title: Regex strip all html except background style url
body: <p>I have the following <code>regex</code> that will find all the background style URLs in my HTML. I'm trying to strip all the HTML except for the background image URLs. My goal is to abstract a list of background image URLs from my HTML page. </p>
  
  <p>Expression <code>URL\(\s*(['"]?)(.*?)\1\s*\)</code></p>
  
  <p>Example HTML</p>
  
  <pre><code>&lt;a href="#"&gt;&lt;img style="background-image: url(http://domain.com/2003-Th.jpg)"&gt;&lt;/a&gt;
  </code></pre>
  
  <p>I'd just like to do the not of this expression. </p>