",
5549 exp_word[0] ? exp_word : "parameter null or not set"
5551 //TODO: how interactive bash aborts expansion mid-command?
5556 if (exp_op == '=') {
5557 /* ${var=[word]} or ${var:=[word]} */
5558 if (isdigit(var[0]) || var[0] == '#') {
5559 /* mimic bash message */
5560 die_if_script("$%s: cannot assign in this way", var);
5563 char *new_var = xasprintf("%s=%s", var, val);
5564 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5568 } /* one of "-=+?" */
5570 *exp_saveptr = exp_save;
5576 *to_be_freed_pp = to_be_freed;
5580 /* Expand all variable references in given string, adding words to list[]
5581 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5582 * to be filled). This routine is extremely tricky: has to deal with
5583 * variables/parameters with whitespace, $* and $@, and constructs like
5584 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5585 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5587 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5588 * expansion of right-hand side of assignment == 1-element expand.
5590 char cant_be_null = 0; /* only bit 0x80 matters */
5591 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5594 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5595 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5596 debug_print_list("expand_vars_to_list", output, n);
5597 n = o_save_ptr(output, n);
5598 debug_print_list("expand_vars_to_list[0]", output, n);
5600 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5602 char *to_be_freed = NULL;
5603 const char *val = NULL;
5604 #if ENABLE_HUSH_TICK
5605 o_string subst_result = NULL_O_STRING;
5607 #if ENABLE_SH_MATH_SUPPORT
5608 char arith_buf[sizeof(arith_t)*3 + 2];
5612 o_addchr(output, '\0');
5613 n = o_save_ptr(output, n);
5617 o_addblock(output, arg, p - arg);
5618 debug_print_list("expand_vars_to_list[1]", output, n);
5620 p = strchr(p, SPECIAL_VAR_SYMBOL);
5622 /* Fetch special var name (if it is indeed one of them)
5623 * and quote bit, force the bit on if singleword expansion -
5624 * important for not getting v=$@ expand to many words. */
5625 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5627 /* Is this variable quoted and thus expansion can't be null?
5628 * "$@" is special. Even if quoted, it can still
5629 * expand to nothing (not even an empty string),
5630 * thus it is excluded. */
5631 if ((first_ch & 0x7f) != '@')
5632 cant_be_null |= first_ch;
5634 switch (first_ch & 0x7f) {
5635 /* Highest bit in first_ch indicates that var is double-quoted */
5639 if (!G.global_argv[1])
5642 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5643 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5644 while (G.global_argv[i]) {
5645 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5646 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5647 if (G.global_argv[i++][0] && G.global_argv[i]) {
5648 /* this argv[] is not empty and not last:
5649 * put terminating NUL, start new word */
5650 o_addchr(output, '\0');
5651 debug_print_list("expand_vars_to_list[2]", output, n);
5652 n = o_save_ptr(output, n);
5653 debug_print_list("expand_vars_to_list[3]", output, n);
5657 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5658 * and in this case should treat it like '$*' - see 'else...' below */
5659 if (first_ch == ('@'|0x80) /* quoted $@ */
5660 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5663 o_addQstr(output, G.global_argv[i]);
5664 if (++i >= G.global_argc)
5666 o_addchr(output, '\0');
5667 debug_print_list("expand_vars_to_list[4]", output, n);
5668 n = o_save_ptr(output, n);
5670 } else { /* quoted $* (or v="$@" case): add as one word */
5672 o_addQstr(output, G.global_argv[i]);
5673 if (!G.global_argv[++i])
5676 o_addchr(output, G.ifs[0]);
5678 output->has_quoted_part = 1;
5682 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5683 /* "Empty variable", used to make "" etc to not disappear */
5684 output->has_quoted_part = 1;
5686 cant_be_null = 0x80;
5688 #if ENABLE_HUSH_TICK
5689 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5690 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5692 /* Can't just stuff it into output o_string,
5693 * expanded result may need to be globbed
5694 * and $IFS-splitted */
5695 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5696 G.last_exitcode = process_command_subs(&subst_result, arg);
5697 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5698 val = subst_result.data;
5701 #if ENABLE_SH_MATH_SUPPORT
5702 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5705 arg++; /* skip '+' */
5706 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5707 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5708 res = expand_and_evaluate_arith(arg, NULL);
5709 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5710 sprintf(arith_buf, ARITH_FMT, res);
5716 val = expand_one_var(&to_be_freed, arg, &p);
5717 IF_HUSH_TICK(store_val:)
5718 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5719 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5720 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5721 if (val && val[0]) {
5722 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5725 } else { /* quoted $VAR, val will be appended below */
5726 output->has_quoted_part = 1;
5727 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5728 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5731 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5733 if (val && val[0]) {
5734 o_addQstr(output, val);
5738 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5739 * Do the check to avoid writing to a const string. */
5740 if (*p != SPECIAL_VAR_SYMBOL)
5741 *p = SPECIAL_VAR_SYMBOL;
5743 #if ENABLE_HUSH_TICK
5744 o_free(&subst_result);
5747 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5751 o_addchr(output, '\0');
5752 n = o_save_ptr(output, n);
5754 debug_print_list("expand_vars_to_list[a]", output, n);
5755 /* this part is literal, and it was already pre-quoted
5756 * if needed (much earlier), do not use o_addQstr here! */
5757 o_addstr_with_NUL(output, arg);
5758 debug_print_list("expand_vars_to_list[b]", output, n);
5759 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5760 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5763 /* allow to reuse list[n] later without re-growth */
5764 output->has_empty_slot = 1;
5766 o_addchr(output, '\0');
5772 static char **expand_variables(char **argv, unsigned expflags)
5776 o_string output = NULL_O_STRING;
5778 output.o_expflags = expflags;
5782 n = expand_vars_to_list(&output, n, *argv);
5785 debug_print_list("expand_variables", &output, n);
5787 /* output.data (malloced in one block) gets returned in "list" */
5788 list = o_finalize_list(&output, n);
5789 debug_print_strings("expand_variables[1]", list);
5793 static char **expand_strvec_to_strvec(char **argv)
5795 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5798 #if ENABLE_HUSH_BASH_COMPAT
5799 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5801 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5805 /* Used for expansion of right hand of assignments,
5806 * $((...)), heredocs, variable espansion parts.
5808 * NB: should NOT do globbing!
5809 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5811 static char *expand_string_to_string(const char *str, int do_unbackslash)
5813 #if !ENABLE_HUSH_BASH_COMPAT
5814 const int do_unbackslash = 1;
5816 char *argv[2], **list;
5818 debug_printf_expand("string_to_string<='%s'\n", str);
5819 /* This is generally an optimization, but it also
5820 * handles "", which otherwise trips over !list[0] check below.
5821 * (is this ever happens that we actually get str="" here?)
5823 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5824 //TODO: Can use on strings with \ too, just unbackslash() them?
5825 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5826 return xstrdup(str);
5829 argv[0] = (char*)str;
5831 list = expand_variables(argv, do_unbackslash
5832 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5833 : EXP_FLAG_SINGLEWORD
5836 if (!list[0] || list[1])
5837 bb_error_msg_and_die("BUG in varexp2");
5838 /* actually, just move string 2*sizeof(char*) bytes back */
5839 overlapping_strcpy((char*)list, list[0]);
5841 unbackslash((char*)list);
5842 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5846 /* Used for "eval" builtin */
5847 static char* expand_strvec_to_string(char **argv)
5851 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5852 /* Convert all NULs to spaces */
5857 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5858 bb_error_msg_and_die("BUG in varexp3");
5859 /* bash uses ' ' regardless of $IFS contents */
5864 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5865 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5869 static char **expand_assignments(char **argv, int count)
5874 G.expanded_assignments = p = NULL;
5875 /* Expand assignments into one string each */
5876 for (i = 0; i < count; i++) {
5877 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5879 G.expanded_assignments = NULL;
5884 static void switch_off_special_sigs(unsigned mask)
5887 while ((mask >>= 1) != 0) {
5892 if (G.traps[sig] && !G.traps[sig][0])
5893 /* trap is '', has to remain SIG_IGN */
5896 G.traps[sig] = NULL;
5898 /* We are here only if no trap or trap was not '' */
5899 install_sighandler(sig, SIG_DFL);
5905 void re_execute_shell(char ***to_free, const char *s,
5906 char *g_argv0, char **g_argv,
5907 char **builtin_argv) NORETURN;
5909 static void reset_traps_to_defaults(void)
5911 /* This function is always called in a child shell
5912 * after fork (not vfork, NOMMU doesn't use this function).
5917 /* Child shells are not interactive.
5918 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5919 * Testcase: (while :; do :; done) + ^Z should background.
5920 * Same goes for SIGTERM, SIGHUP, SIGINT.
5922 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5923 if (!G.traps && !mask)
5924 return; /* already no traps and no special sigs */
5926 /* Switch off special sigs */
5927 switch_off_special_sigs(mask);
5929 G_fatal_sig_mask = 0;
5931 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5932 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5933 * remain set in G.special_sig_mask */
5938 /* Reset all sigs to default except ones with empty traps */
5939 for (sig = 0; sig < NSIG; sig++) {
5941 continue; /* no trap: nothing to do */
5942 if (!G.traps[sig][0])
5943 continue; /* empty trap: has to remain SIG_IGN */
5944 /* sig has non-empty trap, reset it: */
5946 G.traps[sig] = NULL;
5947 /* There is no signal for trap 0 (EXIT) */
5950 install_sighandler(sig, pick_sighandler(sig));
5956 static void re_execute_shell(char ***to_free, const char *s,
5957 char *g_argv0, char **g_argv,
5958 char **builtin_argv) NORETURN;
5959 static void re_execute_shell(char ***to_free, const char *s,
5960 char *g_argv0, char **g_argv,
5961 char **builtin_argv)
5963 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5964 /* delims + 2 * (number of bytes in printed hex numbers) */
5965 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5966 char *heredoc_argv[4];
5967 struct variable *cur;
5968 # if ENABLE_HUSH_FUNCTIONS
5969 struct function *funcp;
5973 unsigned long long empty_trap_mask;
5975 if (!g_argv0) { /* heredoc */
5976 argv = heredoc_argv;
5977 argv[0] = (char *) G.argv0_for_re_execing;
5978 argv[1] = (char *) "-<";
5979 argv[2] = (char *) s;
5981 pp = &argv[3]; /* used as pointer to empty environment */
5987 if (pp) while (*pp++)
5990 empty_trap_mask = 0;
5993 for (sig = 1; sig < NSIG; sig++) {
5994 if (G.traps[sig] && !G.traps[sig][0])
5995 empty_trap_mask |= 1LL << sig;
5999 sprintf(param_buf, NOMMU_HACK_FMT
6000 , (unsigned) G.root_pid
6001 , (unsigned) G.root_ppid
6002 , (unsigned) G.last_bg_pid
6003 , (unsigned) G.last_exitcode
6006 IF_HUSH_LOOPS(, G.depth_of_loop)
6008 # undef NOMMU_HACK_FMT
6009 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6010 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6013 for (cur = G.top_var; cur; cur = cur->next) {
6014 if (!cur->flg_export || cur->flg_read_only)
6017 # if ENABLE_HUSH_FUNCTIONS
6018 for (funcp = G.top_func; funcp; funcp = funcp->next)
6024 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6025 *pp++ = (char *) G.argv0_for_re_execing;
6027 for (cur = G.top_var; cur; cur = cur->next) {
6028 if (strcmp(cur->varstr, hush_version_str) == 0)
6030 if (cur->flg_read_only) {
6031 *pp++ = (char *) "-R";
6032 *pp++ = cur->varstr;
6033 } else if (!cur->flg_export) {
6034 *pp++ = (char *) "-V";
6035 *pp++ = cur->varstr;
6038 # if ENABLE_HUSH_FUNCTIONS
6039 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6040 *pp++ = (char *) "-F";
6041 *pp++ = funcp->name;
6042 *pp++ = funcp->body_as_string;
6045 /* We can pass activated traps here. Say, -Tnn:trap_string
6047 * However, POSIX says that subshells reset signals with traps
6049 * I tested bash-3.2 and it not only does that with true subshells
6050 * of the form ( list ), but with any forked children shells.
