1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (optionally enabled):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
51 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
52 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
53 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
55 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
56 * This is exactly equivalent to let "expression".
59 * grep for "TODO" and fix (some of them are easy)
61 * special variables (done: PWD)
62 * follow IFS rules more precisely, including update semantics
63 * export builtin should be special, its arguments are assignments
64 * and therefore expansion of them should be "one-word" expansion:
65 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
67 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
68 * ls: cannot access i=a: No such file or directory
69 * ls: cannot access b: No such file or directory
70 * Note1: same applies to local builtin.
71 * Note2: bash 3.2.33(1) does this only if export word itself
73 * $ export i=`echo 'aaa bbb'`; echo "$i"
75 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
78 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
80 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
81 #include <malloc.h> /* for malloc_trim */
83 /* #include <dmalloc.h> */
89 #if ENABLE_HUSH_RANDOM_SUPPORT
92 # define CLEAR_RANDOM_T(rnd) ((void)0)
95 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
100 #define LEAK_HUNTING 0
101 #define BUILD_AS_NOMMU 0
102 /* Enable/disable sanity checks. Ok to enable in production,
103 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
104 * Keeping 1 for now even in released versions.
107 /* Slightly bigger (+200 bytes), but faster hush.
108 * So far it only enables a trick with counting SIGCHLDs and forks,
109 * which allows us to do fewer waitpid's.
110 * (we can detect a case where neither forks were done nor SIGCHLDs happened
111 * and therefore waitpid will return the same result as last time)
113 #define ENABLE_HUSH_FAST 0
118 # undef USE_FOR_NOMMU
121 # define USE_FOR_NOMMU(...) __VA_ARGS__
122 # define USE_FOR_MMU(...)
125 #if defined SINGLE_APPLET_MAIN
126 /* STANDALONE does not make sense, and won't compile */
127 # undef CONFIG_FEATURE_SH_STANDALONE
128 # undef ENABLE_FEATURE_SH_STANDALONE
129 # undef IF_FEATURE_SH_STANDALONE
130 # define IF_FEATURE_SH_STANDALONE(...)
131 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
132 # define ENABLE_FEATURE_SH_STANDALONE 0
135 #if !ENABLE_HUSH_INTERACTIVE
136 # undef ENABLE_FEATURE_EDITING
137 # define ENABLE_FEATURE_EDITING 0
138 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
139 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
142 /* Do we support ANY keywords? */
143 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
144 # define HAS_KEYWORDS 1
145 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
146 # define IF_HAS_NO_KEYWORDS(...)
148 # define HAS_KEYWORDS 0
149 # define IF_HAS_KEYWORDS(...)
150 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
153 /* If you comment out one of these below, it will be #defined later
154 * to perform debug printfs to stderr: */
155 #define debug_printf(...) do {} while (0)
156 /* Finer-grained debug switches */
157 #define debug_printf_parse(...) do {} while (0)
158 #define debug_print_tree(a, b) do {} while (0)
159 #define debug_printf_exec(...) do {} while (0)
160 #define debug_printf_env(...) do {} while (0)
161 #define debug_printf_jobs(...) do {} while (0)
162 #define debug_printf_expand(...) do {} while (0)
163 #define debug_printf_glob(...) do {} while (0)
164 #define debug_printf_list(...) do {} while (0)
165 #define debug_printf_subst(...) do {} while (0)
166 #define debug_printf_clean(...) do {} while (0)
168 #define ERR_PTR ((void*)(long)1)
170 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
172 #define SPECIAL_VAR_SYMBOL 3
176 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
178 /* This supports saving pointers malloced in vfork child,
179 * to be freed in the parent.
182 typedef struct nommu_save_t {
184 struct variable *old_vars;
186 char **argv_from_re_execing;
190 typedef enum reserved_style {
199 #if ENABLE_HUSH_LOOPS
206 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
211 /* three pseudo-keywords support contrived "case" syntax: */
212 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
213 RES_MATCH , /* "word)" */
214 RES_CASE_BODY, /* "this command is inside CASE" */
221 typedef struct o_string {
223 int length; /* position where data is appended */
225 /* Protect newly added chars against globbing
226 * (by prepending \ to *, ?, [, \) */
229 /* At least some part of the string was inside '' or "",
230 * possibly empty one: word"", wo''rd etc. */
232 smallint has_empty_slot;
233 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
236 MAYBE_ASSIGNMENT = 0,
237 DEFINITELY_ASSIGNMENT = 1,
239 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
241 /* Used for initialization: o_string foo = NULL_O_STRING; */
242 #define NULL_O_STRING { NULL }
244 /* I can almost use ordinary FILE*. Is open_memstream() universally
245 * available? Where is it documented? */
246 typedef struct in_str {
248 /* eof_flag=1: last char in ->p is really an EOF */
249 char eof_flag; /* meaningless if ->p == NULL */
251 #if ENABLE_HUSH_INTERACTIVE
253 smallint promptmode; /* 0: PS1, 1: PS2 */
256 int (*get) (struct in_str *) FAST_FUNC;
257 int (*peek) (struct in_str *) FAST_FUNC;
259 #define i_getch(input) ((input)->get(input))
260 #define i_peek(input) ((input)->peek(input))
262 /* The descrip member of this structure is only used to make
263 * debugging output pretty */
264 static const struct {
266 signed char default_fd;
269 { O_RDONLY, 0, "<" },
270 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
271 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
272 { O_CREAT|O_RDWR, 1, "<>" },
273 { O_RDONLY, 0, "<<" },
274 /* Should not be needed. Bogus default_fd helps in debugging */
275 /* { O_RDONLY, 77, "<<" }, */
278 struct redir_struct {
279 struct redir_struct *next;
280 char *rd_filename; /* filename */
281 int rd_fd; /* fd to redirect */
282 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
284 smallint rd_type; /* (enum redir_type) */
285 /* note: for heredocs, rd_filename contains heredoc delimiter,
286 * and subsequently heredoc itself; and rd_dup is a bitmask:
287 * bit 0: do we need to trim leading tabs?
288 * bit 1: is heredoc quoted (<<'delim' syntax) ?
291 typedef enum redir_type {
293 REDIRECT_OVERWRITE = 1,
296 REDIRECT_HEREDOC = 4,
297 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
300 REDIRFD_SYNTAX_ERR = -2,
301 REDIRFD_TO_FILE = -1,
302 /* otherwise, rd_fd is redirected to rd_dup */
304 HEREDOC_SKIPTABS = 1,
310 pid_t pid; /* 0 if exited */
311 int assignment_cnt; /* how many argv[i] are assignments? */
312 smallint is_stopped; /* is the command currently running? */
313 smallint cmd_type; /* CMD_xxx */
315 #define CMD_SUBSHELL 1
317 /* used for "[[ EXPR ]]" */
318 #if ENABLE_HUSH_BASH_COMPAT
319 # define CMD_SINGLEWORD_NOGLOB 2
322 /* used for "export noglob=* glob* a=`echo a b`" */
323 //#define CMD_SINGLEWORD_NOGLOB_COND 3
324 // It is hard to implement correctly, it adds significant amounts of tricky code,
325 // and all this is only useful for really obscure export statements
326 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
327 // guards the code which implements it, but I have doubts it works
328 // in all cases (especially with mixed globbed/non-globbed arguments)
330 #if ENABLE_HUSH_FUNCTIONS
331 # define CMD_FUNCDEF 3
334 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
337 char *group_as_string;
339 #if ENABLE_HUSH_FUNCTIONS
340 struct function *child_func;
341 /* This field is used to prevent a bug here:
342 * while...do f1() {a;}; f1; f1() {b;}; f1; done
343 * When we execute "f1() {a;}" cmd, we create new function and clear
344 * cmd->group, cmd->group_as_string, cmd->argv[0].
345 * When we execute "f1() {b;}", we notice that f1 exists,
346 * and that its "parent cmd" struct is still "alive",
347 * we put those fields back into cmd->xxx
348 * (struct function has ->parent_cmd ptr to facilitate that).
349 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
350 * Without this trick, loop would execute a;b;b;b;...
351 * instead of correct sequence a;b;a;b;...
352 * When command is freed, it severs the link
353 * (sets ->child_func->parent_cmd to NULL).
356 char **argv; /* command name and arguments */
357 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
358 * and on execution these are substituted with their values.
359 * Substitution can make _several_ words out of one argv[n]!
360 * Example: argv[0]=='.^C*^C.' here: echo .$*.
361 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
363 struct redir_struct *redirects; /* I/O redirections */
365 /* Is there anything in this command at all? */
366 #define IS_NULL_CMD(cmd) \
367 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
372 int num_cmds; /* total number of commands in pipe */
373 int alive_cmds; /* number of commands running (not exited) */
374 int stopped_cmds; /* number of commands alive, but stopped */
376 int jobid; /* job number */
377 pid_t pgrp; /* process group ID for the job */
378 char *cmdtext; /* name of job */
380 struct command *cmds; /* array of commands in pipe */
381 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
382 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
383 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
385 typedef enum pipe_style {
391 /* Is there anything in this pipe at all? */
392 #define IS_NULL_PIPE(pi) \
393 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
395 /* This holds pointers to the various results of parsing */
396 struct parse_context {
397 /* linked list of pipes */
398 struct pipe *list_head;
399 /* last pipe (being constructed right now) */
401 /* last command in pipe (being constructed right now) */
402 struct command *command;
403 /* last redirect in command->redirects list */
404 struct redir_struct *pending_redirect;
410 smallint ctx_inverted; /* "! cmd | cmd" */
412 smallint ctx_dsemicolon; /* ";;" seen */
414 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
416 /* group we are enclosed in:
417 * example: "if pipe1; pipe2; then pipe3; fi"
418 * when we see "if" or "then", we malloc and copy current context,
419 * and make ->stack point to it. then we parse pipeN.
420 * when closing "then" / fi" / whatever is found,
421 * we move list_head into ->stack->command->group,
422 * copy ->stack into current context, and delete ->stack.
423 * (parsing of { list } and ( list ) doesn't use this method)
425 struct parse_context *stack;
429 /* On program start, environ points to initial environment.
430 * putenv adds new pointers into it, unsetenv removes them.
431 * Neither of these (de)allocates the strings.
432 * setenv allocates new strings in malloc space and does putenv,
433 * and thus setenv is unusable (leaky) for shell's purposes */
434 #define setenv(...) setenv_is_leaky_dont_use()
436 struct variable *next;
437 char *varstr; /* points to "name=" portion */
438 #if ENABLE_HUSH_LOCAL
439 unsigned func_nest_level;
441 int max_len; /* if > 0, name is part of initial env; else name is malloced */
442 smallint flg_export; /* putenv should be done on this var */
443 smallint flg_read_only;
451 #if ENABLE_HUSH_FUNCTIONS
453 struct function *next;
455 struct command *parent_cmd;
458 char *body_as_string;
464 /* "Globals" within this file */
465 /* Sorted roughly by size (smaller offsets == smaller code) */
467 /* interactive_fd != 0 means we are an interactive shell.
468 * If we are, then saved_tty_pgrp can also be != 0, meaning
469 * that controlling tty is available. With saved_tty_pgrp == 0,
470 * job control still works, but terminal signals
471 * (^C, ^Z, ^Y, ^\) won't work at all, and background
472 * process groups can only be created with "cmd &".
473 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
474 * to give tty to the foreground process group,
475 * and will take it back when the group is stopped (^Z)
478 #if ENABLE_HUSH_INTERACTIVE
479 /* 'interactive_fd' is a fd# open to ctty, if we have one
480 * _AND_ if we decided to act interactively */
484 # define G_interactive_fd (G.interactive_fd)
486 # define G_interactive_fd 0
488 #if ENABLE_FEATURE_EDITING
489 line_input_t *line_input_state;
494 #if ENABLE_HUSH_RANDOM_SUPPORT
500 pid_t saved_tty_pgrp;
501 struct pipe *job_list;
502 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
504 # define G_saved_tty_pgrp 0
506 smallint flag_SIGINT;
507 #if ENABLE_HUSH_LOOPS
508 smallint flag_break_continue;
510 #if ENABLE_HUSH_FUNCTIONS
511 /* 0: outside of a function (or sourced file)
512 * -1: inside of a function, ok to use return builtin
513 * 1: return is invoked, skip all till end of func
515 smallint flag_return_in_progress;
518 smallint exiting; /* used to prevent EXIT trap recursion */
519 /* These four support $?, $#, and $1 */
520 smalluint last_exitcode;
521 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
522 smalluint global_args_malloced;
523 /* how many non-NULL argv's we have. NB: $# + 1 */
527 char *argv0_for_re_execing;
529 #if ENABLE_HUSH_LOOPS
530 unsigned depth_break_continue;
531 unsigned depth_of_loop;
535 struct variable *top_var; /* = &G.shell_ver (set in main()) */
536 struct variable shell_ver;
537 #if ENABLE_HUSH_FUNCTIONS
538 struct function *top_func;
539 # if ENABLE_HUSH_LOCAL
540 struct variable **shadowed_vars_pp;
541 unsigned func_nest_level;
544 /* Signal and trap handling */
546 unsigned count_SIGCHLD;
547 unsigned handled_SIGCHLD;
548 smallint we_have_children;
550 /* which signals have non-DFL handler (even with no traps set)? */
551 unsigned non_DFL_mask;
552 char **traps; /* char *traps[NSIG] */
553 sigset_t blocked_set;
554 sigset_t inherited_set;
556 unsigned long memleak_value;
559 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
561 #define G (*ptr_to_globals)
562 /* Not #defining name to G.name - this quickly gets unwieldy
563 * (too many defines). Also, I actually prefer to see when a variable
564 * is global, thus "G." prefix is a useful hint */
565 #define INIT_G() do { \
566 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
570 /* Function prototypes for builtins */
571 static int builtin_cd(char **argv) FAST_FUNC;
572 static int builtin_echo(char **argv) FAST_FUNC;
573 static int builtin_eval(char **argv) FAST_FUNC;
574 static int builtin_exec(char **argv) FAST_FUNC;
575 static int builtin_exit(char **argv) FAST_FUNC;
576 static int builtin_export(char **argv) FAST_FUNC;
578 static int builtin_fg_bg(char **argv) FAST_FUNC;
579 static int builtin_jobs(char **argv) FAST_FUNC;
582 static int builtin_help(char **argv) FAST_FUNC;
584 #if ENABLE_HUSH_LOCAL
585 static int builtin_local(char **argv) FAST_FUNC;
588 static int builtin_memleak(char **argv) FAST_FUNC;
591 static int builtin_printf(char **argv) FAST_FUNC;
593 static int builtin_pwd(char **argv) FAST_FUNC;
594 static int builtin_read(char **argv) FAST_FUNC;
595 static int builtin_set(char **argv) FAST_FUNC;
596 static int builtin_shift(char **argv) FAST_FUNC;
597 static int builtin_source(char **argv) FAST_FUNC;
598 static int builtin_test(char **argv) FAST_FUNC;
599 static int builtin_trap(char **argv) FAST_FUNC;
600 static int builtin_type(char **argv) FAST_FUNC;
601 static int builtin_true(char **argv) FAST_FUNC;
602 static int builtin_umask(char **argv) FAST_FUNC;
603 static int builtin_unset(char **argv) FAST_FUNC;
604 static int builtin_wait(char **argv) FAST_FUNC;
605 #if ENABLE_HUSH_LOOPS
606 static int builtin_break(char **argv) FAST_FUNC;
607 static int builtin_continue(char **argv) FAST_FUNC;
609 #if ENABLE_HUSH_FUNCTIONS
610 static int builtin_return(char **argv) FAST_FUNC;
613 /* Table of built-in functions. They can be forked or not, depending on
614 * context: within pipes, they fork. As simple commands, they do not.
615 * When used in non-forking context, they can change global variables
616 * in the parent shell process. If forked, of course they cannot.
617 * For example, 'unset foo | whatever' will parse and run, but foo will
618 * still be set at the end. */
619 struct built_in_command {
621 int (*function)(char **argv) FAST_FUNC;
624 # define BLTIN(cmd, func, help) { cmd, func, help }
626 # define BLTIN(cmd, func, help) { cmd, func }
630 static const struct built_in_command bltins1[] = {
631 BLTIN("." , builtin_source , "Run commands in a file"),
632 BLTIN(":" , builtin_true , NULL),
634 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
636 #if ENABLE_HUSH_LOOPS
637 BLTIN("break" , builtin_break , "Exit from a loop"),
639 BLTIN("cd" , builtin_cd , "Change directory"),
640 #if ENABLE_HUSH_LOOPS
641 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
643 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
644 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
645 BLTIN("exit" , builtin_exit , "Exit"),
646 BLTIN("export" , builtin_export , "Set environment variables"),
648 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
651 BLTIN("help" , builtin_help , NULL),
654 BLTIN("jobs" , builtin_jobs , "List jobs"),
656 #if ENABLE_HUSH_LOCAL
657 BLTIN("local" , builtin_local , "Set local variables"),
660 BLTIN("memleak" , builtin_memleak , NULL),
662 BLTIN("read" , builtin_read , "Input into variable"),
663 #if ENABLE_HUSH_FUNCTIONS
664 BLTIN("return" , builtin_return , "Return from a function"),
666 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
667 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
668 BLTIN("trap" , builtin_trap , "Trap signals"),
669 BLTIN("type" , builtin_type , "Write a description of command type"),
670 // BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
671 BLTIN("umask" , builtin_umask , "Set file creation mask"),
672 BLTIN("unset" , builtin_unset , "Unset variables"),
673 BLTIN("wait" , builtin_wait , "Wait for process"),
675 /* For now, echo and test are unconditionally enabled.
676 * Maybe make it configurable? */
677 static const struct built_in_command bltins2[] = {
678 BLTIN("[" , builtin_test , NULL),
679 BLTIN("echo" , builtin_echo , NULL),
681 BLTIN("printf" , builtin_printf , NULL),
683 BLTIN("pwd" , builtin_pwd , NULL),
684 BLTIN("test" , builtin_test , NULL),
691 /* prevent disasters with G.debug_indent < 0 */
692 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
693 # define debug_enter() (G.debug_indent++)
694 # define debug_leave() (G.debug_indent--)
696 # define indent() ((void)0)
697 # define debug_enter() ((void)0)
698 # define debug_leave() ((void)0)
702 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
705 #ifndef debug_printf_parse
706 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
709 #ifndef debug_printf_exec
710 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
713 #ifndef debug_printf_env
714 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
717 #ifndef debug_printf_jobs
718 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
719 # define DEBUG_JOBS 1
721 # define DEBUG_JOBS 0
724 #ifndef debug_printf_expand
725 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
726 # define DEBUG_EXPAND 1
728 # define DEBUG_EXPAND 0
731 #ifndef debug_printf_glob
732 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
733 # define DEBUG_GLOB 1
735 # define DEBUG_GLOB 0
738 #ifndef debug_printf_list
739 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
742 #ifndef debug_printf_subst
743 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
746 #ifndef debug_printf_clean
747 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
748 # define DEBUG_CLEAN 1
750 # define DEBUG_CLEAN 0
754 static void debug_print_strings(const char *prefix, char **vv)
757 fprintf(stderr, "%s:\n", prefix);
759 fprintf(stderr, " '%s'\n", *vv++);
762 # define debug_print_strings(prefix, vv) ((void)0)
766 /* Leak hunting. Use hush_leaktool.sh for post-processing.
769 static void *xxmalloc(int lineno, size_t size)
771 void *ptr = xmalloc((size + 0xff) & ~0xff);
772 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
775 static void *xxrealloc(int lineno, void *ptr, size_t size)
777 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
778 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
781 static char *xxstrdup(int lineno, const char *str)
783 char *ptr = xstrdup(str);
784 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
787 static void xxfree(void *ptr)
789 fdprintf(2, "free %p\n", ptr);
792 #define xmalloc(s) xxmalloc(__LINE__, s)
793 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
794 #define xstrdup(s) xxstrdup(__LINE__, s)
795 #define free(p) xxfree(p)
799 /* Syntax and runtime errors. They always abort scripts.
800 * In interactive use they usually discard unparsed and/or unexecuted commands
801 * and return to the prompt.
802 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
805 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
806 # define syntax_error(lineno, msg) syntax_error(msg)
807 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
808 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
809 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
810 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
813 static void die_if_script(unsigned lineno, const char *fmt, ...)
818 bb_error_msg("hush.c:%u", lineno);
821 bb_verror_msg(fmt, p, NULL);
823 if (!G_interactive_fd)
827 static void syntax_error(unsigned lineno, const char *msg)
830 die_if_script(lineno, "syntax error: %s", msg);
832 die_if_script(lineno, "syntax error", NULL);
835 static void syntax_error_at(unsigned lineno, const char *msg)
837 die_if_script(lineno, "syntax error at '%s'", msg);
840 static void syntax_error_unterm_str(unsigned lineno, const char *s)
842 die_if_script(lineno, "syntax error: unterminated %s", s);
845 /* It so happens that all such cases are totally fatal
846 * even if shell is interactive: EOF while looking for closing
847 * delimiter. There is nowhere to read stuff from after that,
848 * it's EOF! The only choice is to terminate.
850 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
851 static void syntax_error_unterm_ch(unsigned lineno, char ch)
853 char msg[2] = { ch, '\0' };
854 syntax_error_unterm_str(lineno, msg);
858 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
863 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
867 # undef die_if_script
869 # undef syntax_error_at
870 # undef syntax_error_unterm_ch
871 # undef syntax_error_unterm_str
872 # undef syntax_error_unexpected_ch
874 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
875 # define syntax_error(msg) syntax_error(__LINE__, msg)
876 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
877 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
878 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
879 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
883 #if ENABLE_HUSH_INTERACTIVE
884 static void cmdedit_update_prompt(void);
886 # define cmdedit_update_prompt() ((void)0)
892 static int is_well_formed_var_name(const char *s, char terminator)
894 if (!s || !(isalpha(*s) || *s == '_'))
897 while (isalnum(*s) || *s == '_')
899 return *s == terminator;
902 /* Replace each \x with x in place, return ptr past NUL. */
903 static char *unbackslash(char *src)
905 char *dst = src = strchrnul(src, '\\');
909 if ((*dst++ = *src++) == '\0')
915 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
936 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
937 v[count1 + count2] = NULL;
940 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
944 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
946 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
947 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
950 #define add_strings_to_strings(strings, add, need_to_dup) \
951 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
954 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
955 static char **add_string_to_strings(char **strings, char *add)
960 return add_strings_to_strings(strings, v, /*dup:*/ 0);
963 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
965 char **ptr = add_string_to_strings(strings, add);
966 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
969 #define add_string_to_strings(strings, add) \
970 xx_add_string_to_strings(__LINE__, strings, add)
973 static void free_strings(char **strings)
988 /* Helpers for setting new $n and restoring them back
990 typedef struct save_arg_t {
994 smallint sv_g_malloced;
997 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1001 sv->sv_argv0 = argv[0];
1002 sv->sv_g_argv = G.global_argv;
1003 sv->sv_g_argc = G.global_argc;
1004 sv->sv_g_malloced = G.global_args_malloced;
1006 argv[0] = G.global_argv[0]; /* retain $0 */
1007 G.global_argv = argv;
1008 G.global_args_malloced = 0;
1016 static void restore_G_args(save_arg_t *sv, char **argv)
1020 if (G.global_args_malloced) {
1021 /* someone ran "set -- arg1 arg2 ...", undo */
1023 while (*++pp) /* note: does not free $0 */
1025 free(G.global_argv);
1027 argv[0] = sv->sv_argv0;
1028 G.global_argv = sv->sv_g_argv;
1029 G.global_argc = sv->sv_g_argc;
1030 G.global_args_malloced = sv->sv_g_malloced;
1034 /* Basic theory of signal handling in shell
1035 * ========================================
1036 * This does not describe what hush does, rather, it is current understanding
1037 * what it _should_ do. If it doesn't, it's a bug.
