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1 | /* execute_command.c -- Execute a COMMAND structure. */ |
2 | ||
3 | /* Copyright (C) 1987,1991 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GNU Bash, the Bourne Again SHell. | |
6 | ||
7 | Bash is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 1, or (at your option) | |
10 | any later version. | |
11 | ||
12 | Bash is distributed in the hope that it will be useful, but WITHOUT | |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with Bash; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | #include <stdio.h> | |
22 | #include <ctype.h> | |
23 | #include <sys/types.h> | |
24 | #include <sys/file.h> | |
25 | #include "posixstat.h" | |
26 | #include "filecntl.h" | |
27 | #include <signal.h> | |
28 | ||
29 | #if !defined (SIGABRT) | |
30 | #define SIGABRT SIGIOT | |
31 | #endif | |
32 | ||
33 | #include <sys/param.h> | |
34 | #include <errno.h> | |
35 | ||
36 | #include "shell.h" | |
37 | #include "y.tab.h" | |
38 | #include "flags.h" | |
39 | #include "hash.h" | |
40 | #include "jobs.h" | |
41 | ||
42 | #include "sysdefs.h" | |
43 | #include <glob/fnmatch.h> | |
44 | ||
45 | #if defined (BUFFERED_INPUT) | |
46 | # include "input.h" | |
47 | #endif | |
48 | ||
49 | #define CMD_NO_WAIT 0x40 /* XXX move to command.h */ | |
50 | #define CMD_LAST_PIPE 0x80 /* XXX ditto */ | |
51 | ||
52 | #if !defined (errno) | |
53 | extern int errno; | |
54 | #endif | |
55 | ||
56 | extern int breaking, continuing, loop_level; | |
57 | extern int interactive, login_shell; | |
58 | ||
59 | #if defined (JOB_CONTROL) | |
60 | extern int job_control; | |
61 | extern int set_job_control (); | |
62 | #endif /* JOB_CONTROL */ | |
63 | ||
64 | extern int getdtablesize (); | |
65 | extern int close (); | |
66 | extern char *strerror (); | |
67 | extern char *string_list (); | |
68 | ||
69 | #if defined (USG) | |
70 | extern pid_t last_made_pid; | |
71 | #endif | |
72 | ||
73 | struct stat SB; | |
74 | ||
75 | extern WORD_LIST *expand_words (), *expand_word (); | |
76 | extern WORD_LIST *expand_word_leave_quoted (); | |
77 | extern char *make_command_string (); | |
78 | ||
79 | extern Function *find_shell_builtin (), *builtin_address (); | |
80 | extern SigHandler *set_sigint_handler (); | |
81 | ||
82 | #if defined (PROCESS_SUBSTITUTION) | |
83 | void close_all_files (); | |
84 | #endif /* PROCESS_SUBSTITUTION */ | |
85 | ||
86 | /* Static functions defined and used in this file. */ | |
87 | static void close_pipes (), do_piping (), execute_disk_command (); | |
88 | static void execute_subshell_builtin_or_function (); | |
89 | static void cleanup_redirects (), cleanup_func_redirects (), bind_lastarg (); | |
90 | static void add_undo_close_redirect (); | |
91 | static int do_redirection_internal (), do_redirections (); | |
92 | static int expandable_redirection_filename (), execute_shell_script (); | |
93 | static int execute_builtin_or_function (), add_undo_redirect (); | |
94 | static char *find_user_command_internal (), *find_user_command_in_path (); | |
95 | ||
96 | /* The value returned by the last synchronous command. */ | |
97 | int last_command_exit_value = 0; | |
98 | ||
99 | /* The list of redirections to preform which will undo the redirections | |
100 | that I made in the shell. */ | |
101 | REDIRECT *redirection_undo_list = (REDIRECT *)NULL; | |
102 | ||
103 | /* Have we just forked, and are we now running in a subshell environment? */ | |
104 | int subshell_environment = 0; | |
105 | ||
106 | /* Use this as the function to call when adding unwind protects so we | |
107 | don't need to know what free() returns. */ | |
108 | void | |
109 | vfree (string) | |
110 | char *string; | |
111 | { | |
112 | free (string); | |
113 | } | |
114 | ||
115 | #define FD_BITMAP_DEFAULT_SIZE 32 | |
116 | /* Functions to allocate and deallocate the structures used to pass | |
117 | information from the shell to its children about file descriptors | |
118 | to close. */ | |
119 | struct fd_bitmap * | |
120 | new_fd_bitmap (size) | |
121 | long size; | |
122 | { | |
123 | struct fd_bitmap *ret; | |
124 | ||
125 | ret = (struct fd_bitmap *)xmalloc (sizeof (struct fd_bitmap)); | |
126 | ||
127 | ret->size = size; | |
128 | ||
129 | if (size) | |
130 | { | |
131 | ret->bitmap = (char *)xmalloc (size); | |
132 | bzero (ret->bitmap, size); | |
133 | } | |
134 | else | |
135 | ret->bitmap = (char *)NULL; | |
136 | return (ret); | |
137 | } | |
138 | ||
139 | void | |
140 | dispose_fd_bitmap (fdbp) | |
141 | struct fd_bitmap *fdbp; | |
142 | { | |
143 | if (fdbp->bitmap) | |
144 | free (fdbp->bitmap); | |
145 | ||
146 | free (fdbp); | |
147 | } | |
148 | ||
149 | void | |
150 | close_fd_bitmap (fdbp) | |
151 | struct fd_bitmap *fdbp; | |
152 | { | |
153 | register int i; | |
154 | ||
155 | if (fdbp) | |
156 | { | |
157 | for (i = 0; i < fdbp->size; i++) | |
158 | if (fdbp->bitmap[i]) | |
159 | { | |
160 | close (i); | |
161 | fdbp->bitmap[i] = 0; | |
162 | } | |
163 | } | |
164 | } | |
165 | ||
166 | /* Execute the command passed in COMMAND. COMMAND is exactly what | |
167 | read_command () places into GLOBAL_COMMAND. See "command.h" for the | |
168 | details of the command structure. | |
169 | ||
170 | EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible | |
171 | return values. Executing a command with nothing in it returns | |
172 | EXECUTION_SUCCESS. */ | |
173 | execute_command (command) | |
174 | COMMAND *command; | |
175 | { | |
176 | struct fd_bitmap *bitmap; | |
177 | int result; | |
178 | ||
179 | bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE); | |
180 | ||
181 | /* Just do the command, but not asynchronously. */ | |
182 | result = execute_command_internal (command, 0, NO_PIPE, NO_PIPE, bitmap); | |
183 | ||
184 | dispose_fd_bitmap (bitmap); | |
185 | ||
186 | #if defined (PROCESS_SUBSTITUTION) | |
187 | unlink_fifo_list (); | |
188 | #endif /* PROCESS_SUBSTITUTION */ | |
189 | ||
190 | return (result); | |
191 | } | |
192 | ||
193 | /* Return 1 if TYPE is a shell control structure type. */ | |
194 | int | |
195 | shell_control_structure (type) | |
196 | enum command_type type; | |
197 | { | |
198 | switch (type) | |
199 | { | |
200 | case cm_for: | |
201 | case cm_case: | |
202 | case cm_while: | |
203 | case cm_until: | |
204 | case cm_if: | |
205 | case cm_group: | |
206 | return (1); | |
207 | ||
208 | default: | |
209 | return (0); | |
210 | } | |
211 | } | |
212 | ||
213 | /* A function to use to unwind_protect the redirection undo list | |
214 | for loops. */ | |
215 | static void | |
216 | cleanup_redirects (list) | |
217 | REDIRECT *list; | |
218 | { | |
219 | do_redirections (list, 1, 0, 0); | |
220 | dispose_redirects (list); | |
221 | } | |
222 | ||
223 | /* Function to unwind_protect the redirections for functions and builtins. */ | |
224 | static void | |
225 | cleanup_func_redirects (list) | |
226 | REDIRECT *list; | |
227 | { | |
228 | do_redirections (list, 1, 0, 0); | |
229 | } | |
230 | ||
231 | #if defined (JOB_CONTROL) | |
232 | /* A function to restore the signal mask to its proper value when the shell | |
233 | is interrupted or errors occur while creating a pipeline. */ | |
234 | static int | |
235 | restore_signal_mask (set) | |
236 | sigset_t set; | |
237 | { | |
238 | return (sigprocmask (SIG_SETMASK, &set, (sigset_t *)NULL)); | |
239 | } | |
240 | #endif /* JOB_CONTROL */ | |
241 | ||
242 | /* A debugging function that can be called from gdb, for instance. */ | |
243 | open_files () | |
244 | { | |
245 | register int i; | |
246 | int f, fd_table_size; | |
247 | ||
248 | fd_table_size = getdtablesize (); | |
249 | ||
250 | fprintf (stderr, "pid %d open files:", getpid ()); | |
251 | for (i = 3; i < fd_table_size; i++) | |
252 | { | |
253 | if ((f = fcntl (i, F_GETFD, 0)) != -1) | |
254 | fprintf (stderr, " %d (%s)", i, f ? "close" : "open"); | |
255 | } | |
256 | fprintf (stderr, "\n"); | |
257 | } | |
258 | ||
259 | execute_command_internal (command, asynchronous, pipe_in, pipe_out, | |
260 | fds_to_close) | |
261 | COMMAND *command; | |
262 | int asynchronous; | |
263 | int pipe_in, pipe_out; | |
264 | struct fd_bitmap *fds_to_close; | |
265 | { | |
266 | int exec_result = EXECUTION_SUCCESS; | |
267 | int invert, ignore_return; | |
268 | REDIRECT *my_undo_list; | |
269 | ||
270 | if (!command || breaking || continuing) | |
271 | return (EXECUTION_SUCCESS); | |
272 | ||
273 | run_pending_traps (); | |
274 | ||
275 | invert = (command->flags & CMD_INVERT_RETURN) != 0; | |
276 | ||
277 | /* If a command was being explicitly run in a subshell, or if it is | |
278 | a shell control-structure, and it has a pipe, then we do the command | |
279 | in a subshell. */ | |
280 | ||
281 | if ((command->flags & CMD_WANT_SUBSHELL) || | |
282 | (command->flags & CMD_FORCE_SUBSHELL) || | |
283 | (shell_control_structure (command->type) && | |
284 | (pipe_out != NO_PIPE || pipe_in != NO_PIPE || asynchronous))) | |
285 | { | |
286 | pid_t paren_pid; | |
287 | ||
288 | /* Fork a subshell, turn off the subshell bit, turn off job | |
289 | control and call execute_command () on the command again. */ | |
290 | paren_pid = make_child (savestring (make_command_string (command)), | |
291 | asynchronous); | |
292 | if (paren_pid == 0) | |
293 | { | |
294 | int user_subshell, return_code; | |
295 | ||
296 | #if defined (JOB_CONTROL) | |
297 | set_sigchld_handler (); | |
298 | #endif /* JOB_CONTROL */ | |
299 | ||
300 | set_sigint_handler (); | |
301 | ||
302 | user_subshell = (command->flags & CMD_WANT_SUBSHELL) != 0; | |
303 | command->flags &= ~(CMD_FORCE_SUBSHELL | CMD_WANT_SUBSHELL); | |
304 | ||
305 | /* If a command is asynchronous in a subshell (like ( foo ) & or | |
306 | the special case of an asynchronous GROUP command where the | |
307 | the subshell bit is turned on down in case cm_group: below), | |
308 | turn off `asynchronous', so that two subshells aren't spawned. | |
309 | ||
310 | This seems semantically correct to me. For example, | |
311 | ( foo ) & seems to say ``do the command `foo' in a subshell | |
312 | environment, but don't wait for that subshell to finish'', | |
313 | and "{ foo ; bar } &" seems to me to be like functions or | |
314 | builtins in the background, which executed in a subshell | |
315 | environment. I just don't see the need to fork two subshells. */ | |
316 | ||
317 | /* Don't fork again, we are already in a subshell. */ | |
318 | asynchronous = 0; | |
319 | ||
320 | /* Subshells are neither login nor interactive. */ | |
321 | login_shell = interactive = 0; | |
322 | ||
323 | subshell_environment = 1; | |
324 | ||
325 | #if defined (JOB_CONTROL) | |
326 | /* Delete all traces that there were any jobs running. This is | |
327 | only for subshells. */ | |
328 | without_job_control (); | |
329 | #endif /* JOB_CONTROL */ | |
330 | do_piping (pipe_in, pipe_out); | |
331 | ||
332 | if (fds_to_close) | |
333 | close_fd_bitmap (fds_to_close); | |
334 | ||
335 | /* Do redirections, then dispose of them before recursive call. */ | |
336 | if (command->redirects) | |
337 | { | |
338 | if (do_redirections (command->redirects, 1, 0, 0) != 0) | |
339 | exit (EXECUTION_FAILURE); | |
340 | ||
341 | dispose_redirects (command->redirects); | |
342 | command->redirects = (REDIRECT *)NULL; | |
343 | } | |
344 | ||
345 | return_code = execute_command_internal | |
346 | (command, asynchronous, NO_PIPE, NO_PIPE, fds_to_close); | |
347 | ||
348 | /* If we were explicitly placed in a subshell with (), we need | |
349 | to do the `shell cleanup' things, such as running traps[0]. */ | |
350 | if (user_subshell) | |
351 | run_exit_trap (); | |
352 | ||
353 | exit (return_code); | |
354 | } | |
355 | else | |
356 | { | |
357 | close_pipes (pipe_in, pipe_out); | |
358 | ||
359 | /* If we are part of a pipeline, and not the end of the pipeline, | |
360 | then we should simply return and let the last command in the | |
361 | pipe be waited for. If we are not in a pipeline, or are the | |
362 | last command in the pipeline, then we wait for the subshell | |
363 | and return its exit status as usual. */ | |
364 | if (pipe_out != NO_PIPE) | |
365 | return (EXECUTION_SUCCESS); | |
366 | ||
367 | if (command->flags & CMD_NO_WAIT) | |
368 | return (EXECUTION_SUCCESS); | |
369 | ||
370 | stop_pipeline (asynchronous, (COMMAND *)NULL); | |
371 | ||
372 | if (!asynchronous) | |
373 | { | |
374 | last_command_exit_value = wait_for (paren_pid); | |
375 | ||
376 | /* If we have to, invert the return value. */ | |
377 | if (invert) | |
378 | { | |
379 | if (last_command_exit_value == EXECUTION_SUCCESS) | |
380 | return (EXECUTION_FAILURE); | |
381 | else | |
382 | return (EXECUTION_SUCCESS); | |
383 | } | |
384 | else | |
385 | return (last_command_exit_value); | |
386 | } | |
387 | else | |
388 | { | |
389 | if (interactive) | |
390 | describe_pid (paren_pid); | |
391 | ||
392 | run_pending_traps (); | |
393 | ||
394 | return (EXECUTION_SUCCESS); | |
395 | } | |
396 | } | |
397 | } | |
398 | ||
399 | /* Handle WHILE FOR CASE etc. with redirections. (Also '&' input | |
400 | redirection.) */ | |
401 | if (do_redirections (command->redirects, 1, 1, 0) != 0) | |
402 | return (EXECUTION_FAILURE); | |
403 | ||
404 | my_undo_list = (REDIRECT *)copy_redirects (redirection_undo_list); | |
405 | ||
406 | begin_unwind_frame ("loop_redirections"); | |
407 | ||
408 | if (my_undo_list) | |
409 | add_unwind_protect ((Function *)cleanup_redirects, my_undo_list); | |
410 | ||
411 | ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0; | |
412 | ||
413 | switch (command->type) | |
414 | { | |
415 | case cm_for: | |
416 | if (ignore_return) | |
417 | command->value.For->flags |= CMD_IGNORE_RETURN; | |
418 | exec_result = execute_for_command (command->value.For); | |
419 | break; | |
420 | ||
421 | case cm_case: | |
422 | if (ignore_return) | |
