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>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (optionally enabled):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
51 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
52 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
53 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
55 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
56 * This is exactly equivalent to let "expression".
59 * grep for "TODO" and fix (some of them are easy)
61 * special variables (done: PWD)
62 * follow IFS rules more precisely, including update semantics
63 * export builtin should be special, its arguments are assignments
64 * and therefore expansion of them should be "one-word" expansion:
65 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
67 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
68 * ls: cannot access i=a: No such file or directory
69 * ls: cannot access b: No such file or directory
70 * Note1: same applies to local builtin.
71 * Note2: bash 3.2.33(1) does this only if export word itself
73 * $ export i=`echo 'aaa bbb'`; echo "$i"
75 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
78 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
80 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
81 #include <malloc.h> /* for malloc_trim */
83 /* #include <dmalloc.h> */
88 #include "shell_common.h"
89 #include "builtin_read.h"
92 #if ENABLE_HUSH_RANDOM_SUPPORT
95 # define CLEAR_RANDOM_T(rnd) ((void)0)
98 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
103 #define LEAK_HUNTING 0
104 #define BUILD_AS_NOMMU 0
105 /* Enable/disable sanity checks. Ok to enable in production,
106 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
107 * Keeping 1 for now even in released versions.
110 /* Slightly bigger (+200 bytes), but faster hush.
111 * So far it only enables a trick with counting SIGCHLDs and forks,
112 * which allows us to do fewer waitpid's.
113 * (we can detect a case where neither forks were done nor SIGCHLDs happened
114 * and therefore waitpid will return the same result as last time)
116 #define ENABLE_HUSH_FAST 0
121 # undef USE_FOR_NOMMU
124 # define USE_FOR_NOMMU(...) __VA_ARGS__
125 # define USE_FOR_MMU(...)
128 #if defined SINGLE_APPLET_MAIN
129 /* STANDALONE does not make sense, and won't compile */
130 # undef CONFIG_FEATURE_SH_STANDALONE
131 # undef ENABLE_FEATURE_SH_STANDALONE
132 # undef IF_FEATURE_SH_STANDALONE
133 # define IF_FEATURE_SH_STANDALONE(...)
134 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
135 # define ENABLE_FEATURE_SH_STANDALONE 0
138 #if !ENABLE_HUSH_INTERACTIVE
139 # undef ENABLE_FEATURE_EDITING
140 # define ENABLE_FEATURE_EDITING 0
141 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
142 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
145 /* Do we support ANY keywords? */
146 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
147 # define HAS_KEYWORDS 1
148 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
149 # define IF_HAS_NO_KEYWORDS(...)
151 # define HAS_KEYWORDS 0
152 # define IF_HAS_KEYWORDS(...)
153 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
156 /* If you comment out one of these below, it will be #defined later
157 * to perform debug printfs to stderr: */
158 #define debug_printf(...) do {} while (0)
159 /* Finer-grained debug switches */
160 #define debug_printf_parse(...) do {} while (0)
161 #define debug_print_tree(a, b) do {} while (0)
162 #define debug_printf_exec(...) do {} while (0)
163 #define debug_printf_env(...) do {} while (0)
164 #define debug_printf_jobs(...) do {} while (0)
165 #define debug_printf_expand(...) do {} while (0)
166 #define debug_printf_glob(...) do {} while (0)
167 #define debug_printf_list(...) do {} while (0)
168 #define debug_printf_subst(...) do {} while (0)
169 #define debug_printf_clean(...) do {} while (0)
171 #define ERR_PTR ((void*)(long)1)
173 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
175 #define SPECIAL_VAR_SYMBOL 3
179 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
181 /* This supports saving pointers malloced in vfork child,
182 * to be freed in the parent.
185 typedef struct nommu_save_t {
187 struct variable *old_vars;
189 char **argv_from_re_execing;
193 typedef enum reserved_style {
202 #if ENABLE_HUSH_LOOPS
209 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
214 /* three pseudo-keywords support contrived "case" syntax: */
215 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
216 RES_MATCH , /* "word)" */
217 RES_CASE_BODY, /* "this command is inside CASE" */
224 typedef struct o_string {
226 int length; /* position where data is appended */
228 /* Protect newly added chars against globbing
229 * (by prepending \ to *, ?, [, \) */
232 /* At least some part of the string was inside '' or "",
233 * possibly empty one: word"", wo''rd etc. */
235 smallint has_empty_slot;
236 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
239 MAYBE_ASSIGNMENT = 0,
240 DEFINITELY_ASSIGNMENT = 1,
242 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
244 /* Used for initialization: o_string foo = NULL_O_STRING; */
245 #define NULL_O_STRING { NULL }
247 /* I can almost use ordinary FILE*. Is open_memstream() universally
248 * available? Where is it documented? */
249 typedef struct in_str {
251 /* eof_flag=1: last char in ->p is really an EOF */
252 char eof_flag; /* meaningless if ->p == NULL */
254 #if ENABLE_HUSH_INTERACTIVE
256 smallint promptmode; /* 0: PS1, 1: PS2 */
259 int (*get) (struct in_str *) FAST_FUNC;
260 int (*peek) (struct in_str *) FAST_FUNC;
262 #define i_getch(input) ((input)->get(input))
263 #define i_peek(input) ((input)->peek(input))
265 /* The descrip member of this structure is only used to make
266 * debugging output pretty */
267 static const struct {
269 signed char default_fd;
272 { O_RDONLY, 0, "<" },
273 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
274 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
275 { O_CREAT|O_RDWR, 1, "<>" },
276 { O_RDONLY, 0, "<<" },
277 /* Should not be needed. Bogus default_fd helps in debugging */
278 /* { O_RDONLY, 77, "<<" }, */
281 struct redir_struct {
282 struct redir_struct *next;
283 char *rd_filename; /* filename */
284 int rd_fd; /* fd to redirect */
285 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
287 smallint rd_type; /* (enum redir_type) */
288 /* note: for heredocs, rd_filename contains heredoc delimiter,
289 * and subsequently heredoc itself; and rd_dup is a bitmask:
290 * bit 0: do we need to trim leading tabs?
291 * bit 1: is heredoc quoted (<<'delim' syntax) ?
294 typedef enum redir_type {
296 REDIRECT_OVERWRITE = 1,
299 REDIRECT_HEREDOC = 4,
300 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
303 REDIRFD_SYNTAX_ERR = -2,
304 REDIRFD_TO_FILE = -1,
305 /* otherwise, rd_fd is redirected to rd_dup */
307 HEREDOC_SKIPTABS = 1,
313 pid_t pid; /* 0 if exited */
314 int assignment_cnt; /* how many argv[i] are assignments? */
315 smallint is_stopped; /* is the command currently running? */
316 smallint cmd_type; /* CMD_xxx */
318 #define CMD_SUBSHELL 1
320 /* used for "[[ EXPR ]]" */
321 #if ENABLE_HUSH_BASH_COMPAT
322 # define CMD_SINGLEWORD_NOGLOB 2
325 /* used for "export noglob=* glob* a=`echo a b`" */
326 //#define CMD_SINGLEWORD_NOGLOB_COND 3
327 // It is hard to implement correctly, it adds significant amounts of tricky code,
328 // and all this is only useful for really obscure export statements
329 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
330 // guards the code which implements it, but I have doubts it works
331 // in all cases (especially with mixed globbed/non-globbed arguments)
333 #if ENABLE_HUSH_FUNCTIONS
334 # define CMD_FUNCDEF 3
337 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
340 char *group_as_string;
342 #if ENABLE_HUSH_FUNCTIONS
343 struct function *child_func;
344 /* This field is used to prevent a bug here:
345 * while...do f1() {a;}; f1; f1() {b;}; f1; done
346 * When we execute "f1() {a;}" cmd, we create new function and clear
347 * cmd->group, cmd->group_as_string, cmd->argv[0].
348 * When we execute "f1() {b;}", we notice that f1 exists,
349 * and that its "parent cmd" struct is still "alive",
350 * we put those fields back into cmd->xxx
351 * (struct function has ->parent_cmd ptr to facilitate that).
352 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
353 * Without this trick, loop would execute a;b;b;b;...
354 * instead of correct sequence a;b;a;b;...
355 * When command is freed, it severs the link
356 * (sets ->child_func->parent_cmd to NULL).
359 char **argv; /* command name and arguments */
360 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
361 * and on execution these are substituted with their values.
362 * Substitution can make _several_ words out of one argv[n]!
363 * Example: argv[0]=='.^C*^C.' here: echo .$*.
364 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
366 struct redir_struct *redirects; /* I/O redirections */
368 /* Is there anything in this command at all? */
369 #define IS_NULL_CMD(cmd) \
370 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
375 int num_cmds; /* total number of commands in pipe */
376 int alive_cmds; /* number of commands running (not exited) */
377 int stopped_cmds; /* number of commands alive, but stopped */
379 int jobid; /* job number */
380 pid_t pgrp; /* process group ID for the job */
381 char *cmdtext; /* name of job */
383 struct command *cmds; /* array of commands in pipe */
384 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
385 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
386 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
388 typedef enum pipe_style {
394 /* Is there anything in this pipe at all? */
395 #define IS_NULL_PIPE(pi) \
396 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
398 /* This holds pointers to the various results of parsing */
399 struct parse_context {
400 /* linked list of pipes */
401 struct pipe *list_head;
402 /* last pipe (being constructed right now) */
404 /* last command in pipe (being constructed right now) */
405 struct command *command;
406 /* last redirect in command->redirects list */
407 struct redir_struct *pending_redirect;
413 smallint ctx_inverted; /* "! cmd | cmd" */
415 smallint ctx_dsemicolon; /* ";;" seen */
417 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
419 /* group we are enclosed in:
420 * example: "if pipe1; pipe2; then pipe3; fi"
421 * when we see "if" or "then", we malloc and copy current context,
422 * and make ->stack point to it. then we parse pipeN.
423 * when closing "then" / fi" / whatever is found,
424 * we move list_head into ->stack->command->group,
425 * copy ->stack into current context, and delete ->stack.
426 * (parsing of { list } and ( list ) doesn't use this method)
428 struct parse_context *stack;
432 /* On program start, environ points to initial environment.
433 * putenv adds new pointers into it, unsetenv removes them.
434 * Neither of these (de)allocates the strings.
435 * setenv allocates new strings in malloc space and does putenv,
436 * and thus setenv is unusable (leaky) for shell's purposes */
437 #define setenv(...) setenv_is_leaky_dont_use()
439 struct variable *next;
440 char *varstr; /* points to "name=" portion */
441 #if ENABLE_HUSH_LOCAL
442 unsigned func_nest_level;
444 int max_len; /* if > 0, name is part of initial env; else name is malloced */
445 smallint flg_export; /* putenv should be done on this var */
446 smallint flg_read_only;
454 #if ENABLE_HUSH_FUNCTIONS
456 struct function *next;
458 struct command *parent_cmd;
461 char *body_as_string;
467 /* "Globals" within this file */
468 /* Sorted roughly by size (smaller offsets == smaller code) */
470 /* interactive_fd != 0 means we are an interactive shell.
471 * If we are, then saved_tty_pgrp can also be != 0, meaning
472 * that controlling tty is available. With saved_tty_pgrp == 0,
473 * job control still works, but terminal signals
474 * (^C, ^Z, ^Y, ^\) won't work at all, and background
475 * process groups can only be created with "cmd &".
476 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
477 * to give tty to the foreground process group,
478 * and will take it back when the group is stopped (^Z)
481 #if ENABLE_HUSH_INTERACTIVE
482 /* 'interactive_fd' is a fd# open to ctty, if we have one
483 * _AND_ if we decided to act interactively */
487 # define G_interactive_fd (G.interactive_fd)
489 # define G_interactive_fd 0
491 #if ENABLE_FEATURE_EDITING
492 line_input_t *line_input_state;
497 #if ENABLE_HUSH_RANDOM_SUPPORT
503 pid_t saved_tty_pgrp;
504 struct pipe *job_list;
505 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
507 # define G_saved_tty_pgrp 0
509 smallint flag_SIGINT;
510 #if ENABLE_HUSH_LOOPS
511 smallint flag_break_continue;
513 #if ENABLE_HUSH_FUNCTIONS
514 /* 0: outside of a function (or sourced file)
515 * -1: inside of a function, ok to use return builtin
516 * 1: return is invoked, skip all till end of func
518 smallint flag_return_in_progress;
521 smallint exiting; /* used to prevent EXIT trap recursion */
522 /* These four support $?, $#, and $1 */
523 smalluint last_exitcode;
524 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
525 smalluint global_args_malloced;
526 smalluint inherited_set_is_saved;
527 /* how many non-NULL argv's we have. NB: $# + 1 */
531 char *argv0_for_re_execing;
533 #if ENABLE_HUSH_LOOPS
534 unsigned depth_break_continue;
535 unsigned depth_of_loop;
539 struct variable *top_var; /* = &G.shell_ver (set in main()) */
540 struct variable shell_ver;
541 #if ENABLE_HUSH_FUNCTIONS
542 struct function *top_func;
543 # if ENABLE_HUSH_LOCAL
544 struct variable **shadowed_vars_pp;
545 unsigned func_nest_level;
548 /* Signal and trap handling */
550 unsigned count_SIGCHLD;
551 unsigned handled_SIGCHLD;
552 smallint we_have_children;
554 /* which signals have non-DFL handler (even with no traps set)? */
555 unsigned non_DFL_mask;
556 char **traps; /* char *traps[NSIG] */
557 sigset_t blocked_set;
558 sigset_t inherited_set;
560 unsigned long memleak_value;
563 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
565 #define G (*ptr_to_globals)
566 /* Not #defining name to G.name - this quickly gets unwieldy
567 * (too many defines). Also, I actually prefer to see when a variable
568 * is global, thus "G." prefix is a useful hint */
569 #define INIT_G() do { \
570 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
574 /* Function prototypes for builtins */
575 static int builtin_cd(char **argv) FAST_FUNC;
576 static int builtin_echo(char **argv) FAST_FUNC;
577 static int builtin_eval(char **argv) FAST_FUNC;
578 static int builtin_exec(char **argv) FAST_FUNC;
579 static int builtin_exit(char **argv) FAST_FUNC;
580 static int builtin_export(char **argv) FAST_FUNC;
582 static int builtin_fg_bg(char **argv) FAST_FUNC;
583 static int builtin_jobs(char **argv) FAST_FUNC;
586 static int builtin_help(char **argv) FAST_FUNC;
588 #if ENABLE_HUSH_LOCAL
589 static int builtin_local(char **argv) FAST_FUNC;
592 static int builtin_memleak(char **argv) FAST_FUNC;
595 static int builtin_printf(char **argv) FAST_FUNC;
597 static int builtin_pwd(char **argv) FAST_FUNC;
598 static int builtin_read(char **argv) FAST_FUNC;
599 static int builtin_set(char **argv) FAST_FUNC;
600 static int builtin_shift(char **argv) FAST_FUNC;
601 static int builtin_source(char **argv) FAST_FUNC;
602 static int builtin_test(char **argv) FAST_FUNC;
603 static int builtin_trap(char **argv) FAST_FUNC;
604 static int builtin_type(char **argv) FAST_FUNC;
605 static int builtin_true(char **argv) FAST_FUNC;
606 static int builtin_umask(char **argv) FAST_FUNC;
607 static int builtin_unset(char **argv) FAST_FUNC;
608 static int builtin_wait(char **argv) FAST_FUNC;
609 #if ENABLE_HUSH_LOOPS
610 static int builtin_break(char **argv) FAST_FUNC;
611 static int builtin_continue(char **argv) FAST_FUNC;
613 #if ENABLE_HUSH_FUNCTIONS
614 static int builtin_return(char **argv) FAST_FUNC;
617 /* Table of built-in functions. They can be forked or not, depending on
618 * context: within pipes, they fork. As simple commands, they do not.
619 * When used in non-forking context, they can change global variables
620 * in the parent shell process. If forked, of course they cannot.
621 * For example, 'unset foo | whatever' will parse and run, but foo will
622 * still be set at the end. */
623 struct built_in_command {
625 int (*function)(char **argv) FAST_FUNC;
628 # define BLTIN(cmd, func, help) { cmd, func, help }
630 # define BLTIN(cmd, func, help) { cmd, func }
634 static const struct built_in_command bltins1[] = {
635 BLTIN("." , builtin_source , "Run commands in a file"),
636 BLTIN(":" , builtin_true , NULL),
638 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
640 #if ENABLE_HUSH_LOOPS
641 BLTIN("break" , builtin_break , "Exit from a loop"),
643 BLTIN("cd" , builtin_cd , "Change directory"),
644 #if ENABLE_HUSH_LOOPS
645 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
647 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
648 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
649 BLTIN("exit" , builtin_exit , "Exit"),
650 BLTIN("export" , builtin_export , "Set environment variables"),
652 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
655 BLTIN("help" , builtin_help , NULL),
658 BLTIN("jobs" , builtin_jobs , "List jobs"),
660 #if ENABLE_HUSH_LOCAL
661 BLTIN("local" , builtin_local , "Set local variables"),
664 BLTIN("memleak" , builtin_memleak , NULL),
666 BLTIN("read" , builtin_read , "Input into variable"),
667 #if ENABLE_HUSH_FUNCTIONS
668 BLTIN("return" , builtin_return , "Return from a function"),
670 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
671 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
672 BLTIN("trap" , builtin_trap , "Trap signals"),
673 BLTIN("type" , builtin_type , "Write a description of command type"),
674 // BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
675 BLTIN("umask" , builtin_umask , "Set file creation mask"),
676 BLTIN("unset" , builtin_unset , "Unset variables"),
677 BLTIN("wait" , builtin_wait , "Wait for process"),
679 /* For now, echo and test are unconditionally enabled.
680 * Maybe make it configurable? */
681 static const struct built_in_command bltins2[] = {
682 BLTIN("[" , builtin_test , NULL),
683 BLTIN("echo" , builtin_echo , NULL),
685 BLTIN("printf" , builtin_printf , NULL),
687 BLTIN("pwd" , builtin_pwd , NULL),
688 BLTIN("test" , builtin_test , NULL),
695 /* prevent disasters with G.debug_indent < 0 */
696 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
697 # define debug_enter() (G.debug_indent++)
698 # define debug_leave() (G.debug_indent--)
700 # define indent() ((void)0)
701 # define debug_enter() ((void)0)
702 # define debug_leave() ((void)0)
706 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
709 #ifndef debug_printf_parse
710 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
713 #ifndef debug_printf_exec
714 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
717 #ifndef debug_printf_env
718 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
721 #ifndef debug_printf_jobs
722 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
723 # define DEBUG_JOBS 1
725 # define DEBUG_JOBS 0
728 #ifndef debug_printf_expand
729 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 # define DEBUG_EXPAND 1
732 # define DEBUG_EXPAND 0
735 #ifndef debug_printf_glob
736 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
737 # define DEBUG_GLOB 1
739 # define DEBUG_GLOB 0
742 #ifndef debug_printf_list
743 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
746 #ifndef debug_printf_subst
747 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
750 #ifndef debug_printf_clean
751 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
752 # define DEBUG_CLEAN 1
754 # define DEBUG_CLEAN 0
758 static void debug_print_strings(const char *prefix, char **vv)
761 fprintf(stderr, "%s:\n", prefix);
763 fprintf(stderr, " '%s'\n", *vv++);
766 # define debug_print_strings(prefix, vv) ((void)0)
770 /* Leak hunting. Use hush_leaktool.sh for post-processing.
773 static void *xxmalloc(int lineno, size_t size)
775 void *ptr = xmalloc((size + 0xff) & ~0xff);
776 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
779 static void *xxrealloc(int lineno, void *ptr, size_t size)
781 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
782 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
785 static char *xxstrdup(int lineno, const char *str)
787 char *ptr = xstrdup(str);
788 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
791 static void xxfree(void *ptr)
793 fdprintf(2, "free %p\n", ptr);
796 #define xmalloc(s) xxmalloc(__LINE__, s)
797 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
798 #define xstrdup(s) xxstrdup(__LINE__, s)
799 #define free(p) xxfree(p)
803 /* Syntax and runtime errors. They always abort scripts.
804 * In interactive use they usually discard unparsed and/or unexecuted commands
805 * and return to the prompt.
806 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
809 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
810 # define syntax_error(lineno, msg) syntax_error(msg)
811 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
812 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
813 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
814 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
817 static void die_if_script(unsigned lineno, const char *fmt, ...)
822 bb_error_msg("hush.c:%u", lineno);
825 bb_verror_msg(fmt, p, NULL);
827 if (!G_interactive_fd)
831 static void syntax_error(unsigned lineno, const char *msg)
834 die_if_script(lineno, "syntax error: %s", msg);
836 die_if_script(lineno, "syntax error", NULL);
839 static void syntax_error_at(unsigned lineno, const char *msg)
841 die_if_script(lineno, "syntax error at '%s'", msg);
844 static void syntax_error_unterm_str(unsigned lineno, const char *s)
846 die_if_script(lineno, "syntax error: unterminated %s", s);
849 /* It so happens that all such cases are totally fatal
850 * even if shell is interactive: EOF while looking for closing
851 * delimiter. There is nowhere to read stuff from after that,
852 * it's EOF! The only choice is to terminate.
854 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
855 static void syntax_error_unterm_ch(unsigned lineno, char ch)
857 char msg[2] = { ch, '\0' };
858 syntax_error_unterm_str(lineno, msg);
862 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
867 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
871 # undef die_if_script
873 # undef syntax_error_at
874 # undef syntax_error_unterm_ch
875 # undef syntax_error_unterm_str
876 # undef syntax_error_unexpected_ch
878 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
879 # define syntax_error(msg) syntax_error(__LINE__, msg)
880 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
881 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
882 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
883 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
887 #if ENABLE_HUSH_INTERACTIVE
888 static void cmdedit_update_prompt(void);
890 # define cmdedit_update_prompt() ((void)0)
896 static int is_well_formed_var_name(const char *s, char terminator)
898 if (!s || !(isalpha(*s) || *s == '_'))
901 while (isalnum(*s) || *s == '_')
903 return *s == terminator;
906 /* Replace each \x with x in place, return ptr past NUL. */
907 static char *unbackslash(char *src)
909 char *dst = src = strchrnul(src, '\\');
913 if ((*dst++ = *src++) == '\0')
919 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
940 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
941 v[count1 + count2] = NULL;
944 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
948 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
950 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
951 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
954 #define add_strings_to_strings(strings, add, need_to_dup) \
955 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
958 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
959 static char **add_string_to_strings(char **strings, char *add)
964 return add_strings_to_strings(strings, v, /*dup:*/ 0);
967 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
969 char **ptr = add_string_to_strings(strings, add);
970 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
973 #define add_string_to_strings(strings, add) \
974 xx_add_string_to_strings(__LINE__, strings, add)
977 static void free_strings(char **strings)
992 /* Helpers for setting new $n and restoring them back
994 typedef struct save_arg_t {
998 smallint sv_g_malloced;
1001 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1005 sv->sv_argv0 = argv[0];
1006 sv->sv_g_argv = G.global_argv;
1007 sv->sv_g_argc = G.global_argc;
1008 sv->sv_g_malloced = G.global_args_malloced;
1010 argv[0] = G.global_argv[0]; /* retain $0 */
1011 G.global_argv = argv;
1012 G.global_args_malloced = 0;
1020 static void restore_G_args(save_arg_t *sv, char **argv)
1024 if (G.global_args_malloced) {
1025 /* someone ran "set -- arg1 arg2 ...", undo */
1027 while (*++pp) /* note: does not free $0 */
1029 free(G.global_argv);
1031 argv[0] = sv->sv_argv0;
1032 G.global_argv = sv->sv_g_argv;
1033 G.global_argc = sv->sv_g_argc;
1034 G.global_args_malloced = sv->sv_g_malloced;
1038 /* Basic theory of signal handling in shell
1039 * ========================================
1040 * This does not describe what hush does, rather, it is current understanding
1041 * what it _should_ do. If it doesn't, it's a bug.