1038 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1040 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1041 * is finished or backgrounded. It is the same in interactive and
1042 * non-interactive shells, and is the same regardless of whether
1043 * a user trap handler is installed or a shell special one is in effect.
1044 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1045 * backgrounds (i.e. stops) or kills all members of currently running
1048 * Wait builtin in interruptible by signals for which user trap is set
1049 * or by SIGINT in interactive shell.
1051 * Trap handlers will execute even within trap handlers. (right?)
1053 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1055 * If job control is off, backgrounded commands ("cmd &")
1056 * have SIGINT, SIGQUIT set to SIG_IGN.
1058 * Commands which are run in command substitution ("`cmd`")
1059 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1061 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1062 * by the shell from its parent.
1064 * Signals which differ from SIG_DFL action
1065 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1068 * SIGTERM (interactive): ignore
1069 * SIGHUP (interactive):
1070 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1071 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1072 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1073 * that all pipe members are stopped. Try this in bash:
1074 * while :; do :; done - ^Z does not background it
1075 * (while :; do :; done) - ^Z backgrounds it
1076 * SIGINT (interactive): wait for last pipe, ignore the rest
1077 * of the command line, show prompt. NB: ^C does not send SIGINT
1078 * to interactive shell while shell is waiting for a pipe,
1079 * since shell is bg'ed (is not in foreground process group).
1080 * Example 1: this waits 5 sec, but does not execute ls:
1081 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1082 * Example 2: this does not wait and does not execute ls:
1083 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1084 * Example 3: this does not wait 5 sec, but executes ls:
1085 * "sleep 5; ls -l" + press ^C
1087 * (What happens to signals which are IGN on shell start?)
1088 * (What happens with signal mask on shell start?)
1090 * Implementation in hush
1091 * ======================
1092 * We use in-kernel pending signal mask to determine which signals were sent.
1093 * We block all signals which we don't want to take action immediately,
1094 * i.e. we block all signals which need to have special handling as described
1095 * above, and all signals which have traps set.
1096 * After each pipe execution, we extract any pending signals via sigtimedwait()
1099 * unsigned non_DFL_mask: a mask of such "special" signals
1100 * sigset_t blocked_set: current blocked signal set
1103 * clear bit in blocked_set unless it is also in non_DFL_mask
1104 * "trap 'cmd' SIGxxx":
1105 * set bit in blocked_set (even if 'cmd' is '')
1106 * after [v]fork, if we plan to be a shell:
1107 * unblock signals with special interactive handling
1108 * (child shell is not interactive),
1109 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1110 * after [v]fork, if we plan to exec:
1111 * POSIX says fork clears pending signal mask in child - no need to clear it.
1112 * Restore blocked signal set to one inherited by shell just prior to exec.
1114 * Note: as a result, we do not use signal handlers much. The only uses
1115 * are to count SIGCHLDs
1116 * and to restore tty pgrp on signal-induced exit.
1119 * Standard says "When a subshell is entered, traps that are not being ignored
1120 * are set to the default actions". bash interprets it so that traps which
1121 * are set to "" (ignore) are NOT reset to defaults. We do the same.
1124 SPECIAL_INTERACTIVE_SIGS = 0
1129 SPECIAL_JOB_SIGS = 0
1137 #if ENABLE_HUSH_FAST
1138 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1141 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1147 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1148 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1149 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1150 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1152 /* Restores tty foreground process group, and exits.
1153 * May be called as signal handler for fatal signal
1154 * (will resend signal to itself, producing correct exit state)
1155 * or called directly with -EXITCODE.
1156 * We also call it if xfunc is exiting. */
1157 static void sigexit(int sig) NORETURN;
1158 static void sigexit(int sig)
1160 /* Disable all signals: job control, SIGPIPE, etc. */
1161 sigprocmask_allsigs(SIG_BLOCK);
1163 /* Careful: we can end up here after [v]fork. Do not restore
1164 * tty pgrp then, only top-level shell process does that */
1165 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1166 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1168 /* Not a signal, just exit */
1172 kill_myself_with_sig(sig); /* does not return */
1176 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1177 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1181 /* Restores tty foreground process group, and exits. */
1182 static void hush_exit(int exitcode) NORETURN;
1183 static void hush_exit(int exitcode)
1185 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1186 /* Prevent recursion:
1187 * trap "echo Hi; exit" EXIT; exit
1189 char *argv[] = { NULL, G.traps[0], NULL };
1198 sigexit(- (exitcode & 0xff));
1204 static int check_and_run_traps(int sig)
1206 static const struct timespec zero_timespec = { 0, 0 };
1207 smalluint save_rcode;
1213 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1218 if (G.traps && G.traps[sig]) {
1219 if (G.traps[sig][0]) {
1220 /* We have user-defined handler */
1221 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1222 save_rcode = G.last_exitcode;
1225 G.last_exitcode = save_rcode;
1226 } /* else: "" trap, ignoring signal */
1229 /* not a trap: special action */
1231 #if ENABLE_HUSH_FAST
1234 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1238 /* Builtin was ^C'ed, make it look prettier: */
1245 /* bash is observed to signal whole process groups,
1246 * not individual processes */
1247 for (job = G.job_list; job; job = job->next) {
1250 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1251 if (kill(- job->pgrp, SIGHUP) == 0)
1252 kill(- job->pgrp, SIGCONT);
1257 default: /* ignored: */
1258 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1266 static const char *get_cwd(int force)
1268 if (force || G.cwd == NULL) {
1269 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1270 * we must not try to free(bb_msg_unknown) */
1271 if (G.cwd == bb_msg_unknown)
1273 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1275 G.cwd = bb_msg_unknown;
1282 * Shell and environment variable support
1284 static struct variable **get_ptr_to_local_var(const char *name)
1286 struct variable **pp;
1287 struct variable *cur;
1292 while ((cur = *pp) != NULL) {
1293 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1300 static struct variable *get_local_var(const char *name)
1302 struct variable **pp = get_ptr_to_local_var(name);
1308 static const char *get_local_var_value(const char *name)
1310 struct variable **pp = get_ptr_to_local_var(name);
1312 return strchr((*pp)->varstr, '=') + 1;
1313 if (strcmp(name, "PPID") == 0)
1314 return utoa(G.root_ppid);
1315 // bash compat: UID? EUID?
1316 #if ENABLE_HUSH_RANDOM_SUPPORT
1317 if (strcmp(name, "RANDOM") == 0) {
1318 return utoa(next_random(&G.random_gen));
1324 /* str holds "NAME=VAL" and is expected to be malloced.
1325 * We take ownership of it.
1327 * 0: do not change export flag
1328 * (if creating new variable, flag will be 0)
1329 * 1: set export flag and putenv the variable
1330 * -1: clear export flag and unsetenv the variable
1331 * flg_read_only is set only when we handle -R var=val
1333 #if !BB_MMU && ENABLE_HUSH_LOCAL
1334 /* all params are used */
1335 #elif BB_MMU && ENABLE_HUSH_LOCAL
1336 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1337 set_local_var(str, flg_export, local_lvl)
1338 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1339 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1340 set_local_var(str, flg_export)
1341 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1342 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1343 set_local_var(str, flg_export, flg_read_only)
1345 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1347 struct variable **var_pp;
1348 struct variable *cur;
1352 eq_sign = strchr(str, '=');
1353 if (!eq_sign) { /* not expected to ever happen? */
1358 name_len = eq_sign - str + 1; /* including '=' */
1359 var_pp = &G.top_var;
1360 while ((cur = *var_pp) != NULL) {
1361 if (strncmp(cur->varstr, str, name_len) != 0) {
1362 var_pp = &cur->next;
1365 /* We found an existing var with this name */
1366 if (cur->flg_read_only) {
1370 bb_error_msg("%s: readonly variable", str);
1374 if (flg_export == -1) { // "&& cur->flg_export" ?
1375 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1380 #if ENABLE_HUSH_LOCAL
1381 if (cur->func_nest_level < local_lvl) {
1382 /* New variable is declared as local,
1383 * and existing one is global, or local
1384 * from enclosing function.
1385 * Remove and save old one: */
1386 *var_pp = cur->next;
1387 cur->next = *G.shadowed_vars_pp;
1388 *G.shadowed_vars_pp = cur;
1389 /* bash 3.2.33(1) and exported vars:
1391 * # f() { local z=a; env | grep ^z; }
1397 if (cur->flg_export)
1402 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1407 if (cur->max_len != 0) {
1408 if (cur->max_len >= strlen(str)) {
1409 /* This one is from startup env, reuse space */
1410 strcpy(cur->varstr, str);
1414 /* max_len == 0 signifies "malloced" var, which we can
1415 * (and has to) free */
1419 goto set_str_and_exp;
1422 /* Not found - create new variable struct */
1423 cur = xzalloc(sizeof(*cur));
1424 #if ENABLE_HUSH_LOCAL
1425 cur->func_nest_level = local_lvl;
1427 cur->next = *var_pp;
1433 cur->flg_read_only = flg_read_only;
1436 if (flg_export == 1)
1437 cur->flg_export = 1;
1438 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1439 cmdedit_update_prompt();
1440 if (cur->flg_export) {
1441 if (flg_export == -1) {
1442 cur->flg_export = 0;
1443 /* unsetenv was already done */
1445 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1446 return putenv(cur->varstr);
1452 /* Used at startup and after each cd */
1453 static void set_pwd_var(int exp)
1455 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1456 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1459 static int unset_local_var_len(const char *name, int name_len)
1461 struct variable *cur;
1462 struct variable **var_pp;
1465 return EXIT_SUCCESS;
1466 var_pp = &G.top_var;
1467 while ((cur = *var_pp) != NULL) {
1468 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1469 if (cur->flg_read_only) {
1470 bb_error_msg("%s: readonly variable", name);
1471 return EXIT_FAILURE;
1473 *var_pp = cur->next;
1474 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1475 bb_unsetenv(cur->varstr);
1476 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1477 cmdedit_update_prompt();
1481 return EXIT_SUCCESS;
1483 var_pp = &cur->next;
1485 return EXIT_SUCCESS;
1488 static int unset_local_var(const char *name)
1490 return unset_local_var_len(name, strlen(name));
1493 static void unset_vars(char **strings)
1501 const char *eq = strchrnul(*v, '=');
1502 unset_local_var_len(*v, (int)(eq - *v));
1508 #if ENABLE_SH_MATH_SUPPORT
1509 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1510 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1511 static char *endofname(const char *name)
1519 if (!is_in_name(*p))
1525 static void arith_set_local_var(const char *name, const char *val, int flags)
1527 /* arith code doesnt malloc space, so do it for it */
1528 char *var = xasprintf("%s=%s", name, val);
1529 set_local_var(var, flags, /*lvl:*/ 0, /*ro:*/ 0);
1535 * Helpers for "var1=val1 var2=val2 cmd" feature
1537 static void add_vars(struct variable *var)
1539 struct variable *next;
1543 var->next = G.top_var;
1545 if (var->flg_export) {
1546 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1547 putenv(var->varstr);
1549 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1555 static struct variable *set_vars_and_save_old(char **strings)
1558 struct variable *old = NULL;
1564 struct variable *var_p;
1565 struct variable **var_pp;
1568 eq = strchr(*s, '=');
1571 var_pp = get_ptr_to_local_var(*s);
1574 /* Remove variable from global linked list */
1576 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1577 *var_pp = var_p->next;
1578 /* Add it to returned list */
1582 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1593 static int FAST_FUNC static_get(struct in_str *i)
1602 static int FAST_FUNC static_peek(struct in_str *i)
1607 #if ENABLE_HUSH_INTERACTIVE
1609 static void cmdedit_update_prompt(void)
1611 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1612 G.PS1 = get_local_var_value("PS1");
1615 G.PS2 = get_local_var_value("PS2");
1623 static const char* setup_prompt_string(int promptmode)
1625 const char *prompt_str;
1626 debug_printf("setup_prompt_string %d ", promptmode);
1627 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1628 /* Set up the prompt */
1629 if (promptmode == 0) { /* PS1 */
1631 /* bash uses $PWD value, even if it is set by user.
1632 * It uses current dir only if PWD is unset.
1633 * We always use current dir. */
1634 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1639 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1640 debug_printf("result '%s'\n", prompt_str);
1644 static void get_user_input(struct in_str *i)
1647 const char *prompt_str;
1649 prompt_str = setup_prompt_string(i->promptmode);
1650 #if ENABLE_FEATURE_EDITING
1651 /* Enable command line editing only while a command line
1652 * is actually being read */
1655 /* buglet: SIGINT will not make new prompt to appear _at once_,
1656 * only after <Enter>. (^C will work) */
1657 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1658 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1659 check_and_run_traps(0);
1660 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1661 i->eof_flag = (r < 0);
1662 if (i->eof_flag) { /* EOF/error detected */
1663 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1664 G.user_input_buf[1] = '\0';
1669 fputs(prompt_str, stdout);
1671 G.user_input_buf[0] = r = fgetc(i->file);
1672 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1673 //do we need check_and_run_traps(0)? (maybe only if stdin)
1674 } while (G.flag_SIGINT);
1675 i->eof_flag = (r == EOF);
1677 i->p = G.user_input_buf;
1680 #endif /* INTERACTIVE */
1682 /* This is the magic location that prints prompts
1683 * and gets data back from the user */
1684 static int FAST_FUNC file_get(struct in_str *i)
1688 /* If there is data waiting, eat it up */
1689 if (i->p && *i->p) {
1690 #if ENABLE_HUSH_INTERACTIVE
1694 if (i->eof_flag && !*i->p)
1696 /* note: ch is never NUL */
1698 /* need to double check i->file because we might be doing something
1699 * more complicated by now, like sourcing or substituting. */
1700 #if ENABLE_HUSH_INTERACTIVE
1701 if (G_interactive_fd && i->promptme && i->file == stdin) {
1704 } while (!*i->p); /* need non-empty line */
1705 i->promptmode = 1; /* PS2 */
1710 do ch = fgetc(i->file); while (ch == '\0');
1712 debug_printf("file_get: got '%c' %d\n", ch, ch);
1713 #if ENABLE_HUSH_INTERACTIVE
1720 /* All callers guarantee this routine will never
1721 * be used right after a newline, so prompting is not needed.
1723 static int FAST_FUNC file_peek(struct in_str *i)
1726 if (i->p && *i->p) {
1727 if (i->eof_flag && !i->p[1])
1730 /* note: ch is never NUL */
1732 do ch = fgetc(i->file); while (ch == '\0');
1733 i->eof_flag = (ch == EOF);
1734 i->peek_buf[0] = ch;
1735 i->peek_buf[1] = '\0';
1737 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1741 static void setup_file_in_str(struct in_str *i, FILE *f)
1743 i->peek = file_peek;
1745 #if ENABLE_HUSH_INTERACTIVE
1747 i->promptmode = 0; /* PS1 */
1753 static void setup_string_in_str(struct in_str *i, const char *s)
1755 i->peek = static_peek;
1756 i->get = static_get;
1757 #if ENABLE_HUSH_INTERACTIVE
1759 i->promptmode = 0; /* PS1 */
1769 #define B_CHUNK (32 * sizeof(char*))
1771 static void o_reset_to_empty_unquoted(o_string *o)
1779 static void o_free(o_string *o)
1782 memset(o, 0, sizeof(*o));
1785 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1790 static void o_grow_by(o_string *o, int len)
1792 if (o->length + len > o->maxlen) {
1793 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1794 o->data = xrealloc(o->data, 1 + o->maxlen);
1798 static void o_addchr(o_string *o, int ch)
1800 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1802 o->data[o->length] = ch;
1804 o->data[o->length] = '\0';
1807 static void o_addblock(o_string *o, const char *str, int len)
1810 memcpy(&o->data[o->length], str, len);
1812 o->data[o->length] = '\0';
1816 static void o_addstr(o_string *o, const char *str)
1818 o_addblock(o, str, strlen(str));
1820 static void nommu_addchr(o_string *o, int ch)
1826 # define nommu_addchr(o, str) ((void)0)
1829 static void o_addstr_with_NUL(o_string *o, const char *str)
1831 o_addblock(o, str, strlen(str) + 1);
1834 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1839 && (*str != '*' && *str != '?' && *str != '[')
1847 #undef HUSH_BRACE_EXP
1849 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1850 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1851 * Apparently, on unquoted $v bash still does globbing
1852 * ("v='*.txt'; echo $v" prints all .txt files),
1853 * but NOT brace expansion! Thus, there should be TWO independent
1854 * quoting mechanisms on $v expansion side: one protects
1855 * $v from brace expansion, and other additionally protects "$v" against globbing.
1856 * We have only second one.
1859 #ifdef HUSH_BRACE_EXP
1860 # define MAYBE_BRACES "{}"
1862 # define MAYBE_BRACES ""
1865 /* My analysis of quoting semantics tells me that state information
1866 * is associated with a destination, not a source.
1868 static void o_addqchr(o_string *o, int ch)
1871 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1876 o->data[o->length] = '\\';
1879 o->data[o->length] = ch;
1881 o->data[o->length] = '\0';
1884 static void o_addQchr(o_string *o, int ch)
1887 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1889 o->data[o->length] = '\\';
1893 o->data[o->length] = ch;
1895 o->data[o->length] = '\0';
1898 static void o_addQstr(o_string *o, const char *str, int len)
1901 o_addblock(o, str, len);
1907 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1908 if (ordinary_cnt > len) /* paranoia */
1910 o_addblock(o, str, ordinary_cnt);
1911 if (ordinary_cnt == len)
1913 str += ordinary_cnt;
1914 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1918 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1920 o->data[o->length] = '\\';
1924 o->data[o->length] = ch;
1926 o->data[o->length] = '\0';
1930 /* A special kind of o_string for $VAR and `cmd` expansion.
1931 * It contains char* list[] at the beginning, which is grown in 16 element
1932 * increments. Actual string data starts at the next multiple of 16 * (char*).
1933 * list[i] contains an INDEX (int!) into this string data.
1934 * It means that if list[] needs to grow, data needs to be moved higher up
1935 * but list[i]'s need not be modified.
1936 * NB: remembering how many list[i]'s you have there is crucial.
1937 * o_finalize_list() operation post-processes this structure - calculates
1938 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1940 #if DEBUG_EXPAND || DEBUG_GLOB
1941 static void debug_print_list(const char *prefix, o_string *o, int n)
1943 char **list = (char**)o->data;
1944 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1948 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1949 prefix, list, n, string_start, o->length, o->maxlen);
1952 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1953 o->data + (int)list[i] + string_start,
1954 o->data + (int)list[i] + string_start);
1958 const char *p = o->data + (int)list[n - 1] + string_start;
1960 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1964 # define debug_print_list(prefix, o, n) ((void)0)
1967 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1968 * in list[n] so that it points past last stored byte so far.
1969 * It returns n+1. */
1970 static int o_save_ptr_helper(o_string *o, int n)
1972 char **list = (char**)o->data;
1976 if (!o->has_empty_slot) {
1977 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1978 string_len = o->length - string_start;
1979 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1980 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1981 /* list[n] points to string_start, make space for 16 more pointers */
1982 o->maxlen += 0x10 * sizeof(list[0]);
1983 o->data = xrealloc(o->data, o->maxlen + 1);
1984 list = (char**)o->data;
1985 memmove(list + n + 0x10, list + n, string_len);
1986 o->length += 0x10 * sizeof(list[0]);
1988 debug_printf_list("list[%d]=%d string_start=%d\n",
1989 n, string_len, string_start);
1992 /* We have empty slot at list[n], reuse without growth */
1993 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1994 string_len = o->length - string_start;
1995 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1996 n, string_len, string_start);
1997 o->has_empty_slot = 0;
1999 list[n] = (char*)(ptrdiff_t)string_len;
2003 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2004 static int o_get_last_ptr(o_string *o, int n)
2006 char **list = (char**)o->data;
2007 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2009 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2012 #ifdef HUSH_BRACE_EXP
2013 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2014 * first, it processes even {a} (no commas), second,
2015 * I didn't manage to make it return strings when they don't match
2016 * existing files. Need to re-implement it.
2020 static int glob_needed(const char *s)
2029 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2035 /* Return pointer to next closing brace or to comma */
2036 static const char *next_brace_sub(const char *cp)
2040 while (*cp != '\0') {
2047 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2049 if (*cp++ == '{') /*}*/
2053 return *cp != '\0' ? cp : NULL;
2055 /* Recursive brace globber. Note: may garble pattern[]. */
2056 static int glob_brace(char *pattern, o_string *o, int n)
2058 char *new_pattern_buf;
2065 debug_printf_glob("glob_brace('%s')\n", pattern);
2071 if (*begin == '{') /*}*/ {
2072 /* Find the first sub-pattern and at the same time
2073 * find the rest after the closing brace */
2074 next = next_brace_sub(begin);
2076 /* An illegal expression */
2079 /*{*/ if (*next == '}') {
2080 /* "{abc}" with no commas - illegal
2081 * brace expr, disregard and skip it */
2087 if (*begin == '\\' && begin[1] != '\0')
2091 debug_printf_glob("begin:%s\n", begin);
2092 debug_printf_glob("next:%s\n", next);
2094 /* Now find the end of the whole brace expression */
2096 /*{*/ while (*rest != '}') {
2097 rest = next_brace_sub(rest);
2099 /* An illegal expression */
2102 debug_printf_glob("rest:%s\n", rest);
2104 rest_len = strlen(++rest) + 1;
2106 /* We are sure the brace expression is well-formed */
2108 /* Allocate working buffer large enough for our work */
2109 new_pattern_buf = xmalloc(strlen(pattern));
2111 /* We have a brace expression. BEGIN points to the opening {,
2112 * NEXT points past the terminator of the first element, and REST
2113 * points past the final }. We will accumulate result names from
2114 * recursive runs for each brace alternative in the buffer using
2119 /* Construct the new glob expression */
2122 mempcpy(new_pattern_buf,
2123 /* We know the prefix for all sub-patterns */
2124 pattern, begin - pattern),
2128 /* Note: glob_brace() may garble new_pattern_buf[].
