1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
85 #include <malloc.h> /* for malloc_trim */
87 /* #include <dmalloc.h> */
92 #include "shell_common.h"
95 #if ENABLE_HUSH_RANDOM_SUPPORT
98 # define CLEAR_RANDOM_T(rnd) ((void)0)
101 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
104 //applet:IF_HUSH(APPLET(hush, _BB_DIR_BIN, _BB_SUID_DROP))
105 //applet:IF_MSH(APPLET(msh, _BB_DIR_BIN, _BB_SUID_DROP))
106 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, _BB_DIR_BIN, _BB_SUID_DROP, sh))
107 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, _BB_DIR_BIN, _BB_SUID_DROP, bash))
109 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
110 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
113 //config: bool "hush"
116 //config: hush is a small shell (25k). It handles the normal flow control
117 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
118 //config: case/esac. Redirections, here documents, $((arithmetic))
119 //config: and functions are supported.
121 //config: It will compile and work on no-mmu systems.
123 //config: It does not handle select, aliases, tilde expansion,
124 //config: &>file and >&file redirection of stdout+stderr.
126 //config:config HUSH_BASH_COMPAT
127 //config: bool "bash-compatible extensions"
129 //config: depends on HUSH
131 //config: Enable bash-compatible extensions.
133 //config:config HUSH_BRACE_EXPANSION
134 //config: bool "Brace expansion"
136 //config: depends on HUSH_BASH_COMPAT
138 //config: Enable {abc,def} extension.
140 //config:config HUSH_HELP
141 //config: bool "help builtin"
143 //config: depends on HUSH
145 //config: Enable help builtin in hush. Code size + ~1 kbyte.
147 //config:config HUSH_INTERACTIVE
148 //config: bool "Interactive mode"
150 //config: depends on HUSH
152 //config: Enable interactive mode (prompt and command editing).
153 //config: Without this, hush simply reads and executes commands
154 //config: from stdin just like a shell script from a file.
155 //config: No prompt, no PS1/PS2 magic shell variables.
157 //config:config HUSH_SAVEHISTORY
158 //config: bool "Save command history to .hush_history"
160 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
162 //config: Enable history saving in hush.
164 //config:config HUSH_JOB
165 //config: bool "Job control"
167 //config: depends on HUSH_INTERACTIVE
169 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
170 //config: command (not entire shell), fg/bg builtins work. Without this option,
171 //config: "cmd &" still works by simply spawning a process and immediately
172 //config: prompting for next command (or executing next command in a script),
173 //config: but no separate process group is formed.
175 //config:config HUSH_TICK
176 //config: bool "Process substitution"
178 //config: depends on HUSH
180 //config: Enable process substitution `command` and $(command) in hush.
182 //config:config HUSH_IF
183 //config: bool "Support if/then/elif/else/fi"
185 //config: depends on HUSH
187 //config: Enable if/then/elif/else/fi in hush.
189 //config:config HUSH_LOOPS
190 //config: bool "Support for, while and until loops"
192 //config: depends on HUSH
194 //config: Enable for, while and until loops in hush.
196 //config:config HUSH_CASE
197 //config: bool "Support case ... esac statement"
199 //config: depends on HUSH
201 //config: Enable case ... esac statement in hush. +400 bytes.
203 //config:config HUSH_FUNCTIONS
204 //config: bool "Support funcname() { commands; } syntax"
206 //config: depends on HUSH
208 //config: Enable support for shell functions in hush. +800 bytes.
210 //config:config HUSH_LOCAL
211 //config: bool "Support local builtin"
213 //config: depends on HUSH_FUNCTIONS
215 //config: Enable support for local variables in functions.
217 //config:config HUSH_RANDOM_SUPPORT
218 //config: bool "Pseudorandom generator and $RANDOM variable"
220 //config: depends on HUSH
222 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
223 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
225 //config:config HUSH_EXPORT_N
226 //config: bool "Support 'export -n' option"
228 //config: depends on HUSH
230 //config: export -n unexports variables. It is a bash extension.
232 //config:config HUSH_MODE_X
233 //config: bool "Support 'hush -x' option and 'set -x' command"
235 //config: depends on HUSH
237 //config: This instructs hush to print commands before execution.
238 //config: Adds ~300 bytes.
241 //config: bool "msh (deprecated: aliased to hush)"
243 //config: select HUSH
245 //config: msh is deprecated and will be removed, please migrate to hush.
248 /* -i (interactive) and -s (read stdin) are also accepted,
249 * but currently do nothing, therefore aren't shown in help.
250 * NOMMU-specific options are not meant to be used by users,
251 * therefore we don't show them either.
253 //usage:#define hush_trivial_usage
254 //usage: "[-nx] [-c SCRIPT]"
255 //usage:#define hush_full_usage ""
256 //usage:#define msh_trivial_usage hush_trivial_usage
257 //usage:#define msh_full_usage ""
258 //usage:#define sh_trivial_usage NOUSAGE_STR
259 //usage:#define sh_full_usage ""
260 //usage:#define bash_trivial_usage NOUSAGE_STR
261 //usage:#define bash_full_usage ""
265 #define LEAK_HUNTING 0
266 #define BUILD_AS_NOMMU 0
267 /* Enable/disable sanity checks. Ok to enable in production,
268 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
269 * Keeping 1 for now even in released versions.
272 /* Slightly bigger (+200 bytes), but faster hush.
273 * So far it only enables a trick with counting SIGCHLDs and forks,
274 * which allows us to do fewer waitpid's.
275 * (we can detect a case where neither forks were done nor SIGCHLDs happened
276 * and therefore waitpid will return the same result as last time)
278 #define ENABLE_HUSH_FAST 0
279 /* TODO: implement simplified code for users which do not need ${var%...} ops
280 * So far ${var%...} ops are always enabled:
282 #define ENABLE_HUSH_DOLLAR_OPS 1
287 # undef USE_FOR_NOMMU
290 # define USE_FOR_NOMMU(...) __VA_ARGS__
291 # define USE_FOR_MMU(...)
294 #include "NUM_APPLETS.h"
296 /* STANDALONE does not make sense, and won't compile */
297 # undef CONFIG_FEATURE_SH_STANDALONE
298 # undef ENABLE_FEATURE_SH_STANDALONE
299 # undef IF_FEATURE_SH_STANDALONE
300 # undef IF_NOT_FEATURE_SH_STANDALONE
301 # define ENABLE_FEATURE_SH_STANDALONE 0
302 # define IF_FEATURE_SH_STANDALONE(...)
303 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
306 #if !ENABLE_HUSH_INTERACTIVE
307 # undef ENABLE_FEATURE_EDITING
308 # define ENABLE_FEATURE_EDITING 0
309 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
310 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
313 /* Do we support ANY keywords? */
314 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
315 # define HAS_KEYWORDS 1
316 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
317 # define IF_HAS_NO_KEYWORDS(...)
319 # define HAS_KEYWORDS 0
320 # define IF_HAS_KEYWORDS(...)
321 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
324 /* If you comment out one of these below, it will be #defined later
325 * to perform debug printfs to stderr: */
326 #define debug_printf(...) do {} while (0)
327 /* Finer-grained debug switches */
328 #define debug_printf_parse(...) do {} while (0)
329 #define debug_print_tree(a, b) do {} while (0)
330 #define debug_printf_exec(...) do {} while (0)
331 #define debug_printf_env(...) do {} while (0)
332 #define debug_printf_jobs(...) do {} while (0)
333 #define debug_printf_expand(...) do {} while (0)
334 #define debug_printf_varexp(...) do {} while (0)
335 #define debug_printf_glob(...) do {} while (0)
336 #define debug_printf_list(...) do {} while (0)
337 #define debug_printf_subst(...) do {} while (0)
338 #define debug_printf_clean(...) do {} while (0)
340 #define ERR_PTR ((void*)(long)1)
342 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
344 #define _SPECIAL_VARS_STR "_*@$!?#"
345 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
346 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
347 #if ENABLE_HUSH_BASH_COMPAT
348 /* Support / and // replace ops */
349 /* Note that // is stored as \ in "encoded" string representation */
350 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
351 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
352 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
354 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
355 # define VAR_SUBST_OPS "%#:-=+?"
356 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
359 #define SPECIAL_VAR_SYMBOL 3
363 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
365 /* This supports saving pointers malloced in vfork child,
366 * to be freed in the parent.
369 typedef struct nommu_save_t {
371 struct variable *old_vars;
373 char **argv_from_re_execing;
386 #if ENABLE_HUSH_LOOPS
393 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
398 /* three pseudo-keywords support contrived "case" syntax: */
399 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
400 RES_MATCH , /* "word)" */
401 RES_CASE_BODY, /* "this command is inside CASE" */
408 typedef struct o_string {
410 int length; /* position where data is appended */
413 /* At least some part of the string was inside '' or "",
414 * possibly empty one: word"", wo''rd etc. */
415 smallint has_quoted_part;
416 smallint has_empty_slot;
417 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
420 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
422 /* Protect newly added chars against globbing
423 * by prepending \ to *, ?, [, \ */
424 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
427 MAYBE_ASSIGNMENT = 0,
428 DEFINITELY_ASSIGNMENT = 1,
430 /* Not an assigment, but next word may be: "if v=xyz cmd;" */
433 /* Used for initialization: o_string foo = NULL_O_STRING; */
434 #define NULL_O_STRING { NULL }
436 /* I can almost use ordinary FILE*. Is open_memstream() universally
437 * available? Where is it documented? */
438 typedef struct in_str {
440 /* eof_flag=1: last char in ->p is really an EOF */
441 char eof_flag; /* meaningless if ->p == NULL */
443 #if ENABLE_HUSH_INTERACTIVE
445 smallint promptmode; /* 0: PS1, 1: PS2 */
448 int (*get) (struct in_str *) FAST_FUNC;
449 int (*peek) (struct in_str *) FAST_FUNC;
451 #define i_getch(input) ((input)->get(input))
452 #define i_peek(input) ((input)->peek(input))
454 /* The descrip member of this structure is only used to make
455 * debugging output pretty */
456 static const struct {
458 signed char default_fd;
461 { O_RDONLY, 0, "<" },
462 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
463 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
464 { O_CREAT|O_RDWR, 1, "<>" },
465 { O_RDONLY, 0, "<<" },
466 /* Should not be needed. Bogus default_fd helps in debugging */
467 /* { O_RDONLY, 77, "<<" }, */
470 struct redir_struct {
471 struct redir_struct *next;
472 char *rd_filename; /* filename */
473 int rd_fd; /* fd to redirect */
474 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
476 smallint rd_type; /* (enum redir_type) */
477 /* note: for heredocs, rd_filename contains heredoc delimiter,
478 * and subsequently heredoc itself; and rd_dup is a bitmask:
479 * bit 0: do we need to trim leading tabs?
480 * bit 1: is heredoc quoted (<<'delim' syntax) ?
483 typedef enum redir_type {
485 REDIRECT_OVERWRITE = 1,
488 REDIRECT_HEREDOC = 4,
489 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
492 REDIRFD_SYNTAX_ERR = -2,
493 REDIRFD_TO_FILE = -1,
494 /* otherwise, rd_fd is redirected to rd_dup */
496 HEREDOC_SKIPTABS = 1,
502 pid_t pid; /* 0 if exited */
503 int assignment_cnt; /* how many argv[i] are assignments? */
504 smallint is_stopped; /* is the command currently running? */
505 smallint cmd_type; /* CMD_xxx */
507 #define CMD_SUBSHELL 1
508 #if ENABLE_HUSH_BASH_COMPAT
509 /* used for "[[ EXPR ]]" */
510 # define CMD_SINGLEWORD_NOGLOB 2
512 #if ENABLE_HUSH_FUNCTIONS
513 # define CMD_FUNCDEF 3
516 smalluint cmd_exitcode;
517 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
520 char *group_as_string;
522 #if ENABLE_HUSH_FUNCTIONS
523 struct function *child_func;
524 /* This field is used to prevent a bug here:
525 * while...do f1() {a;}; f1; f1() {b;}; f1; done
526 * When we execute "f1() {a;}" cmd, we create new function and clear
527 * cmd->group, cmd->group_as_string, cmd->argv[0].
528 * When we execute "f1() {b;}", we notice that f1 exists,
529 * and that its "parent cmd" struct is still "alive",
530 * we put those fields back into cmd->xxx
531 * (struct function has ->parent_cmd ptr to facilitate that).
532 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
533 * Without this trick, loop would execute a;b;b;b;...
534 * instead of correct sequence a;b;a;b;...
535 * When command is freed, it severs the link
536 * (sets ->child_func->parent_cmd to NULL).
539 char **argv; /* command name and arguments */
540 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
541 * and on execution these are substituted with their values.
542 * Substitution can make _several_ words out of one argv[n]!
543 * Example: argv[0]=='.^C*^C.' here: echo .$*.
544 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
546 struct redir_struct *redirects; /* I/O redirections */
548 /* Is there anything in this command at all? */
549 #define IS_NULL_CMD(cmd) \
550 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
554 int num_cmds; /* total number of commands in pipe */
555 int alive_cmds; /* number of commands running (not exited) */
556 int stopped_cmds; /* number of commands alive, but stopped */
558 int jobid; /* job number */
559 pid_t pgrp; /* process group ID for the job */
560 char *cmdtext; /* name of job */
562 struct command *cmds; /* array of commands in pipe */
563 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
564 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
565 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
567 typedef enum pipe_style {
573 /* Is there anything in this pipe at all? */
574 #define IS_NULL_PIPE(pi) \
575 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
577 /* This holds pointers to the various results of parsing */
578 struct parse_context {
579 /* linked list of pipes */
580 struct pipe *list_head;
581 /* last pipe (being constructed right now) */
583 /* last command in pipe (being constructed right now) */
584 struct command *command;
585 /* last redirect in command->redirects list */
586 struct redir_struct *pending_redirect;
592 smallint ctx_inverted; /* "! cmd | cmd" */
594 smallint ctx_dsemicolon; /* ";;" seen */
596 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
598 /* group we are enclosed in:
599 * example: "if pipe1; pipe2; then pipe3; fi"
600 * when we see "if" or "then", we malloc and copy current context,
601 * and make ->stack point to it. then we parse pipeN.
602 * when closing "then" / fi" / whatever is found,
603 * we move list_head into ->stack->command->group,
604 * copy ->stack into current context, and delete ->stack.
605 * (parsing of { list } and ( list ) doesn't use this method)
607 struct parse_context *stack;
611 /* On program start, environ points to initial environment.
612 * putenv adds new pointers into it, unsetenv removes them.
613 * Neither of these (de)allocates the strings.
614 * setenv allocates new strings in malloc space and does putenv,
615 * and thus setenv is unusable (leaky) for shell's purposes */
616 #define setenv(...) setenv_is_leaky_dont_use()
618 struct variable *next;
619 char *varstr; /* points to "name=" portion */
620 #if ENABLE_HUSH_LOCAL
621 unsigned func_nest_level;
623 int max_len; /* if > 0, name is part of initial env; else name is malloced */
624 smallint flg_export; /* putenv should be done on this var */
625 smallint flg_read_only;
633 #if ENABLE_HUSH_FUNCTIONS
635 struct function *next;
637 struct command *parent_cmd;
640 char *body_as_string;
646 /* set -/+o OPT support. (TODO: make it optional)
647 * bash supports the following opts:
658 * interactive-comments on
676 static const char o_opt_strings[] ALIGN1 =
679 #if ENABLE_HUSH_MODE_X
686 #if ENABLE_HUSH_MODE_X
693 /* "Globals" within this file */
694 /* Sorted roughly by size (smaller offsets == smaller code) */
696 /* interactive_fd != 0 means we are an interactive shell.
697 * If we are, then saved_tty_pgrp can also be != 0, meaning
698 * that controlling tty is available. With saved_tty_pgrp == 0,
699 * job control still works, but terminal signals
700 * (^C, ^Z, ^Y, ^\) won't work at all, and background
701 * process groups can only be created with "cmd &".
702 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
703 * to give tty to the foreground process group,
704 * and will take it back when the group is stopped (^Z)
707 #if ENABLE_HUSH_INTERACTIVE
708 /* 'interactive_fd' is a fd# open to ctty, if we have one
709 * _AND_ if we decided to act interactively */
713 # define G_interactive_fd (G.interactive_fd)
715 # define G_interactive_fd 0
717 #if ENABLE_FEATURE_EDITING
718 line_input_t *line_input_state;
723 #if ENABLE_HUSH_RANDOM_SUPPORT
729 pid_t saved_tty_pgrp;
730 struct pipe *job_list;
731 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
733 # define G_saved_tty_pgrp 0
735 char o_opt[NUM_OPT_O];
736 smallint flag_SIGINT;
737 #if ENABLE_HUSH_LOOPS
738 smallint flag_break_continue;
740 #if ENABLE_HUSH_FUNCTIONS
741 /* 0: outside of a function (or sourced file)
742 * -1: inside of a function, ok to use return builtin
743 * 1: return is invoked, skip all till end of func
745 smallint flag_return_in_progress;
747 #if ENABLE_HUSH_MODE_X
748 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
752 smallint exiting; /* used to prevent EXIT trap recursion */
753 /* These four support $?, $#, and $1 */
754 smalluint last_exitcode;
755 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
756 smalluint global_args_malloced;
757 smalluint inherited_set_is_saved;
758 /* how many non-NULL argv's we have. NB: $# + 1 */
762 char *argv0_for_re_execing;
764 #if ENABLE_HUSH_LOOPS
765 unsigned depth_break_continue;
766 unsigned depth_of_loop;
770 struct variable *top_var;
771 char **expanded_assignments;
772 #if ENABLE_HUSH_FUNCTIONS
773 struct function *top_func;
774 # if ENABLE_HUSH_LOCAL
775 struct variable **shadowed_vars_pp;
776 unsigned func_nest_level;
779 /* Signal and trap handling */
781 unsigned count_SIGCHLD;
782 unsigned handled_SIGCHLD;
783 smallint we_have_children;
785 /* which signals have non-DFL handler (even with no traps set)? */
786 unsigned non_DFL_mask;
787 char **traps; /* char *traps[NSIG] */
788 sigset_t blocked_set;
789 sigset_t inherited_set;
791 unsigned long memleak_value;
794 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
796 #define G (*ptr_to_globals)
797 /* Not #defining name to G.name - this quickly gets unwieldy
798 * (too many defines). Also, I actually prefer to see when a variable
799 * is global, thus "G." prefix is a useful hint */
800 #define INIT_G() do { \
801 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
805 /* Function prototypes for builtins */
806 static int builtin_cd(char **argv) FAST_FUNC;
807 static int builtin_echo(char **argv) FAST_FUNC;
808 static int builtin_eval(char **argv) FAST_FUNC;
809 static int builtin_exec(char **argv) FAST_FUNC;
810 static int builtin_exit(char **argv) FAST_FUNC;
811 static int builtin_export(char **argv) FAST_FUNC;
813 static int builtin_fg_bg(char **argv) FAST_FUNC;
814 static int builtin_jobs(char **argv) FAST_FUNC;
817 static int builtin_help(char **argv) FAST_FUNC;
819 #if ENABLE_HUSH_LOCAL
820 static int builtin_local(char **argv) FAST_FUNC;
823 static int builtin_memleak(char **argv) FAST_FUNC;
826 static int builtin_printf(char **argv) FAST_FUNC;
828 static int builtin_pwd(char **argv) FAST_FUNC;
829 static int builtin_read(char **argv) FAST_FUNC;
830 static int builtin_set(char **argv) FAST_FUNC;
831 static int builtin_shift(char **argv) FAST_FUNC;
832 static int builtin_source(char **argv) FAST_FUNC;
833 static int builtin_test(char **argv) FAST_FUNC;
834 static int builtin_trap(char **argv) FAST_FUNC;
835 static int builtin_type(char **argv) FAST_FUNC;
836 static int builtin_true(char **argv) FAST_FUNC;
837 static int builtin_umask(char **argv) FAST_FUNC;
838 static int builtin_unset(char **argv) FAST_FUNC;
839 static int builtin_wait(char **argv) FAST_FUNC;
840 #if ENABLE_HUSH_LOOPS
841 static int builtin_break(char **argv) FAST_FUNC;
842 static int builtin_continue(char **argv) FAST_FUNC;
844 #if ENABLE_HUSH_FUNCTIONS
845 static int builtin_return(char **argv) FAST_FUNC;
848 /* Table of built-in functions. They can be forked or not, depending on
849 * context: within pipes, they fork. As simple commands, they do not.
850 * When used in non-forking context, they can change global variables
851 * in the parent shell process. If forked, of course they cannot.
852 * For example, 'unset foo | whatever' will parse and run, but foo will
853 * still be set at the end. */
854 struct built_in_command {
856 int (*b_function)(char **argv) FAST_FUNC;
859 # define BLTIN(cmd, func, help) { cmd, func, help }
861 # define BLTIN(cmd, func, help) { cmd, func }
865 static const struct built_in_command bltins1[] = {
866 BLTIN("." , builtin_source , "Run commands in a file"),
867 BLTIN(":" , builtin_true , NULL),
869 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
871 #if ENABLE_HUSH_LOOPS
872 BLTIN("break" , builtin_break , "Exit from a loop"),
874 BLTIN("cd" , builtin_cd , "Change directory"),
875 #if ENABLE_HUSH_LOOPS
876 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
878 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
879 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
880 BLTIN("exit" , builtin_exit , "Exit"),
881 BLTIN("export" , builtin_export , "Set environment variables"),
883 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
886 BLTIN("help" , builtin_help , NULL),
889 BLTIN("jobs" , builtin_jobs , "List jobs"),
891 #if ENABLE_HUSH_LOCAL
892 BLTIN("local" , builtin_local , "Set local variables"),
895 BLTIN("memleak" , builtin_memleak , NULL),
897 BLTIN("read" , builtin_read , "Input into variable"),
898 #if ENABLE_HUSH_FUNCTIONS
899 BLTIN("return" , builtin_return , "Return from a function"),
901 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
902 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
903 #if ENABLE_HUSH_BASH_COMPAT
904 BLTIN("source" , builtin_source , "Run commands in a file"),
906 BLTIN("trap" , builtin_trap , "Trap signals"),
907 BLTIN("type" , builtin_type , "Show command type"),
908 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
909 BLTIN("umask" , builtin_umask , "Set file creation mask"),
910 BLTIN("unset" , builtin_unset , "Unset variables"),
911 BLTIN("wait" , builtin_wait , "Wait for process"),
913 /* For now, echo and test are unconditionally enabled.
914 * Maybe make it configurable? */
915 static const struct built_in_command bltins2[] = {
916 BLTIN("[" , builtin_test , NULL),
917 BLTIN("echo" , builtin_echo , NULL),
919 BLTIN("printf" , builtin_printf , NULL),
921 BLTIN("pwd" , builtin_pwd , NULL),
922 BLTIN("test" , builtin_test , NULL),
929 /* prevent disasters with G.debug_indent < 0 */
930 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
931 # define debug_enter() (G.debug_indent++)
932 # define debug_leave() (G.debug_indent--)
934 # define indent() ((void)0)
935 # define debug_enter() ((void)0)
936 # define debug_leave() ((void)0)
940 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
943 #ifndef debug_printf_parse
944 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
947 #ifndef debug_printf_exec
948 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
951 #ifndef debug_printf_env
952 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
955 #ifndef debug_printf_jobs
956 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
957 # define DEBUG_JOBS 1
959 # define DEBUG_JOBS 0
962 #ifndef debug_printf_expand
963 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
964 # define DEBUG_EXPAND 1
966 # define DEBUG_EXPAND 0
969 #ifndef debug_printf_varexp
970 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
973 #ifndef debug_printf_glob
974 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
975 # define DEBUG_GLOB 1
977 # define DEBUG_GLOB 0
980 #ifndef debug_printf_list
981 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
984 #ifndef debug_printf_subst
985 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
988 #ifndef debug_printf_clean
989 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
990 # define DEBUG_CLEAN 1
992 # define DEBUG_CLEAN 0
996 static void debug_print_strings(const char *prefix, char **vv)
999 fprintf(stderr, "%s:\n", prefix);
1001 fprintf(stderr, " '%s'\n", *vv++);
1004 # define debug_print_strings(prefix, vv) ((void)0)
1008 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1011 static void *xxmalloc(int lineno, size_t size)
1013 void *ptr = xmalloc((size + 0xff) & ~0xff);
1014 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1017 static void *xxrealloc(int lineno, void *ptr, size_t size)
1019 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1020 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1023 static char *xxstrdup(int lineno, const char *str)
1025 char *ptr = xstrdup(str);
1026 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1029 static void xxfree(void *ptr)
1031 fdprintf(2, "free %p\n", ptr);
1034 # define xmalloc(s) xxmalloc(__LINE__, s)
1035 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1036 # define xstrdup(s) xxstrdup(__LINE__, s)
1037 # define free(p) xxfree(p)
1041 /* Syntax and runtime errors. They always abort scripts.
1042 * In interactive use they usually discard unparsed and/or unexecuted commands
1043 * and return to the prompt.