423 | command->value.Case->flags |= CMD_IGNORE_RETURN; | |
424 | exec_result = execute_case_command (command->value.Case); | |
425 | break; | |
426 | ||
427 | case cm_while: | |
428 | if (ignore_return) | |
429 | command->value.While->flags |= CMD_IGNORE_RETURN; | |
430 | exec_result = execute_while_command (command->value.While); | |
431 | break; | |
432 | ||
433 | case cm_until: | |
434 | if (ignore_return) | |
435 | command->value.While->flags |= CMD_IGNORE_RETURN; | |
436 | exec_result = execute_until_command (command->value.While); | |
437 | break; | |
438 | ||
439 | case cm_if: | |
440 | if (ignore_return) | |
441 | command->value.If->flags |= CMD_IGNORE_RETURN; | |
442 | exec_result = execute_if_command (command->value.If); | |
443 | break; | |
444 | ||
445 | case cm_group: | |
446 | ||
447 | /* This code can be executed from either of two paths: an explicit | |
448 | '{}' command, or via a function call. If we are executed via a | |
449 | function call, we have already taken care of the function being | |
450 | executed in the background (down there in execute_simple_command ()), | |
451 | and this command should *not* be marked as asynchronous. If we | |
452 | are executing a regular '{}' group command, and asynchronous == 1, | |
453 | we must want to execute the whole command in the background, so we | |
454 | need a subshell, and we want the stuff executed in that subshell | |
455 | (this group command) to be executed in the foreground of that | |
456 | subshell (i.e. there will not be *another* subshell forked). | |
457 | ||
458 | What we do is to force a subshell if asynchronous, and then call | |
459 | execute_command_internal again with asynchronous still set to 1, | |
460 | but with the original group command, so the printed command will | |
461 | look right. | |
462 | ||
463 | The code above that handles forking off subshells will note that | |
464 | both subshell and async are on, and turn off async in the child | |
465 | after forking the subshell (but leave async set in the parent, so | |
466 | the normal call to describe_pid is made). This turning off | |
467 | async is *crucial*; if it is not done, this will fall into an | |
468 | infinite loop of executions through this spot in subshell after | |
469 | subshell until the process limit is exhausted. */ | |
470 | ||
471 | if (asynchronous) | |
472 | { | |
473 | command->flags |= CMD_FORCE_SUBSHELL; | |
474 | exec_result = | |
475 | execute_command_internal (command, 1, pipe_in, pipe_out, | |
476 | fds_to_close); | |
477 | } | |
478 | else | |
479 | { | |
480 | if (ignore_return && command->value.Group->command) | |
481 | command->value.Group->command->flags |= CMD_IGNORE_RETURN; | |
482 | exec_result = | |
483 | execute_command_internal (command->value.Group->command, | |
484 | asynchronous, pipe_in, pipe_out, | |
485 | fds_to_close); | |
486 | } | |
487 | break; | |
488 | ||
489 | case cm_simple: | |
490 | { | |
491 | pid_t last_pid = last_made_pid; | |
492 | ||
493 | #if defined (JOB_CONTROL) | |
494 | extern int already_making_children; | |
495 | #endif /* JOB_CONTROL */ | |
496 | if (ignore_return && command->value.Simple) | |
497 | command->value.Simple->flags |= CMD_IGNORE_RETURN; | |
498 | exec_result = | |
499 | execute_simple_command (command->value.Simple, pipe_in, pipe_out, | |
500 | asynchronous, fds_to_close); | |
501 | ||
502 | /* The temporary environment should be used for only the simple | |
503 | command immediately following its definition. */ | |
504 | dispose_used_env_vars (); | |
505 | ||
506 | #if (defined (Ultrix) && defined (mips)) || !defined (HAVE_ALLOCA) | |
507 | /* Reclaim memory allocated with alloca () on machines which | |
508 | may be using the alloca emulation code. */ | |
509 | (void) alloca (0); | |
510 | #endif /* (Ultrix && mips) || !HAVE_ALLOCA */ | |
511 | ||
512 | if (command->flags & CMD_NO_WAIT) | |
513 | break; | |
514 | ||
515 | /* If we forked to do the command, then we must wait_for () | |
516 | the child. */ | |
517 | #if defined (JOB_CONTROL) | |
518 | if (already_making_children && pipe_out == NO_PIPE) | |
519 | #else | |
520 | if (pipe_out == NO_PIPE) | |
521 | #endif /* JOB_CONTROL */ | |
522 | { | |
523 | if (last_pid != last_made_pid) | |
524 | { | |
525 | stop_pipeline (asynchronous, (COMMAND *)NULL); | |
526 | ||
527 | if (asynchronous) | |
528 | { | |
529 | if (interactive) | |
530 | describe_pid (last_made_pid); | |
531 | } | |
532 | else | |
533 | #if !defined (JOB_CONTROL) | |
534 | /* Do not wait for asynchronous processes started from | |
535 | startup files. */ | |
536 | if (last_made_pid != last_asynchronous_pid) | |
537 | #endif | |
538 | /* When executing a shell function that executes other | |
539 | commands, this causes the last simple command in | |
540 | the function to be waited for twice. */ | |
541 | exec_result = wait_for (last_made_pid); | |
542 | } | |
543 | } | |
544 | } | |
545 | if (!ignore_return && exit_immediately_on_error && !invert && | |
546 | (exec_result != EXECUTION_SUCCESS)) | |
547 | { | |
548 | last_command_exit_value = exec_result; | |
549 | run_pending_traps (); | |
550 | longjmp (top_level, EXITPROG); | |
551 | } | |
552 | ||
553 | break; | |
554 | ||
555 | case cm_connection: | |
556 | switch (command->value.Connection->connector) | |
557 | { | |
558 | /* Do the first command asynchronously. */ | |
559 | case '&': | |
560 | { | |
561 | COMMAND *tc = command->value.Connection->first; | |
562 | REDIRECT *rp = tc->redirects; | |
563 | ||
564 | if (ignore_return && tc) | |
565 | tc->flags |= CMD_IGNORE_RETURN; | |
566 | ||
567 | /* If this shell was compiled without job control, or if job | |
568 | control is not active (e.g., if the shell is not interactive), | |
569 | the standard input for an asynchronous command is /dev/null. */ | |
570 | #if defined (JOB_CONTROL) | |
571 | if (!interactive || !job_control) | |
572 | #endif /* JOB_CONTROL */ | |
573 | { | |
574 | REDIRECT *tr = | |
575 | make_redirection (0, r_inputa_direction, | |
576 | make_word ("/dev/null")); | |
577 | tr->next = tc->redirects; | |
578 | tc->redirects = tr; | |
579 | } | |
580 | ||
581 | exec_result = execute_command_internal (tc, 1, pipe_in, pipe_out, | |
582 | fds_to_close); | |
583 | ||
584 | #if defined (JOB_CONTROL) | |
585 | if (!interactive || !job_control) | |
586 | #endif /* JOB_CONTROL */ | |
587 | { | |
588 | /* Remove the redirection we added above. It matters, | |
589 | especially for loops, which call execute_command () | |
590 | multiple times with the same command. */ | |
591 | REDIRECT *tr, *tl; | |
592 | ||
593 | tr = tc->redirects; | |
594 | do | |
595 | { | |
596 | tl = tc->redirects; | |
597 | tc->redirects = tc->redirects->next; | |
598 | } | |
599 | while (tc->redirects && tc->redirects != rp); | |
600 | ||
601 | tl->next = (REDIRECT *)NULL; | |
602 | dispose_redirects (tr); | |
603 | } | |
604 | ||
605 | { | |
606 | register COMMAND *second; | |
607 | ||
608 | second = command->value.Connection->second; | |
609 | ||
610 | if (second) | |
611 | { | |
612 | if (ignore_return) | |
613 | second->flags |= CMD_IGNORE_RETURN; | |
614 | ||
615 | exec_result = execute_command_internal | |
616 | (second, asynchronous, pipe_in, pipe_out, fds_to_close); | |
617 | } | |
618 | } | |
619 | } | |
620 | break; | |
621 | ||
622 | case ';': | |
623 | /* Just call execute command on both of them. */ | |
624 | if (ignore_return) | |
625 | { | |
626 | if (command->value.Connection->first) | |
627 | command->value.Connection->first->flags |= CMD_IGNORE_RETURN; | |
628 | QUIT; | |
629 | if (command->value.Connection->second) | |
630 | command->value.Connection->second->flags |= CMD_IGNORE_RETURN; | |
631 | } | |
632 | execute_command (command->value.Connection->first); | |
633 | QUIT; | |
634 | exec_result = | |
635 | execute_command_internal (command->value.Connection->second, | |
636 | asynchronous, pipe_in, pipe_out, | |
637 | fds_to_close); | |
638 | break; | |
639 | ||
640 | case '|': | |
641 | { | |
642 | int prev, fildes[2], new_bitmap_size, dummyfd; | |
643 | COMMAND *cmd; | |
644 | int outpipe; | |
645 | struct fd_bitmap *fd_bitmap; | |
646 | ||
647 | #if defined (JOB_CONTROL) | |
648 | COMMAND *lastcmd; | |
649 | int lastpipe[2]; | |
650 | pid_t lastpipe_pid; | |
651 | ||
652 | sigset_t set, oset; | |
653 | BLOCK_CHILD (set, oset); | |
654 | #endif /* JOB_CONTROL */ | |
655 | ||
656 | #if defined (JOB_CONTROL) | |
657 | /* Fork the last command in the pipeline first, then the rest of | |
658 | the commands, to avoid synchronization problems. */ | |
659 | /* Find the last pipeline element */ | |
660 | lastcmd = command; | |
661 | while (lastcmd && lastcmd->type == cm_connection && | |
662 | lastcmd->value.Connection && | |
663 | lastcmd->value.Connection->connector == '|') | |
664 | lastcmd = lastcmd->value.Connection->second; | |
665 | ||
666 | if (pipe (lastpipe) < 0) | |
667 | { | |
668 | report_error ("pipe error: %s", strerror (errno)); | |
669 | terminate_current_pipeline (); | |
670 | kill_current_pipeline (); | |
671 | last_command_exit_value = EXECUTION_FAILURE; | |
672 | throw_to_top_level (); | |
673 | } | |
674 | ||
675 | /* Now execute the rightmost command in the pipeline, but do | |
676 | not wait for it. */ | |
677 | if (ignore_return && lastcmd) | |
678 | lastcmd->flags |= CMD_IGNORE_RETURN; | |
679 | lastcmd->flags |= (CMD_NO_WAIT | CMD_LAST_PIPE); | |
680 | fds_to_close->bitmap[lastpipe[1]] = 1; | |
681 | (void) execute_command_internal | |
682 | (lastcmd, asynchronous, lastpipe[0], pipe_out, fds_to_close); | |
683 | lastpipe_pid = last_made_pid; | |
684 | #endif /* JOB_CONTROL */ | |
685 | ||
686 | prev = pipe_in; | |
687 | cmd = command; | |
688 | ||
689 | while (cmd && | |
690 | cmd->type == cm_connection && | |
691 | cmd->value.Connection && | |
692 | cmd->value.Connection->connector == '|') | |
693 | { | |
694 | /* Make a pipeline between the two commands. */ | |
695 | if (pipe (fildes) < 0) | |
696 | { | |
697 | report_error ("pipe error: %s", strerror (errno)); | |
698 | #if defined (JOB_CONTROL) | |
699 | terminate_current_pipeline (); | |
700 | kill_current_pipeline (); | |
701 | #endif /* JOB_CONTROL */ | |
702 | last_command_exit_value = EXECUTION_FAILURE; | |
703 | /* The unwind-protects installed below will take care | |
704 | of closing all of the open file descriptors. */ | |
705 | throw_to_top_level (); | |
706 | } | |
707 | else | |
708 | { | |
709 | /* Here is a problem: with the new file close-on-exec | |
710 | code, the read end of the pipe (fildes[0]) stays open | |
711 | in the first process, so that process will never get a | |
712 | SIGPIPE. There is no way to signal the first process | |
713 | that it should close fildes[0] after forking, so it | |
714 | remains open. No SIGPIPE is ever sent because there | |
715 | is still a file descriptor open for reading connected | |
716 | to the pipe. We take care of that here. This passes | |
717 | around a bitmap of file descriptors that must be | |
718 | closed after making a child process in | |
719 | execute_simple_command. */ | |
720 | ||
721 | /* We need fd_bitmap to be at least as big as fildes[0]. | |
722 | If fildes[0] is less than fds_to_close->size, then | |
723 | use fds_to_close->size. */ | |
724 | ||
725 | if (fildes[0] < fds_to_close->size) | |
726 | new_bitmap_size = fds_to_close->size; | |
727 | else | |
728 | new_bitmap_size = fildes[0] + 8; | |
729 | ||
730 | fd_bitmap = new_fd_bitmap (new_bitmap_size); | |
731 | ||
732 | /* Now copy the old information into the new bitmap. */ | |
733 | bcopy (fds_to_close->bitmap, fd_bitmap->bitmap, | |
734 | fds_to_close->size); | |
735 | ||
736 | /* And mark the pipe file descriptors to be closed. */ | |
737 | fd_bitmap->bitmap[fildes[0]] = 1; | |
738 | ||
739 | /* In case there are pipe or out-of-processes errors, we | |
740 | want all these file descriptors to be closed when | |
741 | unwind-protects are run, and the storage used for the | |
742 | bitmaps freed up. */ | |
743 | begin_unwind_frame ("pipe-file-descriptors"); | |
744 | add_unwind_protect (dispose_fd_bitmap, fd_bitmap); | |
745 | add_unwind_protect (close_fd_bitmap, fd_bitmap); | |
746 | if (prev >= 0) | |
747 | add_unwind_protect (close, prev); | |
748 | dummyfd = fildes[1]; | |
749 | add_unwind_protect (close, dummyfd); | |
750 | ||
751 | #if defined (JOB_CONTROL) | |
752 | add_unwind_protect (restore_signal_mask, oset); | |
753 | #endif /* JOB_CONTROL */ | |
754 | ||
755 | if (ignore_return && cmd->value.Connection->first) | |
756 | cmd->value.Connection->first->flags |= | |
757 | CMD_IGNORE_RETURN; | |
758 | ||
759 | #if defined (JOB_CONTROL) | |
760 | if (cmd->value.Connection->second == lastcmd) | |
761 | { | |
762 | outpipe = lastpipe[1]; | |
763 | close (fildes[1]); | |
764 | } | |
765 | else | |
766 | #endif /* JOB_CONTROL */ | |
767 | outpipe = fildes[1]; | |
768 | ||
769 | execute_command_internal | |
770 | (cmd->value.Connection->first, asynchronous, prev, | |
771 | outpipe, fd_bitmap); | |
772 | ||
773 | if (prev >= 0) | |
774 | close (prev); | |
775 | ||
776 | prev = fildes[0]; | |
777 | close (outpipe); | |
778 | ||
779 | dispose_fd_bitmap (fd_bitmap); | |
780 | discard_unwind_frame ("pipe-file-descriptors"); | |
781 | } | |
782 | cmd = cmd->value.Connection->second; | |
783 | #if defined (JOB_CONTROL) | |
784 | if (cmd == lastcmd) | |
785 | break; | |
786 | #endif | |
787 | } | |
788 | ||
789 | #if !defined (JOB_CONTROL) | |
790 | /* Now execute the rightmost command in the pipeline. */ | |
791 | if (ignore_return && cmd) | |
792 | cmd->flags |= CMD_IGNORE_RETURN; | |
793 | exec_result = | |
794 | execute_command_internal | |
795 | (cmd, asynchronous, prev, pipe_out, fds_to_close); | |
796 | #endif /* !JOB_CONTROL */ | |
797 | ||
798 | if (prev >= 0) | |
799 | close (prev); | |
800 | ||
801 | #if defined (JOB_CONTROL) | |
802 | UNBLOCK_CHILD (oset); | |
803 | #endif | |