1042 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1044 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1045 * is finished or backgrounded. It is the same in interactive and
1046 * non-interactive shells, and is the same regardless of whether
1047 * a user trap handler is installed or a shell special one is in effect.
1048 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1049 * backgrounds (i.e. stops) or kills all members of currently running
1052 * Wait builtin in interruptible by signals for which user trap is set
1053 * or by SIGINT in interactive shell.
1055 * Trap handlers will execute even within trap handlers. (right?)
1057 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1058 * except for handlers set to '' (empty string).
1060 * If job control is off, backgrounded commands ("cmd &")
1061 * have SIGINT, SIGQUIT set to SIG_IGN.
1063 * Commands which are run in command substitution ("`cmd`")
1064 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1066 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1067 * by the shell from its parent.
1069 * Signals which differ from SIG_DFL action
1070 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1073 * SIGTERM (interactive): ignore
1074 * SIGHUP (interactive):
1075 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1076 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1077 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1078 * that all pipe members are stopped. Try this in bash:
1079 * while :; do :; done - ^Z does not background it
1080 * (while :; do :; done) - ^Z backgrounds it
1081 * SIGINT (interactive): wait for last pipe, ignore the rest
1082 * of the command line, show prompt. NB: ^C does not send SIGINT
1083 * to interactive shell while shell is waiting for a pipe,
1084 * since shell is bg'ed (is not in foreground process group).
1085 * Example 1: this waits 5 sec, but does not execute ls:
1086 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1087 * Example 2: this does not wait and does not execute ls:
1088 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1089 * Example 3: this does not wait 5 sec, but executes ls:
1090 * "sleep 5; ls -l" + press ^C
1092 * (What happens to signals which are IGN on shell start?)
1093 * (What happens with signal mask on shell start?)
1095 * Implementation in hush
1096 * ======================
1097 * We use in-kernel pending signal mask to determine which signals were sent.
1098 * We block all signals which we don't want to take action immediately,
1099 * i.e. we block all signals which need to have special handling as described
1100 * above, and all signals which have traps set.
1101 * After each pipe execution, we extract any pending signals via sigtimedwait()
1104 * unsigned non_DFL_mask: a mask of such "special" signals
1105 * sigset_t blocked_set: current blocked signal set
1108 * clear bit in blocked_set unless it is also in non_DFL_mask
1109 * "trap 'cmd' SIGxxx":
1110 * set bit in blocked_set (even if 'cmd' is '')
1111 * after [v]fork, if we plan to be a shell:
1112 * unblock signals with special interactive handling
1113 * (child shell is not interactive),
1114 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1115 * after [v]fork, if we plan to exec:
1116 * POSIX says fork clears pending signal mask in child - no need to clear it.
1117 * Restore blocked signal set to one inherited by shell just prior to exec.
1119 * Note: as a result, we do not use signal handlers much. The only uses
1120 * are to count SIGCHLDs
1121 * and to restore tty pgrp on signal-induced exit.
1124 * Standard says "When a subshell is entered, traps that are not being ignored
1125 * are set to the default actions". bash interprets it so that traps which
1126 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1129 SPECIAL_INTERACTIVE_SIGS = 0
1134 SPECIAL_JOB_SIGS = 0
1142 #if ENABLE_HUSH_FAST
1143 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1146 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1152 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1153 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1154 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1155 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1157 /* Restores tty foreground process group, and exits.
1158 * May be called as signal handler for fatal signal
1159 * (will resend signal to itself, producing correct exit state)
1160 * or called directly with -EXITCODE.
1161 * We also call it if xfunc is exiting. */
1162 static void sigexit(int sig) NORETURN;
1163 static void sigexit(int sig)
1165 /* Disable all signals: job control, SIGPIPE, etc. */
1166 sigprocmask_allsigs(SIG_BLOCK);
1168 /* Careful: we can end up here after [v]fork. Do not restore
1169 * tty pgrp then, only top-level shell process does that */
1170 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1171 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1173 /* Not a signal, just exit */
1177 kill_myself_with_sig(sig); /* does not return */
1181 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1182 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1186 /* Restores tty foreground process group, and exits. */
1187 static void hush_exit(int exitcode) NORETURN;
1188 static void hush_exit(int exitcode)
1190 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1191 /* Prevent recursion:
1192 * trap "echo Hi; exit" EXIT; exit
1194 char *argv[] = { NULL, G.traps[0], NULL };
1203 sigexit(- (exitcode & 0xff));
1209 static int check_and_run_traps(int sig)
1211 static const struct timespec zero_timespec = { 0, 0 };
1212 smalluint save_rcode;
1218 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1223 if (G.traps && G.traps[sig]) {
1224 if (G.traps[sig][0]) {
1225 /* We have user-defined handler */
1226 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1227 save_rcode = G.last_exitcode;
1230 G.last_exitcode = save_rcode;
1231 } /* else: "" trap, ignoring signal */
1234 /* not a trap: special action */
1236 #if ENABLE_HUSH_FAST
1239 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1243 /* Builtin was ^C'ed, make it look prettier: */
1250 /* bash is observed to signal whole process groups,
1251 * not individual processes */
1252 for (job = G.job_list; job; job = job->next) {
1255 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1256 if (kill(- job->pgrp, SIGHUP) == 0)
1257 kill(- job->pgrp, SIGCONT);
1262 default: /* ignored: */
1263 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1271 static const char *get_cwd(int force)
1273 if (force || G.cwd == NULL) {
1274 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1275 * we must not try to free(bb_msg_unknown) */
1276 if (G.cwd == bb_msg_unknown)
1278 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1280 G.cwd = bb_msg_unknown;
1287 * Shell and environment variable support
1289 static struct variable **get_ptr_to_local_var(const char *name)
1291 struct variable **pp;
1292 struct variable *cur;
1297 while ((cur = *pp) != NULL) {
1298 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1305 static struct variable *get_local_var(const char *name)
1307 struct variable **pp = get_ptr_to_local_var(name);
1313 static const char* FAST_FUNC get_local_var_value(const char *name)
1315 struct variable **pp = get_ptr_to_local_var(name);
1317 return strchr((*pp)->varstr, '=') + 1;
1318 if (strcmp(name, "PPID") == 0)
1319 return utoa(G.root_ppid);
1320 // bash compat: UID? EUID?
1321 #if ENABLE_HUSH_RANDOM_SUPPORT
1322 if (strcmp(name, "RANDOM") == 0) {
1323 return utoa(next_random(&G.random_gen));
1329 /* str holds "NAME=VAL" and is expected to be malloced.
1330 * We take ownership of it.
1332 * 0: do not change export flag
1333 * (if creating new variable, flag will be 0)
1334 * 1: set export flag and putenv the variable
1335 * -1: clear export flag and unsetenv the variable
1336 * flg_read_only is set only when we handle -R var=val
1338 #if !BB_MMU && ENABLE_HUSH_LOCAL
1339 /* all params are used */
1340 #elif BB_MMU && ENABLE_HUSH_LOCAL
1341 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1342 set_local_var(str, flg_export, local_lvl)
1343 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1344 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1345 set_local_var(str, flg_export)
1346 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1347 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1348 set_local_var(str, flg_export, flg_read_only)
1350 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1352 struct variable **var_pp;
1353 struct variable *cur;
1357 eq_sign = strchr(str, '=');
1358 if (!eq_sign) { /* not expected to ever happen? */
1363 name_len = eq_sign - str + 1; /* including '=' */
1364 var_pp = &G.top_var;
1365 while ((cur = *var_pp) != NULL) {
1366 if (strncmp(cur->varstr, str, name_len) != 0) {
1367 var_pp = &cur->next;
1370 /* We found an existing var with this name */
1371 if (cur->flg_read_only) {
1375 bb_error_msg("%s: readonly variable", str);
1379 if (flg_export == -1) { // "&& cur->flg_export" ?
1380 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1385 #if ENABLE_HUSH_LOCAL
1386 if (cur->func_nest_level < local_lvl) {
1387 /* New variable is declared as local,
1388 * and existing one is global, or local
1389 * from enclosing function.
1390 * Remove and save old one: */
1391 *var_pp = cur->next;
1392 cur->next = *G.shadowed_vars_pp;
1393 *G.shadowed_vars_pp = cur;
1394 /* bash 3.2.33(1) and exported vars:
1396 * # f() { local z=a; env | grep ^z; }
1402 if (cur->flg_export)
1407 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1412 if (cur->max_len != 0) {
1413 if (cur->max_len >= strlen(str)) {
1414 /* This one is from startup env, reuse space */
1415 strcpy(cur->varstr, str);
1419 /* max_len == 0 signifies "malloced" var, which we can
1420 * (and has to) free */
1424 goto set_str_and_exp;
1427 /* Not found - create new variable struct */
1428 cur = xzalloc(sizeof(*cur));
1429 #if ENABLE_HUSH_LOCAL
1430 cur->func_nest_level = local_lvl;
1432 cur->next = *var_pp;
1438 cur->flg_read_only = flg_read_only;
1441 if (flg_export == 1)
1442 cur->flg_export = 1;
1443 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1444 cmdedit_update_prompt();
1445 if (cur->flg_export) {
1446 if (flg_export == -1) {
1447 cur->flg_export = 0;
1448 /* unsetenv was already done */
1450 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1451 return putenv(cur->varstr);
1457 /* Used at startup and after each cd */
1458 static void set_pwd_var(int exp)
1460 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1461 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1464 static int unset_local_var_len(const char *name, int name_len)
1466 struct variable *cur;
1467 struct variable **var_pp;
1470 return EXIT_SUCCESS;
1471 var_pp = &G.top_var;
1472 while ((cur = *var_pp) != NULL) {
1473 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1474 if (cur->flg_read_only) {
1475 bb_error_msg("%s: readonly variable", name);
1476 return EXIT_FAILURE;
1478 *var_pp = cur->next;
1479 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1480 bb_unsetenv(cur->varstr);
1481 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1482 cmdedit_update_prompt();
1486 return EXIT_SUCCESS;
1488 var_pp = &cur->next;
1490 return EXIT_SUCCESS;
1493 static int unset_local_var(const char *name)
1495 return unset_local_var_len(name, strlen(name));
1498 static void unset_vars(char **strings)
1506 const char *eq = strchrnul(*v, '=');
1507 unset_local_var_len(*v, (int)(eq - *v));
1513 #if ENABLE_SH_MATH_SUPPORT
1514 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1515 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1516 static char* FAST_FUNC endofname(const char *name)
1524 if (!is_in_name(*p))
1530 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1532 char *var = xasprintf("%s=%s", name, val);
1533 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1539 * Helpers for "var1=val1 var2=val2 cmd" feature
1541 static void add_vars(struct variable *var)
1543 struct variable *next;
1547 var->next = G.top_var;
1549 if (var->flg_export) {
1550 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1551 putenv(var->varstr);
1553 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1559 static struct variable *set_vars_and_save_old(char **strings)
1562 struct variable *old = NULL;
1568 struct variable *var_p;
1569 struct variable **var_pp;
1572 eq = strchr(*s, '=');
1575 var_pp = get_ptr_to_local_var(*s);
1578 /* Remove variable from global linked list */
1580 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1581 *var_pp = var_p->next;
1582 /* Add it to returned list */
1586 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1597 static int FAST_FUNC static_get(struct in_str *i)
1606 static int FAST_FUNC static_peek(struct in_str *i)
1611 #if ENABLE_HUSH_INTERACTIVE
1613 static void cmdedit_update_prompt(void)
1615 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1616 G.PS1 = get_local_var_value("PS1");
1619 G.PS2 = get_local_var_value("PS2");
1627 static const char* setup_prompt_string(int promptmode)
1629 const char *prompt_str;
1630 debug_printf("setup_prompt_string %d ", promptmode);
1631 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1632 /* Set up the prompt */
1633 if (promptmode == 0) { /* PS1 */
1635 /* bash uses $PWD value, even if it is set by user.
1636 * It uses current dir only if PWD is unset.
1637 * We always use current dir. */
1638 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1643 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1644 debug_printf("result '%s'\n", prompt_str);
1648 static void get_user_input(struct in_str *i)
1651 const char *prompt_str;
1653 prompt_str = setup_prompt_string(i->promptmode);
1654 #if ENABLE_FEATURE_EDITING
1655 /* Enable command line editing only while a command line
1656 * is actually being read */
1659 /* buglet: SIGINT will not make new prompt to appear _at once_,
1660 * only after <Enter>. (^C will work) */
1661 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1662 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1663 check_and_run_traps(0);
1664 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1665 i->eof_flag = (r < 0);
1666 if (i->eof_flag) { /* EOF/error detected */
1667 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1668 G.user_input_buf[1] = '\0';
1673 fputs(prompt_str, stdout);
1675 G.user_input_buf[0] = r = fgetc(i->file);
1676 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1677 //do we need check_and_run_traps(0)? (maybe only if stdin)
1678 } while (G.flag_SIGINT);
1679 i->eof_flag = (r == EOF);
1681 i->p = G.user_input_buf;
1684 #endif /* INTERACTIVE */
1686 /* This is the magic location that prints prompts
1687 * and gets data back from the user */
1688 static int FAST_FUNC file_get(struct in_str *i)
1692 /* If there is data waiting, eat it up */
1693 if (i->p && *i->p) {
1694 #if ENABLE_HUSH_INTERACTIVE
1698 if (i->eof_flag && !*i->p)
1700 /* note: ch is never NUL */
1702 /* need to double check i->file because we might be doing something
1703 * more complicated by now, like sourcing or substituting. */
1704 #if ENABLE_HUSH_INTERACTIVE
1705 if (G_interactive_fd && i->promptme && i->file == stdin) {
1708 } while (!*i->p); /* need non-empty line */
1709 i->promptmode = 1; /* PS2 */
1714 do ch = fgetc(i->file); while (ch == '\0');
1716 debug_printf("file_get: got '%c' %d\n", ch, ch);
1717 #if ENABLE_HUSH_INTERACTIVE
1724 /* All callers guarantee this routine will never
1725 * be used right after a newline, so prompting is not needed.
1727 static int FAST_FUNC file_peek(struct in_str *i)
1730 if (i->p && *i->p) {
1731 if (i->eof_flag && !i->p[1])
1734 /* note: ch is never NUL */
1736 do ch = fgetc(i->file); while (ch == '\0');
1737 i->eof_flag = (ch == EOF);
1738 i->peek_buf[0] = ch;
1739 i->peek_buf[1] = '\0';
1741 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1745 static void setup_file_in_str(struct in_str *i, FILE *f)
1747 i->peek = file_peek;
1749 #if ENABLE_HUSH_INTERACTIVE
1751 i->promptmode = 0; /* PS1 */
1757 static void setup_string_in_str(struct in_str *i, const char *s)
1759 i->peek = static_peek;
1760 i->get = static_get;
1761 #if ENABLE_HUSH_INTERACTIVE
1763 i->promptmode = 0; /* PS1 */
1773 #define B_CHUNK (32 * sizeof(char*))
1775 static void o_reset_to_empty_unquoted(o_string *o)
1783 static void o_free(o_string *o)
1786 memset(o, 0, sizeof(*o));
1789 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1794 static void o_grow_by(o_string *o, int len)
1796 if (o->length + len > o->maxlen) {
1797 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1798 o->data = xrealloc(o->data, 1 + o->maxlen);
1802 static void o_addchr(o_string *o, int ch)
1804 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1806 o->data[o->length] = ch;
1808 o->data[o->length] = '\0';
1811 static void o_addblock(o_string *o, const char *str, int len)
1814 memcpy(&o->data[o->length], str, len);
1816 o->data[o->length] = '\0';
1820 static void o_addstr(o_string *o, const char *str)
1822 o_addblock(o, str, strlen(str));
1824 static void nommu_addchr(o_string *o, int ch)
1830 # define nommu_addchr(o, str) ((void)0)
1833 static void o_addstr_with_NUL(o_string *o, const char *str)
1835 o_addblock(o, str, strlen(str) + 1);
1838 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1843 && (*str != '*' && *str != '?' && *str != '[')
1851 #undef HUSH_BRACE_EXP
1853 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1854 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1855 * Apparently, on unquoted $v bash still does globbing
1856 * ("v='*.txt'; echo $v" prints all .txt files),
1857 * but NOT brace expansion! Thus, there should be TWO independent
1858 * quoting mechanisms on $v expansion side: one protects
1859 * $v from brace expansion, and other additionally protects "$v" against globbing.
1860 * We have only second one.
1863 #ifdef HUSH_BRACE_EXP
1864 # define MAYBE_BRACES "{}"
1866 # define MAYBE_BRACES ""
1869 /* My analysis of quoting semantics tells me that state information
1870 * is associated with a destination, not a source.
1872 static void o_addqchr(o_string *o, int ch)
1875 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1880 o->data[o->length] = '\\';
1883 o->data[o->length] = ch;
1885 o->data[o->length] = '\0';
1888 static void o_addQchr(o_string *o, int ch)
1891 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1893 o->data[o->length] = '\\';
1897 o->data[o->length] = ch;
1899 o->data[o->length] = '\0';
1902 static void o_addQstr(o_string *o, const char *str, int len)
1905 o_addblock(o, str, len);
1911 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1912 if (ordinary_cnt > len) /* paranoia */
1914 o_addblock(o, str, ordinary_cnt);
1915 if (ordinary_cnt == len)
1917 str += ordinary_cnt;
1918 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1922 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1924 o->data[o->length] = '\\';
1928 o->data[o->length] = ch;
1930 o->data[o->length] = '\0';
1934 /* A special kind of o_string for $VAR and `cmd` expansion.
1935 * It contains char* list[] at the beginning, which is grown in 16 element
1936 * increments. Actual string data starts at the next multiple of 16 * (char*).
1937 * list[i] contains an INDEX (int!) into this string data.
1938 * It means that if list[] needs to grow, data needs to be moved higher up
1939 * but list[i]'s need not be modified.
1940 * NB: remembering how many list[i]'s you have there is crucial.
1941 * o_finalize_list() operation post-processes this structure - calculates
1942 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1944 #if DEBUG_EXPAND || DEBUG_GLOB
1945 static void debug_print_list(const char *prefix, o_string *o, int n)
1947 char **list = (char**)o->data;
1948 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1952 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1953 prefix, list, n, string_start, o->length, o->maxlen);
1956 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1957 o->data + (int)list[i] + string_start,
1958 o->data + (int)list[i] + string_start);
1962 const char *p = o->data + (int)list[n - 1] + string_start;
1964 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1968 # define debug_print_list(prefix, o, n) ((void)0)
1971 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1972 * in list[n] so that it points past last stored byte so far.
1973 * It returns n+1. */
1974 static int o_save_ptr_helper(o_string *o, int n)
1976 char **list = (char**)o->data;
1980 if (!o->has_empty_slot) {
1981 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1982 string_len = o->length - string_start;
1983 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1984 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1985 /* list[n] points to string_start, make space for 16 more pointers */
1986 o->maxlen += 0x10 * sizeof(list[0]);
1987 o->data = xrealloc(o->data, o->maxlen + 1);
1988 list = (char**)o->data;
1989 memmove(list + n + 0x10, list + n, string_len);
1990 o->length += 0x10 * sizeof(list[0]);
1992 debug_printf_list("list[%d]=%d string_start=%d\n",
1993 n, string_len, string_start);
1996 /* We have empty slot at list[n], reuse without growth */
1997 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1998 string_len = o->length - string_start;
1999 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2000 n, string_len, string_start);
2001 o->has_empty_slot = 0;
2003 list[n] = (char*)(ptrdiff_t)string_len;
2007 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2008 static int o_get_last_ptr(o_string *o, int n)
2010 char **list = (char**)o->data;
2011 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2013 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2016 #ifdef HUSH_BRACE_EXP
2017 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2018 * first, it processes even {a} (no commas), second,
2019 * I didn't manage to make it return strings when they don't match
2020 * existing files. Need to re-implement it.
2024 static int glob_needed(const char *s)
2033 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2039 /* Return pointer to next closing brace or to comma */
2040 static const char *next_brace_sub(const char *cp)
2044 while (*cp != '\0') {
2051 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2053 if (*cp++ == '{') /*}*/
2057 return *cp != '\0' ? cp : NULL;
2059 /* Recursive brace globber. Note: may garble pattern[]. */
2060 static int glob_brace(char *pattern, o_string *o, int n)
2062 char *new_pattern_buf;
2069 debug_printf_glob("glob_brace('%s')\n", pattern);
2075 if (*begin == '{') /*}*/ {
2076 /* Find the first sub-pattern and at the same time
2077 * find the rest after the closing brace */
2078 next = next_brace_sub(begin);
2080 /* An illegal expression */
2083 /*{*/ if (*next == '}') {
2084 /* "{abc}" with no commas - illegal
2085 * brace expr, disregard and skip it */
2091 if (*begin == '\\' && begin[1] != '\0')
2095 debug_printf_glob("begin:%s\n", begin);
2096 debug_printf_glob("next:%s\n", next);
2098 /* Now find the end of the whole brace expression */
2100 /*{*/ while (*rest != '}') {
2101 rest = next_brace_sub(rest);
2103 /* An illegal expression */
2106 debug_printf_glob("rest:%s\n", rest);
2108 rest_len = strlen(++rest) + 1;
2110 /* We are sure the brace expression is well-formed */
2112 /* Allocate working buffer large enough for our work */
2113 new_pattern_buf = xmalloc(strlen(pattern));
2115 /* We have a brace expression. BEGIN points to the opening {,
2116 * NEXT points past the terminator of the first element, and REST
2117 * points past the final }. We will accumulate result names from
2118 * recursive runs for each brace alternative in the buffer using
2123 /* Construct the new glob expression */
2126 mempcpy(new_pattern_buf,
2127 /* We know the prefix for all sub-patterns */
2128 pattern, begin - pattern),
2132 /* Note: glob_brace() may garble new_pattern_buf[].