1044 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1047 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1048 # define syntax_error(lineno, msg) syntax_error(msg)
1049 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1050 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1051 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1052 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1055 static void die_if_script(unsigned lineno, const char *fmt, ...)
1060 bb_error_msg("hush.c:%u", lineno);
1063 bb_verror_msg(fmt, p, NULL);
1065 if (!G_interactive_fd)
1069 static void syntax_error(unsigned lineno, const char *msg)
1072 die_if_script(lineno, "syntax error: %s", msg);
1074 die_if_script(lineno, "syntax error", NULL);
1077 static void syntax_error_at(unsigned lineno, const char *msg)
1079 die_if_script(lineno, "syntax error at '%s'", msg);
1082 static void syntax_error_unterm_str(unsigned lineno, const char *s)
1084 die_if_script(lineno, "syntax error: unterminated %s", s);
1087 /* It so happens that all such cases are totally fatal
1088 * even if shell is interactive: EOF while looking for closing
1089 * delimiter. There is nowhere to read stuff from after that,
1090 * it's EOF! The only choice is to terminate.
1092 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
1093 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1095 char msg[2] = { ch, '\0' };
1096 syntax_error_unterm_str(lineno, msg);
1100 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
1105 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1109 # undef die_if_script
1110 # undef syntax_error
1111 # undef syntax_error_at
1112 # undef syntax_error_unterm_ch
1113 # undef syntax_error_unterm_str
1114 # undef syntax_error_unexpected_ch
1116 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1117 # define syntax_error(msg) syntax_error(__LINE__, msg)
1118 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1119 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1120 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1121 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1125 #if ENABLE_HUSH_INTERACTIVE
1126 static void cmdedit_update_prompt(void);
1128 # define cmdedit_update_prompt() ((void)0)
1132 /* Utility functions
1134 /* Replace each \x with x in place, return ptr past NUL. */
1135 static char *unbackslash(char *src)
1137 char *dst = src = strchrnul(src, '\\');
1141 if ((*dst++ = *src++) == '\0')
1147 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1168 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1169 v[count1 + count2] = NULL;
1172 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1176 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1178 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1179 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1182 #define add_strings_to_strings(strings, add, need_to_dup) \
1183 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1186 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1187 static char **add_string_to_strings(char **strings, char *add)
1192 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1195 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1197 char **ptr = add_string_to_strings(strings, add);
1198 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1201 #define add_string_to_strings(strings, add) \
1202 xx_add_string_to_strings(__LINE__, strings, add)
1205 static void free_strings(char **strings)
1220 /* Helpers for setting new $n and restoring them back
1222 typedef struct save_arg_t {
1226 smallint sv_g_malloced;
1229 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1233 sv->sv_argv0 = argv[0];
1234 sv->sv_g_argv = G.global_argv;
1235 sv->sv_g_argc = G.global_argc;
1236 sv->sv_g_malloced = G.global_args_malloced;
1238 argv[0] = G.global_argv[0]; /* retain $0 */
1239 G.global_argv = argv;
1240 G.global_args_malloced = 0;
1248 static void restore_G_args(save_arg_t *sv, char **argv)
1252 if (G.global_args_malloced) {
1253 /* someone ran "set -- arg1 arg2 ...", undo */
1255 while (*++pp) /* note: does not free $0 */
1257 free(G.global_argv);
1259 argv[0] = sv->sv_argv0;
1260 G.global_argv = sv->sv_g_argv;
1261 G.global_argc = sv->sv_g_argc;
1262 G.global_args_malloced = sv->sv_g_malloced;
1266 /* Basic theory of signal handling in shell
1267 * ========================================
1268 * This does not describe what hush does, rather, it is current understanding
1269 * what it _should_ do. If it doesn't, it's a bug.
1270 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1272 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1273 * is finished or backgrounded. It is the same in interactive and
1274 * non-interactive shells, and is the same regardless of whether
1275 * a user trap handler is installed or a shell special one is in effect.
1276 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1277 * backgrounds (i.e. stops) or kills all members of currently running
1280 * Wait builtin in interruptible by signals for which user trap is set
1281 * or by SIGINT in interactive shell.
1283 * Trap handlers will execute even within trap handlers. (right?)
1285 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1286 * except for handlers set to '' (empty string).
1288 * If job control is off, backgrounded commands ("cmd &")
1289 * have SIGINT, SIGQUIT set to SIG_IGN.
1291 * Commands which are run in command substitution ("`cmd`")
1292 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1294 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1295 * by the shell from its parent.
1297 * Signals which differ from SIG_DFL action
1298 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1301 * SIGTERM (interactive): ignore
1302 * SIGHUP (interactive):
1303 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1304 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1305 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1306 * that all pipe members are stopped. Try this in bash:
1307 * while :; do :; done - ^Z does not background it
1308 * (while :; do :; done) - ^Z backgrounds it
1309 * SIGINT (interactive): wait for last pipe, ignore the rest
1310 * of the command line, show prompt. NB: ^C does not send SIGINT
1311 * to interactive shell while shell is waiting for a pipe,
1312 * since shell is bg'ed (is not in foreground process group).
1313 * Example 1: this waits 5 sec, but does not execute ls:
1314 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1315 * Example 2: this does not wait and does not execute ls:
1316 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1317 * Example 3: this does not wait 5 sec, but executes ls:
1318 * "sleep 5; ls -l" + press ^C
1320 * (What happens to signals which are IGN on shell start?)
1321 * (What happens with signal mask on shell start?)
1323 * Implementation in hush
1324 * ======================
1325 * We use in-kernel pending signal mask to determine which signals were sent.
1326 * We block all signals which we don't want to take action immediately,
1327 * i.e. we block all signals which need to have special handling as described
1328 * above, and all signals which have traps set.
1329 * After each pipe execution, we extract any pending signals via sigtimedwait()
1332 * unsigned non_DFL_mask: a mask of such "special" signals
1333 * sigset_t blocked_set: current blocked signal set
1336 * clear bit in blocked_set unless it is also in non_DFL_mask
1337 * "trap 'cmd' SIGxxx":
1338 * set bit in blocked_set (even if 'cmd' is '')
1339 * after [v]fork, if we plan to be a shell:
1340 * unblock signals with special interactive handling
1341 * (child shell is not interactive),
1342 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1343 * after [v]fork, if we plan to exec:
1344 * POSIX says fork clears pending signal mask in child - no need to clear it.
1345 * Restore blocked signal set to one inherited by shell just prior to exec.
1347 * Note: as a result, we do not use signal handlers much. The only uses
1348 * are to count SIGCHLDs
1349 * and to restore tty pgrp on signal-induced exit.
1352 * Standard says "When a subshell is entered, traps that are not being ignored
1353 * are set to the default actions". bash interprets it so that traps which
1354 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1357 SPECIAL_INTERACTIVE_SIGS = 0
1362 SPECIAL_JOB_SIGS = 0
1370 #if ENABLE_HUSH_FAST
1371 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1374 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1380 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1381 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1382 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1383 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1385 /* Restores tty foreground process group, and exits.
1386 * May be called as signal handler for fatal signal
1387 * (will resend signal to itself, producing correct exit state)
1388 * or called directly with -EXITCODE.
1389 * We also call it if xfunc is exiting. */
1390 static void sigexit(int sig) NORETURN;
1391 static void sigexit(int sig)
1393 /* Disable all signals: job control, SIGPIPE, etc. */
1394 sigprocmask_allsigs(SIG_BLOCK);
1396 /* Careful: we can end up here after [v]fork. Do not restore
1397 * tty pgrp then, only top-level shell process does that */
1398 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1399 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1401 /* Not a signal, just exit */
1405 kill_myself_with_sig(sig); /* does not return */
1409 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1410 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1414 /* Restores tty foreground process group, and exits. */
1415 static void hush_exit(int exitcode) NORETURN;
1416 static void hush_exit(int exitcode)
1418 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1419 /* Prevent recursion:
1420 * trap "echo Hi; exit" EXIT; exit
1423 /* argv[0] is unused */
1424 argv[1] = G.traps[0];
1426 G.exiting = 1; /* prevent EXIT trap recursion */
1427 /* Note: G.traps[0] is not cleared!
1428 * "trap" will still show it, if executed
1435 sigexit(- (exitcode & 0xff));
1442 static int check_and_run_traps(int sig)
1444 /* I want it in rodata, not in bss.
1445 * gcc 4.2.1 puts it in rodata only if it has { 0, 0 }
1446 * initializer. But other compilers may still use bss.
1447 * TODO: find more portable solution.
1449 static const struct timespec zero_timespec = { 0, 0 };
1450 smalluint save_rcode;
1456 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1461 if (G.traps && G.traps[sig]) {
1462 if (G.traps[sig][0]) {
1463 /* We have user-defined handler */
1465 /* argv[0] is unused */
1466 argv[1] = G.traps[sig];
1468 save_rcode = G.last_exitcode;
1470 G.last_exitcode = save_rcode;
1471 } /* else: "" trap, ignoring signal */
1474 /* not a trap: special action */
1476 #if ENABLE_HUSH_FAST
1479 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1483 /* Builtin was ^C'ed, make it look prettier: */
1490 /* bash is observed to signal whole process groups,
1491 * not individual processes */
1492 for (job = G.job_list; job; job = job->next) {
1495 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1496 if (kill(- job->pgrp, SIGHUP) == 0)
1497 kill(- job->pgrp, SIGCONT);
1502 default: /* ignored: */
1503 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1511 static const char *get_cwd(int force)
1513 if (force || G.cwd == NULL) {
1514 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1515 * we must not try to free(bb_msg_unknown) */
1516 if (G.cwd == bb_msg_unknown)
1518 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1520 G.cwd = bb_msg_unknown;
1527 * Shell and environment variable support
1529 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1531 struct variable **pp;
1532 struct variable *cur;
1535 while ((cur = *pp) != NULL) {
1536 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1543 static const char* FAST_FUNC get_local_var_value(const char *name)
1545 struct variable **vpp;
1546 unsigned len = strlen(name);
1548 if (G.expanded_assignments) {
1549 char **cpp = G.expanded_assignments;
1552 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1553 return cp + len + 1;
1558 vpp = get_ptr_to_local_var(name, len);
1560 return (*vpp)->varstr + len + 1;
1562 if (strcmp(name, "PPID") == 0)
1563 return utoa(G.root_ppid);
1564 // bash compat: UID? EUID?
1565 #if ENABLE_HUSH_RANDOM_SUPPORT
1566 if (strcmp(name, "RANDOM") == 0)
1567 return utoa(next_random(&G.random_gen));
1572 /* str holds "NAME=VAL" and is expected to be malloced.
1573 * We take ownership of it.
1575 * 0: do not change export flag
1576 * (if creating new variable, flag will be 0)
1577 * 1: set export flag and putenv the variable
1578 * -1: clear export flag and unsetenv the variable
1579 * flg_read_only is set only when we handle -R var=val
1581 #if !BB_MMU && ENABLE_HUSH_LOCAL
1582 /* all params are used */
1583 #elif BB_MMU && ENABLE_HUSH_LOCAL
1584 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1585 set_local_var(str, flg_export, local_lvl)
1586 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1587 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1588 set_local_var(str, flg_export)
1589 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1590 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1591 set_local_var(str, flg_export, flg_read_only)
1593 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1595 struct variable **var_pp;
1596 struct variable *cur;
1600 eq_sign = strchr(str, '=');
1601 if (!eq_sign) { /* not expected to ever happen? */
1606 name_len = eq_sign - str + 1; /* including '=' */
1607 var_pp = &G.top_var;
1608 while ((cur = *var_pp) != NULL) {
1609 if (strncmp(cur->varstr, str, name_len) != 0) {
1610 var_pp = &cur->next;
1613 /* We found an existing var with this name */
1614 if (cur->flg_read_only) {
1618 bb_error_msg("%s: readonly variable", str);
1622 if (flg_export == -1) { // "&& cur->flg_export" ?
1623 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1628 #if ENABLE_HUSH_LOCAL
1629 if (cur->func_nest_level < local_lvl) {
1630 /* New variable is declared as local,
1631 * and existing one is global, or local
1632 * from enclosing function.
1633 * Remove and save old one: */
1634 *var_pp = cur->next;
1635 cur->next = *G.shadowed_vars_pp;
1636 *G.shadowed_vars_pp = cur;
1637 /* bash 3.2.33(1) and exported vars:
1639 * # f() { local z=a; env | grep ^z; }
1645 if (cur->flg_export)
1650 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1655 if (cur->max_len != 0) {
1656 if (cur->max_len >= strlen(str)) {
1657 /* This one is from startup env, reuse space */
1658 strcpy(cur->varstr, str);
1662 /* max_len == 0 signifies "malloced" var, which we can
1663 * (and has to) free */
1667 goto set_str_and_exp;
1670 /* Not found - create new variable struct */
1671 cur = xzalloc(sizeof(*cur));
1672 #if ENABLE_HUSH_LOCAL
1673 cur->func_nest_level = local_lvl;
1675 cur->next = *var_pp;
1681 cur->flg_read_only = flg_read_only;
1684 if (flg_export == 1)
1685 cur->flg_export = 1;
1686 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1687 cmdedit_update_prompt();
1688 if (cur->flg_export) {
1689 if (flg_export == -1) {
1690 cur->flg_export = 0;
1691 /* unsetenv was already done */
1693 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1694 return putenv(cur->varstr);
1700 /* Used at startup and after each cd */
1701 static void set_pwd_var(int exp)
1703 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1704 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1707 static int unset_local_var_len(const char *name, int name_len)
1709 struct variable *cur;
1710 struct variable **var_pp;
1713 return EXIT_SUCCESS;
1714 var_pp = &G.top_var;
1715 while ((cur = *var_pp) != NULL) {
1716 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1717 if (cur->flg_read_only) {
1718 bb_error_msg("%s: readonly variable", name);
1719 return EXIT_FAILURE;
1721 *var_pp = cur->next;
1722 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1723 bb_unsetenv(cur->varstr);
1724 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1725 cmdedit_update_prompt();
1729 return EXIT_SUCCESS;
1731 var_pp = &cur->next;
1733 return EXIT_SUCCESS;
1736 static int unset_local_var(const char *name)
1738 return unset_local_var_len(name, strlen(name));
1741 static void unset_vars(char **strings)
1749 const char *eq = strchrnul(*v, '=');
1750 unset_local_var_len(*v, (int)(eq - *v));
1756 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1758 char *var = xasprintf("%s=%s", name, val);
1759 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1764 * Helpers for "var1=val1 var2=val2 cmd" feature
1766 static void add_vars(struct variable *var)
1768 struct variable *next;
1772 var->next = G.top_var;
1774 if (var->flg_export) {
1775 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1776 putenv(var->varstr);
1778 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1784 static struct variable *set_vars_and_save_old(char **strings)
1787 struct variable *old = NULL;
1793 struct variable *var_p;
1794 struct variable **var_pp;
1797 eq = strchr(*s, '=');
1799 var_pp = get_ptr_to_local_var(*s, eq - *s);
1801 /* Remove variable from global linked list */
1803 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1804 *var_pp = var_p->next;
1805 /* Add it to returned list */
1809 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1820 static int FAST_FUNC static_get(struct in_str *i)
1830 static int FAST_FUNC static_peek(struct in_str *i)
1835 #if ENABLE_HUSH_INTERACTIVE
1837 static void cmdedit_update_prompt(void)
1839 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1840 G.PS1 = get_local_var_value("PS1");
1843 G.PS2 = get_local_var_value("PS2");
1851 static const char *setup_prompt_string(int promptmode)
1853 const char *prompt_str;
1854 debug_printf("setup_prompt_string %d ", promptmode);
1855 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1856 /* Set up the prompt */
1857 if (promptmode == 0) { /* PS1 */
1859 /* bash uses $PWD value, even if it is set by user.
1860 * It uses current dir only if PWD is unset.
1861 * We always use current dir. */
1862 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1867 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1868 debug_printf("result '%s'\n", prompt_str);
1872 static void get_user_input(struct in_str *i)
1875 const char *prompt_str;
1877 prompt_str = setup_prompt_string(i->promptmode);
1878 # if ENABLE_FEATURE_EDITING
1879 /* Enable command line editing only while a command line
1880 * is actually being read */
1883 /* buglet: SIGINT will not make new prompt to appear _at once_,
1884 * only after <Enter>. (^C will work) */
1885 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1886 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1887 check_and_run_traps(0);
1888 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1889 i->eof_flag = (r < 0);
1890 if (i->eof_flag) { /* EOF/error detected */
1891 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1892 G.user_input_buf[1] = '\0';
1897 fputs(prompt_str, stdout);
1899 G.user_input_buf[0] = r = fgetc(i->file);
1900 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1901 //do we need check_and_run_traps(0)? (maybe only if stdin)
1902 } while (G.flag_SIGINT);
1903 i->eof_flag = (r == EOF);
1905 i->p = G.user_input_buf;
1908 #endif /* INTERACTIVE */
1910 /* This is the magic location that prints prompts
1911 * and gets data back from the user */
1912 static int FAST_FUNC file_get(struct in_str *i)
1916 /* If there is data waiting, eat it up */
1917 if (i->p && *i->p) {
1918 #if ENABLE_HUSH_INTERACTIVE
1922 if (i->eof_flag && !*i->p)
1924 /* note: ch is never NUL */
1926 /* need to double check i->file because we might be doing something
1927 * more complicated by now, like sourcing or substituting. */
1928 #if ENABLE_HUSH_INTERACTIVE
1929 if (G_interactive_fd && i->promptme && i->file == stdin) {
1932 } while (!*i->p); /* need non-empty line */
1933 i->promptmode = 1; /* PS2 */
1938 do ch = fgetc(i->file); while (ch == '\0');
1940 debug_printf("file_get: got '%c' %d\n", ch, ch);
1941 #if ENABLE_HUSH_INTERACTIVE
1948 /* All callers guarantee this routine will never
1949 * be used right after a newline, so prompting is not needed.
1951 static int FAST_FUNC file_peek(struct in_str *i)
1954 if (i->p && *i->p) {
1955 if (i->eof_flag && !i->p[1])
1958 /* note: ch is never NUL */
1960 do ch = fgetc(i->file); while (ch == '\0');
1961 i->eof_flag = (ch == EOF);
1962 i->peek_buf[0] = ch;
1963 i->peek_buf[1] = '\0';
1965 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1969 static void setup_file_in_str(struct in_str *i, FILE *f)
1971 i->peek = file_peek;
1973 #if ENABLE_HUSH_INTERACTIVE
1975 i->promptmode = 0; /* PS1 */
1981 static void setup_string_in_str(struct in_str *i, const char *s)
1983 i->peek = static_peek;
1984 i->get = static_get;
1985 #if ENABLE_HUSH_INTERACTIVE
1987 i->promptmode = 0; /* PS1 */
1997 #define B_CHUNK (32 * sizeof(char*))
1999 static void o_reset_to_empty_unquoted(o_string *o)
2002 o->has_quoted_part = 0;
2007 static void o_free(o_string *o)
2010 memset(o, 0, sizeof(*o));
2013 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2018 static void o_grow_by(o_string *o, int len)
2020 if (o->length + len > o->maxlen) {
2021 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2022 o->data = xrealloc(o->data, 1 + o->maxlen);
2026 static void o_addchr(o_string *o, int ch)
2028 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2030 o->data[o->length] = ch;
2032 o->data[o->length] = '\0';
2035 static void o_addblock(o_string *o, const char *str, int len)
2038 memcpy(&o->data[o->length], str, len);
2040 o->data[o->length] = '\0';
2043 static void o_addstr(o_string *o, const char *str)
2045 o_addblock(o, str, strlen(str));
2049 static void nommu_addchr(o_string *o, int ch)
2055 # define nommu_addchr(o, str) ((void)0)
2058 static void o_addstr_with_NUL(o_string *o, const char *str)
2060 o_addblock(o, str, strlen(str) + 1);
2064 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2065 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2066 * Apparently, on unquoted $v bash still does globbing
2067 * ("v='*.txt'; echo $v" prints all .txt files),
2068 * but NOT brace expansion! Thus, there should be TWO independent
2069 * quoting mechanisms on $v expansion side: one protects
2070 * $v from brace expansion, and other additionally protects "$v" against globbing.
2071 * We have only second one.
2074 #if ENABLE_HUSH_BRACE_EXPANSION
2075 # define MAYBE_BRACES "{}"
2077 # define MAYBE_BRACES ""
2080 /* My analysis of quoting semantics tells me that state information
2081 * is associated with a destination, not a source.
2083 static void o_addqchr(o_string *o, int ch)
2086 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2091 o->data[o->length] = '\\';
2094 o->data[o->length] = ch;
2096 o->data[o->length] = '\0';
2099 static void o_addQchr(o_string *o, int ch)
2102 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2103 && strchr("*?[\\" MAYBE_BRACES, ch)
2106 o->data[o->length] = '\\';
2110 o->data[o->length] = ch;
2112 o->data[o->length] = '\0';
2115 static void o_addqblock(o_string *o, const char *str, int len)
2120 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2121 if (ordinary_cnt > len) /* paranoia */
2123 o_addblock(o, str, ordinary_cnt);
2124 if (ordinary_cnt == len)
2126 str += ordinary_cnt;
2127 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2131 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2133 o->data[o->length] = '\\';
2137 o->data[o->length] = ch;
2139 o->data[o->length] = '\0';
2143 static void o_addQblock(o_string *o, const char *str, int len)
2145 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2146 o_addblock(o, str, len);
2149 o_addqblock(o, str, len);
2152 static void o_addQstr(o_string *o, const char *str)
2154 o_addQblock(o, str, strlen(str));
2157 /* A special kind of o_string for $VAR and `cmd` expansion.
2158 * It contains char* list[] at the beginning, which is grown in 16 element
2159 * increments. Actual string data starts at the next multiple of 16 * (char*).
2160 * list[i] contains an INDEX (int!) into this string data.
2161 * It means that if list[] needs to grow, data needs to be moved higher up
2162 * but list[i]'s need not be modified.
2163 * NB: remembering how many list[i]'s you have there is crucial.
2164 * o_finalize_list() operation post-processes this structure - calculates
2165 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2167 #if DEBUG_EXPAND || DEBUG_GLOB
2168 static void debug_print_list(const char *prefix, o_string *o, int n)
2170 char **list = (char**)o->data;
2171 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2175 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2176 prefix, list, n, string_start, o->length, o->maxlen,
2177 !!(o->o_expflags & EXP_FLAG_GLOB),
2179 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2182 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
2183 o->data + (int)list[i] + string_start,
2184 o->data + (int)list[i] + string_start);
2188 const char *p = o->data + (int)list[n - 1] + string_start;
2190 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2194 # define debug_print_list(prefix, o, n) ((void)0)
2197 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2198 * in list[n] so that it points past last stored byte so far.
2199 * It returns n+1. */
2200 static int o_save_ptr_helper(o_string *o, int n)
2202 char **list = (char**)o->data;
2206 if (!o->has_empty_slot) {
2207 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2208 string_len = o->length - string_start;
2209 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2210 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2211 /* list[n] points to string_start, make space for 16 more pointers */
2212 o->maxlen += 0x10 * sizeof(list[0]);
2213 o->data = xrealloc(o->data, o->maxlen + 1);
2214 list = (char**)o->data;
2215 memmove(list + n + 0x10, list + n, string_len);
2216 o->length += 0x10 * sizeof(list[0]);
2218 debug_printf_list("list[%d]=%d string_start=%d\n",
2219 n, string_len, string_start);
2222 /* We have empty slot at list[n], reuse without growth */
2223 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2224 string_len = o->length - string_start;
2225 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2226 n, string_len, string_start);
2227 o->has_empty_slot = 0;
2229 list[n] = (char*)(uintptr_t)string_len;
2233 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2234 static int o_get_last_ptr(o_string *o, int n)
2236 char **list = (char**)o->data;
2237 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2239 return ((int)(uintptr_t)list[n-1]) + string_start;
2242 #if ENABLE_HUSH_BRACE_EXPANSION
2243 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2244 * first, it processes even {a} (no commas), second,
2245 * I didn't manage to make it return strings when they don't match
2246 * existing files. Need to re-implement it.
