in reply to File Processing...
use Tie::File; I have seen it quite capable of dealing with very large files given very little wiggle room.
Oh, wait, 200MBs? Nevermind.
It doesn't seem that you need exactly 200MBs, as you want to know how to conditionally go over 200MBs; also, you are dealing with text files... is it possible that you actually want to split the file by your 'certain string'?
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