#!/usr/bin/perl -w
use strict;
use diagnostics;
my $file = "$ARGV[0]";
open( DAT, $file ) || die("Can not open file!");
while (<DAT>) {
    my $seq = $_;
    if ( $seq =~ m/^[ATCG]+$/ ) {
        my $DNA = '';
        $DNA = $seq;
        my $revcom = reverse($DNA);
        $revcom =~ tr/ACGTacgt/TGCAtgca/;
        print $revcom;
    }
}