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 * change { and } from special chars to reserved words
54 * $var refs in function do not pick up values set by "var=val func"
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
59 * separate job control from interactiveness
60 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
62 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
64 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
66 /* #include <dmalloc.h> */
73 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
77 /* Debug build knobs */
78 #define LEAK_HUNTING 0
79 #define BUILD_AS_NOMMU 0
80 /* Enable/disable sanity checks. Ok to enable in production,
81 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
82 * Keeping 1 for now even in released versions.
92 # define USE_FOR_NOMMU(...) __VA_ARGS__
93 # define USE_FOR_MMU(...)
96 #if defined SINGLE_APPLET_MAIN
97 /* STANDALONE does not make sense, and won't compile */
98 # undef CONFIG_FEATURE_SH_STANDALONE
99 # undef ENABLE_FEATURE_SH_STANDALONE
100 # undef IF_FEATURE_SH_STANDALONE
101 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 # define ENABLE_FEATURE_SH_STANDALONE 0
103 # define IF_FEATURE_SH_STANDALONE(...)
104 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 #if !ENABLE_HUSH_INTERACTIVE
108 # undef ENABLE_FEATURE_EDITING
109 # define ENABLE_FEATURE_EDITING 0
110 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
111 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
114 /* Do we support ANY keywords? */
115 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
116 # define HAS_KEYWORDS 1
117 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
118 # define IF_HAS_NO_KEYWORDS(...)
120 # define HAS_KEYWORDS 0
121 # define IF_HAS_KEYWORDS(...)
122 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
125 /* If you comment out one of these below, it will be #defined later
126 * to perform debug printfs to stderr: */
127 #define debug_printf(...) do {} while (0)
128 /* Finer-grained debug switches */
129 #define debug_printf_parse(...) do {} while (0)
130 #define debug_print_tree(a, b) do {} while (0)
131 #define debug_printf_exec(...) do {} while (0)
132 #define debug_printf_env(...) do {} while (0)
133 #define debug_printf_jobs(...) do {} while (0)
134 #define debug_printf_expand(...) do {} while (0)
135 #define debug_printf_glob(...) do {} while (0)
136 #define debug_printf_list(...) do {} while (0)
137 #define debug_printf_subst(...) do {} while (0)
138 #define debug_printf_clean(...) do {} while (0)
140 #define ERR_PTR ((void*)(long)1)
142 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
144 #define SPECIAL_VAR_SYMBOL 3
146 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
148 /* This supports saving pointers malloced in vfork child,
149 * to be freed in the parent.
152 typedef struct nommu_save_t {
156 char **argv_from_re_execing;
160 /* The descrip member of this structure is only used to make
161 * debugging output pretty */
162 static const struct {
164 signed char default_fd;
168 { O_RDONLY, 0, "<" },
169 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
170 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
171 { O_RDONLY, 0, "<<" },
172 { O_CREAT|O_RDWR, 1, "<>" },
173 /* Should not be needed. Bogus default_fd helps in debugging */
174 /* { O_RDONLY, 77, "<<" }, */
177 typedef enum reserved_style {
186 #if ENABLE_HUSH_LOOPS
193 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
198 /* two pseudo-keywords support contrived "case" syntax: */
199 RES_MATCH , /* "word)" */
200 RES_CASEI , /* "this command is inside CASE" */
207 typedef struct o_string {
209 int length; /* position where data is appended */
211 /* Protect newly added chars against globbing
212 * (by prepending \ to *, ?, [, \) */
215 /* At least some part of the string was inside '' or "",
216 * possibly empty one: word"", wo''rd etc. */
218 smallint has_empty_slot;
219 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
222 MAYBE_ASSIGNMENT = 0,
223 DEFINITELY_ASSIGNMENT = 1,
225 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
227 /* Used for initialization: o_string foo = NULL_O_STRING; */
228 #define NULL_O_STRING { NULL }
230 /* I can almost use ordinary FILE*. Is open_memstream() universally
231 * available? Where is it documented? */
232 typedef struct in_str {
234 /* eof_flag=1: last char in ->p is really an EOF */
235 char eof_flag; /* meaningless if ->p == NULL */
237 #if ENABLE_HUSH_INTERACTIVE
239 smallint promptmode; /* 0: PS1, 1: PS2 */
242 int (*get) (struct in_str *);
243 int (*peek) (struct in_str *);
245 #define i_getch(input) ((input)->get(input))
246 #define i_peek(input) ((input)->peek(input))
248 struct redir_struct {
249 struct redir_struct *next;
250 char *rd_filename; /* filename */
251 int rd_fd; /* fd to redirect */
252 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
254 smallint rd_type; /* (enum redir_type) */
255 /* note: for heredocs, rd_filename contains heredoc delimiter,
256 * and subsequently heredoc itself; and rd_dup is a bitmask:
257 * 1: do we need to trim leading tabs?
258 * 2: is heredoc quoted (<<'delim' syntax) ?
261 typedef enum redir_type {
262 REDIRECT_INVALID = 0,
264 REDIRECT_OVERWRITE = 2,
266 REDIRECT_HEREDOC = 4,
268 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
271 REDIRFD_SYNTAX_ERR = -2,
272 REDIRFD_TO_FILE = -1,
273 /* otherwise, rd_fd is redirected to rd_dup */
275 HEREDOC_SKIPTABS = 1,
281 pid_t pid; /* 0 if exited */
282 int assignment_cnt; /* how many argv[i] are assignments? */
283 smallint is_stopped; /* is the command currently running? */
284 smallint grp_type; /* GRP_xxx */
286 #define GRP_SUBSHELL 1
287 #if ENABLE_HUSH_FUNCTIONS
288 # define GRP_FUNCTION 2
290 struct pipe *group; /* if non-NULL, this "command" is { list },
291 * ( list ), or a compound statement */
293 char *group_as_string;
295 #if ENABLE_HUSH_FUNCTIONS
296 struct function *child_func;
297 /* This field is used to prevent a bug here:
298 * while...do f1() {a;}; f1; f1 {b;}; f1; done
299 * When we execute "f1() {a;}" cmd, we create new function and clear
300 * cmd->group, cmd->group_as_string, cmd->argv[0].
301 * when we execute "f1 {b;}", we notice that f1 exists,
302 * and that it's "parent cmd" struct is still "alive",
303 * we put those fields back into cmd->xxx
304 * (struct function has ->parent_cmd ptr to facilitate that).
305 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
306 * Without this trick, loop would execute a;b;b;b;...
307 * instead of correct sequence a;b;a;b;...
308 * When command is freed, it severs the link
309 * (sets ->child_func->parent_cmd to NULL).
312 char **argv; /* command name and arguments */
313 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
314 * and on execution these are substituted with their values.
315 * Substitution can make _several_ words out of one argv[n]!
316 * Example: argv[0]=='.^C*^C.' here: echo .$*.
317 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
319 struct redir_struct *redirects; /* I/O redirections */
321 /* Is there anything in this command at all? */
322 #define IS_NULL_CMD(cmd) \
323 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
328 int num_cmds; /* total number of commands in pipe */
329 int alive_cmds; /* number of commands running (not exited) */
330 int stopped_cmds; /* number of commands alive, but stopped */
332 int jobid; /* job number */
333 pid_t pgrp; /* process group ID for the job */
334 char *cmdtext; /* name of job */
336 struct command *cmds; /* array of commands in pipe */
337 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
338 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
339 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
341 typedef enum pipe_style {
347 /* Is there anything in this pipe at all? */
348 #define IS_NULL_PIPE(pi) \
349 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
351 /* This holds pointers to the various results of parsing */
352 struct parse_context {
353 /* linked list of pipes */
354 struct pipe *list_head;
355 /* last pipe (being constructed right now) */
357 /* last command in pipe (being constructed right now) */
358 struct command *command;
359 /* last redirect in command->redirects list */
360 struct redir_struct *pending_redirect;
366 smallint ctx_inverted; /* "! cmd | cmd" */
368 smallint ctx_dsemicolon; /* ";;" seen */
370 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
372 /* group we are enclosed in:
373 * example: "if pipe1; pipe2; then pipe3; fi"
374 * when we see "if" or "then", we malloc and copy current context,
375 * and make ->stack point to it. then we parse pipeN.
376 * when closing "then" / fi" / whatever is found,
377 * we move list_head into ->stack->command->group,
378 * copy ->stack into current context, and delete ->stack.
379 * (parsing of { list } and ( list ) doesn't use this method)
381 struct parse_context *stack;
385 /* On program start, environ points to initial environment.
386 * putenv adds new pointers into it, unsetenv removes them.
387 * Neither of these (de)allocates the strings.
388 * setenv allocates new strings in malloc space and does putenv,
389 * and thus setenv is unusable (leaky) for shell's purposes */
390 #define setenv(...) setenv_is_leaky_dont_use()
392 struct variable *next;
393 char *varstr; /* points to "name=" portion */
394 int max_len; /* if > 0, name is part of initial env; else name is malloced */
395 smallint flg_export; /* putenv should be done on this var */
396 smallint flg_read_only;
404 #if ENABLE_HUSH_FUNCTIONS
406 struct function *next;
408 struct command *parent_cmd;
411 char *body_as_string;
417 /* "Globals" within this file */
418 /* Sorted roughly by size (smaller offsets == smaller code) */
420 /* interactive_fd != 0 means we are an interactive shell.
421 * If we are, then saved_tty_pgrp can also be != 0, meaning
422 * that controlling tty is available. With saved_tty_pgrp == 0,
423 * job control still works, but terminal signals
424 * (^C, ^Z, ^Y, ^\) won't work at all, and background
425 * process groups can only be created with "cmd &".
426 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
427 * to give tty to the foreground process group,
428 * and will take it back when the group is stopped (^Z)
431 #if ENABLE_HUSH_INTERACTIVE
432 /* 'interactive_fd' is a fd# open to ctty, if we have one
433 * _AND_ if we decided to act interactively */
437 # define G_interactive_fd (G.interactive_fd)
439 # define G_interactive_fd 0
441 #if ENABLE_FEATURE_EDITING
442 line_input_t *line_input_state;
449 pid_t saved_tty_pgrp;
450 struct pipe *job_list;
452 smallint flag_SIGINT;
453 #if ENABLE_HUSH_LOOPS
454 smallint flag_break_continue;
456 #if ENABLE_HUSH_FUNCTIONS
457 /* 0: outside of a function (or sourced file)
458 * -1: inside of a function, ok to use return builtin
459 * 1: return is invoked, skip all till end of func
461 smallint flag_return_in_progress;
464 smallint exiting; /* used to prevent EXIT trap recursion */
465 /* These four support $?, $#, and $1 */
466 smalluint last_exitcode;
467 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
468 smalluint global_args_malloced;
469 /* how many non-NULL argv's we have. NB: $# + 1 */
473 char *argv0_for_re_execing;
475 #if ENABLE_HUSH_LOOPS
476 unsigned depth_break_continue;
477 unsigned depth_of_loop;
481 struct variable *top_var; /* = &G.shell_ver (set in main()) */
482 struct variable shell_ver;
483 #if ENABLE_HUSH_FUNCTIONS
484 struct function *top_func;
486 /* Signal and trap handling */
487 // unsigned count_SIGCHLD;
488 // unsigned handled_SIGCHLD;
489 /* which signals have non-DFL handler (even with no traps set)? */
490 unsigned non_DFL_mask;
491 char **traps; /* char *traps[NSIG] */
492 sigset_t blocked_set;
493 sigset_t inherited_set;
495 unsigned long memleak_value;
498 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
500 #define G (*ptr_to_globals)
501 /* Not #defining name to G.name - this quickly gets unwieldy
502 * (too many defines). Also, I actually prefer to see when a variable
503 * is global, thus "G." prefix is a useful hint */
504 #define INIT_G() do { \
505 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
509 /* Function prototypes for builtins */
510 static int builtin_cd(char **argv);
511 static int builtin_echo(char **argv);
512 static int builtin_eval(char **argv);
513 static int builtin_exec(char **argv);
514 static int builtin_exit(char **argv);
515 static int builtin_export(char **argv);
517 static int builtin_fg_bg(char **argv);
518 static int builtin_jobs(char **argv);
521 static int builtin_help(char **argv);
524 static int builtin_memleak(char **argv);
526 static int builtin_pwd(char **argv);
527 static int builtin_read(char **argv);
528 static int builtin_set(char **argv);
529 static int builtin_shift(char **argv);
530 static int builtin_source(char **argv);
531 static int builtin_test(char **argv);
532 static int builtin_trap(char **argv);
533 static int builtin_true(char **argv);
534 static int builtin_umask(char **argv);
535 static int builtin_unset(char **argv);
536 static int builtin_wait(char **argv);
537 #if ENABLE_HUSH_LOOPS
538 static int builtin_break(char **argv);
539 static int builtin_continue(char **argv);
541 #if ENABLE_HUSH_FUNCTIONS
542 static int builtin_return(char **argv);
545 /* Table of built-in functions. They can be forked or not, depending on
546 * context: within pipes, they fork. As simple commands, they do not.
547 * When used in non-forking context, they can change global variables
548 * in the parent shell process. If forked, of course they cannot.
549 * For example, 'unset foo | whatever' will parse and run, but foo will
550 * still be set at the end. */
551 struct built_in_command {
553 int (*function)(char **argv);
556 #define BLTIN(cmd, func, help) { cmd, func, help }
558 #define BLTIN(cmd, func, help) { cmd, func }
562 /* For now, echo and test are unconditionally enabled.
563 * Maybe make it configurable? */
564 static const struct built_in_command bltins[] = {
565 BLTIN("." , builtin_source , "Run commands in a file"),
566 BLTIN(":" , builtin_true , "No-op"),
567 BLTIN("[" , builtin_test , "Test condition"),
569 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
571 #if ENABLE_HUSH_LOOPS
572 BLTIN("break" , builtin_break , "Exit from a loop"),
574 BLTIN("cd" , builtin_cd , "Change directory"),
575 #if ENABLE_HUSH_LOOPS
576 BLTIN("continue", builtin_continue, "Start new loop iteration"),
578 BLTIN("echo" , builtin_echo , "Write to stdout"),
579 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
580 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
581 BLTIN("exit" , builtin_exit , "Exit"),
582 BLTIN("export" , builtin_export , "Set environment variable"),
584 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
587 BLTIN("help" , builtin_help , "List shell built-in commands"),
590 BLTIN("jobs" , builtin_jobs , "List active jobs"),
593 BLTIN("memleak" , builtin_memleak , "Debug tool"),
595 BLTIN("pwd" , builtin_pwd , "Print current directory"),
596 BLTIN("read" , builtin_read , "Input environment variable"),
597 #if ENABLE_HUSH_FUNCTIONS
598 BLTIN("return" , builtin_return , "Return from a function"),
600 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
601 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
602 BLTIN("test" , builtin_test , "Test condition"),
603 BLTIN("trap" , builtin_trap , "Trap signals"),
604 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
605 BLTIN("umask" , builtin_umask , "Set file creation mask"),
606 BLTIN("unset" , builtin_unset , "Unset environment variable"),
607 BLTIN("wait" , builtin_wait , "Wait for process"),
614 /* prevent disasters with G.debug_indent < 0 */
615 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
616 # define debug_enter() (G.debug_indent++)
617 # define debug_leave() (G.debug_indent--)
619 # define indent() ((void)0)
620 # define debug_enter() ((void)0)
621 # define debug_leave() ((void)0)
625 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
628 #ifndef debug_printf_parse
629 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
632 #ifndef debug_printf_exec
633 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
636 #ifndef debug_printf_env
637 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
640 #ifndef debug_printf_jobs
641 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
642 # define DEBUG_JOBS 1
644 # define DEBUG_JOBS 0
647 #ifndef debug_printf_expand
648 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
649 # define DEBUG_EXPAND 1
651 # define DEBUG_EXPAND 0
654 #ifndef debug_printf_glob
655 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
656 # define DEBUG_GLOB 1
658 # define DEBUG_GLOB 0
661 #ifndef debug_printf_list
662 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
665 #ifndef debug_printf_subst
666 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
669 #ifndef debug_printf_clean
670 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
671 # define DEBUG_CLEAN 1
673 # define DEBUG_CLEAN 0
677 static void debug_print_strings(const char *prefix, char **vv)
680 fprintf(stderr, "%s:\n", prefix);
682 fprintf(stderr, " '%s'\n", *vv++);
685 #define debug_print_strings(prefix, vv) ((void)0)
689 /* Leak hunting. Use hush_leaktool.sh for post-processing.
692 static void *xxmalloc(int lineno, size_t size)
694 void *ptr = xmalloc((size + 0xff) & ~0xff);
695 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
698 static void *xxrealloc(int lineno, void *ptr, size_t size)
700 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
701 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
704 static char *xxstrdup(int lineno, const char *str)
706 char *ptr = xstrdup(str);
707 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
710 static void xxfree(void *ptr)
712 fdprintf(2, "free %p\n", ptr);
715 #define xmalloc(s) xxmalloc(__LINE__, s)
716 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
717 #define xstrdup(s) xxstrdup(__LINE__, s)
718 #define free(p) xxfree(p)
722 /* Syntax and runtime errors. They always abort scripts.
723 * In interactive use they usually discard unparsed and/or unexecuted commands
724 * and return to the prompt.
725 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
728 # define die_if_script(lineno, fmt...) die_if_script(fmt)
729 # define syntax_error(lineno, msg) syntax_error(msg)
730 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
731 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
732 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
733 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
736 static void die_if_script(unsigned lineno, const char *fmt, ...)
741 bb_error_msg("hush.c:%u", lineno);
744 bb_verror_msg(fmt, p, NULL);
746 if (!G_interactive_fd)
750 static void syntax_error(unsigned lineno, const char *msg)
753 die_if_script(lineno, "syntax error: %s", msg);
755 die_if_script(lineno, "syntax error", NULL);
758 static void syntax_error_at(unsigned lineno, const char *msg)
760 die_if_script(lineno, "syntax error at '%s'", msg);
763 /* It so happens that all such cases are totally fatal
764 * even if shell is interactive: EOF while looking for closing
765 * delimiter. There is nowhere to read stuff from after that,
766 * it's EOF! The only choice is to terminate.
768 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
769 static void syntax_error_unterm_ch(unsigned lineno, char ch)
774 die_if_script(lineno, "syntax error: unterminated %s", msg);
778 static void syntax_error_unterm_str(unsigned lineno, const char *s)
780 die_if_script(lineno, "syntax error: unterminated %s", s);
783 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
788 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
792 # undef die_if_script
794 # undef syntax_error_at
795 # undef syntax_error_unterm_ch
796 # undef syntax_error_unterm_str
797 # undef syntax_error_unexpected_ch
799 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
800 # define syntax_error(msg) syntax_error(__LINE__, msg)
801 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
802 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
803 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
804 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
808 #if ENABLE_HUSH_INTERACTIVE
809 static void cmdedit_update_prompt(void);
811 # define cmdedit_update_prompt()
817 static int glob_needed(const char *s)
822 if (*s == '*' || *s == '[' || *s == '?')