2133 * That's why we re-copy prefix every time (1st memcpy above).
2135 n = glob_brace(new_pattern_buf, o, n);
2136 /*{*/ if (*next == '}') {
2137 /* We saw the last entry */
2141 next = next_brace_sub(next);
2143 free(new_pattern_buf);
2151 memset(&globdata, 0, sizeof(globdata));
2152 gr = glob(pattern, 0, NULL, &globdata);
2153 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2155 if (gr == GLOB_NOMATCH) {
2156 globfree(&globdata);
2157 /* NB: garbles parameter */
2158 unbackslash(pattern);
2159 o_addstr_with_NUL(o, pattern);
2160 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2161 return o_save_ptr_helper(o, n);
2163 if (gr == GLOB_NOSPACE)
2164 bb_error_msg_and_die(bb_msg_memory_exhausted);
2165 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2166 * but we didn't specify it. Paranoia again. */
2167 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2169 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2170 char **argv = globdata.gl_pathv;
2172 o_addstr_with_NUL(o, *argv);
2173 n = o_save_ptr_helper(o, n);
2179 globfree(&globdata);
2183 /* Performs globbing on last list[],
2184 * saving each result as a new list[].
2186 static int o_glob(o_string *o, int n)
2188 char *pattern, *copy;
2190 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2192 return o_save_ptr_helper(o, n);
2193 pattern = o->data + o_get_last_ptr(o, n);
2194 debug_printf_glob("glob pattern '%s'\n", pattern);
2195 if (!glob_needed(pattern)) {
2196 /* unbackslash last string in o in place, fix length */
2197 o->length = unbackslash(pattern) - o->data;
2198 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2199 return o_save_ptr_helper(o, n);
2202 copy = xstrdup(pattern);
2203 /* "forget" pattern in o */
2204 o->length = pattern - o->data;
2205 n = glob_brace(copy, o, n);
2208 debug_print_list("o_glob returning", o, n);
2215 static int glob_needed(const char *s)
2224 if (*s == '*' || *s == '[' || *s == '?')
2230 /* Performs globbing on last list[],
2231 * saving each result as a new list[].
2233 static int o_glob(o_string *o, int n)
2239 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2241 return o_save_ptr_helper(o, n);
2242 pattern = o->data + o_get_last_ptr(o, n);
2243 debug_printf_glob("glob pattern '%s'\n", pattern);
2244 if (!glob_needed(pattern)) {
2246 /* unbackslash last string in o in place, fix length */
2247 o->length = unbackslash(pattern) - o->data;
2248 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2249 return o_save_ptr_helper(o, n);
2252 memset(&globdata, 0, sizeof(globdata));
2253 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2254 * If we glob "*.\*" and don't find anything, we need
2255 * to fall back to using literal "*.*", but GLOB_NOCHECK
2256 * will return "*.\*"!
2258 gr = glob(pattern, 0, NULL, &globdata);
2259 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2261 if (gr == GLOB_NOMATCH) {
2262 globfree(&globdata);
2265 if (gr == GLOB_NOSPACE)
2266 bb_error_msg_and_die(bb_msg_memory_exhausted);
2267 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2268 * but we didn't specify it. Paranoia again. */
2269 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2271 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2272 char **argv = globdata.gl_pathv;
2273 /* "forget" pattern in o */
2274 o->length = pattern - o->data;
2276 o_addstr_with_NUL(o, *argv);
2277 n = o_save_ptr_helper(o, n);
2283 globfree(&globdata);
2285 debug_print_list("o_glob returning", o, n);
2291 /* If o->o_glob == 1, glob the string so far remembered.
2292 * Otherwise, just finish current list[] and start new */
2293 static int o_save_ptr(o_string *o, int n)
2295 if (o->o_glob) { /* if globbing is requested */
2296 /* If o->has_empty_slot, list[n] was already globbed
2297 * (if it was requested back then when it was filled)
2298 * so don't do that again! */
2299 if (!o->has_empty_slot)
2300 return o_glob(o, n); /* o_save_ptr_helper is inside */
2302 return o_save_ptr_helper(o, n);
2305 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2306 static char **o_finalize_list(o_string *o, int n)
2311 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2313 debug_print_list("finalized", o, n);
2314 debug_printf_expand("finalized n:%d\n", n);
2315 list = (char**)o->data;
2316 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2320 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2326 /* Expansion can recurse */
2327 #if ENABLE_HUSH_TICK
2328 static int process_command_subs(o_string *dest, const char *s);
2330 static char *expand_string_to_string(const char *str);
2332 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2333 parse_stream_dquoted(dest, input, dquote_end)
2335 static int parse_stream_dquoted(o_string *as_string,
2337 struct in_str *input,
2340 /* expand_strvec_to_strvec() takes a list of strings, expands
2341 * all variable references within and returns a pointer to
2342 * a list of expanded strings, possibly with larger number
2343 * of strings. (Think VAR="a b"; echo $VAR).
2344 * This new list is allocated as a single malloc block.
2345 * NULL-terminated list of char* pointers is at the beginning of it,
2346 * followed by strings themself.
2347 * Caller can deallocate entire list by single free(list). */
2349 /* Store given string, finalizing the word and starting new one whenever
2350 * we encounter IFS char(s). This is used for expanding variable values.
2351 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2352 static int expand_on_ifs(o_string *output, int n, const char *str)
2355 int word_len = strcspn(str, G.ifs);
2357 if (output->o_escape || !output->o_glob)
2358 o_addQstr(output, str, word_len);
2359 else /* protect backslashes against globbing up :) */
2360 o_addblock_duplicate_backslash(output, str, word_len);
2363 if (!*str) /* EOL - do not finalize word */
2365 o_addchr(output, '\0');
2366 debug_print_list("expand_on_ifs", output, n);
2367 n = o_save_ptr(output, n);
2368 str += strspn(str, G.ifs); /* skip ifs chars */
2370 debug_print_list("expand_on_ifs[1]", output, n);
2374 /* Helper to expand $((...)) and heredoc body. These act as if
2375 * they are in double quotes, with the exception that they are not :).
2376 * Just the rules are similar: "expand only $var and `cmd`"
2378 * Returns malloced string.
2379 * As an optimization, we return NULL if expansion is not needed.
2381 static char *expand_pseudo_dquoted(const char *str)
2384 struct in_str input;
2385 o_string dest = NULL_O_STRING;
2387 if (strchr(str, '$') == NULL
2388 #if ENABLE_HUSH_TICK
2389 && strchr(str, '`') == NULL
2395 /* We need to expand. Example:
2396 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2398 setup_string_in_str(&input, str);
2399 parse_stream_dquoted(NULL, &dest, &input, EOF);
2400 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2401 exp_str = expand_string_to_string(dest.data);
2402 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2403 o_free_unsafe(&dest);
2407 /* Expand all variable references in given string, adding words to list[]
2408 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2409 * to be filled). This routine is extremely tricky: has to deal with
2410 * variables/parameters with whitespace, $* and $@, and constructs like
2411 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2412 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2414 /* or_mask is either 0 (normal case) or 0x80 -
2415 * expansion of right-hand side of assignment == 1-element expand.
2416 * It will also do no globbing, and thus we must not backslash-quote!
2423 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2424 debug_print_list("expand_vars_to_list", output, n);
2425 n = o_save_ptr(output, n);
2426 debug_print_list("expand_vars_to_list[0]", output, n);
2428 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2431 char *dyn_val = NULL;
2432 const char *val = NULL;
2433 #if ENABLE_HUSH_TICK
2434 o_string subst_result = NULL_O_STRING;
2436 #if ENABLE_SH_MATH_SUPPORT
2437 char arith_buf[sizeof(arith_t)*3 + 2];
2439 o_addblock(output, arg, p - arg);
2440 debug_print_list("expand_vars_to_list[1]", output, n);
2442 p = strchr(p, SPECIAL_VAR_SYMBOL);
2444 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2445 /* "$@" is special. Even if quoted, it can still
2446 * expand to nothing (not even an empty string) */
2447 if ((first_ch & 0x7f) != '@')
2448 ored_ch |= first_ch;
2450 switch (first_ch & 0x7f) {
2451 /* Highest bit in first_ch indicates that var is double-quoted */
2453 val = utoa(G.root_pid);
2455 case '!': /* bg pid */
2456 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2458 case '?': /* exitcode */
2459 val = utoa(G.last_exitcode);
2461 case '#': /* argc */
2462 if (arg[1] != SPECIAL_VAR_SYMBOL)
2463 /* actually, it's a ${#var} */
2465 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2470 if (!G.global_argv[i])
2472 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2473 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2474 smallint sv = output->o_escape;
2475 /* unquoted var's contents should be globbed, so don't escape */
2476 output->o_escape = 0;
2477 while (G.global_argv[i]) {
2478 n = expand_on_ifs(output, n, G.global_argv[i]);
2479 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2480 if (G.global_argv[i++][0] && G.global_argv[i]) {
2481 /* this argv[] is not empty and not last:
2482 * put terminating NUL, start new word */
2483 o_addchr(output, '\0');
2484 debug_print_list("expand_vars_to_list[2]", output, n);
2485 n = o_save_ptr(output, n);
2486 debug_print_list("expand_vars_to_list[3]", output, n);
2489 output->o_escape = sv;
2491 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2492 * and in this case should treat it like '$*' - see 'else...' below */
2493 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2495 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2496 if (++i >= G.global_argc)
2498 o_addchr(output, '\0');
2499 debug_print_list("expand_vars_to_list[4]", output, n);
2500 n = o_save_ptr(output, n);
2502 } else { /* quoted $*: add as one word */
2504 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2505 if (!G.global_argv[++i])
2508 o_addchr(output, G.ifs[0]);
2512 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2513 /* "Empty variable", used to make "" etc to not disappear */
2517 #if ENABLE_HUSH_TICK
2518 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2521 /* Can't just stuff it into output o_string,
2522 * expanded result may need to be globbed
2523 * and $IFS-splitted */
2524 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2525 G.last_exitcode = process_command_subs(&subst_result, arg);
2526 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2527 val = subst_result.data;
2530 #if ENABLE_SH_MATH_SUPPORT
2531 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2532 arith_eval_hooks_t hooks;
2537 arg++; /* skip '+' */
2538 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2539 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2541 exp_str = expand_pseudo_dquoted(arg);
2542 hooks.lookupvar = get_local_var_value;
2543 hooks.setvar = set_local_var_from_halves;
2544 hooks.endofname = endofname;
2545 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2549 const char *msg = "error in arithmetic";
2552 msg = "exponent less than 0";
2555 msg = "divide by 0";
2558 msg = "expression recursion loop detected";
2563 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2564 sprintf(arith_buf, arith_t_fmt, res);
2569 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2571 bool exp_len = false;
2572 bool exp_null = false;
2574 char exp_save = exp_save; /* for compiler */
2575 char exp_op = exp_op; /* for compiler */
2576 char *exp_word = exp_word; /* for compiler */
2580 arg[0] = first_ch & 0x7f;
2582 /* prepare for expansions */
2583 if (var[0] == '#') {
2584 /* handle length expansion ${#var} */
2588 /* maybe handle parameter expansion */
2589 exp_off = strcspn(var, ":-=+?%#");
2593 exp_save = var[exp_off];
2594 exp_null = exp_save == ':';
2595 exp_word = var + exp_off;
2598 exp_op = *exp_word++;
2599 var[exp_off] = '\0';
2603 /* lookup the variable in question */
2604 if (isdigit(var[0])) {
2605 /* handle_dollar() should have vetted var for us */
2607 if (i < G.global_argc)
2608 val = G.global_argv[i];
2609 /* else val remains NULL: $N with too big N */
2611 val = get_local_var_value(var);
2613 /* handle any expansions */
2615 debug_printf_expand("expand: length of '%s' = ", val);
2616 val = utoa(val ? strlen(val) : 0);
2617 debug_printf_expand("%s\n", val);
2618 } else if (exp_off) {
2619 if (exp_op == '%' || exp_op == '#') {
2621 /* we need to do a pattern match */
2624 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2625 if (exp_op == *exp_word) /* ## or %% */
2627 val = dyn_val = xstrdup(val);
2628 loc = scan(dyn_val, exp_word, match_at_left);
2629 if (match_at_left) /* # or ## */
2631 else if (loc) /* % or %% and match was found */
2635 /* we need to do an expansion */
2636 int exp_test = (!val || (exp_null && !val[0]));
2638 exp_test = !exp_test;
2639 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2640 exp_null ? "true" : "false", exp_test);
2642 if (exp_op == '?') {
2643 //TODO: how interactive bash aborts expansion mid-command?
2644 /* ${var?[error_msg_if_unset]} */
2645 /* ${var:?[error_msg_if_unset_or_null]} */
2646 /* mimic bash message */
2647 die_if_script("%s: %s",
2649 exp_word[0] ? exp_word : "parameter null or not set"
2655 if (exp_op == '=') {
2656 /* ${var=[word]} or ${var:=[word]} */
2657 if (isdigit(var[0]) || var[0] == '#') {
2658 /* mimic bash message */
2659 die_if_script("$%s: cannot assign in this way", var);
2662 char *new_var = xasprintf("%s=%s", var, val);
2663 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2669 var[exp_off] = exp_save;
2673 #if ENABLE_HUSH_TICK
2676 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2677 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2679 /* unquoted var's contents should be globbed, so don't escape */
2680 smallint sv = output->o_escape;
2681 output->o_escape = 0;
2682 n = expand_on_ifs(output, n, val);
2684 output->o_escape = sv;
2686 } else { /* quoted $VAR, val will be appended below */
2687 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2690 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2693 o_addQstr(output, val, strlen(val));
2696 /* Do the check to avoid writing to a const string */
2697 if (*p != SPECIAL_VAR_SYMBOL)
2698 *p = SPECIAL_VAR_SYMBOL;
2700 #if ENABLE_HUSH_TICK
2701 o_free(&subst_result);
2704 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2707 debug_print_list("expand_vars_to_list[a]", output, n);
2708 /* this part is literal, and it was already pre-quoted
2709 * if needed (much earlier), do not use o_addQstr here! */
2710 o_addstr_with_NUL(output, arg);
2711 debug_print_list("expand_vars_to_list[b]", output, n);
2712 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2713 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2716 /* allow to reuse list[n] later without re-growth */
2717 output->has_empty_slot = 1;
2719 o_addchr(output, '\0');
2724 static char **expand_variables(char **argv, int or_mask)
2729 o_string output = NULL_O_STRING;
2731 if (or_mask & 0x100) {
2732 output.o_escape = 1; /* protect against globbing for "$var" */
2733 /* (unquoted $var will temporarily switch it off) */
2740 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2743 debug_print_list("expand_variables", &output, n);
2745 /* output.data (malloced in one block) gets returned in "list" */
2746 list = o_finalize_list(&output, n);
2747 debug_print_strings("expand_variables[1]", list);
2751 static char **expand_strvec_to_strvec(char **argv)
2753 return expand_variables(argv, 0x100);
2756 #if ENABLE_HUSH_BASH_COMPAT
2757 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2759 return expand_variables(argv, 0x80);
2763 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2764 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2769 o_string output = NULL_O_STRING;
2774 int is_var = is_well_formed_var_name(*v, '=');
2775 /* is_var * 0x80: singleword expansion for vars */
2776 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2778 /* Subtle! expand_vars_to_list did not glob last word yet.
2779 * It does this only when fed with further data.
2780 * Therefore we set globbing flags AFTER it, not before:
2783 /* if it is not recognizably abc=...; then: */
2784 output.o_escape = !is_var; /* protect against globbing for "$var" */
2785 /* (unquoted $var will temporarily switch it off) */
2786 output.o_glob = !is_var; /* and indeed do globbing */
2789 debug_print_list("expand_cond", &output, n);
2791 /* output.data (malloced in one block) gets returned in "list" */
2792 list = o_finalize_list(&output, n);
2793 debug_print_strings("expand_cond[1]", list);
2798 /* Used for expansion of right hand of assignments */
2799 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2801 static char *expand_string_to_string(const char *str)
2803 char *argv[2], **list;
2805 argv[0] = (char*)str;
2807 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2809 if (!list[0] || list[1])
2810 bb_error_msg_and_die("BUG in varexp2");
2811 /* actually, just move string 2*sizeof(char*) bytes back */
2812 overlapping_strcpy((char*)list, list[0]);
2813 unbackslash((char*)list);
2814 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2818 /* Used for "eval" builtin */
2819 static char* expand_strvec_to_string(char **argv)
2823 list = expand_variables(argv, 0x80);
2824 /* Convert all NULs to spaces */
2829 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2830 bb_error_msg_and_die("BUG in varexp3");
2831 /* bash uses ' ' regardless of $IFS contents */
2836 overlapping_strcpy((char*)list, list[0]);
2837 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2841 static char **expand_assignments(char **argv, int count)
2845 /* Expand assignments into one string each */
2846 for (i = 0; i < count; i++) {
2847 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2855 void re_execute_shell(char ***to_free, const char *s,
2856 char *g_argv0, char **g_argv,
2857 char **builtin_argv) NORETURN;
2859 static void reset_traps_to_defaults(void)
2861 /* This function is always called in a child shell
2862 * after fork (not vfork, NOMMU doesn't use this function).
2867 /* Child shells are not interactive.
2868 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2869 * Testcase: (while :; do :; done) + ^Z should background.
2870 * Same goes for SIGTERM, SIGHUP, SIGINT.
2872 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2873 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2875 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2876 * Stupid. It can be done with *single* &= op, but we can't use
2877 * the fact that G.blocked_set is implemented as a bitmask
2879 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2883 /* Careful. Only if no trap or trap is not "" */
2884 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2885 sigdelset(&G.blocked_set, sig);
2892 /* Our homegrown sig mask is saner to work with :) */
2893 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2895 /* Resetting all traps to default except empty ones */
2896 mask = G.non_DFL_mask;
2897 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2898 if (!G.traps[sig] || !G.traps[sig][0])
2901 G.traps[sig] = NULL;
2902 /* There is no signal for 0 (EXIT) */
2905 /* There was a trap handler, we just removed it.
2906 * But if sig still has non-DFL handling,
2907 * we should not unblock the sig. */
2910 sigdelset(&G.blocked_set, sig);
2912 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2917 static void re_execute_shell(char ***to_free, const char *s,
2918 char *g_argv0, char **g_argv,
2919 char **builtin_argv) NORETURN;
2920 static void re_execute_shell(char ***to_free, const char *s,
2921 char *g_argv0, char **g_argv,
2922 char **builtin_argv)
2924 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2925 /* delims + 2 * (number of bytes in printed hex numbers) */
2926 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2927 char *heredoc_argv[4];
2928 struct variable *cur;
2929 # if ENABLE_HUSH_FUNCTIONS
2930 struct function *funcp;
2934 unsigned long long empty_trap_mask;
2936 if (!g_argv0) { /* heredoc */
2937 argv = heredoc_argv;
2938 argv[0] = (char *) G.argv0_for_re_execing;
2939 argv[1] = (char *) "-<";
2940 argv[2] = (char *) s;
2942 pp = &argv[3]; /* used as pointer to empty environment */
2948 if (pp) while (*pp++)
2951 empty_trap_mask = 0;
2954 for (sig = 1; sig < NSIG; sig++) {
2955 if (G.traps[sig] && !G.traps[sig][0])
2956 empty_trap_mask |= 1LL << sig;
2960 sprintf(param_buf, NOMMU_HACK_FMT
2961 , (unsigned) G.root_pid
2962 , (unsigned) G.root_ppid
2963 , (unsigned) G.last_bg_pid
2964 , (unsigned) G.last_exitcode
2967 IF_HUSH_LOOPS(, G.depth_of_loop)
2969 #undef NOMMU_HACK_FMT
2970 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
2971 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2974 for (cur = G.top_var; cur; cur = cur->next) {
2975 if (!cur->flg_export || cur->flg_read_only)
2978 # if ENABLE_HUSH_FUNCTIONS
2979 for (funcp = G.top_func; funcp; funcp = funcp->next)
2985 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2986 *pp++ = (char *) G.argv0_for_re_execing;
2988 for (cur = G.top_var; cur; cur = cur->next) {
2989 if (cur->varstr == hush_version_str)
2991 if (cur->flg_read_only) {
2992 *pp++ = (char *) "-R";
2993 *pp++ = cur->varstr;
2994 } else if (!cur->flg_export) {
2995 *pp++ = (char *) "-V";
2996 *pp++ = cur->varstr;
2999 # if ENABLE_HUSH_FUNCTIONS
3000 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3001 *pp++ = (char *) "-F";
3002 *pp++ = funcp->name;
3003 *pp++ = funcp->body_as_string;
3006 /* We can pass activated traps here. Say, -Tnn:trap_string
3008 * However, POSIX says that subshells reset signals with traps
3010 * I tested bash-3.2 and it not only does that with true subshells
3011 * of the form ( list ), but with any forked children shells.
3012 * I set trap "echo W" WINCH; and then tried:
3014 * { echo 1; sleep 20; echo 2; } &
3015 * while true; do echo 1; sleep 20; echo 2; break; done &
3016 * true | { echo 1; sleep 20; echo 2; } | cat
3018 * In all these cases sending SIGWINCH to the child shell
3019 * did not run the trap. If I add trap "echo V" WINCH;
3020 * _inside_ group (just before echo 1), it works.
3022 * I conclude it means we don't need to pass active traps here.
3023 * Even if we would use signal handlers instead of signal masking
3024 * in order to implement trap handling,
3025 * exec syscall below resets signals to SIG_DFL for us.
