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)
60 * special variables (done: PWD)
61 * follow IFS rules more precisely, including update semantics
62 * export builtin should be special, its arguments are assignments
63 * and therefore expansion of them should be "one-word" expansion:
64 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
66 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
67 * ls: cannot access i=a: No such file or directory
68 * ls: cannot access b: No such file or directory
69 * Note1: same applies to local builtin.
70 * Note2: bash 3.2.33(1) does this only if export word itself
72 * $ export i=`echo 'aaa bbb'`; echo "$i"
74 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
77 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
79 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
80 #include <malloc.h> /* for malloc_trim */
82 /* #include <dmalloc.h> */
87 #include "shell_common.h"
88 #include "builtin_read.h"
89 #include "builtin_ulimit.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 (*b_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" , shell_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 /* Replace each \x with x in place, return ptr past NUL. */
897 static char *unbackslash(char *src)
899 char *dst = src = strchrnul(src, '\\');
903 if ((*dst++ = *src++) == '\0')
909 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
930 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
931 v[count1 + count2] = NULL;
934 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
938 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
940 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
941 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
944 #define add_strings_to_strings(strings, add, need_to_dup) \
945 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
948 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
949 static char **add_string_to_strings(char **strings, char *add)
954 return add_strings_to_strings(strings, v, /*dup:*/ 0);
957 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
959 char **ptr = add_string_to_strings(strings, add);
960 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
963 #define add_string_to_strings(strings, add) \
964 xx_add_string_to_strings(__LINE__, strings, add)
967 static void free_strings(char **strings)
982 /* Helpers for setting new $n and restoring them back
984 typedef struct save_arg_t {
988 smallint sv_g_malloced;
991 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
995 sv->sv_argv0 = argv[0];
996 sv->sv_g_argv = G.global_argv;
997 sv->sv_g_argc = G.global_argc;
998 sv->sv_g_malloced = G.global_args_malloced;
1000 argv[0] = G.global_argv[0]; /* retain $0 */
1001 G.global_argv = argv;
1002 G.global_args_malloced = 0;
1010 static void restore_G_args(save_arg_t *sv, char **argv)
1014 if (G.global_args_malloced) {
1015 /* someone ran "set -- arg1 arg2 ...", undo */
1017 while (*++pp) /* note: does not free $0 */
1019 free(G.global_argv);
1021 argv[0] = sv->sv_argv0;
1022 G.global_argv = sv->sv_g_argv;
1023 G.global_argc = sv->sv_g_argc;
1024 G.global_args_malloced = sv->sv_g_malloced;
1028 /* Basic theory of signal handling in shell
1029 * ========================================
1030 * This does not describe what hush does, rather, it is current understanding
1031 * what it _should_ do. If it doesn't, it's a bug.
1032 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1034 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1035 * is finished or backgrounded. It is the same in interactive and
1036 * non-interactive shells, and is the same regardless of whether
1037 * a user trap handler is installed or a shell special one is in effect.
1038 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1039 * backgrounds (i.e. stops) or kills all members of currently running
1042 * Wait builtin in interruptible by signals for which user trap is set
1043 * or by SIGINT in interactive shell.
1045 * Trap handlers will execute even within trap handlers. (right?)
1047 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1048 * except for handlers set to '' (empty string).
1050 * If job control is off, backgrounded commands ("cmd &")
1051 * have SIGINT, SIGQUIT set to SIG_IGN.
1053 * Commands which are run in command substitution ("`cmd`")
1054 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1056 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1057 * by the shell from its parent.
1059 * Signals which differ from SIG_DFL action
1060 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1063 * SIGTERM (interactive): ignore
1064 * SIGHUP (interactive):
1065 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1066 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1067 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1068 * that all pipe members are stopped. Try this in bash:
1069 * while :; do :; done - ^Z does not background it
1070 * (while :; do :; done) - ^Z backgrounds it
1071 * SIGINT (interactive): wait for last pipe, ignore the rest
1072 * of the command line, show prompt. NB: ^C does not send SIGINT
1073 * to interactive shell while shell is waiting for a pipe,
1074 * since shell is bg'ed (is not in foreground process group).
1075 * Example 1: this waits 5 sec, but does not execute ls:
1076 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1077 * Example 2: this does not wait and does not execute ls:
1078 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1079 * Example 3: this does not wait 5 sec, but executes ls:
1080 * "sleep 5; ls -l" + press ^C
1082 * (What happens to signals which are IGN on shell start?)
1083 * (What happens with signal mask on shell start?)
1085 * Implementation in hush
1086 * ======================
1087 * We use in-kernel pending signal mask to determine which signals were sent.
1088 * We block all signals which we don't want to take action immediately,
1089 * i.e. we block all signals which need to have special handling as described
1090 * above, and all signals which have traps set.
1091 * After each pipe execution, we extract any pending signals via sigtimedwait()
1094 * unsigned non_DFL_mask: a mask of such "special" signals
1095 * sigset_t blocked_set: current blocked signal set
1098 * clear bit in blocked_set unless it is also in non_DFL_mask
1099 * "trap 'cmd' SIGxxx":
1100 * set bit in blocked_set (even if 'cmd' is '')
1101 * after [v]fork, if we plan to be a shell:
1102 * unblock signals with special interactive handling
1103 * (child shell is not interactive),
1104 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1105 * after [v]fork, if we plan to exec:
1106 * POSIX says fork clears pending signal mask in child - no need to clear it.
1107 * Restore blocked signal set to one inherited by shell just prior to exec.
1109 * Note: as a result, we do not use signal handlers much. The only uses
1110 * are to count SIGCHLDs
1111 * and to restore tty pgrp on signal-induced exit.
1114 * Standard says "When a subshell is entered, traps that are not being ignored
1115 * are set to the default actions". bash interprets it so that traps which
1116 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1119 SPECIAL_INTERACTIVE_SIGS = 0
1124 SPECIAL_JOB_SIGS = 0
1132 #if ENABLE_HUSH_FAST
1133 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1136 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1142 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1143 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1144 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1145 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1147 /* Restores tty foreground process group, and exits.
1148 * May be called as signal handler for fatal signal
1149 * (will resend signal to itself, producing correct exit state)
1150 * or called directly with -EXITCODE.
1151 * We also call it if xfunc is exiting. */
1152 static void sigexit(int sig) NORETURN;
1153 static void sigexit(int sig)
1155 /* Disable all signals: job control, SIGPIPE, etc. */
1156 sigprocmask_allsigs(SIG_BLOCK);
1158 /* Careful: we can end up here after [v]fork. Do not restore
1159 * tty pgrp then, only top-level shell process does that */
1160 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1161 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1163 /* Not a signal, just exit */
1167 kill_myself_with_sig(sig); /* does not return */
1171 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1172 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1176 /* Restores tty foreground process group, and exits. */
1177 static void hush_exit(int exitcode) NORETURN;
1178 static void hush_exit(int exitcode)
1180 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1181 /* Prevent recursion:
1182 * trap "echo Hi; exit" EXIT; exit
1184 char *argv[] = { NULL, G.traps[0], NULL };
1193 sigexit(- (exitcode & 0xff));
1199 static int check_and_run_traps(int sig)
1201 static const struct timespec zero_timespec = { 0, 0 };
1202 smalluint save_rcode;
1208 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1213 if (G.traps && G.traps[sig]) {
1214 if (G.traps[sig][0]) {
1215 /* We have user-defined handler */
1216 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1217 save_rcode = G.last_exitcode;
1220 G.last_exitcode = save_rcode;
1221 } /* else: "" trap, ignoring signal */
1224 /* not a trap: special action */
1226 #if ENABLE_HUSH_FAST
1229 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1233 /* Builtin was ^C'ed, make it look prettier: */
1240 /* bash is observed to signal whole process groups,
1241 * not individual processes */
1242 for (job = G.job_list; job; job = job->next) {
1245 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1246 if (kill(- job->pgrp, SIGHUP) == 0)
1247 kill(- job->pgrp, SIGCONT);
1252 default: /* ignored: */
1253 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1261 static const char *get_cwd(int force)
1263 if (force || G.cwd == NULL) {
1264 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1265 * we must not try to free(bb_msg_unknown) */
1266 if (G.cwd == bb_msg_unknown)
1268 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1270 G.cwd = bb_msg_unknown;
1277 * Shell and environment variable support
1279 static struct variable **get_ptr_to_local_var(const char *name)
1281 struct variable **pp;
1282 struct variable *cur;
1287 while ((cur = *pp) != NULL) {
1288 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1295 static struct variable *get_local_var(const char *name)
1297 struct variable **pp = get_ptr_to_local_var(name);
1303 static const char* FAST_FUNC get_local_var_value(const char *name)
1305 struct variable **pp = get_ptr_to_local_var(name);
1307 return strchr((*pp)->varstr, '=') + 1;
1308 if (strcmp(name, "PPID") == 0)
1309 return utoa(G.root_ppid);
1310 // bash compat: UID? EUID?
1311 #if ENABLE_HUSH_RANDOM_SUPPORT
1312 if (strcmp(name, "RANDOM") == 0) {
1313 return utoa(next_random(&G.random_gen));
1319 /* str holds "NAME=VAL" and is expected to be malloced.
1320 * We take ownership of it.
1322 * 0: do not change export flag
1323 * (if creating new variable, flag will be 0)
1324 * 1: set export flag and putenv the variable
1325 * -1: clear export flag and unsetenv the variable
1326 * flg_read_only is set only when we handle -R var=val
1328 #if !BB_MMU && ENABLE_HUSH_LOCAL
1329 /* all params are used */
1330 #elif BB_MMU && ENABLE_HUSH_LOCAL
1331 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1332 set_local_var(str, flg_export, local_lvl)
1333 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1334 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1335 set_local_var(str, flg_export)
1336 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1337 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1338 set_local_var(str, flg_export, flg_read_only)
1340 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1342 struct variable **var_pp;
1343 struct variable *cur;
1347 eq_sign = strchr(str, '=');
1348 if (!eq_sign) { /* not expected to ever happen? */
1353 name_len = eq_sign - str + 1; /* including '=' */
1354 var_pp = &G.top_var;
1355 while ((cur = *var_pp) != NULL) {
1356 if (strncmp(cur->varstr, str, name_len) != 0) {
1357 var_pp = &cur->next;
1360 /* We found an existing var with this name */
1361 if (cur->flg_read_only) {
1365 bb_error_msg("%s: readonly variable", str);
1369 if (flg_export == -1) { // "&& cur->flg_export" ?
1370 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1375 #if ENABLE_HUSH_LOCAL
1376 if (cur->func_nest_level < local_lvl) {
1377 /* New variable is declared as local,
1378 * and existing one is global, or local
1379 * from enclosing function.
1380 * Remove and save old one: */
1381 *var_pp = cur->next;
1382 cur->next = *G.shadowed_vars_pp;
1383 *G.shadowed_vars_pp = cur;
1384 /* bash 3.2.33(1) and exported vars:
1386 * # f() { local z=a; env | grep ^z; }
1392 if (cur->flg_export)
1397 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1402 if (cur->max_len != 0) {
1403 if (cur->max_len >= strlen(str)) {
1404 /* This one is from startup env, reuse space */
1405 strcpy(cur->varstr, str);
1409 /* max_len == 0 signifies "malloced" var, which we can
1410 * (and has to) free */
1414 goto set_str_and_exp;
1417 /* Not found - create new variable struct */
1418 cur = xzalloc(sizeof(*cur));
1419 #if ENABLE_HUSH_LOCAL
1420 cur->func_nest_level = local_lvl;
1422 cur->next = *var_pp;
1428 cur->flg_read_only = flg_read_only;
1431 if (flg_export == 1)
1432 cur->flg_export = 1;
1433 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1434 cmdedit_update_prompt();
1435 if (cur->flg_export) {
1436 if (flg_export == -1) {
1437 cur->flg_export = 0;
1438 /* unsetenv was already done */
1440 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1441 return putenv(cur->varstr);
1447 /* Used at startup and after each cd */
1448 static void set_pwd_var(int exp)
1450 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1451 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1454 static int unset_local_var_len(const char *name, int name_len)
1456 struct variable *cur;
1457 struct variable **var_pp;
1460 return EXIT_SUCCESS;
1461 var_pp = &G.top_var;
1462 while ((cur = *var_pp) != NULL) {
1463 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1464 if (cur->flg_read_only) {
1465 bb_error_msg("%s: readonly variable", name);
1466 return EXIT_FAILURE;
1468 *var_pp = cur->next;
1469 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1470 bb_unsetenv(cur->varstr);
1471 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1472 cmdedit_update_prompt();
1476 return EXIT_SUCCESS;
1478 var_pp = &cur->next;
1480 return EXIT_SUCCESS;
1483 static int unset_local_var(const char *name)
1485 return unset_local_var_len(name, strlen(name));
1488 static void unset_vars(char **strings)
1496 const char *eq = strchrnul(*v, '=');
1497 unset_local_var_len(*v, (int)(eq - *v));
1503 #if ENABLE_SH_MATH_SUPPORT
1504 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1505 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1506 static char* FAST_FUNC endofname(const char *name)
1514 if (!is_in_name(*p))
1521 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1523 char *var = xasprintf("%s=%s", name, val);
1524 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1529 * Helpers for "var1=val1 var2=val2 cmd" feature
1531 static void add_vars(struct variable *var)
1533 struct variable *next;
1537 var->next = G.top_var;
1539 if (var->flg_export) {
1540 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1541 putenv(var->varstr);
1543 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1549 static struct variable *set_vars_and_save_old(char **strings)
1552 struct variable *old = NULL;
1558 struct variable *var_p;
1559 struct variable **var_pp;
1562 eq = strchr(*s, '=');
1565 var_pp = get_ptr_to_local_var(*s);
1568 /* Remove variable from global linked list */
1570 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1571 *var_pp = var_p->next;
1572 /* Add it to returned list */
1576 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1587 static int FAST_FUNC static_get(struct in_str *i)
1596 static int FAST_FUNC static_peek(struct in_str *i)
1601 #if ENABLE_HUSH_INTERACTIVE
1603 static void cmdedit_update_prompt(void)
1605 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1606 G.PS1 = get_local_var_value("PS1");
1609 G.PS2 = get_local_var_value("PS2");
1617 static const char* setup_prompt_string(int promptmode)
1619 const char *prompt_str;
1620 debug_printf("setup_prompt_string %d ", promptmode);
1621 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1622 /* Set up the prompt */
1623 if (promptmode == 0) { /* PS1 */
1625 /* bash uses $PWD value, even if it is set by user.
1626 * It uses current dir only if PWD is unset.
1627 * We always use current dir. */
1628 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1633 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1634 debug_printf("result '%s'\n", prompt_str);
1638 static void get_user_input(struct in_str *i)
1641 const char *prompt_str;
1643 prompt_str = setup_prompt_string(i->promptmode);
1644 #if ENABLE_FEATURE_EDITING
1645 /* Enable command line editing only while a command line
1646 * is actually being read */
1649 /* buglet: SIGINT will not make new prompt to appear _at once_,
1650 * only after <Enter>. (^C will work) */
1651 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1652 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1653 check_and_run_traps(0);
1654 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1655 i->eof_flag = (r < 0);
1656 if (i->eof_flag) { /* EOF/error detected */
1657 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1658 G.user_input_buf[1] = '\0';
1663 fputs(prompt_str, stdout);
1665 G.user_input_buf[0] = r = fgetc(i->file);
1666 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1667 //do we need check_and_run_traps(0)? (maybe only if stdin)
1668 } while (G.flag_SIGINT);
1669 i->eof_flag = (r == EOF);
1671 i->p = G.user_input_buf;
1674 #endif /* INTERACTIVE */
1676 /* This is the magic location that prints prompts
1677 * and gets data back from the user */
1678 static int FAST_FUNC file_get(struct in_str *i)
1682 /* If there is data waiting, eat it up */
1683 if (i->p && *i->p) {
1684 #if ENABLE_HUSH_INTERACTIVE
1688 if (i->eof_flag && !*i->p)
1690 /* note: ch is never NUL */
1692 /* need to double check i->file because we might be doing something
1693 * more complicated by now, like sourcing or substituting. */
1694 #if ENABLE_HUSH_INTERACTIVE
1695 if (G_interactive_fd && i->promptme && i->file == stdin) {
1698 } while (!*i->p); /* need non-empty line */
1699 i->promptmode = 1; /* PS2 */
1704 do ch = fgetc(i->file); while (ch == '\0');
1706 debug_printf("file_get: got '%c' %d\n", ch, ch);
1707 #if ENABLE_HUSH_INTERACTIVE
1714 /* All callers guarantee this routine will never
1715 * be used right after a newline, so prompting is not needed.
1717 static int FAST_FUNC file_peek(struct in_str *i)
1720 if (i->p && *i->p) {
1721 if (i->eof_flag && !i->p[1])
1724 /* note: ch is never NUL */
1726 do ch = fgetc(i->file); while (ch == '\0');
1727 i->eof_flag = (ch == EOF);
1728 i->peek_buf[0] = ch;
1729 i->peek_buf[1] = '\0';
1731 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1735 static void setup_file_in_str(struct in_str *i, FILE *f)
1737 i->peek = file_peek;
1739 #if ENABLE_HUSH_INTERACTIVE
1741 i->promptmode = 0; /* PS1 */
1747 static void setup_string_in_str(struct in_str *i, const char *s)
1749 i->peek = static_peek;
1750 i->get = static_get;
1751 #if ENABLE_HUSH_INTERACTIVE
1753 i->promptmode = 0; /* PS1 */
1763 #define B_CHUNK (32 * sizeof(char*))
1765 static void o_reset_to_empty_unquoted(o_string *o)
1773 static void o_free(o_string *o)
1776 memset(o, 0, sizeof(*o));
1779 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1784 static void o_grow_by(o_string *o, int len)
1786 if (o->length + len > o->maxlen) {
1787 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1788 o->data = xrealloc(o->data, 1 + o->maxlen);
1792 static void o_addchr(o_string *o, int ch)
1794 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1796 o->data[o->length] = ch;
1798 o->data[o->length] = '\0';
1801 static void o_addblock(o_string *o, const char *str, int len)
1804 memcpy(&o->data[o->length], str, len);
1806 o->data[o->length] = '\0';
1810 static void o_addstr(o_string *o, const char *str)
1812 o_addblock(o, str, strlen(str));
1814 static void nommu_addchr(o_string *o, int ch)
1820 # define nommu_addchr(o, str) ((void)0)
1823 static void o_addstr_with_NUL(o_string *o, const char *str)
1825 o_addblock(o, str, strlen(str) + 1);
1828 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1833 && (*str != '*' && *str != '?' && *str != '[')
1841 #undef HUSH_BRACE_EXP
1843 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1844 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1845 * Apparently, on unquoted $v bash still does globbing
1846 * ("v='*.txt'; echo $v" prints all .txt files),
1847 * but NOT brace expansion! Thus, there should be TWO independent
1848 * quoting mechanisms on $v expansion side: one protects
1849 * $v from brace expansion, and other additionally protects "$v" against globbing.
1850 * We have only second one.
1853 #ifdef HUSH_BRACE_EXP
1854 # define MAYBE_BRACES "{}"
1856 # define MAYBE_BRACES ""
1859 /* My analysis of quoting semantics tells me that state information
1860 * is associated with a destination, not a source.
1862 static void o_addqchr(o_string *o, int ch)
1865 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1870 o->data[o->length] = '\\';
1873 o->data[o->length] = ch;
1875 o->data[o->length] = '\0';
1878 static void o_addQchr(o_string *o, int ch)
1881 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1883 o->data[o->length] = '\\';
1887 o->data[o->length] = ch;
1889 o->data[o->length] = '\0';
1892 static void o_addQstr(o_string *o, const char *str, int len)
1895 o_addblock(o, str, len);
1901 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1902 if (ordinary_cnt > len) /* paranoia */
1904 o_addblock(o, str, ordinary_cnt);
1905 if (ordinary_cnt == len)
1907 str += ordinary_cnt;
1908 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1912 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1914 o->data[o->length] = '\\';
1918 o->data[o->length] = ch;
1920 o->data[o->length] = '\0';
1924 /* A special kind of o_string for $VAR and `cmd` expansion.
1925 * It contains char* list[] at the beginning, which is grown in 16 element
1926 * increments. Actual string data starts at the next multiple of 16 * (char*).
