open $hddfile, '<whateverfile'; 
binmode it;

my $length = -s $hddfile;
my $chunks = $length/ #divided by how ever many chunks you want
my $num = #make this to the amount you divided the file into
my $counter = 0;

my $name = whatever;

foreach (1 .. $num){
    open $temp, '>', "$name$counter";  #should split up file based on whatever size you want
    read $hddfile, my $buf, $chunks;   #someone correct me it im wrong haha
    print $temp, $buf;
$counter++;
}

open $cmpfile, '<file to compare it with';
binmode it;

my $length = -s $cmpfile;
my $chunks = $length/ #divided by how ever many chunks you want

my $num = #match to the division number
my $counter = 0;
my $name = whatever;

foreach (1 .. $num){
    open $temp, '>', "$name$counter";  #should split up file based on whatever size you want
    read $hddfile, my $buf, $chunks;   #someone correct me it im wrong haha
    print $temp, $buf;
$counter++
}