(Mostly) RFC3986 Compliant URL/URI Parsing Regex

rfc3986.regex

/(?(DEFINE)
	(?<defunreserved>[A-Za-z0-9-._~])
	(?<defpctencoded>\%[0-9A-Fa-f]{2})
	(?<defsubdelims>[!$&'()*+,;=])
	(?<defpchar>((?P>defunreserved)|(?P>defpctencoded)|(?P>defsubdelims)|:|@))
	(?<defscheme>[A-Za-z][A-Za-z0-9+-.]*)
	(?<defhierpart>.*?)
	(?<defquery>((?P>defpchar)|\/|\?)*)
	(?<deffragment>((?P>defpchar)|\/|\?)*)
)
^(?'scheme'(?P>defscheme)):\/\/(?'host'(?P>defhierpart))(?'query'\?(?P>defquery))*(?'fragment'\#(?P>deffragment))*$
/gmx

Find RFC3986 here.