1927 * list[i] contains an INDEX (int!) into this string data.
1928 * It means that if list[] needs to grow, data needs to be moved higher up
1929 * but list[i]'s need not be modified.
1930 * NB: remembering how many list[i]'s you have there is crucial.
1931 * o_finalize_list() operation post-processes this structure - calculates
1932 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1934 #if DEBUG_EXPAND || DEBUG_GLOB
1935 static void debug_print_list(const char *prefix, o_string *o, int n)
1937 char **list = (char**)o->data;
1938 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1942 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1943 prefix, list, n, string_start, o->length, o->maxlen);
1946 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1947 o->data + (int)list[i] + string_start,
1948 o->data + (int)list[i] + string_start);
1952 const char *p = o->data + (int)list[n - 1] + string_start;
1954 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1958 # define debug_print_list(prefix, o, n) ((void)0)
1961 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1962 * in list[n] so that it points past last stored byte so far.
1963 * It returns n+1. */
1964 static int o_save_ptr_helper(o_string *o, int n)
1966 char **list = (char**)o->data;
1970 if (!o->has_empty_slot) {
1971 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1972 string_len = o->length - string_start;
1973 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1974 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1975 /* list[n] points to string_start, make space for 16 more pointers */
1976 o->maxlen += 0x10 * sizeof(list[0]);
1977 o->data = xrealloc(o->data, o->maxlen + 1);
1978 list = (char**)o->data;
1979 memmove(list + n + 0x10, list + n, string_len);
1980 o->length += 0x10 * sizeof(list[0]);
1982 debug_printf_list("list[%d]=%d string_start=%d\n",
1983 n, string_len, string_start);
1986 /* We have empty slot at list[n], reuse without growth */
1987 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1988 string_len = o->length - string_start;
1989 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1990 n, string_len, string_start);
1991 o->has_empty_slot = 0;
1993 list[n] = (char*)(ptrdiff_t)string_len;
1997 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1998 static int o_get_last_ptr(o_string *o, int n)
2000 char **list = (char**)o->data;
2001 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2003 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2006 #ifdef HUSH_BRACE_EXP
2007 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2008 * first, it processes even {a} (no commas), second,
2009 * I didn't manage to make it return strings when they don't match
2010 * existing files. Need to re-implement it.
2014 static int glob_needed(const char *s)
2023 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2029 /* Return pointer to next closing brace or to comma */
2030 static const char *next_brace_sub(const char *cp)
2034 while (*cp != '\0') {
2041 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2043 if (*cp++ == '{') /*}*/
2047 return *cp != '\0' ? cp : NULL;
2049 /* Recursive brace globber. Note: may garble pattern[]. */
2050 static int glob_brace(char *pattern, o_string *o, int n)
2052 char *new_pattern_buf;
2059 debug_printf_glob("glob_brace('%s')\n", pattern);
2065 if (*begin == '{') /*}*/ {
2066 /* Find the first sub-pattern and at the same time
2067 * find the rest after the closing brace */
2068 next = next_brace_sub(begin);
2070 /* An illegal expression */
2073 /*{*/ if (*next == '}') {
2074 /* "{abc}" with no commas - illegal
2075 * brace expr, disregard and skip it */
2081 if (*begin == '\\' && begin[1] != '\0')
2085 debug_printf_glob("begin:%s\n", begin);
2086 debug_printf_glob("next:%s\n", next);
2088 /* Now find the end of the whole brace expression */
2090 /*{*/ while (*rest != '}') {
2091 rest = next_brace_sub(rest);
2093 /* An illegal expression */
2096 debug_printf_glob("rest:%s\n", rest);
2098 rest_len = strlen(++rest) + 1;
2100 /* We are sure the brace expression is well-formed */
2102 /* Allocate working buffer large enough for our work */
2103 new_pattern_buf = xmalloc(strlen(pattern));
2105 /* We have a brace expression. BEGIN points to the opening {,
2106 * NEXT points past the terminator of the first element, and REST
2107 * points past the final }. We will accumulate result names from
2108 * recursive runs for each brace alternative in the buffer using
2113 /* Construct the new glob expression */
2116 mempcpy(new_pattern_buf,
2117 /* We know the prefix for all sub-patterns */
2118 pattern, begin - pattern),
2122 /* Note: glob_brace() may garble new_pattern_buf[].
2123 * That's why we re-copy prefix every time (1st memcpy above).
2125 n = glob_brace(new_pattern_buf, o, n);
2126 /*{*/ if (*next == '}') {
2127 /* We saw the last entry */
2131 next = next_brace_sub(next);
2133 free(new_pattern_buf);
2141 memset(&globdata, 0, sizeof(globdata));
2142 gr = glob(pattern, 0, NULL, &globdata);
2143 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2145 if (gr == GLOB_NOMATCH) {
2146 globfree(&globdata);
2147 /* NB: garbles parameter */
2148 unbackslash(pattern);
2149 o_addstr_with_NUL(o, pattern);
2150 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2151 return o_save_ptr_helper(o, n);
2153 if (gr == GLOB_NOSPACE)
2154 bb_error_msg_and_die(bb_msg_memory_exhausted);
2155 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2156 * but we didn't specify it. Paranoia again. */
2157 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2159 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2160 char **argv = globdata.gl_pathv;
2162 o_addstr_with_NUL(o, *argv);
2163 n = o_save_ptr_helper(o, n);
2169 globfree(&globdata);
2173 /* Performs globbing on last list[],
2174 * saving each result as a new list[].
2176 static int o_glob(o_string *o, int n)
2178 char *pattern, *copy;
2180 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2182 return o_save_ptr_helper(o, n);
2183 pattern = o->data + o_get_last_ptr(o, n);
2184 debug_printf_glob("glob pattern '%s'\n", pattern);
2185 if (!glob_needed(pattern)) {
2186 /* unbackslash last string in o in place, fix length */
2187 o->length = unbackslash(pattern) - o->data;
2188 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2189 return o_save_ptr_helper(o, n);
2192 copy = xstrdup(pattern);
2193 /* "forget" pattern in o */
2194 o->length = pattern - o->data;
2195 n = glob_brace(copy, o, n);
2198 debug_print_list("o_glob returning", o, n);
2205 static int glob_needed(const char *s)
2214 if (*s == '*' || *s == '[' || *s == '?')
2220 /* Performs globbing on last list[],
2221 * saving each result as a new list[].
2223 static int o_glob(o_string *o, int n)
2229 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2231 return o_save_ptr_helper(o, n);
2232 pattern = o->data + o_get_last_ptr(o, n);
2233 debug_printf_glob("glob pattern '%s'\n", pattern);
2234 if (!glob_needed(pattern)) {
2236 /* unbackslash last string in o in place, fix length */
2237 o->length = unbackslash(pattern) - o->data;
2238 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2239 return o_save_ptr_helper(o, n);
2242 memset(&globdata, 0, sizeof(globdata));
2243 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2244 * If we glob "*.\*" and don't find anything, we need
2245 * to fall back to using literal "*.*", but GLOB_NOCHECK
2246 * will return "*.\*"!
2248 gr = glob(pattern, 0, NULL, &globdata);
2249 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2251 if (gr == GLOB_NOMATCH) {
2252 globfree(&globdata);
2255 if (gr == GLOB_NOSPACE)
2256 bb_error_msg_and_die(bb_msg_memory_exhausted);
2257 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2258 * but we didn't specify it. Paranoia again. */
2259 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2261 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2262 char **argv = globdata.gl_pathv;
2263 /* "forget" pattern in o */
2264 o->length = pattern - o->data;
2266 o_addstr_with_NUL(o, *argv);
2267 n = o_save_ptr_helper(o, n);
2273 globfree(&globdata);
2275 debug_print_list("o_glob returning", o, n);
2281 /* If o->o_glob == 1, glob the string so far remembered.
2282 * Otherwise, just finish current list[] and start new */
2283 static int o_save_ptr(o_string *o, int n)
2285 if (o->o_glob) { /* if globbing is requested */
2286 /* If o->has_empty_slot, list[n] was already globbed
2287 * (if it was requested back then when it was filled)
2288 * so don't do that again! */
2289 if (!o->has_empty_slot)
2290 return o_glob(o, n); /* o_save_ptr_helper is inside */
2292 return o_save_ptr_helper(o, n);
2295 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2296 static char **o_finalize_list(o_string *o, int n)
2301 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2303 debug_print_list("finalized", o, n);
2304 debug_printf_expand("finalized n:%d\n", n);
2305 list = (char**)o->data;
2306 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2310 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2316 /* Expansion can recurse */
2317 #if ENABLE_HUSH_TICK
2318 static int process_command_subs(o_string *dest, const char *s);
2320 static char *expand_string_to_string(const char *str);
2322 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2323 parse_stream_dquoted(dest, input, dquote_end)
2325 static int parse_stream_dquoted(o_string *as_string,
2327 struct in_str *input,
2330 /* expand_strvec_to_strvec() takes a list of strings, expands
2331 * all variable references within and returns a pointer to
2332 * a list of expanded strings, possibly with larger number
2333 * of strings. (Think VAR="a b"; echo $VAR).
2334 * This new list is allocated as a single malloc block.
2335 * NULL-terminated list of char* pointers is at the beginning of it,
2336 * followed by strings themself.
2337 * Caller can deallocate entire list by single free(list). */
2339 /* Store given string, finalizing the word and starting new one whenever
2340 * we encounter IFS char(s). This is used for expanding variable values.
2341 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2342 static int expand_on_ifs(o_string *output, int n, const char *str)
2345 int word_len = strcspn(str, G.ifs);
2347 if (output->o_escape || !output->o_glob)
2348 o_addQstr(output, str, word_len);
2349 else /* protect backslashes against globbing up :) */
2350 o_addblock_duplicate_backslash(output, str, word_len);
2353 if (!*str) /* EOL - do not finalize word */
2355 o_addchr(output, '\0');
2356 debug_print_list("expand_on_ifs", output, n);
2357 n = o_save_ptr(output, n);
2358 str += strspn(str, G.ifs); /* skip ifs chars */
2360 debug_print_list("expand_on_ifs[1]", output, n);
2364 /* Helper to expand $((...)) and heredoc body. These act as if
2365 * they are in double quotes, with the exception that they are not :).
2366 * Just the rules are similar: "expand only $var and `cmd`"
2368 * Returns malloced string.
2369 * As an optimization, we return NULL if expansion is not needed.
2371 static char *expand_pseudo_dquoted(const char *str)
2374 struct in_str input;
2375 o_string dest = NULL_O_STRING;
2377 if (strchr(str, '$') == NULL
2378 #if ENABLE_HUSH_TICK
2379 && strchr(str, '`') == NULL
2385 /* We need to expand. Example:
2386 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2388 setup_string_in_str(&input, str);
2389 parse_stream_dquoted(NULL, &dest, &input, EOF);
2390 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2391 exp_str = expand_string_to_string(dest.data);
2392 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2393 o_free_unsafe(&dest);
2397 /* Expand all variable references in given string, adding words to list[]
2398 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2399 * to be filled). This routine is extremely tricky: has to deal with
2400 * variables/parameters with whitespace, $* and $@, and constructs like
2401 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2402 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2404 /* or_mask is either 0 (normal case) or 0x80 -
2405 * expansion of right-hand side of assignment == 1-element expand.
2406 * It will also do no globbing, and thus we must not backslash-quote!
2413 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2414 debug_print_list("expand_vars_to_list", output, n);
2415 n = o_save_ptr(output, n);
2416 debug_print_list("expand_vars_to_list[0]", output, n);
2418 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2421 char *dyn_val = NULL;
2422 const char *val = NULL;
2423 #if ENABLE_HUSH_TICK
2424 o_string subst_result = NULL_O_STRING;
2426 #if ENABLE_SH_MATH_SUPPORT
2427 char arith_buf[sizeof(arith_t)*3 + 2];
2429 o_addblock(output, arg, p - arg);
2430 debug_print_list("expand_vars_to_list[1]", output, n);
2432 p = strchr(p, SPECIAL_VAR_SYMBOL);
2434 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2435 /* "$@" is special. Even if quoted, it can still
2436 * expand to nothing (not even an empty string) */
2437 if ((first_ch & 0x7f) != '@')
2438 ored_ch |= first_ch;
2440 switch (first_ch & 0x7f) {
2441 /* Highest bit in first_ch indicates that var is double-quoted */
2443 val = utoa(G.root_pid);
2445 case '!': /* bg pid */
2446 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2448 case '?': /* exitcode */
2449 val = utoa(G.last_exitcode);
2451 case '#': /* argc */
2452 if (arg[1] != SPECIAL_VAR_SYMBOL)
2453 /* actually, it's a ${#var} */
2455 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2460 if (!G.global_argv[i])
2462 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2463 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2464 smallint sv = output->o_escape;
2465 /* unquoted var's contents should be globbed, so don't escape */
2466 output->o_escape = 0;
2467 while (G.global_argv[i]) {
2468 n = expand_on_ifs(output, n, G.global_argv[i]);
2469 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2470 if (G.global_argv[i++][0] && G.global_argv[i]) {
2471 /* this argv[] is not empty and not last:
2472 * put terminating NUL, start new word */
2473 o_addchr(output, '\0');
2474 debug_print_list("expand_vars_to_list[2]", output, n);
2475 n = o_save_ptr(output, n);
2476 debug_print_list("expand_vars_to_list[3]", output, n);
2479 output->o_escape = sv;
2481 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2482 * and in this case should treat it like '$*' - see 'else...' below */
2483 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2485 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2486 if (++i >= G.global_argc)
2488 o_addchr(output, '\0');
2489 debug_print_list("expand_vars_to_list[4]", output, n);
2490 n = o_save_ptr(output, n);
2492 } else { /* quoted $*: add as one word */
2494 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2495 if (!G.global_argv[++i])
2498 o_addchr(output, G.ifs[0]);
2502 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2503 /* "Empty variable", used to make "" etc to not disappear */
2507 #if ENABLE_HUSH_TICK
2508 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2511 /* Can't just stuff it into output o_string,
2512 * expanded result may need to be globbed
2513 * and $IFS-splitted */
2514 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2515 G.last_exitcode = process_command_subs(&subst_result, arg);
2516 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2517 val = subst_result.data;
2520 #if ENABLE_SH_MATH_SUPPORT
2521 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2522 arith_eval_hooks_t hooks;
2527 arg++; /* skip '+' */
2528 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2529 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2531 exp_str = expand_pseudo_dquoted(arg);
2532 hooks.lookupvar = get_local_var_value;
2533 hooks.setvar = set_local_var_from_halves;
2534 hooks.endofname = endofname;
2535 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2539 const char *msg = "error in arithmetic";
2542 msg = "exponent less than 0";
2545 msg = "divide by 0";
2548 msg = "expression recursion loop detected";
2553 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2554 sprintf(arith_buf, arith_t_fmt, res);
2559 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2561 bool exp_len = false;
2562 bool exp_null = false;
2564 char exp_save = exp_save; /* for compiler */
2565 char exp_op = exp_op; /* for compiler */
2566 char *exp_word = exp_word; /* for compiler */
2570 arg[0] = first_ch & 0x7f;
2572 /* prepare for expansions */
2573 if (var[0] == '#') {
2574 /* handle length expansion ${#var} */
2578 /* maybe handle parameter expansion */
2579 exp_off = strcspn(var, ":-=+?%#");
2583 exp_save = var[exp_off];
2584 exp_null = exp_save == ':';
2585 exp_word = var + exp_off;
2588 exp_op = *exp_word++;
2589 var[exp_off] = '\0';
2593 /* lookup the variable in question */
2594 if (isdigit(var[0])) {
2595 /* handle_dollar() should have vetted var for us */
2597 if (i < G.global_argc)
2598 val = G.global_argv[i];
2599 /* else val remains NULL: $N with too big N */
2601 val = get_local_var_value(var);
2603 /* handle any expansions */
2605 debug_printf_expand("expand: length of '%s' = ", val);
2606 val = utoa(val ? strlen(val) : 0);
2607 debug_printf_expand("%s\n", val);
2608 } else if (exp_off) {
2609 if (exp_op == '%' || exp_op == '#') {
2611 /* we need to do a pattern match */
2614 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2615 if (exp_op == *exp_word) /* ## or %% */
2617 val = dyn_val = xstrdup(val);
2618 loc = scan(dyn_val, exp_word, match_at_left);
2619 if (match_at_left) /* # or ## */
2621 else if (loc) /* % or %% and match was found */
2625 /* we need to do an expansion */
2626 int exp_test = (!val || (exp_null && !val[0]));
2628 exp_test = !exp_test;
2629 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2630 exp_null ? "true" : "false", exp_test);
2632 if (exp_op == '?') {
2633 //TODO: how interactive bash aborts expansion mid-command?
2634 /* ${var?[error_msg_if_unset]} */
2635 /* ${var:?[error_msg_if_unset_or_null]} */
2636 /* mimic bash message */
2637 die_if_script("%s: %s",
2639 exp_word[0] ? exp_word : "parameter null or not set"
2645 if (exp_op == '=') {
2646 /* ${var=[word]} or ${var:=[word]} */
2647 if (isdigit(var[0]) || var[0] == '#') {
2648 /* mimic bash message */
2649 die_if_script("$%s: cannot assign in this way", var);
2652 char *new_var = xasprintf("%s=%s", var, val);
2653 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2659 var[exp_off] = exp_save;
2663 #if ENABLE_HUSH_TICK
2666 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2667 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2669 /* unquoted var's contents should be globbed, so don't escape */
2670 smallint sv = output->o_escape;
2671 output->o_escape = 0;
2672 n = expand_on_ifs(output, n, val);
2674 output->o_escape = sv;
2676 } else { /* quoted $VAR, val will be appended below */
2677 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2680 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2683 o_addQstr(output, val, strlen(val));
2686 /* Do the check to avoid writing to a const string */
2687 if (*p != SPECIAL_VAR_SYMBOL)
2688 *p = SPECIAL_VAR_SYMBOL;
2690 #if ENABLE_HUSH_TICK
2691 o_free(&subst_result);
2694 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2697 debug_print_list("expand_vars_to_list[a]", output, n);
2698 /* this part is literal, and it was already pre-quoted
2699 * if needed (much earlier), do not use o_addQstr here! */
2700 o_addstr_with_NUL(output, arg);
2701 debug_print_list("expand_vars_to_list[b]", output, n);
2702 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2703 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2706 /* allow to reuse list[n] later without re-growth */
2707 output->has_empty_slot = 1;
2709 o_addchr(output, '\0');
2714 static char **expand_variables(char **argv, int or_mask)
2719 o_string output = NULL_O_STRING;
2721 if (or_mask & 0x100) {
2722 output.o_escape = 1; /* protect against globbing for "$var" */
2723 /* (unquoted $var will temporarily switch it off) */
2730 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2733 debug_print_list("expand_variables", &output, n);
2735 /* output.data (malloced in one block) gets returned in "list" */
2736 list = o_finalize_list(&output, n);
2737 debug_print_strings("expand_variables[1]", list);
2741 static char **expand_strvec_to_strvec(char **argv)
2743 return expand_variables(argv, 0x100);
2746 #if ENABLE_HUSH_BASH_COMPAT
2747 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2749 return expand_variables(argv, 0x80);
2753 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2754 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2759 o_string output = NULL_O_STRING;
2764 int is_var = is_well_formed_var_name(*v, '=');
2765 /* is_var * 0x80: singleword expansion for vars */
2766 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2768 /* Subtle! expand_vars_to_list did not glob last word yet.
2769 * It does this only when fed with further data.