2129 * That's why we re-copy prefix every time (1st memcpy above).
2131 n = glob_brace(new_pattern_buf, o, n);
2132 /*{*/ if (*next == '}') {
2133 /* We saw the last entry */
2137 next = next_brace_sub(next);
2139 free(new_pattern_buf);
2147 memset(&globdata, 0, sizeof(globdata));
2148 gr = glob(pattern, 0, NULL, &globdata);
2149 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2151 if (gr == GLOB_NOMATCH) {
2152 globfree(&globdata);
2153 /* NB: garbles parameter */
2154 unbackslash(pattern);
2155 o_addstr_with_NUL(o, pattern);
2156 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2157 return o_save_ptr_helper(o, n);
2159 if (gr == GLOB_NOSPACE)
2160 bb_error_msg_and_die(bb_msg_memory_exhausted);
2161 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2162 * but we didn't specify it. Paranoia again. */
2163 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2165 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2166 char **argv = globdata.gl_pathv;
2168 o_addstr_with_NUL(o, *argv);
2169 n = o_save_ptr_helper(o, n);
2175 globfree(&globdata);
2179 /* Performs globbing on last list[],
2180 * saving each result as a new list[].
2182 static int o_glob(o_string *o, int n)
2184 char *pattern, *copy;
2186 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2188 return o_save_ptr_helper(o, n);
2189 pattern = o->data + o_get_last_ptr(o, n);
2190 debug_printf_glob("glob pattern '%s'\n", pattern);
2191 if (!glob_needed(pattern)) {
2192 /* unbackslash last string in o in place, fix length */
2193 o->length = unbackslash(pattern) - o->data;
2194 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2195 return o_save_ptr_helper(o, n);
2198 copy = xstrdup(pattern);
2199 /* "forget" pattern in o */
2200 o->length = pattern - o->data;
2201 n = glob_brace(copy, o, n);
2204 debug_print_list("o_glob returning", o, n);
2211 static int glob_needed(const char *s)
2220 if (*s == '*' || *s == '[' || *s == '?')
2226 /* Performs globbing on last list[],
2227 * saving each result as a new list[].
2229 static int o_glob(o_string *o, int n)
2235 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2237 return o_save_ptr_helper(o, n);
2238 pattern = o->data + o_get_last_ptr(o, n);
2239 debug_printf_glob("glob pattern '%s'\n", pattern);
2240 if (!glob_needed(pattern)) {
2242 /* unbackslash last string in o in place, fix length */
2243 o->length = unbackslash(pattern) - o->data;
2244 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2245 return o_save_ptr_helper(o, n);
2248 memset(&globdata, 0, sizeof(globdata));
2249 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2250 * If we glob "*.\*" and don't find anything, we need
2251 * to fall back to using literal "*.*", but GLOB_NOCHECK
2252 * will return "*.\*"!
2254 gr = glob(pattern, 0, NULL, &globdata);
2255 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2257 if (gr == GLOB_NOMATCH) {
2258 globfree(&globdata);
2261 if (gr == GLOB_NOSPACE)
2262 bb_error_msg_and_die(bb_msg_memory_exhausted);
2263 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2264 * but we didn't specify it. Paranoia again. */
2265 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2267 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2268 char **argv = globdata.gl_pathv;
2269 /* "forget" pattern in o */
2270 o->length = pattern - o->data;
2272 o_addstr_with_NUL(o, *argv);
2273 n = o_save_ptr_helper(o, n);
2279 globfree(&globdata);
2281 debug_print_list("o_glob returning", o, n);
2287 /* If o->o_glob == 1, glob the string so far remembered.
2288 * Otherwise, just finish current list[] and start new */
2289 static int o_save_ptr(o_string *o, int n)
2291 if (o->o_glob) { /* if globbing is requested */
2292 /* If o->has_empty_slot, list[n] was already globbed
2293 * (if it was requested back then when it was filled)
2294 * so don't do that again! */
2295 if (!o->has_empty_slot)
2296 return o_glob(o, n); /* o_save_ptr_helper is inside */
2298 return o_save_ptr_helper(o, n);
2301 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2302 static char **o_finalize_list(o_string *o, int n)
2307 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2309 debug_print_list("finalized", o, n);
2310 debug_printf_expand("finalized n:%d\n", n);
2311 list = (char**)o->data;
2312 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2316 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2322 /* Expansion can recurse */
2323 #if ENABLE_HUSH_TICK
2324 static int process_command_subs(o_string *dest, const char *s);
2326 static char *expand_string_to_string(const char *str);
2328 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2329 parse_stream_dquoted(dest, input, dquote_end)
2331 static int parse_stream_dquoted(o_string *as_string,
2333 struct in_str *input,
2336 /* expand_strvec_to_strvec() takes a list of strings, expands
2337 * all variable references within and returns a pointer to
2338 * a list of expanded strings, possibly with larger number
2339 * of strings. (Think VAR="a b"; echo $VAR).
2340 * This new list is allocated as a single malloc block.
2341 * NULL-terminated list of char* pointers is at the beginning of it,
2342 * followed by strings themself.
2343 * Caller can deallocate entire list by single free(list). */
2345 /* Store given string, finalizing the word and starting new one whenever
2346 * we encounter IFS char(s). This is used for expanding variable values.
2347 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2348 static int expand_on_ifs(o_string *output, int n, const char *str)
2351 int word_len = strcspn(str, G.ifs);
2353 if (output->o_escape || !output->o_glob)
2354 o_addQstr(output, str, word_len);
2355 else /* protect backslashes against globbing up :) */
2356 o_addblock_duplicate_backslash(output, str, word_len);
2359 if (!*str) /* EOL - do not finalize word */
2361 o_addchr(output, '\0');
2362 debug_print_list("expand_on_ifs", output, n);
2363 n = o_save_ptr(output, n);
2364 str += strspn(str, G.ifs); /* skip ifs chars */
2366 debug_print_list("expand_on_ifs[1]", output, n);
2370 /* Helper to expand $((...)) and heredoc body. These act as if
2371 * they are in double quotes, with the exception that they are not :).
2372 * Just the rules are similar: "expand only $var and `cmd`"
2374 * Returns malloced string.
2375 * As an optimization, we return NULL if expansion is not needed.
2377 static char *expand_pseudo_dquoted(const char *str)
2380 struct in_str input;
2381 o_string dest = NULL_O_STRING;
2383 if (strchr(str, '$') == NULL
2384 #if ENABLE_HUSH_TICK
2385 && strchr(str, '`') == NULL
2391 /* We need to expand. Example:
2392 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2394 setup_string_in_str(&input, str);
2395 parse_stream_dquoted(NULL, &dest, &input, EOF);
2396 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2397 exp_str = expand_string_to_string(dest.data);
2398 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2399 o_free_unsafe(&dest);
2403 /* Expand all variable references in given string, adding words to list[]
2404 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2405 * to be filled). This routine is extremely tricky: has to deal with
2406 * variables/parameters with whitespace, $* and $@, and constructs like
2407 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2408 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2410 /* or_mask is either 0 (normal case) or 0x80 -
2411 * expansion of right-hand side of assignment == 1-element expand.
2412 * It will also do no globbing, and thus we must not backslash-quote!
2419 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2420 debug_print_list("expand_vars_to_list", output, n);
2421 n = o_save_ptr(output, n);
2422 debug_print_list("expand_vars_to_list[0]", output, n);
2424 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2427 char *dyn_val = NULL;
2428 const char *val = NULL;
2429 #if ENABLE_HUSH_TICK
2430 o_string subst_result = NULL_O_STRING;
2432 #if ENABLE_SH_MATH_SUPPORT
2433 char arith_buf[sizeof(arith_t)*3 + 2];
2435 o_addblock(output, arg, p - arg);
2436 debug_print_list("expand_vars_to_list[1]", output, n);
2438 p = strchr(p, SPECIAL_VAR_SYMBOL);
2440 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2441 /* "$@" is special. Even if quoted, it can still
2442 * expand to nothing (not even an empty string) */
2443 if ((first_ch & 0x7f) != '@')
2444 ored_ch |= first_ch;
2446 switch (first_ch & 0x7f) {
2447 /* Highest bit in first_ch indicates that var is double-quoted */
2449 val = utoa(G.root_pid);
2451 case '!': /* bg pid */
2452 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2454 case '?': /* exitcode */
2455 val = utoa(G.last_exitcode);
2457 case '#': /* argc */
2458 if (arg[1] != SPECIAL_VAR_SYMBOL)
2459 /* actually, it's a ${#var} */
2461 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2466 if (!G.global_argv[i])
2468 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2469 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2470 smallint sv = output->o_escape;
2471 /* unquoted var's contents should be globbed, so don't escape */
2472 output->o_escape = 0;
2473 while (G.global_argv[i]) {
2474 n = expand_on_ifs(output, n, G.global_argv[i]);
2475 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2476 if (G.global_argv[i++][0] && G.global_argv[i]) {
2477 /* this argv[] is not empty and not last:
2478 * put terminating NUL, start new word */
2479 o_addchr(output, '\0');
2480 debug_print_list("expand_vars_to_list[2]", output, n);
2481 n = o_save_ptr(output, n);
2482 debug_print_list("expand_vars_to_list[3]", output, n);
2485 output->o_escape = sv;
2487 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2488 * and in this case should treat it like '$*' - see 'else...' below */
2489 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2491 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2492 if (++i >= G.global_argc)
2494 o_addchr(output, '\0');
2495 debug_print_list("expand_vars_to_list[4]", output, n);
2496 n = o_save_ptr(output, n);
2498 } else { /* quoted $*: add as one word */
2500 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2501 if (!G.global_argv[++i])
2504 o_addchr(output, G.ifs[0]);
2508 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2509 /* "Empty variable", used to make "" etc to not disappear */
2513 #if ENABLE_HUSH_TICK
2514 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2517 /* Can't just stuff it into output o_string,
2518 * expanded result may need to be globbed
2519 * and $IFS-splitted */
2520 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2521 G.last_exitcode = process_command_subs(&subst_result, arg);
2522 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2523 val = subst_result.data;
2526 #if ENABLE_SH_MATH_SUPPORT
2527 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2528 arith_eval_hooks_t hooks;
2533 arg++; /* skip '+' */
2534 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2535 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2537 exp_str = expand_pseudo_dquoted(arg);
2538 hooks.lookupvar = get_local_var_value;
2539 hooks.setvar = arith_set_local_var;
2540 hooks.endofname = endofname;
2541 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2545 const char *msg = "error in arithmetic";
2548 msg = "exponent less than 0";
2551 msg = "divide by 0";
2554 msg = "expression recursion loop detected";
2559 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2560 sprintf(arith_buf, arith_t_fmt, res);
2565 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2567 bool exp_len = false;
2568 bool exp_null = false;
2570 char exp_save = exp_save; /* for compiler */
2571 char exp_op = exp_op; /* for compiler */
2572 char *exp_word = exp_word; /* for compiler */
2576 arg[0] = first_ch & 0x7f;
2578 /* prepare for expansions */
2579 if (var[0] == '#') {
2580 /* handle length expansion ${#var} */
2584 /* maybe handle parameter expansion */
2585 exp_off = strcspn(var, ":-=+?%#");
2589 exp_save = var[exp_off];
2590 exp_null = exp_save == ':';
2591 exp_word = var + exp_off;
2594 exp_op = *exp_word++;
2595 var[exp_off] = '\0';
2599 /* lookup the variable in question */
2600 if (isdigit(var[0])) {
2601 /* handle_dollar() should have vetted var for us */
2603 if (i < G.global_argc)
2604 val = G.global_argv[i];
2605 /* else val remains NULL: $N with too big N */
2607 val = get_local_var_value(var);
2609 /* handle any expansions */
2611 debug_printf_expand("expand: length of '%s' = ", val);
2612 val = utoa(val ? strlen(val) : 0);
2613 debug_printf_expand("%s\n", val);
2614 } else if (exp_off) {
2615 if (exp_op == '%' || exp_op == '#') {
2617 /* we need to do a pattern match */
2620 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2621 if (exp_op == *exp_word) /* ## or %% */
2623 val = dyn_val = xstrdup(val);
2624 loc = scan(dyn_val, exp_word, match_at_left);
2625 if (match_at_left) /* # or ## */
2627 else if (loc) /* % or %% and match was found */
2631 /* we need to do an expansion */
2632 int exp_test = (!val || (exp_null && !val[0]));
2634 exp_test = !exp_test;
2635 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2636 exp_null ? "true" : "false", exp_test);
2638 if (exp_op == '?') {
2639 //TODO: how interactive bash aborts expansion mid-command?
2640 /* ${var?[error_msg_if_unset]} */
2641 /* ${var:?[error_msg_if_unset_or_null]} */
2642 /* mimic bash message */
2643 die_if_script("%s: %s",
2645 exp_word[0] ? exp_word : "parameter null or not set"
2651 if (exp_op == '=') {
2652 /* ${var=[word]} or ${var:=[word]} */
2653 if (isdigit(var[0]) || var[0] == '#') {
2654 /* mimic bash message */
2655 die_if_script("$%s: cannot assign in this way", var);
2658 char *new_var = xasprintf("%s=%s", var, val);
2659 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2665 var[exp_off] = exp_save;
2669 #if ENABLE_HUSH_TICK
2672 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2673 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2675 /* unquoted var's contents should be globbed, so don't escape */
2676 smallint sv = output->o_escape;
2677 output->o_escape = 0;
2678 n = expand_on_ifs(output, n, val);
2680 output->o_escape = sv;
2682 } else { /* quoted $VAR, val will be appended below */
2683 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2686 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2689 o_addQstr(output, val, strlen(val));
2692 /* Do the check to avoid writing to a const string */
2693 if (*p != SPECIAL_VAR_SYMBOL)
2694 *p = SPECIAL_VAR_SYMBOL;
2696 #if ENABLE_HUSH_TICK
2697 o_free(&subst_result);
2700 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2703 debug_print_list("expand_vars_to_list[a]", output, n);
2704 /* this part is literal, and it was already pre-quoted
2705 * if needed (much earlier), do not use o_addQstr here! */
2706 o_addstr_with_NUL(output, arg);
2707 debug_print_list("expand_vars_to_list[b]", output, n);
2708 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2709 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2712 /* allow to reuse list[n] later without re-growth */
2713 output->has_empty_slot = 1;
2715 o_addchr(output, '\0');
2720 static char **expand_variables(char **argv, int or_mask)
2725 o_string output = NULL_O_STRING;
2727 if (or_mask & 0x100) {
2728 output.o_escape = 1; /* protect against globbing for "$var" */
2729 /* (unquoted $var will temporarily switch it off) */
2736 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2739 debug_print_list("expand_variables", &output, n);
2741 /* output.data (malloced in one block) gets returned in "list" */
2742 list = o_finalize_list(&output, n);
2743 debug_print_strings("expand_variables[1]", list);
2747 static char **expand_strvec_to_strvec(char **argv)
2749 return expand_variables(argv, 0x100);
2752 #if ENABLE_HUSH_BASH_COMPAT
2753 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2755 return expand_variables(argv, 0x80);
2759 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2760 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2765 o_string output = NULL_O_STRING;
2770 int is_var = is_well_formed_var_name(*v, '=');
2771 /* is_var * 0x80: singleword expansion for vars */
2772 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2774 /* Subtle! expand_vars_to_list did not glob last word yet.
2775 * It does this only when fed with further data.
2776 * Therefore we set globbing flags AFTER it, not before:
2779 /* if it is not recognizably abc=...; then: */
2780 output.o_escape = !is_var; /* protect against globbing for "$var" */
2781 /* (unquoted $var will temporarily switch it off) */
2782 output.o_glob = !is_var; /* and indeed do globbing */
2785 debug_print_list("expand_cond", &output, n);
2787 /* output.data (malloced in one block) gets returned in "list" */
2788 list = o_finalize_list(&output, n);
2789 debug_print_strings("expand_cond[1]", list);
2794 /* Used for expansion of right hand of assignments */
2795 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2797 static char *expand_string_to_string(const char *str)
2799 char *argv[2], **list;
2801 argv[0] = (char*)str;
2803 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2805 if (!list[0] || list[1])
2806 bb_error_msg_and_die("BUG in varexp2");
2807 /* actually, just move string 2*sizeof(char*) bytes back */
2808 overlapping_strcpy((char*)list, list[0]);
2809 unbackslash((char*)list);
2810 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2814 /* Used for "eval" builtin */
2815 static char* expand_strvec_to_string(char **argv)
2819 list = expand_variables(argv, 0x80);
2820 /* Convert all NULs to spaces */
2825 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2826 bb_error_msg_and_die("BUG in varexp3");
2827 /* bash uses ' ' regardless of $IFS contents */
2832 overlapping_strcpy((char*)list, list[0]);
2833 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2837 static char **expand_assignments(char **argv, int count)
2841 /* Expand assignments into one string each */
2842 for (i = 0; i < count; i++) {
2843 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2851 void re_execute_shell(char ***to_free, const char *s,
2852 char *g_argv0, char **g_argv,
2853 char **builtin_argv) NORETURN;
2855 static void reset_traps_to_defaults(void)
2857 /* This function is always called in a child shell
2858 * after fork (not vfork, NOMMU doesn't use this function).
2863 /* Child shells are not interactive.
2864 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2865 * Testcase: (while :; do :; done) + ^Z should background.
2866 * Same goes for SIGTERM, SIGHUP, SIGINT.
2868 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2869 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2871 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2872 * Stupid. It can be done with *single* &= op, but we can't use
2873 * the fact that G.blocked_set is implemented as a bitmask
2875 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2879 /* Careful. Only if no trap or trap is not "" */
2880 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2881 sigdelset(&G.blocked_set, sig);
2888 /* Our homegrown sig mask is saner to work with :) */
2889 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2891 /* Resetting all traps to default except empty ones */
2892 mask = G.non_DFL_mask;
2893 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2894 if (!G.traps[sig] || !G.traps[sig][0])
2897 G.traps[sig] = NULL;
2898 /* There is no signal for 0 (EXIT) */
2901 /* There was a trap handler, we just removed it.
2902 * But if sig still has non-DFL handling,
2903 * we should not unblock the sig. */
2906 sigdelset(&G.blocked_set, sig);
2908 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2913 static void re_execute_shell(char ***to_free, const char *s,
2914 char *g_argv0, char **g_argv,
2915 char **builtin_argv) NORETURN;
2916 static void re_execute_shell(char ***to_free, const char *s,
2917 char *g_argv0, char **g_argv,
2918 char **builtin_argv)
2920 char param_buf[sizeof("-$%x:%x:%x:%x:%x") + sizeof(unsigned) * 2];
2921 char *heredoc_argv[4];
2922 struct variable *cur;
2923 # if ENABLE_HUSH_FUNCTIONS
2924 struct function *funcp;
2929 if (!g_argv0) { /* heredoc */
2930 argv = heredoc_argv;
2931 argv[0] = (char *) G.argv0_for_re_execing;
2932 argv[1] = (char *) "-<";
2933 argv[2] = (char *) s;
2935 pp = &argv[3]; /* used as pointer to empty environment */
2941 if (pp) while (*pp++)
2944 sprintf(param_buf, "-$%x:%x:%x:%x:%x" IF_HUSH_LOOPS(":%x")
2945 , (unsigned) G.root_pid
2946 , (unsigned) G.root_ppid
2947 , (unsigned) G.last_bg_pid
2948 , (unsigned) G.last_exitcode
2950 IF_HUSH_LOOPS(, G.depth_of_loop)
2952 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2953 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2956 for (cur = G.top_var; cur; cur = cur->next) {
2957 if (!cur->flg_export || cur->flg_read_only)
2960 # if ENABLE_HUSH_FUNCTIONS
2961 for (funcp = G.top_func; funcp; funcp = funcp->next)
2967 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2968 *pp++ = (char *) G.argv0_for_re_execing;
2970 for (cur = G.top_var; cur; cur = cur->next) {
2971 if (cur->varstr == hush_version_str)
2973 if (cur->flg_read_only) {
2974 *pp++ = (char *) "-R";
2975 *pp++ = cur->varstr;
2976 } else if (!cur->flg_export) {
2977 *pp++ = (char *) "-V";
2978 *pp++ = cur->varstr;
2981 # if ENABLE_HUSH_FUNCTIONS
2982 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2983 *pp++ = (char *) "-F";
2984 *pp++ = funcp->name;
2985 *pp++ = funcp->body_as_string;
2988 /* We can pass activated traps here. Say, -Tnn:trap_string
2990 * However, POSIX says that subshells reset signals with traps
2992 * I tested bash-3.2 and it not only does that with true subshells
2993 * of the form ( list ), but with any forked children shells.
2994 * I set trap "echo W" WINCH; and then tried:
2996 * { echo 1; sleep 20; echo 2; } &
2997 * while true; do echo 1; sleep 20; echo 2; break; done &
2998 * true | { echo 1; sleep 20; echo 2; } | cat
3000 * In all these cases sending SIGWINCH to the child shell
3001 * did not run the trap. If I add trap "echo V" WINCH;
3002 * _inside_ group (just before echo 1), it works.
3004 * I conclude it means we don't need to pass active traps here.
3005 * exec syscall below resets them to SIG_DFL for us.
3007 *pp++ = (char *) "-c";
3010 while (*++builtin_argv)
3011 *pp++ = *builtin_argv;
3012 *pp++ = (char *) "";
3017 /* *pp = NULL; - is already there */
3021 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3022 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3023 execve(bb_busybox_exec_path, argv, pp);
3024 /* Fallback. Useful for init=/bin/hush usage etc */
3025 if (argv[0][0] == '/')
3026 execve(argv[0], argv, pp);
3027 xfunc_error_retval = 127;
3028 bb_error_msg_and_die("can't re-execute the shell");
3030 #endif /* !BB_MMU */
3033 static void setup_heredoc(struct redir_struct *redir)
3035 struct fd_pair pair;
3038 /* the _body_ of heredoc (misleading field name) */
3039 const char *heredoc = redir->rd_filename;
3046 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3047 expanded = expand_pseudo_dquoted(heredoc);
3051 len = strlen(heredoc);
3053 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3055 xmove_fd(pair.rd, redir->rd_fd);
3057 /* Try writing without forking. Newer kernels have
3058 * dynamically growing pipes. Must use non-blocking write! */
3061 written = write(pair.wr, heredoc, len);
3072 ndelay_off(pair.wr);
3074 /* Okay, pipe buffer was not big enough */
3075 /* Note: we must not create a stray child (bastard? :)
3076 * for the unsuspecting parent process. Child creates a grandchild
3077 * and exits before parent execs the process which consumes heredoc
3078 * (that exec happens after we return from this function) */
3084 bb_perror_msg_and_die("vfork");
3087 disable_restore_tty_pgrp_on_exit();
3088 pid = BB_MMU ? fork() : vfork();
3090 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3094 close(redir->rd_fd); /* read side of the pipe */
3096 full_write(pair.wr, heredoc, len); /* may loop or block */
3099 /* Delegate blocking writes to another process */
3100 xmove_fd(pair.wr, STDOUT_FILENO);
3101 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3105 #if ENABLE_HUSH_FAST
3107 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3109 enable_restore_tty_pgrp_on_exit();
3115 wait(NULL); /* wait till child has died */
3118 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3119 * and stderr if they are redirected. */
3120 static int setup_redirects(struct command *prog, int squirrel[])
3123 struct redir_struct *redir;
3125 for (redir = prog->redirects; redir; redir = redir->next) {
3126 if (redir->rd_type == REDIRECT_HEREDOC2) {
3127 /* rd_fd<<HERE case */
3128 if (squirrel && redir->rd_fd < 3
3129 && squirrel[redir->rd_fd] < 0
3131 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3133 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3135 debug_printf_parse("set heredoc '%s'\n",
3136 redir->rd_filename);
3137 setup_heredoc(redir);
3141 if (redir->rd_dup == REDIRFD_TO_FILE) {
3142 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3144 if (redir->rd_filename == NULL) {
3145 /* Something went wrong in the parse.