804 | ||
805 | #if defined (JOB_CONTROL) | |
806 | /* Because we created the processes out of order, we have to | |
807 | reorder the pipeline slightly. */ | |
808 | rotate_the_pipeline (); | |
809 | stop_pipeline (asynchronous, (COMMAND *)NULL); | |
810 | if (asynchronous && interactive) | |
811 | describe_pid (lastpipe_pid); | |
812 | exec_result = wait_for (lastpipe_pid); | |
813 | if (!ignore_return && exit_immediately_on_error && !invert && | |
814 | (exec_result != EXECUTION_SUCCESS)) | |
815 | { | |
816 | last_command_exit_value = exec_result; | |
817 | run_pending_traps (); | |
818 | longjmp (top_level, EXITPROG); | |
819 | } | |
820 | #endif /* JOB_CONTROL */ | |
821 | } | |
822 | break; | |
823 | ||
824 | case AND_AND: | |
825 | if (asynchronous) | |
826 | { | |
827 | /* If we have something like `a && b &', run the && stuff in a | |
828 | subshell. Force a subshell and just call | |
829 | execute_command_internal again. Leave asynchronous on | |
830 | so that we get a report from the parent shell about the | |
831 | background job. */ | |
832 | command->flags |= CMD_FORCE_SUBSHELL; | |
833 | exec_result = execute_command_internal (command, 1, pipe_in, | |
834 | pipe_out, fds_to_close); | |
835 | break; | |
836 | } | |
837 | ||
838 | /* Execute the first command. If the result of that is successful, | |
839 | then execute the second command, otherwise return. */ | |
840 | ||
841 | if (command->value.Connection->first) | |
842 | command->value.Connection->first->flags |= CMD_IGNORE_RETURN; | |
843 | ||
844 | exec_result = execute_command (command->value.Connection->first); | |
845 | QUIT; | |
846 | if (exec_result == EXECUTION_SUCCESS) | |
847 | { | |
848 | if (ignore_return && command->value.Connection->second) | |
849 | command->value.Connection->second->flags |= | |
850 | CMD_IGNORE_RETURN; | |
851 | ||
852 | exec_result = | |
853 | execute_command (command->value.Connection->second); | |
854 | } | |
855 | break; | |
856 | ||
857 | case OR_OR: | |
858 | if (asynchronous) | |
859 | { | |
860 | /* If we have something like `a || b &', run the || stuff in a | |
861 | subshell. Force a subshell and just call | |
862 | execute_command_internal again. Leave asynchronous on | |
863 | so that we get a report from the parent shell about the | |
864 | background job. */ | |
865 | command->flags |= CMD_FORCE_SUBSHELL; | |
866 | exec_result = execute_command_internal (command, 1, pipe_in, | |
867 | pipe_out, fds_to_close); | |
868 | break; | |
869 | } | |
870 | ||
871 | /* Execute the first command. If the result of that is successful, | |
872 | then return, otherwise execute the second command. */ | |
873 | ||
874 | if (command->value.Connection->first) | |
875 | command->value.Connection->first->flags |= CMD_IGNORE_RETURN; | |
876 | ||
877 | exec_result = execute_command (command->value.Connection->first); | |
878 | QUIT; | |
879 | if (exec_result != EXECUTION_SUCCESS) | |
880 | { | |
881 | if (ignore_return && command->value.Connection->second) | |
882 | command->value.Connection->second->flags |= | |
883 | CMD_IGNORE_RETURN; | |
884 | ||
885 | exec_result = | |
886 | execute_command (command->value.Connection->second); | |
887 | } | |
888 | ||
889 | break; | |
890 | ||
891 | default: | |
892 | programming_error ("Bad connector `%d'!", | |
893 | command->value.Connection->connector); | |
894 | longjmp (top_level, DISCARD); | |
895 | break; | |
896 | } | |
897 | break; | |
898 | ||
899 | case cm_function_def: | |
900 | exec_result = intern_function (command->value.Function_def->name, | |
901 | command->value.Function_def->command); | |
902 | break; | |
903 | ||
904 | default: | |
905 | programming_error | |
906 | ("execute_command: Bad command type `%d'!", command->type); | |
907 | } | |
908 | ||
909 | if (my_undo_list) | |
910 | { | |
911 | do_redirections (my_undo_list, 1, 0, 0); | |
912 | dispose_redirects (my_undo_list); | |
913 | } | |
914 | ||
915 | discard_unwind_frame ("loop_redirections"); | |
916 | ||
917 | /* Invert the return value if we have to */ | |
918 | if (invert) | |
919 | { | |
920 | if (exec_result == EXECUTION_SUCCESS) | |
921 | exec_result = EXECUTION_FAILURE; | |
922 | else | |
923 | exec_result = EXECUTION_SUCCESS; | |
924 | } | |
925 | ||
926 | last_command_exit_value = exec_result; | |
927 | run_pending_traps (); | |
928 | return (last_command_exit_value); | |
929 | } | |
930 | ||
931 | /* Execute a FOR command. The syntax is: FOR word_desc IN word_list; | |
932 | DO command; DONE */ | |
933 | execute_for_command (for_command) | |
934 | FOR_COM *for_command; | |
935 | { | |
936 | /* I just noticed that the Bourne shell leaves word_desc bound to the | |
937 | last name in word_list after the FOR statement is done. This seems | |
938 | wrong to me; I thought that the variable binding should be lexically | |
939 | scoped, i.e., only would last the duration of the FOR command. This | |
940 | behaviour can be gotten by turning on the lexical_scoping switch. */ | |
941 | ||
942 | register WORD_LIST *releaser, *list; | |
943 | WORD_DESC *temp = for_command->name; | |
944 | char *identifier; | |
945 | SHELL_VAR *old_value = (SHELL_VAR *)NULL; /* Remember the old value of x. */ | |
946 | int retval = EXECUTION_SUCCESS; | |
947 | extern int dispose_words (); | |
948 | extern int dispose_variable (); | |
949 | ||
950 | if (!check_identifier (temp)) | |
951 | return (EXECUTION_FAILURE); | |
952 | ||
953 | loop_level++; | |
954 | identifier = temp->word; | |
955 | ||
956 | list = releaser = expand_words (for_command->map_list, 0); | |
957 | ||
958 | begin_unwind_frame ("for"); | |
959 | add_unwind_protect (dispose_words, releaser); | |
960 | ||
961 | if (lexical_scoping) | |
962 | { | |
963 | old_value = copy_variable (find_variable (identifier)); | |
964 | if (old_value) | |
965 | add_unwind_protect (dispose_variable, old_value); | |
966 | } | |
967 | ||
968 | while (list) | |
969 | { | |
970 | QUIT; | |
971 | bind_variable (identifier, list->word->word); | |
972 | if (for_command->flags & CMD_IGNORE_RETURN) | |
973 | for_command->action->flags |= CMD_IGNORE_RETURN; | |
974 | execute_command (for_command->action); | |
975 | retval = last_command_exit_value; | |
976 | QUIT; | |
977 | ||
978 | if (breaking) | |
979 | { | |
980 | breaking--; | |
981 | break; | |
982 | } | |
983 | ||
984 | if (continuing) | |
985 | { | |
986 | continuing--; | |
987 | if (continuing) | |
988 | break; | |
989 | } | |
990 | ||
991 | list = list->next; | |
992 | } | |
993 | ||
994 | loop_level--; | |
995 | ||
996 | if (lexical_scoping) | |
997 | { | |
998 | if (!old_value) | |
999 | makunbound (identifier, shell_variables); | |
1000 | else | |
1001 | { | |
1002 | SHELL_VAR *new_value; | |
1003 | ||
1004 | new_value = bind_variable (identifier, value_cell(old_value)); | |
1005 | new_value->attributes = old_value->attributes; | |
1006 | } | |
1007 | } | |
1008 | ||
1009 | run_unwind_frame ("for"); | |
1010 | return (retval); | |
1011 | } | |
1012 | ||
1013 | /* Execute a CASE command. The syntax is: CASE word_desc IN pattern_list ESAC. | |
1014 | The pattern_list is a linked list of pattern clauses; each clause contains | |
1015 | some patterns to compare word_desc against, and an associated command to | |
1016 | execute. */ | |
1017 | execute_case_command (case_command) | |
1018 | CASE_COM *case_command; | |
1019 | { | |
1020 | extern int dispose_words (); | |
1021 | extern char *tilde_expand (); | |
1022 | register WORD_LIST *list; | |
1023 | WORD_LIST *wlist; | |
1024 | PATTERN_LIST *clauses; | |
1025 | char *word; | |
1026 | int retval; | |
1027 | ||
1028 | /* Posix.2 Draft 11.2 says that the word is tilde expanded. */ | |
1029 | if (member ('~', case_command->word->word)) | |
1030 | { | |
1031 | word = tilde_expand (case_command->word->word); | |
1032 | free (case_command->word->word); | |
1033 | case_command->word->word = word; | |
1034 | } | |
1035 | wlist = expand_word (case_command->word, 0); | |
1036 | clauses = case_command->clauses; | |
1037 | word = (wlist) ? string_list (wlist) : savestring (""); | |
1038 | retval = EXECUTION_SUCCESS; | |
1039 | ||
1040 | begin_unwind_frame ("case"); | |
1041 | add_unwind_protect (dispose_words, wlist); | |
1042 | add_unwind_protect ((Function *)vfree, word); | |
1043 | ||
1044 | while (clauses) | |
1045 | { | |
1046 | QUIT; | |
1047 | list = clauses->patterns; | |
1048 | while (list) | |
1049 | { | |
1050 | extern char *quote_string_for_globbing (); | |
1051 | char *t, *pattern; | |
1052 | WORD_LIST *es; | |
1053 | int match, freepat; | |
1054 | ||
1055 | /* Posix.2 draft 11.3 says to do tilde expansion on each member | |
1056 | of the pattern list. */ | |
1057 | if (member ('~', list->word->word)) | |
1058 | { | |
1059 | t = tilde_expand (list->word->word); | |
1060 | free (list->word->word); | |
1061 | list->word->word = t; | |
1062 | } | |
1063 | ||
1064 | es = expand_word_leave_quoted (list->word, 0); | |
1065 | if (es && es->word && es->word->word && *(es->word->word)) | |
1066 | { | |
1067 | pattern = quote_string_for_globbing (es->word->word, 1); | |
1068 | freepat = 1; | |
1069 | } | |
1070 | else | |
1071 | { | |
1072 | pattern = ""; | |
1073 | freepat = 0; | |
1074 | } | |
1075 | ||
1076 | /* Since the pattern does not undergo quote removal according to | |
1077 | Posix.2 section 3.9.4.3, the fnmatch() call must be able to | |
1078 | recognize backslashes as escape characters. */ | |
1079 | match = fnmatch (pattern, word, 0) != FNM_NOMATCH; | |
1080 | if (freepat) | |
1081 | free (pattern); | |
1082 | dispose_words (es); | |
1083 | ||
1084 | if (match) | |
1085 | { | |
1086 | if (clauses->action && | |
1087 | (case_command->flags & CMD_IGNORE_RETURN)) | |
1088 | clauses->action->flags |= CMD_IGNORE_RETURN; | |
1089 | execute_command (clauses->action); | |
1090 | retval = last_command_exit_value; | |
1091 | goto exit_command; | |
1092 | } | |
1093 | ||
1094 | list = list->next; | |
1095 | QUIT; | |
1096 | } | |
1097 | clauses = clauses->next; | |
1098 | } | |
1099 | exit_command: | |
1100 | run_unwind_frame ("case"); | |
1101 | return (retval); | |
1102 | } | |
1103 | ||
1104 | #define CMD_WHILE 0 | |
1105 | #define CMD_UNTIL 1 | |
1106 | ||
1107 | /* The WHILE command. Syntax: WHILE test DO action; DONE. | |
1108 | Repeatedly execute action while executing test produces | |
1109 | EXECUTION_SUCCESS. */ | |
1110 | execute_while_command (while_command) | |
1111 | WHILE_COM *while_command; | |
1112 | { | |
1113 | return (execute_while_or_until (while_command, CMD_WHILE)); | |
1114 | } | |
1115 | ||
1116 | /* UNTIL is just like WHILE except that the test result is negated. */ | |
1117 | execute_until_command (while_command) | |
1118 | WHILE_COM *while_command; | |
1119 | { | |
1120 | return (execute_while_or_until (while_command, CMD_UNTIL)); | |
1121 | } | |
1122 | ||
1123 | /* The body for both while and until. The only difference between the | |
1124 | two is that the test value is treated differently. TYPE is | |
1125 | CMD_WHILE or CMD_UNTIL. The return value for both commands should | |
1126 | be EXECUTION_SUCCESS if no commands in the body are executed, and | |
1127 | the status of the last command executed in the body otherwise. */ | |
1128 | execute_while_or_until (while_command, type) | |
1129 | WHILE_COM *while_command; | |
1130 | int type; | |
1131 | { | |
1132 | extern int breaking; | |
1133 | extern int continuing; | |
1134 | int commands_executed = 0; | |
1135 | int return_value, body_status = EXECUTION_SUCCESS; | |
1136 | ||
1137 | loop_level++; | |
1138 | while_command->test->flags |= CMD_IGNORE_RETURN; | |
1139 | ||
1140 | while (1) | |
1141 | { | |
1142 | return_value = execute_command (while_command->test); | |
1143 | ||
1144 | if (type == CMD_WHILE && return_value != EXECUTION_SUCCESS) | |
1145 | break; | |
1146 | if (type == CMD_UNTIL && return_value == EXECUTION_SUCCESS) | |
1147 | break; | |
1148 | ||
1149 | QUIT; | |
1150 | commands_executed = 1; | |
1151 | ||
1152 | if (while_command->flags & CMD_IGNORE_RETURN) | |
1153 | while_command->action->flags |= CMD_IGNORE_RETURN; | |
1154 | body_status = execute_command (while_command->action); | |
1155 | ||
1156 | QUIT; | |
1157 | ||
1158 | if (breaking) | |
1159 | { | |
1160 | breaking--; | |
1161 | break; | |
1162 | } | |
1163 | ||
1164 | if (continuing) | |
1165 | { | |
1166 | continuing--; | |
1167 | if (continuing) | |
1168 | break; | |
1169 | } | |
1170 | } | |
1171 | loop_level--; | |
1172 | ||
1173 | return (body_status); | |
1174 | } | |
1175 | ||
1176 | /* IF test THEN command [ELSE command]. | |
1177 | IF also allows ELIF in the place of ELSE IF, but | |
1178 | the parser makes *that* stupidity transparent. */ | |
1179 | execute_if_command (if_command) | |
1180 | IF_COM *if_command; | |
1181 | { | |
1182 | int return_value; | |
1183 | ||
1184 | if_command->test->flags |= CMD_IGNORE_RETURN; | |
1185 | return_value = execute_command (if_command->test); | |
1186 | ||
1187 | if (return_value == EXECUTION_SUCCESS) | |
1188 | { | |
1189 | QUIT; | |
1190 | if (if_command->true_case && (if_command->flags & CMD_IGNORE_RETURN)) | |
1191 | if_command->true_case->flags |= CMD_IGNORE_RETURN; | |
1192 | return (execute_command (if_command->true_case)); | |
1193 | } | |
1194 | else | |
1195 | { | |
1196 | QUIT; | |
1197 | ||
1198 | if (if_command->false_case && | |
1199 | (if_command->flags & CMD_IGNORE_RETURN)) | |
1200 | { | |
1201 | if_command->false_case->flags |= CMD_IGNORE_RETURN; | |
1202 | } | |
1203 | ||
1204 | return (execute_command (if_command->false_case)); | |
1205 | } | |
1206 | } | |
1207 | ||
1208 | /* The name of the command that is currently being executed. | |
1209 | `test' needs this, for example. */ | |
1210 | char *this_command_name; | |
1211 | ||
1212 | static void | |
1213 | bind_lastarg (arg) | |
1214 | char *arg; | |
1215 | { | |
1216 | SHELL_VAR *var; | |
1217 | ||
1218 | if (!arg) | |
