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 (maybe optionally enable?):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
52 * grep for "TODO" and fix (some of them are easy)
53 * builtins: ulimit, local
54 * follow IFS rules more precisely, including update semantics
55 * export builtin should be special, its arguments are assignments
56 * and therefore expansion of them should be "one-word" expansion:
57 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
59 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
60 * ls: cannot access i=a: No such file or directory
61 * ls: cannot access b: No such file or directory
62 * Note1: same applies to local builtin when we'll have it.
63 * Note2: bash 3.2.33(1) does this only if export word itself
65 * $ export i=`echo 'aaa bbb'`; echo "$i"
67 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
70 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
72 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
74 /* #include <dmalloc.h> */
81 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
86 #define LEAK_HUNTING 0
87 #define BUILD_AS_NOMMU 0
88 /* Enable/disable sanity checks. Ok to enable in production,
89 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
90 * Keeping 1 for now even in released versions.
93 /* Slightly bigger (+200 bytes), but faster hush.
94 * So far it only enables a trick with counting SIGCHLDs and forks,
95 * which allows us to do fewer waitpid's.
96 * (we can detect a case where neither forks were done nor SIGCHLDs happened
97 * and therefore waitpid will return the same result as last time)
99 #define ENABLE_HUSH_FAST 0
104 # undef USE_FOR_NOMMU
107 # define USE_FOR_NOMMU(...) __VA_ARGS__
108 # define USE_FOR_MMU(...)
111 #if defined SINGLE_APPLET_MAIN
112 /* STANDALONE does not make sense, and won't compile */
113 # undef CONFIG_FEATURE_SH_STANDALONE
114 # undef ENABLE_FEATURE_SH_STANDALONE
115 # undef IF_FEATURE_SH_STANDALONE
116 # define IF_FEATURE_SH_STANDALONE(...)
117 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
118 # define ENABLE_FEATURE_SH_STANDALONE 0
121 #if !ENABLE_HUSH_INTERACTIVE
122 # undef ENABLE_FEATURE_EDITING
123 # define ENABLE_FEATURE_EDITING 0
124 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
125 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
128 /* Do we support ANY keywords? */
129 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
130 # define HAS_KEYWORDS 1
131 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
132 # define IF_HAS_NO_KEYWORDS(...)
134 # define HAS_KEYWORDS 0
135 # define IF_HAS_KEYWORDS(...)
136 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
139 /* If you comment out one of these below, it will be #defined later
140 * to perform debug printfs to stderr: */
141 #define debug_printf(...) do {} while (0)
142 /* Finer-grained debug switches */
143 #define debug_printf_parse(...) do {} while (0)
144 #define debug_print_tree(a, b) do {} while (0)
145 #define debug_printf_exec(...) do {} while (0)
146 #define debug_printf_env(...) do {} while (0)
147 #define debug_printf_jobs(...) do {} while (0)
148 #define debug_printf_expand(...) do {} while (0)
149 #define debug_printf_glob(...) do {} while (0)
150 #define debug_printf_list(...) do {} while (0)
151 #define debug_printf_subst(...) do {} while (0)
152 #define debug_printf_clean(...) do {} while (0)
154 #define ERR_PTR ((void*)(long)1)
156 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
158 #define SPECIAL_VAR_SYMBOL 3
162 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
164 /* This supports saving pointers malloced in vfork child,
165 * to be freed in the parent.
168 typedef struct nommu_save_t {
170 struct variable *old_vars;
172 char **argv_from_re_execing;
176 /* The descrip member of this structure is only used to make
177 * debugging output pretty */
178 static const struct {
180 signed char default_fd;
184 { O_RDONLY, 0, "<" },
185 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
186 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
187 { O_RDONLY, 0, "<<" },
188 { O_CREAT|O_RDWR, 1, "<>" },
189 /* Should not be needed. Bogus default_fd helps in debugging */
190 /* { O_RDONLY, 77, "<<" }, */
193 typedef enum reserved_style {
202 #if ENABLE_HUSH_LOOPS
209 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
214 /* three pseudo-keywords support contrived "case" syntax: */
215 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
216 RES_MATCH , /* "word)" */
217 RES_CASE_BODY, /* "this command is inside CASE" */
224 typedef struct o_string {
226 int length; /* position where data is appended */
228 /* Protect newly added chars against globbing
229 * (by prepending \ to *, ?, [, \) */
232 /* At least some part of the string was inside '' or "",
233 * possibly empty one: word"", wo''rd etc. */
235 smallint has_empty_slot;
236 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
239 MAYBE_ASSIGNMENT = 0,
240 DEFINITELY_ASSIGNMENT = 1,
242 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
244 /* Used for initialization: o_string foo = NULL_O_STRING; */
245 #define NULL_O_STRING { NULL }
247 /* I can almost use ordinary FILE*. Is open_memstream() universally
248 * available? Where is it documented? */
249 typedef struct in_str {
251 /* eof_flag=1: last char in ->p is really an EOF */
252 char eof_flag; /* meaningless if ->p == NULL */
254 #if ENABLE_HUSH_INTERACTIVE
256 smallint promptmode; /* 0: PS1, 1: PS2 */
259 int (*get) (struct in_str *) FAST_FUNC;
260 int (*peek) (struct in_str *) FAST_FUNC;
262 #define i_getch(input) ((input)->get(input))
263 #define i_peek(input) ((input)->peek(input))
265 struct redir_struct {
266 struct redir_struct *next;
267 char *rd_filename; /* filename */
268 int rd_fd; /* fd to redirect */
269 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
271 smallint rd_type; /* (enum redir_type) */
272 /* note: for heredocs, rd_filename contains heredoc delimiter,
273 * and subsequently heredoc itself; and rd_dup is a bitmask:
274 * 1: do we need to trim leading tabs?
275 * 2: is heredoc quoted (<<'delim' syntax) ?
278 typedef enum redir_type {
279 REDIRECT_INVALID = 0,
281 REDIRECT_OVERWRITE = 2,
283 REDIRECT_HEREDOC = 4,
285 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
288 REDIRFD_SYNTAX_ERR = -2,
289 REDIRFD_TO_FILE = -1,
290 /* otherwise, rd_fd is redirected to rd_dup */
292 HEREDOC_SKIPTABS = 1,
298 pid_t pid; /* 0 if exited */
299 int assignment_cnt; /* how many argv[i] are assignments? */
300 smallint is_stopped; /* is the command currently running? */
301 smallint grp_type; /* GRP_xxx */
303 #define GRP_SUBSHELL 1
304 #if ENABLE_HUSH_FUNCTIONS
305 # define GRP_FUNCTION 2
307 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
310 char *group_as_string;
312 #if ENABLE_HUSH_FUNCTIONS
313 struct function *child_func;
314 /* This field is used to prevent a bug here:
315 * while...do f1() {a;}; f1; f1 {b;}; f1; done
316 * When we execute "f1() {a;}" cmd, we create new function and clear
317 * cmd->group, cmd->group_as_string, cmd->argv[0].
318 * when we execute "f1 {b;}", we notice that f1 exists,
319 * and that it's "parent cmd" struct is still "alive",
320 * we put those fields back into cmd->xxx
321 * (struct function has ->parent_cmd ptr to facilitate that).
322 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
323 * Without this trick, loop would execute a;b;b;b;...
324 * instead of correct sequence a;b;a;b;...
325 * When command is freed, it severs the link
326 * (sets ->child_func->parent_cmd to NULL).
329 char **argv; /* command name and arguments */
330 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
331 * and on execution these are substituted with their values.
332 * Substitution can make _several_ words out of one argv[n]!
333 * Example: argv[0]=='.^C*^C.' here: echo .$*.
334 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
336 struct redir_struct *redirects; /* I/O redirections */
338 /* Is there anything in this command at all? */
339 #define IS_NULL_CMD(cmd) \
340 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
345 int num_cmds; /* total number of commands in pipe */
346 int alive_cmds; /* number of commands running (not exited) */
347 int stopped_cmds; /* number of commands alive, but stopped */
349 int jobid; /* job number */
350 pid_t pgrp; /* process group ID for the job */
351 char *cmdtext; /* name of job */
353 struct command *cmds; /* array of commands in pipe */
354 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
355 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
356 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
358 typedef enum pipe_style {
364 /* Is there anything in this pipe at all? */
365 #define IS_NULL_PIPE(pi) \
366 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
368 /* This holds pointers to the various results of parsing */
369 struct parse_context {
370 /* linked list of pipes */
371 struct pipe *list_head;
372 /* last pipe (being constructed right now) */
374 /* last command in pipe (being constructed right now) */
375 struct command *command;
376 /* last redirect in command->redirects list */
377 struct redir_struct *pending_redirect;
383 smallint ctx_inverted; /* "! cmd | cmd" */
385 smallint ctx_dsemicolon; /* ";;" seen */
387 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
389 /* group we are enclosed in:
390 * example: "if pipe1; pipe2; then pipe3; fi"
391 * when we see "if" or "then", we malloc and copy current context,
392 * and make ->stack point to it. then we parse pipeN.
393 * when closing "then" / fi" / whatever is found,
394 * we move list_head into ->stack->command->group,
395 * copy ->stack into current context, and delete ->stack.
396 * (parsing of { list } and ( list ) doesn't use this method)
398 struct parse_context *stack;
402 /* On program start, environ points to initial environment.
403 * putenv adds new pointers into it, unsetenv removes them.
404 * Neither of these (de)allocates the strings.
405 * setenv allocates new strings in malloc space and does putenv,
406 * and thus setenv is unusable (leaky) for shell's purposes */
407 #define setenv(...) setenv_is_leaky_dont_use()
409 struct variable *next;
410 char *varstr; /* points to "name=" portion */
411 #if ENABLE_HUSH_LOCAL
412 unsigned func_nest_level;
414 int max_len; /* if > 0, name is part of initial env; else name is malloced */
415 smallint flg_export; /* putenv should be done on this var */
416 smallint flg_read_only;
424 #if ENABLE_HUSH_FUNCTIONS
426 struct function *next;
428 struct command *parent_cmd;
431 char *body_as_string;
437 /* "Globals" within this file */
438 /* Sorted roughly by size (smaller offsets == smaller code) */
440 /* interactive_fd != 0 means we are an interactive shell.
441 * If we are, then saved_tty_pgrp can also be != 0, meaning
442 * that controlling tty is available. With saved_tty_pgrp == 0,
443 * job control still works, but terminal signals
444 * (^C, ^Z, ^Y, ^\) won't work at all, and background
445 * process groups can only be created with "cmd &".
446 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
447 * to give tty to the foreground process group,
448 * and will take it back when the group is stopped (^Z)
451 #if ENABLE_HUSH_INTERACTIVE
452 /* 'interactive_fd' is a fd# open to ctty, if we have one
453 * _AND_ if we decided to act interactively */
457 # define G_interactive_fd (G.interactive_fd)
459 # define G_interactive_fd 0
461 #if ENABLE_FEATURE_EDITING
462 line_input_t *line_input_state;
469 pid_t saved_tty_pgrp;
470 struct pipe *job_list;
471 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
473 # define G_saved_tty_pgrp 0
475 smallint flag_SIGINT;
476 #if ENABLE_HUSH_LOOPS
477 smallint flag_break_continue;
479 #if ENABLE_HUSH_FUNCTIONS
480 /* 0: outside of a function (or sourced file)
481 * -1: inside of a function, ok to use return builtin
482 * 1: return is invoked, skip all till end of func
484 smallint flag_return_in_progress;
487 smallint exiting; /* used to prevent EXIT trap recursion */
488 /* These four support $?, $#, and $1 */
489 smalluint last_exitcode;
490 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
491 smalluint global_args_malloced;
492 /* how many non-NULL argv's we have. NB: $# + 1 */
496 char *argv0_for_re_execing;
498 #if ENABLE_HUSH_LOOPS
499 unsigned depth_break_continue;
500 unsigned depth_of_loop;
504 struct variable *top_var; /* = &G.shell_ver (set in main()) */
505 struct variable shell_ver;
506 #if ENABLE_HUSH_FUNCTIONS
507 struct function *top_func;
508 # if ENABLE_HUSH_LOCAL
509 struct variable **shadowed_vars_pp;
510 unsigned func_nest_level;
513 /* Signal and trap handling */
515 unsigned count_SIGCHLD;
516 unsigned handled_SIGCHLD;
517 smallint we_have_children;
519 /* which signals have non-DFL handler (even with no traps set)? */
520 unsigned non_DFL_mask;
521 char **traps; /* char *traps[NSIG] */
522 sigset_t blocked_set;
523 sigset_t inherited_set;
525 unsigned long memleak_value;
528 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
530 #define G (*ptr_to_globals)
531 /* Not #defining name to G.name - this quickly gets unwieldy
532 * (too many defines). Also, I actually prefer to see when a variable
533 * is global, thus "G." prefix is a useful hint */
534 #define INIT_G() do { \
535 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
539 /* Function prototypes for builtins */
540 static int builtin_cd(char **argv) FAST_FUNC;
541 static int builtin_echo(char **argv) FAST_FUNC;
542 static int builtin_eval(char **argv) FAST_FUNC;
543 static int builtin_exec(char **argv) FAST_FUNC;
544 static int builtin_exit(char **argv) FAST_FUNC;
545 static int builtin_export(char **argv) FAST_FUNC;
547 static int builtin_fg_bg(char **argv) FAST_FUNC;
548 static int builtin_jobs(char **argv) FAST_FUNC;
551 static int builtin_help(char **argv) FAST_FUNC;
553 #if ENABLE_HUSH_LOCAL
554 static int builtin_local(char **argv) FAST_FUNC;
557 static int builtin_memleak(char **argv) FAST_FUNC;
559 static int builtin_pwd(char **argv) FAST_FUNC;
560 static int builtin_read(char **argv) FAST_FUNC;
561 static int builtin_set(char **argv) FAST_FUNC;
562 static int builtin_shift(char **argv) FAST_FUNC;
563 static int builtin_source(char **argv) FAST_FUNC;
564 static int builtin_test(char **argv) FAST_FUNC;
565 static int builtin_trap(char **argv) FAST_FUNC;
566 static int builtin_type(char **argv) FAST_FUNC;
567 static int builtin_true(char **argv) FAST_FUNC;
568 static int builtin_umask(char **argv) FAST_FUNC;
569 static int builtin_unset(char **argv) FAST_FUNC;
570 static int builtin_wait(char **argv) FAST_FUNC;
571 #if ENABLE_HUSH_LOOPS
572 static int builtin_break(char **argv) FAST_FUNC;
573 static int builtin_continue(char **argv) FAST_FUNC;
575 #if ENABLE_HUSH_FUNCTIONS
576 static int builtin_return(char **argv) FAST_FUNC;
579 /* Table of built-in functions. They can be forked or not, depending on
580 * context: within pipes, they fork. As simple commands, they do not.
581 * When used in non-forking context, they can change global variables
582 * in the parent shell process. If forked, of course they cannot.
583 * For example, 'unset foo | whatever' will parse and run, but foo will
584 * still be set at the end. */
585 struct built_in_command {
587 int (*function)(char **argv) FAST_FUNC;
590 # define BLTIN(cmd, func, help) { cmd, func, help }
592 # define BLTIN(cmd, func, help) { cmd, func }
596 /* For now, echo and test are unconditionally enabled.
597 * Maybe make it configurable? */
598 static const struct built_in_command bltins[] = {
599 BLTIN("." , builtin_source , "Run commands in a file"),
600 BLTIN(":" , builtin_true , "No-op"),
601 BLTIN("[" , builtin_test , "Test condition"),
603 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
605 #if ENABLE_HUSH_LOOPS
606 BLTIN("break" , builtin_break , "Exit from a loop"),
608 BLTIN("cd" , builtin_cd , "Change directory"),
609 #if ENABLE_HUSH_LOOPS
610 BLTIN("continue", builtin_continue, "Start new loop iteration"),
612 BLTIN("echo" , builtin_echo , "Write to stdout"),
613 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
614 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
615 BLTIN("exit" , builtin_exit , "Exit"),
616 BLTIN("export" , builtin_export , "Set environment variable"),
618 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
621 BLTIN("help" , builtin_help , "List shell built-in commands"),
624 BLTIN("jobs" , builtin_jobs , "List active jobs"),
626 #if ENABLE_HUSH_LOCAL
627 BLTIN("local" , builtin_local , "Set local variable"),
630 BLTIN("memleak" , builtin_memleak , "Debug tool"),
632 BLTIN("pwd" , builtin_pwd , "Print current directory"),
633 BLTIN("read" , builtin_read , "Input environment variable"),
634 #if ENABLE_HUSH_FUNCTIONS
635 BLTIN("return" , builtin_return , "Return from a function"),
637 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
638 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
639 BLTIN("test" , builtin_test , "Test condition"),
640 BLTIN("trap" , builtin_trap , "Trap signals"),
641 BLTIN("type" , builtin_type , "Write a description of command type"),
642 // BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
643 BLTIN("umask" , builtin_umask , "Set file creation mask"),
644 BLTIN("unset" , builtin_unset , "Unset environment variable"),
645 BLTIN("wait" , builtin_wait , "Wait for process"),
652 /* prevent disasters with G.debug_indent < 0 */
653 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
654 # define debug_enter() (G.debug_indent++)
655 # define debug_leave() (G.debug_indent--)
657 # define indent() ((void)0)
658 # define debug_enter() ((void)0)
659 # define debug_leave() ((void)0)
663 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
666 #ifndef debug_printf_parse
667 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
670 #ifndef debug_printf_exec
671 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
674 #ifndef debug_printf_env
675 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
678 #ifndef debug_printf_jobs
679 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
680 # define DEBUG_JOBS 1
682 # define DEBUG_JOBS 0
685 #ifndef debug_printf_expand
686 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
687 # define DEBUG_EXPAND 1
689 # define DEBUG_EXPAND 0
692 #ifndef debug_printf_glob
693 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
694 # define DEBUG_GLOB 1
696 # define DEBUG_GLOB 0
699 #ifndef debug_printf_list
700 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
703 #ifndef debug_printf_subst
704 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
707 #ifndef debug_printf_clean
708 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
709 # define DEBUG_CLEAN 1
711 # define DEBUG_CLEAN 0
715 static void debug_print_strings(const char *prefix, char **vv)
718 fprintf(stderr, "%s:\n", prefix);
720 fprintf(stderr, " '%s'\n", *vv++);
723 # define debug_print_strings(prefix, vv) ((void)0)
727 /* Leak hunting. Use hush_leaktool.sh for post-processing.
730 static void *xxmalloc(int lineno, size_t size)
732 void *ptr = xmalloc((size + 0xff) & ~0xff);
733 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
736 static void *xxrealloc(int lineno, void *ptr, size_t size)
738 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
739 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
742 static char *xxstrdup(int lineno, const char *str)
744 char *ptr = xstrdup(str);
745 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
748 static void xxfree(void *ptr)
750 fdprintf(2, "free %p\n", ptr);
753 #define xmalloc(s) xxmalloc(__LINE__, s)
754 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
755 #define xstrdup(s) xxstrdup(__LINE__, s)
756 #define free(p) xxfree(p)
760 /* Syntax and runtime errors. They always abort scripts.
761 * In interactive use they usually discard unparsed and/or unexecuted commands
762 * and return to the prompt.
763 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
766 # define die_if_script(lineno, fmt...) die_if_script(fmt)
767 # define syntax_error(lineno, msg) syntax_error(msg)
768 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
769 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
770 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
771 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
774 static void die_if_script(unsigned lineno, const char *fmt, ...)
779 bb_error_msg("hush.c:%u", lineno);
782 bb_verror_msg(fmt, p, NULL);
784 if (!G_interactive_fd)
788 static void syntax_error(unsigned lineno, const char *msg)
791 die_if_script(lineno, "syntax error: %s", msg);
793 die_if_script(lineno, "syntax error", NULL);
796 static void syntax_error_at(unsigned lineno, const char *msg)
798 die_if_script(lineno, "syntax error at '%s'", msg);
801 static void syntax_error_unterm_str(unsigned lineno, const char *s)
803 die_if_script(lineno, "syntax error: unterminated %s", s);
806 /* It so happens that all such cases are totally fatal
807 * even if shell is interactive: EOF while looking for closing
808 * delimiter. There is nowhere to read stuff from after that,
809 * it's EOF! The only choice is to terminate.
811 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
812 static void syntax_error_unterm_ch(unsigned lineno, char ch)
814 char msg[2] = { ch, '\0' };
815 syntax_error_unterm_str(lineno, msg);
819 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
824 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
828 # undef die_if_script
830 # undef syntax_error_at
831 # undef syntax_error_unterm_ch
832 # undef syntax_error_unterm_str
833 # undef syntax_error_unexpected_ch
835 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
836 # define syntax_error(msg) syntax_error(__LINE__, msg)
837 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
838 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
839 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
840 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
844 #if ENABLE_HUSH_INTERACTIVE
845 static void cmdedit_update_prompt(void);
847 # define cmdedit_update_prompt() ((void)0)
853 static int glob_needed(const char *s)
858 if (*s == '*' || *s == '[' || *s == '?')