2250 static int glob_needed(const char *s)
2259 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2265 /* Return pointer to next closing brace or to comma */
2266 static const char *next_brace_sub(const char *cp)
2270 while (*cp != '\0') {
2277 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2283 return *cp != '\0' ? cp : NULL;
2285 /* Recursive brace globber. Note: may garble pattern[]. */
2286 static int glob_brace(char *pattern, o_string *o, int n)
2288 char *new_pattern_buf;
2295 debug_printf_glob("glob_brace('%s')\n", pattern);
2301 if (*begin == '{') {
2302 /* Find the first sub-pattern and at the same time
2303 * find the rest after the closing brace */
2304 next = next_brace_sub(begin);
2306 /* An illegal expression */
2310 /* "{abc}" with no commas - illegal
2311 * brace expr, disregard and skip it */
2317 if (*begin == '\\' && begin[1] != '\0')
2321 debug_printf_glob("begin:%s\n", begin);
2322 debug_printf_glob("next:%s\n", next);
2324 /* Now find the end of the whole brace expression */
2326 while (*rest != '}') {
2327 rest = next_brace_sub(rest);
2329 /* An illegal expression */
2332 debug_printf_glob("rest:%s\n", rest);
2334 rest_len = strlen(++rest) + 1;
2336 /* We are sure the brace expression is well-formed */
2338 /* Allocate working buffer large enough for our work */
2339 new_pattern_buf = xmalloc(strlen(pattern));
2341 /* We have a brace expression. BEGIN points to the opening {,
2342 * NEXT points past the terminator of the first element, and REST
2343 * points past the final }. We will accumulate result names from
2344 * recursive runs for each brace alternative in the buffer using
2349 /* Construct the new glob expression */
2352 mempcpy(new_pattern_buf,
2353 /* We know the prefix for all sub-patterns */
2354 pattern, begin - pattern),
2358 /* Note: glob_brace() may garble new_pattern_buf[].
2359 * That's why we re-copy prefix every time (1st memcpy above).
2361 n = glob_brace(new_pattern_buf, o, n);
2363 /* We saw the last entry */
2367 next = next_brace_sub(next);
2369 free(new_pattern_buf);
2377 memset(&globdata, 0, sizeof(globdata));
2378 gr = glob(pattern, 0, NULL, &globdata);
2379 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2381 if (gr == GLOB_NOMATCH) {
2382 globfree(&globdata);
2383 /* NB: garbles parameter */
2384 unbackslash(pattern);
2385 o_addstr_with_NUL(o, pattern);
2386 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2387 return o_save_ptr_helper(o, n);
2389 if (gr == GLOB_NOSPACE)
2390 bb_error_msg_and_die(bb_msg_memory_exhausted);
2391 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2392 * but we didn't specify it. Paranoia again. */
2393 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2395 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2396 char **argv = globdata.gl_pathv;
2398 o_addstr_with_NUL(o, *argv);
2399 n = o_save_ptr_helper(o, n);
2405 globfree(&globdata);
2409 /* Performs globbing on last list[],
2410 * saving each result as a new list[].
2412 static int perform_glob(o_string *o, int n)
2414 char *pattern, *copy;
2416 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2418 return o_save_ptr_helper(o, n);
2419 pattern = o->data + o_get_last_ptr(o, n);
2420 debug_printf_glob("glob pattern '%s'\n", pattern);
2421 if (!glob_needed(pattern)) {
2422 /* unbackslash last string in o in place, fix length */
2423 o->length = unbackslash(pattern) - o->data;
2424 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2425 return o_save_ptr_helper(o, n);
2428 copy = xstrdup(pattern);
2429 /* "forget" pattern in o */
2430 o->length = pattern - o->data;
2431 n = glob_brace(copy, o, n);
2434 debug_print_list("perform_glob returning", o, n);
2438 #else /* !HUSH_BRACE_EXPANSION */
2441 static int glob_needed(const char *s)
2450 if (*s == '*' || *s == '[' || *s == '?')
2456 /* Performs globbing on last list[],
2457 * saving each result as a new list[].
2459 static int perform_glob(o_string *o, int n)
2465 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2467 return o_save_ptr_helper(o, n);
2468 pattern = o->data + o_get_last_ptr(o, n);
2469 debug_printf_glob("glob pattern '%s'\n", pattern);
2470 if (!glob_needed(pattern)) {
2472 /* unbackslash last string in o in place, fix length */
2473 o->length = unbackslash(pattern) - o->data;
2474 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2475 return o_save_ptr_helper(o, n);
2478 memset(&globdata, 0, sizeof(globdata));
2479 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2480 * If we glob "*.\*" and don't find anything, we need
2481 * to fall back to using literal "*.*", but GLOB_NOCHECK
2482 * will return "*.\*"!
2484 gr = glob(pattern, 0, NULL, &globdata);
2485 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2487 if (gr == GLOB_NOMATCH) {
2488 globfree(&globdata);
2491 if (gr == GLOB_NOSPACE)
2492 bb_error_msg_and_die(bb_msg_memory_exhausted);
2493 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2494 * but we didn't specify it. Paranoia again. */
2495 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2497 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2498 char **argv = globdata.gl_pathv;
2499 /* "forget" pattern in o */
2500 o->length = pattern - o->data;
2502 o_addstr_with_NUL(o, *argv);
2503 n = o_save_ptr_helper(o, n);
2509 globfree(&globdata);
2511 debug_print_list("perform_glob returning", o, n);
2515 #endif /* !HUSH_BRACE_EXPANSION */
2517 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2518 * Otherwise, just finish current list[] and start new */
2519 static int o_save_ptr(o_string *o, int n)
2521 if (o->o_expflags & EXP_FLAG_GLOB) {
2522 /* If o->has_empty_slot, list[n] was already globbed
2523 * (if it was requested back then when it was filled)
2524 * so don't do that again! */
2525 if (!o->has_empty_slot)
2526 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2528 return o_save_ptr_helper(o, n);
2531 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2532 static char **o_finalize_list(o_string *o, int n)
2537 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2539 debug_print_list("finalized", o, n);
2540 debug_printf_expand("finalized n:%d\n", n);
2541 list = (char**)o->data;
2542 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2546 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2551 static void free_pipe_list(struct pipe *pi);
2553 /* Returns pi->next - next pipe in the list */
2554 static struct pipe *free_pipe(struct pipe *pi)
2559 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2560 for (i = 0; i < pi->num_cmds; i++) {
2561 struct command *command;
2562 struct redir_struct *r, *rnext;
2564 command = &pi->cmds[i];
2565 debug_printf_clean(" command %d:\n", i);
2566 if (command->argv) {
2570 for (a = 0, p = command->argv; *p; a++, p++) {
2571 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2574 free_strings(command->argv);
2575 //command->argv = NULL;
2577 /* not "else if": on syntax error, we may have both! */
2578 if (command->group) {
2579 debug_printf_clean(" begin group (cmd_type:%d)\n",
2581 free_pipe_list(command->group);
2582 debug_printf_clean(" end group\n");
2583 //command->group = NULL;
2585 /* else is crucial here.
2586 * If group != NULL, child_func is meaningless */
2587 #if ENABLE_HUSH_FUNCTIONS
2588 else if (command->child_func) {
2589 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2590 command->child_func->parent_cmd = NULL;
2594 free(command->group_as_string);
2595 //command->group_as_string = NULL;
2597 for (r = command->redirects; r; r = rnext) {
2598 debug_printf_clean(" redirect %d%s",
2599 r->rd_fd, redir_table[r->rd_type].descrip);
2600 /* guard against the case >$FOO, where foo is unset or blank */
2601 if (r->rd_filename) {
2602 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2603 free(r->rd_filename);
2604 //r->rd_filename = NULL;
2606 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2610 //command->redirects = NULL;
2612 free(pi->cmds); /* children are an array, they get freed all at once */
2616 //pi->cmdtext = NULL;
2624 static void free_pipe_list(struct pipe *pi)
2628 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2630 debug_printf_clean("pipe followup code %d\n", pi->followup);
2636 /*** Parsing routines ***/
2638 #ifndef debug_print_tree
2639 static void debug_print_tree(struct pipe *pi, int lvl)
2641 static const char *const PIPE[] = {
2647 static const char *RES[] = {
2648 [RES_NONE ] = "NONE" ,
2651 [RES_THEN ] = "THEN" ,
2652 [RES_ELIF ] = "ELIF" ,
2653 [RES_ELSE ] = "ELSE" ,
2656 # if ENABLE_HUSH_LOOPS
2657 [RES_FOR ] = "FOR" ,
2658 [RES_WHILE] = "WHILE",
2659 [RES_UNTIL] = "UNTIL",
2661 [RES_DONE ] = "DONE" ,
2663 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2666 # if ENABLE_HUSH_CASE
2667 [RES_CASE ] = "CASE" ,
2668 [RES_CASE_IN ] = "CASE_IN" ,
2669 [RES_MATCH] = "MATCH",
2670 [RES_CASE_BODY] = "CASE_BODY",
2671 [RES_ESAC ] = "ESAC" ,
2673 [RES_XXXX ] = "XXXX" ,
2674 [RES_SNTX ] = "SNTX" ,
2676 static const char *const CMDTYPE[] = {
2680 # if ENABLE_HUSH_FUNCTIONS
2689 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2690 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2692 while (prn < pi->num_cmds) {
2693 struct command *command = &pi->cmds[prn];
2694 char **argv = command->argv;
2696 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
2698 command->assignment_cnt);
2699 if (command->group) {
2700 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
2701 CMDTYPE[command->cmd_type],
2704 , " group_as_string:", command->group_as_string
2709 debug_print_tree(command->group, lvl+1);
2713 if (argv) while (*argv) {
2714 fprintf(stderr, " '%s'", *argv);
2717 fprintf(stderr, "\n");
2724 #endif /* debug_print_tree */
2726 static struct pipe *new_pipe(void)
2729 pi = xzalloc(sizeof(struct pipe));
2730 /*pi->followup = 0; - deliberately invalid value */
2731 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2735 /* Command (member of a pipe) is complete, or we start a new pipe
2736 * if ctx->command is NULL.
2737 * No errors possible here.
2739 static int done_command(struct parse_context *ctx)
2741 /* The command is really already in the pipe structure, so
2742 * advance the pipe counter and make a new, null command. */
2743 struct pipe *pi = ctx->pipe;
2744 struct command *command = ctx->command;
2747 if (IS_NULL_CMD(command)) {
2748 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2752 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2753 //debug_print_tree(ctx->list_head, 20);
2755 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2758 /* Only real trickiness here is that the uncommitted
2759 * command structure is not counted in pi->num_cmds. */
2760 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2761 ctx->command = command = &pi->cmds[pi->num_cmds];
2763 memset(command, 0, sizeof(*command));
2764 return pi->num_cmds; /* used only for 0/nonzero check */
2767 static void done_pipe(struct parse_context *ctx, pipe_style type)
2771 debug_printf_parse("done_pipe entered, followup %d\n", type);
2772 /* Close previous command */
2773 not_null = done_command(ctx);
2774 ctx->pipe->followup = type;
2776 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2777 ctx->ctx_inverted = 0;
2778 ctx->pipe->res_word = ctx->ctx_res_w;
2781 /* Without this check, even just <enter> on command line generates
2782 * tree of three NOPs (!). Which is harmless but annoying.
2783 * IOW: it is safe to do it unconditionally. */
2786 || ctx->ctx_res_w == RES_FI
2788 #if ENABLE_HUSH_LOOPS
2789 || ctx->ctx_res_w == RES_DONE
2790 || ctx->ctx_res_w == RES_FOR
2791 || ctx->ctx_res_w == RES_IN
2793 #if ENABLE_HUSH_CASE
2794 || ctx->ctx_res_w == RES_ESAC
2798 debug_printf_parse("done_pipe: adding new pipe: "
2799 "not_null:%d ctx->ctx_res_w:%d\n",
2800 not_null, ctx->ctx_res_w);
2802 ctx->pipe->next = new_p;
2804 /* RES_THEN, RES_DO etc are "sticky" -
2805 * they remain set for pipes inside if/while.
2806 * This is used to control execution.
2807 * RES_FOR and RES_IN are NOT sticky (needed to support
2808 * cases where variable or value happens to match a keyword):
2810 #if ENABLE_HUSH_LOOPS
2811 if (ctx->ctx_res_w == RES_FOR
2812 || ctx->ctx_res_w == RES_IN)
2813 ctx->ctx_res_w = RES_NONE;
2815 #if ENABLE_HUSH_CASE
2816 if (ctx->ctx_res_w == RES_MATCH)
2817 ctx->ctx_res_w = RES_CASE_BODY;
2818 if (ctx->ctx_res_w == RES_CASE)
2819 ctx->ctx_res_w = RES_CASE_IN;
2821 ctx->command = NULL; /* trick done_command below */
2822 /* Create the memory for command, roughly:
2823 * ctx->pipe->cmds = new struct command;
2824 * ctx->command = &ctx->pipe->cmds[0];
2827 //debug_print_tree(ctx->list_head, 10);
2829 debug_printf_parse("done_pipe return\n");
2832 static void initialize_context(struct parse_context *ctx)
2834 memset(ctx, 0, sizeof(*ctx));
2835 ctx->pipe = ctx->list_head = new_pipe();
2836 /* Create the memory for command, roughly:
2837 * ctx->pipe->cmds = new struct command;
2838 * ctx->command = &ctx->pipe->cmds[0];
2843 /* If a reserved word is found and processed, parse context is modified
2844 * and 1 is returned.
2847 struct reserved_combo {
2850 unsigned char assignment_flag;
2854 FLAG_END = (1 << RES_NONE ),
2856 FLAG_IF = (1 << RES_IF ),
2857 FLAG_THEN = (1 << RES_THEN ),
2858 FLAG_ELIF = (1 << RES_ELIF ),
2859 FLAG_ELSE = (1 << RES_ELSE ),
2860 FLAG_FI = (1 << RES_FI ),
2862 # if ENABLE_HUSH_LOOPS
2863 FLAG_FOR = (1 << RES_FOR ),
2864 FLAG_WHILE = (1 << RES_WHILE),
2865 FLAG_UNTIL = (1 << RES_UNTIL),
2866 FLAG_DO = (1 << RES_DO ),
2867 FLAG_DONE = (1 << RES_DONE ),
2868 FLAG_IN = (1 << RES_IN ),
2870 # if ENABLE_HUSH_CASE
2871 FLAG_MATCH = (1 << RES_MATCH),
2872 FLAG_ESAC = (1 << RES_ESAC ),
2874 FLAG_START = (1 << RES_XXXX ),
2877 static const struct reserved_combo* match_reserved_word(o_string *word)
2879 /* Mostly a list of accepted follow-up reserved words.
2880 * FLAG_END means we are done with the sequence, and are ready
2881 * to turn the compound list into a command.
2882 * FLAG_START means the word must start a new compound list.
2884 static const struct reserved_combo reserved_list[] = {
2886 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2887 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2888 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2889 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2890 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2891 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2893 # if ENABLE_HUSH_LOOPS
2894 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2895 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2896 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2897 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2898 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2899 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2901 # if ENABLE_HUSH_CASE
2902 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2903 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2906 const struct reserved_combo *r;
2908 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2909 if (strcmp(word->data, r->literal) == 0)
2914 /* Return 0: not a keyword, 1: keyword
2916 static int reserved_word(o_string *word, struct parse_context *ctx)
2918 # if ENABLE_HUSH_CASE
2919 static const struct reserved_combo reserved_match = {
2920 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2923 const struct reserved_combo *r;
2925 if (word->has_quoted_part)
2927 r = match_reserved_word(word);
2931 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2932 # if ENABLE_HUSH_CASE
2933 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2934 /* "case word IN ..." - IN part starts first MATCH part */
2935 r = &reserved_match;
2938 if (r->flag == 0) { /* '!' */
2939 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2940 syntax_error("! ! command");
2941 ctx->ctx_res_w = RES_SNTX;
2943 ctx->ctx_inverted = 1;
2946 if (r->flag & FLAG_START) {
2947 struct parse_context *old;
2949 old = xmalloc(sizeof(*old));
2950 debug_printf_parse("push stack %p\n", old);
2951 *old = *ctx; /* physical copy */
2952 initialize_context(ctx);
2954 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2955 syntax_error_at(word->data);
2956 ctx->ctx_res_w = RES_SNTX;
2959 /* "{...} fi" is ok. "{...} if" is not
2961 * if { echo foo; } then { echo bar; } fi */
2962 if (ctx->command->group)
2963 done_pipe(ctx, PIPE_SEQ);
2966 ctx->ctx_res_w = r->res;
2967 ctx->old_flag = r->flag;
2968 word->o_assignment = r->assignment_flag;
2970 if (ctx->old_flag & FLAG_END) {
2971 struct parse_context *old;
2973 done_pipe(ctx, PIPE_SEQ);
2974 debug_printf_parse("pop stack %p\n", ctx->stack);
2976 old->command->group = ctx->list_head;
2977 old->command->cmd_type = CMD_NORMAL;
2979 o_addstr(&old->as_string, ctx->as_string.data);
2980 o_free_unsafe(&ctx->as_string);
2981 old->command->group_as_string = xstrdup(old->as_string.data);
2982 debug_printf_parse("pop, remembering as:'%s'\n",
2983 old->command->group_as_string);
2985 *ctx = *old; /* physical copy */
2990 #endif /* HAS_KEYWORDS */
2992 /* Word is complete, look at it and update parsing context.
2993 * Normal return is 0. Syntax errors return 1.
2994 * Note: on return, word is reset, but not o_free'd!
2996 static int done_word(o_string *word, struct parse_context *ctx)
2998 struct command *command = ctx->command;
3000 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3001 if (word->length == 0 && !word->has_quoted_part) {
3002 debug_printf_parse("done_word return 0: true null, ignored\n");
3006 if (ctx->pending_redirect) {
3007 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3008 * only if run as "bash", not "sh" */
3009 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3011 * ...the word that follows the redirection operator
3012 * shall be subjected to tilde expansion, parameter expansion,
3013 * command substitution, arithmetic expansion, and quote
3014 * removal. Pathname expansion shall not be performed
3015 * on the word by a non-interactive shell; an interactive
3016 * shell may perform it, but shall do so only when
3017 * the expansion would result in one word."
3019 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3020 /* Cater for >\file case:
3021 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3022 * Same with heredocs:
3023 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3025 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3026 unbackslash(ctx->pending_redirect->rd_filename);
3027 /* Is it <<"HEREDOC"? */
3028 if (word->has_quoted_part) {
3029 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3032 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3033 ctx->pending_redirect = NULL;
3035 /* If this word wasn't an assignment, next ones definitely
3036 * can't be assignments. Even if they look like ones. */
3037 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3038 && word->o_assignment != WORD_IS_KEYWORD
3040 word->o_assignment = NOT_ASSIGNMENT;
3042 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3043 command->assignment_cnt++;
3044 word->o_assignment = MAYBE_ASSIGNMENT;
3048 # if ENABLE_HUSH_CASE
3049 if (ctx->ctx_dsemicolon
3050 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3052 /* already done when ctx_dsemicolon was set to 1: */
3053 /* ctx->ctx_res_w = RES_MATCH; */
3054 ctx->ctx_dsemicolon = 0;
3057 if (!command->argv /* if it's the first word... */
3058 # if ENABLE_HUSH_LOOPS
3059 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3060 && ctx->ctx_res_w != RES_IN
3062 # if ENABLE_HUSH_CASE
3063 && ctx->ctx_res_w != RES_CASE
3066 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
3067 if (reserved_word(word, ctx)) {
3068 o_reset_to_empty_unquoted(word);
3069 debug_printf_parse("done_word return %d\n",
3070 (ctx->ctx_res_w == RES_SNTX));
3071 return (ctx->ctx_res_w == RES_SNTX);
3073 # if ENABLE_HUSH_BASH_COMPAT
3074 if (strcmp(word->data, "[[") == 0) {
3075 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3081 if (command->group) {
3082 /* "{ echo foo; } echo bar" - bad */
3083 syntax_error_at(word->data);
3084 debug_printf_parse("done_word return 1: syntax error, "
3085 "groups and arglists don't mix\n");
3088 if (word->has_quoted_part
3089 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3090 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3091 /* (otherwise it's known to be not empty and is already safe) */
3093 /* exclude "$@" - it can expand to no word despite "" */
3094 char *p = word->data;
3095 while (p[0] == SPECIAL_VAR_SYMBOL
3096 && (p[1] & 0x7f) == '@'
3097 && p[2] == SPECIAL_VAR_SYMBOL
3101 if (p == word->data || p[0] != '\0') {
3102 /* saw no "$@", or not only "$@" but some
3103 * real text is there too */
3104 /* insert "empty variable" reference, this makes
3105 * e.g. "", $empty"" etc to not disappear */
3106 o_addchr(word, SPECIAL_VAR_SYMBOL);
3107 o_addchr(word, SPECIAL_VAR_SYMBOL);
3110 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3111 debug_print_strings("word appended to argv", command->argv);
3114 #if ENABLE_HUSH_LOOPS
3115 if (ctx->ctx_res_w == RES_FOR) {
3116 if (word->has_quoted_part
3117 || !is_well_formed_var_name(command->argv[0], '\0')
3119 /* bash says just "not a valid identifier" */
3120 syntax_error("not a valid identifier in for");
3123 /* Force FOR to have just one word (variable name) */
3124 /* NB: basically, this makes hush see "for v in ..."
3125 * syntax as if it is "for v; in ...". FOR and IN become
3126 * two pipe structs in parse tree. */
3127 done_pipe(ctx, PIPE_SEQ);
3130 #if ENABLE_HUSH_CASE
3131 /* Force CASE to have just one word */
3132 if (ctx->ctx_res_w == RES_CASE) {
3133 done_pipe(ctx, PIPE_SEQ);
3137 o_reset_to_empty_unquoted(word);
3139 debug_printf_parse("done_word return 0\n");
3144 /* Peek ahead in the input to find out if we have a "&n" construct,
3145 * as in "2>&1", that represents duplicating a file descriptor.
3147 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3148 * REDIRFD_SYNTAX_ERR if syntax error,
3149 * REDIRFD_TO_FILE if no & was seen,
3150 * or the number found.
3153 #define parse_redir_right_fd(as_string, input) \
3154 parse_redir_right_fd(input)
3156 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3162 return REDIRFD_TO_FILE;
3164 ch = i_getch(input); /* get the & */
3165 nommu_addchr(as_string, ch);
3168 ch = i_getch(input);
3169 nommu_addchr(as_string, ch);
3170 return REDIRFD_CLOSE;
3174 while (ch != EOF && isdigit(ch)) {
3175 d = d*10 + (ch-'0');
3177 ch = i_getch(input);
3178 nommu_addchr(as_string, ch);
3183 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3185 bb_error_msg("ambiguous redirect");
3186 return REDIRFD_SYNTAX_ERR;
3189 /* Return code is 0 normal, 1 if a syntax error is detected
3191 static int parse_redirect(struct parse_context *ctx,
3194 struct in_str *input)
3196 struct command *command = ctx->command;
3197 struct redir_struct *redir;
3198 struct redir_struct **redirp;
3201 dup_num = REDIRFD_TO_FILE;
3202 if (style != REDIRECT_HEREDOC) {
3203 /* Check for a '>&1' type redirect */
3204 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3205 if (dup_num == REDIRFD_SYNTAX_ERR)
3208 int ch = i_peek(input);
3209 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3210 if (dup_num) { /* <<-... */
3211 ch = i_getch(input);
3212 nommu_addchr(&ctx->as_string, ch);
3217 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3218 int ch = i_peek(input);
3220 /* >|FILE redirect ("clobbering" >).
3221 * Since we do not support "set -o noclobber" yet,
3222 * >| and > are the same for now. Just eat |.
3224 ch = i_getch(input);
3225 nommu_addchr(&ctx->as_string, ch);
3229 /* Create a new redir_struct and append it to the linked list */
3230 redirp = &command->redirects;
3231 while ((redir = *redirp) != NULL) {
3232 redirp = &(redir->next);
3234 *redirp = redir = xzalloc(sizeof(*redir));
3235 /* redir->next = NULL; */
3236 /* redir->rd_filename = NULL; */
3237 redir->rd_type = style;
3238 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3240 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3241 redir_table[style].descrip);
3243 redir->rd_dup = dup_num;
3244 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3245 /* Erik had a check here that the file descriptor in question
3246 * is legit; I postpone that to "run time"
3247 * A "-" representation of "close me" shows up as a -3 here */
3248 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3249 redir->rd_fd, redir->rd_dup);
3251 /* Set ctx->pending_redirect, so we know what to do at the
3252 * end of the next parsed word. */
3253 ctx->pending_redirect = redir;
3258 /* If a redirect is immediately preceded by a number, that number is
3259 * supposed to tell which file descriptor to redirect. This routine
3260 * looks for such preceding numbers. In an ideal world this routine
3261 * needs to handle all the following classes of redirects...
3262 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3263 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3264 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3265 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3267 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3269 * ... If n is quoted, the number shall not be recognized as part of
3270 * the redirection expression. For example:
3272 * writes the character 2 into file a"
3273 * We are getting it right by setting ->has_quoted_part on any \<char>
3275 * A -1 return means no valid number was found,
3276 * the caller should use the appropriate default for this redirection.