1219 | arg = ""; | |
1220 | var = bind_variable ("_", arg); | |
1221 | var->attributes &= ~att_exported; | |
1222 | } | |
1223 | ||
1224 | /* For catching RETURN in a function. */ | |
1225 | int return_catch_flag = 0; | |
1226 | int return_catch_value; | |
1227 | jmp_buf return_catch; | |
1228 | ||
1229 | /* The meaty part of all the executions. We have to start hacking the | |
1230 | real execution of commands here. Fork a process, set things up, | |
1231 | execute the command. */ | |
1232 | execute_simple_command (simple_command, pipe_in, pipe_out, async, fds_to_close) | |
1233 | SIMPLE_COM *simple_command; | |
1234 | int pipe_in, pipe_out; | |
1235 | struct fd_bitmap *fds_to_close; | |
1236 | { | |
1237 | extern int command_string_index, variable_context, line_number; | |
1238 | extern char *the_printed_command; | |
1239 | extern pid_t last_command_subst_pid; | |
1240 | WORD_LIST *expand_words (), *copy_word_list (); | |
1241 | WORD_LIST *words, *lastword; | |
1242 | char *command_line, *lastarg; | |
1243 | int first_word_quoted, result; | |
1244 | pid_t old_last_command_subst_pid; | |
1245 | ||
1246 | result = EXECUTION_SUCCESS; | |
1247 | ||
1248 | /* If we're in a function, update the pseudo-line-number information. */ | |
1249 | if (variable_context) | |
1250 | line_number++; | |
1251 | ||
1252 | /* Remember what this command line looks like at invocation. */ | |
1253 | command_string_index = 0; | |
1254 | print_simple_command (simple_command); | |
1255 | command_line = (char *)alloca (1 + strlen (the_printed_command)); | |
1256 | strcpy (command_line, the_printed_command); | |
1257 | ||
1258 | first_word_quoted = | |
1259 | simple_command->words ? simple_command->words->word->quoted : 0; | |
1260 | ||
1261 | old_last_command_subst_pid = last_command_subst_pid; | |
1262 | ||
1263 | /* If we are re-running this as the result of executing the `command' | |
1264 | builtin, do not expand the command words a second time. */ | |
1265 | if ((simple_command->flags & CMD_INHIBIT_EXPANSION) == 0) | |
1266 | words = expand_words (simple_command->words); | |
1267 | else | |
1268 | words = copy_word_list (simple_command->words); | |
1269 | ||
1270 | lastarg = (char *)NULL; | |
1271 | begin_unwind_frame ("simple-command"); | |
1272 | ||
1273 | /* It is possible for WORDS not to have anything left in it. | |
1274 | Perhaps all the words consisted of `$foo', and there was | |
1275 | no variable `$foo'. */ | |
1276 | if (words) | |
1277 | { | |
1278 | extern int dispose_words (); | |
1279 | extern Function *last_shell_builtin, *this_shell_builtin; | |
1280 | Function *builtin; | |
1281 | SHELL_VAR *func; | |
1282 | ||
1283 | if (echo_command_at_execute) | |
1284 | { | |
1285 | extern char *indirection_level_string (); | |
1286 | char *line = string_list (words); | |
1287 | ||
1288 | if (line && *line) | |
1289 | fprintf (stderr, "%s%s\n", indirection_level_string (), line); | |
1290 | ||
1291 | if (line) | |
1292 | free (line); | |
1293 | } | |
1294 | ||
1295 | if (simple_command->flags & CMD_NO_FUNCTIONS) | |
1296 | func = (SHELL_VAR *)NULL; | |
1297 | else | |
1298 | func = find_function (words->word->word); | |
1299 | ||
1300 | add_unwind_protect (dispose_words, words); | |
1301 | ||
1302 | QUIT; | |
1303 | ||
1304 | /* Bind the last word in this command to "$_" after execution. */ | |
1305 | for (lastword = words; lastword->next; lastword = lastword->next); | |
1306 | lastarg = lastword->word->word; | |
1307 | ||
1308 | #if defined (JOB_CONTROL) | |
1309 | /* Is this command a job control related thing? */ | |
1310 | if (words->word->word[0] == '%') | |
1311 | { | |
1312 | int result; | |
1313 | ||
1314 | if (async) | |
1315 | this_command_name = "bg"; | |
1316 | else | |
1317 | this_command_name = "fg"; | |
1318 | ||
1319 | last_shell_builtin = this_shell_builtin; | |
1320 | this_shell_builtin = builtin_address (this_command_name); | |
1321 | result = (*this_shell_builtin) (words); | |
1322 | goto return_result; | |
1323 | } | |
1324 | ||
1325 | /* One other possiblilty. The user may want to resume an existing job. | |
1326 | If they do, find out whether this word is a candidate for a running | |
1327 | job. */ | |
1328 | { | |
1329 | char *auto_resume_value; | |
1330 | ||
1331 | if ((auto_resume_value = get_string_value ("auto_resume")) && | |
1332 | !first_word_quoted && | |
1333 | !words->next && | |
1334 | words->word->word[0] && | |
1335 | !simple_command->redirects && | |
1336 | pipe_in == NO_PIPE && | |
1337 | pipe_out == NO_PIPE && | |
1338 | !async) | |
1339 | { | |
1340 | char *word = words->word->word; | |
1341 | register int i, wl = strlen (word), exact; | |
1342 | ||
1343 | exact = strcmp (auto_resume_value, "exact") == 0; | |
1344 | for (i = job_slots - 1; i > -1; i--) | |
1345 | { | |
1346 | if (jobs[i]) | |
1347 | { | |
1348 | register PROCESS *p = jobs[i]->pipe; | |
1349 | do | |
1350 | { | |
1351 | if ((JOBSTATE (i) == JSTOPPED) && | |
1352 | (strncmp (p->command, word, | |
1353 | exact ? strlen (p->command) : wl) == 0)) | |
1354 | { | |
1355 | int started_status; | |
1356 | ||
1357 | run_unwind_frame ("simple-command"); | |
1358 | last_shell_builtin = this_shell_builtin; | |
1359 | this_shell_builtin = builtin_address ("fg"); | |
1360 | ||
1361 | started_status = start_job (i, 1); | |
1362 | ||
1363 | if (started_status < 0) | |
1364 | return (EXECUTION_FAILURE); | |
1365 | else | |
1366 | return (started_status); | |
1367 | } | |
1368 | p = p->next; | |
1369 | } | |
1370 | while (p != jobs[i]->pipe); | |
1371 | } | |
1372 | } | |
1373 | } | |
1374 | } | |
1375 | #endif /* JOB_CONTROL */ | |
1376 | ||
1377 | /* Remember the name of this command globally. */ | |
1378 | this_command_name = words->word->word; | |
1379 | ||
1380 | QUIT; | |
1381 | ||
1382 | /* Not a running job. Do normal command processing. */ | |
1383 | maybe_make_export_env (); | |
1384 | ||
1385 | /* This command could be a shell builtin or a user-defined function. | |
1386 | If so, and we have pipes, then fork a subshell in here. Else, just | |
1387 | do the command. */ | |
1388 | ||
1389 | if (func) | |
1390 | builtin = (Function *)NULL; | |
1391 | else | |
1392 | builtin = find_shell_builtin (this_command_name); | |
1393 | ||
1394 | last_shell_builtin = this_shell_builtin; | |
1395 | this_shell_builtin = builtin; | |
1396 | ||
1397 | if (builtin || func) | |
1398 | { | |
1399 | put_command_name_into_env (this_command_name); | |
1400 | if ((pipe_in != NO_PIPE) || (pipe_out != NO_PIPE) || async) | |
1401 | { | |
1402 | if (make_child (savestring (command_line), async) == 0) | |
1403 | { | |
1404 | execute_subshell_builtin_or_function | |
1405 | (words, simple_command->redirects, builtin, func, | |
1406 | pipe_in, pipe_out, async, fds_to_close, | |
1407 | simple_command->flags); | |
1408 | } | |
1409 | else | |
1410 | { | |
1411 | close_pipes (pipe_in, pipe_out); | |
1412 | goto return_result; | |
1413 | } | |
1414 | } | |
1415 | else | |
1416 | { | |
1417 | result = execute_builtin_or_function | |
1418 | (words, builtin, func, simple_command->redirects, fds_to_close, | |
1419 | simple_command->flags); | |
1420 | ||
1421 | goto return_result; | |
1422 | } | |
1423 | } | |
1424 | ||
1425 | execute_disk_command (words, simple_command->redirects, command_line, | |
1426 | pipe_in, pipe_out, async, fds_to_close); | |
1427 | ||
1428 | goto return_result; | |
1429 | } | |
1430 | else if (pipe_in != NO_PIPE || pipe_out != NO_PIPE || async) | |
1431 | { | |
1432 | /* We have a null command, but we really want a subshell to take | |
1433 | care of it. Just fork, do piping and redirections, and exit. */ | |
1434 | if (make_child (savestring (""), async) == 0) | |
1435 | { | |
1436 | do_piping (pipe_in, pipe_out); | |
1437 | ||
1438 | subshell_environment = 1; | |
1439 | ||
1440 | if (do_redirections (simple_command->redirects, 1, 0, 0) == 0) | |
1441 | exit (EXECUTION_SUCCESS); | |
1442 | else | |
1443 | exit (EXECUTION_FAILURE); | |
1444 | } | |
1445 | else | |
1446 | { | |
1447 | close_pipes (pipe_in, pipe_out); | |
1448 | result = EXECUTION_SUCCESS; | |
1449 | goto return_result; | |
1450 | } | |
1451 | } | |
1452 | else | |
1453 | { | |
1454 | /* Even if there aren't any command names, pretend to do the | |
1455 | redirections that are specified. The user expects the side | |
1456 | effects to take place. If the redirections fail, then return | |
1457 | failure. Otherwise, if a command substitution took place while | |
1458 | expanding the command or a redirection, return the value of that | |
1459 | substitution. Otherwise, return EXECUTION_SUCCESS. */ | |
1460 | ||
1461 | if (do_redirections (simple_command->redirects, 0, 0, 0) != 0) | |
1462 | result = EXECUTION_FAILURE; | |
1463 | else if (old_last_command_subst_pid != last_command_subst_pid) | |
1464 | result = last_command_exit_value; | |
1465 | else | |
1466 | result = EXECUTION_SUCCESS; | |
1467 | } | |
1468 | ||
1469 | return_result: | |
1470 | bind_lastarg (lastarg); | |
1471 | run_unwind_frame ("simple-command"); | |
1472 | return (result); | |
1473 | } | |
1474 | ||
1475 | /* Execute a shell builtin or function in a subshell environment. This | |
1476 | routine does not return; it only calls exit(). If BUILTIN is non-null, | |
1477 | it points to a function to call to execute a shell builtin; otherwise | |
1478 | VAR points at the body of a function to execute. WORDS is the arguments | |
1479 | to the command, REDIRECTS specifies redirections to perform before the | |
1480 | command is executed. */ | |
1481 | static void | |
1482 | execute_subshell_builtin_or_function (words, redirects, builtin, var, | |
1483 | pipe_in, pipe_out, async, fds_to_close, | |
1484 | flags) | |
1485 | WORD_LIST *words; | |
1486 | REDIRECT *redirects; | |
1487 | Function *builtin; | |
1488 | SHELL_VAR *var; | |
1489 | int pipe_in, pipe_out, async; | |
1490 | struct fd_bitmap *fds_to_close; | |
1491 | int flags; | |
1492 | { | |
1493 | extern char **temporary_env, **function_env, **copy_array (); | |
1494 | extern int login_shell, interactive; | |
1495 | #if defined (JOB_CONTROL) | |
1496 | extern int jobs_builtin (); | |
1497 | #endif /* JOB_CONTROL */ | |
1498 | ||
1499 | /* A subshell is neither a login shell nor interactive. */ | |
1500 | login_shell = interactive = 0; | |
1501 | ||
1502 | subshell_environment = 1; | |
1503 | ||
1504 | #if defined (JOB_CONTROL) | |
1505 | /* Eradicate all traces of job control after we fork the subshell, so | |
1506 | all jobs begun by this subshell are in the same process group as | |
1507 | the shell itself. */ | |
1508 | ||
1509 | /* Allow the output of `jobs' to be piped. */ | |
1510 | if (builtin == jobs_builtin && !async && | |
1511 | (pipe_out != NO_PIPE || pipe_in != NO_PIPE)) | |
1512 | kill_current_pipeline (); | |
1513 | else | |
1514 | without_job_control (); | |
1515 | ||
1516 | set_sigchld_handler (); | |
1517 | #endif /* JOB_CONTROL */ | |
1518 | ||
1519 | set_sigint_handler (); | |
1520 | ||
1521 | do_piping (pipe_in, pipe_out); | |
1522 | ||
1523 | if (fds_to_close) | |
1524 | close_fd_bitmap (fds_to_close); | |
1525 | ||
1526 | if (do_redirections (redirects, 1, 0, 0) != 0) | |
1527 | exit (EXECUTION_FAILURE); | |
1528 | ||
1529 | if (builtin) | |
1530 | { | |
1531 | extern jmp_buf top_level; | |
1532 | int result; | |
1533 | ||
1534 | /* Give builtins a place to jump back to on failure, | |
1535 | so we don't go back up to main(). */ | |
1536 | result = setjmp (top_level); | |
1537 | ||
1538 | if (result == EXITPROG) | |
1539 | exit (last_command_exit_value); | |
1540 | else if (result) | |
1541 | exit (EXECUTION_FAILURE); | |
1542 | else | |
1543 | exit ((*builtin) (words->next)); | |
1544 | } | |
1545 | else | |
1546 | { | |
1547 | extern int variable_context, line_number; | |
1548 | extern void dispose_command (), dispose_function_env (); | |
1549 | COMMAND *fc, *tc; | |
1550 | int result, return_val; | |
1551 | ||
1552 | tc = (COMMAND *)function_cell (var); | |
1553 | fc = (COMMAND *)NULL; | |
1554 | ||
1555 | remember_args (words->next, 1); | |
1556 | line_number = 0; | |
1557 | #if defined (JOB_CONTROL) | |
1558 | stop_pipeline (async, (COMMAND *)NULL); | |
1559 | #endif | |
1560 | ||
1561 | begin_unwind_frame ("subshell_function_calling"); | |
1562 | unwind_protect_int (variable_context); | |
1563 | unwind_protect_int (return_catch_flag); | |
1564 | unwind_protect_jmp_buf (return_catch); | |
1565 | add_unwind_protect (dispose_command, fc); | |
1566 | ||
1567 | /* The temporary environment for a function is supposed to apply to | |
1568 | all commands executed in the function. If we have a temporary | |
1569 | environment, copy it to the special `function environment' and | |
1570 | get rid of the temporary environment. */ | |
1571 | if (temporary_env) | |
1572 | { | |
1573 | function_env = copy_array (temporary_env); | |
1574 | add_unwind_protect (dispose_function_env, (char *)NULL); | |
1575 | dispose_used_env_vars (); | |
1576 | } | |
1577 | else | |
1578 | function_env = (char **)NULL; | |
1579 | ||
1580 | /* We can do this because function bodies are always guaranteed to | |
1581 | be group commands, according to the grammar in parse.y. If we | |
1582 | don't do this now, execute_command_internal will graciously fork | |
1583 | another subshell for us, and we'll lose contact with the rest of | |
1584 | the pipeline and fail to get any SIGPIPE that might be sent. */ | |
1585 | ||
1586 | if (tc->type == cm_group) | |
1587 | fc = (COMMAND *)copy_command (tc->value.Group->command); | |
1588 | else | |
1589 | fc = (COMMAND *)copy_command (tc); | |
1590 | ||
1591 | if (fc && (flags & CMD_IGNORE_RETURN)) | |
1592 | fc->flags |= CMD_IGNORE_RETURN; | |
1593 | ||
1594 | /* result = execute_command (fc); doesn't work. | |
1595 | We need to explicitly specify the pipes in and out so that they | |
