Merge branch 'ye/doc-http-proto' into maint
[git.git] / run-command.c
blob75abc478c6da75471e5fdbb55c74efdfcf3ad160
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 GIT_WINDOWS_NATIVE
76 static inline void dup_devnull(int to)
78 int fd = open("/dev/null", O_RDWR);
79 if (fd < 0)
80 die_errno(_("open /dev/null failed"));
81 if (dup2(fd, to) < 0)
82 die_errno(_("dup2(%d,%d) failed"), fd, to);
83 close(fd);
85 #endif
87 static char *locate_in_PATH(const char *file)
89 const char *p = getenv("PATH");
90 struct strbuf buf = STRBUF_INIT;
92 if (!p || !*p)
93 return NULL;
95 while (1) {
96 const char *end = strchrnul(p, ':');
98 strbuf_reset(&buf);
100 /* POSIX specifies an empty entry as the current directory. */
101 if (end != p) {
102 strbuf_add(&buf, p, end - p);
103 strbuf_addch(&buf, '/');
105 strbuf_addstr(&buf, file);
107 if (!access(buf.buf, F_OK))
108 return strbuf_detach(&buf, NULL);
110 if (!*end)
111 break;
112 p = end + 1;
115 strbuf_release(&buf);
116 return NULL;
119 static int exists_in_PATH(const char *file)
121 char *r = locate_in_PATH(file);
122 free(r);
123 return r != NULL;
126 int sane_execvp(const char *file, char * const argv[])
128 if (!execvp(file, argv))
129 return 0; /* cannot happen ;-) */
132 * When a command can't be found because one of the directories
133 * listed in $PATH is unsearchable, execvp reports EACCES, but
134 * careful usability testing (read: analysis of occasional bug
135 * reports) reveals that "No such file or directory" is more
136 * intuitive.
138 * We avoid commands with "/", because execvp will not do $PATH
139 * lookups in that case.
141 * The reassignment of EACCES to errno looks like a no-op below,
142 * but we need to protect against exists_in_PATH overwriting errno.
144 if (errno == EACCES && !strchr(file, '/'))
145 errno = exists_in_PATH(file) ? EACCES : ENOENT;
146 else if (errno == ENOTDIR && !strchr(file, '/'))
147 errno = ENOENT;
148 return -1;
151 static const char **prepare_shell_cmd(const char **argv)
153 int argc, nargc = 0;
154 const char **nargv;
156 for (argc = 0; argv[argc]; argc++)
157 ; /* just counting */
158 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
159 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
161 if (argc < 1)
162 die("BUG: shell command is empty");
164 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
165 #ifndef GIT_WINDOWS_NATIVE
166 nargv[nargc++] = SHELL_PATH;
167 #else
168 nargv[nargc++] = "sh";
169 #endif
170 nargv[nargc++] = "-c";
172 if (argc < 2)
173 nargv[nargc++] = argv[0];
174 else {
175 struct strbuf arg0 = STRBUF_INIT;
176 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
177 nargv[nargc++] = strbuf_detach(&arg0, NULL);
181 for (argc = 0; argv[argc]; argc++)
182 nargv[nargc++] = argv[argc];
183 nargv[nargc] = NULL;
185 return nargv;
188 #ifndef GIT_WINDOWS_NATIVE
189 static int execv_shell_cmd(const char **argv)
191 const char **nargv = prepare_shell_cmd(argv);
192 trace_argv_printf(nargv, "trace: exec:");
193 sane_execvp(nargv[0], (char **)nargv);
194 free(nargv);
195 return -1;
197 #endif
199 #ifndef GIT_WINDOWS_NATIVE
200 static int child_err = 2;
201 static int child_notifier = -1;
203 static void notify_parent(void)
206 * execvp failed. If possible, we'd like to let start_command
207 * know, so failures like ENOENT can be handled right away; but
208 * otherwise, finish_command will still report the error.
