title: What does git rev-parse do?
body: <p>What does <code>git rev-parse</code> do?</p>
  
  <p>I have read the man page but it raised more questions than answers. Things like:</p>
  
  <blockquote>
    <p>Pick out and <strong>massage</strong> parameters</p>
  </blockquote>
  
  <p><em>Massage</em>? What does that mean?</p>
  
  <p>I'm using as a resolver (to SHA1) of revision specifiers, like</p>
  
  <pre><code>git rev-parse HEAD^
  </code></pre>
  
  <p>or</p>
  
  <pre><code>git rev-parse origin/master
  </code></pre>
  
  <p>Is this the command’s purpose? If not, is even correct to use it to achieve this?</p>