2 #include "run-command.h"
5 #include "argv-array.h"
7 struct child_to_clean {
9 struct child_to_clean *next;
11 static struct child_to_clean *children_to_clean;
12 static int installed_child_cleanup_handler;
14 static void cleanup_children(int sig)
16 while (children_to_clean) {
17 struct child_to_clean *p = children_to_clean;
18 children_to_clean = p->next;
24 static void cleanup_children_on_signal(int sig)
26 cleanup_children(sig);
31 static void cleanup_children_on_exit(void)
33 cleanup_children(SIGTERM);
36 static void mark_child_for_cleanup(pid_t pid)
38 struct child_to_clean *p = xmalloc(sizeof(*p));
40 p->next = children_to_clean;
41 children_to_clean = p;
43 if (!installed_child_cleanup_handler) {
44 atexit(cleanup_children_on_exit);
45 sigchain_push_common(cleanup_children_on_signal);
46 installed_child_cleanup_handler = 1;
50 static void clear_child_for_cleanup(pid_t pid)
52 struct child_to_clean **last, *p;
54 last = &children_to_clean;
55 for (p = children_to_clean; p; p = p->next) {
64 static inline void close_pair(int fd[2])
71 static inline void dup_devnull(int to)
73 int fd = open("/dev/null", O_RDWR);
79 static char *locate_in_PATH(const char *file)
81 const char *p = getenv("PATH");
82 struct strbuf buf = STRBUF_INIT;
88 const char *end = strchrnul(p, ':');
92 /* POSIX specifies an empty entry as the current directory. */
94 strbuf_add(&buf, p, end - p);
95 strbuf_addch(&buf, '/');
97 strbuf_addstr(&buf, file);
99 if (!access(buf.buf, F_OK))
100 return strbuf_detach(&buf, NULL);
107 strbuf_release(&buf);
111 static int exists_in_PATH(const char *file)
113 char *r = locate_in_PATH(file);
118 int sane_execvp(const char *file, char * const argv[])
120 if (!execvp(file, argv))
121 return 0; /* cannot happen ;-) */
124 * When a command can't be found because one of the directories
125 * listed in $PATH is unsearchable, execvp reports EACCES, but
126 * careful usability testing (read: analysis of occasional bug
127 * reports) reveals that "No such file or directory" is more
130 * We avoid commands with "/", because execvp will not do $PATH
131 * lookups in that case.
133 * The reassignment of EACCES to errno looks like a no-op below,
134 * but we need to protect against exists_in_PATH overwriting errno.
136 if (errno == EACCES && !strchr(file, '/'))
137 errno = exists_in_PATH(file) ? EACCES : ENOENT;
141 static const char **prepare_shell_cmd(const char **argv)
146 for (argc = 0; argv[argc]; argc++)
147 ; /* just counting */
148 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
149 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
152 die("BUG: shell command is empty");
154 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
155 nargv[nargc++] = "sh";
156 nargv[nargc++] = "-c";
159 nargv[nargc++] = argv[0];
161 struct strbuf arg0 = STRBUF_INIT;
162 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
163 nargv[nargc++] = strbuf_detach(&arg0, NULL);
167 for (argc = 0; argv[argc]; argc++)
168 nargv[nargc++] = argv[argc];
175 static int execv_shell_cmd(const char **argv)
177 const char **nargv = prepare_shell_cmd(argv);
178 trace_argv_printf(nargv, "trace: exec:");
179 sane_execvp(nargv[0], (char **)nargv);
186 static int child_err = 2;
187 static int child_notifier = -1;
189 static void notify_parent(void)
192 * execvp failed. If possible, we'd like to let start_command
193 * know, so failures like ENOENT can be handled right away; but
194 * otherwise, finish_command will still report the error.
196 xwrite(child_notifier, "", 1);
199 static NORETURN void die_child(const char *err, va_list params)
201 vwritef(child_err, "fatal: ", err, params);
205 static void error_child(const char *err, va_list params)
207 vwritef(child_err, "error: ", err, params);
211 static inline void set_cloexec(int fd)
213 int flags = fcntl(fd, F_GETFD);
215 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
218 static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
220 int status, code = -1;
222 int failed_errno = 0;
224 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
228 failed_errno = errno;
229 error("waitpid for %s failed: %s", argv0, strerror(errno));
230 } else if (waiting != pid) {
231 error("waitpid is confused (%s)", argv0);
232 } else if (WIFSIGNALED(status)) {
233 code = WTERMSIG(status);
234 error("%s died of signal %d", argv0, code);
236 * This return value is chosen so that code & 0xff
237 * mimics the exit code that a POSIX shell would report for
238 * a program that died from this signal.