1596 | are closed in all the processes that rely on their being closed. | |
1597 | If they are not, it is possible to not get the SIGPIPE that we | |
1598 | need to kill all the processes sharing the pipe. */ | |
1599 | ||
1600 | variable_context++; | |
1601 | return_catch_flag++; | |
1602 | return_val = setjmp (return_catch); | |
1603 | ||
1604 | if (return_val) | |
1605 | result = return_catch_value; | |
1606 | else | |
1607 | result = | |
1608 | execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close); | |
1609 | ||
1610 | run_unwind_frame ("subshell_function_calling"); | |
1611 | ||
1612 | exit (result); | |
1613 | } | |
1614 | } | |
1615 | ||
1616 | /* Execute a builtin or function in the current shell context. If BUILTIN | |
1617 | is non-null, it is the builtin command to execute, otherwise VAR points | |
1618 | to the body of a function. WORDS are the command's arguments, REDIRECTS | |
1619 | are the redirections to perform. FDS_TO_CLOSE is the usual bitmap of | |
1620 | file descriptors to close. | |
1621 | ||
1622 | If BUILTIN is exec_builtin, the redirections specified in REDIRECTS are | |
1623 | not undone before this function returns. */ | |
1624 | static int | |
1625 | execute_builtin_or_function (words, builtin, var, redirects, | |
1626 | fds_to_close, flags) | |
1627 | WORD_LIST *words; | |
1628 | Function *builtin; | |
1629 | SHELL_VAR *var; | |
1630 | REDIRECT *redirects; | |
1631 | struct fd_bitmap *fds_to_close; | |
1632 | int flags; | |
1633 | { | |
1634 | extern int exec_builtin (), eval_builtin (); | |
1635 | extern char **temporary_env, **function_env, **copy_array (); | |
1636 | int result = EXECUTION_FAILURE; | |
1637 | REDIRECT *saved_undo_list; | |
1638 | ||
1639 | if (do_redirections (redirects, 1, 1, 0) != 0) | |
1640 | return (EXECUTION_FAILURE); | |
1641 | ||
1642 | saved_undo_list = redirection_undo_list; | |
1643 | ||
1644 | /* Calling the "exec" builtin changes redirections forever. */ | |
1645 | if (builtin == exec_builtin) | |
1646 | { | |
1647 | dispose_redirects (saved_undo_list); | |
1648 | saved_undo_list = (REDIRECT *)NULL; | |
1649 | } | |
1650 | else | |
1651 | { | |
1652 | begin_unwind_frame ("saved redirects"); | |
1653 | add_unwind_protect (cleanup_func_redirects, (char *)saved_undo_list); | |
1654 | } | |
1655 | ||
1656 | redirection_undo_list = (REDIRECT *)NULL; | |
1657 | ||
1658 | if (builtin) | |
1659 | { | |
1660 | int old_e_flag = exit_immediately_on_error; | |
1661 | ||
1662 | /* The eval builtin calls parse_and_execute, which does not know about | |
1663 | the setting of flags, and always calls the execution functions with | |
1664 | flags that will exit the shell on an error if -e is set. If the | |
1665 | eval builtin is being called, and we're supposed to ignore the exit | |
1666 | value of the command, we turn the -e flag off ourselves, then | |
1667 | restore it when the command completes. */ | |
1668 | if ((builtin == eval_builtin) && (flags & CMD_IGNORE_RETURN)) | |
1669 | { | |
1670 | begin_unwind_frame ("eval_builtin"); | |
1671 | unwind_protect_int (exit_immediately_on_error); | |
1672 | exit_immediately_on_error = 0; | |
1673 | } | |
1674 | ||
1675 | result = ((*builtin) (words->next)); | |
1676 | ||
1677 | if ((builtin == eval_builtin) && (flags & CMD_IGNORE_RETURN)) | |
1678 | { | |
1679 | exit_immediately_on_error += old_e_flag; | |
1680 | discard_unwind_frame ("eval_builtin"); | |
1681 | } | |
1682 | } | |
1683 | else | |
1684 | { | |
1685 | extern void dispose_command (), dispose_function_env (); | |
1686 | extern int pop_context (); | |
1687 | extern int line_number; | |
1688 | int return_val; | |
1689 | COMMAND *tc; | |
1690 | ||
1691 | tc = (COMMAND *)copy_command (function_cell (var)); | |
1692 | if (tc && (flags & CMD_IGNORE_RETURN)) | |
1693 | tc->flags |= CMD_IGNORE_RETURN; | |
1694 | ||
1695 | begin_unwind_frame ("function_calling"); | |
1696 | push_context (); | |
1697 | add_unwind_protect (pop_context, (char *)NULL); | |
1698 | add_unwind_protect (dispose_command, (char *)tc); | |
1699 | unwind_protect_int (return_catch_flag); | |
1700 | unwind_protect_int (line_number); | |
1701 | unwind_protect_jmp_buf (return_catch); | |
1702 | ||
1703 | /* The temporary environment for a function is supposed to apply to | |
1704 | all commands executed in the function. If we have a temporary | |
1705 | environment, copy it to the special `function environment' and | |
1706 | get rid of the temporary environment. */ | |
1707 | if (temporary_env) | |
1708 | { | |
1709 | function_env = copy_array (temporary_env); | |
1710 | add_unwind_protect (dispose_function_env, (char *)NULL); | |
1711 | dispose_used_env_vars (); | |
1712 | } | |
1713 | else | |
1714 | function_env = (char **)NULL; | |
1715 | ||
1716 | /* Note the second argument of "1", meaning that we discard | |
1717 | the current value of "$*"! This is apparently the right thing. */ | |
1718 | remember_args (words->next, 1); | |
1719 | ||
1720 | line_number = 0; | |
1721 | return_catch_flag++; | |
1722 | return_val = setjmp (return_catch); | |
1723 | ||
1724 | if (return_val) | |
1725 | result = return_catch_value; | |
1726 | else | |
1727 | result = | |
1728 | execute_command_internal (tc, 0, NO_PIPE, NO_PIPE, fds_to_close); | |
1729 | ||
1730 | run_unwind_frame ("function_calling"); | |
1731 | } | |
1732 | ||
1733 | redirection_undo_list = saved_undo_list; | |
1734 | if (builtin != exec_builtin) | |
1735 | discard_unwind_frame ("saved redirects"); | |
1736 | do_redirections (redirection_undo_list, 1, 0, 0); | |
1737 | ||
1738 | return (result); | |
1739 | } | |
1740 | ||
1741 | /* Execute a simple command that is hopefully defined in a disk file | |
1742 | somewhere. | |
1743 | ||
1744 | 1) fork () | |
1745 | 2) connect pipes | |
1746 | 3) look up the command | |
1747 | 4) do redirections | |
1748 | 5) execve () | |
1749 | 6) If the execve failed, see if the file has executable mode set. | |
1750 | If so, and it isn't a directory, then execute its contents as | |
1751 | a shell script. | |
1752 | ||
1753 | Note that the filename hashing stuff has to take place up here, | |
1754 | in the parent. This is probably why the Bourne style shells | |
1755 | don't handle it, since that would require them to go through | |
1756 | this gnarly hair, for no good reason. */ | |
1757 | static void | |
1758 | execute_disk_command (words, redirects, command_line, pipe_in, pipe_out, | |
1759 | async, fds_to_close) | |
1760 | WORD_LIST *words; | |
1761 | REDIRECT *redirects; | |
1762 | char *command_line; | |
1763 | int pipe_in, pipe_out, async; | |
1764 | struct fd_bitmap *fds_to_close; | |
1765 | { | |
1766 | char **make_word_array (), *find_user_command (), *find_hashed_filename (); | |
1767 | char *hashed_file, *command, **args; | |
1768 | ||
1769 | #if defined (RESTRICTED_SHELL) | |
1770 | extern int restricted; | |
1771 | ||
1772 | if (restricted && strchr (words->word->word, '/')) | |
1773 | { | |
1774 | report_error ("%s: restricted: cannot specify `/' in command names", | |
1775 | words->word->word); | |
1776 | last_command_exit_value = EXECUTION_FAILURE; | |
1777 | return; | |
1778 | } | |
1779 | #endif /* RESTRICTED_SHELL */ | |
1780 | ||
1781 | hashed_file = command = (char *)NULL; | |
1782 | ||
1783 | /* Don't waste time trying to find hashed data for a pathname | |
1784 | that is already completely specified. */ | |
1785 | ||
1786 | if (!absolute_program (words->word->word)) | |
1787 | hashed_file = find_hashed_filename (words->word->word); | |
1788 | ||
1789 | /* XXX - this could be a big performance hit... */ | |
1790 | /* If a command found in the hash table no longer exists, we need to | |
1791 | look for it in $PATH. */ | |
1792 | if (hashed_file) | |
1793 | { | |
1794 | int st; | |
1795 | ||
1796 | st = file_status (hashed_file); | |
1797 | if ((st & (FS_EXISTS | FS_EXECABLE)) != (FS_EXISTS | FS_EXECABLE)) | |
1798 | { | |
1799 | remove_hashed_filename (words->word->word); | |
1800 | hashed_file = (char *) NULL; | |
1801 | } | |
1802 | } | |
1803 | ||
1804 | if (hashed_file) | |
1805 | command = savestring (hashed_file); | |
1806 | else | |
1807 | { | |
1808 | /* A command containing a slash is not looked up in PATH. */ | |
1809 | if (absolute_program (words->word->word)) | |
1810 | command = savestring (words->word->word); | |
1811 | else | |
1812 | { | |
1813 | command = find_user_command (words->word->word); | |
1814 | ||
1815 | /* A command name containing a slash is not saved in the | |
1816 | hash table. */ | |
1817 | if (command && !hashing_disabled) | |
1818 | { | |
1819 | extern int dot_found_in_search; | |
1820 | ||
1821 | remember_filename | |
1822 | (words->word->word, command, dot_found_in_search); | |
1823 | ||
1824 | /* Increase the number of hits to 1. */ | |
1825 | find_hashed_filename (words->word->word); | |
1826 | } | |
1827 | } | |
1828 | } | |
1829 | ||
1830 | if (command) | |
1831 | put_command_name_into_env (command); | |
1832 | ||
1833 | /* We have to make the child before we check for the non-existance | |
1834 | of COMMAND, since we want the error messages to be redirected. */ | |
1835 | if (make_child (savestring (command_line), async) == 0) | |
1836 | { | |
1837 | do_piping (pipe_in, pipe_out); | |
1838 | ||
1839 | /* Execve expects the command name to be in args[0]. So we | |
1840 | leave it there, in the same format that the user used to | |
1841 | type it in. */ | |
1842 | args = make_word_array (words); | |
1843 | ||
1844 | if (async) | |
1845 | { | |
1846 | begin_unwind_frame ("async_redirections"); | |
1847 | unwind_protect_int (interactive); | |
1848 | interactive = 0; | |
1849 | } | |
1850 | ||
1851 | subshell_environment = 1; | |
1852 | ||
1853 | if (do_redirections (redirects, 1, 0, 0) != 0) | |
1854 | { | |
1855 | #if defined (PROCESS_SUBSTITUTION) | |
1856 | /* Try to remove named pipes that may have been created as the | |
1857 | result of redirections. */ | |
1858 | unlink_fifo_list (); | |
1859 | #endif /* PROCESS_SUBSTITUTION */ | |
1860 | exit (EXECUTION_FAILURE); | |
1861 | } | |
1862 | ||
1863 | if (async) | |
1864 | run_unwind_frame ("async_redirections"); | |
1865 | ||
1866 | if (!command) | |
1867 | { | |
1868 | report_error ("%s: command not found", args[0]); | |
1869 | exit (EXECUTION_FAILURE); | |
1870 | } | |
1871 | ||
1872 | /* This functionality is now provided by close-on-exec of the | |
1873 | file descriptors manipulated by redirection and piping. | |
1874 | Some file descriptors still need to be closed in all children | |
1875 | because of the way bash does pipes; fds_to_close is a | |
1876 | bitmap of all such file descriptors. */ | |
1877 | if (fds_to_close) | |
1878 | close_fd_bitmap (fds_to_close); | |
1879 | ||
1880 | exit (shell_execve (command, args, export_env)); | |
1881 | } | |
1882 | else | |
1883 | { | |
1884 | /* Make sure that the pipes are closed in the parent. */ | |
1885 | close_pipes (pipe_in, pipe_out); | |
1886 | if (command) | |
1887 | free (command); | |
1888 | } | |
1889 | } | |
1890 | ||
1891 | /* If the operating system on which we're running does not handle | |
1892 | the #! executable format, then help out. SAMPLE is the text read | |
1893 | from the file, SAMPLE_LEN characters. COMMAND is the name of | |
1894 | the script; it and ARGS, the arguments given by the user, will | |
1895 | become arguments to the specified interpreter. ENV is the environment | |
1896 | to pass to the interpreter. | |
1897 | ||
1898 | The word immediately following the #! is the interpreter to execute. | |
1899 | A single argument to the interpreter is allowed. */ | |
1900 | static int | |
1901 | execute_shell_script (sample, sample_len, command, args, env) | |
1902 | unsigned char *sample; | |
1903 | int sample_len; | |
1904 | char *command; | |
1905 | char **args, **env; | |
1906 | { | |
1907 | extern char *shell_name; | |
1908 | register int i; | |
1909 | char *execname, *firstarg; | |
1910 | int start, size_increment, larry; | |
1911 | ||
1912 | /* Find the name of the interpreter to exec. */ | |
1913 | for (i = 2; whitespace (sample[i]) && i < sample_len; i++) | |
1914 | ; | |
1915 | ||
1916 | for (start = i; | |
1917 | !whitespace (sample[i]) && sample[i] != '\n' && i < sample_len; | |
1918 | i++) | |
1919 | ; | |
1920 | ||
1921 | execname = (char *)xmalloc (1 + (i - start)); | |
1922 | strncpy (execname, sample + start, i - start); | |
1923 | execname[i - start] = '\0'; | |
1924 | size_increment = 1; | |
1925 | ||
1926 | /* Now the argument, if any. */ | |
1927 | firstarg = (char *)NULL; | |
1928 | for (start = i; | |
1929 | whitespace (sample[i]) && sample[i] != '\n' && i < sample_len; | |
1930 | i++) | |
1931 | ; | |
1932 | ||
1933 | /* If there is more text on the line, then it is an argument for the | |
1934 | interpreter. */ | |
1935 | if (i < sample_len && sample[i] != '\n' && !whitespace (sample[i])) | |
1936 | { | |
1937 | for (start = i; | |
1938 | !whitespace (sample[i]) && sample[i] != '\n' && i < sample_len; | |
1939 | i++) | |
1940 | ; | |
1941 | firstarg = (char *)xmalloc (1 + (i - start)); | |
1942 | strncpy (firstarg, sample + start, i - start); | |
1943 | firstarg[i - start] = '\0'; | |
1944 | ||
1945 | size_increment = 2; | |
1946 | } | |
1947 | ||
1948 | larry = array_len (args) + size_increment; | |
1949 | ||
1950 | args = (char **)xrealloc (args, (1 + larry) * sizeof (char *)); | |
1951 | ||
1952 | for (i = larry - 1; i; i--) | |
1953 | args[i] = args[i - size_increment]; | |
1954 | ||
1955 | args[0] = execname; | |
1956 | if (firstarg) | |
1957 | { | |
1958 | args[1] = firstarg; | |
1959 | args[2] = command; | |
1960 | } | |
1961 | else | |
1962 | args[1] = command; | |
1963 | ||
1964 | args[larry] = (char *)NULL; | |
1965 | ||
1966 | return (shell_execve (execname, args, env)); | |
1967 | } | |
1968 | ||
1969 | /* Call execve (), handling interpreting shell scripts, and handling | |
1970 | exec failures. */ | |
1971 | int | |