865 static int is_well_formed_var_name(const char *s, char terminator)
867 if (!s || !(isalpha(*s) || *s == '_'))
870 while (isalnum(*s) || *s == '_')
872 return *s == terminator;
875 /* Replace each \x with x in place, return ptr past NUL. */
876 static char *unbackslash(char *src)
882 if ((*dst++ = *src++) == '\0')
888 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
909 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
910 v[count1 + count2] = NULL;
913 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
917 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
919 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
920 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
923 #define add_strings_to_strings(strings, add, need_to_dup) \
924 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
927 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
928 static char **add_string_to_strings(char **strings, char *add)
933 return add_strings_to_strings(strings, v, /*dup:*/ 0);
936 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
938 char **ptr = add_string_to_strings(strings, add);
939 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
942 #define add_string_to_strings(strings, add) \
943 xx_add_string_to_strings(__LINE__, strings, add)
946 static void free_strings(char **strings)
961 /* Helpers for setting new $n and restoring them back
963 typedef struct save_arg_t {
967 smallint sv_g_malloced;
970 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
974 sv->sv_argv0 = argv[0];
975 sv->sv_g_argv = G.global_argv;
976 sv->sv_g_argc = G.global_argc;
977 sv->sv_g_malloced = G.global_args_malloced;
979 argv[0] = G.global_argv[0]; /* retain $0 */
980 G.global_argv = argv;
981 G.global_args_malloced = 0;
989 static void restore_G_args(save_arg_t *sv, char **argv)
993 if (G.global_args_malloced) {
994 /* someone ran "set -- arg1 arg2 ...", undo */
996 while (*++pp) /* note: does not free $0 */
1000 argv[0] = sv->sv_argv0;
1001 G.global_argv = sv->sv_g_argv;
1002 G.global_argc = sv->sv_g_argc;
1003 G.global_args_malloced = sv->sv_g_malloced;
1007 /* Basic theory of signal handling in shell
1008 * ========================================
1009 * This does not describe what hush does, rather, it is current understanding
1010 * what it _should_ do. If it doesn't, it's a bug.
1011 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1013 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1014 * is finished or backgrounded. It is the same in interactive and
1015 * non-interactive shells, and is the same regardless of whether
1016 * a user trap handler is installed or a shell special one is in effect.
1017 * ^C or ^Z from keyboard seem to execute "at once" because it usually
1018 * backgrounds (i.e. stops) or kills all members of currently running
1021 * Wait builtin in interruptible by signals for which user trap is set
1022 * or by SIGINT in interactive shell.
1024 * Trap handlers will execute even within trap handlers. (right?)
1026 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1028 * If job control is off, backgrounded commands ("cmd &")
1029 * have SIGINT, SIGQUIT set to SIG_IGN.
1031 * Commands which are run in command substitution ("`cmd`")
1032 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1034 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1035 * by the shell from its parent.
1037 * Signals which differ from SIG_DFL action
1038 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1041 * SIGTERM (interactive): ignore
1042 * SIGHUP (interactive):
1043 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1044 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1045 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1046 * that all pipe members are stopped. Try this in bash:
1047 * while :; do :; done - ^Z does not background it
1048 * (while :; do :; done) - ^Z backgrounds it
1049 * SIGINT (interactive): wait for last pipe, ignore the rest
1050 * of the command line, show prompt. NB: ^C does not send SIGINT
1051 * to interactive shell while shell is waiting for a pipe,
1052 * since shell is bg'ed (is not in foreground process group).
1053 * Example 1: this waits 5 sec, but does not execute ls:
1054 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1055 * Example 2: this does not wait and does not execute ls:
1056 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1057 * Example 3: this does not wait 5 sec, but executes ls:
1058 * "sleep 5; ls -l" + press ^C
1060 * (What happens to signals which are IGN on shell start?)
1061 * (What happens with signal mask on shell start?)
1063 * Implementation in hush
1064 * ======================
1065 * We use in-kernel pending signal mask to determine which signals were sent.
1066 * We block all signals which we don't want to take action immediately,
1067 * i.e. we block all signals which need to have special handling as described
1068 * above, and all signals which have traps set.
1069 * After each pipe execution, we extract any pending signals via sigtimedwait()
1072 * unsigned non_DFL_mask: a mask of such "special" signals
1073 * sigset_t blocked_set: current blocked signal set
1076 * clear bit in blocked_set unless it is also in non_DFL_mask
1077 * "trap 'cmd' SIGxxx":
1078 * set bit in blocked_set (even if 'cmd' is '')
1079 * after [v]fork, if we plan to be a shell:
1080 * unblock signals with special interactive handling
1081 * (child shell is not interactive),
1082 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1083 * after [v]fork, if we plan to exec:
1084 * POSIX says pending signal mask is cleared in child - no need to clear it.
1085 * Restore blocked signal set to one inherited by shell just prior to exec.
1087 * Note: as a result, we do not use signal handlers much. The only uses
1088 * are to count SIGCHLDs
1089 * and to restore tty pgrp on signal-induced exit.
1092 SPECIAL_INTERACTIVE_SIGS = 0
1097 SPECIAL_JOB_SIGS = 0
1105 #if ENABLE_HUSH_FAST
1106 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1109 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1115 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1116 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1117 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1118 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1120 /* Restores tty foreground process group, and exits.
1121 * May be called as signal handler for fatal signal
1122 * (will resend signal to itself, producing correct exit state)
1123 * or called directly with -EXITCODE.
1124 * We also call it if xfunc is exiting. */
1125 static void sigexit(int sig) NORETURN;
1126 static void sigexit(int sig)
1128 /* Disable all signals: job control, SIGPIPE, etc. */
1129 sigprocmask_allsigs(SIG_BLOCK);
1131 /* Careful: we can end up here after [v]fork. Do not restore
1132 * tty pgrp then, only top-level shell process does that */
1133 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1134 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1136 /* Not a signal, just exit */
1140 kill_myself_with_sig(sig); /* does not return */
1144 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1145 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1149 /* Restores tty foreground process group, and exits. */
1150 static void hush_exit(int exitcode) NORETURN;
1151 static void hush_exit(int exitcode)
1153 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1154 /* Prevent recursion:
1155 * trap "echo Hi; exit" EXIT; exit
1157 char *argv[] = { NULL, G.traps[0], NULL };
1165 fflush(NULL); /* flush all streams */
1166 sigexit(- (exitcode & 0xff));
1172 static int check_and_run_traps(int sig)
1174 static const struct timespec zero_timespec = { 0, 0 };
1175 smalluint save_rcode;
1181 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1186 if (G.traps && G.traps[sig]) {
1187 if (G.traps[sig][0]) {
1188 /* We have user-defined handler */
1189 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1190 save_rcode = G.last_exitcode;
1193 G.last_exitcode = save_rcode;
1194 } /* else: "" trap, ignoring signal */
1197 /* not a trap: special action */
1199 #if ENABLE_HUSH_FAST
1202 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1206 /* Builtin was ^C'ed, make it look prettier: */
1213 /* bash is observed to signal whole process groups,
1214 * not individual processes */
1215 for (job = G.job_list; job; job = job->next) {
1218 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1219 if (kill(- job->pgrp, SIGHUP) == 0)
1220 kill(- job->pgrp, SIGCONT);
1225 default: /* ignored: */
1226 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1234 static const char *set_cwd(void)
1236 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1237 * we must not try to free(bb_msg_unknown) */
1238 if (G.cwd == bb_msg_unknown)
1240 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1242 G.cwd = bb_msg_unknown;
1248 * Shell and environment variable support
1250 static struct variable **get_ptr_to_local_var(const char *name)
1252 struct variable **pp;
1253 struct variable *cur;
1258 while ((cur = *pp) != NULL) {
1259 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1266 static struct variable *get_local_var(const char *name)
1268 struct variable **pp = get_ptr_to_local_var(name);
1274 static const char *get_local_var_value(const char *name)
1276 struct variable **pp = get_ptr_to_local_var(name);
1278 return strchr((*pp)->varstr, '=') + 1;
1282 /* str holds "NAME=VAL" and is expected to be malloced.
1283 * We take ownership of it.
1285 * 0: do not change export flag
1286 * (if creating new variable, flag will be 0)
1287 * 1: set export flag and putenv the variable
1288 * -1: clear export flag and unsetenv the variable
1289 * flg_read_only is set only when we handle -R var=val
1291 #if !BB_MMU && ENABLE_HUSH_LOCAL
1292 /* all params are used */
1293 #elif BB_MMU && ENABLE_HUSH_LOCAL
1294 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1295 set_local_var(str, flg_export, local_lvl)
1296 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1297 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1298 set_local_var(str, flg_export)
1299 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1300 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1301 set_local_var(str, flg_export, flg_read_only)
1303 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1305 struct variable **var_pp;
1306 struct variable *cur;
1310 eq_sign = strchr(str, '=');
1311 if (!eq_sign) { /* not expected to ever happen? */
1316 name_len = eq_sign - str + 1; /* including '=' */
1317 var_pp = &G.top_var;
1318 while ((cur = *var_pp) != NULL) {
1319 if (strncmp(cur->varstr, str, name_len) != 0) {
1320 var_pp = &cur->next;
1323 /* We found an existing var with this name */
1324 if (cur->flg_read_only) {
1328 bb_error_msg("%s: readonly variable", str);
1332 if (flg_export == -1) { // "&& cur->flg_export" ?
1333 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1338 #if ENABLE_HUSH_LOCAL
1339 if (cur->func_nest_level < local_lvl) {
1340 /* New variable is declared as local,
1341 * and existing one is global, or local
1342 * from enclosing function.
1343 * Remove and save old one: */
1344 *var_pp = cur->next;
1345 cur->next = *G.shadowed_vars_pp;
1346 *G.shadowed_vars_pp = cur;
1347 /* bash 3.2.33(1) and exported vars:
1349 * # f() { local z=a; env | grep ^z; }
1355 if (cur->flg_export)
1360 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1365 if (cur->max_len != 0) {
1366 if (cur->max_len >= strlen(str)) {
1367 /* This one is from startup env, reuse space */
1368 strcpy(cur->varstr, str);
1372 /* max_len == 0 signifies "malloced" var, which we can
1373 * (and has to) free */
1377 goto set_str_and_exp;
1380 /* Not found - create new variable struct */
1381 cur = xzalloc(sizeof(*cur));
1382 #if ENABLE_HUSH_LOCAL
1383 cur->func_nest_level = local_lvl;
1385 cur->next = *var_pp;
1391 cur->flg_read_only = flg_read_only;
1394 if (flg_export == 1)
1395 cur->flg_export = 1;
1396 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1397 cmdedit_update_prompt();
1398 if (cur->flg_export) {
1399 if (flg_export == -1) {
1400 cur->flg_export = 0;
1401 /* unsetenv was already done */
1403 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1404 return putenv(cur->varstr);
1410 static int unset_local_var_len(const char *name, int name_len)
1412 struct variable *cur;
1413 struct variable **var_pp;
1416 return EXIT_SUCCESS;
1417 var_pp = &G.top_var;
1418 while ((cur = *var_pp) != NULL) {
1419 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1420 if (cur->flg_read_only) {
1421 bb_error_msg("%s: readonly variable", name);
1422 return EXIT_FAILURE;
1424 *var_pp = cur->next;
1425 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1426 bb_unsetenv(cur->varstr);
1427 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1428 cmdedit_update_prompt();
1432 return EXIT_SUCCESS;
1434 var_pp = &cur->next;
1436 return EXIT_SUCCESS;
1439 static int unset_local_var(const char *name)
1441 return unset_local_var_len(name, strlen(name));
1444 static void unset_vars(char **strings)
1452 const char *eq = strchrnul(*v, '=');
1453 unset_local_var_len(*v, (int)(eq - *v));
1459 #if ENABLE_SH_MATH_SUPPORT
1460 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1461 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1462 static char *endofname(const char *name)
1470 if (!is_in_name(*p))
1476 static void arith_set_local_var(const char *name, const char *val, int flags)
1478 /* arith code doesnt malloc space, so do it for it */
1479 char *var = xasprintf("%s=%s", name, val);
1480 set_local_var(var, flags, /*lvl:*/ 0, /*ro:*/ 0);
1486 * Helpers for "var1=val1 var2=val2 cmd" feature
1488 static void add_vars(struct variable *var)
1490 struct variable *next;
1494 var->next = G.top_var;
1496 if (var->flg_export) {
1497 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1498 putenv(var->varstr);
1500 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1506 static struct variable *set_vars_and_save_old(char **strings)
1509 struct variable *old = NULL;
1515 struct variable *var_p;
1516 struct variable **var_pp;
1519 eq = strchr(*s, '=');
1522 var_pp = get_ptr_to_local_var(*s);
1525 /* Remove variable from global linked list */
1527 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1528 *var_pp = var_p->next;
1529 /* Add it to returned list */
1533 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1544 static int FAST_FUNC static_get(struct in_str *i)
1553 static int FAST_FUNC static_peek(struct in_str *i)
1558 #if ENABLE_HUSH_INTERACTIVE
1560 static void cmdedit_update_prompt(void)
1562 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1563 G.PS1 = get_local_var_value("PS1");
1566 G.PS2 = get_local_var_value("PS2");
1574 static const char* setup_prompt_string(int promptmode)
1576 const char *prompt_str;
1577 debug_printf("setup_prompt_string %d ", promptmode);
1578 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1579 /* Set up the prompt */
1580 if (promptmode == 0) { /* PS1 */
1582 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1587 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1588 debug_printf("result '%s'\n", prompt_str);
1592 static void get_user_input(struct in_str *i)
1595 const char *prompt_str;
1597 prompt_str = setup_prompt_string(i->promptmode);
1598 #if ENABLE_FEATURE_EDITING
1599 /* Enable command line editing only while a command line
1600 * is actually being read */
1603 /* buglet: SIGINT will not make new prompt to appear _at once_,
1604 * only after <Enter>. (^C will work) */
1605 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1606 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1607 check_and_run_traps(0);
1608 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1609 i->eof_flag = (r < 0);
1610 if (i->eof_flag) { /* EOF/error detected */
1611 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1612 G.user_input_buf[1] = '\0';
1617 fputs(prompt_str, stdout);
1619 G.user_input_buf[0] = r = fgetc(i->file);
1620 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1621 //do we need check_and_run_traps(0)? (maybe only if stdin)
1622 } while (G.flag_SIGINT);
1623 i->eof_flag = (r == EOF);
1625 i->p = G.user_input_buf;
1628 #endif /* INTERACTIVE */
1630 /* This is the magic location that prints prompts
1631 * and gets data back from the user */
1632 static int FAST_FUNC file_get(struct in_str *i)
1636 /* If there is data waiting, eat it up */
1637 if (i->p && *i->p) {
1638 #if ENABLE_HUSH_INTERACTIVE
1642 if (i->eof_flag && !*i->p)
1644 /* note: ch is never NUL */
1646 /* need to double check i->file because we might be doing something
1647 * more complicated by now, like sourcing or substituting. */
1648 #if ENABLE_HUSH_INTERACTIVE
1649 if (G_interactive_fd && i->promptme && i->file == stdin) {
1652 } while (!*i->p); /* need non-empty line */
1653 i->promptmode = 1; /* PS2 */
1658 do ch = fgetc(i->file); while (ch == '\0');
1660 debug_printf("file_get: got '%c' %d\n", ch, ch);
1661 #if ENABLE_HUSH_INTERACTIVE
1668 /* All callers guarantee this routine will never
1669 * be used right after a newline, so prompting is not needed.
1671 static int FAST_FUNC file_peek(struct in_str *i)
1674 if (i->p && *i->p) {
1675 if (i->eof_flag && !i->p[1])
1678 /* note: ch is never NUL */
1680 do ch = fgetc(i->file); while (ch == '\0');
1681 i->eof_flag = (ch == EOF);
1682 i->peek_buf[0] = ch;
1683 i->peek_buf[1] = '\0';
1685 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1689 static void setup_file_in_str(struct in_str *i, FILE *f)
1691 i->peek = file_peek;
1693 #if ENABLE_HUSH_INTERACTIVE
1695 i->promptmode = 0; /* PS1 */
1701 static void setup_string_in_str(struct in_str *i, const char *s)
1703 i->peek = static_peek;
1704 i->get = static_get;
1705 #if ENABLE_HUSH_INTERACTIVE
1707 i->promptmode = 0; /* PS1 */
1717 #define B_CHUNK (32 * sizeof(char*))
1719 static void o_reset_to_empty_unquoted(o_string *o)
1727 static void o_free(o_string *o)
1730 memset(o, 0, sizeof(*o));
1733 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1738 static void o_grow_by(o_string *o, int len)
1740 if (o->length + len > o->maxlen) {
1741 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1742 o->data = xrealloc(o->data, 1 + o->maxlen);
1746 static void o_addchr(o_string *o, int ch)
1748 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1750 o->data[o->length] = ch;
1752 o->data[o->length] = '\0';
1755 static void o_addblock(o_string *o, const char *str, int len)
1758 memcpy(&o->data[o->length], str, len);
1760 o->data[o->length] = '\0';
1764 static void o_addstr(o_string *o, const char *str)
1766 o_addblock(o, str, strlen(str));
1768 static void nommu_addchr(o_string *o, int ch)
1774 # define nommu_addchr(o, str) ((void)0)
1777 static void o_addstr_with_NUL(o_string *o, const char *str)
1779 o_addblock(o, str, strlen(str) + 1);
1782 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1787 && (*str != '*' && *str != '?' && *str != '[')
1795 /* My analysis of quoting semantics tells me that state information
1796 * is associated with a destination, not a source.
1798 static void o_addqchr(o_string *o, int ch)
1801 char *found = strchr("*?[\\", ch);
1806 o->data[o->length] = '\\';
1809 o->data[o->length] = ch;
1811 o->data[o->length] = '\0';
1814 static void o_addQchr(o_string *o, int ch)
1817 if (o->o_escape && strchr("*?[\\", ch)) {
1819 o->data[o->length] = '\\';
1823 o->data[o->length] = ch;
1825 o->data[o->length] = '\0';
1828 static void o_addQstr(o_string *o, const char *str, int len)
1831 o_addblock(o, str, len);
1837 int ordinary_cnt = strcspn(str, "*?[\\");
1838 if (ordinary_cnt > len) /* paranoia */
1840 o_addblock(o, str, ordinary_cnt);
1841 if (ordinary_cnt == len)
1843 str += ordinary_cnt;
1844 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1848 if (ch) { /* it is necessarily one of "*?[\\" */
1850 o->data[o->length] = '\\';
1854 o->data[o->length] = ch;
1856 o->data[o->length] = '\0';
1860 /* A special kind of o_string for $VAR and `cmd` expansion.
1861 * It contains char* list[] at the beginning, which is grown in 16 element
1862 * increments. Actual string data starts at the next multiple of 16 * (char*).
1863 * list[i] contains an INDEX (int!) into this string data.
1864 * It means that if list[] needs to grow, data needs to be moved higher up
1865 * but list[i]'s need not be modified.
1866 * NB: remembering how many list[i]'s you have there is crucial.
1867 * o_finalize_list() operation post-processes this structure - calculates
1868 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1870 #if DEBUG_EXPAND || DEBUG_GLOB
1871 static void debug_print_list(const char *prefix, o_string *o, int n)
1873 char **list = (char**)o->data;
1874 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1878 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1879 prefix, list, n, string_start, o->length, o->maxlen);
1882 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1883 o->data + (int)list[i] + string_start,
1884 o->data + (int)list[i] + string_start);
1888 const char *p = o->data + (int)list[n - 1] + string_start;
1890 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1894 # define debug_print_list(prefix, o, n) ((void)0)
1897 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1898 * in list[n] so that it points past last stored byte so far.
1899 * It returns n+1. */
1900 static int o_save_ptr_helper(o_string *o, int n)
1902 char **list = (char**)o->data;
1906 if (!o->has_empty_slot) {
1907 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1908 string_len = o->length - string_start;
1909 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1910 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1911 /* list[n] points to string_start, make space for 16 more pointers */
1912 o->maxlen += 0x10 * sizeof(list[0]);
1913 o->data = xrealloc(o->data, o->maxlen + 1);
1914 list = (char**)o->data;
1915 memmove(list + n + 0x10, list + n, string_len);
1916 o->length += 0x10 * sizeof(list[0]);
1918 debug_printf_list("list[%d]=%d string_start=%d\n",
1919 n, string_len, string_start);
1922 /* We have empty slot at list[n], reuse without growth */
1923 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1924 string_len = o->length - string_start;
1925 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1926 n, string_len, string_start);
1927 o->has_empty_slot = 0;
1929 list[n] = (char*)(ptrdiff_t)string_len;
1933 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1934 static int o_get_last_ptr(o_string *o, int n)
1936 char **list = (char**)o->data;
1937 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1939 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1942 /* o_glob performs globbing on last list[], saving each result
1943 * as a new list[]. */
1944 static int o_glob(o_string *o, int n)
1950 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1952 return o_save_ptr_helper(o, n);
1953 pattern = o->data + o_get_last_ptr(o, n);
1954 debug_printf_glob("glob pattern '%s'\n", pattern);
1955 if (!glob_needed(pattern)) {
1957 o->length = unbackslash(pattern) - o->data;
1958 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1959 return o_save_ptr_helper(o, n);
1962 memset(&globdata, 0, sizeof(globdata));
1963 gr = glob(pattern, 0, NULL, &globdata);
1964 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1965 if (gr == GLOB_NOSPACE)
1966 bb_error_msg_and_die("out of memory during glob");
1967 if (gr == GLOB_NOMATCH) {
1968 globfree(&globdata);
1971 if (gr != 0) { /* GLOB_ABORTED ? */
1972 /* TODO: testcase for bad glob pattern behavior */
1973 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1975 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1976 char **argv = globdata.gl_pathv;
1977 o->length = pattern - o->data; /* "forget" pattern */
1979 o_addstr_with_NUL(o, *argv);
1980 n = o_save_ptr_helper(o, n);
1986 globfree(&globdata);
1988 debug_print_list("o_glob returning", o, n);
1992 /* If o->o_glob == 1, glob the string so far remembered.