241 } else if (WIFEXITED(status)) {
242 code = WEXITSTATUS(status);
244 * Convert special exit code when execvp failed.
248 failed_errno = ENOENT;
251 error("waitpid is confused (%s)", argv0);
254 clear_child_for_cleanup(pid);
256 errno = failed_errno;
260 int start_command(struct child_process *cmd)
262 int need_in, need_out, need_err;
263 int fdin[2], fdout[2], fderr[2];
264 int failed_errno = failed_errno;
267 * In case of errors we must keep the promise to close FDs
268 * that have been passed in via ->in and ->out.
271 need_in = !cmd->no_stdin && cmd->in < 0;
273 if (pipe(fdin) < 0) {
274 failed_errno = errno;
282 need_out = !cmd->no_stdout
283 && !cmd->stdout_to_stderr
286 if (pipe(fdout) < 0) {
287 failed_errno = errno;
297 need_err = !cmd->no_stderr && cmd->err < 0;
299 if (pipe(fderr) < 0) {
300 failed_errno = errno;
310 error("cannot create pipe for %s: %s",
311 cmd->argv[0], strerror(failed_errno));
312 errno = failed_errno;
318 trace_argv_printf(cmd->argv, "trace: run_command:");
324 if (pipe(notify_pipe))
325 notify_pipe[0] = notify_pipe[1] = -1;
330 * Redirect the channel to write syscall error messages to
331 * before redirecting the process's stderr so that all die()
332 * in subsequent call paths use the parent's stderr.
334 if (cmd->no_stderr || need_err) {
336 set_cloexec(child_err);
338 set_die_routine(die_child);
339 set_error_routine(error_child);
341 close(notify_pipe[0]);
342 set_cloexec(notify_pipe[1]);
343 child_notifier = notify_pipe[1];
344 atexit(notify_parent);
351 } else if (cmd->in) {
361 } else if (cmd->err > 1) {
368 else if (cmd->stdout_to_stderr)
373 } else if (cmd->out > 1) {
378 if (cmd->dir && chdir(cmd->dir))
379 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
382 for (; *cmd->env; cmd->env++) {
383 if (strchr(*cmd->env, '='))
384 putenv((char *)*cmd->env);
389 if (cmd->preexec_cb) {
391 * We cannot predict what the pre-exec callback does.
392 * Forgo parent notification.
394 close(child_notifier);
400 execv_git_cmd(cmd->argv);
401 } else if (cmd->use_shell) {
402 execv_shell_cmd(cmd->argv);
404 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
406 if (errno == ENOENT) {
407 if (!cmd->silent_exec_failure)
408 error("cannot run %s: %s", cmd->argv[0],
412 die_errno("cannot exec '%s'", cmd->argv[0]);
416 error("cannot fork() for %s: %s", cmd->argv[0],
417 strerror(failed_errno = errno));
418 else if (cmd->clean_on_exit)
419 mark_child_for_cleanup(cmd->pid);
422 * Wait for child's execvp. If the execvp succeeds (or if fork()
423 * failed), EOF is seen immediately by the parent. Otherwise, the
424 * child process sends a single byte.
425 * Note that use of this infrastructure is completely advisory,
426 * therefore, we keep error checks minimal.
428 close(notify_pipe[1]);
429 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
431 * At this point we know that fork() succeeded, but execvp()
432 * failed. Errors have been reported to our stderr.