6051 * I set trap "echo W" WINCH; and then tried:
6053 * { echo 1; sleep 20; echo 2; } &
6054 * while true; do echo 1; sleep 20; echo 2; break; done &
6055 * true | { echo 1; sleep 20; echo 2; } | cat
6057 * In all these cases sending SIGWINCH to the child shell
6058 * did not run the trap. If I add trap "echo V" WINCH;
6059 * _inside_ group (just before echo 1), it works.
6061 * I conclude it means we don't need to pass active traps here.
6063 *pp++ = (char *) "-c";
6066 while (*++builtin_argv)
6067 *pp++ = *builtin_argv;
6068 *pp++ = (char *) "";
6073 /* *pp = NULL; - is already there */
6077 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6078 /* Don't propagate SIG_IGN to the child */
6079 if (SPECIAL_JOBSTOP_SIGS != 0)
6080 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6081 execve(bb_busybox_exec_path, argv, pp);
6082 /* Fallback. Useful for init=/bin/hush usage etc */
6083 if (argv[0][0] == '/')
6084 execve(argv[0], argv, pp);
6085 xfunc_error_retval = 127;
6086 bb_error_msg_and_die("can't re-execute the shell");
6088 #endif /* !BB_MMU */
6091 static int run_and_free_list(struct pipe *pi);
6093 /* Executing from string: eval, sh -c '...'
6094 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6095 * end_trigger controls how often we stop parsing
6096 * NUL: parse all, execute, return
6097 * ';': parse till ';' or newline, execute, repeat till EOF
6099 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6101 /* Why we need empty flag?
6102 * An obscure corner case "false; ``; echo $?":
6103 * empty command in `` should still set $? to 0.
6104 * But we can't just set $? to 0 at the start,
6105 * this breaks "false; echo `echo $?`" case.
6109 struct pipe *pipe_list;
6111 #if ENABLE_HUSH_INTERACTIVE
6112 if (end_trigger == ';')
6113 inp->promptmode = 0; /* PS1 */
6115 pipe_list = parse_stream(NULL, inp, end_trigger);
6116 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6117 /* If we are in "big" script
6118 * (not in `cmd` or something similar)...
6120 if (pipe_list == ERR_PTR && end_trigger == ';') {
6121 /* Discard cached input (rest of line) */
6122 int ch = inp->last_char;
6123 while (ch != EOF && ch != '\n') {
6124 //bb_error_msg("Discarded:'%c'", ch);
6129 /* This stream isn't empty */
6133 if (!pipe_list && empty)
6134 G.last_exitcode = 0;
6137 debug_print_tree(pipe_list, 0);
6138 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6139 run_and_free_list(pipe_list);
6141 if (G_flag_return_in_progress == 1)
6146 static void parse_and_run_string(const char *s)
6148 struct in_str input;
6149 setup_string_in_str(&input, s);
6150 parse_and_run_stream(&input, '\0');
6153 static void parse_and_run_file(FILE *f)
6155 struct in_str input;
6156 setup_file_in_str(&input, f);
6157 parse_and_run_stream(&input, ';');
6160 #if ENABLE_HUSH_TICK
6161 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6166 char **to_free = NULL;
6170 pid = BB_MMU ? xfork() : xvfork();
6171 if (pid == 0) { /* child */
6172 disable_restore_tty_pgrp_on_exit();
6173 /* Process substitution is not considered to be usual
6174 * 'command execution'.
6175 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6182 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6183 close(channel[0]); /* NB: close _first_, then move fd! */
6184 xmove_fd(channel[1], 1);
6185 /* Prevent it from trying to handle ctrl-z etc */
6186 IF_HUSH_JOB(G.run_list_level = 1;)
6187 /* Awful hack for `trap` or $(trap).
6189 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6190 * contains an example where "trap" is executed in a subshell:
6192 * save_traps=$(trap)
6194 * eval "$save_traps"
6196 * Standard does not say that "trap" in subshell shall print
6197 * parent shell's traps. It only says that its output
6198 * must have suitable form, but then, in the above example
6199 * (which is not supposed to be normative), it implies that.
6201 * bash (and probably other shell) does implement it
6202 * (traps are reset to defaults, but "trap" still shows them),
6203 * but as a result, "trap" logic is hopelessly messed up:
6206 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6207 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6208 * # true | trap <--- trap is in subshell - no output (ditto)
6209 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6210 * trap -- 'echo Ho' SIGWINCH
6211 * # echo `(trap)` <--- in subshell in subshell - output
6212 * trap -- 'echo Ho' SIGWINCH
6213 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6214 * trap -- 'echo Ho' SIGWINCH
6216 * The rules when to forget and when to not forget traps
6217 * get really complex and nonsensical.
6219 * Our solution: ONLY bare $(trap) or `trap` is special.
6221 s = skip_whitespace(s);
6222 if (is_prefixed_with(s, "trap")
6223 && skip_whitespace(s + 4)[0] == '\0'
6225 static const char *const argv[] = { NULL, NULL };
6226 builtin_trap((char**)argv);
6227 fflush_all(); /* important */
6231 reset_traps_to_defaults();
6232 parse_and_run_string(s);
6233 _exit(G.last_exitcode);
6235 /* We re-execute after vfork on NOMMU. This makes this script safe:
6236 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6237 * huge=`cat BIG` # was blocking here forever
6240 re_execute_shell(&to_free,
6250 # if ENABLE_HUSH_FAST
6252 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6253 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6254 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6256 enable_restore_tty_pgrp_on_exit();
6261 return remember_FILE(xfdopen_for_read(channel[0]));
6264 /* Return code is exit status of the process that is run. */
6265 static int process_command_subs(o_string *dest, const char *s)
6268 struct in_str pipe_str;
6270 int status, ch, eol_cnt;
6272 fp = generate_stream_from_string(s, &pid);
6274 /* Now send results of command back into original context */
6275 setup_file_in_str(&pipe_str, fp);
6277 while ((ch = i_getch(&pipe_str)) != EOF) {
6283 o_addchr(dest, '\n');
6286 o_addQchr(dest, ch);
6289 debug_printf("done reading from `cmd` pipe, closing it\n");
6290 fclose_and_forget(fp);
6291 /* We need to extract exitcode. Test case
6292 * "true; echo `sleep 1; false` $?"
6294 safe_waitpid(pid, &status, 0);
6295 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6296 return WEXITSTATUS(status);
6298 #endif /* ENABLE_HUSH_TICK */
6301 static void setup_heredoc(struct redir_struct *redir)
6303 struct fd_pair pair;
6306 /* the _body_ of heredoc (misleading field name) */
6307 const char *heredoc = redir->rd_filename;
6314 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6315 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6319 len = strlen(heredoc);
6321 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6323 xmove_fd(pair.rd, redir->rd_fd);
6325 /* Try writing without forking. Newer kernels have
6326 * dynamically growing pipes. Must use non-blocking write! */
6329 written = write(pair.wr, heredoc, len);
6340 ndelay_off(pair.wr);
6342 /* Okay, pipe buffer was not big enough */
6343 /* Note: we must not create a stray child (bastard? :)
6344 * for the unsuspecting parent process. Child creates a grandchild
6345 * and exits before parent execs the process which consumes heredoc
6346 * (that exec happens after we return from this function) */
6353 disable_restore_tty_pgrp_on_exit();
6354 pid = BB_MMU ? xfork() : xvfork();
6358 close(redir->rd_fd); /* read side of the pipe */
6360 full_write(pair.wr, heredoc, len); /* may loop or block */
6363 /* Delegate blocking writes to another process */
6364 xmove_fd(pair.wr, STDOUT_FILENO);
6365 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6369 #if ENABLE_HUSH_FAST
6371 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6373 enable_restore_tty_pgrp_on_exit();
6379 wait(NULL); /* wait till child has died */
6382 /* fd: redirect wants this fd to be used (e.g. 3>file).
6383 * Move all conflicting internally used fds,
6384 * and remember them so that we can restore them later.
6386 static int save_fds_on_redirect(int fd, int squirrel[3])
6389 /* Handle redirects of fds 0,1,2 */
6391 /* If we collide with an already moved stdio fd... */
6392 if (fd == squirrel[0]) {
6393 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6396 if (fd == squirrel[1]) {
6397 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6400 if (fd == squirrel[2]) {
6401 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6404 /* If we are about to redirect stdio fd, and did not yet move it... */
6405 if (fd <= 2 && squirrel[fd] < 0) {
6406 /* We avoid taking stdio fds */
6407 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6408 if (squirrel[fd] < 0 && errno != EBADF)
6410 return 0; /* "we did not close fd" */
6414 #if ENABLE_HUSH_INTERACTIVE
6415 if (fd != 0 && fd == G.interactive_fd) {
6416 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6421 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6422 * (1) Redirect in a forked child. No need to save FILEs' fds,
6423 * we aren't going to use them anymore, ok to trash.
6424 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6425 * but how are we doing to use them?
6426 * "fileno(fd) = new_fd" can't be done.
6431 return save_FILEs_on_redirect(fd);
6434 static void restore_redirects(int squirrel[3])
6437 for (i = 0; i <= 2; i++) {
6440 /* We simply die on error */
6445 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6447 restore_redirected_FILEs();
6450 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6451 * and stderr if they are redirected. */
6452 static int setup_redirects(struct command *prog, int squirrel[])
6455 struct redir_struct *redir;
6457 for (redir = prog->redirects; redir; redir = redir->next) {
6458 if (redir->rd_type == REDIRECT_HEREDOC2) {
6459 /* "rd_fd<<HERE" case */
6460 save_fds_on_redirect(redir->rd_fd, squirrel);
6461 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6463 debug_printf_parse("set heredoc '%s'\n",
6464 redir->rd_filename);
6465 setup_heredoc(redir);
6469 if (redir->rd_dup == REDIRFD_TO_FILE) {
6470 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6472 if (redir->rd_filename == NULL) {
6475 * "cmd >" (no filename)
6476 * "cmd > <file" (2nd redirect starts too early)
6478 die_if_script("syntax error: %s", "invalid redirect");
6481 mode = redir_table[redir->rd_type].mode;
6482 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6483 openfd = open_or_warn(p, mode);
6486 /* Error message from open_or_warn can be lost
6487 * if stderr has been redirected, but bash
6488 * and ash both lose it as well
6489 * (though zsh doesn't!)
6494 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6495 openfd = redir->rd_dup;
6498 if (openfd != redir->rd_fd) {
6499 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6500 if (openfd == REDIRFD_CLOSE) {
6501 /* "rd_fd >&-" means "close me" */
6503 /* ^^^ optimization: saving may already
6504 * have closed it. If not... */
6505 close(redir->rd_fd);
6508 xdup2(openfd, redir->rd_fd);
6509 if (redir->rd_dup == REDIRFD_TO_FILE)
6510 /* "rd_fd > FILE" */
6512 /* else: "rd_fd > rd_dup" */
6519 static char *find_in_path(const char *arg)
6522 const char *PATH = get_local_var_value("PATH");
6528 const char *end = strchrnul(PATH, ':');
6529 int sz = end - PATH; /* must be int! */
6533 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6535 /* We have xxx::yyyy in $PATH,
6536 * it means "use current dir" */
6539 if (access(ret, F_OK) == 0)
6552 static const struct built_in_command *find_builtin_helper(const char *name,
6553 const struct built_in_command *x,
6554 const struct built_in_command *end)
6557 if (strcmp(name, x->b_cmd) != 0) {
6561 debug_printf_exec("found builtin '%s'\n", name);
6566 static const struct built_in_command *find_builtin1(const char *name)
6568 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6570 static const struct built_in_command *find_builtin(const char *name)
6572 const struct built_in_command *x = find_builtin1(name);
6575 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6578 #if ENABLE_HUSH_FUNCTIONS
6579 static struct function **find_function_slot(const char *name)
6581 struct function **funcpp = &G.top_func;
6583 if (strcmp(name, (*funcpp)->name) == 0) {
6586 funcpp = &(*funcpp)->next;
6591 static const struct function *find_function(const char *name)
6593 const struct function *funcp = *find_function_slot(name);
6595 debug_printf_exec("found function '%s'\n", name);
6599 /* Note: takes ownership on name ptr */
6600 static struct function *new_function(char *name)
6602 struct function **funcpp = find_function_slot(name);
6603 struct function *funcp = *funcpp;
6605 if (funcp != NULL) {
6606 struct command *cmd = funcp->parent_cmd;
6607 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6609 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6611 /* Note: if !funcp->body, do not free body_as_string!