1993 * Otherwise, just finish current list[] and start new */
1994 static int o_save_ptr(o_string *o, int n)
1996 if (o->o_glob) { /* if globbing is requested */
1997 /* If o->has_empty_slot, list[n] was already globbed
1998 * (if it was requested back then when it was filled)
1999 * so don't do that again! */
2000 if (!o->has_empty_slot)
2001 return o_glob(o, n); /* o_save_ptr_helper is inside */
2003 return o_save_ptr_helper(o, n);
2006 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2007 static char **o_finalize_list(o_string *o, int n)
2012 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2014 debug_print_list("finalized", o, n);
2015 debug_printf_expand("finalized n:%d\n", n);
2016 list = (char**)o->data;
2017 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2021 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2027 /* Expansion can recurse */
2028 #if ENABLE_HUSH_TICK
2029 static int process_command_subs(o_string *dest, const char *s);
2031 static char *expand_string_to_string(const char *str);
2033 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2034 parse_stream_dquoted(dest, input, dquote_end)
2036 static int parse_stream_dquoted(o_string *as_string,
2038 struct in_str *input,
2041 /* expand_strvec_to_strvec() takes a list of strings, expands
2042 * all variable references within and returns a pointer to
2043 * a list of expanded strings, possibly with larger number
2044 * of strings. (Think VAR="a b"; echo $VAR).
2045 * This new list is allocated as a single malloc block.
2046 * NULL-terminated list of char* pointers is at the beginning of it,
2047 * followed by strings themself.
2048 * Caller can deallocate entire list by single free(list). */
2050 /* Store given string, finalizing the word and starting new one whenever
2051 * we encounter IFS char(s). This is used for expanding variable values.
2052 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2053 static int expand_on_ifs(o_string *output, int n, const char *str)
2056 int word_len = strcspn(str, G.ifs);
2058 if (output->o_escape || !output->o_glob)
2059 o_addQstr(output, str, word_len);
2060 else /* protect backslashes against globbing up :) */
2061 o_addblock_duplicate_backslash(output, str, word_len);
2064 if (!*str) /* EOL - do not finalize word */
2066 o_addchr(output, '\0');
2067 debug_print_list("expand_on_ifs", output, n);
2068 n = o_save_ptr(output, n);
2069 str += strspn(str, G.ifs); /* skip ifs chars */
2071 debug_print_list("expand_on_ifs[1]", output, n);
2075 /* Helper to expand $((...)) and heredoc body. These act as if
2076 * they are in double quotes, with the exception that they are not :).
2077 * Just the rules are similar: "expand only $var and `cmd`"
2079 * Returns malloced string.
2080 * As an optimization, we return NULL if expansion is not needed.
2082 static char *expand_pseudo_dquoted(const char *str)
2085 struct in_str input;
2086 o_string dest = NULL_O_STRING;
2088 if (strchr(str, '$') == NULL
2089 #if ENABLE_HUSH_TICK
2090 && strchr(str, '`') == NULL
2096 /* We need to expand. Example:
2097 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2099 setup_string_in_str(&input, str);
2100 parse_stream_dquoted(NULL, &dest, &input, EOF);
2101 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2102 exp_str = expand_string_to_string(dest.data);
2103 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2104 o_free_unsafe(&dest);
2108 /* Expand all variable references in given string, adding words to list[]
2109 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2110 * to be filled). This routine is extremely tricky: has to deal with
2111 * variables/parameters with whitespace, $* and $@, and constructs like
2112 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2113 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2115 /* or_mask is either 0 (normal case) or 0x80 -
2116 * expansion of right-hand side of assignment == 1-element expand.
2117 * It will also do no globbing, and thus we must not backslash-quote!
2124 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2125 debug_print_list("expand_vars_to_list", output, n);
2126 n = o_save_ptr(output, n);
2127 debug_print_list("expand_vars_to_list[0]", output, n);
2129 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2132 char *dyn_val = NULL;
2133 const char *val = NULL;
2134 #if ENABLE_HUSH_TICK
2135 o_string subst_result = NULL_O_STRING;
2137 #if ENABLE_SH_MATH_SUPPORT
2138 char arith_buf[sizeof(arith_t)*3 + 2];
2140 o_addblock(output, arg, p - arg);
2141 debug_print_list("expand_vars_to_list[1]", output, n);
2143 p = strchr(p, SPECIAL_VAR_SYMBOL);
2145 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2146 /* "$@" is special. Even if quoted, it can still
2147 * expand to nothing (not even an empty string) */
2148 if ((first_ch & 0x7f) != '@')
2149 ored_ch |= first_ch;
2151 switch (first_ch & 0x7f) {
2152 /* Highest bit in first_ch indicates that var is double-quoted */
2154 val = utoa(G.root_pid);
2156 case '!': /* bg pid */
2157 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2159 case '?': /* exitcode */
2160 val = utoa(G.last_exitcode);
2162 case '#': /* argc */
2163 if (arg[1] != SPECIAL_VAR_SYMBOL)
2164 /* actually, it's a ${#var} */
2166 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2171 if (!G.global_argv[i])
2173 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2174 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2175 smallint sv = output->o_escape;
2176 /* unquoted var's contents should be globbed, so don't escape */
2177 output->o_escape = 0;
2178 while (G.global_argv[i]) {
2179 n = expand_on_ifs(output, n, G.global_argv[i]);
2180 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2181 if (G.global_argv[i++][0] && G.global_argv[i]) {
2182 /* this argv[] is not empty and not last:
2183 * put terminating NUL, start new word */
2184 o_addchr(output, '\0');
2185 debug_print_list("expand_vars_to_list[2]", output, n);
2186 n = o_save_ptr(output, n);
2187 debug_print_list("expand_vars_to_list[3]", output, n);
2190 output->o_escape = sv;
2192 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2193 * and in this case should treat it like '$*' - see 'else...' below */
2194 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2196 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2197 if (++i >= G.global_argc)
2199 o_addchr(output, '\0');
2200 debug_print_list("expand_vars_to_list[4]", output, n);
2201 n = o_save_ptr(output, n);
2203 } else { /* quoted $*: add as one word */
2205 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2206 if (!G.global_argv[++i])
2209 o_addchr(output, G.ifs[0]);
2213 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2214 /* "Empty variable", used to make "" etc to not disappear */
2218 #if ENABLE_HUSH_TICK
2219 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2222 /* Can't just stuff it into output o_string,
2223 * expanded result may need to be globbed
2224 * and $IFS-splitted */
2225 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2226 process_command_subs(&subst_result, arg);
2227 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2228 val = subst_result.data;
2231 #if ENABLE_SH_MATH_SUPPORT
2232 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2233 arith_eval_hooks_t hooks;
2238 arg++; /* skip '+' */
2239 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2240 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2242 exp_str = expand_pseudo_dquoted(arg);
2243 hooks.lookupvar = get_local_var_value;
2244 hooks.setvar = arith_set_local_var;
2245 hooks.endofname = endofname;
2246 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2250 const char *msg = "error in arithmetic";
2253 msg = "exponent less than 0";
2256 msg = "divide by 0";
2259 msg = "expression recursion loop detected";
2264 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2265 sprintf(arith_buf, arith_t_fmt, res);
2270 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2272 bool exp_len = false;
2273 bool exp_null = false;
2275 char exp_save = exp_save; /* for compiler */
2276 char exp_op = exp_op; /* for compiler */
2277 char *exp_word = exp_word; /* for compiler */
2281 arg[0] = first_ch & 0x7f;
2283 /* prepare for expansions */
2284 if (var[0] == '#') {
2285 /* handle length expansion ${#var} */
2289 /* maybe handle parameter expansion */
2290 exp_off = strcspn(var, ":-=+?%#");
2294 exp_save = var[exp_off];
2295 exp_null = exp_save == ':';
2296 exp_word = var + exp_off;
2299 exp_op = *exp_word++;
2300 var[exp_off] = '\0';
2304 /* lookup the variable in question */
2305 if (isdigit(var[0])) {
2306 /* handle_dollar() should have vetted var for us */
2308 if (i < G.global_argc)
2309 val = G.global_argv[i];
2310 /* else val remains NULL: $N with too big N */
2312 val = get_local_var_value(var);
2314 /* handle any expansions */
2316 debug_printf_expand("expand: length of '%s' = ", val);
2317 val = utoa(val ? strlen(val) : 0);
2318 debug_printf_expand("%s\n", val);
2319 } else if (exp_off) {
2320 if (exp_op == '%' || exp_op == '#') {
2322 /* we need to do a pattern match */
2325 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2326 if (exp_op == *exp_word) /* ## or %% */
2328 val = dyn_val = xstrdup(val);
2329 loc = scan(dyn_val, exp_word, match_at_left);
2330 if (match_at_left) /* # or ## */
2332 else if (loc) /* % or %% and match was found */
2336 /* we need to do an expansion */
2337 int exp_test = (!val || (exp_null && !val[0]));
2339 exp_test = !exp_test;
2340 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2341 exp_null ? "true" : "false", exp_test);
2343 if (exp_op == '?') {
2344 //TODO: how interactive bash aborts expansion mid-command?
2345 /* ${var?[error_msg_if_unset]} */
2346 /* ${var:?[error_msg_if_unset_or_null]} */
2347 /* mimic bash message */
2348 die_if_script("%s: %s",
2350 exp_word[0] ? exp_word : "parameter null or not set"
2356 if (exp_op == '=') {
2357 /* ${var=[word]} or ${var:=[word]} */
2358 if (isdigit(var[0]) || var[0] == '#') {
2359 /* mimic bash message */
2360 die_if_script("$%s: cannot assign in this way", var);
2363 char *new_var = xasprintf("%s=%s", var, val);
2364 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2370 var[exp_off] = exp_save;
2374 #if ENABLE_HUSH_TICK
2377 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2378 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2380 /* unquoted var's contents should be globbed, so don't escape */
2381 smallint sv = output->o_escape;
2382 output->o_escape = 0;
2383 n = expand_on_ifs(output, n, val);
2385 output->o_escape = sv;
2387 } else { /* quoted $VAR, val will be appended below */
2388 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2391 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2394 o_addQstr(output, val, strlen(val));
2397 /* Do the check to avoid writing to a const string */
2398 if (*p != SPECIAL_VAR_SYMBOL)
2399 *p = SPECIAL_VAR_SYMBOL;
2401 #if ENABLE_HUSH_TICK
2402 o_free(&subst_result);
2405 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2408 debug_print_list("expand_vars_to_list[a]", output, n);
2409 /* this part is literal, and it was already pre-quoted
2410 * if needed (much earlier), do not use o_addQstr here! */
2411 o_addstr_with_NUL(output, arg);
2412 debug_print_list("expand_vars_to_list[b]", output, n);
2413 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2414 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2417 /* allow to reuse list[n] later without re-growth */
2418 output->has_empty_slot = 1;
2420 o_addchr(output, '\0');
2425 static char **expand_variables(char **argv, int or_mask)
2430 o_string output = NULL_O_STRING;
2432 if (or_mask & 0x100) {
2433 output.o_escape = 1; /* protect against globbing for "$var" */
2434 /* (unquoted $var will temporarily switch it off) */
2441 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2444 debug_print_list("expand_variables", &output, n);
2446 /* output.data (malloced in one block) gets returned in "list" */
2447 list = o_finalize_list(&output, n);
2448 debug_print_strings("expand_variables[1]", list);
2452 static char **expand_strvec_to_strvec(char **argv)
2454 return expand_variables(argv, 0x100);
2457 /* Used for expansion of right hand of assignments */
2458 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2460 static char *expand_string_to_string(const char *str)
2462 char *argv[2], **list;
2464 argv[0] = (char*)str;
2466 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2468 if (!list[0] || list[1])
2469 bb_error_msg_and_die("BUG in varexp2");
2470 /* actually, just move string 2*sizeof(char*) bytes back */
2471 overlapping_strcpy((char*)list, list[0]);
2472 unbackslash((char*)list);
2473 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2477 /* Used for "eval" builtin */
2478 static char* expand_strvec_to_string(char **argv)
2482 list = expand_variables(argv, 0x80);
2483 /* Convert all NULs to spaces */
2488 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2489 bb_error_msg_and_die("BUG in varexp3");
2490 /* bash uses ' ' regardless of $IFS contents */
2495 overlapping_strcpy((char*)list, list[0]);
2496 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2500 static char **expand_assignments(char **argv, int count)
2504 /* Expand assignments into one string each */
2505 for (i = 0; i < count; i++) {
2506 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2514 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2516 static void reset_traps_to_defaults(void)
2518 /* This function is always called in a child shell
2519 * after fork (not vfork, NOMMU doesn't use this function).
2520 * Child shells are not interactive.
2521 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2522 * Testcase: (while :; do :; done) + ^Z should background.
2523 * Same goes for SIGTERM, SIGHUP, SIGINT.
2528 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2531 /* Stupid. It can be done with *single* &= op, but we can't use
2532 * the fact that G.blocked_set is implemented as a bitmask... */
2533 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2537 sigdelset(&G.blocked_set, sig);
2544 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2545 mask = G.non_DFL_mask;
2546 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2550 G.traps[sig] = NULL;
2551 /* There is no signal for 0 (EXIT) */
2554 /* There was a trap handler, we are removing it.
2555 * But if sig still has non-DFL handling,
2556 * we should not unblock it. */
2559 sigdelset(&G.blocked_set, sig);
2561 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2566 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2567 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2569 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2570 char *heredoc_argv[4];
2571 struct variable *cur;
2572 #if ENABLE_HUSH_FUNCTIONS
2573 struct function *funcp;
2578 if (!g_argv0) { /* heredoc */
2579 argv = heredoc_argv;
2580 argv[0] = (char *) G.argv0_for_re_execing;
2581 argv[1] = (char *) "-<";
2582 argv[2] = (char *) s;
2584 pp = &argv[3]; /* used as pointer to empty environment */
2588 sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
2589 , (unsigned) G.root_pid
2590 , (unsigned) G.last_bg_pid
2591 , (unsigned) G.last_exitcode
2592 IF_HUSH_LOOPS(, G.depth_of_loop)
2594 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2595 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2598 for (cur = G.top_var; cur; cur = cur->next) {
2599 if (!cur->flg_export || cur->flg_read_only)
2602 #if ENABLE_HUSH_FUNCTIONS
2603 for (funcp = G.top_func; funcp; funcp = funcp->next)
2609 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2610 *pp++ = (char *) G.argv0_for_re_execing;
2612 for (cur = G.top_var; cur; cur = cur->next) {
2613 if (cur->varstr == hush_version_str)
2615 if (cur->flg_read_only) {
2616 *pp++ = (char *) "-R";
2617 *pp++ = cur->varstr;
2618 } else if (!cur->flg_export) {
2619 *pp++ = (char *) "-V";
2620 *pp++ = cur->varstr;
2623 #if ENABLE_HUSH_FUNCTIONS
2624 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2625 *pp++ = (char *) "-F";
2626 *pp++ = funcp->name;
2627 *pp++ = funcp->body_as_string;
2630 /* We can pass activated traps here. Say, -Tnn:trap_string
2632 * However, POSIX says that subshells reset signals with traps
2634 * I tested bash-3.2 and it not only does that with true subshells
2635 * of the form ( list ), but with any forked children shells.
2636 * I set trap "echo W" WINCH; and then tried:
2638 * { echo 1; sleep 20; echo 2; } &
2639 * while true; do echo 1; sleep 20; echo 2; break; done &
2640 * true | { echo 1; sleep 20; echo 2; } | cat
2642 * In all these cases sending SIGWINCH to the child shell
2643 * did not run the trap. If I add trap "echo V" WINCH;
2644 * _inside_ group (just before echo 1), it works.
2646 * I conclude it means we don't need to pass active traps here.
2647 * exec syscall below resets them to SIG_DFL for us.
2649 *pp++ = (char *) "-c";
2654 /* *pp = NULL; - is already there */
2658 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2659 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2660 execve(bb_busybox_exec_path, argv, pp);
2661 /* Fallback. Useful for init=/bin/hush usage etc */
2662 if (argv[0][0] == '/')
2663 execve(argv[0], argv, pp);
2664 xfunc_error_retval = 127;
2665 bb_error_msg_and_die("can't re-execute the shell");
2667 #endif /* !BB_MMU */
2670 static void setup_heredoc(struct redir_struct *redir)
2672 struct fd_pair pair;
2675 /* the _body_ of heredoc (misleading field name) */
2676 const char *heredoc = redir->rd_filename;
2683 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2684 expanded = expand_pseudo_dquoted(heredoc);
2688 len = strlen(heredoc);
2690 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2692 xmove_fd(pair.rd, redir->rd_fd);
2694 /* Try writing without forking. Newer kernels have
2695 * dynamically growing pipes. Must use non-blocking write! */
2698 written = write(pair.wr, heredoc, len);
2709 ndelay_off(pair.wr);
2711 /* Okay, pipe buffer was not big enough */
2712 /* Note: we must not create a stray child (bastard? :)
2713 * for the unsuspecting parent process. Child creates a grandchild
2714 * and exits before parent execs the process which consumes heredoc
2715 * (that exec happens after we return from this function) */
2721 bb_perror_msg_and_die("vfork");
2724 disable_restore_tty_pgrp_on_exit();
2725 pid = BB_MMU ? fork() : vfork();
2727 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2731 close(redir->rd_fd); /* read side of the pipe */
2733 full_write(pair.wr, heredoc, len); /* may loop or block */
2736 /* Delegate blocking writes to another process */
2737 xmove_fd(pair.wr, STDOUT_FILENO);
2738 re_execute_shell(&to_free, heredoc, NULL, NULL);
2742 #if ENABLE_HUSH_FAST
2744 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2746 enable_restore_tty_pgrp_on_exit();
2752 wait(NULL); /* wait till child has died */
2755 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2756 * and stderr if they are redirected. */
2757 static int setup_redirects(struct command *prog, int squirrel[])
2760 struct redir_struct *redir;
2762 for (redir = prog->redirects; redir; redir = redir->next) {
2763 if (redir->rd_type == REDIRECT_HEREDOC2) {
2764 /* rd_fd<<HERE case */
2765 if (squirrel && redir->rd_fd < 3
2766 && squirrel[redir->rd_fd] < 0
2768 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2770 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2772 debug_printf_parse("set heredoc '%s'\n",
2773 redir->rd_filename);
2774 setup_heredoc(redir);
2778 if (redir->rd_dup == REDIRFD_TO_FILE) {
2779 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2781 if (redir->rd_filename == NULL) {
2782 /* Something went wrong in the parse.
2783 * Pretend it didn't happen */
2784 bb_error_msg("bug in redirect parse");
2787 mode = redir_table[redir->rd_type].mode;
2788 p = expand_string_to_string(redir->rd_filename);
2789 openfd = open_or_warn(p, mode);
2792 /* this could get lost if stderr has been redirected, but
2793 * bash and ash both lose it as well (though zsh doesn't!) */
2794 //what the above comment tries to say?
2798 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2799 openfd = redir->rd_dup;
2802 if (openfd != redir->rd_fd) {
2803 if (squirrel && redir->rd_fd < 3
2804 && squirrel[redir->rd_fd] < 0
2806 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2808 if (openfd == REDIRFD_CLOSE) {
2809 /* "n>-" means "close me" */
2810 close(redir->rd_fd);
2812 xdup2(openfd, redir->rd_fd);
2813 if (redir->rd_dup == REDIRFD_TO_FILE)
2821 static void restore_redirects(int squirrel[])
2824 for (i = 0; i < 3; i++) {
2827 /* We simply die on error */
2834 static void free_pipe_list(struct pipe *head);
2836 /* Return code is the exit status of the pipe */
2837 static void free_pipe(struct pipe *pi)
2840 struct command *command;
2841 struct redir_struct *r, *rnext;
2844 if (pi->stopped_cmds > 0) /* why? */
2846 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2847 for (i = 0; i < pi->num_cmds; i++) {
2848 command = &pi->cmds[i];
2849 debug_printf_clean(" command %d:\n", i);
2850 if (command->argv) {
2851 for (a = 0, p = command->argv; *p; a++, p++) {
2852 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2854 free_strings(command->argv);
2855 command->argv = NULL;
2857 /* not "else if": on syntax error, we may have both! */
2858 if (command->group) {
2859 debug_printf_clean(" begin group (grp_type:%d)\n",
2861 free_pipe_list(command->group);
2862 debug_printf_clean(" end group\n");
2863 command->group = NULL;
2865 /* else is crucial here.
