#!/usr/bin/perl # http://perlmonks.org/?node_id=1137428 use strict; use warnings; open (my $rangeFixed, '<', "rangeFile.txt") or die "Cannot Open File: +rangeFile.txt $!"; $_ = join '', <$rangeFixed>; s/^(IMB,\d+,V1\s,)(\d+),\K (?:.*\n)+ \1\d+,(\d+).*/$3/gmx; open (my $rangeOutput, '>', "test.txt") or die "Cannot Open File: test +.txt: $!"; print $rangeOutput $_; close $rangeOutput;