Another question: are the second and third fields of each record important or can they be thrown away?

Assuming they are unimportant, I suggest you use a hash of arrays (if you want to keep all fourth fields, even if they are repeated) or a hash of hashes (if you want to collapse repeated fourth fields into one item).

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

In reply to Re: Matching Text by CountZero
in thread Matching Text by Anonymous Monk

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