open (IN, "Alu.txt");
open (OUT, ">Alu_lengthsubfam.csv");

while ($a = <IN>){
    @data = split (/t/, $a);

$genelength = $data[7] - $data[6]++;
$subfam = $data[10]
}
    foreach $subfam (0...$#subfam){
        print OUT "$subfam, $genelength{$subfam}n";
}
close (IN);
close (OUT)