[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)
{
	ssize_t unused;
	unused = write(child_notifier, "", 1);
}

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

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

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

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 WIN32
static unsigned __stdcall run_thread(void *data)
{
	struct async *async = data;
	return async->proc(async->proc_in, async->proc_out, async->data);
}
#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 WIN32
	/* 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
	async->proc_in = proc_in;
	async->proc_out = proc_out;
	async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
	if (!async->tid) {
		error("cannot create thread: %s", strerror(errno));
		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 WIN32
	int ret = wait_or_whine(async->pid, "child process", 0);
#else
	DWORD ret = 0;
	if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
		ret = error("waiting for thread failed: %lu", GetLastError());
	else if (!GetExitCodeThread(async->tid, &ret))
		ret = error("cannot get thread exit code: %lu", GetLastError());
	CloseHandle(async->tid);
#endif
	return ret;
}

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	{
90ff12a8 MW	70	ssize_t unused;
90ff12a8 MW	71	unused = write(child_notifier, "", 1);
2b541bf8	72	}
a5487ddf JS	73
	74	static NORETURN void die_child(const char *err, va_list params)
	75	{
	76	char msg[4096];
90ff12a8	77	ssize_t unused;
a5487ddf JS	78	int len = vsnprintf(msg, sizeof(msg), err, params);
	79	if (len > sizeof(msg))
	80	len = sizeof(msg);
	81
90ff12a8 MW	82	unused = write(child_err, "fatal: ", 7);
	83	unused = write(child_err, msg, len);
	84	unused = write(child_err, "\n", 1);
a5487ddf JS	85	exit(128);
	86	}
	87
	88	static inline void set_cloexec(int fd)
	89	{
	90	int flags = fcntl(fd, F_GETFD);
	91	if (flags >= 0)
	92	fcntl(fd, F_SETFD, flags \| FD_CLOEXEC);
	93	}
	94	#endif
	95
ab0b41da JS	96	static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
	97	{
	98	int status, code = -1;
	99	pid_t waiting;
	100	int failed_errno = 0;
	101
	102	while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
	103	; /* nothing */
	104
	105	if (waiting < 0) {
	106	failed_errno = errno;
	107	error("waitpid for %s failed: %s", argv0, strerror(errno));
	108	} else if (waiting != pid) {
	109	error("waitpid is confused (%s)", argv0);
	110	} else if (WIFSIGNALED(status)) {
	111	code = WTERMSIG(status);
	112	error("%s died of signal %d", argv0, code);
	113	/*
	114	* This return value is chosen so that code & 0xff
	115	* mimics the exit code that a POSIX shell would report for
	116	* a program that died from this signal.
	117	*/
	118	code -= 128;
	119	} else if (WIFEXITED(status)) {
	120	code = WEXITSTATUS(status);
	121	/*
	122	* Convert special exit code when execvp failed.
	123	*/
	124	if (code == 127) {
	125	code = -1;
	126	failed_errno = ENOENT;
	127	if (!silent_exec_failure)
	128	error("cannot run %s: %s", argv0,
	129	strerror(ENOENT));
	130	}
	131	} else {
	132	error("waitpid is confused (%s)", argv0);
	133	}
	134	errno = failed_errno;
	135	return code;
	136	}
	137
ebcb5d16	138	int start_command(struct child_process *cmd)
b1bf95bb	139	{
f3b33f1d JS	140	int need_in, need_out, need_err;
f3b33f1d JS	141	int fdin[2], fdout[2], fderr[2];
5a7a3671	142	int failed_errno = failed_errno;
4919bf03	143
c20181e3 JS	144	/*
	145	* In case of errors we must keep the promise to close FDs
	146	* that have been passed in via ->in and ->out.