3146 * Pretend it didn't happen */
3147 bb_error_msg("bug in redirect parse");
3150 mode = redir_table[redir->rd_type].mode;
3151 p = expand_string_to_string(redir->rd_filename);
3152 openfd = open_or_warn(p, mode);
3155 /* this could get lost if stderr has been redirected, but
3156 * bash and ash both lose it as well (though zsh doesn't!) */
3157 //what the above comment tries to say?
3161 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3162 openfd = redir->rd_dup;
3165 if (openfd != redir->rd_fd) {
3166 if (squirrel && redir->rd_fd < 3
3167 && squirrel[redir->rd_fd] < 0
3169 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3171 if (openfd == REDIRFD_CLOSE) {
3172 /* "n>-" means "close me" */
3173 close(redir->rd_fd);
3175 xdup2(openfd, redir->rd_fd);
3176 if (redir->rd_dup == REDIRFD_TO_FILE)
3184 static void restore_redirects(int squirrel[])
3187 for (i = 0; i < 3; i++) {
3190 /* We simply die on error */
3197 static void free_pipe_list(struct pipe *head);
3199 /* Return code is the exit status of the pipe */
3200 static void free_pipe(struct pipe *pi)
3203 struct command *command;
3204 struct redir_struct *r, *rnext;
3207 if (pi->stopped_cmds > 0) /* why? */
3209 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3210 for (i = 0; i < pi->num_cmds; i++) {
3211 command = &pi->cmds[i];
3212 debug_printf_clean(" command %d:\n", i);
3213 if (command->argv) {
3214 for (a = 0, p = command->argv; *p; a++, p++) {
3215 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3217 free_strings(command->argv);
3218 command->argv = NULL;
3220 /* not "else if": on syntax error, we may have both! */
3221 if (command->group) {
3222 debug_printf_clean(" begin group (cmd_type:%d)\n",
3224 free_pipe_list(command->group);
3225 debug_printf_clean(" end group\n");
3226 command->group = NULL;
3228 /* else is crucial here.
3229 * If group != NULL, child_func is meaningless */
3230 #if ENABLE_HUSH_FUNCTIONS
3231 else if (command->child_func) {
3232 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3233 command->child_func->parent_cmd = NULL;
3237 free(command->group_as_string);
3238 command->group_as_string = NULL;
3240 for (r = command->redirects; r; r = rnext) {
3241 debug_printf_clean(" redirect %d%s",
3242 r->rd_fd, redir_table[r->rd_type].descrip);
3243 /* guard against the case >$FOO, where foo is unset or blank */
3244 if (r->rd_filename) {
3245 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3246 free(r->rd_filename);
3247 r->rd_filename = NULL;
3249 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3253 command->redirects = NULL;
3255 free(pi->cmds); /* children are an array, they get freed all at once */
3263 static void free_pipe_list(struct pipe *head)
3265 struct pipe *pi, *next;
3267 for (pi = head; pi; pi = next) {
3269 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3272 debug_printf_clean("pipe followup code %d\n", pi->followup);
3274 /*pi->next = NULL;*/
3280 static int run_list(struct pipe *pi);
3282 #define parse_stream(pstring, input, end_trigger) \
3283 parse_stream(input, end_trigger)
3285 static struct pipe *parse_stream(char **pstring,
3286 struct in_str *input,
3288 static void parse_and_run_string(const char *s);
3291 static char *find_in_path(const char *arg)
3294 const char *PATH = get_local_var_value("PATH");
3300 const char *end = strchrnul(PATH, ':');
3301 int sz = end - PATH; /* must be int! */
3305 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3307 /* We have xxx::yyyy in $PATH,
3308 * it means "use current dir" */
3311 if (access(ret, F_OK) == 0)
3324 static const struct built_in_command* find_builtin_helper(const char *name,
3325 const struct built_in_command *x,
3326 const struct built_in_command *end)
3329 if (strcmp(name, x->cmd) != 0) {
3333 debug_printf_exec("found builtin '%s'\n", name);
3338 static const struct built_in_command* find_builtin1(const char *name)
3340 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3342 static const struct built_in_command* find_builtin(const char *name)
3344 const struct built_in_command *x = find_builtin1(name);
3347 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3350 #if ENABLE_HUSH_FUNCTIONS
3351 static struct function **find_function_slot(const char *name)
3353 struct function **funcpp = &G.top_func;
3355 if (strcmp(name, (*funcpp)->name) == 0) {
3358 funcpp = &(*funcpp)->next;
3363 static const struct function *find_function(const char *name)
3365 const struct function *funcp = *find_function_slot(name);
3367 debug_printf_exec("found function '%s'\n", name);
3371 /* Note: takes ownership on name ptr */
3372 static struct function *new_function(char *name)
3374 struct function **funcpp = find_function_slot(name);
3375 struct function *funcp = *funcpp;
3377 if (funcp != NULL) {
3378 struct command *cmd = funcp->parent_cmd;
3379 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3381 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3383 /* Note: if !funcp->body, do not free body_as_string!
3384 * This is a special case of "-F name body" function:
3385 * body_as_string was not malloced! */
3387 free_pipe_list(funcp->body);
3389 free(funcp->body_as_string);
3393 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3394 cmd->argv[0] = funcp->name;
3395 cmd->group = funcp->body;
3397 cmd->group_as_string = funcp->body_as_string;
3401 debug_printf_exec("remembering new function '%s'\n", name);
3402 funcp = *funcpp = xzalloc(sizeof(*funcp));
3403 /*funcp->next = NULL;*/
3410 static void unset_func(const char *name)
3412 struct function **funcpp = find_function_slot(name);
3413 struct function *funcp = *funcpp;
3415 if (funcp != NULL) {
3416 debug_printf_exec("freeing function '%s'\n", funcp->name);
3417 *funcpp = funcp->next;
3418 /* funcp is unlinked now, deleting it.
3419 * Note: if !funcp->body, the function was created by
3420 * "-F name body", do not free ->body_as_string
3421 * and ->name as they were not malloced. */
3423 free_pipe_list(funcp->body);
3426 free(funcp->body_as_string);
3434 #define exec_function(to_free, funcp, argv) \
3435 exec_function(funcp, argv)
3437 static void exec_function(char ***to_free,
3438 const struct function *funcp,
3439 char **argv) NORETURN;
3440 static void exec_function(char ***to_free,
3441 const struct function *funcp,
3447 argv[0] = G.global_argv[0];
3448 G.global_argv = argv;
3452 /* On MMU, funcp->body is always non-NULL */
3453 n = run_list(funcp->body);
3457 re_execute_shell(to_free,
3458 funcp->body_as_string,
3465 static int run_function(const struct function *funcp, char **argv)
3471 save_and_replace_G_args(&sv, argv);
3473 /* "we are in function, ok to use return" */
3474 sv_flg = G.flag_return_in_progress;
3475 G.flag_return_in_progress = -1;
3476 # if ENABLE_HUSH_LOCAL
3477 G.func_nest_level++;
3480 /* On MMU, funcp->body is always non-NULL */
3483 /* Function defined by -F */
3484 parse_and_run_string(funcp->body_as_string);
3485 rc = G.last_exitcode;
3489 rc = run_list(funcp->body);
3492 # if ENABLE_HUSH_LOCAL
3494 struct variable *var;
3495 struct variable **var_pp;
3497 var_pp = &G.top_var;
3498 while ((var = *var_pp) != NULL) {
3499 if (var->func_nest_level < G.func_nest_level) {
3500 var_pp = &var->next;
3504 if (var->flg_export)
3505 bb_unsetenv(var->varstr);
3506 /* Remove from global list */
3507 *var_pp = var->next;
3513 G.func_nest_level--;
3516 G.flag_return_in_progress = sv_flg;
3518 restore_G_args(&sv, argv);
3522 #endif /* ENABLE_HUSH_FUNCTIONS */
3526 #define exec_builtin(to_free, x, argv) \
3527 exec_builtin(x, argv)
3529 #define exec_builtin(to_free, x, argv) \
3530 exec_builtin(to_free, argv)
3532 static void exec_builtin(char ***to_free,
3533 const struct built_in_command *x,
3534 char **argv) NORETURN;
3535 static void exec_builtin(char ***to_free,
3536 const struct built_in_command *x,
3540 int rcode = x->function(argv);
3544 /* On NOMMU, we must never block!
3545 * Example: { sleep 99 | read line; } & echo Ok
3547 re_execute_shell(to_free,
3556 static void execvp_or_die(char **argv) NORETURN;
3557 static void execvp_or_die(char **argv)
3559 debug_printf_exec("execing '%s'\n", argv[0]);
3560 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3561 execvp(argv[0], argv);
3562 bb_perror_msg("can't execute '%s'", argv[0]);
3563 _exit(127); /* bash compat */
3567 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3568 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3569 #define pseudo_exec(nommu_save, command, argv_expanded) \
3570 pseudo_exec(command, argv_expanded)
3573 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3575 * Don't exit() here. If you don't exec, use _exit instead.
3576 * The at_exit handlers apparently confuse the calling process,
3577 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3578 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3579 char **argv, int assignment_cnt,
3580 char **argv_expanded) NORETURN;
3581 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3582 char **argv, int assignment_cnt,
3583 char **argv_expanded)
3587 /* Case when we are here: ... | var=val | ... */
3588 if (!argv[assignment_cnt])
3589 _exit(EXIT_SUCCESS);
3591 new_env = expand_assignments(argv, assignment_cnt);
3593 set_vars_and_save_old(new_env);
3594 free(new_env); /* optional */
3595 /* we can also destroy set_vars_and_save_old's return value,
3598 nommu_save->new_env = new_env;
3599 nommu_save->old_vars = set_vars_and_save_old(new_env);
3601 if (argv_expanded) {
3602 argv = argv_expanded;
3604 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3606 nommu_save->argv = argv;
3610 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3611 if (strchr(argv[0], '/') != NULL)
3615 /* Check if the command matches any of the builtins.
3616 * Depending on context, this might be redundant. But it's
3617 * easier to waste a few CPU cycles than it is to figure out
3618 * if this is one of those cases.
3621 /* On NOMMU, it is more expensive to re-execute shell
3622 * just in order to run echo or test builtin.
3623 * It's better to skip it here and run corresponding
3624 * non-builtin later. */
3625 const struct built_in_command *x;
3626 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3628 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3631 #if ENABLE_HUSH_FUNCTIONS
3632 /* Check if the command matches any functions */
3634 const struct function *funcp = find_function(argv[0]);
3636 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3641 #if ENABLE_FEATURE_SH_STANDALONE
3642 /* Check if the command matches any busybox applets */
3644 int a = find_applet_by_name(argv[0]);
3646 # if BB_MMU /* see above why on NOMMU it is not allowed */
3647 if (APPLET_IS_NOEXEC(a)) {
3648 debug_printf_exec("running applet '%s'\n", argv[0]);
3649 run_applet_no_and_exit(a, argv);
3652 /* Re-exec ourselves */
3653 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3654 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3655 execv(bb_busybox_exec_path, argv);
3656 /* If they called chroot or otherwise made the binary no longer
3657 * executable, fall through */
3662 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3665 execvp_or_die(argv);
3668 /* Called after [v]fork() in run_pipe
3670 static void pseudo_exec(nommu_save_t *nommu_save,
3671 struct command *command,
3672 char **argv_expanded) NORETURN;
3673 static void pseudo_exec(nommu_save_t *nommu_save,
3674 struct command *command,
3675 char **argv_expanded)
3677 if (command->argv) {
3678 pseudo_exec_argv(nommu_save, command->argv,
3679 command->assignment_cnt, argv_expanded);
3682 if (command->group) {
3683 /* Cases when we are here:
3686 * ... | ( list ) | ...
3687 * ... | { list } | ...
3691 debug_printf_exec("pseudo_exec: run_list\n");
3692 reset_traps_to_defaults();
3693 rcode = run_list(command->group);
3694 /* OK to leak memory by not calling free_pipe_list,
3695 * since this process is about to exit */
3698 re_execute_shell(&nommu_save->argv_from_re_execing,
3699 command->group_as_string,
3706 /* Case when we are here: ... | >file */
3707 debug_printf_exec("pseudo_exec'ed null command\n");
3708 _exit(EXIT_SUCCESS);
3712 static const char *get_cmdtext(struct pipe *pi)
3718 /* This is subtle. ->cmdtext is created only on first backgrounding.
3719 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3720 * On subsequent bg argv is trashed, but we won't use it */
3723 argv = pi->cmds[0].argv;
3724 if (!argv || !argv[0]) {
3725 pi->cmdtext = xzalloc(1);
3731 len += strlen(*argv) + 1;
3735 argv = pi->cmds[0].argv;
3737 len = strlen(*argv);
3738 memcpy(p, *argv, len);
3746 static void insert_bg_job(struct pipe *pi)
3748 struct pipe *job, **jobp;
3751 /* Linear search for the ID of the job to use */
3753 for (job = G.job_list; job; job = job->next)
3754 if (job->jobid >= pi->jobid)
3755 pi->jobid = job->jobid + 1;
3757 /* Add job to the list of running jobs */
3759 while ((job = *jobp) != NULL)
3761 job = *jobp = xmalloc(sizeof(*job));
3763 *job = *pi; /* physical copy */
3765 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3766 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3767 for (i = 0; i < pi->num_cmds; i++) {
3768 job->cmds[i].pid = pi->cmds[i].pid;
3769 /* all other fields are not used and stay zero */
3771 job->cmdtext = xstrdup(get_cmdtext(pi));
3773 if (G_interactive_fd)
3774 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3775 /* Last command's pid goes to $! */
3776 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3777 G.last_jobid = job->jobid;
3780 static void remove_bg_job(struct pipe *pi)
3782 struct pipe *prev_pipe;
3784 if (pi == G.job_list) {
3785 G.job_list = pi->next;
3787 prev_pipe = G.job_list;
3788 while (prev_pipe->next != pi)
3789 prev_pipe = prev_pipe->next;
3790 prev_pipe->next = pi->next;
3793 G.last_jobid = G.job_list->jobid;
3798 /* Remove a backgrounded job */
3799 static void delete_finished_bg_job(struct pipe *pi)
3802 pi->stopped_cmds = 0;
3808 /* Check to see if any processes have exited -- if they
3809 * have, figure out why and see if a job has completed */
3810 static int checkjobs(struct pipe* fg_pipe)
3820 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3822 attributes = WUNTRACED;
3823 if (fg_pipe == NULL)
3824 attributes |= WNOHANG;
3827 #if ENABLE_HUSH_FAST
3828 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3829 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3830 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3831 /* There was neither fork nor SIGCHLD since last waitpid */
3832 /* Avoid doing waitpid syscall if possible */
3833 if (!G.we_have_children) {
3837 if (fg_pipe == NULL) { /* is WNOHANG set? */
3838 /* We have children, but they did not exit
3839 * or stop yet (we saw no SIGCHLD) */
3842 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3846 /* Do we do this right?
3847 * bash-3.00# sleep 20 | false
3849 * [3]+ Stopped sleep 20 | false
3850 * bash-3.00# echo $?
3851 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3852 * [hush 1.14.0: yes we do it right]
3859 #if ENABLE_HUSH_FAST
3860 i = G.count_SIGCHLD;
3862 childpid = waitpid(-1, &status, attributes);
3863 if (childpid <= 0) {
3864 if (childpid && errno != ECHILD)
3865 bb_perror_msg("waitpid");
3866 #if ENABLE_HUSH_FAST
3867 else { /* Until next SIGCHLD, waitpid's are useless */
3868 G.we_have_children = (childpid == 0);
3869 G.handled_SIGCHLD = i;
3870 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3875 dead = WIFEXITED(status) || WIFSIGNALED(status);
3878 if (WIFSTOPPED(status))
3879 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3880 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3881 if (WIFSIGNALED(status))
3882 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3883 childpid, WTERMSIG(status), WEXITSTATUS(status));
3884 if (WIFEXITED(status))
3885 debug_printf_jobs("pid %d exited, exitcode %d\n",
3886 childpid, WEXITSTATUS(status));
3888 /* Were we asked to wait for fg pipe? */
3890 for (i = 0; i < fg_pipe->num_cmds; i++) {
3891 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3892 if (fg_pipe->cmds[i].pid != childpid)
3895 fg_pipe->cmds[i].pid = 0;
3896 fg_pipe->alive_cmds--;
3897 if (i == fg_pipe->num_cmds - 1) {
3898 /* last process gives overall exitstatus */
3899 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3900 rcode = WEXITSTATUS(status);
3901 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3902 /* bash prints killer signal's name for *last*
3903 * process in pipe (prints just newline for SIGINT).
3904 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3906 if (WIFSIGNALED(status)) {
3907 int sig = WTERMSIG(status);
3908 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3912 fg_pipe->cmds[i].is_stopped = 1;
3913 fg_pipe->stopped_cmds++;
3915 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3916 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3917 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3918 /* All processes in fg pipe have exited or stopped */
3919 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3920 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3921 * and "killall -STOP cat" */
3922 if (G_interactive_fd) {
3924 if (fg_pipe->alive_cmds)
3925 insert_bg_job(fg_pipe);
3929 if (!fg_pipe->alive_cmds)
3932 /* There are still running processes in the fg pipe */
3933 goto wait_more; /* do waitpid again */
3935 /* it wasnt fg_pipe, look for process in bg pipes */
3939 /* We asked to wait for bg or orphaned children */
3940 /* No need to remember exitcode in this case */
3941 for (pi = G.job_list; pi; pi = pi->next) {
3942 for (i = 0; i < pi->num_cmds; i++) {
3943 if (pi->cmds[i].pid == childpid)
3944 goto found_pi_and_prognum;
3947 /* Happens when shell is used as init process (init=/bin/sh) */
3948 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3949 continue; /* do waitpid again */
3951 found_pi_and_prognum:
3954 pi->cmds[i].pid = 0;
3956 if (!pi->alive_cmds) {
3957 if (G_interactive_fd)
3958 printf(JOB_STATUS_FORMAT, pi->jobid,
3959 "Done", pi->cmdtext);
3960 delete_finished_bg_job(pi);
3964 pi->cmds[i].is_stopped = 1;
3968 } /* while (waitpid succeeds)... */
3974 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3977 int rcode = checkjobs(fg_pipe);
3978 if (G_saved_tty_pgrp) {
3979 /* Job finished, move the shell to the foreground */
3980 p = getpgrp(); /* our process group id */
3981 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3982 tcsetpgrp(G_interactive_fd, p);
3988 /* Start all the jobs, but don't wait for anything to finish.
3991 * Return code is normally -1, when the caller has to wait for children
3992 * to finish to determine the exit status of the pipe. If the pipe
3993 * is a simple builtin command, however, the action is done by the
3994 * time run_pipe returns, and the exit code is provided as the
3997 * Returns -1 only if started some children. IOW: we have to
3998 * mask out retvals of builtins etc with 0xff!
4000 * The only case when we do not need to [v]fork is when the pipe
4001 * is single, non-backgrounded, non-subshell command. Examples:
4002 * cmd ; ... { list } ; ...
4003 * cmd && ... { list } && ...
4004 * cmd || ... { list } || ...
4005 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4006 * or (if SH_STANDALONE) an applet, and we can run the { list }
4007 * with run_list. If it isn't one of these, we fork and exec cmd.
4009 * Cases when we must fork:
4010 * non-single: cmd | cmd
4011 * backgrounded: cmd & { list } &
4012 * subshell: ( list ) [&]
4014 static NOINLINE int run_pipe(struct pipe *pi)
4016 static const char *const null_ptr = NULL;
4019 struct command *command;
4020 char **argv_expanded;
4023 /* it is not always needed, but we aim to smaller code */
4024 int squirrel[] = { -1, -1, -1 };
4027 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4030 IF_HUSH_JOB(pi->pgrp = -1;)
4031 pi->stopped_cmds = 0;
4032 command = &(pi->cmds[0]);
4033 argv_expanded = NULL;
4035 if (pi->num_cmds != 1
4036 || pi->followup == PIPE_BG
4037 || command->cmd_type == CMD_SUBSHELL
4044 debug_printf_exec(": group:%p argv:'%s'\n",
4045 command->group, command->argv ? command->argv[0] : "NONE");
4047 if (command->group) {
4048 #if ENABLE_HUSH_FUNCTIONS
4049 if (command->cmd_type == CMD_FUNCDEF) {
4050 /* "executing" func () { list } */
4051 struct function *funcp;
4053 funcp = new_function(command->argv[0]);
4054 /* funcp->name is already set to argv[0] */
4055 funcp->body = command->group;
4057 funcp->body_as_string = command->group_as_string;
4058 command->group_as_string = NULL;
4060 command->group = NULL;
4061 command->argv[0] = NULL;
4062 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4063 funcp->parent_cmd = command;
4064 command->child_func = funcp;
4066 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4068 return EXIT_SUCCESS;
4072 debug_printf("non-subshell group\n");
4073 rcode = 1; /* exitcode if redir failed */
4074 if (setup_redirects(command, squirrel) == 0) {
4075 debug_printf_exec(": run_list\n");
4076 rcode = run_list(command->group) & 0xff;
4078 restore_redirects(squirrel);
4079 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4081 debug_printf_exec("run_pipe: return %d\n", rcode);
4085 argv = command->argv ? command->argv : (char **) &null_ptr;
4087 const struct built_in_command *x;
4088 #if ENABLE_HUSH_FUNCTIONS
4089 const struct function *funcp;
4093 char **new_env = NULL;
4094 struct variable *old_vars = NULL;
4096 if (argv[command->assignment_cnt] == NULL) {
4097 /* Assignments, but no command */
4098 /* Ensure redirects take effect. Try "a=t >file" */
4099 rcode = setup_redirects(command, squirrel);
4100 restore_redirects(squirrel);
4101 /* Set shell variables */
4103 p = expand_string_to_string(*argv);
4104 debug_printf_exec("set shell var:'%s'->'%s'\n",
4106 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4109 /* Do we need to flag set_local_var() errors?
