sub traverse_dir {
    my $dir = shift;
    my @entries = glob "$dir/*";
    for my $entry (@entries) {
        if (-f $entry) {
            print "$entry:", -s $entry, "\n";
        } elsif (-d $entry) {
            traverse_dir($entry);
        } else
            # perhaps do something for entries which are neither files nor subdirectories, if that sort of thing exists
        }
    }
}
traverse_dir ".";