Merge branch 'maint-1.8.1' into maint
[git.git] / run-command.c
blob765c2ce0567ad0d75270283397d63eac3674c01a
1 #include "cache.h"
2 #include "run-command.h"
3 #include "exec_cmd.h"
4 #include "sigchain.h"
5 #include "argv-array.h"
7 #ifndef SHELL_PATH
8 # define SHELL_PATH "/bin/sh"
9 #endif
11 struct child_to_clean {
12 pid_t pid;
13 struct child_to_clean *next;
15 static struct child_to_clean *children_to_clean;
16 static int installed_child_cleanup_handler;
18 static void cleanup_children(int sig)
20 while (children_to_clean) {
21 struct child_to_clean *p = children_to_clean;
22 children_to_clean = p->next;
23 kill(p->pid, sig);
24 free(p);
28 static void cleanup_children_on_signal(int sig)
30 cleanup_children(sig);
31 sigchain_pop(sig);
32 raise(sig);
35 static void cleanup_children_on_exit(void)
37 cleanup_children(SIGTERM);
40 static void mark_child_for_cleanup(pid_t pid)
42 struct child_to_clean *p = xmalloc(sizeof(*p));
43 p->pid = pid;
44 p->next = children_to_clean;
45 children_to_clean = p;
47 if (!installed_child_cleanup_handler) {
48 atexit(cleanup_children_on_exit);
49 sigchain_push_common(cleanup_children_on_signal);
50 installed_child_cleanup_handler = 1;
54 static void clear_child_for_cleanup(pid_t pid)
56 struct child_to_clean **pp;
58 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
59 struct child_to_clean *clean_me = *pp;
61 if (clean_me->pid == pid) {
62 *pp = clean_me->next;
63 free(clean_me);
64 return;
69 static inline void close_pair(int fd[2])
71 close(fd[0]);
72 close(fd[1]);
75 #ifndef WIN32
76 static inline void dup_devnull(int to)
78 int fd = open("/dev/null", O_RDWR);
79 dup2(fd, to);
80 close(fd);
82 #endif
84 static char *locate_in_PATH(const char *file)
86 const char *p = getenv("PATH");
87 struct strbuf buf = STRBUF_INIT;
89 if (!p || !*p)
90 return NULL;
92 while (1) {
93 const char *end = strchrnul(p, ':');
95 strbuf_reset(&buf);
97 /* POSIX specifies an empty entry as the current directory. */
98 if (end != p) {
99 strbuf_add(&buf, p, end - p);
100 strbuf_addch(&buf, '/');
102 strbuf_addstr(&buf, file);
104 if (!access(buf.buf, F_OK))
105 return strbuf_detach(&buf, NULL);
107 if (!*end)
108 break;
109 p = end + 1;
112 strbuf_release(&buf);
113 return NULL;
116 static int exists_in_PATH(const char *file)
118 char *r = locate_in_PATH(file);
119 free(r);
120 return r != NULL;
123 int sane_execvp(const char *file, char * const argv[])
125 if (!execvp(file, argv))
126 return 0; /* cannot happen ;-) */
129 * When a command can't be found because one of the directories
130 * listed in $PATH is unsearchable, execvp reports EACCES, but
131 * careful usability testing (read: analysis of occasional bug
132 * reports) reveals that "No such file or directory" is more
133 * intuitive.
135 * We avoid commands with "/", because execvp will not do $PATH
136 * lookups in that case.
138 * The reassignment of EACCES to errno looks like a no-op below,
139 * but we need to protect against exists_in_PATH overwriting errno.