3278 static int redirect_opt_num(o_string *o)
3282 if (o->data == NULL)
3284 num = bb_strtou(o->data, NULL, 10);
3285 if (errno || num < 0)
3287 o_reset_to_empty_unquoted(o);
3292 #define fetch_till_str(as_string, input, word, skip_tabs) \
3293 fetch_till_str(input, word, skip_tabs)
3295 static char *fetch_till_str(o_string *as_string,
3296 struct in_str *input,
3300 o_string heredoc = NULL_O_STRING;
3302 int prev = 0; /* not \ */
3307 ch = i_getch(input);
3309 nommu_addchr(as_string, ch);
3310 if ((ch == '\n' || ch == EOF)
3311 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3313 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3314 heredoc.data[past_EOL] = '\0';
3315 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3316 return heredoc.data;
3318 while (ch == '\n') {
3319 o_addchr(&heredoc, ch);
3322 past_EOL = heredoc.length;
3324 ch = i_getch(input);
3326 nommu_addchr(as_string, ch);
3327 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3331 o_free_unsafe(&heredoc);
3334 o_addchr(&heredoc, ch);
3335 nommu_addchr(as_string, ch);
3336 if (prev == '\\' && ch == '\\')
3337 /* Correctly handle foo\\<eol> (not a line cont.) */
3338 prev = 0; /* not \ */
3344 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3345 * and load them all. There should be exactly heredoc_cnt of them.
3347 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3349 struct pipe *pi = ctx->list_head;
3351 while (pi && heredoc_cnt) {
3353 struct command *cmd = pi->cmds;
3355 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3357 cmd->argv ? cmd->argv[0] : "NONE");
3358 for (i = 0; i < pi->num_cmds; i++) {
3359 struct redir_struct *redir = cmd->redirects;
3361 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3362 i, cmd->argv ? cmd->argv[0] : "NONE");
3364 if (redir->rd_type == REDIRECT_HEREDOC) {
3367 redir->rd_type = REDIRECT_HEREDOC2;
3368 /* redir->rd_dup is (ab)used to indicate <<- */
3369 p = fetch_till_str(&ctx->as_string, input,
3370 redir->rd_filename, redir->rd_dup);
3372 syntax_error("unexpected EOF in here document");
3375 free(redir->rd_filename);
3376 redir->rd_filename = p;
3379 redir = redir->next;
3386 /* Should be 0. If it isn't, it's a parse error */
3388 bb_error_msg_and_die("heredoc BUG 2");
3394 static int run_list(struct pipe *pi);
3396 #define parse_stream(pstring, input, end_trigger) \
3397 parse_stream(input, end_trigger)
3399 static struct pipe *parse_stream(char **pstring,
3400 struct in_str *input,
3404 #if !ENABLE_HUSH_FUNCTIONS
3405 #define parse_group(dest, ctx, input, ch) \
3406 parse_group(ctx, input, ch)
3408 static int parse_group(o_string *dest, struct parse_context *ctx,
3409 struct in_str *input, int ch)
3411 /* dest contains characters seen prior to ( or {.
3412 * Typically it's empty, but for function defs,
3413 * it contains function name (without '()'). */
3414 struct pipe *pipe_list;
3416 struct command *command = ctx->command;
3418 debug_printf_parse("parse_group entered\n");
3419 #if ENABLE_HUSH_FUNCTIONS
3420 if (ch == '(' && !dest->has_quoted_part) {
3422 if (done_word(dest, ctx))
3425 goto skip; /* (... */
3426 if (command->argv[1]) { /* word word ... (... */
3427 syntax_error_unexpected_ch('(');
3430 /* it is "word(..." or "word (..." */
3432 ch = i_getch(input);
3433 while (ch == ' ' || ch == '\t');
3435 syntax_error_unexpected_ch(ch);
3438 nommu_addchr(&ctx->as_string, ch);
3440 ch = i_getch(input);
3441 while (ch == ' ' || ch == '\t' || ch == '\n');
3443 syntax_error_unexpected_ch(ch);
3446 nommu_addchr(&ctx->as_string, ch);
3447 command->cmd_type = CMD_FUNCDEF;
3452 #if 0 /* Prevented by caller */
3453 if (command->argv /* word [word]{... */
3454 || dest->length /* word{... */
3455 || dest->has_quoted_part /* ""{... */
3458 debug_printf_parse("parse_group return 1: "
3459 "syntax error, groups and arglists don't mix\n");
3464 #if ENABLE_HUSH_FUNCTIONS
3470 command->cmd_type = CMD_SUBSHELL;
3472 /* bash does not allow "{echo...", requires whitespace */
3473 ch = i_getch(input);
3474 if (ch != ' ' && ch != '\t' && ch != '\n') {
3475 syntax_error_unexpected_ch(ch);
3478 nommu_addchr(&ctx->as_string, ch);
3483 # define as_string NULL
3485 char *as_string = NULL;
3487 pipe_list = parse_stream(&as_string, input, endch);
3490 o_addstr(&ctx->as_string, as_string);
3492 /* empty ()/{} or parse error? */
3493 if (!pipe_list || pipe_list == ERR_PTR) {
3494 /* parse_stream already emitted error msg */
3497 debug_printf_parse("parse_group return 1: "
3498 "parse_stream returned %p\n", pipe_list);
3501 command->group = pipe_list;
3503 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3504 command->group_as_string = as_string;
3505 debug_printf_parse("end of group, remembering as:'%s'\n",
3506 command->group_as_string);
3510 debug_printf_parse("parse_group return 0\n");
3512 /* command remains "open", available for possible redirects */
3515 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3516 /* Subroutines for copying $(...) and `...` things */
3517 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3519 static void add_till_single_quote(o_string *dest, struct in_str *input)
3522 int ch = i_getch(input);
3524 syntax_error_unterm_ch('\'');
3525 /*xfunc_die(); - redundant */
3532 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3533 static void add_till_double_quote(o_string *dest, struct in_str *input)
3536 int ch = i_getch(input);
3538 syntax_error_unterm_ch('"');
3539 /*xfunc_die(); - redundant */
3543 if (ch == '\\') { /* \x. Copy both chars. */
3545 ch = i_getch(input);
3549 add_till_backquote(dest, input, /*in_dquote:*/ 1);
3553 //if (ch == '$') ...
3556 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3558 * "Within the backquoted style of command substitution, backslash
3559 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3560 * The search for the matching backquote shall be satisfied by the first
3561 * backquote found without a preceding backslash; during this search,
3562 * if a non-escaped backquote is encountered within a shell comment,
3563 * a here-document, an embedded command substitution of the $(command)
3564 * form, or a quoted string, undefined results occur. A single-quoted
3565 * or double-quoted string that begins, but does not end, within the
3566 * "`...`" sequence produces undefined results."
3568 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3570 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3573 int ch = i_getch(input);
3577 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3578 ch = i_getch(input);
3582 && (!in_dquote || ch != '"')
3584 o_addchr(dest, '\\');
3588 syntax_error_unterm_ch('`');
3589 /*xfunc_die(); - redundant */
3594 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3595 * quoting and nested ()s.
3596 * "With the $(command) style of command substitution, all characters
3597 * following the open parenthesis to the matching closing parenthesis
3598 * constitute the command. Any valid shell script can be used for command,
3599 * except a script consisting solely of redirections which produces
3600 * unspecified results."
3602 * echo $(echo '(TEST)' BEST) (TEST) BEST
3603 * echo $(echo 'TEST)' BEST) TEST) BEST
3604 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3606 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3607 * can contain arbitrary constructs, just like $(cmd).
3608 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3609 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3611 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3612 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3615 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3616 # if ENABLE_HUSH_BASH_COMPAT
3617 char end_char2 = end_ch >> 8;
3619 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3622 ch = i_getch(input);
3624 syntax_error_unterm_ch(end_ch);
3625 /*xfunc_die(); - redundant */
3627 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3630 /* we look for closing )) of $((EXPR)) */
3631 if (i_peek(input) == end_ch) {
3632 i_getch(input); /* eat second ')' */
3637 if (ch == '(' || ch == '{') {
3638 ch = (ch == '(' ? ')' : '}');
3639 add_till_closing_bracket(dest, input, ch);
3644 add_till_single_quote(dest, input);
3649 add_till_double_quote(dest, input);
3654 add_till_backquote(dest, input, /*in_dquote:*/ 0);
3659 /* \x. Copy verbatim. Important for \(, \) */
3660 ch = i_getch(input);
3662 syntax_error_unterm_ch(')');
3663 /*xfunc_die(); - redundant */
3671 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3673 /* Return code: 0 for OK, 1 for syntax error */
3675 #define parse_dollar(as_string, dest, input, quote_mask) \
3676 parse_dollar(dest, input, quote_mask)
3677 #define as_string NULL
3679 static int parse_dollar(o_string *as_string,
3681 struct in_str *input, unsigned char quote_mask)
3683 int ch = i_peek(input); /* first character after the $ */
3685 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3687 ch = i_getch(input);
3688 nommu_addchr(as_string, ch);
3690 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3692 debug_printf_parse(": '%c'\n", ch);
3693 o_addchr(dest, ch | quote_mask);
3696 if (!isalnum(ch) && ch != '_')
3698 ch = i_getch(input);
3699 nommu_addchr(as_string, ch);
3701 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3702 } else if (isdigit(ch)) {
3704 ch = i_getch(input);
3705 nommu_addchr(as_string, ch);
3706 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3707 debug_printf_parse(": '%c'\n", ch);
3708 o_addchr(dest, ch | quote_mask);
3709 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3710 } else switch (ch) {
3712 case '!': /* last bg pid */
3713 case '?': /* last exit code */
3714 case '#': /* number of args */
3715 case '*': /* args */
3716 case '@': /* args */
3717 goto make_one_char_var;
3719 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3721 ch = i_getch(input); /* eat '{' */
3722 nommu_addchr(as_string, ch);
3724 ch = i_getch(input); /* first char after '{' */
3725 /* It should be ${?}, or ${#var},
3726 * or even ${?+subst} - operator acting on a special variable,
3727 * or the beginning of variable name.
3730 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3733 syntax_error_unterm_str("${name}");
3734 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3737 nommu_addchr(as_string, ch);
3740 /* It's possible to just call add_till_closing_bracket() at this point.
3741 * However, this regresses some of our testsuite cases
3742 * which check invalid constructs like ${%}.
3743 * Oh well... let's check that the var name part is fine... */
3749 debug_printf_parse(": '%c'\n", ch);
3751 ch = i_getch(input);
3752 nommu_addchr(as_string, ch);
3756 if (!isalnum(ch) && ch != '_') {
3758 unsigned char last_ch;
3759 /* handle parameter expansions
3760 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3762 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3763 goto bad_dollar_syntax;
3765 /* Eat everything until closing '}' (or ':') */
3767 if (ENABLE_HUSH_BASH_COMPAT
3769 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3771 /* It's ${var:N[:M]} thing */
3772 end_ch = '}' * 0x100 + ':';
3774 if (ENABLE_HUSH_BASH_COMPAT
3777 /* It's ${var/[/]pattern[/repl]} thing */
3778 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3780 nommu_addchr(as_string, '/');
3783 end_ch = '}' * 0x100 + '/';
3789 #if ENABLE_HUSH_DOLLAR_OPS
3790 last_ch = add_till_closing_bracket(dest, input, end_ch);
3792 #error Simple code to only allow ${var} is not implemented
3795 o_addstr(as_string, dest->data + pos);
3796 o_addchr(as_string, last_ch);
3799 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3800 /* close the first block: */
3801 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3802 /* while parsing N from ${var:N[:M]}
3803 * or pattern from ${var/[/]pattern[/repl]} */
3804 if ((end_ch & 0xff) == last_ch) {
3805 /* got ':' or '/'- parse the rest */
3810 if (end_ch == '}' * 0x100 + ':') {
3811 /* it's ${var:N} - emulate :999999999 */
3812 o_addstr(dest, "999999999");
3813 } /* else: it's ${var/[/]pattern} */
3818 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3821 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3825 ch = i_getch(input);
3826 nommu_addchr(as_string, ch);
3827 # if ENABLE_SH_MATH_SUPPORT
3828 if (i_peek(input) == '(') {
3829 ch = i_getch(input);
3830 nommu_addchr(as_string, ch);
3831 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3832 o_addchr(dest, /*quote_mask |*/ '+');
3835 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3837 o_addstr(as_string, dest->data + pos);
3838 o_addchr(as_string, ')');
3839 o_addchr(as_string, ')');
3841 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3845 # if ENABLE_HUSH_TICK
3846 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3847 o_addchr(dest, quote_mask | '`');
3850 add_till_closing_bracket(dest, input, ')');
3852 o_addstr(as_string, dest->data + pos);
3853 o_addchr(as_string, ')');
3855 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3861 ch = i_getch(input);
3862 nommu_addchr(as_string, ch);
3864 if (isalnum(ch)) { /* it's $_name or $_123 */
3869 /* TODO: $_ and $-: */
3870 /* $_ Shell or shell script name; or last argument of last command
3871 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3872 * but in command's env, set to full pathname used to invoke it */
3873 /* $- Option flags set by set builtin or shell options (-i etc) */
3875 o_addQchr(dest, '$');
3877 debug_printf_parse("parse_dollar return 0\n");
3883 # if ENABLE_HUSH_BASH_COMPAT
3884 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3885 encode_string(dest, input, dquote_end, process_bkslash)
3887 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
3888 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3889 encode_string(dest, input, dquote_end)
3891 #define as_string NULL
3895 # if ENABLE_HUSH_BASH_COMPAT
3896 /* all parameters are needed, no macro tricks */
3898 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3899 encode_string(as_string, dest, input, dquote_end)
3902 static int encode_string(o_string *as_string,
3904 struct in_str *input,
3906 int process_bkslash)
3908 #if !ENABLE_HUSH_BASH_COMPAT
3909 const int process_bkslash = 1;
3915 ch = i_getch(input);
3917 nommu_addchr(as_string, ch);
3918 if (ch == dquote_end) { /* may be only '"' or EOF */
3919 debug_printf_parse("encode_string return 0\n");
3922 /* note: can't move it above ch == dquote_end check! */
3924 syntax_error_unterm_ch('"');
3925 /*xfunc_die(); - redundant */
3929 next = i_peek(input);
3931 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3932 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3933 if (process_bkslash && ch == '\\') {
3935 syntax_error("\\<eof>");
3939 * "The backslash retains its special meaning [in "..."]
3940 * only when followed by one of the following characters:
3941 * $, `, ", \, or <newline>. A double quote may be quoted
3942 * within double quotes by preceding it with a backslash."
3943 * NB: in (unquoted) heredoc, above does not apply to ",
3944 * therefore we check for it by "next == dquote_end" cond.
3946 if (next == dquote_end || strchr("$`\\\n", next)) {
3947 ch = i_getch(input); /* eat next */
3949 goto again; /* skip \<newline> */
3950 } /* else: ch remains == '\\', and we double it below: */
3951 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
3952 nommu_addchr(as_string, ch);
3956 if (parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80) != 0) {
3957 debug_printf_parse("encode_string return 1: "
3958 "parse_dollar returned non-0\n");
3963 #if ENABLE_HUSH_TICK
3965 //unsigned pos = dest->length;
3966 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3967 o_addchr(dest, 0x80 | '`');
3968 add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"');
3969 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3970 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3974 o_addQchr(dest, ch);
3980 * Scan input until EOF or end_trigger char.
3981 * Return a list of pipes to execute, or NULL on EOF
3982 * or if end_trigger character is met.
3983 * On syntax error, exit is shell is not interactive,
3984 * reset parsing machinery and start parsing anew,
3985 * or return ERR_PTR.
3987 static struct pipe *parse_stream(char **pstring,
3988 struct in_str *input,
3991 struct parse_context ctx;
3992 o_string dest = NULL_O_STRING;
3995 /* Single-quote triggers a bypass of the main loop until its mate is
3996 * found. When recursing, quote state is passed in via dest->o_expflags.
3998 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
3999 end_trigger ? end_trigger : 'X');
4002 /* If very first arg is "" or '', dest.data may end up NULL.
4003 * Preventing this: */
4004 o_addchr(&dest, '\0');
4007 /* We used to separate words on $IFS here. This was wrong.
4008 * $IFS is used only for word splitting when $var is expanded,
4009 * here we should use blank chars as separators, not $IFS
4012 reset: /* we come back here only on syntax errors in interactive shell */
4014 #if ENABLE_HUSH_INTERACTIVE
4015 input->promptmode = 0; /* PS1 */
4017 if (MAYBE_ASSIGNMENT != 0)
4018 dest.o_assignment = MAYBE_ASSIGNMENT;
4019 initialize_context(&ctx);
4022 const char *is_blank;
4023 const char *is_special;
4027 redir_type redir_style;
4029 ch = i_getch(input);
4030 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4031 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4036 syntax_error_unterm_str("here document");
4039 /* end_trigger == '}' case errors out earlier,
4040 * checking only ')' */
4041 if (end_trigger == ')') {
4042 syntax_error_unterm_ch('('); /* exits */
4043 /* goto parse_error; */
4046 if (done_word(&dest, &ctx)) {
4050 done_pipe(&ctx, PIPE_SEQ);
4052 /* If we got nothing... */
4053 /* (this makes bare "&" cmd a no-op.
4054 * bash says: "syntax error near unexpected token '&'") */
4055 if (pi->num_cmds == 0
4056 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4062 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4064 *pstring = ctx.as_string.data;
4066 o_free_unsafe(&ctx.as_string);
4069 debug_printf_parse("parse_stream return %p\n", pi);
4072 nommu_addchr(&ctx.as_string, ch);
4076 next = i_peek(input);
4078 is_special = "{}<>;&|()#'" /* special outside of "str" */
4079 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4080 /* Are { and } special here? */
4081 if (ctx.command->argv /* word [word]{... - non-special */
4082 || dest.length /* word{... - non-special */
4083 || dest.has_quoted_part /* ""{... - non-special */
4084 || (next != ';' /* }; - special */
4085 && next != ')' /* }) - special */
4086 && next != '&' /* }& and }&& ... - special */
4087 && next != '|' /* }|| ... - special */
4088 && !strchr(defifs, next) /* {word - non-special */
4091 /* They are not special, skip "{}" */
4094 is_special = strchr(is_special, ch);
4095 is_blank = strchr(defifs, ch);
4097 if (!is_special && !is_blank) { /* ordinary char */
4099 o_addQchr(&dest, ch);
4100 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4101 || dest.o_assignment == WORD_IS_KEYWORD)
4103 && is_well_formed_var_name(dest.data, '=')
4105 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4111 if (done_word(&dest, &ctx)) {
4115 /* Is this a case when newline is simply ignored?
4117 * "cmd | <newline> cmd ..."
4118 * "case ... in <newline> word) ..."
4120 if (IS_NULL_CMD(ctx.command)
4121 && dest.length == 0 && !dest.has_quoted_part
4125 /* Treat newline as a command separator. */
4126 done_pipe(&ctx, PIPE_SEQ);
4127 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4129 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4134 dest.o_assignment = MAYBE_ASSIGNMENT;
4136 /* note: if (is_blank) continue;
4137 * will still trigger for us */
4141 /* "cmd}" or "cmd }..." without semicolon or &:
4142 * } is an ordinary char in this case, even inside { cmd; }
4143 * Pathological example: { ""}; } should exec "}" cmd
4146 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4147 || dest.length != 0 /* word} */
4148 || dest.has_quoted_part /* ""} */
4152 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4153 goto skip_end_trigger;
4154 /* else: } does terminate a group */
4157 if (end_trigger && end_trigger == ch
4158 && (ch != ';' || heredoc_cnt == 0)
4159 #if ENABLE_HUSH_CASE
4161 || ctx.ctx_res_w != RES_MATCH
4162 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4167 /* This is technically valid:
4168 * { cat <<HERE; }; echo Ok
4172 * but we don't support this.
4173 * We require heredoc to be in enclosing {}/(),
4176 syntax_error_unterm_str("here document");
4179 if (done_word(&dest, &ctx)) {
4182 done_pipe(&ctx, PIPE_SEQ);
4183 dest.o_assignment = MAYBE_ASSIGNMENT;
4184 /* Do we sit outside of any if's, loops or case's? */
4186 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4190 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4192 *pstring = ctx.as_string.data;
4194 o_free_unsafe(&ctx.as_string);
4197 debug_printf_parse("parse_stream return %p: "
4198 "end_trigger char found\n",
4200 return ctx.list_head;
4207 /* Catch <, > before deciding whether this word is
4208 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4211 redir_fd = redirect_opt_num(&dest);
4212 if (done_word(&dest, &ctx)) {
4215 redir_style = REDIRECT_OVERWRITE;
4217 redir_style = REDIRECT_APPEND;
4218 ch = i_getch(input);
4219 nommu_addchr(&ctx.as_string, ch);
4222 else if (next == '(') {
4223 syntax_error(">(process) not supported");
4227 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4229 continue; /* back to top of while (1) */
4231 redir_fd = redirect_opt_num(&dest);
4232 if (done_word(&dest, &ctx)) {
4235 redir_style = REDIRECT_INPUT;
4237 redir_style = REDIRECT_HEREDOC;
4239 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4240 ch = i_getch(input);
4241 nommu_addchr(&ctx.as_string, ch);
4242 } else if (next == '>') {
4243 redir_style = REDIRECT_IO;
4244 ch = i_getch(input);
4245 nommu_addchr(&ctx.as_string, ch);
4248 else if (next == '(') {
4249 syntax_error("<(process) not supported");
4253 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4255 continue; /* back to top of while (1) */
4257 if (dest.length == 0 && !dest.has_quoted_part) {
4258 /* skip "#comment" */
4261 if (ch == EOF || ch == '\n')
4264 /* note: we do not add it to &ctx.as_string */
4266 nommu_addchr(&ctx.as_string, '\n');
4267 continue; /* back to top of while (1) */
4272 /* It's "\<newline>" */
4274 /* Remove trailing '\' from ctx.as_string */
4275 ctx.as_string.data[--ctx.as_string.length] = '\0';
4277 ch = i_getch(input); /* eat it */
4278 continue; /* back to top of while (1) */
4283 if (dest.o_assignment == MAYBE_ASSIGNMENT
4284 /* check that we are not in word in "a=1 2>word b=1": */
4285 && !ctx.pending_redirect
4287 /* ch is a special char and thus this word
4288 * cannot be an assignment */
4289 dest.o_assignment = NOT_ASSIGNMENT;
4292 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4295 case '#': /* non-comment #: "echo a#b" etc */
4296 o_addQchr(&dest, ch);
4300 syntax_error("\\<eof>");
4303 ch = i_getch(input);
4304 /* note: ch != '\n' (that case does not reach this place) */
4305 o_addchr(&dest, '\\');
4306 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4307 o_addchr(&dest, ch);
4308 nommu_addchr(&ctx.as_string, ch);
4309 /* Example: echo Hello \2>file
4310 * we need to know that word 2 is quoted */
4311 dest.has_quoted_part = 1;
4314 if (parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0) != 0) {
4315 debug_printf_parse("parse_stream parse error: "
4316 "parse_dollar returned non-0\n");
4321 dest.has_quoted_part = 1;
4323 ch = i_getch(input);
4325 syntax_error_unterm_ch('\'');
4326 /*xfunc_die(); - redundant */
4328 nommu_addchr(&ctx.as_string, ch);
4331 o_addqchr(&dest, ch);
4335 dest.has_quoted_part = 1;
4336 if (dest.o_assignment == NOT_ASSIGNMENT)
4337 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4338 if (encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4340 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4342 #if ENABLE_HUSH_TICK
4346 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4347 o_addchr(&dest, '`');
4349 add_till_backquote(&dest, input, /*in_dquote:*/ 0);
4351 o_addstr(&ctx.as_string, dest.data + pos);
4352 o_addchr(&ctx.as_string, '`');
4354 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4355 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4360 #if ENABLE_HUSH_CASE
4363 if (done_word(&dest, &ctx)) {
4366 done_pipe(&ctx, PIPE_SEQ);
4367 #if ENABLE_HUSH_CASE
4368 /* Eat multiple semicolons, detect
4369 * whether it means something special */
4374 ch = i_getch(input);
4375 nommu_addchr(&ctx.as_string, ch);
4376 if (ctx.ctx_res_w == RES_CASE_BODY) {
4377 ctx.ctx_dsemicolon = 1;
4378 ctx.ctx_res_w = RES_MATCH;
4384 /* We just finished a cmd. New one may start
4385 * with an assignment */
4386 dest.o_assignment = MAYBE_ASSIGNMENT;
4389 if (done_word(&dest, &ctx)) {
4393 ch = i_getch(input);
4394 nommu_addchr(&ctx.as_string, ch);
4395 done_pipe(&ctx, PIPE_AND);
4397 done_pipe(&ctx, PIPE_BG);
4401 if (done_word(&dest, &ctx)) {
4404 #if ENABLE_HUSH_CASE
4405 if (ctx.ctx_res_w == RES_MATCH)
4406 break; /* we are in case's "word | word)" */
4408 if (next == '|') { /* || */
4409 ch = i_getch(input);
4410 nommu_addchr(&ctx.as_string, ch);
4411 done_pipe(&ctx, PIPE_OR);
4413 /* we could pick up a file descriptor choice here
4414 * with redirect_opt_num(), but bash doesn't do it.
