title: How to reference the initial commit?
body: <p>I've got a script that needs to reference the initial commit in a repository.   git has the special reference <code>HEAD</code>, but doesn't have the corresponding <code>TAIL</code>.  I cannot find anything in <code>git help rev-parse</code> that would seem to help me.</p>
  
  <p>Here's what I'd like to do:</p>
  
  <pre><code>git show TAIL
  </code></pre>
  
  <p>Here's one option I have:</p>
  
  <pre><code>git show `git log --reverse | if read a commit ; then echo $commit ; fi`
  </code></pre>
  
  <p>That's pretty hacky and depends on the output of git log not changing.</p>
  
  <p>Right now I just tag the initial commit and use that as my refspec.  However, I'd like to release a general tool, so that's not a great option.</p>