141 if (errno == EACCES && !strchr(file, '/'))
142 errno = exists_in_PATH(file) ? EACCES : ENOENT;
143 else if (errno == ENOTDIR && !strchr(file, '/'))
144 errno = ENOENT;
145 return -1;
148 static const char **prepare_shell_cmd(const char **argv)
150 int argc, nargc = 0;
151 const char **nargv;
153 for (argc = 0; argv[argc]; argc++)
154 ; /* just counting */
155 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
156 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
158 if (argc < 1)
159 die("BUG: shell command is empty");
161 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
162 #ifndef WIN32
163 nargv[nargc++] = SHELL_PATH;
164 #else
165 nargv[nargc++] = "sh";
166 #endif
167 nargv[nargc++] = "-c";
169 if (argc < 2)
170 nargv[nargc++] = argv[0];
171 else {
172 struct strbuf arg0 = STRBUF_INIT;
173 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
174 nargv[nargc++] = strbuf_detach(&arg0, NULL);
178 for (argc = 0; argv[argc]; argc++)
179 nargv[nargc++] = argv[argc];
180 nargv[nargc] = NULL;
182 return nargv;
185 #ifndef WIN32
186 static int execv_shell_cmd(const char **argv)
188 const char **nargv = prepare_shell_cmd(argv);
189 trace_argv_printf(nargv, "trace: exec:");
190 sane_execvp(nargv[0], (char **)nargv);
191 free(nargv);
192 return -1;
194 #endif
196 #ifndef WIN32
197 static int child_err = 2;
198 static int child_notifier = -1;
200 static void notify_parent(void)
203 * execvp failed. If possible, we'd like to let start_command
204 * know, so failures like ENOENT can be handled right away; but
205 * otherwise, finish_command will still report the error.
207 xwrite(child_notifier, "", 1);
210 static NORETURN void die_child(const char *err, va_list params)
212 vwritef(child_err, "fatal: ", err, params);
213 exit(128);
216 static void error_child(const char *err, va_list params)
218 vwritef(child_err, "error: ", err, params);
220 #endif
222 static inline void set_cloexec(int fd)
224 int flags = fcntl(fd, F_GETFD);
225 if (flags >= 0)
226 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
229 static int wait_or_whine(pid_t pid, const char *argv0)
231 int status, code = -1;
232 pid_t waiting;
233 int failed_errno = 0;
235 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
236 ; /* nothing */
238 if (waiting < 0) {
239 failed_errno = errno;
240 error("waitpid for %s failed: %s", argv0, strerror(errno));
241 } else if (waiting != pid) {
242 error("waitpid is confused (%s)", argv0);
243 } else if (WIFSIGNALED(status)) {
244 code = WTERMSIG(status);
245 if (code != SIGINT && code != SIGQUIT)
246 error("%s died of signal %d", argv0, code);
248 * This return value is chosen so that code & 0xff
249 * mimics the exit code that a POSIX shell would report for
250 * a program that died from this signal.
252 code += 128;
253 } else if (WIFEXITED(status)) {
254 code = WEXITSTATUS(status);
256 * Convert special exit code when execvp failed.
258 if (code == 127) {
259 code = -1;
260 failed_errno = ENOENT;
262 } else {
263 error("waitpid is confused (%s)", argv0);
266 clear_child_for_cleanup(pid);
268 errno = failed_errno;
269 return code;
272 int start_command(struct child_process *cmd)
274 int need_in, need_out, need_err;
275 int fdin[2], fdout[2], fderr[2];
276 int failed_errno;
277 char *str;
280 * In case of errors we must keep the promise to close FDs
281 * that have been passed in via ->in and ->out.
284 need_in = !cmd->no_stdin && cmd->in < 0;
285 if (need_in) {
286 if (pipe(fdin) < 0) {
287 failed_errno = errno;
288 if (cmd->out > 0)
289 close(cmd->out);
290 str = "standard input";
291 goto fail_pipe;
293 cmd->in = fdin[1];
296 need_out = !cmd->no_stdout
297 && !cmd->stdout_to_stderr
298 && cmd->out < 0;
299 if (need_out) {
300 if (pipe(fdout) < 0) {
301 failed_errno = errno;
302 if (need_in)
303 close_pair(fdin);
304 else if (cmd->in)
305 close(cmd->in);
306 str = "standard output";
307 goto fail_pipe;
309 cmd->out = fdout[0];
312 need_err = !cmd->no_stderr && cmd->err < 0;
313 if (need_err) {
314 if (pipe(fderr) < 0) {
315 failed_errno = errno;
316 if (need_in)
317 close_pair(fdin);
318 else if (cmd->in)
319 close(cmd->in);
320 if (need_out)
321 close_pair(fdout);
322 else if (cmd->out)
323 close(cmd->out);
324 str = "standard error";
325 fail_pipe:
326 error("cannot create %s pipe for %s: %s",
327 str, cmd->argv[0], strerror(failed_errno));
328 errno = failed_errno;
329 return -1;
331 cmd->err = fderr[0];
334 trace_argv_printf(cmd->argv, "trace: run_command:");
335 fflush(NULL);
337 #ifndef WIN32
339 int notify_pipe[2];
340 if (pipe(notify_pipe))
341 notify_pipe[0] = notify_pipe[1] = -1;
343 cmd->pid = fork();
344 failed_errno = errno;
345 if (!cmd->pid) {
347 * Redirect the channel to write syscall error messages to
348 * before redirecting the process's stderr so that all die()
349 * in subsequent call paths use the parent's stderr.
