You regexp seems incorrect. [GCA{4}T{4}] is a character class that matches any character of the ones listed, i.e. it's the same as [}4{GCAT]. Also, to make sure you match at a particular position, you should anchor your regex by starting it with ^ to match the beginning of the string.
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^7: Filter and writing error log file by choroba
in thread Filter and writing error log file by newtoperlprog

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