6612 * This is a special case of "-F name body" function:
6613 * body_as_string was not malloced! */
6615 free_pipe_list(funcp->body);
6617 free(funcp->body_as_string);
6621 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6622 cmd->argv[0] = funcp->name;
6623 cmd->group = funcp->body;
6625 cmd->group_as_string = funcp->body_as_string;
6629 debug_printf_exec("remembering new function '%s'\n", name);
6630 funcp = *funcpp = xzalloc(sizeof(*funcp));
6631 /*funcp->next = NULL;*/
6638 static void unset_func(const char *name)
6640 struct function **funcpp = find_function_slot(name);
6641 struct function *funcp = *funcpp;
6643 if (funcp != NULL) {
6644 debug_printf_exec("freeing function '%s'\n", funcp->name);
6645 *funcpp = funcp->next;
6646 /* funcp is unlinked now, deleting it.
6647 * Note: if !funcp->body, the function was created by
6648 * "-F name body", do not free ->body_as_string
6649 * and ->name as they were not malloced. */
6651 free_pipe_list(funcp->body);
6654 free(funcp->body_as_string);
6662 #define exec_function(to_free, funcp, argv) \
6663 exec_function(funcp, argv)
6665 static void exec_function(char ***to_free,
6666 const struct function *funcp,
6667 char **argv) NORETURN;
6668 static void exec_function(char ***to_free,
6669 const struct function *funcp,
6675 argv[0] = G.global_argv[0];
6676 G.global_argv = argv;
6680 /* On MMU, funcp->body is always non-NULL */
6681 n = run_list(funcp->body);
6685 re_execute_shell(to_free,
6686 funcp->body_as_string,
6693 static int run_function(const struct function *funcp, char **argv)
6699 save_and_replace_G_args(&sv, argv);
6701 /* "we are in function, ok to use return" */
6702 sv_flg = G_flag_return_in_progress;
6703 G_flag_return_in_progress = -1;
6704 # if ENABLE_HUSH_LOCAL
6705 G.func_nest_level++;
6708 /* On MMU, funcp->body is always non-NULL */
6711 /* Function defined by -F */
6712 parse_and_run_string(funcp->body_as_string);
6713 rc = G.last_exitcode;
6717 rc = run_list(funcp->body);
6720 # if ENABLE_HUSH_LOCAL
6722 struct variable *var;
6723 struct variable **var_pp;
6725 var_pp = &G.top_var;
6726 while ((var = *var_pp) != NULL) {
6727 if (var->func_nest_level < G.func_nest_level) {
6728 var_pp = &var->next;
6732 if (var->flg_export)
6733 bb_unsetenv(var->varstr);
6734 /* Remove from global list */
6735 *var_pp = var->next;
6741 G.func_nest_level--;
6744 G_flag_return_in_progress = sv_flg;
6746 restore_G_args(&sv, argv);
6750 #endif /* ENABLE_HUSH_FUNCTIONS */
6754 #define exec_builtin(to_free, x, argv) \
6755 exec_builtin(x, argv)
6757 #define exec_builtin(to_free, x, argv) \
6758 exec_builtin(to_free, argv)
6760 static void exec_builtin(char ***to_free,
6761 const struct built_in_command *x,
6762 char **argv) NORETURN;
6763 static void exec_builtin(char ***to_free,
6764 const struct built_in_command *x,
6770 rcode = x->b_function(argv);
6775 /* On NOMMU, we must never block!
6776 * Example: { sleep 99 | read line; } & echo Ok
6778 re_execute_shell(to_free,
6787 static void execvp_or_die(char **argv) NORETURN;
6788 static void execvp_or_die(char **argv)
6791 debug_printf_exec("execing '%s'\n", argv[0]);
6792 /* Don't propagate SIG_IGN to the child */
6793 if (SPECIAL_JOBSTOP_SIGS != 0)
6794 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6795 execvp(argv[0], argv);
6797 if (errno == EACCES) e = 126;
6798 if (errno == ENOENT) e = 127;
6799 bb_perror_msg("can't execute '%s'", argv[0]);
6803 #if ENABLE_HUSH_MODE_X
6804 static void dump_cmd_in_x_mode(char **argv)
6806 if (G_x_mode && argv) {
6807 /* We want to output the line in one write op */
6815 len += strlen(argv[n++]) + 1;
6821 p += sprintf(p, " %s", argv[n++]);
6829 # define dump_cmd_in_x_mode(argv) ((void)0)
6833 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6834 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6835 #define pseudo_exec(nommu_save, command, argv_expanded) \
6836 pseudo_exec(command, argv_expanded)
6839 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6841 * Don't exit() here. If you don't exec, use _exit instead.
6842 * The at_exit handlers apparently confuse the calling process,
6843 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6845 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6846 char **argv, int assignment_cnt,
6847 char **argv_expanded) NORETURN;
6848 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6849 char **argv, int assignment_cnt,
6850 char **argv_expanded)
6854 new_env = expand_assignments(argv, assignment_cnt);
6855 dump_cmd_in_x_mode(new_env);
6857 if (!argv[assignment_cnt]) {
6858 /* Case when we are here: ... | var=val | ...
6859 * (note that we do not exit early, i.e., do not optimize out
6860 * expand_assignments(): think about ... | var=`sleep 1` | ...
6862 free_strings(new_env);
6863 _exit(EXIT_SUCCESS);
6867 set_vars_and_save_old(new_env);
6868 free(new_env); /* optional */
6869 /* we can also destroy set_vars_and_save_old's return value,
6872 nommu_save->new_env = new_env;
6873 nommu_save->old_vars = set_vars_and_save_old(new_env);
6876 if (argv_expanded) {
6877 argv = argv_expanded;
6879 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6881 nommu_save->argv = argv;
6884 dump_cmd_in_x_mode(argv);
6886 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6887 if (strchr(argv[0], '/') != NULL)
6891 /* Check if the command matches any of the builtins.
6892 * Depending on context, this might be redundant. But it's
6893 * easier to waste a few CPU cycles than it is to figure out
6894 * if this is one of those cases.
6897 /* On NOMMU, it is more expensive to re-execute shell
6898 * just in order to run echo or test builtin.
6899 * It's better to skip it here and run corresponding
6900 * non-builtin later. */
6901 const struct built_in_command *x;
6902 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6904 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6907 #if ENABLE_HUSH_FUNCTIONS
6908 /* Check if the command matches any functions */
6910 const struct function *funcp = find_function(argv[0]);
6912 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6917 #if ENABLE_FEATURE_SH_STANDALONE
6918 /* Check if the command matches any busybox applets */
6920 int a = find_applet_by_name(argv[0]);
6922 # if BB_MMU /* see above why on NOMMU it is not allowed */
6923 if (APPLET_IS_NOEXEC(a)) {
6924 /* Do not leak open fds from opened script files etc */
6925 close_all_FILE_list();
6926 debug_printf_exec("running applet '%s'\n", argv[0]);
6927 run_applet_no_and_exit(a, argv);
6930 /* Re-exec ourselves */
6931 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6932 /* Don't propagate SIG_IGN to the child */
6933 if (SPECIAL_JOBSTOP_SIGS != 0)
6934 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6935 execv(bb_busybox_exec_path, argv);
6936 /* If they called chroot or otherwise made the binary no longer
6937 * executable, fall through */
6942 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6945 execvp_or_die(argv);
6948 /* Called after [v]fork() in run_pipe
6950 static void pseudo_exec(nommu_save_t *nommu_save,
6951 struct command *command,
6952 char **argv_expanded) NORETURN;
6953 static void pseudo_exec(nommu_save_t *nommu_save,
6954 struct command *command,
6955 char **argv_expanded)
6957 if (command->argv) {
6958 pseudo_exec_argv(nommu_save, command->argv,
6959 command->assignment_cnt, argv_expanded);
6962 if (command->group) {
6963 /* Cases when we are here:
6966 * ... | ( list ) | ...
6967 * ... | { list } | ...
6971 debug_printf_exec("pseudo_exec: run_list\n");
6972 reset_traps_to_defaults();
6973 rcode = run_list(command->group);
6974 /* OK to leak memory by not calling free_pipe_list,
6975 * since this process is about to exit */
6978 re_execute_shell(&nommu_save->argv_from_re_execing,
6979 command->group_as_string,
6986 /* Case when we are here: ... | >file */
6987 debug_printf_exec("pseudo_exec'ed null command\n");
6988 _exit(EXIT_SUCCESS);
6992 static const char *get_cmdtext(struct pipe *pi)
6998 /* This is subtle. ->cmdtext is created only on first backgrounding.
6999 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7000 * On subsequent bg argv is trashed, but we won't use it */
7004 argv = pi->cmds[0].argv;
7006 pi->cmdtext = xzalloc(1);
7011 len += strlen(*argv) + 1;
7015 argv = pi->cmds[0].argv;
7017 p = stpcpy(p, *argv);
7024 static void insert_bg_job(struct pipe *pi)
7026 struct pipe *job, **jobp;
7029 /* Linear search for the ID of the job to use */
7031 for (job = G.job_list; job; job = job->next)
7032 if (job->jobid >= pi->jobid)
7033 pi->jobid = job->jobid + 1;
7035 /* Add job to the list of running jobs */
7037 while ((job = *jobp) != NULL)
7039 job = *jobp = xmalloc(sizeof(*job));
7041 *job = *pi; /* physical copy */
7043 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7044 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7045 for (i = 0; i < pi->num_cmds; i++) {
7046 job->cmds[i].pid = pi->cmds[i].pid;
7047 /* all other fields are not used and stay zero */
7049 job->cmdtext = xstrdup(get_cmdtext(pi));
7051 if (G_interactive_fd)
7052 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7053 G.last_jobid = job->jobid;
7056 static void remove_bg_job(struct pipe *pi)
7058 struct pipe *prev_pipe;
7060 if (pi == G.job_list) {
7061 G.job_list = pi->next;
7063 prev_pipe = G.job_list;
7064 while (prev_pipe->next != pi)
7065 prev_pipe = prev_pipe->next;
7066 prev_pipe->next = pi->next;
7069 G.last_jobid = G.job_list->jobid;
7074 /* Remove a backgrounded job */
7075 static void delete_finished_bg_job(struct pipe *pi)
7082 static int job_exited_or_stopped(struct pipe *pi)
7086 if (pi->alive_cmds != pi->stopped_cmds)
7089 /* All processes in fg pipe have exited or stopped */
7093 rcode = pi->cmds[i].cmd_exitcode;
7094 /* usually last process gives overall exitstatus,
7095 * but with "set -o pipefail", last *failed* process does */
7096 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7099 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7103 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7110 dead = WIFEXITED(status) || WIFSIGNALED(status);
7113 if (WIFSTOPPED(status))
7114 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7115 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7116 if (WIFSIGNALED(status))
7117 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7118 childpid, WTERMSIG(status), WEXITSTATUS(status));
7119 if (WIFEXITED(status))
7120 debug_printf_jobs("pid %d exited, exitcode %d\n",
7121 childpid, WEXITSTATUS(status));
7123 /* Were we asked to wait for a fg pipe? */
7125 i = fg_pipe->num_cmds;
7130 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7131 if (fg_pipe->cmds[i].pid != childpid)
7135 fg_pipe->cmds[i].pid = 0;
7136 fg_pipe->alive_cmds--;
7137 ex = WEXITSTATUS(status);
7138 /* bash prints killer signal's name for *last*
7139 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7140 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7142 if (WIFSIGNALED(status)) {
7143 int sig = WTERMSIG(status);
7144 if (i == fg_pipe->num_cmds-1)
7145 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7146 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7147 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7148 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7149 * Maybe we need to use sig | 128? */
7152 fg_pipe->cmds[i].cmd_exitcode = ex;
7154 fg_pipe->stopped_cmds++;
7156 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7157 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7158 rcode = job_exited_or_stopped(fg_pipe);
7160 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7161 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7162 * and "killall -STOP cat" */
7163 if (G_interactive_fd) {
7165 if (fg_pipe->alive_cmds != 0)
7166 insert_bg_job(fg_pipe);
7170 if (fg_pipe->alive_cmds == 0)
7173 /* There are still running processes in the fg_pipe */
7176 /* It wasnt in fg_pipe, look for process in bg pipes */
7180 /* We were asked to wait for bg or orphaned children */
7181 /* No need to remember exitcode in this case */
7182 for (pi = G.job_list; pi; pi = pi->next) {
7183 for (i = 0; i < pi->num_cmds; i++) {
7184 if (pi->cmds[i].pid == childpid)
7185 goto found_pi_and_prognum;
7188 /* Happens when shell is used as init process (init=/bin/sh) */
7189 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7190 return -1; /* this wasn't a process from fg_pipe */
7192 found_pi_and_prognum:
7195 pi->cmds[i].pid = 0;
7196 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7197 if (WIFSIGNALED(status))
7198 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7200 if (!pi->alive_cmds) {
7201 if (G_interactive_fd)
7202 printf(JOB_STATUS_FORMAT, pi->jobid,
7203 "Done", pi->cmdtext);
7204 delete_finished_bg_job(pi);
7211 return -1; /* this wasn't a process from fg_pipe */
7214 /* Check to see if any processes have exited -- if they have,
7215 * figure out why and see if a job has completed.