4415 * "echo foo 2| cat" yields "foo 2". */
4418 o_reset_to_empty_unquoted(&ctx.as_string);
4423 #if ENABLE_HUSH_CASE
4424 /* "case... in [(]word)..." - skip '(' */
4425 if (ctx.ctx_res_w == RES_MATCH
4426 && ctx.command->argv == NULL /* not (word|(... */
4427 && dest.length == 0 /* not word(... */
4428 && dest.has_quoted_part == 0 /* not ""(... */
4434 if (parse_group(&dest, &ctx, input, ch) != 0) {
4439 #if ENABLE_HUSH_CASE
4440 if (ctx.ctx_res_w == RES_MATCH)
4444 /* proper use of this character is caught by end_trigger:
4445 * if we see {, we call parse_group(..., end_trigger='}')
4446 * and it will match } earlier (not here). */
4447 syntax_error_unexpected_ch(ch);
4451 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4457 struct parse_context *pctx;
4458 IF_HAS_KEYWORDS(struct parse_context *p2;)
4460 /* Clean up allocated tree.
4461 * Sample for finding leaks on syntax error recovery path.
4462 * Run it from interactive shell, watch pmap `pidof hush`.
4463 * while if false; then false; fi; do break; fi
4464 * Samples to catch leaks at execution:
4465 * while if (true | {true;}); then echo ok; fi; do break; done
4466 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4470 /* Update pipe/command counts,
4471 * otherwise freeing may miss some */
4472 done_pipe(pctx, PIPE_SEQ);
4473 debug_printf_clean("freeing list %p from ctx %p\n",
4474 pctx->list_head, pctx);
4475 debug_print_tree(pctx->list_head, 0);
4476 free_pipe_list(pctx->list_head);
4477 debug_printf_clean("freed list %p\n", pctx->list_head);
4479 o_free_unsafe(&pctx->as_string);
4481 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4485 IF_HAS_KEYWORDS(pctx = p2;)
4486 } while (HAS_KEYWORDS && pctx);
4487 /* Free text, clear all dest fields */
4489 /* If we are not in top-level parse, we return,
4490 * our caller will propagate error.
4492 if (end_trigger != ';') {
4500 /* Discard cached input, force prompt */
4502 IF_HUSH_INTERACTIVE(input->promptme = 1;)
4508 /*** Execution routines ***/
4510 /* Expansion can recurse, need forward decls: */
4511 #if !ENABLE_HUSH_BASH_COMPAT
4512 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4513 #define expand_string_to_string(str, do_unbackslash) \
4514 expand_string_to_string(str)
4516 static char *expand_string_to_string(const char *str, int do_unbackslash);
4517 #if ENABLE_HUSH_TICK
4518 static int process_command_subs(o_string *dest, const char *s);
4521 /* expand_strvec_to_strvec() takes a list of strings, expands
4522 * all variable references within and returns a pointer to
4523 * a list of expanded strings, possibly with larger number
4524 * of strings. (Think VAR="a b"; echo $VAR).
4525 * This new list is allocated as a single malloc block.
4526 * NULL-terminated list of char* pointers is at the beginning of it,
4527 * followed by strings themselves.
4528 * Caller can deallocate entire list by single free(list). */
4530 /* A horde of its helpers come first: */
4532 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4534 while (--len >= 0) {
4537 #if ENABLE_HUSH_BRACE_EXPANSION
4538 if (c == '{' || c == '}') {
4539 /* { -> \{, } -> \} */
4541 /* And now we want to add { or } and continue:
4544 * luckily, just falling throught achieves this.
4550 /* \z -> \\\z; \<eol> -> \\<eol> */
4555 o_addchr(o, *str++);
4561 /* Store given string, finalizing the word and starting new one whenever
4562 * we encounter IFS char(s). This is used for expanding variable values.
4563 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4564 static int expand_on_ifs(o_string *output, int n, const char *str)
4567 int word_len = strcspn(str, G.ifs);
4569 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4570 o_addblock(output, str, word_len);
4572 /* Protect backslashes against globbing up :)
4573 * Example: "v='\*'; echo b$v" prints "b\*"
4574 * (and does not try to glob on "*")
4576 o_addblock_duplicate_backslash(output, str, word_len);
4577 /*/ Why can't we do it easier? */
4578 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4579 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4583 if (!*str) /* EOL - do not finalize word */
4585 o_addchr(output, '\0');
4586 debug_print_list("expand_on_ifs", output, n);
4587 n = o_save_ptr(output, n);
4588 str += strspn(str, G.ifs); /* skip ifs chars */
4590 debug_print_list("expand_on_ifs[1]", output, n);
4594 /* Helper to expand $((...)) and heredoc body. These act as if
4595 * they are in double quotes, with the exception that they are not :).
4596 * Just the rules are similar: "expand only $var and `cmd`"
4598 * Returns malloced string.
4599 * As an optimization, we return NULL if expansion is not needed.
4601 #if !ENABLE_HUSH_BASH_COMPAT
4602 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4603 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4604 encode_then_expand_string(str)
4606 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4609 struct in_str input;
4610 o_string dest = NULL_O_STRING;
4612 if (!strchr(str, '$')
4613 && !strchr(str, '\\')
4614 #if ENABLE_HUSH_TICK
4615 && !strchr(str, '`')
4621 /* We need to expand. Example:
4622 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4624 setup_string_in_str(&input, str);
4625 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4626 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4627 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4628 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4629 o_free_unsafe(&dest);
4633 #if ENABLE_SH_MATH_SUPPORT
4634 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4636 arith_state_t math_state;
4640 math_state.lookupvar = get_local_var_value;
4641 math_state.setvar = set_local_var_from_halves;
4642 //math_state.endofname = endofname;
4643 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4644 res = arith(&math_state, exp_str ? exp_str : arg);
4647 *errmsg_p = math_state.errmsg;
4648 if (math_state.errmsg)
4649 die_if_script(math_state.errmsg);
4654 #if ENABLE_HUSH_BASH_COMPAT
4655 /* ${var/[/]pattern[/repl]} helpers */
4656 static char *strstr_pattern(char *val, const char *pattern, int *size)
4659 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4660 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4667 /* Optimization: if "*pat" did not match the start of "string",
4668 * we know that "tring", "ring" etc will not match too:
4670 if (pattern[0] == '*')
4675 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4677 char *result = NULL;
4678 unsigned res_len = 0;
4679 unsigned repl_len = strlen(repl);
4683 char *s = strstr_pattern(val, pattern, &size);
4687 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4688 memcpy(result + res_len, val, s - val);
4690 strcpy(result + res_len, repl);
4691 res_len += repl_len;
4692 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4698 if (val[0] && result) {
4699 result = xrealloc(result, res_len + strlen(val) + 1);
4700 strcpy(result + res_len, val);
4701 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4703 debug_printf_varexp("result:'%s'\n", result);
4709 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4711 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4713 const char *val = NULL;
4714 char *to_be_freed = NULL;
4719 char exp_save = exp_save; /* for compiler */
4720 char *exp_saveptr; /* points to expansion operator */
4721 char *exp_word = exp_word; /* for compiler */
4724 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4726 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4728 first_char = arg[0] = arg0 & 0x7f;
4731 if (first_char == '#' /* ${#... */
4732 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4734 /* It must be length operator: ${#var} */
4738 /* Maybe handle parameter expansion */
4739 if (exp_saveptr /* if 2nd char is one of expansion operators */
4740 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4742 /* ${?:0}, ${#[:]%0} etc */
4743 exp_saveptr = var + 1;
4745 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4746 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4748 exp_op = exp_save = *exp_saveptr;
4750 exp_word = exp_saveptr + 1;
4751 if (exp_op == ':') {
4752 exp_op = *exp_word++;
4753 //TODO: try ${var:} and ${var:bogus} in non-bash config
4754 if (ENABLE_HUSH_BASH_COMPAT
4755 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4757 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4762 *exp_saveptr = '\0';
4763 } /* else: it's not an expansion op, but bare ${var} */
4766 /* Look up the variable in question */
4767 if (isdigit(var[0])) {
4768 /* parse_dollar should have vetted var for us */
4769 int n = xatoi_positive(var);
4770 if (n < G.global_argc)
4771 val = G.global_argv[n];
4772 /* else val remains NULL: $N with too big N */
4776 val = utoa(G.root_pid);
4778 case '!': /* bg pid */
4779 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4781 case '?': /* exitcode */
4782 val = utoa(G.last_exitcode);
4784 case '#': /* argc */
4785 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4788 val = get_local_var_value(var);
4792 /* Handle any expansions */
4793 if (exp_op == 'L') {
4794 debug_printf_expand("expand: length(%s)=", val);
4795 val = utoa(val ? strlen(val) : 0);
4796 debug_printf_expand("%s\n", val);
4797 } else if (exp_op) {
4798 if (exp_op == '%' || exp_op == '#') {
4799 /* Standard-mandated substring removal ops:
4800 * ${parameter%word} - remove smallest suffix pattern
4801 * ${parameter%%word} - remove largest suffix pattern
4802 * ${parameter#word} - remove smallest prefix pattern
4803 * ${parameter##word} - remove largest prefix pattern
4805 * Word is expanded to produce a glob pattern.
4806 * Then var's value is matched to it and matching part removed.
4808 if (val && val[0]) {
4812 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4813 if (exp_op == *exp_word) /* ## or %% */
4815 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4817 exp_word = exp_exp_word;
4818 /* HACK ALERT. We depend here on the fact that
4819 * G.global_argv and results of utoa and get_local_var_value
4820 * are actually in writable memory:
4821 * scan_and_match momentarily stores NULs there. */
4823 loc = scan_and_match(t, exp_word, scan_flags);
4824 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4825 // exp_op, t, exp_word, loc);
4827 if (loc) { /* match was found */
4828 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4829 val = loc; /* take right part */
4831 val = to_be_freed = xstrndup(val, loc - val); /* left */
4835 #if ENABLE_HUSH_BASH_COMPAT
4836 else if (exp_op == '/' || exp_op == '\\') {
4837 /* It's ${var/[/]pattern[/repl]} thing.
4838 * Note that in encoded form it has TWO parts:
4839 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4840 * and if // is used, it is encoded as \:
4841 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4843 /* Empty variable always gives nothing: */
4844 // "v=''; echo ${v/*/w}" prints "", not "w"
4845 if (val && val[0]) {
4846 /* pattern uses non-standard expansion.
4847 * repl should be unbackslashed and globbed
4848 * by the usual expansion rules:
4850 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4851 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4852 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4853 * v='a bz'; echo ${v/a*z/\z} prints "z"
4854 * (note that a*z _pattern_ is never globbed!)
4856 char *pattern, *repl, *t;
4857 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
4859 pattern = xstrdup(exp_word);
4860 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4861 *p++ = SPECIAL_VAR_SYMBOL;
4863 p = strchr(p, SPECIAL_VAR_SYMBOL);
4865 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
4866 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4867 /* HACK ALERT. We depend here on the fact that
4868 * G.global_argv and results of utoa and get_local_var_value
4869 * are actually in writable memory:
4870 * replace_pattern momentarily stores NULs there. */
4872 to_be_freed = replace_pattern(t,
4874 (repl ? repl : exp_word),
4876 if (to_be_freed) /* at least one replace happened */
4883 else if (exp_op == ':') {
4884 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4885 /* It's ${var:N[:M]} bashism.
4886 * Note that in encoded form it has TWO parts:
4887 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4892 beg = expand_and_evaluate_arith(exp_word, &errmsg);
4895 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4896 *p++ = SPECIAL_VAR_SYMBOL;
4898 p = strchr(p, SPECIAL_VAR_SYMBOL);
4900 len = expand_and_evaluate_arith(exp_word, &errmsg);
4903 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4904 if (len >= 0) { /* bash compat: len < 0 is illegal */
4905 if (beg < 0) /* bash compat */
4907 debug_printf_varexp("from val:'%s'\n", val);
4908 if (len == 0 || !val || beg >= strlen(val)) {
4912 /* Paranoia. What if user entered 9999999999999
4913 * which fits in arith_t but not int? */
4916 val = to_be_freed = xstrndup(val + beg, len);
4918 debug_printf_varexp("val:'%s'\n", val);
4922 die_if_script("malformed ${%s:...}", var);
4925 } else { /* one of "-=+?" */
4926 /* Standard-mandated substitution ops:
4927 * ${var?word} - indicate error if unset
4928 * If var is unset, word (or a message indicating it is unset
4929 * if word is null) is written to standard error
4930 * and the shell exits with a non-zero exit status.
4931 * Otherwise, the value of var is substituted.
4932 * ${var-word} - use default value
4933 * If var is unset, word is substituted.
4934 * ${var=word} - assign and use default value
4935 * If var is unset, word is assigned to var.
4936 * In all cases, final value of var is substituted.
4937 * ${var+word} - use alternative value
4938 * If var is unset, null is substituted.
4939 * Otherwise, word is substituted.
4941 * Word is subjected to tilde expansion, parameter expansion,
4942 * command substitution, and arithmetic expansion.
4943 * If word is not needed, it is not expanded.
4945 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4946 * but also treat null var as if it is unset.
4948 int use_word = (!val || ((exp_save == ':') && !val[0]));
4950 use_word = !use_word;
4951 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4952 (exp_save == ':') ? "true" : "false", use_word);
4954 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4956 exp_word = to_be_freed;
4957 if (exp_op == '?') {
4958 /* mimic bash message */
4959 die_if_script("%s: %s",
4961 exp_word[0] ? exp_word : "parameter null or not set"
4963 //TODO: how interactive bash aborts expansion mid-command?
4968 if (exp_op == '=') {
4969 /* ${var=[word]} or ${var:=[word]} */
4970 if (isdigit(var[0]) || var[0] == '#') {
4971 /* mimic bash message */
4972 die_if_script("$%s: cannot assign in this way", var);
4975 char *new_var = xasprintf("%s=%s", var, val);
4976 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4980 } /* one of "-=+?" */
4982 *exp_saveptr = exp_save;
4988 *to_be_freed_pp = to_be_freed;
4992 /* Expand all variable references in given string, adding words to list[]
4993 * at n, n+1,... positions. Return updated n (so that list[n] is next one
4994 * to be filled). This routine is extremely tricky: has to deal with
4995 * variables/parameters with whitespace, $* and $@, and constructs like
4996 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
4997 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
4999 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5000 * expansion of right-hand side of assignment == 1-element expand.
5002 char cant_be_null = 0; /* only bit 0x80 matters */
5005 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5006 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5007 debug_print_list("expand_vars_to_list", output, n);
5008 n = o_save_ptr(output, n);
5009 debug_print_list("expand_vars_to_list[0]", output, n);
5011 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5013 char *to_be_freed = NULL;
5014 const char *val = NULL;
5015 #if ENABLE_HUSH_TICK
5016 o_string subst_result = NULL_O_STRING;
5018 #if ENABLE_SH_MATH_SUPPORT
5019 char arith_buf[sizeof(arith_t)*3 + 2];
5021 o_addblock(output, arg, p - arg);
5022 debug_print_list("expand_vars_to_list[1]", output, n);
5024 p = strchr(p, SPECIAL_VAR_SYMBOL);
5026 /* Fetch special var name (if it is indeed one of them)
5027 * and quote bit, force the bit on if singleword expansion -
5028 * important for not getting v=$@ expand to many words. */
5029 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5031 /* Is this variable quoted and thus expansion can't be null?
5032 * "$@" is special. Even if quoted, it can still
5033 * expand to nothing (not even an empty string),
5034 * thus it is excluded. */
5035 if ((first_ch & 0x7f) != '@')
5036 cant_be_null |= first_ch;
5038 switch (first_ch & 0x7f) {
5039 /* Highest bit in first_ch indicates that var is double-quoted */
5043 if (!G.global_argv[1])
5046 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5047 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5048 while (G.global_argv[i]) {
5049 n = expand_on_ifs(output, n, G.global_argv[i]);
5050 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5051 if (G.global_argv[i++][0] && G.global_argv[i]) {
5052 /* this argv[] is not empty and not last:
5053 * put terminating NUL, start new word */
5054 o_addchr(output, '\0');
5055 debug_print_list("expand_vars_to_list[2]", output, n);
5056 n = o_save_ptr(output, n);
5057 debug_print_list("expand_vars_to_list[3]", output, n);
5061 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5062 * and in this case should treat it like '$*' - see 'else...' below */
5063 if (first_ch == ('@'|0x80) /* quoted $@ */
5064 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5067 o_addQstr(output, G.global_argv[i]);
5068 if (++i >= G.global_argc)
5070 o_addchr(output, '\0');
5071 debug_print_list("expand_vars_to_list[4]", output, n);
5072 n = o_save_ptr(output, n);
5074 } else { /* quoted $* (or v="$@" case): add as one word */
5076 o_addQstr(output, G.global_argv[i]);
5077 if (!G.global_argv[++i])
5080 o_addchr(output, G.ifs[0]);
5085 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5086 /* "Empty variable", used to make "" etc to not disappear */
5088 cant_be_null = 0x80;
5090 #if ENABLE_HUSH_TICK
5091 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5092 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5094 /* Can't just stuff it into output o_string,
5095 * expanded result may need to be globbed
5096 * and $IFS-splitted */
5097 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5098 G.last_exitcode = process_command_subs(&subst_result, arg);
5099 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5100 val = subst_result.data;
5103 #if ENABLE_SH_MATH_SUPPORT
5104 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5107 arg++; /* skip '+' */
5108 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5109 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5110 res = expand_and_evaluate_arith(arg, NULL);
5111 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5112 sprintf(arith_buf, ARITH_FMT, res);
5118 val = expand_one_var(&to_be_freed, arg, &p);
5119 IF_HUSH_TICK(store_val:)
5120 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5121 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5122 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5123 if (val && val[0]) {
5124 n = expand_on_ifs(output, n, val);
5127 } else { /* quoted $VAR, val will be appended below */
5128 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5129 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5133 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5135 if (val && val[0]) {
5136 o_addQstr(output, val);
5140 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5141 * Do the check to avoid writing to a const string. */
5142 if (*p != SPECIAL_VAR_SYMBOL)
5143 *p = SPECIAL_VAR_SYMBOL;
5145 #if ENABLE_HUSH_TICK
5146 o_free(&subst_result);
5149 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5152 debug_print_list("expand_vars_to_list[a]", output, n);
5153 /* this part is literal, and it was already pre-quoted
5154 * if needed (much earlier), do not use o_addQstr here! */
5155 o_addstr_with_NUL(output, arg);
5156 debug_print_list("expand_vars_to_list[b]", output, n);
5157 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5158 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5161 /* allow to reuse list[n] later without re-growth */
5162 output->has_empty_slot = 1;
5164 o_addchr(output, '\0');
5170 static char **expand_variables(char **argv, unsigned expflags)
5174 o_string output = NULL_O_STRING;
5176 output.o_expflags = expflags;
5180 n = expand_vars_to_list(&output, n, *argv);
5183 debug_print_list("expand_variables", &output, n);
5185 /* output.data (malloced in one block) gets returned in "list" */
5186 list = o_finalize_list(&output, n);
5187 debug_print_strings("expand_variables[1]", list);
5191 static char **expand_strvec_to_strvec(char **argv)
5193 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5196 #if ENABLE_HUSH_BASH_COMPAT
5197 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5199 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5203 /* Used for expansion of right hand of assignments,
5204 * $((...)), heredocs, variable espansion parts.
5206 * NB: should NOT do globbing!
5207 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5209 static char *expand_string_to_string(const char *str, int do_unbackslash)
5211 #if !ENABLE_HUSH_BASH_COMPAT
5212 const int do_unbackslash = 1;
5214 char *argv[2], **list;
5216 debug_printf_expand("string_to_string<='%s'\n", str);
5217 /* This is generally an optimization, but it also
5218 * handles "", which otherwise trips over !list[0] check below.
5219 * (is this ever happens that we actually get str="" here?)
5221 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5222 //TODO: Can use on strings with \ too, just unbackslash() them?
5223 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5224 return xstrdup(str);
5227 argv[0] = (char*)str;
5229 list = expand_variables(argv, do_unbackslash
5230 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5231 : EXP_FLAG_SINGLEWORD
5234 if (!list[0] || list[1])
5235 bb_error_msg_and_die("BUG in varexp2");
5236 /* actually, just move string 2*sizeof(char*) bytes back */
5237 overlapping_strcpy((char*)list, list[0]);
5239 unbackslash((char*)list);
5240 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5244 /* Used for "eval" builtin */
5245 static char* expand_strvec_to_string(char **argv)
5249 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5250 /* Convert all NULs to spaces */
5255 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5256 bb_error_msg_and_die("BUG in varexp3");
5257 /* bash uses ' ' regardless of $IFS contents */
5262 overlapping_strcpy((char*)list, list[0]);
5263 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5267 static char **expand_assignments(char **argv, int count)
5272 G.expanded_assignments = p = NULL;
5273 /* Expand assignments into one string each */
5274 for (i = 0; i < count; i++) {
5275 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5277 G.expanded_assignments = NULL;
5284 void re_execute_shell(char ***to_free, const char *s,
5285 char *g_argv0, char **g_argv,
5286 char **builtin_argv) NORETURN;
5288 static void reset_traps_to_defaults(void)
5290 /* This function is always called in a child shell
5291 * after fork (not vfork, NOMMU doesn't use this function).
5296 /* Child shells are not interactive.
5297 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5298 * Testcase: (while :; do :; done) + ^Z should background.
5299 * Same goes for SIGTERM, SIGHUP, SIGINT.
5301 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5302 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5304 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5305 * Stupid. It can be done with *single* &= op, but we can't use
5306 * the fact that G.blocked_set is implemented as a bitmask
5308 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5312 /* Careful. Only if no trap or trap is not "" */
5313 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5314 sigdelset(&G.blocked_set, sig);
5321 /* Our homegrown sig mask is saner to work with :) */
5322 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5324 /* Resetting all traps to default except empty ones */
5325 mask = G.non_DFL_mask;
5326 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5327 if (!G.traps[sig] || !G.traps[sig][0])
5330 G.traps[sig] = NULL;
5331 /* There is no signal for 0 (EXIT) */
5334 /* There was a trap handler, we just removed it.
5335 * But if sig still has non-DFL handling,
5336 * we should not unblock the sig. */
5339 sigdelset(&G.blocked_set, sig);
5341 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5346 static void re_execute_shell(char ***to_free, const char *s,
5347 char *g_argv0, char **g_argv,
5348 char **builtin_argv) NORETURN;
5349 static void re_execute_shell(char ***to_free, const char *s,
5350 char *g_argv0, char **g_argv,
5351 char **builtin_argv)
5353 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5354 /* delims + 2 * (number of bytes in printed hex numbers) */
5355 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5356 char *heredoc_argv[4];
5357 struct variable *cur;
5358 # if ENABLE_HUSH_FUNCTIONS
5359 struct function *funcp;
5363 unsigned long long empty_trap_mask;
5365 if (!g_argv0) { /* heredoc */
5366 argv = heredoc_argv;
5367 argv[0] = (char *) G.argv0_for_re_execing;
5368 argv[1] = (char *) "-<";
5369 argv[2] = (char *) s;
5371 pp = &argv[3]; /* used as pointer to empty environment */
5377 if (pp) while (*pp++)
5380 empty_trap_mask = 0;
5383 for (sig = 1; sig < NSIG; sig++) {
5384 if (G.traps[sig] && !G.traps[sig][0])
5385 empty_trap_mask |= 1LL << sig;
5389 sprintf(param_buf, NOMMU_HACK_FMT
5390 , (unsigned) G.root_pid
5391 , (unsigned) G.root_ppid
5392 , (unsigned) G.last_bg_pid
5393 , (unsigned) G.last_exitcode
5396 IF_HUSH_LOOPS(, G.depth_of_loop)
5398 # undef NOMMU_HACK_FMT
5399 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5400 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5403 for (cur = G.top_var; cur; cur = cur->next) {
5404 if (!cur->flg_export || cur->flg_read_only)
5407 # if ENABLE_HUSH_FUNCTIONS
5408 for (funcp = G.top_func; funcp; funcp = funcp->next)
5414 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5415 *pp++ = (char *) G.argv0_for_re_execing;
5417 for (cur = G.top_var; cur; cur = cur->next) {
5418 if (strcmp(cur->varstr, hush_version_str) == 0)
5420 if (cur->flg_read_only) {
5421 *pp++ = (char *) "-R";
5422 *pp++ = cur->varstr;
5423 } else if (!cur->flg_export) {
5424 *pp++ = (char *) "-V";
5425 *pp++ = cur->varstr;
5428 # if ENABLE_HUSH_FUNCTIONS
5429 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5430 *pp++ = (char *) "-F";
5431 *pp++ = funcp->name;
5432 *pp++ = funcp->body_as_string;
5435 /* We can pass activated traps here. Say, -Tnn:trap_string
5437 * However, POSIX says that subshells reset signals with traps
5439 * I tested bash-3.2 and it not only does that with true subshells
5440 * of the form ( list ), but with any forked children shells.
5441 * I set trap "echo W" WINCH; and then tried:
5443 * { echo 1; sleep 20; echo 2; } &
5444 * while true; do echo 1; sleep 20; echo 2; break; done &
5445 * true | { echo 1; sleep 20; echo 2; } | cat
5447 * In all these cases sending SIGWINCH to the child shell
5448 * did not run the trap. If I add trap "echo V" WINCH;
5449 * _inside_ group (just before echo 1), it works.
