equivalent to $_SERVER['DOCUMENT_ROOT'] that will work when script is called by cron?
<p>I'm using <code>$_SERVER['DOCUMENT_ROOT']</code> for my include paths so files will figure out where they are running from (i.e. whether they're on live or staging) and it works fine, except for scripts that are run by cron in which I have to hardcode the path. </p>

<p>Is there another variable I could use that could work from both cron and the browser?</p>
