daemonization skeleton

daemon3.py

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+import sys, os
+
+def main():
+    """ An example daemon main routine; writes a datestamp to file
+        /tmp/daemon-log every 10 seconds.
+    """
+    import time
+
+    f = open("/tmp/daemon-log", "w")
+    while 1:
+        f.write('%s\n' % time.ctime(time.time()))
+        f.flush()
+        time.sleep(10)
+
+if __name__ == "__main__":
+    # Do the Unix double-fork magic; see Stevens's book "Advanced
+    # Programming in the UNIX Environment" (Addison-Wesley) for details
+    try:
+        pid = os.fork()
+        if pid > 0:
+            # Exit first parent
+            sys.exit(0)
+    except OSError as e:
+        print ("fork #1 failed: %d (%s)" % (e.errno, e.strerror), file=sys.stderr)
+        sys.exit(1)
+
+    # Decouple from parent environment
+    os.chdir("/")
+    os.setsid(  )
+    os.umask(0)
+
+    # Do second fork
+    try:
+        pid = os.fork(  )
+        if pid > 0:
+            # Exit from second parent; print eventual PID before exiting
+            print ("Daemon PID %d" % pid)
+            sys.exit(0)
+    except OSError as e:
+        print ("fork #2 failed: %d (%s)" % (e.errno, e.strerror), file=sys.stderr)
+        sys.exit(1)
+
+    # Start the daemon main loop
+    main(  )