4110 * "assignment to readonly var" and "putenv error"
4112 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4114 debug_printf_exec("run_pipe: return %d\n", rcode);
4118 /* Expand the rest into (possibly) many strings each */
4120 #if ENABLE_HUSH_BASH_COMPAT
4121 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4122 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4125 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4126 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4127 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4132 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4135 /* if someone gives us an empty string: `cmd with empty output` */
4136 if (!argv_expanded[0]) {
4138 return G.last_exitcode;
4141 x = find_builtin(argv_expanded[0]);
4142 #if ENABLE_HUSH_FUNCTIONS
4145 funcp = find_function(argv_expanded[0]);
4149 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
4150 debug_printf("exec with redirects only\n");
4151 rcode = setup_redirects(command, NULL);
4152 goto clean_up_and_ret1;
4155 /* setup_redirects acts on file descriptors, not FILEs.
4156 * This is perfect for work that comes after exec().
4157 * Is it really safe for inline use? Experimentally,
4158 * things seem to work. */
4159 rcode = setup_redirects(command, squirrel);
4161 new_env = expand_assignments(argv, command->assignment_cnt);
4162 old_vars = set_vars_and_save_old(new_env);
4164 debug_printf_exec(": builtin '%s' '%s'...\n",
4165 x->cmd, argv_expanded[1]);
4166 rcode = x->function(argv_expanded) & 0xff;
4169 #if ENABLE_HUSH_FUNCTIONS
4171 # if ENABLE_HUSH_LOCAL
4172 struct variable **sv;
4173 sv = G.shadowed_vars_pp;
4174 G.shadowed_vars_pp = &old_vars;
4176 debug_printf_exec(": function '%s' '%s'...\n",
4177 funcp->name, argv_expanded[1]);
4178 rcode = run_function(funcp, argv_expanded) & 0xff;
4179 # if ENABLE_HUSH_LOCAL
4180 G.shadowed_vars_pp = sv;
4185 #if ENABLE_FEATURE_SH_STANDALONE
4188 restore_redirects(squirrel);
4189 unset_vars(new_env);
4192 free(argv_expanded);
4193 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4195 debug_printf_exec("run_pipe return %d\n", rcode);
4199 #if ENABLE_FEATURE_SH_STANDALONE
4200 i = find_applet_by_name(argv_expanded[0]);
4201 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4202 rcode = setup_redirects(command, squirrel);
4204 new_env = expand_assignments(argv, command->assignment_cnt);
4205 old_vars = set_vars_and_save_old(new_env);
4206 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4207 argv_expanded[0], argv_expanded[1]);
4208 rcode = run_nofork_applet(i, argv_expanded);
4210 goto clean_up_and_ret;
4213 /* It is neither builtin nor applet. We must fork. */
4217 /* NB: argv_expanded may already be created, and that
4218 * might include `cmd` runs! Do not rerun it! We *must*
4219 * use argv_expanded if it's non-NULL */
4221 /* Going to fork a child per each pipe member */
4225 for (i = 0; i < pi->num_cmds; i++) {
4226 struct fd_pair pipefds;
4228 volatile nommu_save_t nommu_save;
4229 nommu_save.new_env = NULL;
4230 nommu_save.old_vars = NULL;
4231 nommu_save.argv = NULL;
4232 nommu_save.argv_from_re_execing = NULL;
4234 command = &(pi->cmds[i]);
4235 if (command->argv) {
4236 debug_printf_exec(": pipe member '%s' '%s'...\n",
4237 command->argv[0], command->argv[1]);
4239 debug_printf_exec(": pipe member with no argv\n");
4242 /* pipes are inserted between pairs of commands */
4245 if ((i + 1) < pi->num_cmds)
4246 xpiped_pair(pipefds);
4248 command->pid = BB_MMU ? fork() : vfork();
4249 if (!command->pid) { /* child */
4251 disable_restore_tty_pgrp_on_exit();
4252 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4254 /* Every child adds itself to new process group
4255 * with pgid == pid_of_first_child_in_pipe */
4256 if (G.run_list_level == 1 && G_interactive_fd) {
4259 if (pgrp < 0) /* true for 1st process only */
4261 if (setpgid(0, pgrp) == 0
4262 && pi->followup != PIPE_BG
4263 && G_saved_tty_pgrp /* we have ctty */
4265 /* We do it in *every* child, not just first,
4267 tcsetpgrp(G_interactive_fd, pgrp);
4271 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4272 /* 1st cmd in backgrounded pipe
4273 * should have its stdin /dev/null'ed */
4275 if (open(bb_dev_null, O_RDONLY))
4276 xopen("/", O_RDONLY);
4278 xmove_fd(nextin, 0);
4280 xmove_fd(pipefds.wr, 1);
4283 /* Like bash, explicit redirects override pipes,
4284 * and the pipe fd is available for dup'ing. */
4285 if (setup_redirects(command, NULL))
4288 /* Restore default handlers just prior to exec */
4289 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4291 /* Stores to nommu_save list of env vars putenv'ed
4292 * (NOMMU, on MMU we don't need that) */
4293 /* cast away volatility... */
4294 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4295 /* pseudo_exec() does not return */
4298 /* parent or error */
4299 #if ENABLE_HUSH_FAST
4301 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4303 enable_restore_tty_pgrp_on_exit();
4305 /* Clean up after vforked child */
4306 free(nommu_save.argv);
4307 free(nommu_save.argv_from_re_execing);
4308 unset_vars(nommu_save.new_env);
4309 add_vars(nommu_save.old_vars);
4311 free(argv_expanded);
4312 argv_expanded = NULL;
4313 if (command->pid < 0) { /* [v]fork failed */
4314 /* Clearly indicate, was it fork or vfork */
4315 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4319 /* Second and next children need to know pid of first one */
4321 pi->pgrp = command->pid;
4327 if ((i + 1) < pi->num_cmds)
4329 /* Pass read (output) pipe end to next iteration */
4330 nextin = pipefds.rd;
4333 if (!pi->alive_cmds) {
4335 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4340 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4344 #ifndef debug_print_tree
4345 static void debug_print_tree(struct pipe *pi, int lvl)
4347 static const char *const PIPE[] = {
4353 static const char *RES[] = {
4354 [RES_NONE ] = "NONE" ,
4357 [RES_THEN ] = "THEN" ,
4358 [RES_ELIF ] = "ELIF" ,
4359 [RES_ELSE ] = "ELSE" ,
4362 # if ENABLE_HUSH_LOOPS
4363 [RES_FOR ] = "FOR" ,
4364 [RES_WHILE] = "WHILE",
4365 [RES_UNTIL] = "UNTIL",
4367 [RES_DONE ] = "DONE" ,
4369 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4372 # if ENABLE_HUSH_CASE
4373 [RES_CASE ] = "CASE" ,
4374 [RES_CASE_IN ] = "CASE_IN" ,
4375 [RES_MATCH] = "MATCH",
4376 [RES_CASE_BODY] = "CASE_BODY",
4377 [RES_ESAC ] = "ESAC" ,
4379 [RES_XXXX ] = "XXXX" ,
4380 [RES_SNTX ] = "SNTX" ,
4382 static const char *const CMDTYPE[] = {
4386 # if ENABLE_HUSH_FUNCTIONS
4395 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4396 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4398 while (prn < pi->num_cmds) {
4399 struct command *command = &pi->cmds[prn];
4400 char **argv = command->argv;
4402 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4404 command->assignment_cnt);
4405 if (command->group) {
4406 fprintf(stderr, " group %s: (argv=%p)\n",
4407 CMDTYPE[command->cmd_type],
4409 debug_print_tree(command->group, lvl+1);
4413 if (argv) while (*argv) {
4414 fprintf(stderr, " '%s'", *argv);
4417 fprintf(stderr, "\n");
4424 #endif /* debug_print_tree */
4426 /* NB: called by pseudo_exec, and therefore must not modify any
4427 * global data until exec/_exit (we can be a child after vfork!) */
4428 static int run_list(struct pipe *pi)
4430 #if ENABLE_HUSH_CASE
4431 char *case_word = NULL;
4433 #if ENABLE_HUSH_LOOPS
4434 struct pipe *loop_top = NULL;
4435 char **for_lcur = NULL;
4436 char **for_list = NULL;
4438 smallint last_followup;
4440 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4441 smalluint cond_code = 0;
4443 enum { cond_code = 0 };
4446 smallint rword; /* enum reserved_style */
4447 smallint last_rword; /* ditto */
4450 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4453 #if ENABLE_HUSH_LOOPS
4454 /* Check syntax for "for" */
4455 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4456 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4458 /* current word is FOR or IN (BOLD in comments below) */
4459 if (cpipe->next == NULL) {
4460 syntax_error("malformed for");
4462 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4465 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4466 if (cpipe->next->res_word == RES_DO)
4468 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4469 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4470 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4472 syntax_error("malformed for");
4474 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4480 /* Past this point, all code paths should jump to ret: label
4481 * in order to return, no direct "return" statements please.
4482 * This helps to ensure that no memory is leaked. */
4490 last_rword = RES_XXXX;
4492 last_followup = PIPE_SEQ;
4493 rcode = G.last_exitcode;
4495 /* Go through list of pipes, (maybe) executing them. */
4496 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4500 IF_HAS_KEYWORDS(rword = pi->res_word;)
4501 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4502 rword, cond_code, last_rword);
4503 #if ENABLE_HUSH_LOOPS
4504 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4505 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4507 /* start of a loop: remember where loop starts */
4512 /* Still in the same "if...", "then..." or "do..." branch? */
4513 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4514 if ((rcode == 0 && last_followup == PIPE_OR)
4515 || (rcode != 0 && last_followup == PIPE_AND)
4517 /* It is "<true> || CMD" or "<false> && CMD"
4518 * and we should not execute CMD */
4519 debug_printf_exec("skipped cmd because of || or &&\n");
4520 last_followup = pi->followup;
4524 last_followup = pi->followup;
4525 IF_HAS_KEYWORDS(last_rword = rword;)
4528 if (rword == RES_THEN) {
4529 /* if false; then ... fi has exitcode 0! */
4530 G.last_exitcode = rcode = EXIT_SUCCESS;
4531 /* "if <false> THEN cmd": skip cmd */
4535 if (rword == RES_ELSE || rword == RES_ELIF) {
4536 /* "if <true> then ... ELSE/ELIF cmd":
4537 * skip cmd and all following ones */
4542 #if ENABLE_HUSH_LOOPS
4543 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4545 /* first loop through for */
4547 static const char encoded_dollar_at[] ALIGN1 = {
4548 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4549 }; /* encoded representation of "$@" */
4550 static const char *const encoded_dollar_at_argv[] = {
4551 encoded_dollar_at, NULL
4552 }; /* argv list with one element: "$@" */
4555 vals = (char**)encoded_dollar_at_argv;
4556 if (pi->next->res_word == RES_IN) {
4557 /* if no variable values after "in" we skip "for" */
4558 if (!pi->next->cmds[0].argv) {
4559 G.last_exitcode = rcode = EXIT_SUCCESS;
4560 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4563 vals = pi->next->cmds[0].argv;
4564 } /* else: "for var; do..." -> assume "$@" list */
4565 /* create list of variable values */
4566 debug_print_strings("for_list made from", vals);
4567 for_list = expand_strvec_to_strvec(vals);
4568 for_lcur = for_list;
4569 debug_print_strings("for_list", for_list);
4572 /* "for" loop is over, clean up */
4578 /* Insert next value from for_lcur */
4579 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4580 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4583 if (rword == RES_IN) {
4584 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4586 if (rword == RES_DONE) {
4587 continue; /* "done" has no cmds too */
4590 #if ENABLE_HUSH_CASE
4591 if (rword == RES_CASE) {
4592 case_word = expand_strvec_to_string(pi->cmds->argv);
4595 if (rword == RES_MATCH) {
4598 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4600 /* all prev words didn't match, does this one match? */
4601 argv = pi->cmds->argv;
4603 char *pattern = expand_string_to_string(*argv);
4604 /* TODO: which FNM_xxx flags to use? */
4605 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4607 if (cond_code == 0) { /* match! we will execute this branch */
4608 free(case_word); /* make future "word)" stop */
4616 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4618 continue; /* not matched yet, skip this pipe */
4621 /* Just pressing <enter> in shell should check for jobs.
4622 * OTOH, in non-interactive shell this is useless
4623 * and only leads to extra job checks */
4624 if (pi->num_cmds == 0) {
4625 if (G_interactive_fd)
4626 goto check_jobs_and_continue;
4630 /* After analyzing all keywords and conditions, we decided
4631 * to execute this pipe. NB: have to do checkjobs(NULL)
4632 * after run_pipe to collect any background children,
4633 * even if list execution is to be stopped. */
4634 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4637 #if ENABLE_HUSH_LOOPS
4638 G.flag_break_continue = 0;
4640 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4642 /* We ran a builtin, function, or group.
4643 * rcode is already known
4644 * and we don't need to wait for anything. */
4645 G.last_exitcode = rcode;
4646 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4647 check_and_run_traps(0);
4648 #if ENABLE_HUSH_LOOPS
4649 /* Was it "break" or "continue"? */
4650 if (G.flag_break_continue) {
4651 smallint fbc = G.flag_break_continue;
4652 /* We might fall into outer *loop*,
4653 * don't want to break it too */
4655 G.depth_break_continue--;
4656 if (G.depth_break_continue == 0)
4657 G.flag_break_continue = 0;
4658 /* else: e.g. "continue 2" should *break* once, *then* continue */
4659 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4660 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4661 goto check_jobs_and_break;
4662 /* "continue": simulate end of loop */
4667 #if ENABLE_HUSH_FUNCTIONS
4668 if (G.flag_return_in_progress == 1) {
4669 /* same as "goto check_jobs_and_break" */
4674 } else if (pi->followup == PIPE_BG) {
4675 /* What does bash do with attempts to background builtins? */
4676 /* even bash 3.2 doesn't do that well with nested bg:
4677 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4678 * I'm NOT treating inner &'s as jobs */
4679 check_and_run_traps(0);
4681 if (G.run_list_level == 1)
4684 G.last_exitcode = rcode = EXIT_SUCCESS;
4685 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4688 if (G.run_list_level == 1 && G_interactive_fd) {
4689 /* Waits for completion, then fg's main shell */
4690 rcode = checkjobs_and_fg_shell(pi);
4691 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4692 check_and_run_traps(0);
4695 { /* This one just waits for completion */
4696 rcode = checkjobs(pi);
4697 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4698 check_and_run_traps(0);
4700 G.last_exitcode = rcode;
4704 /* Analyze how result affects subsequent commands */
4706 if (rword == RES_IF || rword == RES_ELIF)
4709 #if ENABLE_HUSH_LOOPS
4710 /* Beware of "while false; true; do ..."! */
4711 if (pi->next && pi->next->res_word == RES_DO) {
4712 if (rword == RES_WHILE) {
4714 /* "while false; do...done" - exitcode 0 */
4715 G.last_exitcode = rcode = EXIT_SUCCESS;
4716 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4717 goto check_jobs_and_break;
4720 if (rword == RES_UNTIL) {
4722 debug_printf_exec(": until expr is true: breaking\n");
4723 check_jobs_and_break:
4731 check_jobs_and_continue:
4738 #if ENABLE_HUSH_LOOPS
4743 #if ENABLE_HUSH_CASE
4747 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4751 /* Select which version we will use */
4752 static int run_and_free_list(struct pipe *pi)
4755 debug_printf_exec("run_and_free_list entered\n");
4757 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4758 rcode = run_list(pi);
4760 /* free_pipe_list has the side effect of clearing memory.
4761 * In the long run that function can be merged with run_list,
4762 * but doing that now would hobble the debugging effort. */
4764 debug_printf_exec("run_and_free_list return %d\n", rcode);
4769 static struct pipe *new_pipe(void)
4772 pi = xzalloc(sizeof(struct pipe));
4773 /*pi->followup = 0; - deliberately invalid value */
4774 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4778 /* Command (member of a pipe) is complete, or we start a new pipe
4779 * if ctx->command is NULL.
4780 * No errors possible here.
4782 static int done_command(struct parse_context *ctx)
4784 /* The command is really already in the pipe structure, so
4785 * advance the pipe counter and make a new, null command. */
4786 struct pipe *pi = ctx->pipe;
4787 struct command *command = ctx->command;
4790 if (IS_NULL_CMD(command)) {
4791 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4795 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4796 //debug_print_tree(ctx->list_head, 20);
4798 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4801 /* Only real trickiness here is that the uncommitted
4802 * command structure is not counted in pi->num_cmds. */
4803 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4804 ctx->command = command = &pi->cmds[pi->num_cmds];
4806 memset(command, 0, sizeof(*command));
4807 return pi->num_cmds; /* used only for 0/nonzero check */
4810 static void done_pipe(struct parse_context *ctx, pipe_style type)
4814 debug_printf_parse("done_pipe entered, followup %d\n", type);
4815 /* Close previous command */
4816 not_null = done_command(ctx);
4817 ctx->pipe->followup = type;
4819 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4820 ctx->ctx_inverted = 0;
4821 ctx->pipe->res_word = ctx->ctx_res_w;
4824 /* Without this check, even just <enter> on command line generates
4825 * tree of three NOPs (!). Which is harmless but annoying.
4826 * IOW: it is safe to do it unconditionally. */
4829 || ctx->ctx_res_w == RES_FI
4831 #if ENABLE_HUSH_LOOPS
4832 || ctx->ctx_res_w == RES_DONE
4833 || ctx->ctx_res_w == RES_FOR
4834 || ctx->ctx_res_w == RES_IN
4836 #if ENABLE_HUSH_CASE
4837 || ctx->ctx_res_w == RES_ESAC
4841 debug_printf_parse("done_pipe: adding new pipe: "
4842 "not_null:%d ctx->ctx_res_w:%d\n",
4843 not_null, ctx->ctx_res_w);
4845 ctx->pipe->next = new_p;
4847 /* RES_THEN, RES_DO etc are "sticky" -
4848 * they remain set for pipes inside if/while.
4849 * This is used to control execution.
4850 * RES_FOR and RES_IN are NOT sticky (needed to support
4851 * cases where variable or value happens to match a keyword):
4853 #if ENABLE_HUSH_LOOPS
4854 if (ctx->ctx_res_w == RES_FOR
4855 || ctx->ctx_res_w == RES_IN)
4856 ctx->ctx_res_w = RES_NONE;
4858 #if ENABLE_HUSH_CASE
4859 if (ctx->ctx_res_w == RES_MATCH)
4860 ctx->ctx_res_w = RES_CASE_BODY;
4861 if (ctx->ctx_res_w == RES_CASE)
4862 ctx->ctx_res_w = RES_CASE_IN;
4864 ctx->command = NULL; /* trick done_command below */
4865 /* Create the memory for command, roughly:
4866 * ctx->pipe->cmds = new struct command;
4867 * ctx->command = &ctx->pipe->cmds[0];
4870 //debug_print_tree(ctx->list_head, 10);
4872 debug_printf_parse("done_pipe return\n");
4875 static void initialize_context(struct parse_context *ctx)
4877 memset(ctx, 0, sizeof(*ctx));
4878 ctx->pipe = ctx->list_head = new_pipe();
4879 /* Create the memory for command, roughly:
4880 * ctx->pipe->cmds = new struct command;
4881 * ctx->command = &ctx->pipe->cmds[0];
4886 /* If a reserved word is found and processed, parse context is modified
4887 * and 1 is returned.
4890 struct reserved_combo {
4893 unsigned char assignment_flag;
4897 FLAG_END = (1 << RES_NONE ),
4899 FLAG_IF = (1 << RES_IF ),
4900 FLAG_THEN = (1 << RES_THEN ),
4901 FLAG_ELIF = (1 << RES_ELIF ),
4902 FLAG_ELSE = (1 << RES_ELSE ),
4903 FLAG_FI = (1 << RES_FI ),
4905 # if ENABLE_HUSH_LOOPS
4906 FLAG_FOR = (1 << RES_FOR ),
4907 FLAG_WHILE = (1 << RES_WHILE),
4908 FLAG_UNTIL = (1 << RES_UNTIL),
4909 FLAG_DO = (1 << RES_DO ),
4910 FLAG_DONE = (1 << RES_DONE ),
4911 FLAG_IN = (1 << RES_IN ),
4913 # if ENABLE_HUSH_CASE
4914 FLAG_MATCH = (1 << RES_MATCH),
4915 FLAG_ESAC = (1 << RES_ESAC ),
4917 FLAG_START = (1 << RES_XXXX ),
4920 static const struct reserved_combo* match_reserved_word(o_string *word)
4922 /* Mostly a list of accepted follow-up reserved words.
4923 * FLAG_END means we are done with the sequence, and are ready
4924 * to turn the compound list into a command.
4925 * FLAG_START means the word must start a new compound list.
4927 static const struct reserved_combo reserved_list[] = {
4929 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4930 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4931 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4932 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4933 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4934 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4936 # if ENABLE_HUSH_LOOPS
4937 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4938 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4939 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4940 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4941 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4942 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4944 # if ENABLE_HUSH_CASE
4945 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4946 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4949 const struct reserved_combo *r;
4951 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4952 if (strcmp(word->data, r->literal) == 0)
4957 /* Return 0: not a keyword, 1: keyword
4959 static int reserved_word(o_string *word, struct parse_context *ctx)
4961 # if ENABLE_HUSH_CASE
4962 static const struct reserved_combo reserved_match = {
4963 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4966 const struct reserved_combo *r;
4970 r = match_reserved_word(word);
4974 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4975 # if ENABLE_HUSH_CASE
4976 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
4977 /* "case word IN ..." - IN part starts first MATCH part */
4978 r = &reserved_match;
4981 if (r->flag == 0) { /* '!' */
4982 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4983 syntax_error("! ! command");
4984 ctx->ctx_res_w = RES_SNTX;
4986 ctx->ctx_inverted = 1;
4989 if (r->flag & FLAG_START) {
4990 struct parse_context *old;
4992 old = xmalloc(sizeof(*old));
4993 debug_printf_parse("push stack %p\n", old);
4994 *old = *ctx; /* physical copy */
4995 initialize_context(ctx);
4997 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4998 syntax_error_at(word->data);
4999 ctx->ctx_res_w = RES_SNTX;
5002 /* "{...} fi" is ok. "{...} if" is not
5004 * if { echo foo; } then { echo bar; } fi */
5005 if (ctx->command->group)
5006 done_pipe(ctx, PIPE_SEQ);
5009 ctx->ctx_res_w = r->res;
5010 ctx->old_flag = r->flag;
5011 word->o_assignment = r->assignment_flag;
5013 if (ctx->old_flag & FLAG_END) {
5014 struct parse_context *old;
5016 done_pipe(ctx, PIPE_SEQ);
5017 debug_printf_parse("pop stack %p\n", ctx->stack);
5019 old->command->group = ctx->list_head;
5020 old->command->cmd_type = CMD_NORMAL;
5022 o_addstr(&old->as_string, ctx->as_string.data);
5023 o_free_unsafe(&ctx->as_string);
5024 old->command->group_as_string = xstrdup(old->as_string.data);
5025 debug_printf_parse("pop, remembering as:'%s'\n",
5026 old->command->group_as_string);
5028 *ctx = *old; /* physical copy */
5033 #endif /* HAS_KEYWORDS */
5035 /* Word is complete, look at it and update parsing context.