2770 * Therefore we set globbing flags AFTER it, not before:
2773 /* if it is not recognizably abc=...; then: */
2774 output.o_escape = !is_var; /* protect against globbing for "$var" */
2775 /* (unquoted $var will temporarily switch it off) */
2776 output.o_glob = !is_var; /* and indeed do globbing */
2779 debug_print_list("expand_cond", &output, n);
2781 /* output.data (malloced in one block) gets returned in "list" */
2782 list = o_finalize_list(&output, n);
2783 debug_print_strings("expand_cond[1]", list);
2788 /* Used for expansion of right hand of assignments */
2789 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2791 static char *expand_string_to_string(const char *str)
2793 char *argv[2], **list;
2795 argv[0] = (char*)str;
2797 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2799 if (!list[0] || list[1])
2800 bb_error_msg_and_die("BUG in varexp2");
2801 /* actually, just move string 2*sizeof(char*) bytes back */
2802 overlapping_strcpy((char*)list, list[0]);
2803 unbackslash((char*)list);
2804 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2808 /* Used for "eval" builtin */
2809 static char* expand_strvec_to_string(char **argv)
2813 list = expand_variables(argv, 0x80);
2814 /* Convert all NULs to spaces */
2819 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2820 bb_error_msg_and_die("BUG in varexp3");
2821 /* bash uses ' ' regardless of $IFS contents */
2826 overlapping_strcpy((char*)list, list[0]);
2827 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2831 static char **expand_assignments(char **argv, int count)
2835 /* Expand assignments into one string each */
2836 for (i = 0; i < count; i++) {
2837 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2845 void re_execute_shell(char ***to_free, const char *s,
2846 char *g_argv0, char **g_argv,
2847 char **builtin_argv) NORETURN;
2849 static void reset_traps_to_defaults(void)
2851 /* This function is always called in a child shell
2852 * after fork (not vfork, NOMMU doesn't use this function).
2857 /* Child shells are not interactive.
2858 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2859 * Testcase: (while :; do :; done) + ^Z should background.
2860 * Same goes for SIGTERM, SIGHUP, SIGINT.
2862 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2863 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2865 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2866 * Stupid. It can be done with *single* &= op, but we can't use
2867 * the fact that G.blocked_set is implemented as a bitmask
2869 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2873 /* Careful. Only if no trap or trap is not "" */
2874 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2875 sigdelset(&G.blocked_set, sig);
2882 /* Our homegrown sig mask is saner to work with :) */
2883 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2885 /* Resetting all traps to default except empty ones */
2886 mask = G.non_DFL_mask;
2887 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2888 if (!G.traps[sig] || !G.traps[sig][0])
2891 G.traps[sig] = NULL;
2892 /* There is no signal for 0 (EXIT) */
2895 /* There was a trap handler, we just removed it.
2896 * But if sig still has non-DFL handling,
2897 * we should not unblock the sig. */
2900 sigdelset(&G.blocked_set, sig);
2902 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2907 static void re_execute_shell(char ***to_free, const char *s,
2908 char *g_argv0, char **g_argv,
2909 char **builtin_argv) NORETURN;
2910 static void re_execute_shell(char ***to_free, const char *s,
2911 char *g_argv0, char **g_argv,
2912 char **builtin_argv)
2914 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2915 /* delims + 2 * (number of bytes in printed hex numbers) */
2916 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2917 char *heredoc_argv[4];
2918 struct variable *cur;
2919 # if ENABLE_HUSH_FUNCTIONS
2920 struct function *funcp;
2924 unsigned long long empty_trap_mask;
2926 if (!g_argv0) { /* heredoc */
2927 argv = heredoc_argv;
2928 argv[0] = (char *) G.argv0_for_re_execing;
2929 argv[1] = (char *) "-<";
2930 argv[2] = (char *) s;
2932 pp = &argv[3]; /* used as pointer to empty environment */
2938 if (pp) while (*pp++)
2941 empty_trap_mask = 0;
2944 for (sig = 1; sig < NSIG; sig++) {
2945 if (G.traps[sig] && !G.traps[sig][0])
2946 empty_trap_mask |= 1LL << sig;
2950 sprintf(param_buf, NOMMU_HACK_FMT
2951 , (unsigned) G.root_pid
2952 , (unsigned) G.root_ppid
2953 , (unsigned) G.last_bg_pid
2954 , (unsigned) G.last_exitcode
2957 IF_HUSH_LOOPS(, G.depth_of_loop)
2959 #undef NOMMU_HACK_FMT
2960 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
2961 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2964 for (cur = G.top_var; cur; cur = cur->next) {
2965 if (!cur->flg_export || cur->flg_read_only)
2968 # if ENABLE_HUSH_FUNCTIONS
2969 for (funcp = G.top_func; funcp; funcp = funcp->next)
2975 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2976 *pp++ = (char *) G.argv0_for_re_execing;
2978 for (cur = G.top_var; cur; cur = cur->next) {
2979 if (cur->varstr == hush_version_str)
2981 if (cur->flg_read_only) {
2982 *pp++ = (char *) "-R";
2983 *pp++ = cur->varstr;
2984 } else if (!cur->flg_export) {
2985 *pp++ = (char *) "-V";
2986 *pp++ = cur->varstr;
2989 # if ENABLE_HUSH_FUNCTIONS
2990 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2991 *pp++ = (char *) "-F";
2992 *pp++ = funcp->name;
2993 *pp++ = funcp->body_as_string;
2996 /* We can pass activated traps here. Say, -Tnn:trap_string
2998 * However, POSIX says that subshells reset signals with traps
3000 * I tested bash-3.2 and it not only does that with true subshells
3001 * of the form ( list ), but with any forked children shells.
3002 * I set trap "echo W" WINCH; and then tried:
3004 * { echo 1; sleep 20; echo 2; } &
3005 * while true; do echo 1; sleep 20; echo 2; break; done &
3006 * true | { echo 1; sleep 20; echo 2; } | cat
3008 * In all these cases sending SIGWINCH to the child shell
3009 * did not run the trap. If I add trap "echo V" WINCH;
3010 * _inside_ group (just before echo 1), it works.
3012 * I conclude it means we don't need to pass active traps here.
3013 * Even if we would use signal handlers instead of signal masking
3014 * in order to implement trap handling,
3015 * exec syscall below resets signals to SIG_DFL for us.
3017 *pp++ = (char *) "-c";
3020 while (*++builtin_argv)
3021 *pp++ = *builtin_argv;
3022 *pp++ = (char *) "";
3027 /* *pp = NULL; - is already there */
3031 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3032 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3033 execve(bb_busybox_exec_path, argv, pp);
3034 /* Fallback. Useful for init=/bin/hush usage etc */
3035 if (argv[0][0] == '/')
3036 execve(argv[0], argv, pp);
3037 xfunc_error_retval = 127;
3038 bb_error_msg_and_die("can't re-execute the shell");
3040 #endif /* !BB_MMU */
3043 static void setup_heredoc(struct redir_struct *redir)
3045 struct fd_pair pair;
3048 /* the _body_ of heredoc (misleading field name) */
3049 const char *heredoc = redir->rd_filename;
3056 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3057 expanded = expand_pseudo_dquoted(heredoc);
3061 len = strlen(heredoc);
3063 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3065 xmove_fd(pair.rd, redir->rd_fd);
3067 /* Try writing without forking. Newer kernels have
3068 * dynamically growing pipes. Must use non-blocking write! */
3071 written = write(pair.wr, heredoc, len);
3082 ndelay_off(pair.wr);
3084 /* Okay, pipe buffer was not big enough */
3085 /* Note: we must not create a stray child (bastard? :)
3086 * for the unsuspecting parent process. Child creates a grandchild
3087 * and exits before parent execs the process which consumes heredoc
3088 * (that exec happens after we return from this function) */
3094 bb_perror_msg_and_die("vfork");
3097 disable_restore_tty_pgrp_on_exit();
3098 pid = BB_MMU ? fork() : vfork();
3100 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3104 close(redir->rd_fd); /* read side of the pipe */
3106 full_write(pair.wr, heredoc, len); /* may loop or block */
3109 /* Delegate blocking writes to another process */
3110 xmove_fd(pair.wr, STDOUT_FILENO);
3111 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3115 #if ENABLE_HUSH_FAST
3117 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3119 enable_restore_tty_pgrp_on_exit();
3125 wait(NULL); /* wait till child has died */
3128 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3129 * and stderr if they are redirected. */
3130 static int setup_redirects(struct command *prog, int squirrel[])
3133 struct redir_struct *redir;
3135 for (redir = prog->redirects; redir; redir = redir->next) {
3136 if (redir->rd_type == REDIRECT_HEREDOC2) {
3137 /* rd_fd<<HERE case */
3138 if (squirrel && redir->rd_fd < 3
3139 && squirrel[redir->rd_fd] < 0
3141 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3143 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3145 debug_printf_parse("set heredoc '%s'\n",
3146 redir->rd_filename);
3147 setup_heredoc(redir);
3151 if (redir->rd_dup == REDIRFD_TO_FILE) {
3152 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3154 if (redir->rd_filename == NULL) {
3155 /* Something went wrong in the parse.
3156 * Pretend it didn't happen */
3157 bb_error_msg("bug in redirect parse");
3160 mode = redir_table[redir->rd_type].mode;
3161 p = expand_string_to_string(redir->rd_filename);
3162 openfd = open_or_warn(p, mode);
3165 /* this could get lost if stderr has been redirected, but
3166 * bash and ash both lose it as well (though zsh doesn't!) */
3167 //what the above comment tries to say?
3171 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3172 openfd = redir->rd_dup;
3175 if (openfd != redir->rd_fd) {
3176 if (squirrel && redir->rd_fd < 3
3177 && squirrel[redir->rd_fd] < 0
3179 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3181 if (openfd == REDIRFD_CLOSE) {
3182 /* "n>-" means "close me" */
3183 close(redir->rd_fd);
3185 xdup2(openfd, redir->rd_fd);
3186 if (redir->rd_dup == REDIRFD_TO_FILE)
3194 static void restore_redirects(int squirrel[])
3197 for (i = 0; i < 3; i++) {
3200 /* We simply die on error */
3207 static void free_pipe_list(struct pipe *head);
3209 /* Return code is the exit status of the pipe */
3210 static void free_pipe(struct pipe *pi)
3213 struct command *command;
3214 struct redir_struct *r, *rnext;
3217 if (pi->stopped_cmds > 0) /* why? */
3219 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3220 for (i = 0; i < pi->num_cmds; i++) {
3221 command = &pi->cmds[i];
3222 debug_printf_clean(" command %d:\n", i);
3223 if (command->argv) {
3224 for (a = 0, p = command->argv; *p; a++, p++) {
3225 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3227 free_strings(command->argv);
3228 command->argv = NULL;
3230 /* not "else if": on syntax error, we may have both! */
3231 if (command->group) {
3232 debug_printf_clean(" begin group (cmd_type:%d)\n",
3234 free_pipe_list(command->group);
3235 debug_printf_clean(" end group\n");
3236 command->group = NULL;
3238 /* else is crucial here.
3239 * If group != NULL, child_func is meaningless */
3240 #if ENABLE_HUSH_FUNCTIONS
3241 else if (command->child_func) {
3242 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3243 command->child_func->parent_cmd = NULL;
3247 free(command->group_as_string);
3248 command->group_as_string = NULL;
3250 for (r = command->redirects; r; r = rnext) {
3251 debug_printf_clean(" redirect %d%s",
3252 r->rd_fd, redir_table[r->rd_type].descrip);
3253 /* guard against the case >$FOO, where foo is unset or blank */
3254 if (r->rd_filename) {
3255 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3256 free(r->rd_filename);
3257 r->rd_filename = NULL;
3259 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3263 command->redirects = NULL;
3265 free(pi->cmds); /* children are an array, they get freed all at once */
3273 static void free_pipe_list(struct pipe *head)
3275 struct pipe *pi, *next;
3277 for (pi = head; pi; pi = next) {
3279 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3282 debug_printf_clean("pipe followup code %d\n", pi->followup);
3284 /*pi->next = NULL;*/
3290 static int run_list(struct pipe *pi);
3292 #define parse_stream(pstring, input, end_trigger) \
3293 parse_stream(input, end_trigger)
3295 static struct pipe *parse_stream(char **pstring,
3296 struct in_str *input,
3298 static void parse_and_run_string(const char *s);
3301 static char *find_in_path(const char *arg)
3304 const char *PATH = get_local_var_value("PATH");
3310 const char *end = strchrnul(PATH, ':');
3311 int sz = end - PATH; /* must be int! */
3315 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3317 /* We have xxx::yyyy in $PATH,
3318 * it means "use current dir" */
3321 if (access(ret, F_OK) == 0)
3334 static const struct built_in_command* find_builtin_helper(const char *name,
3335 const struct built_in_command *x,
3336 const struct built_in_command *end)
3339 if (strcmp(name, x->b_cmd) != 0) {
3343 debug_printf_exec("found builtin '%s'\n", name);
3348 static const struct built_in_command* find_builtin1(const char *name)
3350 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3352 static const struct built_in_command* find_builtin(const char *name)
3354 const struct built_in_command *x = find_builtin1(name);
3357 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3360 #if ENABLE_HUSH_FUNCTIONS
3361 static struct function **find_function_slot(const char *name)
3363 struct function **funcpp = &G.top_func;
3365 if (strcmp(name, (*funcpp)->name) == 0) {
3368 funcpp = &(*funcpp)->next;
3373 static const struct function *find_function(const char *name)
3375 const struct function *funcp = *find_function_slot(name);
3377 debug_printf_exec("found function '%s'\n", name);
3381 /* Note: takes ownership on name ptr */
3382 static struct function *new_function(char *name)
3384 struct function **funcpp = find_function_slot(name);
3385 struct function *funcp = *funcpp;
3387 if (funcp != NULL) {
3388 struct command *cmd = funcp->parent_cmd;
3389 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3391 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3393 /* Note: if !funcp->body, do not free body_as_string!
3394 * This is a special case of "-F name body" function:
3395 * body_as_string was not malloced! */
3397 free_pipe_list(funcp->body);
3399 free(funcp->body_as_string);
3403 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3404 cmd->argv[0] = funcp->name;
3405 cmd->group = funcp->body;
3407 cmd->group_as_string = funcp->body_as_string;
3411 debug_printf_exec("remembering new function '%s'\n", name);
3412 funcp = *funcpp = xzalloc(sizeof(*funcp));
3413 /*funcp->next = NULL;*/
3420 static void unset_func(const char *name)
3422 struct function **funcpp = find_function_slot(name);
3423 struct function *funcp = *funcpp;
3425 if (funcp != NULL) {
3426 debug_printf_exec("freeing function '%s'\n", funcp->name);
3427 *funcpp = funcp->next;
3428 /* funcp is unlinked now, deleting it.
3429 * Note: if !funcp->body, the function was created by
3430 * "-F name body", do not free ->body_as_string
3431 * and ->name as they were not malloced. */
3433 free_pipe_list(funcp->body);
3436 free(funcp->body_as_string);
3444 #define exec_function(to_free, funcp, argv) \
3445 exec_function(funcp, argv)
3447 static void exec_function(char ***to_free,
3448 const struct function *funcp,
3449 char **argv) NORETURN;
3450 static void exec_function(char ***to_free,
3451 const struct function *funcp,
3457 argv[0] = G.global_argv[0];
3458 G.global_argv = argv;
3462 /* On MMU, funcp->body is always non-NULL */
3463 n = run_list(funcp->body);
3467 re_execute_shell(to_free,
3468 funcp->body_as_string,
3475 static int run_function(const struct function *funcp, char **argv)
3481 save_and_replace_G_args(&sv, argv);
3483 /* "we are in function, ok to use return" */
3484 sv_flg = G.flag_return_in_progress;
3485 G.flag_return_in_progress = -1;
3486 # if ENABLE_HUSH_LOCAL
3487 G.func_nest_level++;
3490 /* On MMU, funcp->body is always non-NULL */
3493 /* Function defined by -F */
3494 parse_and_run_string(funcp->body_as_string);
3495 rc = G.last_exitcode;
3499 rc = run_list(funcp->body);
3502 # if ENABLE_HUSH_LOCAL
3504 struct variable *var;
3505 struct variable **var_pp;
3507 var_pp = &G.top_var;
3508 while ((var = *var_pp) != NULL) {
3509 if (var->func_nest_level < G.func_nest_level) {
3510 var_pp = &var->next;
3514 if (var->flg_export)
3515 bb_unsetenv(var->varstr);
3516 /* Remove from global list */
3517 *var_pp = var->next;
3523 G.func_nest_level--;
3526 G.flag_return_in_progress = sv_flg;
3528 restore_G_args(&sv, argv);
3532 #endif /* ENABLE_HUSH_FUNCTIONS */
3536 #define exec_builtin(to_free, x, argv) \
3537 exec_builtin(x, argv)
3539 #define exec_builtin(to_free, x, argv) \
3540 exec_builtin(to_free, argv)
3542 static void exec_builtin(char ***to_free,
3543 const struct built_in_command *x,
3544 char **argv) NORETURN;
3545 static void exec_builtin(char ***to_free,
3546 const struct built_in_command *x,
3550 int rcode = x->b_function(argv);
3554 /* On NOMMU, we must never block!
3555 * Example: { sleep 99 | read line; } & echo Ok
3557 re_execute_shell(to_free,
3566 static void execvp_or_die(char **argv) NORETURN;
3567 static void execvp_or_die(char **argv)
3569 debug_printf_exec("execing '%s'\n", argv[0]);
3570 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3571 execvp(argv[0], argv);
3572 bb_perror_msg("can't execute '%s'", argv[0]);
3573 _exit(127); /* bash compat */
3577 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3578 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3579 #define pseudo_exec(nommu_save, command, argv_expanded) \
3580 pseudo_exec(command, argv_expanded)
3583 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3585 * Don't exit() here. If you don't exec, use _exit instead.
3586 * The at_exit handlers apparently confuse the calling process,
3587 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3588 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3589 char **argv, int assignment_cnt,
3590 char **argv_expanded) NORETURN;
3591 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3592 char **argv, int assignment_cnt,
3593 char **argv_expanded)
3597 /* Case when we are here: ... | var=val | ... */
3598 if (!argv[assignment_cnt])
3599 _exit(EXIT_SUCCESS);
3601 new_env = expand_assignments(argv, assignment_cnt);
3603 set_vars_and_save_old(new_env);
3604 free(new_env); /* optional */
3605 /* we can also destroy set_vars_and_save_old's return value,
3608 nommu_save->new_env = new_env;
3609 nommu_save->old_vars = set_vars_and_save_old(new_env);
3611 if (argv_expanded) {
3612 argv = argv_expanded;
3614 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3616 nommu_save->argv = argv;
3620 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3621 if (strchr(argv[0], '/') != NULL)
3625 /* Check if the command matches any of the builtins.
3626 * Depending on context, this might be redundant. But it's
3627 * easier to waste a few CPU cycles than it is to figure out
3628 * if this is one of those cases.
3631 /* On NOMMU, it is more expensive to re-execute shell
3632 * just in order to run echo or test builtin.
3633 * It's better to skip it here and run corresponding
3634 * non-builtin later. */
3635 const struct built_in_command *x;
3636 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3638 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3641 #if ENABLE_HUSH_FUNCTIONS
3642 /* Check if the command matches any functions */
3644 const struct function *funcp = find_function(argv[0]);
3646 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3651 #if ENABLE_FEATURE_SH_STANDALONE
3652 /* Check if the command matches any busybox applets */
3654 int a = find_applet_by_name(argv[0]);
3656 # if BB_MMU /* see above why on NOMMU it is not allowed */
3657 if (APPLET_IS_NOEXEC(a)) {
3658 debug_printf_exec("running applet '%s'\n", argv[0]);
3659 run_applet_no_and_exit(a, argv);
3662 /* Re-exec ourselves */
3663 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3664 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3665 execv(bb_busybox_exec_path, argv);
3666 /* If they called chroot or otherwise made the binary no longer
3667 * executable, fall through */
3672 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3675 execvp_or_die(argv);
3678 /* Called after [v]fork() in run_pipe
3680 static void pseudo_exec(nommu_save_t *nommu_save,
3681 struct command *command,
3682 char **argv_expanded) NORETURN;
3683 static void pseudo_exec(nommu_save_t *nommu_save,
3684 struct command *command,
3685 char **argv_expanded)
3687 if (command->argv) {
3688 pseudo_exec_argv(nommu_save, command->argv,
3689 command->assignment_cnt, argv_expanded);
3692 if (command->group) {
3693 /* Cases when we are here:
3696 * ... | ( list ) | ...
3697 * ... | { list } | ...