2866 * If group != NULL, child_func is meaningless */
2867 #if ENABLE_HUSH_FUNCTIONS
2868 else if (command->child_func) {
2869 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2870 command->child_func->parent_cmd = NULL;
2874 free(command->group_as_string);
2875 command->group_as_string = NULL;
2877 for (r = command->redirects; r; r = rnext) {
2878 debug_printf_clean(" redirect %d%s",
2879 r->rd_fd, redir_table[r->rd_type].descrip);
2880 /* guard against the case >$FOO, where foo is unset or blank */
2881 if (r->rd_filename) {
2882 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2883 free(r->rd_filename);
2884 r->rd_filename = NULL;
2886 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2890 command->redirects = NULL;
2892 free(pi->cmds); /* children are an array, they get freed all at once */
2900 static void free_pipe_list(struct pipe *head)
2902 struct pipe *pi, *next;
2904 for (pi = head; pi; pi = next) {
2906 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2909 debug_printf_clean("pipe followup code %d\n", pi->followup);
2911 /*pi->next = NULL;*/
2917 static int run_list(struct pipe *pi);
2919 #define parse_stream(pstring, input, end_trigger) \
2920 parse_stream(input, end_trigger)
2922 static struct pipe *parse_stream(char **pstring,
2923 struct in_str *input,
2925 static void parse_and_run_string(const char *s);
2928 static char *find_in_path(const char *arg)
2931 const char *PATH = get_local_var_value("PATH");
2937 const char *end = strchrnul(PATH, ':');
2938 int sz = end - PATH; /* must be int! */
2942 ret = xasprintf("%.*s/%s", sz, PATH, arg);
2944 /* We have xxx::yyyy in $PATH,
2945 * it means "use current dir" */
2948 if (access(ret, F_OK) == 0)
2961 static const struct built_in_command* find_builtin(const char *name)
2963 const struct built_in_command *x;
2964 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2965 if (strcmp(name, x->cmd) != 0)
2967 debug_printf_exec("found builtin '%s'\n", name);
2973 #if ENABLE_HUSH_FUNCTIONS
2974 static const struct function *find_function(const char *name)
2976 const struct function *funcp = G.top_func;
2978 if (strcmp(name, funcp->name) == 0) {
2981 funcp = funcp->next;
2984 debug_printf_exec("found function '%s'\n", name);
2988 /* Note: takes ownership on name ptr */
2989 static struct function *new_function(char *name)
2991 struct function *funcp;
2992 struct function **funcpp = &G.top_func;
2994 while ((funcp = *funcpp) != NULL) {
2995 struct command *cmd;
2997 if (strcmp(funcp->name, name) != 0) {
2998 funcpp = &funcp->next;
3002 cmd = funcp->parent_cmd;
3003 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3005 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3007 /* Note: if !funcp->body, do not free body_as_string!
3008 * This is a special case of "-F name body" function:
3009 * body_as_string was not malloced! */
3011 free_pipe_list(funcp->body);
3013 free(funcp->body_as_string);
3017 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3018 cmd->argv[0] = funcp->name;
3019 cmd->group = funcp->body;
3021 cmd->group_as_string = funcp->body_as_string;
3026 debug_printf_exec("remembering new function '%s'\n", name);
3027 funcp = *funcpp = xzalloc(sizeof(*funcp));
3028 /*funcp->next = NULL;*/
3034 static void unset_func(const char *name)
3036 struct function *funcp;
3037 struct function **funcpp = &G.top_func;
3039 while ((funcp = *funcpp) != NULL) {
3040 if (strcmp(funcp->name, name) == 0) {
3041 *funcpp = funcp->next;
3042 /* funcp is unlinked now, deleting it.
3043 * Note: if !funcp->body, the function was created by
3044 * "-F name body", do not free ->body_as_string
3045 * and ->name as they were not malloced. */
3047 free_pipe_list(funcp->body);
3050 free(funcp->body_as_string);
3056 funcpp = &funcp->next;
3061 #define exec_function(nommu_save, funcp, argv) \
3062 exec_function(funcp, argv)
3064 static void exec_function(nommu_save_t *nommu_save,
3065 const struct function *funcp,
3066 char **argv) NORETURN;
3067 static void exec_function(nommu_save_t *nommu_save,
3068 const struct function *funcp,
3074 argv[0] = G.global_argv[0];
3075 G.global_argv = argv;
3079 /* On MMU, funcp->body is always non-NULL */
3080 n = run_list(funcp->body);
3084 re_execute_shell(&nommu_save->argv_from_re_execing,
3085 funcp->body_as_string,
3091 static int run_function(const struct function *funcp, char **argv)
3097 save_and_replace_G_args(&sv, argv);
3099 /* "we are in function, ok to use return" */
3100 sv_flg = G.flag_return_in_progress;
3101 G.flag_return_in_progress = -1;
3102 #if ENABLE_HUSH_LOCAL
3103 G.func_nest_level++;
3106 /* On MMU, funcp->body is always non-NULL */
3109 /* Function defined by -F */
3110 parse_and_run_string(funcp->body_as_string);
3111 rc = G.last_exitcode;
3115 rc = run_list(funcp->body);
3118 #if ENABLE_HUSH_LOCAL
3120 struct variable *var;
3121 struct variable **var_pp;
3123 var_pp = &G.top_var;
3124 while ((var = *var_pp) != NULL) {
3125 if (var->func_nest_level < G.func_nest_level) {
3126 var_pp = &var->next;
3130 if (var->flg_export)
3131 bb_unsetenv(var->varstr);
3132 /* Remove from global list */
3133 *var_pp = var->next;
3139 G.func_nest_level--;
3142 G.flag_return_in_progress = sv_flg;
3144 restore_G_args(&sv, argv);
3148 #endif /* ENABLE_HUSH_FUNCTIONS */
3152 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3153 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3154 #define pseudo_exec(nommu_save, command, argv_expanded) \
3155 pseudo_exec(command, argv_expanded)
3158 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3160 * Don't exit() here. If you don't exec, use _exit instead.
3161 * The at_exit handlers apparently confuse the calling process,
3162 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3163 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3164 char **argv, int assignment_cnt,
3165 char **argv_expanded) NORETURN;
3166 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3167 char **argv, int assignment_cnt,
3168 char **argv_expanded)
3172 /* Case when we are here: ... | var=val | ... */
3173 if (!argv[assignment_cnt])
3174 _exit(EXIT_SUCCESS);
3176 new_env = expand_assignments(argv, assignment_cnt);
3178 set_vars_and_save_old(new_env);
3179 free(new_env); /* optional */
3180 /* we can also destroy set_vars_and_save_old's return value,
3183 nommu_save->new_env = new_env;
3184 nommu_save->old_vars = set_vars_and_save_old(new_env);
3186 if (argv_expanded) {
3187 argv = argv_expanded;
3189 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3191 nommu_save->argv = argv;
3195 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3196 if (strchr(argv[0], '/') != NULL)
3200 /* On NOMMU, we must never block!
3201 * Example: { sleep 99999 | read line } & echo Ok
3202 * read builtin will block on read syscall, leaving parent blocked
3203 * in vfork. Therefore we can't do this:
3206 /* Check if the command matches any of the builtins.
3207 * Depending on context, this might be redundant. But it's
3208 * easier to waste a few CPU cycles than it is to figure out
3209 * if this is one of those cases.
3213 const struct built_in_command *x = find_builtin(argv[0]);
3215 rcode = x->function(argv);
3221 #if ENABLE_HUSH_FUNCTIONS
3222 /* Check if the command matches any functions */
3224 const struct function *funcp = find_function(argv[0]);
3226 exec_function(nommu_save, funcp, argv);
3231 #if ENABLE_FEATURE_SH_STANDALONE
3232 /* Check if the command matches any busybox applets */
3234 int a = find_applet_by_name(argv[0]);
3236 # if BB_MMU /* see above why on NOMMU it is not allowed */
3237 if (APPLET_IS_NOEXEC(a)) {
3238 debug_printf_exec("running applet '%s'\n", argv[0]);
3239 run_applet_no_and_exit(a, argv);
3242 /* Re-exec ourselves */
3243 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3244 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3245 execv(bb_busybox_exec_path, argv);
3246 /* If they called chroot or otherwise made the binary no longer
3247 * executable, fall through */
3252 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3255 debug_printf_exec("execing '%s'\n", argv[0]);
3256 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3257 execvp(argv[0], argv);
3258 bb_perror_msg("can't execute '%s'", argv[0]);
3259 _exit(EXIT_FAILURE);
3262 /* Called after [v]fork() in run_pipe
3264 static void pseudo_exec(nommu_save_t *nommu_save,
3265 struct command *command,
3266 char **argv_expanded) NORETURN;
3267 static void pseudo_exec(nommu_save_t *nommu_save,
3268 struct command *command,
3269 char **argv_expanded)
3271 if (command->argv) {
3272 pseudo_exec_argv(nommu_save, command->argv,
3273 command->assignment_cnt, argv_expanded);
3276 if (command->group) {
3277 /* Cases when we are here:
3280 * ... | ( list ) | ...
3281 * ... | { list } | ...
3285 debug_printf_exec("pseudo_exec: run_list\n");
3286 reset_traps_to_defaults();
3287 rcode = run_list(command->group);
3288 /* OK to leak memory by not calling free_pipe_list,
3289 * since this process is about to exit */
3292 re_execute_shell(&nommu_save->argv_from_re_execing,
3293 command->group_as_string,
3299 /* Case when we are here: ... | >file */
3300 debug_printf_exec("pseudo_exec'ed null command\n");
3301 _exit(EXIT_SUCCESS);
3305 static const char *get_cmdtext(struct pipe *pi)
3311 /* This is subtle. ->cmdtext is created only on first backgrounding.
3312 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3313 * On subsequent bg argv is trashed, but we won't use it */
3316 argv = pi->cmds[0].argv;
3317 if (!argv || !argv[0]) {
3318 pi->cmdtext = xzalloc(1);
3324 len += strlen(*argv) + 1;
3328 argv = pi->cmds[0].argv;
3330 len = strlen(*argv);
3331 memcpy(p, *argv, len);
3339 static void insert_bg_job(struct pipe *pi)
3341 struct pipe *job, **jobp;
3344 /* Linear search for the ID of the job to use */
3346 for (job = G.job_list; job; job = job->next)
3347 if (job->jobid >= pi->jobid)
3348 pi->jobid = job->jobid + 1;
3350 /* Add job to the list of running jobs */
3352 while ((job = *jobp) != NULL)
3354 job = *jobp = xmalloc(sizeof(*job));
3356 *job = *pi; /* physical copy */
3358 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3359 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3360 for (i = 0; i < pi->num_cmds; i++) {
3361 job->cmds[i].pid = pi->cmds[i].pid;
3362 /* all other fields are not used and stay zero */
3364 job->cmdtext = xstrdup(get_cmdtext(pi));
3366 if (G_interactive_fd)
3367 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3368 /* Last command's pid goes to $! */
3369 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3370 G.last_jobid = job->jobid;
3373 static void remove_bg_job(struct pipe *pi)
3375 struct pipe *prev_pipe;
3377 if (pi == G.job_list) {
3378 G.job_list = pi->next;
3380 prev_pipe = G.job_list;
3381 while (prev_pipe->next != pi)
3382 prev_pipe = prev_pipe->next;
3383 prev_pipe->next = pi->next;
3386 G.last_jobid = G.job_list->jobid;
3391 /* Remove a backgrounded job */
3392 static void delete_finished_bg_job(struct pipe *pi)
3395 pi->stopped_cmds = 0;
3401 /* Check to see if any processes have exited -- if they
3402 * have, figure out why and see if a job has completed */
3403 static int checkjobs(struct pipe* fg_pipe)
3413 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3415 attributes = WUNTRACED;
3416 if (fg_pipe == NULL)
3417 attributes |= WNOHANG;
3420 #if ENABLE_HUSH_FAST
3421 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3422 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3423 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3424 /* There was neither fork nor SIGCHLD since last waitpid */
3425 /* Avoid doing waitpid syscall if possible */
3426 if (!G.we_have_children) {
3430 if (fg_pipe == NULL) { /* is WNOHANG set? */
3431 /* We have children, but they did not exit
3432 * or stop yet (we saw no SIGCHLD) */
3435 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3439 /* Do we do this right?
3440 * bash-3.00# sleep 20 | false
3442 * [3]+ Stopped sleep 20 | false
3443 * bash-3.00# echo $?
3444 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3445 * [hush 1.14.0: yes we do it right]
3452 #if ENABLE_HUSH_FAST
3453 i = G.count_SIGCHLD;
3455 childpid = waitpid(-1, &status, attributes);
3456 if (childpid <= 0) {
3457 if (childpid && errno != ECHILD)
3458 bb_perror_msg("waitpid");
3459 #if ENABLE_HUSH_FAST
3460 else { /* Until next SIGCHLD, waitpid's are useless */
3461 G.we_have_children = (childpid == 0);
3462 G.handled_SIGCHLD = i;
3463 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3468 dead = WIFEXITED(status) || WIFSIGNALED(status);
3471 if (WIFSTOPPED(status))
3472 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3473 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3474 if (WIFSIGNALED(status))
3475 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3476 childpid, WTERMSIG(status), WEXITSTATUS(status));
3477 if (WIFEXITED(status))
3478 debug_printf_jobs("pid %d exited, exitcode %d\n",
3479 childpid, WEXITSTATUS(status));
3481 /* Were we asked to wait for fg pipe? */
3483 for (i = 0; i < fg_pipe->num_cmds; i++) {
3484 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3485 if (fg_pipe->cmds[i].pid != childpid)
3488 fg_pipe->cmds[i].pid = 0;
3489 fg_pipe->alive_cmds--;
3490 if (i == fg_pipe->num_cmds - 1) {
3491 /* last process gives overall exitstatus */
3492 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3493 rcode = WEXITSTATUS(status);
3494 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3495 /* bash prints killing signal's name for *last*
3496 * process in pipe (prints just newline for SIGINT).
3497 * Mimic this. Example: "sleep 5" + ^\
3499 if (WIFSIGNALED(status)) {
3500 int sig = WTERMSIG(status);
3501 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3505 fg_pipe->cmds[i].is_stopped = 1;
3506 fg_pipe->stopped_cmds++;
3508 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3509 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3510 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3511 /* All processes in fg pipe have exited or stopped */
3512 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3513 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3514 * and "killall -STOP cat" */
3515 if (G_interactive_fd) {
3517 if (fg_pipe->alive_cmds)
3518 insert_bg_job(fg_pipe);
3522 if (!fg_pipe->alive_cmds)
3525 /* There are still running processes in the fg pipe */
3526 goto wait_more; /* do waitpid again */
3528 /* it wasnt fg_pipe, look for process in bg pipes */
3532 /* We asked to wait for bg or orphaned children */
3533 /* No need to remember exitcode in this case */
3534 for (pi = G.job_list; pi; pi = pi->next) {
3535 for (i = 0; i < pi->num_cmds; i++) {
3536 if (pi->cmds[i].pid == childpid)
3537 goto found_pi_and_prognum;
3540 /* Happens when shell is used as init process (init=/bin/sh) */
3541 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3542 continue; /* do waitpid again */
3544 found_pi_and_prognum:
3547 pi->cmds[i].pid = 0;
3549 if (!pi->alive_cmds) {
3550 if (G_interactive_fd)
3551 printf(JOB_STATUS_FORMAT, pi->jobid,
3552 "Done", pi->cmdtext);
3553 delete_finished_bg_job(pi);
3557 pi->cmds[i].is_stopped = 1;
3561 } /* while (waitpid succeeds)... */
3567 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3570 int rcode = checkjobs(fg_pipe);
3571 if (G_saved_tty_pgrp) {
3572 /* Job finished, move the shell to the foreground */
3573 p = getpgrp(); /* our process group id */
3574 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3575 tcsetpgrp(G_interactive_fd, p);
3581 /* Start all the jobs, but don't wait for anything to finish.
3584 * Return code is normally -1, when the caller has to wait for children
3585 * to finish to determine the exit status of the pipe. If the pipe
3586 * is a simple builtin command, however, the action is done by the
3587 * time run_pipe returns, and the exit code is provided as the
3590 * Returns -1 only if started some children. IOW: we have to
3591 * mask out retvals of builtins etc with 0xff!
3593 * The only case when we do not need to [v]fork is when the pipe
3594 * is single, non-backgrounded, non-subshell command. Examples:
3595 * cmd ; ... { list } ; ...
3596 * cmd && ... { list } && ...
3597 * cmd || ... { list } || ...
3598 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3599 * or (if SH_STANDALONE) an applet, and we can run the { list }
3600 * with run_list. If it isn't one of these, we fork and exec cmd.
3602 * Cases when we must fork:
3603 * non-single: cmd | cmd
3604 * backgrounded: cmd & { list } &
3605 * subshell: ( list ) [&]
3607 static int run_pipe(struct pipe *pi)
3609 static const char *const null_ptr = NULL;
3612 struct command *command;
3613 char **argv_expanded;
3616 /* it is not always needed, but we aim to smaller code */
3617 int squirrel[] = { -1, -1, -1 };
3620 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3623 IF_HUSH_JOB(pi->pgrp = -1;)
3624 pi->stopped_cmds = 0;
3625 command = &(pi->cmds[0]);
3626 argv_expanded = NULL;
3628 if (pi->num_cmds != 1
3629 || pi->followup == PIPE_BG
3630 || command->grp_type == GRP_SUBSHELL
3637 debug_printf_exec(": group:%p argv:'%s'\n",
3638 command->group, command->argv ? command->argv[0] : "NONE");
3640 if (command->group) {
3641 #if ENABLE_HUSH_FUNCTIONS
3642 if (command->grp_type == GRP_FUNCTION) {
3643 /* "executing" func () { list } */
3644 struct function *funcp;
3646 funcp = new_function(command->argv[0]);
3647 /* funcp->name is already set to argv[0] */
3648 funcp->body = command->group;
3650 funcp->body_as_string = command->group_as_string;
3651 command->group_as_string = NULL;
3653 command->group = NULL;
3654 command->argv[0] = NULL;
3655 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3656 funcp->parent_cmd = command;
3657 command->child_func = funcp;
3659 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3661 return EXIT_SUCCESS;
3665 debug_printf("non-subshell group\n");
3666 rcode = 1; /* exitcode if redir failed */
3667 if (setup_redirects(command, squirrel) == 0) {
3668 debug_printf_exec(": run_list\n");
3669 rcode = run_list(command->group) & 0xff;
3671 restore_redirects(squirrel);
3672 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3674 debug_printf_exec("run_pipe: return %d\n", rcode);
3678 argv = command->argv ? command->argv : (char **) &null_ptr;
3680 const struct built_in_command *x;
3681 #if ENABLE_HUSH_FUNCTIONS
3682 const struct function *funcp;
3686 char **new_env = NULL;
3687 struct variable *old_vars = NULL;
3689 if (argv[command->assignment_cnt] == NULL) {
3690 /* Assignments, but no command */
3691 /* Ensure redirects take effect. Try "a=t >file" */
3692 rcode = setup_redirects(command, squirrel);
3693 restore_redirects(squirrel);
3694 /* Set shell variables */
3696 p = expand_string_to_string(*argv);
3697 debug_printf_exec("set shell var:'%s'->'%s'\n",
3699 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
3702 /* Do we need to flag set_local_var() errors?
3703 * "assignment to readonly var" and "putenv error"
3705 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3707 debug_printf_exec("run_pipe: return %d\n", rcode);
3711 /* Expand the rest into (possibly) many strings each */
3712 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3714 x = find_builtin(argv_expanded[0]);
3715 #if ENABLE_HUSH_FUNCTIONS
3718 funcp = find_function(argv_expanded[0]);
3722 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3723 debug_printf("exec with redirects only\n");
3724 rcode = setup_redirects(command, NULL);
3725 goto clean_up_and_ret1;
3728 /* setup_redirects acts on file descriptors, not FILEs.
3729 * This is perfect for work that comes after exec().
