$file_vol="data-vol1.txt";
    open (DB,"$file_vol") or die;
    @content=<DB>;
    $prev = 'nonesuch';
    @out = grep($_ ne $prev && ($prev = $_), @content);

    $vallid=@out;
    $y=0;
            open("LIST", ">$file_vol.flt") or die "Can't Open File: $!"; 
        while($y<=$vallid){
                    print LIST "$out[$y]";
                 }
            $y++;
        }