3701 debug_printf_exec("pseudo_exec: run_list\n");
3702 reset_traps_to_defaults();
3703 rcode = run_list(command->group);
3704 /* OK to leak memory by not calling free_pipe_list,
3705 * since this process is about to exit */
3708 re_execute_shell(&nommu_save->argv_from_re_execing,
3709 command->group_as_string,
3716 /* Case when we are here: ... | >file */
3717 debug_printf_exec("pseudo_exec'ed null command\n");
3718 _exit(EXIT_SUCCESS);
3722 static const char *get_cmdtext(struct pipe *pi)
3728 /* This is subtle. ->cmdtext is created only on first backgrounding.
3729 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3730 * On subsequent bg argv is trashed, but we won't use it */
3733 argv = pi->cmds[0].argv;
3734 if (!argv || !argv[0]) {
3735 pi->cmdtext = xzalloc(1);
3741 len += strlen(*argv) + 1;
3745 argv = pi->cmds[0].argv;
3747 len = strlen(*argv);
3748 memcpy(p, *argv, len);
3756 static void insert_bg_job(struct pipe *pi)
3758 struct pipe *job, **jobp;
3761 /* Linear search for the ID of the job to use */
3763 for (job = G.job_list; job; job = job->next)
3764 if (job->jobid >= pi->jobid)
3765 pi->jobid = job->jobid + 1;
3767 /* Add job to the list of running jobs */
3769 while ((job = *jobp) != NULL)
3771 job = *jobp = xmalloc(sizeof(*job));
3773 *job = *pi; /* physical copy */
3775 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3776 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3777 for (i = 0; i < pi->num_cmds; i++) {
3778 job->cmds[i].pid = pi->cmds[i].pid;
3779 /* all other fields are not used and stay zero */
3781 job->cmdtext = xstrdup(get_cmdtext(pi));
3783 if (G_interactive_fd)
3784 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3785 /* Last command's pid goes to $! */
3786 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3787 G.last_jobid = job->jobid;
3790 static void remove_bg_job(struct pipe *pi)
3792 struct pipe *prev_pipe;
3794 if (pi == G.job_list) {
3795 G.job_list = pi->next;
3797 prev_pipe = G.job_list;
3798 while (prev_pipe->next != pi)
3799 prev_pipe = prev_pipe->next;
3800 prev_pipe->next = pi->next;
3803 G.last_jobid = G.job_list->jobid;
3808 /* Remove a backgrounded job */
3809 static void delete_finished_bg_job(struct pipe *pi)
3812 pi->stopped_cmds = 0;
3818 /* Check to see if any processes have exited -- if they
3819 * have, figure out why and see if a job has completed */
3820 static int checkjobs(struct pipe* fg_pipe)
3830 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3832 attributes = WUNTRACED;
3833 if (fg_pipe == NULL)
3834 attributes |= WNOHANG;
3837 #if ENABLE_HUSH_FAST
3838 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3839 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3840 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3841 /* There was neither fork nor SIGCHLD since last waitpid */
3842 /* Avoid doing waitpid syscall if possible */
3843 if (!G.we_have_children) {
3847 if (fg_pipe == NULL) { /* is WNOHANG set? */
3848 /* We have children, but they did not exit
3849 * or stop yet (we saw no SIGCHLD) */
3852 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3856 /* Do we do this right?
3857 * bash-3.00# sleep 20 | false
3859 * [3]+ Stopped sleep 20 | false
3860 * bash-3.00# echo $?
3861 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3862 * [hush 1.14.0: yes we do it right]
3869 #if ENABLE_HUSH_FAST
3870 i = G.count_SIGCHLD;
3872 childpid = waitpid(-1, &status, attributes);
3873 if (childpid <= 0) {
3874 if (childpid && errno != ECHILD)
3875 bb_perror_msg("waitpid");
3876 #if ENABLE_HUSH_FAST
3877 else { /* Until next SIGCHLD, waitpid's are useless */
3878 G.we_have_children = (childpid == 0);
3879 G.handled_SIGCHLD = i;
3880 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3885 dead = WIFEXITED(status) || WIFSIGNALED(status);
3888 if (WIFSTOPPED(status))
3889 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3890 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3891 if (WIFSIGNALED(status))
3892 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3893 childpid, WTERMSIG(status), WEXITSTATUS(status));
3894 if (WIFEXITED(status))
3895 debug_printf_jobs("pid %d exited, exitcode %d\n",
3896 childpid, WEXITSTATUS(status));
3898 /* Were we asked to wait for fg pipe? */
3900 for (i = 0; i < fg_pipe->num_cmds; i++) {
3901 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3902 if (fg_pipe->cmds[i].pid != childpid)
3905 fg_pipe->cmds[i].pid = 0;
3906 fg_pipe->alive_cmds--;
3907 if (i == fg_pipe->num_cmds - 1) {
3908 /* last process gives overall exitstatus */
3909 rcode = WEXITSTATUS(status);
3910 /* bash prints killer signal's name for *last*
3911 * process in pipe (prints just newline for SIGINT).
3912 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3914 if (WIFSIGNALED(status)) {
3915 int sig = WTERMSIG(status);
3916 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3917 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3918 * Maybe we need to use sig | 128? */
3921 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3924 fg_pipe->cmds[i].is_stopped = 1;
3925 fg_pipe->stopped_cmds++;
3927 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3928 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3929 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3930 /* All processes in fg pipe have exited or stopped */
3931 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3932 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3933 * and "killall -STOP cat" */
3934 if (G_interactive_fd) {
3936 if (fg_pipe->alive_cmds)
3937 insert_bg_job(fg_pipe);
3941 if (!fg_pipe->alive_cmds)
3944 /* There are still running processes in the fg pipe */
3945 goto wait_more; /* do waitpid again */
3947 /* it wasnt fg_pipe, look for process in bg pipes */
3951 /* We asked to wait for bg or orphaned children */
3952 /* No need to remember exitcode in this case */
3953 for (pi = G.job_list; pi; pi = pi->next) {
3954 for (i = 0; i < pi->num_cmds; i++) {
3955 if (pi->cmds[i].pid == childpid)
3956 goto found_pi_and_prognum;
3959 /* Happens when shell is used as init process (init=/bin/sh) */
3960 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3961 continue; /* do waitpid again */
3963 found_pi_and_prognum:
3966 pi->cmds[i].pid = 0;
3968 if (!pi->alive_cmds) {
3969 if (G_interactive_fd)
3970 printf(JOB_STATUS_FORMAT, pi->jobid,
3971 "Done", pi->cmdtext);
3972 delete_finished_bg_job(pi);
3976 pi->cmds[i].is_stopped = 1;
3980 } /* while (waitpid succeeds)... */
3986 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3989 int rcode = checkjobs(fg_pipe);
3990 if (G_saved_tty_pgrp) {
3991 /* Job finished, move the shell to the foreground */
3992 p = getpgrp(); /* our process group id */
3993 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3994 tcsetpgrp(G_interactive_fd, p);
4000 /* Start all the jobs, but don't wait for anything to finish.
4003 * Return code is normally -1, when the caller has to wait for children
4004 * to finish to determine the exit status of the pipe. If the pipe
4005 * is a simple builtin command, however, the action is done by the
4006 * time run_pipe returns, and the exit code is provided as the
4009 * Returns -1 only if started some children. IOW: we have to
4010 * mask out retvals of builtins etc with 0xff!
4012 * The only case when we do not need to [v]fork is when the pipe
4013 * is single, non-backgrounded, non-subshell command. Examples:
4014 * cmd ; ... { list } ; ...
4015 * cmd && ... { list } && ...
4016 * cmd || ... { list } || ...
4017 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4018 * or (if SH_STANDALONE) an applet, and we can run the { list }
4019 * with run_list. If it isn't one of these, we fork and exec cmd.
4021 * Cases when we must fork:
4022 * non-single: cmd | cmd
4023 * backgrounded: cmd & { list } &
4024 * subshell: ( list ) [&]
4026 static NOINLINE int run_pipe(struct pipe *pi)
4028 static const char *const null_ptr = NULL;
4031 struct command *command;
4032 char **argv_expanded;
4035 /* it is not always needed, but we aim to smaller code */
4036 int squirrel[] = { -1, -1, -1 };
4039 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4042 IF_HUSH_JOB(pi->pgrp = -1;)
4043 pi->stopped_cmds = 0;
4044 command = &(pi->cmds[0]);
4045 argv_expanded = NULL;
4047 if (pi->num_cmds != 1
4048 || pi->followup == PIPE_BG
4049 || command->cmd_type == CMD_SUBSHELL
4056 debug_printf_exec(": group:%p argv:'%s'\n",
4057 command->group, command->argv ? command->argv[0] : "NONE");
4059 if (command->group) {
4060 #if ENABLE_HUSH_FUNCTIONS
4061 if (command->cmd_type == CMD_FUNCDEF) {
4062 /* "executing" func () { list } */
4063 struct function *funcp;
4065 funcp = new_function(command->argv[0]);
4066 /* funcp->name is already set to argv[0] */
4067 funcp->body = command->group;
4069 funcp->body_as_string = command->group_as_string;
4070 command->group_as_string = NULL;
4072 command->group = NULL;
4073 command->argv[0] = NULL;
4074 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4075 funcp->parent_cmd = command;
4076 command->child_func = funcp;
4078 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4080 return EXIT_SUCCESS;
4084 debug_printf("non-subshell group\n");
4085 rcode = 1; /* exitcode if redir failed */
4086 if (setup_redirects(command, squirrel) == 0) {
4087 debug_printf_exec(": run_list\n");
4088 rcode = run_list(command->group) & 0xff;
4090 restore_redirects(squirrel);
4091 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4093 debug_printf_exec("run_pipe: return %d\n", rcode);
4097 argv = command->argv ? command->argv : (char **) &null_ptr;
4099 const struct built_in_command *x;
4100 #if ENABLE_HUSH_FUNCTIONS
4101 const struct function *funcp;
4105 char **new_env = NULL;
4106 struct variable *old_vars = NULL;
4108 if (argv[command->assignment_cnt] == NULL) {
4109 /* Assignments, but no command */
4110 /* Ensure redirects take effect. Try "a=t >file" */
4111 rcode = setup_redirects(command, squirrel);
4112 //FIXME: "false; q=`false`; echo $?" should print 1
4113 restore_redirects(squirrel);
4114 /* Set shell variables */
4116 p = expand_string_to_string(*argv);
4117 debug_printf_exec("set shell var:'%s'->'%s'\n",
4119 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4122 /* Do we need to flag set_local_var() errors?
4123 * "assignment to readonly var" and "putenv error"
4125 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4127 debug_printf_exec("run_pipe: return %d\n", rcode);
4131 /* Expand the rest into (possibly) many strings each */
4133 #if ENABLE_HUSH_BASH_COMPAT
4134 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4135 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4138 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4139 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4140 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4145 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4148 /* if someone gives us an empty string: `cmd with empty output` */
4149 if (!argv_expanded[0]) {
4150 free(argv_expanded);
4152 return G.last_exitcode;
4155 x = find_builtin(argv_expanded[0]);
4156 #if ENABLE_HUSH_FUNCTIONS
4159 funcp = find_function(argv_expanded[0]);
4163 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4164 debug_printf("exec with redirects only\n");
4165 rcode = setup_redirects(command, NULL);
4166 goto clean_up_and_ret1;
4169 /* setup_redirects acts on file descriptors, not FILEs.
4170 * This is perfect for work that comes after exec().
4171 * Is it really safe for inline use? Experimentally,
4172 * things seem to work. */
4173 rcode = setup_redirects(command, squirrel);
4175 new_env = expand_assignments(argv, command->assignment_cnt);
4176 old_vars = set_vars_and_save_old(new_env);
4178 debug_printf_exec(": builtin '%s' '%s'...\n",
4179 x->cmd, argv_expanded[1]);
4180 rcode = x->b_function(argv_expanded) & 0xff;
4183 #if ENABLE_HUSH_FUNCTIONS
4185 # if ENABLE_HUSH_LOCAL
4186 struct variable **sv;
4187 sv = G.shadowed_vars_pp;
4188 G.shadowed_vars_pp = &old_vars;
4190 debug_printf_exec(": function '%s' '%s'...\n",
4191 funcp->name, argv_expanded[1]);
4192 rcode = run_function(funcp, argv_expanded) & 0xff;
4193 # if ENABLE_HUSH_LOCAL
4194 G.shadowed_vars_pp = sv;
4199 #if ENABLE_FEATURE_SH_STANDALONE
4202 restore_redirects(squirrel);
4203 unset_vars(new_env);
4206 free(argv_expanded);
4207 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4209 debug_printf_exec("run_pipe return %d\n", rcode);
4213 #if ENABLE_FEATURE_SH_STANDALONE
4214 i = find_applet_by_name(argv_expanded[0]);
4215 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4216 rcode = setup_redirects(command, squirrel);
4218 new_env = expand_assignments(argv, command->assignment_cnt);
4219 old_vars = set_vars_and_save_old(new_env);
4220 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4221 argv_expanded[0], argv_expanded[1]);
4222 rcode = run_nofork_applet(i, argv_expanded);
4224 goto clean_up_and_ret;
4227 /* It is neither builtin nor applet. We must fork. */
4231 /* NB: argv_expanded may already be created, and that
4232 * might include `cmd` runs! Do not rerun it! We *must*
4233 * use argv_expanded if it's non-NULL */
4235 /* Going to fork a child per each pipe member */
4239 for (i = 0; i < pi->num_cmds; i++) {
4240 struct fd_pair pipefds;
4242 volatile nommu_save_t nommu_save;
4243 nommu_save.new_env = NULL;
4244 nommu_save.old_vars = NULL;
4245 nommu_save.argv = NULL;
4246 nommu_save.argv_from_re_execing = NULL;
4248 command = &(pi->cmds[i]);
4249 if (command->argv) {
4250 debug_printf_exec(": pipe member '%s' '%s'...\n",
4251 command->argv[0], command->argv[1]);
4253 debug_printf_exec(": pipe member with no argv\n");
4256 /* pipes are inserted between pairs of commands */
4259 if ((i + 1) < pi->num_cmds)
4260 xpiped_pair(pipefds);
4262 command->pid = BB_MMU ? fork() : vfork();
4263 if (!command->pid) { /* child */
4265 disable_restore_tty_pgrp_on_exit();
4266 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4268 /* Every child adds itself to new process group
4269 * with pgid == pid_of_first_child_in_pipe */
4270 if (G.run_list_level == 1 && G_interactive_fd) {
4273 if (pgrp < 0) /* true for 1st process only */
4275 if (setpgid(0, pgrp) == 0
4276 && pi->followup != PIPE_BG
4277 && G_saved_tty_pgrp /* we have ctty */
4279 /* We do it in *every* child, not just first,
4281 tcsetpgrp(G_interactive_fd, pgrp);
4285 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4286 /* 1st cmd in backgrounded pipe
4287 * should have its stdin /dev/null'ed */
4289 if (open(bb_dev_null, O_RDONLY))
4290 xopen("/", O_RDONLY);
4292 xmove_fd(nextin, 0);
4294 xmove_fd(pipefds.wr, 1);
4297 /* Like bash, explicit redirects override pipes,
4298 * and the pipe fd is available for dup'ing. */
4299 if (setup_redirects(command, NULL))
4302 /* Restore default handlers just prior to exec */
4303 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4305 /* Stores to nommu_save list of env vars putenv'ed
4306 * (NOMMU, on MMU we don't need that) */
4307 /* cast away volatility... */
4308 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4309 /* pseudo_exec() does not return */
4312 /* parent or error */
4313 #if ENABLE_HUSH_FAST
4315 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4317 enable_restore_tty_pgrp_on_exit();
4319 /* Clean up after vforked child */
4320 free(nommu_save.argv);
4321 free(nommu_save.argv_from_re_execing);
4322 unset_vars(nommu_save.new_env);
4323 add_vars(nommu_save.old_vars);
4325 free(argv_expanded);
4326 argv_expanded = NULL;
4327 if (command->pid < 0) { /* [v]fork failed */
4328 /* Clearly indicate, was it fork or vfork */
4329 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4333 /* Second and next children need to know pid of first one */
4335 pi->pgrp = command->pid;
4341 if ((i + 1) < pi->num_cmds)
4343 /* Pass read (output) pipe end to next iteration */
4344 nextin = pipefds.rd;
4347 if (!pi->alive_cmds) {
4349 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4354 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4358 #ifndef debug_print_tree
4359 static void debug_print_tree(struct pipe *pi, int lvl)
4361 static const char *const PIPE[] = {
4367 static const char *RES[] = {
4368 [RES_NONE ] = "NONE" ,
4371 [RES_THEN ] = "THEN" ,
4372 [RES_ELIF ] = "ELIF" ,
4373 [RES_ELSE ] = "ELSE" ,
4376 # if ENABLE_HUSH_LOOPS
4377 [RES_FOR ] = "FOR" ,
4378 [RES_WHILE] = "WHILE",
4379 [RES_UNTIL] = "UNTIL",
4381 [RES_DONE ] = "DONE" ,
4383 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4386 # if ENABLE_HUSH_CASE
4387 [RES_CASE ] = "CASE" ,
4388 [RES_CASE_IN ] = "CASE_IN" ,
4389 [RES_MATCH] = "MATCH",
4390 [RES_CASE_BODY] = "CASE_BODY",
4391 [RES_ESAC ] = "ESAC" ,
4393 [RES_XXXX ] = "XXXX" ,
4394 [RES_SNTX ] = "SNTX" ,
4396 static const char *const CMDTYPE[] = {
4400 # if ENABLE_HUSH_FUNCTIONS
4409 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4410 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4412 while (prn < pi->num_cmds) {
4413 struct command *command = &pi->cmds[prn];
4414 char **argv = command->argv;
4416 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4418 command->assignment_cnt);
4419 if (command->group) {
4420 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4421 CMDTYPE[command->cmd_type],
4424 , " group_as_string:", command->group_as_string
4429 debug_print_tree(command->group, lvl+1);
4433 if (argv) while (*argv) {
4434 fprintf(stderr, " '%s'", *argv);
4437 fprintf(stderr, "\n");
4444 #endif /* debug_print_tree */
4446 /* NB: called by pseudo_exec, and therefore must not modify any
4447 * global data until exec/_exit (we can be a child after vfork!) */
4448 static int run_list(struct pipe *pi)
4450 #if ENABLE_HUSH_CASE
4451 char *case_word = NULL;
4453 #if ENABLE_HUSH_LOOPS
4454 struct pipe *loop_top = NULL;
4455 char **for_lcur = NULL;
4456 char **for_list = NULL;
4458 smallint last_followup;
4460 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4461 smalluint cond_code = 0;
4463 enum { cond_code = 0 };
4466 smallint rword; /* enum reserved_style */
4467 smallint last_rword; /* ditto */
4470 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4473 #if ENABLE_HUSH_LOOPS
4474 /* Check syntax for "for" */
4475 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4476 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4478 /* current word is FOR or IN (BOLD in comments below) */
4479 if (cpipe->next == NULL) {
4480 syntax_error("malformed for");
4482 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4485 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4486 if (cpipe->next->res_word == RES_DO)
4488 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4489 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4490 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4492 syntax_error("malformed for");
4494 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4500 /* Past this point, all code paths should jump to ret: label
4501 * in order to return, no direct "return" statements please.
