if($mystring){
    dosumpton(split(/\./, $mystring));
} elsif (not defined $mystring){
    dosumpton("nogames");
} else {
    # Something went wrong and we should be notified about it
}

##</code><code>##

my @args = split /\./, $mystring;
pop @args while (@args and !$args[-1]);
dosumpton(@args);