351 if (cmd->no_stderr || need_err) {
352 child_err = dup(2);
353 set_cloexec(child_err);
355 set_die_routine(die_child);
356 set_error_routine(error_child);
358 close(notify_pipe[0]);
359 set_cloexec(notify_pipe[1]);
360 child_notifier = notify_pipe[1];
361 atexit(notify_parent);
363 if (cmd->no_stdin)
364 dup_devnull(0);
365 else if (need_in) {
366 dup2(fdin[0], 0);
367 close_pair(fdin);
368 } else if (cmd->in) {
369 dup2(cmd->in, 0);
370 close(cmd->in);
373 if (cmd->no_stderr)
374 dup_devnull(2);
375 else if (need_err) {
376 dup2(fderr[1], 2);
377 close_pair(fderr);
378 } else if (cmd->err > 1) {
379 dup2(cmd->err, 2);
380 close(cmd->err);
383 if (cmd->no_stdout)
384 dup_devnull(1);
385 else if (cmd->stdout_to_stderr)
386 dup2(2, 1);
387 else if (need_out) {
388 dup2(fdout[1], 1);
389 close_pair(fdout);
390 } else if (cmd->out > 1) {
391 dup2(cmd->out, 1);
392 close(cmd->out);
395 if (cmd->dir && chdir(cmd->dir))
396 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
397 cmd->dir);
398 if (cmd->env) {
399 for (; *cmd->env; cmd->env++) {
400 if (strchr(*cmd->env, '='))
401 putenv((char *)*cmd->env);
402 else
403 unsetenv(*cmd->env);
406 if (cmd->git_cmd) {
407 execv_git_cmd(cmd->argv);
408 } else if (cmd->use_shell) {
409 execv_shell_cmd(cmd->argv);
410 } else {
411 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
413 if (errno == ENOENT) {
414 if (!cmd->silent_exec_failure)
415 error("cannot run %s: %s", cmd->argv[0],
416 strerror(ENOENT));
417 exit(127);
418 } else {
419 die_errno("cannot exec '%s'", cmd->argv[0]);
422 if (cmd->pid < 0)
423 error("cannot fork() for %s: %s", cmd->argv[0],
424 strerror(errno));
425 else if (cmd->clean_on_exit)
426 mark_child_for_cleanup(cmd->pid);
429 * Wait for child's execvp. If the execvp succeeds (or if fork()
430 * failed), EOF is seen immediately by the parent. Otherwise, the
431 * child process sends a single byte.
432 * Note that use of this infrastructure is completely advisory,
433 * therefore, we keep error checks minimal.
435 close(notify_pipe[1]);
436 if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
438 * At this point we know that fork() succeeded, but execvp()
439 * failed. Errors have been reported to our stderr.
