use Digest::MD5 qw(md5_hex);

sub genGUID {
    my $seed = shift;
    my $md5 = uc md5_hex ($seed);
    my @octets = $md5 =~ /(.{2})/g;

    substr $octets[6], 0, 1, '4'; # GUID Version 4
    substr $octets[8], 0, 1, '8'; # draft-leach-uuids-guids-01.txt GUID variant
    my $GUID = "{@octets[0..3]-@octets[4..5]-@octets[6..7]-@octets[8..9]-@octets[10..15]}";

    $GUID =~ s/ //g;
    return $GUID;
}