You say you want to check for a pattern in 20 characters taken from a file, and you want to do this "instead of not checking entire file." But you're already not checking the entire file if you are only checking 20 characters from the file, so...

Please see How do I post a question effectively?, How (Not) To Ask A Question and in particular I know what I mean. Why don't you?.

In reply to Re: checking for pattern match with in a small chunk of data by AnomalousMonk
in thread checking for pattern match with in a small chunk of data by Anonymous Monk

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