3027 *pp++ = (char *) "-c";
3030 while (*++builtin_argv)
3031 *pp++ = *builtin_argv;
3032 *pp++ = (char *) "";
3037 /* *pp = NULL; - is already there */
3041 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3042 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3043 execve(bb_busybox_exec_path, argv, pp);
3044 /* Fallback. Useful for init=/bin/hush usage etc */
3045 if (argv[0][0] == '/')
3046 execve(argv[0], argv, pp);
3047 xfunc_error_retval = 127;
3048 bb_error_msg_and_die("can't re-execute the shell");
3050 #endif /* !BB_MMU */
3053 static void setup_heredoc(struct redir_struct *redir)
3055 struct fd_pair pair;
3058 /* the _body_ of heredoc (misleading field name) */
3059 const char *heredoc = redir->rd_filename;
3066 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3067 expanded = expand_pseudo_dquoted(heredoc);
3071 len = strlen(heredoc);
3073 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3075 xmove_fd(pair.rd, redir->rd_fd);
3077 /* Try writing without forking. Newer kernels have
3078 * dynamically growing pipes. Must use non-blocking write! */
3081 written = write(pair.wr, heredoc, len);
3092 ndelay_off(pair.wr);
3094 /* Okay, pipe buffer was not big enough */
3095 /* Note: we must not create a stray child (bastard? :)
3096 * for the unsuspecting parent process. Child creates a grandchild
3097 * and exits before parent execs the process which consumes heredoc
3098 * (that exec happens after we return from this function) */
3104 bb_perror_msg_and_die("vfork");
3107 disable_restore_tty_pgrp_on_exit();
3108 pid = BB_MMU ? fork() : vfork();
3110 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3114 close(redir->rd_fd); /* read side of the pipe */
3116 full_write(pair.wr, heredoc, len); /* may loop or block */
3119 /* Delegate blocking writes to another process */
3120 xmove_fd(pair.wr, STDOUT_FILENO);
3121 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3125 #if ENABLE_HUSH_FAST
3127 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3129 enable_restore_tty_pgrp_on_exit();
3135 wait(NULL); /* wait till child has died */
3138 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3139 * and stderr if they are redirected. */
3140 static int setup_redirects(struct command *prog, int squirrel[])
3143 struct redir_struct *redir;
3145 for (redir = prog->redirects; redir; redir = redir->next) {
3146 if (redir->rd_type == REDIRECT_HEREDOC2) {
3147 /* rd_fd<<HERE case */
3148 if (squirrel && redir->rd_fd < 3
3149 && squirrel[redir->rd_fd] < 0
3151 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3153 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3155 debug_printf_parse("set heredoc '%s'\n",
3156 redir->rd_filename);
3157 setup_heredoc(redir);
3161 if (redir->rd_dup == REDIRFD_TO_FILE) {
3162 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3164 if (redir->rd_filename == NULL) {
3165 /* Something went wrong in the parse.
3166 * Pretend it didn't happen */
3167 bb_error_msg("bug in redirect parse");
3170 mode = redir_table[redir->rd_type].mode;
3171 p = expand_string_to_string(redir->rd_filename);
3172 openfd = open_or_warn(p, mode);
3175 /* this could get lost if stderr has been redirected, but
3176 * bash and ash both lose it as well (though zsh doesn't!) */
3177 //what the above comment tries to say?
3181 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3182 openfd = redir->rd_dup;
3185 if (openfd != redir->rd_fd) {
3186 if (squirrel && redir->rd_fd < 3
3187 && squirrel[redir->rd_fd] < 0
3189 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3191 if (openfd == REDIRFD_CLOSE) {
3192 /* "n>-" means "close me" */
3193 close(redir->rd_fd);
3195 xdup2(openfd, redir->rd_fd);
3196 if (redir->rd_dup == REDIRFD_TO_FILE)
3204 static void restore_redirects(int squirrel[])
3207 for (i = 0; i < 3; i++) {
3210 /* We simply die on error */
3217 static void free_pipe_list(struct pipe *head);
3219 /* Return code is the exit status of the pipe */
3220 static void free_pipe(struct pipe *pi)
3223 struct command *command;
3224 struct redir_struct *r, *rnext;
3227 if (pi->stopped_cmds > 0) /* why? */
3229 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3230 for (i = 0; i < pi->num_cmds; i++) {
3231 command = &pi->cmds[i];
3232 debug_printf_clean(" command %d:\n", i);
3233 if (command->argv) {
3234 for (a = 0, p = command->argv; *p; a++, p++) {
3235 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3237 free_strings(command->argv);
3238 command->argv = NULL;
3240 /* not "else if": on syntax error, we may have both! */
3241 if (command->group) {
3242 debug_printf_clean(" begin group (cmd_type:%d)\n",
3244 free_pipe_list(command->group);
3245 debug_printf_clean(" end group\n");
3246 command->group = NULL;
3248 /* else is crucial here.
3249 * If group != NULL, child_func is meaningless */
3250 #if ENABLE_HUSH_FUNCTIONS
3251 else if (command->child_func) {
3252 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3253 command->child_func->parent_cmd = NULL;
3257 free(command->group_as_string);
3258 command->group_as_string = NULL;
3260 for (r = command->redirects; r; r = rnext) {
3261 debug_printf_clean(" redirect %d%s",
3262 r->rd_fd, redir_table[r->rd_type].descrip);
3263 /* guard against the case >$FOO, where foo is unset or blank */
3264 if (r->rd_filename) {
3265 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3266 free(r->rd_filename);
3267 r->rd_filename = NULL;
3269 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3273 command->redirects = NULL;
3275 free(pi->cmds); /* children are an array, they get freed all at once */
3283 static void free_pipe_list(struct pipe *head)
3285 struct pipe *pi, *next;
3287 for (pi = head; pi; pi = next) {
3289 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3292 debug_printf_clean("pipe followup code %d\n", pi->followup);
3294 /*pi->next = NULL;*/
3300 static int run_list(struct pipe *pi);
3302 #define parse_stream(pstring, input, end_trigger) \
3303 parse_stream(input, end_trigger)
3305 static struct pipe *parse_stream(char **pstring,
3306 struct in_str *input,
3308 static void parse_and_run_string(const char *s);
3311 static char *find_in_path(const char *arg)
3314 const char *PATH = get_local_var_value("PATH");
3320 const char *end = strchrnul(PATH, ':');
3321 int sz = end - PATH; /* must be int! */
3325 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3327 /* We have xxx::yyyy in $PATH,
3328 * it means "use current dir" */
3331 if (access(ret, F_OK) == 0)
3344 static const struct built_in_command* find_builtin_helper(const char *name,
3345 const struct built_in_command *x,
3346 const struct built_in_command *end)
3349 if (strcmp(name, x->cmd) != 0) {
3353 debug_printf_exec("found builtin '%s'\n", name);
3358 static const struct built_in_command* find_builtin1(const char *name)
3360 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3362 static const struct built_in_command* find_builtin(const char *name)
3364 const struct built_in_command *x = find_builtin1(name);
3367 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3370 #if ENABLE_HUSH_FUNCTIONS
3371 static struct function **find_function_slot(const char *name)
3373 struct function **funcpp = &G.top_func;
3375 if (strcmp(name, (*funcpp)->name) == 0) {
3378 funcpp = &(*funcpp)->next;
3383 static const struct function *find_function(const char *name)
3385 const struct function *funcp = *find_function_slot(name);
3387 debug_printf_exec("found function '%s'\n", name);
3391 /* Note: takes ownership on name ptr */
3392 static struct function *new_function(char *name)
3394 struct function **funcpp = find_function_slot(name);
3395 struct function *funcp = *funcpp;
3397 if (funcp != NULL) {
3398 struct command *cmd = funcp->parent_cmd;
3399 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3401 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3403 /* Note: if !funcp->body, do not free body_as_string!
3404 * This is a special case of "-F name body" function:
3405 * body_as_string was not malloced! */
3407 free_pipe_list(funcp->body);
3409 free(funcp->body_as_string);
3413 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3414 cmd->argv[0] = funcp->name;
3415 cmd->group = funcp->body;
3417 cmd->group_as_string = funcp->body_as_string;
3421 debug_printf_exec("remembering new function '%s'\n", name);
3422 funcp = *funcpp = xzalloc(sizeof(*funcp));
3423 /*funcp->next = NULL;*/
3430 static void unset_func(const char *name)
3432 struct function **funcpp = find_function_slot(name);
3433 struct function *funcp = *funcpp;
3435 if (funcp != NULL) {
3436 debug_printf_exec("freeing function '%s'\n", funcp->name);
3437 *funcpp = funcp->next;
3438 /* funcp is unlinked now, deleting it.
3439 * Note: if !funcp->body, the function was created by
3440 * "-F name body", do not free ->body_as_string
3441 * and ->name as they were not malloced. */
3443 free_pipe_list(funcp->body);
3446 free(funcp->body_as_string);
3454 #define exec_function(to_free, funcp, argv) \
3455 exec_function(funcp, argv)
3457 static void exec_function(char ***to_free,
3458 const struct function *funcp,
3459 char **argv) NORETURN;
3460 static void exec_function(char ***to_free,
3461 const struct function *funcp,
3467 argv[0] = G.global_argv[0];
3468 G.global_argv = argv;
3472 /* On MMU, funcp->body is always non-NULL */
3473 n = run_list(funcp->body);
3477 re_execute_shell(to_free,
3478 funcp->body_as_string,
3485 static int run_function(const struct function *funcp, char **argv)
3491 save_and_replace_G_args(&sv, argv);
3493 /* "we are in function, ok to use return" */
3494 sv_flg = G.flag_return_in_progress;
3495 G.flag_return_in_progress = -1;
3496 # if ENABLE_HUSH_LOCAL
3497 G.func_nest_level++;
3500 /* On MMU, funcp->body is always non-NULL */
3503 /* Function defined by -F */
3504 parse_and_run_string(funcp->body_as_string);
3505 rc = G.last_exitcode;
3509 rc = run_list(funcp->body);
3512 # if ENABLE_HUSH_LOCAL
3514 struct variable *var;
3515 struct variable **var_pp;
3517 var_pp = &G.top_var;
3518 while ((var = *var_pp) != NULL) {
3519 if (var->func_nest_level < G.func_nest_level) {
3520 var_pp = &var->next;
3524 if (var->flg_export)
3525 bb_unsetenv(var->varstr);
3526 /* Remove from global list */
3527 *var_pp = var->next;
3533 G.func_nest_level--;
3536 G.flag_return_in_progress = sv_flg;
3538 restore_G_args(&sv, argv);
3542 #endif /* ENABLE_HUSH_FUNCTIONS */
3546 #define exec_builtin(to_free, x, argv) \
3547 exec_builtin(x, argv)
3549 #define exec_builtin(to_free, x, argv) \
3550 exec_builtin(to_free, argv)
3552 static void exec_builtin(char ***to_free,
3553 const struct built_in_command *x,
3554 char **argv) NORETURN;
3555 static void exec_builtin(char ***to_free,
3556 const struct built_in_command *x,
3560 int rcode = x->function(argv);
3564 /* On NOMMU, we must never block!
3565 * Example: { sleep 99 | read line; } & echo Ok
3567 re_execute_shell(to_free,
3576 static void execvp_or_die(char **argv) NORETURN;
3577 static void execvp_or_die(char **argv)
3579 debug_printf_exec("execing '%s'\n", argv[0]);
3580 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3581 execvp(argv[0], argv);
3582 bb_perror_msg("can't execute '%s'", argv[0]);
3583 _exit(127); /* bash compat */
3587 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3588 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3589 #define pseudo_exec(nommu_save, command, argv_expanded) \
3590 pseudo_exec(command, argv_expanded)
3593 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3595 * Don't exit() here. If you don't exec, use _exit instead.
3596 * The at_exit handlers apparently confuse the calling process,
3597 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3598 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3599 char **argv, int assignment_cnt,
3600 char **argv_expanded) NORETURN;
3601 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3602 char **argv, int assignment_cnt,
3603 char **argv_expanded)
3607 /* Case when we are here: ... | var=val | ... */
3608 if (!argv[assignment_cnt])
3609 _exit(EXIT_SUCCESS);
3611 new_env = expand_assignments(argv, assignment_cnt);
3613 set_vars_and_save_old(new_env);
3614 free(new_env); /* optional */
3615 /* we can also destroy set_vars_and_save_old's return value,
3618 nommu_save->new_env = new_env;
3619 nommu_save->old_vars = set_vars_and_save_old(new_env);
3621 if (argv_expanded) {
3622 argv = argv_expanded;
3624 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3626 nommu_save->argv = argv;
3630 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3631 if (strchr(argv[0], '/') != NULL)
3635 /* Check if the command matches any of the builtins.
3636 * Depending on context, this might be redundant. But it's
3637 * easier to waste a few CPU cycles than it is to figure out
3638 * if this is one of those cases.
3641 /* On NOMMU, it is more expensive to re-execute shell
3642 * just in order to run echo or test builtin.
3643 * It's better to skip it here and run corresponding
3644 * non-builtin later. */
3645 const struct built_in_command *x;
3646 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3648 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3651 #if ENABLE_HUSH_FUNCTIONS
3652 /* Check if the command matches any functions */
3654 const struct function *funcp = find_function(argv[0]);
3656 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3661 #if ENABLE_FEATURE_SH_STANDALONE
3662 /* Check if the command matches any busybox applets */
3664 int a = find_applet_by_name(argv[0]);
3666 # if BB_MMU /* see above why on NOMMU it is not allowed */
3667 if (APPLET_IS_NOEXEC(a)) {
3668 debug_printf_exec("running applet '%s'\n", argv[0]);
3669 run_applet_no_and_exit(a, argv);
3672 /* Re-exec ourselves */
3673 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3674 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3675 execv(bb_busybox_exec_path, argv);
3676 /* If they called chroot or otherwise made the binary no longer
3677 * executable, fall through */
3682 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3685 execvp_or_die(argv);
3688 /* Called after [v]fork() in run_pipe
3690 static void pseudo_exec(nommu_save_t *nommu_save,
3691 struct command *command,
3692 char **argv_expanded) NORETURN;
3693 static void pseudo_exec(nommu_save_t *nommu_save,
3694 struct command *command,
3695 char **argv_expanded)
3697 if (command->argv) {
3698 pseudo_exec_argv(nommu_save, command->argv,
3699 command->assignment_cnt, argv_expanded);
3702 if (command->group) {
3703 /* Cases when we are here:
3706 * ... | ( list ) | ...
3707 * ... | { list } | ...
3711 debug_printf_exec("pseudo_exec: run_list\n");
3712 reset_traps_to_defaults();
3713 rcode = run_list(command->group);
3714 /* OK to leak memory by not calling free_pipe_list,
3715 * since this process is about to exit */
3718 re_execute_shell(&nommu_save->argv_from_re_execing,
3719 command->group_as_string,
3726 /* Case when we are here: ... | >file */
3727 debug_printf_exec("pseudo_exec'ed null command\n");
3728 _exit(EXIT_SUCCESS);
3732 static const char *get_cmdtext(struct pipe *pi)
3738 /* This is subtle. ->cmdtext is created only on first backgrounding.
3739 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3740 * On subsequent bg argv is trashed, but we won't use it */
3743 argv = pi->cmds[0].argv;
3744 if (!argv || !argv[0]) {
3745 pi->cmdtext = xzalloc(1);
3751 len += strlen(*argv) + 1;
3755 argv = pi->cmds[0].argv;
3757 len = strlen(*argv);
3758 memcpy(p, *argv, len);
3766 static void insert_bg_job(struct pipe *pi)
3768 struct pipe *job, **jobp;
3771 /* Linear search for the ID of the job to use */
3773 for (job = G.job_list; job; job = job->next)
3774 if (job->jobid >= pi->jobid)
3775 pi->jobid = job->jobid + 1;
3777 /* Add job to the list of running jobs */
3779 while ((job = *jobp) != NULL)
3781 job = *jobp = xmalloc(sizeof(*job));
3783 *job = *pi; /* physical copy */
3785 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3786 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3787 for (i = 0; i < pi->num_cmds; i++) {
3788 job->cmds[i].pid = pi->cmds[i].pid;
3789 /* all other fields are not used and stay zero */
3791 job->cmdtext = xstrdup(get_cmdtext(pi));
3793 if (G_interactive_fd)
3794 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3795 /* Last command's pid goes to $! */
3796 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3797 G.last_jobid = job->jobid;
3800 static void remove_bg_job(struct pipe *pi)
3802 struct pipe *prev_pipe;
3804 if (pi == G.job_list) {
3805 G.job_list = pi->next;
3807 prev_pipe = G.job_list;
3808 while (prev_pipe->next != pi)
3809 prev_pipe = prev_pipe->next;
3810 prev_pipe->next = pi->next;
3813 G.last_jobid = G.job_list->jobid;
3818 /* Remove a backgrounded job */
3819 static void delete_finished_bg_job(struct pipe *pi)
3822 pi->stopped_cmds = 0;
3828 /* Check to see if any processes have exited -- if they
3829 * have, figure out why and see if a job has completed */
3830 static int checkjobs(struct pipe* fg_pipe)
3840 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3842 attributes = WUNTRACED;
3843 if (fg_pipe == NULL)
3844 attributes |= WNOHANG;
3847 #if ENABLE_HUSH_FAST
3848 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3849 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3850 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3851 /* There was neither fork nor SIGCHLD since last waitpid */
3852 /* Avoid doing waitpid syscall if possible */
3853 if (!G.we_have_children) {
3857 if (fg_pipe == NULL) { /* is WNOHANG set? */
3858 /* We have children, but they did not exit
3859 * or stop yet (we saw no SIGCHLD) */
3862 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3866 /* Do we do this right?
3867 * bash-3.00# sleep 20 | false
3869 * [3]+ Stopped sleep 20 | false
3870 * bash-3.00# echo $?
3871 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3872 * [hush 1.14.0: yes we do it right]
3879 #if ENABLE_HUSH_FAST
3880 i = G.count_SIGCHLD;
3882 childpid = waitpid(-1, &status, attributes);
3883 if (childpid <= 0) {
3884 if (childpid && errno != ECHILD)
3885 bb_perror_msg("waitpid");
3886 #if ENABLE_HUSH_FAST
3887 else { /* Until next SIGCHLD, waitpid's are useless */
3888 G.we_have_children = (childpid == 0);
3889 G.handled_SIGCHLD = i;
3890 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3895 dead = WIFEXITED(status) || WIFSIGNALED(status);
3898 if (WIFSTOPPED(status))
3899 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3900 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3901 if (WIFSIGNALED(status))
3902 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3903 childpid, WTERMSIG(status), WEXITSTATUS(status));
3904 if (WIFEXITED(status))
3905 debug_printf_jobs("pid %d exited, exitcode %d\n",
3906 childpid, WEXITSTATUS(status));
3908 /* Were we asked to wait for fg pipe? */
3910 for (i = 0; i < fg_pipe->num_cmds; i++) {
3911 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3912 if (fg_pipe->cmds[i].pid != childpid)
3915 fg_pipe->cmds[i].pid = 0;
3916 fg_pipe->alive_cmds--;
3917 if (i == fg_pipe->num_cmds - 1) {
3918 /* last process gives overall exitstatus */
3919 rcode = WEXITSTATUS(status);
3920 /* bash prints killer signal's name for *last*
3921 * process in pipe (prints just newline for SIGINT).
3922 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3924 if (WIFSIGNALED(status)) {
3925 int sig = WTERMSIG(status);
3926 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3927 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3928 * Maybe we need to use sig | 128? */
3931 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3934 fg_pipe->cmds[i].is_stopped = 1;
3935 fg_pipe->stopped_cmds++;
3937 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3938 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3939 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3940 /* All processes in fg pipe have exited or stopped */
3941 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3942 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3943 * and "killall -STOP cat" */
3944 if (G_interactive_fd) {
3946 if (fg_pipe->alive_cmds)
3947 insert_bg_job(fg_pipe);
3951 if (!fg_pipe->alive_cmds)
3954 /* There are still running processes in the fg pipe */
3955 goto wait_more; /* do waitpid again */
3957 /* it wasnt fg_pipe, look for process in bg pipes */
3961 /* We asked to wait for bg or orphaned children */
3962 /* No need to remember exitcode in this case */
3963 for (pi = G.job_list; pi; pi = pi->next) {
3964 for (i = 0; i < pi->num_cmds; i++) {
3965 if (pi->cmds[i].pid == childpid)
3966 goto found_pi_and_prognum;
3969 /* Happens when shell is used as init process (init=/bin/sh) */
3970 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3971 continue; /* do waitpid again */
3973 found_pi_and_prognum:
3976 pi->cmds[i].pid = 0;
3978 if (!pi->alive_cmds) {
3979 if (G_interactive_fd)
3980 printf(JOB_STATUS_FORMAT, pi->jobid,
3981 "Done", pi->cmdtext);
3982 delete_finished_bg_job(pi);
3986 pi->cmds[i].is_stopped = 1;
3990 } /* while (waitpid succeeds)... */
3996 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3999 int rcode = checkjobs(fg_pipe);
4000 if (G_saved_tty_pgrp) {
4001 /* Job finished, move the shell to the foreground */
4002 p = getpgrp(); /* our process group id */
4003 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4004 tcsetpgrp(G_interactive_fd, p);
4010 /* Start all the jobs, but don't wait for anything to finish.
4013 * Return code is normally -1, when the caller has to wait for children
4014 * to finish to determine the exit status of the pipe. If the pipe
4015 * is a simple builtin command, however, the action is done by the
4016 * time run_pipe returns, and the exit code is provided as the
4019 * Returns -1 only if started some children. IOW: we have to
4020 * mask out retvals of builtins etc with 0xff!
4022 * The only case when we do not need to [v]fork is when the pipe
4023 * is single, non-backgrounded, non-subshell command. Examples:
4024 * cmd ; ... { list } ; ...
4025 * cmd && ... { list } && ...
4026 * cmd || ... { list } || ...
4027 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4028 * or (if SH_STANDALONE) an applet, and we can run the { list }
4029 * with run_list. If it isn't one of these, we fork and exec cmd.
4031 * Cases when we must fork:
4032 * non-single: cmd | cmd
4033 * backgrounded: cmd & { list } &
4034 * subshell: ( list ) [&]
4036 static NOINLINE int run_pipe(struct pipe *pi)
4038 static const char *const null_ptr = NULL;
4041 struct command *command;
4042 char **argv_expanded;
4045 /* it is not always needed, but we aim to smaller code */
4046 int squirrel[] = { -1, -1, -1 };
4049 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4052 IF_HUSH_JOB(pi->pgrp = -1;)
4053 pi->stopped_cmds = 0;
4054 command = &(pi->cmds[0]);
4055 argv_expanded = NULL;
4057 if (pi->num_cmds != 1
4058 || pi->followup == PIPE_BG
4059 || command->cmd_type == CMD_SUBSHELL
4066 debug_printf_exec(": group:%p argv:'%s'\n",
4067 command->group, command->argv ? command->argv[0] : "NONE");
4069 if (command->group) {
4070 #if ENABLE_HUSH_FUNCTIONS
4071 if (command->cmd_type == CMD_FUNCDEF) {
4072 /* "executing" func () { list } */
4073 struct function *funcp;
4075 funcp = new_function(command->argv[0]);
4076 /* funcp->name is already set to argv[0] */
4077 funcp->body = command->group;
4079 funcp->body_as_string = command->group_as_string;
4080 command->group_as_string = NULL;
4082 command->group = NULL;
4083 command->argv[0] = NULL;
4084 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4085 funcp->parent_cmd = command;
4086 command->child_func = funcp;
4088 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4090 return EXIT_SUCCESS;
4094 debug_printf("non-subshell group\n");
4095 rcode = 1; /* exitcode if redir failed */
4096 if (setup_redirects(command, squirrel) == 0) {
4097 debug_printf_exec(": run_list\n");
4098 rcode = run_list(command->group) & 0xff;
4100 restore_redirects(squirrel);
4101 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4103 debug_printf_exec("run_pipe: return %d\n", rcode);
4107 argv = command->argv ? command->argv : (char **) &null_ptr;
4109 const struct built_in_command *x;
4110 #if ENABLE_HUSH_FUNCTIONS
4111 const struct function *funcp;
4115 char **new_env = NULL;
4116 struct variable *old_vars = NULL;
4118 if (argv[command->assignment_cnt] == NULL) {
4119 /* Assignments, but no command */
4120 /* Ensure redirects take effect. Try "a=t >file" */
4121 rcode = setup_redirects(command, squirrel);
4122 restore_redirects(squirrel);
4123 /* Set shell variables */
4125 p = expand_string_to_string(*argv);
4126 debug_printf_exec("set shell var:'%s'->'%s'\n",
4128 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4131 /* Do we need to flag set_local_var() errors?
