title: From within an ISAPI filter, how to determine the virtual path for an IIS application?
body: <p>Is there a way, inside an ISAPI Filter, to determine the virtual path for the IIS application or virtual directory? </p>
  
  <p>It's basically the same question as <a href="https://stackoverflow.com/questions/1271260">IIS Root Path vs Path of virtual directory</a>, but rather than within an ASP.NET application, I want this from within an ISAPI filter.</p>
  
  <p>Does the value of the server variable APPL_MD_PATH always ends with the actual virtual path of an application?  Is it true that the format of APPL_MD_PATH is always</p>
  
  <pre><code>/LM/W3SVC/&lt;sitenumber&gt;/ROOT/&lt;Website_vdir&gt;
  </code></pre>
  
  <p>?</p>