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 "$i"
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
85 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
86 || defined(__APPLE__) \
88 # include <malloc.h> /* for malloc_trim */
91 /* #include <dmalloc.h> */
96 #include "shell_common.h"
99 #if ENABLE_HUSH_RANDOM_SUPPORT
102 # define CLEAR_RANDOM_T(rnd) ((void)0)
105 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
108 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
109 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
110 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
111 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
113 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
114 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
117 //config: bool "hush"
120 //config: hush is a small shell (25k). It handles the normal flow control
121 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
122 //config: case/esac. Redirections, here documents, $((arithmetic))
123 //config: and functions are supported.
125 //config: It will compile and work on no-mmu systems.
127 //config: It does not handle select, aliases, tilde expansion,
128 //config: &>file and >&file redirection of stdout+stderr.
130 //config:config HUSH_BASH_COMPAT
131 //config: bool "bash-compatible extensions"
133 //config: depends on HUSH
135 //config: Enable bash-compatible extensions.
137 //config:config HUSH_BRACE_EXPANSION
138 //config: bool "Brace expansion"
140 //config: depends on HUSH_BASH_COMPAT
142 //config: Enable {abc,def} extension.
144 //config:config HUSH_HELP
145 //config: bool "help builtin"
147 //config: depends on HUSH
149 //config: Enable help builtin in hush. Code size + ~1 kbyte.
151 //config:config HUSH_INTERACTIVE
152 //config: bool "Interactive mode"
154 //config: depends on HUSH
156 //config: Enable interactive mode (prompt and command editing).
157 //config: Without this, hush simply reads and executes commands
158 //config: from stdin just like a shell script from a file.
159 //config: No prompt, no PS1/PS2 magic shell variables.
161 //config:config HUSH_SAVEHISTORY
162 //config: bool "Save command history to .hush_history"
164 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
166 //config: Enable history saving in hush.
168 //config:config HUSH_JOB
169 //config: bool "Job control"
171 //config: depends on HUSH_INTERACTIVE
173 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
174 //config: command (not entire shell), fg/bg builtins work. Without this option,
175 //config: "cmd &" still works by simply spawning a process and immediately
176 //config: prompting for next command (or executing next command in a script),
177 //config: but no separate process group is formed.
179 //config:config HUSH_TICK
180 //config: bool "Process substitution"
182 //config: depends on HUSH
184 //config: Enable process substitution `command` and $(command) in hush.
186 //config:config HUSH_IF
187 //config: bool "Support if/then/elif/else/fi"
189 //config: depends on HUSH
191 //config: Enable if/then/elif/else/fi in hush.
193 //config:config HUSH_LOOPS
194 //config: bool "Support for, while and until loops"
196 //config: depends on HUSH
198 //config: Enable for, while and until loops in hush.
200 //config:config HUSH_CASE
201 //config: bool "Support case ... esac statement"
203 //config: depends on HUSH
205 //config: Enable case ... esac statement in hush. +400 bytes.
207 //config:config HUSH_FUNCTIONS
208 //config: bool "Support funcname() { commands; } syntax"
210 //config: depends on HUSH
212 //config: Enable support for shell functions in hush. +800 bytes.
214 //config:config HUSH_LOCAL
215 //config: bool "Support local builtin"
217 //config: depends on HUSH_FUNCTIONS
219 //config: Enable support for local variables in functions.
221 //config:config HUSH_RANDOM_SUPPORT
222 //config: bool "Pseudorandom generator and $RANDOM variable"
224 //config: depends on HUSH
226 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
227 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
229 //config:config HUSH_EXPORT_N
230 //config: bool "Support 'export -n' option"
232 //config: depends on HUSH
234 //config: export -n unexports variables. It is a bash extension.
236 //config:config HUSH_MODE_X
237 //config: bool "Support 'hush -x' option and 'set -x' command"
239 //config: depends on HUSH
241 //config: This instructs hush to print commands before execution.
242 //config: Adds ~300 bytes.
245 //config: bool "msh (deprecated: aliased to hush)"
247 //config: select HUSH
249 //config: msh is deprecated and will be removed, please migrate to hush.
252 /* -i (interactive) and -s (read stdin) are also accepted,
253 * but currently do nothing, therefore aren't shown in help.
254 * NOMMU-specific options are not meant to be used by users,
255 * therefore we don't show them either.
257 //usage:#define hush_trivial_usage
258 //usage: "[-nx] [-c SCRIPT]"
259 //usage:#define hush_full_usage ""
260 //usage:#define msh_trivial_usage hush_trivial_usage
261 //usage:#define msh_full_usage ""
262 //usage:#define sh_trivial_usage NOUSAGE_STR
263 //usage:#define sh_full_usage ""
264 //usage:#define bash_trivial_usage NOUSAGE_STR
265 //usage:#define bash_full_usage ""
269 #define LEAK_HUNTING 0
270 #define BUILD_AS_NOMMU 0
271 /* Enable/disable sanity checks. Ok to enable in production,
272 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
273 * Keeping 1 for now even in released versions.
276 /* Slightly bigger (+200 bytes), but faster hush.
277 * So far it only enables a trick with counting SIGCHLDs and forks,
278 * which allows us to do fewer waitpid's.
279 * (we can detect a case where neither forks were done nor SIGCHLDs happened
280 * and therefore waitpid will return the same result as last time)
282 #define ENABLE_HUSH_FAST 0
283 /* TODO: implement simplified code for users which do not need ${var%...} ops
284 * So far ${var%...} ops are always enabled:
286 #define ENABLE_HUSH_DOLLAR_OPS 1
291 # undef USE_FOR_NOMMU
294 # define USE_FOR_NOMMU(...) __VA_ARGS__
295 # define USE_FOR_MMU(...)
298 #include "NUM_APPLETS.h"
300 /* STANDALONE does not make sense, and won't compile */
301 # undef CONFIG_FEATURE_SH_STANDALONE
302 # undef ENABLE_FEATURE_SH_STANDALONE
303 # undef IF_FEATURE_SH_STANDALONE
304 # undef IF_NOT_FEATURE_SH_STANDALONE
305 # define ENABLE_FEATURE_SH_STANDALONE 0
306 # define IF_FEATURE_SH_STANDALONE(...)
307 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
310 #if !ENABLE_HUSH_INTERACTIVE
311 # undef ENABLE_FEATURE_EDITING
312 # define ENABLE_FEATURE_EDITING 0
313 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
314 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
317 /* Do we support ANY keywords? */
318 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
319 # define HAS_KEYWORDS 1
320 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
321 # define IF_HAS_NO_KEYWORDS(...)
323 # define HAS_KEYWORDS 0
324 # define IF_HAS_KEYWORDS(...)
325 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
328 /* If you comment out one of these below, it will be #defined later
329 * to perform debug printfs to stderr: */
330 #define debug_printf(...) do {} while (0)
331 /* Finer-grained debug switches */
332 #define debug_printf_parse(...) do {} while (0)
333 #define debug_print_tree(a, b) do {} while (0)
334 #define debug_printf_exec(...) do {} while (0)
335 #define debug_printf_env(...) do {} while (0)
336 #define debug_printf_jobs(...) do {} while (0)
337 #define debug_printf_expand(...) do {} while (0)
338 #define debug_printf_varexp(...) do {} while (0)
339 #define debug_printf_glob(...) do {} while (0)
340 #define debug_printf_list(...) do {} while (0)
341 #define debug_printf_subst(...) do {} while (0)
342 #define debug_printf_clean(...) do {} while (0)
344 #define ERR_PTR ((void*)(long)1)
346 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
348 #define _SPECIAL_VARS_STR "_*@$!?#"
349 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
350 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
351 #if ENABLE_HUSH_BASH_COMPAT
352 /* Support / and // replace ops */
353 /* Note that // is stored as \ in "encoded" string representation */
354 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
355 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
356 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
358 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
359 # define VAR_SUBST_OPS "%#:-=+?"
360 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
363 #define SPECIAL_VAR_SYMBOL 3
367 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
369 /* This supports saving pointers malloced in vfork child,
370 * to be freed in the parent.
373 typedef struct nommu_save_t {
375 struct variable *old_vars;
377 char **argv_from_re_execing;
390 #if ENABLE_HUSH_LOOPS
397 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
402 /* three pseudo-keywords support contrived "case" syntax: */
403 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
404 RES_MATCH , /* "word)" */
405 RES_CASE_BODY, /* "this command is inside CASE" */
412 typedef struct o_string {
414 int length; /* position where data is appended */
417 /* At least some part of the string was inside '' or "",
418 * possibly empty one: word"", wo''rd etc. */
419 smallint has_quoted_part;
420 smallint has_empty_slot;
421 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
424 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
426 /* Protect newly added chars against globbing
427 * by prepending \ to *, ?, [, \ */
428 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
431 MAYBE_ASSIGNMENT = 0,
432 DEFINITELY_ASSIGNMENT = 1,
434 /* Not an assigment, but next word may be: "if v=xyz cmd;" */
437 /* Used for initialization: o_string foo = NULL_O_STRING; */
438 #define NULL_O_STRING { NULL }
440 /* I can almost use ordinary FILE*. Is open_memstream() universally
441 * available? Where is it documented? */
442 typedef struct in_str {
444 /* eof_flag=1: last char in ->p is really an EOF */
445 char eof_flag; /* meaningless if ->p == NULL */
447 #if ENABLE_HUSH_INTERACTIVE
448 smallint promptmode; /* 0: PS1, 1: PS2 */
451 int (*get) (struct in_str *) FAST_FUNC;
452 int (*peek) (struct in_str *) FAST_FUNC;
454 #define i_getch(input) ((input)->get(input))
455 #define i_peek(input) ((input)->peek(input))
457 /* The descrip member of this structure is only used to make
458 * debugging output pretty */
459 static const struct {
461 signed char default_fd;
464 { O_RDONLY, 0, "<" },
465 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
466 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
467 { O_CREAT|O_RDWR, 1, "<>" },
468 { O_RDONLY, 0, "<<" },
469 /* Should not be needed. Bogus default_fd helps in debugging */
470 /* { O_RDONLY, 77, "<<" }, */
473 struct redir_struct {
474 struct redir_struct *next;
475 char *rd_filename; /* filename */
476 int rd_fd; /* fd to redirect */
477 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
479 smallint rd_type; /* (enum redir_type) */
480 /* note: for heredocs, rd_filename contains heredoc delimiter,
481 * and subsequently heredoc itself; and rd_dup is a bitmask:
482 * bit 0: do we need to trim leading tabs?
483 * bit 1: is heredoc quoted (<<'delim' syntax) ?
486 typedef enum redir_type {
488 REDIRECT_OVERWRITE = 1,
491 REDIRECT_HEREDOC = 4,
492 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
495 REDIRFD_SYNTAX_ERR = -2,
496 REDIRFD_TO_FILE = -1,
497 /* otherwise, rd_fd is redirected to rd_dup */
499 HEREDOC_SKIPTABS = 1,
505 pid_t pid; /* 0 if exited */
506 int assignment_cnt; /* how many argv[i] are assignments? */
507 smallint is_stopped; /* is the command currently running? */
508 smallint cmd_type; /* CMD_xxx */
510 #define CMD_SUBSHELL 1
511 #if ENABLE_HUSH_BASH_COMPAT
512 /* used for "[[ EXPR ]]" */
513 # define CMD_SINGLEWORD_NOGLOB 2
515 #if ENABLE_HUSH_FUNCTIONS
516 # define CMD_FUNCDEF 3
519 smalluint cmd_exitcode;
520 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
523 char *group_as_string;
525 #if ENABLE_HUSH_FUNCTIONS
526 struct function *child_func;
527 /* This field is used to prevent a bug here:
528 * while...do f1() {a;}; f1; f1() {b;}; f1; done
529 * When we execute "f1() {a;}" cmd, we create new function and clear
530 * cmd->group, cmd->group_as_string, cmd->argv[0].
531 * When we execute "f1() {b;}", we notice that f1 exists,
532 * and that its "parent cmd" struct is still "alive",
533 * we put those fields back into cmd->xxx
534 * (struct function has ->parent_cmd ptr to facilitate that).
535 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
536 * Without this trick, loop would execute a;b;b;b;...
537 * instead of correct sequence a;b;a;b;...
538 * When command is freed, it severs the link
539 * (sets ->child_func->parent_cmd to NULL).
542 char **argv; /* command name and arguments */
543 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
544 * and on execution these are substituted with their values.
545 * Substitution can make _several_ words out of one argv[n]!
546 * Example: argv[0]=='.^C*^C.' here: echo .$*.
547 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
549 struct redir_struct *redirects; /* I/O redirections */
551 /* Is there anything in this command at all? */
552 #define IS_NULL_CMD(cmd) \
553 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
557 int num_cmds; /* total number of commands in pipe */
558 int alive_cmds; /* number of commands running (not exited) */
559 int stopped_cmds; /* number of commands alive, but stopped */
561 int jobid; /* job number */
562 pid_t pgrp; /* process group ID for the job */
563 char *cmdtext; /* name of job */
565 struct command *cmds; /* array of commands in pipe */
566 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
567 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
568 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
570 typedef enum pipe_style {
576 /* Is there anything in this pipe at all? */
577 #define IS_NULL_PIPE(pi) \
578 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
580 /* This holds pointers to the various results of parsing */
581 struct parse_context {
582 /* linked list of pipes */
583 struct pipe *list_head;
584 /* last pipe (being constructed right now) */
586 /* last command in pipe (being constructed right now) */
587 struct command *command;
588 /* last redirect in command->redirects list */
589 struct redir_struct *pending_redirect;
595 smallint ctx_inverted; /* "! cmd | cmd" */
597 smallint ctx_dsemicolon; /* ";;" seen */
599 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
601 /* group we are enclosed in:
602 * example: "if pipe1; pipe2; then pipe3; fi"
603 * when we see "if" or "then", we malloc and copy current context,
604 * and make ->stack point to it. then we parse pipeN.
605 * when closing "then" / fi" / whatever is found,
606 * we move list_head into ->stack->command->group,
607 * copy ->stack into current context, and delete ->stack.
608 * (parsing of { list } and ( list ) doesn't use this method)
610 struct parse_context *stack;
614 /* On program start, environ points to initial environment.
615 * putenv adds new pointers into it, unsetenv removes them.
616 * Neither of these (de)allocates the strings.
617 * setenv allocates new strings in malloc space and does putenv,
618 * and thus setenv is unusable (leaky) for shell's purposes */
619 #define setenv(...) setenv_is_leaky_dont_use()
621 struct variable *next;
622 char *varstr; /* points to "name=" portion */
623 #if ENABLE_HUSH_LOCAL
624 unsigned func_nest_level;
626 int max_len; /* if > 0, name is part of initial env; else name is malloced */
627 smallint flg_export; /* putenv should be done on this var */
628 smallint flg_read_only;
636 #if ENABLE_HUSH_FUNCTIONS
638 struct function *next;
640 struct command *parent_cmd;
643 char *body_as_string;
649 /* set -/+o OPT support. (TODO: make it optional)
650 * bash supports the following opts:
661 * interactive-comments on
679 static const char o_opt_strings[] ALIGN1 =
682 #if ENABLE_HUSH_MODE_X
689 #if ENABLE_HUSH_MODE_X
696 /* "Globals" within this file */
697 /* Sorted roughly by size (smaller offsets == smaller code) */
699 /* interactive_fd != 0 means we are an interactive shell.
700 * If we are, then saved_tty_pgrp can also be != 0, meaning
701 * that controlling tty is available. With saved_tty_pgrp == 0,
702 * job control still works, but terminal signals
703 * (^C, ^Z, ^Y, ^\) won't work at all, and background
704 * process groups can only be created with "cmd &".
705 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
706 * to give tty to the foreground process group,
707 * and will take it back when the group is stopped (^Z)
710 #if ENABLE_HUSH_INTERACTIVE
711 /* 'interactive_fd' is a fd# open to ctty, if we have one
712 * _AND_ if we decided to act interactively */
716 # define G_interactive_fd (G.interactive_fd)
718 # define G_interactive_fd 0
720 #if ENABLE_FEATURE_EDITING
721 line_input_t *line_input_state;
726 #if ENABLE_HUSH_RANDOM_SUPPORT
732 pid_t saved_tty_pgrp;
733 struct pipe *job_list;
734 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
736 # define G_saved_tty_pgrp 0
738 char o_opt[NUM_OPT_O];
739 #if ENABLE_HUSH_MODE_X
740 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
744 smallint flag_SIGINT;
745 #if ENABLE_HUSH_LOOPS
746 smallint flag_break_continue;
748 #if ENABLE_HUSH_FUNCTIONS
749 /* 0: outside of a function (or sourced file)
750 * -1: inside of a function, ok to use return builtin
751 * 1: return is invoked, skip all till end of func
753 smallint flag_return_in_progress;
755 smallint exiting; /* used to prevent EXIT trap recursion */
756 /* These four support $?, $#, and $1 */
757 smalluint last_exitcode;
758 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
759 smalluint global_args_malloced;
760 smalluint inherited_set_is_saved;
761 /* how many non-NULL argv's we have. NB: $# + 1 */
765 char *argv0_for_re_execing;
767 #if ENABLE_HUSH_LOOPS
768 unsigned depth_break_continue;
769 unsigned depth_of_loop;
773 struct variable *top_var;
774 char **expanded_assignments;
775 #if ENABLE_HUSH_FUNCTIONS
776 struct function *top_func;
777 # if ENABLE_HUSH_LOCAL
778 struct variable **shadowed_vars_pp;
779 unsigned func_nest_level;
782 /* Signal and trap handling */
784 unsigned count_SIGCHLD;
785 unsigned handled_SIGCHLD;
786 smallint we_have_children;
788 /* which signals have non-DFL handler (even with no traps set)? */
789 unsigned non_DFL_mask;
790 char **traps; /* char *traps[NSIG] */
791 sigset_t blocked_set;
792 sigset_t inherited_set;
794 unsigned long memleak_value;
797 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
799 #define G (*ptr_to_globals)
800 /* Not #defining name to G.name - this quickly gets unwieldy
801 * (too many defines). Also, I actually prefer to see when a variable
802 * is global, thus "G." prefix is a useful hint */
803 #define INIT_G() do { \
804 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
808 /* Function prototypes for builtins */
809 static int builtin_cd(char **argv) FAST_FUNC;
810 static int builtin_echo(char **argv) FAST_FUNC;
811 static int builtin_eval(char **argv) FAST_FUNC;
812 static int builtin_exec(char **argv) FAST_FUNC;
813 static int builtin_exit(char **argv) FAST_FUNC;
814 static int builtin_export(char **argv) FAST_FUNC;
816 static int builtin_fg_bg(char **argv) FAST_FUNC;
817 static int builtin_jobs(char **argv) FAST_FUNC;
820 static int builtin_help(char **argv) FAST_FUNC;
822 #if ENABLE_HUSH_LOCAL
823 static int builtin_local(char **argv) FAST_FUNC;
826 static int builtin_memleak(char **argv) FAST_FUNC;
829 static int builtin_printf(char **argv) FAST_FUNC;
831 static int builtin_pwd(char **argv) FAST_FUNC;
832 static int builtin_read(char **argv) FAST_FUNC;
833 static int builtin_set(char **argv) FAST_FUNC;
834 static int builtin_shift(char **argv) FAST_FUNC;
835 static int builtin_source(char **argv) FAST_FUNC;
836 static int builtin_test(char **argv) FAST_FUNC;
837 static int builtin_trap(char **argv) FAST_FUNC;
838 static int builtin_type(char **argv) FAST_FUNC;
839 static int builtin_true(char **argv) FAST_FUNC;
840 static int builtin_umask(char **argv) FAST_FUNC;
841 static int builtin_unset(char **argv) FAST_FUNC;
842 static int builtin_wait(char **argv) FAST_FUNC;
843 #if ENABLE_HUSH_LOOPS
844 static int builtin_break(char **argv) FAST_FUNC;
845 static int builtin_continue(char **argv) FAST_FUNC;
847 #if ENABLE_HUSH_FUNCTIONS
848 static int builtin_return(char **argv) FAST_FUNC;
851 /* Table of built-in functions. They can be forked or not, depending on
852 * context: within pipes, they fork. As simple commands, they do not.
853 * When used in non-forking context, they can change global variables
854 * in the parent shell process. If forked, of course they cannot.
855 * For example, 'unset foo | whatever' will parse and run, but foo will
856 * still be set at the end. */
857 struct built_in_command {
859 int (*b_function)(char **argv) FAST_FUNC;
862 # define BLTIN(cmd, func, help) { cmd, func, help }
864 # define BLTIN(cmd, func, help) { cmd, func }
868 static const struct built_in_command bltins1[] = {
869 BLTIN("." , builtin_source , "Run commands in a file"),
870 BLTIN(":" , builtin_true , NULL),
872 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
874 #if ENABLE_HUSH_LOOPS
875 BLTIN("break" , builtin_break , "Exit from a loop"),
877 BLTIN("cd" , builtin_cd , "Change directory"),
878 #if ENABLE_HUSH_LOOPS
879 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
881 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
882 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
883 BLTIN("exit" , builtin_exit , "Exit"),
884 BLTIN("export" , builtin_export , "Set environment variables"),
886 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
889 BLTIN("help" , builtin_help , NULL),
892 BLTIN("jobs" , builtin_jobs , "List jobs"),
894 #if ENABLE_HUSH_LOCAL
895 BLTIN("local" , builtin_local , "Set local variables"),
898 BLTIN("memleak" , builtin_memleak , NULL),
900 BLTIN("read" , builtin_read , "Input into variable"),
901 #if ENABLE_HUSH_FUNCTIONS
902 BLTIN("return" , builtin_return , "Return from a function"),
904 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
905 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
906 #if ENABLE_HUSH_BASH_COMPAT
907 BLTIN("source" , builtin_source , "Run commands in a file"),
909 BLTIN("trap" , builtin_trap , "Trap signals"),
910 BLTIN("type" , builtin_type , "Show command type"),
911 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
912 BLTIN("umask" , builtin_umask , "Set file creation mask"),
913 BLTIN("unset" , builtin_unset , "Unset variables"),
914 BLTIN("wait" , builtin_wait , "Wait for process"),
916 /* For now, echo and test are unconditionally enabled.
917 * Maybe make it configurable? */
918 static const struct built_in_command bltins2[] = {
919 BLTIN("[" , builtin_test , NULL),
920 BLTIN("echo" , builtin_echo , NULL),
922 BLTIN("printf" , builtin_printf , NULL),
924 BLTIN("pwd" , builtin_pwd , NULL),
925 BLTIN("test" , builtin_test , NULL),
932 /* prevent disasters with G.debug_indent < 0 */
933 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
934 # define debug_enter() (G.debug_indent++)
935 # define debug_leave() (G.debug_indent--)
937 # define indent() ((void)0)
938 # define debug_enter() ((void)0)
939 # define debug_leave() ((void)0)
943 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
946 #ifndef debug_printf_parse
947 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
950 #ifndef debug_printf_exec
951 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
954 #ifndef debug_printf_env
955 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
958 #ifndef debug_printf_jobs
959 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
960 # define DEBUG_JOBS 1
962 # define DEBUG_JOBS 0
965 #ifndef debug_printf_expand
966 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
967 # define DEBUG_EXPAND 1
969 # define DEBUG_EXPAND 0
972 #ifndef debug_printf_varexp
973 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
976 #ifndef debug_printf_glob
977 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
978 # define DEBUG_GLOB 1
980 # define DEBUG_GLOB 0
983 #ifndef debug_printf_list
984 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
987 #ifndef debug_printf_subst
988 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
991 #ifndef debug_printf_clean
992 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
993 # define DEBUG_CLEAN 1
995 # define DEBUG_CLEAN 0
999 static void debug_print_strings(const char *prefix, char **vv)
1002 fdprintf(2, "%s:\n", prefix);
1004 fdprintf(2, " '%s'\n", *vv++);
1007 # define debug_print_strings(prefix, vv) ((void)0)
1011 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1014 static void *xxmalloc(int lineno, size_t size)
1016 void *ptr = xmalloc((size + 0xff) & ~0xff);
1017 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1020 static void *xxrealloc(int lineno, void *ptr, size_t size)
1022 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1023 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1026 static char *xxstrdup(int lineno, const char *str)
1028 char *ptr = xstrdup(str);
1029 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1032 static void xxfree(void *ptr)
1034 fdprintf(2, "free %p\n", ptr);
1037 # define xmalloc(s) xxmalloc(__LINE__, s)
1038 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1039 # define xstrdup(s) xxstrdup(__LINE__, s)
1040 # define free(p) xxfree(p)
1044 /* Syntax and runtime errors. They always abort scripts.
1045 * In interactive use they usually discard unparsed and/or unexecuted commands
1046 * and return to the prompt.
1047 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1050 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1051 # define syntax_error(lineno, msg) syntax_error(msg)
1052 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1053 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1054 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1055 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1058 static void die_if_script(unsigned lineno, const char *fmt, ...)