434 wait_or_whine(cmd->pid, cmd->argv[0],
435 cmd->silent_exec_failure);
436 failed_errno = errno;
439 close(notify_pipe[0]);
444 int fhin = 0, fhout = 1, fherr = 2;
445 const char **sargv = cmd->argv;
446 char **env = environ;
449 fhin = open("/dev/null", O_RDWR);
456 fherr = open("/dev/null", O_RDWR);
458 fherr = dup(fderr[1]);
459 else if (cmd->err > 2)
460 fherr = dup(cmd->err);
463 fhout = open("/dev/null", O_RDWR);
464 else if (cmd->stdout_to_stderr)
467 fhout = dup(fdout[1]);
468 else if (cmd->out > 1)
469 fhout = dup(cmd->out);
472 env = make_augmented_environ(cmd->env);
475 cmd->argv = prepare_git_cmd(cmd->argv);
476 } else if (cmd->use_shell) {
477 cmd->argv = prepare_shell_cmd(cmd->argv);
480 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
482 failed_errno = errno;
483 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
484 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
485 if (cmd->clean_on_exit && cmd->pid >= 0)
486 mark_child_for_cleanup(cmd->pid);
516 errno = failed_errno;
538 int finish_command(struct child_process *cmd)
540 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
543 int run_command(struct child_process *cmd)
545 int code = start_command(cmd);
548 return finish_command(cmd);
551 static void prepare_run_command_v_opt(struct child_process *cmd,
555 memset(cmd, 0, sizeof(*cmd));
557 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
558 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
559 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
560 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
561 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
562 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
565 int run_command_v_opt(const char **argv, int opt)
567 struct child_process cmd;
568 prepare_run_command_v_opt(&cmd, argv, opt);
569 return run_command(&cmd);
572 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
574 struct child_process cmd;
575 prepare_run_command_v_opt(&cmd, argv, opt);
578 return run_command(&cmd);
582 static pthread_t main_thread;
583 static int main_thread_set;
584 static pthread_key_t async_key;
586 static void *run_thread(void *data)
588 struct async *async = data;
591 pthread_setspecific(async_key, async);
592 ret = async->proc(async->proc_in, async->proc_out, async->data);
596 static NORETURN void die_async(const char *err, va_list params)
598 vreportf("fatal: ", err, params);
600 if (!pthread_equal(main_thread, pthread_self())) {
601 struct async *async = pthread_getspecific(async_key);
602 if (async->proc_in >= 0)
603 close(async->proc_in);
604 if (async->proc_out >= 0)
605 close(async->proc_out);
606 pthread_exit((void *)128);
613 int start_async(struct async *async)
615 int need_in, need_out;
616 int fdin[2], fdout[2];
617 int proc_in, proc_out;
619 need_in = async->in < 0;
621 if (pipe(fdin) < 0) {
624 return error("cannot create pipe: %s", strerror(errno));
629 need_out = async->out < 0;
631 if (pipe(fdout) < 0) {
636 return error("cannot create pipe: %s", strerror(errno));
638 async->out = fdout[0];
651 proc_out = async->out;
656 /* Flush stdio before fork() to avoid cloning buffers */
660 if (async->pid < 0) {
661 error("fork (async) failed: %s", strerror(errno));
669 exit(!!async->proc(proc_in, proc_out, async->data));
672 mark_child_for_cleanup(async->pid);
684 if (!main_thread_set) {
686 * We assume that the first time that start_async is called
687 * it is from the main thread.
690 main_thread = pthread_self();
691 pthread_key_create(&async_key, NULL);
692 set_die_routine(die_async);
696 set_cloexec(proc_in);
698 set_cloexec(proc_out);
699 async->proc_in = proc_in;
700 async->proc_out = proc_out;
702 int err = pthread_create(&async->tid, NULL, run_thread, async);
704 error("cannot create thread: %s", strerror(err));
724 int finish_async(struct async *async)
727 return wait_or_whine(async->pid, "child process", 0);
729 void *ret = (void *)(intptr_t)(-1);
731 if (pthread_join(async->tid, &ret))
732 error("pthread_join failed");
733 return (int)(intptr_t)ret;
737 int run_hook(const char *index_file, const char *name, ...)
739 struct child_process hook;
740 struct argv_array argv = ARGV_ARRAY_INIT;
741 const char *p, *env[2];
742 char index[PATH_MAX];
746 if (access(git_path("hooks/%s", name), X_OK) < 0)
749 va_start(args, name);
750 argv_array_push(&argv, git_path("hooks/%s", name));
751 while ((p = va_arg(args, const char *)))
752 argv_array_push(&argv, p);
755 memset(&hook, 0, sizeof(hook));
756 hook.argv = argv.argv;
758 hook.stdout_to_stderr = 1;
760 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
766 ret = run_command(&hook);
767 argv_array_clear(&argv);