829 static int is_well_formed_var_name(const char *s, char terminator)
831 if (!s || !(isalpha(*s) || *s == '_'))
834 while (isalnum(*s) || *s == '_')
836 return *s == terminator;
839 /* Replace each \x with x in place, return ptr past NUL. */
840 static char *unbackslash(char *src)
846 if ((*dst++ = *src++) == '\0')
852 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
873 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
874 v[count1 + count2] = NULL;
877 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
881 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
883 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
884 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
887 #define add_strings_to_strings(strings, add, need_to_dup) \
888 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
891 static char **add_string_to_strings(char **strings, char *add)
896 return add_strings_to_strings(strings, v, /*dup:*/ 0);
899 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
901 char **ptr = add_string_to_strings(strings, add);
902 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
905 #define add_string_to_strings(strings, add) \
906 xx_add_string_to_strings(__LINE__, strings, add)
909 static void putenv_all(char **strings)
914 debug_printf_env("putenv '%s'\n", *strings);
919 static char **putenv_all_and_save_old(char **strings)
929 eq = strchr(*strings, '=');
932 v = getenv(*strings);
935 /* v points to VAL in VAR=VAL, go back to VAR */
936 v -= (eq - *strings) + 1;
937 old = add_string_to_strings(old, v);
946 static void free_strings_and_unsetenv(char **strings, int unset)
956 debug_printf_env("unsetenv '%s'\n", *v);
964 static void free_strings(char **strings)
966 free_strings_and_unsetenv(strings, 0);
970 /* Helpers for setting new $n and restoring them back
972 typedef struct save_arg_t {
976 smallint sv_g_malloced;
979 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
983 sv->sv_argv0 = argv[0];
984 sv->sv_g_argv = G.global_argv;
985 sv->sv_g_argc = G.global_argc;
986 sv->sv_g_malloced = G.global_args_malloced;
988 argv[0] = G.global_argv[0]; /* retain $0 */
989 G.global_argv = argv;
990 G.global_args_malloced = 0;
998 static void restore_G_args(save_arg_t *sv, char **argv)
1002 if (G.global_args_malloced) {
1003 /* someone ran "set -- arg1 arg2 ...", undo */
1005 while (*++pp) /* note: does not free $0 */
1007 free(G.global_argv);
1009 argv[0] = sv->sv_argv0;
1010 G.global_argv = sv->sv_g_argv;
1011 G.global_argc = sv->sv_g_argc;
1012 G.global_args_malloced = sv->sv_g_malloced;
1016 /* Basic theory of signal handling in shell
1017 * ========================================
1018 * This does not describe what hush does, rather, it is current understanding
1019 * what it _should_ do. If it doesn't, it's a bug.
1020 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1022 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1023 * is finished or backgrounded. It is the same in interactive and
1024 * non-interactive shells, and is the same regardless of whether
1025 * a user trap handler is installed or a shell special one is in effect.
1026 * ^C or ^Z from keyboard seem to execute "at once" because it usually
1027 * backgrounds (i.e. stops) or kills all members of currently running
1030 * Wait builtin in interruptible by signals for which user trap is set
1031 * or by SIGINT in interactive shell.
1033 * Trap handlers will execute even within trap handlers. (right?)
1035 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1037 * If job control is off, backgrounded commands ("cmd &")
1038 * have SIGINT, SIGQUIT set to SIG_IGN.
1040 * Commands run in command substitution ("`cmd`")
1041 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1043 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
1044 * by the shell from its parent.
1046 * Siganls which differ from SIG_DFL action
1047 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1050 * SIGTERM (interactive): ignore
1051 * SIGHUP (interactive):
1052 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1053 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1054 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1055 * that all pipe members are stopped. Try this in bash:
1056 * while :; do :; done - ^Z does not background it
1057 * (while :; do :; done) - ^Z backgrounds it
1058 * SIGINT (interactive): wait for last pipe, ignore the rest
1059 * of the command line, show prompt. NB: ^C does not send SIGINT
1060 * to interactive shell while shell is waiting for a pipe,
1061 * since shell is bg'ed (is not in foreground process group).
1062 * Example 1: this waits 5 sec, but does not execute ls:
1063 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1064 * Example 2: this does not wait and does not execute ls:
1065 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1066 * Example 3: this does not wait 5 sec, but executes ls:
1067 * "sleep 5; ls -l" + press ^C
1069 * (What happens to signals which are IGN on shell start?)
1070 * (What happens with signal mask on shell start?)
1072 * Implementation in hush
1073 * ======================
1074 * We use in-kernel pending signal mask to determine which signals were sent.
1075 * We block all signals which we don't want to take action immediately,
1076 * i.e. we block all signals which need to have special handling as described
1077 * above, and all signals which have traps set.
1078 * After each pipe execution, we extract any pending signals via sigtimedwait()
1081 * unsigned non_DFL_mask: a mask of such "special" signals
1082 * sigset_t blocked_set: current blocked signal set
1085 * clear bit in blocked_set unless it is also in non_DFL_mask
1086 * "trap 'cmd' SIGxxx":
1087 * set bit in blocked_set (even if 'cmd' is '')
1088 * after [v]fork, if we plan to be a shell:
1089 * unblock signals with special interactive handling
1090 * (child shell is not interactive),
1091 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1092 * after [v]fork, if we plan to exec:
1093 * POSIX says pending signal mask is cleared in child - no need to clear it.
1094 * Restore blocked signal set to one inherited by shell just prior to exec.
1096 * Note: as a result, we do not use signal handlers much. The only uses
1097 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1098 * and to restore tty pgrp on signal-induced exit.
1101 SPECIAL_INTERACTIVE_SIGS = 0
1107 SPECIAL_JOB_SIGS = 0
1114 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1116 // G.count_SIGCHLD++;
1121 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1122 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1123 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1124 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1126 /* Restores tty foreground process group, and exits.
1127 * May be called as signal handler for fatal signal
1128 * (will resend signal to itself, producing correct exit state)
1129 * or called directly with -EXITCODE.
1130 * We also call it if xfunc is exiting. */
1131 static void sigexit(int sig) NORETURN;
1132 static void sigexit(int sig)
1134 /* Disable all signals: job control, SIGPIPE, etc. */
1135 sigprocmask_allsigs(SIG_BLOCK);
1137 /* Careful: we can end up here after [v]fork. Do not restore
1138 * tty pgrp then, only top-level shell process does that */
1139 if (G.saved_tty_pgrp && getpid() == G.root_pid)
1140 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1142 /* Not a signal, just exit */
1146 kill_myself_with_sig(sig); /* does not return */
1150 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1151 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1155 /* Restores tty foreground process group, and exits. */
1156 static void hush_exit(int exitcode) NORETURN;
1157 static void hush_exit(int exitcode)
1159 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1160 /* Prevent recursion:
1161 * trap "echo Hi; exit" EXIT; exit
1163 char *argv[] = { NULL, G.traps[0], NULL };
1171 fflush(NULL); /* flush all streams */
1172 sigexit(- (exitcode & 0xff));
1178 static int check_and_run_traps(int sig)
1180 static const struct timespec zero_timespec = { 0, 0 };
1181 smalluint save_rcode;
1187 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1192 if (G.traps && G.traps[sig]) {
1193 if (G.traps[sig][0]) {
1194 /* We have user-defined handler */
1195 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1196 save_rcode = G.last_exitcode;
1199 G.last_exitcode = save_rcode;
1200 } /* else: "" trap, ignoring signal */
1203 /* not a trap: special action */
1206 // G.count_SIGCHLD++;
1209 /* Builtin was ^C'ed, make it look prettier: */
1216 /* bash is observed to signal whole process groups,
1217 * not individual processes */
1218 for (job = G.job_list; job; job = job->next) {
1221 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1222 if (kill(- job->pgrp, SIGHUP) == 0)
1223 kill(- job->pgrp, SIGCONT);
1228 default: /* ignored: */
1229 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1237 static const char *set_cwd(void)
1239 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1240 * we must not try to free(bb_msg_unknown) */
1241 if (G.cwd == bb_msg_unknown)
1243 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1245 G.cwd = bb_msg_unknown;
1250 /* Get/check local shell variables */
1251 static struct variable *get_local_var(const char *name)
1253 struct variable *cur;
1259 for (cur = G.top_var; cur; cur = cur->next) {
1260 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1266 static const char *get_local_var_value(const char *src)
1268 struct variable *var = get_local_var(src);
1270 return strchr(var->varstr, '=') + 1;
1274 /* str holds "NAME=VAL" and is expected to be malloced.
1275 * We take ownership of it.
1277 * 0: do not change export flag
1278 * (if creating new variable, flag will be 0)
1279 * 1: set export flag and putenv the variable
1280 * -1: clear export flag and unsetenv the variable
1281 * flg_read_only is set only when we handle -R var=val
1284 #define set_local_var(str, flg_export, flg_read_only) \
1285 set_local_var(str, flg_export)
1287 static int set_local_var(char *str, int flg_export, int flg_read_only)
1289 struct variable *cur;
1293 eq_sign = strchr(str, '=');
1294 if (!eq_sign) { /* not expected to ever happen? */
1299 name_len = eq_sign - str + 1; /* including '=' */
1300 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1302 if (strncmp(cur->varstr, str, name_len) != 0) {
1304 /* Bail out. Note that now cur points
1305 * to last var in linked list */
1311 /* We found an existing var with this name */
1312 if (cur->flg_read_only) {
1316 bb_error_msg("%s: readonly variable", str);
1320 if (flg_export == -1) {
1321 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1326 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1331 if (cur->max_len >= strlen(str)) {
1332 /* This one is from startup env, reuse space */
1333 strcpy(cur->varstr, str);
1336 /* max_len == 0 signifies "malloced" var, which we can
1337 * (and has to) free */
1341 goto set_str_and_exp;
1344 /* Not found - create next variable struct */
1345 cur->next = xzalloc(sizeof(*cur));
1351 cur->flg_read_only = flg_read_only;
1354 if (flg_export == 1)
1355 cur->flg_export = 1;
1356 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1357 cmdedit_update_prompt();
1358 if (cur->flg_export) {
1359 if (flg_export == -1) {
1360 cur->flg_export = 0;
1361 /* unsetenv was already done */
1363 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1364 return putenv(cur->varstr);
1370 static int unset_local_var(const char *name)
1372 struct variable *cur;
1373 struct variable *prev = prev; /* for gcc */
1377 return EXIT_SUCCESS;
1378 name_len = strlen(name);
1381 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1382 if (cur->flg_read_only) {
1383 bb_error_msg("%s: readonly variable", name);
1384 return EXIT_FAILURE;
1386 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1387 * is ro, and we cannot reach this code on the 1st pass */
1388 prev->next = cur->next;
1389 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1390 bb_unsetenv(cur->varstr);
1391 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1392 cmdedit_update_prompt();
1396 return EXIT_SUCCESS;
1401 return EXIT_SUCCESS;
1404 #if ENABLE_SH_MATH_SUPPORT
1405 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1406 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1407 static char *endofname(const char *name)
1415 if (!is_in_name(*p))
1421 static void arith_set_local_var(const char *name, const char *val, int flags)
1423 /* arith code doesnt malloc space, so do it for it */
1424 char *var = xasprintf("%s=%s", name, val);
1425 set_local_var(var, flags, 0);
1433 static int static_get(struct in_str *i)
1442 static int static_peek(struct in_str *i)
1447 #if ENABLE_HUSH_INTERACTIVE
1449 static void cmdedit_update_prompt(void)
1451 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1452 G.PS1 = get_local_var_value("PS1");
1455 G.PS2 = get_local_var_value("PS2");
1463 static const char* setup_prompt_string(int promptmode)
1465 const char *prompt_str;
1466 debug_printf("setup_prompt_string %d ", promptmode);
1467 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1468 /* Set up the prompt */
1469 if (promptmode == 0) { /* PS1 */
1471 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1476 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1477 debug_printf("result '%s'\n", prompt_str);
1481 static void get_user_input(struct in_str *i)
1484 const char *prompt_str;
1486 prompt_str = setup_prompt_string(i->promptmode);
1487 #if ENABLE_FEATURE_EDITING
1488 /* Enable command line editing only while a command line
1489 * is actually being read */
1492 /* buglet: SIGINT will not make new prompt to appear _at once_,
1493 * only after <Enter>. (^C will work) */
1494 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1495 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1496 check_and_run_traps(0);
1497 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1498 i->eof_flag = (r < 0);
1499 if (i->eof_flag) { /* EOF/error detected */
1500 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1501 G.user_input_buf[1] = '\0';
1506 fputs(prompt_str, stdout);
1508 G.user_input_buf[0] = r = fgetc(i->file);
1509 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1510 //do we need check_and_run_traps(0)? (maybe only if stdin)
1511 } while (G.flag_SIGINT);
1512 i->eof_flag = (r == EOF);
1514 i->p = G.user_input_buf;
1517 #endif /* INTERACTIVE */
1519 /* This is the magic location that prints prompts
1520 * and gets data back from the user */
1521 static int file_get(struct in_str *i)
1525 /* If there is data waiting, eat it up */
1526 if (i->p && *i->p) {
1527 #if ENABLE_HUSH_INTERACTIVE
1531 if (i->eof_flag && !*i->p)
1533 /* note: ch is never NUL */
1535 /* need to double check i->file because we might be doing something
1536 * more complicated by now, like sourcing or substituting. */
1537 #if ENABLE_HUSH_INTERACTIVE
1538 if (G_interactive_fd && i->promptme && i->file == stdin) {
1541 } while (!*i->p); /* need non-empty line */
1542 i->promptmode = 1; /* PS2 */
1547 do ch = fgetc(i->file); while (ch == '\0');
1549 debug_printf("file_get: got '%c' %d\n", ch, ch);
1550 #if ENABLE_HUSH_INTERACTIVE
1557 /* All callers guarantee this routine will never
1558 * be used right after a newline, so prompting is not needed.
1560 static int file_peek(struct in_str *i)
1563 if (i->p && *i->p) {
1564 if (i->eof_flag && !i->p[1])
1567 /* note: ch is never NUL */
1569 do ch = fgetc(i->file); while (ch == '\0');
1570 i->eof_flag = (ch == EOF);
1571 i->peek_buf[0] = ch;
1572 i->peek_buf[1] = '\0';
1574 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1578 static void setup_file_in_str(struct in_str *i, FILE *f)
1580 i->peek = file_peek;
1582 #if ENABLE_HUSH_INTERACTIVE
1584 i->promptmode = 0; /* PS1 */
1590 static void setup_string_in_str(struct in_str *i, const char *s)
1592 i->peek = static_peek;
1593 i->get = static_get;
1594 #if ENABLE_HUSH_INTERACTIVE
1596 i->promptmode = 0; /* PS1 */
1606 #define B_CHUNK (32 * sizeof(char*))
1608 static void o_reset_to_empty_unquoted(o_string *o)
1616 static void o_free(o_string *o)
1619 memset(o, 0, sizeof(*o));
1622 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1627 static void o_grow_by(o_string *o, int len)
1629 if (o->length + len > o->maxlen) {
1630 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1631 o->data = xrealloc(o->data, 1 + o->maxlen);
1635 static void o_addchr(o_string *o, int ch)
1637 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1639 o->data[o->length] = ch;
1641 o->data[o->length] = '\0';
1644 static void o_addblock(o_string *o, const char *str, int len)
1647 memcpy(&o->data[o->length], str, len);
1649 o->data[o->length] = '\0';
1653 static void o_addstr(o_string *o, const char *str)
1655 o_addblock(o, str, strlen(str));
1657 static void nommu_addchr(o_string *o, int ch)
1663 #define nommu_addchr(o, str) ((void)0)
1666 static void o_addstr_with_NUL(o_string *o, const char *str)
1668 o_addblock(o, str, strlen(str) + 1);
1671 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1676 && (*str != '*' && *str != '?' && *str != '[')
1684 /* My analysis of quoting semantics tells me that state information
1685 * is associated with a destination, not a source.
1687 static void o_addqchr(o_string *o, int ch)
1690 char *found = strchr("*?[\\", ch);
1695 o->data[o->length] = '\\';
1698 o->data[o->length] = ch;
1700 o->data[o->length] = '\0';
1703 static void o_addQchr(o_string *o, int ch)
1706 if (o->o_escape && strchr("*?[\\", ch)) {
1708 o->data[o->length] = '\\';
1712 o->data[o->length] = ch;
1714 o->data[o->length] = '\0';
1717 static void o_addQstr(o_string *o, const char *str, int len)
1720 o_addblock(o, str, len);
1726 int ordinary_cnt = strcspn(str, "*?[\\");
1727 if (ordinary_cnt > len) /* paranoia */
1729 o_addblock(o, str, ordinary_cnt);
1730 if (ordinary_cnt == len)
1732 str += ordinary_cnt;
1733 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1737 if (ch) { /* it is necessarily one of "*?[\\" */
1739 o->data[o->length] = '\\';
1743 o->data[o->length] = ch;
1745 o->data[o->length] = '\0';
1749 /* A special kind of o_string for $VAR and `cmd` expansion.
1750 * It contains char* list[] at the beginning, which is grown in 16 element
1751 * increments. Actual string data starts at the next multiple of 16 * (char*).
1752 * list[i] contains an INDEX (int!) into this string data.
1753 * It means that if list[] needs to grow, data needs to be moved higher up
1754 * but list[i]'s need not be modified.
1755 * NB: remembering how many list[i]'s you have there is crucial.
1756 * o_finalize_list() operation post-processes this structure - calculates
1757 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1759 #if DEBUG_EXPAND || DEBUG_GLOB
1760 static void debug_print_list(const char *prefix, o_string *o, int n)
1762 char **list = (char**)o->data;
1763 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1767 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1768 prefix, list, n, string_start, o->length, o->maxlen);
1771 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1772 o->data + (int)list[i] + string_start,
1773 o->data + (int)list[i] + string_start);
1777 const char *p = o->data + (int)list[n - 1] + string_start;
1779 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1783 #define debug_print_list(prefix, o, n) ((void)0)
1786 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1787 * in list[n] so that it points past last stored byte so far.
1788 * It returns n+1. */
1789 static int o_save_ptr_helper(o_string *o, int n)
1791 char **list = (char**)o->data;
1795 if (!o->has_empty_slot) {
1796 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1797 string_len = o->length - string_start;
1798 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1799 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1800 /* list[n] points to string_start, make space for 16 more pointers */
1801 o->maxlen += 0x10 * sizeof(list[0]);
1802 o->data = xrealloc(o->data, o->maxlen + 1);
1803 list = (char**)o->data;
1804 memmove(list + n + 0x10, list + n, string_len);
1805 o->length += 0x10 * sizeof(list[0]);
1807 debug_printf_list("list[%d]=%d string_start=%d\n",
1808 n, string_len, string_start);
1811 /* We have empty slot at list[n], reuse without growth */
1812 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1813 string_len = o->length - string_start;
1814 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1815 n, string_len, string_start);
1816 o->has_empty_slot = 0;
1818 list[n] = (char*)(ptrdiff_t)string_len;
1822 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1823 static int o_get_last_ptr(o_string *o, int n)
1825 char **list = (char**)o->data;
1826 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1828 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1831 /* o_glob performs globbing on last list[], saving each result
1832 * as a new list[]. */
1833 static int o_glob(o_string *o, int n)
1839 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1841 return o_save_ptr_helper(o, n);
1842 pattern = o->data + o_get_last_ptr(o, n);
1843 debug_printf_glob("glob pattern '%s'\n", pattern);
1844 if (!glob_needed(pattern)) {
1846 o->length = unbackslash(pattern) - o->data;
1847 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1848 return o_save_ptr_helper(o, n);
1851 memset(&globdata, 0, sizeof(globdata));
1852 gr = glob(pattern, 0, NULL, &globdata);
1853 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1854 if (gr == GLOB_NOSPACE)
1855 bb_error_msg_and_die("out of memory during glob");
1856 if (gr == GLOB_NOMATCH) {
1857 globfree(&globdata);
1860 if (gr != 0) { /* GLOB_ABORTED ? */
1861 /* TODO: testcase for bad glob pattern behavior */
1862 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1864 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1865 char **argv = globdata.gl_pathv;
1866 o->length = pattern - o->data; /* "forget" pattern */
1868 o_addstr_with_NUL(o, *argv);
1869 n = o_save_ptr_helper(o, n);
1875 globfree(&globdata);
1877 debug_print_list("o_glob returning", o, n);
1881 /* If o->o_glob == 1, glob the string so far remembered.
1882 * Otherwise, just finish current list[] and start new */
1883 static int o_save_ptr(o_string *o, int n)
1885 if (o->o_glob) { /* if globbing is requested */
1886 /* If o->has_empty_slot, list[n] was already globbed
1887 * (if it was requested back then when it was filled)
1888 * so don't do that again! */
1889 if (!o->has_empty_slot)
1890 return o_glob(o, n); /* o_save_ptr_helper is inside */
1892 return o_save_ptr_helper(o, n);
1895 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1896 static char **o_finalize_list(o_string *o, int n)
1901 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1903 debug_print_list("finalized", o, n);
1904 debug_printf_expand("finalized n:%d\n", n);
1905 list = (char**)o->data;
1906 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1910 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1916 /* Expansion can recurse */
1917 #if ENABLE_HUSH_TICK
1918 static int process_command_subs(o_string *dest, const char *s);
1920 static char *expand_string_to_string(const char *str);
1922 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1923 parse_stream_dquoted(dest, input, dquote_end)
1925 static int parse_stream_dquoted(o_string *as_string,
1927 struct in_str *input,
1930 /* expand_strvec_to_strvec() takes a list of strings, expands
1931 * all variable references within and returns a pointer to
1932 * a list of expanded strings, possibly with larger number
1933 * of strings. (Think VAR="a b"; echo $VAR).
