title: extract UID from /etc/passwd using RegEx
body: <p>I would like to extract UID from /etc/passwd file which looks like this-</p>
  
  <pre><code>www-data:x:33:33:www-data:/var/www:/bin/sh
  </code></pre>
  
  <p>The problem I'm facing is that even if I match first 33, the second 33 (GID) is also getting matched. How I match first occurrence only?</p>
  
  <p>So far I've this- <code>[\d]+</code></p>