From the looks of things, I believe (meaning this is untested) the reason you're getting this error is because * has a special meaning inside of a regex. It denotes the previous character as something that may occur zero or more times. Unfortunately, your's is empty -- it doesn't have anything to match. (Maybe your *. is in the wrong order?)

Try putting something in front: /^.*\.ORD_API_log$/ That would matching anything that ended in .ORD_API_log. Of course, as someone else mentioned, it'd be easier to check the end and just forget about the beginning: /\.ORD_API_log$/ Hope this helps,