1934 * This new list is allocated as a single malloc block.
1935 * NULL-terminated list of char* pointers is at the beginning of it,
1936 * followed by strings themself.
1937 * Caller can deallocate entire list by single free(list). */
1939 /* Store given string, finalizing the word and starting new one whenever
1940 * we encounter IFS char(s). This is used for expanding variable values.
1941 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1942 static int expand_on_ifs(o_string *output, int n, const char *str)
1945 int word_len = strcspn(str, G.ifs);
1947 if (output->o_escape || !output->o_glob)
1948 o_addQstr(output, str, word_len);
1949 else /* protect backslashes against globbing up :) */
1950 o_addblock_duplicate_backslash(output, str, word_len);
1953 if (!*str) /* EOL - do not finalize word */
1955 o_addchr(output, '\0');
1956 debug_print_list("expand_on_ifs", output, n);
1957 n = o_save_ptr(output, n);
1958 str += strspn(str, G.ifs); /* skip ifs chars */
1960 debug_print_list("expand_on_ifs[1]", output, n);
1964 /* Helper to expand $((...)) and heredoc body. These act as if
1965 * they are in double quotes, with the exception that they are not :).
1966 * Just the rules are similar: "expand only $var and `cmd`"
1968 * Returns malloced string.
1969 * As an optimization, we return NULL if expansion is not needed.
1971 static char *expand_pseudo_dquoted(const char *str)
1974 struct in_str input;
1975 o_string dest = NULL_O_STRING;
1977 if (strchr(str, '$') == NULL
1978 #if ENABLE_HUSH_TICK
1979 && strchr(str, '`') == NULL
1985 /* We need to expand. Example:
1986 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1988 setup_string_in_str(&input, str);
1989 parse_stream_dquoted(NULL, &dest, &input, EOF);
1990 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1991 exp_str = expand_string_to_string(dest.data);
1992 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1993 o_free_unsafe(&dest);
1997 /* Expand all variable references in given string, adding words to list[]
1998 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1999 * to be filled). This routine is extremely tricky: has to deal with
2000 * variables/parameters with whitespace, $* and $@, and constructs like
2001 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2002 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2004 /* or_mask is either 0 (normal case) or 0x80
2005 * (expansion of right-hand side of assignment == 1-element expand.
2006 * It will also do no globbing, and thus we must not backslash-quote!) */
2013 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2014 debug_print_list("expand_vars_to_list", output, n);
2015 n = o_save_ptr(output, n);
2016 debug_print_list("expand_vars_to_list[0]", output, n);
2018 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2021 char *dyn_val = NULL;
2022 const char *val = NULL;
2023 #if ENABLE_HUSH_TICK
2024 o_string subst_result = NULL_O_STRING;
2026 #if ENABLE_SH_MATH_SUPPORT
2027 char arith_buf[sizeof(arith_t)*3 + 2];
2029 o_addblock(output, arg, p - arg);
2030 debug_print_list("expand_vars_to_list[1]", output, n);
2032 p = strchr(p, SPECIAL_VAR_SYMBOL);
2034 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2035 /* "$@" is special. Even if quoted, it can still
2036 * expand to nothing (not even an empty string) */
2037 if ((first_ch & 0x7f) != '@')
2038 ored_ch |= first_ch;
2040 switch (first_ch & 0x7f) {
2041 /* Highest bit in first_ch indicates that var is double-quoted */
2043 val = utoa(G.root_pid);
2045 case '!': /* bg pid */
2046 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2048 case '?': /* exitcode */
2049 val = utoa(G.last_exitcode);
2051 case '#': /* argc */
2052 if (arg[1] != SPECIAL_VAR_SYMBOL)
2053 /* actually, it's a ${#var} */
2055 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2060 if (!G.global_argv[i])
2062 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2063 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2064 smallint sv = output->o_escape;
2065 /* unquoted var's contents should be globbed, so don't escape */
2066 output->o_escape = 0;
2067 while (G.global_argv[i]) {
2068 n = expand_on_ifs(output, n, G.global_argv[i]);
2069 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2070 if (G.global_argv[i++][0] && G.global_argv[i]) {
2071 /* this argv[] is not empty and not last:
2072 * put terminating NUL, start new word */
2073 o_addchr(output, '\0');
2074 debug_print_list("expand_vars_to_list[2]", output, n);
2075 n = o_save_ptr(output, n);
2076 debug_print_list("expand_vars_to_list[3]", output, n);
2079 output->o_escape = sv;
2081 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2082 * and in this case should treat it like '$*' - see 'else...' below */
2083 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2085 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2086 if (++i >= G.global_argc)
2088 o_addchr(output, '\0');
2089 debug_print_list("expand_vars_to_list[4]", output, n);
2090 n = o_save_ptr(output, n);
2092 } else { /* quoted $*: add as one word */
2094 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2095 if (!G.global_argv[++i])
2098 o_addchr(output, G.ifs[0]);
2102 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2103 /* "Empty variable", used to make "" etc to not disappear */
2107 #if ENABLE_HUSH_TICK
2108 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2111 /* Can't just stuff it into output o_string,
2112 * expanded result may need to be globbed
2113 * and $IFS-splitted */
2114 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2115 process_command_subs(&subst_result, arg);
2116 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2117 val = subst_result.data;
2120 #if ENABLE_SH_MATH_SUPPORT
2121 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2122 arith_eval_hooks_t hooks;
2127 arg++; /* skip '+' */
2128 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2129 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2131 exp_str = expand_pseudo_dquoted(arg);
2132 hooks.lookupvar = get_local_var_value;
2133 hooks.setvar = arith_set_local_var;
2134 hooks.endofname = endofname;
2135 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2139 const char *msg = "error in arithmetic";
2142 msg = "exponent less than 0";
2145 msg = "divide by 0";
2148 msg = "expression recursion loop detected";
2153 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2154 sprintf(arith_buf, arith_t_fmt, res);
2159 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2161 bool exp_len = false;
2162 bool exp_null = false;
2164 char exp_save = exp_save; /* for compiler */
2165 char exp_op = exp_op; /* for compiler */
2166 char *exp_word = exp_word; /* for compiler */
2170 arg[0] = first_ch & 0x7f;
2172 /* prepare for expansions */
2173 if (var[0] == '#') {
2174 /* handle length expansion ${#var} */
2178 /* maybe handle parameter expansion */
2179 exp_off = strcspn(var, ":-=+?%#");
2183 exp_save = var[exp_off];
2184 exp_null = exp_save == ':';
2185 exp_word = var + exp_off;
2188 exp_op = *exp_word++;
2189 var[exp_off] = '\0';
2193 /* lookup the variable in question */
2194 if (isdigit(var[0])) {
2195 /* handle_dollar() should have vetted var for us */
2197 if (i < G.global_argc)
2198 val = G.global_argv[i];
2199 /* else val remains NULL: $N with too big N */
2201 val = get_local_var_value(var);
2203 /* handle any expansions */
2205 debug_printf_expand("expand: length of '%s' = ", val);
2206 val = utoa(val ? strlen(val) : 0);
2207 debug_printf_expand("%s\n", val);
2208 } else if (exp_off) {
2209 if (exp_op == '%' || exp_op == '#') {
2211 /* we need to do a pattern match */
2214 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2215 if (exp_op == *exp_word) /* ## or %% */
2217 val = dyn_val = xstrdup(val);
2218 loc = scan(dyn_val, exp_word, match_at_left);
2219 if (match_at_left) /* # or ## */
2221 else if (loc) /* % or %% and match was found */
2225 /* we need to do an expansion */
2226 int exp_test = (!val || (exp_null && !val[0]));
2228 exp_test = !exp_test;
2229 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2230 exp_null ? "true" : "false", exp_test);
2232 if (exp_op == '?') {
2233 //TODO: how interactive bash aborts expansion mid-command?
2234 /* ${var?[error_msg_if_unset]} */
2235 /* ${var:?[error_msg_if_unset_or_null]} */
2236 /* mimic bash message */
2237 die_if_script("%s: %s",
2239 exp_word[0] ? exp_word : "parameter null or not set"
2245 if (exp_op == '=') {
2246 /* ${var=[word]} or ${var:=[word]} */
2247 if (isdigit(var[0]) || var[0] == '#') {
2248 /* mimic bash message */
2249 die_if_script("$%s: cannot assign in this way", var);
2252 char *new_var = xasprintf("%s=%s", var, val);
2253 set_local_var(new_var, 0, 0);
2259 var[exp_off] = exp_save;
2263 #if ENABLE_HUSH_TICK
2266 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2267 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2269 /* unquoted var's contents should be globbed, so don't escape */
2270 smallint sv = output->o_escape;
2271 output->o_escape = 0;
2272 n = expand_on_ifs(output, n, val);
2274 output->o_escape = sv;
2276 } else { /* quoted $VAR, val will be appended below */
2277 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2280 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2283 o_addQstr(output, val, strlen(val));
2286 /* Do the check to avoid writing to a const string */
2287 if (*p != SPECIAL_VAR_SYMBOL)
2288 *p = SPECIAL_VAR_SYMBOL;
2290 #if ENABLE_HUSH_TICK
2291 o_free(&subst_result);
2294 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2297 debug_print_list("expand_vars_to_list[a]", output, n);
2298 /* this part is literal, and it was already pre-quoted
2299 * if needed (much earlier), do not use o_addQstr here! */
2300 o_addstr_with_NUL(output, arg);
2301 debug_print_list("expand_vars_to_list[b]", output, n);
2302 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2303 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2306 /* allow to reuse list[n] later without re-growth */
2307 output->has_empty_slot = 1;
2309 o_addchr(output, '\0');
2314 static char **expand_variables(char **argv, int or_mask)
2319 o_string output = NULL_O_STRING;
2321 if (or_mask & 0x100) {
2322 output.o_escape = 1; /* protect against globbing for "$var" */
2323 /* (unquoted $var will temporarily switch it off) */
2330 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2333 debug_print_list("expand_variables", &output, n);
2335 /* output.data (malloced in one block) gets returned in "list" */
2336 list = o_finalize_list(&output, n);
2337 debug_print_strings("expand_variables[1]", list);
2341 static char **expand_strvec_to_strvec(char **argv)
2343 return expand_variables(argv, 0x100);
2346 /* Used for expansion of right hand of assignments */
2347 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2349 static char *expand_string_to_string(const char *str)
2351 char *argv[2], **list;
2353 argv[0] = (char*)str;
2355 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2357 if (!list[0] || list[1])
2358 bb_error_msg_and_die("BUG in varexp2");
2359 /* actually, just move string 2*sizeof(char*) bytes back */
2360 overlapping_strcpy((char*)list, list[0]);
2361 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2365 /* Used for "eval" builtin */
2366 static char* expand_strvec_to_string(char **argv)
2370 list = expand_variables(argv, 0x80);
2371 /* Convert all NULs to spaces */
2376 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2377 bb_error_msg_and_die("BUG in varexp3");
2378 /* bash uses ' ' regardless of $IFS contents */
2383 overlapping_strcpy((char*)list, list[0]);
2384 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2388 static char **expand_assignments(char **argv, int count)
2392 /* Expand assignments into one string each */
2393 for (i = 0; i < count; i++) {
2394 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2402 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2404 static void reset_traps_to_defaults(void)
2406 /* This function is always called in a child shell
2407 * after fork (not vfork, NOMMU doesn't use this function).
2408 * Child shells are not interactive.
2409 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2410 * Testcase: (while :; do :; done) + ^Z should background.
2411 * Same goes for SIGTERM, SIGHUP, SIGINT.
2416 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2419 /* Stupid. It can be done with *single* &= op, but we can't use
2420 * the fact that G.blocked_set is implemented as a bitmask... */
2421 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2425 sigdelset(&G.blocked_set, sig);
2432 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2433 mask = G.non_DFL_mask;
2434 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2438 G.traps[sig] = NULL;
2439 /* There is no signal for 0 (EXIT) */
2442 /* There was a trap handler, we are removing it.
2443 * But if sig still has non-DFL handling,
2444 * we should not unblock it. */
2447 sigdelset(&G.blocked_set, sig);
2449 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2454 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2455 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2457 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2458 char *heredoc_argv[4];
2459 struct variable *cur;
2460 #if ENABLE_HUSH_FUNCTIONS
2461 struct function *funcp;
2466 if (!g_argv0) { /* heredoc */
2467 argv = heredoc_argv;
2468 argv[0] = (char *) G.argv0_for_re_execing;
2469 argv[1] = (char *) "-<";
2470 argv[2] = (char *) s;
2472 pp = &argv[3]; /* used as pointer to empty environment */
2476 sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
2477 , (unsigned) G.root_pid
2478 , (unsigned) G.last_bg_pid
2479 , (unsigned) G.last_exitcode
2480 IF_HUSH_LOOPS(, G.depth_of_loop)
2482 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2483 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2486 for (cur = G.top_var; cur; cur = cur->next) {
2487 if (!cur->flg_export || cur->flg_read_only)
2490 #if ENABLE_HUSH_FUNCTIONS
2491 for (funcp = G.top_func; funcp; funcp = funcp->next)
2497 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2498 *pp++ = (char *) G.argv0_for_re_execing;
2500 for (cur = G.top_var; cur; cur = cur->next) {
2501 if (cur->varstr == hush_version_str)
2503 if (cur->flg_read_only) {
2504 *pp++ = (char *) "-R";
2505 *pp++ = cur->varstr;
2506 } else if (!cur->flg_export) {
2507 *pp++ = (char *) "-V";
2508 *pp++ = cur->varstr;
2511 #if ENABLE_HUSH_FUNCTIONS
2512 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2513 *pp++ = (char *) "-F";
2514 *pp++ = funcp->name;
2515 *pp++ = funcp->body_as_string;
2518 /* We can pass activated traps here. Say, -Tnn:trap_string
2520 * However, POSIX says that subshells reset signals with traps
2522 * I tested bash-3.2 and it not only does that with true subshells
2523 * of the form ( list ), but with any forked children shells.
2524 * I set trap "echo W" WINCH; and then tried:
2526 * { echo 1; sleep 20; echo 2; } &
2527 * while true; do echo 1; sleep 20; echo 2; break; done &
2528 * true | { echo 1; sleep 20; echo 2; } | cat
2530 * In all these cases sending SIGWINCH to the child shell
2531 * did not run the trap. If I add trap "echo V" WINCH;
2532 * _inside_ group (just before echo 1), it works.
2534 * I conclude it means we don't need to pass active traps here.
2535 * exec syscall below resets them to SIG_DFL for us.
2537 *pp++ = (char *) "-c";
2542 /* *pp = NULL; - is already there */
2546 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2547 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2548 execve(bb_busybox_exec_path, argv, pp);
2549 /* Fallback. Useful for init=/bin/hush usage etc */
2550 if (argv[0][0] == '/')
2551 execve(argv[0], argv, pp);
2552 xfunc_error_retval = 127;
2553 bb_error_msg_and_die("can't re-execute the shell");
2555 #endif /* !BB_MMU */
2558 static void setup_heredoc(struct redir_struct *redir)
2560 struct fd_pair pair;
2563 /* the _body_ of heredoc (misleading field name) */
2564 const char *heredoc = redir->rd_filename;
2571 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2572 expanded = expand_pseudo_dquoted(heredoc);
2576 len = strlen(heredoc);
2578 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2580 xmove_fd(pair.rd, redir->rd_fd);
2582 /* Try writing without forking. Newer kernels have
2583 * dynamically growing pipes. Must use non-blocking write! */
2586 written = write(pair.wr, heredoc, len);
2597 ndelay_off(pair.wr);
2599 /* Okay, pipe buffer was not big enough */
2600 /* Note: we must not create a stray child (bastard? :)
2601 * for the unsuspecting parent process. Child creates a grandchild
2602 * and exits before parent execs the process which consumes heredoc
2603 * (that exec happens after we return from this function) */
2609 bb_perror_msg_and_die("vfork");
2612 disable_restore_tty_pgrp_on_exit();
2613 pid = BB_MMU ? fork() : vfork();
2615 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2619 close(redir->rd_fd); /* read side of the pipe */
2621 full_write(pair.wr, heredoc, len); /* may loop or block */
2624 /* Delegate blocking writes to another process */
2625 xmove_fd(pair.wr, STDOUT_FILENO);
2626 re_execute_shell(&to_free, heredoc, NULL, NULL);
2630 enable_restore_tty_pgrp_on_exit();
2636 wait(NULL); /* wait till child has died */
2639 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2640 * and stderr if they are redirected. */
2641 static int setup_redirects(struct command *prog, int squirrel[])
2644 struct redir_struct *redir;
2646 for (redir = prog->redirects; redir; redir = redir->next) {
2647 if (redir->rd_type == REDIRECT_HEREDOC2) {
2648 /* rd_fd<<HERE case */
2649 if (squirrel && redir->rd_fd < 3
2650 && squirrel[redir->rd_fd] < 0
2652 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2654 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2656 debug_printf_parse("set heredoc '%s'\n",
2657 redir->rd_filename);
2658 setup_heredoc(redir);
2662 if (redir->rd_dup == REDIRFD_TO_FILE) {
2663 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2665 if (redir->rd_filename == NULL) {
2666 /* Something went wrong in the parse.
2667 * Pretend it didn't happen */
2668 bb_error_msg("bug in redirect parse");
2671 mode = redir_table[redir->rd_type].mode;
2672 p = expand_string_to_string(redir->rd_filename);
2673 openfd = open_or_warn(p, mode);
2676 /* this could get lost if stderr has been redirected, but
2677 * bash and ash both lose it as well (though zsh doesn't!) */
2678 //what the above comment tries to say?
2682 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2683 openfd = redir->rd_dup;
2686 if (openfd != redir->rd_fd) {
2687 if (squirrel && redir->rd_fd < 3
2688 && squirrel[redir->rd_fd] < 0
2690 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2692 if (openfd == REDIRFD_CLOSE) {
2693 /* "n>-" means "close me" */
2694 close(redir->rd_fd);
2696 xdup2(openfd, redir->rd_fd);
2697 if (redir->rd_dup == REDIRFD_TO_FILE)
2705 static void restore_redirects(int squirrel[])
2708 for (i = 0; i < 3; i++) {
2711 /* We simply die on error */
2718 static void free_pipe_list(struct pipe *head);
2720 /* Return code is the exit status of the pipe */
2721 static void free_pipe(struct pipe *pi)
2724 struct command *command;
2725 struct redir_struct *r, *rnext;
2728 if (pi->stopped_cmds > 0) /* why? */
2730 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2731 for (i = 0; i < pi->num_cmds; i++) {
2732 command = &pi->cmds[i];
2733 debug_printf_clean(" command %d:\n", i);
2734 if (command->argv) {
2735 for (a = 0, p = command->argv; *p; a++, p++) {
2736 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2738 free_strings(command->argv);
2739 command->argv = NULL;
2741 /* not "else if": on syntax error, we may have both! */
2742 if (command->group) {
2743 debug_printf_clean(" begin group (grp_type:%d)\n",
2745 free_pipe_list(command->group);
2746 debug_printf_clean(" end group\n");
2747 command->group = NULL;
2749 /* else is crucial here.
