If memory isn't an issue, my first choice would be to hash each line by sender, into a hash who's keys are senders and who's values are an array of lines per sender. At the end of the program, iterate over each sender, opening a file, writing the sender's lines to it, and closing the file.

In reply to Re: Parse data into large number of output files. by steves
in thread Parse data into large number of output files. by Rhys

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