[thirdparty/git.git] / run-command.c

#include "cache.h"
#include "run-command.h"
#include "exec_cmd.h"

static inline void close_pair(int fd[2])
{
	close(fd[0]);
	close(fd[1]);
}

#ifndef WIN32
static inline void dup_devnull(int to)
{
	int fd = open("/dev/null", O_RDWR);
	dup2(fd, to);
	close(fd);
}
#endif

static const char **prepare_shell_cmd(const char **argv)
{
	int argc, nargc = 0;
	const char **nargv;

	for (argc = 0; argv[argc]; argc++)
		; /* just counting */
	/* +1 for NULL, +3 for "sh -c" plus extra $0 */
	nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));

	if (argc < 1)
		die("BUG: shell command is empty");

	if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
		nargv[nargc++] = "sh";
		nargv[nargc++] = "-c";

		if (argc < 2)
			nargv[nargc++] = argv[0];
		else {
			struct strbuf arg0 = STRBUF_INIT;
			strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
			nargv[nargc++] = strbuf_detach(&arg0, NULL);
		}
	}

	for (argc = 0; argv[argc]; argc++)
		nargv[nargc++] = argv[argc];
	nargv[nargc] = NULL;

	return nargv;
}

#ifndef WIN32
static int execv_shell_cmd(const char **argv)
{
	const char **nargv = prepare_shell_cmd(argv);
	trace_argv_printf(nargv, "trace: exec:");
	execvp(nargv[0], (char **)nargv);
	free(nargv);
	return -1;
}
#endif

#ifndef WIN32
static int child_err = 2;
static int child_notifier = -1;

static void notify_parent(void)
{
	write(child_notifier, "", 1);
}

static NORETURN void die_child(const char *err, va_list params)
{
	char msg[4096];
	int len = vsnprintf(msg, sizeof(msg), err, params);
	if (len > sizeof(msg))
		len = sizeof(msg);

	write(child_err, "fatal: ", 7);
	write(child_err, msg, len);
	write(child_err, "\n", 1);
	exit(128);
}
#endif

static inline void set_cloexec(int fd)
{
	int flags = fcntl(fd, F_GETFD);
	if (flags >= 0)
		fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
}

static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
{
	int status, code = -1;
	pid_t waiting;
	int failed_errno = 0;

	while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
		;	/* nothing */

	if (waiting < 0) {
		failed_errno = errno;
		error("waitpid for %s failed: %s", argv0, strerror(errno));
	} else if (waiting != pid) {
		error("waitpid is confused (%s)", argv0);
	} else if (WIFSIGNALED(status)) {
		code = WTERMSIG(status);
		error("%s died of signal %d", argv0, code);
		/*
		 * This return value is chosen so that code & 0xff
		 * mimics the exit code that a POSIX shell would report for
		 * a program that died from this signal.
		 */
		code -= 128;
	} else if (WIFEXITED(status)) {
		code = WEXITSTATUS(status);
		/*
		 * Convert special exit code when execvp failed.
		 */
		if (code == 127) {
			code = -1;
			failed_errno = ENOENT;
			if (!silent_exec_failure)
				error("cannot run %s: %s", argv0,
					strerror(ENOENT));
		}
	} else {
		error("waitpid is confused (%s)", argv0);
	}
	errno = failed_errno;
	return code;
}

int start_command(struct child_process *cmd)
{
	int need_in, need_out, need_err;
	int fdin[2], fdout[2], fderr[2];
	int failed_errno = failed_errno;

	/*
	 * In case of errors we must keep the promise to close FDs
	 * that have been passed in via ->in and ->out.
	 */

	need_in = !cmd->no_stdin && cmd->in < 0;
	if (need_in) {
		if (pipe(fdin) < 0) {
			failed_errno = errno;
			if (cmd->out > 0)
				close(cmd->out);
			goto fail_pipe;
		}
		cmd->in = fdin[1];
	}

	need_out = !cmd->no_stdout
		&& !cmd->stdout_to_stderr
		&& cmd->out < 0;
	if (need_out) {
		if (pipe(fdout) < 0) {
			failed_errno = errno;
			if (need_in)
				close_pair(fdin);
			else if (cmd->in)
				close(cmd->in);
			goto fail_pipe;
		}
		cmd->out = fdout[0];
	}

	need_err = !cmd->no_stderr && cmd->err < 0;
	if (need_err) {
		if (pipe(fderr) < 0) {
			failed_errno = errno;
			if (need_in)
				close_pair(fdin);
			else if (cmd->in)
				close(cmd->in);
			if (need_out)
				close_pair(fdout);
			else if (cmd->out)
				close(cmd->out);
fail_pipe:
			error("cannot create pipe for %s: %s",
				cmd->argv[0], strerror(failed_errno));
			errno = failed_errno;
			return -1;
		}
		cmd->err = fderr[0];
	}

	trace_argv_printf(cmd->argv, "trace: run_command:");