2750 * If group != NULL, child_func is meaningless */
2751 #if ENABLE_HUSH_FUNCTIONS
2752 else if (command->child_func) {
2753 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2754 command->child_func->parent_cmd = NULL;
2758 free(command->group_as_string);
2759 command->group_as_string = NULL;
2761 for (r = command->redirects; r; r = rnext) {
2762 debug_printf_clean(" redirect %d%s",
2763 r->rd_fd, redir_table[r->rd_type].descrip);
2764 /* guard against the case >$FOO, where foo is unset or blank */
2765 if (r->rd_filename) {
2766 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2767 free(r->rd_filename);
2768 r->rd_filename = NULL;
2770 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2774 command->redirects = NULL;
2776 free(pi->cmds); /* children are an array, they get freed all at once */
2784 static void free_pipe_list(struct pipe *head)
2786 struct pipe *pi, *next;
2788 for (pi = head; pi; pi = next) {
2790 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2793 debug_printf_clean("pipe followup code %d\n", pi->followup);
2795 /*pi->next = NULL;*/
2801 static int run_list(struct pipe *pi);
2803 #define parse_stream(pstring, input, end_trigger) \
2804 parse_stream(input, end_trigger)
2806 static struct pipe *parse_stream(char **pstring,
2807 struct in_str *input,
2809 static void parse_and_run_string(const char *s);
2812 static const struct built_in_command* find_builtin(const char *name)
2814 const struct built_in_command *x;
2815 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2816 if (strcmp(name, x->cmd) != 0)
2818 debug_printf_exec("found builtin '%s'\n", name);
2824 #if ENABLE_HUSH_FUNCTIONS
2825 static const struct function *find_function(const char *name)
2827 const struct function *funcp = G.top_func;
2829 if (strcmp(name, funcp->name) == 0) {
2832 funcp = funcp->next;
2835 debug_printf_exec("found function '%s'\n", name);
2839 /* Note: takes ownership on name ptr */
2840 static struct function *new_function(char *name)
2842 struct function *funcp;
2843 struct function **funcpp = &G.top_func;
2845 while ((funcp = *funcpp) != NULL) {
2846 struct command *cmd;
2848 if (strcmp(funcp->name, name) != 0) {
2849 funcpp = &funcp->next;
2853 cmd = funcp->parent_cmd;
2854 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2856 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2858 /* Note: if !funcp->body, do not free body_as_string!
2859 * This is a special case of "-F name body" function:
2860 * body_as_string was not malloced! */
2862 free_pipe_list(funcp->body);
2864 free(funcp->body_as_string);
2868 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2869 cmd->argv[0] = funcp->name;
2870 cmd->group = funcp->body;
2872 cmd->group_as_string = funcp->body_as_string;
2877 debug_printf_exec("remembering new function '%s'\n", name);
2878 funcp = *funcpp = xzalloc(sizeof(*funcp));
2879 /*funcp->next = NULL;*/
2885 static void unset_func(const char *name)
2887 struct function *funcp;
2888 struct function **funcpp = &G.top_func;
2890 while ((funcp = *funcpp) != NULL) {
2891 if (strcmp(funcp->name, name) == 0) {
2892 *funcpp = funcp->next;
2893 /* funcp is unlinked now, deleting it */
2895 /* Note: if !funcp->body, do not free body_as_string!
2896 * This is a special case of "-F name body" function:
2897 * body_as_string was not malloced! */
2899 free_pipe_list(funcp->body);
2901 free(funcp->body_as_string);
2907 funcpp = &funcp->next;
2912 #define exec_function(nommu_save, funcp, argv) \
2913 exec_function(funcp, argv)
2915 static void exec_function(nommu_save_t *nommu_save,
2916 const struct function *funcp,
2917 char **argv) NORETURN;
2918 static void exec_function(nommu_save_t *nommu_save,
2919 const struct function *funcp,
2925 argv[0] = G.global_argv[0];
2926 G.global_argv = argv;
2930 /* On MMU, funcp->body is always non-NULL */
2931 n = run_list(funcp->body);
2935 re_execute_shell(&nommu_save->argv_from_re_execing,
2936 funcp->body_as_string,
2942 static int run_function(const struct function *funcp, char **argv)
2946 #if ENABLE_HUSH_FUNCTIONS
2950 save_and_replace_G_args(&sv, argv);
2951 #if ENABLE_HUSH_FUNCTIONS
2952 /* "we are in function, ok to use return" */
2953 sv_flg = G.flag_return_in_progress;
2954 G.flag_return_in_progress = -1;
2957 /* On MMU, funcp->body is always non-NULL */
2960 /* Function defined by -F */
2961 parse_and_run_string(funcp->body_as_string);
2962 rc = G.last_exitcode;
2966 rc = run_list(funcp->body);
2969 #if ENABLE_HUSH_FUNCTIONS
2970 G.flag_return_in_progress = sv_flg;
2972 restore_G_args(&sv, argv);
2980 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2981 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2982 #define pseudo_exec(nommu_save, command, argv_expanded) \
2983 pseudo_exec(command, argv_expanded)
2986 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2988 * Don't exit() here. If you don't exec, use _exit instead.
2989 * The at_exit handlers apparently confuse the calling process,
2990 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2991 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2992 char **argv, int assignment_cnt,
2993 char **argv_expanded) NORETURN;
2994 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2995 char **argv, int assignment_cnt,
2996 char **argv_expanded)
3000 /* Case when we are here: ... | var=val | ... */
3001 if (!argv[assignment_cnt])
3002 _exit(EXIT_SUCCESS);
3004 new_env = expand_assignments(argv, assignment_cnt);
3006 putenv_all(new_env);
3007 free(new_env); /* optional */
3009 nommu_save->new_env = new_env;
3010 nommu_save->old_env = putenv_all_and_save_old(new_env);
3012 if (argv_expanded) {
3013 argv = argv_expanded;
3015 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3017 nommu_save->argv = argv;
3021 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3022 if (strchr(argv[0], '/') != NULL)
3026 /* On NOMMU, we must never block!
3027 * Example: { sleep 99999 | read line } & echo Ok
3028 * read builtin will block on read syscall, leaving parent blocked
3029 * in vfork. Therefore we can't do this:
3032 /* Check if the command matches any of the builtins.
3033 * Depending on context, this might be redundant. But it's
3034 * easier to waste a few CPU cycles than it is to figure out
3035 * if this is one of those cases.
3039 const struct built_in_command *x = find_builtin(argv[0]);
3041 rcode = x->function(argv);
3047 #if ENABLE_HUSH_FUNCTIONS
3048 /* Check if the command matches any functions */
3050 const struct function *funcp = find_function(argv[0]);
3052 exec_function(nommu_save, funcp, argv);
3057 #if ENABLE_FEATURE_SH_STANDALONE
3058 /* Check if the command matches any busybox applets */
3060 int a = find_applet_by_name(argv[0]);
3062 # if BB_MMU /* see above why on NOMMU it is not allowed */
3063 if (APPLET_IS_NOEXEC(a)) {
3064 debug_printf_exec("running applet '%s'\n", argv[0]);
3065 run_applet_no_and_exit(a, argv);
3068 /* Re-exec ourselves */
3069 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3070 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3071 execv(bb_busybox_exec_path, argv);
3072 /* If they called chroot or otherwise made the binary no longer
3073 * executable, fall through */
3078 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3081 debug_printf_exec("execing '%s'\n", argv[0]);
3082 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3083 execvp(argv[0], argv);
3084 bb_perror_msg("can't execute '%s'", argv[0]);
3085 _exit(EXIT_FAILURE);
3088 /* Called after [v]fork() in run_pipe
3090 static void pseudo_exec(nommu_save_t *nommu_save,
3091 struct command *command,
3092 char **argv_expanded) NORETURN;
3093 static void pseudo_exec(nommu_save_t *nommu_save,
3094 struct command *command,
3095 char **argv_expanded)
3097 if (command->argv) {
3098 pseudo_exec_argv(nommu_save, command->argv,
3099 command->assignment_cnt, argv_expanded);
3102 if (command->group) {
3103 /* Cases when we are here:
3106 * ... | ( list ) | ...
3107 * ... | { list } | ...
3111 debug_printf_exec("pseudo_exec: run_list\n");
3112 reset_traps_to_defaults();
3113 rcode = run_list(command->group);
3114 /* OK to leak memory by not calling free_pipe_list,
3115 * since this process is about to exit */
3118 re_execute_shell(&nommu_save->argv_from_re_execing,
3119 command->group_as_string,
3125 /* Case when we are here: ... | >file */
3126 debug_printf_exec("pseudo_exec'ed null command\n");
3127 _exit(EXIT_SUCCESS);
3131 static const char *get_cmdtext(struct pipe *pi)
3137 /* This is subtle. ->cmdtext is created only on first backgrounding.
3138 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3139 * On subsequent bg argv is trashed, but we won't use it */
3142 argv = pi->cmds[0].argv;
3143 if (!argv || !argv[0]) {
3144 pi->cmdtext = xzalloc(1);
3150 len += strlen(*argv) + 1;
3154 argv = pi->cmds[0].argv;
3156 len = strlen(*argv);
3157 memcpy(p, *argv, len);
3165 static void insert_bg_job(struct pipe *pi)
3167 struct pipe *job, **jobp;
3170 /* Linear search for the ID of the job to use */
3172 for (job = G.job_list; job; job = job->next)
3173 if (job->jobid >= pi->jobid)
3174 pi->jobid = job->jobid + 1;
3176 /* Add job to the list of running jobs */
3178 while ((job = *jobp) != NULL)
3180 job = *jobp = xmalloc(sizeof(*job));
3182 *job = *pi; /* physical copy */
3184 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3185 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3186 for (i = 0; i < pi->num_cmds; i++) {
3187 job->cmds[i].pid = pi->cmds[i].pid;
3188 /* all other fields are not used and stay zero */
3190 job->cmdtext = xstrdup(get_cmdtext(pi));
3192 if (G_interactive_fd)
3193 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3194 /* Last command's pid goes to $! */
3195 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3196 G.last_jobid = job->jobid;
3199 static void remove_bg_job(struct pipe *pi)
3201 struct pipe *prev_pipe;
3203 if (pi == G.job_list) {
3204 G.job_list = pi->next;
3206 prev_pipe = G.job_list;
3207 while (prev_pipe->next != pi)
3208 prev_pipe = prev_pipe->next;
3209 prev_pipe->next = pi->next;
3212 G.last_jobid = G.job_list->jobid;
3217 /* Remove a backgrounded job */
3218 static void delete_finished_bg_job(struct pipe *pi)
3221 pi->stopped_cmds = 0;
3227 /* Check to see if any processes have exited -- if they
3228 * have, figure out why and see if a job has completed */
3229 static int checkjobs(struct pipe* fg_pipe)
3239 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3242 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3243 // /* avoid doing syscall, nothing there anyway */
3246 attributes = WUNTRACED;
3247 if (fg_pipe == NULL)
3248 attributes |= WNOHANG;
3250 /* Do we do this right?
3251 * bash-3.00# sleep 20 | false
3253 * [3]+ Stopped sleep 20 | false
3254 * bash-3.00# echo $?
3255 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3256 * [hush 1.14.0: yes we do it right]
3263 // i = G.count_SIGCHLD;
3264 childpid = waitpid(-1, &status, attributes);
3265 if (childpid <= 0) {
3266 if (childpid && errno != ECHILD)
3267 bb_perror_msg("waitpid");
3268 // else /* Until next SIGCHLD, waitpid's are useless */
3269 // G.handled_SIGCHLD = i;
3272 dead = WIFEXITED(status) || WIFSIGNALED(status);
3275 if (WIFSTOPPED(status))
3276 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3277 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3278 if (WIFSIGNALED(status))
3279 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3280 childpid, WTERMSIG(status), WEXITSTATUS(status));
3281 if (WIFEXITED(status))
3282 debug_printf_jobs("pid %d exited, exitcode %d\n",
3283 childpid, WEXITSTATUS(status));
3285 /* Were we asked to wait for fg pipe? */
3287 for (i = 0; i < fg_pipe->num_cmds; i++) {
3288 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3289 if (fg_pipe->cmds[i].pid != childpid)
3292 fg_pipe->cmds[i].pid = 0;
3293 fg_pipe->alive_cmds--;
3294 if (i == fg_pipe->num_cmds - 1) {
3295 /* last process gives overall exitstatus */
3296 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3297 rcode = WEXITSTATUS(status);
3298 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3299 /* bash prints killing signal's name for *last*
3300 * process in pipe (prints just newline for SIGINT).
3301 * Mimic this. Example: "sleep 5" + ^\
3303 if (WIFSIGNALED(status)) {
3304 int sig = WTERMSIG(status);
3305 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3309 fg_pipe->cmds[i].is_stopped = 1;
3310 fg_pipe->stopped_cmds++;
3312 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3313 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3314 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3315 /* All processes in fg pipe have exited or stopped */
3316 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3317 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3318 * and "killall -STOP cat" */
3319 if (G_interactive_fd) {
3321 if (fg_pipe->alive_cmds)
3322 insert_bg_job(fg_pipe);
3327 /* There are still running processes in the fg pipe */
3328 goto wait_more; /* do waitpid again */
3330 /* it wasnt fg_pipe, look for process in bg pipes */
3334 /* We asked to wait for bg or orphaned children */
3335 /* No need to remember exitcode in this case */
3336 for (pi = G.job_list; pi; pi = pi->next) {
3337 for (i = 0; i < pi->num_cmds; i++) {
3338 if (pi->cmds[i].pid == childpid)
3339 goto found_pi_and_prognum;
3342 /* Happens when shell is used as init process (init=/bin/sh) */
3343 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3344 continue; /* do waitpid again */
3346 found_pi_and_prognum:
3349 pi->cmds[i].pid = 0;
3351 if (!pi->alive_cmds) {
3352 if (G_interactive_fd)
3353 printf(JOB_STATUS_FORMAT, pi->jobid,
3354 "Done", pi->cmdtext);
3355 delete_finished_bg_job(pi);
3359 pi->cmds[i].is_stopped = 1;
3363 } /* while (waitpid succeeds)... */
3369 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3372 int rcode = checkjobs(fg_pipe);
3373 if (G.saved_tty_pgrp) {
3374 /* Job finished, move the shell to the foreground */
3375 p = getpgrp(); /* our process group id */
3376 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3377 tcsetpgrp(G_interactive_fd, p);
3383 /* Start all the jobs, but don't wait for anything to finish.
3386 * Return code is normally -1, when the caller has to wait for children
3387 * to finish to determine the exit status of the pipe. If the pipe
3388 * is a simple builtin command, however, the action is done by the
3389 * time run_pipe returns, and the exit code is provided as the
3392 * Returns -1 only if started some children. IOW: we have to
3393 * mask out retvals of builtins etc with 0xff!
3395 * The only case when we do not need to [v]fork is when the pipe
3396 * is single, non-backgrounded, non-subshell command. Examples:
3397 * cmd ; ... { list } ; ...
3398 * cmd && ... { list } && ...
3399 * cmd || ... { list } || ...
3400 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3401 * or (if SH_STANDALONE) an applet, and we can run the { list }
3402 * with run_list. If it isn't one of these, we fork and exec cmd.
3404 * Cases when we must fork:
3405 * non-single: cmd | cmd
3406 * backgrounded: cmd & { list } &
3407 * subshell: ( list ) [&]
3409 static int run_pipe(struct pipe *pi)
3411 static const char *const null_ptr = NULL;
3414 struct command *command;
3415 char **argv_expanded;
3418 /* it is not always needed, but we aim to smaller code */
3419 int squirrel[] = { -1, -1, -1 };
3422 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3425 IF_HUSH_JOB(pi->pgrp = -1;)
3426 pi->stopped_cmds = 0;
3427 command = &(pi->cmds[0]);
3428 argv_expanded = NULL;
3430 if (pi->num_cmds != 1
3431 || pi->followup == PIPE_BG
3432 || command->grp_type == GRP_SUBSHELL
3439 debug_printf_exec(": group:%p argv:'%s'\n",
3440 command->group, command->argv ? command->argv[0] : "NONE");
3442 if (command->group) {
3443 #if ENABLE_HUSH_FUNCTIONS
3444 if (command->grp_type == GRP_FUNCTION) {
3445 /* "executing" func () { list } */
3446 struct function *funcp;
3448 funcp = new_function(command->argv[0]);
3449 /* funcp->name is already set to argv[0] */
3450 funcp->body = command->group;
3452 funcp->body_as_string = command->group_as_string;
3453 command->group_as_string = NULL;
3455 command->group = NULL;
3456 command->argv[0] = NULL;
3457 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3458 funcp->parent_cmd = command;
3459 command->child_func = funcp;
3461 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3463 return EXIT_SUCCESS;
3467 debug_printf("non-subshell group\n");
3468 rcode = 1; /* exitcode if redir failed */
3469 if (setup_redirects(command, squirrel) == 0) {
3470 debug_printf_exec(": run_list\n");
3471 rcode = run_list(command->group) & 0xff;
3473 restore_redirects(squirrel);
3474 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3476 debug_printf_exec("run_pipe: return %d\n", rcode);
3480 argv = command->argv ? command->argv : (char **) &null_ptr;
3482 const struct built_in_command *x;
3483 #if ENABLE_HUSH_FUNCTIONS
3484 const struct function *funcp;
3488 char **new_env = NULL;
3489 char **old_env = NULL;
3491 if (argv[command->assignment_cnt] == NULL) {
3492 /* Assignments, but no command */
3493 /* Ensure redirects take effect. Try "a=t >file" */
3494 rcode = setup_redirects(command, squirrel);
3495 restore_redirects(squirrel);
3496 /* Set shell variables */
3498 p = expand_string_to_string(*argv);
3499 debug_printf_exec("set shell var:'%s'->'%s'\n",
3501 set_local_var(p, 0, 0);
3504 /* Do we need to flag set_local_var() errors?
3505 * "assignment to readonly var" and "putenv error"
3507 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3509 debug_printf_exec("run_pipe: return %d\n", rcode);
3513 /* Expand the rest into (possibly) many strings each */
3514 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3516 x = find_builtin(argv_expanded[0]);
3517 #if ENABLE_HUSH_FUNCTIONS
3520 funcp = find_function(argv_expanded[0]);
3524 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3525 debug_printf("exec with redirects only\n");
3526 rcode = setup_redirects(command, NULL);
3527 goto clean_up_and_ret1;
3530 /* setup_redirects acts on file descriptors, not FILEs.
3531 * This is perfect for work that comes after exec().
