While your point is flawlessly made, I'm curious about one thing: Did you go back and re-run the program using split? If the file gets cached, you may be seeing artificial improvements. This is where the BenchMark.pm module can really help in a comparison like this.

Without seeing your data, I imagine you'd take one line that matched your criteria, and one that didn't. Then write a comparison using both a passing and failing case with your data, duplicated to use split one way, and the regexp the other. This eliminates the file system as a possible source of artificial improvements.

There was a dicussion about whether split was faster than a regexp or not, rather recently. I don't recall the outcome, but that node may be worth hunting up.

--Chris

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