	147	*/
	148
e4507ae8	149	need_in = !cmd->no_stdin && cmd->in < 0;
4919bf03	150	if (need_in) {
c20181e3	151	if (pipe(fdin) < 0) {
0ac77ec3	152	failed_errno = errno;
c20181e3 JS	153	if (cmd->out > 0)
c20181e3 JS	154	close(cmd->out);
0ac77ec3	155	goto fail_pipe;
c20181e3	156	}
4919bf03	157	cmd->in = fdin[1];
4919bf03 SP	158	}
4919bf03 SP	159
e4507ae8 SP	160	need_out = !cmd->no_stdout
	161	&& !cmd->stdout_to_stderr
	162	&& cmd->out < 0;
f4bba25b SP	163	if (need_out) {
f4bba25b SP	164	if (pipe(fdout) < 0) {
0ac77ec3	165	failed_errno = errno;
f4bba25b SP	166	if (need_in)
f4bba25b SP	167	close_pair(fdin);
c20181e3 JS	168	else if (cmd->in)
c20181e3 JS	169	close(cmd->in);
0ac77ec3	170	goto fail_pipe;
f4bba25b SP	171	}
f4bba25b SP	172	cmd->out = fdout[0];
f4bba25b SP	173	}
f4bba25b SP	174
b73a4397	175	need_err = !cmd->no_stderr && cmd->err < 0;
f3b33f1d JS	176	if (need_err) {
f3b33f1d JS	177	if (pipe(fderr) < 0) {
0ac77ec3	178	failed_errno = errno;
f3b33f1d JS	179	if (need_in)
f3b33f1d JS	180	close_pair(fdin);
c20181e3 JS	181	else if (cmd->in)
c20181e3 JS	182	close(cmd->in);
f3b33f1d JS	183	if (need_out)
f3b33f1d JS	184	close_pair(fdout);
c20181e3 JS	185	else if (cmd->out)
c20181e3 JS	186	close(cmd->out);
0ac77ec3 JS	187	fail_pipe:
	188	error("cannot create pipe for %s: %s",
	189	cmd->argv[0], strerror(failed_errno));
	190	errno = failed_errno;
	191	return -1;
f3b33f1d JS	192	}
	193	cmd->err = fderr[0];
	194	}
	195
8852f5d7 JS	196	trace_argv_printf(cmd->argv, "trace: run_command:");
8852f5d7 JS	197
71064e3f	198	#ifndef WIN32
2b541bf8 JS	199	{
	200	int notify_pipe[2];
	201	if (pipe(notify_pipe))
	202	notify_pipe[0] = notify_pipe[1] = -1;
	203
7d0b18a4	204	fflush(NULL);
ebcb5d16	205	cmd->pid = fork();
ebcb5d16	206	if (!cmd->pid) {
a5487ddf JS	207	/*
	208	* Redirect the channel to write syscall error messages to
	209	* before redirecting the process's stderr so that all die()
	210	* in subsequent call paths use the parent's stderr.
	211	*/
	212	if (cmd->no_stderr \|\| need_err) {
	213	child_err = dup(2);
	214	set_cloexec(child_err);
	215	}
	216	set_die_routine(die_child);
	217
2b541bf8 JS	218	close(notify_pipe[0]);
	219	set_cloexec(notify_pipe[1]);
	220	child_notifier = notify_pipe[1];
	221	atexit(notify_parent);
	222
e4507ae8 SP	223	if (cmd->no_stdin)
	224	dup_devnull(0);
	225	else if (need_in) {
4919bf03	226	dup2(fdin[0], 0);
9dc09c76	227	close_pair(fdin);
4919bf03 SP	228	} else if (cmd->in) {
	229	dup2(cmd->in, 0);
	230	close(cmd->in);
95d3c4f5	231	}
4919bf03	232
ce2cf27a CC	233	if (cmd->no_stderr)
	234	dup_devnull(2);
	235	else if (need_err) {
	236	dup2(fderr[1], 2);
	237	close_pair(fderr);
4f41b611 SP	238	} else if (cmd->err > 1) {
	239	dup2(cmd->err, 2);
	240	close(cmd->err);
ce2cf27a CC	241	}
ce2cf27a CC	242
e4507ae8 SP	243	if (cmd->no_stdout)
	244	dup_devnull(1);
	245	else if (cmd->stdout_to_stderr)
cd83c74c	246	dup2(2, 1);
f4bba25b SP	247	else if (need_out) {
	248	dup2(fdout[1], 1);
	249	close_pair(fdout);
	250	} else if (cmd->out > 1) {
	251	dup2(cmd->out, 1);
	252	close(cmd->out);
	253	}
	254
1568fea0	255	if (cmd->dir && chdir(cmd->dir))
d824cbba TR	256	die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
d824cbba TR	257	cmd->dir);
ee493148	258	if (cmd->env) {
3427b375 AR	259	for (; *cmd->env; cmd->env++) {
3427b375 AR	260	if (strchr(*cmd->env, '='))
4b25d091	261	putenv((char )cmd->env);
3427b375 AR	262	else
	263	unsetenv(*cmd->env);
	264	}
ee493148	265	}
2b541bf8 JS	266	if (cmd->preexec_cb) {
	267	/*
	268	* We cannot predict what the pre-exec callback does.