5036 * Normal return is 0. Syntax errors return 1.
5037 * Note: on return, word is reset, but not o_free'd!
5039 static int done_word(o_string *word, struct parse_context *ctx)
5041 struct command *command = ctx->command;
5043 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5044 if (word->length == 0 && word->o_quoted == 0) {
5045 debug_printf_parse("done_word return 0: true null, ignored\n");
5049 if (ctx->pending_redirect) {
5050 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5051 * only if run as "bash", not "sh" */
5052 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5054 * ...the word that follows the redirection operator
5055 * shall be subjected to tilde expansion, parameter expansion,
5056 * command substitution, arithmetic expansion, and quote
5057 * removal. Pathname expansion shall not be performed
5058 * on the word by a non-interactive shell; an interactive
5059 * shell may perform it, but shall do so only when
5060 * the expansion would result in one word."
5062 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5063 /* Cater for >\file case:
5064 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5065 * Same with heredocs:
5066 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5068 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5069 unbackslash(ctx->pending_redirect->rd_filename);
5070 /* Is it <<"HEREDOC"? */
5071 if (word->o_quoted) {
5072 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5075 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5076 ctx->pending_redirect = NULL;
5078 /* If this word wasn't an assignment, next ones definitely
5079 * can't be assignments. Even if they look like ones. */
5080 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5081 && word->o_assignment != WORD_IS_KEYWORD
5083 word->o_assignment = NOT_ASSIGNMENT;
5085 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5086 command->assignment_cnt++;
5087 word->o_assignment = MAYBE_ASSIGNMENT;
5091 # if ENABLE_HUSH_CASE
5092 if (ctx->ctx_dsemicolon
5093 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5095 /* already done when ctx_dsemicolon was set to 1: */
5096 /* ctx->ctx_res_w = RES_MATCH; */
5097 ctx->ctx_dsemicolon = 0;
5100 if (!command->argv /* if it's the first word... */
5101 # if ENABLE_HUSH_LOOPS
5102 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5103 && ctx->ctx_res_w != RES_IN
5105 # if ENABLE_HUSH_CASE
5106 && ctx->ctx_res_w != RES_CASE
5109 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5110 if (reserved_word(word, ctx)) {
5111 o_reset_to_empty_unquoted(word);
5112 debug_printf_parse("done_word return %d\n",
5113 (ctx->ctx_res_w == RES_SNTX));
5114 return (ctx->ctx_res_w == RES_SNTX);
5116 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5117 if (strcmp(word->data, "export") == 0
5118 # if ENABLE_HUSH_LOCAL
5119 || strcmp(word->data, "local") == 0
5122 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5125 # if ENABLE_HUSH_BASH_COMPAT
5126 if (strcmp(word->data, "[[") == 0) {
5127 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5133 if (command->group) {
5134 /* "{ echo foo; } echo bar" - bad */
5135 syntax_error_at(word->data);
5136 debug_printf_parse("done_word return 1: syntax error, "
5137 "groups and arglists don't mix\n");
5140 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5141 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5142 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5143 /* (otherwise it's known to be not empty and is already safe) */
5145 /* exclude "$@" - it can expand to no word despite "" */
5146 char *p = word->data;
5147 while (p[0] == SPECIAL_VAR_SYMBOL
5148 && (p[1] & 0x7f) == '@'
5149 && p[2] == SPECIAL_VAR_SYMBOL
5153 if (p == word->data || p[0] != '\0') {
5154 /* saw no "$@", or not only "$@" but some
5155 * real text is there too */
5156 /* insert "empty variable" reference, this makes
5157 * e.g. "", $empty"" etc to not disappear */
5158 o_addchr(word, SPECIAL_VAR_SYMBOL);
5159 o_addchr(word, SPECIAL_VAR_SYMBOL);
5162 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5163 debug_print_strings("word appended to argv", command->argv);
5166 #if ENABLE_HUSH_LOOPS
5167 if (ctx->ctx_res_w == RES_FOR) {
5169 || !is_well_formed_var_name(command->argv[0], '\0')
5171 /* bash says just "not a valid identifier" */
5172 syntax_error("not a valid identifier in for");
5175 /* Force FOR to have just one word (variable name) */
5176 /* NB: basically, this makes hush see "for v in ..."
5177 * syntax as if it is "for v; in ...". FOR and IN become
5178 * two pipe structs in parse tree. */
5179 done_pipe(ctx, PIPE_SEQ);
5182 #if ENABLE_HUSH_CASE
5183 /* Force CASE to have just one word */
5184 if (ctx->ctx_res_w == RES_CASE) {
5185 done_pipe(ctx, PIPE_SEQ);
5189 o_reset_to_empty_unquoted(word);
5191 debug_printf_parse("done_word return 0\n");
5196 /* Peek ahead in the input to find out if we have a "&n" construct,
5197 * as in "2>&1", that represents duplicating a file descriptor.
5199 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5200 * REDIRFD_SYNTAX_ERR if syntax error,
5201 * REDIRFD_TO_FILE if no & was seen,
5202 * or the number found.
5205 #define parse_redir_right_fd(as_string, input) \
5206 parse_redir_right_fd(input)
5208 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5214 return REDIRFD_TO_FILE;
5216 ch = i_getch(input); /* get the & */
5217 nommu_addchr(as_string, ch);
5220 ch = i_getch(input);
5221 nommu_addchr(as_string, ch);
5222 return REDIRFD_CLOSE;
5226 while (ch != EOF && isdigit(ch)) {
5227 d = d*10 + (ch-'0');
5229 ch = i_getch(input);
5230 nommu_addchr(as_string, ch);
5235 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5237 bb_error_msg("ambiguous redirect");
5238 return REDIRFD_SYNTAX_ERR;
5241 /* Return code is 0 normal, 1 if a syntax error is detected
5243 static int parse_redirect(struct parse_context *ctx,
5246 struct in_str *input)
5248 struct command *command = ctx->command;
5249 struct redir_struct *redir;
5250 struct redir_struct **redirp;
5253 dup_num = REDIRFD_TO_FILE;
5254 if (style != REDIRECT_HEREDOC) {
5255 /* Check for a '>&1' type redirect */
5256 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5257 if (dup_num == REDIRFD_SYNTAX_ERR)
5260 int ch = i_peek(input);
5261 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5262 if (dup_num) { /* <<-... */
5263 ch = i_getch(input);
5264 nommu_addchr(&ctx->as_string, ch);
5269 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5270 int ch = i_peek(input);
5272 /* >|FILE redirect ("clobbering" >).
5273 * Since we do not support "set -o noclobber" yet,
5274 * >| and > are the same for now. Just eat |.
5276 ch = i_getch(input);
5277 nommu_addchr(&ctx->as_string, ch);
5281 /* Create a new redir_struct and append it to the linked list */
5282 redirp = &command->redirects;
5283 while ((redir = *redirp) != NULL) {
5284 redirp = &(redir->next);
5286 *redirp = redir = xzalloc(sizeof(*redir));
5287 /* redir->next = NULL; */
5288 /* redir->rd_filename = NULL; */
5289 redir->rd_type = style;
5290 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5292 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5293 redir_table[style].descrip);
5295 redir->rd_dup = dup_num;
5296 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5297 /* Erik had a check here that the file descriptor in question
5298 * is legit; I postpone that to "run time"
5299 * A "-" representation of "close me" shows up as a -3 here */
5300 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5301 redir->rd_fd, redir->rd_dup);
5303 /* Set ctx->pending_redirect, so we know what to do at the
5304 * end of the next parsed word. */
5305 ctx->pending_redirect = redir;
5310 /* If a redirect is immediately preceded by a number, that number is
5311 * supposed to tell which file descriptor to redirect. This routine
5312 * looks for such preceding numbers. In an ideal world this routine
5313 * needs to handle all the following classes of redirects...
5314 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5315 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5316 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5317 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5319 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5321 * ... If n is quoted, the number shall not be recognized as part of
5322 * the redirection expression. For example:
5324 * writes the character 2 into file a"
5325 * We are getting it right by setting ->o_quoted on any \<char>
5327 * A -1 return means no valid number was found,
5328 * the caller should use the appropriate default for this redirection.
5330 static int redirect_opt_num(o_string *o)
5334 if (o->data == NULL)
5336 num = bb_strtou(o->data, NULL, 10);
5337 if (errno || num < 0)
5339 o_reset_to_empty_unquoted(o);
5344 #define fetch_till_str(as_string, input, word, skip_tabs) \
5345 fetch_till_str(input, word, skip_tabs)
5347 static char *fetch_till_str(o_string *as_string,
5348 struct in_str *input,
5352 o_string heredoc = NULL_O_STRING;
5358 ch = i_getch(input);
5359 nommu_addchr(as_string, ch);
5361 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5362 heredoc.data[past_EOL] = '\0';
5363 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5364 return heredoc.data;
5367 o_addchr(&heredoc, ch);
5368 past_EOL = heredoc.length;
5371 ch = i_getch(input);
5372 nommu_addchr(as_string, ch);
5373 } while (skip_tabs && ch == '\t');
5374 } while (ch == '\n');
5377 o_free_unsafe(&heredoc);
5380 o_addchr(&heredoc, ch);
5381 nommu_addchr(as_string, ch);
5385 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5386 * and load them all. There should be exactly heredoc_cnt of them.
5388 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5390 struct pipe *pi = ctx->list_head;
5392 while (pi && heredoc_cnt) {
5394 struct command *cmd = pi->cmds;
5396 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5398 cmd->argv ? cmd->argv[0] : "NONE");
5399 for (i = 0; i < pi->num_cmds; i++) {
5400 struct redir_struct *redir = cmd->redirects;
5402 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5403 i, cmd->argv ? cmd->argv[0] : "NONE");
5405 if (redir->rd_type == REDIRECT_HEREDOC) {
5408 redir->rd_type = REDIRECT_HEREDOC2;
5409 /* redir->rd_dup is (ab)used to indicate <<- */
5410 p = fetch_till_str(&ctx->as_string, input,
5411 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5413 syntax_error("unexpected EOF in here document");
5416 free(redir->rd_filename);
5417 redir->rd_filename = p;
5420 redir = redir->next;
5427 /* Should be 0. If it isn't, it's a parse error */
5429 bb_error_msg_and_die("heredoc BUG 2");
5435 #if ENABLE_HUSH_TICK
5436 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5445 pid = BB_MMU ? fork() : vfork();
5447 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5449 if (pid == 0) { /* child */
5450 disable_restore_tty_pgrp_on_exit();
5451 /* Process substitution is not considered to be usual
5452 * 'command execution'.
5453 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5460 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5461 close(channel[0]); /* NB: close _first_, then move fd! */
5462 xmove_fd(channel[1], 1);
5463 /* Prevent it from trying to handle ctrl-z etc */
5464 IF_HUSH_JOB(G.run_list_level = 1;)
5465 /* Awful hack for `trap` or $(trap).
5467 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5468 * contains an example where "trap" is executed in a subshell:
5470 * save_traps=$(trap)
5472 * eval "$save_traps"
5474 * Standard does not say that "trap" in subshell shall print
5475 * parent shell's traps. It only says that its output
5476 * must have suitable form, but then, in the above example
5477 * (which is not supposed to be normative), it implies that.
5479 * bash (and probably other shell) does implement it
5480 * (traps are reset to defaults, but "trap" still shows them),
5481 * but as a result, "trap" logic is hopelessly messed up:
5484 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5485 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5486 * # true | trap <--- trap is in subshell - no output (ditto)
5487 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5488 * trap -- 'echo Ho' SIGWINCH
5489 * # echo `(trap)` <--- in subshell in subshell - output
5490 * trap -- 'echo Ho' SIGWINCH
5491 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5492 * trap -- 'echo Ho' SIGWINCH
5494 * The rules when to forget and when to not forget traps
5495 * get really complex and nonsensical.
5497 * Our solution: ONLY bare $(trap) or `trap` is special.
5499 s = skip_whitespace(s);
5500 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5502 static const char *const argv[] = { NULL, NULL };
5503 builtin_trap((char**)argv);
5504 exit(0); /* not _exit() - we need to fflush */
5507 reset_traps_to_defaults();
5508 parse_and_run_string(s);
5509 _exit(G.last_exitcode);
5511 /* We re-execute after vfork on NOMMU. This makes this script safe:
5512 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5513 * huge=`cat BIG` # was blocking here forever
5516 re_execute_shell(&to_free,
5526 # if ENABLE_HUSH_FAST
5528 //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);
5530 enable_restore_tty_pgrp_on_exit();
5535 close_on_exec_on(channel[0]);
5536 return xfdopen_for_read(channel[0]);
5539 /* Return code is exit status of the process that is run. */
5540 static int process_command_subs(o_string *dest, const char *s)
5543 struct in_str pipe_str;
5545 int status, ch, eol_cnt;
5547 fp = generate_stream_from_string(s, &pid);
5549 /* Now send results of command back into original context */
5550 setup_file_in_str(&pipe_str, fp);
5552 while ((ch = i_getch(&pipe_str)) != EOF) {
5558 o_addchr(dest, '\n');
5561 o_addQchr(dest, ch);
5564 debug_printf("done reading from `cmd` pipe, closing it\n");
5566 /* We need to extract exitcode. Test case
5567 * "true; echo `sleep 1; false` $?"
5569 safe_waitpid(pid, &status, 0);
5570 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5571 return WEXITSTATUS(status);
5573 #endif /* ENABLE_HUSH_TICK */
5575 static int parse_group(o_string *dest, struct parse_context *ctx,
5576 struct in_str *input, int ch)
5578 /* dest contains characters seen prior to ( or {.
5579 * Typically it's empty, but for function defs,
5580 * it contains function name (without '()'). */
5581 struct pipe *pipe_list;
5583 struct command *command = ctx->command;
5585 debug_printf_parse("parse_group entered\n");
5586 #if ENABLE_HUSH_FUNCTIONS
5587 if (ch == '(' && !dest->o_quoted) {
5589 if (done_word(dest, ctx))
5592 goto skip; /* (... */
5593 if (command->argv[1]) { /* word word ... (... */
5594 syntax_error_unexpected_ch('(');
5597 /* it is "word(..." or "word (..." */
5599 ch = i_getch(input);
5600 while (ch == ' ' || ch == '\t');
5602 syntax_error_unexpected_ch(ch);
5605 nommu_addchr(&ctx->as_string, ch);
5607 ch = i_getch(input);
5608 while (ch == ' ' || ch == '\t' || ch == '\n');
5610 syntax_error_unexpected_ch(ch);
5613 nommu_addchr(&ctx->as_string, ch);
5614 command->cmd_type = CMD_FUNCDEF;
5619 #if 0 /* Prevented by caller */
5620 if (command->argv /* word [word]{... */
5621 || dest->length /* word{... */
5622 || dest->o_quoted /* ""{... */
5625 debug_printf_parse("parse_group return 1: "
5626 "syntax error, groups and arglists don't mix\n");
5631 #if ENABLE_HUSH_FUNCTIONS
5637 command->cmd_type = CMD_SUBSHELL;
5639 /* bash does not allow "{echo...", requires whitespace */
5640 ch = i_getch(input);
5641 if (ch != ' ' && ch != '\t' && ch != '\n') {
5642 syntax_error_unexpected_ch(ch);
5645 nommu_addchr(&ctx->as_string, ch);
5650 char *as_string = NULL;
5652 pipe_list = parse_stream(&as_string, input, endch);
5655 o_addstr(&ctx->as_string, as_string);
5657 /* empty ()/{} or parse error? */
5658 if (!pipe_list || pipe_list == ERR_PTR) {
5659 /* parse_stream already emitted error msg */
5663 debug_printf_parse("parse_group return 1: "
5664 "parse_stream returned %p\n", pipe_list);
5667 command->group = pipe_list;
5669 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5670 command->group_as_string = as_string;
5671 debug_printf_parse("end of group, remembering as:'%s'\n",
5672 command->group_as_string);
5675 debug_printf_parse("parse_group return 0\n");
5677 /* command remains "open", available for possible redirects */
5680 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5681 /* Subroutines for copying $(...) and `...` things */
5682 static void add_till_backquote(o_string *dest, struct in_str *input);
5684 static void add_till_single_quote(o_string *dest, struct in_str *input)
5687 int ch = i_getch(input);
5689 syntax_error_unterm_ch('\'');
5690 /*xfunc_die(); - redundant */
5697 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5698 static void add_till_double_quote(o_string *dest, struct in_str *input)
5701 int ch = i_getch(input);
5703 syntax_error_unterm_ch('"');
5704 /*xfunc_die(); - redundant */
5708 if (ch == '\\') { /* \x. Copy both chars. */
5710 ch = i_getch(input);
5714 add_till_backquote(dest, input);
5718 //if (ch == '$') ...
5721 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5723 * "Within the backquoted style of command substitution, backslash
5724 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5725 * The search for the matching backquote shall be satisfied by the first
5726 * backquote found without a preceding backslash; during this search,
5727 * if a non-escaped backquote is encountered within a shell comment,
5728 * a here-document, an embedded command substitution of the $(command)
5729 * form, or a quoted string, undefined results occur. A single-quoted
5730 * or double-quoted string that begins, but does not end, within the
5731 * "`...`" sequence produces undefined results."
5733 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5735 static void add_till_backquote(o_string *dest, struct in_str *input)
5738 int ch = i_getch(input);
5740 syntax_error_unterm_ch('`');
5741 /*xfunc_die(); - redundant */
5746 /* \x. Copy both chars unless it is \` */
5747 int ch2 = i_getch(input);
5749 syntax_error_unterm_ch('`');
5750 /*xfunc_die(); - redundant */
5752 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5759 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5760 * quoting and nested ()s.
5761 * "With the $(command) style of command substitution, all characters
5762 * following the open parenthesis to the matching closing parenthesis
5763 * constitute the command. Any valid shell script can be used for command,
5764 * except a script consisting solely of redirections which produces
5765 * unspecified results."
5767 * echo $(echo '(TEST)' BEST) (TEST) BEST
5768 * echo $(echo 'TEST)' BEST) TEST) BEST
5769 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5771 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5775 int ch = i_getch(input);
5777 syntax_error_unterm_ch(')');
5778 /*xfunc_die(); - redundant */
5786 if (i_peek(input) == ')') {
5794 add_till_single_quote(dest, input);
5799 add_till_double_quote(dest, input);
5804 /* \x. Copy verbatim. Important for \(, \) */
5805 ch = i_getch(input);
5807 syntax_error_unterm_ch(')');
5808 /*xfunc_die(); - redundant */
5815 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5817 /* Return code: 0 for OK, 1 for syntax error */
5819 #define handle_dollar(as_string, dest, input) \
5820 handle_dollar(dest, input)
5822 static int handle_dollar(o_string *as_string,
5824 struct in_str *input)
5826 int ch = i_peek(input); /* first character after the $ */
5827 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5829 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5831 ch = i_getch(input);
5832 nommu_addchr(as_string, ch);
5834 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5836 debug_printf_parse(": '%c'\n", ch);
5837 o_addchr(dest, ch | quote_mask);
5840 if (!isalnum(ch) && ch != '_')
5842 ch = i_getch(input);
5843 nommu_addchr(as_string, ch);
5845 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5846 } else if (isdigit(ch)) {
5848 ch = i_getch(input);
5849 nommu_addchr(as_string, ch);
5850 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5851 debug_printf_parse(": '%c'\n", ch);
5852 o_addchr(dest, ch | quote_mask);
5853 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5854 } else switch (ch) {
5856 case '!': /* last bg pid */
5857 case '?': /* last exit code */
5858 case '#': /* number of args */
5859 case '*': /* args */
5860 case '@': /* args */
5861 goto make_one_char_var;
5863 bool first_char, all_digits;
5866 ch = i_getch(input);
5867 nommu_addchr(as_string, ch);
5868 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5870 /* TODO: maybe someone will try to escape the '}' */
5875 ch = i_getch(input);
5876 nommu_addchr(as_string, ch);
5883 /* ${#var}: length of var contents */
5890 /* They're being verbose and doing ${?} */
5891 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5896 && ( (all_digits && !isdigit(ch))
5897 || (!all_digits && !isalnum(ch) && ch != '_')
5900 /* handle parameter expansions
5901 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5906 case ':': /* null modifier */
5907 if (expansion == 0) {
5908 debug_printf_parse(": null modifier\n");
5913 case '#': /* remove prefix */
5914 case '%': /* remove suffix */
5915 if (expansion == 0) {
5916 debug_printf_parse(": remove suffix/prefix\n");
5921 case '-': /* default value */
5922 case '=': /* assign default */
5923 case '+': /* alternative */
5924 case '?': /* error indicate */
5925 debug_printf_parse(": parameter expansion\n");
5930 syntax_error_unterm_str("${name}");
5931 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5936 debug_printf_parse(": '%c'\n", ch);
5937 o_addchr(dest, ch | quote_mask);
5941 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5944 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
5949 ch = i_getch(input);
5950 nommu_addchr(as_string, ch);
5951 # if ENABLE_SH_MATH_SUPPORT
5952 if (i_peek(input) == '(') {
5953 ch = i_getch(input);
5954 nommu_addchr(as_string, ch);
5955 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5956 o_addchr(dest, /*quote_mask |*/ '+');
5960 add_till_closing_paren(dest, input, true);
5963 o_addstr(as_string, dest->data + pos);
5964 o_addchr(as_string, ')');
5965 o_addchr(as_string, ')');
5968 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5972 # if ENABLE_HUSH_TICK
5973 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5974 o_addchr(dest, quote_mask | '`');
5978 add_till_closing_paren(dest, input, false);
5981 o_addstr(as_string, dest->data + pos);
5982 o_addchr(as_string, '`');
5985 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5991 ch = i_getch(input);
5992 nommu_addchr(as_string, ch);
5994 if (isalnum(ch)) { /* it's $_name or $_123 */
5999 /* TODO: $_ and $-: */
6000 /* $_ Shell or shell script name; or last argument of last command
6001 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6002 * but in command's env, set to full pathname used to invoke it */
6003 /* $- Option flags set by set builtin or shell options (-i etc) */
6005 o_addQchr(dest, '$');
6007 debug_printf_parse("handle_dollar return 0\n");
6012 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6013 parse_stream_dquoted(dest, input, dquote_end)
6015 static int parse_stream_dquoted(o_string *as_string,
6017 struct in_str *input,
6024 ch = i_getch(input);
6026 nommu_addchr(as_string, ch);
6027 if (ch == dquote_end) { /* may be only '"' or EOF */
6028 if (dest->o_assignment == NOT_ASSIGNMENT)
6029 dest->o_escape ^= 1;
6030 debug_printf_parse("parse_stream_dquoted return 0\n");
6033 /* note: can't move it above ch == dquote_end check! */
6035 syntax_error_unterm_ch('"');
6036 /*xfunc_die(); - redundant */
6040 next = i_peek(input);
6042 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6043 ch, ch, dest->o_escape);
6046 syntax_error("\\<eof>");
6050 * "The backslash retains its special meaning [in "..."]