1063 bb_error_msg("hush.c:%u", lineno);
1066 bb_verror_msg(fmt, p, NULL);
1068 if (!G_interactive_fd)
1072 static void syntax_error(unsigned lineno, const char *msg)
1075 die_if_script(lineno, "syntax error: %s", msg);
1077 die_if_script(lineno, "syntax error", NULL);
1080 static void syntax_error_at(unsigned lineno, const char *msg)
1082 die_if_script(lineno, "syntax error at '%s'", msg);
1085 static void syntax_error_unterm_str(unsigned lineno, const char *s)
1087 die_if_script(lineno, "syntax error: unterminated %s", s);
1090 /* It so happens that all such cases are totally fatal
1091 * even if shell is interactive: EOF while looking for closing
1092 * delimiter. There is nowhere to read stuff from after that,
1093 * it's EOF! The only choice is to terminate.
1095 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
1096 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1098 char msg[2] = { ch, '\0' };
1099 syntax_error_unterm_str(lineno, msg);
1103 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
1108 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1112 # undef die_if_script
1113 # undef syntax_error
1114 # undef syntax_error_at
1115 # undef syntax_error_unterm_ch
1116 # undef syntax_error_unterm_str
1117 # undef syntax_error_unexpected_ch
1119 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1120 # define syntax_error(msg) syntax_error(__LINE__, msg)
1121 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1122 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1123 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1124 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1128 #if ENABLE_HUSH_INTERACTIVE
1129 static void cmdedit_update_prompt(void);
1131 # define cmdedit_update_prompt() ((void)0)
1135 /* Utility functions
1137 /* Replace each \x with x in place, return ptr past NUL. */
1138 static char *unbackslash(char *src)
1140 char *dst = src = strchrnul(src, '\\');
1144 if ((*dst++ = *src++) == '\0')
1150 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1171 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1172 v[count1 + count2] = NULL;
1175 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1179 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1181 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1182 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1185 #define add_strings_to_strings(strings, add, need_to_dup) \
1186 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1189 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1190 static char **add_string_to_strings(char **strings, char *add)
1195 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1198 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1200 char **ptr = add_string_to_strings(strings, add);
1201 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1204 #define add_string_to_strings(strings, add) \
1205 xx_add_string_to_strings(__LINE__, strings, add)
1208 static void free_strings(char **strings)
1223 /* Helpers for setting new $n and restoring them back
1225 typedef struct save_arg_t {
1229 smallint sv_g_malloced;
1232 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1236 sv->sv_argv0 = argv[0];
1237 sv->sv_g_argv = G.global_argv;
1238 sv->sv_g_argc = G.global_argc;
1239 sv->sv_g_malloced = G.global_args_malloced;
1241 argv[0] = G.global_argv[0]; /* retain $0 */
1242 G.global_argv = argv;
1243 G.global_args_malloced = 0;
1251 static void restore_G_args(save_arg_t *sv, char **argv)
1255 if (G.global_args_malloced) {
1256 /* someone ran "set -- arg1 arg2 ...", undo */
1258 while (*++pp) /* note: does not free $0 */
1260 free(G.global_argv);
1262 argv[0] = sv->sv_argv0;
1263 G.global_argv = sv->sv_g_argv;
1264 G.global_argc = sv->sv_g_argc;
1265 G.global_args_malloced = sv->sv_g_malloced;
1269 /* Basic theory of signal handling in shell
1270 * ========================================
1271 * This does not describe what hush does, rather, it is current understanding
1272 * what it _should_ do. If it doesn't, it's a bug.
1273 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1275 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1276 * is finished or backgrounded. It is the same in interactive and
1277 * non-interactive shells, and is the same regardless of whether
1278 * a user trap handler is installed or a shell special one is in effect.
1279 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1280 * backgrounds (i.e. stops) or kills all members of currently running
1283 * Wait builtin in interruptible by signals for which user trap is set
1284 * or by SIGINT in interactive shell.
1286 * Trap handlers will execute even within trap handlers. (right?)
1288 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1289 * except for handlers set to '' (empty string).
1291 * If job control is off, backgrounded commands ("cmd &")
1292 * have SIGINT, SIGQUIT set to SIG_IGN.
1294 * Commands which are run in command substitution ("`cmd`")
1295 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1297 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1298 * by the shell from its parent.
1300 * Signals which differ from SIG_DFL action
1301 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1304 * SIGTERM (interactive): ignore
1305 * SIGHUP (interactive):
1306 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1307 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1308 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1309 * that all pipe members are stopped. Try this in bash:
1310 * while :; do :; done - ^Z does not background it
1311 * (while :; do :; done) - ^Z backgrounds it
1312 * SIGINT (interactive): wait for last pipe, ignore the rest
1313 * of the command line, show prompt. NB: ^C does not send SIGINT
1314 * to interactive shell while shell is waiting for a pipe,
1315 * since shell is bg'ed (is not in foreground process group).
1316 * Example 1: this waits 5 sec, but does not execute ls:
1317 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1318 * Example 2: this does not wait and does not execute ls:
1319 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1320 * Example 3: this does not wait 5 sec, but executes ls:
1321 * "sleep 5; ls -l" + press ^C
1323 * (What happens to signals which are IGN on shell start?)
1324 * (What happens with signal mask on shell start?)
1326 * Implementation in hush
1327 * ======================
1328 * We use in-kernel pending signal mask to determine which signals were sent.
1329 * We block all signals which we don't want to take action immediately,
1330 * i.e. we block all signals which need to have special handling as described
1331 * above, and all signals which have traps set.
1332 * After each pipe execution, we extract any pending signals via sigtimedwait()
1335 * unsigned non_DFL_mask: a mask of such "special" signals
1336 * sigset_t blocked_set: current blocked signal set
1339 * clear bit in blocked_set unless it is also in non_DFL_mask
1340 * "trap 'cmd' SIGxxx":
1341 * set bit in blocked_set (even if 'cmd' is '')
1342 * after [v]fork, if we plan to be a shell:
1343 * unblock signals with special interactive handling
1344 * (child shell is not interactive),
1345 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1346 * after [v]fork, if we plan to exec:
1347 * POSIX says fork clears pending signal mask in child - no need to clear it.
1348 * Restore blocked signal set to one inherited by shell just prior to exec.
1350 * Note: as a result, we do not use signal handlers much. The only uses
1351 * are to count SIGCHLDs
1352 * and to restore tty pgrp on signal-induced exit.
1355 * Standard says "When a subshell is entered, traps that are not being ignored
1356 * are set to the default actions". bash interprets it so that traps which
1357 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1360 SPECIAL_INTERACTIVE_SIGS = 0
1365 SPECIAL_JOB_SIGS = 0
1373 #if ENABLE_HUSH_FAST
1374 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1377 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1383 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1384 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1385 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1386 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1388 /* Restores tty foreground process group, and exits.
1389 * May be called as signal handler for fatal signal
1390 * (will resend signal to itself, producing correct exit state)
1391 * or called directly with -EXITCODE.
1392 * We also call it if xfunc is exiting. */
1393 static void sigexit(int sig) NORETURN;
1394 static void sigexit(int sig)
1396 /* Disable all signals: job control, SIGPIPE, etc. */
1397 sigprocmask_allsigs(SIG_BLOCK);
1399 /* Careful: we can end up here after [v]fork. Do not restore
1400 * tty pgrp then, only top-level shell process does that */
1401 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1402 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1404 /* Not a signal, just exit */
1408 kill_myself_with_sig(sig); /* does not return */
1412 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1413 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1417 /* Restores tty foreground process group, and exits. */
1418 static void hush_exit(int exitcode) NORETURN;
1419 static void hush_exit(int exitcode)
1422 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1423 /* Prevent recursion:
1424 * trap "echo Hi; exit" EXIT; exit
1427 /* argv[0] is unused */
1428 argv[1] = G.traps[0];
1430 G.exiting = 1; /* prevent EXIT trap recursion */
1431 /* Note: G.traps[0] is not cleared!
1432 * "trap" will still show it, if executed
1437 #if ENABLE_FEATURE_CLEAN_UP
1439 struct variable *cur_var;
1440 if (G.cwd != bb_msg_unknown)
1442 cur_var = G.top_var;
1444 struct variable *tmp = cur_var;
1445 if (!cur_var->max_len)
1446 free(cur_var->varstr);
1447 cur_var = cur_var->next;
1455 sigexit(- (exitcode & 0xff));
1462 static int check_and_run_traps(int sig)
1464 /* I want it in rodata, not in bss.
1465 * gcc 4.2.1 puts it in rodata only if it has { 0, 0 }
1466 * initializer. But other compilers may still use bss.
1467 * TODO: find more portable solution.
1469 static const struct timespec zero_timespec = { 0, 0 };
1470 smalluint save_rcode;
1476 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1481 if (G.traps && G.traps[sig]) {
1482 if (G.traps[sig][0]) {
1483 /* We have user-defined handler */
1485 /* argv[0] is unused */
1486 argv[1] = G.traps[sig];
1488 save_rcode = G.last_exitcode;
1490 G.last_exitcode = save_rcode;
1491 } /* else: "" trap, ignoring signal */
1494 /* not a trap: special action */
1496 #if ENABLE_HUSH_FAST
1499 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1503 /* Builtin was ^C'ed, make it look prettier: */
1510 /* bash is observed to signal whole process groups,
1511 * not individual processes */
1512 for (job = G.job_list; job; job = job->next) {
1515 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1516 if (kill(- job->pgrp, SIGHUP) == 0)
1517 kill(- job->pgrp, SIGCONT);
1522 default: /* ignored: */
1523 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1531 static const char *get_cwd(int force)
1533 if (force || G.cwd == NULL) {
1534 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1535 * we must not try to free(bb_msg_unknown) */
1536 if (G.cwd == bb_msg_unknown)
1538 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1540 G.cwd = bb_msg_unknown;
1547 * Shell and environment variable support
1549 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1551 struct variable **pp;
1552 struct variable *cur;
1555 while ((cur = *pp) != NULL) {
1556 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1563 static const char* FAST_FUNC get_local_var_value(const char *name)
1565 struct variable **vpp;
1566 unsigned len = strlen(name);
1568 if (G.expanded_assignments) {
1569 char **cpp = G.expanded_assignments;
1572 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1573 return cp + len + 1;
1578 vpp = get_ptr_to_local_var(name, len);
1580 return (*vpp)->varstr + len + 1;
1582 if (strcmp(name, "PPID") == 0)
1583 return utoa(G.root_ppid);
1584 // bash compat: UID? EUID?
1585 #if ENABLE_HUSH_RANDOM_SUPPORT
1586 if (strcmp(name, "RANDOM") == 0)
1587 return utoa(next_random(&G.random_gen));
1592 /* str holds "NAME=VAL" and is expected to be malloced.
1593 * We take ownership of it.
1595 * 0: do not change export flag
1596 * (if creating new variable, flag will be 0)
1597 * 1: set export flag and putenv the variable
1598 * -1: clear export flag and unsetenv the variable
1599 * flg_read_only is set only when we handle -R var=val
1601 #if !BB_MMU && ENABLE_HUSH_LOCAL
1602 /* all params are used */
1603 #elif BB_MMU && ENABLE_HUSH_LOCAL
1604 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1605 set_local_var(str, flg_export, local_lvl)
1606 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1607 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1608 set_local_var(str, flg_export)
1609 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1610 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1611 set_local_var(str, flg_export, flg_read_only)
1613 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1615 struct variable **var_pp;
1616 struct variable *cur;
1620 eq_sign = strchr(str, '=');
1621 if (!eq_sign) { /* not expected to ever happen? */
1626 name_len = eq_sign - str + 1; /* including '=' */
1627 var_pp = &G.top_var;
1628 while ((cur = *var_pp) != NULL) {
1629 if (strncmp(cur->varstr, str, name_len) != 0) {
1630 var_pp = &cur->next;
1633 /* We found an existing var with this name */
1634 if (cur->flg_read_only) {
1638 bb_error_msg("%s: readonly variable", str);
1642 if (flg_export == -1) { // "&& cur->flg_export" ?
1643 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1648 #if ENABLE_HUSH_LOCAL
1649 if (cur->func_nest_level < local_lvl) {
1650 /* New variable is declared as local,
1651 * and existing one is global, or local
1652 * from enclosing function.
1653 * Remove and save old one: */
1654 *var_pp = cur->next;
1655 cur->next = *G.shadowed_vars_pp;
1656 *G.shadowed_vars_pp = cur;
1657 /* bash 3.2.33(1) and exported vars:
1659 * # f() { local z=a; env | grep ^z; }
1665 if (cur->flg_export)
1670 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1675 if (cur->max_len != 0) {
1676 if (cur->max_len >= strlen(str)) {
1677 /* This one is from startup env, reuse space */
1678 strcpy(cur->varstr, str);
1682 /* max_len == 0 signifies "malloced" var, which we can
1683 * (and has to) free */
1687 goto set_str_and_exp;
1690 /* Not found - create new variable struct */
1691 cur = xzalloc(sizeof(*cur));
1692 #if ENABLE_HUSH_LOCAL
1693 cur->func_nest_level = local_lvl;
1695 cur->next = *var_pp;
1701 cur->flg_read_only = flg_read_only;
1704 if (flg_export == 1)
1705 cur->flg_export = 1;
1706 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1707 cmdedit_update_prompt();
1708 if (cur->flg_export) {
1709 if (flg_export == -1) {
1710 cur->flg_export = 0;
1711 /* unsetenv was already done */
1713 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1714 return putenv(cur->varstr);
1720 /* Used at startup and after each cd */
1721 static void set_pwd_var(int exp)
1723 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1724 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1727 static int unset_local_var_len(const char *name, int name_len)
1729 struct variable *cur;
1730 struct variable **var_pp;
1733 return EXIT_SUCCESS;
1734 var_pp = &G.top_var;
1735 while ((cur = *var_pp) != NULL) {
1736 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1737 if (cur->flg_read_only) {
1738 bb_error_msg("%s: readonly variable", name);
1739 return EXIT_FAILURE;
1741 *var_pp = cur->next;
1742 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1743 bb_unsetenv(cur->varstr);
1744 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1745 cmdedit_update_prompt();
1749 return EXIT_SUCCESS;
1751 var_pp = &cur->next;
1753 return EXIT_SUCCESS;
1756 static int unset_local_var(const char *name)
1758 return unset_local_var_len(name, strlen(name));
1761 static void unset_vars(char **strings)
1769 const char *eq = strchrnul(*v, '=');
1770 unset_local_var_len(*v, (int)(eq - *v));
1776 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1778 char *var = xasprintf("%s=%s", name, val);
1779 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1784 * Helpers for "var1=val1 var2=val2 cmd" feature
1786 static void add_vars(struct variable *var)
1788 struct variable *next;
1792 var->next = G.top_var;
1794 if (var->flg_export) {
1795 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1796 putenv(var->varstr);
1798 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1804 static struct variable *set_vars_and_save_old(char **strings)
1807 struct variable *old = NULL;
1813 struct variable *var_p;
1814 struct variable **var_pp;
1817 eq = strchr(*s, '=');
1819 var_pp = get_ptr_to_local_var(*s, eq - *s);
1821 /* Remove variable from global linked list */
1823 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1824 *var_pp = var_p->next;
1825 /* Add it to returned list */
1829 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1840 static int FAST_FUNC static_get(struct in_str *i)
1850 static int FAST_FUNC static_peek(struct in_str *i)
1855 #if ENABLE_HUSH_INTERACTIVE
1857 static void cmdedit_update_prompt(void)
1859 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1860 G.PS1 = get_local_var_value("PS1");
1863 G.PS2 = get_local_var_value("PS2");
1871 static const char *setup_prompt_string(int promptmode)
1873 const char *prompt_str;
1874 debug_printf("setup_prompt_string %d ", promptmode);
1875 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1876 /* Set up the prompt */
1877 if (promptmode == 0) { /* PS1 */
1879 /* bash uses $PWD value, even if it is set by user.
1880 * It uses current dir only if PWD is unset.
1881 * We always use current dir. */
1882 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1887 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1888 debug_printf("result '%s'\n", prompt_str);
1892 static void get_user_input(struct in_str *i)
1895 const char *prompt_str;
1897 prompt_str = setup_prompt_string(i->promptmode);
1898 # if ENABLE_FEATURE_EDITING
1899 /* Enable command line editing only while a command line
1900 * is actually being read */
1903 /* buglet: SIGINT will not make new prompt to appear _at once_,
1904 * only after <Enter>. (^C will work) */
1905 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1906 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1907 check_and_run_traps(0);
1908 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1909 i->eof_flag = (r < 0);
1910 if (i->eof_flag) { /* EOF/error detected */
1911 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1912 G.user_input_buf[1] = '\0';
1917 fputs(prompt_str, stdout);
1919 G.user_input_buf[0] = r = fgetc(i->file);
1920 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1921 //do we need check_and_run_traps(0)? (maybe only if stdin)
1922 } while (G.flag_SIGINT);
1923 i->eof_flag = (r == EOF);
1925 i->p = G.user_input_buf;
1928 #endif /* INTERACTIVE */
1930 /* This is the magic location that prints prompts
1931 * and gets data back from the user */
1932 static int FAST_FUNC file_get(struct in_str *i)
1936 /* If there is data waiting, eat it up */
1937 if (i->p && *i->p) {
1938 #if ENABLE_HUSH_INTERACTIVE
1942 if (i->eof_flag && !*i->p)
1944 /* note: ch is never NUL */
1946 /* need to double check i->file because we might be doing something
1947 * more complicated by now, like sourcing or substituting. */
1948 #if ENABLE_HUSH_INTERACTIVE
1949 if (G_interactive_fd && i->file == stdin) {
1952 } while (!*i->p); /* need non-empty line */
1953 i->promptmode = 1; /* PS2 */
1957 do ch = fgetc(i->file); while (ch == '\0');
1959 debug_printf("file_get: got '%c' %d\n", ch, ch);
1963 /* All callers guarantee this routine will never
1964 * be used right after a newline, so prompting is not needed.
1966 static int FAST_FUNC file_peek(struct in_str *i)
1969 if (i->p && *i->p) {
1970 if (i->eof_flag && !i->p[1])
1973 /* note: ch is never NUL */
1975 do ch = fgetc(i->file); while (ch == '\0');
1976 i->eof_flag = (ch == EOF);
1977 i->peek_buf[0] = ch;
1978 i->peek_buf[1] = '\0';
1980 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1984 static void setup_file_in_str(struct in_str *i, FILE *f)
1986 memset(i, 0, sizeof(*i));
1987 i->peek = file_peek;
1989 /* i->promptmode = 0; - PS1 (memset did it) */
1994 static void setup_string_in_str(struct in_str *i, const char *s)
1996 memset(i, 0, sizeof(*i));
1997 i->peek = static_peek;
1998 i->get = static_get;
1999 /* i->promptmode = 0; - PS1 (memset did it) */
2001 /* i->eof_flag = 0; */
2008 #define B_CHUNK (32 * sizeof(char*))
2010 static void o_reset_to_empty_unquoted(o_string *o)
2013 o->has_quoted_part = 0;
2018 static void o_free(o_string *o)
2021 memset(o, 0, sizeof(*o));
2024 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2029 static void o_grow_by(o_string *o, int len)
2031 if (o->length + len > o->maxlen) {
2032 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2033 o->data = xrealloc(o->data, 1 + o->maxlen);
2037 static void o_addchr(o_string *o, int ch)
2039 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2041 o->data[o->length] = ch;
2043 o->data[o->length] = '\0';
2046 static void o_addblock(o_string *o, const char *str, int len)
2049 memcpy(&o->data[o->length], str, len);
2051 o->data[o->length] = '\0';
2054 static void o_addstr(o_string *o, const char *str)
2056 o_addblock(o, str, strlen(str));
2060 static void nommu_addchr(o_string *o, int ch)
2066 # define nommu_addchr(o, str) ((void)0)
2069 static void o_addstr_with_NUL(o_string *o, const char *str)
2071 o_addblock(o, str, strlen(str) + 1);
2075 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2076 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2077 * Apparently, on unquoted $v bash still does globbing
2078 * ("v='*.txt'; echo $v" prints all .txt files),
2079 * but NOT brace expansion! Thus, there should be TWO independent
2080 * quoting mechanisms on $v expansion side: one protects
2081 * $v from brace expansion, and other additionally protects "$v" against globbing.
2082 * We have only second one.
2085 #if ENABLE_HUSH_BRACE_EXPANSION
2086 # define MAYBE_BRACES "{}"
2088 # define MAYBE_BRACES ""
2091 /* My analysis of quoting semantics tells me that state information
2092 * is associated with a destination, not a source.
2094 static void o_addqchr(o_string *o, int ch)
2097 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2102 o->data[o->length] = '\\';
2105 o->data[o->length] = ch;
2107 o->data[o->length] = '\0';
2110 static void o_addQchr(o_string *o, int ch)
2113 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2114 && strchr("*?[\\" MAYBE_BRACES, ch)
2117 o->data[o->length] = '\\';
2121 o->data[o->length] = ch;
2123 o->data[o->length] = '\0';
2126 static void o_addqblock(o_string *o, const char *str, int len)
2131 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2132 if (ordinary_cnt > len) /* paranoia */
2134 o_addblock(o, str, ordinary_cnt);
2135 if (ordinary_cnt == len)
2137 str += ordinary_cnt;
2138 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2142 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2144 o->data[o->length] = '\\';
2148 o->data[o->length] = ch;
2150 o->data[o->length] = '\0';
2154 static void o_addQblock(o_string *o, const char *str, int len)
2156 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2157 o_addblock(o, str, len);
2160 o_addqblock(o, str, len);
2163 static void o_addQstr(o_string *o, const char *str)
2165 o_addQblock(o, str, strlen(str));
2168 /* A special kind of o_string for $VAR and `cmd` expansion.
2169 * It contains char* list[] at the beginning, which is grown in 16 element
2170 * increments. Actual string data starts at the next multiple of 16 * (char*).
2171 * list[i] contains an INDEX (int!) into this string data.
2172 * It means that if list[] needs to grow, data needs to be moved higher up
2173 * but list[i]'s need not be modified.
2174 * NB: remembering how many list[i]'s you have there is crucial.
2175 * o_finalize_list() operation post-processes this structure - calculates
2176 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2178 #if DEBUG_EXPAND || DEBUG_GLOB
2179 static void debug_print_list(const char *prefix, o_string *o, int n)
2181 char **list = (char**)o->data;
2182 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2186 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2187 prefix, list, n, string_start, o->length, o->maxlen,
2188 !!(o->o_expflags & EXP_FLAG_GLOB),
2190 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2193 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2194 o->data + (int)(uintptr_t)list[i] + string_start,
2195 o->data + (int)(uintptr_t)list[i] + string_start);
2199 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2201 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2205 # define debug_print_list(prefix, o, n) ((void)0)
2208 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2209 * in list[n] so that it points past last stored byte so far.
2210 * It returns n+1. */
2211 static int o_save_ptr_helper(o_string *o, int n)
2213 char **list = (char**)o->data;
2217 if (!o->has_empty_slot) {
2218 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2219 string_len = o->length - string_start;
2220 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2221 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2222 /* list[n] points to string_start, make space for 16 more pointers */
2223 o->maxlen += 0x10 * sizeof(list[0]);
2224 o->data = xrealloc(o->data, o->maxlen + 1);
2225 list = (char**)o->data;
2226 memmove(list + n + 0x10, list + n, string_len);
2227 o->length += 0x10 * sizeof(list[0]);
2229 debug_printf_list("list[%d]=%d string_start=%d\n",
2230 n, string_len, string_start);
2233 /* We have empty slot at list[n], reuse without growth */
2234 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2235 string_len = o->length - string_start;
2236 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2237 n, string_len, string_start);
2238 o->has_empty_slot = 0;
2240 list[n] = (char*)(uintptr_t)string_len;
2244 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2245 static int o_get_last_ptr(o_string *o, int n)
2247 char **list = (char**)o->data;
2248 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2250 return ((int)(uintptr_t)list[n-1]) + string_start;
2253 #if ENABLE_HUSH_BRACE_EXPANSION
2254 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2255 * first, it processes even {a} (no commas), second,
2256 * I didn't manage to make it return strings when they don't match
2257 * existing files. Need to re-implement it.
2261 static int glob_needed(const char *s)
2270 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2276 /* Return pointer to next closing brace or to comma */
2277 static const char *next_brace_sub(const char *cp)
2281 while (*cp != '\0') {
2288 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2294 return *cp != '\0' ? cp : NULL;
2296 /* Recursive brace globber. Note: may garble pattern[]. */
2297 static int glob_brace(char *pattern, o_string *o, int n)
2299 char *new_pattern_buf;
2306 debug_printf_glob("glob_brace('%s')\n", pattern);
2312 if (*begin == '{') {
2313 /* Find the first sub-pattern and at the same time
2314 * find the rest after the closing brace */
2315 next = next_brace_sub(begin);
2317 /* An illegal expression */
2321 /* "{abc}" with no commas - illegal
2322 * brace expr, disregard and skip it */
2328 if (*begin == '\\' && begin[1] != '\0')
2332 debug_printf_glob("begin:%s\n", begin);
2333 debug_printf_glob("next:%s\n", next);
2335 /* Now find the end of the whole brace expression */
2337 while (*rest != '}') {
2338 rest = next_brace_sub(rest);
2340 /* An illegal expression */
2343 debug_printf_glob("rest:%s\n", rest);
2345 rest_len = strlen(++rest) + 1;
2347 /* We are sure the brace expression is well-formed */
2349 /* Allocate working buffer large enough for our work */
2350 new_pattern_buf = xmalloc(strlen(pattern));
2352 /* We have a brace expression. BEGIN points to the opening {,
2353 * NEXT points past the terminator of the first element, and REST
2354 * points past the final }. We will accumulate result names from
2355 * recursive runs for each brace alternative in the buffer using
2360 /* Construct the new glob expression */
2363 mempcpy(new_pattern_buf,
2364 /* We know the prefix for all sub-patterns */
2365 pattern, begin - pattern),
2369 /* Note: glob_brace() may garble new_pattern_buf[].
