diff --git a/pylot/core/util/utils.py b/pylot/core/util/utils.py
new file mode 100644
index 00000000..fd1fa215
--- /dev/null
+++ b/pylot/core/util/utils.py
@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+#
+# -*- coding: utf-8 -*-
+
+import re
+
+def fnConstructor(s):
+
+    badchars = re.compile(r'[^A-Za-z0-9_. ]+|^\.|\.$|^ | $|^$')
+    badsuffix = re.compile(r'(aux|com[1-9]|con|lpt[1-9]|prn)(\.|$)')
+
+    fn = badchars.sub('_', s)
+
+    if badsuffix.match(fn):
+        fn = '_' + fn
+    return fn