run-command: forbid using run_command with piped output
[git/git.git] / run-command.c
1 #include "cache.h"
2 #include "run-command.h"
3 #include "exec_cmd.h"
4 #include "sigchain.h"
5 #include "argv-array.h"
6
7 #ifndef SHELL_PATH
8 # define SHELL_PATH "/bin/sh"
9 #endif
10
11 void child_process_init(struct child_process *child)
12 {
13 memset(child, 0, sizeof(*child));
14 argv_array_init(&child->args);
15 argv_array_init(&child->env_array);
16 }
17
18 struct child_to_clean {
19 pid_t pid;
20 struct child_to_clean *next;
21 };
22 static struct child_to_clean *children_to_clean;
23 static int installed_child_cleanup_handler;
24
25 static void cleanup_children(int sig)
26 {
27 while (children_to_clean) {
28 struct child_to_clean *p = children_to_clean;
29 children_to_clean = p->next;
30 kill(p->pid, sig);
31 free(p);
32 }
33 }
34
35 static void cleanup_children_on_signal(int sig)
36 {
37 cleanup_children(sig);
38 sigchain_pop(sig);
39 raise(sig);
40 }
41
42 static void cleanup_children_on_exit(void)
43 {
44 cleanup_children(SIGTERM);
45 }
46
47 static void mark_child_for_cleanup(pid_t pid)
48 {
49 struct child_to_clean *p = xmalloc(sizeof(*p));
50 p->pid = pid;
51 p->next = children_to_clean;
52 children_to_clean = p;
53
54 if (!installed_child_cleanup_handler) {
55 atexit(cleanup_children_on_exit);
56 sigchain_push_common(cleanup_children_on_signal);
57 installed_child_cleanup_handler = 1;
58 }
59 }
60
61 static void clear_child_for_cleanup(pid_t pid)
62 {
63 struct child_to_clean **pp;
64
65 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
66 struct child_to_clean *clean_me = *pp;
67
68 if (clean_me->pid == pid) {
69 *pp = clean_me->next;
70 free(clean_me);
71 return;
72 }
73 }
74 }
75
76 static inline void close_pair(int fd[2])
77 {
78 close(fd[0]);
79 close(fd[1]);
80 }
81
82 #ifndef GIT_WINDOWS_NATIVE
83 static inline void dup_devnull(int to)
84 {
85 int fd = open("/dev/null", O_RDWR);
86 if (fd < 0)
87 die_errno(_("open /dev/null failed"));
88 if (dup2(fd, to) < 0)
89 die_errno(_("dup2(%d,%d) failed"), fd, to);
90 close(fd);
91 }
92 #endif
93
94 static char *locate_in_PATH(const char *file)
95 {
96 const char *p = getenv("PATH");
97 struct strbuf buf = STRBUF_INIT;
98
99 if (!p || !*p)
100 return NULL;
101
102 while (1) {
103 const char *end = strchrnul(p, ':');
104
105 strbuf_reset(&buf);
106
107 /* POSIX specifies an empty entry as the current directory. */
108 if (end != p) {
109 strbuf_add(&buf, p, end - p);
110 strbuf_addch(&buf, '/');
111 }
112 strbuf_addstr(&buf, file);
113
114 if (!access(buf.buf, F_OK))
115 return strbuf_detach(&buf, NULL);
116
117 if (!*end)
118 break;
119 p = end + 1;
120 }
121
122 strbuf_release(&buf);
123 return NULL;
124 }
125
126 static int exists_in_PATH(const char *file)
127 {
128 char *r = locate_in_PATH(file);
129 free(r);
130 return r != NULL;
131 }
132
133 int sane_execvp(const char *file, char * const argv[])
134 {
135 if (!execvp(file, argv))
136 return 0; /* cannot happen ;-) */
137
138 /*
139 * When a command can't be found because one of the directories
140 * listed in $PATH is unsearchable, execvp reports EACCES, but
141 * careful usability testing (read: analysis of occasional bug
142 * reports) reveals that "No such file or directory" is more
143 * intuitive.