5451 * I conclude it means we don't need to pass active traps here.
5452 * Even if we would use signal handlers instead of signal masking
5453 * in order to implement trap handling,
5454 * exec syscall below resets signals to SIG_DFL for us.
5456 *pp++ = (char *) "-c";
5459 while (*++builtin_argv)
5460 *pp++ = *builtin_argv;
5461 *pp++ = (char *) "";
5466 /* *pp = NULL; - is already there */
5470 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5471 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5472 execve(bb_busybox_exec_path, argv, pp);
5473 /* Fallback. Useful for init=/bin/hush usage etc */
5474 if (argv[0][0] == '/')
5475 execve(argv[0], argv, pp);
5476 xfunc_error_retval = 127;
5477 bb_error_msg_and_die("can't re-execute the shell");
5479 #endif /* !BB_MMU */
5482 static int run_and_free_list(struct pipe *pi);
5484 /* Executing from string: eval, sh -c '...'
5485 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5486 * end_trigger controls how often we stop parsing
5487 * NUL: parse all, execute, return
5488 * ';': parse till ';' or newline, execute, repeat till EOF
5490 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5492 /* Why we need empty flag?
5493 * An obscure corner case "false; ``; echo $?":
5494 * empty command in `` should still set $? to 0.
5495 * But we can't just set $? to 0 at the start,
5496 * this breaks "false; echo `echo $?`" case.
5500 struct pipe *pipe_list;
5502 pipe_list = parse_stream(NULL, inp, end_trigger);
5503 if (!pipe_list) { /* EOF */
5505 G.last_exitcode = 0;
5508 debug_print_tree(pipe_list, 0);
5509 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5510 run_and_free_list(pipe_list);
5515 static void parse_and_run_string(const char *s)
5517 struct in_str input;
5518 setup_string_in_str(&input, s);
5519 parse_and_run_stream(&input, '\0');
5522 static void parse_and_run_file(FILE *f)
5524 struct in_str input;
5525 setup_file_in_str(&input, f);
5526 parse_and_run_stream(&input, ';');
5529 #if ENABLE_HUSH_TICK
5530 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5535 char **to_free = NULL;
5539 pid = BB_MMU ? xfork() : xvfork();
5540 if (pid == 0) { /* child */
5541 disable_restore_tty_pgrp_on_exit();
5542 /* Process substitution is not considered to be usual
5543 * 'command execution'.
5544 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5551 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5552 close(channel[0]); /* NB: close _first_, then move fd! */
5553 xmove_fd(channel[1], 1);
5554 /* Prevent it from trying to handle ctrl-z etc */
5555 IF_HUSH_JOB(G.run_list_level = 1;)
5556 /* Awful hack for `trap` or $(trap).
5558 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5559 * contains an example where "trap" is executed in a subshell:
5561 * save_traps=$(trap)
5563 * eval "$save_traps"
5565 * Standard does not say that "trap" in subshell shall print
5566 * parent shell's traps. It only says that its output
5567 * must have suitable form, but then, in the above example
5568 * (which is not supposed to be normative), it implies that.
5570 * bash (and probably other shell) does implement it
5571 * (traps are reset to defaults, but "trap" still shows them),
5572 * but as a result, "trap" logic is hopelessly messed up:
5575 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5576 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5577 * # true | trap <--- trap is in subshell - no output (ditto)
5578 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5579 * trap -- 'echo Ho' SIGWINCH
5580 * # echo `(trap)` <--- in subshell in subshell - output
5581 * trap -- 'echo Ho' SIGWINCH
5582 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5583 * trap -- 'echo Ho' SIGWINCH
5585 * The rules when to forget and when to not forget traps
5586 * get really complex and nonsensical.
5588 * Our solution: ONLY bare $(trap) or `trap` is special.
5590 s = skip_whitespace(s);
5591 if (strncmp(s, "trap", 4) == 0
5592 && skip_whitespace(s + 4)[0] == '\0'
5594 static const char *const argv[] = { NULL, NULL };
5595 builtin_trap((char**)argv);
5596 exit(0); /* not _exit() - we need to fflush */
5599 reset_traps_to_defaults();
5600 parse_and_run_string(s);
5601 _exit(G.last_exitcode);
5603 /* We re-execute after vfork on NOMMU. This makes this script safe:
5604 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5605 * huge=`cat BIG` # was blocking here forever
5608 re_execute_shell(&to_free,
5618 # if ENABLE_HUSH_FAST
5620 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5621 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5622 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5624 enable_restore_tty_pgrp_on_exit();
5629 close_on_exec_on(channel[0]);
5630 return xfdopen_for_read(channel[0]);
5633 /* Return code is exit status of the process that is run. */
5634 static int process_command_subs(o_string *dest, const char *s)
5637 struct in_str pipe_str;
5639 int status, ch, eol_cnt;
5641 fp = generate_stream_from_string(s, &pid);
5643 /* Now send results of command back into original context */
5644 setup_file_in_str(&pipe_str, fp);
5646 while ((ch = i_getch(&pipe_str)) != EOF) {
5652 o_addchr(dest, '\n');
5655 o_addQchr(dest, ch);
5658 debug_printf("done reading from `cmd` pipe, closing it\n");
5660 /* We need to extract exitcode. Test case
5661 * "true; echo `sleep 1; false` $?"
5663 safe_waitpid(pid, &status, 0);
5664 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5665 return WEXITSTATUS(status);
5667 #endif /* ENABLE_HUSH_TICK */
5670 static void setup_heredoc(struct redir_struct *redir)
5672 struct fd_pair pair;
5675 /* the _body_ of heredoc (misleading field name) */
5676 const char *heredoc = redir->rd_filename;
5683 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5684 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5688 len = strlen(heredoc);
5690 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5692 xmove_fd(pair.rd, redir->rd_fd);
5694 /* Try writing without forking. Newer kernels have
5695 * dynamically growing pipes. Must use non-blocking write! */
5698 written = write(pair.wr, heredoc, len);
5709 ndelay_off(pair.wr);
5711 /* Okay, pipe buffer was not big enough */
5712 /* Note: we must not create a stray child (bastard? :)
5713 * for the unsuspecting parent process. Child creates a grandchild
5714 * and exits before parent execs the process which consumes heredoc
5715 * (that exec happens after we return from this function) */
5722 disable_restore_tty_pgrp_on_exit();
5723 pid = BB_MMU ? xfork() : xvfork();
5727 close(redir->rd_fd); /* read side of the pipe */
5729 full_write(pair.wr, heredoc, len); /* may loop or block */
5732 /* Delegate blocking writes to another process */
5733 xmove_fd(pair.wr, STDOUT_FILENO);
5734 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5738 #if ENABLE_HUSH_FAST
5740 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5742 enable_restore_tty_pgrp_on_exit();
5748 wait(NULL); /* wait till child has died */
5751 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5752 * and stderr if they are redirected. */
5753 static int setup_redirects(struct command *prog, int squirrel[])
5756 struct redir_struct *redir;
5758 for (redir = prog->redirects; redir; redir = redir->next) {
5759 if (redir->rd_type == REDIRECT_HEREDOC2) {
5760 /* rd_fd<<HERE case */
5761 if (squirrel && redir->rd_fd < 3
5762 && squirrel[redir->rd_fd] < 0
5764 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5766 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5768 debug_printf_parse("set heredoc '%s'\n",
5769 redir->rd_filename);
5770 setup_heredoc(redir);
5774 if (redir->rd_dup == REDIRFD_TO_FILE) {
5775 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5777 if (redir->rd_filename == NULL) {
5778 /* Something went wrong in the parse.
5779 * Pretend it didn't happen */
5780 bb_error_msg("bug in redirect parse");
5783 mode = redir_table[redir->rd_type].mode;
5784 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
5785 openfd = open_or_warn(p, mode);
5788 /* this could get lost if stderr has been redirected, but
5789 * bash and ash both lose it as well (though zsh doesn't!) */
5790 //what the above comment tries to say?
5794 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5795 openfd = redir->rd_dup;
5798 if (openfd != redir->rd_fd) {
5799 if (squirrel && redir->rd_fd < 3
5800 && squirrel[redir->rd_fd] < 0
5802 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5804 if (openfd == REDIRFD_CLOSE) {
5805 /* "n>-" means "close me" */
5806 close(redir->rd_fd);
5808 xdup2(openfd, redir->rd_fd);
5809 if (redir->rd_dup == REDIRFD_TO_FILE)
5817 static void restore_redirects(int squirrel[])
5820 for (i = 0; i < 3; i++) {
5823 /* We simply die on error */
5829 static char *find_in_path(const char *arg)
5832 const char *PATH = get_local_var_value("PATH");
5838 const char *end = strchrnul(PATH, ':');
5839 int sz = end - PATH; /* must be int! */
5843 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5845 /* We have xxx::yyyy in $PATH,
5846 * it means "use current dir" */
5849 if (access(ret, F_OK) == 0)
5862 static const struct built_in_command *find_builtin_helper(const char *name,
5863 const struct built_in_command *x,
5864 const struct built_in_command *end)
5867 if (strcmp(name, x->b_cmd) != 0) {
5871 debug_printf_exec("found builtin '%s'\n", name);
5876 static const struct built_in_command *find_builtin1(const char *name)
5878 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5880 static const struct built_in_command *find_builtin(const char *name)
5882 const struct built_in_command *x = find_builtin1(name);
5885 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5888 #if ENABLE_HUSH_FUNCTIONS
5889 static struct function **find_function_slot(const char *name)
5891 struct function **funcpp = &G.top_func;
5893 if (strcmp(name, (*funcpp)->name) == 0) {
5896 funcpp = &(*funcpp)->next;
5901 static const struct function *find_function(const char *name)
5903 const struct function *funcp = *find_function_slot(name);
5905 debug_printf_exec("found function '%s'\n", name);
5909 /* Note: takes ownership on name ptr */
5910 static struct function *new_function(char *name)
5912 struct function **funcpp = find_function_slot(name);
5913 struct function *funcp = *funcpp;
5915 if (funcp != NULL) {
5916 struct command *cmd = funcp->parent_cmd;
5917 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5919 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5921 /* Note: if !funcp->body, do not free body_as_string!
5922 * This is a special case of "-F name body" function:
5923 * body_as_string was not malloced! */
5925 free_pipe_list(funcp->body);
5927 free(funcp->body_as_string);
5931 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5932 cmd->argv[0] = funcp->name;
5933 cmd->group = funcp->body;
5935 cmd->group_as_string = funcp->body_as_string;
5939 debug_printf_exec("remembering new function '%s'\n", name);
5940 funcp = *funcpp = xzalloc(sizeof(*funcp));
5941 /*funcp->next = NULL;*/
5948 static void unset_func(const char *name)
5950 struct function **funcpp = find_function_slot(name);
5951 struct function *funcp = *funcpp;
5953 if (funcp != NULL) {
5954 debug_printf_exec("freeing function '%s'\n", funcp->name);
5955 *funcpp = funcp->next;
5956 /* funcp is unlinked now, deleting it.
5957 * Note: if !funcp->body, the function was created by
5958 * "-F name body", do not free ->body_as_string
5959 * and ->name as they were not malloced. */
5961 free_pipe_list(funcp->body);
5964 free(funcp->body_as_string);
5972 #define exec_function(to_free, funcp, argv) \
5973 exec_function(funcp, argv)
5975 static void exec_function(char ***to_free,
5976 const struct function *funcp,
5977 char **argv) NORETURN;
5978 static void exec_function(char ***to_free,
5979 const struct function *funcp,
5985 argv[0] = G.global_argv[0];
5986 G.global_argv = argv;
5990 /* On MMU, funcp->body is always non-NULL */
5991 n = run_list(funcp->body);
5995 re_execute_shell(to_free,
5996 funcp->body_as_string,
6003 static int run_function(const struct function *funcp, char **argv)
6009 save_and_replace_G_args(&sv, argv);
6011 /* "we are in function, ok to use return" */
6012 sv_flg = G.flag_return_in_progress;
6013 G.flag_return_in_progress = -1;
6014 # if ENABLE_HUSH_LOCAL
6015 G.func_nest_level++;
6018 /* On MMU, funcp->body is always non-NULL */
6021 /* Function defined by -F */
6022 parse_and_run_string(funcp->body_as_string);
6023 rc = G.last_exitcode;
6027 rc = run_list(funcp->body);
6030 # if ENABLE_HUSH_LOCAL
6032 struct variable *var;
6033 struct variable **var_pp;
6035 var_pp = &G.top_var;
6036 while ((var = *var_pp) != NULL) {
6037 if (var->func_nest_level < G.func_nest_level) {
6038 var_pp = &var->next;
6042 if (var->flg_export)
6043 bb_unsetenv(var->varstr);
6044 /* Remove from global list */
6045 *var_pp = var->next;
6051 G.func_nest_level--;
6054 G.flag_return_in_progress = sv_flg;
6056 restore_G_args(&sv, argv);
6060 #endif /* ENABLE_HUSH_FUNCTIONS */
6064 #define exec_builtin(to_free, x, argv) \
6065 exec_builtin(x, argv)
6067 #define exec_builtin(to_free, x, argv) \
6068 exec_builtin(to_free, argv)
6070 static void exec_builtin(char ***to_free,
6071 const struct built_in_command *x,
6072 char **argv) NORETURN;
6073 static void exec_builtin(char ***to_free,
6074 const struct built_in_command *x,
6078 int rcode = x->b_function(argv);
6082 /* On NOMMU, we must never block!
6083 * Example: { sleep 99 | read line; } & echo Ok
6085 re_execute_shell(to_free,
6094 static void execvp_or_die(char **argv) NORETURN;
6095 static void execvp_or_die(char **argv)
6097 debug_printf_exec("execing '%s'\n", argv[0]);
6098 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6099 execvp(argv[0], argv);
6100 bb_perror_msg("can't execute '%s'", argv[0]);
6101 _exit(127); /* bash compat */
6104 #if ENABLE_HUSH_MODE_X
6105 static void dump_cmd_in_x_mode(char **argv)
6107 if (G_x_mode && argv) {
6108 /* We want to output the line in one write op */
6116 len += strlen(argv[n++]) + 1;
6122 p += sprintf(p, " %s", argv[n++]);
6130 # define dump_cmd_in_x_mode(argv) ((void)0)
6134 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6135 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6136 #define pseudo_exec(nommu_save, command, argv_expanded) \
6137 pseudo_exec(command, argv_expanded)
6140 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6142 * Don't exit() here. If you don't exec, use _exit instead.
6143 * The at_exit handlers apparently confuse the calling process,
6144 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6145 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6146 char **argv, int assignment_cnt,
6147 char **argv_expanded) NORETURN;
6148 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6149 char **argv, int assignment_cnt,
6150 char **argv_expanded)
6154 new_env = expand_assignments(argv, assignment_cnt);
6155 dump_cmd_in_x_mode(new_env);
6157 if (!argv[assignment_cnt]) {
6158 /* Case when we are here: ... | var=val | ...
6159 * (note that we do not exit early, i.e., do not optimize out
6160 * expand_assignments(): think about ... | var=`sleep 1` | ...
6162 free_strings(new_env);
6163 _exit(EXIT_SUCCESS);
6167 set_vars_and_save_old(new_env);
6168 free(new_env); /* optional */
6169 /* we can also destroy set_vars_and_save_old's return value,
6172 nommu_save->new_env = new_env;
6173 nommu_save->old_vars = set_vars_and_save_old(new_env);
6176 if (argv_expanded) {
6177 argv = argv_expanded;
6179 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6181 nommu_save->argv = argv;
6184 dump_cmd_in_x_mode(argv);
6186 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6187 if (strchr(argv[0], '/') != NULL)
6191 /* Check if the command matches any of the builtins.
6192 * Depending on context, this might be redundant. But it's
6193 * easier to waste a few CPU cycles than it is to figure out
6194 * if this is one of those cases.
6197 /* On NOMMU, it is more expensive to re-execute shell
6198 * just in order to run echo or test builtin.
6199 * It's better to skip it here and run corresponding
6200 * non-builtin later. */
6201 const struct built_in_command *x;
6202 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6204 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6207 #if ENABLE_HUSH_FUNCTIONS
6208 /* Check if the command matches any functions */
6210 const struct function *funcp = find_function(argv[0]);
6212 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6217 #if ENABLE_FEATURE_SH_STANDALONE
6218 /* Check if the command matches any busybox applets */
6220 int a = find_applet_by_name(argv[0]);
6222 # if BB_MMU /* see above why on NOMMU it is not allowed */
6223 if (APPLET_IS_NOEXEC(a)) {
6224 debug_printf_exec("running applet '%s'\n", argv[0]);
6225 run_applet_no_and_exit(a, argv);
6228 /* Re-exec ourselves */
6229 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6230 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6231 execv(bb_busybox_exec_path, argv);
6232 /* If they called chroot or otherwise made the binary no longer
6233 * executable, fall through */
6238 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6241 execvp_or_die(argv);
6244 /* Called after [v]fork() in run_pipe
6246 static void pseudo_exec(nommu_save_t *nommu_save,
6247 struct command *command,
6248 char **argv_expanded) NORETURN;
6249 static void pseudo_exec(nommu_save_t *nommu_save,
6250 struct command *command,
6251 char **argv_expanded)
6253 if (command->argv) {
6254 pseudo_exec_argv(nommu_save, command->argv,
6255 command->assignment_cnt, argv_expanded);
6258 if (command->group) {
6259 /* Cases when we are here:
6262 * ... | ( list ) | ...
6263 * ... | { list } | ...
6267 debug_printf_exec("pseudo_exec: run_list\n");
6268 reset_traps_to_defaults();
6269 rcode = run_list(command->group);
6270 /* OK to leak memory by not calling free_pipe_list,
6271 * since this process is about to exit */
6274 re_execute_shell(&nommu_save->argv_from_re_execing,
6275 command->group_as_string,
6282 /* Case when we are here: ... | >file */
6283 debug_printf_exec("pseudo_exec'ed null command\n");
6284 _exit(EXIT_SUCCESS);
6288 static const char *get_cmdtext(struct pipe *pi)
6294 /* This is subtle. ->cmdtext is created only on first backgrounding.
6295 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6296 * On subsequent bg argv is trashed, but we won't use it */
6299 argv = pi->cmds[0].argv;
6300 if (!argv || !argv[0]) {
6301 pi->cmdtext = xzalloc(1);
6307 len += strlen(*argv) + 1;
6311 argv = pi->cmds[0].argv;
6313 len = strlen(*argv);
6314 memcpy(p, *argv, len);
6322 static void insert_bg_job(struct pipe *pi)
6324 struct pipe *job, **jobp;
6327 /* Linear search for the ID of the job to use */
6329 for (job = G.job_list; job; job = job->next)
6330 if (job->jobid >= pi->jobid)
6331 pi->jobid = job->jobid + 1;
6333 /* Add job to the list of running jobs */
6335 while ((job = *jobp) != NULL)
6337 job = *jobp = xmalloc(sizeof(*job));
6339 *job = *pi; /* physical copy */
6341 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6342 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6343 for (i = 0; i < pi->num_cmds; i++) {
6344 job->cmds[i].pid = pi->cmds[i].pid;
6345 /* all other fields are not used and stay zero */
6347 job->cmdtext = xstrdup(get_cmdtext(pi));
6349 if (G_interactive_fd)
6350 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6351 G.last_jobid = job->jobid;
6354 static void remove_bg_job(struct pipe *pi)
6356 struct pipe *prev_pipe;
6358 if (pi == G.job_list) {
6359 G.job_list = pi->next;
6361 prev_pipe = G.job_list;
6362 while (prev_pipe->next != pi)
6363 prev_pipe = prev_pipe->next;
6364 prev_pipe->next = pi->next;
6367 G.last_jobid = G.job_list->jobid;
6372 /* Remove a backgrounded job */
6373 static void delete_finished_bg_job(struct pipe *pi)
6380 /* Check to see if any processes have exited -- if they
6381 * have, figure out why and see if a job has completed */
6382 static int checkjobs(struct pipe *fg_pipe)
6392 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6394 attributes = WUNTRACED;
6395 if (fg_pipe == NULL)
6396 attributes |= WNOHANG;
6399 #if ENABLE_HUSH_FAST
6400 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6401 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6402 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6403 /* There was neither fork nor SIGCHLD since last waitpid */
6404 /* Avoid doing waitpid syscall if possible */
6405 if (!G.we_have_children) {
6409 if (fg_pipe == NULL) { /* is WNOHANG set? */
6410 /* We have children, but they did not exit
6411 * or stop yet (we saw no SIGCHLD) */
6414 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6418 /* Do we do this right?
6419 * bash-3.00# sleep 20 | false
6421 * [3]+ Stopped sleep 20 | false
6422 * bash-3.00# echo $?
6423 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6424 * [hush 1.14.0: yes we do it right]
6431 #if ENABLE_HUSH_FAST
6432 i = G.count_SIGCHLD;
6434 childpid = waitpid(-1, &status, attributes);
6435 if (childpid <= 0) {
6436 if (childpid && errno != ECHILD)
6437 bb_perror_msg("waitpid");
6438 #if ENABLE_HUSH_FAST
6439 else { /* Until next SIGCHLD, waitpid's are useless */
6440 G.we_have_children = (childpid == 0);
6441 G.handled_SIGCHLD = i;
6442 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6447 dead = WIFEXITED(status) || WIFSIGNALED(status);
6450 if (WIFSTOPPED(status))
6451 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6452 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6453 if (WIFSIGNALED(status))
6454 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6455 childpid, WTERMSIG(status), WEXITSTATUS(status));
6456 if (WIFEXITED(status))
6457 debug_printf_jobs("pid %d exited, exitcode %d\n",
6458 childpid, WEXITSTATUS(status));
6460 /* Were we asked to wait for fg pipe? */
6462 i = fg_pipe->num_cmds;
6464 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6465 if (fg_pipe->cmds[i].pid != childpid)
6469 fg_pipe->cmds[i].pid = 0;
6470 fg_pipe->alive_cmds--;
6471 ex = WEXITSTATUS(status);
6472 /* bash prints killer signal's name for *last*
6473 * process in pipe (prints just newline for SIGINT).
6474 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6476 if (WIFSIGNALED(status)) {
6477 int sig = WTERMSIG(status);
6478 if (i == fg_pipe->num_cmds-1)
6479 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6480 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6481 * Maybe we need to use sig | 128? */
6484 fg_pipe->cmds[i].cmd_exitcode = ex;
6486 fg_pipe->cmds[i].is_stopped = 1;
6487 fg_pipe->stopped_cmds++;
6489 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6490 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6491 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6492 /* All processes in fg pipe have exited or stopped */
6493 i = fg_pipe->num_cmds;
6495 rcode = fg_pipe->cmds[i].cmd_exitcode;
6496 /* usually last process gives overall exitstatus,
6497 * but with "set -o pipefail", last *failed* process does */
6498 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6501 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6502 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6503 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6504 * and "killall -STOP cat" */
6505 if (G_interactive_fd) {
6507 if (fg_pipe->alive_cmds != 0)
6508 insert_bg_job(fg_pipe);
6512 if (fg_pipe->alive_cmds == 0)
6515 /* There are still running processes in the fg pipe */
6516 goto wait_more; /* do waitpid again */
6518 /* it wasnt fg_pipe, look for process in bg pipes */
6522 /* We asked to wait for bg or orphaned children */
6523 /* No need to remember exitcode in this case */
6524 for (pi = G.job_list; pi; pi = pi->next) {
6525 for (i = 0; i < pi->num_cmds; i++) {
6526 if (pi->cmds[i].pid == childpid)
6527 goto found_pi_and_prognum;
6530 /* Happens when shell is used as init process (init=/bin/sh) */
6531 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6532 continue; /* do waitpid again */
6534 found_pi_and_prognum:
6537 pi->cmds[i].pid = 0;
6539 if (!pi->alive_cmds) {
6540 if (G_interactive_fd)
6541 printf(JOB_STATUS_FORMAT, pi->jobid,
6542 "Done", pi->cmdtext);
6543 delete_finished_bg_job(pi);
6547 pi->cmds[i].is_stopped = 1;
6551 } /* while (waitpid succeeds)... */
6557 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6560 int rcode = checkjobs(fg_pipe);
6561 if (G_saved_tty_pgrp) {
6562 /* Job finished, move the shell to the foreground */
6563 p = getpgrp(); /* our process group id */
6564 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6565 tcsetpgrp(G_interactive_fd, p);
6571 /* Start all the jobs, but don't wait for anything to finish.
6574 * Return code is normally -1, when the caller has to wait for children
6575 * to finish to determine the exit status of the pipe. If the pipe
6576 * is a simple builtin command, however, the action is done by the
6577 * time run_pipe returns, and the exit code is provided as the
6580 * Returns -1 only if started some children. IOW: we have to
6581 * mask out retvals of builtins etc with 0xff!
6583 * The only case when we do not need to [v]fork is when the pipe
6584 * is single, non-backgrounded, non-subshell command. Examples:
6585 * cmd ; ... { list } ; ...