7217 * If non-NULL fg_pipe: wait for its completion or stop.
7218 * Return its exitcode or zero if stopped.
7220 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7221 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7222 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7223 * or 0 if no children changed status.
7225 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7226 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7227 * or 0 if no children changed status.
7229 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7235 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7237 attributes = WUNTRACED;
7238 if (fg_pipe == NULL)
7239 attributes |= WNOHANG;
7242 #if ENABLE_HUSH_FAST
7243 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7244 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7245 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7246 /* There was neither fork nor SIGCHLD since last waitpid */
7247 /* Avoid doing waitpid syscall if possible */
7248 if (!G.we_have_children) {
7252 if (fg_pipe == NULL) { /* is WNOHANG set? */
7253 /* We have children, but they did not exit
7254 * or stop yet (we saw no SIGCHLD) */
7257 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7261 /* Do we do this right?
7262 * bash-3.00# sleep 20 | false
7264 * [3]+ Stopped sleep 20 | false
7265 * bash-3.00# echo $?
7266 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7267 * [hush 1.14.0: yes we do it right]
7271 #if ENABLE_HUSH_FAST
7273 i = G.count_SIGCHLD;
7275 childpid = waitpid(-1, &status, attributes);
7276 if (childpid <= 0) {
7277 if (childpid && errno != ECHILD)
7278 bb_perror_msg("waitpid");
7279 #if ENABLE_HUSH_FAST
7280 else { /* Until next SIGCHLD, waitpid's are useless */
7281 G.we_have_children = (childpid == 0);
7282 G.handled_SIGCHLD = i;
7283 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7286 /* ECHILD (no children), or 0 (no change in children status) */
7290 rcode = process_wait_result(fg_pipe, childpid, status);
7292 /* fg_pipe exited or stopped */
7295 if (childpid == waitfor_pid) {
7296 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7297 rcode = WEXITSTATUS(status);
7298 if (WIFSIGNALED(status))
7299 rcode = 128 + WTERMSIG(status);
7300 if (WIFSTOPPED(status))
7301 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7302 rcode = 128 + WSTOPSIG(status);
7304 break; /* "wait PID" called us, give it exitcode+1 */
7306 /* This wasn't one of our processes, or */
7307 /* fg_pipe still has running processes, do waitpid again */
7308 } /* while (waitpid succeeds)... */
7314 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7317 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7318 if (G_saved_tty_pgrp) {
7319 /* Job finished, move the shell to the foreground */
7320 p = getpgrp(); /* our process group id */
7321 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7322 tcsetpgrp(G_interactive_fd, p);
7328 /* Start all the jobs, but don't wait for anything to finish.
7331 * Return code is normally -1, when the caller has to wait for children
7332 * to finish to determine the exit status of the pipe. If the pipe
7333 * is a simple builtin command, however, the action is done by the
7334 * time run_pipe returns, and the exit code is provided as the
7337 * Returns -1 only if started some children. IOW: we have to
7338 * mask out retvals of builtins etc with 0xff!
7340 * The only case when we do not need to [v]fork is when the pipe
7341 * is single, non-backgrounded, non-subshell command. Examples:
7342 * cmd ; ... { list } ; ...
7343 * cmd && ... { list } && ...
7344 * cmd || ... { list } || ...
7345 * If it is, then we can run cmd as a builtin, NOFORK,
7346 * or (if SH_STANDALONE) an applet, and we can run the { list }
7347 * with run_list. If it isn't one of these, we fork and exec cmd.
7349 * Cases when we must fork:
7350 * non-single: cmd | cmd
7351 * backgrounded: cmd & { list } &
7352 * subshell: ( list ) [&]
7354 #if !ENABLE_HUSH_MODE_X
7355 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7356 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7358 static int redirect_and_varexp_helper(char ***new_env_p,
7359 struct variable **old_vars_p,
7360 struct command *command,
7362 char **argv_expanded)
7364 /* setup_redirects acts on file descriptors, not FILEs.
7365 * This is perfect for work that comes after exec().
7366 * Is it really safe for inline use? Experimentally,
7367 * things seem to work. */
7368 int rcode = setup_redirects(command, squirrel);
7370 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7371 *new_env_p = new_env;
7372 dump_cmd_in_x_mode(new_env);
7373 dump_cmd_in_x_mode(argv_expanded);
7375 *old_vars_p = set_vars_and_save_old(new_env);
7379 static NOINLINE int run_pipe(struct pipe *pi)
7381 static const char *const null_ptr = NULL;
7385 struct command *command;
7386 char **argv_expanded;
7388 /* it is not always needed, but we aim to smaller code */
7389 int squirrel[] = { -1, -1, -1 };
7392 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7395 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7396 * Result should be 3 lines: q w e, qwe, q w e
7398 G.ifs = get_local_var_value("IFS");
7402 IF_HUSH_JOB(pi->pgrp = -1;)
7403 pi->stopped_cmds = 0;
7404 command = &pi->cmds[0];
7405 argv_expanded = NULL;
7407 if (pi->num_cmds != 1
7408 || pi->followup == PIPE_BG
7409 || command->cmd_type == CMD_SUBSHELL
7416 debug_printf_exec(": group:%p argv:'%s'\n",
7417 command->group, command->argv ? command->argv[0] : "NONE");
7419 if (command->group) {
7420 #if ENABLE_HUSH_FUNCTIONS
7421 if (command->cmd_type == CMD_FUNCDEF) {
7422 /* "executing" func () { list } */
7423 struct function *funcp;
7425 funcp = new_function(command->argv[0]);
7426 /* funcp->name is already set to argv[0] */
7427 funcp->body = command->group;
7429 funcp->body_as_string = command->group_as_string;
7430 command->group_as_string = NULL;
7432 command->group = NULL;
7433 command->argv[0] = NULL;
7434 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7435 funcp->parent_cmd = command;
7436 command->child_func = funcp;
7438 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7440 return EXIT_SUCCESS;
7444 debug_printf("non-subshell group\n");
7445 rcode = 1; /* exitcode if redir failed */
7446 if (setup_redirects(command, squirrel) == 0) {
7447 debug_printf_exec(": run_list\n");
7448 rcode = run_list(command->group) & 0xff;
7450 restore_redirects(squirrel);
7451 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7453 debug_printf_exec("run_pipe: return %d\n", rcode);
7457 argv = command->argv ? command->argv : (char **) &null_ptr;
7459 const struct built_in_command *x;
7460 #if ENABLE_HUSH_FUNCTIONS
7461 const struct function *funcp;
7465 char **new_env = NULL;
7466 struct variable *old_vars = NULL;
7468 if (argv[command->assignment_cnt] == NULL) {
7469 /* Assignments, but no command */
7470 /* Ensure redirects take effect (that is, create files).
7471 * Try "a=t >file" */
7472 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7473 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7474 /* Set shell variables */
7478 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7479 /* Do we need to flag set_local_var() errors?
7480 * "assignment to readonly var" and "putenv error"
7485 /* Redirect error sets $? to 1. Otherwise,
7486 * if evaluating assignment value set $?, retain it.
7487 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7489 rcode = G.last_exitcode;
7490 /* Exit, _skipping_ variable restoring code: */
7491 goto clean_up_and_ret0;
7493 #else /* Older, bigger, but more correct code */
7495 rcode = setup_redirects(command, squirrel);
7496 restore_redirects(squirrel);
7497 /* Set shell variables */
7499 bb_putchar_stderr('+');
7501 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7503 fprintf(stderr, " %s", p);
7504 debug_printf_exec("set shell var:'%s'->'%s'\n",
7506 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7507 /* Do we need to flag set_local_var() errors?
7508 * "assignment to readonly var" and "putenv error"
7513 bb_putchar_stderr('\n');
7514 /* Redirect error sets $? to 1. Otherwise,
7515 * if evaluating assignment value set $?, retain it.
