diff --git a/src/util.py b/src/util.py
--- a/src/util.py
+++ b/src/util.py
@@ -1,3 +1,38 @@
+import os
+import sys
+
+
+def spawnDaemon(fun):
+	# do the UNIX double-fork magic, see Stevens' "Advanced
+	# Programming in the UNIX Environment" for details (ISBN 0201563177)
+	try:
+		pid = os.fork()
+		if pid > 0:
+			# parent process, return and keep running
+			return
+	except OSError as e:
+		print("fork #1 failed: {0} ({1})".format(e.errno,e.strerror),file=sys.stderr)
+		sys.exit(1)
+
+	os.setsid()
+
+	# do second fork
+	try:
+		pid = os.fork()
+		if pid > 0:
+			# exit from second parent
+			print("[{0}] server running".format(pid))
+			sys.exit(0)
+	except OSError as e:
+		print("fork #2 failed: {0} ({1})".format(e.errno,e.strerror),file=sys.stderr)
+		sys.exit(1)
+
+	fun()
+
+	# all done
+	os._exit(os.EX_OK)
+
+
 class Progress:
 	def __init__(self,n,i0=0):
 		self._n=n