I've spent hours trying to find an answer to this question...so I need an expert. I have a large text file with a alpha-numeric code on each line (several thousand lines in total). All I want to do, is remove duplicates. When I say remove, I mean totally remove....not leave one....remove all. So for example if the text file had the following in it; abcdef abcdef jdbfdn xjxbjh What you should end up with after running the script is; jdbfdn xjxbjh I need a command/batch way of doing this....not an app, as I need to be able to do it via a command line script. If anyone knows of a command line tool which can do this I'd appreciate it. Cheers guys.