my ($alpha_num, $any_three, $final_dot)
    = $url =~ m|www.([A-Z a-z 0-9]+)(.{3})(.)|x;
print '$alpha_num=[', defined $alpha_num ? $alpha_num : '<undef>', ']';
print '$any_three=[', defined $any_three ? $any_three : '<undef>', ']';
print '$final_dot=[', defined $final_dot ? $final_dot : '<undef>', ']';