6586 * cmd && ... { list } && ...
6587 * cmd || ... { list } || ...
6588 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
6589 * or (if SH_STANDALONE) an applet, and we can run the { list }
6590 * with run_list. If it isn't one of these, we fork and exec cmd.
6592 * Cases when we must fork:
6593 * non-single: cmd | cmd
6594 * backgrounded: cmd & { list } &
6595 * subshell: ( list ) [&]
6597 #if !ENABLE_HUSH_MODE_X
6598 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6599 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6601 static int redirect_and_varexp_helper(char ***new_env_p,
6602 struct variable **old_vars_p,
6603 struct command *command,
6605 char **argv_expanded)
6607 /* setup_redirects acts on file descriptors, not FILEs.
6608 * This is perfect for work that comes after exec().
6609 * Is it really safe for inline use? Experimentally,
6610 * things seem to work. */
6611 int rcode = setup_redirects(command, squirrel);
6613 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6614 *new_env_p = new_env;
6615 dump_cmd_in_x_mode(new_env);
6616 dump_cmd_in_x_mode(argv_expanded);
6618 *old_vars_p = set_vars_and_save_old(new_env);
6622 static NOINLINE int run_pipe(struct pipe *pi)
6624 static const char *const null_ptr = NULL;
6628 struct command *command;
6629 char **argv_expanded;
6631 /* it is not always needed, but we aim to smaller code */
6632 int squirrel[] = { -1, -1, -1 };
6635 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6638 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6639 * Result should be 3 lines: q w e, qwe, q w e
6641 G.ifs = get_local_var_value("IFS");
6645 IF_HUSH_JOB(pi->pgrp = -1;)
6646 pi->stopped_cmds = 0;
6647 command = &pi->cmds[0];
6648 argv_expanded = NULL;
6650 if (pi->num_cmds != 1
6651 || pi->followup == PIPE_BG
6652 || command->cmd_type == CMD_SUBSHELL
6659 debug_printf_exec(": group:%p argv:'%s'\n",
6660 command->group, command->argv ? command->argv[0] : "NONE");
6662 if (command->group) {
6663 #if ENABLE_HUSH_FUNCTIONS
6664 if (command->cmd_type == CMD_FUNCDEF) {
6665 /* "executing" func () { list } */
6666 struct function *funcp;
6668 funcp = new_function(command->argv[0]);
6669 /* funcp->name is already set to argv[0] */
6670 funcp->body = command->group;
6672 funcp->body_as_string = command->group_as_string;
6673 command->group_as_string = NULL;
6675 command->group = NULL;
6676 command->argv[0] = NULL;
6677 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6678 funcp->parent_cmd = command;
6679 command->child_func = funcp;
6681 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6683 return EXIT_SUCCESS;
6687 debug_printf("non-subshell group\n");
6688 rcode = 1; /* exitcode if redir failed */
6689 if (setup_redirects(command, squirrel) == 0) {
6690 debug_printf_exec(": run_list\n");
6691 rcode = run_list(command->group) & 0xff;
6693 restore_redirects(squirrel);
6694 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6696 debug_printf_exec("run_pipe: return %d\n", rcode);
6700 argv = command->argv ? command->argv : (char **) &null_ptr;
6702 const struct built_in_command *x;
6703 #if ENABLE_HUSH_FUNCTIONS
6704 const struct function *funcp;
6708 char **new_env = NULL;
6709 struct variable *old_vars = NULL;
6711 if (argv[command->assignment_cnt] == NULL) {
6712 /* Assignments, but no command */
6713 /* Ensure redirects take effect (that is, create files).
6714 * Try "a=t >file" */
6715 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6716 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6717 /* Set shell variables */
6721 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6722 /* Do we need to flag set_local_var() errors?
6723 * "assignment to readonly var" and "putenv error"
6728 /* Redirect error sets $? to 1. Otherwise,
6729 * if evaluating assignment value set $?, retain it.
6730 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6732 rcode = G.last_exitcode;
6733 /* Exit, _skipping_ variable restoring code: */
6734 goto clean_up_and_ret0;
6736 #else /* Older, bigger, but more correct code */
6738 rcode = setup_redirects(command, squirrel);
6739 restore_redirects(squirrel);
6740 /* Set shell variables */
6742 bb_putchar_stderr('+');
6744 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
6746 fprintf(stderr, " %s", p);
6747 debug_printf_exec("set shell var:'%s'->'%s'\n",
6749 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6750 /* Do we need to flag set_local_var() errors?
6751 * "assignment to readonly var" and "putenv error"
6756 bb_putchar_stderr('\n');
6757 /* Redirect error sets $? to 1. Otherwise,
6758 * if evaluating assignment value set $?, retain it.
6759 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6761 rcode = G.last_exitcode;
6762 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6764 debug_printf_exec("run_pipe: return %d\n", rcode);
6769 /* Expand the rest into (possibly) many strings each */
6771 #if ENABLE_HUSH_BASH_COMPAT
6772 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6773 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6777 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6780 /* if someone gives us an empty string: `cmd with empty output` */
6781 if (!argv_expanded[0]) {
6782 free(argv_expanded);
6784 return G.last_exitcode;
6787 x = find_builtin(argv_expanded[0]);
6788 #if ENABLE_HUSH_FUNCTIONS
6791 funcp = find_function(argv_expanded[0]);
6795 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6796 debug_printf("exec with redirects only\n");
6797 rcode = setup_redirects(command, NULL);
6798 goto clean_up_and_ret1;
6801 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6804 debug_printf_exec(": builtin '%s' '%s'...\n",
6805 x->b_cmd, argv_expanded[1]);
6806 rcode = x->b_function(argv_expanded) & 0xff;
6809 #if ENABLE_HUSH_FUNCTIONS
6811 # if ENABLE_HUSH_LOCAL
6812 struct variable **sv;
6813 sv = G.shadowed_vars_pp;
6814 G.shadowed_vars_pp = &old_vars;
6816 debug_printf_exec(": function '%s' '%s'...\n",
6817 funcp->name, argv_expanded[1]);
6818 rcode = run_function(funcp, argv_expanded) & 0xff;
6819 # if ENABLE_HUSH_LOCAL
6820 G.shadowed_vars_pp = sv;
6826 unset_vars(new_env);
6828 /* clean_up_and_ret0: */
6829 restore_redirects(squirrel);
6831 free(argv_expanded);
6832 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6834 debug_printf_exec("run_pipe return %d\n", rcode);
6838 if (ENABLE_FEATURE_SH_STANDALONE) {
6839 int n = find_applet_by_name(argv_expanded[0]);
6840 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6841 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6843 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6844 argv_expanded[0], argv_expanded[1]);
6845 rcode = run_nofork_applet(n, argv_expanded);
6847 goto clean_up_and_ret;
6850 /* It is neither builtin nor applet. We must fork. */
6854 /* NB: argv_expanded may already be created, and that
6855 * might include `cmd` runs! Do not rerun it! We *must*
6856 * use argv_expanded if it's non-NULL */
6858 /* Going to fork a child per each pipe member */
6863 while (cmd_no < pi->num_cmds) {
6864 struct fd_pair pipefds;
6866 volatile nommu_save_t nommu_save;
6867 nommu_save.new_env = NULL;
6868 nommu_save.old_vars = NULL;
6869 nommu_save.argv = NULL;
6870 nommu_save.argv_from_re_execing = NULL;
6872 command = &pi->cmds[cmd_no];
6874 if (command->argv) {
6875 debug_printf_exec(": pipe member '%s' '%s'...\n",
6876 command->argv[0], command->argv[1]);
6878 debug_printf_exec(": pipe member with no argv\n");
6881 /* pipes are inserted between pairs of commands */
6884 if (cmd_no < pi->num_cmds)
6885 xpiped_pair(pipefds);
6887 command->pid = BB_MMU ? fork() : vfork();
6888 if (!command->pid) { /* child */
6890 disable_restore_tty_pgrp_on_exit();
6891 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6893 /* Every child adds itself to new process group
6894 * with pgid == pid_of_first_child_in_pipe */
6895 if (G.run_list_level == 1 && G_interactive_fd) {
6898 if (pgrp < 0) /* true for 1st process only */
6900 if (setpgid(0, pgrp) == 0
6901 && pi->followup != PIPE_BG
6902 && G_saved_tty_pgrp /* we have ctty */
6904 /* We do it in *every* child, not just first,
6906 tcsetpgrp(G_interactive_fd, pgrp);
6910 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6911 /* 1st cmd in backgrounded pipe
6912 * should have its stdin /dev/null'ed */
6914 if (open(bb_dev_null, O_RDONLY))
6915 xopen("/", O_RDONLY);
6917 xmove_fd(next_infd, 0);
6919 xmove_fd(pipefds.wr, 1);
6922 /* Like bash, explicit redirects override pipes,
6923 * and the pipe fd is available for dup'ing. */
6924 if (setup_redirects(command, NULL))
6927 /* Restore default handlers just prior to exec */
6928 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6930 /* Stores to nommu_save list of env vars putenv'ed
6931 * (NOMMU, on MMU we don't need that) */
6932 /* cast away volatility... */
6933 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6934 /* pseudo_exec() does not return */
6937 /* parent or error */
6938 #if ENABLE_HUSH_FAST
6940 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6942 enable_restore_tty_pgrp_on_exit();
6944 /* Clean up after vforked child */
6945 free(nommu_save.argv);
6946 free(nommu_save.argv_from_re_execing);
6947 unset_vars(nommu_save.new_env);
6948 add_vars(nommu_save.old_vars);
6950 free(argv_expanded);
6951 argv_expanded = NULL;
6952 if (command->pid < 0) { /* [v]fork failed */
6953 /* Clearly indicate, was it fork or vfork */
6954 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6958 /* Second and next children need to know pid of first one */
6960 pi->pgrp = command->pid;
6966 if (cmd_no < pi->num_cmds)
6968 /* Pass read (output) pipe end to next iteration */
6969 next_infd = pipefds.rd;
6972 if (!pi->alive_cmds) {
6974 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
6979 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
6983 /* NB: called by pseudo_exec, and therefore must not modify any
6984 * global data until exec/_exit (we can be a child after vfork!) */
6985 static int run_list(struct pipe *pi)
6987 #if ENABLE_HUSH_CASE
6988 char *case_word = NULL;
6990 #if ENABLE_HUSH_LOOPS
6991 struct pipe *loop_top = NULL;
6992 char **for_lcur = NULL;
6993 char **for_list = NULL;
6995 smallint last_followup;
6997 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
6998 smalluint cond_code = 0;
7000 enum { cond_code = 0 };
7003 smallint rword; /* RES_foo */
7004 smallint last_rword; /* ditto */
7007 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7010 #if ENABLE_HUSH_LOOPS
7011 /* Check syntax for "for" */
7012 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
7013 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7015 /* current word is FOR or IN (BOLD in comments below) */
7016 if (cpipe->next == NULL) {
7017 syntax_error("malformed for");
7019 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7022 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7023 if (cpipe->next->res_word == RES_DO)
7025 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7026 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7027 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7029 syntax_error("malformed for");
7031 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7037 /* Past this point, all code paths should jump to ret: label
7038 * in order to return, no direct "return" statements please.
7039 * This helps to ensure that no memory is leaked. */
7047 last_rword = RES_XXXX;
7049 last_followup = PIPE_SEQ;
7050 rcode = G.last_exitcode;
7052 /* Go through list of pipes, (maybe) executing them. */
7053 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7057 IF_HAS_KEYWORDS(rword = pi->res_word;)
7058 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7059 rword, cond_code, last_rword);
7060 #if ENABLE_HUSH_LOOPS
7061 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7062 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7064 /* start of a loop: remember where loop starts */
7069 /* Still in the same "if...", "then..." or "do..." branch? */
7070 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7071 if ((rcode == 0 && last_followup == PIPE_OR)
7072 || (rcode != 0 && last_followup == PIPE_AND)
7074 /* It is "<true> || CMD" or "<false> && CMD"
7075 * and we should not execute CMD */
7076 debug_printf_exec("skipped cmd because of || or &&\n");
7077 last_followup = pi->followup;
7081 last_followup = pi->followup;
7082 IF_HAS_KEYWORDS(last_rword = rword;)
7085 if (rword == RES_THEN) {
7086 /* if false; then ... fi has exitcode 0! */
7087 G.last_exitcode = rcode = EXIT_SUCCESS;
7088 /* "if <false> THEN cmd": skip cmd */
7092 if (rword == RES_ELSE || rword == RES_ELIF) {
7093 /* "if <true> then ... ELSE/ELIF cmd":
7094 * skip cmd and all following ones */
7099 #if ENABLE_HUSH_LOOPS
7100 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7102 /* first loop through for */
7104 static const char encoded_dollar_at[] ALIGN1 = {
7105 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7106 }; /* encoded representation of "$@" */
7107 static const char *const encoded_dollar_at_argv[] = {
7108 encoded_dollar_at, NULL
7109 }; /* argv list with one element: "$@" */
7112 vals = (char**)encoded_dollar_at_argv;
7113 if (pi->next->res_word == RES_IN) {
7114 /* if no variable values after "in" we skip "for" */
7115 if (!pi->next->cmds[0].argv) {
7116 G.last_exitcode = rcode = EXIT_SUCCESS;
7117 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7120 vals = pi->next->cmds[0].argv;
7121 } /* else: "for var; do..." -> assume "$@" list */
7122 /* create list of variable values */
7123 debug_print_strings("for_list made from", vals);
7124 for_list = expand_strvec_to_strvec(vals);
7125 for_lcur = for_list;
7126 debug_print_strings("for_list", for_list);
7129 /* "for" loop is over, clean up */
7135 /* Insert next value from for_lcur */
7136 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7137 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7140 if (rword == RES_IN) {
7141 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7143 if (rword == RES_DONE) {
7144 continue; /* "done" has no cmds too */
7147 #if ENABLE_HUSH_CASE
7148 if (rword == RES_CASE) {
7149 case_word = expand_strvec_to_string(pi->cmds->argv);
7152 if (rword == RES_MATCH) {
7155 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7157 /* all prev words didn't match, does this one match? */
7158 argv = pi->cmds->argv;
7160 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7161 /* TODO: which FNM_xxx flags to use? */
7162 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7164 if (cond_code == 0) { /* match! we will execute this branch */
7165 free(case_word); /* make future "word)" stop */
7173 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7175 continue; /* not matched yet, skip this pipe */
7178 /* Just pressing <enter> in shell should check for jobs.
7179 * OTOH, in non-interactive shell this is useless
7180 * and only leads to extra job checks */
7181 if (pi->num_cmds == 0) {
7182 if (G_interactive_fd)
7183 goto check_jobs_and_continue;
7187 /* After analyzing all keywords and conditions, we decided
7188 * to execute this pipe. NB: have to do checkjobs(NULL)
7189 * after run_pipe to collect any background children,
7190 * even if list execution is to be stopped. */
7191 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7194 #if ENABLE_HUSH_LOOPS
7195 G.flag_break_continue = 0;
7197 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7199 /* We ran a builtin, function, or group.
7200 * rcode is already known
7201 * and we don't need to wait for anything. */
7202 G.last_exitcode = rcode;
7203 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7204 check_and_run_traps(0);
7205 #if ENABLE_HUSH_LOOPS
7206 /* Was it "break" or "continue"? */
7207 if (G.flag_break_continue) {
7208 smallint fbc = G.flag_break_continue;
7209 /* We might fall into outer *loop*,
7210 * don't want to break it too */
7212 G.depth_break_continue--;
7213 if (G.depth_break_continue == 0)
7214 G.flag_break_continue = 0;
7215 /* else: e.g. "continue 2" should *break* once, *then* continue */
7216 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7217 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7218 goto check_jobs_and_break;
7219 /* "continue": simulate end of loop */
7224 #if ENABLE_HUSH_FUNCTIONS
7225 if (G.flag_return_in_progress == 1) {
7226 /* same as "goto check_jobs_and_break" */
7231 } else if (pi->followup == PIPE_BG) {
7232 /* What does bash do with attempts to background builtins? */
7233 /* even bash 3.2 doesn't do that well with nested bg:
7234 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7235 * I'm NOT treating inner &'s as jobs */
7236 check_and_run_traps(0);
7238 if (G.run_list_level == 1)
7241 /* Last command's pid goes to $! */
7242 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7243 G.last_exitcode = rcode = EXIT_SUCCESS;
7244 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7247 if (G.run_list_level == 1 && G_interactive_fd) {
7248 /* Waits for completion, then fg's main shell */
7249 rcode = checkjobs_and_fg_shell(pi);
7250 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7251 check_and_run_traps(0);
7254 { /* This one just waits for completion */
7255 rcode = checkjobs(pi);
7256 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7257 check_and_run_traps(0);
7259 G.last_exitcode = rcode;
7263 /* Analyze how result affects subsequent commands */
7265 if (rword == RES_IF || rword == RES_ELIF)
7268 #if ENABLE_HUSH_LOOPS
7269 /* Beware of "while false; true; do ..."! */
7270 if (pi->next && pi->next->res_word == RES_DO) {
7271 if (rword == RES_WHILE) {
7273 /* "while false; do...done" - exitcode 0 */
7274 G.last_exitcode = rcode = EXIT_SUCCESS;
7275 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7276 goto check_jobs_and_break;
7279 if (rword == RES_UNTIL) {
7281 debug_printf_exec(": until expr is true: breaking\n");
7282 check_jobs_and_break:
7290 check_jobs_and_continue:
7297 #if ENABLE_HUSH_LOOPS
7302 #if ENABLE_HUSH_CASE
7306 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7310 /* Select which version we will use */
7311 static int run_and_free_list(struct pipe *pi)
7314 debug_printf_exec("run_and_free_list entered\n");
7315 if (!G.o_opt[OPT_O_NOEXEC]) {
7316 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7317 rcode = run_list(pi);
7319 /* free_pipe_list has the side effect of clearing memory.
7320 * In the long run that function can be merged with run_list,
7321 * but doing that now would hobble the debugging effort. */
7323 debug_printf_exec("run_and_free_list return %d\n", rcode);
7328 /* Called a few times only (or even once if "sh -c") */
7329 static void init_sigmasks(void)
7333 sigset_t old_blocked_set;
7335 if (!G.inherited_set_is_saved) {
7336 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7337 G.inherited_set = G.blocked_set;
7339 old_blocked_set = G.blocked_set;
7341 mask = (1 << SIGQUIT);
7342 if (G_interactive_fd) {
7343 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7344 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7345 mask |= SPECIAL_JOB_SIGS;
7347 G.non_DFL_mask = mask;
7352 sigaddset(&G.blocked_set, sig);
7356 sigdelset(&G.blocked_set, SIGCHLD);
7358 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7359 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7361 /* POSIX allows shell to re-enable SIGCHLD
7362 * even if it was SIG_IGN on entry */
7363 #if ENABLE_HUSH_FAST
7364 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7365 if (!G.inherited_set_is_saved)
7366 signal(SIGCHLD, SIGCHLD_handler);
7368 if (!G.inherited_set_is_saved)
7369 signal(SIGCHLD, SIG_DFL);
7372 G.inherited_set_is_saved = 1;
7377 static void maybe_set_to_sigexit(int sig)
7379 void (*handler)(int);
7380 /* non_DFL_mask'ed signals are, well, masked,
7381 * no need to set handler for them.
7383 if (!((G.non_DFL_mask >> sig) & 1)) {
7384 handler = signal(sig, sigexit);
7385 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7386 signal(sig, handler);
7389 /* Set handlers to restore tty pgrp and exit */
7390 static void set_fatal_handlers(void)
7392 /* We _must_ restore tty pgrp on fatal signals */
7394 maybe_set_to_sigexit(SIGILL );
7395 maybe_set_to_sigexit(SIGFPE );
7396 maybe_set_to_sigexit(SIGBUS );
7397 maybe_set_to_sigexit(SIGSEGV);
7398 maybe_set_to_sigexit(SIGTRAP);
7399 } /* else: hush is perfect. what SEGV? */
7400 maybe_set_to_sigexit(SIGABRT);
7401 /* bash 3.2 seems to handle these just like 'fatal' ones */
7402 maybe_set_to_sigexit(SIGPIPE);
7403 maybe_set_to_sigexit(SIGALRM);
7404 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7405 * if we aren't interactive... but in this case
7406 * we never want to restore pgrp on exit, and this fn is not called */
7407 /*maybe_set_to_sigexit(SIGHUP );*/
7408 /*maybe_set_to_sigexit(SIGTERM);*/
7409 /*maybe_set_to_sigexit(SIGINT );*/
7413 static int set_mode(int state, char mode, const char *o_opt)
7418 G.o_opt[OPT_O_NOEXEC] = state;
7421 IF_HUSH_MODE_X(G_x_mode = state;)
7425 /* "set -+o" without parameter.
7426 * in bash, set -o produces this output:
7430 * We always use the second form.
7432 const char *p = o_opt_strings;
7435 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7441 idx = index_in_strings(o_opt_strings, o_opt);
7443 G.o_opt[idx] = state;
7447 return EXIT_FAILURE;
7449 return EXIT_SUCCESS;
7452 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7453 int hush_main(int argc, char **argv)
7456 unsigned builtin_argc;
7458 struct variable *cur_var;
7459 struct variable shell_ver;
7462 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7463 G.last_exitcode = EXIT_SUCCESS;
7465 G.argv0_for_re_execing = argv[0];
7467 /* Deal with HUSH_VERSION */
7468 memset(&shell_ver, 0, sizeof(shell_ver));
7469 shell_ver.flg_export = 1;
7470 shell_ver.flg_read_only = 1;
7471 /* Code which handles ${var<op>...} needs writable values for all variables,
7472 * therefore we xstrdup: */
7473 shell_ver.varstr = xstrdup(hush_version_str),
7474 G.top_var = &shell_ver;
7475 /* Create shell local variables from the values
7476 * currently living in the environment */
7477 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7478 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7479 cur_var = G.top_var;
7482 char *value = strchr(*e, '=');
7483 if (value) { /* paranoia */
7484 cur_var->next = xzalloc(sizeof(*cur_var));
7485 cur_var = cur_var->next;
7486 cur_var->varstr = *e;
7487 cur_var->max_len = strlen(*e);
7488 cur_var->flg_export = 1;
7492 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7493 debug_printf_env("putenv '%s'\n", shell_ver.varstr);
7494 putenv(shell_ver.varstr);
7497 set_pwd_var(/*exp:*/ 1);
7498 /* bash also exports SHLVL and _,
7499 * and sets (but doesn't export) the following variables:
7501 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7502 * BASH_VERSION='3.2.0(1)-release'
7504 * MACHTYPE=i386-pc-linux-gnu
7506 * HOSTNAME=<xxxxxxxxxx>
7507 * PPID=<NNNNN> - we also do it elsewhere
7518 * PIPESTATUS=([0]="0")
7519 * HISTFILE=/<xxx>/.bash_history
7523 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7525 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7535 #if ENABLE_FEATURE_EDITING
7536 G.line_input_state = new_line_input_t(FOR_SHELL);
7537 # if defined MAX_HISTORY && MAX_HISTORY > 0 && ENABLE_HUSH_SAVEHISTORY
7539 const char *hp = get_local_var_value("HISTFILE");
7541 hp = get_local_var_value("HOME");
7543 G.line_input_state->hist_file = concat_path_file(hp, ".hush_history");
7544 //set_local_var(xasprintf("HISTFILE=%s", ...));
7551 G.global_argc = argc;
7552 G.global_argv = argv;
7553 /* Initialize some more globals to non-zero values */
7554 cmdedit_update_prompt();
7556 if (setjmp(die_jmp)) {
7557 /* xfunc has failed! die die die */
7558 /* no EXIT traps, this is an escape hatch! */
7560 hush_exit(xfunc_error_retval);
7563 /* Shell is non-interactive at first. We need to call
7564 * init_sigmasks() if we are going to execute "sh <script>",
7565 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7566 * If we later decide that we are interactive, we run init_sigmasks()
7567 * in order to intercept (more) signals.
7571 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7574 opt = getopt(argc, argv, "+c:xins"
7577 # if ENABLE_HUSH_FUNCTIONS
7587 * sh ... -c 'script'
7588 * sh ... -c 'script' ARG0 [ARG1...]
7589 * On NOMMU, if builtin_argc != 0,
7590 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7591 * "" needs to be replaced with NULL
7592 * and BARGV vector fed to builtin function.