7516 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7518 rcode = G.last_exitcode;
7519 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7521 debug_printf_exec("run_pipe: return %d\n", rcode);
7526 /* Expand the rest into (possibly) many strings each */
7527 #if ENABLE_HUSH_BASH_COMPAT
7528 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7529 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7533 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7536 /* if someone gives us an empty string: `cmd with empty output` */
7537 if (!argv_expanded[0]) {
7538 free(argv_expanded);
7540 return G.last_exitcode;
7543 x = find_builtin(argv_expanded[0]);
7544 #if ENABLE_HUSH_FUNCTIONS
7547 funcp = find_function(argv_expanded[0]);
7551 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7552 debug_printf("exec with redirects only\n");
7553 rcode = setup_redirects(command, NULL);
7554 /* rcode=1 can be if redir file can't be opened */
7555 goto clean_up_and_ret1;
7558 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7561 debug_printf_exec(": builtin '%s' '%s'...\n",
7562 x->b_cmd, argv_expanded[1]);
7564 rcode = x->b_function(argv_expanded) & 0xff;
7567 #if ENABLE_HUSH_FUNCTIONS
7569 # if ENABLE_HUSH_LOCAL
7570 struct variable **sv;
7571 sv = G.shadowed_vars_pp;
7572 G.shadowed_vars_pp = &old_vars;
7574 debug_printf_exec(": function '%s' '%s'...\n",
7575 funcp->name, argv_expanded[1]);
7576 rcode = run_function(funcp, argv_expanded) & 0xff;
7577 # if ENABLE_HUSH_LOCAL
7578 G.shadowed_vars_pp = sv;
7584 unset_vars(new_env);
7586 /* clean_up_and_ret0: */
7587 restore_redirects(squirrel);
7589 free(argv_expanded);
7590 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7592 debug_printf_exec("run_pipe return %d\n", rcode);
7596 if (ENABLE_FEATURE_SH_NOFORK) {
7597 int n = find_applet_by_name(argv_expanded[0]);
7598 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7599 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7601 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7602 argv_expanded[0], argv_expanded[1]);
7603 rcode = run_nofork_applet(n, argv_expanded);
7605 goto clean_up_and_ret;
7608 /* It is neither builtin nor applet. We must fork. */
7612 /* NB: argv_expanded may already be created, and that
7613 * might include `cmd` runs! Do not rerun it! We *must*
7614 * use argv_expanded if it's non-NULL */
7616 /* Going to fork a child per each pipe member */
7621 while (cmd_no < pi->num_cmds) {
7622 struct fd_pair pipefds;
7624 volatile nommu_save_t nommu_save;
7625 nommu_save.new_env = NULL;
7626 nommu_save.old_vars = NULL;
7627 nommu_save.argv = NULL;
7628 nommu_save.argv_from_re_execing = NULL;
7630 command = &pi->cmds[cmd_no];
7632 if (command->argv) {
7633 debug_printf_exec(": pipe member '%s' '%s'...\n",
7634 command->argv[0], command->argv[1]);
7636 debug_printf_exec(": pipe member with no argv\n");
7639 /* pipes are inserted between pairs of commands */
7642 if (cmd_no < pi->num_cmds)
7643 xpiped_pair(pipefds);
7645 command->pid = BB_MMU ? fork() : vfork();
7646 if (!command->pid) { /* child */
7648 disable_restore_tty_pgrp_on_exit();
7649 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7651 /* Every child adds itself to new process group
7652 * with pgid == pid_of_first_child_in_pipe */
7653 if (G.run_list_level == 1 && G_interactive_fd) {
7656 if (pgrp < 0) /* true for 1st process only */
7658 if (setpgid(0, pgrp) == 0
7659 && pi->followup != PIPE_BG
7660 && G_saved_tty_pgrp /* we have ctty */
7662 /* We do it in *every* child, not just first,
7664 tcsetpgrp(G_interactive_fd, pgrp);
7668 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7669 /* 1st cmd in backgrounded pipe
7670 * should have its stdin /dev/null'ed */
7672 if (open(bb_dev_null, O_RDONLY))
7673 xopen("/", O_RDONLY);
7675 xmove_fd(next_infd, 0);
7677 xmove_fd(pipefds.wr, 1);
7680 /* Like bash, explicit redirects override pipes,
7681 * and the pipe fd (fd#1) is available for dup'ing:
7682 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7683 * of cmd1 goes into pipe.
7685 if (setup_redirects(command, NULL)) {
7686 /* Happens when redir file can't be opened:
7687 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7689 * hush: can't open '/qwe/rty': No such file or directory
7691 * (echo BAR is not executed, it hits _exit(1) below)
7696 /* Stores to nommu_save list of env vars putenv'ed
7697 * (NOMMU, on MMU we don't need that) */
7698 /* cast away volatility... */
7699 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7700 /* pseudo_exec() does not return */
7703 /* parent or error */
7704 #if ENABLE_HUSH_FAST
7706 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7708 enable_restore_tty_pgrp_on_exit();
7710 /* Clean up after vforked child */
7711 free(nommu_save.argv);
7712 free(nommu_save.argv_from_re_execing);
7713 unset_vars(nommu_save.new_env);
7714 add_vars(nommu_save.old_vars);
7716 free(argv_expanded);
7717 argv_expanded = NULL;
7718 if (command->pid < 0) { /* [v]fork failed */
7719 /* Clearly indicate, was it fork or vfork */
7720 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7724 /* Second and next children need to know pid of first one */
7726 pi->pgrp = command->pid;
7732 if (cmd_no < pi->num_cmds)
7734 /* Pass read (output) pipe end to next iteration */
7735 next_infd = pipefds.rd;
7738 if (!pi->alive_cmds) {
7740 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7745 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7749 /* NB: called by pseudo_exec, and therefore must not modify any
7750 * global data until exec/_exit (we can be a child after vfork!) */
7751 static int run_list(struct pipe *pi)
7753 #if ENABLE_HUSH_CASE
7754 char *case_word = NULL;
7756 #if ENABLE_HUSH_LOOPS
7757 struct pipe *loop_top = NULL;
7758 char **for_lcur = NULL;
7759 char **for_list = NULL;
7761 smallint last_followup;
7763 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7764 smalluint cond_code = 0;
7766 enum { cond_code = 0 };
7769 smallint rword; /* RES_foo */
7770 smallint last_rword; /* ditto */
7773 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7776 #if ENABLE_HUSH_LOOPS
7777 /* Check syntax for "for" */
7780 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7781 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7783 /* current word is FOR or IN (BOLD in comments below) */
7784 if (cpipe->next == NULL) {
7785 syntax_error("malformed for");
7787 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7790 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7791 if (cpipe->next->res_word == RES_DO)
7793 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7794 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7795 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7797 syntax_error("malformed for");
7799 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7806 /* Past this point, all code paths should jump to ret: label
7807 * in order to return, no direct "return" statements please.
7808 * This helps to ensure that no memory is leaked. */
7816 last_rword = RES_XXXX;
7818 last_followup = PIPE_SEQ;
7819 rcode = G.last_exitcode;
7821 /* Go through list of pipes, (maybe) executing them. */
7822 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7827 if (G_flag_return_in_progress == 1)
7830 IF_HAS_KEYWORDS(rword = pi->res_word;)
7831 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7832 rword, cond_code, last_rword);
7833 #if ENABLE_HUSH_LOOPS
7834 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7835 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7837 /* start of a loop: remember where loop starts */
7842 /* Still in the same "if...", "then..." or "do..." branch? */
7843 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7844 if ((rcode == 0 && last_followup == PIPE_OR)
7845 || (rcode != 0 && last_followup == PIPE_AND)
7847 /* It is "<true> || CMD" or "<false> && CMD"
7848 * and we should not execute CMD */
7849 debug_printf_exec("skipped cmd because of || or &&\n");
7850 last_followup = pi->followup;
7851 goto dont_check_jobs_but_continue;
7854 last_followup = pi->followup;
7855 IF_HAS_KEYWORDS(last_rword = rword;)
7858 if (rword == RES_THEN) {
7859 /* if false; then ... fi has exitcode 0! */
7860 G.last_exitcode = rcode = EXIT_SUCCESS;
7861 /* "if <false> THEN cmd": skip cmd */
7865 if (rword == RES_ELSE || rword == RES_ELIF) {
7866 /* "if <true> then ... ELSE/ELIF cmd":
7867 * skip cmd and all following ones */
7872 #if ENABLE_HUSH_LOOPS
7873 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7875 /* first loop through for */
7877 static const char encoded_dollar_at[] ALIGN1 = {
7878 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7879 }; /* encoded representation of "$@" */
7880 static const char *const encoded_dollar_at_argv[] = {
7881 encoded_dollar_at, NULL
7882 }; /* argv list with one element: "$@" */
7885 vals = (char**)encoded_dollar_at_argv;
7886 if (pi->next->res_word == RES_IN) {
7887 /* if no variable values after "in" we skip "for" */
7888 if (!pi->next->cmds[0].argv) {
7889 G.last_exitcode = rcode = EXIT_SUCCESS;
7890 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7893 vals = pi->next->cmds[0].argv;
7894 } /* else: "for var; do..." -> assume "$@" list */
7895 /* create list of variable values */
7896 debug_print_strings("for_list made from", vals);
7897 for_list = expand_strvec_to_strvec(vals);
7898 for_lcur = for_list;
7899 debug_print_strings("for_list", for_list);
7902 /* "for" loop is over, clean up */
7908 /* Insert next value from for_lcur */
7909 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7910 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7913 if (rword == RES_IN) {
7914 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7916 if (rword == RES_DONE) {
7917 continue; /* "done" has no cmds too */
7920 #if ENABLE_HUSH_CASE
7921 if (rword == RES_CASE) {
7922 debug_printf_exec("CASE cond_code:%d\n", cond_code);
7923 case_word = expand_strvec_to_string(pi->cmds->argv);
7926 if (rword == RES_MATCH) {
7929 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
7930 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7932 /* all prev words didn't match, does this one match? */
7933 argv = pi->cmds->argv;
7935 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7936 /* TODO: which FNM_xxx flags to use? */
7937 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7939 if (cond_code == 0) { /* match! we will execute this branch */
7941 case_word = NULL; /* make future "word)" stop */
7948 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7949 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
7951 continue; /* not matched yet, skip this pipe */
7953 if (rword == RES_ESAC) {
7954 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
7956 /* "case" did not match anything: still set $? (to 0) */
7957 G.last_exitcode = rcode = EXIT_SUCCESS;
7961 /* Just pressing <enter> in shell should check for jobs.
7962 * OTOH, in non-interactive shell this is useless
7963 * and only leads to extra job checks */
7964 if (pi->num_cmds == 0) {
7965 if (G_interactive_fd)
7966 goto check_jobs_and_continue;
7970 /* After analyzing all keywords and conditions, we decided
7971 * to execute this pipe. NB: have to do checkjobs(NULL)
7972 * after run_pipe to collect any background children,
7973 * even if list execution is to be stopped. */
7974 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7975 #if ENABLE_HUSH_LOOPS
7976 G.flag_break_continue = 0;
7978 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
7980 /* We ran a builtin, function, or group.
7981 * rcode is already known
7982 * and we don't need to wait for anything. */
7983 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7984 G.last_exitcode = rcode;
7985 check_and_run_traps();
7986 #if ENABLE_HUSH_LOOPS
7987 /* Was it "break" or "continue"? */
7988 if (G.flag_break_continue) {
7989 smallint fbc = G.flag_break_continue;
7990 /* We might fall into outer *loop*,
7991 * don't want to break it too */
7993 G.depth_break_continue--;
7994 if (G.depth_break_continue == 0)
7995 G.flag_break_continue = 0;
7996 /* else: e.g. "continue 2" should *break* once, *then* continue */
7997 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7998 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7999 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8002 /* "continue": simulate end of loop */
8007 if (G_flag_return_in_progress == 1) {
8008 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8011 } else if (pi->followup == PIPE_BG) {
8012 /* What does bash do with attempts to background builtins? */
8013 /* even bash 3.2 doesn't do that well with nested bg:
8014 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8015 * I'm NOT treating inner &'s as jobs */
8017 if (G.run_list_level == 1)
8020 /* Last command's pid goes to $! */
8021 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8022 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8023 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8024 rcode = EXIT_SUCCESS;
8028 if (G.run_list_level == 1 && G_interactive_fd) {
8029 /* Waits for completion, then fg's main shell */
8030 rcode = checkjobs_and_fg_shell(pi);
8031 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8035 /* This one just waits for completion */
8036 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8037 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8039 G.last_exitcode = rcode;
8040 check_and_run_traps();
8043 /* Analyze how result affects subsequent commands */
8045 if (rword == RES_IF || rword == RES_ELIF)
8048 check_jobs_and_continue:
8049 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8050 dont_check_jobs_but_continue: ;
8051 #if ENABLE_HUSH_LOOPS
8052 /* Beware of "while false; true; do ..."! */
8054 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8055 /* check for RES_DONE is needed for "while ...; do \n done" case */
8057 if (rword == RES_WHILE) {
8059 /* "while false; do...done" - exitcode 0 */
8060 G.last_exitcode = rcode = EXIT_SUCCESS;
8061 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8065 if (rword == RES_UNTIL) {
8067 debug_printf_exec(": until expr is true: breaking\n");
8078 #if ENABLE_HUSH_LOOPS
8083 #if ENABLE_HUSH_CASE
8087 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8091 /* Select which version we will use */
8092 static int run_and_free_list(struct pipe *pi)
8095 debug_printf_exec("run_and_free_list entered\n");
8096 if (!G.o_opt[OPT_O_NOEXEC]) {
8097 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8098 rcode = run_list(pi);
8100 /* free_pipe_list has the side effect of clearing memory.
