$pathroot variable is similar to the
environment variable set by the web server, except that it does not
contain state or function/MIME-type information (see
section 1.1.6 on URL syntax).
$pathroot is the URL
path (or file path if run from the command line) to the source of the
current Vortex script. It is set once at script startup. The
$pathroot variable was added in version 2.1.867816000 19970702.