144 *
145 * We avoid commands with "/", because execvp will not do $PATH
146 * lookups in that case.
147 *
148 * The reassignment of EACCES to errno looks like a no-op below,
149 * but we need to protect against exists_in_PATH overwriting errno.
150 */
151 if (errno == EACCES && !strchr(file, '/'))
152 errno = exists_in_PATH(file) ? EACCES : ENOENT;
153 else if (errno == ENOTDIR && !strchr(file, '/'))
154 errno = ENOENT;
155 return -1;
156 }
157
158 static const char **prepare_shell_cmd(const char **argv)
159 {
160 int argc, nargc = 0;
161 const char **nargv;
162
163 for (argc = 0; argv[argc]; argc++)
164 ; /* just counting */
165 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
166 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
167
168 if (argc < 1)
169 die("BUG: shell command is empty");
170
171 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
172 #ifndef GIT_WINDOWS_NATIVE
173 nargv[nargc++] = SHELL_PATH;
174 #else
175 nargv[nargc++] = "sh";
176 #endif
177 nargv[nargc++] = "-c";
178
179 if (argc < 2)
180 nargv[nargc++] = argv[0];
181 else {
182 struct strbuf arg0 = STRBUF_INIT;
183 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
184 nargv[nargc++] = strbuf_detach(&arg0, NULL);
185 }
186 }
187
188 for (argc = 0; argv[argc]; argc++)
189 nargv[nargc++] = argv[argc];
190 nargv[nargc] = NULL;
191
192 return nargv;
193 }
194
195 #ifndef GIT_WINDOWS_NATIVE
196 static int execv_shell_cmd(const char **argv)
197 {
198 const char **nargv = prepare_shell_cmd(argv);
199 trace_argv_printf(nargv, "trace: exec:");
200 sane_execvp(nargv[0], (char **)nargv);
201 free(nargv);
202 return -1;
203 }
204 #endif
205
206 #ifndef GIT_WINDOWS_NATIVE
207 static int child_err = 2;
208 static int child_notifier = -1;
209
210 static void notify_parent(void)
211 {
212 /*
213 * execvp failed. If possible, we'd like to let start_command
214 * know, so failures like ENOENT can be handled right away; but
215 * otherwise, finish_command will still report the error.
216 */
217 xwrite(child_notifier, "", 1);
218 }
219
220 static NORETURN void die_child(const char *err, va_list params)
221 {
222 vwritef(child_err, "fatal: ", err, params);
223 exit(128);
224 }
225
226 static void error_child(const char *err, va_list params)
227 {
228 vwritef(child_err, "error: ", err, params);
229 }
230 #endif
231
232 static inline void set_cloexec(int fd)
233 {
234 int flags = fcntl(fd, F_GETFD);
235 if (flags >= 0)
236 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
237 }
238
239 static int wait_or_whine(pid_t pid, const char *argv0)
240 {
241 int status, code = -1;
242 pid_t waiting;
243 int failed_errno = 0;
244
245 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
246 ; /* nothing */
247
248 if (waiting < 0) {
249 failed_errno = errno;
250 error("waitpid for %s failed: %s", argv0, strerror(errno));
251 } else if (waiting != pid) {
252 error("waitpid is confused (%s)", argv0);
253 } else if (WIFSIGNALED(status)) {
254 code = WTERMSIG(status);
255 if (code != SIGINT && code != SIGQUIT)
256 error("%s died of signal %d", argv0, code);
257 /*
258 * This return value is chosen so that code & 0xff
259 * mimics the exit code that a POSIX shell would report for
260 * a program that died from this signal.
261 */
262 code += 128;
263 } else if (WIFEXITED(status)) {
264 code = WEXITSTATUS(status);
265 /*
266 * Convert special exit code when execvp failed.
