[PATCH v4 8/9] index-helper: add --detach

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/git-index-helper.txt |  3 +++
 index-helper.c                     | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-index-helper.txt b/Documentation/git-index-helper.txt
index ad40366..9ced091 100644
--- a/Documentation/git-index-helper.txt
+++ b/Documentation/git-index-helper.txt
@@ -31,6 +31,9 @@ OPTIONS
 	for reading an index, but because it will happen in the
 	background, it's not noticable. `--strict` is enabled by default.
 
+--detach::
+	Detach from the shell.
+
 NOTES
 -----
 On UNIX-like systems, $GIT_DIR/index-helper.pid contains the process
diff --git a/index-helper.c b/index-helper.c
index 1140bc0..4dd9656 100644
--- a/index-helper.c
+++ b/index-helper.c
@@ -14,7 +14,7 @@ struct shm {
 
 static struct shm shm_index;
 static struct shm shm_base_index;
-static int to_verify = 1;
+static int daemonized, to_verify = 1;
 
 static void release_index_shm(struct shm *is)
 {
@@ -33,6 +33,8 @@ static void cleanup_shm(void)
 
 static void cleanup(void)
 {
+	if (daemonized)
+		return;
 	unlink(git_path("index-helper.pid"));
 	cleanup_shm();
 }
@@ -172,12 +174,13 @@ int main(int argc, char **argv)
 	static struct lock_file lock;
 	struct strbuf sb = STRBUF_INIT;
 	const char *prefix;
-	int fd, idle_in_minutes = 10;
+	int fd, idle_in_minutes = 10, detach = 0;
 	struct option options[] = {
 		OPT_INTEGER(0, "exit-after", &idle_in_minutes,
 			    N_("exit if not used after some minutes")),
 		OPT_BOOL(0, "strict", &to_verify,
 			 "verify shared memory after creating"),
+		OPT_BOOL(0, "detach", &detach, "detach the process"),
 		OPT_END()
 	};
 
@@ -202,6 +205,9 @@ int main(int argc, char **argv)
 	atexit(cleanup);
 	sigchain_push_common(cleanup_on_signal);
 
+	if (detach && daemonize(&daemonized))
+		die_errno("unable to detach");
+
 	if (!idle_in_minutes)
 		idle_in_minutes = 0xffffffff / 60;
 	loop(sb.buf, idle_in_minutes * 60);
-- 
2.2.0.513.g477eb31