title: Does git have anything like `svn propset svn:keywords` or pre-/post-commit hooks?
body: <p>Browsing through the git documentation, I can't see anything analogous to SVN's commit hooks or the "propset" features that can, say, update a version number or copyright notice within a file whenever it is committed to the repository.</p>
  
  <p>Are git users expected to write external scripts for this sort of functionality (which doesn't seem out of the question) or have I just missed something obvious?</p>
  
  <p><em>Edit</em> : Just to be clear, I'm more interested in, e.g.,</p>
  
  <pre><code>svn propset svn:keywords "Author Date Id Revision" expl3.dtx
  </code></pre>
  
  <p>where a string like this:</p>
  
  <pre><code>$Id: expl3.dtx 780 2008-08-30 12:32:34Z morten $
  </code></pre>
  
  <p>is kept up-to-date with the relevant info whenever a commit occurs.</p>