4132 * "assignment to readonly var" and "putenv error"
4134 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4136 debug_printf_exec("run_pipe: return %d\n", rcode);
4140 /* Expand the rest into (possibly) many strings each */
4142 #if ENABLE_HUSH_BASH_COMPAT
4143 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4144 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4147 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4148 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4149 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4154 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4157 /* if someone gives us an empty string: `cmd with empty output` */
4158 if (!argv_expanded[0]) {
4159 free(argv_expanded);
4161 return G.last_exitcode;
4164 x = find_builtin(argv_expanded[0]);
4165 #if ENABLE_HUSH_FUNCTIONS
4168 funcp = find_function(argv_expanded[0]);
4172 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
4173 debug_printf("exec with redirects only\n");
4174 rcode = setup_redirects(command, NULL);
4175 goto clean_up_and_ret1;
4178 /* setup_redirects acts on file descriptors, not FILEs.
4179 * This is perfect for work that comes after exec().
4180 * Is it really safe for inline use? Experimentally,
4181 * things seem to work. */
4182 rcode = setup_redirects(command, squirrel);
4184 new_env = expand_assignments(argv, command->assignment_cnt);
4185 old_vars = set_vars_and_save_old(new_env);
4187 debug_printf_exec(": builtin '%s' '%s'...\n",
4188 x->cmd, argv_expanded[1]);
4189 rcode = x->function(argv_expanded) & 0xff;
4192 #if ENABLE_HUSH_FUNCTIONS
4194 # if ENABLE_HUSH_LOCAL
4195 struct variable **sv;
4196 sv = G.shadowed_vars_pp;
4197 G.shadowed_vars_pp = &old_vars;
4199 debug_printf_exec(": function '%s' '%s'...\n",
4200 funcp->name, argv_expanded[1]);
4201 rcode = run_function(funcp, argv_expanded) & 0xff;
4202 # if ENABLE_HUSH_LOCAL
4203 G.shadowed_vars_pp = sv;
4208 #if ENABLE_FEATURE_SH_STANDALONE
4211 restore_redirects(squirrel);
4212 unset_vars(new_env);
4215 free(argv_expanded);
4216 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4218 debug_printf_exec("run_pipe return %d\n", rcode);
4222 #if ENABLE_FEATURE_SH_STANDALONE
4223 i = find_applet_by_name(argv_expanded[0]);
4224 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4225 rcode = setup_redirects(command, squirrel);
4227 new_env = expand_assignments(argv, command->assignment_cnt);
4228 old_vars = set_vars_and_save_old(new_env);
4229 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4230 argv_expanded[0], argv_expanded[1]);
4231 rcode = run_nofork_applet(i, argv_expanded);
4233 goto clean_up_and_ret;
4236 /* It is neither builtin nor applet. We must fork. */
4240 /* NB: argv_expanded may already be created, and that
4241 * might include `cmd` runs! Do not rerun it! We *must*
4242 * use argv_expanded if it's non-NULL */
4244 /* Going to fork a child per each pipe member */
4248 for (i = 0; i < pi->num_cmds; i++) {
4249 struct fd_pair pipefds;
4251 volatile nommu_save_t nommu_save;
4252 nommu_save.new_env = NULL;
4253 nommu_save.old_vars = NULL;
4254 nommu_save.argv = NULL;
4255 nommu_save.argv_from_re_execing = NULL;
4257 command = &(pi->cmds[i]);
4258 if (command->argv) {
4259 debug_printf_exec(": pipe member '%s' '%s'...\n",
4260 command->argv[0], command->argv[1]);
4262 debug_printf_exec(": pipe member with no argv\n");
4265 /* pipes are inserted between pairs of commands */
4268 if ((i + 1) < pi->num_cmds)
4269 xpiped_pair(pipefds);
4271 command->pid = BB_MMU ? fork() : vfork();
4272 if (!command->pid) { /* child */
4274 disable_restore_tty_pgrp_on_exit();
4275 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4277 /* Every child adds itself to new process group
4278 * with pgid == pid_of_first_child_in_pipe */
4279 if (G.run_list_level == 1 && G_interactive_fd) {
4282 if (pgrp < 0) /* true for 1st process only */
4284 if (setpgid(0, pgrp) == 0
4285 && pi->followup != PIPE_BG
4286 && G_saved_tty_pgrp /* we have ctty */
4288 /* We do it in *every* child, not just first,
4290 tcsetpgrp(G_interactive_fd, pgrp);
4294 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4295 /* 1st cmd in backgrounded pipe
4296 * should have its stdin /dev/null'ed */
4298 if (open(bb_dev_null, O_RDONLY))
4299 xopen("/", O_RDONLY);
4301 xmove_fd(nextin, 0);
4303 xmove_fd(pipefds.wr, 1);
4306 /* Like bash, explicit redirects override pipes,
4307 * and the pipe fd is available for dup'ing. */
4308 if (setup_redirects(command, NULL))
4311 /* Restore default handlers just prior to exec */
4312 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4314 /* Stores to nommu_save list of env vars putenv'ed
4315 * (NOMMU, on MMU we don't need that) */
4316 /* cast away volatility... */
4317 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4318 /* pseudo_exec() does not return */
4321 /* parent or error */
4322 #if ENABLE_HUSH_FAST
4324 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4326 enable_restore_tty_pgrp_on_exit();
4328 /* Clean up after vforked child */
4329 free(nommu_save.argv);
4330 free(nommu_save.argv_from_re_execing);
4331 unset_vars(nommu_save.new_env);
4332 add_vars(nommu_save.old_vars);
4334 free(argv_expanded);
4335 argv_expanded = NULL;
4336 if (command->pid < 0) { /* [v]fork failed */
4337 /* Clearly indicate, was it fork or vfork */
4338 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4342 /* Second and next children need to know pid of first one */
4344 pi->pgrp = command->pid;
4350 if ((i + 1) < pi->num_cmds)
4352 /* Pass read (output) pipe end to next iteration */
4353 nextin = pipefds.rd;
4356 if (!pi->alive_cmds) {
4358 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4363 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4367 #ifndef debug_print_tree
4368 static void debug_print_tree(struct pipe *pi, int lvl)
4370 static const char *const PIPE[] = {
4376 static const char *RES[] = {
4377 [RES_NONE ] = "NONE" ,
4380 [RES_THEN ] = "THEN" ,
4381 [RES_ELIF ] = "ELIF" ,
4382 [RES_ELSE ] = "ELSE" ,
4385 # if ENABLE_HUSH_LOOPS
4386 [RES_FOR ] = "FOR" ,
4387 [RES_WHILE] = "WHILE",
4388 [RES_UNTIL] = "UNTIL",
4390 [RES_DONE ] = "DONE" ,
4392 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4395 # if ENABLE_HUSH_CASE
4396 [RES_CASE ] = "CASE" ,
4397 [RES_CASE_IN ] = "CASE_IN" ,
4398 [RES_MATCH] = "MATCH",
4399 [RES_CASE_BODY] = "CASE_BODY",
4400 [RES_ESAC ] = "ESAC" ,
4402 [RES_XXXX ] = "XXXX" ,
4403 [RES_SNTX ] = "SNTX" ,
4405 static const char *const CMDTYPE[] = {
4409 # if ENABLE_HUSH_FUNCTIONS
4418 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4419 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4421 while (prn < pi->num_cmds) {
4422 struct command *command = &pi->cmds[prn];
4423 char **argv = command->argv;
4425 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4427 command->assignment_cnt);
4428 if (command->group) {
4429 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4430 CMDTYPE[command->cmd_type],
4433 , " group_as_string:", command->group_as_string
4438 debug_print_tree(command->group, lvl+1);
4442 if (argv) while (*argv) {
4443 fprintf(stderr, " '%s'", *argv);
4446 fprintf(stderr, "\n");
4453 #endif /* debug_print_tree */
4455 /* NB: called by pseudo_exec, and therefore must not modify any
4456 * global data until exec/_exit (we can be a child after vfork!) */
4457 static int run_list(struct pipe *pi)
4459 #if ENABLE_HUSH_CASE
4460 char *case_word = NULL;
4462 #if ENABLE_HUSH_LOOPS
4463 struct pipe *loop_top = NULL;
4464 char **for_lcur = NULL;
4465 char **for_list = NULL;
4467 smallint last_followup;
4469 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4470 smalluint cond_code = 0;
4472 enum { cond_code = 0 };
4475 smallint rword; /* enum reserved_style */
4476 smallint last_rword; /* ditto */
4479 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4482 #if ENABLE_HUSH_LOOPS
4483 /* Check syntax for "for" */
4484 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4485 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4487 /* current word is FOR or IN (BOLD in comments below) */
4488 if (cpipe->next == NULL) {
4489 syntax_error("malformed for");
4491 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4494 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4495 if (cpipe->next->res_word == RES_DO)
4497 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4498 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4499 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4501 syntax_error("malformed for");
4503 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4509 /* Past this point, all code paths should jump to ret: label
4510 * in order to return, no direct "return" statements please.
4511 * This helps to ensure that no memory is leaked. */
4519 last_rword = RES_XXXX;
4521 last_followup = PIPE_SEQ;
4522 rcode = G.last_exitcode;
4524 /* Go through list of pipes, (maybe) executing them. */
4525 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4529 IF_HAS_KEYWORDS(rword = pi->res_word;)
4530 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4531 rword, cond_code, last_rword);
4532 #if ENABLE_HUSH_LOOPS
4533 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4534 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4536 /* start of a loop: remember where loop starts */
4541 /* Still in the same "if...", "then..." or "do..." branch? */
4542 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4543 if ((rcode == 0 && last_followup == PIPE_OR)
4544 || (rcode != 0 && last_followup == PIPE_AND)
4546 /* It is "<true> || CMD" or "<false> && CMD"
4547 * and we should not execute CMD */
4548 debug_printf_exec("skipped cmd because of || or &&\n");
4549 last_followup = pi->followup;
4553 last_followup = pi->followup;
4554 IF_HAS_KEYWORDS(last_rword = rword;)
4557 if (rword == RES_THEN) {
4558 /* if false; then ... fi has exitcode 0! */
4559 G.last_exitcode = rcode = EXIT_SUCCESS;
4560 /* "if <false> THEN cmd": skip cmd */
4564 if (rword == RES_ELSE || rword == RES_ELIF) {
4565 /* "if <true> then ... ELSE/ELIF cmd":
4566 * skip cmd and all following ones */
4571 #if ENABLE_HUSH_LOOPS
4572 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4574 /* first loop through for */
4576 static const char encoded_dollar_at[] ALIGN1 = {
4577 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4578 }; /* encoded representation of "$@" */
4579 static const char *const encoded_dollar_at_argv[] = {
4580 encoded_dollar_at, NULL
4581 }; /* argv list with one element: "$@" */
4584 vals = (char**)encoded_dollar_at_argv;
4585 if (pi->next->res_word == RES_IN) {
4586 /* if no variable values after "in" we skip "for" */
4587 if (!pi->next->cmds[0].argv) {
4588 G.last_exitcode = rcode = EXIT_SUCCESS;
4589 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4592 vals = pi->next->cmds[0].argv;
4593 } /* else: "for var; do..." -> assume "$@" list */
4594 /* create list of variable values */
4595 debug_print_strings("for_list made from", vals);
4596 for_list = expand_strvec_to_strvec(vals);
4597 for_lcur = for_list;
4598 debug_print_strings("for_list", for_list);
4601 /* "for" loop is over, clean up */
4607 /* Insert next value from for_lcur */
4608 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4609 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4612 if (rword == RES_IN) {
4613 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4615 if (rword == RES_DONE) {
4616 continue; /* "done" has no cmds too */
4619 #if ENABLE_HUSH_CASE
4620 if (rword == RES_CASE) {
4621 case_word = expand_strvec_to_string(pi->cmds->argv);
4624 if (rword == RES_MATCH) {
4627 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4629 /* all prev words didn't match, does this one match? */
4630 argv = pi->cmds->argv;
4632 char *pattern = expand_string_to_string(*argv);
4633 /* TODO: which FNM_xxx flags to use? */
4634 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4636 if (cond_code == 0) { /* match! we will execute this branch */
4637 free(case_word); /* make future "word)" stop */
4645 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4647 continue; /* not matched yet, skip this pipe */
4650 /* Just pressing <enter> in shell should check for jobs.
4651 * OTOH, in non-interactive shell this is useless
4652 * and only leads to extra job checks */
4653 if (pi->num_cmds == 0) {
4654 if (G_interactive_fd)
4655 goto check_jobs_and_continue;
4659 /* After analyzing all keywords and conditions, we decided
4660 * to execute this pipe. NB: have to do checkjobs(NULL)
4661 * after run_pipe to collect any background children,
4662 * even if list execution is to be stopped. */
4663 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4666 #if ENABLE_HUSH_LOOPS
4667 G.flag_break_continue = 0;
4669 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4671 /* We ran a builtin, function, or group.
4672 * rcode is already known
4673 * and we don't need to wait for anything. */
4674 G.last_exitcode = rcode;
4675 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4676 check_and_run_traps(0);
4677 #if ENABLE_HUSH_LOOPS
4678 /* Was it "break" or "continue"? */
4679 if (G.flag_break_continue) {
4680 smallint fbc = G.flag_break_continue;
4681 /* We might fall into outer *loop*,
4682 * don't want to break it too */
4684 G.depth_break_continue--;
4685 if (G.depth_break_continue == 0)
4686 G.flag_break_continue = 0;
4687 /* else: e.g. "continue 2" should *break* once, *then* continue */
4688 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4689 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4690 goto check_jobs_and_break;
4691 /* "continue": simulate end of loop */
4696 #if ENABLE_HUSH_FUNCTIONS
4697 if (G.flag_return_in_progress == 1) {
4698 /* same as "goto check_jobs_and_break" */
4703 } else if (pi->followup == PIPE_BG) {
4704 /* What does bash do with attempts to background builtins? */
4705 /* even bash 3.2 doesn't do that well with nested bg:
4706 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4707 * I'm NOT treating inner &'s as jobs */
4708 check_and_run_traps(0);
4710 if (G.run_list_level == 1)
4713 G.last_exitcode = rcode = EXIT_SUCCESS;
4714 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4717 if (G.run_list_level == 1 && G_interactive_fd) {
4718 /* Waits for completion, then fg's main shell */
4719 rcode = checkjobs_and_fg_shell(pi);
4720 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4721 check_and_run_traps(0);
4724 { /* This one just waits for completion */
4725 rcode = checkjobs(pi);
4726 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4727 check_and_run_traps(0);
4729 G.last_exitcode = rcode;
4733 /* Analyze how result affects subsequent commands */
4735 if (rword == RES_IF || rword == RES_ELIF)
4738 #if ENABLE_HUSH_LOOPS
4739 /* Beware of "while false; true; do ..."! */
4740 if (pi->next && pi->next->res_word == RES_DO) {
4741 if (rword == RES_WHILE) {
4743 /* "while false; do...done" - exitcode 0 */
4744 G.last_exitcode = rcode = EXIT_SUCCESS;
4745 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4746 goto check_jobs_and_break;
4749 if (rword == RES_UNTIL) {
4751 debug_printf_exec(": until expr is true: breaking\n");
4752 check_jobs_and_break:
4760 check_jobs_and_continue:
4767 #if ENABLE_HUSH_LOOPS
4772 #if ENABLE_HUSH_CASE
4776 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4780 /* Select which version we will use */
4781 static int run_and_free_list(struct pipe *pi)
4784 debug_printf_exec("run_and_free_list entered\n");
4786 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4787 rcode = run_list(pi);
4789 /* free_pipe_list has the side effect of clearing memory.
4790 * In the long run that function can be merged with run_list,
4791 * but doing that now would hobble the debugging effort. */
4793 debug_printf_exec("run_and_free_list return %d\n", rcode);
4798 static struct pipe *new_pipe(void)
4801 pi = xzalloc(sizeof(struct pipe));
4802 /*pi->followup = 0; - deliberately invalid value */
4803 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4807 /* Command (member of a pipe) is complete, or we start a new pipe
4808 * if ctx->command is NULL.
4809 * No errors possible here.
4811 static int done_command(struct parse_context *ctx)
4813 /* The command is really already in the pipe structure, so
4814 * advance the pipe counter and make a new, null command. */
4815 struct pipe *pi = ctx->pipe;
4816 struct command *command = ctx->command;
4819 if (IS_NULL_CMD(command)) {
4820 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4824 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4825 //debug_print_tree(ctx->list_head, 20);
4827 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4830 /* Only real trickiness here is that the uncommitted
4831 * command structure is not counted in pi->num_cmds. */
4832 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4833 ctx->command = command = &pi->cmds[pi->num_cmds];
4835 memset(command, 0, sizeof(*command));
4836 return pi->num_cmds; /* used only for 0/nonzero check */
4839 static void done_pipe(struct parse_context *ctx, pipe_style type)
4843 debug_printf_parse("done_pipe entered, followup %d\n", type);
4844 /* Close previous command */
4845 not_null = done_command(ctx);
4846 ctx->pipe->followup = type;
4848 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4849 ctx->ctx_inverted = 0;
4850 ctx->pipe->res_word = ctx->ctx_res_w;
4853 /* Without this check, even just <enter> on command line generates
4854 * tree of three NOPs (!). Which is harmless but annoying.
4855 * IOW: it is safe to do it unconditionally. */
4858 || ctx->ctx_res_w == RES_FI
4860 #if ENABLE_HUSH_LOOPS
4861 || ctx->ctx_res_w == RES_DONE
4862 || ctx->ctx_res_w == RES_FOR
4863 || ctx->ctx_res_w == RES_IN
4865 #if ENABLE_HUSH_CASE
4866 || ctx->ctx_res_w == RES_ESAC
4870 debug_printf_parse("done_pipe: adding new pipe: "
4871 "not_null:%d ctx->ctx_res_w:%d\n",
4872 not_null, ctx->ctx_res_w);
4874 ctx->pipe->next = new_p;
4876 /* RES_THEN, RES_DO etc are "sticky" -
4877 * they remain set for pipes inside if/while.
4878 * This is used to control execution.
4879 * RES_FOR and RES_IN are NOT sticky (needed to support
4880 * cases where variable or value happens to match a keyword):
4882 #if ENABLE_HUSH_LOOPS
4883 if (ctx->ctx_res_w == RES_FOR
4884 || ctx->ctx_res_w == RES_IN)
4885 ctx->ctx_res_w = RES_NONE;
4887 #if ENABLE_HUSH_CASE
4888 if (ctx->ctx_res_w == RES_MATCH)
4889 ctx->ctx_res_w = RES_CASE_BODY;
4890 if (ctx->ctx_res_w == RES_CASE)
4891 ctx->ctx_res_w = RES_CASE_IN;
4893 ctx->command = NULL; /* trick done_command below */
4894 /* Create the memory for command, roughly:
4895 * ctx->pipe->cmds = new struct command;
4896 * ctx->command = &ctx->pipe->cmds[0];
4899 //debug_print_tree(ctx->list_head, 10);
4901 debug_printf_parse("done_pipe return\n");
4904 static void initialize_context(struct parse_context *ctx)
4906 memset(ctx, 0, sizeof(*ctx));
4907 ctx->pipe = ctx->list_head = new_pipe();
4908 /* Create the memory for command, roughly:
4909 * ctx->pipe->cmds = new struct command;
4910 * ctx->command = &ctx->pipe->cmds[0];
4915 /* If a reserved word is found and processed, parse context is modified
4916 * and 1 is returned.
4919 struct reserved_combo {
4922 unsigned char assignment_flag;
4926 FLAG_END = (1 << RES_NONE ),
4928 FLAG_IF = (1 << RES_IF ),
4929 FLAG_THEN = (1 << RES_THEN ),
4930 FLAG_ELIF = (1 << RES_ELIF ),
4931 FLAG_ELSE = (1 << RES_ELSE ),
4932 FLAG_FI = (1 << RES_FI ),
4934 # if ENABLE_HUSH_LOOPS
4935 FLAG_FOR = (1 << RES_FOR ),
4936 FLAG_WHILE = (1 << RES_WHILE),
4937 FLAG_UNTIL = (1 << RES_UNTIL),
4938 FLAG_DO = (1 << RES_DO ),
4939 FLAG_DONE = (1 << RES_DONE ),
4940 FLAG_IN = (1 << RES_IN ),
4942 # if ENABLE_HUSH_CASE
4943 FLAG_MATCH = (1 << RES_MATCH),
4944 FLAG_ESAC = (1 << RES_ESAC ),
4946 FLAG_START = (1 << RES_XXXX ),
4949 static const struct reserved_combo* match_reserved_word(o_string *word)
4951 /* Mostly a list of accepted follow-up reserved words.
4952 * FLAG_END means we are done with the sequence, and are ready
4953 * to turn the compound list into a command.
4954 * FLAG_START means the word must start a new compound list.
4956 static const struct reserved_combo reserved_list[] = {
4958 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4959 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4960 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4961 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4962 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4963 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4965 # if ENABLE_HUSH_LOOPS
4966 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4967 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4968 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4969 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4970 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4971 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4973 # if ENABLE_HUSH_CASE
4974 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4975 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4978 const struct reserved_combo *r;
4980 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4981 if (strcmp(word->data, r->literal) == 0)
4986 /* Return 0: not a keyword, 1: keyword
4988 static int reserved_word(o_string *word, struct parse_context *ctx)
4990 # if ENABLE_HUSH_CASE
4991 static const struct reserved_combo reserved_match = {
4992 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4995 const struct reserved_combo *r;
4999 r = match_reserved_word(word);
5003 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5004 # if ENABLE_HUSH_CASE
5005 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5006 /* "case word IN ..." - IN part starts first MATCH part */
5007 r = &reserved_match;
5010 if (r->flag == 0) { /* '!' */
5011 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5012 syntax_error("! ! command");
5013 ctx->ctx_res_w = RES_SNTX;
5015 ctx->ctx_inverted = 1;
5018 if (r->flag & FLAG_START) {
5019 struct parse_context *old;
5021 old = xmalloc(sizeof(*old));
5022 debug_printf_parse("push stack %p\n", old);
5023 *old = *ctx; /* physical copy */
5024 initialize_context(ctx);
5026 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5027 syntax_error_at(word->data);
5028 ctx->ctx_res_w = RES_SNTX;
5031 /* "{...} fi" is ok. "{...} if" is not
5033 * if { echo foo; } then { echo bar; } fi */
5034 if (ctx->command->group)
5035 done_pipe(ctx, PIPE_SEQ);
5038 ctx->ctx_res_w = r->res;
5039 ctx->old_flag = r->flag;
5040 word->o_assignment = r->assignment_flag;
5042 if (ctx->old_flag & FLAG_END) {
5043 struct parse_context *old;
5045 done_pipe(ctx, PIPE_SEQ);
5046 debug_printf_parse("pop stack %p\n", ctx->stack);
5048 old->command->group = ctx->list_head;
5049 old->command->cmd_type = CMD_NORMAL;
5051 o_addstr(&old->as_string, ctx->as_string.data);
5052 o_free_unsafe(&ctx->as_string);
5053 old->command->group_as_string = xstrdup(old->as_string.data);
5054 debug_printf_parse("pop, remembering as:'%s'\n",
5055 old->command->group_as_string);
5057 *ctx = *old; /* physical copy */
5062 #endif /* HAS_KEYWORDS */
5064 /* Word is complete, look at it and update parsing context.