	269	* Forgo parent notification.
	270	*/
	271	close(child_notifier);
	272	child_notifier = -1;
	273
ccf08bc3	274	cmd->preexec_cb();
2b541bf8	275	}
f1000898 SP	276	if (cmd->git_cmd) {
f1000898 SP	277	execv_git_cmd(cmd->argv);
8dba1e63 JK	278	} else if (cmd->use_shell) {
8dba1e63 JK	279	execv_shell_cmd(cmd->argv);
77cb17e9	280	} else {
f1000898	281	execvp(cmd->argv[0], (char const) cmd->argv);
128aed68	282	}
a5487ddf JS	283	/*
	284	* Do not check for cmd->silent_exec_failure; the parent
	285	* process will check it when it sees this exit code.
	286	*/
	287	if (errno == ENOENT)
	288	exit(127);
	289	else
	290	die_errno("cannot exec '%s'", cmd->argv[0]);
b1bf95bb	291	}
0ac77ec3 JS	292	if (cmd->pid < 0)
	293	error("cannot fork() for %s: %s", cmd->argv[0],
	294	strerror(failed_errno = errno));
2b541bf8 JS	295
	296	/*
	297	* Wait for child's execvp. If the execvp succeeds (or if fork()
	298	* failed), EOF is seen immediately by the parent. Otherwise, the
	299	* child process sends a single byte.
	300	* Note that use of this infrastructure is completely advisory,
	301	* therefore, we keep error checks minimal.
	302	*/
	303	close(notify_pipe[1]);
	304	if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
	305	/*
	306	* At this point we know that fork() succeeded, but execvp()
	307	* failed. Errors have been reported to our stderr.
	308	*/
	309	wait_or_whine(cmd->pid, cmd->argv[0],
	310	cmd->silent_exec_failure);
	311	failed_errno = errno;
	312	cmd->pid = -1;
	313	}
	314	close(notify_pipe[0]);
	315	}
ba26f296	316	#else
0d30ad71	317	{
75301f90	318	int fhin = 0, fhout = 1, fherr = 2;
108ac313	319	const char **sargv = cmd->argv;
ba26f296	320	char **env = environ;
ba26f296	321
75301f90 JS	322	if (cmd->no_stdin)
	323	fhin = open("/dev/null", O_RDWR);
	324	else if (need_in)
	325	fhin = dup(fdin[0]);
	326	else if (cmd->in)
	327	fhin = dup(cmd->in);
	328
	329	if (cmd->no_stderr)
	330	fherr = open("/dev/null", O_RDWR);
	331	else if (need_err)
	332	fherr = dup(fderr[1]);
a886ba28 JH	333	else if (cmd->err > 2)
a886ba28 JH	334	fherr = dup(cmd->err);
75301f90 JS	335
	336	if (cmd->no_stdout)
	337	fhout = open("/dev/null", O_RDWR);
	338	else if (cmd->stdout_to_stderr)
	339	fhout = dup(fherr);
	340	else if (need_out)
	341	fhout = dup(fdout[1]);
	342	else if (cmd->out > 1)
	343	fhout = dup(cmd->out);
ba26f296 JS	344
	345	if (cmd->dir)
	346	die("chdir in start_command() not implemented");
2affea41 JS	347	if (cmd->env)
2affea41 JS	348	env = make_augmented_environ(cmd->env);
ba26f296 JS	349
ba26f296 JS	350	if (cmd->git_cmd) {
108ac313	351	cmd->argv = prepare_git_cmd(cmd->argv);
8dba1e63 JK	352	} else if (cmd->use_shell) {
8dba1e63 JK	353	cmd->argv = prepare_shell_cmd(cmd->argv);
ba26f296 JS	354	}
ba26f296 JS	355
75301f90 JS	356	cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
75301f90 JS	357	fhin, fhout, fherr);
0ac77ec3	358	failed_errno = errno;
c024beb5	359	if (cmd->pid < 0 && (!cmd->silent_exec_failure \|\| errno != ENOENT))
0ac77ec3	360	error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
ba26f296 JS	361
	362	if (cmd->env)
	363	free_environ(env);
	364	if (cmd->git_cmd)
108ac313	365	free(cmd->argv);
ba26f296	366
108ac313	367	cmd->argv = sargv;
75301f90 JS	368	if (fhin != 0)