8101 * In the long run that function can be merged with run_list,
8102 * but doing that now would hobble the debugging effort. */
8104 debug_printf_exec("run_and_free_list return %d\n", rcode);
8109 static void install_sighandlers(unsigned mask)
8111 sighandler_t old_handler;
8113 while ((mask >>= 1) != 0) {
8117 old_handler = install_sighandler(sig, pick_sighandler(sig));
8118 /* POSIX allows shell to re-enable SIGCHLD
8119 * even if it was SIG_IGN on entry.
8120 * Therefore we skip IGN check for it:
8124 if (old_handler == SIG_IGN) {
8125 /* oops... restore back to IGN, and record this fact */
8126 install_sighandler(sig, old_handler);
8128 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8130 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8135 /* Called a few times only (or even once if "sh -c") */
8136 static void install_special_sighandlers(void)
8140 /* Which signals are shell-special? */
8141 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8142 if (G_interactive_fd) {
8143 mask |= SPECIAL_INTERACTIVE_SIGS;
8144 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8145 mask |= SPECIAL_JOBSTOP_SIGS;
8147 /* Careful, do not re-install handlers we already installed */
8148 if (G.special_sig_mask != mask) {
8149 unsigned diff = mask & ~G.special_sig_mask;
8150 G.special_sig_mask = mask;
8151 install_sighandlers(diff);
8157 /* Set handlers to restore tty pgrp and exit */
8158 static void install_fatal_sighandlers(void)
8162 /* We will restore tty pgrp on these signals */
8164 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8165 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8166 + (1 << SIGBUS ) * HUSH_DEBUG
8167 + (1 << SIGSEGV) * HUSH_DEBUG
8168 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8170 /* bash 3.2 seems to handle these just like 'fatal' ones */
8173 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8174 * if we aren't interactive... but in this case
8175 * we never want to restore pgrp on exit, and this fn is not called
8177 /*+ (1 << SIGHUP )*/
8178 /*+ (1 << SIGTERM)*/
8179 /*+ (1 << SIGINT )*/
8181 G_fatal_sig_mask = mask;
8183 install_sighandlers(mask);
8187 static int set_mode(int state, char mode, const char *o_opt)
8192 G.o_opt[OPT_O_NOEXEC] = state;
8195 IF_HUSH_MODE_X(G_x_mode = state;)
8199 /* "set -+o" without parameter.
8200 * in bash, set -o produces this output:
8204 * We always use the second form.
8206 const char *p = o_opt_strings;
8209 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8215 idx = index_in_strings(o_opt_strings, o_opt);
8217 G.o_opt[idx] = state;
8221 return EXIT_FAILURE;
8223 return EXIT_SUCCESS;
8226 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8227 int hush_main(int argc, char **argv)
8230 OPT_login = (1 << 0),
8234 unsigned builtin_argc;
8236 struct variable *cur_var;
8237 struct variable *shell_ver;
8240 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8241 G.last_exitcode = EXIT_SUCCESS;
8243 #if ENABLE_HUSH_FAST
8244 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8247 G.argv0_for_re_execing = argv[0];
8249 /* Deal with HUSH_VERSION */
8250 shell_ver = xzalloc(sizeof(*shell_ver));
8251 shell_ver->flg_export = 1;
8252 shell_ver->flg_read_only = 1;
8253 /* Code which handles ${var<op>...} needs writable values for all variables,
8254 * therefore we xstrdup: */
8255 shell_ver->varstr = xstrdup(hush_version_str);
8256 /* Create shell local variables from the values
8257 * currently living in the environment */
8258 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8259 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8260 G.top_var = shell_ver;
8261 cur_var = G.top_var;
8264 char *value = strchr(*e, '=');
8265 if (value) { /* paranoia */
8266 cur_var->next = xzalloc(sizeof(*cur_var));
8267 cur_var = cur_var->next;
8268 cur_var->varstr = *e;
8269 cur_var->max_len = strlen(*e);
8270 cur_var->flg_export = 1;
8274 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8275 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8276 putenv(shell_ver->varstr);
8279 set_pwd_var(/*exp:*/ 1);
8281 #if ENABLE_HUSH_BASH_COMPAT
8282 /* Set (but not export) HOSTNAME unless already set */
8283 if (!get_local_var_value("HOSTNAME")) {
8286 set_local_var_from_halves("HOSTNAME", uts.nodename);
8288 /* bash also exports SHLVL and _,
8289 * and sets (but doesn't export) the following variables:
8291 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8292 * BASH_VERSION='3.2.0(1)-release'
8294 * MACHTYPE=i386-pc-linux-gnu
8296 * PPID=<NNNNN> - we also do it elsewhere
8307 * PIPESTATUS=([0]="0")
8308 * HISTFILE=/<xxx>/.bash_history
8312 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8314 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8325 #if ENABLE_FEATURE_EDITING
8326 G.line_input_state = new_line_input_t(FOR_SHELL);
8329 /* Initialize some more globals to non-zero values */
8330 cmdedit_update_prompt();
8332 die_func = restore_ttypgrp_and__exit;
8334 /* Shell is non-interactive at first. We need to call
8335 * install_special_sighandlers() if we are going to execute "sh <script>",
8336 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8337 * If we later decide that we are interactive, we run install_special_sighandlers()
8338 * in order to intercept (more) signals.
8342 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8343 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8346 opt = getopt(argc, argv, "+c:xinsl"
8349 # if ENABLE_HUSH_FUNCTIONS
8359 * sh ... -c 'script'
8360 * sh ... -c 'script' ARG0 [ARG1...]
8361 * On NOMMU, if builtin_argc != 0,
8362 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8363 * "" needs to be replaced with NULL
8364 * and BARGV vector fed to builtin function.
8365 * Note: the form without ARG0 never happens:
8366 * sh ... -c 'builtin' BARGV... ""
8369 G.root_pid = getpid();
8370 G.root_ppid = getppid();
8372 G.global_argv = argv + optind;
8373 G.global_argc = argc - optind;
8375 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8376 const struct built_in_command *x;
8378 install_special_sighandlers();
8379 x = find_builtin(optarg);
8380 if (x) { /* paranoia */
8381 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8382 G.global_argv += builtin_argc;
8383 G.global_argv[-1] = NULL; /* replace "" */
8385 G.last_exitcode = x->b_function(argv + optind - 1);
8389 if (!G.global_argv[0]) {
8390 /* -c 'script' (no params): prevent empty $0 */
8391 G.global_argv--; /* points to argv[i] of 'script' */
8392 G.global_argv[0] = argv[0];
8394 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8395 install_special_sighandlers();
8396 parse_and_run_string(optarg);
8399 /* Well, we cannot just declare interactiveness,
8400 * we have to have some stuff (ctty, etc) */
8401 /* G_interactive_fd++; */
8404 /* "-s" means "read from stdin", but this is how we always
8405 * operate, so simply do nothing here. */
8411 case '<': /* "big heredoc" support */
8412 full_write1_str(optarg);
8415 unsigned long long empty_trap_mask;
8417 G.root_pid = bb_strtou(optarg, &optarg, 16);
8419 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8421 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8423 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8425 builtin_argc = bb_strtou(optarg, &optarg, 16);
8427 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8428 if (empty_trap_mask != 0) {
8430 install_special_sighandlers();
8431 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8432 for (sig = 1; sig < NSIG; sig++) {
8433 if (empty_trap_mask & (1LL << sig)) {
8434 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8435 install_sighandler(sig, SIG_IGN);
8439 # if ENABLE_HUSH_LOOPS
8441 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8447 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8449 # if ENABLE_HUSH_FUNCTIONS
8451 struct function *funcp = new_function(optarg);
8452 /* funcp->name is already set to optarg */
8453 /* funcp->body is set to NULL. It's a special case. */
8454 funcp->body_as_string = argv[optind];
8462 if (set_mode(1, opt, NULL) == 0) /* no error */
8466 fprintf(stderr, "Usage: sh [FILE]...\n"
8467 " or: sh -c command [args]...\n\n");
8473 } /* option parsing loop */
8475 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8476 G.global_argc = argc - (optind - 1);
8477 G.global_argv = argv + (optind - 1);
8478 G.global_argv[0] = argv[0];
8481 G.root_pid = getpid();
8482 G.root_ppid = getppid();
8485 /* If we are login shell... */
8486 if (flags & OPT_login) {
8488 debug_printf("sourcing /etc/profile\n");
8489 input = fopen_for_read("/etc/profile");
8490 if (input != NULL) {
8491 remember_FILE(input);
8492 install_special_sighandlers();
8493 parse_and_run_file(input);
8494 fclose_and_forget(input);
8496 /* bash: after sourcing /etc/profile,
8497 * tries to source (in the given order):
8498 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8499 * stopping on first found. --noprofile turns this off.
8500 * bash also sources ~/.bash_logout on exit.
8501 * If called as sh, skips .bash_XXX files.
8505 if (G.global_argv[1]) {
8508 * "bash <script>" (which is never interactive (unless -i?))
8509 * sources $BASH_ENV here (without scanning $PATH).
8510 * If called as sh, does the same but with $ENV.
8511 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8515 debug_printf("running script '%s'\n", G.global_argv[0]);
8516 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8517 input = xfopen_for_read(G.global_argv[0]);
8518 xfunc_error_retval = 1;
8519 remember_FILE(input);
8520 install_special_sighandlers();
8521 parse_and_run_file(input);
8522 #if ENABLE_FEATURE_CLEAN_UP
8523 fclose_and_forget(input);
8528 /* Up to here, shell was non-interactive. Now it may become one.
8529 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8532 /* A shell is interactive if the '-i' flag was given,
8533 * or if all of the following conditions are met:
8535 * no arguments remaining or the -s flag given
8536 * standard input is a terminal
8537 * standard output is a terminal
8538 * Refer to Posix.2, the description of the 'sh' utility.
8541 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8542 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8543 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8544 if (G_saved_tty_pgrp < 0)
8545 G_saved_tty_pgrp = 0;
8547 /* try to dup stdin to high fd#, >= 255 */
8548 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8549 if (G_interactive_fd < 0) {
8550 /* try to dup to any fd */
8551 G_interactive_fd = dup(STDIN_FILENO);
8552 if (G_interactive_fd < 0) {
8554 G_interactive_fd = 0;
8555 G_saved_tty_pgrp = 0;
8558 // TODO: track & disallow any attempts of user
8559 // to (inadvertently) close/redirect G_interactive_fd
8561 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8562 if (G_interactive_fd) {
8563 close_on_exec_on(G_interactive_fd);
8565 if (G_saved_tty_pgrp) {
8566 /* If we were run as 'hush &', sleep until we are
8567 * in the foreground (tty pgrp == our pgrp).
