title: Finding a url in NSString
body: <p>How can I search a <code>NSString</code> for a url in Xcode iOS? 
  For instance, If scan it for </p>
  
  <blockquote>
    <p>HTTP://</p>
  </blockquote>
  
  <p>and detect where the end of that url is and return the url string.</p>
  
  <pre><code>     NSSearchFieldCell Class Reference
  </code></pre>
  
  <p>is only available on Mac development.</p>