#!/usr/bin/perl -w use strict; my $infile = 'JPStream.csv'; my $outfile = 'new1.csv'; open IN, "< $infile" or die "Can't open $infile : $!"; open OUT, "> $outfile" or die "Can't open $outfile : $!"; my %seen; my %seen2; while () { next if /^$/; chomp; if ( ! $seen2{$_} ) { print OUT "$_ Not in the last Traceroute ^\n"; } last if /^$/; $seen{$_}++; %seen2 = (); } while () { next if /^$/; chomp; if ( ! $seen{$_} ) { print OUT "$_ Not in the last Traceroute^^\n"; } last if /^$/; $seen2{$_}++; %seen = (); } }