2370 * That's why we re-copy prefix every time (1st memcpy above).
2372 n = glob_brace(new_pattern_buf, o, n);
2374 /* We saw the last entry */
2378 next = next_brace_sub(next);
2380 free(new_pattern_buf);
2388 memset(&globdata, 0, sizeof(globdata));
2389 gr = glob(pattern, 0, NULL, &globdata);
2390 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2392 if (gr == GLOB_NOMATCH) {
2393 globfree(&globdata);
2394 /* NB: garbles parameter */
2395 unbackslash(pattern);
2396 o_addstr_with_NUL(o, pattern);
2397 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2398 return o_save_ptr_helper(o, n);
2400 if (gr == GLOB_NOSPACE)
2401 bb_error_msg_and_die(bb_msg_memory_exhausted);
2402 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2403 * but we didn't specify it. Paranoia again. */
2404 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2406 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2407 char **argv = globdata.gl_pathv;
2409 o_addstr_with_NUL(o, *argv);
2410 n = o_save_ptr_helper(o, n);
2416 globfree(&globdata);
2420 /* Performs globbing on last list[],
2421 * saving each result as a new list[].
2423 static int perform_glob(o_string *o, int n)
2425 char *pattern, *copy;
2427 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2429 return o_save_ptr_helper(o, n);
2430 pattern = o->data + o_get_last_ptr(o, n);
2431 debug_printf_glob("glob pattern '%s'\n", pattern);
2432 if (!glob_needed(pattern)) {
2433 /* unbackslash last string in o in place, fix length */
2434 o->length = unbackslash(pattern) - o->data;
2435 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2436 return o_save_ptr_helper(o, n);
2439 copy = xstrdup(pattern);
2440 /* "forget" pattern in o */
2441 o->length = pattern - o->data;
2442 n = glob_brace(copy, o, n);
2445 debug_print_list("perform_glob returning", o, n);
2449 #else /* !HUSH_BRACE_EXPANSION */
2452 static int glob_needed(const char *s)
2461 if (*s == '*' || *s == '[' || *s == '?')
2467 /* Performs globbing on last list[],
2468 * saving each result as a new list[].
2470 static int perform_glob(o_string *o, int n)
2476 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2478 return o_save_ptr_helper(o, n);
2479 pattern = o->data + o_get_last_ptr(o, n);
2480 debug_printf_glob("glob pattern '%s'\n", pattern);
2481 if (!glob_needed(pattern)) {
2483 /* unbackslash last string in o in place, fix length */
2484 o->length = unbackslash(pattern) - o->data;
2485 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2486 return o_save_ptr_helper(o, n);
2489 memset(&globdata, 0, sizeof(globdata));
2490 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2491 * If we glob "*.\*" and don't find anything, we need
2492 * to fall back to using literal "*.*", but GLOB_NOCHECK
2493 * will return "*.\*"!
2495 gr = glob(pattern, 0, NULL, &globdata);
2496 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2498 if (gr == GLOB_NOMATCH) {
2499 globfree(&globdata);
2502 if (gr == GLOB_NOSPACE)
2503 bb_error_msg_and_die(bb_msg_memory_exhausted);
2504 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2505 * but we didn't specify it. Paranoia again. */
2506 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2508 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2509 char **argv = globdata.gl_pathv;
2510 /* "forget" pattern in o */
2511 o->length = pattern - o->data;
2513 o_addstr_with_NUL(o, *argv);
2514 n = o_save_ptr_helper(o, n);
2520 globfree(&globdata);
2522 debug_print_list("perform_glob returning", o, n);
2526 #endif /* !HUSH_BRACE_EXPANSION */
2528 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2529 * Otherwise, just finish current list[] and start new */
2530 static int o_save_ptr(o_string *o, int n)
2532 if (o->o_expflags & EXP_FLAG_GLOB) {
2533 /* If o->has_empty_slot, list[n] was already globbed
2534 * (if it was requested back then when it was filled)
2535 * so don't do that again! */
2536 if (!o->has_empty_slot)
2537 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2539 return o_save_ptr_helper(o, n);
2542 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2543 static char **o_finalize_list(o_string *o, int n)
2548 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2550 debug_print_list("finalized", o, n);
2551 debug_printf_expand("finalized n:%d\n", n);
2552 list = (char**)o->data;
2553 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2557 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2562 static void free_pipe_list(struct pipe *pi);
2564 /* Returns pi->next - next pipe in the list */
2565 static struct pipe *free_pipe(struct pipe *pi)
2570 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2571 for (i = 0; i < pi->num_cmds; i++) {
2572 struct command *command;
2573 struct redir_struct *r, *rnext;
2575 command = &pi->cmds[i];
2576 debug_printf_clean(" command %d:\n", i);
2577 if (command->argv) {
2581 for (a = 0, p = command->argv; *p; a++, p++) {
2582 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2585 free_strings(command->argv);
2586 //command->argv = NULL;
2588 /* not "else if": on syntax error, we may have both! */
2589 if (command->group) {
2590 debug_printf_clean(" begin group (cmd_type:%d)\n",
2592 free_pipe_list(command->group);
2593 debug_printf_clean(" end group\n");
2594 //command->group = NULL;
2596 /* else is crucial here.
2597 * If group != NULL, child_func is meaningless */
2598 #if ENABLE_HUSH_FUNCTIONS
2599 else if (command->child_func) {
2600 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2601 command->child_func->parent_cmd = NULL;
2605 free(command->group_as_string);
2606 //command->group_as_string = NULL;
2608 for (r = command->redirects; r; r = rnext) {
2609 debug_printf_clean(" redirect %d%s",
2610 r->rd_fd, redir_table[r->rd_type].descrip);
2611 /* guard against the case >$FOO, where foo is unset or blank */
2612 if (r->rd_filename) {
2613 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2614 free(r->rd_filename);
2615 //r->rd_filename = NULL;
2617 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2621 //command->redirects = NULL;
2623 free(pi->cmds); /* children are an array, they get freed all at once */
2627 //pi->cmdtext = NULL;
2635 static void free_pipe_list(struct pipe *pi)
2639 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2641 debug_printf_clean("pipe followup code %d\n", pi->followup);
2647 /*** Parsing routines ***/
2649 #ifndef debug_print_tree
2650 static void debug_print_tree(struct pipe *pi, int lvl)
2652 static const char *const PIPE[] = {
2658 static const char *RES[] = {
2659 [RES_NONE ] = "NONE" ,
2662 [RES_THEN ] = "THEN" ,
2663 [RES_ELIF ] = "ELIF" ,
2664 [RES_ELSE ] = "ELSE" ,
2667 # if ENABLE_HUSH_LOOPS
2668 [RES_FOR ] = "FOR" ,
2669 [RES_WHILE] = "WHILE",
2670 [RES_UNTIL] = "UNTIL",
2672 [RES_DONE ] = "DONE" ,
2674 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2677 # if ENABLE_HUSH_CASE
2678 [RES_CASE ] = "CASE" ,
2679 [RES_CASE_IN ] = "CASE_IN" ,
2680 [RES_MATCH] = "MATCH",
2681 [RES_CASE_BODY] = "CASE_BODY",
2682 [RES_ESAC ] = "ESAC" ,
2684 [RES_XXXX ] = "XXXX" ,
2685 [RES_SNTX ] = "SNTX" ,
2687 static const char *const CMDTYPE[] = {
2691 # if ENABLE_HUSH_FUNCTIONS
2700 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2701 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2703 while (prn < pi->num_cmds) {
2704 struct command *command = &pi->cmds[prn];
2705 char **argv = command->argv;
2707 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
2709 command->assignment_cnt);
2710 if (command->group) {
2711 fdprintf(2, " group %s: (argv=%p)%s%s\n",
2712 CMDTYPE[command->cmd_type],
2715 , " group_as_string:", command->group_as_string
2720 debug_print_tree(command->group, lvl+1);
2724 if (argv) while (*argv) {
2725 fdprintf(2, " '%s'", *argv);
2735 #endif /* debug_print_tree */
2737 static struct pipe *new_pipe(void)
2740 pi = xzalloc(sizeof(struct pipe));
2741 /*pi->followup = 0; - deliberately invalid value */
2742 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2746 /* Command (member of a pipe) is complete, or we start a new pipe
2747 * if ctx->command is NULL.
2748 * No errors possible here.
2750 static int done_command(struct parse_context *ctx)
2752 /* The command is really already in the pipe structure, so
2753 * advance the pipe counter and make a new, null command. */
2754 struct pipe *pi = ctx->pipe;
2755 struct command *command = ctx->command;
2758 if (IS_NULL_CMD(command)) {
2759 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2763 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2764 //debug_print_tree(ctx->list_head, 20);
2766 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2769 /* Only real trickiness here is that the uncommitted
2770 * command structure is not counted in pi->num_cmds. */
2771 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2772 ctx->command = command = &pi->cmds[pi->num_cmds];
2774 memset(command, 0, sizeof(*command));
2775 return pi->num_cmds; /* used only for 0/nonzero check */
2778 static void done_pipe(struct parse_context *ctx, pipe_style type)
2782 debug_printf_parse("done_pipe entered, followup %d\n", type);
2783 /* Close previous command */
2784 not_null = done_command(ctx);
2785 ctx->pipe->followup = type;
2787 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2788 ctx->ctx_inverted = 0;
2789 ctx->pipe->res_word = ctx->ctx_res_w;
2792 /* Without this check, even just <enter> on command line generates
2793 * tree of three NOPs (!). Which is harmless but annoying.
2794 * IOW: it is safe to do it unconditionally. */
2797 || ctx->ctx_res_w == RES_FI
2799 #if ENABLE_HUSH_LOOPS
2800 || ctx->ctx_res_w == RES_DONE
2801 || ctx->ctx_res_w == RES_FOR
2802 || ctx->ctx_res_w == RES_IN
2804 #if ENABLE_HUSH_CASE
2805 || ctx->ctx_res_w == RES_ESAC
2809 debug_printf_parse("done_pipe: adding new pipe: "
2810 "not_null:%d ctx->ctx_res_w:%d\n",
2811 not_null, ctx->ctx_res_w);
2813 ctx->pipe->next = new_p;
2815 /* RES_THEN, RES_DO etc are "sticky" -
2816 * they remain set for pipes inside if/while.
2817 * This is used to control execution.
2818 * RES_FOR and RES_IN are NOT sticky (needed to support
2819 * cases where variable or value happens to match a keyword):
2821 #if ENABLE_HUSH_LOOPS
2822 if (ctx->ctx_res_w == RES_FOR
2823 || ctx->ctx_res_w == RES_IN)
2824 ctx->ctx_res_w = RES_NONE;
2826 #if ENABLE_HUSH_CASE
2827 if (ctx->ctx_res_w == RES_MATCH)
2828 ctx->ctx_res_w = RES_CASE_BODY;
2829 if (ctx->ctx_res_w == RES_CASE)
2830 ctx->ctx_res_w = RES_CASE_IN;
2832 ctx->command = NULL; /* trick done_command below */
2833 /* Create the memory for command, roughly:
2834 * ctx->pipe->cmds = new struct command;
2835 * ctx->command = &ctx->pipe->cmds[0];
2838 //debug_print_tree(ctx->list_head, 10);
2840 debug_printf_parse("done_pipe return\n");
2843 static void initialize_context(struct parse_context *ctx)
2845 memset(ctx, 0, sizeof(*ctx));
2846 ctx->pipe = ctx->list_head = new_pipe();
2847 /* Create the memory for command, roughly:
2848 * ctx->pipe->cmds = new struct command;
2849 * ctx->command = &ctx->pipe->cmds[0];
2854 /* If a reserved word is found and processed, parse context is modified
2855 * and 1 is returned.
2858 struct reserved_combo {
2861 unsigned char assignment_flag;
2865 FLAG_END = (1 << RES_NONE ),
2867 FLAG_IF = (1 << RES_IF ),
2868 FLAG_THEN = (1 << RES_THEN ),
2869 FLAG_ELIF = (1 << RES_ELIF ),
2870 FLAG_ELSE = (1 << RES_ELSE ),
2871 FLAG_FI = (1 << RES_FI ),
2873 # if ENABLE_HUSH_LOOPS
2874 FLAG_FOR = (1 << RES_FOR ),
2875 FLAG_WHILE = (1 << RES_WHILE),
2876 FLAG_UNTIL = (1 << RES_UNTIL),
2877 FLAG_DO = (1 << RES_DO ),
2878 FLAG_DONE = (1 << RES_DONE ),
2879 FLAG_IN = (1 << RES_IN ),
2881 # if ENABLE_HUSH_CASE
2882 FLAG_MATCH = (1 << RES_MATCH),
2883 FLAG_ESAC = (1 << RES_ESAC ),
2885 FLAG_START = (1 << RES_XXXX ),
2888 static const struct reserved_combo* match_reserved_word(o_string *word)
2890 /* Mostly a list of accepted follow-up reserved words.
2891 * FLAG_END means we are done with the sequence, and are ready
2892 * to turn the compound list into a command.
2893 * FLAG_START means the word must start a new compound list.
2895 static const struct reserved_combo reserved_list[] = {
2897 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2898 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2899 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2900 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2901 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2902 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2904 # if ENABLE_HUSH_LOOPS
2905 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2906 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2907 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2908 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2909 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2910 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2912 # if ENABLE_HUSH_CASE
2913 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2914 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2917 const struct reserved_combo *r;
2919 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2920 if (strcmp(word->data, r->literal) == 0)
2925 /* Return 0: not a keyword, 1: keyword
2927 static int reserved_word(o_string *word, struct parse_context *ctx)
2929 # if ENABLE_HUSH_CASE
2930 static const struct reserved_combo reserved_match = {
2931 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2934 const struct reserved_combo *r;
2936 if (word->has_quoted_part)
2938 r = match_reserved_word(word);
2942 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2943 # if ENABLE_HUSH_CASE
2944 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2945 /* "case word IN ..." - IN part starts first MATCH part */
2946 r = &reserved_match;
2949 if (r->flag == 0) { /* '!' */
2950 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2951 syntax_error("! ! command");
2952 ctx->ctx_res_w = RES_SNTX;
2954 ctx->ctx_inverted = 1;
2957 if (r->flag & FLAG_START) {
2958 struct parse_context *old;
2960 old = xmalloc(sizeof(*old));
2961 debug_printf_parse("push stack %p\n", old);
2962 *old = *ctx; /* physical copy */
2963 initialize_context(ctx);
2965 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2966 syntax_error_at(word->data);
2967 ctx->ctx_res_w = RES_SNTX;
2970 /* "{...} fi" is ok. "{...} if" is not
2972 * if { echo foo; } then { echo bar; } fi */
2973 if (ctx->command->group)
2974 done_pipe(ctx, PIPE_SEQ);
2977 ctx->ctx_res_w = r->res;
2978 ctx->old_flag = r->flag;
2979 word->o_assignment = r->assignment_flag;
2981 if (ctx->old_flag & FLAG_END) {
2982 struct parse_context *old;
2984 done_pipe(ctx, PIPE_SEQ);
2985 debug_printf_parse("pop stack %p\n", ctx->stack);
2987 old->command->group = ctx->list_head;
2988 old->command->cmd_type = CMD_NORMAL;
2990 o_addstr(&old->as_string, ctx->as_string.data);
2991 o_free_unsafe(&ctx->as_string);
2992 old->command->group_as_string = xstrdup(old->as_string.data);
2993 debug_printf_parse("pop, remembering as:'%s'\n",
2994 old->command->group_as_string);
2996 *ctx = *old; /* physical copy */
3001 #endif /* HAS_KEYWORDS */
3003 /* Word is complete, look at it and update parsing context.
3004 * Normal return is 0. Syntax errors return 1.
3005 * Note: on return, word is reset, but not o_free'd!
3007 static int done_word(o_string *word, struct parse_context *ctx)
3009 struct command *command = ctx->command;
3011 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3012 if (word->length == 0 && !word->has_quoted_part) {
3013 debug_printf_parse("done_word return 0: true null, ignored\n");
3017 if (ctx->pending_redirect) {
3018 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3019 * only if run as "bash", not "sh" */
3020 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3022 * ...the word that follows the redirection operator
3023 * shall be subjected to tilde expansion, parameter expansion,
3024 * command substitution, arithmetic expansion, and quote
3025 * removal. Pathname expansion shall not be performed
3026 * on the word by a non-interactive shell; an interactive
3027 * shell may perform it, but shall do so only when
3028 * the expansion would result in one word."
3030 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3031 /* Cater for >\file case:
3032 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3033 * Same with heredocs:
3034 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3036 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3037 unbackslash(ctx->pending_redirect->rd_filename);
3038 /* Is it <<"HEREDOC"? */
3039 if (word->has_quoted_part) {
3040 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3043 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3044 ctx->pending_redirect = NULL;
3046 /* If this word wasn't an assignment, next ones definitely
3047 * can't be assignments. Even if they look like ones. */
3048 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3049 && word->o_assignment != WORD_IS_KEYWORD
3051 word->o_assignment = NOT_ASSIGNMENT;
3053 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3054 command->assignment_cnt++;
3055 word->o_assignment = MAYBE_ASSIGNMENT;
3059 # if ENABLE_HUSH_CASE
3060 if (ctx->ctx_dsemicolon
3061 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3063 /* already done when ctx_dsemicolon was set to 1: */
3064 /* ctx->ctx_res_w = RES_MATCH; */
3065 ctx->ctx_dsemicolon = 0;
3068 if (!command->argv /* if it's the first word... */
3069 # if ENABLE_HUSH_LOOPS
3070 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3071 && ctx->ctx_res_w != RES_IN
3073 # if ENABLE_HUSH_CASE
3074 && ctx->ctx_res_w != RES_CASE
3077 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
3078 if (reserved_word(word, ctx)) {
3079 o_reset_to_empty_unquoted(word);
3080 debug_printf_parse("done_word return %d\n",
3081 (ctx->ctx_res_w == RES_SNTX));
3082 return (ctx->ctx_res_w == RES_SNTX);
3084 # if ENABLE_HUSH_BASH_COMPAT
3085 if (strcmp(word->data, "[[") == 0) {
3086 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3092 if (command->group) {
3093 /* "{ echo foo; } echo bar" - bad */
3094 syntax_error_at(word->data);
3095 debug_printf_parse("done_word return 1: syntax error, "
3096 "groups and arglists don't mix\n");
3099 if (word->has_quoted_part
3100 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3101 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3102 /* (otherwise it's known to be not empty and is already safe) */
3104 /* exclude "$@" - it can expand to no word despite "" */
3105 char *p = word->data;
3106 while (p[0] == SPECIAL_VAR_SYMBOL
3107 && (p[1] & 0x7f) == '@'
3108 && p[2] == SPECIAL_VAR_SYMBOL
3112 if (p == word->data || p[0] != '\0') {
3113 /* saw no "$@", or not only "$@" but some
3114 * real text is there too */
3115 /* insert "empty variable" reference, this makes
3116 * e.g. "", $empty"" etc to not disappear */
3117 o_addchr(word, SPECIAL_VAR_SYMBOL);
3118 o_addchr(word, SPECIAL_VAR_SYMBOL);
3121 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3122 debug_print_strings("word appended to argv", command->argv);
3125 #if ENABLE_HUSH_LOOPS
3126 if (ctx->ctx_res_w == RES_FOR) {
3127 if (word->has_quoted_part
3128 || !is_well_formed_var_name(command->argv[0], '\0')
3130 /* bash says just "not a valid identifier" */
3131 syntax_error("not a valid identifier in for");
3134 /* Force FOR to have just one word (variable name) */
3135 /* NB: basically, this makes hush see "for v in ..."
3136 * syntax as if it is "for v; in ...". FOR and IN become
3137 * two pipe structs in parse tree. */
3138 done_pipe(ctx, PIPE_SEQ);
3141 #if ENABLE_HUSH_CASE
3142 /* Force CASE to have just one word */
3143 if (ctx->ctx_res_w == RES_CASE) {
3144 done_pipe(ctx, PIPE_SEQ);
3148 o_reset_to_empty_unquoted(word);
3150 debug_printf_parse("done_word return 0\n");
3155 /* Peek ahead in the input to find out if we have a "&n" construct,
3156 * as in "2>&1", that represents duplicating a file descriptor.
3158 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3159 * REDIRFD_SYNTAX_ERR if syntax error,
3160 * REDIRFD_TO_FILE if no & was seen,
3161 * or the number found.
3164 #define parse_redir_right_fd(as_string, input) \
3165 parse_redir_right_fd(input)
3167 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3173 return REDIRFD_TO_FILE;
3175 ch = i_getch(input); /* get the & */
3176 nommu_addchr(as_string, ch);
3179 ch = i_getch(input);
3180 nommu_addchr(as_string, ch);
3181 return REDIRFD_CLOSE;
3185 while (ch != EOF && isdigit(ch)) {
3186 d = d*10 + (ch-'0');
3188 ch = i_getch(input);
3189 nommu_addchr(as_string, ch);
3194 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3196 bb_error_msg("ambiguous redirect");
3197 return REDIRFD_SYNTAX_ERR;
3200 /* Return code is 0 normal, 1 if a syntax error is detected
3202 static int parse_redirect(struct parse_context *ctx,
3205 struct in_str *input)
3207 struct command *command = ctx->command;
3208 struct redir_struct *redir;
3209 struct redir_struct **redirp;
3212 dup_num = REDIRFD_TO_FILE;
3213 if (style != REDIRECT_HEREDOC) {
3214 /* Check for a '>&1' type redirect */
3215 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3216 if (dup_num == REDIRFD_SYNTAX_ERR)
3219 int ch = i_peek(input);
3220 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3221 if (dup_num) { /* <<-... */
3222 ch = i_getch(input);
3223 nommu_addchr(&ctx->as_string, ch);
3228 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3229 int ch = i_peek(input);
3231 /* >|FILE redirect ("clobbering" >).
3232 * Since we do not support "set -o noclobber" yet,
3233 * >| and > are the same for now. Just eat |.
3235 ch = i_getch(input);
3236 nommu_addchr(&ctx->as_string, ch);
3240 /* Create a new redir_struct and append it to the linked list */
3241 redirp = &command->redirects;
3242 while ((redir = *redirp) != NULL) {
3243 redirp = &(redir->next);
3245 *redirp = redir = xzalloc(sizeof(*redir));
3246 /* redir->next = NULL; */
3247 /* redir->rd_filename = NULL; */
3248 redir->rd_type = style;
3249 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3251 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3252 redir_table[style].descrip);
3254 redir->rd_dup = dup_num;
3255 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3256 /* Erik had a check here that the file descriptor in question
3257 * is legit; I postpone that to "run time"
3258 * A "-" representation of "close me" shows up as a -3 here */
3259 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3260 redir->rd_fd, redir->rd_dup);
3262 /* Set ctx->pending_redirect, so we know what to do at the
3263 * end of the next parsed word. */
3264 ctx->pending_redirect = redir;
3269 /* If a redirect is immediately preceded by a number, that number is
3270 * supposed to tell which file descriptor to redirect. This routine
3271 * looks for such preceding numbers. In an ideal world this routine
3272 * needs to handle all the following classes of redirects...
3273 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3274 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3275 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3276 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3278 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3280 * ... If n is quoted, the number shall not be recognized as part of
3281 * the redirection expression. For example:
3283 * writes the character 2 into file a"
3284 * We are getting it right by setting ->has_quoted_part on any \<char>
3286 * A -1 return means no valid number was found,
3287 * the caller should use the appropriate default for this redirection.
3289 static int redirect_opt_num(o_string *o)
3293 if (o->data == NULL)
3295 num = bb_strtou(o->data, NULL, 10);
3296 if (errno || num < 0)
3298 o_reset_to_empty_unquoted(o);
3303 #define fetch_till_str(as_string, input, word, skip_tabs) \
3304 fetch_till_str(input, word, skip_tabs)
3306 static char *fetch_till_str(o_string *as_string,
3307 struct in_str *input,
3311 o_string heredoc = NULL_O_STRING;
3313 int prev = 0; /* not \ */
3318 ch = i_getch(input);
3320 nommu_addchr(as_string, ch);
3321 if ((ch == '\n' || ch == EOF)
3322 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3324 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3325 heredoc.data[past_EOL] = '\0';
3326 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3327 return heredoc.data;
3329 while (ch == '\n') {
3330 o_addchr(&heredoc, ch);
3333 past_EOL = heredoc.length;
3335 ch = i_getch(input);
3337 nommu_addchr(as_string, ch);
3338 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3342 o_free_unsafe(&heredoc);
3345 o_addchr(&heredoc, ch);
3346 nommu_addchr(as_string, ch);
3347 if (prev == '\\' && ch == '\\')
3348 /* Correctly handle foo\\<eol> (not a line cont.) */
3349 prev = 0; /* not \ */
3355 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3356 * and load them all. There should be exactly heredoc_cnt of them.