8568 * If we get started under a job aware app (like bash),
8569 * make sure we are now in charge so we don't fight over
8570 * who gets the foreground */
8572 pid_t shell_pgrp = getpgrp();
8573 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8574 if (G_saved_tty_pgrp == shell_pgrp)
8576 /* send TTIN to ourself (should stop us) */
8577 kill(- shell_pgrp, SIGTTIN);
8581 /* Install more signal handlers */
8582 install_special_sighandlers();
8584 if (G_saved_tty_pgrp) {
8585 /* Set other signals to restore saved_tty_pgrp */
8586 install_fatal_sighandlers();
8587 /* Put ourselves in our own process group
8588 * (bash, too, does this only if ctty is available) */
8589 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8590 /* Grab control of the terminal */
8591 tcsetpgrp(G_interactive_fd, getpid());
8593 enable_restore_tty_pgrp_on_exit();
8595 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8597 const char *hp = get_local_var_value("HISTFILE");
8599 hp = get_local_var_value("HOME");
8601 hp = concat_path_file(hp, ".hush_history");
8606 G.line_input_state->hist_file = hp;
8607 //set_local_var(xasprintf("HISTFILE=%s", ...));
8609 # if ENABLE_FEATURE_SH_HISTFILESIZE
8610 hp = get_local_var_value("HISTFILESIZE");
8611 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8616 install_special_sighandlers();
8618 #elif ENABLE_HUSH_INTERACTIVE
8619 /* No job control compiled in, only prompt/line editing */
8620 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8621 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8622 if (G_interactive_fd < 0) {
8623 /* try to dup to any fd */
8624 G_interactive_fd = dup(STDIN_FILENO);
8625 if (G_interactive_fd < 0)
8627 G_interactive_fd = 0;
8630 if (G_interactive_fd) {
8631 close_on_exec_on(G_interactive_fd);
8633 install_special_sighandlers();
8635 /* We have interactiveness code disabled */
8636 install_special_sighandlers();
8639 * if interactive but not a login shell, sources ~/.bashrc
8640 * (--norc turns this off, --rcfile <file> overrides)
8643 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8644 /* note: ash and hush share this string */
8645 printf("\n\n%s %s\n"
8646 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8649 "hush - the humble shell"
8653 parse_and_run_file(stdin);
8656 hush_exit(G.last_exitcode);
8661 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8662 int msh_main(int argc, char **argv)
8664 bb_error_msg("msh is deprecated, please use hush instead");
8665 return hush_main(argc, argv);
8673 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8678 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8685 return applet_main_func(argc, argv - argc);
8688 static int FAST_FUNC builtin_test(char **argv)
8690 return run_applet_main(argv, test_main);
8693 static int FAST_FUNC builtin_echo(char **argv)
8695 return run_applet_main(argv, echo_main);
8699 static int FAST_FUNC builtin_printf(char **argv)
8701 return run_applet_main(argv, printf_main);
8705 static char **skip_dash_dash(char **argv)
8708 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8713 static int FAST_FUNC builtin_eval(char **argv)
8715 int rcode = EXIT_SUCCESS;
8717 argv = skip_dash_dash(argv);
8719 char *str = expand_strvec_to_string(argv);
8721 * eval "echo Hi; done" ("done" is syntax error):
8722 * "echo Hi" will not execute too.
8724 parse_and_run_string(str);
8726 rcode = G.last_exitcode;
8731 static int FAST_FUNC builtin_cd(char **argv)
8735 argv = skip_dash_dash(argv);
8737 if (newdir == NULL) {
8738 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8739 * bash says "bash: cd: HOME not set" and does nothing
8742 const char *home = get_local_var_value("HOME");
8743 newdir = home ? home : "/";
8745 if (chdir(newdir)) {
8746 /* Mimic bash message exactly */
8747 bb_perror_msg("cd: %s", newdir);
8748 return EXIT_FAILURE;
8750 /* Read current dir (get_cwd(1) is inside) and set PWD.
8751 * Note: do not enforce exporting. If PWD was unset or unexported,
8752 * set it again, but do not export. bash does the same.
8754 set_pwd_var(/*exp:*/ 0);
8755 return EXIT_SUCCESS;
8758 static int FAST_FUNC builtin_exec(char **argv)
8760 argv = skip_dash_dash(argv);
8761 if (argv[0] == NULL)
8762 return EXIT_SUCCESS; /* bash does this */
8764 /* Careful: we can end up here after [v]fork. Do not restore
8765 * tty pgrp then, only top-level shell process does that */
8766 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8767 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8769 /* TODO: if exec fails, bash does NOT exit! We do.
8770 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8771 * and tcsetpgrp, and this is inherently racy.
8773 execvp_or_die(argv);
8776 static int FAST_FUNC builtin_exit(char **argv)
8778 debug_printf_exec("%s()\n", __func__);
8780 /* interactive bash:
8781 * # trap "echo EEE" EXIT
8784 * There are stopped jobs.
8785 * (if there are _stopped_ jobs, running ones don't count)
8788 * EEE (then bash exits)
8790 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8793 /* note: EXIT trap is run by hush_exit */
8794 argv = skip_dash_dash(argv);
8795 if (argv[0] == NULL)
8796 hush_exit(G.last_exitcode);
8797 /* mimic bash: exit 123abc == exit 255 + error msg */
8798 xfunc_error_retval = 255;
8799 /* bash: exit -2 == exit 254, no error msg */
8800 hush_exit(xatoi(argv[0]) & 0xff);
8803 static void print_escaped(const char *s)
8808 const char *p = strchrnul(s, '\'');
8809 /* print 'xxxx', possibly just '' */
8810 printf("'%.*s'", (int)(p - s), s);
8815 /* s points to '; print "'''...'''" */
8817 do putchar('\''); while (*++s == '\'');
8822 #if !ENABLE_HUSH_LOCAL
8823 #define helper_export_local(argv, exp, lvl) \
8824 helper_export_local(argv, exp)
8826 static void helper_export_local(char **argv, int exp, int lvl)
8830 char *name_end = strchrnul(name, '=');
8832 /* So far we do not check that name is valid (TODO?) */
8834 if (*name_end == '\0') {
8835 struct variable *var, **vpp;
8837 vpp = get_ptr_to_local_var(name, name_end - name);
8838 var = vpp ? *vpp : NULL;
8840 if (exp == -1) { /* unexporting? */
8841 /* export -n NAME (without =VALUE) */
8843 var->flg_export = 0;
8844 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8846 } /* else: export -n NOT_EXISTING_VAR: no-op */
8849 if (exp == 1) { /* exporting? */
8850 /* export NAME (without =VALUE) */
8852 var->flg_export = 1;
8853 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8854 putenv(var->varstr);
8858 #if ENABLE_HUSH_LOCAL
8859 if (exp == 0 /* local? */
8860 && var && var->func_nest_level == lvl
8862 /* "local x=abc; ...; local x" - ignore second local decl */
8866 /* Exporting non-existing variable.
8867 * bash does not put it in environment,
8868 * but remembers that it is exported,
8869 * and does put it in env when it is set later.
8870 * We just set it to "" and export. */
8871 /* Or, it's "local NAME" (without =VALUE).
8872 * bash sets the value to "". */
8873 name = xasprintf("%s=", name);
8875 /* (Un)exporting/making local NAME=VALUE */
8876 name = xstrdup(name);
8878 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8882 static int FAST_FUNC builtin_export(char **argv)
8884 unsigned opt_unexport;
8886 #if ENABLE_HUSH_EXPORT_N
8887 /* "!": do not abort on errors */
8888 opt_unexport = getopt32(argv, "!n");
8889 if (opt_unexport == (uint32_t)-1)
8890 return EXIT_FAILURE;
8897 if (argv[0] == NULL) {
8904 /* ash emits: export VAR='VAL'
8905 * bash: declare -x VAR="VAL"
8906 * we follow ash example */
8907 const char *s = *e++;
8908 const char *p = strchr(s, '=');
8910 if (!p) /* wtf? take next variable */
8913 printf("export %.*s", (int)(p - s) + 1, s);
8914 print_escaped(p + 1);
8918 /*fflush_all(); - done after each builtin anyway */
8920 return EXIT_SUCCESS;
8923 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8925 return EXIT_SUCCESS;
8928 #if ENABLE_HUSH_LOCAL
8929 static int FAST_FUNC builtin_local(char **argv)
8931 if (G.func_nest_level == 0) {
8932 bb_error_msg("%s: not in a function", argv[0]);
8933 return EXIT_FAILURE; /* bash compat */
8935 helper_export_local(argv, 0, G.func_nest_level);
8936 return EXIT_SUCCESS;
8940 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8941 static int FAST_FUNC builtin_unset(char **argv)
8946 /* "!": do not abort on errors */
8947 /* "+": stop at 1st non-option */
8948 opts = getopt32(argv, "!+vf");
8949 if (opts == (unsigned)-1)
8950 return EXIT_FAILURE;
8952 bb_error_msg("unset: -v and -f are exclusive");
8953 return EXIT_FAILURE;
8959 if (!(opts & 2)) { /* not -f */
8960 if (unset_local_var(*argv)) {
8961 /* unset <nonexistent_var> doesn't fail.
8962 * Error is when one tries to unset RO var.
8963 * Message was printed by unset_local_var. */
8967 #if ENABLE_HUSH_FUNCTIONS
8977 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8978 * built-in 'set' handler
8980 * set [-abCefhmnuvx] [-o option] [argument...]
8981 * set [+abCefhmnuvx] [+o option] [argument...]
8982 * set -- [argument...]
8985 * Implementations shall support the options in both their hyphen and
8986 * plus-sign forms. These options can also be specified as options to sh.
8988 * Write out all variables and their values: set
8989 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8990 * Turn on the -x and -v options: set -xv
8991 * Unset all positional parameters: set --
8992 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8993 * Set the positional parameters to the expansion of x, even if x expands
8994 * with a leading '-' or '+': set -- $x
8996 * So far, we only support "set -- [argument...]" and some of the short names.
8998 static int FAST_FUNC builtin_set(char **argv)
9001 char **pp, **g_argv;
9002 char *arg = *++argv;
9006 for (e = G.top_var; e; e = e->next)
9008 return EXIT_SUCCESS;
9012 if (strcmp(arg, "--") == 0) {
9016 if (arg[0] != '+' && arg[0] != '-')
9018 for (n = 1; arg[n]; ++n) {
9019 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9021 if (arg[n] == 'o' && argv[1])
9024 } while ((arg = *++argv) != NULL);
9025 /* Now argv[0] is 1st argument */
9028 return EXIT_SUCCESS;
9031 /* NB: G.global_argv[0] ($0) is never freed/changed */
9032 g_argv = G.global_argv;
9033 if (G.global_args_malloced) {
9039 G.global_args_malloced = 1;
9040 pp = xzalloc(sizeof(pp[0]) * 2);
9041 pp[0] = g_argv[0]; /* retain $0 */
9044 /* This realloc's G.global_argv */
9045 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9052 return EXIT_SUCCESS;
9054 /* Nothing known, so abort */
9056 bb_error_msg("set: %s: invalid option", arg);
9057 return EXIT_FAILURE;
9060 static int FAST_FUNC builtin_shift(char **argv)
9063 argv = skip_dash_dash(argv);
9067 if (n >= 0 && n < G.global_argc) {
9068 if (G.global_args_malloced) {
9071 free(G.global_argv[m++]);
9074 memmove(&G.global_argv[1], &G.global_argv[n+1],
9075 G.global_argc * sizeof(G.global_argv[0]));
9076 return EXIT_SUCCESS;
9078 return EXIT_FAILURE;
9081 /* Interruptibility of read builtin in bash
9082 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9084 * Empty trap makes read ignore corresponding signal, for any signal.
9087 * - terminates non-interactive shell;
9088 * - interrupts read in interactive shell;
9089 * if it has non-empty trap:
9090 * - executes trap and returns to command prompt in interactive shell;
9091 * - executes trap and returns to read in non-interactive shell;
9093 * - is ignored (does not interrupt) read in interactive shell;
9094 * - terminates non-interactive shell;
9095 * if it has non-empty trap:
9096 * - executes trap and returns to read;
9098 * - terminates shell (regardless of interactivity);
9099 * if it has non-empty trap:
9100 * - executes trap and returns to read;
9102 static int FAST_FUNC builtin_read(char **argv)
9112 /* "!": do not abort on errors.
9113 * Option string must start with "sr" to match BUILTIN_READ_xxx
9115 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9116 if (read_flags == (uint32_t)-1)
9117 return EXIT_FAILURE;
9119 ifs = get_local_var_value("IFS"); /* can be NULL */
9122 r = shell_builtin_read(set_local_var_from_halves,
9132 if ((uintptr_t)r == 1 && errno == EINTR) {
9133 unsigned sig = check_and_run_traps();
9134 if (sig && sig != SIGINT)
9138 if ((uintptr_t)r > 1) {
9139 bb_error_msg("%s", r);
9140 r = (char*)(uintptr_t)1;
9143 return (uintptr_t)r;
9146 static int FAST_FUNC builtin_trap(char **argv)
9152 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9157 /* No args: print all trapped */
9158 for (i = 0; i < NSIG; ++i) {
9161 print_escaped(G.traps[i]);
9162 /* note: bash adds "SIG", but only if invoked
9163 * as "bash". If called as "sh", or if set -o posix,
9164 * then it prints short signal names.
