I'm not to good at writing regular expressions so if someone could help me I would really appreciate it. Basically I have bunch a files in a directory that look like the this "clog_b43.jus11_07172002_00.ab.err". I want to get rid of everthing but "07172002_00.ab.err". How can I write a regular expression to do this. I'm actually trying to find the answer in the regualre expression book by O'Reilly.