sub _split_options {
    my ($opts) = @_;

    while (my ($k, $v) = each %$opts) {
        print "$k = $v\n";
    }

    print("\n");

    while (my ($k, $v) = each %$opts) {
        print "$k = $v\n";
    }
}

my %opts = qw( a 1 b 2 c 3 d 4 );
scalar each %opts;
_split_options(\%opts);