merge process.[ch] with application.[ch]

[osmocom-bb.git] / src / application.c

diff --git a/src/application.c b/src/application.c
index 96b4204..5f8f447 100644 (file)
--- a/src/application.c
+++ b/src/application.c
@@ -1,5 +1,6 @@
 /* Utility functions to setup applications */
 /*
+ * (C) 2010 by Harald Welte <laforge@gnumonks.org>
  * (C) 2011 by Holger Hans Peter Freyther
  *
  * All Rights Reserved
@@ -24,6 +25,11 @@
 #include <osmocom/core/logging.h>
 
 #include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
 
 struct log_target *osmo_stderr_target;
 
@@ -47,3 +53,50 @@ int osmo_init_logging(const struct log_info *log_info)
        log_set_all_filter(osmo_stderr_target, 1);
        return 0;
 }
+
+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;
+}