Perl regex

$url="http://www.webmasterstalks.com";

$url =~ m|(\w+)://([^/:]+)(:\d+)?/(.*)|;
$protocol = $1;
$domainName = $2;
$uri = "/" . $4;

if ($3 =~ /:(\d+)/) { $portNo = $1} else { $portNo = 80}
#print $domainName."\n";
($host,$domain) = $domainName =~ /^([^\.]+)\.(.*)$/;

my $tld_re = qr/( \w+ )/x;