210 xwrite(child_notifier, "", 1);
213 static NORETURN void die_child(const char *err, va_list params)
215 vwritef(child_err, "fatal: ", err, params);
216 exit(128);
219 static void error_child(const char *err, va_list params)
221 vwritef(child_err, "error: ", err, params);
223 #endif
225 static inline void set_cloexec(int fd)
227 int flags = fcntl(fd, F_GETFD);
228 if (flags >= 0)
229 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
232 static int wait_or_whine(pid_t pid, const char *argv0)
234 int status, code = -1;
235 pid_t waiting;
236 int failed_errno = 0;
238 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
239 ; /* nothing */
241 if (waiting < 0) {
242 failed_errno = errno;
243 error("waitpid for %s failed: %s", argv0, strerror(errno));
244 } else if (waiting != pid) {
245 error("waitpid is confused (%s)", argv0);
246 } else if (WIFSIGNALED(status)) {
247 code = WTERMSIG(status);
248 if (code != SIGINT && code != SIGQUIT)
249 error("%s died of signal %d", argv0, code);
251 * This return value is chosen so that code & 0xff
252 * mimics the exit code that a POSIX shell would report for
253 * a program that died from this signal.
255 code += 128;
256 } else if (WIFEXITED(status)) {
257 code = WEXITSTATUS(status);
259 * Convert special exit code when execvp failed.
261 if (code == 127) {
262 code = -1;
263 failed_errno = ENOENT;
265 } else {
266 error("waitpid is confused (%s)", argv0);
269 clear_child_for_cleanup(pid);
271 errno = failed_errno;
272 return code;
275 int start_command(struct child_process *cmd)
277 int need_in, need_out, need_err;
278 int fdin[2], fdout[2], fderr[2];
279 int failed_errno;
280 char *str;
283 * In case of errors we must keep the promise to close FDs
284 * that have been passed in via ->in and ->out.
287 need_in = !cmd->no_stdin && cmd->in < 0;
288 if (need_in) {
289 if (pipe(fdin) < 0) {
290 failed_errno = errno;
291 if (cmd->out > 0)
292 close(cmd->out);
293 str = "standard input";
294 goto fail_pipe;
296 cmd->in = fdin[1];
299 need_out = !cmd->no_stdout
300 && !cmd->stdout_to_stderr
301 && cmd->out < 0;
302 if (need_out) {
303 if (pipe(fdout) < 0) {
304 failed_errno = errno;
305 if (need_in)
306 close_pair(fdin);
307 else if (cmd->in)
308 close(cmd->in);
309 str = "standard output";
310 goto fail_pipe;
312 cmd->out = fdout[0];
315 need_err = !cmd->no_stderr && cmd->err < 0;
316 if (need_err) {
317 if (pipe(fderr) < 0) {
318 failed_errno = errno;
319 if (need_in)
320 close_pair(fdin);
321 else if (cmd->in)
322 close(cmd->in);
323 if (need_out)
324 close_pair(fdout);
325 else if (cmd->out)
326 close(cmd->out);
327 str = "standard error";
328 fail_pipe:
329 error("cannot create %s pipe for %s: %s",
330 str, cmd->argv[0], strerror(failed_errno));
331 errno = failed_errno;
332 return -1;
334 cmd->err = fderr[0];
337 trace_argv_printf(cmd->argv, "trace: run_command:");
338 fflush(NULL);
340 #ifndef GIT_WINDOWS_NATIVE
342 int notify_pipe[2];
343 if (pipe(notify_pipe))
344 notify_pipe[0] = notify_pipe[1] = -1;
346 cmd->pid = fork();
347 failed_errno = errno;
348 if (!cmd->pid) {
350 * Redirect the channel to write syscall error messages to
351 * before redirecting the process's stderr so that all die()
352 * in subsequent call paths use the parent's stderr.