	369	close(fhin);
	370	if (fhout != 1)
	371	close(fhout);
	372	if (fherr != 2)
	373	close(fherr);
0d30ad71	374	}
ba26f296 JS	375	#endif
	376
	377	if (cmd->pid < 0) {
	378	if (need_in)
	379	close_pair(fdin);
	380	else if (cmd->in)
	381	close(cmd->in);
	382	if (need_out)
	383	close_pair(fdout);
	384	else if (cmd->out)
	385	close(cmd->out);
	386	if (need_err)
	387	close_pair(fderr);
0ac77ec3 JS	388	errno = failed_errno;
0ac77ec3 JS	389	return -1;
ba26f296	390	}
4919bf03 SP	391
	392	if (need_in)
	393	close(fdin[0]);
	394	else if (cmd->in)
	395	close(cmd->in);
	396
f4bba25b SP	397	if (need_out)
f4bba25b SP	398	close(fdout[1]);
c20181e3	399	else if (cmd->out)
f4bba25b SP	400	close(cmd->out);
f4bba25b SP	401
f3b33f1d JS	402	if (need_err)
f3b33f1d JS	403	close(fderr[1]);
4f41b611 SP	404	else if (cmd->err)
4f41b611 SP	405	close(cmd->err);
f3b33f1d	406
ebcb5d16 SP	407	return 0;
	408	}
	409
2d22c208 JS	410	int finish_command(struct child_process *cmd)
2d22c208 JS	411	{
c024beb5	412	return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
2d22c208 JS	413	}
2d22c208 JS	414
ebcb5d16 SP	415	int run_command(struct child_process *cmd)
	416	{
	417	int code = start_command(cmd);
	418	if (code)
	419	return code;
	420	return finish_command(cmd);
	421	}
	422
1568fea0	423	static void prepare_run_command_v_opt(struct child_process *cmd,
ee493148 AR	424	const char **argv,
ee493148 AR	425	int opt)
1568fea0 AR	426	{
	427	memset(cmd, 0, sizeof(*cmd));
	428	cmd->argv = argv;
	429	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
	430	cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
	431	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
c024beb5	432	cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
8dba1e63	433	cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
1568fea0 AR	434	}
1568fea0 AR	435
f1000898 SP	436	int run_command_v_opt(const char **argv, int opt)
	437	{
	438	struct child_process cmd;
1568fea0 AR	439	prepare_run_command_v_opt(&cmd, argv, opt);
	440	return run_command(&cmd);
	441	}
	442
ee493148 AR	443	int run_command_v_opt_cd_env(const char *argv, int opt, const char dir, const char const env)
	444	{
	445	struct child_process cmd;
	446	prepare_run_command_v_opt(&cmd, argv, opt);
	447	cmd.dir = dir;
	448	cmd.env = env;
	449	return run_command(&cmd);
	450	}
2d22c208	451
71064e3f	452	#ifdef WIN32
d7fa500f	453	static unsigned __stdcall run_thread(void *data)
618ebe9f JS	454	{
618ebe9f JS	455	struct async *async = data;
ae6a5609	456	return async->proc(async->proc_in, async->proc_out, async->data);
618ebe9f JS	457	}
	458	#endif
	459
2d22c208 JS	460	int start_async(struct async *async)
2d22c208 JS	461	{
ae6a5609 EFL	462	int need_in, need_out;
	463	int fdin[2], fdout[2];
	464	int proc_in, proc_out;
2d22c208	465
ae6a5609 EFL	466	need_in = async->in < 0;
	467	if (need_in) {
	468	if (pipe(fdin) < 0) {
	469	if (async->out > 0)
	470	close(async->out);
	471	return error("cannot create pipe: %s", strerror(errno));
	472	}
	473	async->in = fdin[1];
	474	}
	475
	476	need_out = async->out < 0;
	477	if (need_out) {
	478	if (pipe(fdout) < 0) {
	479	if (need_in)
	480	close_pair(fdin);
	481	else if (async->in)
	482	close(async->in);
	483	return error("cannot create pipe: %s", strerror(errno));
