2 #include "run-command.h"
5 #include "argv-array.h"
8 # define SHELL_PATH "/bin/sh"
11 struct child_to_clean {
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;
28 static void cleanup_children_on_signal(int sig)
30 cleanup_children(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));
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) {
69 static inline void close_pair(int fd[2])
76 static inline void dup_devnull(int to)
78 int fd = open("/dev/null", O_RDWR);
84 static char *locate_in_PATH(const char *file)
86 const char *p = getenv("PATH");
87 struct strbuf buf = STRBUF_INIT;
93 const char *end = strchrnul(p, ':');
97 /* POSIX specifies an empty entry as the current directory. */
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);
112 strbuf_release(&buf);
116 static int exists_in_PATH(const char *file)
118 char *r = locate_in_PATH(file);
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
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, '/'))
148 static const char **prepare_shell_cmd(const char **argv)
153 for (argc = 0; argv[argc]; argc++)
154 ; /* just counting */
155 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
156 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
159 die("BUG: shell command is empty");
161 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
163 nargv[nargc++] = SHELL_PATH;
165 nargv[nargc++] = "sh";
167 nargv[nargc++] = "-c";
170 nargv[nargc++] = argv[0];
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];
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);
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);
216 static void error_child(const char *err, va_list params)
218 vwritef(child_err, "error: ", err, params);
222 static inline void set_cloexec(int fd)
224 int flags = fcntl(fd, F_GETFD);
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;
233 int failed_errno = 0;
235 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
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.
253 } else if (WIFEXITED(status)) {
254 code = WEXITSTATUS(status);
256 * Convert special exit code when execvp failed.
260 failed_errno = ENOENT;
263 error("waitpid is confused (%s)", argv0);
266 clear_child_for_cleanup(pid);
268 errno = failed_errno;
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 = failed_errno;
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;
286 if (pipe(fdin) < 0) {
287 failed_errno = errno;
290 str = "standard input";
296 need_out = !cmd->no_stdout
297 && !cmd->stdout_to_stderr
300 if (pipe(fdout) < 0) {
301 failed_errno = errno;
306 str = "standard output";
312 need_err = !cmd->no_stderr && cmd->err < 0;
314 if (pipe(fderr) < 0) {
315 failed_errno = errno;
324 str = "standard error";
326 error("cannot create %s pipe for %s: %s",
327 str, cmd->argv[0], strerror(failed_errno));
328 errno = failed_errno;
334 trace_argv_printf(cmd->argv, "trace: run_command:");
340 if (pipe(notify_pipe))
341 notify_pipe[0] = notify_pipe[1] = -1;
346 * Redirect the channel to write syscall error messages to
347 * before redirecting the process's stderr so that all die()
348 * in subsequent call paths use the parent's stderr.
350 if (cmd->no_stderr || need_err) {
352 set_cloexec(child_err);
354 set_die_routine(die_child);
355 set_error_routine(error_child);
357 close(notify_pipe[0]);
358 set_cloexec(notify_pipe[1]);
359 child_notifier = notify_pipe[1];
360 atexit(notify_parent);
367 } else if (cmd->in) {
377 } else if (cmd->err > 1) {
384 else if (cmd->stdout_to_stderr)
389 } else if (cmd->out > 1) {
394 if (cmd->dir && chdir(cmd->dir))
395 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
398 for (; *cmd->env; cmd->env++) {
399 if (strchr(*cmd->env, '='))
400 putenv((char *)*cmd->env);
406 execv_git_cmd(cmd->argv);
407 } else if (cmd->use_shell) {
408 execv_shell_cmd(cmd->argv);
410 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
412 if (errno == ENOENT) {
413 if (!cmd->silent_exec_failure)
414 error("cannot run %s: %s", cmd->argv[0],
418 die_errno("cannot exec '%s'", cmd->argv[0]);
422 error("cannot fork() for %s: %s", cmd->argv[0],
423 strerror(failed_errno = errno));
424 else if (cmd->clean_on_exit)
425 mark_child_for_cleanup(cmd->pid);
428 * Wait for child's execvp. If the execvp succeeds (or if fork()
429 * failed), EOF is seen immediately by the parent. Otherwise, the
430 * child process sends a single byte.
431 * Note that use of this infrastructure is completely advisory,
432 * therefore, we keep error checks minimal.
434 close(notify_pipe[1]);
435 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
437 * At this point we know that fork() succeeded, but execvp()
438 * failed. Errors have been reported to our stderr.