267 */
268 if (code == 127) {
269 code = -1;
270 failed_errno = ENOENT;
271 }
272 } else {
273 error("waitpid is confused (%s)", argv0);
274 }
275
276 clear_child_for_cleanup(pid);
277
278 errno = failed_errno;
279 return code;
280 }
281
282 int start_command(struct child_process *cmd)
283 {
284 int need_in, need_out, need_err;
285 int fdin[2], fdout[2], fderr[2];
286 int failed_errno;
287 char *str;
288
289 if (!cmd->argv)
290 cmd->argv = cmd->args.argv;
291 if (!cmd->env)
292 cmd->env = cmd->env_array.argv;
293
294 /*
295 * In case of errors we must keep the promise to close FDs
296 * that have been passed in via ->in and ->out.
297 */
298
299 need_in = !cmd->no_stdin && cmd->in < 0;
300 if (need_in) {
301 if (pipe(fdin) < 0) {
302 failed_errno = errno;
303 if (cmd->out > 0)
304 close(cmd->out);
305 str = "standard input";
306 goto fail_pipe;
307 }
308 cmd->in = fdin[1];
309 }
310
311 need_out = !cmd->no_stdout
312 && !cmd->stdout_to_stderr
313 && cmd->out < 0;
314 if (need_out) {
315 if (pipe(fdout) < 0) {
316 failed_errno = errno;
317 if (need_in)
318 close_pair(fdin);
319 else if (cmd->in)
320 close(cmd->in);
321 str = "standard output";
322 goto fail_pipe;
323 }
324 cmd->out = fdout[0];
325 }
326
327 need_err = !cmd->no_stderr && cmd->err < 0;
328 if (need_err) {
329 if (pipe(fderr) < 0) {
330 failed_errno = errno;
331 if (need_in)
332 close_pair(fdin);
333 else if (cmd->in)
334 close(cmd->in);
335 if (need_out)
336 close_pair(fdout);
337 else if (cmd->out)
338 close(cmd->out);
339 str = "standard error";
340 fail_pipe:
341 error("cannot create %s pipe for %s: %s",
342 str, cmd->argv[0], strerror(failed_errno));
343 argv_array_clear(&cmd->args);
344 argv_array_clear(&cmd->env_array);
345 errno = failed_errno;
346 return -1;
347 }
348 cmd->err = fderr[0];
349 }
350
351 trace_argv_printf(cmd->argv, "trace: run_command:");
352 fflush(NULL);
353
354 #ifndef GIT_WINDOWS_NATIVE
355 {
356 int notify_pipe[2];
357 if (pipe(notify_pipe))
358 notify_pipe[0] = notify_pipe[1] = -1;
359
360 cmd->pid = fork();
361 failed_errno = errno;
362 if (!cmd->pid) {
363 /*
364 * Redirect the channel to write syscall error messages to
365 * before redirecting the process's stderr so that all die()
366 * in subsequent call paths use the parent's stderr.
367 */
368 if (cmd->no_stderr || need_err) {
369 child_err = dup(2);
370 set_cloexec(child_err);
371 }
372 set_die_routine(die_child);
373 set_error_routine(error_child);
374
375 close(notify_pipe[0]);
376 set_cloexec(notify_pipe[1]);
377 child_notifier = notify_pipe[1];
378 atexit(notify_parent);
379
380 if (cmd->no_stdin)
381 dup_devnull(0);
382 else if (need_in) {
383 dup2(fdin[0], 0);
384 close_pair(fdin);
385 } else if (cmd->in) {
386 dup2(cmd->in, 0);
387 close(cmd->in);
388 }
389
390 if (cmd->no_stderr)
391 dup_devnull(2);
392 else if (need_err) {
393 dup2(fderr[1], 2);
394 close_pair(fderr);
395 } else if (cmd->err > 1) {
396 dup2(cmd->err, 2);
397 close(cmd->err);
398 }
399
400 if (cmd->no_stdout)
401 dup_devnull(1);
402 else if (cmd->stdout_to_stderr)
403 dup2(2, 1);
404 else if (need_out) {
405 dup2(fdout[1], 1);
406 close_pair(fdout);
407 } else if (cmd->out > 1) {
408 dup2(cmd->out, 1);
409 close(cmd->out);
410 }
411
412 if (cmd->dir && chdir(cmd->dir))
413 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
414 cmd->dir);
415 if (cmd->env) {
416 for (; *cmd->env; cmd->env++) {
417 if (strchr(*cmd->env, '='))
418 putenv((char *)*cmd->env);
419 else
420 unsetenv(*cmd->env);
421 }
422 }
423 if (cmd->git_cmd)
424 execv_git_cmd(cmd->argv);
425 else if (cmd->use_shell)
426 execv_shell_cmd(cmd->argv);
427 else
428 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
429 if (errno == ENOENT) {
430 if (!cmd->silent_exec_failure)
431 error("cannot run %s: %s", cmd->argv[0],
432 strerror(ENOENT));
433 exit(127);
434 } else {
435 die_errno("cannot exec '%s'", cmd->argv[0]);
436 }
437 }
438 if (cmd->pid < 0)
439 error("cannot fork() for %s: %s", cmd->argv[0],
440 strerror(errno));
441 else if (cmd->clean_on_exit)
442 mark_child_for_cleanup(cmd->pid);
443
444 /*
445 * Wait for child's execvp. If the execvp succeeds (or if fork()
446 * failed), EOF is seen immediately by the parent. Otherwise, the
447 * child process sends a single byte.