5065 * Normal return is 0. Syntax errors return 1.
5066 * Note: on return, word is reset, but not o_free'd!
5068 static int done_word(o_string *word, struct parse_context *ctx)
5070 struct command *command = ctx->command;
5072 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5073 if (word->length == 0 && word->o_quoted == 0) {
5074 debug_printf_parse("done_word return 0: true null, ignored\n");
5078 if (ctx->pending_redirect) {
5079 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5080 * only if run as "bash", not "sh" */
5081 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5083 * ...the word that follows the redirection operator
5084 * shall be subjected to tilde expansion, parameter expansion,
5085 * command substitution, arithmetic expansion, and quote
5086 * removal. Pathname expansion shall not be performed
5087 * on the word by a non-interactive shell; an interactive
5088 * shell may perform it, but shall do so only when
5089 * the expansion would result in one word."
5091 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5092 /* Cater for >\file case:
5093 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5094 * Same with heredocs:
5095 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5097 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5098 unbackslash(ctx->pending_redirect->rd_filename);
5099 /* Is it <<"HEREDOC"? */
5100 if (word->o_quoted) {
5101 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5104 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5105 ctx->pending_redirect = NULL;
5107 /* If this word wasn't an assignment, next ones definitely
5108 * can't be assignments. Even if they look like ones. */
5109 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5110 && word->o_assignment != WORD_IS_KEYWORD
5112 word->o_assignment = NOT_ASSIGNMENT;
5114 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5115 command->assignment_cnt++;
5116 word->o_assignment = MAYBE_ASSIGNMENT;
5120 # if ENABLE_HUSH_CASE
5121 if (ctx->ctx_dsemicolon
5122 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5124 /* already done when ctx_dsemicolon was set to 1: */
5125 /* ctx->ctx_res_w = RES_MATCH; */
5126 ctx->ctx_dsemicolon = 0;
5129 if (!command->argv /* if it's the first word... */
5130 # if ENABLE_HUSH_LOOPS
5131 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5132 && ctx->ctx_res_w != RES_IN
5134 # if ENABLE_HUSH_CASE
5135 && ctx->ctx_res_w != RES_CASE
5138 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5139 if (reserved_word(word, ctx)) {
5140 o_reset_to_empty_unquoted(word);
5141 debug_printf_parse("done_word return %d\n",
5142 (ctx->ctx_res_w == RES_SNTX));
5143 return (ctx->ctx_res_w == RES_SNTX);
5145 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5146 if (strcmp(word->data, "export") == 0
5147 # if ENABLE_HUSH_LOCAL
5148 || strcmp(word->data, "local") == 0
5151 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5154 # if ENABLE_HUSH_BASH_COMPAT
5155 if (strcmp(word->data, "[[") == 0) {
5156 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5162 if (command->group) {
5163 /* "{ echo foo; } echo bar" - bad */
5164 syntax_error_at(word->data);
5165 debug_printf_parse("done_word return 1: syntax error, "
5166 "groups and arglists don't mix\n");
5169 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5170 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5171 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5172 /* (otherwise it's known to be not empty and is already safe) */
5174 /* exclude "$@" - it can expand to no word despite "" */
5175 char *p = word->data;
5176 while (p[0] == SPECIAL_VAR_SYMBOL
5177 && (p[1] & 0x7f) == '@'
5178 && p[2] == SPECIAL_VAR_SYMBOL
5182 if (p == word->data || p[0] != '\0') {
5183 /* saw no "$@", or not only "$@" but some
5184 * real text is there too */
5185 /* insert "empty variable" reference, this makes
5186 * e.g. "", $empty"" etc to not disappear */
5187 o_addchr(word, SPECIAL_VAR_SYMBOL);
5188 o_addchr(word, SPECIAL_VAR_SYMBOL);
5191 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5192 debug_print_strings("word appended to argv", command->argv);
5195 #if ENABLE_HUSH_LOOPS
5196 if (ctx->ctx_res_w == RES_FOR) {
5198 || !is_well_formed_var_name(command->argv[0], '\0')
5200 /* bash says just "not a valid identifier" */
5201 syntax_error("not a valid identifier in for");
5204 /* Force FOR to have just one word (variable name) */
5205 /* NB: basically, this makes hush see "for v in ..."
5206 * syntax as if it is "for v; in ...". FOR and IN become
5207 * two pipe structs in parse tree. */
5208 done_pipe(ctx, PIPE_SEQ);
5211 #if ENABLE_HUSH_CASE
5212 /* Force CASE to have just one word */
5213 if (ctx->ctx_res_w == RES_CASE) {
5214 done_pipe(ctx, PIPE_SEQ);
5218 o_reset_to_empty_unquoted(word);
5220 debug_printf_parse("done_word return 0\n");
5225 /* Peek ahead in the input to find out if we have a "&n" construct,
5226 * as in "2>&1", that represents duplicating a file descriptor.
5228 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5229 * REDIRFD_SYNTAX_ERR if syntax error,
5230 * REDIRFD_TO_FILE if no & was seen,
5231 * or the number found.
5234 #define parse_redir_right_fd(as_string, input) \
5235 parse_redir_right_fd(input)
5237 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5243 return REDIRFD_TO_FILE;
5245 ch = i_getch(input); /* get the & */
5246 nommu_addchr(as_string, ch);
5249 ch = i_getch(input);
5250 nommu_addchr(as_string, ch);
5251 return REDIRFD_CLOSE;
5255 while (ch != EOF && isdigit(ch)) {
5256 d = d*10 + (ch-'0');
5258 ch = i_getch(input);
5259 nommu_addchr(as_string, ch);
5264 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5266 bb_error_msg("ambiguous redirect");
5267 return REDIRFD_SYNTAX_ERR;
5270 /* Return code is 0 normal, 1 if a syntax error is detected
5272 static int parse_redirect(struct parse_context *ctx,
5275 struct in_str *input)
5277 struct command *command = ctx->command;
5278 struct redir_struct *redir;
5279 struct redir_struct **redirp;
5282 dup_num = REDIRFD_TO_FILE;
5283 if (style != REDIRECT_HEREDOC) {
5284 /* Check for a '>&1' type redirect */
5285 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5286 if (dup_num == REDIRFD_SYNTAX_ERR)
5289 int ch = i_peek(input);
5290 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5291 if (dup_num) { /* <<-... */
5292 ch = i_getch(input);
5293 nommu_addchr(&ctx->as_string, ch);
5298 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5299 int ch = i_peek(input);
5301 /* >|FILE redirect ("clobbering" >).
5302 * Since we do not support "set -o noclobber" yet,
5303 * >| and > are the same for now. Just eat |.
5305 ch = i_getch(input);
5306 nommu_addchr(&ctx->as_string, ch);
5310 /* Create a new redir_struct and append it to the linked list */
5311 redirp = &command->redirects;
5312 while ((redir = *redirp) != NULL) {
5313 redirp = &(redir->next);
5315 *redirp = redir = xzalloc(sizeof(*redir));
5316 /* redir->next = NULL; */
5317 /* redir->rd_filename = NULL; */
5318 redir->rd_type = style;
5319 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5321 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5322 redir_table[style].descrip);
5324 redir->rd_dup = dup_num;
5325 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5326 /* Erik had a check here that the file descriptor in question
5327 * is legit; I postpone that to "run time"
5328 * A "-" representation of "close me" shows up as a -3 here */
5329 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5330 redir->rd_fd, redir->rd_dup);
5332 /* Set ctx->pending_redirect, so we know what to do at the
5333 * end of the next parsed word. */
5334 ctx->pending_redirect = redir;
5339 /* If a redirect is immediately preceded by a number, that number is
5340 * supposed to tell which file descriptor to redirect. This routine
5341 * looks for such preceding numbers. In an ideal world this routine
5342 * needs to handle all the following classes of redirects...
5343 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5344 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5345 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5346 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5348 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5350 * ... If n is quoted, the number shall not be recognized as part of
5351 * the redirection expression. For example:
5353 * writes the character 2 into file a"
5354 * We are getting it right by setting ->o_quoted on any \<char>
5356 * A -1 return means no valid number was found,
5357 * the caller should use the appropriate default for this redirection.
5359 static int redirect_opt_num(o_string *o)
5363 if (o->data == NULL)
5365 num = bb_strtou(o->data, NULL, 10);
5366 if (errno || num < 0)
5368 o_reset_to_empty_unquoted(o);
5373 #define fetch_till_str(as_string, input, word, skip_tabs) \
5374 fetch_till_str(input, word, skip_tabs)
5376 static char *fetch_till_str(o_string *as_string,
5377 struct in_str *input,
5381 o_string heredoc = NULL_O_STRING;
5387 ch = i_getch(input);
5388 nommu_addchr(as_string, ch);
5390 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5391 heredoc.data[past_EOL] = '\0';
5392 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5393 return heredoc.data;
5396 o_addchr(&heredoc, ch);
5397 past_EOL = heredoc.length;
5400 ch = i_getch(input);
5401 nommu_addchr(as_string, ch);
5402 } while (skip_tabs && ch == '\t');
5403 } while (ch == '\n');
5406 o_free_unsafe(&heredoc);
5409 o_addchr(&heredoc, ch);
5410 nommu_addchr(as_string, ch);
5414 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5415 * and load them all. There should be exactly heredoc_cnt of them.
5417 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5419 struct pipe *pi = ctx->list_head;
5421 while (pi && heredoc_cnt) {
5423 struct command *cmd = pi->cmds;
5425 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5427 cmd->argv ? cmd->argv[0] : "NONE");
5428 for (i = 0; i < pi->num_cmds; i++) {
5429 struct redir_struct *redir = cmd->redirects;
5431 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5432 i, cmd->argv ? cmd->argv[0] : "NONE");
5434 if (redir->rd_type == REDIRECT_HEREDOC) {
5437 redir->rd_type = REDIRECT_HEREDOC2;
5438 /* redir->rd_dup is (ab)used to indicate <<- */
5439 p = fetch_till_str(&ctx->as_string, input,
5440 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5442 syntax_error("unexpected EOF in here document");
5445 free(redir->rd_filename);
5446 redir->rd_filename = p;
5449 redir = redir->next;
5456 /* Should be 0. If it isn't, it's a parse error */
5458 bb_error_msg_and_die("heredoc BUG 2");
5464 #if ENABLE_HUSH_TICK
5465 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5470 char **to_free = NULL;
5474 pid = BB_MMU ? fork() : vfork();
5476 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5478 if (pid == 0) { /* child */
5479 disable_restore_tty_pgrp_on_exit();
5480 /* Process substitution is not considered to be usual
5481 * 'command execution'.
5482 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5489 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5490 close(channel[0]); /* NB: close _first_, then move fd! */
5491 xmove_fd(channel[1], 1);
5492 /* Prevent it from trying to handle ctrl-z etc */
5493 IF_HUSH_JOB(G.run_list_level = 1;)
5494 /* Awful hack for `trap` or $(trap).
5496 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5497 * contains an example where "trap" is executed in a subshell:
5499 * save_traps=$(trap)
5501 * eval "$save_traps"
5503 * Standard does not say that "trap" in subshell shall print
5504 * parent shell's traps. It only says that its output
5505 * must have suitable form, but then, in the above example
5506 * (which is not supposed to be normative), it implies that.
5508 * bash (and probably other shell) does implement it
5509 * (traps are reset to defaults, but "trap" still shows them),
5510 * but as a result, "trap" logic is hopelessly messed up:
5513 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5514 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5515 * # true | trap <--- trap is in subshell - no output (ditto)
5516 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5517 * trap -- 'echo Ho' SIGWINCH
5518 * # echo `(trap)` <--- in subshell in subshell - output
5519 * trap -- 'echo Ho' SIGWINCH
5520 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5521 * trap -- 'echo Ho' SIGWINCH
5523 * The rules when to forget and when to not forget traps
5524 * get really complex and nonsensical.
5526 * Our solution: ONLY bare $(trap) or `trap` is special.
5528 s = skip_whitespace(s);
5529 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5531 static const char *const argv[] = { NULL, NULL };
5532 builtin_trap((char**)argv);
5533 exit(0); /* not _exit() - we need to fflush */
5536 reset_traps_to_defaults();
5537 parse_and_run_string(s);
5538 _exit(G.last_exitcode);
5540 /* We re-execute after vfork on NOMMU. This makes this script safe:
5541 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5542 * huge=`cat BIG` # was blocking here forever
5545 re_execute_shell(&to_free,
5555 # if ENABLE_HUSH_FAST
5557 //bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5559 enable_restore_tty_pgrp_on_exit();
5564 close_on_exec_on(channel[0]);
5565 return xfdopen_for_read(channel[0]);
5568 /* Return code is exit status of the process that is run. */
5569 static int process_command_subs(o_string *dest, const char *s)
5572 struct in_str pipe_str;
5574 int status, ch, eol_cnt;
5576 fp = generate_stream_from_string(s, &pid);
5578 /* Now send results of command back into original context */
5579 setup_file_in_str(&pipe_str, fp);
5581 while ((ch = i_getch(&pipe_str)) != EOF) {
5587 o_addchr(dest, '\n');
5590 o_addQchr(dest, ch);
5593 debug_printf("done reading from `cmd` pipe, closing it\n");
5595 /* We need to extract exitcode. Test case
5596 * "true; echo `sleep 1; false` $?"
5598 safe_waitpid(pid, &status, 0);
5599 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5600 return WEXITSTATUS(status);
5602 #endif /* ENABLE_HUSH_TICK */
5604 #if !ENABLE_HUSH_FUNCTIONS
5605 #define parse_group(dest, ctx, input, ch) \
5606 parse_group(ctx, input, ch)
5608 static int parse_group(o_string *dest, struct parse_context *ctx,
5609 struct in_str *input, int ch)
5611 /* dest contains characters seen prior to ( or {.
5612 * Typically it's empty, but for function defs,
5613 * it contains function name (without '()'). */
5614 struct pipe *pipe_list;
5616 struct command *command = ctx->command;
5618 debug_printf_parse("parse_group entered\n");
5619 #if ENABLE_HUSH_FUNCTIONS
5620 if (ch == '(' && !dest->o_quoted) {
5622 if (done_word(dest, ctx))
5625 goto skip; /* (... */
5626 if (command->argv[1]) { /* word word ... (... */
5627 syntax_error_unexpected_ch('(');
5630 /* it is "word(..." or "word (..." */
5632 ch = i_getch(input);
5633 while (ch == ' ' || ch == '\t');
5635 syntax_error_unexpected_ch(ch);
5638 nommu_addchr(&ctx->as_string, ch);
5640 ch = i_getch(input);
5641 while (ch == ' ' || ch == '\t' || ch == '\n');
5643 syntax_error_unexpected_ch(ch);
5646 nommu_addchr(&ctx->as_string, ch);
5647 command->cmd_type = CMD_FUNCDEF;
5652 #if 0 /* Prevented by caller */
5653 if (command->argv /* word [word]{... */
5654 || dest->length /* word{... */
5655 || dest->o_quoted /* ""{... */
5658 debug_printf_parse("parse_group return 1: "
5659 "syntax error, groups and arglists don't mix\n");
5664 #if ENABLE_HUSH_FUNCTIONS
5670 command->cmd_type = CMD_SUBSHELL;
5672 /* bash does not allow "{echo...", requires whitespace */
5673 ch = i_getch(input);
5674 if (ch != ' ' && ch != '\t' && ch != '\n') {
5675 syntax_error_unexpected_ch(ch);
5678 nommu_addchr(&ctx->as_string, ch);
5683 char *as_string = NULL;
5685 pipe_list = parse_stream(&as_string, input, endch);
5688 o_addstr(&ctx->as_string, as_string);
5690 /* empty ()/{} or parse error? */
5691 if (!pipe_list || pipe_list == ERR_PTR) {
5692 /* parse_stream already emitted error msg */
5696 debug_printf_parse("parse_group return 1: "
5697 "parse_stream returned %p\n", pipe_list);
5700 command->group = pipe_list;
5702 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5703 command->group_as_string = as_string;
5704 debug_printf_parse("end of group, remembering as:'%s'\n",
5705 command->group_as_string);
5708 debug_printf_parse("parse_group return 0\n");
5710 /* command remains "open", available for possible redirects */
5713 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5714 /* Subroutines for copying $(...) and `...` things */
5715 static void add_till_backquote(o_string *dest, struct in_str *input);
5717 static void add_till_single_quote(o_string *dest, struct in_str *input)
5720 int ch = i_getch(input);
5722 syntax_error_unterm_ch('\'');
5723 /*xfunc_die(); - redundant */
5730 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5731 static void add_till_double_quote(o_string *dest, struct in_str *input)
5734 int ch = i_getch(input);
5736 syntax_error_unterm_ch('"');
5737 /*xfunc_die(); - redundant */
5741 if (ch == '\\') { /* \x. Copy both chars. */
5743 ch = i_getch(input);
5747 add_till_backquote(dest, input);
5751 //if (ch == '$') ...
5754 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5756 * "Within the backquoted style of command substitution, backslash
5757 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5758 * The search for the matching backquote shall be satisfied by the first
5759 * backquote found without a preceding backslash; during this search,
5760 * if a non-escaped backquote is encountered within a shell comment,
5761 * a here-document, an embedded command substitution of the $(command)
5762 * form, or a quoted string, undefined results occur. A single-quoted
5763 * or double-quoted string that begins, but does not end, within the
5764 * "`...`" sequence produces undefined results."
5766 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5768 static void add_till_backquote(o_string *dest, struct in_str *input)
5771 int ch = i_getch(input);
5773 syntax_error_unterm_ch('`');
5774 /*xfunc_die(); - redundant */
5779 /* \x. Copy both chars unless it is \` */
5780 int ch2 = i_getch(input);
5782 syntax_error_unterm_ch('`');
5783 /*xfunc_die(); - redundant */
5785 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5792 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5793 * quoting and nested ()s.
5794 * "With the $(command) style of command substitution, all characters
5795 * following the open parenthesis to the matching closing parenthesis
5796 * constitute the command. Any valid shell script can be used for command,
5797 * except a script consisting solely of redirections which produces
5798 * unspecified results."
5800 * echo $(echo '(TEST)' BEST) (TEST) BEST
5801 * echo $(echo 'TEST)' BEST) TEST) BEST
5802 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5804 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5808 int ch = i_getch(input);
5810 syntax_error_unterm_ch(')');
5811 /*xfunc_die(); - redundant */
5819 if (i_peek(input) == ')') {
5827 add_till_single_quote(dest, input);
5832 add_till_double_quote(dest, input);
5837 /* \x. Copy verbatim. Important for \(, \) */
5838 ch = i_getch(input);
5840 syntax_error_unterm_ch(')');
5841 /*xfunc_die(); - redundant */
5848 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5850 /* Return code: 0 for OK, 1 for syntax error */
5852 #define handle_dollar(as_string, dest, input) \
5853 handle_dollar(dest, input)
5855 static int handle_dollar(o_string *as_string,
5857 struct in_str *input)
5859 int ch = i_peek(input); /* first character after the $ */
5860 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5862 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5864 ch = i_getch(input);
5865 nommu_addchr(as_string, ch);
5867 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5869 debug_printf_parse(": '%c'\n", ch);
5870 o_addchr(dest, ch | quote_mask);
5873 if (!isalnum(ch) && ch != '_')
5875 ch = i_getch(input);
5876 nommu_addchr(as_string, ch);
5878 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5879 } else if (isdigit(ch)) {
5881 ch = i_getch(input);
5882 nommu_addchr(as_string, ch);
5883 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5884 debug_printf_parse(": '%c'\n", ch);
5885 o_addchr(dest, ch | quote_mask);
5886 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5887 } else switch (ch) {
5889 case '!': /* last bg pid */
5890 case '?': /* last exit code */
5891 case '#': /* number of args */
5892 case '*': /* args */
5893 case '@': /* args */
5894 goto make_one_char_var;
5896 bool first_char, all_digits;
5899 ch = i_getch(input);
5900 nommu_addchr(as_string, ch);
5901 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5903 /* TODO: maybe someone will try to escape the '}' */
5908 ch = i_getch(input);
5909 nommu_addchr(as_string, ch);
5916 /* ${#var}: length of var contents */
5923 /* They're being verbose and doing ${?} */
5924 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5929 && ( (all_digits && !isdigit(ch))
5930 || (!all_digits && !isalnum(ch) && ch != '_')
5933 /* handle parameter expansions
5934 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5939 case ':': /* null modifier */
5940 if (expansion == 0) {
5941 debug_printf_parse(": null modifier\n");
5946 case '#': /* remove prefix */
5947 case '%': /* remove suffix */
5948 if (expansion == 0) {
5949 debug_printf_parse(": remove suffix/prefix\n");
5954 case '-': /* default value */
5955 case '=': /* assign default */
5956 case '+': /* alternative */
5957 case '?': /* error indicate */
5958 debug_printf_parse(": parameter expansion\n");
5963 syntax_error_unterm_str("${name}");
5964 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5969 debug_printf_parse(": '%c'\n", ch);
5970 o_addchr(dest, ch | quote_mask);
5974 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5977 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
5982 ch = i_getch(input);
5983 nommu_addchr(as_string, ch);
5984 # if ENABLE_SH_MATH_SUPPORT
5985 if (i_peek(input) == '(') {
5986 ch = i_getch(input);
5987 nommu_addchr(as_string, ch);
5988 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5989 o_addchr(dest, /*quote_mask |*/ '+');
5993 add_till_closing_paren(dest, input, true);
5996 o_addstr(as_string, dest->data + pos);
5997 o_addchr(as_string, ')');
5998 o_addchr(as_string, ')');
6001 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6005 # if ENABLE_HUSH_TICK
6006 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6007 o_addchr(dest, quote_mask | '`');
6011 add_till_closing_paren(dest, input, false);
6014 o_addstr(as_string, dest->data + pos);
6015 o_addchr(as_string, ')');
6018 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6024 ch = i_getch(input);
6025 nommu_addchr(as_string, ch);
6027 if (isalnum(ch)) { /* it's $_name or $_123 */
6032 /* TODO: $_ and $-: */
6033 /* $_ Shell or shell script name; or last argument of last command
6034 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6035 * but in command's env, set to full pathname used to invoke it */
6036 /* $- Option flags set by set builtin or shell options (-i etc) */
6038 o_addQchr(dest, '$');
6040 debug_printf_parse("handle_dollar return 0\n");
6045 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6046 parse_stream_dquoted(dest, input, dquote_end)
6048 static int parse_stream_dquoted(o_string *as_string,
6050 struct in_str *input,
6057 ch = i_getch(input);
6059 nommu_addchr(as_string, ch);
6060 if (ch == dquote_end) { /* may be only '"' or EOF */
6061 if (dest->o_assignment == NOT_ASSIGNMENT)
6062 dest->o_escape ^= 1;
6063 debug_printf_parse("parse_stream_dquoted return 0\n");
6066 /* note: can't move it above ch == dquote_end check! */
6068 syntax_error_unterm_ch('"');
6069 /*xfunc_die(); - redundant */
6073 next = i_peek(input);
6075 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6076 ch, ch, dest->o_escape);
6079 syntax_error("\\<eof>");
6083 * "The backslash retains its special meaning [in "..."]
