title: What is the difference between uuid -v4 and uuidgen?
body: <p>I am creating some Jenkins tokens for githooks and I was using <code>uuidgen</code>. </p>
  
  <p>My coworker said they normally use <code>uuid -v4</code> and after <code>sudo apt-get</code>-ing <code>uuid</code>, <code>uuid -v4</code> and <code>uuidgen</code> appear to be the same:</p>
  
  <pre><code>$ uuid -v4
  832dce77-ddec-4cc5-9872-47a81456653f
  $ uuidgen
  a321bc87-a1b5-4cc5-b6b5-feaf3a610ab8
  </code></pre>
  
  <p>For reference: I am running this on Ubuntu.</p>
  
  <p>What is the difference between them? Are they they same? </p>