448 * Note that use of this infrastructure is completely advisory,
449 * therefore, we keep error checks minimal.
450 */
451 close(notify_pipe[1]);
452 if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
453 /*
454 * At this point we know that fork() succeeded, but execvp()
455 * failed. Errors have been reported to our stderr.
456 */
457 wait_or_whine(cmd->pid, cmd->argv[0]);
458 failed_errno = errno;
459 cmd->pid = -1;
460 }
461 close(notify_pipe[0]);
462 }
463 #else
464 {
465 int fhin = 0, fhout = 1, fherr = 2;
466 const char **sargv = cmd->argv;
467
468 if (cmd->no_stdin)
469 fhin = open("/dev/null", O_RDWR);
470 else if (need_in)
471 fhin = dup(fdin[0]);
472 else if (cmd->in)
473 fhin = dup(cmd->in);
474
475 if (cmd->no_stderr)
476 fherr = open("/dev/null", O_RDWR);
477 else if (need_err)
478 fherr = dup(fderr[1]);
479 else if (cmd->err > 2)
480 fherr = dup(cmd->err);
481
482 if (cmd->no_stdout)
483 fhout = open("/dev/null", O_RDWR);
484 else if (cmd->stdout_to_stderr)
485 fhout = dup(fherr);
486 else if (need_out)
487 fhout = dup(fdout[1]);
488 else if (cmd->out > 1)
489 fhout = dup(cmd->out);
490
491 if (cmd->git_cmd)
492 cmd->argv = prepare_git_cmd(cmd->argv);
493 else if (cmd->use_shell)
494 cmd->argv = prepare_shell_cmd(cmd->argv);
495
496 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
497 cmd->dir, fhin, fhout, fherr);
498 failed_errno = errno;
499 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
500 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
501 if (cmd->clean_on_exit && cmd->pid >= 0)
502 mark_child_for_cleanup(cmd->pid);
503
504 if (cmd->git_cmd)
505 free(cmd->argv);
506
507 cmd->argv = sargv;
508 if (fhin != 0)
509 close(fhin);
510 if (fhout != 1)
511 close(fhout);
512 if (fherr != 2)
513 close(fherr);
514 }
515 #endif
516
517 if (cmd->pid < 0) {
518 if (need_in)
519 close_pair(fdin);
520 else if (cmd->in)
521 close(cmd->in);
522 if (need_out)
523 close_pair(fdout);
524 else if (cmd->out)
525 close(cmd->out);
526 if (need_err)
527 close_pair(fderr);
528 else if (cmd->err)
529 close(cmd->err);
530 argv_array_clear(&cmd->args);
531 argv_array_clear(&cmd->env_array);
532 errno = failed_errno;
533 return -1;
534 }
535
536 if (need_in)
537 close(fdin[0]);
538 else if (cmd->in)
539 close(cmd->in);
540
541 if (need_out)
542 close(fdout[1]);
543 else if (cmd->out)
544 close(cmd->out);
545
546 if (need_err)
547 close(fderr[1]);
548 else if (cmd->err)
549 close(cmd->err);
550
551 return 0;
552 }
553
554 int finish_command(struct child_process *cmd)
555 {
556 int ret = wait_or_whine(cmd->pid, cmd->argv[0]);
557 argv_array_clear(&cmd->args);
558 argv_array_clear(&cmd->env_array);
559 return ret;
560 }
561
562 int run_command(struct child_process *cmd)
563 {
564 int code;
565
566 if (cmd->out < 0 || cmd->err < 0)
567 die("BUG: run_command with a pipe can cause deadlock");
568
569 code = start_command(cmd);
570 if (code)
571 return code;
572 return finish_command(cmd);
573 }
574
575 int run_command_v_opt(const char **argv, int opt)
576 {
577 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
578 }
579
580 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
581 {