#ifndef WIN32
{
	int notify_pipe[2];
	if (pipe(notify_pipe))
		notify_pipe[0] = notify_pipe[1] = -1;

	fflush(NULL);
	cmd->pid = fork();
	if (!cmd->pid) {
		/*
		 * Redirect the channel to write syscall error messages to
		 * before redirecting the process's stderr so that all die()
		 * in subsequent call paths use the parent's stderr.
		 */
		if (cmd->no_stderr || need_err) {
			child_err = dup(2);
			set_cloexec(child_err);
		}
		set_die_routine(die_child);

		close(notify_pipe[0]);
		set_cloexec(notify_pipe[1]);
		child_notifier = notify_pipe[1];
		atexit(notify_parent);

		if (cmd->no_stdin)
			dup_devnull(0);
		else if (need_in) {
			dup2(fdin[0], 0);
			close_pair(fdin);
		} else if (cmd->in) {
			dup2(cmd->in, 0);
			close(cmd->in);
		}

		if (cmd->no_stderr)
			dup_devnull(2);
		else if (need_err) {
			dup2(fderr[1], 2);
			close_pair(fderr);
		} else if (cmd->err > 1) {
			dup2(cmd->err, 2);
			close(cmd->err);
		}

		if (cmd->no_stdout)
			dup_devnull(1);
		else if (cmd->stdout_to_stderr)
			dup2(2, 1);
		else if (need_out) {
			dup2(fdout[1], 1);
			close_pair(fdout);
		} else if (cmd->out > 1) {
			dup2(cmd->out, 1);
			close(cmd->out);
		}

		if (cmd->dir && chdir(cmd->dir))
			die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
			    cmd->dir);
		if (cmd->env) {
			for (; *cmd->env; cmd->env++) {
				if (strchr(*cmd->env, '='))
					putenv((char *)*cmd->env);
				else
					unsetenv(*cmd->env);
			}
		}
		if (cmd->preexec_cb) {
			/*
			 * We cannot predict what the pre-exec callback does.
			 * Forgo parent notification.
			 */
			close(child_notifier);
			child_notifier = -1;

			cmd->preexec_cb();
		}
		if (cmd->git_cmd) {
			execv_git_cmd(cmd->argv);
		} else if (cmd->use_shell) {
			execv_shell_cmd(cmd->argv);
		} else {
			execvp(cmd->argv[0], (char *const*) cmd->argv);
		}
		/*
		 * Do not check for cmd->silent_exec_failure; the parent
		 * process will check it when it sees this exit code.
		 */
		if (errno == ENOENT)
			exit(127);
		else
			die_errno("cannot exec '%s'", cmd->argv[0]);
	}
	if (cmd->pid < 0)
		error("cannot fork() for %s: %s", cmd->argv[0],
			strerror(failed_errno = errno));

	/*
	 * Wait for child's execvp. If the execvp succeeds (or if fork()
	 * failed), EOF is seen immediately by the parent. Otherwise, the
	 * child process sends a single byte.
	 * Note that use of this infrastructure is completely advisory,
	 * therefore, we keep error checks minimal.
	 */
	close(notify_pipe[1]);
	if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
		/*
		 * At this point we know that fork() succeeded, but execvp()
		 * failed. Errors have been reported to our stderr.
		 */
		wait_or_whine(cmd->pid, cmd->argv[0],
			      cmd->silent_exec_failure);
		failed_errno = errno;
		cmd->pid = -1;
	}
	close(notify_pipe[0]);
}
#else
{
	int fhin = 0, fhout = 1, fherr = 2;
	const char **sargv = cmd->argv;
	char **env = environ;

	if (cmd->no_stdin)
		fhin = open("/dev/null", O_RDWR);
	else if (need_in)
		fhin = dup(fdin[0]);
	else if (cmd->in)
		fhin = dup(cmd->in);

	if (cmd->no_stderr)
		fherr = open("/dev/null", O_RDWR);
	else if (need_err)
		fherr = dup(fderr[1]);
	else if (cmd->err > 2)
		fherr = dup(cmd->err);

	if (cmd->no_stdout)
		fhout = open("/dev/null", O_RDWR);
	else if (cmd->stdout_to_stderr)
		fhout = dup(fherr);
	else if (need_out)
		fhout = dup(fdout[1]);
	else if (cmd->out > 1)
		fhout = dup(cmd->out);

	if (cmd->dir)
		die("chdir in start_command() not implemented");
	if (cmd->env)
		env = make_augmented_environ(cmd->env);

	if (cmd->git_cmd) {
		cmd->argv = prepare_git_cmd(cmd->argv);
	} else if (cmd->use_shell) {
		cmd->argv = prepare_shell_cmd(cmd->argv);
	}

	cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
				  fhin, fhout, fherr);
	failed_errno = errno;
	if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
		error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));

	if (cmd->env)
		free_environ(env);
	if (cmd->git_cmd)
		free(cmd->argv);

	cmd->argv = sargv;
	if (fhin != 0)
		close(fhin);
	if (fhout != 1)
		close(fhout);
	if (fherr != 2)
		close(fherr);
}
#endif

	if (cmd->pid < 0) {
		if (need_in)
			close_pair(fdin);
		else if (cmd->in)
			close(cmd->in);
		if (need_out)
			close_pair(fdout);
		else if (cmd->out)
			close(cmd->out);
		if (need_err)
			close_pair(fderr);
		errno = failed_errno;
		return -1;
	}

	if (need_in)
		close(fdin[0]);
	else if (cmd->in)
		close(cmd->in);

	if (need_out)
		close(fdout[1]);
	else if (cmd->out)
		close(cmd->out);

	if (need_err)
		close(fderr[1]);
	else if (cmd->err)
		close(cmd->err);

	return 0;
}

int finish_command(struct child_process *cmd)
{
	return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
}

int run_command(struct child_process *cmd)
{
	int code = start_command(cmd);
	if (code)
		return code;
	return finish_command(cmd);
}

static void prepare_run_command_v_opt(struct child_process *cmd,
				      const char **argv,
				      int opt)
{
	memset(cmd, 0, sizeof(*cmd));
	cmd->argv = argv;
	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
	cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
	cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
	cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
}

int run_command_v_opt(const char **argv, int opt)
{
	struct child_process cmd;
	prepare_run_command_v_opt(&cmd, argv, opt);
	return run_command(&cmd);
}

int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
{
	struct child_process cmd;
	prepare_run_command_v_opt(&cmd, argv, opt);
	cmd.dir = dir;
	cmd.env = env;
	return run_command(&cmd);
}

#ifdef ASYNC_AS_THREAD
static void *run_thread(void *data)
{
	struct async *async = data;
	intptr_t ret = async->proc(async->proc_in, async->proc_out, async->data);
	return (void *)ret;
}
#endif

int start_async(struct async *async)
{
	int need_in, need_out;
	int fdin[2], fdout[2];
	int proc_in, proc_out;

	need_in = async->in < 0;
	if (need_in) {
		if (pipe(fdin) < 0) {
			if (async->out > 0)
				close(async->out);
			return error("cannot create pipe: %s", strerror(errno));
		}
		async->in = fdin[1];
	}

	need_out = async->out < 0;
	if (need_out) {
		if (pipe(fdout) < 0) {
			if (need_in)
				close_pair(fdin);
			else if (async->in)
				close(async->in);
			return error("cannot create pipe: %s", strerror(errno));
		}
		async->out = fdout[0];
	}

	if (need_in)
		proc_in = fdin[0];
	else if (async->in)
		proc_in = async->in;
	else
		proc_in = -1;

	if (need_out)
		proc_out = fdout[1];
	else if (async->out)
		proc_out = async->out;
	else
		proc_out = -1;

#ifndef ASYNC_AS_THREAD
	/* Flush stdio before fork() to avoid cloning buffers */
	fflush(NULL);

	async->pid = fork();
	if (async->pid < 0) {
		error("fork (async) failed: %s", strerror(errno));
		goto error;
	}
	if (!async->pid) {
		if (need_in)
			close(fdin[1]);
		if (need_out)
			close(fdout[0]);
		exit(!!async->proc(proc_in, proc_out, async->data));
	}

	if (need_in)
		close(fdin[0]);
	else if (async->in)
		close(async->in);

	if (need_out)
		close(fdout[1]);
	else if (async->out)
		close(async->out);
#else
	if (proc_in >= 0)
		set_cloexec(proc_in);
	if (proc_out >= 0)
		set_cloexec(proc_out);
	async->proc_in = proc_in;
	async->proc_out = proc_out;
	{
		int err = pthread_create(&async->tid, NULL, run_thread, async);
		if (err) {
			error("cannot create thread: %s", strerror(err));
			goto error;
		}
	}
#endif
	return 0;

error:
	if (need_in)
		close_pair(fdin);
	else if (async->in)
		close(async->in);

	if (need_out)
		close_pair(fdout);
	else if (async->out)
		close(async->out);
	return -1;
}

int finish_async(struct async *async)
{
#ifndef ASYNC_AS_THREAD
	return wait_or_whine(async->pid, "child process", 0);
#else
	void *ret = (void *)(intptr_t)(-1);

	if (pthread_join(async->tid, &ret))
		error("pthread_join failed");
	return (int)(intptr_t)ret;
#endif
}

