I have this script I have written, which seems to work (or it seems to haha), but it is lacking in speed. For a 16 MB file it takes 9-10 secs for it to complete and I will need to use it on 256 MB files in the future. I was hoping I could get some help in speeding it up, if at all possible.

use strict;
use warnings;

open my $file, '<', shift;
binmode($file);

my %seen = ();

while ( read( $file, my $buf, 1 ) ) {
    if ( !$seen{$buf} ) {
        $seen{$buf} = 1;
    }
    else {
        $seen{$buf}++;
    }
}
print "$_ - $seen{$_}\n" for ( keys %seen );
[download]

Any help in speeding this up would be much appreciated. :)