3532 * Is it really safe for inline use? Experimentally,
3533 * things seem to work. */
3534 rcode = setup_redirects(command, squirrel);
3536 new_env = expand_assignments(argv, command->assignment_cnt);
3537 old_env = putenv_all_and_save_old(new_env);
3539 debug_printf_exec(": builtin '%s' '%s'...\n",
3540 x->cmd, argv_expanded[1]);
3541 rcode = x->function(argv_expanded) & 0xff;
3544 #if ENABLE_HUSH_FUNCTIONS
3546 debug_printf_exec(": function '%s' '%s'...\n",
3547 funcp->name, argv_expanded[1]);
3548 rcode = run_function(funcp, argv_expanded) & 0xff;
3552 #if ENABLE_FEATURE_SH_STANDALONE
3555 restore_redirects(squirrel);
3556 free_strings_and_unsetenv(new_env, 1);
3557 putenv_all(old_env);
3558 /* Free the pointers, but the strings themselves
3559 * are in environ now, don't use free_strings! */
3562 free(argv_expanded);
3563 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3565 debug_printf_exec("run_pipe return %d\n", rcode);
3569 #if ENABLE_FEATURE_SH_STANDALONE
3570 i = find_applet_by_name(argv_expanded[0]);
3571 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3572 rcode = setup_redirects(command, squirrel);
3574 new_env = expand_assignments(argv, command->assignment_cnt);
3575 old_env = putenv_all_and_save_old(new_env);
3576 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3577 argv_expanded[0], argv_expanded[1]);
3578 rcode = run_nofork_applet(i, argv_expanded);
3580 goto clean_up_and_ret;
3583 /* It is neither builtin nor applet. We must fork. */
3587 /* NB: argv_expanded may already be created, and that
3588 * might include `cmd` runs! Do not rerun it! We *must*
3589 * use argv_expanded if it's non-NULL */
3591 /* Going to fork a child per each pipe member */
3595 for (i = 0; i < pi->num_cmds; i++) {
3596 struct fd_pair pipefds;
3598 volatile nommu_save_t nommu_save;
3599 nommu_save.new_env = NULL;
3600 nommu_save.old_env = NULL;
3601 nommu_save.argv = NULL;
3602 nommu_save.argv_from_re_execing = NULL;
3604 command = &(pi->cmds[i]);
3605 if (command->argv) {
3606 debug_printf_exec(": pipe member '%s' '%s'...\n",
3607 command->argv[0], command->argv[1]);
3609 debug_printf_exec(": pipe member with no argv\n");
3612 /* pipes are inserted between pairs of commands */
3615 if ((i + 1) < pi->num_cmds)
3616 xpiped_pair(pipefds);
3618 command->pid = BB_MMU ? fork() : vfork();
3619 if (!command->pid) { /* child */
3621 disable_restore_tty_pgrp_on_exit();
3623 /* Every child adds itself to new process group
3624 * with pgid == pid_of_first_child_in_pipe */
3625 if (G.run_list_level == 1 && G_interactive_fd) {
3628 if (pgrp < 0) /* true for 1st process only */
3630 if (setpgid(0, pgrp) == 0
3631 && pi->followup != PIPE_BG
3632 && G.saved_tty_pgrp /* we have ctty */
3634 /* We do it in *every* child, not just first,
3636 tcsetpgrp(G_interactive_fd, pgrp);
3640 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3641 /* 1st cmd in backgrounded pipe
3642 * should have its stdin /dev/null'ed */
3644 if (open(bb_dev_null, O_RDONLY))
3645 xopen("/", O_RDONLY);
3647 xmove_fd(nextin, 0);
3649 xmove_fd(pipefds.wr, 1);
3652 /* Like bash, explicit redirects override pipes,
3653 * and the pipe fd is available for dup'ing. */
3654 if (setup_redirects(command, NULL))
3657 /* Restore default handlers just prior to exec */
3658 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3660 /* Stores to nommu_save list of env vars putenv'ed
3661 * (NOMMU, on MMU we don't need that) */
3662 /* cast away volatility... */
3663 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3664 /* pseudo_exec() does not return */
3667 /* parent or error */
3668 enable_restore_tty_pgrp_on_exit();
3670 /* Clean up after vforked child */
3671 free(nommu_save.argv);
3672 free(nommu_save.argv_from_re_execing);
3673 free_strings_and_unsetenv(nommu_save.new_env, 1);
3674 putenv_all(nommu_save.old_env);
3675 /* Free the pointers, but the strings themselves
3676 * are in environ now, don't use free_strings! */
3677 free(nommu_save.old_env);
3679 free(argv_expanded);
3680 argv_expanded = NULL;
3681 if (command->pid < 0) { /* [v]fork failed */
3682 /* Clearly indicate, was it fork or vfork */
3683 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3687 /* Second and next children need to know pid of first one */
3689 pi->pgrp = command->pid;
3695 if ((i + 1) < pi->num_cmds)
3697 /* Pass read (output) pipe end to next iteration */
3698 nextin = pipefds.rd;
3701 if (!pi->alive_cmds) {
3703 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3708 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3712 #ifndef debug_print_tree
3713 static void debug_print_tree(struct pipe *pi, int lvl)
3715 static const char *const PIPE[] = {
3721 static const char *RES[] = {
3722 [RES_NONE ] = "NONE" ,
3725 [RES_THEN ] = "THEN" ,
3726 [RES_ELIF ] = "ELIF" ,
3727 [RES_ELSE ] = "ELSE" ,
3730 #if ENABLE_HUSH_LOOPS
3731 [RES_FOR ] = "FOR" ,
3732 [RES_WHILE] = "WHILE",
3733 [RES_UNTIL] = "UNTIL",
3735 [RES_DONE ] = "DONE" ,
3737 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3740 #if ENABLE_HUSH_CASE
3741 [RES_CASE ] = "CASE" ,
3742 [RES_MATCH] = "MATCH",
3743 [RES_CASEI] = "CASEI",
3744 [RES_ESAC ] = "ESAC" ,
3746 [RES_XXXX ] = "XXXX" ,
3747 [RES_SNTX ] = "SNTX" ,
3749 static const char *const GRPTYPE[] = {
3752 #if ENABLE_HUSH_FUNCTIONS
3761 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3762 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3764 while (prn < pi->num_cmds) {
3765 struct command *command = &pi->cmds[prn];
3766 char **argv = command->argv;
3768 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3770 command->assignment_cnt);
3771 if (command->group) {
3772 fprintf(stderr, " group %s: (argv=%p)\n",
3773 GRPTYPE[command->grp_type],
3775 debug_print_tree(command->group, lvl+1);
3779 if (argv) while (*argv) {
3780 fprintf(stderr, " '%s'", *argv);
3783 fprintf(stderr, "\n");
3792 /* NB: called by pseudo_exec, and therefore must not modify any
3793 * global data until exec/_exit (we can be a child after vfork!) */
3794 static int run_list(struct pipe *pi)
3796 #if ENABLE_HUSH_CASE
3797 char *case_word = NULL;
3799 #if ENABLE_HUSH_LOOPS
3800 struct pipe *loop_top = NULL;
3801 char *for_varname = NULL;
3802 char **for_lcur = NULL;
3803 char **for_list = NULL;
3805 smallint last_followup;
3807 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3808 smalluint cond_code = 0;
3810 enum { cond_code = 0 };
3813 smallint rword; /* enum reserved_style */
3814 smallint last_rword; /* ditto */
3817 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3820 #if ENABLE_HUSH_LOOPS
3821 /* Check syntax for "for" */
3822 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3823 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3825 /* current word is FOR or IN (BOLD in comments below) */
3826 if (cpipe->next == NULL) {
3827 syntax_error("malformed for");
3829 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3832 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3833 if (cpipe->next->res_word == RES_DO)
3835 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3836 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3837 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3839 syntax_error("malformed for");
3841 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3847 /* Past this point, all code paths should jump to ret: label
3848 * in order to return, no direct "return" statements please.
3849 * This helps to ensure that no memory is leaked. */
3857 last_rword = RES_XXXX;
3859 last_followup = PIPE_SEQ;
3860 rcode = G.last_exitcode;
3862 /* Go through list of pipes, (maybe) executing them. */
3863 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3867 IF_HAS_KEYWORDS(rword = pi->res_word;)
3868 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3869 rword, cond_code, last_rword);
3870 #if ENABLE_HUSH_LOOPS
3871 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3872 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3874 /* start of a loop: remember where loop starts */
3879 /* Still in the same "if...", "then..." or "do..." branch? */
3880 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3881 if ((rcode == 0 && last_followup == PIPE_OR)
3882 || (rcode != 0 && last_followup == PIPE_AND)
3884 /* It is "<true> || CMD" or "<false> && CMD"
3885 * and we should not execute CMD */
3886 debug_printf_exec("skipped cmd because of || or &&\n");
3887 last_followup = pi->followup;
3891 last_followup = pi->followup;
3892 IF_HAS_KEYWORDS(last_rword = rword;)
3895 if (rword == RES_THEN) {
3896 /* if false; then ... fi has exitcode 0! */
3897 G.last_exitcode = rcode = EXIT_SUCCESS;
3898 /* "if <false> THEN cmd": skip cmd */
3902 if (rword == RES_ELSE || rword == RES_ELIF) {
3903 /* "if <true> then ... ELSE/ELIF cmd":
3904 * skip cmd and all following ones */
3909 #if ENABLE_HUSH_LOOPS
3910 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3912 /* first loop through for */
3914 static const char encoded_dollar_at[] ALIGN1 = {
3915 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3916 }; /* encoded representation of "$@" */
3917 static const char *const encoded_dollar_at_argv[] = {
3918 encoded_dollar_at, NULL
3919 }; /* argv list with one element: "$@" */
3922 vals = (char**)encoded_dollar_at_argv;
3923 if (pi->next->res_word == RES_IN) {
3924 /* if no variable values after "in" we skip "for" */
3925 if (!pi->next->cmds[0].argv) {
3926 G.last_exitcode = rcode = EXIT_SUCCESS;
3927 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3930 vals = pi->next->cmds[0].argv;
3931 } /* else: "for var; do..." -> assume "$@" list */
3932 /* create list of variable values */
3933 debug_print_strings("for_list made from", vals);
3934 for_list = expand_strvec_to_strvec(vals);
3935 for_lcur = for_list;
3936 debug_print_strings("for_list", for_list);
3937 for_varname = pi->cmds[0].argv[0];
3938 pi->cmds[0].argv[0] = NULL;
3940 free(pi->cmds[0].argv[0]);
3942 /* "for" loop is over, clean up */
3946 pi->cmds[0].argv[0] = for_varname;
3949 /* Insert next value from for_lcur */
3950 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3951 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3952 pi->cmds[0].assignment_cnt = 1;
3954 if (rword == RES_IN) {
3955 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3957 if (rword == RES_DONE) {
3958 continue; /* "done" has no cmds too */
3961 #if ENABLE_HUSH_CASE
3962 if (rword == RES_CASE) {
3963 case_word = expand_strvec_to_string(pi->cmds->argv);
3966 if (rword == RES_MATCH) {
3969 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3971 /* all prev words didn't match, does this one match? */
3972 argv = pi->cmds->argv;
3974 char *pattern = expand_string_to_string(*argv);
3975 /* TODO: which FNM_xxx flags to use? */
3976 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3978 if (cond_code == 0) { /* match! we will execute this branch */
3979 free(case_word); /* make future "word)" stop */
3987 if (rword == RES_CASEI) { /* inside of a case branch */
3989 continue; /* not matched yet, skip this pipe */
3992 /* Just pressing <enter> in shell should check for jobs.
3993 * OTOH, in non-interactive shell this is useless
3994 * and only leads to extra job checks */
3995 if (pi->num_cmds == 0) {
3996 if (G_interactive_fd)
3997 goto check_jobs_and_continue;
4001 /* After analyzing all keywords and conditions, we decided
4002 * to execute this pipe. NB: have to do checkjobs(NULL)
4003 * after run_pipe to collect any background children,
4004 * even if list execution is to be stopped. */
4005 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4008 #if ENABLE_HUSH_LOOPS
4009 G.flag_break_continue = 0;
4011 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4013 /* We ran a builtin, function, or group.
4014 * rcode is already known
4015 * and we don't need to wait for anything. */
4016 G.last_exitcode = rcode;
4017 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4018 check_and_run_traps(0);
4019 #if ENABLE_HUSH_LOOPS
4020 /* Was it "break" or "continue"? */
4021 if (G.flag_break_continue) {
4022 smallint fbc = G.flag_break_continue;
4023 /* We might fall into outer *loop*,
4024 * don't want to break it too */
4026 G.depth_break_continue--;
4027 if (G.depth_break_continue == 0)
4028 G.flag_break_continue = 0;
4029 /* else: e.g. "continue 2" should *break* once, *then* continue */
4030 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4031 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4032 goto check_jobs_and_break;
4033 /* "continue": simulate end of loop */
4038 #if ENABLE_HUSH_FUNCTIONS
4039 if (G.flag_return_in_progress == 1)
4040 goto check_jobs_and_break;
4042 } else if (pi->followup == PIPE_BG) {
4043 /* What does bash do with attempts to background builtins? */
4044 /* even bash 3.2 doesn't do that well with nested bg:
4045 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4046 * I'm NOT treating inner &'s as jobs */
4047 check_and_run_traps(0);
4049 if (G.run_list_level == 1)
4052 G.last_exitcode = rcode = EXIT_SUCCESS;
4053 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4056 if (G.run_list_level == 1 && G_interactive_fd) {
4057 /* Waits for completion, then fg's main shell */
4058 rcode = checkjobs_and_fg_shell(pi);
4059 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4060 check_and_run_traps(0);
4063 { /* This one just waits for completion */
4064 rcode = checkjobs(pi);
4065 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4066 check_and_run_traps(0);
4068 G.last_exitcode = rcode;
4072 /* Analyze how result affects subsequent commands */
4074 if (rword == RES_IF || rword == RES_ELIF)
4077 #if ENABLE_HUSH_LOOPS
4078 /* Beware of "while false; true; do ..."! */
4079 if (pi->next && pi->next->res_word == RES_DO) {
4080 if (rword == RES_WHILE) {
4082 /* "while false; do...done" - exitcode 0 */
4083 G.last_exitcode = rcode = EXIT_SUCCESS;
4084 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4085 goto check_jobs_and_break;
4088 if (rword == RES_UNTIL) {
4090 debug_printf_exec(": until expr is true: breaking\n");
4091 check_jobs_and_break:
4099 check_jobs_and_continue:
4106 #if ENABLE_HUSH_LOOPS
4111 #if ENABLE_HUSH_CASE
4115 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4119 /* Select which version we will use */
4120 static int run_and_free_list(struct pipe *pi)
4123 debug_printf_exec("run_and_free_list entered\n");
4125 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4126 rcode = run_list(pi);
4128 /* free_pipe_list has the side effect of clearing memory.
4129 * In the long run that function can be merged with run_list,
4130 * but doing that now would hobble the debugging effort. */
4132 debug_printf_exec("run_and_free_list return %d\n", rcode);
4137 static struct pipe *new_pipe(void)
4140 pi = xzalloc(sizeof(struct pipe));
4141 /*pi->followup = 0; - deliberately invalid value */
4142 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4146 /* Command (member of a pipe) is complete, or we start a new pipe
4147 * if ctx->command is NULL.
4148 * No errors possible here.
4150 static int done_command(struct parse_context *ctx)
4152 /* The command is really already in the pipe structure, so
4153 * advance the pipe counter and make a new, null command. */
4154 struct pipe *pi = ctx->pipe;
4155 struct command *command = ctx->command;
4158 if (IS_NULL_CMD(command)) {
4159 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4163 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4164 //debug_print_tree(ctx->list_head, 20);
4166 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4169 /* Only real trickiness here is that the uncommitted
4170 * command structure is not counted in pi->num_cmds. */
4171 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4172 ctx->command = command = &pi->cmds[pi->num_cmds];
4174 memset(command, 0, sizeof(*command));
4175 return pi->num_cmds; /* used only for 0/nonzero check */
4178 static void done_pipe(struct parse_context *ctx, pipe_style type)
4182 debug_printf_parse("done_pipe entered, followup %d\n", type);
4183 /* Close previous command */
4184 not_null = done_command(ctx);
4185 ctx->pipe->followup = type;
4187 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4188 ctx->ctx_inverted = 0;
4189 ctx->pipe->res_word = ctx->ctx_res_w;
4192 /* Without this check, even just <enter> on command line generates
4193 * tree of three NOPs (!). Which is harmless but annoying.
4194 * IOW: it is safe to do it unconditionally. */
4197 || ctx->ctx_res_w == RES_FI
4199 #if ENABLE_HUSH_LOOPS
4200 || ctx->ctx_res_w == RES_DONE
4201 || ctx->ctx_res_w == RES_FOR
4202 || ctx->ctx_res_w == RES_IN
4204 #if ENABLE_HUSH_CASE
4205 || ctx->ctx_res_w == RES_ESAC
4209 debug_printf_parse("done_pipe: adding new pipe: "
4210 "not_null:%d ctx->ctx_res_w:%d\n",
4211 not_null, ctx->ctx_res_w);
4213 ctx->pipe->next = new_p;
4215 /* RES_THEN, RES_DO etc are "sticky" -
4216 * they remain set for pipes inside if/while.
4217 * This is used to control execution.
4218 * RES_FOR and RES_IN are NOT sticky (needed to support
4219 * cases where variable or value happens to match a keyword):
4221 #if ENABLE_HUSH_LOOPS
4222 if (ctx->ctx_res_w == RES_FOR
4223 || ctx->ctx_res_w == RES_IN)
4224 ctx->ctx_res_w = RES_NONE;
4226 #if ENABLE_HUSH_CASE
4227 if (ctx->ctx_res_w == RES_MATCH)
4228 ctx->ctx_res_w = RES_CASEI;
4230 ctx->command = NULL; /* trick done_command below */
4231 /* Create the memory for command, roughly:
4232 * ctx->pipe->cmds = new struct command;
4233 * ctx->command = &ctx->pipe->cmds[0];
4236 //debug_print_tree(ctx->list_head, 10);
4238 debug_printf_parse("done_pipe return\n");
4241 static void initialize_context(struct parse_context *ctx)
4243 memset(ctx, 0, sizeof(*ctx));
4244 ctx->pipe = ctx->list_head = new_pipe();
4245 /* Create the memory for command, roughly:
4246 * ctx->pipe->cmds = new struct command;
4247 * ctx->command = &ctx->pipe->cmds[0];
4252 /* If a reserved word is found and processed, parse context is modified
4253 * and 1 is returned.
4256 struct reserved_combo {
4259 unsigned char assignment_flag;
4263 FLAG_END = (1 << RES_NONE ),
4265 FLAG_IF = (1 << RES_IF ),
4266 FLAG_THEN = (1 << RES_THEN ),
4267 FLAG_ELIF = (1 << RES_ELIF ),
4268 FLAG_ELSE = (1 << RES_ELSE ),
4269 FLAG_FI = (1 << RES_FI ),
4271 #if ENABLE_HUSH_LOOPS
4272 FLAG_FOR = (1 << RES_FOR ),
4273 FLAG_WHILE = (1 << RES_WHILE),
4274 FLAG_UNTIL = (1 << RES_UNTIL),
4275 FLAG_DO = (1 << RES_DO ),
4276 FLAG_DONE = (1 << RES_DONE ),
4277 FLAG_IN = (1 << RES_IN ),
4279 #if ENABLE_HUSH_CASE
4280 FLAG_MATCH = (1 << RES_MATCH),
4281 FLAG_ESAC = (1 << RES_ESAC ),
4283 FLAG_START = (1 << RES_XXXX ),
4286 static const struct reserved_combo* match_reserved_word(o_string *word)
4288 /* Mostly a list of accepted follow-up reserved words.
4289 * FLAG_END means we are done with the sequence, and are ready
4290 * to turn the compound list into a command.
4291 * FLAG_START means the word must start a new compound list.
4293 static const struct reserved_combo reserved_list[] = {
4295 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4296 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4297 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4298 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4299 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4300 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4302 #if ENABLE_HUSH_LOOPS
4303 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4304 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4305 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4306 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4307 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4308 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4310 #if ENABLE_HUSH_CASE
4311 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4312 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4315 const struct reserved_combo *r;
4317 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4318 if (strcmp(word->data, r->literal) == 0)
4323 /* Return 0: not a keyword, 1: keyword
4325 static int reserved_word(o_string *word, struct parse_context *ctx)
4327 #if ENABLE_HUSH_CASE
4328 static const struct reserved_combo reserved_match = {
4329 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4332 const struct reserved_combo *r;
4336 r = match_reserved_word(word);
4340 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4341 #if ENABLE_HUSH_CASE
4342 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4343 /* "case word IN ..." - IN part starts first match part */
4344 r = &reserved_match;
4347 if (r->flag == 0) { /* '!' */
4348 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4349 syntax_error("! ! command");
4350 ctx->ctx_res_w = RES_SNTX;
4352 ctx->ctx_inverted = 1;
4355 if (r->flag & FLAG_START) {
4356 struct parse_context *old;
4358 old = xmalloc(sizeof(*old));
4359 debug_printf_parse("push stack %p\n", old);
4360 *old = *ctx; /* physical copy */
4361 initialize_context(ctx);
4363 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4364 syntax_error_at(word->data);
4365 ctx->ctx_res_w = RES_SNTX;
4368 /* "{...} fi" is ok. "{...} if" is not
4370 * if { echo foo; } then { echo bar; } fi */
4371 if (ctx->command->group)
4372 done_pipe(ctx, PIPE_SEQ);
4375 ctx->ctx_res_w = r->res;
4376 ctx->old_flag = r->flag;
4377 word->o_assignment = r->assignment_flag;
4379 if (ctx->old_flag & FLAG_END) {
4380 struct parse_context *old;
4382 done_pipe(ctx, PIPE_SEQ);
4383 debug_printf_parse("pop stack %p\n", ctx->stack);
4385 old->command->group = ctx->list_head;
4386 old->command->grp_type = GRP_NORMAL;
4388 o_addstr(&old->as_string, ctx->as_string.data);
4389 o_free_unsafe(&ctx->as_string);
4390 old->command->group_as_string = xstrdup(old->as_string.data);
4391 debug_printf_parse("pop, remembering as:'%s'\n",
4392 old->command->group_as_string);
4394 *ctx = *old; /* physical copy */
4401 /* Word is complete, look at it and update parsing context.
4402 * Normal return is 0. Syntax errors return 1.
4403 * Note: on return, word is reset, but not o_free'd!
