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authorHarald Welte <laforge@gnumonks.org>2013-04-10 14:06:25 +0200
committerHarald Welte <laforge@gnumonks.org>2013-04-10 14:06:25 +0200
commit4ad6c932c9ad85d555b3a4ba1de4f433e1f39757 (patch)
tree7d401527bc43cfad56e22158084e7c508971ea66
parent9964203e0362ff27757b196571c7c681ce688de4 (diff)
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daemonize after gpsd connection is established; gps fix might take time
-rw-r--r--gpsdate.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/gpsdate.c b/gpsdate.c
index c424330..9ea0808 100644
--- a/gpsdate.c
+++ b/gpsdate.c
@@ -34,7 +34,10 @@
#include <unistd.h>
#include <string.h>
#include <syslog.h>
+
#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#include <gps.h>
@@ -73,6 +76,53 @@ static void callback(struct gps_data_t *gpsdata)
}
}
+static int osmo_daemonize(void)
+{
+ int rc;
+ pid_t pid, sid;
+
+ /* Check if parent PID == init, in which case we are already a daemon */
+ if (getppid() == 1)
+ return -EEXIST;
+
+ /* Fork from the parent process */
+ pid = fork();
+ if (pid < 0) {
+ /* some error happened */
+ return pid;
+ }
+
+ if (pid > 0) {
+ /* if we have received a positive PID, then we are the parent
+ * and can exit */
+ exit(0);
+ }
+
+ /* FIXME: do we really want this? */
+ umask(0);
+
+ /* Create a new session and set process group ID */
+ sid = setsid();
+ if (sid < 0)
+ return sid;
+
+ /* Change to the /tmp directory, which prevents the CWD from being locked
+ * and unable to remove it */
+ rc = chdir("/tmp");
+ if (rc < 0)
+ return rc;
+
+ /* Redirect stdio to /dev/null */
+/* since C89/C99 says stderr is a macro, we can safely do this! */
+#ifdef stderr
+ freopen("/dev/null", "r", stdin);
+ freopen("/dev/null", "w", stdout);
+ freopen("/dev/null", "w", stderr);
+#endif
+
+ return 0;
+}
+
int main(int argc, char **argv)
{
char *host = "localhost";
@@ -98,6 +148,8 @@ int main(int argc, char **argv)
exit(EXIT_FAILURE);
}
+ osmo_daemonize();
+
gps_stream(&gpsdata, WATCH_ENABLE|WATCH_JSON, NULL);
gps_mainloop(&gpsdata, 5000000, callback);