354 if (cmd->no_stderr || need_err) {
355 child_err = dup(2);
356 set_cloexec(child_err);
358 set_die_routine(die_child);
359 set_error_routine(error_child);
361 close(notify_pipe[0]);
362 set_cloexec(notify_pipe[1]);
363 child_notifier = notify_pipe[1];
364 atexit(notify_parent);
366 if (cmd->no_stdin)
367 dup_devnull(0);
368 else if (need_in) {
369 dup2(fdin[0], 0);
370 close_pair(fdin);
371 } else if (cmd->in) {
372 dup2(cmd->in, 0);
373 close(cmd->in);
376 if (cmd->no_stderr)
377 dup_devnull(2);
378 else if (need_err) {
379 dup2(fderr[1], 2);
380 close_pair(fderr);
381 } else if (cmd->err > 1) {
382 dup2(cmd->err, 2);
383 close(cmd->err);
386 if (cmd->no_stdout)
387 dup_devnull(1);
388 else if (cmd->stdout_to_stderr)
389 dup2(2, 1);
390 else if (need_out) {
391 dup2(fdout[1], 1);
392 close_pair(fdout);
393 } else if (cmd->out > 1) {
394 dup2(cmd->out, 1);
395 close(cmd->out);
398 if (cmd->dir && chdir(cmd->dir))
399 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
400 cmd->dir);
401 if (cmd->env) {
402 for (; *cmd->env; cmd->env++) {
403 if (strchr(*cmd->env, '='))
404 putenv((char *)*cmd->env);
405 else
406 unsetenv(*cmd->env);
409 if (cmd->git_cmd)
410 execv_git_cmd(cmd->argv);
411 else if (cmd->use_shell)
412 execv_shell_cmd(cmd->argv);
413 else
414 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
415 if (errno == ENOENT) {
416 if (!cmd->silent_exec_failure)
417 error("cannot run %s: %s", cmd->argv[0],
418 strerror(ENOENT));
419 exit(127);
420 } else {
421 die_errno("cannot exec '%s'", cmd->argv[0]);
424 if (cmd->pid < 0)
425 error("cannot fork() for %s: %s", cmd->argv[0],
426 strerror(errno));
427 else if (cmd->clean_on_exit)
428 mark_child_for_cleanup(cmd->pid);
431 * Wait for child's execvp. If the execvp succeeds (or if fork()
432 * failed), EOF is seen immediately by the parent. Otherwise, the
433 * child process sends a single byte.
434 * Note that use of this infrastructure is completely advisory,
435 * therefore, we keep error checks minimal.
437 close(notify_pipe[1]);
438 if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
440 * At this point we know that fork() succeeded, but execvp()
441 * failed. Errors have been reported to our stderr.
443 wait_or_whine(cmd->pid, cmd->argv[0]);
444 failed_errno = errno;
445 cmd->pid = -1;
447 close(notify_pipe[0]);
449 #else
451 int fhin = 0, fhout = 1, fherr = 2;
452 const char **sargv = cmd->argv;
453 char **env = environ;
455 if (cmd->no_stdin)
456 fhin = open("/dev/null", O_RDWR);
457 else if (need_in)
458 fhin = dup(fdin[0]);
459 else if (cmd->in)
460 fhin = dup(cmd->in);
462 if (cmd->no_stderr)
463 fherr = open("/dev/null", O_RDWR);
464 else if (need_err)
465 fherr = dup(fderr[1]);
466 else if (cmd->err > 2)
467 fherr = dup(cmd->err);
469 if (cmd->no_stdout)
470 fhout = open("/dev/null", O_RDWR);
471 else if (cmd->stdout_to_stderr)
472 fhout = dup(fherr);
473 else if (need_out)
474 fhout = dup(fdout[1]);
475 else if (cmd->out > 1)
476 fhout = dup(cmd->out);
478 if (cmd->env)
479 env = make_augmented_environ(cmd->env);
481 if (cmd->git_cmd)
482 cmd->argv = prepare_git_cmd(cmd->argv);
483 else if (cmd->use_shell)
484 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;
591 static pthread_key_t async_die_counter;
593 static void *run_thread(void *data)
595 struct async *async = data;
596 intptr_t ret;
598 pthread_setspecific(async_key, async);
599 ret = async->proc(async->proc_in, async->proc_out, async->data);
600 return (void *)ret;
603 static NORETURN void die_async(const char *err, va_list params)
605 vreportf("fatal: ", err, params);
607 if (!pthread_equal(main_thread, pthread_self())) {
608 struct async *async = pthread_getspecific(async_key);
609 if (async->proc_in >= 0)
610 close(async->proc_in);
611 if (async->proc_out >= 0)
612 close(async->proc_out);
613 pthread_exit((void *)128);
616 exit(128);
619 static int async_die_is_recursing(void)
621 void *ret = pthread_getspecific(async_die_counter);
