title: xmllint unknown option '--xpath'
body: <p>I've seen this syntax several places (eg, <a href="https://github.com/jakepetroules/wherefrom/blob/master/wherefrom#L49" rel="noreferrer">here</a>):</p>
  
  <p><code>xmllint --xpath '/plist/array/string/text()' tmp.xml</code>, used to query a particular XML node using an xpath selector. However, I'm getting the error <code>Unknown option --xpath</code> when I try to execute this on my machine (mac os x snow leopard).</p>
  
  <p>Looking more closely at the man page for xmllint, I don't see the <code>--xpath</code> option documented...</p>
  
  <p>Am I just totally missing something here?</p>