441 wait_or_whine(cmd->pid, cmd->argv[0]);
442 failed_errno = errno;
443 cmd->pid = -1;
445 close(notify_pipe[0]);
448 #else
450 int fhin = 0, fhout = 1, fherr = 2;
451 const char **sargv = cmd->argv;
452 char **env = environ;
454 if (cmd->no_stdin)
455 fhin = open("/dev/null", O_RDWR);
456 else if (need_in)
457 fhin = dup(fdin[0]);
458 else if (cmd->in)
459 fhin = dup(cmd->in);
461 if (cmd->no_stderr)
462 fherr = open("/dev/null", O_RDWR);
463 else if (need_err)
464 fherr = dup(fderr[1]);
465 else if (cmd->err > 2)
466 fherr = dup(cmd->err);
468 if (cmd->no_stdout)
469 fhout = open("/dev/null", O_RDWR);
470 else if (cmd->stdout_to_stderr)
471 fhout = dup(fherr);
472 else if (need_out)
473 fhout = dup(fdout[1]);
474 else if (cmd->out > 1)
475 fhout = dup(cmd->out);
477 if (cmd->env)
478 env = make_augmented_environ(cmd->env);
480 if (cmd->git_cmd) {
481 cmd->argv = prepare_git_cmd(cmd->argv);
482 } else if (cmd->use_shell) {
483 cmd->argv = prepare_shell_cmd(cmd->argv);
486 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
487 fhin, fhout, fherr);
488 failed_errno = errno;
489 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
490 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
491 if (cmd->clean_on_exit && cmd->pid >= 0)
492 mark_child_for_cleanup(cmd->pid);
494 if (cmd->env)
495 free_environ(env);
496 if (cmd->git_cmd)
497 free(cmd->argv);
499 cmd->argv = sargv;
500 if (fhin != 0)
501 close(fhin);
502 if (fhout != 1)
503 close(fhout);
504 if (fherr != 2)
505 close(fherr);
507 #endif
509 if (cmd->pid < 0) {
510 if (need_in)
511 close_pair(fdin);
512 else if (cmd->in)
513 close(cmd->in);
514 if (need_out)
515 close_pair(fdout);
516 else if (cmd->out)
517 close(cmd->out);
518 if (need_err)
519 close_pair(fderr);
520 else if (cmd->err)
521 close(cmd->err);
522 errno = failed_errno;
523 return -1;
526 if (need_in)
527 close(fdin[0]);
528 else if (cmd->in)
529 close(cmd->in);
531 if (need_out)
532 close(fdout[1]);
533 else if (cmd->out)
534 close(cmd->out);
536 if (need_err)
537 close(fderr[1]);
538 else if (cmd->err)
539 close(cmd->err);
541 return 0;
544 int finish_command(struct child_process *cmd)
546 return wait_or_whine(cmd->pid, cmd->argv[0]);
549 int run_command(struct child_process *cmd)
551 int code = start_command(cmd);
552 if (code)
553 return code;
554 return finish_command(cmd);
557 static void prepare_run_command_v_opt(struct child_process *cmd,
558 const char **argv,
559 int opt)
561 memset(cmd, 0, sizeof(*cmd));
562 cmd->argv = argv;
563 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
564 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
565 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
566 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
567 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
568 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
571 int run_command_v_opt(const char **argv, int opt)
573 struct child_process cmd;
574 prepare_run_command_v_opt(&cmd, argv, opt);
575 return run_command(&cmd);
578 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
580 struct child_process cmd;
581 prepare_run_command_v_opt(&cmd, argv, opt);
582 cmd.dir = dir;
583 cmd.env = env;
584 return run_command(&cmd);
587 #ifndef NO_PTHREADS
588 static pthread_t main_thread;
589 static int main_thread_set;
590 static pthread_key_t async_key;
592 static void *run_thread(void *data)
594 struct async *async = data;
595 intptr_t ret;
597 pthread_setspecific(async_key, async);
598 ret = async->proc(async->proc_in, async->proc_out, async->data);
599 return (void *)ret;
602 static NORETURN void die_async(const char *err, va_list params)
604 vreportf("fatal: ", err, params);