582 struct child_process cmd = CHILD_PROCESS_INIT;
583 cmd.argv = argv;
584 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
585 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
586 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
587 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
588 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
589 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
590 cmd.dir = dir;
591 cmd.env = env;
592 return run_command(&cmd);
593 }
594
595 #ifndef NO_PTHREADS
596 static pthread_t main_thread;
597 static int main_thread_set;
598 static pthread_key_t async_key;
599 static pthread_key_t async_die_counter;
600
601 static void *run_thread(void *data)
602 {
603 struct async *async = data;
604 intptr_t ret;
605
606 pthread_setspecific(async_key, async);
607 ret = async->proc(async->proc_in, async->proc_out, async->data);
608 return (void *)ret;
609 }
610
611 static NORETURN void die_async(const char *err, va_list params)
612 {
613 vreportf("fatal: ", err, params);
614
615 if (!pthread_equal(main_thread, pthread_self())) {
616 struct async *async = pthread_getspecific(async_key);
617 if (async->proc_in >= 0)
618 close(async->proc_in);
619 if (async->proc_out >= 0)
620 close(async->proc_out);
621 pthread_exit((void *)128);
622 }
623
624 exit(128);
625 }
626
627 static int async_die_is_recursing(void)
628 {
629 void *ret = pthread_getspecific(async_die_counter);
630 pthread_setspecific(async_die_counter, (void *)1);
631 return ret != NULL;
632 }
633
634 #else
635
636 static struct {
637 void (**handlers)(void);
638 size_t nr;
639 size_t alloc;
640 } git_atexit_hdlrs;
641
642 static int git_atexit_installed;
643
644 static void git_atexit_dispatch(void)
645 {
646 size_t i;
647
648 for (i=git_atexit_hdlrs.nr ; i ; i--)
649 git_atexit_hdlrs.handlers[i-1]();
650 }
651
652 static void git_atexit_clear(void)
653 {
654 free(git_atexit_hdlrs.handlers);
655 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
656 git_atexit_installed = 0;
657 }
658
659 #undef atexit
660 int git_atexit(void (*handler)(void))
661 {
662 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
663 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
664 if (!git_atexit_installed) {
665 if (atexit(&git_atexit_dispatch))
666 return -1;
667 git_atexit_installed = 1;
668 }
669 return 0;
670 }
671 #define atexit git_atexit
672
673 #endif
674
675 int start_async(struct async *async)
676 {
677 int need_in, need_out;
678 int fdin[2], fdout[2];
679 int proc_in, proc_out;
680
681 need_in = async->in < 0;
682 if (need_in) {
683 if (pipe(fdin) < 0) {
684 if (async->out > 0)
685 close(async->out);
686 return error("cannot create pipe: %s", strerror(errno));
687 }
688 async->in = fdin[1];
689 }
690
691 need_out = async->out < 0;
692 if (need_out) {
693 if (pipe(fdout) < 0) {
694 if (need_in)
695 close_pair(fdin);
696 else if (async->in)
697 close(async->in);
698 return error("cannot create pipe: %s", strerror(errno));
699 }
700 async->out = fdout[0];
701 }
702
703 if (need_in)
704 proc_in = fdin[0];
705 else if (async->in)
706 proc_in = async->in;
707 else
708 proc_in = -1;
709
710 if (need_out)
711 proc_out = fdout[1];
712 else if (async->out)