6084 * only when followed by one of the following characters:
6085 * $, `, ", \, or <newline>. A double quote may be quoted
6086 * within double quotes by preceding it with a backslash."
6088 if (strchr("$`\"\\\n", next) != NULL) {
6089 ch = i_getch(input);
6091 o_addqchr(dest, ch);
6092 nommu_addchr(as_string, ch);
6095 o_addqchr(dest, '\\');
6096 nommu_addchr(as_string, '\\');
6101 if (handle_dollar(as_string, dest, input) != 0) {
6102 debug_printf_parse("parse_stream_dquoted return 1: "
6103 "handle_dollar returned non-0\n");
6108 #if ENABLE_HUSH_TICK
6110 //int pos = dest->length;
6111 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6112 o_addchr(dest, 0x80 | '`');
6113 add_till_backquote(dest, input);
6114 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6115 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6119 o_addQchr(dest, ch);
6121 && (dest->o_assignment == MAYBE_ASSIGNMENT
6122 || dest->o_assignment == WORD_IS_KEYWORD)
6123 && is_well_formed_var_name(dest->data, '=')
6125 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6131 * Scan input until EOF or end_trigger char.
6132 * Return a list of pipes to execute, or NULL on EOF
6133 * or if end_trigger character is met.
6134 * On syntax error, exit is shell is not interactive,
6135 * reset parsing machinery and start parsing anew,
6136 * or return ERR_PTR.
6138 static struct pipe *parse_stream(char **pstring,
6139 struct in_str *input,
6142 struct parse_context ctx;
6143 o_string dest = NULL_O_STRING;
6147 /* Double-quote state is handled in the state variable is_in_dquote.
6148 * A single-quote triggers a bypass of the main loop until its mate is
6149 * found. When recursing, quote state is passed in via dest->o_escape.
6151 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6152 end_trigger ? end_trigger : 'X');
6155 /* If very first arg is "" or '', dest.data may end up NULL.
6156 * Preventing this: */
6157 o_addchr(&dest, '\0');
6160 G.ifs = get_local_var_value("IFS");
6165 #if ENABLE_HUSH_INTERACTIVE
6166 input->promptmode = 0; /* PS1 */
6168 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6169 initialize_context(&ctx);
6174 const char *is_special;
6178 redir_type redir_style;
6181 /* dest.o_quoted = 1; - already is (see below) */
6182 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6185 /* We reached closing '"' */
6188 ch = i_getch(input);
6189 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6190 ch, ch, dest.o_escape);
6195 syntax_error_unterm_str("here document");
6198 /* end_trigger == '}' case errors out earlier,
6199 * checking only ')' */
6200 if (end_trigger == ')') {
6201 syntax_error_unterm_ch('('); /* exits */
6202 /* goto parse_error; */
6205 if (done_word(&dest, &ctx)) {
6209 done_pipe(&ctx, PIPE_SEQ);
6211 /* If we got nothing... */
6212 /* (this makes bare "&" cmd a no-op.
6213 * bash says: "syntax error near unexpected token '&'") */
6214 if (pi->num_cmds == 0
6215 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6221 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6223 *pstring = ctx.as_string.data;
6225 o_free_unsafe(&ctx.as_string);
6228 debug_printf_parse("parse_stream return %p\n", pi);
6231 nommu_addchr(&ctx.as_string, ch);
6235 next = i_peek(input);
6237 is_special = "{}<>;&|()#'" /* special outside of "str" */
6238 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6239 /* Are { and } special here? */
6240 if (ctx.command->argv /* word [word]{... */
6241 || dest.length /* word{... */
6242 || dest.o_quoted /* ""{... */
6243 || (next != ';' && next != ')' && !strchr(G.ifs, next)) /* {word */
6245 /* They are not special, skip "{}" */
6248 is_special = strchr(is_special, ch);
6249 is_ifs = strchr(G.ifs, ch);
6251 if (!is_special && !is_ifs) { /* ordinary char */
6253 o_addQchr(&dest, ch);
6254 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6255 || dest.o_assignment == WORD_IS_KEYWORD)
6257 && is_well_formed_var_name(dest.data, '=')
6259 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6265 if (done_word(&dest, &ctx)) {
6269 #if ENABLE_HUSH_CASE
6270 /* "case ... in <newline> word) ..." -
6271 * newlines are ignored (but ';' wouldn't be) */
6272 if (ctx.command->argv == NULL
6273 && ctx.ctx_res_w == RES_MATCH
6278 /* Treat newline as a command separator. */
6279 done_pipe(&ctx, PIPE_SEQ);
6280 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6282 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6287 dest.o_assignment = MAYBE_ASSIGNMENT;
6289 /* note: if (is_ifs) continue;
6290 * will still trigger for us */
6294 /* "cmd}" or "cmd }..." without semicolon or &:
6295 * } is an ordinary char in this case, even inside { cmd; }
6296 * Pathological example: { ""}; } should exec "}" cmd
6299 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6300 || dest.length != 0 /* word} */
6301 || dest.o_quoted /* ""} */
6305 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6306 goto skip_end_trigger;
6307 /* else: } does terminate a group */
6310 if (end_trigger && end_trigger == ch
6311 && (ch != ';' || heredoc_cnt == 0)
6312 #if ENABLE_HUSH_CASE
6314 || ctx.ctx_res_w != RES_MATCH
6315 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6320 /* This is technically valid:
6321 * { cat <<HERE; }; echo Ok
6325 * but we don't support this.
6326 * We require heredoc to be in enclosing {}/(),
6329 syntax_error_unterm_str("here document");
6332 if (done_word(&dest, &ctx)) {
6335 done_pipe(&ctx, PIPE_SEQ);
6336 dest.o_assignment = MAYBE_ASSIGNMENT;
6337 /* Do we sit outside of any if's, loops or case's? */
6339 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6343 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6345 *pstring = ctx.as_string.data;
6347 o_free_unsafe(&ctx.as_string);
6350 debug_printf_parse("parse_stream return %p: "
6351 "end_trigger char found\n",
6353 return ctx.list_head;
6360 /* Catch <, > before deciding whether this word is
6361 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6364 redir_fd = redirect_opt_num(&dest);
6365 if (done_word(&dest, &ctx)) {
6368 redir_style = REDIRECT_OVERWRITE;
6370 redir_style = REDIRECT_APPEND;
6371 ch = i_getch(input);
6372 nommu_addchr(&ctx.as_string, ch);
6375 else if (next == '(') {
6376 syntax_error(">(process) not supported");
6380 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6382 continue; /* back to top of while (1) */
6384 redir_fd = redirect_opt_num(&dest);
6385 if (done_word(&dest, &ctx)) {
6388 redir_style = REDIRECT_INPUT;
6390 redir_style = REDIRECT_HEREDOC;
6392 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6393 ch = i_getch(input);
6394 nommu_addchr(&ctx.as_string, ch);
6395 } else if (next == '>') {
6396 redir_style = REDIRECT_IO;
6397 ch = i_getch(input);
6398 nommu_addchr(&ctx.as_string, ch);
6401 else if (next == '(') {
6402 syntax_error("<(process) not supported");
6406 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6408 continue; /* back to top of while (1) */
6411 if (dest.o_assignment == MAYBE_ASSIGNMENT
6412 /* check that we are not in word in "a=1 2>word b=1": */
6413 && !ctx.pending_redirect
6415 /* ch is a special char and thus this word
6416 * cannot be an assignment */
6417 dest.o_assignment = NOT_ASSIGNMENT;
6420 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6424 if (dest.length == 0) {
6427 if (ch == EOF || ch == '\n')
6430 /* note: we do not add it to &ctx.as_string */
6432 nommu_addchr(&ctx.as_string, '\n');
6434 o_addQchr(&dest, ch);
6439 syntax_error("\\<eof>");
6442 ch = i_getch(input);
6444 o_addchr(&dest, '\\');
6445 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6446 o_addchr(&dest, ch);
6447 nommu_addchr(&ctx.as_string, ch);
6448 /* Example: echo Hello \2>file
6449 * we need to know that word 2 is quoted */
6454 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6455 ctx.as_string.data[--ctx.as_string.length] = '\0';
6460 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6461 debug_printf_parse("parse_stream parse error: "
6462 "handle_dollar returned non-0\n");
6469 ch = i_getch(input);
6471 syntax_error_unterm_ch('\'');
6472 /*xfunc_die(); - redundant */
6474 nommu_addchr(&ctx.as_string, ch);
6477 o_addqchr(&dest, ch);
6482 is_in_dquote ^= 1; /* invert */
6483 if (dest.o_assignment == NOT_ASSIGNMENT)
6486 #if ENABLE_HUSH_TICK
6491 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6492 o_addchr(&dest, '`');
6496 add_till_backquote(&dest, input);
6498 o_addstr(&ctx.as_string, dest.data + pos);
6499 o_addchr(&ctx.as_string, '`');
6501 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6502 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6507 #if ENABLE_HUSH_CASE
6510 if (done_word(&dest, &ctx)) {
6513 done_pipe(&ctx, PIPE_SEQ);
6514 #if ENABLE_HUSH_CASE
6515 /* Eat multiple semicolons, detect
6516 * whether it means something special */
6521 ch = i_getch(input);
6522 nommu_addchr(&ctx.as_string, ch);
6523 if (ctx.ctx_res_w == RES_CASE_BODY) {
6524 ctx.ctx_dsemicolon = 1;
6525 ctx.ctx_res_w = RES_MATCH;
6531 /* We just finished a cmd. New one may start
6532 * with an assignment */
6533 dest.o_assignment = MAYBE_ASSIGNMENT;
6536 if (done_word(&dest, &ctx)) {
6540 ch = i_getch(input);
6541 nommu_addchr(&ctx.as_string, ch);
6542 done_pipe(&ctx, PIPE_AND);
6544 done_pipe(&ctx, PIPE_BG);
6548 if (done_word(&dest, &ctx)) {
6551 #if ENABLE_HUSH_CASE
6552 if (ctx.ctx_res_w == RES_MATCH)
6553 break; /* we are in case's "word | word)" */
6555 if (next == '|') { /* || */
6556 ch = i_getch(input);
6557 nommu_addchr(&ctx.as_string, ch);
6558 done_pipe(&ctx, PIPE_OR);
6560 /* we could pick up a file descriptor choice here
6561 * with redirect_opt_num(), but bash doesn't do it.
6562 * "echo foo 2| cat" yields "foo 2". */
6565 o_reset_to_empty_unquoted(&ctx.as_string);
6570 #if ENABLE_HUSH_CASE
6571 /* "case... in [(]word)..." - skip '(' */
6572 if (ctx.ctx_res_w == RES_MATCH
6573 && ctx.command->argv == NULL /* not (word|(... */
6574 && dest.length == 0 /* not word(... */
6575 && dest.o_quoted == 0 /* not ""(... */
6581 if (parse_group(&dest, &ctx, input, ch) != 0) {
6586 #if ENABLE_HUSH_CASE
6587 if (ctx.ctx_res_w == RES_MATCH)
6591 /* proper use of this character is caught by end_trigger:
6592 * if we see {, we call parse_group(..., end_trigger='}')
6593 * and it will match } earlier (not here). */
6594 syntax_error_unexpected_ch(ch);
6598 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6604 struct parse_context *pctx;
6605 IF_HAS_KEYWORDS(struct parse_context *p2;)
6607 /* Clean up allocated tree.
6608 * Sample for finding leaks on syntax error recovery path.
6609 * Run it from interactive shell, watch pmap `pidof hush`.
6610 * while if false; then false; fi; do break; fi
6611 * Samples to catch leaks at execution:
6612 * while if (true | {true;}); then echo ok; fi; do break; done
6613 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6617 /* Update pipe/command counts,
6618 * otherwise freeing may miss some */
6619 done_pipe(pctx, PIPE_SEQ);
6620 debug_printf_clean("freeing list %p from ctx %p\n",
6621 pctx->list_head, pctx);
6622 debug_print_tree(pctx->list_head, 0);
6623 free_pipe_list(pctx->list_head);
6624 debug_printf_clean("freed list %p\n", pctx->list_head);
6626 o_free_unsafe(&pctx->as_string);
6628 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6632 IF_HAS_KEYWORDS(pctx = p2;)
6633 } while (HAS_KEYWORDS && pctx);
6634 /* Free text, clear all dest fields */
6636 /* If we are not in top-level parse, we return,
6637 * our caller will propagate error.
6639 if (end_trigger != ';') {
6647 /* Discard cached input, force prompt */
6649 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6654 /* Executing from string: eval, sh -c '...'
6655 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6656 * end_trigger controls how often we stop parsing
6657 * NUL: parse all, execute, return
6658 * ';': parse till ';' or newline, execute, repeat till EOF
6660 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6662 /* Why we need empty flag?
6663 * An obscure corner case "false; ``; echo $?":
6664 * empty command in `` should still set $? to 0.
6665 * But we can't just set $? to 0 at the start,
6666 * this breaks "false; echo `echo $?`" case.
6670 struct pipe *pipe_list;
6672 pipe_list = parse_stream(NULL, inp, end_trigger);
6673 if (!pipe_list) { /* EOF */
6675 G.last_exitcode = 0;
6678 debug_print_tree(pipe_list, 0);
6679 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6680 run_and_free_list(pipe_list);
6685 static void parse_and_run_string(const char *s)
6687 struct in_str input;
6688 setup_string_in_str(&input, s);
6689 parse_and_run_stream(&input, '\0');
6692 static void parse_and_run_file(FILE *f)
6694 struct in_str input;
6695 setup_file_in_str(&input, f);
6696 parse_and_run_stream(&input, ';');
6699 /* Called a few times only (or even once if "sh -c") */
6700 static void init_sigmasks(void)
6704 sigset_t old_blocked_set;
6706 if (!G.inherited_set_is_saved) {
6707 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6708 G.inherited_set = G.blocked_set;
6710 old_blocked_set = G.blocked_set;
6712 mask = (1 << SIGQUIT);
6713 if (G_interactive_fd) {
6714 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6715 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6716 mask |= SPECIAL_JOB_SIGS;
6718 G.non_DFL_mask = mask;
6723 sigaddset(&G.blocked_set, sig);
6727 sigdelset(&G.blocked_set, SIGCHLD);
6729 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6730 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6732 /* POSIX allows shell to re-enable SIGCHLD
6733 * even if it was SIG_IGN on entry */
6734 #if ENABLE_HUSH_FAST
6735 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6736 if (!G.inherited_set_is_saved)
6737 signal(SIGCHLD, SIGCHLD_handler);
6739 if (!G.inherited_set_is_saved)
6740 signal(SIGCHLD, SIG_DFL);
6743 G.inherited_set_is_saved = 1;
6748 static void maybe_set_to_sigexit(int sig)
6750 void (*handler)(int);
6751 /* non_DFL_mask'ed signals are, well, masked,
6752 * no need to set handler for them.
6754 if (!((G.non_DFL_mask >> sig) & 1)) {
6755 handler = signal(sig, sigexit);
6756 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6757 signal(sig, handler);
6760 /* Set handlers to restore tty pgrp and exit */
6761 static void set_fatal_handlers(void)
6763 /* We _must_ restore tty pgrp on fatal signals */
6765 maybe_set_to_sigexit(SIGILL );
6766 maybe_set_to_sigexit(SIGFPE );
6767 maybe_set_to_sigexit(SIGBUS );
6768 maybe_set_to_sigexit(SIGSEGV);
6769 maybe_set_to_sigexit(SIGTRAP);
6770 } /* else: hush is perfect. what SEGV? */
6771 maybe_set_to_sigexit(SIGABRT);
6772 /* bash 3.2 seems to handle these just like 'fatal' ones */
6773 maybe_set_to_sigexit(SIGPIPE);
6774 maybe_set_to_sigexit(SIGALRM);
6775 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6776 * if we aren't interactive... but in this case
6777 * we never want to restore pgrp on exit, and this fn is not called */
6778 /*maybe_set_to_sigexit(SIGHUP );*/
6779 /*maybe_set_to_sigexit(SIGTERM);*/
6780 /*maybe_set_to_sigexit(SIGINT );*/
6784 static int set_mode(const char cstate, const char mode)
6786 int state = (cstate == '-' ? 1 : 0);
6788 case 'n': G.fake_mode = state; break;
6789 case 'x': /*G.debug_mode = state;*/ break;
6790 default: return EXIT_FAILURE;
6792 return EXIT_SUCCESS;
6795 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6796 int hush_main(int argc, char **argv)
6798 static const struct variable const_shell_ver = {
6800 .varstr = (char*)hush_version_str,
6801 .max_len = 1, /* 0 can provoke free(name) */
6806 unsigned builtin_argc;
6808 struct variable *cur_var;
6811 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6812 G.last_exitcode = EXIT_SUCCESS;
6814 G.argv0_for_re_execing = argv[0];
6816 /* Deal with HUSH_VERSION */
6817 G.shell_ver = const_shell_ver; /* copying struct here */
6818 G.top_var = &G.shell_ver;
6819 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6820 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6821 /* Initialize our shell local variables with the values
6822 * currently living in the environment */
6823 cur_var = G.top_var;
6826 char *value = strchr(*e, '=');
6827 if (value) { /* paranoia */
6828 cur_var->next = xzalloc(sizeof(*cur_var));
6829 cur_var = cur_var->next;
6830 cur_var->varstr = *e;
6831 cur_var->max_len = strlen(*e);
6832 cur_var->flg_export = 1;
6836 /* reinstate HUSH_VERSION */
6837 debug_printf_env("putenv '%s'\n", hush_version_str);
6838 putenv((char *)hush_version_str);
6841 set_pwd_var(/*exp:*/ 1);
6842 /* bash also exports SHLVL and _,
6843 * and sets (but doesn't export) the following variables:
6845 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6846 * BASH_VERSION='3.2.0(1)-release'
6848 * MACHTYPE=i386-pc-linux-gnu
6850 * HOSTNAME=<xxxxxxxxxx>
6851 * PPID=<NNNNN> - we also do it elsewhere
6862 * PIPESTATUS=([0]="0")
6863 * HISTFILE=/<xxx>/.bash_history
6867 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6869 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6879 #if ENABLE_FEATURE_EDITING
6880 G.line_input_state = new_line_input_t(FOR_SHELL);
6882 G.global_argc = argc;
6883 G.global_argv = argv;
6884 /* Initialize some more globals to non-zero values */
6885 cmdedit_update_prompt();
6887 if (setjmp(die_jmp)) {
6888 /* xfunc has failed! die die die */
6889 /* no EXIT traps, this is an escape hatch! */
6891 hush_exit(xfunc_error_retval);
6894 /* Shell is non-interactive at first. We need to call
6895 * init_sigmasks() if we are going to execute "sh <script>",
6896 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6897 * If we later decide that we are interactive, we run init_sigmasks()
6898 * in order to intercept (more) signals.
6902 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6905 opt = getopt(argc, argv, "+c:xins"
6908 # if ENABLE_HUSH_FUNCTIONS
6918 * sh ... -c 'script'
6919 * sh ... -c 'script' ARG0 [ARG1...]
6920 * On NOMMU, if builtin_argc != 0,
6921 * sh ... -c 'builtin' [BARGV...] "" ARG0 [ARG1...]
6922 * "" needs to be replaced with NULL
6923 * and BARGV vector fed to builtin function.
6924 * Note: this form never happens:
6925 * sh ... -c 'builtin' [BARGV...] ""
6928 G.root_pid = getpid();
6929 G.root_ppid = getppid();
6931 G.global_argv = argv + optind;
6932 G.global_argc = argc - optind;
6934 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6935 const struct built_in_command *x;
6938 x = find_builtin(optarg);
6939 if (x) { /* paranoia */
6940 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6941 G.global_argv += builtin_argc;
6942 G.global_argv[-1] = NULL; /* replace "" */
6943 G.last_exitcode = x->function(argv + optind - 1);
6947 if (!G.global_argv[0]) {
6948 /* -c 'script' (no params): prevent empty $0 */
6949 G.global_argv--; /* points to argv[i] of 'script' */
6950 G.global_argv[0] = argv[0];
6952 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6954 parse_and_run_string(optarg);
6957 /* Well, we cannot just declare interactiveness,
6958 * we have to have some stuff (ctty, etc) */
6959 /* G_interactive_fd++; */
6962 /* "-s" means "read from stdin", but this is how we always
6963 * operate, so simply do nothing here. */
6966 case '<': /* "big heredoc" support */
6967 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6970 unsigned long long empty_trap_mask;
6972 G.root_pid = bb_strtou(optarg, &optarg, 16);
6974 G.root_ppid = bb_strtou(optarg, &optarg, 16);
6976 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6978 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6980 builtin_argc = bb_strtou(optarg, &optarg, 16);
6982 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
6983 if (empty_trap_mask != 0) {
6986 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6987 for (sig = 1; sig < NSIG; sig++) {
6988 if (empty_trap_mask & (1LL << sig)) {
6989 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
6990 sigaddset(&G.blocked_set, sig);
6993 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6995 # if ENABLE_HUSH_LOOPS
6997 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7003 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7005 # if ENABLE_HUSH_FUNCTIONS
7007 struct function *funcp = new_function(optarg);
7008 /* funcp->name is already set to optarg */
7009 /* funcp->body is set to NULL. It's a special case. */
7010 funcp->body_as_string = argv[optind];
7018 if (!set_mode('-', opt))
7022 fprintf(stderr, "Usage: sh [FILE]...\n"
7023 " or: sh -c command [args]...\n\n");
7029 } /* option parsing loop */
7032 G.root_pid = getpid();
7033 G.root_ppid = getppid();
7036 /* If we are login shell... */
7037 if (argv[0] && argv[0][0] == '-') {
7039 debug_printf("sourcing /etc/profile\n");
7040 input = fopen_for_read("/etc/profile");
7041 if (input != NULL) {
7042 close_on_exec_on(fileno(input));
7044 parse_and_run_file(input);
7047 /* bash: after sourcing /etc/profile,
7048 * tries to source (in the given order):
7049 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7050 * stopping on first found. --noprofile turns this off.