3358 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3360 struct pipe *pi = ctx->list_head;
3362 while (pi && heredoc_cnt) {
3364 struct command *cmd = pi->cmds;
3366 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3368 cmd->argv ? cmd->argv[0] : "NONE");
3369 for (i = 0; i < pi->num_cmds; i++) {
3370 struct redir_struct *redir = cmd->redirects;
3372 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3373 i, cmd->argv ? cmd->argv[0] : "NONE");
3375 if (redir->rd_type == REDIRECT_HEREDOC) {
3378 redir->rd_type = REDIRECT_HEREDOC2;
3379 /* redir->rd_dup is (ab)used to indicate <<- */
3380 p = fetch_till_str(&ctx->as_string, input,
3381 redir->rd_filename, redir->rd_dup);
3383 syntax_error("unexpected EOF in here document");
3386 free(redir->rd_filename);
3387 redir->rd_filename = p;
3390 redir = redir->next;
3397 /* Should be 0. If it isn't, it's a parse error */
3399 bb_error_msg_and_die("heredoc BUG 2");
3405 static int run_list(struct pipe *pi);
3407 #define parse_stream(pstring, input, end_trigger) \
3408 parse_stream(input, end_trigger)
3410 static struct pipe *parse_stream(char **pstring,
3411 struct in_str *input,
3415 #if !ENABLE_HUSH_FUNCTIONS
3416 #define parse_group(dest, ctx, input, ch) \
3417 parse_group(ctx, input, ch)
3419 static int parse_group(o_string *dest, struct parse_context *ctx,
3420 struct in_str *input, int ch)
3422 /* dest contains characters seen prior to ( or {.
3423 * Typically it's empty, but for function defs,
3424 * it contains function name (without '()'). */
3425 struct pipe *pipe_list;
3427 struct command *command = ctx->command;
3429 debug_printf_parse("parse_group entered\n");
3430 #if ENABLE_HUSH_FUNCTIONS
3431 if (ch == '(' && !dest->has_quoted_part) {
3433 if (done_word(dest, ctx))
3436 goto skip; /* (... */
3437 if (command->argv[1]) { /* word word ... (... */
3438 syntax_error_unexpected_ch('(');
3441 /* it is "word(..." or "word (..." */
3443 ch = i_getch(input);
3444 while (ch == ' ' || ch == '\t');
3446 syntax_error_unexpected_ch(ch);
3449 nommu_addchr(&ctx->as_string, ch);
3451 ch = i_getch(input);
3452 while (ch == ' ' || ch == '\t' || ch == '\n');
3454 syntax_error_unexpected_ch(ch);
3457 nommu_addchr(&ctx->as_string, ch);
3458 command->cmd_type = CMD_FUNCDEF;
3463 #if 0 /* Prevented by caller */
3464 if (command->argv /* word [word]{... */
3465 || dest->length /* word{... */
3466 || dest->has_quoted_part /* ""{... */
3469 debug_printf_parse("parse_group return 1: "
3470 "syntax error, groups and arglists don't mix\n");
3475 #if ENABLE_HUSH_FUNCTIONS
3481 command->cmd_type = CMD_SUBSHELL;
3483 /* bash does not allow "{echo...", requires whitespace */
3484 ch = i_getch(input);
3485 if (ch != ' ' && ch != '\t' && ch != '\n') {
3486 syntax_error_unexpected_ch(ch);
3489 nommu_addchr(&ctx->as_string, ch);
3494 # define as_string NULL
3496 char *as_string = NULL;
3498 pipe_list = parse_stream(&as_string, input, endch);
3501 o_addstr(&ctx->as_string, as_string);
3503 /* empty ()/{} or parse error? */
3504 if (!pipe_list || pipe_list == ERR_PTR) {
3505 /* parse_stream already emitted error msg */
3508 debug_printf_parse("parse_group return 1: "
3509 "parse_stream returned %p\n", pipe_list);
3512 command->group = pipe_list;
3514 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3515 command->group_as_string = as_string;
3516 debug_printf_parse("end of group, remembering as:'%s'\n",
3517 command->group_as_string);
3521 debug_printf_parse("parse_group return 0\n");
3523 /* command remains "open", available for possible redirects */
3526 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3527 /* Subroutines for copying $(...) and `...` things */
3528 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3530 static void add_till_single_quote(o_string *dest, struct in_str *input)
3533 int ch = i_getch(input);
3535 syntax_error_unterm_ch('\'');
3536 /*xfunc_die(); - redundant */
3543 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3544 static void add_till_double_quote(o_string *dest, struct in_str *input)
3547 int ch = i_getch(input);
3549 syntax_error_unterm_ch('"');
3550 /*xfunc_die(); - redundant */
3554 if (ch == '\\') { /* \x. Copy both chars. */
3556 ch = i_getch(input);
3560 add_till_backquote(dest, input, /*in_dquote:*/ 1);
3564 //if (ch == '$') ...
3567 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3569 * "Within the backquoted style of command substitution, backslash
3570 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3571 * The search for the matching backquote shall be satisfied by the first
3572 * backquote found without a preceding backslash; during this search,
3573 * if a non-escaped backquote is encountered within a shell comment,
3574 * a here-document, an embedded command substitution of the $(command)
3575 * form, or a quoted string, undefined results occur. A single-quoted
3576 * or double-quoted string that begins, but does not end, within the
3577 * "`...`" sequence produces undefined results."
3579 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3581 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3584 int ch = i_getch(input);
3588 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3589 ch = i_getch(input);
3593 && (!in_dquote || ch != '"')
3595 o_addchr(dest, '\\');
3599 syntax_error_unterm_ch('`');
3600 /*xfunc_die(); - redundant */
3605 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3606 * quoting and nested ()s.
3607 * "With the $(command) style of command substitution, all characters
3608 * following the open parenthesis to the matching closing parenthesis
3609 * constitute the command. Any valid shell script can be used for command,
3610 * except a script consisting solely of redirections which produces
3611 * unspecified results."
3613 * echo $(echo '(TEST)' BEST) (TEST) BEST
3614 * echo $(echo 'TEST)' BEST) TEST) BEST
3615 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3617 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3618 * can contain arbitrary constructs, just like $(cmd).
3619 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3620 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3622 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3623 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3626 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3627 # if ENABLE_HUSH_BASH_COMPAT
3628 char end_char2 = end_ch >> 8;
3630 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3633 ch = i_getch(input);
3635 syntax_error_unterm_ch(end_ch);
3636 /*xfunc_die(); - redundant */
3638 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3641 /* we look for closing )) of $((EXPR)) */
3642 if (i_peek(input) == end_ch) {
3643 i_getch(input); /* eat second ')' */
3648 if (ch == '(' || ch == '{') {
3649 ch = (ch == '(' ? ')' : '}');
3650 add_till_closing_bracket(dest, input, ch);
3655 add_till_single_quote(dest, input);
3660 add_till_double_quote(dest, input);
3665 add_till_backquote(dest, input, /*in_dquote:*/ 0);
3670 /* \x. Copy verbatim. Important for \(, \) */
3671 ch = i_getch(input);
3673 syntax_error_unterm_ch(')');
3674 /*xfunc_die(); - redundant */
3682 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3684 /* Return code: 0 for OK, 1 for syntax error */
3686 #define parse_dollar(as_string, dest, input, quote_mask) \
3687 parse_dollar(dest, input, quote_mask)
3688 #define as_string NULL
3690 static int parse_dollar(o_string *as_string,
3692 struct in_str *input, unsigned char quote_mask)
3694 int ch = i_peek(input); /* first character after the $ */
3696 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3698 ch = i_getch(input);
3699 nommu_addchr(as_string, ch);
3701 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3703 debug_printf_parse(": '%c'\n", ch);
3704 o_addchr(dest, ch | quote_mask);
3707 if (!isalnum(ch) && ch != '_')
3709 ch = i_getch(input);
3710 nommu_addchr(as_string, ch);
3712 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3713 } else if (isdigit(ch)) {
3715 ch = i_getch(input);
3716 nommu_addchr(as_string, ch);
3717 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3718 debug_printf_parse(": '%c'\n", ch);
3719 o_addchr(dest, ch | quote_mask);
3720 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3721 } else switch (ch) {
3723 case '!': /* last bg pid */
3724 case '?': /* last exit code */
3725 case '#': /* number of args */
3726 case '*': /* args */
3727 case '@': /* args */
3728 goto make_one_char_var;
3730 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3732 ch = i_getch(input); /* eat '{' */
3733 nommu_addchr(as_string, ch);
3735 ch = i_getch(input); /* first char after '{' */
3736 /* It should be ${?}, or ${#var},
3737 * or even ${?+subst} - operator acting on a special variable,
3738 * or the beginning of variable name.
3741 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3744 syntax_error_unterm_str("${name}");
3745 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3748 nommu_addchr(as_string, ch);
3751 /* It's possible to just call add_till_closing_bracket() at this point.
3752 * However, this regresses some of our testsuite cases
3753 * which check invalid constructs like ${%}.
3754 * Oh well... let's check that the var name part is fine... */
3760 debug_printf_parse(": '%c'\n", ch);
3762 ch = i_getch(input);
3763 nommu_addchr(as_string, ch);
3767 if (!isalnum(ch) && ch != '_') {
3769 unsigned char last_ch;
3770 /* handle parameter expansions
3771 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3773 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3774 goto bad_dollar_syntax;
3776 /* Eat everything until closing '}' (or ':') */
3778 if (ENABLE_HUSH_BASH_COMPAT
3780 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3782 /* It's ${var:N[:M]} thing */
3783 end_ch = '}' * 0x100 + ':';
3785 if (ENABLE_HUSH_BASH_COMPAT
3788 /* It's ${var/[/]pattern[/repl]} thing */
3789 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3791 nommu_addchr(as_string, '/');
3794 end_ch = '}' * 0x100 + '/';
3800 #if ENABLE_HUSH_DOLLAR_OPS
3801 last_ch = add_till_closing_bracket(dest, input, end_ch);
3803 #error Simple code to only allow ${var} is not implemented
3806 o_addstr(as_string, dest->data + pos);
3807 o_addchr(as_string, last_ch);
3810 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3811 /* close the first block: */
3812 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3813 /* while parsing N from ${var:N[:M]}
3814 * or pattern from ${var/[/]pattern[/repl]} */
3815 if ((end_ch & 0xff) == last_ch) {
3816 /* got ':' or '/'- parse the rest */
3821 if (end_ch == '}' * 0x100 + ':') {
3822 /* it's ${var:N} - emulate :999999999 */
3823 o_addstr(dest, "999999999");
3824 } /* else: it's ${var/[/]pattern} */
3829 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3832 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3836 ch = i_getch(input);
3837 nommu_addchr(as_string, ch);
3838 # if ENABLE_SH_MATH_SUPPORT
3839 if (i_peek(input) == '(') {
3840 ch = i_getch(input);
3841 nommu_addchr(as_string, ch);
3842 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3843 o_addchr(dest, /*quote_mask |*/ '+');
3846 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3848 o_addstr(as_string, dest->data + pos);
3849 o_addchr(as_string, ')');
3850 o_addchr(as_string, ')');
3852 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3856 # if ENABLE_HUSH_TICK
3857 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3858 o_addchr(dest, quote_mask | '`');
3861 add_till_closing_bracket(dest, input, ')');
3863 o_addstr(as_string, dest->data + pos);
3864 o_addchr(as_string, ')');
3866 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3872 ch = i_getch(input);
3873 nommu_addchr(as_string, ch);
3875 if (isalnum(ch)) { /* it's $_name or $_123 */
3880 /* TODO: $_ and $-: */
3881 /* $_ Shell or shell script name; or last argument of last command
3882 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3883 * but in command's env, set to full pathname used to invoke it */
3884 /* $- Option flags set by set builtin or shell options (-i etc) */
3886 o_addQchr(dest, '$');
3888 debug_printf_parse("parse_dollar return 0\n");
3894 # if ENABLE_HUSH_BASH_COMPAT
3895 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3896 encode_string(dest, input, dquote_end, process_bkslash)
3898 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
3899 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3900 encode_string(dest, input, dquote_end)
3902 #define as_string NULL
3906 # if ENABLE_HUSH_BASH_COMPAT
3907 /* all parameters are needed, no macro tricks */
3909 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3910 encode_string(as_string, dest, input, dquote_end)
3913 static int encode_string(o_string *as_string,
3915 struct in_str *input,
3917 int process_bkslash)
3919 #if !ENABLE_HUSH_BASH_COMPAT
3920 const int process_bkslash = 1;
3926 ch = i_getch(input);
3928 nommu_addchr(as_string, ch);
3929 if (ch == dquote_end) { /* may be only '"' or EOF */
3930 debug_printf_parse("encode_string return 0\n");
3933 /* note: can't move it above ch == dquote_end check! */
3935 syntax_error_unterm_ch('"');
3936 /*xfunc_die(); - redundant */
3940 next = i_peek(input);
3942 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3943 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3944 if (process_bkslash && ch == '\\') {
3946 syntax_error("\\<eof>");
3950 * "The backslash retains its special meaning [in "..."]
3951 * only when followed by one of the following characters:
3952 * $, `, ", \, or <newline>. A double quote may be quoted
3953 * within double quotes by preceding it with a backslash."
3954 * NB: in (unquoted) heredoc, above does not apply to ",
3955 * therefore we check for it by "next == dquote_end" cond.
3957 if (next == dquote_end || strchr("$`\\\n", next)) {
3958 ch = i_getch(input); /* eat next */
3960 goto again; /* skip \<newline> */
3961 } /* else: ch remains == '\\', and we double it below: */
3962 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
3963 nommu_addchr(as_string, ch);
3967 if (parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80) != 0) {
3968 debug_printf_parse("encode_string return 1: "
3969 "parse_dollar returned non-0\n");
3974 #if ENABLE_HUSH_TICK
3976 //unsigned pos = dest->length;
3977 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3978 o_addchr(dest, 0x80 | '`');
3979 add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"');
3980 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3981 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3985 o_addQchr(dest, ch);
3991 * Scan input until EOF or end_trigger char.
3992 * Return a list of pipes to execute, or NULL on EOF
3993 * or if end_trigger character is met.
3994 * On syntax error, exit is shell is not interactive,
3995 * reset parsing machinery and start parsing anew,
3996 * or return ERR_PTR.
3998 static struct pipe *parse_stream(char **pstring,
3999 struct in_str *input,
4002 struct parse_context ctx;
4003 o_string dest = NULL_O_STRING;
4006 /* Single-quote triggers a bypass of the main loop until its mate is
4007 * found. When recursing, quote state is passed in via dest->o_expflags.
4009 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4010 end_trigger ? end_trigger : 'X');
4013 /* If very first arg is "" or '', dest.data may end up NULL.
4014 * Preventing this: */
4015 o_addchr(&dest, '\0');
4018 /* We used to separate words on $IFS here. This was wrong.
4019 * $IFS is used only for word splitting when $var is expanded,
4020 * here we should use blank chars as separators, not $IFS
4023 reset: /* we come back here only on syntax errors in interactive shell */
4025 if (MAYBE_ASSIGNMENT != 0)
4026 dest.o_assignment = MAYBE_ASSIGNMENT;
4027 initialize_context(&ctx);
4030 const char *is_blank;
4031 const char *is_special;
4035 redir_type redir_style;
4037 ch = i_getch(input);
4038 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4039 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4044 syntax_error_unterm_str("here document");
4047 /* end_trigger == '}' case errors out earlier,
4048 * checking only ')' */
4049 if (end_trigger == ')') {
4050 syntax_error_unterm_ch('('); /* exits */
4051 /* goto parse_error; */
4054 if (done_word(&dest, &ctx)) {
4058 done_pipe(&ctx, PIPE_SEQ);
4060 /* If we got nothing... */
4061 /* (this makes bare "&" cmd a no-op.
4062 * bash says: "syntax error near unexpected token '&'") */
4063 if (pi->num_cmds == 0
4064 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4070 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4072 *pstring = ctx.as_string.data;
4074 o_free_unsafe(&ctx.as_string);
4077 debug_printf_parse("parse_stream return %p\n", pi);
4080 nommu_addchr(&ctx.as_string, ch);
4084 next = i_peek(input);
4086 is_special = "{}<>;&|()#'" /* special outside of "str" */
4087 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4088 /* Are { and } special here? */
4089 if (ctx.command->argv /* word [word]{... - non-special */
4090 || dest.length /* word{... - non-special */
4091 || dest.has_quoted_part /* ""{... - non-special */
4092 || (next != ';' /* }; - special */
4093 && next != ')' /* }) - special */
4094 && next != '&' /* }& and }&& ... - special */
4095 && next != '|' /* }|| ... - special */
4096 && !strchr(defifs, next) /* {word - non-special */
4099 /* They are not special, skip "{}" */
4102 is_special = strchr(is_special, ch);
4103 is_blank = strchr(defifs, ch);
4105 if (!is_special && !is_blank) { /* ordinary char */
4107 o_addQchr(&dest, ch);
4108 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4109 || dest.o_assignment == WORD_IS_KEYWORD)
4111 && is_well_formed_var_name(dest.data, '=')
4113 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4119 if (done_word(&dest, &ctx)) {
4123 /* Is this a case when newline is simply ignored?
4125 * "cmd | <newline> cmd ..."
4126 * "case ... in <newline> word) ..."
4128 if (IS_NULL_CMD(ctx.command)
4129 && dest.length == 0 && !dest.has_quoted_part
4131 /* This newline can be ignored. But...
4132 * Without check #1, interactive shell
4133 * ignores even bare <newline>,
4134 * and shows the continuation prompt:
4135 * ps1_prompt$ <enter>
4136 * ps2> _ <=== wrong, should be ps1
4137 * Without check #2, "cmd & <newline>"
4138 * is similarly mistreated.
4139 * (BTW, this makes "cmd & cmd"
4140 * and "cmd && cmd" non-orthogonal.
4141 * Really, ask yourself, why
4142 * "cmd && <newline>" doesn't start
4143 * cmd but waits for more input?
4146 struct pipe *pi = ctx.list_head;
4147 if (pi->num_cmds != 0 /* check #1 */
4148 && pi->followup != PIPE_BG /* check #2 */
4153 /* Treat newline as a command separator. */
4154 done_pipe(&ctx, PIPE_SEQ);
4155 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4157 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4162 dest.o_assignment = MAYBE_ASSIGNMENT;
4164 /* note: if (is_blank) continue;
4165 * will still trigger for us */
4169 /* "cmd}" or "cmd }..." without semicolon or &:
4170 * } is an ordinary char in this case, even inside { cmd; }
4171 * Pathological example: { ""}; } should exec "}" cmd
4174 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4175 || dest.length != 0 /* word} */
4176 || dest.has_quoted_part /* ""} */
4180 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4181 goto skip_end_trigger;
4182 /* else: } does terminate a group */
4185 if (end_trigger && end_trigger == ch
4186 && (ch != ';' || heredoc_cnt == 0)
4187 #if ENABLE_HUSH_CASE
4189 || ctx.ctx_res_w != RES_MATCH
4190 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4195 /* This is technically valid:
4196 * { cat <<HERE; }; echo Ok
4200 * but we don't support this.
4201 * We require heredoc to be in enclosing {}/(),
4204 syntax_error_unterm_str("here document");
4207 if (done_word(&dest, &ctx)) {
4210 done_pipe(&ctx, PIPE_SEQ);
4211 dest.o_assignment = MAYBE_ASSIGNMENT;
4212 /* Do we sit outside of any if's, loops or case's? */
4214 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4218 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4220 *pstring = ctx.as_string.data;
4222 o_free_unsafe(&ctx.as_string);
4225 debug_printf_parse("parse_stream return %p: "
4226 "end_trigger char found\n",
4228 return ctx.list_head;
4235 /* Catch <, > before deciding whether this word is
4236 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4239 redir_fd = redirect_opt_num(&dest);
4240 if (done_word(&dest, &ctx)) {
4243 redir_style = REDIRECT_OVERWRITE;
4245 redir_style = REDIRECT_APPEND;
4246 ch = i_getch(input);
4247 nommu_addchr(&ctx.as_string, ch);
4250 else if (next == '(') {
4251 syntax_error(">(process) not supported");
4255 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4257 continue; /* back to top of while (1) */
4259 redir_fd = redirect_opt_num(&dest);
4260 if (done_word(&dest, &ctx)) {
4263 redir_style = REDIRECT_INPUT;
4265 redir_style = REDIRECT_HEREDOC;
4267 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4268 ch = i_getch(input);
4269 nommu_addchr(&ctx.as_string, ch);
4270 } else if (next == '>') {
4271 redir_style = REDIRECT_IO;
4272 ch = i_getch(input);
4273 nommu_addchr(&ctx.as_string, ch);
4276 else if (next == '(') {
4277 syntax_error("<(process) not supported");
4281 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4283 continue; /* back to top of while (1) */
4285 if (dest.length == 0 && !dest.has_quoted_part) {
4286 /* skip "#comment" */
4289 if (ch == EOF || ch == '\n')
4292 /* note: we do not add it to &ctx.as_string */
4294 nommu_addchr(&ctx.as_string, '\n');
4295 continue; /* back to top of while (1) */
4300 /* It's "\<newline>" */
4302 /* Remove trailing '\' from ctx.as_string */
4303 ctx.as_string.data[--ctx.as_string.length] = '\0';
4305 ch = i_getch(input); /* eat it */
4306 continue; /* back to top of while (1) */
4311 if (dest.o_assignment == MAYBE_ASSIGNMENT
4312 /* check that we are not in word in "a=1 2>word b=1": */
4313 && !ctx.pending_redirect
4315 /* ch is a special char and thus this word
4316 * cannot be an assignment */
4317 dest.o_assignment = NOT_ASSIGNMENT;
4320 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4323 case '#': /* non-comment #: "echo a#b" etc */
4324 o_addQchr(&dest, ch);
4328 syntax_error("\\<eof>");
4331 ch = i_getch(input);
4332 /* note: ch != '\n' (that case does not reach this place) */
4333 o_addchr(&dest, '\\');
4334 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4335 o_addchr(&dest, ch);
4336 nommu_addchr(&ctx.as_string, ch);
4337 /* Example: echo Hello \2>file
4338 * we need to know that word 2 is quoted */
4339 dest.has_quoted_part = 1;
4342 if (parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0) != 0) {
4343 debug_printf_parse("parse_stream parse error: "
4344 "parse_dollar returned non-0\n");
4349 dest.has_quoted_part = 1;
4351 ch = i_getch(input);
4353 syntax_error_unterm_ch('\'');
4354 /*xfunc_die(); - redundant */
4356 nommu_addchr(&ctx.as_string, ch);
4359 o_addqchr(&dest, ch);
4363 dest.has_quoted_part = 1;
4364 if (dest.o_assignment == NOT_ASSIGNMENT)
4365 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4366 if (encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4368 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4370 #if ENABLE_HUSH_TICK
4374 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4375 o_addchr(&dest, '`');
4377 add_till_backquote(&dest, input, /*in_dquote:*/ 0);
4379 o_addstr(&ctx.as_string, dest.data + pos);
4380 o_addchr(&ctx.as_string, '`');
4382 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4383 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4388 #if ENABLE_HUSH_CASE
4391 if (done_word(&dest, &ctx)) {
4394 done_pipe(&ctx, PIPE_SEQ);
4395 #if ENABLE_HUSH_CASE
4396 /* Eat multiple semicolons, detect
4397 * whether it means something special */
4402 ch = i_getch(input);
4403 nommu_addchr(&ctx.as_string, ch);
4404 if (ctx.ctx_res_w == RES_CASE_BODY) {
4405 ctx.ctx_dsemicolon = 1;
4406 ctx.ctx_res_w = RES_MATCH;
4412 /* We just finished a cmd. New one may start
4413 * with an assignment */
4414 dest.o_assignment = MAYBE_ASSIGNMENT;
4417 if (done_word(&dest, &ctx)) {
4421 ch = i_getch(input);
4422 nommu_addchr(&ctx.as_string, ch);
4423 done_pipe(&ctx, PIPE_AND);
4425 done_pipe(&ctx, PIPE_BG);
4429 if (done_word(&dest, &ctx)) {
4432 #if ENABLE_HUSH_CASE
4433 if (ctx.ctx_res_w == RES_MATCH)
4434 break; /* we are in case's "word | word)" */
4436 if (next == '|') { /* || */
4437 ch = i_getch(input);
4438 nommu_addchr(&ctx.as_string, ch);
4439 done_pipe(&ctx, PIPE_OR);
4441 /* we could pick up a file descriptor choice here
4442 * with redirect_opt_num(), but bash doesn't do it.