1972 | shell_execve (command, args, env) | |
1973 | char *command; | |
1974 | char **args, **env; | |
1975 | { | |
1976 | #if defined (isc386) && defined (_POSIX_SOURCE) | |
1977 | __setostype (0); /* Turn on USGr3 semantics. */ | |
1978 | execve (command, args, env); | |
1979 | __setostype (1); /* Turn the POSIX semantics back on. */ | |
1980 | #else | |
1981 | execve (command, args, env); | |
1982 | #endif /* !(isc386 && _POSIX_SOURCE) */ | |
1983 | ||
1984 | /* If we get to this point, then start checking out the file. | |
1985 | Maybe it is something we can hack ourselves. */ | |
1986 | { | |
1987 | struct stat finfo; | |
1988 | ||
1989 | if (errno != ENOEXEC) | |
1990 | { | |
1991 | if ((stat (command, &finfo) == 0) && | |
1992 | (S_ISDIR (finfo.st_mode))) | |
1993 | report_error ("%s: is a directory", args[0]); | |
1994 | else | |
1995 | file_error (command); | |
1996 | ||
1997 | return (EXECUTION_FAILURE); | |
1998 | } | |
1999 | else | |
2000 | { | |
2001 | /* This file is executable. | |
2002 | If it begins with #!, then help out people with losing operating | |
2003 | systems. Otherwise, check to see if it is a binary file by seeing | |
2004 | if the first line (or up to 30 characters) are in the ASCII set. | |
2005 | Execute the contents as shell commands. */ | |
2006 | extern char *shell_name; | |
2007 | int larray = array_len (args) + 1; | |
2008 | int i, should_exec = 0; | |
2009 | ||
2010 | { | |
2011 | int fd = open (command, O_RDONLY); | |
2012 | if (fd != -1) | |
2013 | { | |
2014 | unsigned char sample[80]; | |
2015 | int sample_len = read (fd, &sample[0], 80); | |
2016 | ||
2017 | close (fd); | |
2018 | ||
2019 | if (sample_len == 0) | |
2020 | return (EXECUTION_SUCCESS); | |
2021 | ||
2022 | /* Is this supposed to be an executable script? */ | |
2023 | /* If so, the format of the line is "#! interpreter [argument]". | |
2024 | A single argument is allowed. The BSD kernel restricts | |
2025 | the length of the entire line to 32 characters (32 bytes | |
2026 | being the size of the BSD exec header), but we allow 80 | |
2027 | characters. */ | |
2028 | ||
2029 | if (sample_len > 0 && sample[0] == '#' && sample[1] == '!') | |
2030 | return (execute_shell_script (sample, sample_len, command, | |
2031 | args, env)); | |
2032 | #if defined (NOTDEF) | |
2033 | #if defined (HAVE_CSH) && ( defined (Bsd) || defined (Ultrix) ) | |
2034 | /* If this system has Csh, then keep the old | |
2035 | BSD semantics. */ | |
2036 | else if (sample_len > 0 && sample[0] == '#') | |
2037 | { | |
2038 | /* Scripts starting with a # are for Csh. */ | |
2039 | shell_name = savestring ("/bin/csh"); | |
2040 | should_exec = 1; | |
2041 | } | |
2042 | #endif /* HAVE_CSH */ | |
2043 | #endif /* NOTDEF */ | |
2044 | else if ((sample_len != -1) && | |
2045 | check_binary_file (sample, sample_len)) | |
2046 | { | |
2047 | report_error ("%s: cannot execute binary file", command); | |
2048 | return (EX_BINARY_FILE); | |
2049 | } | |
2050 | } | |
2051 | } | |
2052 | #if defined (JOB_CONTROL) | |
2053 | /* Forget about the way that job control was working. We are | |
2054 | in a subshell. */ | |
2055 | without_job_control (); | |
2056 | #endif /* JOB_CONTROL */ | |
2057 | #if defined (ALIAS) | |
2058 | /* Forget about any aliases that we knew of. We are in a subshell. */ | |
2059 | delete_all_aliases (); | |
2060 | #endif /* ALIAS */ | |
2061 | ||
2062 | #if defined (JOB_CONTROL) | |
2063 | set_sigchld_handler (); | |
2064 | #endif /* JOB_CONTROL */ | |
2065 | set_sigint_handler (); | |
2066 | ||
2067 | /* Insert the name of this shell into the argument list. */ | |
2068 | args = (char **)xrealloc (args, (1 + larray) * sizeof (char *)); | |
2069 | ||
2070 | for (i = larray - 1; i; i--) | |
2071 | args[i] = args[i - 1]; | |
2072 | ||
2073 | args[0] = shell_name; | |
2074 | args[1] = command; | |
2075 | args[larray] = (char *)NULL; | |
2076 | ||
2077 | if (args[0][0] == '-') | |
2078 | args[0]++; | |
2079 | ||
2080 | if (should_exec) | |
2081 | { | |
2082 | struct stat finfo; | |
2083 | ||
2084 | #if defined (isc386) && defined (_POSIX_SOURCE) | |
2085 | __setostype (0); /* Turn on USGr3 semantics. */ | |
2086 | execve (shell_name, args, env); | |
2087 | __setostype (1); /* Turn the POSIX semantics back on. */ | |
2088 | #else | |
2089 | execve (shell_name, args, env); | |
2090 | #endif /* isc386 && _POSIX_SOURCE */ | |
2091 | ||
2092 | /* Oh, no! We couldn't even exec this! */ | |
2093 | if ((stat (args[0], &finfo) == 0) && (S_ISDIR (finfo.st_mode))) | |
2094 | report_error ("%s: is a directory", args[0]); | |
2095 | else | |
2096 | file_error (args[0]); | |
2097 | ||
2098 | return (EXECUTION_FAILURE); | |
2099 | } | |
2100 | else | |
2101 | { | |
2102 | extern jmp_buf subshell_top_level; | |
2103 | extern int subshell_argc; | |
2104 | extern char **subshell_argv; | |
2105 | extern char **subshell_envp; | |
2106 | ||
2107 | subshell_argc = larray; | |
2108 | subshell_argv = args; | |
2109 | subshell_envp = env; | |
2110 | longjmp (subshell_top_level, 1); | |
2111 | } | |
2112 | } | |
2113 | } | |
2114 | } | |
2115 | ||
2116 | #if defined (PROCESS_SUBSTITUTION) | |
2117 | void | |
2118 | close_all_files () | |
2119 | { | |
2120 | register int i, fd_table_size; | |
2121 | ||
2122 | fd_table_size = getdtablesize (); | |
2123 | ||
2124 | for (i = 3; i < fd_table_size; i++) | |
2125 | close (i); | |
2126 | } | |
2127 | #endif /* PROCESS_SUBSTITUTION */ | |
2128 | ||
2129 | static void | |
2130 | close_pipes (in, out) | |
2131 | int in, out; | |
2132 | { | |
2133 | if (in >= 0) close (in); | |
2134 | if (out >= 0) close (out); | |
2135 | } | |
2136 | ||
2137 | /* Redirect input and output to be from and to the specified pipes. | |
2138 | NO_PIPE and REDIRECT_BOTH are handled correctly. */ | |
2139 | static void | |
2140 | do_piping (pipe_in, pipe_out) | |
2141 | int pipe_in, pipe_out; | |
2142 | { | |
2143 | if (pipe_in != NO_PIPE) | |
2144 | { | |
2145 | dup2 (pipe_in, 0); | |
2146 | close (pipe_in); | |
2147 | } | |
2148 | if (pipe_out != NO_PIPE) | |
2149 | { | |
2150 | dup2 (pipe_out, 1); | |
2151 | close (pipe_out); | |
2152 | ||
2153 | if (pipe_out == REDIRECT_BOTH) | |
2154 | dup2 (1, 2); | |
2155 | } | |
2156 | } | |
2157 | ||
2158 | /* Defined in flags.c. Non-zero means don't overwrite existing files. */ | |
2159 | extern int noclobber; | |
2160 | ||
2161 | #define AMBIGUOUS_REDIRECT -1 | |
2162 | #define NOCLOBBER_REDIRECT -2 | |
2163 | #define RESTRICTED_REDIRECT -3 /* Only can happen in restricted shells. */ | |
2164 | ||
2165 | /* Perform the redirections on LIST. If FOR_REAL, then actually make | |
2166 | input and output file descriptors, otherwise just do whatever is | |
2167 | neccessary for side effecting. INTERNAL says to remember how to | |
2168 | undo the redirections later, if non-zero. If SET_CLEXEC is non-zero, | |
2169 | file descriptors opened in do_redirection () have their close-on-exec | |
2170 | flag set. */ | |
2171 | static int | |
2172 | do_redirections (list, for_real, internal, set_clexec) | |
2173 | REDIRECT *list; | |
2174 | int for_real, internal; | |
2175 | { | |
2176 | register int error; | |
2177 | register REDIRECT *temp = list; | |
2178 | ||
2179 | if (internal && redirection_undo_list) | |
2180 | { | |
2181 | dispose_redirects (redirection_undo_list); | |
2182 | redirection_undo_list = (REDIRECT *)NULL; | |
2183 | } | |
2184 | ||
2185 | while (temp) | |
2186 | { | |
2187 | extern char *strerror (); | |
2188 | ||
2189 | error = do_redirection_internal (temp, for_real, internal, set_clexec); | |
2190 | ||
2191 | if (error) | |
2192 | { | |
2193 | char *redirection_expand (), *itos (); | |
2194 | char *filename; | |
2195 | ||
2196 | if (expandable_redirection_filename (temp)) | |
2197 | { | |
2198 | filename = redirection_expand (temp->redirectee.filename); | |
2199 | if (!filename) | |
2200 | filename = savestring (""); | |
2201 | } | |
2202 | else | |
2203 | filename = itos (temp->redirectee.dest); | |
2204 | ||
2205 | switch (error) | |
2206 | { | |
2207 | case AMBIGUOUS_REDIRECT: | |
2208 | report_error ("%s: Ambiguous redirect", filename); | |
2209 | break; | |
2210 | ||
2211 | case NOCLOBBER_REDIRECT: | |
2212 | report_error ("%s: Cannot clobber existing file", filename); | |
2213 | break; | |
2214 | ||
2215 | #if defined (RESTRICTED_SHELL) | |
2216 | case RESTRICTED_REDIRECT: | |
2217 | report_error ("%s: output redirection restricted", filename); | |
2218 | break; | |
2219 | #endif /* RESTRICTED_SHELL */ | |
2220 | ||
2221 | default: | |
2222 | report_error ("%s: %s", filename, strerror (error)); | |
2223 | break; | |
2224 | } | |
2225 | ||
2226 | free (filename); | |
2227 | return (error); | |
2228 | } | |
2229 | ||
2230 | temp = temp->next; | |
2231 | } | |
2232 | return (0); | |
2233 | } | |
2234 | ||
2235 | /* Return non-zero if the redirection pointed to by REDIRECT has a | |
2236 | redirectee.filename that can be expanded. */ | |
2237 | static int | |
2238 | expandable_redirection_filename (redirect) | |
2239 | REDIRECT *redirect; | |
2240 | { | |
2241 | int result; | |
2242 | ||
2243 | switch (redirect->instruction) | |
2244 | { | |
2245 | case r_output_direction: | |
2246 | case r_appending_to: | |
2247 | case r_input_direction: | |
2248 | case r_inputa_direction: | |
2249 | case r_err_and_out: | |
2250 | case r_input_output: | |
2251 | case r_output_force: | |
2252 | case r_duplicating_input_word: | |
2253 | case r_duplicating_output_word: | |
2254 | result = 1; | |
2255 | break; | |
2256 | ||
2257 | default: | |
2258 | result = 0; | |
2259 | } | |
2260 | return (result); | |
2261 | } | |
2262 | \f | |
2263 | /* Expand the word in WORD returning a string. If WORD expands to | |
2264 | multiple words (or no words), then return NULL. */ | |
2265 | char * | |
2266 | redirection_expand (word) | |
2267 | WORD_DESC *word; | |
2268 | { | |
2269 | char *result; | |
2270 | WORD_LIST *make_word_list (), *expand_words_no_vars (); | |
2271 | WORD_LIST *tlist1, *tlist2; | |
2272 | ||
2273 | tlist1 = make_word_list (copy_word (word), (WORD_LIST *)NULL); | |
2274 | tlist2 = expand_words_no_vars (tlist1); | |
2275 | dispose_words (tlist1); | |
2276 | ||
2277 | if (!tlist2 || tlist2->next) | |
2278 | { | |
2279 | /* We expanded to no words, or to more than a single word. | |
2280 | Dispose of the word list and return NULL. */ | |
2281 | if (tlist2) | |
2282 | dispose_words (tlist2); | |
2283 | return ((char *)NULL); | |
2284 | } | |
2285 | result = string_list (tlist2); | |
2286 | dispose_words (tlist2); | |
2287 | ||
2288 | return (result); | |
2289 | } | |
2290 | ||
2291 | /* Do the specific redirection requested. Returns errno in case of error. | |
2292 | If FOR_REAL is zero, then just do whatever is neccessary to produce the | |
2293 | appropriate side effects. REMEMBERING, if non-zero, says to remember | |
2294 | how to undo each redirection. If SET_CLEXEC is non-zero, then | |
2295 | we set all file descriptors > 2 that we open to be close-on-exec. */ | |
2296 | static int | |
2297 | do_redirection_internal (redirect, for_real, remembering, set_clexec) | |
2298 | REDIRECT *redirect; | |
2299 | int for_real, remembering; | |
2300 | { | |
2301 | WORD_DESC *redirectee = redirect->redirectee.filename; | |
2302 | int fd, redirector = redirect->redirector; | |
2303 | char *redirectee_word; | |
2304 | enum r_instruction ri = redirect->instruction; | |
2305 | REDIRECT *new_redirect; | |
2306 | ||
2307 | if (ri == r_duplicating_input_word || ri == r_duplicating_output_word) | |
2308 | { | |
2309 | /* We have [N]>&WORD or [N]<&WORD. Expand WORD, then translate | |
2310 | the redirection into a new one and continue. */ | |
2311 | redirectee_word = redirection_expand (redirectee); | |
2312 | ||
2313 | if (redirectee_word[0] == '-' && redirectee_word[1] == '\0') | |
2314 | { | |
2315 | new_redirect = make_redirection (redirector, r_close_this, 0); | |
2316 | } | |
2317 | else if (all_digits (redirectee_word)) | |
2318 | { | |
2319 | if (ri == r_duplicating_input_word) | |
2320 | { | |
2321 | new_redirect = make_redirection | |
2322 | (redirector, r_duplicating_input, atoi (redirectee_word)); | |
2323 | } | |
2324 | else | |
2325 | { | |
2326 | new_redirect = make_redirection | |
2327 | (redirector, r_duplicating_output, atoi (redirectee_word)); | |
2328 | } | |
2329 | } | |
2330 | else if (ri == r_duplicating_output_word && redirector == 1) | |
2331 | { | |
2332 | new_redirect = make_redirection | |
2333 | (1, r_err_and_out, make_word (redirectee_word)); | |
2334 | } | |
2335 | else | |
2336 | { | |
2337 | free (redirectee_word); | |
2338 | return (AMBIGUOUS_REDIRECT); | |
2339 | } | |
2340 | ||
2341 | free (redirectee_word); | |
2342 | ||
2343 | /* Set up the variables needed by the rest of the function from the | |
2344 | new redirection. */ | |
2345 | if (new_redirect->instruction == r_err_and_out) | |
2346 | { | |
2347 | char *alloca_hack; | |
2348 | ||
2349 | /* Copy the word without allocating any memory that must be | |
2350 | explicitly freed. */ | |
2351 | redirectee = (WORD_DESC *)alloca (sizeof (WORD_DESC)); | |
2352 | bcopy (new_redirect->redirectee.filename, | |
2353 | redirectee, sizeof (WORD_DESC)); | |
2354 | ||
2355 | alloca_hack = (char *) | |
2356 | alloca (1 + strlen (new_redirect->redirectee.filename->word)); | |
2357 | redirectee->word = alloca_hack; | |
2358 | strcpy (redirectee->word, new_redirect->redirectee.filename->word); | |
2359 | } | |
2360 | else | |
2361 | /* It's guaranteed to be an integer, and shouldn't be freed. */ | |
2362 | redirectee = new_redirect->redirectee.filename; | |
2363 | ||
2364 | redirector = new_redirect->redirector; | |
2365 | ri = new_redirect->instruction; | |
2366 | ||
2367 | /* Overwrite the flags element of the old redirect with the new value. */ | |
2368 | redirect->flags = new_redirect->flags; | |
2369 | dispose_redirects (new_redirect); | |
