Actually it is my intent to read and find matches only in every second line. The input line as a format like this. >headline1 linethatactuallycontainsthematchesiminterestedin1 >headline2 linethatactuallycontainsthematchesiminterestedin2 But thanks for mentioning. It might have been a great ocersight. Like the oversight I actually made (did not replace both lines with nextline)