6051 * only when followed by one of the following characters:
6052 * $, `, ", \, or <newline>. A double quote may be quoted
6053 * within double quotes by preceding it with a backslash."
6055 if (strchr("$`\"\\\n", next) != NULL) {
6056 ch = i_getch(input);
6058 o_addqchr(dest, ch);
6059 nommu_addchr(as_string, ch);
6062 o_addqchr(dest, '\\');
6063 nommu_addchr(as_string, '\\');
6068 if (handle_dollar(as_string, dest, input) != 0) {
6069 debug_printf_parse("parse_stream_dquoted return 1: "
6070 "handle_dollar returned non-0\n");
6075 #if ENABLE_HUSH_TICK
6077 //int pos = dest->length;
6078 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6079 o_addchr(dest, 0x80 | '`');
6080 add_till_backquote(dest, input);
6081 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6082 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6086 o_addQchr(dest, ch);
6088 && (dest->o_assignment == MAYBE_ASSIGNMENT
6089 || dest->o_assignment == WORD_IS_KEYWORD)
6090 && is_well_formed_var_name(dest->data, '=')
6092 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6098 * Scan input until EOF or end_trigger char.
6099 * Return a list of pipes to execute, or NULL on EOF
6100 * or if end_trigger character is met.
6101 * On syntax error, exit is shell is not interactive,
6102 * reset parsing machinery and start parsing anew,
6103 * or return ERR_PTR.
6105 static struct pipe *parse_stream(char **pstring,
6106 struct in_str *input,
6109 struct parse_context ctx;
6110 o_string dest = NULL_O_STRING;
6114 /* Double-quote state is handled in the state variable is_in_dquote.
6115 * A single-quote triggers a bypass of the main loop until its mate is
6116 * found. When recursing, quote state is passed in via dest->o_escape.
6118 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6119 end_trigger ? end_trigger : 'X');
6122 /* If very first arg is "" or '', dest.data may end up NULL.
6123 * Preventing this: */
6124 o_addchr(&dest, '\0');
6127 G.ifs = get_local_var_value("IFS");
6132 #if ENABLE_HUSH_INTERACTIVE
6133 input->promptmode = 0; /* PS1 */
6135 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6136 initialize_context(&ctx);
6141 const char *is_special;
6145 redir_type redir_style;
6148 /* dest.o_quoted = 1; - already is (see below) */
6149 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6152 /* We reached closing '"' */
6155 ch = i_getch(input);
6156 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6157 ch, ch, dest.o_escape);
6162 syntax_error_unterm_str("here document");
6165 /* end_trigger == '}' case errors out earlier,
6166 * checking only ')' */
6167 if (end_trigger == ')') {
6168 syntax_error_unterm_ch('('); /* exits */
6169 /* goto parse_error; */
6172 if (done_word(&dest, &ctx)) {
6176 done_pipe(&ctx, PIPE_SEQ);
6178 /* If we got nothing... */
6179 /* (this makes bare "&" cmd a no-op.
6180 * bash says: "syntax error near unexpected token '&'") */
6181 if (pi->num_cmds == 0
6182 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6188 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6190 *pstring = ctx.as_string.data;
6192 o_free_unsafe(&ctx.as_string);
6195 debug_printf_parse("parse_stream return %p\n", pi);
6198 nommu_addchr(&ctx.as_string, ch);
6202 next = i_peek(input);
6204 is_special = "{}<>;&|()#'" /* special outside of "str" */
6205 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6206 /* Are { and } special here? */
6207 if (ctx.command->argv /* word [word]{... */
6208 || dest.length /* word{... */
6209 || dest.o_quoted /* ""{... */
6210 || (next != ';' && next != ')' && !strchr(G.ifs, next)) /* {word */
6212 /* They are not special, skip "{}" */
6215 is_special = strchr(is_special, ch);
6216 is_ifs = strchr(G.ifs, ch);
6218 if (!is_special && !is_ifs) { /* ordinary char */
6220 o_addQchr(&dest, ch);
6221 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6222 || dest.o_assignment == WORD_IS_KEYWORD)
6224 && is_well_formed_var_name(dest.data, '=')
6226 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6232 if (done_word(&dest, &ctx)) {
6236 #if ENABLE_HUSH_CASE
6237 /* "case ... in <newline> word) ..." -
6238 * newlines are ignored (but ';' wouldn't be) */
6239 if (ctx.command->argv == NULL
6240 && ctx.ctx_res_w == RES_MATCH
6245 /* Treat newline as a command separator. */
6246 done_pipe(&ctx, PIPE_SEQ);
6247 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6249 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6254 dest.o_assignment = MAYBE_ASSIGNMENT;
6256 /* note: if (is_ifs) continue;
6257 * will still trigger for us */
6261 /* "cmd}" or "cmd }..." without semicolon or &:
6262 * } is an ordinary char in this case, even inside { cmd; }
6263 * Pathological example: { ""}; } should exec "}" cmd
6266 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6267 || dest.length != 0 /* word} */
6268 || dest.o_quoted /* ""} */
6272 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6273 goto skip_end_trigger;
6274 /* else: } does terminate a group */
6277 if (end_trigger && end_trigger == ch
6278 && (ch != ';' || heredoc_cnt == 0)
6279 #if ENABLE_HUSH_CASE
6281 || ctx.ctx_res_w != RES_MATCH
6282 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6287 /* This is technically valid:
6288 * { cat <<HERE; }; echo Ok
6292 * but we don't support this.
6293 * We require heredoc to be in enclosing {}/(),
6296 syntax_error_unterm_str("here document");
6299 if (done_word(&dest, &ctx)) {
6302 done_pipe(&ctx, PIPE_SEQ);
6303 dest.o_assignment = MAYBE_ASSIGNMENT;
6304 /* Do we sit outside of any if's, loops or case's? */
6306 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6310 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6312 *pstring = ctx.as_string.data;
6314 o_free_unsafe(&ctx.as_string);
6317 debug_printf_parse("parse_stream return %p: "
6318 "end_trigger char found\n",
6320 return ctx.list_head;
6327 /* Catch <, > before deciding whether this word is
6328 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6331 redir_fd = redirect_opt_num(&dest);
6332 if (done_word(&dest, &ctx)) {
6335 redir_style = REDIRECT_OVERWRITE;
6337 redir_style = REDIRECT_APPEND;
6338 ch = i_getch(input);
6339 nommu_addchr(&ctx.as_string, ch);
6342 else if (next == '(') {
6343 syntax_error(">(process) not supported");
6347 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6349 continue; /* back to top of while (1) */
6351 redir_fd = redirect_opt_num(&dest);
6352 if (done_word(&dest, &ctx)) {
6355 redir_style = REDIRECT_INPUT;
6357 redir_style = REDIRECT_HEREDOC;
6359 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6360 ch = i_getch(input);
6361 nommu_addchr(&ctx.as_string, ch);
6362 } else if (next == '>') {
6363 redir_style = REDIRECT_IO;
6364 ch = i_getch(input);
6365 nommu_addchr(&ctx.as_string, ch);
6368 else if (next == '(') {
6369 syntax_error("<(process) not supported");
6373 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6375 continue; /* back to top of while (1) */
6378 if (dest.o_assignment == MAYBE_ASSIGNMENT
6379 /* check that we are not in word in "a=1 2>word b=1": */
6380 && !ctx.pending_redirect
6382 /* ch is a special char and thus this word
6383 * cannot be an assignment */
6384 dest.o_assignment = NOT_ASSIGNMENT;
6387 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6391 if (dest.length == 0) {
6394 if (ch == EOF || ch == '\n')
6397 /* note: we do not add it to &ctx.as_string */
6399 nommu_addchr(&ctx.as_string, '\n');
6401 o_addQchr(&dest, ch);
6406 syntax_error("\\<eof>");
6409 ch = i_getch(input);
6411 o_addchr(&dest, '\\');
6412 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6413 o_addchr(&dest, ch);
6414 nommu_addchr(&ctx.as_string, ch);
6415 /* Example: echo Hello \2>file
6416 * we need to know that word 2 is quoted */
6421 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6422 ctx.as_string.data[--ctx.as_string.length] = '\0';
6427 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6428 debug_printf_parse("parse_stream parse error: "
6429 "handle_dollar returned non-0\n");
6436 ch = i_getch(input);
6438 syntax_error_unterm_ch('\'');
6439 /*xfunc_die(); - redundant */
6441 nommu_addchr(&ctx.as_string, ch);
6444 o_addqchr(&dest, ch);
6449 is_in_dquote ^= 1; /* invert */
6450 if (dest.o_assignment == NOT_ASSIGNMENT)
6453 #if ENABLE_HUSH_TICK
6458 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6459 o_addchr(&dest, '`');
6463 add_till_backquote(&dest, input);
6465 o_addstr(&ctx.as_string, dest.data + pos);
6466 o_addchr(&ctx.as_string, '`');
6468 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6469 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6474 #if ENABLE_HUSH_CASE
6477 if (done_word(&dest, &ctx)) {
6480 done_pipe(&ctx, PIPE_SEQ);
6481 #if ENABLE_HUSH_CASE
6482 /* Eat multiple semicolons, detect
6483 * whether it means something special */
6488 ch = i_getch(input);
6489 nommu_addchr(&ctx.as_string, ch);
6490 if (ctx.ctx_res_w == RES_CASE_BODY) {
6491 ctx.ctx_dsemicolon = 1;
6492 ctx.ctx_res_w = RES_MATCH;
6498 /* We just finished a cmd. New one may start
6499 * with an assignment */
6500 dest.o_assignment = MAYBE_ASSIGNMENT;
6503 if (done_word(&dest, &ctx)) {
6507 ch = i_getch(input);
6508 nommu_addchr(&ctx.as_string, ch);
6509 done_pipe(&ctx, PIPE_AND);
6511 done_pipe(&ctx, PIPE_BG);
6515 if (done_word(&dest, &ctx)) {
6518 #if ENABLE_HUSH_CASE
6519 if (ctx.ctx_res_w == RES_MATCH)
6520 break; /* we are in case's "word | word)" */
6522 if (next == '|') { /* || */
6523 ch = i_getch(input);
6524 nommu_addchr(&ctx.as_string, ch);
6525 done_pipe(&ctx, PIPE_OR);
6527 /* we could pick up a file descriptor choice here
6528 * with redirect_opt_num(), but bash doesn't do it.
6529 * "echo foo 2| cat" yields "foo 2". */
6534 #if ENABLE_HUSH_CASE
6535 /* "case... in [(]word)..." - skip '(' */
6536 if (ctx.ctx_res_w == RES_MATCH
6537 && ctx.command->argv == NULL /* not (word|(... */
6538 && dest.length == 0 /* not word(... */
6539 && dest.o_quoted == 0 /* not ""(... */
6545 if (parse_group(&dest, &ctx, input, ch) != 0) {
6550 #if ENABLE_HUSH_CASE
6551 if (ctx.ctx_res_w == RES_MATCH)
6555 /* proper use of this character is caught by end_trigger:
6556 * if we see {, we call parse_group(..., end_trigger='}')
6557 * and it will match } earlier (not here). */
6558 syntax_error_unexpected_ch(ch);
6562 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6568 struct parse_context *pctx;
6569 IF_HAS_KEYWORDS(struct parse_context *p2;)
6571 /* Clean up allocated tree.
6572 * Sample for finding leaks on syntax error recovery path.
6573 * Run it from interactive shell, watch pmap `pidof hush`.
6574 * while if false; then false; fi; do break; fi
6575 * Samples to catch leaks at execution:
6576 * while if (true | {true;}); then echo ok; fi; do break; done
6577 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6581 /* Update pipe/command counts,
6582 * otherwise freeing may miss some */
6583 done_pipe(pctx, PIPE_SEQ);
6584 debug_printf_clean("freeing list %p from ctx %p\n",
6585 pctx->list_head, pctx);
6586 debug_print_tree(pctx->list_head, 0);
6587 free_pipe_list(pctx->list_head);
6588 debug_printf_clean("freed list %p\n", pctx->list_head);
6590 o_free_unsafe(&pctx->as_string);
6592 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6596 IF_HAS_KEYWORDS(pctx = p2;)
6597 } while (HAS_KEYWORDS && pctx);
6598 /* Free text, clear all dest fields */
6600 /* If we are not in top-level parse, we return,
6601 * our caller will propagate error.
6603 if (end_trigger != ';') {
6611 /* Discard cached input, force prompt */
6613 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6618 /* Executing from string: eval, sh -c '...'
6619 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6620 * end_trigger controls how often we stop parsing
6621 * NUL: parse all, execute, return
6622 * ';': parse till ';' or newline, execute, repeat till EOF
6624 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6626 /* Why we need empty flag?
6627 * An obscure corner case "false; ``; echo $?":
6628 * empty command in `` should still set $? to 0.
6629 * But we can't just set $? to 0 at the start,
6630 * this breaks "false; echo `echo $?`" case.
6634 struct pipe *pipe_list;
6636 pipe_list = parse_stream(NULL, inp, end_trigger);
6637 if (!pipe_list) { /* EOF */
6639 G.last_exitcode = 0;
6642 debug_print_tree(pipe_list, 0);
6643 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6644 run_and_free_list(pipe_list);
6649 static void parse_and_run_string(const char *s)
6651 struct in_str input;
6652 setup_string_in_str(&input, s);
6653 parse_and_run_stream(&input, '\0');
6656 static void parse_and_run_file(FILE *f)
6658 struct in_str input;
6659 setup_file_in_str(&input, f);
6660 parse_and_run_stream(&input, ';');
6663 /* Called a few times only (or even once if "sh -c") */
6664 static void block_signals(int second_time)
6669 mask = (1 << SIGQUIT);
6670 if (G_interactive_fd) {
6671 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6672 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6673 mask |= SPECIAL_JOB_SIGS;
6675 G.non_DFL_mask = mask;
6678 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6682 sigaddset(&G.blocked_set, sig);
6686 sigdelset(&G.blocked_set, SIGCHLD);
6688 sigprocmask(SIG_SETMASK, &G.blocked_set,
6689 second_time ? NULL : &G.inherited_set);
6690 /* POSIX allows shell to re-enable SIGCHLD
6691 * even if it was SIG_IGN on entry */
6692 #if ENABLE_HUSH_FAST
6693 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6695 signal(SIGCHLD, SIGCHLD_handler);
6698 signal(SIGCHLD, SIG_DFL);
6704 static void maybe_set_to_sigexit(int sig)
6706 void (*handler)(int);
6707 /* non_DFL_mask'ed signals are, well, masked,
6708 * no need to set handler for them.
6710 if (!((G.non_DFL_mask >> sig) & 1)) {
6711 handler = signal(sig, sigexit);
6712 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6713 signal(sig, handler);
6716 /* Set handlers to restore tty pgrp and exit */
6717 static void set_fatal_handlers(void)
6719 /* We _must_ restore tty pgrp on fatal signals */
6721 maybe_set_to_sigexit(SIGILL );
6722 maybe_set_to_sigexit(SIGFPE );
6723 maybe_set_to_sigexit(SIGBUS );
6724 maybe_set_to_sigexit(SIGSEGV);
6725 maybe_set_to_sigexit(SIGTRAP);
6726 } /* else: hush is perfect. what SEGV? */
6727 maybe_set_to_sigexit(SIGABRT);
6728 /* bash 3.2 seems to handle these just like 'fatal' ones */
6729 maybe_set_to_sigexit(SIGPIPE);
6730 maybe_set_to_sigexit(SIGALRM);
6731 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6732 * if we aren't interactive... but in this case
6733 * we never want to restore pgrp on exit, and this fn is not called */
6734 /*maybe_set_to_sigexit(SIGHUP );*/
6735 /*maybe_set_to_sigexit(SIGTERM);*/
6736 /*maybe_set_to_sigexit(SIGINT );*/
6740 static int set_mode(const char cstate, const char mode)
6742 int state = (cstate == '-' ? 1 : 0);
6744 case 'n': G.fake_mode = state; break;
6745 case 'x': /*G.debug_mode = state;*/ break;
6746 default: return EXIT_FAILURE;
6748 return EXIT_SUCCESS;
6751 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6752 int hush_main(int argc, char **argv)
6754 static const struct variable const_shell_ver = {
6756 .varstr = (char*)hush_version_str,
6757 .max_len = 1, /* 0 can provoke free(name) */
6761 int signal_mask_is_inited = 0;
6763 unsigned builtin_argc;
6765 struct variable *cur_var;
6768 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6769 G.last_exitcode = EXIT_SUCCESS;
6771 G.argv0_for_re_execing = argv[0];
6773 /* Deal with HUSH_VERSION */
6774 G.shell_ver = const_shell_ver; /* copying struct here */
6775 G.top_var = &G.shell_ver;
6776 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6777 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6778 /* Initialize our shell local variables with the values
6779 * currently living in the environment */
6780 cur_var = G.top_var;
6783 char *value = strchr(*e, '=');
6784 if (value) { /* paranoia */
6785 cur_var->next = xzalloc(sizeof(*cur_var));
6786 cur_var = cur_var->next;
6787 cur_var->varstr = *e;
6788 cur_var->max_len = strlen(*e);
6789 cur_var->flg_export = 1;
6793 /* reinstate HUSH_VERSION */
6794 debug_printf_env("putenv '%s'\n", hush_version_str);
6795 putenv((char *)hush_version_str);
6798 set_pwd_var(/*exp:*/ 1);
6799 /* bash also exports SHLVL and _,
6800 * and sets (but doesn't export) the following variables:
6802 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6803 * BASH_VERSION='3.2.0(1)-release'
6805 * MACHTYPE=i386-pc-linux-gnu
6807 * HOSTNAME=<xxxxxxxxxx>
6808 * PPID=<NNNNN> - we also do it elsewhere
6819 * PIPESTATUS=([0]="0")
6820 * HISTFILE=/<xxx>/.bash_history
6824 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6826 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6836 #if ENABLE_FEATURE_EDITING
6837 G.line_input_state = new_line_input_t(FOR_SHELL);
6839 G.global_argc = argc;
6840 G.global_argv = argv;
6841 /* Initialize some more globals to non-zero values */
6842 cmdedit_update_prompt();
6844 if (setjmp(die_jmp)) {
6845 /* xfunc has failed! die die die */
6846 /* no EXIT traps, this is an escape hatch! */
6848 hush_exit(xfunc_error_retval);
6851 /* Shell is non-interactive at first. We need to call
6852 * block_signals(0) if we are going to execute "sh <script>",
6853 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6854 * If we later decide that we are interactive, we run block_signals(0)
6855 * (or re-run block_signals(1) if we ran block_signals(0) before)
6856 * in order to intercept (more) signals.
6860 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6863 opt = getopt(argc, argv, "+c:xins"
6866 # if ENABLE_HUSH_FUNCTIONS
6876 * sh ... -c 'script'
6877 * sh ... -c 'script' ARG0 [ARG1...]
6878 * On NOMMU, if builtin_argc != 0,
6879 * sh ... -c 'builtin' [BARGV...] "" ARG0 [ARG1...]
6880 * "" needs to be replaced with NULL
6881 * and BARGV vector fed to builtin function.
6882 * Note: this form never happens:
6883 * sh ... -c 'builtin' [BARGV...] ""
6886 G.root_pid = getpid();
6887 G.root_ppid = getppid();
6889 G.global_argv = argv + optind;
6890 G.global_argc = argc - optind;
6892 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6893 const struct built_in_command *x;
6895 block_signals(0); /* 0: called 1st time */
6896 x = find_builtin(optarg);
6897 if (x) { /* paranoia */
6898 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6899 G.global_argv += builtin_argc;
6900 G.global_argv[-1] = NULL; /* replace "" */
6901 G.last_exitcode = x->function(argv + optind - 1);
6905 if (!G.global_argv[0]) {
6906 /* -c 'script' (no params): prevent empty $0 */
6907 G.global_argv--; /* points to argv[i] of 'script' */
6908 G.global_argv[0] = argv[0];
6910 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6911 block_signals(0); /* 0: called 1st time */
6912 parse_and_run_string(optarg);
6915 /* Well, we cannot just declare interactiveness,
6916 * we have to have some stuff (ctty, etc) */
6917 /* G_interactive_fd++; */
6920 /* "-s" means "read from stdin", but this is how we always
6921 * operate, so simply do nothing here. */
6924 case '<': /* "big heredoc" support */
6925 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6928 G.root_pid = bb_strtou(optarg, &optarg, 16);
6930 G.root_ppid = bb_strtou(optarg, &optarg, 16);
6932 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6934 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6936 builtin_argc = bb_strtou(optarg, &optarg, 16);
6937 # if ENABLE_HUSH_LOOPS
6939 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6944 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
6946 # if ENABLE_HUSH_FUNCTIONS
6948 struct function *funcp = new_function(optarg);
6949 /* funcp->name is already set to optarg */
6950 /* funcp->body is set to NULL. It's a special case. */
6951 funcp->body_as_string = argv[optind];
6959 if (!set_mode('-', opt))
6963 fprintf(stderr, "Usage: sh [FILE]...\n"
6964 " or: sh -c command [args]...\n\n");
6970 } /* option parsing loop */
6973 G.root_pid = getpid();
6974 G.root_ppid = getppid();
6977 /* If we are login shell... */
6978 if (argv[0] && argv[0][0] == '-') {
6980 debug_printf("sourcing /etc/profile\n");
6981 input = fopen_for_read("/etc/profile");
6982 if (input != NULL) {
6983 close_on_exec_on(fileno(input));
6984 block_signals(0); /* 0: called 1st time */
6985 signal_mask_is_inited = 1;
6986 parse_and_run_file(input);
6989 /* bash: after sourcing /etc/profile,
6990 * tries to source (in the given order):
6991 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6992 * stopping on first found. --noprofile turns this off.
6993 * bash also sources ~/.bash_logout on exit.