2370 | } | |
2371 | ||
2372 | switch (ri) | |
2373 | { | |
2374 | case r_output_direction: | |
2375 | case r_appending_to: | |
2376 | case r_input_direction: | |
2377 | case r_inputa_direction: | |
2378 | case r_err_and_out: /* command &>filename */ | |
2379 | case r_input_output: | |
2380 | case r_output_force: | |
2381 | ||
2382 | if (!(redirectee_word = redirection_expand (redirectee))) | |
2383 | return (AMBIGUOUS_REDIRECT); | |
2384 | ||
2385 | #if defined (RESTRICTED_SHELL) | |
2386 | if (restricted && (ri == r_output_direction || | |
2387 | ri == r_input_output || | |
2388 | ri == r_err_and_out || | |
2389 | ri == r_appending_to || | |
2390 | ri == r_output_force)) | |
2391 | { | |
2392 | free(redirectee_word); | |
2393 | return (RESTRICTED_REDIRECT); | |
2394 | } | |
2395 | #endif /* RESTRICTED_SHELL */ | |
2396 | ||
2397 | /* If we are in noclobber mode, you are not allowed to overwrite | |
2398 | existing files. Check first. */ | |
2399 | if (noclobber && (ri == r_output_direction || | |
2400 | ri == r_input_output || | |
2401 | ri == r_err_and_out)) | |
2402 | { | |
2403 | struct stat buf; | |
2404 | int stat_result; | |
2405 | ||
2406 | stat_result = stat (redirectee_word, &buf); | |
2407 | if ((stat_result == 0) && (S_ISREG (buf.st_mode))) | |
2408 | { | |
2409 | free (redirectee_word); | |
2410 | return (NOCLOBBER_REDIRECT); | |
2411 | } | |
2412 | /* If the file was not there, make sure we use exclusive open so | |
2413 | that if it's created before we open it, our open will fail. */ | |
2414 | if (stat_result != 0) | |
2415 | redirect->flags |= O_EXCL; | |
2416 | fd = open (redirectee_word, redirect->flags, 0666); | |
2417 | if (fd < 0 && errno == EEXIST) | |
2418 | { | |
2419 | free (redirectee_word); | |
2420 | return (NOCLOBBER_REDIRECT); | |
2421 | } | |
2422 | } | |
2423 | else | |
2424 | { | |
2425 | fd = open (redirectee_word, redirect->flags, 0666); | |
2426 | #if defined (AFS_CREATE_BUG) | |
2427 | if (fd < 0 && errno == EACCES) | |
2428 | fd = open (redirectee_word, (redirect->flags & ~O_CREAT), 0666); | |
2429 | #endif /* AFS_CREATE_BUG */ | |
2430 | } | |
2431 | ||
2432 | free (redirectee_word); | |
2433 | ||
2434 | if (fd < 0 ) | |
2435 | return (errno); | |
2436 | ||
2437 | if (for_real) | |
2438 | { | |
2439 | if (remembering) | |
2440 | /* Only setup to undo it if the thing to undo is active. */ | |
2441 | if ((fd != redirector) && (fcntl (redirector, F_GETFD, 0) != -1)) | |
2442 | add_undo_redirect (redirector); | |
2443 | else | |
2444 | add_undo_close_redirect (redirector); | |
2445 | ||
2446 | if ((fd != redirector) && (dup2 (fd, redirector) < 0)) | |
2447 | return (errno); | |
2448 | ||
2449 | #if defined (BUFFERED_INPUT) | |
2450 | if (ri == r_input_direction || ri == r_inputa_direction || | |
2451 | ri == r_input_output) | |
2452 | duplicate_buffered_stream (fd, redirector); | |
2453 | #endif /* BUFFERED_INPUT */ | |
2454 | ||
2455 | /* | |
2456 | * If we're remembering, then this is the result of a while, for | |
2457 | * or until loop with a loop redirection, or a function/builtin | |
2458 | * executing in the parent shell with a redirection. In the | |
2459 | * function/builtin case, we want to set all file descriptors > 2 | |
2460 | * to be close-on-exec to duplicate the effect of the old | |
2461 | * for i = 3 to NOFILE close(i) loop. In the case of the loops, | |
2462 | * both sh and ksh leave the file descriptors open across execs. | |
2463 | * The Posix standard mentions only the exec builtin. | |
2464 | */ | |
2465 | if (set_clexec && (redirector > 2)) | |
2466 | SET_CLOSE_ON_EXEC (redirector); | |
2467 | } | |
2468 | ||
2469 | if (fd != redirector) | |
2470 | { | |
2471 | #if defined (BUFFERED_INPUT) | |
2472 | if (ri == r_input_direction || ri == r_inputa_direction || | |
2473 | ri == r_input_output) | |
2474 | close_buffered_fd (fd); | |
2475 | else | |
2476 | #endif /* !BUFFERED_INPUT */ | |
2477 | close (fd); /* Don't close what we just opened! */ | |
2478 | } | |
2479 | ||
2480 | /* If we are hacking both stdout and stderr, do the stderr | |
2481 | redirection here. */ | |
2482 | if (ri == r_err_and_out) | |
2483 | { | |
2484 | if (for_real) | |
2485 | { | |
2486 | if (remembering) | |
2487 | add_undo_redirect (2); | |
2488 | if (dup2 (1, 2) < 0) | |
2489 | return (errno); | |
2490 | } | |
2491 | } | |
2492 | break; | |
2493 | ||
2494 | case r_reading_until: | |
2495 | case r_deblank_reading_until: | |
2496 | { | |
2497 | /* REDIRECTEE is a pointer to a WORD_DESC containing the text of | |
2498 | the new input. Place it in a temporary file. */ | |
2499 | int document_index = 0; | |
2500 | char *document = (char *)NULL; | |
2501 | ||
2502 | /* Expand the text if the word that was specified had no quoting. | |
2503 | Note that the text that we expand is treated exactly as if it | |
2504 | were surrounded by double-quotes. */ | |
2505 | ||
2506 | if (!redirectee) | |
2507 | document = savestring (""); | |
2508 | else | |
2509 | { | |
2510 | if (!redirectee->quoted) | |
2511 | { | |
2512 | WORD_LIST *temp_word_list = | |
2513 | (WORD_LIST *)expand_string (redirectee->word, | |
2514 | Q_HERE_DOCUMENT); | |
2515 | ||
2516 | document = string_list (temp_word_list); | |
2517 | if (!document) | |
2518 | document = savestring (""); | |
2519 | dispose_words (temp_word_list); | |
2520 | } | |
2521 | else | |
2522 | { | |
2523 | document = redirectee->word; | |
2524 | } | |
2525 | document_index = strlen (document); | |
2526 | ||
2527 | { | |
2528 | char filename[40]; | |
2529 | pid_t pid = getpid (); | |
2530 | ||
2531 | /* Make the filename for the temp file. */ | |
2532 | sprintf (filename, "/tmp/t%d-sh", pid); | |
2533 | ||
2534 | fd = open (filename, O_TRUNC | O_WRONLY | O_CREAT, 0666); | |
2535 | if (fd < 0) | |
2536 | { | |
2537 | if (!redirectee->quoted) | |
2538 | free (document); | |
2539 | return (errno); | |
2540 | } | |
2541 | ||
2542 | write (fd, document, document_index); | |
2543 | close (fd); | |
2544 | ||
2545 | if (!redirectee->quoted) | |
2546 | free (document); | |
2547 | ||
2548 | /* Make the document really temporary. Also make it the | |
2549 | input. */ | |
2550 | fd = open (filename, O_RDONLY, 0666); | |
2551 | ||
2552 | if (unlink (filename) < 0 || fd < 0) | |
2553 | return (errno); | |
2554 | ||
2555 | if (for_real) | |
2556 | { | |
2557 | if (remembering) | |
2558 | /* Only setup to undo it if the thing to undo is active. */ | |
2559 | if ((fd != redirector) && | |
2560 | (fcntl (redirector, F_GETFD, 0) != -1)) | |
2561 | add_undo_redirect (redirector); | |
2562 | else | |
2563 | add_undo_close_redirect (redirector); | |
2564 | ||
2565 | if (dup2 (fd, redirector) < 0) | |
2566 | return (errno); | |
2567 | ||
2568 | #if defined (BUFFERED_INPUT) | |
2569 | duplicate_buffered_stream (fd, redirector); | |
2570 | #endif | |
2571 | ||
2572 | if (set_clexec && (redirector > 2)) | |
2573 | SET_CLOSE_ON_EXEC (redirector); | |
2574 | } | |
2575 | ||
2576 | #if defined (BUFFERED_INPUT) | |
2577 | close_buffered_fd (fd); | |
2578 | #else | |
2579 | close (fd); | |
2580 | #endif | |
2581 | } | |
2582 | } | |
2583 | } | |
2584 | break; | |
2585 | ||
2586 | case r_duplicating_input: | |
2587 | case r_duplicating_output: | |
2588 | if (for_real && ((int)redirectee != redirector)) | |
2589 | { | |
2590 | if (remembering) | |
2591 | /* Only setup to undo it if the thing to undo is active. */ | |
2592 | if (fcntl (redirector, F_GETFD, 0) != -1) | |
2593 | add_undo_redirect (redirector); | |
2594 | else | |
2595 | add_undo_close_redirect (redirector); | |
2596 | ||
2597 | /* This is correct. 2>&1 means dup2 (1, 2); */ | |
2598 | if (dup2 ((int)redirectee, redirector) < 0) | |
2599 | return (errno); | |
2600 | ||
2601 | #if defined (BUFFERED_INPUT) | |
2602 | if (ri == r_duplicating_input) | |
2603 | duplicate_buffered_stream ((int)redirectee, redirector); | |
2604 | #endif /* BUFFERED_INPUT */ | |
2605 | ||
2606 | /* First duplicate the close-on-exec state of redirectee. dup2 | |
2607 | leaves the flag unset on the new descriptor, which means it | |
2608 | stays open. Only set the close-on-exec bit for file descriptors | |
2609 | greater than 2 in any case, since 0-2 should always be open | |
2610 | unless closed by something like `exec 2<&-'. */ | |
2611 | /* if ((already_set || set_unconditionally) && (ok_to_set)) | |
2612 | set_it () */ | |
2613 | if (((fcntl ((int)redirectee, F_GETFD, 0) == 1) || set_clexec) && | |
2614 | (redirector > 2)) | |
2615 | SET_CLOSE_ON_EXEC (redirector); | |
2616 | } | |
2617 | break; | |
2618 | ||
2619 | case r_close_this: | |
2620 | if (for_real) | |
2621 | { | |
2622 | if (remembering && (fcntl (redirector, F_GETFD, 0) != -1)) | |
2623 | add_undo_redirect (redirector); | |
2624 | ||
2625 | #if defined (BUFFERED_INPUT) | |
2626 | close_buffered_fd (redirector); | |
2627 | #else /* !BUFFERED_INPUT */ | |
2628 | close (redirector); | |
2629 | #endif /* !BUFFERED_INPUT */ | |
2630 | } | |
2631 | break; | |
2632 | } | |
2633 | return (0); | |
2634 | } | |
2635 | ||
2636 | #define SHELL_FD_BASE 10 | |
2637 | ||
2638 | /* Remember the file descriptor associated with the slot FD, | |
2639 | on REDIRECTION_UNDO_LIST. Note that the list will be reversed | |
2640 | before it is executed. */ | |
2641 | static int | |
2642 | add_undo_redirect (fd) | |
2643 | int fd; | |
2644 | { | |
2645 | int new_fd, clexec_flag; | |
2646 | REDIRECT *new_redirect, *closer; | |
2647 | ||
2648 | new_fd = fcntl (fd, F_DUPFD, SHELL_FD_BASE); | |
2649 | ||
2650 | if (new_fd < 0) | |
2651 | { | |
2652 | file_error ("redirection error"); | |
2653 | return (-1); | |
2654 | } | |
2655 | else | |
2656 | { | |
2657 | clexec_flag = fcntl (fd, F_GETFD, 0); | |
2658 | closer = make_redirection (new_fd, r_close_this, 0); | |
2659 | new_redirect = make_redirection (fd, r_duplicating_input, new_fd); | |
2660 | new_redirect->next = closer; | |
2661 | closer->next = redirection_undo_list; | |
2662 | redirection_undo_list = new_redirect; | |
2663 | /* | |
2664 | * File descriptors used only for saving others should always be | |
2665 | * marked close-on-exec. Unfortunately, we have to preserve the | |
2666 | * close-on-exec state of the file descriptor we are saving, since | |
2667 | * fcntl (F_DUPFD) sets the new file descriptor to remain open | |
2668 | * across execs. If, however, the file descriptor whose state we | |
2669 | * are saving is <= 2, we can just set the close-on-exec flag, | |
2670 | * because file descriptors 0-2 should always be open-on-exec, | |
2671 | * and the restore above in do_redirection() will take care of it. | |
2672 | */ | |
2673 | if (clexec_flag || fd < 3) | |
2674 | SET_CLOSE_ON_EXEC (new_fd); | |
2675 | } | |
2676 | return (0); | |
2677 | } | |
2678 | ||
2679 | /* Set up to close FD when we are finished with the current command | |
2680 | and its redirections. */ | |
2681 | static void | |
2682 | add_undo_close_redirect (fd) | |
2683 | int fd; | |
2684 | { | |
2685 | REDIRECT *closer; | |
2686 | ||
2687 | closer = make_redirection (fd, r_close_this, 0); | |
2688 | closer->next = redirection_undo_list; | |
2689 | redirection_undo_list = closer; | |
2690 | } | |
2691 | ||
2692 | intern_function (name, function) | |
2693 | WORD_DESC *name; | |
2694 | COMMAND *function; | |
2695 | { | |
2696 | SHELL_VAR *var; | |
2697 | ||
2698 | if (!check_identifier (name)) | |
2699 | return (EXECUTION_FAILURE); | |
2700 | ||
2701 | var = find_function (name->word); | |
2702 | if (var && readonly_p (var)) | |
2703 | { | |
2704 | report_error ("%s: readonly function", var->name); | |
2705 | return (EXECUTION_FAILURE); | |
2706 | } | |
2707 | ||
2708 | bind_function (name->word, function); | |
2709 | return (EXECUTION_SUCCESS); | |
2710 | } | |
2711 | ||
2712 | /* Make sure that identifier is a valid shell identifier, i.e. | |
2713 | does not contain a dollar sign, nor is quoted in any way. Nor | |
2714 | does it consist of all digits. */ | |
2715 | check_identifier (word) | |
2716 | WORD_DESC *word; | |
2717 | { | |
2718 | if (word->dollar_present || word->quoted || all_digits (word->word)) | |
2719 | { | |
2720 | report_error ("`%s' is not a valid identifier", word->word); | |
2721 | return (0); | |
2722 | } | |
2723 | else | |
2724 | return (1); | |
2725 | } | |
2726 | ||
2727 | #define u_mode_bits(x) (((x) & 0000700) >> 6) | |
2728 | #define g_mode_bits(x) (((x) & 0000070) >> 3) | |
2729 | #define o_mode_bits(x) (((x) & 0000007) >> 0) | |
2730 | #define X_BIT(x) (x & 1) | |
2731 | ||
2732 | /* Return some flags based on information about this file. | |
2733 | The EXISTS bit is non-zero if the file is found. | |
2734 | The EXECABLE bit is non-zero the file is executble. | |
2735 | Zero is returned if the file is not found. */ | |
2736 | int | |
2737 | file_status (name) | |
2738 | char *name; | |
2739 | { | |
2740 | struct stat finfo; | |
2741 | static int user_id = -1; | |
2742 | ||
2743 | /* Determine whether this file exists or not. */ | |
2744 | if (stat (name, &finfo) < 0) | |
2745 | return (0); | |
2746 | ||
2747 | /* If the file is a directory, then it is not "executable" in the | |
2748 | sense of the shell. */ | |
2749 | if (S_ISDIR (finfo.st_mode)) | |
2750 | return (FS_EXISTS); | |
2751 | ||
2752 | /* Find out if the file is actually executable. By definition, the | |
2753 | only other criteria is that the file has an execute bit set that | |
2754 | we can use. */ | |
2755 | if (user_id == -1) | |
2756 | user_id = geteuid (); | |
2757 | ||
2758 | /* Root only requires execute permission for any of owner, group or | |
2759 | others to be able to exec a file. */ | |
2760 | if (user_id == 0) | |
2761 | { | |
2762 | int bits; | |
2763 | ||
2764 | bits = (u_mode_bits (finfo.st_mode) | | |
2765 | g_mode_bits (finfo.st_mode) | | |
2766 | o_mode_bits (finfo.st_mode)); | |
2767 | ||
2768 | if (X_BIT (bits)) | |
2769 | return (FS_EXISTS | FS_EXECABLE); | |