int run_hook(const char *index_file, const char *name, ...)
{
	struct child_process hook;
	const char **argv = NULL, *env[2];
	char index[PATH_MAX];
	va_list args;
	int ret;
	size_t i = 0, alloc = 0;

	if (access(git_path("hooks/%s", name), X_OK) < 0)
		return 0;

	va_start(args, name);
	ALLOC_GROW(argv, i + 1, alloc);
	argv[i++] = git_path("hooks/%s", name);
	while (argv[i-1]) {
		ALLOC_GROW(argv, i + 1, alloc);
		argv[i++] = va_arg(args, const char *);
	}
	va_end(args);

	memset(&hook, 0, sizeof(hook));
	hook.argv = argv;
	hook.no_stdin = 1;
	hook.stdout_to_stderr = 1;
	if (index_file) {
		snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
		env[0] = index;
		env[1] = NULL;
		hook.env = env;
	}

	ret = run_command(&hook);
	free(argv);
	return ret;
}
Commit	Line	Data
b1bf95bb JW	1	#include "cache.h"
b1bf95bb JW	2	#include "run-command.h"
77cb17e9	3	#include "exec_cmd.h"
b1bf95bb	4
9dc09c76 SP	5	static inline void close_pair(int fd[2])
	6	{
	7	close(fd[0]);
	8	close(fd[1]);
	9	}
	10
75301f90	11	#ifndef WIN32
e4507ae8 SP	12	static inline void dup_devnull(int to)
	13	{
	14	int fd = open("/dev/null", O_RDWR);
	15	dup2(fd, to);
	16	close(fd);
	17	}
75301f90	18	#endif
e4507ae8	19
8dba1e63 JK	20	static const char prepare_shell_cmd(const char argv)
	21	{
	22	int argc, nargc = 0;
	23	const char **nargv;
	24
	25	for (argc = 0; argv[argc]; argc++)
	26	; /* just counting */
	27	/* +1 for NULL, +3 for "sh -c" plus extra $0 */
	28	nargv = xmalloc(sizeof(nargv) (argc + 1 + 3));
	29
	30	if (argc < 1)
	31	die("BUG: shell command is empty");
	32
f445644f JK	33	if (strcspn(argv[0], "\|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
	34	nargv[nargc++] = "sh";
	35	nargv[nargc++] = "-c";
8dba1e63	36
f445644f JK	37	if (argc < 2)
	38	nargv[nargc++] = argv[0];
	39	else {
	40	struct strbuf arg0 = STRBUF_INIT;
	41	strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
	42	nargv[nargc++] = strbuf_detach(&arg0, NULL);
	43	}
8dba1e63 JK	44	}
	45
	46	for (argc = 0; argv[argc]; argc++)
	47	nargv[nargc++] = argv[argc];
	48	nargv[nargc] = NULL;
	49
	50	return nargv;
	51	}
	52
	53	#ifndef WIN32
	54	static int execv_shell_cmd(const char **argv)
	55	{
	56	const char **nargv = prepare_shell_cmd(argv);
	57	trace_argv_printf(nargv, "trace: exec:");
	58	execvp(nargv[0], (char **)nargv);
	59	free(nargv);
	60	return -1;
	61	}
	62	#endif
	63
a5487ddf JS	64	#ifndef WIN32
a5487ddf JS	65	static int child_err = 2;
2b541bf8 JS	66	static int child_notifier = -1;
	67
	68	static void notify_parent(void)
	69	{
	70	write(child_notifier, "", 1);
	71	}
a5487ddf JS	72
	73	static NORETURN void die_child(const char *err, va_list params)
	74	{
	75	char msg[4096];
	76	int len = vsnprintf(msg, sizeof(msg), err, params);
	77	if (len > sizeof(msg))
	78	len = sizeof(msg);
	79
	80	write(child_err, "fatal: ", 7);
	81	write(child_err, msg, len);
	82	write(child_err, "\n", 1);
	83	exit(128);
	84	}
200a76b7	85	#endif
a5487ddf JS	86
	87	static inline void set_cloexec(int fd)
	88	{
	89	int flags = fcntl(fd, F_GETFD);
	90	if (flags >= 0)
	91	fcntl(fd, F_SETFD, flags \| FD_CLOEXEC);
	92	}
a5487ddf	93
ab0b41da JS	94	static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
	95	{
	96	int status, code = -1;
	97	pid_t waiting;
	98	int failed_errno = 0;
	99
	100	while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
	101	; /* nothing */
	102
	103	if (waiting < 0) {
	104	failed_errno = errno;
	105	error("waitpid for %s failed: %s", argv0, strerror(errno));
	106	} else if (waiting != pid) {
	107	error("waitpid is confused (%s)", argv0);
	108	} else if (WIFSIGNALED(status)) {
