JSFiddle - React, Tailwind, and code Playground

JavaScript

var fullUrl = "http://something.com/File/?URL=http://www.wireshock.com/&IP=0.0.0.0&CAT=BLOG&USER=MAND\\DEFAULT\\market4080";
var matches = fullUrl.match(/URL=(.+)\&IP=/);
if (matches.length > 1) {
    alert(matches[1]);   
}