3730 * Is it really safe for inline use? Experimentally,
3731 * things seem to work. */
3732 rcode = setup_redirects(command, squirrel);
3734 new_env = expand_assignments(argv, command->assignment_cnt);
3735 old_vars = set_vars_and_save_old(new_env);
3737 debug_printf_exec(": builtin '%s' '%s'...\n",
3738 x->cmd, argv_expanded[1]);
3739 rcode = x->function(argv_expanded) & 0xff;
3742 #if ENABLE_HUSH_FUNCTIONS
3744 # if ENABLE_HUSH_LOCAL
3745 struct variable **sv;
3746 sv = G.shadowed_vars_pp;
3747 G.shadowed_vars_pp = &old_vars;
3749 debug_printf_exec(": function '%s' '%s'...\n",
3750 funcp->name, argv_expanded[1]);
3751 rcode = run_function(funcp, argv_expanded) & 0xff;
3752 # if ENABLE_HUSH_LOCAL
3753 G.shadowed_vars_pp = sv;
3758 #if ENABLE_FEATURE_SH_STANDALONE
3761 restore_redirects(squirrel);
3762 unset_vars(new_env);
3765 free(argv_expanded);
3766 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3768 debug_printf_exec("run_pipe return %d\n", rcode);
3772 #if ENABLE_FEATURE_SH_STANDALONE
3773 i = find_applet_by_name(argv_expanded[0]);
3774 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3775 rcode = setup_redirects(command, squirrel);
3777 new_env = expand_assignments(argv, command->assignment_cnt);
3778 old_vars = set_vars_and_save_old(new_env);
3779 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3780 argv_expanded[0], argv_expanded[1]);
3781 rcode = run_nofork_applet(i, argv_expanded);
3783 goto clean_up_and_ret;
3786 /* It is neither builtin nor applet. We must fork. */
3790 /* NB: argv_expanded may already be created, and that
3791 * might include `cmd` runs! Do not rerun it! We *must*
3792 * use argv_expanded if it's non-NULL */
3794 /* Going to fork a child per each pipe member */
3798 for (i = 0; i < pi->num_cmds; i++) {
3799 struct fd_pair pipefds;
3801 volatile nommu_save_t nommu_save;
3802 nommu_save.new_env = NULL;
3803 nommu_save.old_vars = NULL;
3804 nommu_save.argv = NULL;
3805 nommu_save.argv_from_re_execing = NULL;
3807 command = &(pi->cmds[i]);
3808 if (command->argv) {
3809 debug_printf_exec(": pipe member '%s' '%s'...\n",
3810 command->argv[0], command->argv[1]);
3812 debug_printf_exec(": pipe member with no argv\n");
3815 /* pipes are inserted between pairs of commands */
3818 if ((i + 1) < pi->num_cmds)
3819 xpiped_pair(pipefds);
3821 command->pid = BB_MMU ? fork() : vfork();
3822 if (!command->pid) { /* child */
3824 disable_restore_tty_pgrp_on_exit();
3826 /* Every child adds itself to new process group
3827 * with pgid == pid_of_first_child_in_pipe */
3828 if (G.run_list_level == 1 && G_interactive_fd) {
3831 if (pgrp < 0) /* true for 1st process only */
3833 if (setpgid(0, pgrp) == 0
3834 && pi->followup != PIPE_BG
3835 && G_saved_tty_pgrp /* we have ctty */
3837 /* We do it in *every* child, not just first,
3839 tcsetpgrp(G_interactive_fd, pgrp);
3843 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3844 /* 1st cmd in backgrounded pipe
3845 * should have its stdin /dev/null'ed */
3847 if (open(bb_dev_null, O_RDONLY))
3848 xopen("/", O_RDONLY);
3850 xmove_fd(nextin, 0);
3852 xmove_fd(pipefds.wr, 1);
3855 /* Like bash, explicit redirects override pipes,
3856 * and the pipe fd is available for dup'ing. */
3857 if (setup_redirects(command, NULL))
3860 /* Restore default handlers just prior to exec */
3861 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3863 /* Stores to nommu_save list of env vars putenv'ed
3864 * (NOMMU, on MMU we don't need that) */
3865 /* cast away volatility... */
3866 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3867 /* pseudo_exec() does not return */
3870 /* parent or error */
3871 #if ENABLE_HUSH_FAST
3873 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3875 enable_restore_tty_pgrp_on_exit();
3877 /* Clean up after vforked child */
3878 free(nommu_save.argv);
3879 free(nommu_save.argv_from_re_execing);
3880 unset_vars(nommu_save.new_env);
3881 add_vars(nommu_save.old_vars);
3883 free(argv_expanded);
3884 argv_expanded = NULL;
3885 if (command->pid < 0) { /* [v]fork failed */
3886 /* Clearly indicate, was it fork or vfork */
3887 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3891 /* Second and next children need to know pid of first one */
3893 pi->pgrp = command->pid;
3899 if ((i + 1) < pi->num_cmds)
3901 /* Pass read (output) pipe end to next iteration */
3902 nextin = pipefds.rd;
3905 if (!pi->alive_cmds) {
3907 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3912 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3916 #ifndef debug_print_tree
3917 static void debug_print_tree(struct pipe *pi, int lvl)
3919 static const char *const PIPE[] = {
3925 static const char *RES[] = {
3926 [RES_NONE ] = "NONE" ,
3929 [RES_THEN ] = "THEN" ,
3930 [RES_ELIF ] = "ELIF" ,
3931 [RES_ELSE ] = "ELSE" ,
3934 #if ENABLE_HUSH_LOOPS
3935 [RES_FOR ] = "FOR" ,
3936 [RES_WHILE] = "WHILE",
3937 [RES_UNTIL] = "UNTIL",
3939 [RES_DONE ] = "DONE" ,
3941 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3944 #if ENABLE_HUSH_CASE
3945 [RES_CASE ] = "CASE" ,
3946 [RES_CASE_IN ] = "CASE_IN" ,
3947 [RES_MATCH] = "MATCH",
3948 [RES_CASE_BODY] = "CASE_BODY",
3949 [RES_ESAC ] = "ESAC" ,
3951 [RES_XXXX ] = "XXXX" ,
3952 [RES_SNTX ] = "SNTX" ,
3954 static const char *const GRPTYPE[] = {
3957 #if ENABLE_HUSH_FUNCTIONS
3966 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3967 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3969 while (prn < pi->num_cmds) {
3970 struct command *command = &pi->cmds[prn];
3971 char **argv = command->argv;
3973 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3975 command->assignment_cnt);
3976 if (command->group) {
3977 fprintf(stderr, " group %s: (argv=%p)\n",
3978 GRPTYPE[command->grp_type],
3980 debug_print_tree(command->group, lvl+1);
3984 if (argv) while (*argv) {
3985 fprintf(stderr, " '%s'", *argv);
3988 fprintf(stderr, "\n");
3997 /* NB: called by pseudo_exec, and therefore must not modify any
3998 * global data until exec/_exit (we can be a child after vfork!) */
3999 static int run_list(struct pipe *pi)
4001 #if ENABLE_HUSH_CASE
4002 char *case_word = NULL;
4004 #if ENABLE_HUSH_LOOPS
4005 struct pipe *loop_top = NULL;
4006 char **for_lcur = NULL;
4007 char **for_list = NULL;
4009 smallint last_followup;
4011 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4012 smalluint cond_code = 0;
4014 enum { cond_code = 0 };
4017 smallint rword; /* enum reserved_style */
4018 smallint last_rword; /* ditto */
4021 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4024 #if ENABLE_HUSH_LOOPS
4025 /* Check syntax for "for" */
4026 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4027 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4029 /* current word is FOR or IN (BOLD in comments below) */
4030 if (cpipe->next == NULL) {
4031 syntax_error("malformed for");
4033 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4036 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4037 if (cpipe->next->res_word == RES_DO)
4039 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4040 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4041 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4043 syntax_error("malformed for");
4045 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4051 /* Past this point, all code paths should jump to ret: label
4052 * in order to return, no direct "return" statements please.
4053 * This helps to ensure that no memory is leaked. */
4061 last_rword = RES_XXXX;
4063 last_followup = PIPE_SEQ;
4064 rcode = G.last_exitcode;
4066 /* Go through list of pipes, (maybe) executing them. */
4067 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4071 IF_HAS_KEYWORDS(rword = pi->res_word;)
4072 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4073 rword, cond_code, last_rword);
4074 #if ENABLE_HUSH_LOOPS
4075 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4076 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4078 /* start of a loop: remember where loop starts */
4083 /* Still in the same "if...", "then..." or "do..." branch? */
4084 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4085 if ((rcode == 0 && last_followup == PIPE_OR)
4086 || (rcode != 0 && last_followup == PIPE_AND)
4088 /* It is "<true> || CMD" or "<false> && CMD"
4089 * and we should not execute CMD */
4090 debug_printf_exec("skipped cmd because of || or &&\n");
4091 last_followup = pi->followup;
4095 last_followup = pi->followup;
4096 IF_HAS_KEYWORDS(last_rword = rword;)
4099 if (rword == RES_THEN) {
4100 /* if false; then ... fi has exitcode 0! */
4101 G.last_exitcode = rcode = EXIT_SUCCESS;
4102 /* "if <false> THEN cmd": skip cmd */
4106 if (rword == RES_ELSE || rword == RES_ELIF) {
4107 /* "if <true> then ... ELSE/ELIF cmd":
4108 * skip cmd and all following ones */
4113 #if ENABLE_HUSH_LOOPS
4114 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4116 /* first loop through for */
4118 static const char encoded_dollar_at[] ALIGN1 = {
4119 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4120 }; /* encoded representation of "$@" */
4121 static const char *const encoded_dollar_at_argv[] = {
4122 encoded_dollar_at, NULL
4123 }; /* argv list with one element: "$@" */
4126 vals = (char**)encoded_dollar_at_argv;
4127 if (pi->next->res_word == RES_IN) {
4128 /* if no variable values after "in" we skip "for" */
4129 if (!pi->next->cmds[0].argv) {
4130 G.last_exitcode = rcode = EXIT_SUCCESS;
4131 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4134 vals = pi->next->cmds[0].argv;
4135 } /* else: "for var; do..." -> assume "$@" list */
4136 /* create list of variable values */
4137 debug_print_strings("for_list made from", vals);
4138 for_list = expand_strvec_to_strvec(vals);
4139 for_lcur = for_list;
4140 debug_print_strings("for_list", for_list);
4143 /* "for" loop is over, clean up */
4149 /* Insert next value from for_lcur */
4150 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4151 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4154 if (rword == RES_IN) {
4155 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4157 if (rword == RES_DONE) {
4158 continue; /* "done" has no cmds too */
4161 #if ENABLE_HUSH_CASE
4162 if (rword == RES_CASE) {
4163 case_word = expand_strvec_to_string(pi->cmds->argv);
4166 if (rword == RES_MATCH) {
4169 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4171 /* all prev words didn't match, does this one match? */
4172 argv = pi->cmds->argv;
4174 char *pattern = expand_string_to_string(*argv);
4175 /* TODO: which FNM_xxx flags to use? */
4176 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4178 if (cond_code == 0) { /* match! we will execute this branch */
4179 free(case_word); /* make future "word)" stop */
4187 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4189 continue; /* not matched yet, skip this pipe */
4192 /* Just pressing <enter> in shell should check for jobs.
4193 * OTOH, in non-interactive shell this is useless
4194 * and only leads to extra job checks */
4195 if (pi->num_cmds == 0) {
4196 if (G_interactive_fd)
4197 goto check_jobs_and_continue;
4201 /* After analyzing all keywords and conditions, we decided
4202 * to execute this pipe. NB: have to do checkjobs(NULL)
4203 * after run_pipe to collect any background children,
4204 * even if list execution is to be stopped. */
4205 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4208 #if ENABLE_HUSH_LOOPS
4209 G.flag_break_continue = 0;
4211 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4213 /* We ran a builtin, function, or group.
4214 * rcode is already known
4215 * and we don't need to wait for anything. */
4216 G.last_exitcode = rcode;
4217 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4218 check_and_run_traps(0);
4219 #if ENABLE_HUSH_LOOPS
4220 /* Was it "break" or "continue"? */
4221 if (G.flag_break_continue) {
4222 smallint fbc = G.flag_break_continue;
4223 /* We might fall into outer *loop*,
4224 * don't want to break it too */
4226 G.depth_break_continue--;
4227 if (G.depth_break_continue == 0)
4228 G.flag_break_continue = 0;
4229 /* else: e.g. "continue 2" should *break* once, *then* continue */
4230 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4231 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4232 goto check_jobs_and_break;
4233 /* "continue": simulate end of loop */
4238 #if ENABLE_HUSH_FUNCTIONS
4239 if (G.flag_return_in_progress == 1) {
4240 /* same as "goto check_jobs_and_break" */
4245 } else if (pi->followup == PIPE_BG) {
4246 /* What does bash do with attempts to background builtins? */
4247 /* even bash 3.2 doesn't do that well with nested bg:
4248 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4249 * I'm NOT treating inner &'s as jobs */
4250 check_and_run_traps(0);
4252 if (G.run_list_level == 1)
4255 G.last_exitcode = rcode = EXIT_SUCCESS;
4256 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4259 if (G.run_list_level == 1 && G_interactive_fd) {
4260 /* Waits for completion, then fg's main shell */
4261 rcode = checkjobs_and_fg_shell(pi);
4262 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4263 check_and_run_traps(0);
4266 { /* This one just waits for completion */
4267 rcode = checkjobs(pi);
4268 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4269 check_and_run_traps(0);
4271 G.last_exitcode = rcode;
4275 /* Analyze how result affects subsequent commands */
4277 if (rword == RES_IF || rword == RES_ELIF)
4280 #if ENABLE_HUSH_LOOPS
4281 /* Beware of "while false; true; do ..."! */
4282 if (pi->next && pi->next->res_word == RES_DO) {
4283 if (rword == RES_WHILE) {
4285 /* "while false; do...done" - exitcode 0 */
4286 G.last_exitcode = rcode = EXIT_SUCCESS;
4287 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4288 goto check_jobs_and_break;
4291 if (rword == RES_UNTIL) {
4293 debug_printf_exec(": until expr is true: breaking\n");
4294 check_jobs_and_break:
4302 check_jobs_and_continue:
4309 #if ENABLE_HUSH_LOOPS
4314 #if ENABLE_HUSH_CASE
4318 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4322 /* Select which version we will use */
4323 static int run_and_free_list(struct pipe *pi)
4326 debug_printf_exec("run_and_free_list entered\n");
4328 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4329 rcode = run_list(pi);
4331 /* free_pipe_list has the side effect of clearing memory.
4332 * In the long run that function can be merged with run_list,
4333 * but doing that now would hobble the debugging effort. */
4335 debug_printf_exec("run_and_free_list return %d\n", rcode);
4340 static struct pipe *new_pipe(void)
4343 pi = xzalloc(sizeof(struct pipe));
4344 /*pi->followup = 0; - deliberately invalid value */
4345 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4349 /* Command (member of a pipe) is complete, or we start a new pipe
4350 * if ctx->command is NULL.
4351 * No errors possible here.
4353 static int done_command(struct parse_context *ctx)
4355 /* The command is really already in the pipe structure, so
4356 * advance the pipe counter and make a new, null command. */
4357 struct pipe *pi = ctx->pipe;
4358 struct command *command = ctx->command;
4361 if (IS_NULL_CMD(command)) {
4362 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4366 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4367 //debug_print_tree(ctx->list_head, 20);
4369 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4372 /* Only real trickiness here is that the uncommitted
4373 * command structure is not counted in pi->num_cmds. */
4374 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4375 ctx->command = command = &pi->cmds[pi->num_cmds];
4377 memset(command, 0, sizeof(*command));
4378 return pi->num_cmds; /* used only for 0/nonzero check */
4381 static void done_pipe(struct parse_context *ctx, pipe_style type)
4385 debug_printf_parse("done_pipe entered, followup %d\n", type);
4386 /* Close previous command */
4387 not_null = done_command(ctx);
4388 ctx->pipe->followup = type;
4390 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4391 ctx->ctx_inverted = 0;
4392 ctx->pipe->res_word = ctx->ctx_res_w;
4395 /* Without this check, even just <enter> on command line generates
4396 * tree of three NOPs (!). Which is harmless but annoying.
4397 * IOW: it is safe to do it unconditionally. */
4400 || ctx->ctx_res_w == RES_FI
4402 #if ENABLE_HUSH_LOOPS
4403 || ctx->ctx_res_w == RES_DONE
4404 || ctx->ctx_res_w == RES_FOR
4405 || ctx->ctx_res_w == RES_IN
4407 #if ENABLE_HUSH_CASE
4408 || ctx->ctx_res_w == RES_ESAC
4412 debug_printf_parse("done_pipe: adding new pipe: "
4413 "not_null:%d ctx->ctx_res_w:%d\n",
4414 not_null, ctx->ctx_res_w);
4416 ctx->pipe->next = new_p;
4418 /* RES_THEN, RES_DO etc are "sticky" -
4419 * they remain set for pipes inside if/while.
4420 * This is used to control execution.
4421 * RES_FOR and RES_IN are NOT sticky (needed to support
4422 * cases where variable or value happens to match a keyword):
4424 #if ENABLE_HUSH_LOOPS
4425 if (ctx->ctx_res_w == RES_FOR
4426 || ctx->ctx_res_w == RES_IN)
4427 ctx->ctx_res_w = RES_NONE;
4429 #if ENABLE_HUSH_CASE
4430 if (ctx->ctx_res_w == RES_MATCH)
4431 ctx->ctx_res_w = RES_CASE_BODY;
4432 if (ctx->ctx_res_w == RES_CASE)
4433 ctx->ctx_res_w = RES_CASE_IN;
4435 ctx->command = NULL; /* trick done_command below */
4436 /* Create the memory for command, roughly:
4437 * ctx->pipe->cmds = new struct command;
4438 * ctx->command = &ctx->pipe->cmds[0];
4441 //debug_print_tree(ctx->list_head, 10);
4443 debug_printf_parse("done_pipe return\n");
4446 static void initialize_context(struct parse_context *ctx)
4448 memset(ctx, 0, sizeof(*ctx));
4449 ctx->pipe = ctx->list_head = new_pipe();
4450 /* Create the memory for command, roughly:
4451 * ctx->pipe->cmds = new struct command;
4452 * ctx->command = &ctx->pipe->cmds[0];
4457 /* If a reserved word is found and processed, parse context is modified
4458 * and 1 is returned.
4461 struct reserved_combo {
4464 unsigned char assignment_flag;
4468 FLAG_END = (1 << RES_NONE ),
4470 FLAG_IF = (1 << RES_IF ),
4471 FLAG_THEN = (1 << RES_THEN ),
4472 FLAG_ELIF = (1 << RES_ELIF ),
4473 FLAG_ELSE = (1 << RES_ELSE ),
4474 FLAG_FI = (1 << RES_FI ),
4476 #if ENABLE_HUSH_LOOPS
4477 FLAG_FOR = (1 << RES_FOR ),
4478 FLAG_WHILE = (1 << RES_WHILE),
4479 FLAG_UNTIL = (1 << RES_UNTIL),
4480 FLAG_DO = (1 << RES_DO ),
4481 FLAG_DONE = (1 << RES_DONE ),
4482 FLAG_IN = (1 << RES_IN ),
4484 #if ENABLE_HUSH_CASE
4485 FLAG_MATCH = (1 << RES_MATCH),
4486 FLAG_ESAC = (1 << RES_ESAC ),
4488 FLAG_START = (1 << RES_XXXX ),
4491 static const struct reserved_combo* match_reserved_word(o_string *word)
4493 /* Mostly a list of accepted follow-up reserved words.
4494 * FLAG_END means we are done with the sequence, and are ready
4495 * to turn the compound list into a command.
4496 * FLAG_START means the word must start a new compound list.
4498 static const struct reserved_combo reserved_list[] = {
4500 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4501 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4502 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4503 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4504 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4505 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4507 #if ENABLE_HUSH_LOOPS
4508 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4509 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4510 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4511 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4512 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4513 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4515 #if ENABLE_HUSH_CASE
4516 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4517 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4520 const struct reserved_combo *r;
4522 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4523 if (strcmp(word->data, r->literal) == 0)
4528 /* Return 0: not a keyword, 1: keyword
4530 static int reserved_word(o_string *word, struct parse_context *ctx)
4532 #if ENABLE_HUSH_CASE
4533 static const struct reserved_combo reserved_match = {
4534 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4537 const struct reserved_combo *r;
4541 r = match_reserved_word(word);
4545 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4546 #if ENABLE_HUSH_CASE
4547 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
4548 /* "case word IN ..." - IN part starts first MATCH part */
4549 r = &reserved_match;
4552 if (r->flag == 0) { /* '!' */
4553 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4554 syntax_error("! ! command");
4555 ctx->ctx_res_w = RES_SNTX;
4557 ctx->ctx_inverted = 1;
4560 if (r->flag & FLAG_START) {
4561 struct parse_context *old;
4563 old = xmalloc(sizeof(*old));
4564 debug_printf_parse("push stack %p\n", old);
4565 *old = *ctx; /* physical copy */
4566 initialize_context(ctx);
4568 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4569 syntax_error_at(word->data);
4570 ctx->ctx_res_w = RES_SNTX;
4573 /* "{...} fi" is ok. "{...} if" is not
4575 * if { echo foo; } then { echo bar; } fi */
4576 if (ctx->command->group)
4577 done_pipe(ctx, PIPE_SEQ);
4580 ctx->ctx_res_w = r->res;
4581 ctx->old_flag = r->flag;
4582 word->o_assignment = r->assignment_flag;
4584 if (ctx->old_flag & FLAG_END) {
4585 struct parse_context *old;
4587 done_pipe(ctx, PIPE_SEQ);
4588 debug_printf_parse("pop stack %p\n", ctx->stack);
4590 old->command->group = ctx->list_head;
4591 old->command->grp_type = GRP_NORMAL;
4593 o_addstr(&old->as_string, ctx->as_string.data);
4594 o_free_unsafe(&ctx->as_string);
4595 old->command->group_as_string = xstrdup(old->as_string.data);
4596 debug_printf_parse("pop, remembering as:'%s'\n",
4597 old->command->group_as_string);
4599 *ctx = *old; /* physical copy */
4606 /* Word is complete, look at it and update parsing context.