2770 | } | |
2771 | ||
2772 | /* If we are the owner of the file, the owner execute bit applies. */ | |
2773 | if (user_id == finfo.st_uid && X_BIT (u_mode_bits (finfo.st_mode))) | |
2774 | return (FS_EXISTS | FS_EXECABLE); | |
2775 | ||
2776 | /* If we are in the owning group, the group permissions apply. */ | |
2777 | if (group_member (finfo.st_gid) && X_BIT (g_mode_bits (finfo.st_mode))) | |
2778 | return (FS_EXISTS | FS_EXECABLE); | |
2779 | ||
2780 | /* If `others' have execute permission to the file, then so do we, | |
2781 | since we are also `others'. */ | |
2782 | if (X_BIT (o_mode_bits (finfo.st_mode))) | |
2783 | return (FS_EXISTS | FS_EXECABLE); | |
2784 | else | |
2785 | return (FS_EXISTS); | |
2786 | } | |
2787 | ||
2788 | /* Return non-zero if FILE exists and is executable. | |
2789 | Note that this function is the definition of what an | |
2790 | executable file is; do not change this unless YOU know | |
2791 | what an executable file is. */ | |
2792 | int | |
2793 | executable_file (file) | |
2794 | char *file; | |
2795 | { | |
2796 | if (file_status (file) & FS_EXECABLE) | |
2797 | return (1); | |
2798 | else | |
2799 | return (0); | |
2800 | } | |
2801 | ||
2802 | /* DOT_FOUND_IN_SEARCH becomes non-zero when find_user_command () | |
2803 | encounters a `.' as the directory pathname while scanning the | |
2804 | list of possible pathnames; i.e., if `.' comes before the directory | |
2805 | containing the file of interest. */ | |
2806 | int dot_found_in_search = 0; | |
2807 | ||
2808 | /* Locate the executable file referenced by NAME, searching along | |
2809 | the contents of the shell PATH variable. Return a new string | |
2810 | which is the full pathname to the file, or NULL if the file | |
2811 | couldn't be found. If a file is found that isn't executable, | |
2812 | and that is the only match, then return that. */ | |
2813 | char * | |
2814 | find_user_command (name) | |
2815 | char *name; | |
2816 | { | |
2817 | return (find_user_command_internal (name, FS_EXEC_PREFERRED)); | |
2818 | } | |
2819 | ||
2820 | /* Locate the file referenced by NAME, searching along the contents | |
2821 | of the shell PATH variable. Return a new string which is the full | |
2822 | pathname to the file, or NULL if the file couldn't be found. This | |
2823 | returns the first file found. */ | |
2824 | char * | |
2825 | find_path_file (name) | |
2826 | char *name; | |
2827 | { | |
2828 | return (find_user_command_internal (name, FS_EXISTS)); | |
2829 | } | |
2830 | ||
2831 | static char * | |
2832 | find_user_command_internal (name, flags) | |
2833 | char *name; | |
2834 | int flags; | |
2835 | { | |
2836 | char *path_list = (char *)NULL; | |
2837 | SHELL_VAR *var; | |
2838 | ||
2839 | /* Search for the value of PATH in both the temporary environment, and | |
2840 | in the regular list of variables. */ | |
2841 | if (var = find_variable_internal ("PATH", 1)) | |
2842 | path_list = value_cell (var); | |
2843 | ||
2844 | if (!path_list) | |
2845 | return (savestring (name)); | |
2846 | ||
2847 | return (find_user_command_in_path (name, path_list, flags)); | |
2848 | } | |
2849 | ||
2850 | /* Return the next element from PATH_LIST, a colon separated list of | |
2851 | paths. PATH_INDEX_POINTER is the address of an index into PATH_LIST; | |
2852 | the index is modified by this function. | |
2853 | Return the next element of PATH_LIST or NULL if there are no more. */ | |
2854 | static char * | |
2855 | get_next_path_element (path_list, path_index_pointer) | |
2856 | char *path_list; | |
2857 | int *path_index_pointer; | |
2858 | { | |
2859 | extern char *extract_colon_unit (); | |
2860 | char *path; | |
2861 | ||
2862 | path = extract_colon_unit (path_list, path_index_pointer); | |
2863 | ||
2864 | if (!path) | |
2865 | return (path); | |
2866 | ||
2867 | if (!*path) | |
2868 | { | |
2869 | free (path); | |
2870 | path = savestring ("."); | |
2871 | } | |
2872 | ||
2873 | return (path); | |
2874 | } | |
2875 | ||
2876 | char * | |
2877 | user_command_matches (name, flags, state) | |
2878 | char *name; | |
2879 | int flags, state; | |
2880 | { | |
2881 | register int i; | |
2882 | char *path_list; | |
2883 | int path_index; | |
2884 | char *path_element; | |
2885 | char *match; | |
2886 | static char **match_list = NULL; | |
2887 | static int match_list_size = 0; | |
2888 | static int match_index = 0; | |
2889 | ||
2890 | if (!state) | |
2891 | { | |
2892 | /* Create the list of matches. */ | |
2893 | if (!match_list) | |
2894 | { | |
2895 | match_list = | |
2896 | (char **) xmalloc ((match_list_size = 5) * sizeof(char *)); | |
2897 | ||
2898 | for (i = 0; i < match_list_size; i++) | |
2899 | match_list[i] = 0; | |
2900 | } | |
2901 | ||
2902 | /* Clear out the old match list. */ | |
2903 | for (i = 0; i < match_list_size; i++) | |
2904 | match_list[i] = NULL; | |
2905 | ||
2906 | /* We haven't found any files yet. */ | |
2907 | match_index = 0; | |
2908 | ||
2909 | path_list = get_string_value ("PATH"); | |
2910 | path_index = 0; | |
2911 | ||
2912 | while (path_list && path_list[path_index]) | |
2913 | { | |
2914 | char *find_user_command_in_path (); | |
2915 | ||
2916 | path_element = get_next_path_element (path_list, &path_index); | |
2917 | ||
2918 | if (!path_element) | |
2919 | break; | |
2920 | ||
2921 | match = find_user_command_in_path (name, path_element, flags); | |
2922 | ||
2923 | free (path_element); | |
2924 | ||
2925 | if (!match) | |
2926 | continue; | |
2927 | ||
2928 | if (match_index + 1 == match_list_size) | |
2929 | match_list = (char **)xrealloc | |
2930 | (match_list, ((match_list_size += 10) + 1) * sizeof (char *)); | |
2931 | match_list[match_index++] = match; | |
2932 | match_list[match_index] = (char *)NULL; | |
2933 | } | |
2934 | ||
2935 | /* We haven't returned any strings yet. */ | |
2936 | match_index = 0; | |
2937 | } | |
2938 | ||
2939 | match = match_list[match_index]; | |
2940 | ||
2941 | if (match) | |
2942 | match_index++; | |
2943 | ||
2944 | return (match); | |
2945 | } | |
2946 | ||
2947 | /* Return 1 if PATH1 and PATH2 are the same file. This is kind of | |
2948 | expensive. If non-NULL STP1 and STP2 point to stat structures | |
2949 | corresponding to PATH1 and PATH2, respectively. */ | |
2950 | int | |
2951 | same_file (path1, path2, stp1, stp2) | |
2952 | char *path1, *path2; | |
2953 | struct stat *stp1, *stp2; | |
2954 | { | |
2955 | struct stat st1, st2; | |
2956 | ||
2957 | if (stp1 == NULL) | |
2958 | { | |
2959 | if (stat (path1, &st1) != 0) | |
2960 | return (0); | |
2961 | stp1 = &st1; | |
2962 | } | |
2963 | ||
2964 | if (stp2 == NULL) | |
2965 | { | |
2966 | if (stat (path2, &st2) != 0) | |
2967 | return (0); | |
2968 | stp2 = &st2; | |
2969 | } | |
2970 | ||
2971 | return ((stp1->st_dev == stp2->st_dev) && (stp1->st_ino == stp2->st_ino)); | |
2972 | } | |
2973 | ||
2974 | /* This does the dirty work for find_path_file () and find_user_command (). | |
2975 | NAME is the name of the file to search for. | |
2976 | PATH_LIST is a colon separated list of directories to search. | |
2977 | FLAGS contains bit fields which control the files which are eligible. | |
2978 | Some values are: | |
2979 | FS_EXEC_ONLY: The file must be an executable to be found. | |
2980 | FS_EXEC_PREFERRED: If we can't find an executable, then the | |
2981 | the first file matching NAME will do. | |
2982 | FS_EXISTS: The first file found will do. | |
2983 | */ | |
2984 | static char * | |
2985 | find_user_command_in_path (name, path_list, flags) | |
2986 | char *name; | |
2987 | char *path_list; | |
2988 | int flags; | |
2989 | { | |
2990 | char *full_path, *path, *file_to_lose_on; | |
2991 | int status, path_index, name_len; | |
2992 | struct stat finfo; | |
2993 | ||
2994 | name_len = strlen (name); | |
2995 | ||
2996 | /* The file name which we would try to execute, except that it isn't | |
2997 | possible to execute it. This is the first file that matches the | |
2998 | name that we are looking for while we are searching $PATH for a | |
2999 | suitable one to execute. If we cannot find a suitable executable | |
3000 | file, then we use this one. */ | |
3001 | file_to_lose_on = (char *)NULL; | |
3002 | ||
3003 | /* We haven't started looking, so we certainly haven't seen | |
3004 | a `.' as the directory path yet. */ | |
3005 | dot_found_in_search = 0; | |
3006 | ||
3007 | if (absolute_program (name)) | |
3008 | { | |
3009 | full_path = (char *)xmalloc (1 + name_len); | |
3010 | strcpy (full_path, name); | |
3011 | ||
3012 | status = file_status (full_path); | |
3013 | ||
3014 | if (!(status & FS_EXISTS)) | |
3015 | return (0); | |
3016 | ||
3017 | if ((flags & FS_EXEC_ONLY) && (status & FS_EXECABLE)) | |
3018 | return (full_path); | |
3019 | else | |
3020 | { | |
3021 | free (full_path); | |
3022 | return ((char *)NULL); | |
3023 | } | |
3024 | } | |
3025 | ||
3026 | /* Find out the location of the current working directory. */ | |
3027 | stat (".", &finfo); | |
3028 | ||
3029 | path_index = 0; | |
3030 | while (path_list && path_list[path_index]) | |
3031 | { | |
3032 | /* Allow the user to interrupt out of a lengthy path search. */ | |
3033 | QUIT; | |
3034 | ||
3035 | path = get_next_path_element (path_list, &path_index); | |
3036 | ||
3037 | if (!path) | |
3038 | break; | |
3039 | ||
3040 | if (*path == '~') | |
3041 | { | |
3042 | char *tilde_expand (); | |
3043 | char *t = tilde_expand (path); | |
3044 | free (path); | |
3045 | path = t; | |
3046 | } | |
3047 | ||
3048 | /* Remember the location of "." in the path, in all its forms | |
3049 | (as long as they begin with a `.', e.g. `./.') */ | |
3050 | if ((*path == '.') && | |
3051 | same_file (".", path, &finfo, (struct stat *)NULL)) | |
3052 | dot_found_in_search = 1; | |
3053 | ||
3054 | full_path = (char *)xmalloc (2 + strlen (path) + name_len); | |
3055 | sprintf (full_path, "%s/%s", path, name); | |
3056 | free (path); | |
3057 | ||
3058 | status = file_status (full_path); | |
3059 | ||
3060 | if (!(status & FS_EXISTS)) | |
3061 | goto next_file; | |
3062 | ||
3063 | /* The file exists. If the caller simply wants the first file, | |
3064 | here it is. */ | |
3065 | if (flags & FS_EXISTS) | |
3066 | return (full_path); | |
3067 | ||
3068 | /* If the file is executable, then it satisfies the cases of | |
3069 | EXEC_ONLY and EXEC_PREFERRED. Return this file unconditionally. */ | |
3070 | if (status & FS_EXECABLE) | |
3071 | { | |
3072 | if (file_to_lose_on) | |
3073 | free (file_to_lose_on); | |
3074 | ||
3075 | return (full_path); | |
3076 | } | |
3077 | ||
3078 | /* The file is not executable, but it does exist. If we prefer | |
3079 | an executable, then remember this one if it is the first one | |
3080 | we have found. */ | |
3081 | if (flags & FS_EXEC_PREFERRED) | |
3082 | { | |
3083 | if (!file_to_lose_on) | |
3084 | file_to_lose_on = savestring (full_path); | |
3085 | } | |
3086 | ||
3087 | next_file: | |
3088 | free (full_path); | |
3089 | } | |
3090 | ||
3091 | /* We didn't find exactly what the user was looking for. Return | |
3092 | the contents of FILE_TO_LOSE_ON which is NULL when the search | |
3093 | required an executable, or non-NULL if a file was found and the | |
3094 | search would accept a non-executable as a last resort. */ | |
3095 | return (file_to_lose_on); | |
3096 | } | |
3097 | ||
3098 | /* Given a string containing units of information separated by colons, | |
3099 | return the next one pointed to by INDX, or NULL if there are no more. | |
3100 | Advance INDX to the character after the colon. */ | |
3101 | char * | |
3102 | extract_colon_unit (string, indx) | |
3103 | char *string; | |
3104 | int *indx; | |
3105 | { | |
3106 | int i, start; | |
3107 | ||
3108 | i = *indx; | |
3109 | ||
3110 | if (!string || (i >= strlen (string))) | |
3111 | return ((char *)NULL); | |
3112 | ||
3113 | /* Each call to this routine leaves the index pointing at a colon if | |
3114 | there is more to the path. If I is > 0, then increment past the | |
3115 | `:'. If I is 0, then the path has a leading colon. Trailing colons | |
3116 | are handled OK by the `else' part of the if statement; an empty | |
3117 | string is returned in that case. */ | |
3118 | if (i && string[i] == ':') | |
3119 | i++; | |
3120 | ||
3121 | start = i; | |
3122 | ||
3123 | while (string[i] && string[i] != ':') i++; | |
3124 | ||
3125 | *indx = i; | |
3126 | ||
3127 | if (i == start) | |
3128 | { | |
3129 | if (string[i]) | |
3130 | (*indx)++; | |
3131 | ||
3132 | /* Return "" in the case of a trailing `:'. */ | |
3133 | return (savestring ("")); | |
3134 | } | |
3135 | else | |
3136 | { | |
3137 | char *value; | |
3138 | ||
3139 | value = (char *)xmalloc (1 + (i - start)); | |
3140 | strncpy (value, &string[start], (i - start)); | |
3141 | value [i - start] = '\0'; | |
3142 | ||
3143 | return (value); | |
3144 | } | |
3145 | } | |
3146 | ||
3147 | /* Return non-zero if the characters from SAMPLE are not all valid | |
3148 | characters to be found in the first line of a shell script. We | |
3149 | check up to the first newline, or SAMPLE_LEN, whichever comes first. | |
3150 | All of the characters must be printable or whitespace. */ | |
3151 | ||
3152 | #if !defined (isspace) | |
3153 | #define isspace(c) ((c) == ' ' || (c) == '\t' || (c) == '\n' || (c) == '\f') | |
3154 | #endif | |
3155 | ||
3156 | #if !defined (isprint) | |
3157 | #define isprint(c) (isletter(c) || digit(c) || ispunct(c)) | |
3158 | #endif | |
3159 | ||
3160 | int | |
3161 | check_binary_file (sample, sample_len) | |
3162 | unsigned char *sample; | |
3163 | int sample_len; | |
3164 | { | |
3165 | register int i; | |
3166 | ||
3167 | for (i = 0; i < sample_len; i++) | |
3168 | { | |
3169 | if (sample[i] == '\n') | |
3170 | break; | |
3171 | ||
3172 | if (!isspace (sample[i]) && !isprint (sample[i])) | |
3173 | return (1); | |
3174 | } | |
3175 | return (0); | |
3176 | } |