6994 * If called as sh, skips .bash_XXX files.
7001 * "bash <script>" (which is never interactive (unless -i?))
7002 * sources $BASH_ENV here (without scanning $PATH).
7003 * If called as sh, does the same but with $ENV.
7005 debug_printf("running script '%s'\n", argv[optind]);
7006 G.global_argv = argv + optind;
7007 G.global_argc = argc - optind;
7008 input = xfopen_for_read(argv[optind]);
7009 close_on_exec_on(fileno(input));
7010 if (!signal_mask_is_inited)
7011 block_signals(0); /* 0: called 1st time */
7012 parse_and_run_file(input);
7013 #if ENABLE_FEATURE_CLEAN_UP
7019 /* Up to here, shell was non-interactive. Now it may become one.
7020 * NB: don't forget to (re)run block_signals(0/1) as needed.
7023 /* A shell is interactive if the '-i' flag was given,
7024 * or if all of the following conditions are met:
7026 * no arguments remaining or the -s flag given
7027 * standard input is a terminal
7028 * standard output is a terminal
7029 * Refer to Posix.2, the description of the 'sh' utility.
7032 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7033 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7034 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7035 if (G_saved_tty_pgrp < 0)
7036 G_saved_tty_pgrp = 0;
7038 /* try to dup stdin to high fd#, >= 255 */
7039 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7040 if (G_interactive_fd < 0) {
7041 /* try to dup to any fd */
7042 G_interactive_fd = dup(STDIN_FILENO);
7043 if (G_interactive_fd < 0) {
7045 G_interactive_fd = 0;
7046 G_saved_tty_pgrp = 0;
7049 // TODO: track & disallow any attempts of user
7050 // to (inadvertently) close/redirect G_interactive_fd
7052 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7053 if (G_interactive_fd) {
7054 close_on_exec_on(G_interactive_fd);
7056 if (G_saved_tty_pgrp) {
7057 /* If we were run as 'hush &', sleep until we are
7058 * in the foreground (tty pgrp == our pgrp).
7059 * If we get started under a job aware app (like bash),
7060 * make sure we are now in charge so we don't fight over
7061 * who gets the foreground */
7063 pid_t shell_pgrp = getpgrp();
7064 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7065 if (G_saved_tty_pgrp == shell_pgrp)
7067 /* send TTIN to ourself (should stop us) */
7068 kill(- shell_pgrp, SIGTTIN);
7072 /* Block some signals */
7073 block_signals(signal_mask_is_inited);
7075 if (G_saved_tty_pgrp) {
7076 /* Set other signals to restore saved_tty_pgrp */
7077 set_fatal_handlers();
7078 /* Put ourselves in our own process group
7079 * (bash, too, does this only if ctty is available) */
7080 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7081 /* Grab control of the terminal */
7082 tcsetpgrp(G_interactive_fd, getpid());
7084 /* -1 is special - makes xfuncs longjmp, not exit
7085 * (we reset die_sleep = 0 whereever we [v]fork) */
7086 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7087 } else if (!signal_mask_is_inited) {
7088 block_signals(0); /* 0: called 1st time */
7089 } /* else: block_signals(0) was done before */
7090 #elif ENABLE_HUSH_INTERACTIVE
7091 /* No job control compiled in, only prompt/line editing */
7092 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7093 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7094 if (G_interactive_fd < 0) {
7095 /* try to dup to any fd */
7096 G_interactive_fd = dup(STDIN_FILENO);
7097 if (G_interactive_fd < 0)
7099 G_interactive_fd = 0;
7102 if (G_interactive_fd) {
7103 close_on_exec_on(G_interactive_fd);
7104 block_signals(signal_mask_is_inited);
7105 } else if (!signal_mask_is_inited) {
7109 /* We have interactiveness code disabled */
7110 if (!signal_mask_is_inited) {
7115 * if interactive but not a login shell, sources ~/.bashrc
7116 * (--norc turns this off, --rcfile <file> overrides)
7119 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7120 /* note: ash and hush share this string */
7121 printf("\n\n%s %s\n"
7122 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7125 "hush - the humble shell"
7129 parse_and_run_file(stdin);
7132 #if ENABLE_FEATURE_CLEAN_UP
7133 if (G.cwd != bb_msg_unknown)
7135 cur_var = G.top_var->next;
7137 struct variable *tmp = cur_var;
7138 if (!cur_var->max_len)
7139 free(cur_var->varstr);
7140 cur_var = cur_var->next;
7144 hush_exit(G.last_exitcode);
7149 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7150 int lash_main(int argc, char **argv)
7152 bb_error_msg("lash is deprecated, please use hush instead");
7153 return hush_main(argc, argv);
7158 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7159 int msh_main(int argc, char **argv)
7161 //bb_error_msg("msh is deprecated, please use hush instead");
7162 return hush_main(argc, argv);
7170 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7175 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7182 return applet_main_func(argc, argv - argc);
7185 static int FAST_FUNC builtin_test(char **argv)
7187 return run_applet_main(argv, test_main);
7190 static int FAST_FUNC builtin_echo(char **argv)
7192 return run_applet_main(argv, echo_main);
7196 static int FAST_FUNC builtin_printf(char **argv)
7198 return run_applet_main(argv, printf_main);
7202 static int FAST_FUNC builtin_eval(char **argv)
7204 int rcode = EXIT_SUCCESS;
7207 char *str = expand_strvec_to_string(argv);
7209 * eval "echo Hi; done" ("done" is syntax error):
7210 * "echo Hi" will not execute too.
7212 parse_and_run_string(str);
7214 rcode = G.last_exitcode;
7219 static int FAST_FUNC builtin_cd(char **argv)
7221 const char *newdir = argv[1];
7222 if (newdir == NULL) {
7223 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7224 * bash says "bash: cd: HOME not set" and does nothing
7227 const char *home = get_local_var_value("HOME");
7228 newdir = home ? home : "/";
7230 if (chdir(newdir)) {
7231 /* Mimic bash message exactly */
7232 bb_perror_msg("cd: %s", newdir);
7233 return EXIT_FAILURE;
7235 /* Read current dir (get_cwd(1) is inside) and set PWD.
7236 * Note: do not enforce exporting. If PWD was unset or unexported,
7237 * set it again, but do not export. bash does the same.
7239 set_pwd_var(/*exp:*/ 0);
7240 return EXIT_SUCCESS;
7243 static int FAST_FUNC builtin_exec(char **argv)
7245 if (*++argv == NULL)
7246 return EXIT_SUCCESS; /* bash does this */
7248 /* Careful: we can end up here after [v]fork. Do not restore
7249 * tty pgrp then, only top-level shell process does that */
7250 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7251 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7253 /* TODO: if exec fails, bash does NOT exit! We do.
7254 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7255 * and tcsetpgrp, and this is inherently racy.
7257 execvp_or_die(argv);
7260 static int FAST_FUNC builtin_exit(char **argv)
7262 debug_printf_exec("%s()\n", __func__);
7264 /* interactive bash:
7265 * # trap "echo EEE" EXIT
7268 * There are stopped jobs.
7269 * (if there are _stopped_ jobs, running ones don't count)
7272 # EEE (then bash exits)
7274 * we can use G.exiting = -1 as indicator "last cmd was exit"
7277 /* note: EXIT trap is run by hush_exit */
7278 if (*++argv == NULL)
7279 hush_exit(G.last_exitcode);
7280 /* mimic bash: exit 123abc == exit 255 + error msg */
7281 xfunc_error_retval = 255;
7282 /* bash: exit -2 == exit 254, no error msg */
7283 hush_exit(xatoi(*argv) & 0xff);
7286 static void print_escaped(const char *s)
7291 const char *p = strchrnul(s, '\'');
7292 /* print 'xxxx', possibly just '' */
7293 printf("'%.*s'", (int)(p - s), s);
7298 /* s points to '; print "'''...'''" */
7300 do putchar('\''); while (*++s == '\'');
7305 #if !ENABLE_HUSH_LOCAL
7306 #define helper_export_local(argv, exp, lvl) \
7307 helper_export_local(argv, exp)
7309 static void helper_export_local(char **argv, int exp, int lvl)
7314 /* So far we do not check that name is valid (TODO?) */
7316 if (strchr(name, '=') == NULL) {
7317 struct variable *var;
7319 var = get_local_var(name);
7320 if (exp == -1) { /* unexporting? */
7321 /* export -n NAME (without =VALUE) */
7323 var->flg_export = 0;
7324 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7326 } /* else: export -n NOT_EXISTING_VAR: no-op */
7329 if (exp == 1) { /* exporting? */
7330 /* export NAME (without =VALUE) */
7332 var->flg_export = 1;
7333 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7334 putenv(var->varstr);
7338 /* Exporting non-existing variable.
7339 * bash does not put it in environment,
7340 * but remembers that it is exported,
7341 * and does put it in env when it is set later.
7342 * We just set it to "" and export. */
7343 /* Or, it's "local NAME" (without =VALUE).
7344 * bash sets the value to "". */
7345 name = xasprintf("%s=", name);
7347 /* (Un)exporting/making local NAME=VALUE */
7348 name = xstrdup(name);
7350 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7354 static int FAST_FUNC builtin_export(char **argv)
7356 unsigned opt_unexport;
7358 #if ENABLE_HUSH_EXPORT_N
7359 /* "!": do not abort on errors */
7360 opt_unexport = getopt32(argv, "!n");
7361 if (opt_unexport == (uint32_t)-1)
7362 return EXIT_FAILURE;
7369 if (argv[0] == NULL) {
7376 /* ash emits: export VAR='VAL'
7377 * bash: declare -x VAR="VAL"
7378 * we follow ash example */
7379 const char *s = *e++;
7380 const char *p = strchr(s, '=');
7382 if (!p) /* wtf? take next variable */
7385 printf("export %.*s", (int)(p - s) + 1, s);
7386 print_escaped(p + 1);
7390 /*fflush_all(); - done after each builtin anyway */
7392 return EXIT_SUCCESS;
7395 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7397 return EXIT_SUCCESS;
7400 #if ENABLE_HUSH_LOCAL
7401 static int FAST_FUNC builtin_local(char **argv)
7403 if (G.func_nest_level == 0) {
7404 bb_error_msg("%s: not in a function", argv[0]);
7405 return EXIT_FAILURE; /* bash compat */
7407 helper_export_local(argv, 0, G.func_nest_level);
7408 return EXIT_SUCCESS;
7412 static int FAST_FUNC builtin_trap(char **argv)
7418 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7423 /* No args: print all trapped */
7424 for (i = 0; i < NSIG; ++i) {
7427 print_escaped(G.traps[i]);
7428 /* note: bash adds "SIG", but only if invoked
7429 * as "bash". If called as "sh", or if set -o posix,
7430 * then it prints short signal names.
7431 * We are printing short names: */
7432 printf(" %s\n", get_signame(i));
7435 /*fflush_all(); - done after each builtin anyway */
7436 return EXIT_SUCCESS;
7440 /* If first arg is a number: reset all specified signals */
7441 sig = bb_strtou(*argv, NULL, 10);
7447 sig = get_signum(*argv++);
7448 if (sig < 0 || sig >= NSIG) {
7450 /* Mimic bash message exactly */
7451 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7456 G.traps[sig] = xstrdup(new_cmd);
7458 debug_printf("trap: setting SIG%s (%i) to '%s'",
7459 get_signame(sig), sig, G.traps[sig]);
7461 /* There is no signal for 0 (EXIT) */
7466 sigaddset(&G.blocked_set, sig);
7468 /* There was a trap handler, we are removing it
7469 * (if sig has non-DFL handling,
7470 * we don't need to do anything) */
7471 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7473 sigdelset(&G.blocked_set, sig);
7476 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7480 if (!argv[1]) { /* no second arg */
7481 bb_error_msg("trap: invalid arguments");
7482 return EXIT_FAILURE;
7485 /* First arg is "-": reset all specified to default */
7486 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7487 /* Everything else: set arg as signal handler
7488 * (includes "" case, which ignores signal) */
7489 if (argv[0][0] == '-') {
7490 if (argv[0][1] == '\0') { /* "-" */
7491 /* new_cmd remains NULL: "reset these sigs" */
7494 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7497 /* else: "-something", no special meaning */
7502 goto process_sig_list;
7505 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7506 static int FAST_FUNC builtin_type(char **argv)
7508 int ret = EXIT_SUCCESS;
7514 if (0) {} /* make conditional compile easier below */
7515 /*else if (find_alias(*argv))
7516 type = "an alias";*/
7517 #if ENABLE_HUSH_FUNCTIONS
7518 else if (find_function(*argv))
7519 type = "a function";
7521 else if (find_builtin(*argv))
7522 type = "a shell builtin";
7523 else if ((path = find_in_path(*argv)) != NULL)
7526 bb_error_msg("type: %s: not found", *argv);
7531 printf("%s is %s\n", *argv, type);
7539 /* built-in 'fg' and 'bg' handler */
7540 static int FAST_FUNC builtin_fg_bg(char **argv)
7545 if (!G_interactive_fd)
7546 return EXIT_FAILURE;
7548 /* If they gave us no args, assume they want the last backgrounded task */
7550 for (pi = G.job_list; pi; pi = pi->next) {
7551 if (pi->jobid == G.last_jobid) {
7555 bb_error_msg("%s: no current job", argv[0]);
7556 return EXIT_FAILURE;
7558 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7559 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7560 return EXIT_FAILURE;
7562 for (pi = G.job_list; pi; pi = pi->next) {
7563 if (pi->jobid == jobnum) {
7567 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7568 return EXIT_FAILURE;
7570 /* TODO: bash prints a string representation
7571 * of job being foregrounded (like "sleep 1 | cat") */
7572 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7573 /* Put the job into the foreground. */
7574 tcsetpgrp(G_interactive_fd, pi->pgrp);
7577 /* Restart the processes in the job */
7578 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7579 for (i = 0; i < pi->num_cmds; i++) {
7580 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7581 pi->cmds[i].is_stopped = 0;
7583 pi->stopped_cmds = 0;
7585 i = kill(- pi->pgrp, SIGCONT);
7587 if (errno == ESRCH) {
7588 delete_finished_bg_job(pi);
7589 return EXIT_SUCCESS;
7591 bb_perror_msg("kill (SIGCONT)");
7594 if (argv[0][0] == 'f') {
7596 return checkjobs_and_fg_shell(pi);
7598 return EXIT_SUCCESS;
7602 #if ENABLE_HUSH_HELP
7603 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7605 const struct built_in_command *x;
7608 "Built-in commands:\n"
7609 "------------------\n");
7610 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7612 printf("%s\t%s\n", x->cmd, x->descr);
7615 return EXIT_SUCCESS;
7620 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7623 const char *status_string;
7625 for (job = G.job_list; job; job = job->next) {
7626 if (job->alive_cmds == job->stopped_cmds)
7627 status_string = "Stopped";
7629 status_string = "Running";
7631 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7633 return EXIT_SUCCESS;
7638 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7643 # ifdef M_TRIM_THRESHOLD
7644 /* Optional. Reduces probability of false positives */
7647 /* Crude attempt to find where "free memory" starts,
7648 * sans fragmentation. */
7650 l = (unsigned long)p;
7653 if (l < (unsigned long)p) l = (unsigned long)p;
7656 if (!G.memleak_value)
7657 G.memleak_value = l;
7659 l -= G.memleak_value;
7666 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7671 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7674 return EXIT_SUCCESS;
7677 static int FAST_FUNC builtin_read(char **argv)
7680 const char *name = "REPLY";
7684 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
7685 * and _after_ that_ it will complain */
7686 if (!is_well_formed_var_name(name, '\0')) {
7687 /* Mimic bash message */
7688 bb_error_msg("read: '%s': not a valid identifier", name);
7693 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
7695 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
7696 return set_local_var(string, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7699 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7700 * built-in 'set' handler
7702 * set [-abCefhmnuvx] [-o option] [argument...]
7703 * set [+abCefhmnuvx] [+o option] [argument...]
7704 * set -- [argument...]
7707 * Implementations shall support the options in both their hyphen and
7708 * plus-sign forms. These options can also be specified as options to sh.
7710 * Write out all variables and their values: set
7711 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7712 * Turn on the -x and -v options: set -xv
7713 * Unset all positional parameters: set --
7714 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7715 * Set the positional parameters to the expansion of x, even if x expands
7716 * with a leading '-' or '+': set -- $x
7718 * So far, we only support "set -- [argument...]" and some of the short names.
7720 static int FAST_FUNC builtin_set(char **argv)
7723 char **pp, **g_argv;
7724 char *arg = *++argv;
7728 for (e = G.top_var; e; e = e->next)
7730 return EXIT_SUCCESS;
7734 if (!strcmp(arg, "--")) {
7738 if (arg[0] != '+' && arg[0] != '-')
7740 for (n = 1; arg[n]; ++n)
7741 if (set_mode(arg[0], arg[n]))
7743 } while ((arg = *++argv) != NULL);
7744 /* Now argv[0] is 1st argument */
7747 return EXIT_SUCCESS;
7750 /* NB: G.global_argv[0] ($0) is never freed/changed */
7751 g_argv = G.global_argv;
7752 if (G.global_args_malloced) {
7758 G.global_args_malloced = 1;
7759 pp = xzalloc(sizeof(pp[0]) * 2);
7760 pp[0] = g_argv[0]; /* retain $0 */
7763 /* This realloc's G.global_argv */
7764 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7771 return EXIT_SUCCESS;
7773 /* Nothing known, so abort */
7775 bb_error_msg("set: %s: invalid option", arg);
7776 return EXIT_FAILURE;
7779 static int FAST_FUNC builtin_shift(char **argv)
7785 if (n >= 0 && n < G.global_argc) {
7786 if (G.global_args_malloced) {
7789 free(G.global_argv[m++]);
7792 memmove(&G.global_argv[1], &G.global_argv[n+1],
7793 G.global_argc * sizeof(G.global_argv[0]));
7794 return EXIT_SUCCESS;
7796 return EXIT_FAILURE;
7799 static int FAST_FUNC builtin_source(char **argv)
7804 #if ENABLE_HUSH_FUNCTIONS
7808 if (*++argv == NULL)
7809 return EXIT_FAILURE;
7811 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7812 input = fopen_for_read(arg_path);
7815 input = fopen_or_warn(*argv, "r");
7817 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7818 return EXIT_FAILURE;
7820 close_on_exec_on(fileno(input));
7822 #if ENABLE_HUSH_FUNCTIONS
7823 sv_flg = G.flag_return_in_progress;
7824 /* "we are inside sourced file, ok to use return" */
7825 G.flag_return_in_progress = -1;
7827 save_and_replace_G_args(&sv, argv);
7829 parse_and_run_file(input);
7832 restore_G_args(&sv, argv);
7833 #if ENABLE_HUSH_FUNCTIONS
7834 G.flag_return_in_progress = sv_flg;
7837 return G.last_exitcode;
7840 static int FAST_FUNC builtin_umask(char **argv)
7847 mode_t old_mask = mask;
7850 rc = bb_parse_mode(argv[1], &mask);
7855 * bash: umask: 'q': invalid symbolic mode operator
7856 * bash: umask: 999: octal number out of range
7858 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7863 printf("%04o\n", (unsigned) mask);
7864 /* fall through and restore mask which we set to 0 */
7868 return !rc; /* rc != 0 - success */
7871 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7872 static int FAST_FUNC builtin_unset(char **argv)
7877 /* "!": do not abort on errors */
7878 /* "+": stop at 1st non-option */
7879 opts = getopt32(argv, "!+vf");
7880 if (opts == (unsigned)-1)
7881 return EXIT_FAILURE;
7883 bb_error_msg("unset: -v and -f are exclusive");
7884 return EXIT_FAILURE;
7890 if (!(opts & 2)) { /* not -f */
7891 if (unset_local_var(*argv)) {
7892 /* unset <nonexistent_var> doesn't fail.
7893 * Error is when one tries to unset RO var.
7894 * Message was printed by unset_local_var. */
7898 #if ENABLE_HUSH_FUNCTIONS
7908 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7909 static int FAST_FUNC builtin_wait(char **argv)
7911 int ret = EXIT_SUCCESS;
7914 if (*++argv == NULL) {
7915 /* Don't care about wait results */
7916 /* Note 1: must wait until there are no more children */
7917 /* Note 2: must be interruptible */
7919 * $ sleep 3 & sleep 6 & wait
7924 * $ sleep 3 & sleep 6 & wait
7928 * ^C <-- after ~4 sec from keyboard
7931 sigaddset(&G.blocked_set, SIGCHLD);
7932 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7935 if (errno == ECHILD)
7937 /* Wait for SIGCHLD or any other signal of interest */
7938 /* sigtimedwait with infinite timeout: */
7939 sig = sigwaitinfo(&G.blocked_set, NULL);
7941 sig = check_and_run_traps(sig);
7942 if (sig && sig != SIGCHLD) { /* see note 2 */
7948 sigdelset(&G.blocked_set, SIGCHLD);
7949 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7953 /* This is probably buggy wrt interruptible-ness */
7955 pid_t pid = bb_strtou(*argv, NULL, 10);
7957 /* mimic bash message */
7958 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7959 return EXIT_FAILURE;
7961 if (waitpid(pid, &status, 0) == pid) {
7962 if (WIFSIGNALED(status))
7963 ret = 128 + WTERMSIG(status);
7964 else if (WIFEXITED(status))
7965 ret = WEXITSTATUS(status);
7969 bb_perror_msg("wait %s", *argv);
7978 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7979 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7982 def = bb_strtou(argv[1], NULL, 10);
7983 if (errno || def < def_min || argv[2]) {
7984 bb_error_msg("%s: bad arguments", argv[0]);
7992 #if ENABLE_HUSH_LOOPS
7993 static int FAST_FUNC builtin_break(char **argv)
7996 if (G.depth_of_loop == 0) {
7997 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7998 return EXIT_SUCCESS; /* bash compat */
8000 G.flag_break_continue++; /* BC_BREAK = 1 */
8002 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8003 if (depth == UINT_MAX)
8004 G.flag_break_continue = BC_BREAK;
8005 if (G.depth_of_loop < depth)
8006 G.depth_break_continue = G.depth_of_loop;
8008 return EXIT_SUCCESS;
8011 static int FAST_FUNC builtin_continue(char **argv)
8013 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8014 return builtin_break(argv);
8018 #if ENABLE_HUSH_FUNCTIONS
8019 static int FAST_FUNC builtin_return(char **argv)
8023 if (G.flag_return_in_progress != -1) {
8024 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8025 return EXIT_FAILURE; /* bash compat */
8028 G.flag_return_in_progress = 1;
8031 * out of range: wraps around at 256, does not error out
8032 * non-numeric param:
8033 * f() { false; return qwe; }; f; echo $?
8034 * bash: return: qwe: numeric argument required <== we do this
8035 * 255 <== we also do this
8037 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);