4502 * This helps to ensure that no memory is leaked. */
4510 last_rword = RES_XXXX;
4512 last_followup = PIPE_SEQ;
4513 rcode = G.last_exitcode;
4515 /* Go through list of pipes, (maybe) executing them. */
4516 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4520 IF_HAS_KEYWORDS(rword = pi->res_word;)
4521 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4522 rword, cond_code, last_rword);
4523 #if ENABLE_HUSH_LOOPS
4524 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4525 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4527 /* start of a loop: remember where loop starts */
4532 /* Still in the same "if...", "then..." or "do..." branch? */
4533 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4534 if ((rcode == 0 && last_followup == PIPE_OR)
4535 || (rcode != 0 && last_followup == PIPE_AND)
4537 /* It is "<true> || CMD" or "<false> && CMD"
4538 * and we should not execute CMD */
4539 debug_printf_exec("skipped cmd because of || or &&\n");
4540 last_followup = pi->followup;
4544 last_followup = pi->followup;
4545 IF_HAS_KEYWORDS(last_rword = rword;)
4548 if (rword == RES_THEN) {
4549 /* if false; then ... fi has exitcode 0! */
4550 G.last_exitcode = rcode = EXIT_SUCCESS;
4551 /* "if <false> THEN cmd": skip cmd */
4555 if (rword == RES_ELSE || rword == RES_ELIF) {
4556 /* "if <true> then ... ELSE/ELIF cmd":
4557 * skip cmd and all following ones */
4562 #if ENABLE_HUSH_LOOPS
4563 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4565 /* first loop through for */
4567 static const char encoded_dollar_at[] ALIGN1 = {
4568 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4569 }; /* encoded representation of "$@" */
4570 static const char *const encoded_dollar_at_argv[] = {
4571 encoded_dollar_at, NULL
4572 }; /* argv list with one element: "$@" */
4575 vals = (char**)encoded_dollar_at_argv;
4576 if (pi->next->res_word == RES_IN) {
4577 /* if no variable values after "in" we skip "for" */
4578 if (!pi->next->cmds[0].argv) {
4579 G.last_exitcode = rcode = EXIT_SUCCESS;
4580 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4583 vals = pi->next->cmds[0].argv;
4584 } /* else: "for var; do..." -> assume "$@" list */
4585 /* create list of variable values */
4586 debug_print_strings("for_list made from", vals);
4587 for_list = expand_strvec_to_strvec(vals);
4588 for_lcur = for_list;
4589 debug_print_strings("for_list", for_list);
4592 /* "for" loop is over, clean up */
4598 /* Insert next value from for_lcur */
4599 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4600 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4603 if (rword == RES_IN) {
4604 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4606 if (rword == RES_DONE) {
4607 continue; /* "done" has no cmds too */
4610 #if ENABLE_HUSH_CASE
4611 if (rword == RES_CASE) {
4612 case_word = expand_strvec_to_string(pi->cmds->argv);
4615 if (rword == RES_MATCH) {
4618 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4620 /* all prev words didn't match, does this one match? */
4621 argv = pi->cmds->argv;
4623 char *pattern = expand_string_to_string(*argv);
4624 /* TODO: which FNM_xxx flags to use? */
4625 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4627 if (cond_code == 0) { /* match! we will execute this branch */
4628 free(case_word); /* make future "word)" stop */
4636 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4638 continue; /* not matched yet, skip this pipe */
4641 /* Just pressing <enter> in shell should check for jobs.
4642 * OTOH, in non-interactive shell this is useless
4643 * and only leads to extra job checks */
4644 if (pi->num_cmds == 0) {
4645 if (G_interactive_fd)
4646 goto check_jobs_and_continue;
4650 /* After analyzing all keywords and conditions, we decided
4651 * to execute this pipe. NB: have to do checkjobs(NULL)
4652 * after run_pipe to collect any background children,
4653 * even if list execution is to be stopped. */
4654 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4657 #if ENABLE_HUSH_LOOPS
4658 G.flag_break_continue = 0;
4660 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4662 /* We ran a builtin, function, or group.
4663 * rcode is already known
4664 * and we don't need to wait for anything. */
4665 G.last_exitcode = rcode;
4666 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4667 check_and_run_traps(0);
4668 #if ENABLE_HUSH_LOOPS
4669 /* Was it "break" or "continue"? */
4670 if (G.flag_break_continue) {
4671 smallint fbc = G.flag_break_continue;
4672 /* We might fall into outer *loop*,
4673 * don't want to break it too */
4675 G.depth_break_continue--;
4676 if (G.depth_break_continue == 0)
4677 G.flag_break_continue = 0;
4678 /* else: e.g. "continue 2" should *break* once, *then* continue */
4679 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4680 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4681 goto check_jobs_and_break;
4682 /* "continue": simulate end of loop */
4687 #if ENABLE_HUSH_FUNCTIONS
4688 if (G.flag_return_in_progress == 1) {
4689 /* same as "goto check_jobs_and_break" */
4694 } else if (pi->followup == PIPE_BG) {
4695 /* What does bash do with attempts to background builtins? */
4696 /* even bash 3.2 doesn't do that well with nested bg:
4697 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4698 * I'm NOT treating inner &'s as jobs */
4699 check_and_run_traps(0);
4701 if (G.run_list_level == 1)
4704 G.last_exitcode = rcode = EXIT_SUCCESS;
4705 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4708 if (G.run_list_level == 1 && G_interactive_fd) {
4709 /* Waits for completion, then fg's main shell */
4710 rcode = checkjobs_and_fg_shell(pi);
4711 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4712 check_and_run_traps(0);
4715 { /* This one just waits for completion */
4716 rcode = checkjobs(pi);
4717 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4718 check_and_run_traps(0);
4720 G.last_exitcode = rcode;
4724 /* Analyze how result affects subsequent commands */
4726 if (rword == RES_IF || rword == RES_ELIF)
4729 #if ENABLE_HUSH_LOOPS
4730 /* Beware of "while false; true; do ..."! */
4731 if (pi->next && pi->next->res_word == RES_DO) {
4732 if (rword == RES_WHILE) {
4734 /* "while false; do...done" - exitcode 0 */
4735 G.last_exitcode = rcode = EXIT_SUCCESS;
4736 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4737 goto check_jobs_and_break;
4740 if (rword == RES_UNTIL) {
4742 debug_printf_exec(": until expr is true: breaking\n");
4743 check_jobs_and_break:
4751 check_jobs_and_continue:
4758 #if ENABLE_HUSH_LOOPS
4763 #if ENABLE_HUSH_CASE
4767 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4771 /* Select which version we will use */
4772 static int run_and_free_list(struct pipe *pi)
4775 debug_printf_exec("run_and_free_list entered\n");
4777 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4778 rcode = run_list(pi);
4780 /* free_pipe_list has the side effect of clearing memory.
4781 * In the long run that function can be merged with run_list,
4782 * but doing that now would hobble the debugging effort. */
4784 debug_printf_exec("run_and_free_list return %d\n", rcode);
4789 static struct pipe *new_pipe(void)
4792 pi = xzalloc(sizeof(struct pipe));
4793 /*pi->followup = 0; - deliberately invalid value */
4794 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4798 /* Command (member of a pipe) is complete, or we start a new pipe
4799 * if ctx->command is NULL.
4800 * No errors possible here.
4802 static int done_command(struct parse_context *ctx)
4804 /* The command is really already in the pipe structure, so
4805 * advance the pipe counter and make a new, null command. */
4806 struct pipe *pi = ctx->pipe;
4807 struct command *command = ctx->command;
4810 if (IS_NULL_CMD(command)) {
4811 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4815 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4816 //debug_print_tree(ctx->list_head, 20);
4818 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4821 /* Only real trickiness here is that the uncommitted
4822 * command structure is not counted in pi->num_cmds. */
4823 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4824 ctx->command = command = &pi->cmds[pi->num_cmds];
4826 memset(command, 0, sizeof(*command));
4827 return pi->num_cmds; /* used only for 0/nonzero check */
4830 static void done_pipe(struct parse_context *ctx, pipe_style type)
4834 debug_printf_parse("done_pipe entered, followup %d\n", type);
4835 /* Close previous command */
4836 not_null = done_command(ctx);
4837 ctx->pipe->followup = type;
4839 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4840 ctx->ctx_inverted = 0;
4841 ctx->pipe->res_word = ctx->ctx_res_w;
4844 /* Without this check, even just <enter> on command line generates
4845 * tree of three NOPs (!). Which is harmless but annoying.
4846 * IOW: it is safe to do it unconditionally. */
4849 || ctx->ctx_res_w == RES_FI
4851 #if ENABLE_HUSH_LOOPS
4852 || ctx->ctx_res_w == RES_DONE
4853 || ctx->ctx_res_w == RES_FOR
4854 || ctx->ctx_res_w == RES_IN
4856 #if ENABLE_HUSH_CASE
4857 || ctx->ctx_res_w == RES_ESAC
4861 debug_printf_parse("done_pipe: adding new pipe: "
4862 "not_null:%d ctx->ctx_res_w:%d\n",
4863 not_null, ctx->ctx_res_w);
4865 ctx->pipe->next = new_p;
4867 /* RES_THEN, RES_DO etc are "sticky" -
4868 * they remain set for pipes inside if/while.
4869 * This is used to control execution.
4870 * RES_FOR and RES_IN are NOT sticky (needed to support
4871 * cases where variable or value happens to match a keyword):
4873 #if ENABLE_HUSH_LOOPS
4874 if (ctx->ctx_res_w == RES_FOR
4875 || ctx->ctx_res_w == RES_IN)
4876 ctx->ctx_res_w = RES_NONE;
4878 #if ENABLE_HUSH_CASE
4879 if (ctx->ctx_res_w == RES_MATCH)
4880 ctx->ctx_res_w = RES_CASE_BODY;
4881 if (ctx->ctx_res_w == RES_CASE)
4882 ctx->ctx_res_w = RES_CASE_IN;
4884 ctx->command = NULL; /* trick done_command below */
4885 /* Create the memory for command, roughly:
4886 * ctx->pipe->cmds = new struct command;
4887 * ctx->command = &ctx->pipe->cmds[0];
4890 //debug_print_tree(ctx->list_head, 10);
4892 debug_printf_parse("done_pipe return\n");
4895 static void initialize_context(struct parse_context *ctx)
4897 memset(ctx, 0, sizeof(*ctx));
4898 ctx->pipe = ctx->list_head = new_pipe();
4899 /* Create the memory for command, roughly:
4900 * ctx->pipe->cmds = new struct command;
4901 * ctx->command = &ctx->pipe->cmds[0];
4906 /* If a reserved word is found and processed, parse context is modified
4907 * and 1 is returned.
4910 struct reserved_combo {
4913 unsigned char assignment_flag;
4917 FLAG_END = (1 << RES_NONE ),
4919 FLAG_IF = (1 << RES_IF ),
4920 FLAG_THEN = (1 << RES_THEN ),
4921 FLAG_ELIF = (1 << RES_ELIF ),
4922 FLAG_ELSE = (1 << RES_ELSE ),
4923 FLAG_FI = (1 << RES_FI ),
4925 # if ENABLE_HUSH_LOOPS
4926 FLAG_FOR = (1 << RES_FOR ),
4927 FLAG_WHILE = (1 << RES_WHILE),
4928 FLAG_UNTIL = (1 << RES_UNTIL),
4929 FLAG_DO = (1 << RES_DO ),
4930 FLAG_DONE = (1 << RES_DONE ),
4931 FLAG_IN = (1 << RES_IN ),
4933 # if ENABLE_HUSH_CASE
4934 FLAG_MATCH = (1 << RES_MATCH),
4935 FLAG_ESAC = (1 << RES_ESAC ),
4937 FLAG_START = (1 << RES_XXXX ),
4940 static const struct reserved_combo* match_reserved_word(o_string *word)
4942 /* Mostly a list of accepted follow-up reserved words.
4943 * FLAG_END means we are done with the sequence, and are ready
4944 * to turn the compound list into a command.
4945 * FLAG_START means the word must start a new compound list.
4947 static const struct reserved_combo reserved_list[] = {
4949 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4950 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4951 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4952 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4953 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4954 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4956 # if ENABLE_HUSH_LOOPS
4957 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4958 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4959 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4960 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4961 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4962 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4964 # if ENABLE_HUSH_CASE
4965 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4966 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4969 const struct reserved_combo *r;
4971 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4972 if (strcmp(word->data, r->literal) == 0)
4977 /* Return 0: not a keyword, 1: keyword
4979 static int reserved_word(o_string *word, struct parse_context *ctx)
4981 # if ENABLE_HUSH_CASE
4982 static const struct reserved_combo reserved_match = {
4983 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4986 const struct reserved_combo *r;
4990 r = match_reserved_word(word);
4994 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4995 # if ENABLE_HUSH_CASE
4996 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
4997 /* "case word IN ..." - IN part starts first MATCH part */
4998 r = &reserved_match;
5001 if (r->flag == 0) { /* '!' */
5002 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5003 syntax_error("! ! command");
5004 ctx->ctx_res_w = RES_SNTX;
5006 ctx->ctx_inverted = 1;
5009 if (r->flag & FLAG_START) {
5010 struct parse_context *old;
5012 old = xmalloc(sizeof(*old));
5013 debug_printf_parse("push stack %p\n", old);
5014 *old = *ctx; /* physical copy */
5015 initialize_context(ctx);
5017 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5018 syntax_error_at(word->data);
5019 ctx->ctx_res_w = RES_SNTX;
5022 /* "{...} fi" is ok. "{...} if" is not
5024 * if { echo foo; } then { echo bar; } fi */
5025 if (ctx->command->group)
5026 done_pipe(ctx, PIPE_SEQ);
5029 ctx->ctx_res_w = r->res;
5030 ctx->old_flag = r->flag;
5031 word->o_assignment = r->assignment_flag;
5033 if (ctx->old_flag & FLAG_END) {
5034 struct parse_context *old;
5036 done_pipe(ctx, PIPE_SEQ);
5037 debug_printf_parse("pop stack %p\n", ctx->stack);
5039 old->command->group = ctx->list_head;
5040 old->command->cmd_type = CMD_NORMAL;
5042 o_addstr(&old->as_string, ctx->as_string.data);
5043 o_free_unsafe(&ctx->as_string);
5044 old->command->group_as_string = xstrdup(old->as_string.data);
5045 debug_printf_parse("pop, remembering as:'%s'\n",
5046 old->command->group_as_string);
5048 *ctx = *old; /* physical copy */
5053 #endif /* HAS_KEYWORDS */
5055 /* Word is complete, look at it and update parsing context.
5056 * Normal return is 0. Syntax errors return 1.
5057 * Note: on return, word is reset, but not o_free'd!
5059 static int done_word(o_string *word, struct parse_context *ctx)
5061 struct command *command = ctx->command;
5063 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5064 if (word->length == 0 && word->o_quoted == 0) {
5065 debug_printf_parse("done_word return 0: true null, ignored\n");
5069 if (ctx->pending_redirect) {
5070 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5071 * only if run as "bash", not "sh" */
5072 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5074 * ...the word that follows the redirection operator
5075 * shall be subjected to tilde expansion, parameter expansion,
5076 * command substitution, arithmetic expansion, and quote
5077 * removal. Pathname expansion shall not be performed
5078 * on the word by a non-interactive shell; an interactive
5079 * shell may perform it, but shall do so only when
5080 * the expansion would result in one word."
5082 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5083 /* Cater for >\file case:
5084 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5085 * Same with heredocs:
5086 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5088 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5089 unbackslash(ctx->pending_redirect->rd_filename);
5090 /* Is it <<"HEREDOC"? */
5091 if (word->o_quoted) {
5092 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5095 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5096 ctx->pending_redirect = NULL;
5098 /* If this word wasn't an assignment, next ones definitely
5099 * can't be assignments. Even if they look like ones. */
5100 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5101 && word->o_assignment != WORD_IS_KEYWORD
5103 word->o_assignment = NOT_ASSIGNMENT;
5105 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5106 command->assignment_cnt++;
5107 word->o_assignment = MAYBE_ASSIGNMENT;
5111 # if ENABLE_HUSH_CASE
5112 if (ctx->ctx_dsemicolon
5113 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5115 /* already done when ctx_dsemicolon was set to 1: */
5116 /* ctx->ctx_res_w = RES_MATCH; */
5117 ctx->ctx_dsemicolon = 0;
5120 if (!command->argv /* if it's the first word... */
5121 # if ENABLE_HUSH_LOOPS
5122 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5123 && ctx->ctx_res_w != RES_IN
5125 # if ENABLE_HUSH_CASE
5126 && ctx->ctx_res_w != RES_CASE
5129 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5130 if (reserved_word(word, ctx)) {
5131 o_reset_to_empty_unquoted(word);
5132 debug_printf_parse("done_word return %d\n",
5133 (ctx->ctx_res_w == RES_SNTX));
5134 return (ctx->ctx_res_w == RES_SNTX);
5136 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5137 if (strcmp(word->data, "export") == 0
5138 # if ENABLE_HUSH_LOCAL
5139 || strcmp(word->data, "local") == 0
5142 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5145 # if ENABLE_HUSH_BASH_COMPAT
5146 if (strcmp(word->data, "[[") == 0) {
5147 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5153 if (command->group) {
5154 /* "{ echo foo; } echo bar" - bad */
5155 syntax_error_at(word->data);
5156 debug_printf_parse("done_word return 1: syntax error, "
5157 "groups and arglists don't mix\n");
5160 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5161 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5162 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5163 /* (otherwise it's known to be not empty and is already safe) */
5165 /* exclude "$@" - it can expand to no word despite "" */
5166 char *p = word->data;
5167 while (p[0] == SPECIAL_VAR_SYMBOL
5168 && (p[1] & 0x7f) == '@'
5169 && p[2] == SPECIAL_VAR_SYMBOL
5173 if (p == word->data || p[0] != '\0') {
5174 /* saw no "$@", or not only "$@" but some
5175 * real text is there too */
5176 /* insert "empty variable" reference, this makes
5177 * e.g. "", $empty"" etc to not disappear */
5178 o_addchr(word, SPECIAL_VAR_SYMBOL);
5179 o_addchr(word, SPECIAL_VAR_SYMBOL);
5182 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5183 debug_print_strings("word appended to argv", command->argv);
5186 #if ENABLE_HUSH_LOOPS
5187 if (ctx->ctx_res_w == RES_FOR) {
5189 || !is_well_formed_var_name(command->argv[0], '\0')
5191 /* bash says just "not a valid identifier" */
5192 syntax_error("not a valid identifier in for");
5195 /* Force FOR to have just one word (variable name) */
5196 /* NB: basically, this makes hush see "for v in ..."
5197 * syntax as if it is "for v; in ...". FOR and IN become
5198 * two pipe structs in parse tree. */
5199 done_pipe(ctx, PIPE_SEQ);
5202 #if ENABLE_HUSH_CASE
5203 /* Force CASE to have just one word */
5204 if (ctx->ctx_res_w == RES_CASE) {
5205 done_pipe(ctx, PIPE_SEQ);
5209 o_reset_to_empty_unquoted(word);
5211 debug_printf_parse("done_word return 0\n");
5216 /* Peek ahead in the input to find out if we have a "&n" construct,
5217 * as in "2>&1", that represents duplicating a file descriptor.
5219 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5220 * REDIRFD_SYNTAX_ERR if syntax error,
5221 * REDIRFD_TO_FILE if no & was seen,
5222 * or the number found.
5225 #define parse_redir_right_fd(as_string, input) \
5226 parse_redir_right_fd(input)
5228 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5234 return REDIRFD_TO_FILE;
5236 ch = i_getch(input); /* get the & */
5237 nommu_addchr(as_string, ch);
5240 ch = i_getch(input);
5241 nommu_addchr(as_string, ch);
5242 return REDIRFD_CLOSE;
5246 while (ch != EOF && isdigit(ch)) {
5247 d = d*10 + (ch-'0');
5249 ch = i_getch(input);
5250 nommu_addchr(as_string, ch);
5255 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5257 bb_error_msg("ambiguous redirect");
5258 return REDIRFD_SYNTAX_ERR;
5261 /* Return code is 0 normal, 1 if a syntax error is detected
5263 static int parse_redirect(struct parse_context *ctx,
5266 struct in_str *input)
5268 struct command *command = ctx->command;
5269 struct redir_struct *redir;
5270 struct redir_struct **redirp;
5273 dup_num = REDIRFD_TO_FILE;
5274 if (style != REDIRECT_HEREDOC) {
5275 /* Check for a '>&1' type redirect */
5276 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5277 if (dup_num == REDIRFD_SYNTAX_ERR)
5280 int ch = i_peek(input);
5281 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5282 if (dup_num) { /* <<-... */
5283 ch = i_getch(input);
5284 nommu_addchr(&ctx->as_string, ch);
5289 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5290 int ch = i_peek(input);
5292 /* >|FILE redirect ("clobbering" >).
5293 * Since we do not support "set -o noclobber" yet,
5294 * >| and > are the same for now. Just eat |.
