title: Is it possible for $_SERVER['SCRIPT_FILENAME'] to not be set?
body: <p>Hey everyone, some background info:</p>
  
  <p>In the config file for my website, I set the mysql database name, username and password based on the contents of <code>$_SERVER['HTTP_HOST']</code>. Because it is possible for this variable to not be set in the case of old (HTTP 1.0) requests and cron jobs, I include a file that spoofs the <code>$_SERVER['HTTP_HOST']</code> value based on the value found in <code>$_SERVER['SCRIPT_FILENAME']</code>.</p>
  
  <p>However, I'm still noticing errors in my log files every now and then (it's rare, once every 2 weeks or so, but it still happens) where it tries to connect to MySQL on the production site using the login information for the local testing environment.</p>
  
  <p>Is there a possibility for <code>$_SERVER['SCRIPT_FILENAME']</code> to be empty?</p>