title: curl usage to get header
body: <p>Why does this not work:</p>
  
  <pre><code>curl -X HEAD http://www.google.com
  </code></pre>
  
  <p>But these both work just fine:</p>
  
  <pre><code>curl -I http://www.google.com
  
  curl -X GET http://www.google.com
  </code></pre>