4405 static int done_word(o_string *word, struct parse_context *ctx)
4407 struct command *command = ctx->command;
4409 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4410 if (word->length == 0 && word->o_quoted == 0) {
4411 debug_printf_parse("done_word return 0: true null, ignored\n");
4415 if (ctx->pending_redirect) {
4416 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4417 * only if run as "bash", not "sh" */
4418 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4420 * ...the word that follows the redirection operator
4421 * shall be subjected to tilde expansion, parameter expansion,
4422 * command substitution, arithmetic expansion, and quote
4423 * removal. Pathname expansion shall not be performed
4424 * on the word by a non-interactive shell; an interactive
4425 * shell may perform it, but shall do so only when
4426 * the expansion would result in one word."
4428 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4429 /* Cater for >\file case:
4430 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4431 * Same with heredocs:
4432 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4434 unbackslash(ctx->pending_redirect->rd_filename);
4435 /* Is it <<"HEREDOC"? */
4436 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4439 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4441 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4442 ctx->pending_redirect = NULL;
4444 /* If this word wasn't an assignment, next ones definitely
4445 * can't be assignments. Even if they look like ones. */
4446 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4447 && word->o_assignment != WORD_IS_KEYWORD
4449 word->o_assignment = NOT_ASSIGNMENT;
4451 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4452 command->assignment_cnt++;
4453 word->o_assignment = MAYBE_ASSIGNMENT;
4457 # if ENABLE_HUSH_CASE
4458 if (ctx->ctx_dsemicolon
4459 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4461 /* already done when ctx_dsemicolon was set to 1: */
4462 /* ctx->ctx_res_w = RES_MATCH; */
4463 ctx->ctx_dsemicolon = 0;
4466 if (!command->argv /* if it's the first word... */
4467 # if ENABLE_HUSH_LOOPS
4468 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4469 && ctx->ctx_res_w != RES_IN
4472 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4473 if (reserved_word(word, ctx)) {
4474 o_reset_to_empty_unquoted(word);
4475 debug_printf_parse("done_word return %d\n",
4476 (ctx->ctx_res_w == RES_SNTX));
4477 return (ctx->ctx_res_w == RES_SNTX);
4481 if (command->group) {
4482 /* "{ echo foo; } echo bar" - bad */
4483 syntax_error_at(word->data);
4484 debug_printf_parse("done_word return 1: syntax error, "
4485 "groups and arglists don't mix\n");
4488 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4489 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4490 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4491 /* (otherwise it's known to be not empty and is already safe) */
4493 /* exclude "$@" - it can expand to no word despite "" */
4494 char *p = word->data;
4495 while (p[0] == SPECIAL_VAR_SYMBOL
4496 && (p[1] & 0x7f) == '@'
4497 && p[2] == SPECIAL_VAR_SYMBOL
4501 if (p == word->data || p[0] != '\0') {
4502 /* saw no "$@", or not only "$@" but some
4503 * real text is there too */
4504 /* insert "empty variable" reference, this makes
4505 * e.g. "", $empty"" etc to not disappear */
4506 o_addchr(word, SPECIAL_VAR_SYMBOL);
4507 o_addchr(word, SPECIAL_VAR_SYMBOL);
4510 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4511 debug_print_strings("word appended to argv", command->argv);
4514 #if ENABLE_HUSH_LOOPS
4515 if (ctx->ctx_res_w == RES_FOR) {
4517 || !is_well_formed_var_name(command->argv[0], '\0')
4519 /* bash says just "not a valid identifier" */
4520 syntax_error("not a valid identifier in for");
4523 /* Force FOR to have just one word (variable name) */
4524 /* NB: basically, this makes hush see "for v in ..."
4525 * syntax as if it is "for v; in ...". FOR and IN become
4526 * two pipe structs in parse tree. */
4527 done_pipe(ctx, PIPE_SEQ);
4530 #if ENABLE_HUSH_CASE
4531 /* Force CASE to have just one word */
4532 if (ctx->ctx_res_w == RES_CASE) {
4533 done_pipe(ctx, PIPE_SEQ);
4537 o_reset_to_empty_unquoted(word);
4539 debug_printf_parse("done_word return 0\n");
4544 /* Peek ahead in the input to find out if we have a "&n" construct,
4545 * as in "2>&1", that represents duplicating a file descriptor.
4547 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4548 * REDIRFD_SYNTAX_ERR if syntax error,
4549 * REDIRFD_TO_FILE if no & was seen,
4550 * or the number found.
4553 #define parse_redir_right_fd(as_string, input) \
4554 parse_redir_right_fd(input)
4556 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4562 return REDIRFD_TO_FILE;
4564 ch = i_getch(input); /* get the & */
4565 nommu_addchr(as_string, ch);
4568 ch = i_getch(input);
4569 nommu_addchr(as_string, ch);
4570 return REDIRFD_CLOSE;
4574 while (ch != EOF && isdigit(ch)) {
4575 d = d*10 + (ch-'0');
4577 ch = i_getch(input);
4578 nommu_addchr(as_string, ch);
4583 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4585 bb_error_msg("ambiguous redirect");
4586 return REDIRFD_SYNTAX_ERR;
4589 /* Return code is 0 normal, 1 if a syntax error is detected
4591 static int parse_redirect(struct parse_context *ctx,
4594 struct in_str *input)
4596 struct command *command = ctx->command;
4597 struct redir_struct *redir;
4598 struct redir_struct **redirp;
4601 dup_num = REDIRFD_TO_FILE;
4602 if (style != REDIRECT_HEREDOC) {
4603 /* Check for a '>&1' type redirect */
4604 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4605 if (dup_num == REDIRFD_SYNTAX_ERR)
4608 int ch = i_peek(input);
4609 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4610 if (dup_num) { /* <<-... */
4611 ch = i_getch(input);
4612 nommu_addchr(&ctx->as_string, ch);
4617 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4618 int ch = i_peek(input);
4620 /* >|FILE redirect ("clobbering" >).
4621 * Since we do not support "set -o noclobber" yet,
4622 * >| and > are the same for now. Just eat |.
4624 ch = i_getch(input);
4625 nommu_addchr(&ctx->as_string, ch);
4629 /* Create a new redir_struct and append it to the linked list */
4630 redirp = &command->redirects;
4631 while ((redir = *redirp) != NULL) {
4632 redirp = &(redir->next);
4634 *redirp = redir = xzalloc(sizeof(*redir));
4635 /* redir->next = NULL; */
4636 /* redir->rd_filename = NULL; */
4637 redir->rd_type = style;
4638 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4640 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4641 redir_table[style].descrip);
4643 redir->rd_dup = dup_num;
4644 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4645 /* Erik had a check here that the file descriptor in question
4646 * is legit; I postpone that to "run time"
4647 * A "-" representation of "close me" shows up as a -3 here */
4648 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4649 redir->rd_fd, redir->rd_dup);
4651 /* Set ctx->pending_redirect, so we know what to do at the
4652 * end of the next parsed word. */
4653 ctx->pending_redirect = redir;
4658 /* If a redirect is immediately preceded by a number, that number is
4659 * supposed to tell which file descriptor to redirect. This routine
4660 * looks for such preceding numbers. In an ideal world this routine
4661 * needs to handle all the following classes of redirects...
4662 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4663 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4664 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4665 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4667 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4669 * ... If n is quoted, the number shall not be recognized as part of
4670 * the redirection expression. For example:
4672 * writes the character 2 into file a"
4673 * We are getting it right by setting ->o_quoted on any \<char>
4675 * A -1 return means no valid number was found,
4676 * the caller should use the appropriate default for this redirection.
4678 static int redirect_opt_num(o_string *o)
4682 if (o->data == NULL)
4684 num = bb_strtou(o->data, NULL, 10);
4685 if (errno || num < 0)
4687 o_reset_to_empty_unquoted(o);
4692 #define fetch_till_str(as_string, input, word, skip_tabs) \
4693 fetch_till_str(input, word, skip_tabs)
4695 static char *fetch_till_str(o_string *as_string,
4696 struct in_str *input,
4700 o_string heredoc = NULL_O_STRING;
4706 ch = i_getch(input);
4707 nommu_addchr(as_string, ch);
4709 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4710 heredoc.data[past_EOL] = '\0';
4711 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4712 return heredoc.data;
4715 o_addchr(&heredoc, ch);
4716 past_EOL = heredoc.length;
4719 ch = i_getch(input);
4720 nommu_addchr(as_string, ch);
4721 } while (skip_tabs && ch == '\t');
4722 } while (ch == '\n');
4725 o_free_unsafe(&heredoc);
4728 o_addchr(&heredoc, ch);
4729 nommu_addchr(as_string, ch);
4733 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4734 * and load them all. There should be exactly heredoc_cnt of them.
4736 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4738 struct pipe *pi = ctx->list_head;
4740 while (pi && heredoc_cnt) {
4742 struct command *cmd = pi->cmds;
4744 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4746 cmd->argv ? cmd->argv[0] : "NONE");
4747 for (i = 0; i < pi->num_cmds; i++) {
4748 struct redir_struct *redir = cmd->redirects;
4750 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4751 i, cmd->argv ? cmd->argv[0] : "NONE");
4753 if (redir->rd_type == REDIRECT_HEREDOC) {
4756 redir->rd_type = REDIRECT_HEREDOC2;
4757 /* redir->dup is (ab)used to indicate <<- */
4758 p = fetch_till_str(&ctx->as_string, input,
4759 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4761 syntax_error("unexpected EOF in here document");
4764 free(redir->rd_filename);
4765 redir->rd_filename = p;
4768 redir = redir->next;
4775 /* Should be 0. If it isn't, it's a parse error */
4777 bb_error_msg_and_die("heredoc BUG 2");
4783 #if ENABLE_HUSH_TICK
4784 static FILE *generate_stream_from_string(const char *s)
4787 int pid, channel[2];
4793 pid = BB_MMU ? fork() : vfork();
4795 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4797 if (pid == 0) { /* child */
4798 disable_restore_tty_pgrp_on_exit();
4799 /* Process substitution is not considered to be usual
4800 * 'command execution'.
4801 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4808 close(channel[0]); /* NB: close _first_, then move fd! */
4809 xmove_fd(channel[1], 1);
4810 /* Prevent it from trying to handle ctrl-z etc */
4811 IF_HUSH_JOB(G.run_list_level = 1;)
4813 reset_traps_to_defaults();
4814 parse_and_run_string(s);
4815 _exit(G.last_exitcode);
4817 /* We re-execute after vfork on NOMMU. This makes this script safe:
4818 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4819 * huge=`cat BIG` # was blocking here forever
4822 re_execute_shell(&to_free,
4830 enable_restore_tty_pgrp_on_exit();
4835 pf = fdopen(channel[0], "r");
4839 /* Return code is exit status of the process that is run. */
4840 static int process_command_subs(o_string *dest, const char *s)
4843 struct in_str pipe_str;
4846 pf = generate_stream_from_string(s);
4849 close_on_exec_on(fileno(pf));
4851 /* Now send results of command back into original context */
4852 setup_file_in_str(&pipe_str, pf);
4854 while ((ch = i_getch(&pipe_str)) != EOF) {
4860 o_addchr(dest, '\n');
4863 o_addQchr(dest, ch);
4866 debug_printf("done reading from pipe, pclose()ing\n");
4867 /* Note: we got EOF, and we just close the read end of the pipe.
4868 * We do not wait for the `cmd` child to terminate. bash and ash do.
4870 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4871 * `false`; echo $? - bash outputs "1"
4874 debug_printf("closed FILE from child. return 0\n");
4879 static int parse_group(o_string *dest, struct parse_context *ctx,
4880 struct in_str *input, int ch)
4882 /* dest contains characters seen prior to ( or {.
4883 * Typically it's empty, but for function defs,
4884 * it contains function name (without '()'). */
4885 struct pipe *pipe_list;
4887 struct command *command = ctx->command;
4889 debug_printf_parse("parse_group entered\n");
4890 #if ENABLE_HUSH_FUNCTIONS
4891 if (ch == '(' && !dest->o_quoted) {
4893 if (done_word(dest, ctx))
4896 goto skip; /* (... */
4897 if (command->argv[1]) { /* word word ... (... */
4898 syntax_error_unexpected_ch('(');
4901 /* it is "word(..." or "word (..." */
4903 ch = i_getch(input);
4904 while (ch == ' ' || ch == '\t');
4906 syntax_error_unexpected_ch(ch);
4909 nommu_addchr(&ctx->as_string, ch);
4911 ch = i_getch(input);
4912 while (ch == ' ' || ch == '\t' || ch == '\n');
4914 syntax_error_unexpected_ch(ch);
4917 nommu_addchr(&ctx->as_string, ch);
4918 command->grp_type = GRP_FUNCTION;
4922 if (command->argv /* word [word]{... */
4923 || dest->length /* word{... */
4924 || dest->o_quoted /* ""{... */
4927 debug_printf_parse("parse_group return 1: "
4928 "syntax error, groups and arglists don't mix\n");
4932 #if ENABLE_HUSH_FUNCTIONS
4938 command->grp_type = GRP_SUBSHELL;
4940 /* bash does not allow "{echo...", requires whitespace */
4941 ch = i_getch(input);
4942 if (ch != ' ' && ch != '\t' && ch != '\n') {
4943 syntax_error_unexpected_ch(ch);
4946 nommu_addchr(&ctx->as_string, ch);
4951 char *as_string = NULL;
4953 pipe_list = parse_stream(&as_string, input, endch);
4956 o_addstr(&ctx->as_string, as_string);
4958 /* empty ()/{} or parse error? */
4959 if (!pipe_list || pipe_list == ERR_PTR) {
4960 /* parse_stream already emitted error msg */
4964 debug_printf_parse("parse_group return 1: "
4965 "parse_stream returned %p\n", pipe_list);
4968 command->group = pipe_list;
4970 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4971 command->group_as_string = as_string;
4972 debug_printf_parse("end of group, remembering as:'%s'\n",
4973 command->group_as_string);
4976 debug_printf_parse("parse_group return 0\n");
4978 /* command remains "open", available for possible redirects */
4981 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4982 /* Subroutines for copying $(...) and `...` things */
4983 static void add_till_backquote(o_string *dest, struct in_str *input);
4985 static void add_till_single_quote(o_string *dest, struct in_str *input)
4988 int ch = i_getch(input);
4990 syntax_error_unterm_ch('\'');
4991 /*xfunc_die(); - redundant */
4998 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4999 static void add_till_double_quote(o_string *dest, struct in_str *input)
5002 int ch = i_getch(input);
5004 syntax_error_unterm_ch('"');
5005 /*xfunc_die(); - redundant */
5009 if (ch == '\\') { /* \x. Copy both chars. */
5011 ch = i_getch(input);
5015 add_till_backquote(dest, input);
5019 //if (ch == '$') ...
5022 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5024 * "Within the backquoted style of command substitution, backslash
5025 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5026 * The search for the matching backquote shall be satisfied by the first
5027 * backquote found without a preceding backslash; during this search,
5028 * if a non-escaped backquote is encountered within a shell comment,
5029 * a here-document, an embedded command substitution of the $(command)
5030 * form, or a quoted string, undefined results occur. A single-quoted
5031 * or double-quoted string that begins, but does not end, within the
5032 * "`...`" sequence produces undefined results."
5034 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5036 static void add_till_backquote(o_string *dest, struct in_str *input)
5039 int ch = i_getch(input);
5041 syntax_error_unterm_ch('`');
5042 /*xfunc_die(); - redundant */
5047 /* \x. Copy both chars unless it is \` */
5048 int ch2 = i_getch(input);
5050 syntax_error_unterm_ch('`');
5051 /*xfunc_die(); - redundant */
5053 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5060 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5061 * quoting and nested ()s.
5062 * "With the $(command) style of command substitution, all characters
5063 * following the open parenthesis to the matching closing parenthesis
5064 * constitute the command. Any valid shell script can be used for command,
5065 * except a script consisting solely of redirections which produces
5066 * unspecified results."
5068 * echo $(echo '(TEST)' BEST) (TEST) BEST
5069 * echo $(echo 'TEST)' BEST) TEST) BEST
5070 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5072 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5076 int ch = i_getch(input);
5078 syntax_error_unterm_ch(')');
5079 /*xfunc_die(); - redundant */
5087 if (i_peek(input) == ')') {
5095 add_till_single_quote(dest, input);
5100 add_till_double_quote(dest, input);
5105 /* \x. Copy verbatim. Important for \(, \) */
5106 ch = i_getch(input);
5108 syntax_error_unterm_ch(')');
5109 /*xfunc_die(); - redundant */
5116 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5118 /* Return code: 0 for OK, 1 for syntax error */
5120 #define handle_dollar(as_string, dest, input) \
5121 handle_dollar(dest, input)
5123 static int handle_dollar(o_string *as_string,
5125 struct in_str *input)
5128 int ch = i_peek(input); /* first character after the $ */
5129 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5131 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5133 ch = i_getch(input);
5134 nommu_addchr(as_string, ch);
5136 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5138 debug_printf_parse(": '%c'\n", ch);
5139 o_addchr(dest, ch | quote_mask);
5142 if (!isalnum(ch) && ch != '_')
5144 ch = i_getch(input);
5145 nommu_addchr(as_string, ch);
5147 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5148 } else if (isdigit(ch)) {
5150 ch = i_getch(input);
5151 nommu_addchr(as_string, ch);
5152 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5153 debug_printf_parse(": '%c'\n", ch);
5154 o_addchr(dest, ch | quote_mask);
5155 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5156 } else switch (ch) {
5158 case '!': /* last bg pid */
5159 case '?': /* last exit code */
5160 case '#': /* number of args */
5161 case '*': /* args */
5162 case '@': /* args */
5163 goto make_one_char_var;
5165 bool first_char, all_digits;
5167 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5168 ch = i_getch(input);
5169 nommu_addchr(as_string, ch);
5170 /* TODO: maybe someone will try to escape the '}' */
5175 ch = i_getch(input);
5176 nommu_addchr(as_string, ch);
5183 /* ${#var}: length of var contents */
5193 && ( (all_digits && !isdigit(ch))
5194 || (!all_digits && !isalnum(ch) && ch != '_')
5197 /* handle parameter expansions
5198 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5203 case ':': /* null modifier */
5204 if (expansion == 0) {
5205 debug_printf_parse(": null modifier\n");
5210 case '#': /* remove prefix */
5211 case '%': /* remove suffix */
5212 if (expansion == 0) {
5213 debug_printf_parse(": remove suffix/prefix\n");
5218 case '-': /* default value */
5219 case '=': /* assign default */
5220 case '+': /* alternative */
5221 case '?': /* error indicate */
5222 debug_printf_parse(": parameter expansion\n");
5227 syntax_error_unterm_str("${name}");
5228 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5233 debug_printf_parse(": '%c'\n", ch);
5234 o_addchr(dest, ch | quote_mask);
5238 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5241 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5246 ch = i_getch(input);
5247 nommu_addchr(as_string, ch);
5248 # if ENABLE_SH_MATH_SUPPORT
5249 if (i_peek(input) == '(') {
5250 ch = i_getch(input);
5251 nommu_addchr(as_string, ch);
5252 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5253 o_addchr(dest, /*quote_mask |*/ '+');
5257 add_till_closing_paren(dest, input, true);
5260 o_addstr(as_string, dest->data + pos);
5261 o_addchr(as_string, ')');
5262 o_addchr(as_string, ')');
5265 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5269 # if ENABLE_HUSH_TICK
5270 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5271 o_addchr(dest, quote_mask | '`');
5275 add_till_closing_paren(dest, input, false);
5278 o_addstr(as_string, dest->data + pos);
5279 o_addchr(as_string, '`');
5282 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5288 ch = i_getch(input);
5289 nommu_addchr(as_string, ch);
5291 if (isalnum(ch)) { /* it's $_name or $_123 */
5297 /* $_ Shell or shell script name; or last cmd name */
5298 /* $- Option flags set by set builtin or shell options (-i etc) */
5300 o_addQchr(dest, '$');
5302 debug_printf_parse("handle_dollar return 0\n");
5307 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5308 parse_stream_dquoted(dest, input, dquote_end)
5310 static int parse_stream_dquoted(o_string *as_string,
5312 struct in_str *input,
5319 ch = i_getch(input);
5321 nommu_addchr(as_string, ch);
5322 if (ch == dquote_end) { /* may be only '"' or EOF */
5323 if (dest->o_assignment == NOT_ASSIGNMENT)
5324 dest->o_escape ^= 1;
5325 debug_printf_parse("parse_stream_dquoted return 0\n");
5328 /* note: can't move it above ch == dquote_end check! */
5330 syntax_error_unterm_ch('"');
5331 /*xfunc_die(); - redundant */
5335 next = i_peek(input);
5337 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5338 ch, ch, dest->o_escape);
5341 syntax_error("\\<eof>");
5345 * "The backslash retains its special meaning [in "..."]
