How to Extract URL Fields in Perl Using Regex

$url = param('url');

print "url=$url<BR>\n";

# use m|...| so that we do not need to use a lot of "\/"

$url =~ m|(\w+)://([^/:]+)(:\d+)?/(.*)|;  

$protocol   = $1;

$domainName = $2;

$uri        = "/" . $4;

print "\$3=$3<BR>\n";

# Extract port number or default to 80

if ($3 =~ /:(\d+)/) { 

    $portNo = $1;

} else { 

    $portNo = 80;

}

# Print the extracted fields

print "protocol=$protocol<BR>\n"

    . "domainName=$domainName<BR>\n"

    . "portNo=$portNo<BR>\n"

    . "uri=$uri<BR>\n";