4443 * "echo foo 2| cat" yields "foo 2". */
4446 o_reset_to_empty_unquoted(&ctx.as_string);
4451 #if ENABLE_HUSH_CASE
4452 /* "case... in [(]word)..." - skip '(' */
4453 if (ctx.ctx_res_w == RES_MATCH
4454 && ctx.command->argv == NULL /* not (word|(... */
4455 && dest.length == 0 /* not word(... */
4456 && dest.has_quoted_part == 0 /* not ""(... */
4462 if (parse_group(&dest, &ctx, input, ch) != 0) {
4467 #if ENABLE_HUSH_CASE
4468 if (ctx.ctx_res_w == RES_MATCH)
4472 /* proper use of this character is caught by end_trigger:
4473 * if we see {, we call parse_group(..., end_trigger='}')
4474 * and it will match } earlier (not here). */
4475 syntax_error_unexpected_ch(ch);
4479 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4485 struct parse_context *pctx;
4486 IF_HAS_KEYWORDS(struct parse_context *p2;)
4488 /* Clean up allocated tree.
4489 * Sample for finding leaks on syntax error recovery path.
4490 * Run it from interactive shell, watch pmap `pidof hush`.
4491 * while if false; then false; fi; do break; fi
4492 * Samples to catch leaks at execution:
4493 * while if (true | {true;}); then echo ok; fi; do break; done
4494 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4498 /* Update pipe/command counts,
4499 * otherwise freeing may miss some */
4500 done_pipe(pctx, PIPE_SEQ);
4501 debug_printf_clean("freeing list %p from ctx %p\n",
4502 pctx->list_head, pctx);
4503 debug_print_tree(pctx->list_head, 0);
4504 free_pipe_list(pctx->list_head);
4505 debug_printf_clean("freed list %p\n", pctx->list_head);
4507 o_free_unsafe(&pctx->as_string);
4509 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4513 IF_HAS_KEYWORDS(pctx = p2;)
4514 } while (HAS_KEYWORDS && pctx);
4515 /* Free text, clear all dest fields */
4517 /* If we are not in top-level parse, we return,
4518 * our caller will propagate error.
4520 if (end_trigger != ';') {
4528 /* Discard cached input, force prompt */
4535 /*** Execution routines ***/
4537 /* Expansion can recurse, need forward decls: */
4538 #if !ENABLE_HUSH_BASH_COMPAT
4539 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4540 #define expand_string_to_string(str, do_unbackslash) \
4541 expand_string_to_string(str)
4543 static char *expand_string_to_string(const char *str, int do_unbackslash);
4544 #if ENABLE_HUSH_TICK
4545 static int process_command_subs(o_string *dest, const char *s);
4548 /* expand_strvec_to_strvec() takes a list of strings, expands
4549 * all variable references within and returns a pointer to
4550 * a list of expanded strings, possibly with larger number
4551 * of strings. (Think VAR="a b"; echo $VAR).
4552 * This new list is allocated as a single malloc block.
4553 * NULL-terminated list of char* pointers is at the beginning of it,
4554 * followed by strings themselves.
4555 * Caller can deallocate entire list by single free(list). */
4557 /* A horde of its helpers come first: */
4559 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4561 while (--len >= 0) {
4564 #if ENABLE_HUSH_BRACE_EXPANSION
4565 if (c == '{' || c == '}') {
4566 /* { -> \{, } -> \} */
4568 /* And now we want to add { or } and continue:
4571 * luckily, just falling throught achieves this.
4577 /* \z -> \\\z; \<eol> -> \\<eol> */
4582 o_addchr(o, *str++);
4588 /* Store given string, finalizing the word and starting new one whenever
4589 * we encounter IFS char(s). This is used for expanding variable values.
4590 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4591 static int expand_on_ifs(o_string *output, int n, const char *str)
4594 int word_len = strcspn(str, G.ifs);
4596 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4597 o_addblock(output, str, word_len);
4599 /* Protect backslashes against globbing up :)
4600 * Example: "v='\*'; echo b$v" prints "b\*"
4601 * (and does not try to glob on "*")
4603 o_addblock_duplicate_backslash(output, str, word_len);
4604 /*/ Why can't we do it easier? */
4605 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4606 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4610 if (!*str) /* EOL - do not finalize word */
4612 o_addchr(output, '\0');
4613 debug_print_list("expand_on_ifs", output, n);
4614 n = o_save_ptr(output, n);
4615 str += strspn(str, G.ifs); /* skip ifs chars */
4617 debug_print_list("expand_on_ifs[1]", output, n);
4621 /* Helper to expand $((...)) and heredoc body. These act as if
4622 * they are in double quotes, with the exception that they are not :).
4623 * Just the rules are similar: "expand only $var and `cmd`"
4625 * Returns malloced string.
4626 * As an optimization, we return NULL if expansion is not needed.
4628 #if !ENABLE_HUSH_BASH_COMPAT
4629 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4630 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4631 encode_then_expand_string(str)
4633 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4636 struct in_str input;
4637 o_string dest = NULL_O_STRING;
4639 if (!strchr(str, '$')
4640 && !strchr(str, '\\')
4641 #if ENABLE_HUSH_TICK
4642 && !strchr(str, '`')
4648 /* We need to expand. Example:
4649 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4651 setup_string_in_str(&input, str);
4652 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4653 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4654 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4655 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4656 o_free_unsafe(&dest);
4660 #if ENABLE_SH_MATH_SUPPORT
4661 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4663 arith_state_t math_state;
4667 math_state.lookupvar = get_local_var_value;
4668 math_state.setvar = set_local_var_from_halves;
4669 //math_state.endofname = endofname;
4670 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4671 res = arith(&math_state, exp_str ? exp_str : arg);
4674 *errmsg_p = math_state.errmsg;
4675 if (math_state.errmsg)
4676 die_if_script(math_state.errmsg);
4681 #if ENABLE_HUSH_BASH_COMPAT
4682 /* ${var/[/]pattern[/repl]} helpers */
4683 static char *strstr_pattern(char *val, const char *pattern, int *size)
4686 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4687 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4694 /* Optimization: if "*pat" did not match the start of "string",
4695 * we know that "tring", "ring" etc will not match too:
4697 if (pattern[0] == '*')
4702 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4704 char *result = NULL;
4705 unsigned res_len = 0;
4706 unsigned repl_len = strlen(repl);
4710 char *s = strstr_pattern(val, pattern, &size);
4714 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4715 memcpy(result + res_len, val, s - val);
4717 strcpy(result + res_len, repl);
4718 res_len += repl_len;
4719 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4725 if (val[0] && result) {
4726 result = xrealloc(result, res_len + strlen(val) + 1);
4727 strcpy(result + res_len, val);
4728 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4730 debug_printf_varexp("result:'%s'\n", result);
4736 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4738 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4740 const char *val = NULL;
4741 char *to_be_freed = NULL;
4746 char exp_save = exp_save; /* for compiler */
4747 char *exp_saveptr; /* points to expansion operator */
4748 char *exp_word = exp_word; /* for compiler */
4751 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4753 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4755 first_char = arg[0] = arg0 & 0x7f;
4758 if (first_char == '#' /* ${#... */
4759 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4761 /* It must be length operator: ${#var} */
4765 /* Maybe handle parameter expansion */
4766 if (exp_saveptr /* if 2nd char is one of expansion operators */
4767 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4769 /* ${?:0}, ${#[:]%0} etc */
4770 exp_saveptr = var + 1;
4772 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4773 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4775 exp_op = exp_save = *exp_saveptr;
4777 exp_word = exp_saveptr + 1;
4778 if (exp_op == ':') {
4779 exp_op = *exp_word++;
4780 //TODO: try ${var:} and ${var:bogus} in non-bash config
4781 if (ENABLE_HUSH_BASH_COMPAT
4782 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4784 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4789 *exp_saveptr = '\0';
4790 } /* else: it's not an expansion op, but bare ${var} */
4793 /* Look up the variable in question */
4794 if (isdigit(var[0])) {
4795 /* parse_dollar should have vetted var for us */
4796 int n = xatoi_positive(var);
4797 if (n < G.global_argc)
4798 val = G.global_argv[n];
4799 /* else val remains NULL: $N with too big N */
4803 val = utoa(G.root_pid);
4805 case '!': /* bg pid */
4806 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4808 case '?': /* exitcode */
4809 val = utoa(G.last_exitcode);
4811 case '#': /* argc */
4812 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4815 val = get_local_var_value(var);
4819 /* Handle any expansions */
4820 if (exp_op == 'L') {
4821 debug_printf_expand("expand: length(%s)=", val);
4822 val = utoa(val ? strlen(val) : 0);
4823 debug_printf_expand("%s\n", val);
4824 } else if (exp_op) {
4825 if (exp_op == '%' || exp_op == '#') {
4826 /* Standard-mandated substring removal ops:
4827 * ${parameter%word} - remove smallest suffix pattern
4828 * ${parameter%%word} - remove largest suffix pattern
4829 * ${parameter#word} - remove smallest prefix pattern
4830 * ${parameter##word} - remove largest prefix pattern
4832 * Word is expanded to produce a glob pattern.
4833 * Then var's value is matched to it and matching part removed.
4835 if (val && val[0]) {
4839 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4840 if (exp_op == *exp_word) /* ## or %% */
4842 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4844 exp_word = exp_exp_word;
4845 /* HACK ALERT. We depend here on the fact that
4846 * G.global_argv and results of utoa and get_local_var_value
4847 * are actually in writable memory:
4848 * scan_and_match momentarily stores NULs there. */
4850 loc = scan_and_match(t, exp_word, scan_flags);
4851 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4852 // exp_op, t, exp_word, loc);
4854 if (loc) { /* match was found */
4855 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4856 val = loc; /* take right part */
4858 val = to_be_freed = xstrndup(val, loc - val); /* left */
4862 #if ENABLE_HUSH_BASH_COMPAT
4863 else if (exp_op == '/' || exp_op == '\\') {
4864 /* It's ${var/[/]pattern[/repl]} thing.
4865 * Note that in encoded form it has TWO parts:
4866 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4867 * and if // is used, it is encoded as \:
4868 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4870 /* Empty variable always gives nothing: */
4871 // "v=''; echo ${v/*/w}" prints "", not "w"
4872 if (val && val[0]) {
4873 /* pattern uses non-standard expansion.
4874 * repl should be unbackslashed and globbed
4875 * by the usual expansion rules:
4877 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4878 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4879 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4880 * v='a bz'; echo ${v/a*z/\z} prints "z"
4881 * (note that a*z _pattern_ is never globbed!)
4883 char *pattern, *repl, *t;
4884 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
4886 pattern = xstrdup(exp_word);
4887 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4888 *p++ = SPECIAL_VAR_SYMBOL;
4890 p = strchr(p, SPECIAL_VAR_SYMBOL);
4892 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
4893 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4894 /* HACK ALERT. We depend here on the fact that
4895 * G.global_argv and results of utoa and get_local_var_value
4896 * are actually in writable memory:
4897 * replace_pattern momentarily stores NULs there. */
4899 to_be_freed = replace_pattern(t,
4901 (repl ? repl : exp_word),
4903 if (to_be_freed) /* at least one replace happened */
4910 else if (exp_op == ':') {
4911 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4912 /* It's ${var:N[:M]} bashism.
4913 * Note that in encoded form it has TWO parts:
4914 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4919 beg = expand_and_evaluate_arith(exp_word, &errmsg);
4922 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4923 *p++ = SPECIAL_VAR_SYMBOL;
4925 p = strchr(p, SPECIAL_VAR_SYMBOL);
4927 len = expand_and_evaluate_arith(exp_word, &errmsg);
4930 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4931 if (len >= 0) { /* bash compat: len < 0 is illegal */
4932 if (beg < 0) /* bash compat */
4934 debug_printf_varexp("from val:'%s'\n", val);
4935 if (len == 0 || !val || beg >= strlen(val)) {
4939 /* Paranoia. What if user entered 9999999999999
4940 * which fits in arith_t but not int? */
4943 val = to_be_freed = xstrndup(val + beg, len);
4945 debug_printf_varexp("val:'%s'\n", val);
4949 die_if_script("malformed ${%s:...}", var);
4952 } else { /* one of "-=+?" */
4953 /* Standard-mandated substitution ops:
4954 * ${var?word} - indicate error if unset
4955 * If var is unset, word (or a message indicating it is unset
4956 * if word is null) is written to standard error
4957 * and the shell exits with a non-zero exit status.
4958 * Otherwise, the value of var is substituted.
4959 * ${var-word} - use default value
4960 * If var is unset, word is substituted.
4961 * ${var=word} - assign and use default value
4962 * If var is unset, word is assigned to var.
4963 * In all cases, final value of var is substituted.
4964 * ${var+word} - use alternative value
4965 * If var is unset, null is substituted.
4966 * Otherwise, word is substituted.
4968 * Word is subjected to tilde expansion, parameter expansion,
4969 * command substitution, and arithmetic expansion.
4970 * If word is not needed, it is not expanded.
4972 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4973 * but also treat null var as if it is unset.
4975 int use_word = (!val || ((exp_save == ':') && !val[0]));
4977 use_word = !use_word;
4978 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4979 (exp_save == ':') ? "true" : "false", use_word);
4981 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4983 exp_word = to_be_freed;
4984 if (exp_op == '?') {
4985 /* mimic bash message */
4986 die_if_script("%s: %s",
4988 exp_word[0] ? exp_word : "parameter null or not set"
4990 //TODO: how interactive bash aborts expansion mid-command?
4995 if (exp_op == '=') {
4996 /* ${var=[word]} or ${var:=[word]} */
4997 if (isdigit(var[0]) || var[0] == '#') {
4998 /* mimic bash message */
4999 die_if_script("$%s: cannot assign in this way", var);
5002 char *new_var = xasprintf("%s=%s", var, val);
5003 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5007 } /* one of "-=+?" */
5009 *exp_saveptr = exp_save;
5015 *to_be_freed_pp = to_be_freed;
5019 /* Expand all variable references in given string, adding words to list[]
5020 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5021 * to be filled). This routine is extremely tricky: has to deal with
5022 * variables/parameters with whitespace, $* and $@, and constructs like
5023 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5024 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5026 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5027 * expansion of right-hand side of assignment == 1-element expand.
5029 char cant_be_null = 0; /* only bit 0x80 matters */
5032 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5033 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5034 debug_print_list("expand_vars_to_list", output, n);
5035 n = o_save_ptr(output, n);
5036 debug_print_list("expand_vars_to_list[0]", output, n);
5038 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5040 char *to_be_freed = NULL;
5041 const char *val = NULL;
5042 #if ENABLE_HUSH_TICK
5043 o_string subst_result = NULL_O_STRING;
5045 #if ENABLE_SH_MATH_SUPPORT
5046 char arith_buf[sizeof(arith_t)*3 + 2];
5048 o_addblock(output, arg, p - arg);
5049 debug_print_list("expand_vars_to_list[1]", output, n);
5051 p = strchr(p, SPECIAL_VAR_SYMBOL);
5053 /* Fetch special var name (if it is indeed one of them)
5054 * and quote bit, force the bit on if singleword expansion -
5055 * important for not getting v=$@ expand to many words. */
5056 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5058 /* Is this variable quoted and thus expansion can't be null?
5059 * "$@" is special. Even if quoted, it can still
5060 * expand to nothing (not even an empty string),
5061 * thus it is excluded. */
5062 if ((first_ch & 0x7f) != '@')
5063 cant_be_null |= first_ch;
5065 switch (first_ch & 0x7f) {
5066 /* Highest bit in first_ch indicates that var is double-quoted */
5070 if (!G.global_argv[1])
5073 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5074 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5075 while (G.global_argv[i]) {
5076 n = expand_on_ifs(output, n, G.global_argv[i]);
5077 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5078 if (G.global_argv[i++][0] && G.global_argv[i]) {
5079 /* this argv[] is not empty and not last:
5080 * put terminating NUL, start new word */
5081 o_addchr(output, '\0');
5082 debug_print_list("expand_vars_to_list[2]", output, n);
5083 n = o_save_ptr(output, n);
5084 debug_print_list("expand_vars_to_list[3]", output, n);
5088 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5089 * and in this case should treat it like '$*' - see 'else...' below */
5090 if (first_ch == ('@'|0x80) /* quoted $@ */
5091 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5094 o_addQstr(output, G.global_argv[i]);
5095 if (++i >= G.global_argc)
5097 o_addchr(output, '\0');
5098 debug_print_list("expand_vars_to_list[4]", output, n);
5099 n = o_save_ptr(output, n);
5101 } else { /* quoted $* (or v="$@" case): add as one word */
5103 o_addQstr(output, G.global_argv[i]);
5104 if (!G.global_argv[++i])
5107 o_addchr(output, G.ifs[0]);
5112 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5113 /* "Empty variable", used to make "" etc to not disappear */
5115 cant_be_null = 0x80;
5117 #if ENABLE_HUSH_TICK
5118 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5119 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5121 /* Can't just stuff it into output o_string,
5122 * expanded result may need to be globbed
5123 * and $IFS-splitted */
5124 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5125 G.last_exitcode = process_command_subs(&subst_result, arg);
5126 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5127 val = subst_result.data;
5130 #if ENABLE_SH_MATH_SUPPORT
5131 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5134 arg++; /* skip '+' */
5135 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5136 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5137 res = expand_and_evaluate_arith(arg, NULL);
5138 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5139 sprintf(arith_buf, ARITH_FMT, res);
5145 val = expand_one_var(&to_be_freed, arg, &p);
5146 IF_HUSH_TICK(store_val:)
5147 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5148 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5149 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5150 if (val && val[0]) {
5151 n = expand_on_ifs(output, n, val);
5154 } else { /* quoted $VAR, val will be appended below */
5155 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5156 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5160 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5162 if (val && val[0]) {
5163 o_addQstr(output, val);
5167 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5168 * Do the check to avoid writing to a const string. */
5169 if (*p != SPECIAL_VAR_SYMBOL)
5170 *p = SPECIAL_VAR_SYMBOL;
5172 #if ENABLE_HUSH_TICK
5173 o_free(&subst_result);
5176 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5179 debug_print_list("expand_vars_to_list[a]", output, n);
5180 /* this part is literal, and it was already pre-quoted
5181 * if needed (much earlier), do not use o_addQstr here! */
5182 o_addstr_with_NUL(output, arg);
5183 debug_print_list("expand_vars_to_list[b]", output, n);
5184 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5185 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5188 /* allow to reuse list[n] later without re-growth */
5189 output->has_empty_slot = 1;
5191 o_addchr(output, '\0');
5197 static char **expand_variables(char **argv, unsigned expflags)
5201 o_string output = NULL_O_STRING;
5203 output.o_expflags = expflags;
5207 n = expand_vars_to_list(&output, n, *argv);
5210 debug_print_list("expand_variables", &output, n);
5212 /* output.data (malloced in one block) gets returned in "list" */
5213 list = o_finalize_list(&output, n);
5214 debug_print_strings("expand_variables[1]", list);
5218 static char **expand_strvec_to_strvec(char **argv)
5220 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5223 #if ENABLE_HUSH_BASH_COMPAT
5224 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5226 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5230 /* Used for expansion of right hand of assignments,
5231 * $((...)), heredocs, variable espansion parts.
5233 * NB: should NOT do globbing!
5234 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5236 static char *expand_string_to_string(const char *str, int do_unbackslash)
5238 #if !ENABLE_HUSH_BASH_COMPAT
5239 const int do_unbackslash = 1;
5241 char *argv[2], **list;
5243 debug_printf_expand("string_to_string<='%s'\n", str);
5244 /* This is generally an optimization, but it also
5245 * handles "", which otherwise trips over !list[0] check below.
5246 * (is this ever happens that we actually get str="" here?)
5248 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5249 //TODO: Can use on strings with \ too, just unbackslash() them?
5250 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5251 return xstrdup(str);
5254 argv[0] = (char*)str;
5256 list = expand_variables(argv, do_unbackslash
5257 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5258 : EXP_FLAG_SINGLEWORD
5261 if (!list[0] || list[1])
5262 bb_error_msg_and_die("BUG in varexp2");
5263 /* actually, just move string 2*sizeof(char*) bytes back */
5264 overlapping_strcpy((char*)list, list[0]);
5266 unbackslash((char*)list);
5267 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5271 /* Used for "eval" builtin */
5272 static char* expand_strvec_to_string(char **argv)
5276 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5277 /* Convert all NULs to spaces */
5282 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5283 bb_error_msg_and_die("BUG in varexp3");
5284 /* bash uses ' ' regardless of $IFS contents */
5289 overlapping_strcpy((char*)list, list[0]);
5290 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5294 static char **expand_assignments(char **argv, int count)
5299 G.expanded_assignments = p = NULL;
5300 /* Expand assignments into one string each */
5301 for (i = 0; i < count; i++) {
5302 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5304 G.expanded_assignments = NULL;
5311 void re_execute_shell(char ***to_free, const char *s,
5312 char *g_argv0, char **g_argv,
5313 char **builtin_argv) NORETURN;
5315 static void reset_traps_to_defaults(void)
5317 /* This function is always called in a child shell
5318 * after fork (not vfork, NOMMU doesn't use this function).
5323 /* Child shells are not interactive.
5324 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5325 * Testcase: (while :; do :; done) + ^Z should background.
5326 * Same goes for SIGTERM, SIGHUP, SIGINT.
5328 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5329 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5331 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5332 * Stupid. It can be done with *single* &= op, but we can't use
5333 * the fact that G.blocked_set is implemented as a bitmask
5335 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5339 /* Careful. Only if no trap or trap is not "" */
5340 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5341 sigdelset(&G.blocked_set, sig);
5348 /* Our homegrown sig mask is saner to work with :) */
5349 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5351 /* Resetting all traps to default except empty ones */
5352 mask = G.non_DFL_mask;
5353 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5354 if (!G.traps[sig] || !G.traps[sig][0])
5357 G.traps[sig] = NULL;
5358 /* There is no signal for 0 (EXIT) */
5361 /* There was a trap handler, we just removed it.
5362 * But if sig still has non-DFL handling,
5363 * we should not unblock the sig. */
5366 sigdelset(&G.blocked_set, sig);
5368 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5373 static void re_execute_shell(char ***to_free, const char *s,
5374 char *g_argv0, char **g_argv,
5375 char **builtin_argv) NORETURN;
5376 static void re_execute_shell(char ***to_free, const char *s,
5377 char *g_argv0, char **g_argv,
5378 char **builtin_argv)
5380 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5381 /* delims + 2 * (number of bytes in printed hex numbers) */
5382 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5383 char *heredoc_argv[4];
5384 struct variable *cur;
5385 # if ENABLE_HUSH_FUNCTIONS
5386 struct function *funcp;
5390 unsigned long long empty_trap_mask;
5392 if (!g_argv0) { /* heredoc */
5393 argv = heredoc_argv;
5394 argv[0] = (char *) G.argv0_for_re_execing;
5395 argv[1] = (char *) "-<";
5396 argv[2] = (char *) s;
5398 pp = &argv[3]; /* used as pointer to empty environment */
5404 if (pp) while (*pp++)
5407 empty_trap_mask = 0;
5410 for (sig = 1; sig < NSIG; sig++) {
5411 if (G.traps[sig] && !G.traps[sig][0])
5412 empty_trap_mask |= 1LL << sig;
5416 sprintf(param_buf, NOMMU_HACK_FMT
5417 , (unsigned) G.root_pid
5418 , (unsigned) G.root_ppid
5419 , (unsigned) G.last_bg_pid
5420 , (unsigned) G.last_exitcode
5423 IF_HUSH_LOOPS(, G.depth_of_loop)
5425 # undef NOMMU_HACK_FMT
5426 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5427 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5430 for (cur = G.top_var; cur; cur = cur->next) {
5431 if (!cur->flg_export || cur->flg_read_only)
5434 # if ENABLE_HUSH_FUNCTIONS
5435 for (funcp = G.top_func; funcp; funcp = funcp->next)
5441 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5442 *pp++ = (char *) G.argv0_for_re_execing;
5444 for (cur = G.top_var; cur; cur = cur->next) {
5445 if (strcmp(cur->varstr, hush_version_str) == 0)
5447 if (cur->flg_read_only) {
5448 *pp++ = (char *) "-R";
5449 *pp++ = cur->varstr;
5450 } else if (!cur->flg_export) {
5451 *pp++ = (char *) "-V";
5452 *pp++ = cur->varstr;
5455 # if ENABLE_HUSH_FUNCTIONS
5456 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5457 *pp++ = (char *) "-F";
5458 *pp++ = funcp->name;
5459 *pp++ = funcp->body_as_string;
5462 /* We can pass activated traps here. Say, -Tnn:trap_string
5464 * However, POSIX says that subshells reset signals with traps
5466 * I tested bash-3.2 and it not only does that with true subshells
5467 * of the form ( list ), but with any forked children shells.