5296 ch = i_getch(input);
5297 nommu_addchr(&ctx->as_string, ch);
5301 /* Create a new redir_struct and append it to the linked list */
5302 redirp = &command->redirects;
5303 while ((redir = *redirp) != NULL) {
5304 redirp = &(redir->next);
5306 *redirp = redir = xzalloc(sizeof(*redir));
5307 /* redir->next = NULL; */
5308 /* redir->rd_filename = NULL; */
5309 redir->rd_type = style;
5310 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5312 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5313 redir_table[style].descrip);
5315 redir->rd_dup = dup_num;
5316 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5317 /* Erik had a check here that the file descriptor in question
5318 * is legit; I postpone that to "run time"
5319 * A "-" representation of "close me" shows up as a -3 here */
5320 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5321 redir->rd_fd, redir->rd_dup);
5323 /* Set ctx->pending_redirect, so we know what to do at the
5324 * end of the next parsed word. */
5325 ctx->pending_redirect = redir;
5330 /* If a redirect is immediately preceded by a number, that number is
5331 * supposed to tell which file descriptor to redirect. This routine
5332 * looks for such preceding numbers. In an ideal world this routine
5333 * needs to handle all the following classes of redirects...
5334 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5335 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5336 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5337 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5339 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5341 * ... If n is quoted, the number shall not be recognized as part of
5342 * the redirection expression. For example:
5344 * writes the character 2 into file a"
5345 * We are getting it right by setting ->o_quoted on any \<char>
5347 * A -1 return means no valid number was found,
5348 * the caller should use the appropriate default for this redirection.
5350 static int redirect_opt_num(o_string *o)
5354 if (o->data == NULL)
5356 num = bb_strtou(o->data, NULL, 10);
5357 if (errno || num < 0)
5359 o_reset_to_empty_unquoted(o);
5364 #define fetch_till_str(as_string, input, word, skip_tabs) \
5365 fetch_till_str(input, word, skip_tabs)
5367 static char *fetch_till_str(o_string *as_string,
5368 struct in_str *input,
5372 o_string heredoc = NULL_O_STRING;
5378 ch = i_getch(input);
5379 nommu_addchr(as_string, ch);
5381 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5382 heredoc.data[past_EOL] = '\0';
5383 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5384 return heredoc.data;
5387 o_addchr(&heredoc, ch);
5388 past_EOL = heredoc.length;
5391 ch = i_getch(input);
5392 nommu_addchr(as_string, ch);
5393 } while (skip_tabs && ch == '\t');
5394 } while (ch == '\n');
5397 o_free_unsafe(&heredoc);
5400 o_addchr(&heredoc, ch);
5401 nommu_addchr(as_string, ch);
5405 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5406 * and load them all. There should be exactly heredoc_cnt of them.
5408 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5410 struct pipe *pi = ctx->list_head;
5412 while (pi && heredoc_cnt) {
5414 struct command *cmd = pi->cmds;
5416 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5418 cmd->argv ? cmd->argv[0] : "NONE");
5419 for (i = 0; i < pi->num_cmds; i++) {
5420 struct redir_struct *redir = cmd->redirects;
5422 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5423 i, cmd->argv ? cmd->argv[0] : "NONE");
5425 if (redir->rd_type == REDIRECT_HEREDOC) {
5428 redir->rd_type = REDIRECT_HEREDOC2;
5429 /* redir->rd_dup is (ab)used to indicate <<- */
5430 p = fetch_till_str(&ctx->as_string, input,
5431 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5433 syntax_error("unexpected EOF in here document");
5436 free(redir->rd_filename);
5437 redir->rd_filename = p;
5440 redir = redir->next;
5447 /* Should be 0. If it isn't, it's a parse error */
5449 bb_error_msg_and_die("heredoc BUG 2");
5455 #if ENABLE_HUSH_TICK
5456 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5461 char **to_free = NULL;
5465 pid = BB_MMU ? fork() : vfork();
5467 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5469 if (pid == 0) { /* child */
5470 disable_restore_tty_pgrp_on_exit();
5471 /* Process substitution is not considered to be usual
5472 * 'command execution'.
5473 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5480 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5481 close(channel[0]); /* NB: close _first_, then move fd! */
5482 xmove_fd(channel[1], 1);
5483 /* Prevent it from trying to handle ctrl-z etc */
5484 IF_HUSH_JOB(G.run_list_level = 1;)
5485 /* Awful hack for `trap` or $(trap).
5487 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5488 * contains an example where "trap" is executed in a subshell:
5490 * save_traps=$(trap)
5492 * eval "$save_traps"
5494 * Standard does not say that "trap" in subshell shall print
5495 * parent shell's traps. It only says that its output
5496 * must have suitable form, but then, in the above example
5497 * (which is not supposed to be normative), it implies that.
5499 * bash (and probably other shell) does implement it
5500 * (traps are reset to defaults, but "trap" still shows them),
5501 * but as a result, "trap" logic is hopelessly messed up:
5504 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5505 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5506 * # true | trap <--- trap is in subshell - no output (ditto)
5507 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5508 * trap -- 'echo Ho' SIGWINCH
5509 * # echo `(trap)` <--- in subshell in subshell - output
5510 * trap -- 'echo Ho' SIGWINCH
5511 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5512 * trap -- 'echo Ho' SIGWINCH
5514 * The rules when to forget and when to not forget traps
5515 * get really complex and nonsensical.
5517 * Our solution: ONLY bare $(trap) or `trap` is special.
5519 s = skip_whitespace(s);
5520 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5522 static const char *const argv[] = { NULL, NULL };
5523 builtin_trap((char**)argv);
5524 exit(0); /* not _exit() - we need to fflush */
5527 reset_traps_to_defaults();
5528 parse_and_run_string(s);
5529 _exit(G.last_exitcode);
5531 /* We re-execute after vfork on NOMMU. This makes this script safe:
5532 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5533 * huge=`cat BIG` # was blocking here forever
5536 re_execute_shell(&to_free,
5546 # if ENABLE_HUSH_FAST
5548 //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);
5550 enable_restore_tty_pgrp_on_exit();
5555 close_on_exec_on(channel[0]);
5556 return xfdopen_for_read(channel[0]);
5559 /* Return code is exit status of the process that is run. */
5560 static int process_command_subs(o_string *dest, const char *s)
5563 struct in_str pipe_str;
5565 int status, ch, eol_cnt;
5567 fp = generate_stream_from_string(s, &pid);
5569 /* Now send results of command back into original context */
5570 setup_file_in_str(&pipe_str, fp);
5572 while ((ch = i_getch(&pipe_str)) != EOF) {
5578 o_addchr(dest, '\n');
5581 o_addQchr(dest, ch);
5584 debug_printf("done reading from `cmd` pipe, closing it\n");
5586 /* We need to extract exitcode. Test case
5587 * "true; echo `sleep 1; false` $?"
5589 safe_waitpid(pid, &status, 0);
5590 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5591 return WEXITSTATUS(status);
5593 #endif /* ENABLE_HUSH_TICK */
5595 #if !ENABLE_HUSH_FUNCTIONS
5596 #define parse_group(dest, ctx, input, ch) \
5597 parse_group(ctx, input, ch)
5599 static int parse_group(o_string *dest, struct parse_context *ctx,
5600 struct in_str *input, int ch)
5602 /* dest contains characters seen prior to ( or {.
5603 * Typically it's empty, but for function defs,
5604 * it contains function name (without '()'). */
5605 struct pipe *pipe_list;
5607 struct command *command = ctx->command;
5609 debug_printf_parse("parse_group entered\n");
5610 #if ENABLE_HUSH_FUNCTIONS
5611 if (ch == '(' && !dest->o_quoted) {
5613 if (done_word(dest, ctx))
5616 goto skip; /* (... */
5617 if (command->argv[1]) { /* word word ... (... */
5618 syntax_error_unexpected_ch('(');
5621 /* it is "word(..." or "word (..." */
5623 ch = i_getch(input);
5624 while (ch == ' ' || ch == '\t');
5626 syntax_error_unexpected_ch(ch);
5629 nommu_addchr(&ctx->as_string, ch);
5631 ch = i_getch(input);
5632 while (ch == ' ' || ch == '\t' || ch == '\n');
5634 syntax_error_unexpected_ch(ch);
5637 nommu_addchr(&ctx->as_string, ch);
5638 command->cmd_type = CMD_FUNCDEF;
5643 #if 0 /* Prevented by caller */
5644 if (command->argv /* word [word]{... */
5645 || dest->length /* word{... */
5646 || dest->o_quoted /* ""{... */
5649 debug_printf_parse("parse_group return 1: "
5650 "syntax error, groups and arglists don't mix\n");
5655 #if ENABLE_HUSH_FUNCTIONS
5661 command->cmd_type = CMD_SUBSHELL;
5663 /* bash does not allow "{echo...", requires whitespace */
5664 ch = i_getch(input);
5665 if (ch != ' ' && ch != '\t' && ch != '\n') {
5666 syntax_error_unexpected_ch(ch);
5669 nommu_addchr(&ctx->as_string, ch);
5674 char *as_string = NULL;
5676 pipe_list = parse_stream(&as_string, input, endch);
5679 o_addstr(&ctx->as_string, as_string);
5681 /* empty ()/{} or parse error? */
5682 if (!pipe_list || pipe_list == ERR_PTR) {
5683 /* parse_stream already emitted error msg */
5687 debug_printf_parse("parse_group return 1: "
5688 "parse_stream returned %p\n", pipe_list);
5691 command->group = pipe_list;
5693 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5694 command->group_as_string = as_string;
5695 debug_printf_parse("end of group, remembering as:'%s'\n",
5696 command->group_as_string);
5699 debug_printf_parse("parse_group return 0\n");
5701 /* command remains "open", available for possible redirects */
5704 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5705 /* Subroutines for copying $(...) and `...` things */
5706 static void add_till_backquote(o_string *dest, struct in_str *input);
5708 static void add_till_single_quote(o_string *dest, struct in_str *input)
5711 int ch = i_getch(input);
5713 syntax_error_unterm_ch('\'');
5714 /*xfunc_die(); - redundant */
5721 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5722 static void add_till_double_quote(o_string *dest, struct in_str *input)
5725 int ch = i_getch(input);
5727 syntax_error_unterm_ch('"');
5728 /*xfunc_die(); - redundant */
5732 if (ch == '\\') { /* \x. Copy both chars. */
5734 ch = i_getch(input);
5738 add_till_backquote(dest, input);
5742 //if (ch == '$') ...
5745 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5747 * "Within the backquoted style of command substitution, backslash
5748 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5749 * The search for the matching backquote shall be satisfied by the first
5750 * backquote found without a preceding backslash; during this search,
5751 * if a non-escaped backquote is encountered within a shell comment,
5752 * a here-document, an embedded command substitution of the $(command)
5753 * form, or a quoted string, undefined results occur. A single-quoted
5754 * or double-quoted string that begins, but does not end, within the
5755 * "`...`" sequence produces undefined results."
5757 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5759 static void add_till_backquote(o_string *dest, struct in_str *input)
5762 int ch = i_getch(input);
5764 syntax_error_unterm_ch('`');
5765 /*xfunc_die(); - redundant */
5770 /* \x. Copy both chars unless it is \` */
5771 int ch2 = i_getch(input);
5773 syntax_error_unterm_ch('`');
5774 /*xfunc_die(); - redundant */
5776 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5783 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5784 * quoting and nested ()s.
5785 * "With the $(command) style of command substitution, all characters
5786 * following the open parenthesis to the matching closing parenthesis
5787 * constitute the command. Any valid shell script can be used for command,
5788 * except a script consisting solely of redirections which produces
5789 * unspecified results."
5791 * echo $(echo '(TEST)' BEST) (TEST) BEST
5792 * echo $(echo 'TEST)' BEST) TEST) BEST
5793 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5795 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5799 int ch = i_getch(input);
5801 syntax_error_unterm_ch(')');
5802 /*xfunc_die(); - redundant */
5810 if (i_peek(input) == ')') {
5818 add_till_single_quote(dest, input);
5823 add_till_double_quote(dest, input);
5828 /* \x. Copy verbatim. Important for \(, \) */
5829 ch = i_getch(input);
5831 syntax_error_unterm_ch(')');
5832 /*xfunc_die(); - redundant */
5839 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5841 /* Return code: 0 for OK, 1 for syntax error */
5843 #define handle_dollar(as_string, dest, input) \
5844 handle_dollar(dest, input)
5846 static int handle_dollar(o_string *as_string,
5848 struct in_str *input)
5850 int ch = i_peek(input); /* first character after the $ */
5851 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5853 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5855 ch = i_getch(input);
5856 nommu_addchr(as_string, ch);
5858 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5860 debug_printf_parse(": '%c'\n", ch);
5861 o_addchr(dest, ch | quote_mask);
5864 if (!isalnum(ch) && ch != '_')
5866 ch = i_getch(input);
5867 nommu_addchr(as_string, ch);
5869 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5870 } else if (isdigit(ch)) {
5872 ch = i_getch(input);
5873 nommu_addchr(as_string, ch);
5874 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5875 debug_printf_parse(": '%c'\n", ch);
5876 o_addchr(dest, ch | quote_mask);
5877 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5878 } else switch (ch) {
5880 case '!': /* last bg pid */
5881 case '?': /* last exit code */
5882 case '#': /* number of args */
5883 case '*': /* args */
5884 case '@': /* args */
5885 goto make_one_char_var;
5887 bool first_char, all_digits;
5890 ch = i_getch(input);
5891 nommu_addchr(as_string, ch);
5892 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5894 /* TODO: maybe someone will try to escape the '}' */
5899 ch = i_getch(input);
5900 nommu_addchr(as_string, ch);
5907 /* ${#var}: length of var contents */
5914 /* They're being verbose and doing ${?} */
5915 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5920 && ( (all_digits && !isdigit(ch))
5921 || (!all_digits && !isalnum(ch) && ch != '_')
5924 /* handle parameter expansions
5925 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5930 case ':': /* null modifier */
5931 if (expansion == 0) {
5932 debug_printf_parse(": null modifier\n");
5937 case '#': /* remove prefix */
5938 case '%': /* remove suffix */
5939 if (expansion == 0) {
5940 debug_printf_parse(": remove suffix/prefix\n");
5945 case '-': /* default value */
5946 case '=': /* assign default */
5947 case '+': /* alternative */
5948 case '?': /* error indicate */
5949 debug_printf_parse(": parameter expansion\n");
5954 syntax_error_unterm_str("${name}");
5955 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5960 debug_printf_parse(": '%c'\n", ch);
5961 o_addchr(dest, ch | quote_mask);
5965 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5968 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
5973 ch = i_getch(input);
5974 nommu_addchr(as_string, ch);
5975 # if ENABLE_SH_MATH_SUPPORT
5976 if (i_peek(input) == '(') {
5977 ch = i_getch(input);
5978 nommu_addchr(as_string, ch);
5979 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5980 o_addchr(dest, /*quote_mask |*/ '+');
5984 add_till_closing_paren(dest, input, true);
5987 o_addstr(as_string, dest->data + pos);
5988 o_addchr(as_string, ')');
5989 o_addchr(as_string, ')');
5992 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5996 # if ENABLE_HUSH_TICK
5997 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5998 o_addchr(dest, quote_mask | '`');
6002 add_till_closing_paren(dest, input, false);
6005 o_addstr(as_string, dest->data + pos);
6006 o_addchr(as_string, ')');
6009 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6015 ch = i_getch(input);
6016 nommu_addchr(as_string, ch);
6018 if (isalnum(ch)) { /* it's $_name or $_123 */
6023 /* TODO: $_ and $-: */
6024 /* $_ Shell or shell script name; or last argument of last command
6025 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6026 * but in command's env, set to full pathname used to invoke it */
6027 /* $- Option flags set by set builtin or shell options (-i etc) */
6029 o_addQchr(dest, '$');
6031 debug_printf_parse("handle_dollar return 0\n");
6036 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6037 parse_stream_dquoted(dest, input, dquote_end)
6039 static int parse_stream_dquoted(o_string *as_string,
6041 struct in_str *input,
6048 ch = i_getch(input);
6050 nommu_addchr(as_string, ch);
6051 if (ch == dquote_end) { /* may be only '"' or EOF */
6052 if (dest->o_assignment == NOT_ASSIGNMENT)
6053 dest->o_escape ^= 1;
6054 debug_printf_parse("parse_stream_dquoted return 0\n");
6057 /* note: can't move it above ch == dquote_end check! */
6059 syntax_error_unterm_ch('"');
6060 /*xfunc_die(); - redundant */
6064 next = i_peek(input);
6066 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6067 ch, ch, dest->o_escape);
6070 syntax_error("\\<eof>");
6074 * "The backslash retains its special meaning [in "..."]
6075 * only when followed by one of the following characters:
6076 * $, `, ", \, or <newline>. A double quote may be quoted
6077 * within double quotes by preceding it with a backslash."
6079 if (strchr("$`\"\\\n", next) != NULL) {
6080 ch = i_getch(input);
6082 o_addqchr(dest, ch);
6083 nommu_addchr(as_string, ch);
6086 o_addqchr(dest, '\\');
6087 nommu_addchr(as_string, '\\');
6092 if (handle_dollar(as_string, dest, input) != 0) {
6093 debug_printf_parse("parse_stream_dquoted return 1: "
6094 "handle_dollar returned non-0\n");
6099 #if ENABLE_HUSH_TICK
6101 //int pos = dest->length;
6102 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6103 o_addchr(dest, 0x80 | '`');
6104 add_till_backquote(dest, input);
6105 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6106 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6110 o_addQchr(dest, ch);
6112 && (dest->o_assignment == MAYBE_ASSIGNMENT
6113 || dest->o_assignment == WORD_IS_KEYWORD)
6114 && is_well_formed_var_name(dest->data, '=')
6116 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6122 * Scan input until EOF or end_trigger char.
6123 * Return a list of pipes to execute, or NULL on EOF
6124 * or if end_trigger character is met.
6125 * On syntax error, exit is shell is not interactive,
6126 * reset parsing machinery and start parsing anew,
6127 * or return ERR_PTR.
6129 static struct pipe *parse_stream(char **pstring,
6130 struct in_str *input,
6133 struct parse_context ctx;
6134 o_string dest = NULL_O_STRING;
6138 /* Double-quote state is handled in the state variable is_in_dquote.
6139 * A single-quote triggers a bypass of the main loop until its mate is
6140 * found. When recursing, quote state is passed in via dest->o_escape.
6142 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6143 end_trigger ? end_trigger : 'X');
6146 /* If very first arg is "" or '', dest.data may end up NULL.
6147 * Preventing this: */
6148 o_addchr(&dest, '\0');
6151 G.ifs = get_local_var_value("IFS");
6156 #if ENABLE_HUSH_INTERACTIVE
6157 input->promptmode = 0; /* PS1 */
6159 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6160 initialize_context(&ctx);
6165 const char *is_special;
6169 redir_type redir_style;
6172 /* dest.o_quoted = 1; - already is (see below) */
6173 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6176 /* We reached closing '"' */
6179 ch = i_getch(input);
6180 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6181 ch, ch, dest.o_escape);
6186 syntax_error_unterm_str("here document");
6189 /* end_trigger == '}' case errors out earlier,
6190 * checking only ')' */
6191 if (end_trigger == ')') {
6192 syntax_error_unterm_ch('('); /* exits */
6193 /* goto parse_error; */
6196 if (done_word(&dest, &ctx)) {
6200 done_pipe(&ctx, PIPE_SEQ);
6202 /* If we got nothing... */
6203 /* (this makes bare "&" cmd a no-op.