	109	code = WTERMSIG(status);
	110	error("%s died of signal %d", argv0, code);
	111	/*
	112	* This return value is chosen so that code & 0xff
	113	* mimics the exit code that a POSIX shell would report for
	114	* a program that died from this signal.
	115	*/
	116	code -= 128;
	117	} else if (WIFEXITED(status)) {
	118	code = WEXITSTATUS(status);
	119	/*
	120	* Convert special exit code when execvp failed.
	121	*/
	122	if (code == 127) {
	123	code = -1;
	124	failed_errno = ENOENT;
	125	if (!silent_exec_failure)
	126	error("cannot run %s: %s", argv0,
	127	strerror(ENOENT));
	128	}
	129	} else {
	130	error("waitpid is confused (%s)", argv0);
	131	}
	132	errno = failed_errno;
	133	return code;
	134	}
	135
ebcb5d16	136	int start_command(struct child_process *cmd)
b1bf95bb	137	{
f3b33f1d JS	138	int need_in, need_out, need_err;
f3b33f1d JS	139	int fdin[2], fdout[2], fderr[2];
5a7a3671	140	int failed_errno = failed_errno;
4919bf03	141
c20181e3 JS	142	/*
	143	* In case of errors we must keep the promise to close FDs
	144	* that have been passed in via ->in and ->out.
	145	*/
	146
e4507ae8	147	need_in = !cmd->no_stdin && cmd->in < 0;
4919bf03	148	if (need_in) {
c20181e3	149	if (pipe(fdin) < 0) {
0ac77ec3	150	failed_errno = errno;
c20181e3 JS	151	if (cmd->out > 0)
c20181e3 JS	152	close(cmd->out);
0ac77ec3	153	goto fail_pipe;
c20181e3	154	}
4919bf03	155	cmd->in = fdin[1];
4919bf03 SP	156	}
4919bf03 SP	157
e4507ae8 SP	158	need_out = !cmd->no_stdout
	159	&& !cmd->stdout_to_stderr
	160	&& cmd->out < 0;
f4bba25b SP	161	if (need_out) {
f4bba25b SP	162	if (pipe(fdout) < 0) {
0ac77ec3	163	failed_errno = errno;
f4bba25b SP	164	if (need_in)
f4bba25b SP	165	close_pair(fdin);
c20181e3 JS	166	else if (cmd->in)
c20181e3 JS	167	close(cmd->in);
0ac77ec3	168	goto fail_pipe;
f4bba25b SP	169	}
f4bba25b SP	170	cmd->out = fdout[0];
f4bba25b SP	171	}
f4bba25b SP	172
b73a4397	173	need_err = !cmd->no_stderr && cmd->err < 0;
f3b33f1d JS	174	if (need_err) {
f3b33f1d JS	175	if (pipe(fderr) < 0) {
0ac77ec3	176	failed_errno = errno;
f3b33f1d JS	177	if (need_in)
f3b33f1d JS	178	close_pair(fdin);
c20181e3 JS	179	else if (cmd->in)
c20181e3 JS	180	close(cmd->in);
f3b33f1d JS	181	if (need_out)
f3b33f1d JS	182	close_pair(fdout);
c20181e3 JS	183	else if (cmd->out)
c20181e3 JS	184	close(cmd->out);
0ac77ec3 JS	185	fail_pipe:
	186	error("cannot create pipe for %s: %s",
	187	cmd->argv[0], strerror(failed_errno));
	188	errno = failed_errno;
	189	return -1;
f3b33f1d JS	190	}
	191	cmd->err = fderr[0];
	192	}
	193
8852f5d7 JS	194	trace_argv_printf(cmd->argv, "trace: run_command:");
8852f5d7 JS	195
71064e3f	196	#ifndef WIN32
2b541bf8 JS	197	{
	198	int notify_pipe[2];
	199	if (pipe(notify_pipe))
	200	notify_pipe[0] = notify_pipe[1] = -1;
	201
7d0b18a4	202	fflush(NULL);
ebcb5d16	203	cmd->pid = fork();
ebcb5d16	204	if (!cmd->pid) {
a5487ddf JS	205	/*
	206	* Redirect the channel to write syscall error messages to
	207	* before redirecting the process's stderr so that all die()
	208	* in subsequent call paths use the parent's stderr.
	209	*/
	210	if (cmd->no_stderr \|\| need_err) {
	211	child_err = dup(2);
	212	set_cloexec(child_err);
	213	}
	214	set_die_routine(die_child);
	215
2b541bf8 JS	216	close(notify_pipe[0]);
	217	set_cloexec(notify_pipe[1]);
	218	child_notifier = notify_pipe[1];
	219	atexit(notify_parent);
	220
e4507ae8 SP	221	if (cmd->no_stdin)
	222	dup_devnull(0);
	223	else if (need_in) {
4919bf03	224	dup2(fdin[0], 0);
9dc09c76	225	close_pair(fdin);
4919bf03 SP	226	} else if (cmd->in) {
	227	dup2(cmd->in, 0);
	228	close(cmd->in);
95d3c4f5	229	}