5468 * I set trap "echo W" WINCH; and then tried:
5470 * { echo 1; sleep 20; echo 2; } &
5471 * while true; do echo 1; sleep 20; echo 2; break; done &
5472 * true | { echo 1; sleep 20; echo 2; } | cat
5474 * In all these cases sending SIGWINCH to the child shell
5475 * did not run the trap. If I add trap "echo V" WINCH;
5476 * _inside_ group (just before echo 1), it works.
5478 * I conclude it means we don't need to pass active traps here.
5479 * Even if we would use signal handlers instead of signal masking
5480 * in order to implement trap handling,
5481 * exec syscall below resets signals to SIG_DFL for us.
5483 *pp++ = (char *) "-c";
5486 while (*++builtin_argv)
5487 *pp++ = *builtin_argv;
5488 *pp++ = (char *) "";
5493 /* *pp = NULL; - is already there */
5497 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5498 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5499 execve(bb_busybox_exec_path, argv, pp);
5500 /* Fallback. Useful for init=/bin/hush usage etc */
5501 if (argv[0][0] == '/')
5502 execve(argv[0], argv, pp);
5503 xfunc_error_retval = 127;
5504 bb_error_msg_and_die("can't re-execute the shell");
5506 #endif /* !BB_MMU */
5509 static int run_and_free_list(struct pipe *pi);
5511 /* Executing from string: eval, sh -c '...'
5512 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5513 * end_trigger controls how often we stop parsing
5514 * NUL: parse all, execute, return
5515 * ';': parse till ';' or newline, execute, repeat till EOF
5517 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5519 /* Why we need empty flag?
5520 * An obscure corner case "false; ``; echo $?":
5521 * empty command in `` should still set $? to 0.
5522 * But we can't just set $? to 0 at the start,
5523 * this breaks "false; echo `echo $?`" case.
5527 struct pipe *pipe_list;
5529 #if ENABLE_HUSH_INTERACTIVE
5530 if (end_trigger == ';')
5531 inp->promptmode = 0; /* PS1 */
5533 pipe_list = parse_stream(NULL, inp, end_trigger);
5534 if (!pipe_list) { /* EOF */
5536 G.last_exitcode = 0;
5539 debug_print_tree(pipe_list, 0);
5540 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5541 run_and_free_list(pipe_list);
5546 static void parse_and_run_string(const char *s)
5548 struct in_str input;
5549 setup_string_in_str(&input, s);
5550 parse_and_run_stream(&input, '\0');
5553 static void parse_and_run_file(FILE *f)
5555 struct in_str input;
5556 setup_file_in_str(&input, f);
5557 parse_and_run_stream(&input, ';');
5560 #if ENABLE_HUSH_TICK
5561 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5566 char **to_free = NULL;
5570 pid = BB_MMU ? xfork() : xvfork();
5571 if (pid == 0) { /* child */
5572 disable_restore_tty_pgrp_on_exit();
5573 /* Process substitution is not considered to be usual
5574 * 'command execution'.
5575 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5582 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5583 close(channel[0]); /* NB: close _first_, then move fd! */
5584 xmove_fd(channel[1], 1);
5585 /* Prevent it from trying to handle ctrl-z etc */
5586 IF_HUSH_JOB(G.run_list_level = 1;)
5587 /* Awful hack for `trap` or $(trap).
5589 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5590 * contains an example where "trap" is executed in a subshell:
5592 * save_traps=$(trap)
5594 * eval "$save_traps"
5596 * Standard does not say that "trap" in subshell shall print
5597 * parent shell's traps. It only says that its output
5598 * must have suitable form, but then, in the above example
5599 * (which is not supposed to be normative), it implies that.
5601 * bash (and probably other shell) does implement it
5602 * (traps are reset to defaults, but "trap" still shows them),
5603 * but as a result, "trap" logic is hopelessly messed up:
5606 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5607 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5608 * # true | trap <--- trap is in subshell - no output (ditto)
5609 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5610 * trap -- 'echo Ho' SIGWINCH
5611 * # echo `(trap)` <--- in subshell in subshell - output
5612 * trap -- 'echo Ho' SIGWINCH
5613 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5614 * trap -- 'echo Ho' SIGWINCH
5616 * The rules when to forget and when to not forget traps
5617 * get really complex and nonsensical.
5619 * Our solution: ONLY bare $(trap) or `trap` is special.
5621 s = skip_whitespace(s);
5622 if (strncmp(s, "trap", 4) == 0
5623 && skip_whitespace(s + 4)[0] == '\0'
5625 static const char *const argv[] = { NULL, NULL };
5626 builtin_trap((char**)argv);
5627 exit(0); /* not _exit() - we need to fflush */
5630 reset_traps_to_defaults();
5631 parse_and_run_string(s);
5632 _exit(G.last_exitcode);
5634 /* We re-execute after vfork on NOMMU. This makes this script safe:
5635 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5636 * huge=`cat BIG` # was blocking here forever
5639 re_execute_shell(&to_free,
5649 # if ENABLE_HUSH_FAST
5651 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5652 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5653 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5655 enable_restore_tty_pgrp_on_exit();
5660 close_on_exec_on(channel[0]);
5661 return xfdopen_for_read(channel[0]);
5664 /* Return code is exit status of the process that is run. */
5665 static int process_command_subs(o_string *dest, const char *s)
5668 struct in_str pipe_str;
5670 int status, ch, eol_cnt;
5672 fp = generate_stream_from_string(s, &pid);
5674 /* Now send results of command back into original context */
5675 setup_file_in_str(&pipe_str, fp);
5677 while ((ch = i_getch(&pipe_str)) != EOF) {
5683 o_addchr(dest, '\n');
5686 o_addQchr(dest, ch);
5689 debug_printf("done reading from `cmd` pipe, closing it\n");
5691 /* We need to extract exitcode. Test case
5692 * "true; echo `sleep 1; false` $?"
5694 safe_waitpid(pid, &status, 0);
5695 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5696 return WEXITSTATUS(status);
5698 #endif /* ENABLE_HUSH_TICK */
5701 static void setup_heredoc(struct redir_struct *redir)
5703 struct fd_pair pair;
5706 /* the _body_ of heredoc (misleading field name) */
5707 const char *heredoc = redir->rd_filename;
5714 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5715 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5719 len = strlen(heredoc);
5721 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5723 xmove_fd(pair.rd, redir->rd_fd);
5725 /* Try writing without forking. Newer kernels have
5726 * dynamically growing pipes. Must use non-blocking write! */
5729 written = write(pair.wr, heredoc, len);
5740 ndelay_off(pair.wr);
5742 /* Okay, pipe buffer was not big enough */
5743 /* Note: we must not create a stray child (bastard? :)
5744 * for the unsuspecting parent process. Child creates a grandchild
5745 * and exits before parent execs the process which consumes heredoc
5746 * (that exec happens after we return from this function) */
5753 disable_restore_tty_pgrp_on_exit();
5754 pid = BB_MMU ? xfork() : xvfork();
5758 close(redir->rd_fd); /* read side of the pipe */
5760 full_write(pair.wr, heredoc, len); /* may loop or block */
5763 /* Delegate blocking writes to another process */
5764 xmove_fd(pair.wr, STDOUT_FILENO);
5765 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5769 #if ENABLE_HUSH_FAST
5771 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5773 enable_restore_tty_pgrp_on_exit();
5779 wait(NULL); /* wait till child has died */
5782 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5783 * and stderr if they are redirected. */
5784 static int setup_redirects(struct command *prog, int squirrel[])
5787 struct redir_struct *redir;
5789 for (redir = prog->redirects; redir; redir = redir->next) {
5790 if (redir->rd_type == REDIRECT_HEREDOC2) {
5791 /* rd_fd<<HERE case */
5792 if (squirrel && redir->rd_fd < 3
5793 && squirrel[redir->rd_fd] < 0
5795 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5797 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5799 debug_printf_parse("set heredoc '%s'\n",
5800 redir->rd_filename);
5801 setup_heredoc(redir);
5805 if (redir->rd_dup == REDIRFD_TO_FILE) {
5806 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5808 if (redir->rd_filename == NULL) {
5809 /* Something went wrong in the parse.
5810 * Pretend it didn't happen */
5811 bb_error_msg("bug in redirect parse");
5814 mode = redir_table[redir->rd_type].mode;
5815 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
5816 openfd = open_or_warn(p, mode);
5819 /* this could get lost if stderr has been redirected, but
5820 * bash and ash both lose it as well (though zsh doesn't!) */
5821 //what the above comment tries to say?
5825 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5826 openfd = redir->rd_dup;
5829 if (openfd != redir->rd_fd) {
5830 if (squirrel && redir->rd_fd < 3
5831 && squirrel[redir->rd_fd] < 0
5833 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5835 if (openfd == REDIRFD_CLOSE) {
5836 /* "n>-" means "close me" */
5837 close(redir->rd_fd);
5839 xdup2(openfd, redir->rd_fd);
5840 if (redir->rd_dup == REDIRFD_TO_FILE)
5848 static void restore_redirects(int squirrel[])
5851 for (i = 0; i < 3; i++) {
5854 /* We simply die on error */
5860 static char *find_in_path(const char *arg)
5863 const char *PATH = get_local_var_value("PATH");
5869 const char *end = strchrnul(PATH, ':');
5870 int sz = end - PATH; /* must be int! */
5874 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5876 /* We have xxx::yyyy in $PATH,
5877 * it means "use current dir" */
5880 if (access(ret, F_OK) == 0)
5893 static const struct built_in_command *find_builtin_helper(const char *name,
5894 const struct built_in_command *x,
5895 const struct built_in_command *end)
5898 if (strcmp(name, x->b_cmd) != 0) {
5902 debug_printf_exec("found builtin '%s'\n", name);
5907 static const struct built_in_command *find_builtin1(const char *name)
5909 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5911 static const struct built_in_command *find_builtin(const char *name)
5913 const struct built_in_command *x = find_builtin1(name);
5916 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5919 #if ENABLE_HUSH_FUNCTIONS
5920 static struct function **find_function_slot(const char *name)
5922 struct function **funcpp = &G.top_func;
5924 if (strcmp(name, (*funcpp)->name) == 0) {
5927 funcpp = &(*funcpp)->next;
5932 static const struct function *find_function(const char *name)
5934 const struct function *funcp = *find_function_slot(name);
5936 debug_printf_exec("found function '%s'\n", name);
5940 /* Note: takes ownership on name ptr */
5941 static struct function *new_function(char *name)
5943 struct function **funcpp = find_function_slot(name);
5944 struct function *funcp = *funcpp;
5946 if (funcp != NULL) {
5947 struct command *cmd = funcp->parent_cmd;
5948 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5950 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5952 /* Note: if !funcp->body, do not free body_as_string!
5953 * This is a special case of "-F name body" function:
5954 * body_as_string was not malloced! */
5956 free_pipe_list(funcp->body);
5958 free(funcp->body_as_string);
5962 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5963 cmd->argv[0] = funcp->name;
5964 cmd->group = funcp->body;
5966 cmd->group_as_string = funcp->body_as_string;
5970 debug_printf_exec("remembering new function '%s'\n", name);
5971 funcp = *funcpp = xzalloc(sizeof(*funcp));
5972 /*funcp->next = NULL;*/
5979 static void unset_func(const char *name)
5981 struct function **funcpp = find_function_slot(name);
5982 struct function *funcp = *funcpp;
5984 if (funcp != NULL) {
5985 debug_printf_exec("freeing function '%s'\n", funcp->name);
5986 *funcpp = funcp->next;
5987 /* funcp is unlinked now, deleting it.
5988 * Note: if !funcp->body, the function was created by
5989 * "-F name body", do not free ->body_as_string
5990 * and ->name as they were not malloced. */
5992 free_pipe_list(funcp->body);
5995 free(funcp->body_as_string);
6003 #define exec_function(to_free, funcp, argv) \
6004 exec_function(funcp, argv)
6006 static void exec_function(char ***to_free,
6007 const struct function *funcp,
6008 char **argv) NORETURN;
6009 static void exec_function(char ***to_free,
6010 const struct function *funcp,
6016 argv[0] = G.global_argv[0];
6017 G.global_argv = argv;
6021 /* On MMU, funcp->body is always non-NULL */
6022 n = run_list(funcp->body);
6026 re_execute_shell(to_free,
6027 funcp->body_as_string,
6034 static int run_function(const struct function *funcp, char **argv)
6040 save_and_replace_G_args(&sv, argv);
6042 /* "we are in function, ok to use return" */
6043 sv_flg = G.flag_return_in_progress;
6044 G.flag_return_in_progress = -1;
6045 # if ENABLE_HUSH_LOCAL
6046 G.func_nest_level++;
6049 /* On MMU, funcp->body is always non-NULL */
6052 /* Function defined by -F */
6053 parse_and_run_string(funcp->body_as_string);
6054 rc = G.last_exitcode;
6058 rc = run_list(funcp->body);
6061 # if ENABLE_HUSH_LOCAL
6063 struct variable *var;
6064 struct variable **var_pp;
6066 var_pp = &G.top_var;
6067 while ((var = *var_pp) != NULL) {
6068 if (var->func_nest_level < G.func_nest_level) {
6069 var_pp = &var->next;
6073 if (var->flg_export)
6074 bb_unsetenv(var->varstr);
6075 /* Remove from global list */
6076 *var_pp = var->next;
6082 G.func_nest_level--;
6085 G.flag_return_in_progress = sv_flg;
6087 restore_G_args(&sv, argv);
6091 #endif /* ENABLE_HUSH_FUNCTIONS */
6095 #define exec_builtin(to_free, x, argv) \
6096 exec_builtin(x, argv)
6098 #define exec_builtin(to_free, x, argv) \
6099 exec_builtin(to_free, argv)
6101 static void exec_builtin(char ***to_free,
6102 const struct built_in_command *x,
6103 char **argv) NORETURN;
6104 static void exec_builtin(char ***to_free,
6105 const struct built_in_command *x,
6111 rcode = x->b_function(argv);
6116 /* On NOMMU, we must never block!
6117 * Example: { sleep 99 | read line; } & echo Ok
6119 re_execute_shell(to_free,
6128 static void execvp_or_die(char **argv) NORETURN;
6129 static void execvp_or_die(char **argv)
6131 debug_printf_exec("execing '%s'\n", argv[0]);
6132 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6133 execvp(argv[0], argv);
6134 bb_perror_msg("can't execute '%s'", argv[0]);
6135 _exit(127); /* bash compat */
6138 #if ENABLE_HUSH_MODE_X
6139 static void dump_cmd_in_x_mode(char **argv)
6141 if (G_x_mode && argv) {
6142 /* We want to output the line in one write op */
6150 len += strlen(argv[n++]) + 1;
6156 p += sprintf(p, " %s", argv[n++]);
6164 # define dump_cmd_in_x_mode(argv) ((void)0)
6168 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6169 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6170 #define pseudo_exec(nommu_save, command, argv_expanded) \
6171 pseudo_exec(command, argv_expanded)
6174 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6176 * Don't exit() here. If you don't exec, use _exit instead.
6177 * The at_exit handlers apparently confuse the calling process,
6178 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6179 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6180 char **argv, int assignment_cnt,
6181 char **argv_expanded) NORETURN;
6182 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6183 char **argv, int assignment_cnt,
6184 char **argv_expanded)
6188 new_env = expand_assignments(argv, assignment_cnt);
6189 dump_cmd_in_x_mode(new_env);
6191 if (!argv[assignment_cnt]) {
6192 /* Case when we are here: ... | var=val | ...
6193 * (note that we do not exit early, i.e., do not optimize out
6194 * expand_assignments(): think about ... | var=`sleep 1` | ...
6196 free_strings(new_env);
6197 _exit(EXIT_SUCCESS);
6201 set_vars_and_save_old(new_env);
6202 free(new_env); /* optional */
6203 /* we can also destroy set_vars_and_save_old's return value,
6206 nommu_save->new_env = new_env;
6207 nommu_save->old_vars = set_vars_and_save_old(new_env);
6210 if (argv_expanded) {
6211 argv = argv_expanded;
6213 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6215 nommu_save->argv = argv;
6218 dump_cmd_in_x_mode(argv);
6220 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6221 if (strchr(argv[0], '/') != NULL)
6225 /* Check if the command matches any of the builtins.
6226 * Depending on context, this might be redundant. But it's
6227 * easier to waste a few CPU cycles than it is to figure out
6228 * if this is one of those cases.
6231 /* On NOMMU, it is more expensive to re-execute shell
6232 * just in order to run echo or test builtin.
6233 * It's better to skip it here and run corresponding
6234 * non-builtin later. */
6235 const struct built_in_command *x;
6236 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6238 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6241 #if ENABLE_HUSH_FUNCTIONS
6242 /* Check if the command matches any functions */
6244 const struct function *funcp = find_function(argv[0]);
6246 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6251 #if ENABLE_FEATURE_SH_STANDALONE
6252 /* Check if the command matches any busybox applets */
6254 int a = find_applet_by_name(argv[0]);
6256 # if BB_MMU /* see above why on NOMMU it is not allowed */
6257 if (APPLET_IS_NOEXEC(a)) {
6258 debug_printf_exec("running applet '%s'\n", argv[0]);
6259 run_applet_no_and_exit(a, argv);
6262 /* Re-exec ourselves */
6263 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6264 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6265 execv(bb_busybox_exec_path, argv);
6266 /* If they called chroot or otherwise made the binary no longer
6267 * executable, fall through */
6272 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6275 execvp_or_die(argv);
6278 /* Called after [v]fork() in run_pipe
6280 static void pseudo_exec(nommu_save_t *nommu_save,
6281 struct command *command,
6282 char **argv_expanded) NORETURN;
6283 static void pseudo_exec(nommu_save_t *nommu_save,
6284 struct command *command,
6285 char **argv_expanded)
6287 if (command->argv) {
6288 pseudo_exec_argv(nommu_save, command->argv,
6289 command->assignment_cnt, argv_expanded);
6292 if (command->group) {
6293 /* Cases when we are here:
6296 * ... | ( list ) | ...
6297 * ... | { list } | ...
6301 debug_printf_exec("pseudo_exec: run_list\n");
6302 reset_traps_to_defaults();
6303 rcode = run_list(command->group);
6304 /* OK to leak memory by not calling free_pipe_list,
6305 * since this process is about to exit */
6308 re_execute_shell(&nommu_save->argv_from_re_execing,
6309 command->group_as_string,
6316 /* Case when we are here: ... | >file */
6317 debug_printf_exec("pseudo_exec'ed null command\n");
6318 _exit(EXIT_SUCCESS);
6322 static const char *get_cmdtext(struct pipe *pi)
6328 /* This is subtle. ->cmdtext is created only on first backgrounding.
6329 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6330 * On subsequent bg argv is trashed, but we won't use it */
6333 argv = pi->cmds[0].argv;
6334 if (!argv || !argv[0]) {
6335 pi->cmdtext = xzalloc(1);
6341 len += strlen(*argv) + 1;
6345 argv = pi->cmds[0].argv;
6347 len = strlen(*argv);
6348 memcpy(p, *argv, len);
6356 static void insert_bg_job(struct pipe *pi)
6358 struct pipe *job, **jobp;
6361 /* Linear search for the ID of the job to use */
6363 for (job = G.job_list; job; job = job->next)
6364 if (job->jobid >= pi->jobid)
6365 pi->jobid = job->jobid + 1;
6367 /* Add job to the list of running jobs */
6369 while ((job = *jobp) != NULL)
6371 job = *jobp = xmalloc(sizeof(*job));
6373 *job = *pi; /* physical copy */
6375 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6376 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6377 for (i = 0; i < pi->num_cmds; i++) {
6378 job->cmds[i].pid = pi->cmds[i].pid;
6379 /* all other fields are not used and stay zero */
6381 job->cmdtext = xstrdup(get_cmdtext(pi));
6383 if (G_interactive_fd)
6384 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6385 G.last_jobid = job->jobid;
6388 static void remove_bg_job(struct pipe *pi)
6390 struct pipe *prev_pipe;
6392 if (pi == G.job_list) {
6393 G.job_list = pi->next;
6395 prev_pipe = G.job_list;
6396 while (prev_pipe->next != pi)
6397 prev_pipe = prev_pipe->next;
6398 prev_pipe->next = pi->next;
6401 G.last_jobid = G.job_list->jobid;
6406 /* Remove a backgrounded job */
6407 static void delete_finished_bg_job(struct pipe *pi)
6414 /* Check to see if any processes have exited -- if they
6415 * have, figure out why and see if a job has completed */
6416 static int checkjobs(struct pipe *fg_pipe)
6426 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6428 attributes = WUNTRACED;
6429 if (fg_pipe == NULL)
6430 attributes |= WNOHANG;
6433 #if ENABLE_HUSH_FAST
6434 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6435 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6436 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6437 /* There was neither fork nor SIGCHLD since last waitpid */
6438 /* Avoid doing waitpid syscall if possible */
6439 if (!G.we_have_children) {
6443 if (fg_pipe == NULL) { /* is WNOHANG set? */
6444 /* We have children, but they did not exit
6445 * or stop yet (we saw no SIGCHLD) */
6448 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6452 /* Do we do this right?
6453 * bash-3.00# sleep 20 | false
6455 * [3]+ Stopped sleep 20 | false
6456 * bash-3.00# echo $?
6457 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6458 * [hush 1.14.0: yes we do it right]
6465 #if ENABLE_HUSH_FAST
6466 i = G.count_SIGCHLD;
6468 childpid = waitpid(-1, &status, attributes);
6469 if (childpid <= 0) {
6470 if (childpid && errno != ECHILD)
6471 bb_perror_msg("waitpid");
6472 #if ENABLE_HUSH_FAST
6473 else { /* Until next SIGCHLD, waitpid's are useless */
6474 G.we_have_children = (childpid == 0);
6475 G.handled_SIGCHLD = i;
6476 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6481 dead = WIFEXITED(status) || WIFSIGNALED(status);
6484 if (WIFSTOPPED(status))
6485 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6486 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6487 if (WIFSIGNALED(status))
6488 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6489 childpid, WTERMSIG(status), WEXITSTATUS(status));
6490 if (WIFEXITED(status))
6491 debug_printf_jobs("pid %d exited, exitcode %d\n",
6492 childpid, WEXITSTATUS(status));
6494 /* Were we asked to wait for fg pipe? */
6496 i = fg_pipe->num_cmds;
6498 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6499 if (fg_pipe->cmds[i].pid != childpid)
6503 fg_pipe->cmds[i].pid = 0;
6504 fg_pipe->alive_cmds--;
6505 ex = WEXITSTATUS(status);
6506 /* bash prints killer signal's name for *last*
6507 * process in pipe (prints just newline for SIGINT).
6508 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6510 if (WIFSIGNALED(status)) {
6511 int sig = WTERMSIG(status);
6512 if (i == fg_pipe->num_cmds-1)
6513 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6514 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6515 * Maybe we need to use sig | 128? */
6518 fg_pipe->cmds[i].cmd_exitcode = ex;
6520 fg_pipe->cmds[i].is_stopped = 1;
6521 fg_pipe->stopped_cmds++;
6523 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6524 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6525 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6526 /* All processes in fg pipe have exited or stopped */
6527 i = fg_pipe->num_cmds;
6529 rcode = fg_pipe->cmds[i].cmd_exitcode;
6530 /* usually last process gives overall exitstatus,
6531 * but with "set -o pipefail", last *failed* process does */
6532 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6535 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6536 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6537 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6538 * and "killall -STOP cat" */
6539 if (G_interactive_fd) {
6541 if (fg_pipe->alive_cmds != 0)
6542 insert_bg_job(fg_pipe);
6546 if (fg_pipe->alive_cmds == 0)
6549 /* There are still running processes in the fg pipe */
6550 goto wait_more; /* do waitpid again */
6552 /* it wasnt fg_pipe, look for process in bg pipes */
6556 /* We asked to wait for bg or orphaned children */
6557 /* No need to remember exitcode in this case */
6558 for (pi = G.job_list; pi; pi = pi->next) {
6559 for (i = 0; i < pi->num_cmds; i++) {
6560 if (pi->cmds[i].pid == childpid)
6561 goto found_pi_and_prognum;
6564 /* Happens when shell is used as init process (init=/bin/sh) */
6565 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6566 continue; /* do waitpid again */
6568 found_pi_and_prognum:
6571 pi->cmds[i].pid = 0;
6573 if (!pi->alive_cmds) {
6574 if (G_interactive_fd)
6575 printf(JOB_STATUS_FORMAT, pi->jobid,
6576 "Done", pi->cmdtext);
6577 delete_finished_bg_job(pi);
6581 pi->cmds[i].is_stopped = 1;
6585 } /* while (waitpid succeeds)... */
6591 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6594 int rcode = checkjobs(fg_pipe);
6595 if (G_saved_tty_pgrp) {
6596 /* Job finished, move the shell to the foreground */
6597 p = getpgrp(); /* our process group id */
6598 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6599 tcsetpgrp(G_interactive_fd, p);
6605 /* Start all the jobs, but don't wait for anything to finish.
