What have you tried? What worked? What didn't? See How do I post a question effectively?

Please see How can I remove duplicate elements from a list or array? in perlfaq4. This won't exactly fit your need, but it should give you the tools necessary to attack the problem. You may also need to consult split and/or print, depending on your level of experience.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

In reply to Re: Remove unique lines from file by kennethk
in thread Remove unique lines from file by Anonymous Monk

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