5346 * only when followed by one of the following characters:
5347 * $, `, ", \, or <newline>. A double quote may be quoted
5348 * within double quotes by preceding it with a backslash.
5350 if (strchr("$`\"\\", next) != NULL) {
5351 ch = i_getch(input);
5352 o_addqchr(dest, ch);
5353 nommu_addchr(as_string, ch);
5355 o_addqchr(dest, '\\');
5356 nommu_addchr(as_string, '\\');
5361 if (handle_dollar(as_string, dest, input) != 0) {
5362 debug_printf_parse("parse_stream_dquoted return 1: "
5363 "handle_dollar returned non-0\n");
5368 #if ENABLE_HUSH_TICK
5370 //int pos = dest->length;
5371 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5372 o_addchr(dest, 0x80 | '`');
5373 add_till_backquote(dest, input);
5374 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5375 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5379 o_addQchr(dest, ch);
5381 && (dest->o_assignment == MAYBE_ASSIGNMENT
5382 || dest->o_assignment == WORD_IS_KEYWORD)
5383 && is_well_formed_var_name(dest->data, '=')
5385 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5391 * Scan input until EOF or end_trigger char.
5392 * Return a list of pipes to execute, or NULL on EOF
5393 * or if end_trigger character is met.
5394 * On syntax error, exit is shell is not interactive,
5395 * reset parsing machinery and start parsing anew,
5396 * or return ERR_PTR.
5398 static struct pipe *parse_stream(char **pstring,
5399 struct in_str *input,
5402 struct parse_context ctx;
5403 o_string dest = NULL_O_STRING;
5407 /* Double-quote state is handled in the state variable is_in_dquote.
5408 * A single-quote triggers a bypass of the main loop until its mate is
5409 * found. When recursing, quote state is passed in via dest->o_escape.
5411 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5412 end_trigger ? : 'X');
5415 G.ifs = get_local_var_value("IFS");
5420 #if ENABLE_HUSH_INTERACTIVE
5421 input->promptmode = 0; /* PS1 */
5423 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5424 initialize_context(&ctx);
5429 const char *is_special;
5433 redir_type redir_style;
5436 /* dest.o_quoted = 1; - already is (see below) */
5437 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5440 /* We reached closing '"' */
5443 ch = i_getch(input);
5444 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5445 ch, ch, dest.o_escape);
5450 syntax_error_unterm_str("here document");
5453 /* end_trigger == '}' case errors out earlier,
5454 * checking only ')' */
5455 if (end_trigger == ')') {
5456 syntax_error_unterm_ch('('); /* exits */
5457 /* goto parse_error; */
5460 if (done_word(&dest, &ctx)) {
5464 done_pipe(&ctx, PIPE_SEQ);
5466 /* If we got nothing... */
5467 /* (this makes bare "&" cmd a no-op.
5468 * bash says: "syntax error near unexpected token '&'") */
5469 if (pi->num_cmds == 0
5470 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5476 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5478 *pstring = ctx.as_string.data;
5480 o_free_unsafe(&ctx.as_string);
5483 debug_printf_parse("parse_stream return %p\n", pi);
5486 nommu_addchr(&ctx.as_string, ch);
5487 is_ifs = strchr(G.ifs, ch);
5488 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5489 "\\$\"" IF_HUSH_TICK("`") /* always special */
5492 if (!is_special && !is_ifs) { /* ordinary char */
5494 o_addQchr(&dest, ch);
5495 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5496 || dest.o_assignment == WORD_IS_KEYWORD)
5498 && is_well_formed_var_name(dest.data, '=')
5500 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5506 if (done_word(&dest, &ctx)) {
5510 #if ENABLE_HUSH_CASE
5511 /* "case ... in <newline> word) ..." -
5512 * newlines are ignored (but ';' wouldn't be) */
5513 if (ctx.command->argv == NULL
5514 && ctx.ctx_res_w == RES_MATCH
5519 /* Treat newline as a command separator. */
5520 done_pipe(&ctx, PIPE_SEQ);
5521 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5523 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5528 dest.o_assignment = MAYBE_ASSIGNMENT;
5530 /* note: if (is_ifs) continue;
5531 * will still trigger for us */
5535 /* "cmd}" or "cmd }..." without semicolon or &:
5536 * } is an ordinary char in this case, even inside { cmd; }
5537 * Pathological example: { ""}; } should exec "}" cmd
5540 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5541 || dest.length != 0 /* word} */
5542 || dest.o_quoted /* ""} */
5546 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5547 goto skip_end_trigger;
5548 /* else: } does terminate a group */
5551 if (end_trigger && end_trigger == ch
5552 && (heredoc_cnt == 0 || end_trigger != ';')
5555 /* This is technically valid:
5556 * { cat <<HERE; }; echo Ok
5560 * but we don't support this.
5561 * We require heredoc to be in enclosing {}/(),
5564 syntax_error_unterm_str("here document");
5567 if (done_word(&dest, &ctx)) {
5570 done_pipe(&ctx, PIPE_SEQ);
5571 dest.o_assignment = MAYBE_ASSIGNMENT;
5572 /* Do we sit outside of any if's, loops or case's? */
5574 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5578 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5580 *pstring = ctx.as_string.data;
5582 o_free_unsafe(&ctx.as_string);
5585 debug_printf_parse("parse_stream return %p: "
5586 "end_trigger char found\n",
5588 return ctx.list_head;
5597 next = i_peek(input);
5600 /* Catch <, > before deciding whether this word is
5601 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5604 redir_fd = redirect_opt_num(&dest);
5605 if (done_word(&dest, &ctx)) {
5608 redir_style = REDIRECT_OVERWRITE;
5610 redir_style = REDIRECT_APPEND;
5611 ch = i_getch(input);
5612 nommu_addchr(&ctx.as_string, ch);
5615 else if (next == '(') {
5616 syntax_error(">(process) not supported");
5620 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5622 continue; /* back to top of while (1) */
5624 redir_fd = redirect_opt_num(&dest);
5625 if (done_word(&dest, &ctx)) {
5628 redir_style = REDIRECT_INPUT;
5630 redir_style = REDIRECT_HEREDOC;
5632 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5633 ch = i_getch(input);
5634 nommu_addchr(&ctx.as_string, ch);
5635 } else if (next == '>') {
5636 redir_style = REDIRECT_IO;
5637 ch = i_getch(input);
5638 nommu_addchr(&ctx.as_string, ch);
5641 else if (next == '(') {
5642 syntax_error("<(process) not supported");
5646 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5648 continue; /* back to top of while (1) */
5651 if (dest.o_assignment == MAYBE_ASSIGNMENT
5652 /* check that we are not in word in "a=1 2>word b=1": */
5653 && !ctx.pending_redirect
5655 /* ch is a special char and thus this word
5656 * cannot be an assignment */
5657 dest.o_assignment = NOT_ASSIGNMENT;
5662 if (dest.length == 0) {
5665 if (ch == EOF || ch == '\n')
5668 /* note: we do not add it to &ctx.as_string */
5670 nommu_addchr(&ctx.as_string, '\n');
5672 o_addQchr(&dest, ch);
5677 syntax_error("\\<eof>");
5680 o_addchr(&dest, '\\');
5681 ch = i_getch(input);
5682 nommu_addchr(&ctx.as_string, ch);
5683 o_addchr(&dest, ch);
5684 /* Example: echo Hello \2>file
5685 * we need to know that word 2 is quoted */
5689 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5690 debug_printf_parse("parse_stream parse error: "
5691 "handle_dollar returned non-0\n");
5698 ch = i_getch(input);
5700 syntax_error_unterm_ch('\'');
5701 /*xfunc_die(); - redundant */
5703 nommu_addchr(&ctx.as_string, ch);
5706 if (dest.o_assignment == NOT_ASSIGNMENT)
5707 o_addqchr(&dest, ch);
5709 o_addchr(&dest, ch);
5714 is_in_dquote ^= 1; /* invert */
5715 if (dest.o_assignment == NOT_ASSIGNMENT)
5718 #if ENABLE_HUSH_TICK
5723 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5724 o_addchr(&dest, '`');
5728 add_till_backquote(&dest, input);
5730 o_addstr(&ctx.as_string, dest.data + pos);
5731 o_addchr(&ctx.as_string, '`');
5733 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5734 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5739 #if ENABLE_HUSH_CASE
5742 if (done_word(&dest, &ctx)) {
5745 done_pipe(&ctx, PIPE_SEQ);
5746 #if ENABLE_HUSH_CASE
5747 /* Eat multiple semicolons, detect
5748 * whether it means something special */
5753 ch = i_getch(input);
5754 nommu_addchr(&ctx.as_string, ch);
5755 if (ctx.ctx_res_w == RES_CASEI) {
5756 ctx.ctx_dsemicolon = 1;
5757 ctx.ctx_res_w = RES_MATCH;
5763 /* We just finished a cmd. New one may start
5764 * with an assignment */
5765 dest.o_assignment = MAYBE_ASSIGNMENT;
5768 if (done_word(&dest, &ctx)) {
5772 ch = i_getch(input);
5773 nommu_addchr(&ctx.as_string, ch);
5774 done_pipe(&ctx, PIPE_AND);
5776 done_pipe(&ctx, PIPE_BG);
5780 if (done_word(&dest, &ctx)) {
5783 #if ENABLE_HUSH_CASE
5784 if (ctx.ctx_res_w == RES_MATCH)
5785 break; /* we are in case's "word | word)" */
5787 if (next == '|') { /* || */
5788 ch = i_getch(input);
5789 nommu_addchr(&ctx.as_string, ch);
5790 done_pipe(&ctx, PIPE_OR);
5792 /* we could pick up a file descriptor choice here
5793 * with redirect_opt_num(), but bash doesn't do it.
5794 * "echo foo 2| cat" yields "foo 2". */
5799 #if ENABLE_HUSH_CASE
5800 /* "case... in [(]word)..." - skip '(' */
5801 if (ctx.ctx_res_w == RES_MATCH
5802 && ctx.command->argv == NULL /* not (word|(... */
5803 && dest.length == 0 /* not word(... */
5804 && dest.o_quoted == 0 /* not ""(... */
5810 if (parse_group(&dest, &ctx, input, ch) != 0) {
5815 #if ENABLE_HUSH_CASE
5816 if (ctx.ctx_res_w == RES_MATCH)
5820 /* proper use of this character is caught by end_trigger:
5821 * if we see {, we call parse_group(..., end_trigger='}')
5822 * and it will match } earlier (not here). */
5823 syntax_error_unexpected_ch(ch);
5827 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5833 struct parse_context *pctx;
5834 IF_HAS_KEYWORDS(struct parse_context *p2;)
5836 /* Clean up allocated tree.
5837 * Samples for finding leaks on syntax error recovery path.
5838 * Run them from interactive shell, watch pmap `pidof hush`.
5839 * while if false; then false; fi do break; done
5841 * while if false; then false; fi; do break; fi
5842 * Samples to catch leaks at execution:
5843 * while if (true | {true;}); then echo ok; fi; do break; done
5844 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5848 /* Update pipe/command counts,
5849 * otherwise freeing may miss some */
5850 done_pipe(pctx, PIPE_SEQ);
5851 debug_printf_clean("freeing list %p from ctx %p\n",
5852 pctx->list_head, pctx);
5853 debug_print_tree(pctx->list_head, 0);
5854 free_pipe_list(pctx->list_head);
5855 debug_printf_clean("freed list %p\n", pctx->list_head);
5857 o_free_unsafe(&pctx->as_string);
5859 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5863 IF_HAS_KEYWORDS(pctx = p2;)
5864 } while (HAS_KEYWORDS && pctx);
5865 /* Free text, clear all dest fields */
5867 /* If we are not in top-level parse, we return,
5868 * our caller will propagate error.
5870 if (end_trigger != ';') {
5878 /* Discard cached input, force prompt */
5880 IF_HUSH_INTERACTIVE(input->promptme = 1;)
5885 /* Executing from string: eval, sh -c '...'
5886 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5887 * end_trigger controls how often we stop parsing
5888 * NUL: parse all, execute, return
5889 * ';': parse till ';' or newline, execute, repeat till EOF
5891 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5894 struct pipe *pipe_list;
5896 pipe_list = parse_stream(NULL, inp, end_trigger);
5897 if (!pipe_list) /* EOF */
5899 debug_print_tree(pipe_list, 0);
5900 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5901 run_and_free_list(pipe_list);
5905 static void parse_and_run_string(const char *s)
5907 struct in_str input;
5908 setup_string_in_str(&input, s);
5909 parse_and_run_stream(&input, '\0');
5912 static void parse_and_run_file(FILE *f)
5914 struct in_str input;
5915 setup_file_in_str(&input, f);
5916 parse_and_run_stream(&input, ';');
5919 /* Called a few times only (or even once if "sh -c") */
5920 static void block_signals(int second_time)
5925 mask = (1 << SIGQUIT);
5926 if (G_interactive_fd) {
5927 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5928 if (G.saved_tty_pgrp) /* we have ctty, job control sigs work */
5929 mask |= SPECIAL_JOB_SIGS;
5931 G.non_DFL_mask = mask;
5934 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5938 sigaddset(&G.blocked_set, sig);
5942 sigdelset(&G.blocked_set, SIGCHLD);
5944 sigprocmask(SIG_SETMASK, &G.blocked_set,
5945 second_time ? NULL : &G.inherited_set);
5946 /* POSIX allows shell to re-enable SIGCHLD
5947 * even if it was SIG_IGN on entry */
5948 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5950 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5955 static void maybe_set_to_sigexit(int sig)
5957 void (*handler)(int);
5958 /* non_DFL_mask'ed signals are, well, masked,
5959 * no need to set handler for them.
5961 if (!((G.non_DFL_mask >> sig) & 1)) {
5962 handler = signal(sig, sigexit);
5963 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5964 signal(sig, handler);
5967 /* Set handlers to restore tty pgrp and exit */
5968 static void set_fatal_handlers(void)
5970 /* We _must_ restore tty pgrp on fatal signals */
5972 maybe_set_to_sigexit(SIGILL );
5973 maybe_set_to_sigexit(SIGFPE );
5974 maybe_set_to_sigexit(SIGBUS );
5975 maybe_set_to_sigexit(SIGSEGV);
5976 maybe_set_to_sigexit(SIGTRAP);
5977 } /* else: hush is perfect. what SEGV? */
5978 maybe_set_to_sigexit(SIGABRT);
5979 /* bash 3.2 seems to handle these just like 'fatal' ones */
5980 maybe_set_to_sigexit(SIGPIPE);
5981 maybe_set_to_sigexit(SIGALRM);
5982 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
5983 * if we aren't interactive... but in this case
5984 * we never want to restore pgrp on exit, and this fn is not called */
5985 /*maybe_set_to_sigexit(SIGHUP );*/
5986 /*maybe_set_to_sigexit(SIGTERM);*/
5987 /*maybe_set_to_sigexit(SIGINT );*/
5991 static int set_mode(const char cstate, const char mode)
5993 int state = (cstate == '-' ? 1 : 0);
5995 case 'n': G.fake_mode = state; break;
5996 case 'x': /*G.debug_mode = state;*/ break;
5997 default: return EXIT_FAILURE;
5999 return EXIT_SUCCESS;
6002 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6003 int hush_main(int argc, char **argv)
6005 static const struct variable const_shell_ver = {
6007 .varstr = (char*)hush_version_str,
6008 .max_len = 1, /* 0 can provoke free(name) */
6012 int signal_mask_is_inited = 0;
6015 struct variable *cur_var;
6018 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6019 G.last_exitcode = EXIT_SUCCESS;
6021 G.argv0_for_re_execing = argv[0];
6023 /* Deal with HUSH_VERSION */
6024 G.shell_ver = const_shell_ver; /* copying struct here */
6025 G.top_var = &G.shell_ver;
6026 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6027 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6028 /* Initialize our shell local variables with the values
6029 * currently living in the environment */
6030 cur_var = G.top_var;
6033 char *value = strchr(*e, '=');
6034 if (value) { /* paranoia */
6035 cur_var->next = xzalloc(sizeof(*cur_var));
6036 cur_var = cur_var->next;
6037 cur_var->varstr = *e;
6038 cur_var->max_len = strlen(*e);
6039 cur_var->flg_export = 1;
6043 debug_printf_env("putenv '%s'\n", hush_version_str);
6044 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6045 #if ENABLE_FEATURE_EDITING
6046 G.line_input_state = new_line_input_t(FOR_SHELL);
6048 G.global_argc = argc;
6049 G.global_argv = argv;
6050 /* Initialize some more globals to non-zero values */
6052 cmdedit_update_prompt();
6054 if (setjmp(die_jmp)) {
6055 /* xfunc has failed! die die die */
6056 /* no EXIT traps, this is an escape hatch! */
6058 hush_exit(xfunc_error_retval);
6061 /* Shell is non-interactive at first. We need to call
6062 * block_signals(0) if we are going to execute "sh <script>",
6063 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6064 * If we later decide that we are interactive, we run block_signals(0)
6065 * (or re-run block_signals(1) if we ran block_signals(0) before)
6066 * in order to intercept (more) signals.
6070 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6072 opt = getopt(argc, argv, "c:xins"
6075 # if ENABLE_HUSH_FUNCTIONS
6085 G.root_pid = getpid();
6086 G.global_argv = argv + optind;
6087 if (!argv[optind]) {
6088 /* -c 'script' (no params): prevent empty $0 */
6089 *--G.global_argv = argv[0];
6091 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6092 G.global_argc = argc - optind;
6093 block_signals(0); /* 0: called 1st time */
6094 parse_and_run_string(optarg);
6097 /* Well, we cannot just declare interactiveness,
6098 * we have to have some stuff (ctty, etc) */
6099 /* G_interactive_fd++; */
6102 /* "-s" means "read from stdin", but this is how we always
6103 * operate, so simply do nothing here. */
6106 case '<': /* "big heredoc" support */
6107 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6110 G.root_pid = bb_strtou(optarg, &optarg, 16);
6112 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6114 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6115 # if ENABLE_HUSH_LOOPS
6117 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6122 set_local_var(xstrdup(optarg), 0, opt == 'R');
6124 # if ENABLE_HUSH_FUNCTIONS
6126 struct function *funcp = new_function(optarg);
6127 /* funcp->name is already set to optarg */
6128 /* funcp->body is set to NULL. It's a special case. */
6129 funcp->body_as_string = argv[optind];
6137 if (!set_mode('-', opt))
6141 fprintf(stderr, "Usage: sh [FILE]...\n"
6142 " or: sh -c command [args]...\n\n");
6148 } /* option parsing loop */
6151 G.root_pid = getpid();
6153 /* If we are login shell... */
6154 if (argv[0] && argv[0][0] == '-') {
6156 debug_printf("sourcing /etc/profile\n");
6157 input = fopen_for_read("/etc/profile");
6158 if (input != NULL) {
6159 close_on_exec_on(fileno(input));
6160 block_signals(0); /* 0: called 1st time */
6161 signal_mask_is_inited = 1;
6162 parse_and_run_file(input);
6165 /* bash: after sourcing /etc/profile,
6166 * tries to source (in the given order):
6167 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6168 * stopping of first found. --noprofile turns this off.
6169 * bash also sources ~/.bash_logout on exit.
6170 * If called as sh, skips .bash_XXX files.
6177 * "bash <script>" (which is never interactive (unless -i?))
6178 * sources $BASH_ENV here (without scanning $PATH).
6179 * If called as sh, does the same but with $ENV.
6181 debug_printf("running script '%s'\n", argv[optind]);
6182 G.global_argv = argv + optind;
6183 G.global_argc = argc - optind;
6184 input = xfopen_for_read(argv[optind]);
6185 close_on_exec_on(fileno(input));
6186 if (!signal_mask_is_inited)
6187 block_signals(0); /* 0: called 1st time */
6188 parse_and_run_file(input);
6189 #if ENABLE_FEATURE_CLEAN_UP
6195 /* Up to here, shell was non-interactive. Now it may become one.