6608 * Return code is normally -1, when the caller has to wait for children
6609 * to finish to determine the exit status of the pipe. If the pipe
6610 * is a simple builtin command, however, the action is done by the
6611 * time run_pipe returns, and the exit code is provided as the
6614 * Returns -1 only if started some children. IOW: we have to
6615 * mask out retvals of builtins etc with 0xff!
6617 * The only case when we do not need to [v]fork is when the pipe
6618 * is single, non-backgrounded, non-subshell command. Examples:
6619 * cmd ; ... { list } ; ...
6620 * cmd && ... { list } && ...
6621 * cmd || ... { list } || ...
6622 * If it is, then we can run cmd as a builtin, NOFORK,
6623 * or (if SH_STANDALONE) an applet, and we can run the { list }
6624 * with run_list. If it isn't one of these, we fork and exec cmd.
6626 * Cases when we must fork:
6627 * non-single: cmd | cmd
6628 * backgrounded: cmd & { list } &
6629 * subshell: ( list ) [&]
6631 #if !ENABLE_HUSH_MODE_X
6632 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6633 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6635 static int redirect_and_varexp_helper(char ***new_env_p,
6636 struct variable **old_vars_p,
6637 struct command *command,
6639 char **argv_expanded)
6641 /* setup_redirects acts on file descriptors, not FILEs.
6642 * This is perfect for work that comes after exec().
6643 * Is it really safe for inline use? Experimentally,
6644 * things seem to work. */
6645 int rcode = setup_redirects(command, squirrel);
6647 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6648 *new_env_p = new_env;
6649 dump_cmd_in_x_mode(new_env);
6650 dump_cmd_in_x_mode(argv_expanded);
6652 *old_vars_p = set_vars_and_save_old(new_env);
6656 static NOINLINE int run_pipe(struct pipe *pi)
6658 static const char *const null_ptr = NULL;
6662 struct command *command;
6663 char **argv_expanded;
6665 /* it is not always needed, but we aim to smaller code */
6666 int squirrel[] = { -1, -1, -1 };
6669 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6672 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6673 * Result should be 3 lines: q w e, qwe, q w e
6675 G.ifs = get_local_var_value("IFS");
6679 IF_HUSH_JOB(pi->pgrp = -1;)
6680 pi->stopped_cmds = 0;
6681 command = &pi->cmds[0];
6682 argv_expanded = NULL;
6684 if (pi->num_cmds != 1
6685 || pi->followup == PIPE_BG
6686 || command->cmd_type == CMD_SUBSHELL
6693 debug_printf_exec(": group:%p argv:'%s'\n",
6694 command->group, command->argv ? command->argv[0] : "NONE");
6696 if (command->group) {
6697 #if ENABLE_HUSH_FUNCTIONS
6698 if (command->cmd_type == CMD_FUNCDEF) {
6699 /* "executing" func () { list } */
6700 struct function *funcp;
6702 funcp = new_function(command->argv[0]);
6703 /* funcp->name is already set to argv[0] */
6704 funcp->body = command->group;
6706 funcp->body_as_string = command->group_as_string;
6707 command->group_as_string = NULL;
6709 command->group = NULL;
6710 command->argv[0] = NULL;
6711 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6712 funcp->parent_cmd = command;
6713 command->child_func = funcp;
6715 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6717 return EXIT_SUCCESS;
6721 debug_printf("non-subshell group\n");
6722 rcode = 1; /* exitcode if redir failed */
6723 if (setup_redirects(command, squirrel) == 0) {
6724 debug_printf_exec(": run_list\n");
6725 rcode = run_list(command->group) & 0xff;
6727 restore_redirects(squirrel);
6728 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6730 debug_printf_exec("run_pipe: return %d\n", rcode);
6734 argv = command->argv ? command->argv : (char **) &null_ptr;
6736 const struct built_in_command *x;
6737 #if ENABLE_HUSH_FUNCTIONS
6738 const struct function *funcp;
6742 char **new_env = NULL;
6743 struct variable *old_vars = NULL;
6745 if (argv[command->assignment_cnt] == NULL) {
6746 /* Assignments, but no command */
6747 /* Ensure redirects take effect (that is, create files).
6748 * Try "a=t >file" */
6749 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6750 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6751 /* Set shell variables */
6755 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6756 /* Do we need to flag set_local_var() errors?
6757 * "assignment to readonly var" and "putenv error"
6762 /* Redirect error sets $? to 1. Otherwise,
6763 * if evaluating assignment value set $?, retain it.
6764 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6766 rcode = G.last_exitcode;
6767 /* Exit, _skipping_ variable restoring code: */
6768 goto clean_up_and_ret0;
6770 #else /* Older, bigger, but more correct code */
6772 rcode = setup_redirects(command, squirrel);
6773 restore_redirects(squirrel);
6774 /* Set shell variables */
6776 bb_putchar_stderr('+');
6778 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
6780 fprintf(stderr, " %s", p);
6781 debug_printf_exec("set shell var:'%s'->'%s'\n",
6783 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6784 /* Do we need to flag set_local_var() errors?
6785 * "assignment to readonly var" and "putenv error"
6790 bb_putchar_stderr('\n');
6791 /* Redirect error sets $? to 1. Otherwise,
6792 * if evaluating assignment value set $?, retain it.
6793 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6795 rcode = G.last_exitcode;
6796 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6798 debug_printf_exec("run_pipe: return %d\n", rcode);
6803 /* Expand the rest into (possibly) many strings each */
6804 #if ENABLE_HUSH_BASH_COMPAT
6805 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6806 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6810 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6813 /* if someone gives us an empty string: `cmd with empty output` */
6814 if (!argv_expanded[0]) {
6815 free(argv_expanded);
6817 return G.last_exitcode;
6820 x = find_builtin(argv_expanded[0]);
6821 #if ENABLE_HUSH_FUNCTIONS
6824 funcp = find_function(argv_expanded[0]);
6828 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6829 debug_printf("exec with redirects only\n");
6830 rcode = setup_redirects(command, NULL);
6831 goto clean_up_and_ret1;
6834 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6837 debug_printf_exec(": builtin '%s' '%s'...\n",
6838 x->b_cmd, argv_expanded[1]);
6840 rcode = x->b_function(argv_expanded) & 0xff;
6843 #if ENABLE_HUSH_FUNCTIONS
6845 # if ENABLE_HUSH_LOCAL
6846 struct variable **sv;
6847 sv = G.shadowed_vars_pp;
6848 G.shadowed_vars_pp = &old_vars;
6850 debug_printf_exec(": function '%s' '%s'...\n",
6851 funcp->name, argv_expanded[1]);
6852 rcode = run_function(funcp, argv_expanded) & 0xff;
6853 # if ENABLE_HUSH_LOCAL
6854 G.shadowed_vars_pp = sv;
6860 unset_vars(new_env);
6862 /* clean_up_and_ret0: */
6863 restore_redirects(squirrel);
6865 free(argv_expanded);
6866 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6868 debug_printf_exec("run_pipe return %d\n", rcode);
6872 if (ENABLE_FEATURE_SH_NOFORK) {
6873 int n = find_applet_by_name(argv_expanded[0]);
6874 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6875 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6877 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6878 argv_expanded[0], argv_expanded[1]);
6879 rcode = run_nofork_applet(n, argv_expanded);
6881 goto clean_up_and_ret;
6884 /* It is neither builtin nor applet. We must fork. */
6888 /* NB: argv_expanded may already be created, and that
6889 * might include `cmd` runs! Do not rerun it! We *must*
6890 * use argv_expanded if it's non-NULL */
6892 /* Going to fork a child per each pipe member */
6897 while (cmd_no < pi->num_cmds) {
6898 struct fd_pair pipefds;
6900 volatile nommu_save_t nommu_save;
6901 nommu_save.new_env = NULL;
6902 nommu_save.old_vars = NULL;
6903 nommu_save.argv = NULL;
6904 nommu_save.argv_from_re_execing = NULL;
6906 command = &pi->cmds[cmd_no];
6908 if (command->argv) {
6909 debug_printf_exec(": pipe member '%s' '%s'...\n",
6910 command->argv[0], command->argv[1]);
6912 debug_printf_exec(": pipe member with no argv\n");
6915 /* pipes are inserted between pairs of commands */
6918 if (cmd_no < pi->num_cmds)
6919 xpiped_pair(pipefds);
6921 command->pid = BB_MMU ? fork() : vfork();
6922 if (!command->pid) { /* child */
6924 disable_restore_tty_pgrp_on_exit();
6925 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6927 /* Every child adds itself to new process group
6928 * with pgid == pid_of_first_child_in_pipe */
6929 if (G.run_list_level == 1 && G_interactive_fd) {
6932 if (pgrp < 0) /* true for 1st process only */
6934 if (setpgid(0, pgrp) == 0
6935 && pi->followup != PIPE_BG
6936 && G_saved_tty_pgrp /* we have ctty */
6938 /* We do it in *every* child, not just first,
6940 tcsetpgrp(G_interactive_fd, pgrp);
6944 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6945 /* 1st cmd in backgrounded pipe
6946 * should have its stdin /dev/null'ed */
6948 if (open(bb_dev_null, O_RDONLY))
6949 xopen("/", O_RDONLY);
6951 xmove_fd(next_infd, 0);
6953 xmove_fd(pipefds.wr, 1);
6956 /* Like bash, explicit redirects override pipes,
6957 * and the pipe fd is available for dup'ing. */
6958 if (setup_redirects(command, NULL))
6961 /* Restore default handlers just prior to exec */
6962 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6964 /* Stores to nommu_save list of env vars putenv'ed
6965 * (NOMMU, on MMU we don't need that) */
6966 /* cast away volatility... */
6967 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6968 /* pseudo_exec() does not return */
6971 /* parent or error */
6972 #if ENABLE_HUSH_FAST
6974 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6976 enable_restore_tty_pgrp_on_exit();
6978 /* Clean up after vforked child */
6979 free(nommu_save.argv);
6980 free(nommu_save.argv_from_re_execing);
6981 unset_vars(nommu_save.new_env);
6982 add_vars(nommu_save.old_vars);
6984 free(argv_expanded);
6985 argv_expanded = NULL;
6986 if (command->pid < 0) { /* [v]fork failed */
6987 /* Clearly indicate, was it fork or vfork */
6988 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6992 /* Second and next children need to know pid of first one */
6994 pi->pgrp = command->pid;
7000 if (cmd_no < pi->num_cmds)
7002 /* Pass read (output) pipe end to next iteration */
7003 next_infd = pipefds.rd;
7006 if (!pi->alive_cmds) {
7008 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7013 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7017 /* NB: called by pseudo_exec, and therefore must not modify any
7018 * global data until exec/_exit (we can be a child after vfork!) */
7019 static int run_list(struct pipe *pi)
7021 #if ENABLE_HUSH_CASE
7022 char *case_word = NULL;
7024 #if ENABLE_HUSH_LOOPS
7025 struct pipe *loop_top = NULL;
7026 char **for_lcur = NULL;
7027 char **for_list = NULL;
7029 smallint last_followup;
7031 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7032 smalluint cond_code = 0;
7034 enum { cond_code = 0 };
7037 smallint rword; /* RES_foo */
7038 smallint last_rword; /* ditto */
7041 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7044 #if ENABLE_HUSH_LOOPS
7045 /* Check syntax for "for" */
7048 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7049 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7051 /* current word is FOR or IN (BOLD in comments below) */
7052 if (cpipe->next == NULL) {
7053 syntax_error("malformed for");
7055 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7058 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7059 if (cpipe->next->res_word == RES_DO)
7061 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7062 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7063 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7065 syntax_error("malformed for");
7067 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7074 /* Past this point, all code paths should jump to ret: label
7075 * in order to return, no direct "return" statements please.
7076 * This helps to ensure that no memory is leaked. */
7084 last_rword = RES_XXXX;
7086 last_followup = PIPE_SEQ;
7087 rcode = G.last_exitcode;
7089 /* Go through list of pipes, (maybe) executing them. */
7090 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7094 IF_HAS_KEYWORDS(rword = pi->res_word;)
7095 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7096 rword, cond_code, last_rword);
7097 #if ENABLE_HUSH_LOOPS
7098 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7099 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7101 /* start of a loop: remember where loop starts */
7106 /* Still in the same "if...", "then..." or "do..." branch? */
7107 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7108 if ((rcode == 0 && last_followup == PIPE_OR)
7109 || (rcode != 0 && last_followup == PIPE_AND)
7111 /* It is "<true> || CMD" or "<false> && CMD"
7112 * and we should not execute CMD */
7113 debug_printf_exec("skipped cmd because of || or &&\n");
7114 last_followup = pi->followup;
7118 last_followup = pi->followup;
7119 IF_HAS_KEYWORDS(last_rword = rword;)
7122 if (rword == RES_THEN) {
7123 /* if false; then ... fi has exitcode 0! */
7124 G.last_exitcode = rcode = EXIT_SUCCESS;
7125 /* "if <false> THEN cmd": skip cmd */
7129 if (rword == RES_ELSE || rword == RES_ELIF) {
7130 /* "if <true> then ... ELSE/ELIF cmd":
7131 * skip cmd and all following ones */
7136 #if ENABLE_HUSH_LOOPS
7137 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7139 /* first loop through for */
7141 static const char encoded_dollar_at[] ALIGN1 = {
7142 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7143 }; /* encoded representation of "$@" */
7144 static const char *const encoded_dollar_at_argv[] = {
7145 encoded_dollar_at, NULL
7146 }; /* argv list with one element: "$@" */
7149 vals = (char**)encoded_dollar_at_argv;
7150 if (pi->next->res_word == RES_IN) {
7151 /* if no variable values after "in" we skip "for" */
7152 if (!pi->next->cmds[0].argv) {
7153 G.last_exitcode = rcode = EXIT_SUCCESS;
7154 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7157 vals = pi->next->cmds[0].argv;
7158 } /* else: "for var; do..." -> assume "$@" list */
7159 /* create list of variable values */
7160 debug_print_strings("for_list made from", vals);
7161 for_list = expand_strvec_to_strvec(vals);
7162 for_lcur = for_list;
7163 debug_print_strings("for_list", for_list);
7166 /* "for" loop is over, clean up */
7172 /* Insert next value from for_lcur */
7173 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7174 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7177 if (rword == RES_IN) {
7178 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7180 if (rword == RES_DONE) {
7181 continue; /* "done" has no cmds too */
7184 #if ENABLE_HUSH_CASE
7185 if (rword == RES_CASE) {
7186 case_word = expand_strvec_to_string(pi->cmds->argv);
7189 if (rword == RES_MATCH) {
7192 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7194 /* all prev words didn't match, does this one match? */
7195 argv = pi->cmds->argv;
7197 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7198 /* TODO: which FNM_xxx flags to use? */
7199 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7201 if (cond_code == 0) { /* match! we will execute this branch */
7202 free(case_word); /* make future "word)" stop */
7210 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7212 continue; /* not matched yet, skip this pipe */
7215 /* Just pressing <enter> in shell should check for jobs.
7216 * OTOH, in non-interactive shell this is useless
7217 * and only leads to extra job checks */
7218 if (pi->num_cmds == 0) {
7219 if (G_interactive_fd)
7220 goto check_jobs_and_continue;
7224 /* After analyzing all keywords and conditions, we decided
7225 * to execute this pipe. NB: have to do checkjobs(NULL)
7226 * after run_pipe to collect any background children,
7227 * even if list execution is to be stopped. */
7228 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7231 #if ENABLE_HUSH_LOOPS
7232 G.flag_break_continue = 0;
7234 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7236 /* We ran a builtin, function, or group.
7237 * rcode is already known
7238 * and we don't need to wait for anything. */
7239 G.last_exitcode = rcode;
7240 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7241 check_and_run_traps(0);
7242 #if ENABLE_HUSH_LOOPS
7243 /* Was it "break" or "continue"? */
7244 if (G.flag_break_continue) {
7245 smallint fbc = G.flag_break_continue;
7246 /* We might fall into outer *loop*,
7247 * don't want to break it too */
7249 G.depth_break_continue--;
7250 if (G.depth_break_continue == 0)
7251 G.flag_break_continue = 0;
7252 /* else: e.g. "continue 2" should *break* once, *then* continue */
7253 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7254 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7255 goto check_jobs_and_break;
7256 /* "continue": simulate end of loop */
7261 #if ENABLE_HUSH_FUNCTIONS
7262 if (G.flag_return_in_progress == 1) {
7263 /* same as "goto check_jobs_and_break" */
7268 } else if (pi->followup == PIPE_BG) {
7269 /* What does bash do with attempts to background builtins? */
7270 /* even bash 3.2 doesn't do that well with nested bg:
7271 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7272 * I'm NOT treating inner &'s as jobs */
7273 check_and_run_traps(0);
7275 if (G.run_list_level == 1)
7278 /* Last command's pid goes to $! */
7279 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7280 G.last_exitcode = rcode = EXIT_SUCCESS;
7281 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7284 if (G.run_list_level == 1 && G_interactive_fd) {
7285 /* Waits for completion, then fg's main shell */
7286 rcode = checkjobs_and_fg_shell(pi);
7287 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7288 check_and_run_traps(0);
7291 { /* This one just waits for completion */
7292 rcode = checkjobs(pi);
7293 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7294 check_and_run_traps(0);
7296 G.last_exitcode = rcode;
7300 /* Analyze how result affects subsequent commands */
7302 if (rword == RES_IF || rword == RES_ELIF)
7305 #if ENABLE_HUSH_LOOPS
7306 /* Beware of "while false; true; do ..."! */
7307 if (pi->next && pi->next->res_word == RES_DO) {
7308 if (rword == RES_WHILE) {
7310 /* "while false; do...done" - exitcode 0 */
7311 G.last_exitcode = rcode = EXIT_SUCCESS;
7312 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7313 goto check_jobs_and_break;
7316 if (rword == RES_UNTIL) {
7318 debug_printf_exec(": until expr is true: breaking\n");
7319 check_jobs_and_break:
7327 check_jobs_and_continue:
7334 #if ENABLE_HUSH_LOOPS
7339 #if ENABLE_HUSH_CASE
7343 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7347 /* Select which version we will use */
7348 static int run_and_free_list(struct pipe *pi)
7351 debug_printf_exec("run_and_free_list entered\n");
7352 if (!G.o_opt[OPT_O_NOEXEC]) {
7353 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7354 rcode = run_list(pi);
7356 /* free_pipe_list has the side effect of clearing memory.
7357 * In the long run that function can be merged with run_list,
7358 * but doing that now would hobble the debugging effort. */
7360 debug_printf_exec("run_and_free_list return %d\n", rcode);
7365 /* Called a few times only (or even once if "sh -c") */
7366 static void init_sigmasks(void)
7370 sigset_t old_blocked_set;
7372 if (!G.inherited_set_is_saved) {
7373 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7374 G.inherited_set = G.blocked_set;
7376 old_blocked_set = G.blocked_set;
7378 mask = (1 << SIGQUIT);
7379 if (G_interactive_fd) {
7380 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7381 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7382 mask |= SPECIAL_JOB_SIGS;
7384 G.non_DFL_mask = mask;
7389 sigaddset(&G.blocked_set, sig);
7393 sigdelset(&G.blocked_set, SIGCHLD);
7395 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7396 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7398 /* POSIX allows shell to re-enable SIGCHLD
7399 * even if it was SIG_IGN on entry */
7400 #if ENABLE_HUSH_FAST
7401 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7402 if (!G.inherited_set_is_saved)
7403 signal(SIGCHLD, SIGCHLD_handler);
7405 if (!G.inherited_set_is_saved)
7406 signal(SIGCHLD, SIG_DFL);
7409 G.inherited_set_is_saved = 1;
7414 static void maybe_set_to_sigexit(int sig)
7416 void (*handler)(int);
7417 /* non_DFL_mask'ed signals are, well, masked,
7418 * no need to set handler for them.
7420 if (!((G.non_DFL_mask >> sig) & 1)) {
7421 handler = signal(sig, sigexit);
7422 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7423 signal(sig, handler);
7426 /* Set handlers to restore tty pgrp and exit */
7427 static void set_fatal_handlers(void)
7429 /* We _must_ restore tty pgrp on fatal signals */
7431 maybe_set_to_sigexit(SIGILL );
7432 maybe_set_to_sigexit(SIGFPE );
7433 maybe_set_to_sigexit(SIGBUS );
7434 maybe_set_to_sigexit(SIGSEGV);
7435 maybe_set_to_sigexit(SIGTRAP);
7436 } /* else: hush is perfect. what SEGV? */
7437 maybe_set_to_sigexit(SIGABRT);
7438 /* bash 3.2 seems to handle these just like 'fatal' ones */
7439 maybe_set_to_sigexit(SIGPIPE);
7440 maybe_set_to_sigexit(SIGALRM);
7441 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7442 * if we aren't interactive... but in this case
7443 * we never want to restore pgrp on exit, and this fn is not called */
7444 /*maybe_set_to_sigexit(SIGHUP );*/
7445 /*maybe_set_to_sigexit(SIGTERM);*/
7446 /*maybe_set_to_sigexit(SIGINT );*/
7450 static int set_mode(int state, char mode, const char *o_opt)
7455 G.o_opt[OPT_O_NOEXEC] = state;
7458 IF_HUSH_MODE_X(G_x_mode = state;)
7462 /* "set -+o" without parameter.
7463 * in bash, set -o produces this output:
7467 * We always use the second form.
7469 const char *p = o_opt_strings;
7472 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7478 idx = index_in_strings(o_opt_strings, o_opt);
7480 G.o_opt[idx] = state;
7484 return EXIT_FAILURE;
7486 return EXIT_SUCCESS;
7489 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7490 int hush_main(int argc, char **argv)
7493 unsigned builtin_argc;
7495 struct variable *cur_var;
7496 struct variable *shell_ver;
7499 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7500 G.last_exitcode = EXIT_SUCCESS;
7502 G.argv0_for_re_execing = argv[0];
7504 /* Deal with HUSH_VERSION */
7505 shell_ver = xzalloc(sizeof(*shell_ver));
7506 shell_ver->flg_export = 1;
7507 shell_ver->flg_read_only = 1;
7508 /* Code which handles ${var<op>...} needs writable values for all variables,
7509 * therefore we xstrdup: */
7510 shell_ver->varstr = xstrdup(hush_version_str);
7511 /* Create shell local variables from the values
7512 * currently living in the environment */
7513 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7514 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7515 G.top_var = shell_ver;
7516 cur_var = G.top_var;
7519 char *value = strchr(*e, '=');
7520 if (value) { /* paranoia */
7521 cur_var->next = xzalloc(sizeof(*cur_var));
7522 cur_var = cur_var->next;
7523 cur_var->varstr = *e;
7524 cur_var->max_len = strlen(*e);
7525 cur_var->flg_export = 1;
7529 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7530 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
7531 putenv(shell_ver->varstr);
7534 set_pwd_var(/*exp:*/ 1);
7535 /* bash also exports SHLVL and _,
7536 * and sets (but doesn't export) the following variables:
7538 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7539 * BASH_VERSION='3.2.0(1)-release'
7541 * MACHTYPE=i386-pc-linux-gnu
7543 * HOSTNAME=<xxxxxxxxxx>
7544 * PPID=<NNNNN> - we also do it elsewhere
7555 * PIPESTATUS=([0]="0")
7556 * HISTFILE=/<xxx>/.bash_history
7560 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7562 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7572 #if ENABLE_FEATURE_EDITING
7573 G.line_input_state = new_line_input_t(FOR_SHELL);
7574 # if defined MAX_HISTORY && MAX_HISTORY > 0 && ENABLE_HUSH_SAVEHISTORY
7576 const char *hp = get_local_var_value("HISTFILE");
7578 hp = get_local_var_value("HOME");
7580 G.line_input_state->hist_file = concat_path_file(hp, ".hush_history");
7581 //set_local_var(xasprintf("HISTFILE=%s", ...));
7588 G.global_argc = argc;
7589 G.global_argv = argv;
7590 /* Initialize some more globals to non-zero values */
7591 cmdedit_update_prompt();
7593 if (setjmp(die_jmp)) {
7594 /* xfunc has failed! die die die */
7595 /* no EXIT traps, this is an escape hatch! */
7597 hush_exit(xfunc_error_retval);
7600 /* Shell is non-interactive at first. We need to call
7601 * init_sigmasks() if we are going to execute "sh <script>",
7602 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7603 * If we later decide that we are interactive, we run init_sigmasks()
7604 * in order to intercept (more) signals.
7608 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7611 opt = getopt(argc, argv, "+c:xins"
7614 # if ENABLE_HUSH_FUNCTIONS
7624 * sh ... -c 'script'
7625 * sh ... -c 'script' ARG0 [ARG1...]
7626 * On NOMMU, if builtin_argc != 0,
7627 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7628 * "" needs to be replaced with NULL
7629 * and BARGV vector fed to builtin function.