4919bf03	230
ce2cf27a CC	231	if (cmd->no_stderr)
	232	dup_devnull(2);
	233	else if (need_err) {
	234	dup2(fderr[1], 2);
	235	close_pair(fderr);
4f41b611 SP	236	} else if (cmd->err > 1) {
	237	dup2(cmd->err, 2);
	238	close(cmd->err);
ce2cf27a CC	239	}
ce2cf27a CC	240
e4507ae8 SP	241	if (cmd->no_stdout)
	242	dup_devnull(1);
	243	else if (cmd->stdout_to_stderr)
cd83c74c	244	dup2(2, 1);
f4bba25b SP	245	else if (need_out) {
	246	dup2(fdout[1], 1);
	247	close_pair(fdout);
	248	} else if (cmd->out > 1) {
	249	dup2(cmd->out, 1);
	250	close(cmd->out);
	251	}
	252
1568fea0	253	if (cmd->dir && chdir(cmd->dir))
d824cbba TR	254	die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
d824cbba TR	255	cmd->dir);
ee493148	256	if (cmd->env) {
3427b375 AR	257	for (; *cmd->env; cmd->env++) {
3427b375 AR	258	if (strchr(*cmd->env, '='))
4b25d091	259	putenv((char )cmd->env);
3427b375 AR	260	else
	261	unsetenv(*cmd->env);
	262	}
ee493148	263	}
2b541bf8 JS	264	if (cmd->preexec_cb) {
	265	/*
	266	* We cannot predict what the pre-exec callback does.
	267	* Forgo parent notification.
	268	*/
	269	close(child_notifier);
	270	child_notifier = -1;
	271
ccf08bc3	272	cmd->preexec_cb();
2b541bf8	273	}
f1000898 SP	274	if (cmd->git_cmd) {
f1000898 SP	275	execv_git_cmd(cmd->argv);
8dba1e63 JK	276	} else if (cmd->use_shell) {
8dba1e63 JK	277	execv_shell_cmd(cmd->argv);
77cb17e9	278	} else {
f1000898	279	execvp(cmd->argv[0], (char const) cmd->argv);
128aed68	280	}
a5487ddf JS	281	/*
	282	* Do not check for cmd->silent_exec_failure; the parent
	283	* process will check it when it sees this exit code.
	284	*/
	285	if (errno == ENOENT)
	286	exit(127);
	287	else
	288	die_errno("cannot exec '%s'", cmd->argv[0]);
b1bf95bb	289	}
0ac77ec3 JS	290	if (cmd->pid < 0)
	291	error("cannot fork() for %s: %s", cmd->argv[0],
	292	strerror(failed_errno = errno));
2b541bf8 JS	293
	294	/*
	295	* Wait for child's execvp. If the execvp succeeds (or if fork()
	296	* failed), EOF is seen immediately by the parent. Otherwise, the
	297	* child process sends a single byte.
	298	* Note that use of this infrastructure is completely advisory,
	299	* therefore, we keep error checks minimal.
	300	*/
	301	close(notify_pipe[1]);
	302	if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
	303	/*
	304	* At this point we know that fork() succeeded, but execvp()
	305	* failed. Errors have been reported to our stderr.
	306	*/
	307	wait_or_whine(cmd->pid, cmd->argv[0],
	308	cmd->silent_exec_failure);
	309	failed_errno = errno;
	310	cmd->pid = -1;
	311	}
	312	close(notify_pipe[0]);
	313	}
ba26f296	314	#else
0d30ad71	315	{
75301f90	316	int fhin = 0, fhout = 1, fherr = 2;
108ac313	317	const char **sargv = cmd->argv;
ba26f296	318	char **env = environ;
ba26f296	319
75301f90 JS	320	if (cmd->no_stdin)
	321	fhin = open("/dev/null", O_RDWR);
	322	else if (need_in)
	323	fhin = dup(fdin[0]);
	324	else if (cmd->in)
	325	fhin = dup(cmd->in);
	326
	327	if (cmd->no_stderr)
	328	fherr = open("/dev/null", O_RDWR);
	329	else if (need_err)
	330	fherr = dup(fderr[1]);
76d44c8c JH	331	else if (cmd->err > 2)
76d44c8c JH	332	fherr = dup(cmd->err);
75301f90 JS	333
	334	if (cmd->no_stdout)
	335	fhout = open("/dev/null", O_RDWR);
	336	else if (cmd->stdout_to_stderr)
	337	fhout = dup(fherr);
	338	else if (need_out)
	339	fhout = dup(fdout[1]);
	340	else if (cmd->out > 1)
	341	fhout = dup(cmd->out);
ba26f296 JS	342
	343	if (cmd->dir)
	344	die("chdir in start_command() not implemented");
2affea41 JS	345	if (cmd->env)
2affea41 JS	346	env = make_augmented_environ(cmd->env);
ba26f296 JS	347
ba26f296 JS	348	if (cmd->git_cmd) {