622 pthread_setspecific(async_die_counter, (void *)1);
623 return ret != NULL;
626 #endif
628 int start_async(struct async *async)
630 int need_in, need_out;
631 int fdin[2], fdout[2];
632 int proc_in, proc_out;
634 need_in = async->in < 0;
635 if (need_in) {
636 if (pipe(fdin) < 0) {
637 if (async->out > 0)
638 close(async->out);
639 return error("cannot create pipe: %s", strerror(errno));
641 async->in = fdin[1];
644 need_out = async->out < 0;
645 if (need_out) {
646 if (pipe(fdout) < 0) {
647 if (need_in)
648 close_pair(fdin);
649 else if (async->in)
650 close(async->in);
651 return error("cannot create pipe: %s", strerror(errno));
653 async->out = fdout[0];
656 if (need_in)
657 proc_in = fdin[0];
658 else if (async->in)
659 proc_in = async->in;
660 else
661 proc_in = -1;
663 if (need_out)
664 proc_out = fdout[1];
665 else if (async->out)
666 proc_out = async->out;
667 else
668 proc_out = -1;
670 #ifdef NO_PTHREADS
671 /* Flush stdio before fork() to avoid cloning buffers */
672 fflush(NULL);
674 async->pid = fork();
675 if (async->pid < 0) {
676 error("fork (async) failed: %s", strerror(errno));
677 goto error;
679 if (!async->pid) {
680 if (need_in)
681 close(fdin[1]);
682 if (need_out)
683 close(fdout[0]);
684 exit(!!async->proc(proc_in, proc_out, async->data));
687 mark_child_for_cleanup(async->pid);
689 if (need_in)
690 close(fdin[0]);
691 else if (async->in)
692 close(async->in);
694 if (need_out)
695 close(fdout[1]);
696 else if (async->out)
697 close(async->out);
698 #else
699 if (!main_thread_set) {
701 * We assume that the first time that start_async is called
702 * it is from the main thread.
704 main_thread_set = 1;
705 main_thread = pthread_self();
706 pthread_key_create(&async_key, NULL);
707 pthread_key_create(&async_die_counter, NULL);
708 set_die_routine(die_async);
709 set_die_is_recursing_routine(async_die_is_recursing);
712 if (proc_in >= 0)
713 set_cloexec(proc_in);
714 if (proc_out >= 0)
715 set_cloexec(proc_out);
716 async->proc_in = proc_in;
717 async->proc_out = proc_out;
719 int err = pthread_create(&async->tid, NULL, run_thread, async);
720 if (err) {
721 error("cannot create thread: %s", strerror(err));
722 goto error;
725 #endif
726 return 0;
728 error:
729 if (need_in)
730 close_pair(fdin);
731 else if (async->in)
732 close(async->in);
734 if (need_out)
735 close_pair(fdout);
736 else if (async->out)
737 close(async->out);
738 return -1;
741 int finish_async(struct async *async)
743 #ifdef NO_PTHREADS
744 return wait_or_whine(async->pid, "child process");
745 #else
746 void *ret = (void *)(intptr_t)(-1);
748 if (pthread_join(async->tid, &ret))
749 error("pthread_join failed");
750 return (int)(intptr_t)ret;
751 #endif
754 char *find_hook(const char *name)
756 char *path = git_path("hooks/%s", name);
757 if (access(path, X_OK) < 0)
758 path = NULL;
760 return path;
763 int run_hook_ve(const char *const *env, const char *name, va_list args)
765 struct child_process hook;
766 struct argv_array argv = ARGV_ARRAY_INIT;
767 const char *p;
768 int ret;
770 p = find_hook(name);
771 if (!p)
772 return 0;
774 argv_array_push(&argv, p);
776 while ((p = va_arg(args, const char *)))
777 argv_array_push(&argv, p);
779 memset(&hook, 0, sizeof(hook));
780 hook.argv = argv.argv;
781 hook.env = env;
782 hook.no_stdin = 1;
783 hook.stdout_to_stderr = 1;
785 ret = run_command(&hook);
786 argv_array_clear(&argv);
787 return ret;
790 int run_hook_le(const char *const *env, const char *name, ...)
792 va_list args;
793 int ret;
795 va_start(args, name);
796 ret = run_hook_ve(env, name, args);
797 va_end(args);
799 return ret;
802 int run_hook_with_custom_index(const char *index_file, const char *name, ...)
804 const char *hook_env[3] = { NULL };
805 char index[PATH_MAX];
806 va_list args;
807 int ret;
809 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
810 hook_env[0] = index;
812 va_start(args, name);
813 ret = run_hook_ve(hook_env, name, args);
814 va_end(args);
816 return ret;