7630 * Note: the form without ARG0 never happens:
7631 * sh ... -c 'builtin' BARGV... ""
7634 G.root_pid = getpid();
7635 G.root_ppid = getppid();
7637 G.global_argv = argv + optind;
7638 G.global_argc = argc - optind;
7640 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7641 const struct built_in_command *x;
7644 x = find_builtin(optarg);
7645 if (x) { /* paranoia */
7646 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7647 G.global_argv += builtin_argc;
7648 G.global_argv[-1] = NULL; /* replace "" */
7650 G.last_exitcode = x->b_function(argv + optind - 1);
7654 if (!G.global_argv[0]) {
7655 /* -c 'script' (no params): prevent empty $0 */
7656 G.global_argv--; /* points to argv[i] of 'script' */
7657 G.global_argv[0] = argv[0];
7659 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7661 parse_and_run_string(optarg);
7664 /* Well, we cannot just declare interactiveness,
7665 * we have to have some stuff (ctty, etc) */
7666 /* G_interactive_fd++; */
7669 /* "-s" means "read from stdin", but this is how we always
7670 * operate, so simply do nothing here. */
7673 case '<': /* "big heredoc" support */
7674 full_write1_str(optarg);
7677 unsigned long long empty_trap_mask;
7679 G.root_pid = bb_strtou(optarg, &optarg, 16);
7681 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7683 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7685 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7687 builtin_argc = bb_strtou(optarg, &optarg, 16);
7689 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7690 if (empty_trap_mask != 0) {
7693 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7694 for (sig = 1; sig < NSIG; sig++) {
7695 if (empty_trap_mask & (1LL << sig)) {
7696 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7697 sigaddset(&G.blocked_set, sig);
7700 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7702 # if ENABLE_HUSH_LOOPS
7704 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7710 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7712 # if ENABLE_HUSH_FUNCTIONS
7714 struct function *funcp = new_function(optarg);
7715 /* funcp->name is already set to optarg */
7716 /* funcp->body is set to NULL. It's a special case. */
7717 funcp->body_as_string = argv[optind];
7725 if (set_mode(1, opt, NULL) == 0) /* no error */
7729 fprintf(stderr, "Usage: sh [FILE]...\n"
7730 " or: sh -c command [args]...\n\n");
7736 } /* option parsing loop */
7739 G.root_pid = getpid();
7740 G.root_ppid = getppid();
7743 /* If we are login shell... */
7744 if (argv[0] && argv[0][0] == '-') {
7746 debug_printf("sourcing /etc/profile\n");
7747 input = fopen_for_read("/etc/profile");
7748 if (input != NULL) {
7749 close_on_exec_on(fileno(input));
7751 parse_and_run_file(input);
7754 /* bash: after sourcing /etc/profile,
7755 * tries to source (in the given order):
7756 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7757 * stopping on first found. --noprofile turns this off.
7758 * bash also sources ~/.bash_logout on exit.
7759 * If called as sh, skips .bash_XXX files.
7766 * "bash <script>" (which is never interactive (unless -i?))
7767 * sources $BASH_ENV here (without scanning $PATH).
7768 * If called as sh, does the same but with $ENV.
7770 debug_printf("running script '%s'\n", argv[optind]);
7771 G.global_argv = argv + optind;
7772 G.global_argc = argc - optind;
7773 input = xfopen_for_read(argv[optind]);
7774 close_on_exec_on(fileno(input));
7776 parse_and_run_file(input);
7777 #if ENABLE_FEATURE_CLEAN_UP
7783 /* Up to here, shell was non-interactive. Now it may become one.
7784 * NB: don't forget to (re)run init_sigmasks() as needed.
7787 /* A shell is interactive if the '-i' flag was given,
7788 * or if all of the following conditions are met:
7790 * no arguments remaining or the -s flag given
7791 * standard input is a terminal
7792 * standard output is a terminal
7793 * Refer to Posix.2, the description of the 'sh' utility.
7796 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7797 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7798 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7799 if (G_saved_tty_pgrp < 0)
7800 G_saved_tty_pgrp = 0;
7802 /* try to dup stdin to high fd#, >= 255 */
7803 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7804 if (G_interactive_fd < 0) {
7805 /* try to dup to any fd */
7806 G_interactive_fd = dup(STDIN_FILENO);
7807 if (G_interactive_fd < 0) {
7809 G_interactive_fd = 0;
7810 G_saved_tty_pgrp = 0;
7813 // TODO: track & disallow any attempts of user
7814 // to (inadvertently) close/redirect G_interactive_fd
7816 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7817 if (G_interactive_fd) {
7818 close_on_exec_on(G_interactive_fd);
7820 if (G_saved_tty_pgrp) {
7821 /* If we were run as 'hush &', sleep until we are
7822 * in the foreground (tty pgrp == our pgrp).
7823 * If we get started under a job aware app (like bash),
7824 * make sure we are now in charge so we don't fight over
7825 * who gets the foreground */
7827 pid_t shell_pgrp = getpgrp();
7828 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7829 if (G_saved_tty_pgrp == shell_pgrp)
7831 /* send TTIN to ourself (should stop us) */
7832 kill(- shell_pgrp, SIGTTIN);
7836 /* Block some signals */
7839 if (G_saved_tty_pgrp) {
7840 /* Set other signals to restore saved_tty_pgrp */
7841 set_fatal_handlers();
7842 /* Put ourselves in our own process group
7843 * (bash, too, does this only if ctty is available) */
7844 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7845 /* Grab control of the terminal */
7846 tcsetpgrp(G_interactive_fd, getpid());
7848 /* -1 is special - makes xfuncs longjmp, not exit
7849 * (we reset die_sleep = 0 whereever we [v]fork) */
7850 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7854 #elif ENABLE_HUSH_INTERACTIVE
7855 /* No job control compiled in, only prompt/line editing */
7856 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7857 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7858 if (G_interactive_fd < 0) {
7859 /* try to dup to any fd */
7860 G_interactive_fd = dup(STDIN_FILENO);
7861 if (G_interactive_fd < 0)
7863 G_interactive_fd = 0;
7866 if (G_interactive_fd) {
7867 close_on_exec_on(G_interactive_fd);
7871 /* We have interactiveness code disabled */
7875 * if interactive but not a login shell, sources ~/.bashrc
7876 * (--norc turns this off, --rcfile <file> overrides)
7879 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7880 /* note: ash and hush share this string */
7881 printf("\n\n%s %s\n"
7882 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7885 "hush - the humble shell"
7889 parse_and_run_file(stdin);
7892 hush_exit(G.last_exitcode);
7897 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7898 int msh_main(int argc, char **argv)
7900 //bb_error_msg("msh is deprecated, please use hush instead");
7901 return hush_main(argc, argv);
7909 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7914 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7921 return applet_main_func(argc, argv - argc);
7924 static int FAST_FUNC builtin_test(char **argv)
7926 return run_applet_main(argv, test_main);
7929 static int FAST_FUNC builtin_echo(char **argv)
7931 return run_applet_main(argv, echo_main);
7935 static int FAST_FUNC builtin_printf(char **argv)
7937 return run_applet_main(argv, printf_main);
7941 static char **skip_dash_dash(char **argv)
7944 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7949 static int FAST_FUNC builtin_eval(char **argv)
7951 int rcode = EXIT_SUCCESS;
7953 argv = skip_dash_dash(argv);
7955 char *str = expand_strvec_to_string(argv);
7957 * eval "echo Hi; done" ("done" is syntax error):
7958 * "echo Hi" will not execute too.
7960 parse_and_run_string(str);
7962 rcode = G.last_exitcode;
7967 static int FAST_FUNC builtin_cd(char **argv)
7971 argv = skip_dash_dash(argv);
7973 if (newdir == NULL) {
7974 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7975 * bash says "bash: cd: HOME not set" and does nothing
7978 const char *home = get_local_var_value("HOME");
7979 newdir = home ? home : "/";
7981 if (chdir(newdir)) {
7982 /* Mimic bash message exactly */
7983 bb_perror_msg("cd: %s", newdir);
7984 return EXIT_FAILURE;
7986 /* Read current dir (get_cwd(1) is inside) and set PWD.
7987 * Note: do not enforce exporting. If PWD was unset or unexported,
7988 * set it again, but do not export. bash does the same.
7990 set_pwd_var(/*exp:*/ 0);
7991 return EXIT_SUCCESS;
7994 static int FAST_FUNC builtin_exec(char **argv)
7996 argv = skip_dash_dash(argv);
7997 if (argv[0] == NULL)
7998 return EXIT_SUCCESS; /* bash does this */
8000 /* Careful: we can end up here after [v]fork. Do not restore
8001 * tty pgrp then, only top-level shell process does that */
8002 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8003 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8005 /* TODO: if exec fails, bash does NOT exit! We do.
8006 * We'll need to undo sigprocmask (it's inside execvp_or_die)
8007 * and tcsetpgrp, and this is inherently racy.
8009 execvp_or_die(argv);
8012 static int FAST_FUNC builtin_exit(char **argv)
8014 debug_printf_exec("%s()\n", __func__);
8016 /* interactive bash:
8017 * # trap "echo EEE" EXIT
8020 * There are stopped jobs.
8021 * (if there are _stopped_ jobs, running ones don't count)
8024 # EEE (then bash exits)
8026 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8029 /* note: EXIT trap is run by hush_exit */
8030 argv = skip_dash_dash(argv);
8031 if (argv[0] == NULL)
8032 hush_exit(G.last_exitcode);
8033 /* mimic bash: exit 123abc == exit 255 + error msg */
8034 xfunc_error_retval = 255;
8035 /* bash: exit -2 == exit 254, no error msg */
8036 hush_exit(xatoi(argv[0]) & 0xff);
8039 static void print_escaped(const char *s)
8044 const char *p = strchrnul(s, '\'');
8045 /* print 'xxxx', possibly just '' */
8046 printf("'%.*s'", (int)(p - s), s);
8051 /* s points to '; print "'''...'''" */
8053 do putchar('\''); while (*++s == '\'');
8058 #if !ENABLE_HUSH_LOCAL
8059 #define helper_export_local(argv, exp, lvl) \
8060 helper_export_local(argv, exp)
8062 static void helper_export_local(char **argv, int exp, int lvl)
8066 char *name_end = strchrnul(name, '=');
8068 /* So far we do not check that name is valid (TODO?) */
8070 if (*name_end == '\0') {
8071 struct variable *var, **vpp;
8073 vpp = get_ptr_to_local_var(name, name_end - name);
8074 var = vpp ? *vpp : NULL;
8076 if (exp == -1) { /* unexporting? */
8077 /* export -n NAME (without =VALUE) */
8079 var->flg_export = 0;
8080 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8082 } /* else: export -n NOT_EXISTING_VAR: no-op */
8085 if (exp == 1) { /* exporting? */
8086 /* export NAME (without =VALUE) */
8088 var->flg_export = 1;
8089 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8090 putenv(var->varstr);
8094 /* Exporting non-existing variable.
8095 * bash does not put it in environment,
8096 * but remembers that it is exported,
8097 * and does put it in env when it is set later.
8098 * We just set it to "" and export. */
8099 /* Or, it's "local NAME" (without =VALUE).
8100 * bash sets the value to "". */
8101 name = xasprintf("%s=", name);
8103 /* (Un)exporting/making local NAME=VALUE */
8104 name = xstrdup(name);
8106 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8110 static int FAST_FUNC builtin_export(char **argv)
8112 unsigned opt_unexport;
8114 #if ENABLE_HUSH_EXPORT_N
8115 /* "!": do not abort on errors */
8116 opt_unexport = getopt32(argv, "!n");
8117 if (opt_unexport == (uint32_t)-1)
8118 return EXIT_FAILURE;
8125 if (argv[0] == NULL) {
8132 /* ash emits: export VAR='VAL'
8133 * bash: declare -x VAR="VAL"
8134 * we follow ash example */
8135 const char *s = *e++;
8136 const char *p = strchr(s, '=');
8138 if (!p) /* wtf? take next variable */
8141 printf("export %.*s", (int)(p - s) + 1, s);
8142 print_escaped(p + 1);
8146 /*fflush_all(); - done after each builtin anyway */
8148 return EXIT_SUCCESS;
8151 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8153 return EXIT_SUCCESS;
8156 #if ENABLE_HUSH_LOCAL
8157 static int FAST_FUNC builtin_local(char **argv)
8159 if (G.func_nest_level == 0) {
8160 bb_error_msg("%s: not in a function", argv[0]);
8161 return EXIT_FAILURE; /* bash compat */
8163 helper_export_local(argv, 0, G.func_nest_level);
8164 return EXIT_SUCCESS;
8168 static int FAST_FUNC builtin_trap(char **argv)
8174 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8179 /* No args: print all trapped */
8180 for (i = 0; i < NSIG; ++i) {
8183 print_escaped(G.traps[i]);
8184 /* note: bash adds "SIG", but only if invoked
8185 * as "bash". If called as "sh", or if set -o posix,
8186 * then it prints short signal names.
8187 * We are printing short names: */
8188 printf(" %s\n", get_signame(i));
8191 /*fflush_all(); - done after each builtin anyway */
8192 return EXIT_SUCCESS;
8196 /* If first arg is a number: reset all specified signals */
8197 sig = bb_strtou(*argv, NULL, 10);
8203 sig = get_signum(*argv++);
8204 if (sig < 0 || sig >= NSIG) {
8206 /* Mimic bash message exactly */
8207 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8212 G.traps[sig] = xstrdup(new_cmd);
8214 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8215 get_signame(sig), sig, G.traps[sig]);
8217 /* There is no signal for 0 (EXIT) */
8222 sigaddset(&G.blocked_set, sig);
8224 /* There was a trap handler, we are removing it
8225 * (if sig has non-DFL handling,
8226 * we don't need to do anything) */
8227 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8229 sigdelset(&G.blocked_set, sig);
8232 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8236 if (!argv[1]) { /* no second arg */
8237 bb_error_msg("trap: invalid arguments");
8238 return EXIT_FAILURE;
8241 /* First arg is "-": reset all specified to default */
8242 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8243 /* Everything else: set arg as signal handler
8244 * (includes "" case, which ignores signal) */
8245 if (argv[0][0] == '-') {
8246 if (argv[0][1] == '\0') { /* "-" */
8247 /* new_cmd remains NULL: "reset these sigs" */
8250 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8253 /* else: "-something", no special meaning */
8258 goto process_sig_list;
8261 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8262 static int FAST_FUNC builtin_type(char **argv)
8264 int ret = EXIT_SUCCESS;
8270 if (0) {} /* make conditional compile easier below */
8271 /*else if (find_alias(*argv))
8272 type = "an alias";*/
8273 #if ENABLE_HUSH_FUNCTIONS
8274 else if (find_function(*argv))
8275 type = "a function";
8277 else if (find_builtin(*argv))
8278 type = "a shell builtin";
8279 else if ((path = find_in_path(*argv)) != NULL)
8282 bb_error_msg("type: %s: not found", *argv);
8287 printf("%s is %s\n", *argv, type);
8295 /* built-in 'fg' and 'bg' handler */
8296 static int FAST_FUNC builtin_fg_bg(char **argv)
8301 if (!G_interactive_fd)
8302 return EXIT_FAILURE;
8304 /* If they gave us no args, assume they want the last backgrounded task */
8306 for (pi = G.job_list; pi; pi = pi->next) {
8307 if (pi->jobid == G.last_jobid) {
8311 bb_error_msg("%s: no current job", argv[0]);
8312 return EXIT_FAILURE;
8314 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8315 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8316 return EXIT_FAILURE;
8318 for (pi = G.job_list; pi; pi = pi->next) {
8319 if (pi->jobid == jobnum) {
8323 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8324 return EXIT_FAILURE;
8326 /* TODO: bash prints a string representation
8327 * of job being foregrounded (like "sleep 1 | cat") */
8328 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8329 /* Put the job into the foreground. */
8330 tcsetpgrp(G_interactive_fd, pi->pgrp);
8333 /* Restart the processes in the job */
8334 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8335 for (i = 0; i < pi->num_cmds; i++) {
8336 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8337 pi->cmds[i].is_stopped = 0;
8339 pi->stopped_cmds = 0;
8341 i = kill(- pi->pgrp, SIGCONT);
8343 if (errno == ESRCH) {
8344 delete_finished_bg_job(pi);
8345 return EXIT_SUCCESS;
8347 bb_perror_msg("kill (SIGCONT)");
8350 if (argv[0][0] == 'f') {
8352 return checkjobs_and_fg_shell(pi);
8354 return EXIT_SUCCESS;
8358 #if ENABLE_HUSH_HELP
8359 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8361 const struct built_in_command *x;
8364 "Built-in commands:\n"
8365 "------------------\n");
8366 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8368 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8371 return EXIT_SUCCESS;
8376 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8379 const char *status_string;
8381 for (job = G.job_list; job; job = job->next) {
8382 if (job->alive_cmds == job->stopped_cmds)
8383 status_string = "Stopped";
8385 status_string = "Running";
8387 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8389 return EXIT_SUCCESS;
8394 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8399 # ifdef M_TRIM_THRESHOLD
8400 /* Optional. Reduces probability of false positives */
8403 /* Crude attempt to find where "free memory" starts,
8404 * sans fragmentation. */
8406 l = (unsigned long)p;
8409 if (l < (unsigned long)p) l = (unsigned long)p;
8412 if (!G.memleak_value)
8413 G.memleak_value = l;
8415 l -= G.memleak_value;
8422 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8427 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8430 return EXIT_SUCCESS;
8433 static int FAST_FUNC builtin_read(char **argv)
8442 /* "!": do not abort on errors.
8443 * Option string must start with "sr" to match BUILTIN_READ_xxx
8445 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8446 if (read_flags == (uint32_t)-1)
8447 return EXIT_FAILURE;
8450 r = shell_builtin_read(set_local_var_from_halves,
8452 get_local_var_value("IFS"), /* can be NULL */
8460 if ((uintptr_t)r > 1) {
8461 bb_error_msg("%s", r);
8462 r = (char*)(uintptr_t)1;
8465 return (uintptr_t)r;
8468 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8469 * built-in 'set' handler
8471 * set [-abCefhmnuvx] [-o option] [argument...]
8472 * set [+abCefhmnuvx] [+o option] [argument...]
8473 * set -- [argument...]
8476 * Implementations shall support the options in both their hyphen and
8477 * plus-sign forms. These options can also be specified as options to sh.
8479 * Write out all variables and their values: set
8480 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8481 * Turn on the -x and -v options: set -xv
8482 * Unset all positional parameters: set --
8483 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8484 * Set the positional parameters to the expansion of x, even if x expands
8485 * with a leading '-' or '+': set -- $x
8487 * So far, we only support "set -- [argument...]" and some of the short names.
8489 static int FAST_FUNC builtin_set(char **argv)
8492 char **pp, **g_argv;
8493 char *arg = *++argv;
8497 for (e = G.top_var; e; e = e->next)
8499 return EXIT_SUCCESS;
8503 if (strcmp(arg, "--") == 0) {
8507 if (arg[0] != '+' && arg[0] != '-')
8509 for (n = 1; arg[n]; ++n) {
8510 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8512 if (arg[n] == 'o' && argv[1])
8515 } while ((arg = *++argv) != NULL);
8516 /* Now argv[0] is 1st argument */
8519 return EXIT_SUCCESS;
8522 /* NB: G.global_argv[0] ($0) is never freed/changed */
8523 g_argv = G.global_argv;
8524 if (G.global_args_malloced) {
8530 G.global_args_malloced = 1;
8531 pp = xzalloc(sizeof(pp[0]) * 2);
8532 pp[0] = g_argv[0]; /* retain $0 */
8535 /* This realloc's G.global_argv */
8536 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8543 return EXIT_SUCCESS;
8545 /* Nothing known, so abort */
8547 bb_error_msg("set: %s: invalid option", arg);
8548 return EXIT_FAILURE;
8551 static int FAST_FUNC builtin_shift(char **argv)
8554 argv = skip_dash_dash(argv);
8558 if (n >= 0 && n < G.global_argc) {
8559 if (G.global_args_malloced) {
8562 free(G.global_argv[m++]);
8565 memmove(&G.global_argv[1], &G.global_argv[n+1],
8566 G.global_argc * sizeof(G.global_argv[0]));
8567 return EXIT_SUCCESS;
8569 return EXIT_FAILURE;
8572 static int FAST_FUNC builtin_source(char **argv)
8574 char *arg_path, *filename;
8577 #if ENABLE_HUSH_FUNCTIONS
8581 argv = skip_dash_dash(argv);
8584 /* bash says: "bash: .: filename argument required" */
8585 return 2; /* bash compat */
8588 if (!strchr(filename, '/')) {
8589 arg_path = find_in_path(filename);
8591 filename = arg_path;
8593 input = fopen_or_warn(filename, "r");
8596 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8597 return EXIT_FAILURE;
8599 close_on_exec_on(fileno(input));
8601 #if ENABLE_HUSH_FUNCTIONS
8602 sv_flg = G.flag_return_in_progress;
8603 /* "we are inside sourced file, ok to use return" */
8604 G.flag_return_in_progress = -1;
8606 save_and_replace_G_args(&sv, argv);
8608 parse_and_run_file(input);
8611 restore_G_args(&sv, argv);
8612 #if ENABLE_HUSH_FUNCTIONS
8613 G.flag_return_in_progress = sv_flg;
8616 return G.last_exitcode;
8619 static int FAST_FUNC builtin_umask(char **argv)
8625 argv = skip_dash_dash(argv);
8627 mode_t old_mask = mask;
8630 rc = bb_parse_mode(argv[0], &mask);
8635 * bash: umask: 'q': invalid symbolic mode operator
8636 * bash: umask: 999: octal number out of range
8638 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8643 printf("%04o\n", (unsigned) mask);
8644 /* fall through and restore mask which we set to 0 */
8648 return !rc; /* rc != 0 - success */
8651 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8652 static int FAST_FUNC builtin_unset(char **argv)
8657 /* "!": do not abort on errors */
8658 /* "+": stop at 1st non-option */
8659 opts = getopt32(argv, "!+vf");
8660 if (opts == (unsigned)-1)
8661 return EXIT_FAILURE;
8663 bb_error_msg("unset: -v and -f are exclusive");
8664 return EXIT_FAILURE;
8670 if (!(opts & 2)) { /* not -f */
8671 if (unset_local_var(*argv)) {
8672 /* unset <nonexistent_var> doesn't fail.
8673 * Error is when one tries to unset RO var.
8674 * Message was printed by unset_local_var. */
8678 #if ENABLE_HUSH_FUNCTIONS
8688 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8689 static int FAST_FUNC builtin_wait(char **argv)
8691 int ret = EXIT_SUCCESS;
8694 argv = skip_dash_dash(argv);
8695 if (argv[0] == NULL) {
8696 /* Don't care about wait results */
8697 /* Note 1: must wait until there are no more children */
8698 /* Note 2: must be interruptible */
8700 * $ sleep 3 & sleep 6 & wait
8705 * $ sleep 3 & sleep 6 & wait
8709 * ^C <-- after ~4 sec from keyboard
8712 sigaddset(&G.blocked_set, SIGCHLD);
8713 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8716 if (errno == ECHILD)
8718 /* Wait for SIGCHLD or any other signal of interest */
8719 /* sigtimedwait with infinite timeout: */
8720 sig = sigwaitinfo(&G.blocked_set, NULL);
8722 sig = check_and_run_traps(sig);
8723 if (sig && sig != SIGCHLD) { /* see note 2 */
8729 sigdelset(&G.blocked_set, SIGCHLD);
8730 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8734 /* This is probably buggy wrt interruptible-ness */
8736 pid_t pid = bb_strtou(*argv, NULL, 10);
8738 /* mimic bash message */
8739 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8740 return EXIT_FAILURE;
8742 if (waitpid(pid, &status, 0) == pid) {
8743 if (WIFSIGNALED(status))
8744 ret = 128 + WTERMSIG(status);
8745 else if (WIFEXITED(status))
8746 ret = WEXITSTATUS(status);
8750 bb_perror_msg("wait %s", *argv);
8759 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8760 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8763 def = bb_strtou(argv[1], NULL, 10);
8764 if (errno || def < def_min || argv[2]) {
8765 bb_error_msg("%s: bad arguments", argv[0]);
8773 #if ENABLE_HUSH_LOOPS
8774 static int FAST_FUNC builtin_break(char **argv)
8777 if (G.depth_of_loop == 0) {
8778 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8779 return EXIT_SUCCESS; /* bash compat */
8781 G.flag_break_continue++; /* BC_BREAK = 1 */
8783 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8784 if (depth == UINT_MAX)
8785 G.flag_break_continue = BC_BREAK;
8786 if (G.depth_of_loop < depth)
8787 G.depth_break_continue = G.depth_of_loop;
8789 return EXIT_SUCCESS;
8792 static int FAST_FUNC builtin_continue(char **argv)
8794 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8795 return builtin_break(argv);
8799 #if ENABLE_HUSH_FUNCTIONS
8800 static int FAST_FUNC builtin_return(char **argv)
8804 if (G.flag_return_in_progress != -1) {
8805 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8806 return EXIT_FAILURE; /* bash compat */
8809 G.flag_return_in_progress = 1;
8812 * out of range: wraps around at 256, does not error out
8813 * non-numeric param:
8814 * f() { false; return qwe; }; f; echo $?
8815 * bash: return: qwe: numeric argument required <== we do this
8816 * 255 <== we also do this
8818 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);