440 wait_or_whine(cmd->pid, cmd->argv[0]);
441 failed_errno = errno;
444 close(notify_pipe[0]);
449 int fhin = 0, fhout = 1, fherr = 2;
450 const char **sargv = cmd->argv;
451 char **env = environ;
454 fhin = open("/dev/null", O_RDWR);
461 fherr = open("/dev/null", O_RDWR);
463 fherr = dup(fderr[1]);
464 else if (cmd->err > 2)
465 fherr = dup(cmd->err);
468 fhout = open("/dev/null", O_RDWR);
469 else if (cmd->stdout_to_stderr)
472 fhout = dup(fdout[1]);
473 else if (cmd->out > 1)
474 fhout = dup(cmd->out);
477 env = make_augmented_environ(cmd->env);
480 cmd->argv = prepare_git_cmd(cmd->argv);
481 } else if (cmd->use_shell) {
482 cmd->argv = prepare_shell_cmd(cmd->argv);
485 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
487 failed_errno = errno;
488 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
489 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
490 if (cmd->clean_on_exit && cmd->pid >= 0)
491 mark_child_for_cleanup(cmd->pid);
521 errno = failed_errno;
543 int finish_command(struct child_process *cmd)
545 return wait_or_whine(cmd->pid, cmd->argv[0]);
548 int run_command(struct child_process *cmd)
550 int code = start_command(cmd);
553 return finish_command(cmd);
556 static void prepare_run_command_v_opt(struct child_process *cmd,
560 memset(cmd, 0, sizeof(*cmd));
562 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
563 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
564 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
565 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
566 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
567 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
570 int run_command_v_opt(const char **argv, int opt)
572 struct child_process cmd;
573 prepare_run_command_v_opt(&cmd, argv, opt);
574 return run_command(&cmd);
577 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
579 struct child_process cmd;
580 prepare_run_command_v_opt(&cmd, argv, opt);
583 return run_command(&cmd);
587 static pthread_t main_thread;
588 static int main_thread_set;
589 static pthread_key_t async_key;
591 static void *run_thread(void *data)
593 struct async *async = data;
596 pthread_setspecific(async_key, async);
597 ret = async->proc(async->proc_in, async->proc_out, async->data);
601 static NORETURN void die_async(const char *err, va_list params)
603 vreportf("fatal: ", err, params);
605 if (!pthread_equal(main_thread, pthread_self())) {
606 struct async *async = pthread_getspecific(async_key);
607 if (async->proc_in >= 0)
608 close(async->proc_in);
609 if (async->proc_out >= 0)
610 close(async->proc_out);
611 pthread_exit((void *)128);
618 int start_async(struct async *async)
620 int need_in, need_out;
621 int fdin[2], fdout[2];
622 int proc_in, proc_out;
624 need_in = async->in < 0;
626 if (pipe(fdin) < 0) {
629 return error("cannot create pipe: %s", strerror(errno));
634 need_out = async->out < 0;
636 if (pipe(fdout) < 0) {
641 return error("cannot create pipe: %s", strerror(errno));
643 async->out = fdout[0];
656 proc_out = async->out;
661 /* Flush stdio before fork() to avoid cloning buffers */
665 if (async->pid < 0) {
666 error("fork (async) failed: %s", strerror(errno));
674 exit(!!async->proc(proc_in, proc_out, async->data));
677 mark_child_for_cleanup(async->pid);
689 if (!main_thread_set) {
691 * We assume that the first time that start_async is called
692 * it is from the main thread.
695 main_thread = pthread_self();
696 pthread_key_create(&async_key, NULL);
697 set_die_routine(die_async);
701 set_cloexec(proc_in);
703 set_cloexec(proc_out);
704 async->proc_in = proc_in;
705 async->proc_out = proc_out;
707 int err = pthread_create(&async->tid, NULL, run_thread, async);
709 error("cannot create thread: %s", strerror(err));
729 int finish_async(struct async *async)
732 return wait_or_whine(async->pid, "child process");
734 void *ret = (void *)(intptr_t)(-1);
736 if (pthread_join(async->tid, &ret))
737 error("pthread_join failed");
738 return (int)(intptr_t)ret;
742 char *find_hook(const char *name)
744 char *path = git_path("hooks/%s", name);
745 if (access(path, X_OK) < 0)
751 int run_hook(const char *index_file, const char *name, ...)
753 struct child_process hook;
754 struct argv_array argv = ARGV_ARRAY_INIT;
755 const char *p, *env[2];
756 char index[PATH_MAX];
764 argv_array_push(&argv, p);
766 va_start(args, name);
767 while ((p = va_arg(args, const char *)))
768 argv_array_push(&argv, p);
771 memset(&hook, 0, sizeof(hook));
772 hook.argv = argv.argv;
774 hook.stdout_to_stderr = 1;
776 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
782 ret = run_command(&hook);
783 argv_array_clear(&argv);