6196 * NB: don't forget to (re)run block_signals(0/1) as needed.
6199 /* A shell is interactive if the '-i' flag was given, or if all of
6200 * the following conditions are met:
6202 * no arguments remaining or the -s flag given
6203 * standard input is a terminal
6204 * standard output is a terminal
6205 * Refer to Posix.2, the description of the 'sh' utility.
6208 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6209 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6210 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6211 if (G.saved_tty_pgrp < 0)
6212 G.saved_tty_pgrp = 0;
6214 /* try to dup stdin to high fd#, >= 255 */
6215 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6216 if (G_interactive_fd < 0) {
6217 /* try to dup to any fd */
6218 G_interactive_fd = dup(STDIN_FILENO);
6219 if (G_interactive_fd < 0) {
6221 G_interactive_fd = 0;
6222 G.saved_tty_pgrp = 0;
6225 // TODO: track & disallow any attempts of user
6226 // to (inadvertently) close/redirect G_interactive_fd
6228 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6229 if (G_interactive_fd) {
6230 close_on_exec_on(G_interactive_fd);
6232 if (G.saved_tty_pgrp) {
6233 /* If we were run as 'hush &', sleep until we are
6234 * in the foreground (tty pgrp == our pgrp).
6235 * If we get started under a job aware app (like bash),
6236 * make sure we are now in charge so we don't fight over
6237 * who gets the foreground */
6239 pid_t shell_pgrp = getpgrp();
6240 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6241 if (G.saved_tty_pgrp == shell_pgrp)
6243 /* send TTIN to ourself (should stop us) */
6244 kill(- shell_pgrp, SIGTTIN);
6248 /* Block some signals */
6249 block_signals(signal_mask_is_inited);
6251 if (G.saved_tty_pgrp) {
6252 /* Set other signals to restore saved_tty_pgrp */
6253 set_fatal_handlers();
6254 /* Put ourselves in our own process group
6255 * (bash, too, does this only if ctty is available) */
6256 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6257 /* Grab control of the terminal */
6258 tcsetpgrp(G_interactive_fd, getpid());
6260 /* -1 is special - makes xfuncs longjmp, not exit
6261 * (we reset die_sleep = 0 whereever we [v]fork) */
6262 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6263 } else if (!signal_mask_is_inited) {
6264 block_signals(0); /* 0: called 1st time */
6265 } /* else: block_signals(0) was done before */
6266 #elif ENABLE_HUSH_INTERACTIVE
6267 /* No job control compiled in, only prompt/line editing */
6268 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6269 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6270 if (G_interactive_fd < 0) {
6271 /* try to dup to any fd */
6272 G_interactive_fd = dup(STDIN_FILENO);
6273 if (G_interactive_fd < 0)
6275 G_interactive_fd = 0;
6278 if (G_interactive_fd) {
6279 close_on_exec_on(G_interactive_fd);
6280 block_signals(signal_mask_is_inited);
6281 } else if (!signal_mask_is_inited) {
6285 /* We have interactiveness code disabled */
6286 if (!signal_mask_is_inited) {
6291 * if interactive but not a login shell, sources ~/.bashrc
6292 * (--norc turns this off, --rcfile <file> overrides)
6295 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6296 printf("\n\n%s hush - the humble shell\n", bb_banner);
6297 if (ENABLE_HUSH_HELP)
6298 puts("Enter 'help' for a list of built-in commands.");
6302 parse_and_run_file(stdin);
6305 #if ENABLE_FEATURE_CLEAN_UP
6306 if (G.cwd != bb_msg_unknown)
6308 cur_var = G.top_var->next;
6310 struct variable *tmp = cur_var;
6311 if (!cur_var->max_len)
6312 free(cur_var->varstr);
6313 cur_var = cur_var->next;
6317 hush_exit(G.last_exitcode);
6322 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6323 int lash_main(int argc, char **argv)
6325 //bb_error_msg("lash is deprecated, please use hush instead");
6326 return hush_main(argc, argv);
6334 static int builtin_true(char **argv UNUSED_PARAM)
6339 static int builtin_test(char **argv)
6346 return test_main(argc, argv - argc);
6349 static int builtin_echo(char **argv)
6356 return echo_main(argc, argv - argc);
6359 static int builtin_eval(char **argv)
6361 int rcode = EXIT_SUCCESS;
6364 char *str = expand_strvec_to_string(argv);
6366 * eval "echo Hi; done" ("done" is syntax error):
6367 * "echo Hi" will not execute too.
6369 parse_and_run_string(str);
6371 rcode = G.last_exitcode;
6376 static int builtin_cd(char **argv)
6378 const char *newdir = argv[1];
6379 if (newdir == NULL) {
6380 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6381 * bash says "bash: cd: HOME not set" and does nothing
6384 newdir = get_local_var_value("HOME") ? : "/";
6386 if (chdir(newdir)) {
6387 /* Mimic bash message exactly */
6388 bb_perror_msg("cd: %s", newdir);
6389 return EXIT_FAILURE;
6392 return EXIT_SUCCESS;
6395 static int builtin_exec(char **argv)
6397 if (*++argv == NULL)
6398 return EXIT_SUCCESS; /* bash does this */
6403 /* TODO: if exec fails, bash does NOT exit! We do... */
6404 pseudo_exec_argv(&dummy, argv, 0, NULL);
6409 static int builtin_exit(char **argv)
6411 debug_printf_exec("%s()\n", __func__);
6413 /* interactive bash:
6414 * # trap "echo EEE" EXIT
6417 * There are stopped jobs.
6418 * (if there are _stopped_ jobs, running ones don't count)
6421 # EEE (then bash exits)
6423 * we can use G.exiting = -1 as indicator "last cmd was exit"
6426 /* note: EXIT trap is run by hush_exit */
6427 if (*++argv == NULL)
6428 hush_exit(G.last_exitcode);
6429 /* mimic bash: exit 123abc == exit 255 + error msg */
6430 xfunc_error_retval = 255;
6431 /* bash: exit -2 == exit 254, no error msg */
6432 hush_exit(xatoi(*argv) & 0xff);
6435 static void print_escaped(const char *s)
6441 p = strchrnul(s, '\'');
6442 /* print 'xxxx', possibly just '' */
6443 printf("'%.*s'", (int)(p - s), s);
6448 /* s points to '; print "'''...'''" */
6450 do putchar('\''); while (*++s == '\'');
6455 static int builtin_export(char **argv)
6457 unsigned opt_unexport;
6459 if (argv[1] == NULL) {
6466 /* ash emits: export VAR='VAL'
6467 * bash: declare -x VAR="VAL"
6468 * we follow ash example */
6469 const char *s = *e++;
6470 const char *p = strchr(s, '=');
6472 if (!p) /* wtf? take next variable */
6475 printf("export %.*s", (int)(p - s) + 1, s);
6476 print_escaped(p + 1);
6480 /*fflush(stdout); - done after each builtin anyway */
6482 return EXIT_SUCCESS;
6485 #if ENABLE_HUSH_EXPORT_N
6486 /* "!": do not abort on errors */
6487 /* "+": stop at 1st non-option */
6488 opt_unexport = getopt32(argv, "!+n");
6489 if (opt_unexport == (unsigned)-1)
6490 return EXIT_FAILURE;
6500 /* So far we do not check that name is valid (TODO?) */
6502 if (strchr(name, '=') == NULL) {
6503 struct variable *var;
6505 var = get_local_var(name);
6507 /* export -n NAME (without =VALUE) */
6509 var->flg_export = 0;
6510 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6512 } /* else: export -n NOT_EXISTING_VAR: no-op */
6515 /* export NAME (without =VALUE) */
6517 var->flg_export = 1;
6518 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6519 putenv(var->varstr);
6522 /* Exporting non-existing variable.
6523 * bash does not put it in environment,
6524 * but remembers that it is exported,
6525 * and does put it in env when it is set later.
6526 * We just set it to "" and export. */
6527 name = xasprintf("%s=", name);
6529 /* (Un)exporting NAME=VALUE */
6530 name = xstrdup(name);
6533 /*export:*/ (opt_unexport ? -1 : 1),
6538 return EXIT_SUCCESS;
6541 static int builtin_trap(char **argv)
6547 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6552 /* No args: print all trapped */
6553 for (i = 0; i < NSIG; ++i) {
6556 print_escaped(G.traps[i]);
6557 printf(" %s\n", get_signame(i));
6560 /*fflush(stdout); - done after each builtin anyway */
6561 return EXIT_SUCCESS;
6565 /* If first arg is a number: reset all specified signals */
6566 sig = bb_strtou(*argv, NULL, 10);
6572 sig = get_signum(*argv++);
6573 if (sig < 0 || sig >= NSIG) {
6575 /* Mimic bash message exactly */
6576 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6581 G.traps[sig] = xstrdup(new_cmd);
6583 debug_printf("trap: setting SIG%s (%i) to '%s'",
6584 get_signame(sig), sig, G.traps[sig]);
6586 /* There is no signal for 0 (EXIT) */
6591 sigaddset(&G.blocked_set, sig);
6593 /* There was a trap handler, we are removing it
6594 * (if sig has non-DFL handling,
6595 * we don't need to do anything) */
6596 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6598 sigdelset(&G.blocked_set, sig);
6601 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6605 if (!argv[1]) { /* no second arg */
6606 bb_error_msg("trap: invalid arguments");
6607 return EXIT_FAILURE;
6610 /* First arg is "-": reset all specified to default */
6611 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6612 /* Everything else: set arg as signal handler
6613 * (includes "" case, which ignores signal) */
6614 if (argv[0][0] == '-') {
6615 if (argv[0][1] == '\0') { /* "-" */
6616 /* new_cmd remains NULL: "reset these sigs" */
6619 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6622 /* else: "-something", no special meaning */
6627 goto process_sig_list;
6631 /* built-in 'fg' and 'bg' handler */
6632 static int builtin_fg_bg(char **argv)
6637 if (!G_interactive_fd)
6638 return EXIT_FAILURE;
6640 /* If they gave us no args, assume they want the last backgrounded task */
6642 for (pi = G.job_list; pi; pi = pi->next) {
6643 if (pi->jobid == G.last_jobid) {
6647 bb_error_msg("%s: no current job", argv[0]);
6648 return EXIT_FAILURE;
6650 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6651 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6652 return EXIT_FAILURE;
6654 for (pi = G.job_list; pi; pi = pi->next) {
6655 if (pi->jobid == jobnum) {
6659 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6660 return EXIT_FAILURE;
6662 /* TODO: bash prints a string representation
6663 * of job being foregrounded (like "sleep 1 | cat") */
6664 if (argv[0][0] == 'f' && G.saved_tty_pgrp) {
6665 /* Put the job into the foreground. */
6666 tcsetpgrp(G_interactive_fd, pi->pgrp);
6669 /* Restart the processes in the job */
6670 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6671 for (i = 0; i < pi->num_cmds; i++) {
6672 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6673 pi->cmds[i].is_stopped = 0;
6675 pi->stopped_cmds = 0;
6677 i = kill(- pi->pgrp, SIGCONT);
6679 if (errno == ESRCH) {
6680 delete_finished_bg_job(pi);
6681 return EXIT_SUCCESS;
6683 bb_perror_msg("kill (SIGCONT)");
6686 if (argv[0][0] == 'f') {
6688 return checkjobs_and_fg_shell(pi);
6690 return EXIT_SUCCESS;
6694 #if ENABLE_HUSH_HELP
6695 static int builtin_help(char **argv UNUSED_PARAM)
6697 const struct built_in_command *x;
6700 "Built-in commands:\n"
6701 "------------------\n");
6702 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6703 printf("%s\t%s\n", x->cmd, x->descr);
6706 return EXIT_SUCCESS;
6711 static int builtin_jobs(char **argv UNUSED_PARAM)
6714 const char *status_string;
6716 for (job = G.job_list; job; job = job->next) {
6717 if (job->alive_cmds == job->stopped_cmds)
6718 status_string = "Stopped";
6720 status_string = "Running";
6722 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6724 return EXIT_SUCCESS;
6729 static int builtin_memleak(char **argv UNUSED_PARAM)
6734 /* Crude attempt to find where "free memory" starts,
6735 * sans fragmentation. */
6737 l = (unsigned long)p;
6740 if (l < (unsigned long)p) l = (unsigned long)p;
6743 if (!G.memleak_value)
6744 G.memleak_value = l;
6746 l -= G.memleak_value;
6753 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6758 static int builtin_pwd(char **argv UNUSED_PARAM)
6761 return EXIT_SUCCESS;
6764 static int builtin_read(char **argv)
6767 const char *name = "REPLY";
6771 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6772 * and _after_ that_ it will complain */
6773 if (!is_well_formed_var_name(name, '\0')) {
6774 /* Mimic bash message */
6775 bb_error_msg("read: '%s': not a valid identifier", name);
6780 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6782 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6783 return set_local_var(string, 0, 0);
6786 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6787 * built-in 'set' handler
6789 * set [-abCefhmnuvx] [-o option] [argument...]
6790 * set [+abCefhmnuvx] [+o option] [argument...]
6791 * set -- [argument...]
6794 * Implementations shall support the options in both their hyphen and
6795 * plus-sign forms. These options can also be specified as options to sh.
6797 * Write out all variables and their values: set
6798 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6799 * Turn on the -x and -v options: set -xv
6800 * Unset all positional parameters: set --
6801 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6802 * Set the positional parameters to the expansion of x, even if x expands
6803 * with a leading '-' or '+': set -- $x
6805 * So far, we only support "set -- [argument...]" and some of the short names.
6807 static int builtin_set(char **argv)
6810 char **pp, **g_argv;
6811 char *arg = *++argv;
6815 for (e = G.top_var; e; e = e->next)
6817 return EXIT_SUCCESS;
6821 if (!strcmp(arg, "--")) {
6825 if (arg[0] != '+' && arg[0] != '-')
6827 for (n = 1; arg[n]; ++n)
6828 if (set_mode(arg[0], arg[n]))
6830 } while ((arg = *++argv) != NULL);
6831 /* Now argv[0] is 1st argument */
6834 return EXIT_SUCCESS;
6837 /* NB: G.global_argv[0] ($0) is never freed/changed */
6838 g_argv = G.global_argv;
6839 if (G.global_args_malloced) {
6845 G.global_args_malloced = 1;
6846 pp = xzalloc(sizeof(pp[0]) * 2);
6847 pp[0] = g_argv[0]; /* retain $0 */
6850 /* This realloc's G.global_argv */
6851 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6858 return EXIT_SUCCESS;
6860 /* Nothing known, so abort */
6862 bb_error_msg("set: %s: invalid option", arg);
6863 return EXIT_FAILURE;
6866 static int builtin_shift(char **argv)
6872 if (n >= 0 && n < G.global_argc) {
6873 if (G.global_args_malloced) {
6876 free(G.global_argv[m++]);
6879 memmove(&G.global_argv[1], &G.global_argv[n+1],
6880 G.global_argc * sizeof(G.global_argv[0]));
6881 return EXIT_SUCCESS;
6883 return EXIT_FAILURE;
6886 static int builtin_source(char **argv)
6891 #if ENABLE_HUSH_FUNCTIONS
6895 if (*++argv == NULL)
6896 return EXIT_FAILURE;
6898 if (strchr(*argv, '/') == NULL
6899 && (PATH = get_local_var_value("PATH")) != NULL
6901 /* Search through $PATH */
6903 const char *end = strchrnul(PATH, ':');
6904 int sz = end - PATH; /* must be int! */
6907 char *tmp = xasprintf("%.*s/%s", sz, PATH, *argv);
6908 input = fopen_for_read(tmp);
6911 /* We have xxx::yyyy in $PATH,
6912 * it means "use current dir" */
6913 input = fopen_for_read(*argv);
6922 input = fopen_or_warn(*argv, "r");
6924 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6925 return EXIT_FAILURE;
6928 close_on_exec_on(fileno(input));
6930 #if ENABLE_HUSH_FUNCTIONS
6931 sv_flg = G.flag_return_in_progress;
6932 /* "we are inside sourced file, ok to use return" */
6933 G.flag_return_in_progress = -1;
6935 save_and_replace_G_args(&sv, argv);
6937 parse_and_run_file(input);
6940 restore_G_args(&sv, argv);
6941 #if ENABLE_HUSH_FUNCTIONS
6942 G.flag_return_in_progress = sv_flg;
6945 return G.last_exitcode;
6948 static int builtin_umask(char **argv)
6955 mode_t old_mask = mask;
6958 rc = bb_parse_mode(argv[1], &mask);
6963 * bash: umask: 'q': invalid symbolic mode operator
6964 * bash: umask: 999: octal number out of range
6966 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
6971 printf("%04o\n", (unsigned) mask);
6972 /* fall through and restore mask which we set to 0 */
6976 return !rc; /* rc != 0 - success */
6979 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6980 static int builtin_unset(char **argv)
6985 /* "!": do not abort on errors */
6986 /* "+": stop at 1st non-option */
6987 opts = getopt32(argv, "!+vf");
6988 if (opts == (unsigned)-1)
6989 return EXIT_FAILURE;
6991 bb_error_msg("unset: -v and -f are exclusive");
6992 return EXIT_FAILURE;
6998 if (!(opts & 2)) { /* not -f */
6999 if (unset_local_var(*argv)) {
7000 /* unset <nonexistent_var> doesn't fail.
7001 * Error is when one tries to unset RO var.
7002 * Message was printed by unset_local_var. */
7006 #if ENABLE_HUSH_FUNCTIONS
7016 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7017 static int builtin_wait(char **argv)
7019 int ret = EXIT_SUCCESS;
7022 if (*++argv == NULL) {
7023 /* Don't care about wait results */
7024 /* Note 1: must wait until there are no more children */
7025 /* Note 2: must be interruptible */
7027 * $ sleep 3 & sleep 6 & wait
7032 * $ sleep 3 & sleep 6 & wait
7036 * ^C <-- after ~4 sec from keyboard
7039 sigaddset(&G.blocked_set, SIGCHLD);
7040 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7043 if (errno == ECHILD)
7045 /* Wait for SIGCHLD or any other signal of interest */
7046 /* sigtimedwait with infinite timeout: */
7047 sig = sigwaitinfo(&G.blocked_set, NULL);
7049 sig = check_and_run_traps(sig);
7050 if (sig && sig != SIGCHLD) { /* see note 2 */
7056 sigdelset(&G.blocked_set, SIGCHLD);
7057 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7061 /* This is probably buggy wrt interruptible-ness */
7063 pid_t pid = bb_strtou(*argv, NULL, 10);
7065 /* mimic bash message */
7066 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7067 return EXIT_FAILURE;
7069 if (waitpid(pid, &status, 0) == pid) {
7070 if (WIFSIGNALED(status))
7071 ret = 128 + WTERMSIG(status);
7072 else if (WIFEXITED(status))
7073 ret = WEXITSTATUS(status);
7077 bb_perror_msg("wait %s", *argv);
7086 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7087 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7090 def = bb_strtou(argv[1], NULL, 10);
7091 if (errno || def < def_min || argv[2]) {
7092 bb_error_msg("%s: bad arguments", argv[0]);
7100 #if ENABLE_HUSH_LOOPS
7101 static int builtin_break(char **argv)
7104 if (G.depth_of_loop == 0) {
7105 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7106 return EXIT_SUCCESS; /* bash compat */
7108 G.flag_break_continue++; /* BC_BREAK = 1 */
7110 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7111 if (depth == UINT_MAX)
7112 G.flag_break_continue = BC_BREAK;
7113 if (G.depth_of_loop < depth)
7114 G.depth_break_continue = G.depth_of_loop;
7116 return EXIT_SUCCESS;
7119 static int builtin_continue(char **argv)
7121 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7122 return builtin_break(argv);
7126 #if ENABLE_HUSH_FUNCTIONS
7127 static int builtin_return(char **argv)
7131 if (G.flag_return_in_progress != -1) {
7132 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7133 return EXIT_FAILURE; /* bash compat */
7136 G.flag_return_in_progress = 1;
7139 * out of range: wraps around at 256, does not error out
7140 * non-numeric param:
7141 * f() { false; return qwe; }; f; echo $?
7142 * bash: return: qwe: numeric argument required <== we do this
7143 * 255 <== we also do this
7145 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);