713 proc_out = async->out;
714 else
715 proc_out = -1;
716
717 #ifdef NO_PTHREADS
718 /* Flush stdio before fork() to avoid cloning buffers */
719 fflush(NULL);
720
721 async->pid = fork();
722 if (async->pid < 0) {
723 error("fork (async) failed: %s", strerror(errno));
724 goto error;
725 }
726 if (!async->pid) {
727 if (need_in)
728 close(fdin[1]);
729 if (need_out)
730 close(fdout[0]);
731 git_atexit_clear();
732 exit(!!async->proc(proc_in, proc_out, async->data));
733 }
734
735 mark_child_for_cleanup(async->pid);
736
737 if (need_in)
738 close(fdin[0]);
739 else if (async->in)
740 close(async->in);
741
742 if (need_out)
743 close(fdout[1]);
744 else if (async->out)
745 close(async->out);
746 #else
747 if (!main_thread_set) {
748 /*
749 * We assume that the first time that start_async is called
750 * it is from the main thread.
751 */
752 main_thread_set = 1;
753 main_thread = pthread_self();
754 pthread_key_create(&async_key, NULL);
755 pthread_key_create(&async_die_counter, NULL);
756 set_die_routine(die_async);
757 set_die_is_recursing_routine(async_die_is_recursing);
758 }
759
760 if (proc_in >= 0)
761 set_cloexec(proc_in);
762 if (proc_out >= 0)
763 set_cloexec(proc_out);
764 async->proc_in = proc_in;
765 async->proc_out = proc_out;
766 {
767 int err = pthread_create(&async->tid, NULL, run_thread, async);
768 if (err) {
769 error("cannot create thread: %s", strerror(err));
770 goto error;
771 }
772 }
773 #endif
774 return 0;
775
776 error:
777 if (need_in)
778 close_pair(fdin);
779 else if (async->in)
780 close(async->in);
781
782 if (need_out)
783 close_pair(fdout);
784 else if (async->out)
785 close(async->out);
786 return -1;
787 }
788
789 int finish_async(struct async *async)
790 {
791 #ifdef NO_PTHREADS
792 return wait_or_whine(async->pid, "child process");
793 #else
794 void *ret = (void *)(intptr_t)(-1);
795
796 if (pthread_join(async->tid, &ret))
797 error("pthread_join failed");
798 return (int)(intptr_t)ret;
799 #endif
800 }
801
802 char *find_hook(const char *name)
803 {
804 char *path = git_path("hooks/%s", name);
805 if (access(path, X_OK) < 0)
806 path = NULL;
807
808 return path;
809 }
810
811 int run_hook_ve(const char *const *env, const char *name, va_list args)
812 {
813 struct child_process hook = CHILD_PROCESS_INIT;
814 const char *p;
815
816 p = find_hook(name);
817 if (!p)
818 return 0;
819
820 argv_array_push(&hook.args, p);
821 while ((p = va_arg(args, const char *)))
822 argv_array_push(&hook.args, p);
823 hook.env = env;
824 hook.no_stdin = 1;
825 hook.stdout_to_stderr = 1;
826
827 return run_command(&hook);
828 }
829
830 int run_hook_le(const char *const *env, const char *name, ...)
831 {
832 va_list args;
833 int ret;
834
835 va_start(args, name);
836 ret = run_hook_ve(env, name, args);
837 va_end(args);
838
839 return ret;
840 }
841
842 int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint)
843 {
844 cmd->out = -1;
845 if (start_command(cmd) < 0)
846 return -1;
847
848 if (strbuf_read(buf, cmd->out, hint) < 0) {
849 close(cmd->out);
850 finish_command(cmd); /* throw away exit code */
851 return -1;
852 }
853
854 close(cmd->out);
855 return finish_command(cmd);
856 }