Mine

<?php// IP regular expressions$dec_octet = '(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])';$h16 = '[\dA-F]{1,4}';$ipv4 = "(?:$dec_octet\.){3}$dec_octet";$ls32 = "(?:$h16:$h16|$ipv4)";$ipv6_construct = array(	array(false,	'',		'{6}',	$ls32),	array(false,	'::',	'{5}',	$ls32),	array('',		':',	'{4}',	$ls32),	array('{1,2}',	':',	'{3}',	$ls32),	array('{1,3}',	':',	'{2}',	$ls32),	array('{1,4}',	':',	'',		$ls32),	array('{1,5}',	':',	false,	$ls32),	array('{1,6}',	':',	false,	$h16),	array('{1,7}',	':',	false,	''));$ipv6 = '(?:';foreach ($ipv6_construct as $ip_type){	$ipv6 .= '(?:';	if ($ip_type[0] !== false)	{		$ipv6 .= "(?:$h16:)" . $ip_type[0];	}	$ipv6 .= $ip_type[1];	if ($ip_type[2] !== false)	{		$ipv6 .= "(?:$h16:)" . $ip_type[2];	}	$ipv6 .= $ip_type[3] . ')|';}$ipv6 = substr($ipv6, 0, -1) . ')';echo 'IPv4: ' . $ipv4 . "<br />\nIPv6: " . $ipv6 . "<br />\n";// URL regular expressions$pct_encoded = "%[\dA-F]{2}";$unreserved = 'a-z0-9\-._~';$sub_delims = '!$&\'()*+,;=';$pchar = "(?:[$unreserved$sub_delims:@|]+|$pct_encoded)"; // rfc: no "|"$scheme = '[a-z][a-z\d+\-.]*';$reg_name = "(?:[$unreserved$sub_delims|]+|$pct_encoded)+"; // rfc: * instead of + and no "|"$userinfo = "(?:(?:[$unreserved$sub_delims:]+|$pct_encoded))*";$ipv4_simple = '[0-9.]+';$ipv6_simple = '\[[a-z0-9.:]+\]';$host = "(?:$reg_name|$ipv4_simple|$ipv6_simple)";$port = '\d*';$authority = "(?:$userinfo@)?$host(?::$port)?";$segment = "$pchar*";$path_abempty = "(?:/$segment)*";$hier_part = "/{2}$authority$path_abempty";$query = "(?:[$unreserved$sub_delims:@/?|]+|$pct_encoded)*"; // pchar | "/" | "?", rfc: no "|"$fragment = $query;$url =  "$scheme:$hier_part(?:\?$query)?(?:\#$fragment)?";echo 'URL: ' . $url . "<br />\n";// no scheme, shortened authority, but host has to start with www.$www_url =  "www\.$reg_name(?::$port)?$path_abempty(?:\?$query)?(?:\#$fragment)?";echo 'www.URL: ' . $www_url . "<br />\n";// no schema and no authority$relative_url = "$segment$path_abempty(?:\?$query)?(?:\#$fragment)?";echo 'relative URL: ' . $relative_url . "<br />\n";?>