	484	}
	485	async->out = fdout[0];
	486	}
	487
	488	if (need_in)
	489	proc_in = fdin[0];
	490	else if (async->in)
	491	proc_in = async->in;
	492	else
	493	proc_in = -1;
	494
	495	if (need_out)
	496	proc_out = fdout[1];
	497	else if (async->out)
	498	proc_out = async->out;
	499	else
	500	proc_out = -1;
2d22c208	501
71064e3f	502	#ifndef WIN32
2c3766f0 AM	503	/* Flush stdio before fork() to avoid cloning buffers */
	504	fflush(NULL);
	505
2d22c208 JS	506	async->pid = fork();
	507	if (async->pid < 0) {
	508	error("fork (async) failed: %s", strerror(errno));
ae6a5609	509	goto error;
2d22c208 JS	510	}
2d22c208 JS	511	if (!async->pid) {
ae6a5609 EFL	512	if (need_in)
	513	close(fdin[1]);
	514	if (need_out)
	515	close(fdout[0]);
	516	exit(!!async->proc(proc_in, proc_out, async->data));
2d22c208	517	}
ae6a5609 EFL	518
	519	if (need_in)
	520	close(fdin[0]);
	521	else if (async->in)
	522	close(async->in);
	523
	524	if (need_out)
	525	close(fdout[1]);
	526	else if (async->out)
	527	close(async->out);
618ebe9f	528	#else
ae6a5609 EFL	529	async->proc_in = proc_in;
ae6a5609 EFL	530	async->proc_out = proc_out;
618ebe9f JS	531	async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
	532	if (!async->tid) {
	533	error("cannot create thread: %s", strerror(errno));
ae6a5609	534	goto error;
618ebe9f JS	535	}
618ebe9f JS	536	#endif
2d22c208	537	return 0;
ae6a5609 EFL	538
	539	error:
	540	if (need_in)
	541	close_pair(fdin);
	542	else if (async->in)
	543	close(async->in);
	544
	545	if (need_out)
	546	close_pair(fdout);
	547	else if (async->out)
	548	close(async->out);
	549	return -1;
2d22c208 JS	550	}
	551
	552	int finish_async(struct async *async)
	553	{
71064e3f	554	#ifndef WIN32
c024beb5	555	int ret = wait_or_whine(async->pid, "child process", 0);
618ebe9f JS	556	#else
	557	DWORD ret = 0;
	558	if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
	559	ret = error("waiting for thread failed: %lu", GetLastError());
	560	else if (!GetExitCodeThread(async->tid, &ret))
	561	ret = error("cannot get thread exit code: %lu", GetLastError());
	562	CloseHandle(async->tid);
	563	#endif
2d22c208 JS	564	return ret;
2d22c208 JS	565	}
ae98a008 SB	566
	567	int run_hook(const char index_file, const char name, ...)
	568	{
	569	struct child_process hook;
14e6298f	570	const char *argv = NULL, env[2];
ae98a008 SB	571	char index[PATH_MAX];
	572	va_list args;
	573	int ret;
14e6298f	574	size_t i = 0, alloc = 0;
ae98a008	575
cf94ca8e SB	576	if (access(git_path("hooks/%s", name), X_OK) < 0)
	577	return 0;
	578
ae98a008	579	va_start(args, name);
14e6298f SB	580	ALLOC_GROW(argv, i + 1, alloc);
	581	argv[i++] = git_path("hooks/%s", name);
	582	while (argv[i-1]) {
	583	ALLOC_GROW(argv, i + 1, alloc);
	584	argv[i++] = va_arg(args, const char *);
	585	}
ae98a008 SB	586	va_end(args);
ae98a008 SB	587
ae98a008 SB	588	memset(&hook, 0, sizeof(hook));
	589	hook.argv = argv;
	590	hook.no_stdin = 1;
	591	hook.stdout_to_stderr = 1;
	592	if (index_file) {
	593	snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
	594	env[0] = index;
	595	env[1] = NULL;
	596	hook.env = env;
	597	}
	598
0ac77ec3	599	ret = run_command(&hook);
14e6298f	600	free(argv);
ae98a008 SB	601	return ret;
ae98a008 SB	602	}