606 if (!pthread_equal(main_thread, pthread_self())) {
607 struct async *async = pthread_getspecific(async_key);
608 if (async->proc_in >= 0)
609 close(async->proc_in);
610 if (async->proc_out >= 0)
611 close(async->proc_out);
612 pthread_exit((void *)128);
615 exit(128);
617 #endif
619 int start_async(struct async *async)
621 int need_in, need_out;
622 int fdin[2], fdout[2];
623 int proc_in, proc_out;
625 need_in = async->in < 0;
626 if (need_in) {
627 if (pipe(fdin) < 0) {
628 if (async->out > 0)
629 close(async->out);
630 return error("cannot create pipe: %s", strerror(errno));
632 async->in = fdin[1];
635 need_out = async->out < 0;
636 if (need_out) {
637 if (pipe(fdout) < 0) {
638 if (need_in)
639 close_pair(fdin);
640 else if (async->in)
641 close(async->in);
642 return error("cannot create pipe: %s", strerror(errno));
644 async->out = fdout[0];
647 if (need_in)
648 proc_in = fdin[0];
649 else if (async->in)
650 proc_in = async->in;
651 else
652 proc_in = -1;
654 if (need_out)
655 proc_out = fdout[1];
656 else if (async->out)
657 proc_out = async->out;
658 else
659 proc_out = -1;
661 #ifdef NO_PTHREADS
662 /* Flush stdio before fork() to avoid cloning buffers */
663 fflush(NULL);
665 async->pid = fork();
666 if (async->pid < 0) {
667 error("fork (async) failed: %s", strerror(errno));
668 goto error;
670 if (!async->pid) {
671 if (need_in)
672 close(fdin[1]);
673 if (need_out)
674 close(fdout[0]);
675 exit(!!async->proc(proc_in, proc_out, async->data));
678 mark_child_for_cleanup(async->pid);
680 if (need_in)
681 close(fdin[0]);
682 else if (async->in)
683 close(async->in);
685 if (need_out)
686 close(fdout[1]);
687 else if (async->out)
688 close(async->out);
689 #else
690 if (!main_thread_set) {
692 * We assume that the first time that start_async is called
693 * it is from the main thread.
695 main_thread_set = 1;
696 main_thread = pthread_self();
697 pthread_key_create(&async_key, NULL);
698 set_die_routine(die_async);
701 if (proc_in >= 0)
702 set_cloexec(proc_in);
703 if (proc_out >= 0)
704 set_cloexec(proc_out);
705 async->proc_in = proc_in;
706 async->proc_out = proc_out;
708 int err = pthread_create(&async->tid, NULL, run_thread, async);
709 if (err) {
710 error("cannot create thread: %s", strerror(err));
711 goto error;
714 #endif
715 return 0;
717 error:
718 if (need_in)
719 close_pair(fdin);
720 else if (async->in)
721 close(async->in);
723 if (need_out)
724 close_pair(fdout);
725 else if (async->out)
726 close(async->out);
727 return -1;
730 int finish_async(struct async *async)
732 #ifdef NO_PTHREADS
733 return wait_or_whine(async->pid, "child process");
734 #else
735 void *ret = (void *)(intptr_t)(-1);
737 if (pthread_join(async->tid, &ret))
738 error("pthread_join failed");
739 return (int)(intptr_t)ret;
740 #endif
743 char *find_hook(const char *name)
745 char *path = git_path("hooks/%s", name);
746 if (access(path, X_OK) < 0)
747 path = NULL;
749 return path;
752 int run_hook(const char *index_file, const char *name, ...)
754 struct child_process hook;
755 struct argv_array argv = ARGV_ARRAY_INIT;
756 const char *p, *env[2];
757 char index[PATH_MAX];
758 va_list args;
759 int ret;
761 p = find_hook(name);
762 if (!p)
763 return 0;
765 argv_array_push(&argv, p);
767 va_start(args, name);
768 while ((p = va_arg(args, const char *)))
769 argv_array_push(&argv, p);
770 va_end(args);
772 memset(&hook, 0, sizeof(hook));
773 hook.argv = argv.argv;
774 hook.no_stdin = 1;
775 hook.stdout_to_stderr = 1;
776 if (index_file) {
777 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
778 env[0] = index;
779 env[1] = NULL;
780 hook.env = env;
783 ret = run_command(&hook);
784 argv_array_clear(&argv);
785 return ret;