108ac313	349	cmd->argv = prepare_git_cmd(cmd->argv);
8dba1e63 JK	350	} else if (cmd->use_shell) {
8dba1e63 JK	351	cmd->argv = prepare_shell_cmd(cmd->argv);
ba26f296 JS	352	}
ba26f296 JS	353
75301f90 JS	354	cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
75301f90 JS	355	fhin, fhout, fherr);
0ac77ec3	356	failed_errno = errno;
c024beb5	357	if (cmd->pid < 0 && (!cmd->silent_exec_failure \|\| errno != ENOENT))
0ac77ec3	358	error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
ba26f296 JS	359
	360	if (cmd->env)
	361	free_environ(env);
	362	if (cmd->git_cmd)
108ac313	363	free(cmd->argv);
ba26f296	364
108ac313	365	cmd->argv = sargv;
75301f90 JS	366	if (fhin != 0)
	367	close(fhin);
	368	if (fhout != 1)
	369	close(fhout);
	370	if (fherr != 2)
	371	close(fherr);
0d30ad71	372	}
ba26f296 JS	373	#endif
	374
	375	if (cmd->pid < 0) {
	376	if (need_in)
	377	close_pair(fdin);
	378	else if (cmd->in)
	379	close(cmd->in);
	380	if (need_out)
	381	close_pair(fdout);
	382	else if (cmd->out)
	383	close(cmd->out);
	384	if (need_err)
	385	close_pair(fderr);
0ac77ec3 JS	386	errno = failed_errno;
0ac77ec3 JS	387	return -1;
ba26f296	388	}
4919bf03 SP	389
	390	if (need_in)
	391	close(fdin[0]);
	392	else if (cmd->in)
	393	close(cmd->in);
	394
f4bba25b SP	395	if (need_out)
f4bba25b SP	396	close(fdout[1]);
c20181e3	397	else if (cmd->out)
f4bba25b SP	398	close(cmd->out);
f4bba25b SP	399
f3b33f1d JS	400	if (need_err)
f3b33f1d JS	401	close(fderr[1]);
4f41b611 SP	402	else if (cmd->err)
4f41b611 SP	403	close(cmd->err);
f3b33f1d	404
ebcb5d16 SP	405	return 0;
	406	}
	407
2d22c208 JS	408	int finish_command(struct child_process *cmd)
2d22c208 JS	409	{
c024beb5	410	return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
2d22c208 JS	411	}
2d22c208 JS	412
ebcb5d16 SP	413	int run_command(struct child_process *cmd)
	414	{
	415	int code = start_command(cmd);
	416	if (code)
	417	return code;
	418	return finish_command(cmd);
	419	}
	420
1568fea0	421	static void prepare_run_command_v_opt(struct child_process *cmd,
ee493148 AR	422	const char **argv,
ee493148 AR	423	int opt)
1568fea0 AR	424	{
	425	memset(cmd, 0, sizeof(*cmd));
	426	cmd->argv = argv;
	427	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
	428	cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
	429	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
c024beb5	430	cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
8dba1e63	431	cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
1568fea0 AR	432	}
1568fea0 AR	433
f1000898 SP	434	int run_command_v_opt(const char **argv, int opt)
	435	{
	436	struct child_process cmd;
1568fea0 AR	437	prepare_run_command_v_opt(&cmd, argv, opt);
	438	return run_command(&cmd);
	439	}
	440
ee493148 AR	441	int run_command_v_opt_cd_env(const char *argv, int opt, const char dir, const char const env)
	442	{
	443	struct child_process cmd;
	444	prepare_run_command_v_opt(&cmd, argv, opt);
	445	cmd.dir = dir;
	446	cmd.env = env;
	447	return run_command(&cmd);
	448	}
2d22c208	449
200a76b7 JS	450	#ifdef ASYNC_AS_THREAD
200a76b7 JS	451	static void run_thread(void data)
618ebe9f JS	452	{
618ebe9f JS	453	struct async *async = data;
200a76b7 JS	454	intptr_t ret = async->proc(async->proc_in, async->proc_out, async->data);
200a76b7 JS	455	return (void *)ret;
618ebe9f JS	456	}
	457	#endif
	458
2d22c208 JS	459	int start_async(struct async *async)
2d22c208 JS	460	{
ae6a5609 EFL	461	int need_in, need_out;
	462	int fdin[2], fdout[2];
	463	int proc_in, proc_out;
2d22c208	464
ae6a5609 EFL	465	need_in = async->in < 0;
	466	if (need_in) {