6204 * bash says: "syntax error near unexpected token '&'") */
6205 if (pi->num_cmds == 0
6206 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6212 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6214 *pstring = ctx.as_string.data;
6216 o_free_unsafe(&ctx.as_string);
6219 debug_printf_parse("parse_stream return %p\n", pi);
6222 nommu_addchr(&ctx.as_string, ch);
6226 next = i_peek(input);
6228 is_special = "{}<>;&|()#'" /* special outside of "str" */
6229 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6230 /* Are { and } special here? */
6231 if (ctx.command->argv /* word [word]{... */
6232 || dest.length /* word{... */
6233 || dest.o_quoted /* ""{... */
6234 || (next != ';' && next != ')' && !strchr(G.ifs, next)) /* {word */
6236 /* They are not special, skip "{}" */
6239 is_special = strchr(is_special, ch);
6240 is_ifs = strchr(G.ifs, ch);
6242 if (!is_special && !is_ifs) { /* ordinary char */
6244 o_addQchr(&dest, ch);
6245 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6246 || dest.o_assignment == WORD_IS_KEYWORD)
6248 && is_well_formed_var_name(dest.data, '=')
6250 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6256 if (done_word(&dest, &ctx)) {
6260 #if ENABLE_HUSH_CASE
6261 /* "case ... in <newline> word) ..." -
6262 * newlines are ignored (but ';' wouldn't be) */
6263 if (ctx.command->argv == NULL
6264 && ctx.ctx_res_w == RES_MATCH
6269 /* Treat newline as a command separator. */
6270 done_pipe(&ctx, PIPE_SEQ);
6271 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6273 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6278 dest.o_assignment = MAYBE_ASSIGNMENT;
6280 /* note: if (is_ifs) continue;
6281 * will still trigger for us */
6285 /* "cmd}" or "cmd }..." without semicolon or &:
6286 * } is an ordinary char in this case, even inside { cmd; }
6287 * Pathological example: { ""}; } should exec "}" cmd
6290 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6291 || dest.length != 0 /* word} */
6292 || dest.o_quoted /* ""} */
6296 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6297 goto skip_end_trigger;
6298 /* else: } does terminate a group */
6301 if (end_trigger && end_trigger == ch
6302 && (ch != ';' || heredoc_cnt == 0)
6303 #if ENABLE_HUSH_CASE
6305 || ctx.ctx_res_w != RES_MATCH
6306 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6311 /* This is technically valid:
6312 * { cat <<HERE; }; echo Ok
6316 * but we don't support this.
6317 * We require heredoc to be in enclosing {}/(),
6320 syntax_error_unterm_str("here document");
6323 if (done_word(&dest, &ctx)) {
6326 done_pipe(&ctx, PIPE_SEQ);
6327 dest.o_assignment = MAYBE_ASSIGNMENT;
6328 /* Do we sit outside of any if's, loops or case's? */
6330 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6334 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6336 *pstring = ctx.as_string.data;
6338 o_free_unsafe(&ctx.as_string);
6341 debug_printf_parse("parse_stream return %p: "
6342 "end_trigger char found\n",
6344 return ctx.list_head;
6351 /* Catch <, > before deciding whether this word is
6352 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6355 redir_fd = redirect_opt_num(&dest);
6356 if (done_word(&dest, &ctx)) {
6359 redir_style = REDIRECT_OVERWRITE;
6361 redir_style = REDIRECT_APPEND;
6362 ch = i_getch(input);
6363 nommu_addchr(&ctx.as_string, ch);
6366 else if (next == '(') {
6367 syntax_error(">(process) not supported");
6371 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6373 continue; /* back to top of while (1) */
6375 redir_fd = redirect_opt_num(&dest);
6376 if (done_word(&dest, &ctx)) {
6379 redir_style = REDIRECT_INPUT;
6381 redir_style = REDIRECT_HEREDOC;
6383 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6384 ch = i_getch(input);
6385 nommu_addchr(&ctx.as_string, ch);
6386 } else if (next == '>') {
6387 redir_style = REDIRECT_IO;
6388 ch = i_getch(input);
6389 nommu_addchr(&ctx.as_string, ch);
6392 else if (next == '(') {
6393 syntax_error("<(process) not supported");
6397 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6399 continue; /* back to top of while (1) */
6402 if (dest.o_assignment == MAYBE_ASSIGNMENT
6403 /* check that we are not in word in "a=1 2>word b=1": */
6404 && !ctx.pending_redirect
6406 /* ch is a special char and thus this word
6407 * cannot be an assignment */
6408 dest.o_assignment = NOT_ASSIGNMENT;
6411 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6415 if (dest.length == 0) {
6418 if (ch == EOF || ch == '\n')
6421 /* note: we do not add it to &ctx.as_string */
6423 nommu_addchr(&ctx.as_string, '\n');
6425 o_addQchr(&dest, ch);
6430 syntax_error("\\<eof>");
6433 ch = i_getch(input);
6435 o_addchr(&dest, '\\');
6436 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6437 o_addchr(&dest, ch);
6438 nommu_addchr(&ctx.as_string, ch);
6439 /* Example: echo Hello \2>file
6440 * we need to know that word 2 is quoted */
6445 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6446 ctx.as_string.data[--ctx.as_string.length] = '\0';
6451 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6452 debug_printf_parse("parse_stream parse error: "
6453 "handle_dollar returned non-0\n");
6460 ch = i_getch(input);
6462 syntax_error_unterm_ch('\'');
6463 /*xfunc_die(); - redundant */
6465 nommu_addchr(&ctx.as_string, ch);
6468 o_addqchr(&dest, ch);
6473 is_in_dquote ^= 1; /* invert */
6474 if (dest.o_assignment == NOT_ASSIGNMENT)
6477 #if ENABLE_HUSH_TICK
6482 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6483 o_addchr(&dest, '`');
6487 add_till_backquote(&dest, input);
6489 o_addstr(&ctx.as_string, dest.data + pos);
6490 o_addchr(&ctx.as_string, '`');
6492 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6493 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6498 #if ENABLE_HUSH_CASE
6501 if (done_word(&dest, &ctx)) {
6504 done_pipe(&ctx, PIPE_SEQ);
6505 #if ENABLE_HUSH_CASE
6506 /* Eat multiple semicolons, detect
6507 * whether it means something special */
6512 ch = i_getch(input);
6513 nommu_addchr(&ctx.as_string, ch);
6514 if (ctx.ctx_res_w == RES_CASE_BODY) {
6515 ctx.ctx_dsemicolon = 1;
6516 ctx.ctx_res_w = RES_MATCH;
6522 /* We just finished a cmd. New one may start
6523 * with an assignment */
6524 dest.o_assignment = MAYBE_ASSIGNMENT;
6527 if (done_word(&dest, &ctx)) {
6531 ch = i_getch(input);
6532 nommu_addchr(&ctx.as_string, ch);
6533 done_pipe(&ctx, PIPE_AND);
6535 done_pipe(&ctx, PIPE_BG);
6539 if (done_word(&dest, &ctx)) {
6542 #if ENABLE_HUSH_CASE
6543 if (ctx.ctx_res_w == RES_MATCH)
6544 break; /* we are in case's "word | word)" */
6546 if (next == '|') { /* || */
6547 ch = i_getch(input);
6548 nommu_addchr(&ctx.as_string, ch);
6549 done_pipe(&ctx, PIPE_OR);
6551 /* we could pick up a file descriptor choice here
6552 * with redirect_opt_num(), but bash doesn't do it.
6553 * "echo foo 2| cat" yields "foo 2". */
6556 o_reset_to_empty_unquoted(&ctx.as_string);
6561 #if ENABLE_HUSH_CASE
6562 /* "case... in [(]word)..." - skip '(' */
6563 if (ctx.ctx_res_w == RES_MATCH
6564 && ctx.command->argv == NULL /* not (word|(... */
6565 && dest.length == 0 /* not word(... */
6566 && dest.o_quoted == 0 /* not ""(... */
6572 if (parse_group(&dest, &ctx, input, ch) != 0) {
6577 #if ENABLE_HUSH_CASE
6578 if (ctx.ctx_res_w == RES_MATCH)
6582 /* proper use of this character is caught by end_trigger:
6583 * if we see {, we call parse_group(..., end_trigger='}')
6584 * and it will match } earlier (not here). */
6585 syntax_error_unexpected_ch(ch);
6589 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6595 struct parse_context *pctx;
6596 IF_HAS_KEYWORDS(struct parse_context *p2;)
6598 /* Clean up allocated tree.
6599 * Sample for finding leaks on syntax error recovery path.
6600 * Run it from interactive shell, watch pmap `pidof hush`.
6601 * while if false; then false; fi; do break; fi
6602 * Samples to catch leaks at execution:
6603 * while if (true | {true;}); then echo ok; fi; do break; done
6604 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6608 /* Update pipe/command counts,
6609 * otherwise freeing may miss some */
6610 done_pipe(pctx, PIPE_SEQ);
6611 debug_printf_clean("freeing list %p from ctx %p\n",
6612 pctx->list_head, pctx);
6613 debug_print_tree(pctx->list_head, 0);
6614 free_pipe_list(pctx->list_head);
6615 debug_printf_clean("freed list %p\n", pctx->list_head);
6617 o_free_unsafe(&pctx->as_string);
6619 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6623 IF_HAS_KEYWORDS(pctx = p2;)
6624 } while (HAS_KEYWORDS && pctx);
6625 /* Free text, clear all dest fields */
6627 /* If we are not in top-level parse, we return,
6628 * our caller will propagate error.
6630 if (end_trigger != ';') {
6638 /* Discard cached input, force prompt */
6640 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6645 /* Executing from string: eval, sh -c '...'
6646 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6647 * end_trigger controls how often we stop parsing
6648 * NUL: parse all, execute, return
6649 * ';': parse till ';' or newline, execute, repeat till EOF
6651 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6653 /* Why we need empty flag?
6654 * An obscure corner case "false; ``; echo $?":
6655 * empty command in `` should still set $? to 0.
6656 * But we can't just set $? to 0 at the start,
6657 * this breaks "false; echo `echo $?`" case.
6661 struct pipe *pipe_list;
6663 pipe_list = parse_stream(NULL, inp, end_trigger);
6664 if (!pipe_list) { /* EOF */
6666 G.last_exitcode = 0;
6669 debug_print_tree(pipe_list, 0);
6670 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6671 run_and_free_list(pipe_list);
6676 static void parse_and_run_string(const char *s)
6678 struct in_str input;
6679 setup_string_in_str(&input, s);
6680 parse_and_run_stream(&input, '\0');
6683 static void parse_and_run_file(FILE *f)
6685 struct in_str input;
6686 setup_file_in_str(&input, f);
6687 parse_and_run_stream(&input, ';');
6690 /* Called a few times only (or even once if "sh -c") */
6691 static void init_sigmasks(void)
6695 sigset_t old_blocked_set;
6697 if (!G.inherited_set_is_saved) {
6698 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6699 G.inherited_set = G.blocked_set;
6701 old_blocked_set = G.blocked_set;
6703 mask = (1 << SIGQUIT);
6704 if (G_interactive_fd) {
6705 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6706 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6707 mask |= SPECIAL_JOB_SIGS;
6709 G.non_DFL_mask = mask;
6714 sigaddset(&G.blocked_set, sig);
6718 sigdelset(&G.blocked_set, SIGCHLD);
6720 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6721 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6723 /* POSIX allows shell to re-enable SIGCHLD
6724 * even if it was SIG_IGN on entry */
6725 #if ENABLE_HUSH_FAST
6726 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6727 if (!G.inherited_set_is_saved)
6728 signal(SIGCHLD, SIGCHLD_handler);
6730 if (!G.inherited_set_is_saved)
6731 signal(SIGCHLD, SIG_DFL);
6734 G.inherited_set_is_saved = 1;
6739 static void maybe_set_to_sigexit(int sig)
6741 void (*handler)(int);
6742 /* non_DFL_mask'ed signals are, well, masked,
6743 * no need to set handler for them.
6745 if (!((G.non_DFL_mask >> sig) & 1)) {
6746 handler = signal(sig, sigexit);
6747 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6748 signal(sig, handler);
6751 /* Set handlers to restore tty pgrp and exit */
6752 static void set_fatal_handlers(void)
6754 /* We _must_ restore tty pgrp on fatal signals */
6756 maybe_set_to_sigexit(SIGILL );
6757 maybe_set_to_sigexit(SIGFPE );
6758 maybe_set_to_sigexit(SIGBUS );
6759 maybe_set_to_sigexit(SIGSEGV);
6760 maybe_set_to_sigexit(SIGTRAP);
6761 } /* else: hush is perfect. what SEGV? */
6762 maybe_set_to_sigexit(SIGABRT);
6763 /* bash 3.2 seems to handle these just like 'fatal' ones */
6764 maybe_set_to_sigexit(SIGPIPE);
6765 maybe_set_to_sigexit(SIGALRM);
6766 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6767 * if we aren't interactive... but in this case
6768 * we never want to restore pgrp on exit, and this fn is not called */
6769 /*maybe_set_to_sigexit(SIGHUP );*/
6770 /*maybe_set_to_sigexit(SIGTERM);*/
6771 /*maybe_set_to_sigexit(SIGINT );*/
6775 static int set_mode(const char cstate, const char mode)
6777 int state = (cstate == '-' ? 1 : 0);
6779 case 'n': G.fake_mode = state; break;
6780 case 'x': /*G.debug_mode = state;*/ break;
6781 default: return EXIT_FAILURE;
6783 return EXIT_SUCCESS;
6786 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6787 int hush_main(int argc, char **argv)
6789 static const struct variable const_shell_ver = {
6791 .varstr = (char*)hush_version_str,
6792 .max_len = 1, /* 0 can provoke free(name) */
6797 unsigned builtin_argc;
6799 struct variable *cur_var;
6802 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6803 G.last_exitcode = EXIT_SUCCESS;
6805 G.argv0_for_re_execing = argv[0];
6807 /* Deal with HUSH_VERSION */
6808 G.shell_ver = const_shell_ver; /* copying struct here */
6809 G.top_var = &G.shell_ver;
6810 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6811 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6812 /* Initialize our shell local variables with the values
6813 * currently living in the environment */
6814 cur_var = G.top_var;
6817 char *value = strchr(*e, '=');
6818 if (value) { /* paranoia */
6819 cur_var->next = xzalloc(sizeof(*cur_var));
6820 cur_var = cur_var->next;
6821 cur_var->varstr = *e;
6822 cur_var->max_len = strlen(*e);
6823 cur_var->flg_export = 1;
6827 /* reinstate HUSH_VERSION */
6828 debug_printf_env("putenv '%s'\n", hush_version_str);
6829 putenv((char *)hush_version_str);
6832 set_pwd_var(/*exp:*/ 1);
6833 /* bash also exports SHLVL and _,
6834 * and sets (but doesn't export) the following variables:
6836 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6837 * BASH_VERSION='3.2.0(1)-release'
6839 * MACHTYPE=i386-pc-linux-gnu
6841 * HOSTNAME=<xxxxxxxxxx>
6842 * PPID=<NNNNN> - we also do it elsewhere
6853 * PIPESTATUS=([0]="0")
6854 * HISTFILE=/<xxx>/.bash_history
6858 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6860 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6870 #if ENABLE_FEATURE_EDITING
6871 G.line_input_state = new_line_input_t(FOR_SHELL);
6873 G.global_argc = argc;
6874 G.global_argv = argv;
6875 /* Initialize some more globals to non-zero values */
6876 cmdedit_update_prompt();
6878 if (setjmp(die_jmp)) {
6879 /* xfunc has failed! die die die */
6880 /* no EXIT traps, this is an escape hatch! */
6882 hush_exit(xfunc_error_retval);
6885 /* Shell is non-interactive at first. We need to call
6886 * init_sigmasks() if we are going to execute "sh <script>",
6887 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6888 * If we later decide that we are interactive, we run init_sigmasks()
6889 * in order to intercept (more) signals.
6893 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6896 opt = getopt(argc, argv, "+c:xins"
6899 # if ENABLE_HUSH_FUNCTIONS
6909 * sh ... -c 'script'
6910 * sh ... -c 'script' ARG0 [ARG1...]
6911 * On NOMMU, if builtin_argc != 0,
6912 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6913 * "" needs to be replaced with NULL
6914 * and BARGV vector fed to builtin function.
6915 * Note: the form without ARG0 never happens:
6916 * sh ... -c 'builtin' BARGV... ""
6919 G.root_pid = getpid();
6920 G.root_ppid = getppid();
6922 G.global_argv = argv + optind;
6923 G.global_argc = argc - optind;
6925 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6926 const struct built_in_command *x;
6929 x = find_builtin(optarg);
6930 if (x) { /* paranoia */
6931 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6932 G.global_argv += builtin_argc;
6933 G.global_argv[-1] = NULL; /* replace "" */
6934 G.last_exitcode = x->b_function(argv + optind - 1);
6938 if (!G.global_argv[0]) {
6939 /* -c 'script' (no params): prevent empty $0 */
6940 G.global_argv--; /* points to argv[i] of 'script' */
6941 G.global_argv[0] = argv[0];
6943 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6945 parse_and_run_string(optarg);
6948 /* Well, we cannot just declare interactiveness,
6949 * we have to have some stuff (ctty, etc) */
6950 /* G_interactive_fd++; */
6953 /* "-s" means "read from stdin", but this is how we always
6954 * operate, so simply do nothing here. */
6957 case '<': /* "big heredoc" support */
6958 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6961 unsigned long long empty_trap_mask;
6963 G.root_pid = bb_strtou(optarg, &optarg, 16);
6965 G.root_ppid = bb_strtou(optarg, &optarg, 16);
6967 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6969 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6971 builtin_argc = bb_strtou(optarg, &optarg, 16);
6973 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
6974 if (empty_trap_mask != 0) {
6977 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6978 for (sig = 1; sig < NSIG; sig++) {
6979 if (empty_trap_mask & (1LL << sig)) {
6980 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
6981 sigaddset(&G.blocked_set, sig);
6984 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6986 # if ENABLE_HUSH_LOOPS
6988 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6994 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
6996 # if ENABLE_HUSH_FUNCTIONS
6998 struct function *funcp = new_function(optarg);
6999 /* funcp->name is already set to optarg */
7000 /* funcp->body is set to NULL. It's a special case. */
7001 funcp->body_as_string = argv[optind];
7009 if (!set_mode('-', opt))
7013 fprintf(stderr, "Usage: sh [FILE]...\n"
7014 " or: sh -c command [args]...\n\n");
7020 } /* option parsing loop */
7023 G.root_pid = getpid();
7024 G.root_ppid = getppid();
7027 /* If we are login shell... */
7028 if (argv[0] && argv[0][0] == '-') {
7030 debug_printf("sourcing /etc/profile\n");
7031 input = fopen_for_read("/etc/profile");
7032 if (input != NULL) {
7033 close_on_exec_on(fileno(input));
7035 parse_and_run_file(input);
7038 /* bash: after sourcing /etc/profile,
7039 * tries to source (in the given order):
7040 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7041 * stopping on first found. --noprofile turns this off.
7042 * bash also sources ~/.bash_logout on exit.
7043 * If called as sh, skips .bash_XXX files.
7050 * "bash <script>" (which is never interactive (unless -i?))
7051 * sources $BASH_ENV here (without scanning $PATH).
7052 * If called as sh, does the same but with $ENV.
7054 debug_printf("running script '%s'\n", argv[optind]);
7055 G.global_argv = argv + optind;
7056 G.global_argc = argc - optind;
7057 input = xfopen_for_read(argv[optind]);
7058 close_on_exec_on(fileno(input));
7060 parse_and_run_file(input);
7061 #if ENABLE_FEATURE_CLEAN_UP
7067 /* Up to here, shell was non-interactive. Now it may become one.
7068 * NB: don't forget to (re)run init_sigmasks() as needed.
7071 /* A shell is interactive if the '-i' flag was given,
7072 * or if all of the following conditions are met:
7074 * no arguments remaining or the -s flag given
7075 * standard input is a terminal
7076 * standard output is a terminal
7077 * Refer to Posix.2, the description of the 'sh' utility.
7080 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7081 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7082 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7083 if (G_saved_tty_pgrp < 0)
7084 G_saved_tty_pgrp = 0;
7086 /* try to dup stdin to high fd#, >= 255 */
7087 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7088 if (G_interactive_fd < 0) {
7089 /* try to dup to any fd */
7090 G_interactive_fd = dup(STDIN_FILENO);
7091 if (G_interactive_fd < 0) {
7093 G_interactive_fd = 0;
7094 G_saved_tty_pgrp = 0;
7097 // TODO: track & disallow any attempts of user
7098 // to (inadvertently) close/redirect G_interactive_fd
7100 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7101 if (G_interactive_fd) {
7102 close_on_exec_on(G_interactive_fd);
7104 if (G_saved_tty_pgrp) {
7105 /* If we were run as 'hush &', sleep until we are
7106 * in the foreground (tty pgrp == our pgrp).