7593 * Note: the form without ARG0 never happens:
7594 * sh ... -c 'builtin' BARGV... ""
7597 G.root_pid = getpid();
7598 G.root_ppid = getppid();
7600 G.global_argv = argv + optind;
7601 G.global_argc = argc - optind;
7603 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7604 const struct built_in_command *x;
7607 x = find_builtin(optarg);
7608 if (x) { /* paranoia */
7609 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7610 G.global_argv += builtin_argc;
7611 G.global_argv[-1] = NULL; /* replace "" */
7612 G.last_exitcode = x->b_function(argv + optind - 1);
7616 if (!G.global_argv[0]) {
7617 /* -c 'script' (no params): prevent empty $0 */
7618 G.global_argv--; /* points to argv[i] of 'script' */
7619 G.global_argv[0] = argv[0];
7621 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7623 parse_and_run_string(optarg);
7626 /* Well, we cannot just declare interactiveness,
7627 * we have to have some stuff (ctty, etc) */
7628 /* G_interactive_fd++; */
7631 /* "-s" means "read from stdin", but this is how we always
7632 * operate, so simply do nothing here. */
7635 case '<': /* "big heredoc" support */
7636 full_write1_str(optarg);
7639 unsigned long long empty_trap_mask;
7641 G.root_pid = bb_strtou(optarg, &optarg, 16);
7643 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7645 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7647 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7649 builtin_argc = bb_strtou(optarg, &optarg, 16);
7651 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7652 if (empty_trap_mask != 0) {
7655 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7656 for (sig = 1; sig < NSIG; sig++) {
7657 if (empty_trap_mask & (1LL << sig)) {
7658 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7659 sigaddset(&G.blocked_set, sig);
7662 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7664 # if ENABLE_HUSH_LOOPS
7666 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7672 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7674 # if ENABLE_HUSH_FUNCTIONS
7676 struct function *funcp = new_function(optarg);
7677 /* funcp->name is already set to optarg */
7678 /* funcp->body is set to NULL. It's a special case. */
7679 funcp->body_as_string = argv[optind];
7687 if (set_mode(1, opt, NULL) == 0) /* no error */
7691 fprintf(stderr, "Usage: sh [FILE]...\n"
7692 " or: sh -c command [args]...\n\n");
7698 } /* option parsing loop */
7701 G.root_pid = getpid();
7702 G.root_ppid = getppid();
7705 /* If we are login shell... */
7706 if (argv[0] && argv[0][0] == '-') {
7708 debug_printf("sourcing /etc/profile\n");
7709 input = fopen_for_read("/etc/profile");
7710 if (input != NULL) {
7711 close_on_exec_on(fileno(input));
7713 parse_and_run_file(input);
7716 /* bash: after sourcing /etc/profile,
7717 * tries to source (in the given order):
7718 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7719 * stopping on first found. --noprofile turns this off.
7720 * bash also sources ~/.bash_logout on exit.
7721 * If called as sh, skips .bash_XXX files.
7728 * "bash <script>" (which is never interactive (unless -i?))
7729 * sources $BASH_ENV here (without scanning $PATH).
7730 * If called as sh, does the same but with $ENV.
7732 debug_printf("running script '%s'\n", argv[optind]);
7733 G.global_argv = argv + optind;
7734 G.global_argc = argc - optind;
7735 input = xfopen_for_read(argv[optind]);
7736 close_on_exec_on(fileno(input));
7738 parse_and_run_file(input);
7739 #if ENABLE_FEATURE_CLEAN_UP
7745 /* Up to here, shell was non-interactive. Now it may become one.
7746 * NB: don't forget to (re)run init_sigmasks() as needed.
7749 /* A shell is interactive if the '-i' flag was given,
7750 * or if all of the following conditions are met:
7752 * no arguments remaining or the -s flag given
7753 * standard input is a terminal
7754 * standard output is a terminal
7755 * Refer to Posix.2, the description of the 'sh' utility.
7758 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7759 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7760 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7761 if (G_saved_tty_pgrp < 0)
7762 G_saved_tty_pgrp = 0;
7764 /* try to dup stdin to high fd#, >= 255 */
7765 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7766 if (G_interactive_fd < 0) {
7767 /* try to dup to any fd */
7768 G_interactive_fd = dup(STDIN_FILENO);
7769 if (G_interactive_fd < 0) {
7771 G_interactive_fd = 0;
7772 G_saved_tty_pgrp = 0;
7775 // TODO: track & disallow any attempts of user
7776 // to (inadvertently) close/redirect G_interactive_fd
7778 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7779 if (G_interactive_fd) {
7780 close_on_exec_on(G_interactive_fd);
7782 if (G_saved_tty_pgrp) {
7783 /* If we were run as 'hush &', sleep until we are
7784 * in the foreground (tty pgrp == our pgrp).
7785 * If we get started under a job aware app (like bash),
7786 * make sure we are now in charge so we don't fight over
7787 * who gets the foreground */
7789 pid_t shell_pgrp = getpgrp();
7790 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7791 if (G_saved_tty_pgrp == shell_pgrp)
7793 /* send TTIN to ourself (should stop us) */
7794 kill(- shell_pgrp, SIGTTIN);
7798 /* Block some signals */
7801 if (G_saved_tty_pgrp) {
7802 /* Set other signals to restore saved_tty_pgrp */
7803 set_fatal_handlers();
7804 /* Put ourselves in our own process group
7805 * (bash, too, does this only if ctty is available) */
7806 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7807 /* Grab control of the terminal */
7808 tcsetpgrp(G_interactive_fd, getpid());
7810 /* -1 is special - makes xfuncs longjmp, not exit
7811 * (we reset die_sleep = 0 whereever we [v]fork) */
7812 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7816 #elif ENABLE_HUSH_INTERACTIVE
7817 /* No job control compiled in, only prompt/line editing */
7818 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7819 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7820 if (G_interactive_fd < 0) {
7821 /* try to dup to any fd */
7822 G_interactive_fd = dup(STDIN_FILENO);
7823 if (G_interactive_fd < 0)
7825 G_interactive_fd = 0;
7828 if (G_interactive_fd) {
7829 close_on_exec_on(G_interactive_fd);
7833 /* We have interactiveness code disabled */
7837 * if interactive but not a login shell, sources ~/.bashrc
7838 * (--norc turns this off, --rcfile <file> overrides)
7841 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7842 /* note: ash and hush share this string */
7843 printf("\n\n%s %s\n"
7844 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7847 "hush - the humble shell"
7851 parse_and_run_file(stdin);
7854 #if ENABLE_FEATURE_CLEAN_UP
7855 if (G.cwd != bb_msg_unknown)
7857 cur_var = G.top_var->next;
7859 struct variable *tmp = cur_var;
7860 if (!cur_var->max_len)
7861 free(cur_var->varstr);
7862 cur_var = cur_var->next;
7866 hush_exit(G.last_exitcode);
7871 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7872 int msh_main(int argc, char **argv)
7874 //bb_error_msg("msh is deprecated, please use hush instead");
7875 return hush_main(argc, argv);
7883 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7888 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7895 return applet_main_func(argc, argv - argc);
7898 static int FAST_FUNC builtin_test(char **argv)
7900 return run_applet_main(argv, test_main);
7903 static int FAST_FUNC builtin_echo(char **argv)
7905 return run_applet_main(argv, echo_main);
7909 static int FAST_FUNC builtin_printf(char **argv)
7911 return run_applet_main(argv, printf_main);
7915 static char **skip_dash_dash(char **argv)
7918 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7923 static int FAST_FUNC builtin_eval(char **argv)
7925 int rcode = EXIT_SUCCESS;
7927 argv = skip_dash_dash(argv);
7929 char *str = expand_strvec_to_string(argv);
7931 * eval "echo Hi; done" ("done" is syntax error):
7932 * "echo Hi" will not execute too.
7934 parse_and_run_string(str);
7936 rcode = G.last_exitcode;
7941 static int FAST_FUNC builtin_cd(char **argv)
7945 argv = skip_dash_dash(argv);
7947 if (newdir == NULL) {
7948 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7949 * bash says "bash: cd: HOME not set" and does nothing
7952 const char *home = get_local_var_value("HOME");
7953 newdir = home ? home : "/";
7955 if (chdir(newdir)) {
7956 /* Mimic bash message exactly */
7957 bb_perror_msg("cd: %s", newdir);
7958 return EXIT_FAILURE;
7960 /* Read current dir (get_cwd(1) is inside) and set PWD.
7961 * Note: do not enforce exporting. If PWD was unset or unexported,
7962 * set it again, but do not export. bash does the same.
7964 set_pwd_var(/*exp:*/ 0);
7965 return EXIT_SUCCESS;
7968 static int FAST_FUNC builtin_exec(char **argv)
7970 argv = skip_dash_dash(argv);
7971 if (argv[0] == NULL)
7972 return EXIT_SUCCESS; /* bash does this */
7974 /* Careful: we can end up here after [v]fork. Do not restore
7975 * tty pgrp then, only top-level shell process does that */
7976 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7977 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7979 /* TODO: if exec fails, bash does NOT exit! We do.
7980 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7981 * and tcsetpgrp, and this is inherently racy.
7983 execvp_or_die(argv);
7986 static int FAST_FUNC builtin_exit(char **argv)
7988 debug_printf_exec("%s()\n", __func__);
7990 /* interactive bash:
7991 * # trap "echo EEE" EXIT
7994 * There are stopped jobs.
7995 * (if there are _stopped_ jobs, running ones don't count)
7998 # EEE (then bash exits)
8000 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8003 /* note: EXIT trap is run by hush_exit */
8004 argv = skip_dash_dash(argv);
8005 if (argv[0] == NULL)
8006 hush_exit(G.last_exitcode);
8007 /* mimic bash: exit 123abc == exit 255 + error msg */
8008 xfunc_error_retval = 255;
8009 /* bash: exit -2 == exit 254, no error msg */
8010 hush_exit(xatoi(argv[0]) & 0xff);
8013 static void print_escaped(const char *s)
8018 const char *p = strchrnul(s, '\'');
8019 /* print 'xxxx', possibly just '' */
8020 printf("'%.*s'", (int)(p - s), s);
8025 /* s points to '; print "'''...'''" */
8027 do putchar('\''); while (*++s == '\'');
8032 #if !ENABLE_HUSH_LOCAL
8033 #define helper_export_local(argv, exp, lvl) \
8034 helper_export_local(argv, exp)
8036 static void helper_export_local(char **argv, int exp, int lvl)
8040 char *name_end = strchrnul(name, '=');
8042 /* So far we do not check that name is valid (TODO?) */
8044 if (*name_end == '\0') {
8045 struct variable *var, **vpp;
8047 vpp = get_ptr_to_local_var(name, name_end - name);
8048 var = vpp ? *vpp : NULL;
8050 if (exp == -1) { /* unexporting? */
8051 /* export -n NAME (without =VALUE) */
8053 var->flg_export = 0;
8054 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8056 } /* else: export -n NOT_EXISTING_VAR: no-op */
8059 if (exp == 1) { /* exporting? */
8060 /* export NAME (without =VALUE) */
8062 var->flg_export = 1;
8063 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8064 putenv(var->varstr);
8068 /* Exporting non-existing variable.
8069 * bash does not put it in environment,
8070 * but remembers that it is exported,
8071 * and does put it in env when it is set later.
8072 * We just set it to "" and export. */
8073 /* Or, it's "local NAME" (without =VALUE).
8074 * bash sets the value to "". */
8075 name = xasprintf("%s=", name);
8077 /* (Un)exporting/making local NAME=VALUE */
8078 name = xstrdup(name);
8080 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8084 static int FAST_FUNC builtin_export(char **argv)
8086 unsigned opt_unexport;
8088 #if ENABLE_HUSH_EXPORT_N
8089 /* "!": do not abort on errors */
8090 opt_unexport = getopt32(argv, "!n");
8091 if (opt_unexport == (uint32_t)-1)
8092 return EXIT_FAILURE;
8099 if (argv[0] == NULL) {
8106 /* ash emits: export VAR='VAL'
8107 * bash: declare -x VAR="VAL"
8108 * we follow ash example */
8109 const char *s = *e++;
8110 const char *p = strchr(s, '=');
8112 if (!p) /* wtf? take next variable */
8115 printf("export %.*s", (int)(p - s) + 1, s);
8116 print_escaped(p + 1);
8120 /*fflush_all(); - done after each builtin anyway */
8122 return EXIT_SUCCESS;
8125 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8127 return EXIT_SUCCESS;
8130 #if ENABLE_HUSH_LOCAL
8131 static int FAST_FUNC builtin_local(char **argv)
8133 if (G.func_nest_level == 0) {
8134 bb_error_msg("%s: not in a function", argv[0]);
8135 return EXIT_FAILURE; /* bash compat */
8137 helper_export_local(argv, 0, G.func_nest_level);
8138 return EXIT_SUCCESS;
8142 static int FAST_FUNC builtin_trap(char **argv)
8148 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8153 /* No args: print all trapped */
8154 for (i = 0; i < NSIG; ++i) {
8157 print_escaped(G.traps[i]);
8158 /* note: bash adds "SIG", but only if invoked
8159 * as "bash". If called as "sh", or if set -o posix,
8160 * then it prints short signal names.
8161 * We are printing short names: */
8162 printf(" %s\n", get_signame(i));
8165 /*fflush_all(); - done after each builtin anyway */
8166 return EXIT_SUCCESS;
8170 /* If first arg is a number: reset all specified signals */
8171 sig = bb_strtou(*argv, NULL, 10);
8177 sig = get_signum(*argv++);
8178 if (sig < 0 || sig >= NSIG) {
8180 /* Mimic bash message exactly */
8181 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8186 G.traps[sig] = xstrdup(new_cmd);
8188 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8189 get_signame(sig), sig, G.traps[sig]);
8191 /* There is no signal for 0 (EXIT) */
8196 sigaddset(&G.blocked_set, sig);
8198 /* There was a trap handler, we are removing it
8199 * (if sig has non-DFL handling,
8200 * we don't need to do anything) */
8201 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8203 sigdelset(&G.blocked_set, sig);
8206 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8210 if (!argv[1]) { /* no second arg */
8211 bb_error_msg("trap: invalid arguments");
8212 return EXIT_FAILURE;
8215 /* First arg is "-": reset all specified to default */
8216 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8217 /* Everything else: set arg as signal handler
8218 * (includes "" case, which ignores signal) */
8219 if (argv[0][0] == '-') {
8220 if (argv[0][1] == '\0') { /* "-" */
8221 /* new_cmd remains NULL: "reset these sigs" */
8224 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8227 /* else: "-something", no special meaning */
8232 goto process_sig_list;
8235 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8236 static int FAST_FUNC builtin_type(char **argv)
8238 int ret = EXIT_SUCCESS;
8244 if (0) {} /* make conditional compile easier below */
8245 /*else if (find_alias(*argv))
8246 type = "an alias";*/
8247 #if ENABLE_HUSH_FUNCTIONS
8248 else if (find_function(*argv))
8249 type = "a function";
8251 else if (find_builtin(*argv))
8252 type = "a shell builtin";
8253 else if ((path = find_in_path(*argv)) != NULL)
8256 bb_error_msg("type: %s: not found", *argv);
8261 printf("%s is %s\n", *argv, type);
8269 /* built-in 'fg' and 'bg' handler */
8270 static int FAST_FUNC builtin_fg_bg(char **argv)
8275 if (!G_interactive_fd)
8276 return EXIT_FAILURE;
8278 /* If they gave us no args, assume they want the last backgrounded task */
8280 for (pi = G.job_list; pi; pi = pi->next) {
8281 if (pi->jobid == G.last_jobid) {
8285 bb_error_msg("%s: no current job", argv[0]);
8286 return EXIT_FAILURE;
8288 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8289 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8290 return EXIT_FAILURE;
8292 for (pi = G.job_list; pi; pi = pi->next) {
8293 if (pi->jobid == jobnum) {
8297 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8298 return EXIT_FAILURE;
8300 /* TODO: bash prints a string representation
8301 * of job being foregrounded (like "sleep 1 | cat") */
8302 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8303 /* Put the job into the foreground. */
8304 tcsetpgrp(G_interactive_fd, pi->pgrp);
8307 /* Restart the processes in the job */
8308 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8309 for (i = 0; i < pi->num_cmds; i++) {
8310 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8311 pi->cmds[i].is_stopped = 0;
8313 pi->stopped_cmds = 0;
8315 i = kill(- pi->pgrp, SIGCONT);
8317 if (errno == ESRCH) {
8318 delete_finished_bg_job(pi);
8319 return EXIT_SUCCESS;
8321 bb_perror_msg("kill (SIGCONT)");
8324 if (argv[0][0] == 'f') {
8326 return checkjobs_and_fg_shell(pi);
8328 return EXIT_SUCCESS;
8332 #if ENABLE_HUSH_HELP
8333 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8335 const struct built_in_command *x;
8338 "Built-in commands:\n"
8339 "------------------\n");
8340 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8342 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8345 return EXIT_SUCCESS;
8350 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8353 const char *status_string;
8355 for (job = G.job_list; job; job = job->next) {
8356 if (job->alive_cmds == job->stopped_cmds)
8357 status_string = "Stopped";
8359 status_string = "Running";
8361 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8363 return EXIT_SUCCESS;
8368 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8373 # ifdef M_TRIM_THRESHOLD
8374 /* Optional. Reduces probability of false positives */
8377 /* Crude attempt to find where "free memory" starts,
8378 * sans fragmentation. */
8380 l = (unsigned long)p;
8383 if (l < (unsigned long)p) l = (unsigned long)p;
8386 if (!G.memleak_value)
8387 G.memleak_value = l;
8389 l -= G.memleak_value;
8396 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8401 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8404 return EXIT_SUCCESS;
8407 static int FAST_FUNC builtin_read(char **argv)
8416 /* "!": do not abort on errors.
8417 * Option string must start with "sr" to match BUILTIN_READ_xxx
8419 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8420 if (read_flags == (uint32_t)-1)
8421 return EXIT_FAILURE;
8424 r = shell_builtin_read(set_local_var_from_halves,
8426 get_local_var_value("IFS"), /* can be NULL */
8434 if ((uintptr_t)r > 1) {
8435 bb_error_msg("%s", r);
8436 r = (char*)(uintptr_t)1;
8439 return (uintptr_t)r;
8442 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8443 * built-in 'set' handler
8445 * set [-abCefhmnuvx] [-o option] [argument...]
8446 * set [+abCefhmnuvx] [+o option] [argument...]
8447 * set -- [argument...]
8450 * Implementations shall support the options in both their hyphen and
8451 * plus-sign forms. These options can also be specified as options to sh.
8453 * Write out all variables and their values: set
8454 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8455 * Turn on the -x and -v options: set -xv
8456 * Unset all positional parameters: set --
8457 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8458 * Set the positional parameters to the expansion of x, even if x expands
8459 * with a leading '-' or '+': set -- $x
8461 * So far, we only support "set -- [argument...]" and some of the short names.
8463 static int FAST_FUNC builtin_set(char **argv)
8466 char **pp, **g_argv;
8467 char *arg = *++argv;
8471 for (e = G.top_var; e; e = e->next)
8473 return EXIT_SUCCESS;
8477 if (strcmp(arg, "--") == 0) {
8481 if (arg[0] != '+' && arg[0] != '-')
8483 for (n = 1; arg[n]; ++n) {
8484 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8486 if (arg[n] == 'o' && argv[1])
8489 } while ((arg = *++argv) != NULL);
8490 /* Now argv[0] is 1st argument */
8493 return EXIT_SUCCESS;
8496 /* NB: G.global_argv[0] ($0) is never freed/changed */
8497 g_argv = G.global_argv;
8498 if (G.global_args_malloced) {
8504 G.global_args_malloced = 1;
8505 pp = xzalloc(sizeof(pp[0]) * 2);
8506 pp[0] = g_argv[0]; /* retain $0 */
8509 /* This realloc's G.global_argv */
8510 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8517 return EXIT_SUCCESS;
8519 /* Nothing known, so abort */
8521 bb_error_msg("set: %s: invalid option", arg);
8522 return EXIT_FAILURE;
8525 static int FAST_FUNC builtin_shift(char **argv)
8528 argv = skip_dash_dash(argv);
8532 if (n >= 0 && n < G.global_argc) {
8533 if (G.global_args_malloced) {
8536 free(G.global_argv[m++]);
8539 memmove(&G.global_argv[1], &G.global_argv[n+1],
8540 G.global_argc * sizeof(G.global_argv[0]));
8541 return EXIT_SUCCESS;
8543 return EXIT_FAILURE;
8546 static int FAST_FUNC builtin_source(char **argv)
8548 char *arg_path, *filename;
8551 #if ENABLE_HUSH_FUNCTIONS
8555 argv = skip_dash_dash(argv);
8558 /* bash says: "bash: .: filename argument required" */
8559 return 2; /* bash compat */
8562 if (!strchr(filename, '/')) {
8563 arg_path = find_in_path(filename);
8565 filename = arg_path;
8567 input = fopen_or_warn(filename, "r");
8570 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8571 return EXIT_FAILURE;
8573 close_on_exec_on(fileno(input));
8575 #if ENABLE_HUSH_FUNCTIONS
8576 sv_flg = G.flag_return_in_progress;
8577 /* "we are inside sourced file, ok to use return" */
8578 G.flag_return_in_progress = -1;
8580 save_and_replace_G_args(&sv, argv);
8582 parse_and_run_file(input);
8585 restore_G_args(&sv, argv);
8586 #if ENABLE_HUSH_FUNCTIONS
8587 G.flag_return_in_progress = sv_flg;
8590 return G.last_exitcode;
8593 static int FAST_FUNC builtin_umask(char **argv)
8599 argv = skip_dash_dash(argv);
8601 mode_t old_mask = mask;
8604 rc = bb_parse_mode(argv[0], &mask);
8609 * bash: umask: 'q': invalid symbolic mode operator
8610 * bash: umask: 999: octal number out of range
8612 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8617 printf("%04o\n", (unsigned) mask);
8618 /* fall through and restore mask which we set to 0 */
8622 return !rc; /* rc != 0 - success */
8625 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8626 static int FAST_FUNC builtin_unset(char **argv)
8631 /* "!": do not abort on errors */
8632 /* "+": stop at 1st non-option */
8633 opts = getopt32(argv, "!+vf");
8634 if (opts == (unsigned)-1)
8635 return EXIT_FAILURE;
8637 bb_error_msg("unset: -v and -f are exclusive");
8638 return EXIT_FAILURE;
8644 if (!(opts & 2)) { /* not -f */
8645 if (unset_local_var(*argv)) {
8646 /* unset <nonexistent_var> doesn't fail.
8647 * Error is when one tries to unset RO var.
8648 * Message was printed by unset_local_var. */
8652 #if ENABLE_HUSH_FUNCTIONS
8662 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8663 static int FAST_FUNC builtin_wait(char **argv)
8665 int ret = EXIT_SUCCESS;
8668 argv = skip_dash_dash(argv);
8669 if (argv[0] == NULL) {
8670 /* Don't care about wait results */
8671 /* Note 1: must wait until there are no more children */
8672 /* Note 2: must be interruptible */
8674 * $ sleep 3 & sleep 6 & wait
8679 * $ sleep 3 & sleep 6 & wait
8683 * ^C <-- after ~4 sec from keyboard
8686 sigaddset(&G.blocked_set, SIGCHLD);
8687 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8690 if (errno == ECHILD)
8692 /* Wait for SIGCHLD or any other signal of interest */
8693 /* sigtimedwait with infinite timeout: */
8694 sig = sigwaitinfo(&G.blocked_set, NULL);
8696 sig = check_and_run_traps(sig);
8697 if (sig && sig != SIGCHLD) { /* see note 2 */
8703 sigdelset(&G.blocked_set, SIGCHLD);
8704 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8708 /* This is probably buggy wrt interruptible-ness */
8710 pid_t pid = bb_strtou(*argv, NULL, 10);
8712 /* mimic bash message */
8713 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8714 return EXIT_FAILURE;
8716 if (waitpid(pid, &status, 0) == pid) {
8717 if (WIFSIGNALED(status))
8718 ret = 128 + WTERMSIG(status);
8719 else if (WIFEXITED(status))
8720 ret = WEXITSTATUS(status);
8724 bb_perror_msg("wait %s", *argv);
8733 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8734 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8737 def = bb_strtou(argv[1], NULL, 10);
8738 if (errno || def < def_min || argv[2]) {
8739 bb_error_msg("%s: bad arguments", argv[0]);
8747 #if ENABLE_HUSH_LOOPS
8748 static int FAST_FUNC builtin_break(char **argv)
8751 if (G.depth_of_loop == 0) {
8752 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8753 return EXIT_SUCCESS; /* bash compat */
8755 G.flag_break_continue++; /* BC_BREAK = 1 */
8757 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8758 if (depth == UINT_MAX)
8759 G.flag_break_continue = BC_BREAK;
8760 if (G.depth_of_loop < depth)
8761 G.depth_break_continue = G.depth_of_loop;
8763 return EXIT_SUCCESS;
8766 static int FAST_FUNC builtin_continue(char **argv)
8768 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8769 return builtin_break(argv);
8773 #if ENABLE_HUSH_FUNCTIONS
8774 static int FAST_FUNC builtin_return(char **argv)
8778 if (G.flag_return_in_progress != -1) {
8779 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8780 return EXIT_FAILURE; /* bash compat */
8783 G.flag_return_in_progress = 1;
8786 * out of range: wraps around at 256, does not error out
8787 * non-numeric param:
8788 * f() { false; return qwe; }; f; echo $?
8789 * bash: return: qwe: numeric argument required <== we do this
8790 * 255 <== we also do this
8792 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);