	467	if (pipe(fdin) < 0) {
	468	if (async->out > 0)
	469	close(async->out);
	470	return error("cannot create pipe: %s", strerror(errno));
	471	}
	472	async->in = fdin[1];
	473	}
	474
	475	need_out = async->out < 0;
	476	if (need_out) {
	477	if (pipe(fdout) < 0) {
	478	if (need_in)
	479	close_pair(fdin);
	480	else if (async->in)
	481	close(async->in);
	482	return error("cannot create pipe: %s", strerror(errno));
	483	}
	484	async->out = fdout[0];
	485	}
	486
	487	if (need_in)
	488	proc_in = fdin[0];
	489	else if (async->in)
	490	proc_in = async->in;
	491	else
	492	proc_in = -1;
	493
	494	if (need_out)
	495	proc_out = fdout[1];
	496	else if (async->out)
	497	proc_out = async->out;
	498	else
	499	proc_out = -1;
2d22c208	500
200a76b7	501	#ifndef ASYNC_AS_THREAD
2c3766f0 AM	502	/* Flush stdio before fork() to avoid cloning buffers */
	503	fflush(NULL);
	504
2d22c208 JS	505	async->pid = fork();
	506	if (async->pid < 0) {
	507	error("fork (async) failed: %s", strerror(errno));
ae6a5609	508	goto error;
2d22c208 JS	509	}
2d22c208 JS	510	if (!async->pid) {
ae6a5609 EFL	511	if (need_in)
	512	close(fdin[1]);
	513	if (need_out)
	514	close(fdout[0]);
	515	exit(!!async->proc(proc_in, proc_out, async->data));
2d22c208	516	}
ae6a5609 EFL	517
	518	if (need_in)
	519	close(fdin[0]);
	520	else if (async->in)
	521	close(async->in);
	522
	523	if (need_out)
	524	close(fdout[1]);
	525	else if (async->out)
	526	close(async->out);
618ebe9f	527	#else
200a76b7 JS	528	if (proc_in >= 0)
	529	set_cloexec(proc_in);
	530	if (proc_out >= 0)
	531	set_cloexec(proc_out);
ae6a5609 EFL	532	async->proc_in = proc_in;
ae6a5609 EFL	533	async->proc_out = proc_out;
200a76b7 JS	534	{
	535	int err = pthread_create(&async->tid, NULL, run_thread, async);
	536	if (err) {
	537	error("cannot create thread: %s", strerror(err));
	538	goto error;
	539	}
618ebe9f JS	540	}
618ebe9f JS	541	#endif
2d22c208	542	return 0;
ae6a5609 EFL	543
	544	error:
	545	if (need_in)
	546	close_pair(fdin);
	547	else if (async->in)
	548	close(async->in);
	549
	550	if (need_out)
	551	close_pair(fdout);
	552	else if (async->out)
	553	close(async->out);
	554	return -1;
2d22c208 JS	555	}
	556
	557	int finish_async(struct async *async)
	558	{
200a76b7 JS	559	#ifndef ASYNC_AS_THREAD
200a76b7 JS	560	return wait_or_whine(async->pid, "child process", 0);
618ebe9f	561	#else
200a76b7 JS	562	void ret = (void )(intptr_t)(-1);
	563
	564	if (pthread_join(async->tid, &ret))
	565	error("pthread_join failed");
	566	return (int)(intptr_t)ret;
618ebe9f	567	#endif
2d22c208	568	}
ae98a008 SB	569
	570	int run_hook(const char index_file, const char name, ...)
	571	{
	572	struct child_process hook;
14e6298f	573	const char *argv = NULL, env[2];
ae98a008 SB	574	char index[PATH_MAX];
	575	va_list args;
	576	int ret;
14e6298f	577	size_t i = 0, alloc = 0;
ae98a008	578
cf94ca8e SB	579	if (access(git_path("hooks/%s", name), X_OK) < 0)
	580	return 0;
	581
ae98a008	582	va_start(args, name);
14e6298f SB	583	ALLOC_GROW(argv, i + 1, alloc);
	584	argv[i++] = git_path("hooks/%s", name);
	585	while (argv[i-1]) {
	586	ALLOC_GROW(argv, i + 1, alloc);
	587	argv[i++] = va_arg(args, const char *);
	588	}
ae98a008 SB	589	va_end(args);
ae98a008 SB	590
ae98a008 SB	591	memset(&hook, 0, sizeof(hook));
	592	hook.argv = argv;
	593	hook.no_stdin = 1;
	594	hook.stdout_to_stderr = 1;
	595	if (index_file) {
	596	snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
	597	env[0] = index;
	598	env[1] = NULL;
	599	hook.env = env;
	600	}
	601
0ac77ec3	602	ret = run_command(&hook);
14e6298f	603	free(argv);
ae98a008 SB	604	return ret;
ae98a008 SB	605	}