7051 * bash also sources ~/.bash_logout on exit.
7052 * If called as sh, skips .bash_XXX files.
7059 * "bash <script>" (which is never interactive (unless -i?))
7060 * sources $BASH_ENV here (without scanning $PATH).
7061 * If called as sh, does the same but with $ENV.
7063 debug_printf("running script '%s'\n", argv[optind]);
7064 G.global_argv = argv + optind;
7065 G.global_argc = argc - optind;
7066 input = xfopen_for_read(argv[optind]);
7067 close_on_exec_on(fileno(input));
7069 parse_and_run_file(input);
7070 #if ENABLE_FEATURE_CLEAN_UP
7076 /* Up to here, shell was non-interactive. Now it may become one.
7077 * NB: don't forget to (re)run init_sigmasks() as needed.
7080 /* A shell is interactive if the '-i' flag was given,
7081 * or if all of the following conditions are met:
7083 * no arguments remaining or the -s flag given
7084 * standard input is a terminal
7085 * standard output is a terminal
7086 * Refer to Posix.2, the description of the 'sh' utility.
7089 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7090 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7091 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7092 if (G_saved_tty_pgrp < 0)
7093 G_saved_tty_pgrp = 0;
7095 /* try to dup stdin to high fd#, >= 255 */
7096 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7097 if (G_interactive_fd < 0) {
7098 /* try to dup to any fd */
7099 G_interactive_fd = dup(STDIN_FILENO);
7100 if (G_interactive_fd < 0) {
7102 G_interactive_fd = 0;
7103 G_saved_tty_pgrp = 0;
7106 // TODO: track & disallow any attempts of user
7107 // to (inadvertently) close/redirect G_interactive_fd
7109 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7110 if (G_interactive_fd) {
7111 close_on_exec_on(G_interactive_fd);
7113 if (G_saved_tty_pgrp) {
7114 /* If we were run as 'hush &', sleep until we are
7115 * in the foreground (tty pgrp == our pgrp).
7116 * If we get started under a job aware app (like bash),
7117 * make sure we are now in charge so we don't fight over
7118 * who gets the foreground */
7120 pid_t shell_pgrp = getpgrp();
7121 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7122 if (G_saved_tty_pgrp == shell_pgrp)
7124 /* send TTIN to ourself (should stop us) */
7125 kill(- shell_pgrp, SIGTTIN);
7129 /* Block some signals */
7132 if (G_saved_tty_pgrp) {
7133 /* Set other signals to restore saved_tty_pgrp */
7134 set_fatal_handlers();
7135 /* Put ourselves in our own process group
7136 * (bash, too, does this only if ctty is available) */
7137 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7138 /* Grab control of the terminal */
7139 tcsetpgrp(G_interactive_fd, getpid());
7141 /* -1 is special - makes xfuncs longjmp, not exit
7142 * (we reset die_sleep = 0 whereever we [v]fork) */
7143 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7147 #elif ENABLE_HUSH_INTERACTIVE
7148 /* No job control compiled in, only prompt/line editing */
7149 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7150 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7151 if (G_interactive_fd < 0) {
7152 /* try to dup to any fd */
7153 G_interactive_fd = dup(STDIN_FILENO);
7154 if (G_interactive_fd < 0)
7156 G_interactive_fd = 0;
7159 if (G_interactive_fd) {
7160 close_on_exec_on(G_interactive_fd);
7164 /* We have interactiveness code disabled */
7168 * if interactive but not a login shell, sources ~/.bashrc
7169 * (--norc turns this off, --rcfile <file> overrides)
7172 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7173 /* note: ash and hush share this string */
7174 printf("\n\n%s %s\n"
7175 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7178 "hush - the humble shell"
7182 parse_and_run_file(stdin);
7185 #if ENABLE_FEATURE_CLEAN_UP
7186 if (G.cwd != bb_msg_unknown)
7188 cur_var = G.top_var->next;
7190 struct variable *tmp = cur_var;
7191 if (!cur_var->max_len)
7192 free(cur_var->varstr);
7193 cur_var = cur_var->next;
7197 hush_exit(G.last_exitcode);
7202 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7203 int lash_main(int argc, char **argv)
7205 bb_error_msg("lash is deprecated, please use hush instead");
7206 return hush_main(argc, argv);
7211 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7212 int msh_main(int argc, char **argv)
7214 //bb_error_msg("msh is deprecated, please use hush instead");
7215 return hush_main(argc, argv);
7223 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7228 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7235 return applet_main_func(argc, argv - argc);
7238 static int FAST_FUNC builtin_test(char **argv)
7240 return run_applet_main(argv, test_main);
7243 static int FAST_FUNC builtin_echo(char **argv)
7245 return run_applet_main(argv, echo_main);
7249 static int FAST_FUNC builtin_printf(char **argv)
7251 return run_applet_main(argv, printf_main);
7255 static int FAST_FUNC builtin_eval(char **argv)
7257 int rcode = EXIT_SUCCESS;
7260 char *str = expand_strvec_to_string(argv);
7262 * eval "echo Hi; done" ("done" is syntax error):
7263 * "echo Hi" will not execute too.
7265 parse_and_run_string(str);
7267 rcode = G.last_exitcode;
7272 static int FAST_FUNC builtin_cd(char **argv)
7274 const char *newdir = argv[1];
7275 if (newdir == NULL) {
7276 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7277 * bash says "bash: cd: HOME not set" and does nothing
7280 const char *home = get_local_var_value("HOME");
7281 newdir = home ? home : "/";
7283 if (chdir(newdir)) {
7284 /* Mimic bash message exactly */
7285 bb_perror_msg("cd: %s", newdir);
7286 return EXIT_FAILURE;
7288 /* Read current dir (get_cwd(1) is inside) and set PWD.
7289 * Note: do not enforce exporting. If PWD was unset or unexported,
7290 * set it again, but do not export. bash does the same.
7292 set_pwd_var(/*exp:*/ 0);
7293 return EXIT_SUCCESS;
7296 static int FAST_FUNC builtin_exec(char **argv)
7298 if (*++argv == NULL)
7299 return EXIT_SUCCESS; /* bash does this */
7301 /* Careful: we can end up here after [v]fork. Do not restore
7302 * tty pgrp then, only top-level shell process does that */
7303 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7304 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7306 /* TODO: if exec fails, bash does NOT exit! We do.
7307 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7308 * and tcsetpgrp, and this is inherently racy.
7310 execvp_or_die(argv);
7313 static int FAST_FUNC builtin_exit(char **argv)
7315 debug_printf_exec("%s()\n", __func__);
7317 /* interactive bash:
7318 * # trap "echo EEE" EXIT
7321 * There are stopped jobs.
7322 * (if there are _stopped_ jobs, running ones don't count)
7325 # EEE (then bash exits)
7327 * we can use G.exiting = -1 as indicator "last cmd was exit"
7330 /* note: EXIT trap is run by hush_exit */
7331 if (*++argv == NULL)
7332 hush_exit(G.last_exitcode);
7333 /* mimic bash: exit 123abc == exit 255 + error msg */
7334 xfunc_error_retval = 255;
7335 /* bash: exit -2 == exit 254, no error msg */
7336 hush_exit(xatoi(*argv) & 0xff);
7339 static void print_escaped(const char *s)
7344 const char *p = strchrnul(s, '\'');
7345 /* print 'xxxx', possibly just '' */
7346 printf("'%.*s'", (int)(p - s), s);
7351 /* s points to '; print "'''...'''" */
7353 do putchar('\''); while (*++s == '\'');
7358 #if !ENABLE_HUSH_LOCAL
7359 #define helper_export_local(argv, exp, lvl) \
7360 helper_export_local(argv, exp)
7362 static void helper_export_local(char **argv, int exp, int lvl)
7367 /* So far we do not check that name is valid (TODO?) */
7369 if (strchr(name, '=') == NULL) {
7370 struct variable *var;
7372 var = get_local_var(name);
7373 if (exp == -1) { /* unexporting? */
7374 /* export -n NAME (without =VALUE) */
7376 var->flg_export = 0;
7377 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7379 } /* else: export -n NOT_EXISTING_VAR: no-op */
7382 if (exp == 1) { /* exporting? */
7383 /* export NAME (without =VALUE) */
7385 var->flg_export = 1;
7386 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7387 putenv(var->varstr);
7391 /* Exporting non-existing variable.
7392 * bash does not put it in environment,
7393 * but remembers that it is exported,
7394 * and does put it in env when it is set later.
7395 * We just set it to "" and export. */
7396 /* Or, it's "local NAME" (without =VALUE).
7397 * bash sets the value to "". */
7398 name = xasprintf("%s=", name);
7400 /* (Un)exporting/making local NAME=VALUE */
7401 name = xstrdup(name);
7403 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7407 static int FAST_FUNC builtin_export(char **argv)
7409 unsigned opt_unexport;
7411 #if ENABLE_HUSH_EXPORT_N
7412 /* "!": do not abort on errors */
7413 opt_unexport = getopt32(argv, "!n");
7414 if (opt_unexport == (uint32_t)-1)
7415 return EXIT_FAILURE;
7422 if (argv[0] == NULL) {
7429 /* ash emits: export VAR='VAL'
7430 * bash: declare -x VAR="VAL"
7431 * we follow ash example */
7432 const char *s = *e++;
7433 const char *p = strchr(s, '=');
7435 if (!p) /* wtf? take next variable */
7438 printf("export %.*s", (int)(p - s) + 1, s);
7439 print_escaped(p + 1);
7443 /*fflush_all(); - done after each builtin anyway */
7445 return EXIT_SUCCESS;
7448 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7450 return EXIT_SUCCESS;
7453 #if ENABLE_HUSH_LOCAL
7454 static int FAST_FUNC builtin_local(char **argv)
7456 if (G.func_nest_level == 0) {
7457 bb_error_msg("%s: not in a function", argv[0]);
7458 return EXIT_FAILURE; /* bash compat */
7460 helper_export_local(argv, 0, G.func_nest_level);
7461 return EXIT_SUCCESS;
7465 static int FAST_FUNC builtin_trap(char **argv)
7471 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7476 /* No args: print all trapped */
7477 for (i = 0; i < NSIG; ++i) {
7480 print_escaped(G.traps[i]);
7481 /* note: bash adds "SIG", but only if invoked
7482 * as "bash". If called as "sh", or if set -o posix,
7483 * then it prints short signal names.
7484 * We are printing short names: */
7485 printf(" %s\n", get_signame(i));
7488 /*fflush_all(); - done after each builtin anyway */
7489 return EXIT_SUCCESS;
7493 /* If first arg is a number: reset all specified signals */
7494 sig = bb_strtou(*argv, NULL, 10);
7500 sig = get_signum(*argv++);
7501 if (sig < 0 || sig >= NSIG) {
7503 /* Mimic bash message exactly */
7504 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7509 G.traps[sig] = xstrdup(new_cmd);
7511 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7512 get_signame(sig), sig, G.traps[sig]);
7514 /* There is no signal for 0 (EXIT) */
7519 sigaddset(&G.blocked_set, sig);
7521 /* There was a trap handler, we are removing it
7522 * (if sig has non-DFL handling,
7523 * we don't need to do anything) */
7524 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7526 sigdelset(&G.blocked_set, sig);
7529 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7533 if (!argv[1]) { /* no second arg */
7534 bb_error_msg("trap: invalid arguments");
7535 return EXIT_FAILURE;
7538 /* First arg is "-": reset all specified to default */
7539 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7540 /* Everything else: set arg as signal handler
7541 * (includes "" case, which ignores signal) */
7542 if (argv[0][0] == '-') {
7543 if (argv[0][1] == '\0') { /* "-" */
7544 /* new_cmd remains NULL: "reset these sigs" */
7547 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7550 /* else: "-something", no special meaning */
7555 goto process_sig_list;
7558 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7559 static int FAST_FUNC builtin_type(char **argv)
7561 int ret = EXIT_SUCCESS;
7567 if (0) {} /* make conditional compile easier below */
7568 /*else if (find_alias(*argv))
7569 type = "an alias";*/
7570 #if ENABLE_HUSH_FUNCTIONS
7571 else if (find_function(*argv))
7572 type = "a function";
7574 else if (find_builtin(*argv))
7575 type = "a shell builtin";
7576 else if ((path = find_in_path(*argv)) != NULL)
7579 bb_error_msg("type: %s: not found", *argv);
7584 printf("%s is %s\n", *argv, type);
7592 /* built-in 'fg' and 'bg' handler */
7593 static int FAST_FUNC builtin_fg_bg(char **argv)
7598 if (!G_interactive_fd)
7599 return EXIT_FAILURE;
7601 /* If they gave us no args, assume they want the last backgrounded task */
7603 for (pi = G.job_list; pi; pi = pi->next) {
7604 if (pi->jobid == G.last_jobid) {
7608 bb_error_msg("%s: no current job", argv[0]);
7609 return EXIT_FAILURE;
7611 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7612 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7613 return EXIT_FAILURE;
7615 for (pi = G.job_list; pi; pi = pi->next) {
7616 if (pi->jobid == jobnum) {
7620 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7621 return EXIT_FAILURE;
7623 /* TODO: bash prints a string representation
7624 * of job being foregrounded (like "sleep 1 | cat") */
7625 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7626 /* Put the job into the foreground. */
7627 tcsetpgrp(G_interactive_fd, pi->pgrp);
7630 /* Restart the processes in the job */
7631 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7632 for (i = 0; i < pi->num_cmds; i++) {
7633 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7634 pi->cmds[i].is_stopped = 0;
7636 pi->stopped_cmds = 0;
7638 i = kill(- pi->pgrp, SIGCONT);
7640 if (errno == ESRCH) {
7641 delete_finished_bg_job(pi);
7642 return EXIT_SUCCESS;
7644 bb_perror_msg("kill (SIGCONT)");
7647 if (argv[0][0] == 'f') {
7649 return checkjobs_and_fg_shell(pi);
7651 return EXIT_SUCCESS;
7655 #if ENABLE_HUSH_HELP
7656 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7658 const struct built_in_command *x;
7661 "Built-in commands:\n"
7662 "------------------\n");
7663 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7665 printf("%s\t%s\n", x->cmd, x->descr);
7668 return EXIT_SUCCESS;
7673 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7676 const char *status_string;
7678 for (job = G.job_list; job; job = job->next) {
7679 if (job->alive_cmds == job->stopped_cmds)
7680 status_string = "Stopped";
7682 status_string = "Running";
7684 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7686 return EXIT_SUCCESS;
7691 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7696 # ifdef M_TRIM_THRESHOLD
7697 /* Optional. Reduces probability of false positives */
7700 /* Crude attempt to find where "free memory" starts,
7701 * sans fragmentation. */
7703 l = (unsigned long)p;
7706 if (l < (unsigned long)p) l = (unsigned long)p;
7709 if (!G.memleak_value)
7710 G.memleak_value = l;
7712 l -= G.memleak_value;
7719 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7724 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7727 return EXIT_SUCCESS;
7730 static int FAST_FUNC builtin_read(char **argv)
7739 /* "!": do not abort on errors.
7740 * Option string must start with "sr" to match BUILTIN_READ_xxx
7742 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7743 if (read_flags == (uint32_t)-1)
7744 return EXIT_FAILURE;
7747 r = shell_builtin_read(set_local_var_from_halves,
7749 get_local_var_value("IFS"), /* can be NULL */
7757 if ((uintptr_t)r > 1) {
7758 bb_error_msg("%s", r);
7759 r = (char*)(uintptr_t)1;
7762 return (uintptr_t)r;
7765 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7766 * built-in 'set' handler
7768 * set [-abCefhmnuvx] [-o option] [argument...]
7769 * set [+abCefhmnuvx] [+o option] [argument...]
7770 * set -- [argument...]
7773 * Implementations shall support the options in both their hyphen and
7774 * plus-sign forms. These options can also be specified as options to sh.
7776 * Write out all variables and their values: set
7777 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7778 * Turn on the -x and -v options: set -xv
7779 * Unset all positional parameters: set --
7780 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7781 * Set the positional parameters to the expansion of x, even if x expands
7782 * with a leading '-' or '+': set -- $x
7784 * So far, we only support "set -- [argument...]" and some of the short names.
7786 static int FAST_FUNC builtin_set(char **argv)
7789 char **pp, **g_argv;
7790 char *arg = *++argv;
7794 for (e = G.top_var; e; e = e->next)
7796 return EXIT_SUCCESS;
7800 if (!strcmp(arg, "--")) {
7804 if (arg[0] != '+' && arg[0] != '-')
7806 for (n = 1; arg[n]; ++n)
7807 if (set_mode(arg[0], arg[n]))
7809 } while ((arg = *++argv) != NULL);
7810 /* Now argv[0] is 1st argument */
7813 return EXIT_SUCCESS;
7816 /* NB: G.global_argv[0] ($0) is never freed/changed */
7817 g_argv = G.global_argv;
7818 if (G.global_args_malloced) {
7824 G.global_args_malloced = 1;
7825 pp = xzalloc(sizeof(pp[0]) * 2);
7826 pp[0] = g_argv[0]; /* retain $0 */
7829 /* This realloc's G.global_argv */
7830 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7837 return EXIT_SUCCESS;
7839 /* Nothing known, so abort */
7841 bb_error_msg("set: %s: invalid option", arg);
7842 return EXIT_FAILURE;
7845 static int FAST_FUNC builtin_shift(char **argv)
7851 if (n >= 0 && n < G.global_argc) {
7852 if (G.global_args_malloced) {
7855 free(G.global_argv[m++]);
7858 memmove(&G.global_argv[1], &G.global_argv[n+1],
7859 G.global_argc * sizeof(G.global_argv[0]));
7860 return EXIT_SUCCESS;
7862 return EXIT_FAILURE;
7865 static int FAST_FUNC builtin_source(char **argv)
7870 #if ENABLE_HUSH_FUNCTIONS
7874 if (*++argv == NULL)
7875 return EXIT_FAILURE;
7877 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7878 input = fopen_for_read(arg_path);
7881 input = fopen_or_warn(*argv, "r");
7883 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7884 return EXIT_FAILURE;
7886 close_on_exec_on(fileno(input));
7888 #if ENABLE_HUSH_FUNCTIONS
7889 sv_flg = G.flag_return_in_progress;
7890 /* "we are inside sourced file, ok to use return" */
7891 G.flag_return_in_progress = -1;
7893 save_and_replace_G_args(&sv, argv);
7895 parse_and_run_file(input);
7898 restore_G_args(&sv, argv);
7899 #if ENABLE_HUSH_FUNCTIONS
7900 G.flag_return_in_progress = sv_flg;
7903 return G.last_exitcode;
7906 static int FAST_FUNC builtin_umask(char **argv)
7913 mode_t old_mask = mask;
7916 rc = bb_parse_mode(argv[1], &mask);
7921 * bash: umask: 'q': invalid symbolic mode operator
7922 * bash: umask: 999: octal number out of range
7924 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7929 printf("%04o\n", (unsigned) mask);
7930 /* fall through and restore mask which we set to 0 */
7934 return !rc; /* rc != 0 - success */
7937 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7938 static int FAST_FUNC builtin_unset(char **argv)
7943 /* "!": do not abort on errors */
7944 /* "+": stop at 1st non-option */
7945 opts = getopt32(argv, "!+vf");
7946 if (opts == (unsigned)-1)
7947 return EXIT_FAILURE;
7949 bb_error_msg("unset: -v and -f are exclusive");
7950 return EXIT_FAILURE;
7956 if (!(opts & 2)) { /* not -f */
7957 if (unset_local_var(*argv)) {
7958 /* unset <nonexistent_var> doesn't fail.
7959 * Error is when one tries to unset RO var.
7960 * Message was printed by unset_local_var. */
7964 #if ENABLE_HUSH_FUNCTIONS
7974 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7975 static int FAST_FUNC builtin_wait(char **argv)
7977 int ret = EXIT_SUCCESS;
7980 if (*++argv == NULL) {
7981 /* Don't care about wait results */
7982 /* Note 1: must wait until there are no more children */
7983 /* Note 2: must be interruptible */
7985 * $ sleep 3 & sleep 6 & wait
7990 * $ sleep 3 & sleep 6 & wait
7994 * ^C <-- after ~4 sec from keyboard
7997 sigaddset(&G.blocked_set, SIGCHLD);
7998 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8001 if (errno == ECHILD)
8003 /* Wait for SIGCHLD or any other signal of interest */
8004 /* sigtimedwait with infinite timeout: */
8005 sig = sigwaitinfo(&G.blocked_set, NULL);
8007 sig = check_and_run_traps(sig);
8008 if (sig && sig != SIGCHLD) { /* see note 2 */
8014 sigdelset(&G.blocked_set, SIGCHLD);
8015 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8019 /* This is probably buggy wrt interruptible-ness */
8021 pid_t pid = bb_strtou(*argv, NULL, 10);
8023 /* mimic bash message */
8024 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8025 return EXIT_FAILURE;
8027 if (waitpid(pid, &status, 0) == pid) {
8028 if (WIFSIGNALED(status))
8029 ret = 128 + WTERMSIG(status);
8030 else if (WIFEXITED(status))
8031 ret = WEXITSTATUS(status);
8035 bb_perror_msg("wait %s", *argv);
8044 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8045 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8048 def = bb_strtou(argv[1], NULL, 10);
8049 if (errno || def < def_min || argv[2]) {
8050 bb_error_msg("%s: bad arguments", argv[0]);
8058 #if ENABLE_HUSH_LOOPS
8059 static int FAST_FUNC builtin_break(char **argv)
8062 if (G.depth_of_loop == 0) {
8063 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8064 return EXIT_SUCCESS; /* bash compat */
8066 G.flag_break_continue++; /* BC_BREAK = 1 */
8068 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8069 if (depth == UINT_MAX)
8070 G.flag_break_continue = BC_BREAK;
8071 if (G.depth_of_loop < depth)
8072 G.depth_break_continue = G.depth_of_loop;
8074 return EXIT_SUCCESS;
8077 static int FAST_FUNC builtin_continue(char **argv)
8079 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8080 return builtin_break(argv);
8084 #if ENABLE_HUSH_FUNCTIONS
8085 static int FAST_FUNC builtin_return(char **argv)
8089 if (G.flag_return_in_progress != -1) {
8090 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8091 return EXIT_FAILURE; /* bash compat */
8094 G.flag_return_in_progress = 1;
8097 * out of range: wraps around at 256, does not error out
8098 * non-numeric param:
8099 * f() { false; return qwe; }; f; echo $?
8100 * bash: return: qwe: numeric argument required <== we do this
8101 * 255 <== we also do this
8103 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);