4607 * Normal return is 0. Syntax errors return 1.
4608 * Note: on return, word is reset, but not o_free'd!
4610 static int done_word(o_string *word, struct parse_context *ctx)
4612 struct command *command = ctx->command;
4614 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4615 if (word->length == 0 && word->o_quoted == 0) {
4616 debug_printf_parse("done_word return 0: true null, ignored\n");
4620 if (ctx->pending_redirect) {
4621 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4622 * only if run as "bash", not "sh" */
4623 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4625 * ...the word that follows the redirection operator
4626 * shall be subjected to tilde expansion, parameter expansion,
4627 * command substitution, arithmetic expansion, and quote
4628 * removal. Pathname expansion shall not be performed
4629 * on the word by a non-interactive shell; an interactive
4630 * shell may perform it, but shall do so only when
4631 * the expansion would result in one word."
4633 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4634 /* Cater for >\file case:
4635 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4636 * Same with heredocs:
4637 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4639 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
4640 unbackslash(ctx->pending_redirect->rd_filename);
4641 /* Is it <<"HEREDOC"? */
4642 if (word->o_quoted) {
4643 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4646 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4647 ctx->pending_redirect = NULL;
4649 /* If this word wasn't an assignment, next ones definitely
4650 * can't be assignments. Even if they look like ones. */
4651 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4652 && word->o_assignment != WORD_IS_KEYWORD
4654 word->o_assignment = NOT_ASSIGNMENT;
4656 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4657 command->assignment_cnt++;
4658 word->o_assignment = MAYBE_ASSIGNMENT;
4662 # if ENABLE_HUSH_CASE
4663 if (ctx->ctx_dsemicolon
4664 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4666 /* already done when ctx_dsemicolon was set to 1: */
4667 /* ctx->ctx_res_w = RES_MATCH; */
4668 ctx->ctx_dsemicolon = 0;
4671 if (!command->argv /* if it's the first word... */
4672 # if ENABLE_HUSH_LOOPS
4673 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4674 && ctx->ctx_res_w != RES_IN
4676 # if ENABLE_HUSH_CASE
4677 && ctx->ctx_res_w != RES_CASE
4680 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4681 if (reserved_word(word, ctx)) {
4682 o_reset_to_empty_unquoted(word);
4683 debug_printf_parse("done_word return %d\n",
4684 (ctx->ctx_res_w == RES_SNTX));
4685 return (ctx->ctx_res_w == RES_SNTX);
4689 if (command->group) {
4690 /* "{ echo foo; } echo bar" - bad */
4691 syntax_error_at(word->data);
4692 debug_printf_parse("done_word return 1: syntax error, "
4693 "groups and arglists don't mix\n");
4696 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4697 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4698 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4699 /* (otherwise it's known to be not empty and is already safe) */
4701 /* exclude "$@" - it can expand to no word despite "" */
4702 char *p = word->data;
4703 while (p[0] == SPECIAL_VAR_SYMBOL
4704 && (p[1] & 0x7f) == '@'
4705 && p[2] == SPECIAL_VAR_SYMBOL
4709 if (p == word->data || p[0] != '\0') {
4710 /* saw no "$@", or not only "$@" but some
4711 * real text is there too */
4712 /* insert "empty variable" reference, this makes
4713 * e.g. "", $empty"" etc to not disappear */
4714 o_addchr(word, SPECIAL_VAR_SYMBOL);
4715 o_addchr(word, SPECIAL_VAR_SYMBOL);
4718 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4719 debug_print_strings("word appended to argv", command->argv);
4722 #if ENABLE_HUSH_LOOPS
4723 if (ctx->ctx_res_w == RES_FOR) {
4725 || !is_well_formed_var_name(command->argv[0], '\0')
4727 /* bash says just "not a valid identifier" */
4728 syntax_error("not a valid identifier in for");
4731 /* Force FOR to have just one word (variable name) */
4732 /* NB: basically, this makes hush see "for v in ..."
4733 * syntax as if it is "for v; in ...". FOR and IN become
4734 * two pipe structs in parse tree. */
4735 done_pipe(ctx, PIPE_SEQ);
4738 #if ENABLE_HUSH_CASE
4739 /* Force CASE to have just one word */
4740 if (ctx->ctx_res_w == RES_CASE) {
4741 done_pipe(ctx, PIPE_SEQ);
4745 o_reset_to_empty_unquoted(word);
4747 debug_printf_parse("done_word return 0\n");
4752 /* Peek ahead in the input to find out if we have a "&n" construct,
4753 * as in "2>&1", that represents duplicating a file descriptor.
4755 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4756 * REDIRFD_SYNTAX_ERR if syntax error,
4757 * REDIRFD_TO_FILE if no & was seen,
4758 * or the number found.
4761 #define parse_redir_right_fd(as_string, input) \
4762 parse_redir_right_fd(input)
4764 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4770 return REDIRFD_TO_FILE;
4772 ch = i_getch(input); /* get the & */
4773 nommu_addchr(as_string, ch);
4776 ch = i_getch(input);
4777 nommu_addchr(as_string, ch);
4778 return REDIRFD_CLOSE;
4782 while (ch != EOF && isdigit(ch)) {
4783 d = d*10 + (ch-'0');
4785 ch = i_getch(input);
4786 nommu_addchr(as_string, ch);
4791 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4793 bb_error_msg("ambiguous redirect");
4794 return REDIRFD_SYNTAX_ERR;
4797 /* Return code is 0 normal, 1 if a syntax error is detected
4799 static int parse_redirect(struct parse_context *ctx,
4802 struct in_str *input)
4804 struct command *command = ctx->command;
4805 struct redir_struct *redir;
4806 struct redir_struct **redirp;
4809 dup_num = REDIRFD_TO_FILE;
4810 if (style != REDIRECT_HEREDOC) {
4811 /* Check for a '>&1' type redirect */
4812 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4813 if (dup_num == REDIRFD_SYNTAX_ERR)
4816 int ch = i_peek(input);
4817 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4818 if (dup_num) { /* <<-... */
4819 ch = i_getch(input);
4820 nommu_addchr(&ctx->as_string, ch);
4825 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4826 int ch = i_peek(input);
4828 /* >|FILE redirect ("clobbering" >).
4829 * Since we do not support "set -o noclobber" yet,
4830 * >| and > are the same for now. Just eat |.
4832 ch = i_getch(input);
4833 nommu_addchr(&ctx->as_string, ch);
4837 /* Create a new redir_struct and append it to the linked list */
4838 redirp = &command->redirects;
4839 while ((redir = *redirp) != NULL) {
4840 redirp = &(redir->next);
4842 *redirp = redir = xzalloc(sizeof(*redir));
4843 /* redir->next = NULL; */
4844 /* redir->rd_filename = NULL; */
4845 redir->rd_type = style;
4846 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4848 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4849 redir_table[style].descrip);
4851 redir->rd_dup = dup_num;
4852 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4853 /* Erik had a check here that the file descriptor in question
4854 * is legit; I postpone that to "run time"
4855 * A "-" representation of "close me" shows up as a -3 here */
4856 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4857 redir->rd_fd, redir->rd_dup);
4859 /* Set ctx->pending_redirect, so we know what to do at the
4860 * end of the next parsed word. */
4861 ctx->pending_redirect = redir;
4866 /* If a redirect is immediately preceded by a number, that number is
4867 * supposed to tell which file descriptor to redirect. This routine
4868 * looks for such preceding numbers. In an ideal world this routine
4869 * needs to handle all the following classes of redirects...
4870 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4871 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4872 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4873 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4875 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4877 * ... If n is quoted, the number shall not be recognized as part of
4878 * the redirection expression. For example:
4880 * writes the character 2 into file a"
4881 * We are getting it right by setting ->o_quoted on any \<char>
4883 * A -1 return means no valid number was found,
4884 * the caller should use the appropriate default for this redirection.
4886 static int redirect_opt_num(o_string *o)
4890 if (o->data == NULL)
4892 num = bb_strtou(o->data, NULL, 10);
4893 if (errno || num < 0)
4895 o_reset_to_empty_unquoted(o);
4900 #define fetch_till_str(as_string, input, word, skip_tabs) \
4901 fetch_till_str(input, word, skip_tabs)
4903 static char *fetch_till_str(o_string *as_string,
4904 struct in_str *input,
4908 o_string heredoc = NULL_O_STRING;
4914 ch = i_getch(input);
4915 nommu_addchr(as_string, ch);
4917 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4918 heredoc.data[past_EOL] = '\0';
4919 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4920 return heredoc.data;
4923 o_addchr(&heredoc, ch);
4924 past_EOL = heredoc.length;
4927 ch = i_getch(input);
4928 nommu_addchr(as_string, ch);
4929 } while (skip_tabs && ch == '\t');
4930 } while (ch == '\n');
4933 o_free_unsafe(&heredoc);
4936 o_addchr(&heredoc, ch);
4937 nommu_addchr(as_string, ch);
4941 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4942 * and load them all. There should be exactly heredoc_cnt of them.
4944 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4946 struct pipe *pi = ctx->list_head;
4948 while (pi && heredoc_cnt) {
4950 struct command *cmd = pi->cmds;
4952 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4954 cmd->argv ? cmd->argv[0] : "NONE");
4955 for (i = 0; i < pi->num_cmds; i++) {
4956 struct redir_struct *redir = cmd->redirects;
4958 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4959 i, cmd->argv ? cmd->argv[0] : "NONE");
4961 if (redir->rd_type == REDIRECT_HEREDOC) {
4964 redir->rd_type = REDIRECT_HEREDOC2;
4965 /* redir->dup is (ab)used to indicate <<- */
4966 p = fetch_till_str(&ctx->as_string, input,
4967 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4969 syntax_error("unexpected EOF in here document");
4972 free(redir->rd_filename);
4973 redir->rd_filename = p;
4976 redir = redir->next;
4983 /* Should be 0. If it isn't, it's a parse error */
4985 bb_error_msg_and_die("heredoc BUG 2");
4991 #if ENABLE_HUSH_TICK
4992 static FILE *generate_stream_from_string(const char *s)
4995 int pid, channel[2];
5001 pid = BB_MMU ? fork() : vfork();
5003 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5005 if (pid == 0) { /* child */
5006 disable_restore_tty_pgrp_on_exit();
5007 /* Process substitution is not considered to be usual
5008 * 'command execution'.
5009 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5016 close(channel[0]); /* NB: close _first_, then move fd! */
5017 xmove_fd(channel[1], 1);
5018 /* Prevent it from trying to handle ctrl-z etc */
5019 IF_HUSH_JOB(G.run_list_level = 1;)
5021 reset_traps_to_defaults();
5022 parse_and_run_string(s);
5023 _exit(G.last_exitcode);
5025 /* We re-execute after vfork on NOMMU. This makes this script safe:
5026 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5027 * huge=`cat BIG` # was blocking here forever
5030 re_execute_shell(&to_free,
5038 #if ENABLE_HUSH_FAST
5040 //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);
5042 enable_restore_tty_pgrp_on_exit();
5047 pf = fdopen(channel[0], "r");
5051 /* Return code is exit status of the process that is run. */
5052 static int process_command_subs(o_string *dest, const char *s)
5055 struct in_str pipe_str;
5058 pf = generate_stream_from_string(s);
5061 close_on_exec_on(fileno(pf));
5063 /* Now send results of command back into original context */
5064 setup_file_in_str(&pipe_str, pf);
5066 while ((ch = i_getch(&pipe_str)) != EOF) {
5072 o_addchr(dest, '\n');
5075 o_addQchr(dest, ch);
5078 debug_printf("done reading from pipe, pclose()ing\n");
5079 /* Note: we got EOF, and we just close the read end of the pipe.
5080 * We do not wait for the `cmd` child to terminate. bash and ash do.
5082 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
5083 * `false`; echo $? - bash outputs "1"
5086 debug_printf("closed FILE from child. return 0\n");
5091 static int parse_group(o_string *dest, struct parse_context *ctx,
5092 struct in_str *input, int ch)
5094 /* dest contains characters seen prior to ( or {.
5095 * Typically it's empty, but for function defs,
5096 * it contains function name (without '()'). */
5097 struct pipe *pipe_list;
5099 struct command *command = ctx->command;
5101 debug_printf_parse("parse_group entered\n");
5102 #if ENABLE_HUSH_FUNCTIONS
5103 if (ch == '(' && !dest->o_quoted) {
5105 if (done_word(dest, ctx))
5108 goto skip; /* (... */
5109 if (command->argv[1]) { /* word word ... (... */
5110 syntax_error_unexpected_ch('(');
5113 /* it is "word(..." or "word (..." */
5115 ch = i_getch(input);
5116 while (ch == ' ' || ch == '\t');
5118 syntax_error_unexpected_ch(ch);
5121 nommu_addchr(&ctx->as_string, ch);
5123 ch = i_getch(input);
5124 while (ch == ' ' || ch == '\t' || ch == '\n');
5126 syntax_error_unexpected_ch(ch);
5129 nommu_addchr(&ctx->as_string, ch);
5130 command->grp_type = GRP_FUNCTION;
5134 if (command->argv /* word [word]{... */
5135 || dest->length /* word{... */
5136 || dest->o_quoted /* ""{... */
5139 debug_printf_parse("parse_group return 1: "
5140 "syntax error, groups and arglists don't mix\n");
5144 #if ENABLE_HUSH_FUNCTIONS
5150 command->grp_type = GRP_SUBSHELL;
5152 /* bash does not allow "{echo...", requires whitespace */
5153 ch = i_getch(input);
5154 if (ch != ' ' && ch != '\t' && ch != '\n') {
5155 syntax_error_unexpected_ch(ch);
5158 nommu_addchr(&ctx->as_string, ch);
5163 char *as_string = NULL;
5165 pipe_list = parse_stream(&as_string, input, endch);
5168 o_addstr(&ctx->as_string, as_string);
5170 /* empty ()/{} or parse error? */
5171 if (!pipe_list || pipe_list == ERR_PTR) {
5172 /* parse_stream already emitted error msg */
5176 debug_printf_parse("parse_group return 1: "
5177 "parse_stream returned %p\n", pipe_list);
5180 command->group = pipe_list;
5182 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5183 command->group_as_string = as_string;
5184 debug_printf_parse("end of group, remembering as:'%s'\n",
5185 command->group_as_string);
5188 debug_printf_parse("parse_group return 0\n");
5190 /* command remains "open", available for possible redirects */
5193 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5194 /* Subroutines for copying $(...) and `...` things */
5195 static void add_till_backquote(o_string *dest, struct in_str *input);
5197 static void add_till_single_quote(o_string *dest, struct in_str *input)
5200 int ch = i_getch(input);
5202 syntax_error_unterm_ch('\'');
5203 /*xfunc_die(); - redundant */
5210 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5211 static void add_till_double_quote(o_string *dest, struct in_str *input)
5214 int ch = i_getch(input);
5216 syntax_error_unterm_ch('"');
5217 /*xfunc_die(); - redundant */
5221 if (ch == '\\') { /* \x. Copy both chars. */
5223 ch = i_getch(input);
5227 add_till_backquote(dest, input);
5231 //if (ch == '$') ...
5234 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5236 * "Within the backquoted style of command substitution, backslash
5237 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5238 * The search for the matching backquote shall be satisfied by the first
5239 * backquote found without a preceding backslash; during this search,
5240 * if a non-escaped backquote is encountered within a shell comment,
5241 * a here-document, an embedded command substitution of the $(command)
5242 * form, or a quoted string, undefined results occur. A single-quoted
5243 * or double-quoted string that begins, but does not end, within the
5244 * "`...`" sequence produces undefined results."
5246 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5248 static void add_till_backquote(o_string *dest, struct in_str *input)
5251 int ch = i_getch(input);
5253 syntax_error_unterm_ch('`');
5254 /*xfunc_die(); - redundant */
5259 /* \x. Copy both chars unless it is \` */
5260 int ch2 = i_getch(input);
5262 syntax_error_unterm_ch('`');
5263 /*xfunc_die(); - redundant */
5265 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5272 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5273 * quoting and nested ()s.
5274 * "With the $(command) style of command substitution, all characters
5275 * following the open parenthesis to the matching closing parenthesis
5276 * constitute the command. Any valid shell script can be used for command,
5277 * except a script consisting solely of redirections which produces
5278 * unspecified results."
5280 * echo $(echo '(TEST)' BEST) (TEST) BEST
5281 * echo $(echo 'TEST)' BEST) TEST) BEST
5282 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5284 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5288 int ch = i_getch(input);
5290 syntax_error_unterm_ch(')');
5291 /*xfunc_die(); - redundant */
5299 if (i_peek(input) == ')') {
5307 add_till_single_quote(dest, input);
5312 add_till_double_quote(dest, input);
5317 /* \x. Copy verbatim. Important for \(, \) */
5318 ch = i_getch(input);
5320 syntax_error_unterm_ch(')');
5321 /*xfunc_die(); - redundant */
5328 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5330 /* Return code: 0 for OK, 1 for syntax error */
5332 #define handle_dollar(as_string, dest, input) \
5333 handle_dollar(dest, input)
5335 static int handle_dollar(o_string *as_string,
5337 struct in_str *input)
5339 int ch = i_peek(input); /* first character after the $ */
5340 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5342 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5344 ch = i_getch(input);
5345 nommu_addchr(as_string, ch);
5347 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5349 debug_printf_parse(": '%c'\n", ch);
5350 o_addchr(dest, ch | quote_mask);
5353 if (!isalnum(ch) && ch != '_')
5355 ch = i_getch(input);
5356 nommu_addchr(as_string, ch);
5358 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5359 } else if (isdigit(ch)) {
5361 ch = i_getch(input);
5362 nommu_addchr(as_string, ch);
5363 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5364 debug_printf_parse(": '%c'\n", ch);
5365 o_addchr(dest, ch | quote_mask);
5366 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5367 } else switch (ch) {
5369 case '!': /* last bg pid */
5370 case '?': /* last exit code */
5371 case '#': /* number of args */
5372 case '*': /* args */
5373 case '@': /* args */
5374 goto make_one_char_var;
5376 bool first_char, all_digits;
5379 ch = i_getch(input);
5380 nommu_addchr(as_string, ch);
5381 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5383 /* TODO: maybe someone will try to escape the '}' */
5388 ch = i_getch(input);
5389 nommu_addchr(as_string, ch);
5396 /* ${#var}: length of var contents */
5403 /* They're being verbose and doing ${?} */
5404 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5409 && ( (all_digits && !isdigit(ch))
5410 || (!all_digits && !isalnum(ch) && ch != '_')
5413 /* handle parameter expansions
5414 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5419 case ':': /* null modifier */
5420 if (expansion == 0) {
5421 debug_printf_parse(": null modifier\n");
5426 case '#': /* remove prefix */
5427 case '%': /* remove suffix */
5428 if (expansion == 0) {
5429 debug_printf_parse(": remove suffix/prefix\n");
5434 case '-': /* default value */
5435 case '=': /* assign default */
5436 case '+': /* alternative */
5437 case '?': /* error indicate */
5438 debug_printf_parse(": parameter expansion\n");
5443 syntax_error_unterm_str("${name}");
5444 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5449 debug_printf_parse(": '%c'\n", ch);
5450 o_addchr(dest, ch | quote_mask);
5454 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5457 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5462 ch = i_getch(input);
5463 nommu_addchr(as_string, ch);
5464 # if ENABLE_SH_MATH_SUPPORT
5465 if (i_peek(input) == '(') {
5466 ch = i_getch(input);
5467 nommu_addchr(as_string, ch);
5468 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5469 o_addchr(dest, /*quote_mask |*/ '+');
5473 add_till_closing_paren(dest, input, true);
5476 o_addstr(as_string, dest->data + pos);
5477 o_addchr(as_string, ')');
5478 o_addchr(as_string, ')');
5481 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5485 # if ENABLE_HUSH_TICK
5486 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5487 o_addchr(dest, quote_mask | '`');
5491 add_till_closing_paren(dest, input, false);
5494 o_addstr(as_string, dest->data + pos);
5495 o_addchr(as_string, '`');
5498 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5504 ch = i_getch(input);
5505 nommu_addchr(as_string, ch);
5507 if (isalnum(ch)) { /* it's $_name or $_123 */
5513 /* $_ Shell or shell script name; or last cmd name */
5514 /* $- Option flags set by set builtin or shell options (-i etc) */
5516 o_addQchr(dest, '$');
5518 debug_printf_parse("handle_dollar return 0\n");
5523 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5524 parse_stream_dquoted(dest, input, dquote_end)
5526 static int parse_stream_dquoted(o_string *as_string,
5528 struct in_str *input,
5535 ch = i_getch(input);
5537 nommu_addchr(as_string, ch);
5538 if (ch == dquote_end) { /* may be only '"' or EOF */
5539 if (dest->o_assignment == NOT_ASSIGNMENT)
5540 dest->o_escape ^= 1;
5541 debug_printf_parse("parse_stream_dquoted return 0\n");
5544 /* note: can't move it above ch == dquote_end check! */
5546 syntax_error_unterm_ch('"');
5547 /*xfunc_die(); - redundant */
5551 next = i_peek(input);
5553 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5554 ch, ch, dest->o_escape);
5557 syntax_error("\\<eof>");
5561 * "The backslash retains its special meaning [in "..."]
