title: How to split a string at the first colon
body: <pre><code>$str = "X-Storage-Url: https://pathofanapi";
  </code></pre>
  
  <p>I would like to split this into an array ("X-Storage-Url", "https://pathofanapi").</p>
  
  <p>Could someone tell me the regex for this ? Regex has always been my weakness.</p>
  
  <p>Thanks.</p>