7107 * If we get started under a job aware app (like bash),
7108 * make sure we are now in charge so we don't fight over
7109 * who gets the foreground */
7111 pid_t shell_pgrp = getpgrp();
7112 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7113 if (G_saved_tty_pgrp == shell_pgrp)
7115 /* send TTIN to ourself (should stop us) */
7116 kill(- shell_pgrp, SIGTTIN);
7120 /* Block some signals */
7123 if (G_saved_tty_pgrp) {
7124 /* Set other signals to restore saved_tty_pgrp */
7125 set_fatal_handlers();
7126 /* Put ourselves in our own process group
7127 * (bash, too, does this only if ctty is available) */
7128 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7129 /* Grab control of the terminal */
7130 tcsetpgrp(G_interactive_fd, getpid());
7132 /* -1 is special - makes xfuncs longjmp, not exit
7133 * (we reset die_sleep = 0 whereever we [v]fork) */
7134 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7138 #elif ENABLE_HUSH_INTERACTIVE
7139 /* No job control compiled in, only prompt/line editing */
7140 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7141 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7142 if (G_interactive_fd < 0) {
7143 /* try to dup to any fd */
7144 G_interactive_fd = dup(STDIN_FILENO);
7145 if (G_interactive_fd < 0)
7147 G_interactive_fd = 0;
7150 if (G_interactive_fd) {
7151 close_on_exec_on(G_interactive_fd);
7155 /* We have interactiveness code disabled */
7159 * if interactive but not a login shell, sources ~/.bashrc
7160 * (--norc turns this off, --rcfile <file> overrides)
7163 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7164 /* note: ash and hush share this string */
7165 printf("\n\n%s %s\n"
7166 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7169 "hush - the humble shell"
7173 parse_and_run_file(stdin);
7176 #if ENABLE_FEATURE_CLEAN_UP
7177 if (G.cwd != bb_msg_unknown)
7179 cur_var = G.top_var->next;
7181 struct variable *tmp = cur_var;
7182 if (!cur_var->max_len)
7183 free(cur_var->varstr);
7184 cur_var = cur_var->next;
7188 hush_exit(G.last_exitcode);
7193 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7194 int lash_main(int argc, char **argv)
7196 bb_error_msg("lash is deprecated, please use hush instead");
7197 return hush_main(argc, argv);
7202 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7203 int msh_main(int argc, char **argv)
7205 //bb_error_msg("msh is deprecated, please use hush instead");
7206 return hush_main(argc, argv);
7214 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7219 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7226 return applet_main_func(argc, argv - argc);
7229 static int FAST_FUNC builtin_test(char **argv)
7231 return run_applet_main(argv, test_main);
7234 static int FAST_FUNC builtin_echo(char **argv)
7236 return run_applet_main(argv, echo_main);
7240 static int FAST_FUNC builtin_printf(char **argv)
7242 return run_applet_main(argv, printf_main);
7246 static int FAST_FUNC builtin_eval(char **argv)
7248 int rcode = EXIT_SUCCESS;
7251 char *str = expand_strvec_to_string(argv);
7253 * eval "echo Hi; done" ("done" is syntax error):
7254 * "echo Hi" will not execute too.
7256 parse_and_run_string(str);
7258 rcode = G.last_exitcode;
7263 static int FAST_FUNC builtin_cd(char **argv)
7265 const char *newdir = argv[1];
7266 if (newdir == NULL) {
7267 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7268 * bash says "bash: cd: HOME not set" and does nothing
7271 const char *home = get_local_var_value("HOME");
7272 newdir = home ? home : "/";
7274 if (chdir(newdir)) {
7275 /* Mimic bash message exactly */
7276 bb_perror_msg("cd: %s", newdir);
7277 return EXIT_FAILURE;
7279 /* Read current dir (get_cwd(1) is inside) and set PWD.
7280 * Note: do not enforce exporting. If PWD was unset or unexported,
7281 * set it again, but do not export. bash does the same.
7283 set_pwd_var(/*exp:*/ 0);
7284 return EXIT_SUCCESS;
7287 static int FAST_FUNC builtin_exec(char **argv)
7289 if (*++argv == NULL)
7290 return EXIT_SUCCESS; /* bash does this */
7292 /* Careful: we can end up here after [v]fork. Do not restore
7293 * tty pgrp then, only top-level shell process does that */
7294 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7295 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7297 /* TODO: if exec fails, bash does NOT exit! We do.
7298 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7299 * and tcsetpgrp, and this is inherently racy.
7301 execvp_or_die(argv);
7304 static int FAST_FUNC builtin_exit(char **argv)
7306 debug_printf_exec("%s()\n", __func__);
7308 /* interactive bash:
7309 * # trap "echo EEE" EXIT
7312 * There are stopped jobs.
7313 * (if there are _stopped_ jobs, running ones don't count)
7316 # EEE (then bash exits)
7318 * we can use G.exiting = -1 as indicator "last cmd was exit"
7321 /* note: EXIT trap is run by hush_exit */
7322 if (*++argv == NULL)
7323 hush_exit(G.last_exitcode);
7324 /* mimic bash: exit 123abc == exit 255 + error msg */
7325 xfunc_error_retval = 255;
7326 /* bash: exit -2 == exit 254, no error msg */
7327 hush_exit(xatoi(*argv) & 0xff);
7330 static void print_escaped(const char *s)
7335 const char *p = strchrnul(s, '\'');
7336 /* print 'xxxx', possibly just '' */
7337 printf("'%.*s'", (int)(p - s), s);
7342 /* s points to '; print "'''...'''" */
7344 do putchar('\''); while (*++s == '\'');
7349 #if !ENABLE_HUSH_LOCAL
7350 #define helper_export_local(argv, exp, lvl) \
7351 helper_export_local(argv, exp)
7353 static void helper_export_local(char **argv, int exp, int lvl)
7358 /* So far we do not check that name is valid (TODO?) */
7360 if (strchr(name, '=') == NULL) {
7361 struct variable *var;
7363 var = get_local_var(name);
7364 if (exp == -1) { /* unexporting? */
7365 /* export -n NAME (without =VALUE) */
7367 var->flg_export = 0;
7368 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7370 } /* else: export -n NOT_EXISTING_VAR: no-op */
7373 if (exp == 1) { /* exporting? */
7374 /* export NAME (without =VALUE) */
7376 var->flg_export = 1;
7377 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7378 putenv(var->varstr);
7382 /* Exporting non-existing variable.
7383 * bash does not put it in environment,
7384 * but remembers that it is exported,
7385 * and does put it in env when it is set later.
7386 * We just set it to "" and export. */
7387 /* Or, it's "local NAME" (without =VALUE).
7388 * bash sets the value to "". */
7389 name = xasprintf("%s=", name);
7391 /* (Un)exporting/making local NAME=VALUE */
7392 name = xstrdup(name);
7394 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7398 static int FAST_FUNC builtin_export(char **argv)
7400 unsigned opt_unexport;
7402 #if ENABLE_HUSH_EXPORT_N
7403 /* "!": do not abort on errors */
7404 opt_unexport = getopt32(argv, "!n");
7405 if (opt_unexport == (uint32_t)-1)
7406 return EXIT_FAILURE;
7413 if (argv[0] == NULL) {
7420 /* ash emits: export VAR='VAL'
7421 * bash: declare -x VAR="VAL"
7422 * we follow ash example */
7423 const char *s = *e++;
7424 const char *p = strchr(s, '=');
7426 if (!p) /* wtf? take next variable */
7429 printf("export %.*s", (int)(p - s) + 1, s);
7430 print_escaped(p + 1);
7434 /*fflush_all(); - done after each builtin anyway */
7436 return EXIT_SUCCESS;
7439 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7441 return EXIT_SUCCESS;
7444 #if ENABLE_HUSH_LOCAL
7445 static int FAST_FUNC builtin_local(char **argv)
7447 if (G.func_nest_level == 0) {
7448 bb_error_msg("%s: not in a function", argv[0]);
7449 return EXIT_FAILURE; /* bash compat */
7451 helper_export_local(argv, 0, G.func_nest_level);
7452 return EXIT_SUCCESS;
7456 static int FAST_FUNC builtin_trap(char **argv)
7462 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7467 /* No args: print all trapped */
7468 for (i = 0; i < NSIG; ++i) {
7471 print_escaped(G.traps[i]);
7472 /* note: bash adds "SIG", but only if invoked
7473 * as "bash". If called as "sh", or if set -o posix,
7474 * then it prints short signal names.
7475 * We are printing short names: */
7476 printf(" %s\n", get_signame(i));
7479 /*fflush_all(); - done after each builtin anyway */
7480 return EXIT_SUCCESS;
7484 /* If first arg is a number: reset all specified signals */
7485 sig = bb_strtou(*argv, NULL, 10);
7491 sig = get_signum(*argv++);
7492 if (sig < 0 || sig >= NSIG) {
7494 /* Mimic bash message exactly */
7495 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7500 G.traps[sig] = xstrdup(new_cmd);
7502 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7503 get_signame(sig), sig, G.traps[sig]);
7505 /* There is no signal for 0 (EXIT) */
7510 sigaddset(&G.blocked_set, sig);
7512 /* There was a trap handler, we are removing it
7513 * (if sig has non-DFL handling,
7514 * we don't need to do anything) */
7515 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7517 sigdelset(&G.blocked_set, sig);
7520 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7524 if (!argv[1]) { /* no second arg */
7525 bb_error_msg("trap: invalid arguments");
7526 return EXIT_FAILURE;
7529 /* First arg is "-": reset all specified to default */
7530 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7531 /* Everything else: set arg as signal handler
7532 * (includes "" case, which ignores signal) */
7533 if (argv[0][0] == '-') {
7534 if (argv[0][1] == '\0') { /* "-" */
7535 /* new_cmd remains NULL: "reset these sigs" */
7538 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7541 /* else: "-something", no special meaning */
7546 goto process_sig_list;
7549 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7550 static int FAST_FUNC builtin_type(char **argv)
7552 int ret = EXIT_SUCCESS;
7558 if (0) {} /* make conditional compile easier below */
7559 /*else if (find_alias(*argv))
7560 type = "an alias";*/
7561 #if ENABLE_HUSH_FUNCTIONS
7562 else if (find_function(*argv))
7563 type = "a function";
7565 else if (find_builtin(*argv))
7566 type = "a shell builtin";
7567 else if ((path = find_in_path(*argv)) != NULL)
7570 bb_error_msg("type: %s: not found", *argv);
7575 printf("%s is %s\n", *argv, type);
7583 /* built-in 'fg' and 'bg' handler */
7584 static int FAST_FUNC builtin_fg_bg(char **argv)
7589 if (!G_interactive_fd)
7590 return EXIT_FAILURE;
7592 /* If they gave us no args, assume they want the last backgrounded task */
7594 for (pi = G.job_list; pi; pi = pi->next) {
7595 if (pi->jobid == G.last_jobid) {
7599 bb_error_msg("%s: no current job", argv[0]);
7600 return EXIT_FAILURE;
7602 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7603 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7604 return EXIT_FAILURE;
7606 for (pi = G.job_list; pi; pi = pi->next) {
7607 if (pi->jobid == jobnum) {
7611 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7612 return EXIT_FAILURE;
7614 /* TODO: bash prints a string representation
7615 * of job being foregrounded (like "sleep 1 | cat") */
7616 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7617 /* Put the job into the foreground. */
7618 tcsetpgrp(G_interactive_fd, pi->pgrp);
7621 /* Restart the processes in the job */
7622 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7623 for (i = 0; i < pi->num_cmds; i++) {
7624 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7625 pi->cmds[i].is_stopped = 0;
7627 pi->stopped_cmds = 0;
7629 i = kill(- pi->pgrp, SIGCONT);
7631 if (errno == ESRCH) {
7632 delete_finished_bg_job(pi);
7633 return EXIT_SUCCESS;
7635 bb_perror_msg("kill (SIGCONT)");
7638 if (argv[0][0] == 'f') {
7640 return checkjobs_and_fg_shell(pi);
7642 return EXIT_SUCCESS;
7646 #if ENABLE_HUSH_HELP
7647 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7649 const struct built_in_command *x;
7652 "Built-in commands:\n"
7653 "------------------\n");
7654 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7656 printf("%s\t%s\n", x->b_cmd, x->b_descr);
7659 return EXIT_SUCCESS;
7664 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7667 const char *status_string;
7669 for (job = G.job_list; job; job = job->next) {
7670 if (job->alive_cmds == job->stopped_cmds)
7671 status_string = "Stopped";
7673 status_string = "Running";
7675 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7677 return EXIT_SUCCESS;
7682 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7687 # ifdef M_TRIM_THRESHOLD
7688 /* Optional. Reduces probability of false positives */
7691 /* Crude attempt to find where "free memory" starts,
7692 * sans fragmentation. */
7694 l = (unsigned long)p;
7697 if (l < (unsigned long)p) l = (unsigned long)p;
7700 if (!G.memleak_value)
7701 G.memleak_value = l;
7703 l -= G.memleak_value;
7710 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7715 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7718 return EXIT_SUCCESS;
7721 static int FAST_FUNC builtin_read(char **argv)
7730 /* "!": do not abort on errors.
7731 * Option string must start with "sr" to match BUILTIN_READ_xxx
7733 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7734 if (read_flags == (uint32_t)-1)
7735 return EXIT_FAILURE;
7738 r = shell_builtin_read(set_local_var_from_halves,
7740 get_local_var_value("IFS"), /* can be NULL */
7748 if ((uintptr_t)r > 1) {
7749 bb_error_msg("%s", r);
7750 r = (char*)(uintptr_t)1;
7753 return (uintptr_t)r;
7756 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7757 * built-in 'set' handler
7759 * set [-abCefhmnuvx] [-o option] [argument...]
7760 * set [+abCefhmnuvx] [+o option] [argument...]
7761 * set -- [argument...]
7764 * Implementations shall support the options in both their hyphen and
7765 * plus-sign forms. These options can also be specified as options to sh.
7767 * Write out all variables and their values: set
7768 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7769 * Turn on the -x and -v options: set -xv
7770 * Unset all positional parameters: set --
7771 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7772 * Set the positional parameters to the expansion of x, even if x expands
7773 * with a leading '-' or '+': set -- $x
7775 * So far, we only support "set -- [argument...]" and some of the short names.
7777 static int FAST_FUNC builtin_set(char **argv)
7780 char **pp, **g_argv;
7781 char *arg = *++argv;
7785 for (e = G.top_var; e; e = e->next)
7787 return EXIT_SUCCESS;
7791 if (!strcmp(arg, "--")) {
7795 if (arg[0] != '+' && arg[0] != '-')
7797 for (n = 1; arg[n]; ++n)
7798 if (set_mode(arg[0], arg[n]))
7800 } while ((arg = *++argv) != NULL);
7801 /* Now argv[0] is 1st argument */
7804 return EXIT_SUCCESS;
7807 /* NB: G.global_argv[0] ($0) is never freed/changed */
7808 g_argv = G.global_argv;
7809 if (G.global_args_malloced) {
7815 G.global_args_malloced = 1;
7816 pp = xzalloc(sizeof(pp[0]) * 2);
7817 pp[0] = g_argv[0]; /* retain $0 */
7820 /* This realloc's G.global_argv */
7821 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7828 return EXIT_SUCCESS;
7830 /* Nothing known, so abort */
7832 bb_error_msg("set: %s: invalid option", arg);
7833 return EXIT_FAILURE;
7836 static int FAST_FUNC builtin_shift(char **argv)
7842 if (n >= 0 && n < G.global_argc) {
7843 if (G.global_args_malloced) {
7846 free(G.global_argv[m++]);
7849 memmove(&G.global_argv[1], &G.global_argv[n+1],
7850 G.global_argc * sizeof(G.global_argv[0]));
7851 return EXIT_SUCCESS;
7853 return EXIT_FAILURE;
7856 static int FAST_FUNC builtin_source(char **argv)
7861 #if ENABLE_HUSH_FUNCTIONS
7865 if (*++argv == NULL)
7866 return EXIT_FAILURE;
7868 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7869 input = fopen_for_read(arg_path);
7872 input = fopen_or_warn(*argv, "r");
7874 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7875 return EXIT_FAILURE;
7877 close_on_exec_on(fileno(input));
7879 #if ENABLE_HUSH_FUNCTIONS
7880 sv_flg = G.flag_return_in_progress;
7881 /* "we are inside sourced file, ok to use return" */
7882 G.flag_return_in_progress = -1;
7884 save_and_replace_G_args(&sv, argv);
7886 parse_and_run_file(input);
7889 restore_G_args(&sv, argv);
7890 #if ENABLE_HUSH_FUNCTIONS
7891 G.flag_return_in_progress = sv_flg;
7894 return G.last_exitcode;
7897 static int FAST_FUNC builtin_umask(char **argv)
7904 mode_t old_mask = mask;
7907 rc = bb_parse_mode(argv[1], &mask);
7912 * bash: umask: 'q': invalid symbolic mode operator
7913 * bash: umask: 999: octal number out of range
7915 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7920 printf("%04o\n", (unsigned) mask);
7921 /* fall through and restore mask which we set to 0 */
7925 return !rc; /* rc != 0 - success */
7928 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7929 static int FAST_FUNC builtin_unset(char **argv)
7934 /* "!": do not abort on errors */
7935 /* "+": stop at 1st non-option */
7936 opts = getopt32(argv, "!+vf");
7937 if (opts == (unsigned)-1)
7938 return EXIT_FAILURE;
7940 bb_error_msg("unset: -v and -f are exclusive");
7941 return EXIT_FAILURE;
7947 if (!(opts & 2)) { /* not -f */
7948 if (unset_local_var(*argv)) {
7949 /* unset <nonexistent_var> doesn't fail.
7950 * Error is when one tries to unset RO var.
7951 * Message was printed by unset_local_var. */
7955 #if ENABLE_HUSH_FUNCTIONS
7965 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7966 static int FAST_FUNC builtin_wait(char **argv)
7968 int ret = EXIT_SUCCESS;
7971 if (*++argv == NULL) {
7972 /* Don't care about wait results */
7973 /* Note 1: must wait until there are no more children */
7974 /* Note 2: must be interruptible */
7976 * $ sleep 3 & sleep 6 & wait
7981 * $ sleep 3 & sleep 6 & wait
7985 * ^C <-- after ~4 sec from keyboard
7988 sigaddset(&G.blocked_set, SIGCHLD);
7989 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7992 if (errno == ECHILD)
7994 /* Wait for SIGCHLD or any other signal of interest */
7995 /* sigtimedwait with infinite timeout: */
7996 sig = sigwaitinfo(&G.blocked_set, NULL);
7998 sig = check_and_run_traps(sig);
7999 if (sig && sig != SIGCHLD) { /* see note 2 */
8005 sigdelset(&G.blocked_set, SIGCHLD);
8006 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8010 /* This is probably buggy wrt interruptible-ness */
8012 pid_t pid = bb_strtou(*argv, NULL, 10);
8014 /* mimic bash message */
8015 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8016 return EXIT_FAILURE;
8018 if (waitpid(pid, &status, 0) == pid) {
8019 if (WIFSIGNALED(status))
8020 ret = 128 + WTERMSIG(status);
8021 else if (WIFEXITED(status))
8022 ret = WEXITSTATUS(status);
8026 bb_perror_msg("wait %s", *argv);
8035 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8036 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8039 def = bb_strtou(argv[1], NULL, 10);
8040 if (errno || def < def_min || argv[2]) {
8041 bb_error_msg("%s: bad arguments", argv[0]);
8049 #if ENABLE_HUSH_LOOPS
8050 static int FAST_FUNC builtin_break(char **argv)
8053 if (G.depth_of_loop == 0) {
8054 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8055 return EXIT_SUCCESS; /* bash compat */
8057 G.flag_break_continue++; /* BC_BREAK = 1 */
8059 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8060 if (depth == UINT_MAX)
8061 G.flag_break_continue = BC_BREAK;
8062 if (G.depth_of_loop < depth)
8063 G.depth_break_continue = G.depth_of_loop;
8065 return EXIT_SUCCESS;
8068 static int FAST_FUNC builtin_continue(char **argv)
8070 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8071 return builtin_break(argv);
8075 #if ENABLE_HUSH_FUNCTIONS
8076 static int FAST_FUNC builtin_return(char **argv)
8080 if (G.flag_return_in_progress != -1) {
8081 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8082 return EXIT_FAILURE; /* bash compat */
8085 G.flag_return_in_progress = 1;
8088 * out of range: wraps around at 256, does not error out
8089 * non-numeric param:
8090 * f() { false; return qwe; }; f; echo $?
8091 * bash: return: qwe: numeric argument required <== we do this
8092 * 255 <== we also do this
8094 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);