5562 * only when followed by one of the following characters:
5563 * $, `, ", \, or <newline>. A double quote may be quoted
5564 * within double quotes by preceding it with a backslash."
5566 if (strchr("$`\"\\\n", next) != NULL) {
5567 ch = i_getch(input);
5569 o_addqchr(dest, ch);
5570 nommu_addchr(as_string, ch);
5573 o_addqchr(dest, '\\');
5574 nommu_addchr(as_string, '\\');
5579 if (handle_dollar(as_string, dest, input) != 0) {
5580 debug_printf_parse("parse_stream_dquoted return 1: "
5581 "handle_dollar returned non-0\n");
5586 #if ENABLE_HUSH_TICK
5588 //int pos = dest->length;
5589 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5590 o_addchr(dest, 0x80 | '`');
5591 add_till_backquote(dest, input);
5592 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5593 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5597 o_addQchr(dest, ch);
5599 && (dest->o_assignment == MAYBE_ASSIGNMENT
5600 || dest->o_assignment == WORD_IS_KEYWORD)
5601 && is_well_formed_var_name(dest->data, '=')
5603 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5609 * Scan input until EOF or end_trigger char.
5610 * Return a list of pipes to execute, or NULL on EOF
5611 * or if end_trigger character is met.
5612 * On syntax error, exit is shell is not interactive,
5613 * reset parsing machinery and start parsing anew,
5614 * or return ERR_PTR.
5616 static struct pipe *parse_stream(char **pstring,
5617 struct in_str *input,
5620 struct parse_context ctx;
5621 o_string dest = NULL_O_STRING;
5625 /* Double-quote state is handled in the state variable is_in_dquote.
5626 * A single-quote triggers a bypass of the main loop until its mate is
5627 * found. When recursing, quote state is passed in via dest->o_escape.
5629 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5630 end_trigger ? : 'X');
5633 G.ifs = get_local_var_value("IFS");
5638 #if ENABLE_HUSH_INTERACTIVE
5639 input->promptmode = 0; /* PS1 */
5641 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5642 initialize_context(&ctx);
5647 const char *is_special;
5651 redir_type redir_style;
5654 /* dest.o_quoted = 1; - already is (see below) */
5655 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5658 /* We reached closing '"' */
5661 ch = i_getch(input);
5662 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5663 ch, ch, dest.o_escape);
5668 syntax_error_unterm_str("here document");
5671 /* end_trigger == '}' case errors out earlier,
5672 * checking only ')' */
5673 if (end_trigger == ')') {
5674 syntax_error_unterm_ch('('); /* exits */
5675 /* goto parse_error; */
5678 if (done_word(&dest, &ctx)) {
5682 done_pipe(&ctx, PIPE_SEQ);
5684 /* If we got nothing... */
5685 /* (this makes bare "&" cmd a no-op.
5686 * bash says: "syntax error near unexpected token '&'") */
5687 if (pi->num_cmds == 0
5688 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5694 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5696 *pstring = ctx.as_string.data;
5698 o_free_unsafe(&ctx.as_string);
5701 debug_printf_parse("parse_stream return %p\n", pi);
5704 nommu_addchr(&ctx.as_string, ch);
5705 is_ifs = strchr(G.ifs, ch);
5706 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5707 "\\$\"" IF_HUSH_TICK("`") /* always special */
5710 if (!is_special && !is_ifs) { /* ordinary char */
5712 o_addQchr(&dest, ch);
5713 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5714 || dest.o_assignment == WORD_IS_KEYWORD)
5716 && is_well_formed_var_name(dest.data, '=')
5718 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5724 if (done_word(&dest, &ctx)) {
5728 #if ENABLE_HUSH_CASE
5729 /* "case ... in <newline> word) ..." -
5730 * newlines are ignored (but ';' wouldn't be) */
5731 if (ctx.command->argv == NULL
5732 && ctx.ctx_res_w == RES_MATCH
5737 /* Treat newline as a command separator. */
5738 done_pipe(&ctx, PIPE_SEQ);
5739 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5741 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5746 dest.o_assignment = MAYBE_ASSIGNMENT;
5748 /* note: if (is_ifs) continue;
5749 * will still trigger for us */
5753 /* "cmd}" or "cmd }..." without semicolon or &:
5754 * } is an ordinary char in this case, even inside { cmd; }
5755 * Pathological example: { ""}; } should exec "}" cmd
5758 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5759 || dest.length != 0 /* word} */
5760 || dest.o_quoted /* ""} */
5764 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5765 goto skip_end_trigger;
5766 /* else: } does terminate a group */
5769 if (end_trigger && end_trigger == ch
5770 && (ch != ';' || heredoc_cnt == 0)
5771 #if ENABLE_HUSH_CASE
5773 || ctx.ctx_res_w != RES_MATCH
5774 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
5779 /* This is technically valid:
5780 * { cat <<HERE; }; echo Ok
5784 * but we don't support this.
5785 * We require heredoc to be in enclosing {}/(),
5788 syntax_error_unterm_str("here document");
5791 if (done_word(&dest, &ctx)) {
5794 done_pipe(&ctx, PIPE_SEQ);
5795 dest.o_assignment = MAYBE_ASSIGNMENT;
5796 /* Do we sit outside of any if's, loops or case's? */
5798 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5802 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5804 *pstring = ctx.as_string.data;
5806 o_free_unsafe(&ctx.as_string);
5809 debug_printf_parse("parse_stream return %p: "
5810 "end_trigger char found\n",
5812 return ctx.list_head;
5821 next = i_peek(input);
5824 /* Catch <, > before deciding whether this word is
5825 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5828 redir_fd = redirect_opt_num(&dest);
5829 if (done_word(&dest, &ctx)) {
5832 redir_style = REDIRECT_OVERWRITE;
5834 redir_style = REDIRECT_APPEND;
5835 ch = i_getch(input);
5836 nommu_addchr(&ctx.as_string, ch);
5839 else if (next == '(') {
5840 syntax_error(">(process) not supported");
5844 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5846 continue; /* back to top of while (1) */
5848 redir_fd = redirect_opt_num(&dest);
5849 if (done_word(&dest, &ctx)) {
5852 redir_style = REDIRECT_INPUT;
5854 redir_style = REDIRECT_HEREDOC;
5856 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5857 ch = i_getch(input);
5858 nommu_addchr(&ctx.as_string, ch);
5859 } else if (next == '>') {
5860 redir_style = REDIRECT_IO;
5861 ch = i_getch(input);
5862 nommu_addchr(&ctx.as_string, ch);
5865 else if (next == '(') {
5866 syntax_error("<(process) not supported");
5870 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5872 continue; /* back to top of while (1) */
5875 if (dest.o_assignment == MAYBE_ASSIGNMENT
5876 /* check that we are not in word in "a=1 2>word b=1": */
5877 && !ctx.pending_redirect
5879 /* ch is a special char and thus this word
5880 * cannot be an assignment */
5881 dest.o_assignment = NOT_ASSIGNMENT;
5886 if (dest.length == 0) {
5889 if (ch == EOF || ch == '\n')
5892 /* note: we do not add it to &ctx.as_string */
5894 nommu_addchr(&ctx.as_string, '\n');
5896 o_addQchr(&dest, ch);
5901 syntax_error("\\<eof>");
5904 ch = i_getch(input);
5906 o_addchr(&dest, '\\');
5907 nommu_addchr(&ctx.as_string, '\\');
5908 o_addchr(&dest, ch);
5909 nommu_addchr(&ctx.as_string, ch);
5910 /* Example: echo Hello \2>file
5911 * we need to know that word 2 is quoted */
5916 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5917 debug_printf_parse("parse_stream parse error: "
5918 "handle_dollar returned non-0\n");
5925 ch = i_getch(input);
5927 syntax_error_unterm_ch('\'');
5928 /*xfunc_die(); - redundant */
5930 nommu_addchr(&ctx.as_string, ch);
5933 o_addqchr(&dest, ch);
5938 is_in_dquote ^= 1; /* invert */
5939 if (dest.o_assignment == NOT_ASSIGNMENT)
5942 #if ENABLE_HUSH_TICK
5947 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5948 o_addchr(&dest, '`');
5952 add_till_backquote(&dest, input);
5954 o_addstr(&ctx.as_string, dest.data + pos);
5955 o_addchr(&ctx.as_string, '`');
5957 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5958 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5963 #if ENABLE_HUSH_CASE
5966 if (done_word(&dest, &ctx)) {
5969 done_pipe(&ctx, PIPE_SEQ);
5970 #if ENABLE_HUSH_CASE
5971 /* Eat multiple semicolons, detect
5972 * whether it means something special */
5977 ch = i_getch(input);
5978 nommu_addchr(&ctx.as_string, ch);
5979 if (ctx.ctx_res_w == RES_CASE_BODY) {
5980 ctx.ctx_dsemicolon = 1;
5981 ctx.ctx_res_w = RES_MATCH;
5987 /* We just finished a cmd. New one may start
5988 * with an assignment */
5989 dest.o_assignment = MAYBE_ASSIGNMENT;
5992 if (done_word(&dest, &ctx)) {
5996 ch = i_getch(input);
5997 nommu_addchr(&ctx.as_string, ch);
5998 done_pipe(&ctx, PIPE_AND);
6000 done_pipe(&ctx, PIPE_BG);
6004 if (done_word(&dest, &ctx)) {
6007 #if ENABLE_HUSH_CASE
6008 if (ctx.ctx_res_w == RES_MATCH)
6009 break; /* we are in case's "word | word)" */
6011 if (next == '|') { /* || */
6012 ch = i_getch(input);
6013 nommu_addchr(&ctx.as_string, ch);
6014 done_pipe(&ctx, PIPE_OR);
6016 /* we could pick up a file descriptor choice here
6017 * with redirect_opt_num(), but bash doesn't do it.
6018 * "echo foo 2| cat" yields "foo 2". */
6023 #if ENABLE_HUSH_CASE
6024 /* "case... in [(]word)..." - skip '(' */
6025 if (ctx.ctx_res_w == RES_MATCH
6026 && ctx.command->argv == NULL /* not (word|(... */
6027 && dest.length == 0 /* not word(... */
6028 && dest.o_quoted == 0 /* not ""(... */
6034 if (parse_group(&dest, &ctx, input, ch) != 0) {
6039 #if ENABLE_HUSH_CASE
6040 if (ctx.ctx_res_w == RES_MATCH)
6044 /* proper use of this character is caught by end_trigger:
6045 * if we see {, we call parse_group(..., end_trigger='}')
6046 * and it will match } earlier (not here). */
6047 syntax_error_unexpected_ch(ch);
6051 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6057 struct parse_context *pctx;
6058 IF_HAS_KEYWORDS(struct parse_context *p2;)
6060 /* Clean up allocated tree.
6061 * Samples for finding leaks on syntax error recovery path.
6062 * Run them from interactive shell, watch pmap `pidof hush`.
6063 * while if false; then false; fi do break; done
6065 * while if false; then false; fi; do break; fi
6066 * Samples to catch leaks at execution:
6067 * while if (true | {true;}); then echo ok; fi; do break; done
6068 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6072 /* Update pipe/command counts,
6073 * otherwise freeing may miss some */
6074 done_pipe(pctx, PIPE_SEQ);
6075 debug_printf_clean("freeing list %p from ctx %p\n",
6076 pctx->list_head, pctx);
6077 debug_print_tree(pctx->list_head, 0);
6078 free_pipe_list(pctx->list_head);
6079 debug_printf_clean("freed list %p\n", pctx->list_head);
6081 o_free_unsafe(&pctx->as_string);
6083 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6087 IF_HAS_KEYWORDS(pctx = p2;)
6088 } while (HAS_KEYWORDS && pctx);
6089 /* Free text, clear all dest fields */
6091 /* If we are not in top-level parse, we return,
6092 * our caller will propagate error.
6094 if (end_trigger != ';') {
6102 /* Discard cached input, force prompt */
6104 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6109 /* Executing from string: eval, sh -c '...'
6110 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6111 * end_trigger controls how often we stop parsing
6112 * NUL: parse all, execute, return
6113 * ';': parse till ';' or newline, execute, repeat till EOF
6115 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6118 struct pipe *pipe_list;
6120 pipe_list = parse_stream(NULL, inp, end_trigger);
6121 if (!pipe_list) /* EOF */
6123 debug_print_tree(pipe_list, 0);
6124 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6125 run_and_free_list(pipe_list);
6129 static void parse_and_run_string(const char *s)
6131 struct in_str input;
6132 setup_string_in_str(&input, s);
6133 parse_and_run_stream(&input, '\0');
6136 static void parse_and_run_file(FILE *f)
6138 struct in_str input;
6139 setup_file_in_str(&input, f);
6140 parse_and_run_stream(&input, ';');
6143 /* Called a few times only (or even once if "sh -c") */
6144 static void block_signals(int second_time)
6149 mask = (1 << SIGQUIT);
6150 if (G_interactive_fd) {
6151 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6152 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6153 mask |= SPECIAL_JOB_SIGS;
6155 G.non_DFL_mask = mask;
6158 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6162 sigaddset(&G.blocked_set, sig);
6166 sigdelset(&G.blocked_set, SIGCHLD);
6168 sigprocmask(SIG_SETMASK, &G.blocked_set,
6169 second_time ? NULL : &G.inherited_set);
6170 /* POSIX allows shell to re-enable SIGCHLD
6171 * even if it was SIG_IGN on entry */
6172 #if ENABLE_HUSH_FAST
6173 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6175 signal(SIGCHLD, SIGCHLD_handler);
6178 signal(SIGCHLD, SIG_DFL);
6184 static void maybe_set_to_sigexit(int sig)
6186 void (*handler)(int);
6187 /* non_DFL_mask'ed signals are, well, masked,
6188 * no need to set handler for them.
6190 if (!((G.non_DFL_mask >> sig) & 1)) {
6191 handler = signal(sig, sigexit);
6192 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6193 signal(sig, handler);
6196 /* Set handlers to restore tty pgrp and exit */
6197 static void set_fatal_handlers(void)
6199 /* We _must_ restore tty pgrp on fatal signals */
6201 maybe_set_to_sigexit(SIGILL );
6202 maybe_set_to_sigexit(SIGFPE );
6203 maybe_set_to_sigexit(SIGBUS );
6204 maybe_set_to_sigexit(SIGSEGV);
6205 maybe_set_to_sigexit(SIGTRAP);
6206 } /* else: hush is perfect. what SEGV? */
6207 maybe_set_to_sigexit(SIGABRT);
6208 /* bash 3.2 seems to handle these just like 'fatal' ones */
6209 maybe_set_to_sigexit(SIGPIPE);
6210 maybe_set_to_sigexit(SIGALRM);
6211 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6212 * if we aren't interactive... but in this case
6213 * we never want to restore pgrp on exit, and this fn is not called */
6214 /*maybe_set_to_sigexit(SIGHUP );*/
6215 /*maybe_set_to_sigexit(SIGTERM);*/
6216 /*maybe_set_to_sigexit(SIGINT );*/
6220 static int set_mode(const char cstate, const char mode)
6222 int state = (cstate == '-' ? 1 : 0);
6224 case 'n': G.fake_mode = state; break;
6225 case 'x': /*G.debug_mode = state;*/ break;
6226 default: return EXIT_FAILURE;
6228 return EXIT_SUCCESS;
6231 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6232 int hush_main(int argc, char **argv)
6234 static const struct variable const_shell_ver = {
6236 .varstr = (char*)hush_version_str,
6237 .max_len = 1, /* 0 can provoke free(name) */
6241 int signal_mask_is_inited = 0;
6244 struct variable *cur_var;
6247 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6248 G.last_exitcode = EXIT_SUCCESS;
6250 G.argv0_for_re_execing = argv[0];
6252 /* Deal with HUSH_VERSION */
6253 G.shell_ver = const_shell_ver; /* copying struct here */
6254 G.top_var = &G.shell_ver;
6255 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6256 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6257 /* Initialize our shell local variables with the values
6258 * currently living in the environment */
6259 cur_var = G.top_var;
6262 char *value = strchr(*e, '=');
6263 if (value) { /* paranoia */
6264 cur_var->next = xzalloc(sizeof(*cur_var));
6265 cur_var = cur_var->next;
6266 cur_var->varstr = *e;
6267 cur_var->max_len = strlen(*e);
6268 cur_var->flg_export = 1;
6272 debug_printf_env("putenv '%s'\n", hush_version_str);
6273 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6274 #if ENABLE_FEATURE_EDITING
6275 G.line_input_state = new_line_input_t(FOR_SHELL);
6277 G.global_argc = argc;
6278 G.global_argv = argv;
6279 /* Initialize some more globals to non-zero values */
6281 cmdedit_update_prompt();
6283 if (setjmp(die_jmp)) {
6284 /* xfunc has failed! die die die */
6285 /* no EXIT traps, this is an escape hatch! */
6287 hush_exit(xfunc_error_retval);
6290 /* Shell is non-interactive at first. We need to call
6291 * block_signals(0) if we are going to execute "sh <script>",
6292 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6293 * If we later decide that we are interactive, we run block_signals(0)
6294 * (or re-run block_signals(1) if we ran block_signals(0) before)
6295 * in order to intercept (more) signals.
6299 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6301 opt = getopt(argc, argv, "c:xins"
6304 # if ENABLE_HUSH_FUNCTIONS
6314 G.root_pid = getpid();
6315 G.global_argv = argv + optind;
6316 if (!argv[optind]) {
6317 /* -c 'script' (no params): prevent empty $0 */
6318 *--G.global_argv = argv[0];
6320 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6321 G.global_argc = argc - optind;
6322 block_signals(0); /* 0: called 1st time */
6323 parse_and_run_string(optarg);
6326 /* Well, we cannot just declare interactiveness,
6327 * we have to have some stuff (ctty, etc) */
6328 /* G_interactive_fd++; */
6331 /* "-s" means "read from stdin", but this is how we always
6332 * operate, so simply do nothing here. */
6335 case '<': /* "big heredoc" support */
6336 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6339 G.root_pid = bb_strtou(optarg, &optarg, 16);
6341 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6343 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6344 # if ENABLE_HUSH_LOOPS
6346 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6351 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
6353 # if ENABLE_HUSH_FUNCTIONS
6355 struct function *funcp = new_function(optarg);
6356 /* funcp->name is already set to optarg */
6357 /* funcp->body is set to NULL. It's a special case. */
6358 funcp->body_as_string = argv[optind];
6366 if (!set_mode('-', opt))
6370 fprintf(stderr, "Usage: sh [FILE]...\n"
6371 " or: sh -c command [args]...\n\n");
6377 } /* option parsing loop */
6380 G.root_pid = getpid();
6382 /* If we are login shell... */
6383 if (argv[0] && argv[0][0] == '-') {
6385 debug_printf("sourcing /etc/profile\n");
6386 input = fopen_for_read("/etc/profile");
6387 if (input != NULL) {
6388 close_on_exec_on(fileno(input));
6389 block_signals(0); /* 0: called 1st time */
6390 signal_mask_is_inited = 1;
6391 parse_and_run_file(input);
6394 /* bash: after sourcing /etc/profile,
6395 * tries to source (in the given order):
6396 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6397 * stopping on first found. --noprofile turns this off.
6398 * bash also sources ~/.bash_logout on exit.
6399 * If called as sh, skips .bash_XXX files.
6406 * "bash <script>" (which is never interactive (unless -i?))
6407 * sources $BASH_ENV here (without scanning $PATH).
6408 * If called as sh, does the same but with $ENV.
6410 debug_printf("running script '%s'\n", argv[optind]);
6411 G.global_argv = argv + optind;
6412 G.global_argc = argc - optind;
6413 input = xfopen_for_read(argv[optind]);
6414 close_on_exec_on(fileno(input));
6415 if (!signal_mask_is_inited)
6416 block_signals(0); /* 0: called 1st time */
6417 parse_and_run_file(input);
6418 #if ENABLE_FEATURE_CLEAN_UP
6424 /* Up to here, shell was non-interactive. Now it may become one.
6425 * NB: don't forget to (re)run block_signals(0/1) as needed.