9165 * We are printing short names: */
9166 printf(" %s\n", get_signame(i));
9169 /*fflush_all(); - done after each builtin anyway */
9170 return EXIT_SUCCESS;
9174 /* If first arg is a number: reset all specified signals */
9175 sig = bb_strtou(*argv, NULL, 10);
9181 sighandler_t handler;
9183 sig = get_signum(*argv++);
9184 if (sig < 0 || sig >= NSIG) {
9186 /* Mimic bash message exactly */
9187 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9192 G.traps[sig] = xstrdup(new_cmd);
9194 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9195 get_signame(sig), sig, G.traps[sig]);
9197 /* There is no signal for 0 (EXIT) */
9202 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9204 /* We are removing trap handler */
9205 handler = pick_sighandler(sig);
9206 install_sighandler(sig, handler);
9211 if (!argv[1]) { /* no second arg */
9212 bb_error_msg("trap: invalid arguments");
9213 return EXIT_FAILURE;
9216 /* First arg is "-": reset all specified to default */
9217 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9218 /* Everything else: set arg as signal handler
9219 * (includes "" case, which ignores signal) */
9220 if (argv[0][0] == '-') {
9221 if (argv[0][1] == '\0') { /* "-" */
9222 /* new_cmd remains NULL: "reset these sigs" */
9225 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9228 /* else: "-something", no special meaning */
9233 goto process_sig_list;
9236 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9237 static int FAST_FUNC builtin_type(char **argv)
9239 int ret = EXIT_SUCCESS;
9245 if (0) {} /* make conditional compile easier below */
9246 /*else if (find_alias(*argv))
9247 type = "an alias";*/
9248 #if ENABLE_HUSH_FUNCTIONS
9249 else if (find_function(*argv))
9250 type = "a function";
9252 else if (find_builtin(*argv))
9253 type = "a shell builtin";
9254 else if ((path = find_in_path(*argv)) != NULL)
9257 bb_error_msg("type: %s: not found", *argv);
9262 printf("%s is %s\n", *argv, type);
9270 static struct pipe *parse_jobspec(const char *str)
9275 if (sscanf(str, "%%%d", &jobnum) != 1) {
9276 bb_error_msg("bad argument '%s'", str);
9279 for (pi = G.job_list; pi; pi = pi->next) {
9280 if (pi->jobid == jobnum) {
9284 bb_error_msg("%d: no such job", jobnum);
9288 /* built-in 'fg' and 'bg' handler */
9289 static int FAST_FUNC builtin_fg_bg(char **argv)
9294 if (!G_interactive_fd)
9295 return EXIT_FAILURE;
9297 /* If they gave us no args, assume they want the last backgrounded task */
9299 for (pi = G.job_list; pi; pi = pi->next) {
9300 if (pi->jobid == G.last_jobid) {
9304 bb_error_msg("%s: no current job", argv[0]);
9305 return EXIT_FAILURE;
9308 pi = parse_jobspec(argv[1]);
9310 return EXIT_FAILURE;
9312 /* TODO: bash prints a string representation
9313 * of job being foregrounded (like "sleep 1 | cat") */
9314 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9315 /* Put the job into the foreground. */
9316 tcsetpgrp(G_interactive_fd, pi->pgrp);
9319 /* Restart the processes in the job */
9320 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9321 for (i = 0; i < pi->num_cmds; i++) {
9322 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9324 pi->stopped_cmds = 0;
9326 i = kill(- pi->pgrp, SIGCONT);
9328 if (errno == ESRCH) {
9329 delete_finished_bg_job(pi);
9330 return EXIT_SUCCESS;
9332 bb_perror_msg("kill (SIGCONT)");
9335 if (argv[0][0] == 'f') {
9337 return checkjobs_and_fg_shell(pi);
9339 return EXIT_SUCCESS;
9343 #if ENABLE_HUSH_HELP
9344 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9346 const struct built_in_command *x;
9349 "Built-in commands:\n"
9350 "------------------\n");
9351 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9353 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9355 return EXIT_SUCCESS;
9359 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9360 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9362 show_history(G.line_input_state);
9363 return EXIT_SUCCESS;
9368 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9371 const char *status_string;
9373 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9374 for (job = G.job_list; job; job = job->next) {
9375 if (job->alive_cmds == job->stopped_cmds)
9376 status_string = "Stopped";
9378 status_string = "Running";
9380 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9382 return EXIT_SUCCESS;
9387 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9392 # ifdef M_TRIM_THRESHOLD
9393 /* Optional. Reduces probability of false positives */
9396 /* Crude attempt to find where "free memory" starts,
9397 * sans fragmentation. */
9399 l = (unsigned long)p;
9402 if (l < (unsigned long)p) l = (unsigned long)p;
9408 struct mallinfo mi = mallinfo();
9409 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9410 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9414 if (!G.memleak_value)
9415 G.memleak_value = l;
9417 l -= G.memleak_value;
9424 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9429 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9432 return EXIT_SUCCESS;
9435 static int FAST_FUNC builtin_source(char **argv)
9437 char *arg_path, *filename;
9440 #if ENABLE_HUSH_FUNCTIONS
9444 argv = skip_dash_dash(argv);
9447 /* bash says: "bash: .: filename argument required" */
9448 return 2; /* bash compat */
9451 if (!strchr(filename, '/')) {
9452 arg_path = find_in_path(filename);
9454 filename = arg_path;
9456 input = remember_FILE(fopen_or_warn(filename, "r"));
9459 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9460 /* POSIX: non-interactive shell should abort here,
9461 * not merely fail. So far no one complained :)
9463 return EXIT_FAILURE;
9466 #if ENABLE_HUSH_FUNCTIONS
9467 sv_flg = G_flag_return_in_progress;
9468 /* "we are inside sourced file, ok to use return" */
9469 G_flag_return_in_progress = -1;
9472 save_and_replace_G_args(&sv, argv);
9474 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9475 G.last_exitcode = 0;
9476 parse_and_run_file(input);
9477 fclose_and_forget(input);
9480 restore_G_args(&sv, argv);
9481 #if ENABLE_HUSH_FUNCTIONS
9482 G_flag_return_in_progress = sv_flg;
9485 return G.last_exitcode;
9488 static int FAST_FUNC builtin_umask(char **argv)
9495 argv = skip_dash_dash(argv);
9497 mode_t old_mask = mask;
9499 /* numeric umasks are taken as-is */
9500 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9501 if (!isdigit(argv[0][0]))
9503 mask = bb_parse_mode(argv[0], mask);
9504 if (!isdigit(argv[0][0]))
9506 if ((unsigned)mask > 0777) {
9509 * bash: umask: 'q': invalid symbolic mode operator
9510 * bash: umask: 999: octal number out of range
9512 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9517 printf("%04o\n", (unsigned) mask);
9518 /* fall through and restore mask which we set to 0 */
9522 return !rc; /* rc != 0 - success */
9525 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9526 #if !ENABLE_HUSH_JOB
9527 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9529 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9536 if (!sigisemptyset(&G.pending_set))
9539 /* waitpid is not interruptible by SA_RESTARTed
9540 * signals which we use. Thus, this ugly dance:
9543 /* Make sure possible SIGCHLD is stored in kernel's
9544 * pending signal mask before we call waitpid.
9545 * Or else we may race with SIGCHLD, lose it,
9546 * and get stuck in sigsuspend...
9548 sigfillset(&oldset); /* block all signals, remember old set */
9549 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9551 if (!sigisemptyset(&G.pending_set)) {
9552 /* Crap! we raced with some signal! */
9556 /*errno = 0; - checkjobs does this */
9557 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9558 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9559 debug_printf_exec("checkjobs:%d\n", ret);
9562 int rcode = job_exited_or_stopped(waitfor_pipe);
9563 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9566 sigprocmask(SIG_SETMASK, &oldset, NULL);
9571 /* if ECHILD, there are no children (ret is -1 or 0) */
9572 /* if ret == 0, no children changed state */
9573 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9574 if (errno == ECHILD || ret) {
9576 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9578 sigprocmask(SIG_SETMASK, &oldset, NULL);
9581 /* Wait for SIGCHLD or any other signal */
9582 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9583 /* Note: sigsuspend invokes signal handler */
9584 sigsuspend(&oldset);
9586 sigprocmask(SIG_SETMASK, &oldset, NULL);
9588 /* So, did we get a signal? */
9589 sig = check_and_run_traps();
9590 if (sig /*&& sig != SIGCHLD - always true */) {
9594 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9599 static int FAST_FUNC builtin_wait(char **argv)
9604 argv = skip_dash_dash(argv);
9605 if (argv[0] == NULL) {
9606 /* Don't care about wait results */
9607 /* Note 1: must wait until there are no more children */
9608 /* Note 2: must be interruptible */
9610 * $ sleep 3 & sleep 6 & wait
9615 * $ sleep 3 & sleep 6 & wait
9619 * ^C <-- after ~4 sec from keyboard
9622 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9626 pid_t pid = bb_strtou(*argv, NULL, 10);
9627 if (errno || pid <= 0) {
9629 if (argv[0][0] == '%') {
9630 struct pipe *wait_pipe;
9631 wait_pipe = parse_jobspec(*argv);
9633 ret = job_exited_or_stopped(wait_pipe);
9635 ret = wait_for_child_or_signal(wait_pipe, 0);
9640 /* mimic bash message */
9641 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9643 continue; /* bash checks all argv[] */
9646 /* Do we have such child? */
9647 ret = waitpid(pid, &status, WNOHANG);
9650 if (errno == ECHILD) {
9651 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9652 /* "wait $!" but last bg task has already exited. Try:
9653 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9654 * In bash it prints exitcode 0, then 3.
9655 * In dash, it is 127.
9657 /* ret = G.last_bg_pid_exitstatus - FIXME */
9659 /* Example: "wait 1". mimic bash message */
9660 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9664 bb_perror_msg("wait %s", *argv);
9667 continue; /* bash checks all argv[] */
9670 /* Yes, and it still runs */
9671 ret = wait_for_child_or_signal(NULL, pid);
9673 /* Yes, and it just exited */
9674 process_wait_result(NULL, pid, status);
9675 ret = WEXITSTATUS(status);
9676 if (WIFSIGNALED(status))
9677 ret = 128 + WTERMSIG(status);
9684 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9685 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9688 def = bb_strtou(argv[1], NULL, 10);
9689 if (errno || def < def_min || argv[2]) {
9690 bb_error_msg("%s: bad arguments", argv[0]);
9698 #if ENABLE_HUSH_LOOPS
9699 static int FAST_FUNC builtin_break(char **argv)
9702 if (G.depth_of_loop == 0) {
9703 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9704 /* if we came from builtin_continue(), need to undo "= 1" */
9705 G.flag_break_continue = 0;
9706 return EXIT_SUCCESS; /* bash compat */
9708 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9710 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9711 if (depth == UINT_MAX)
9712 G.flag_break_continue = BC_BREAK;
9713 if (G.depth_of_loop < depth)
9714 G.depth_break_continue = G.depth_of_loop;
9716 return EXIT_SUCCESS;
9719 static int FAST_FUNC builtin_continue(char **argv)
9721 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9722 return builtin_break(argv);
9726 #if ENABLE_HUSH_FUNCTIONS
9727 static int FAST_FUNC builtin_return(char **argv)
9731 if (G_flag_return_in_progress != -1) {
9732 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9733 return EXIT_FAILURE; /* bash compat */
9736 G_flag_return_in_progress = 1;
9739 * out of range: wraps around at 256, does not error out
9740 * non-numeric param:
9741 * f() { false; return qwe; }; f; echo $?
9742 * bash: return: qwe: numeric argument required <== we do this
9743 * 255 <== we also do this
9745 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);