6428 /* A shell is interactive if the '-i' flag was given,
6429 * or if all of the following conditions are met:
6431 * no arguments remaining or the -s flag given
6432 * standard input is a terminal
6433 * standard output is a terminal
6434 * Refer to Posix.2, the description of the 'sh' utility.
6437 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6438 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6439 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
6440 if (G_saved_tty_pgrp < 0)
6441 G_saved_tty_pgrp = 0;
6443 /* try to dup stdin to high fd#, >= 255 */
6444 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6445 if (G_interactive_fd < 0) {
6446 /* try to dup to any fd */
6447 G_interactive_fd = dup(STDIN_FILENO);
6448 if (G_interactive_fd < 0) {
6450 G_interactive_fd = 0;
6451 G_saved_tty_pgrp = 0;
6454 // TODO: track & disallow any attempts of user
6455 // to (inadvertently) close/redirect G_interactive_fd
6457 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6458 if (G_interactive_fd) {
6459 close_on_exec_on(G_interactive_fd);
6461 if (G_saved_tty_pgrp) {
6462 /* If we were run as 'hush &', sleep until we are
6463 * in the foreground (tty pgrp == our pgrp).
6464 * If we get started under a job aware app (like bash),
6465 * make sure we are now in charge so we don't fight over
6466 * who gets the foreground */
6468 pid_t shell_pgrp = getpgrp();
6469 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6470 if (G_saved_tty_pgrp == shell_pgrp)
6472 /* send TTIN to ourself (should stop us) */
6473 kill(- shell_pgrp, SIGTTIN);
6477 /* Block some signals */
6478 block_signals(signal_mask_is_inited);
6480 if (G_saved_tty_pgrp) {
6481 /* Set other signals to restore saved_tty_pgrp */
6482 set_fatal_handlers();
6483 /* Put ourselves in our own process group
6484 * (bash, too, does this only if ctty is available) */
6485 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6486 /* Grab control of the terminal */
6487 tcsetpgrp(G_interactive_fd, getpid());
6489 /* -1 is special - makes xfuncs longjmp, not exit
6490 * (we reset die_sleep = 0 whereever we [v]fork) */
6491 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6492 } else if (!signal_mask_is_inited) {
6493 block_signals(0); /* 0: called 1st time */
6494 } /* else: block_signals(0) was done before */
6495 #elif ENABLE_HUSH_INTERACTIVE
6496 /* No job control compiled in, only prompt/line editing */
6497 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6498 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6499 if (G_interactive_fd < 0) {
6500 /* try to dup to any fd */
6501 G_interactive_fd = dup(STDIN_FILENO);
6502 if (G_interactive_fd < 0)
6504 G_interactive_fd = 0;
6507 if (G_interactive_fd) {
6508 close_on_exec_on(G_interactive_fd);
6509 block_signals(signal_mask_is_inited);
6510 } else if (!signal_mask_is_inited) {
6514 /* We have interactiveness code disabled */
6515 if (!signal_mask_is_inited) {
6520 * if interactive but not a login shell, sources ~/.bashrc
6521 * (--norc turns this off, --rcfile <file> overrides)
6524 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6525 printf("\n\n%s hush - the humble shell\n", bb_banner);
6526 if (ENABLE_HUSH_HELP)
6527 puts("Enter 'help' for a list of built-in commands.");
6531 parse_and_run_file(stdin);
6534 #if ENABLE_FEATURE_CLEAN_UP
6535 if (G.cwd != bb_msg_unknown)
6537 cur_var = G.top_var->next;
6539 struct variable *tmp = cur_var;
6540 if (!cur_var->max_len)
6541 free(cur_var->varstr);
6542 cur_var = cur_var->next;
6546 hush_exit(G.last_exitcode);
6551 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6552 int lash_main(int argc, char **argv)
6554 //bb_error_msg("lash is deprecated, please use hush instead");
6555 return hush_main(argc, argv);
6563 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
6568 static int FAST_FUNC builtin_test(char **argv)
6575 return test_main(argc, argv - argc);
6578 static int FAST_FUNC builtin_echo(char **argv)
6585 return echo_main(argc, argv - argc);
6588 static int FAST_FUNC builtin_eval(char **argv)
6590 int rcode = EXIT_SUCCESS;
6593 char *str = expand_strvec_to_string(argv);
6595 * eval "echo Hi; done" ("done" is syntax error):
6596 * "echo Hi" will not execute too.
6598 parse_and_run_string(str);
6600 rcode = G.last_exitcode;
6605 static int FAST_FUNC builtin_cd(char **argv)
6607 const char *newdir = argv[1];
6608 if (newdir == NULL) {
6609 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6610 * bash says "bash: cd: HOME not set" and does nothing
6613 newdir = get_local_var_value("HOME") ? : "/";
6615 if (chdir(newdir)) {
6616 /* Mimic bash message exactly */
6617 bb_perror_msg("cd: %s", newdir);
6618 return EXIT_FAILURE;
6621 return EXIT_SUCCESS;
6624 static int FAST_FUNC builtin_exec(char **argv)
6626 if (*++argv == NULL)
6627 return EXIT_SUCCESS; /* bash does this */
6632 /* TODO: if exec fails, bash does NOT exit! We do... */
6633 pseudo_exec_argv(&dummy, argv, 0, NULL);
6638 static int FAST_FUNC builtin_exit(char **argv)
6640 debug_printf_exec("%s()\n", __func__);
6642 /* interactive bash:
6643 * # trap "echo EEE" EXIT
6646 * There are stopped jobs.
6647 * (if there are _stopped_ jobs, running ones don't count)
6650 # EEE (then bash exits)
6652 * we can use G.exiting = -1 as indicator "last cmd was exit"
6655 /* note: EXIT trap is run by hush_exit */
6656 if (*++argv == NULL)
6657 hush_exit(G.last_exitcode);
6658 /* mimic bash: exit 123abc == exit 255 + error msg */
6659 xfunc_error_retval = 255;
6660 /* bash: exit -2 == exit 254, no error msg */
6661 hush_exit(xatoi(*argv) & 0xff);
6664 static void print_escaped(const char *s)
6670 p = strchrnul(s, '\'');
6671 /* print 'xxxx', possibly just '' */
6672 printf("'%.*s'", (int)(p - s), s);
6677 /* s points to '; print "'''...'''" */
6679 do putchar('\''); while (*++s == '\'');
6684 #if !ENABLE_HUSH_LOCAL
6685 #define helper_export_local(argv, exp, lvl) \
6686 helper_export_local(argv, exp)
6688 static void helper_export_local(char **argv, int exp, int lvl)
6693 /* So far we do not check that name is valid (TODO?) */
6695 if (strchr(name, '=') == NULL) {
6696 struct variable *var;
6698 var = get_local_var(name);
6699 if (exp == -1) { /* unexporting? */
6700 /* export -n NAME (without =VALUE) */
6702 var->flg_export = 0;
6703 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6705 } /* else: export -n NOT_EXISTING_VAR: no-op */
6708 if (exp == 1) { /* exporting? */
6709 /* export NAME (without =VALUE) */
6711 var->flg_export = 1;
6712 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6713 putenv(var->varstr);
6717 /* Exporting non-existing variable.
6718 * bash does not put it in environment,
6719 * but remembers that it is exported,
6720 * and does put it in env when it is set later.
6721 * We just set it to "" and export. */
6722 /* Or, it's "local NAME" (without =VALUE).
6723 * bash sets the value to "". */
6724 name = xasprintf("%s=", name);
6726 /* (Un)exporting/making local NAME=VALUE */
6727 name = xstrdup(name);
6729 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
6733 static int FAST_FUNC builtin_export(char **argv)
6735 unsigned opt_unexport;
6737 if (argv[1] == NULL) {
6744 /* ash emits: export VAR='VAL'
6745 * bash: declare -x VAR="VAL"
6746 * we follow ash example */
6747 const char *s = *e++;
6748 const char *p = strchr(s, '=');
6750 if (!p) /* wtf? take next variable */
6753 printf("export %.*s", (int)(p - s) + 1, s);
6754 print_escaped(p + 1);
6758 /*fflush(stdout); - done after each builtin anyway */
6760 return EXIT_SUCCESS;
6763 #if ENABLE_HUSH_EXPORT_N
6764 /* "!": do not abort on errors */
6765 /* "+": stop at 1st non-option */
6766 opt_unexport = getopt32(argv, "!+n");
6767 if (opt_unexport == (unsigned)-1)
6768 return EXIT_FAILURE;
6775 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
6777 return EXIT_SUCCESS;
6780 #if ENABLE_HUSH_LOCAL
6781 static int FAST_FUNC builtin_local(char **argv)
6783 if (G.func_nest_level == 0) {
6784 bb_error_msg("%s: not in a function", argv[0]);
6785 return EXIT_FAILURE; /* bash compat */
6787 helper_export_local(argv, 0, G.func_nest_level);
6788 return EXIT_SUCCESS;
6792 static int FAST_FUNC builtin_trap(char **argv)
6798 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6803 /* No args: print all trapped */
6804 for (i = 0; i < NSIG; ++i) {
6807 print_escaped(G.traps[i]);
6808 printf(" %s\n", get_signame(i));
6811 /*fflush(stdout); - done after each builtin anyway */
6812 return EXIT_SUCCESS;
6816 /* If first arg is a number: reset all specified signals */
6817 sig = bb_strtou(*argv, NULL, 10);
6823 sig = get_signum(*argv++);
6824 if (sig < 0 || sig >= NSIG) {
6826 /* Mimic bash message exactly */
6827 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6832 G.traps[sig] = xstrdup(new_cmd);
6834 debug_printf("trap: setting SIG%s (%i) to '%s'",
6835 get_signame(sig), sig, G.traps[sig]);
6837 /* There is no signal for 0 (EXIT) */
6842 sigaddset(&G.blocked_set, sig);
6844 /* There was a trap handler, we are removing it
6845 * (if sig has non-DFL handling,
6846 * we don't need to do anything) */
6847 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6849 sigdelset(&G.blocked_set, sig);
6852 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6856 if (!argv[1]) { /* no second arg */
6857 bb_error_msg("trap: invalid arguments");
6858 return EXIT_FAILURE;
6861 /* First arg is "-": reset all specified to default */
6862 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6863 /* Everything else: set arg as signal handler
6864 * (includes "" case, which ignores signal) */
6865 if (argv[0][0] == '-') {
6866 if (argv[0][1] == '\0') { /* "-" */
6867 /* new_cmd remains NULL: "reset these sigs" */
6870 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6873 /* else: "-something", no special meaning */
6878 goto process_sig_list;
6881 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
6882 static int FAST_FUNC builtin_type(char **argv)
6884 int ret = EXIT_SUCCESS;
6890 if (0) {} /* make conditional compile easier below */
6891 /*else if (find_alias(*argv))
6892 type = "an alias";*/
6893 #if ENABLE_HUSH_FUNCTIONS
6894 else if (find_function(*argv))
6895 type = "a function";
6897 else if (find_builtin(*argv))
6898 type = "a shell builtin";
6899 else if ((path = find_in_path(*argv)) != NULL)
6902 bb_error_msg("type: %s: not found", *argv);
6907 printf("%s is %s\n", *argv, type);
6915 /* built-in 'fg' and 'bg' handler */
6916 static int FAST_FUNC builtin_fg_bg(char **argv)
6921 if (!G_interactive_fd)
6922 return EXIT_FAILURE;
6924 /* If they gave us no args, assume they want the last backgrounded task */
6926 for (pi = G.job_list; pi; pi = pi->next) {
6927 if (pi->jobid == G.last_jobid) {
6931 bb_error_msg("%s: no current job", argv[0]);
6932 return EXIT_FAILURE;
6934 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6935 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6936 return EXIT_FAILURE;
6938 for (pi = G.job_list; pi; pi = pi->next) {
6939 if (pi->jobid == jobnum) {
6943 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6944 return EXIT_FAILURE;
6946 /* TODO: bash prints a string representation
6947 * of job being foregrounded (like "sleep 1 | cat") */
6948 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
6949 /* Put the job into the foreground. */
6950 tcsetpgrp(G_interactive_fd, pi->pgrp);
6953 /* Restart the processes in the job */
6954 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6955 for (i = 0; i < pi->num_cmds; i++) {
6956 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6957 pi->cmds[i].is_stopped = 0;
6959 pi->stopped_cmds = 0;
6961 i = kill(- pi->pgrp, SIGCONT);
6963 if (errno == ESRCH) {
6964 delete_finished_bg_job(pi);
6965 return EXIT_SUCCESS;
6967 bb_perror_msg("kill (SIGCONT)");
6970 if (argv[0][0] == 'f') {
6972 return checkjobs_and_fg_shell(pi);
6974 return EXIT_SUCCESS;
6978 #if ENABLE_HUSH_HELP
6979 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
6981 const struct built_in_command *x;
6984 "Built-in commands:\n"
6985 "------------------\n");
6986 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6987 printf("%s\t%s\n", x->cmd, x->descr);
6990 return EXIT_SUCCESS;
6995 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
6998 const char *status_string;
7000 for (job = G.job_list; job; job = job->next) {
7001 if (job->alive_cmds == job->stopped_cmds)
7002 status_string = "Stopped";
7004 status_string = "Running";
7006 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7008 return EXIT_SUCCESS;
7013 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7018 /* Crude attempt to find where "free memory" starts,
7019 * sans fragmentation. */
7021 l = (unsigned long)p;
7024 if (l < (unsigned long)p) l = (unsigned long)p;
7027 if (!G.memleak_value)
7028 G.memleak_value = l;
7030 l -= G.memleak_value;
7037 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7042 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7045 return EXIT_SUCCESS;
7048 static int FAST_FUNC builtin_read(char **argv)
7051 const char *name = "REPLY";
7055 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
7056 * and _after_ that_ it will complain */
7057 if (!is_well_formed_var_name(name, '\0')) {
7058 /* Mimic bash message */
7059 bb_error_msg("read: '%s': not a valid identifier", name);
7064 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
7066 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
7067 return set_local_var(string, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7070 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7071 * built-in 'set' handler
7073 * set [-abCefhmnuvx] [-o option] [argument...]
7074 * set [+abCefhmnuvx] [+o option] [argument...]
7075 * set -- [argument...]
7078 * Implementations shall support the options in both their hyphen and
7079 * plus-sign forms. These options can also be specified as options to sh.
7081 * Write out all variables and their values: set
7082 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7083 * Turn on the -x and -v options: set -xv
7084 * Unset all positional parameters: set --
7085 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7086 * Set the positional parameters to the expansion of x, even if x expands
7087 * with a leading '-' or '+': set -- $x
7089 * So far, we only support "set -- [argument...]" and some of the short names.
7091 static int FAST_FUNC builtin_set(char **argv)
7094 char **pp, **g_argv;
7095 char *arg = *++argv;
7099 for (e = G.top_var; e; e = e->next)
7101 return EXIT_SUCCESS;
7105 if (!strcmp(arg, "--")) {
7109 if (arg[0] != '+' && arg[0] != '-')
7111 for (n = 1; arg[n]; ++n)
7112 if (set_mode(arg[0], arg[n]))
7114 } while ((arg = *++argv) != NULL);
7115 /* Now argv[0] is 1st argument */
7118 return EXIT_SUCCESS;
7121 /* NB: G.global_argv[0] ($0) is never freed/changed */
7122 g_argv = G.global_argv;
7123 if (G.global_args_malloced) {
7129 G.global_args_malloced = 1;
7130 pp = xzalloc(sizeof(pp[0]) * 2);
7131 pp[0] = g_argv[0]; /* retain $0 */
7134 /* This realloc's G.global_argv */
7135 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7142 return EXIT_SUCCESS;
7144 /* Nothing known, so abort */
7146 bb_error_msg("set: %s: invalid option", arg);
7147 return EXIT_FAILURE;
7150 static int FAST_FUNC builtin_shift(char **argv)
7156 if (n >= 0 && n < G.global_argc) {
7157 if (G.global_args_malloced) {
7160 free(G.global_argv[m++]);
7163 memmove(&G.global_argv[1], &G.global_argv[n+1],
7164 G.global_argc * sizeof(G.global_argv[0]));
7165 return EXIT_SUCCESS;
7167 return EXIT_FAILURE;
7170 static int FAST_FUNC builtin_source(char **argv)
7175 #if ENABLE_HUSH_FUNCTIONS
7179 if (*++argv == NULL)
7180 return EXIT_FAILURE;
7182 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7183 input = fopen_for_read(arg_path);
7186 input = fopen_or_warn(*argv, "r");
7188 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7189 return EXIT_FAILURE;
7191 close_on_exec_on(fileno(input));
7193 #if ENABLE_HUSH_FUNCTIONS
7194 sv_flg = G.flag_return_in_progress;
7195 /* "we are inside sourced file, ok to use return" */
7196 G.flag_return_in_progress = -1;
7198 save_and_replace_G_args(&sv, argv);
7200 parse_and_run_file(input);
7203 restore_G_args(&sv, argv);
7204 #if ENABLE_HUSH_FUNCTIONS
7205 G.flag_return_in_progress = sv_flg;
7208 return G.last_exitcode;
7211 static int FAST_FUNC builtin_umask(char **argv)
7218 mode_t old_mask = mask;
7221 rc = bb_parse_mode(argv[1], &mask);
7226 * bash: umask: 'q': invalid symbolic mode operator
7227 * bash: umask: 999: octal number out of range
7229 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7234 printf("%04o\n", (unsigned) mask);
7235 /* fall through and restore mask which we set to 0 */
7239 return !rc; /* rc != 0 - success */
7242 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7243 static int FAST_FUNC builtin_unset(char **argv)
7248 /* "!": do not abort on errors */
7249 /* "+": stop at 1st non-option */
7250 opts = getopt32(argv, "!+vf");
7251 if (opts == (unsigned)-1)
7252 return EXIT_FAILURE;
7254 bb_error_msg("unset: -v and -f are exclusive");
7255 return EXIT_FAILURE;
7261 if (!(opts & 2)) { /* not -f */
7262 if (unset_local_var(*argv)) {
7263 /* unset <nonexistent_var> doesn't fail.
7264 * Error is when one tries to unset RO var.
7265 * Message was printed by unset_local_var. */
7269 #if ENABLE_HUSH_FUNCTIONS
7279 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7280 static int FAST_FUNC builtin_wait(char **argv)
7282 int ret = EXIT_SUCCESS;
7285 if (*++argv == NULL) {
7286 /* Don't care about wait results */
7287 /* Note 1: must wait until there are no more children */
7288 /* Note 2: must be interruptible */
7290 * $ sleep 3 & sleep 6 & wait
7295 * $ sleep 3 & sleep 6 & wait
7299 * ^C <-- after ~4 sec from keyboard
7302 sigaddset(&G.blocked_set, SIGCHLD);
7303 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7306 if (errno == ECHILD)
7308 /* Wait for SIGCHLD or any other signal of interest */
7309 /* sigtimedwait with infinite timeout: */
7310 sig = sigwaitinfo(&G.blocked_set, NULL);
7312 sig = check_and_run_traps(sig);
7313 if (sig && sig != SIGCHLD) { /* see note 2 */
7319 sigdelset(&G.blocked_set, SIGCHLD);
7320 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7324 /* This is probably buggy wrt interruptible-ness */
7326 pid_t pid = bb_strtou(*argv, NULL, 10);
7328 /* mimic bash message */
7329 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7330 return EXIT_FAILURE;
7332 if (waitpid(pid, &status, 0) == pid) {
7333 if (WIFSIGNALED(status))
7334 ret = 128 + WTERMSIG(status);
7335 else if (WIFEXITED(status))
7336 ret = WEXITSTATUS(status);
7340 bb_perror_msg("wait %s", *argv);
7349 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7350 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7353 def = bb_strtou(argv[1], NULL, 10);
7354 if (errno || def < def_min || argv[2]) {
7355 bb_error_msg("%s: bad arguments", argv[0]);
7363 #if ENABLE_HUSH_LOOPS
7364 static int FAST_FUNC builtin_break(char **argv)
7367 if (G.depth_of_loop == 0) {
7368 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7369 return EXIT_SUCCESS; /* bash compat */
7371 G.flag_break_continue++; /* BC_BREAK = 1 */
7373 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7374 if (depth == UINT_MAX)
7375 G.flag_break_continue = BC_BREAK;
7376 if (G.depth_of_loop < depth)
7377 G.depth_break_continue = G.depth_of_loop;
7379 return EXIT_SUCCESS;
7382 static int FAST_FUNC builtin_continue(char **argv)
7384 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7385 return builtin_break(argv);
7389 #if ENABLE_HUSH_FUNCTIONS
7390 static int FAST_FUNC builtin_return(char **argv)
7394 if (G.flag_return_in_progress != -1) {
7395 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7396 return EXIT_FAILURE; /* bash compat */
7399 G.flag_return_in_progress = 1;
7402 * out of range: wraps around at 256, does not error out
7403 * non-numeric param:
7404 * f() { false; return qwe; }; f; echo $?
7405 * bash: return: qwe: numeric argument required <== we do this
7406 * 255 <== we also do this
7408 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);