__FILE__, SCRIPT_FILENAME, and DOCUMENT_ROOT (if you use one of the methods mentioned previously).

Also note that if the name of the last directory in the document root includes a space, the methods described above for setting DOCUMENT_ROOT will return a value that drops the everything past the space.
Andy Staudacher, gmx.ch add ast before @
20-Dec-2005 09:02
The following code is licensed under the GPL and it is from the gallery.menalto.com project.
<?php
    /**
     * Fix the superglobal $_COOKIE to conform with RFC 2965
     *
     * We don't use $_COOKIE[$cookiename], because it doesn't conform to RFC 2965 (the
     * cookie standard), i.e. in $_COOKIE, we don't get the cookie with the most specific path for
     * a given cookie name, we get the cookie with the least specific cookie path.
     * This function does it exactly the other way around, to a) fix our cookie/login problems and
     * to b) conform with the RFC.
     * The PHP bug was already fixed in spring 2005, but we will have to deal with broken PHP
     * versions for a long time. See http://bugs.php.net/bug.php?id=32802.
     *
     * Fixes also another PHP cookie bug. PHP doesn't expect the cookie header to have
     * quoted-strings, but they are perfectly legal according to RFC 2965.
     *
     * The third bug fixed here is an MS Internet Explorer (IE) bug. When using default cookie
     * domains (no leading dot, don't set the domain in set-cookie), IE is supposed to return only
     * cookies that have the exact request-host as their domain.
     * Example: Cookies stored in the browser with cookie domains: .example.com, .www.example.com,
     *          example.com, www.example.com
     *          The request-host is www.example.com. Thus, IE should return all those cookies but
     *          the example.com cookie, because it's a default domain cookie and it doesn't match
     *          exactly the request-host. But IE returns the example.com cookie too.
     * As MS decided that it returns the cookie with the best domain-match first (unspecified in
     * RFC 2965), this wouldn't be a problem if PHP didn't select the last cookie in the
     * HTTP_COOKIE header. But with fixCookieVars(), this case is also fixed.
     *
     * This function reevaluates the HTTP Cookie header and populates $_COOKIE with the correct
     * cookies. We fix only non-array and non '[', ']' containing cookies for simplicity. To fix
     * our login problem, we'd have to fix only the GALLERYSID cookie anyway.
     *
     * @param boolean force the reevaluation of the HTTP header string Cookie
     * @param boolean unset static variable for testability
     */
    function fixCookieVars($force=false, $unset=false)
?>
The source code can be found at:
http://cvs.sourceforge.net/viewcvs.py/gallery/gallery2/
modules/core/classes/GalleryUtilities.class?rev=1.146&view=markup
info at meshkaat dot com
06-Dec-2005 09:03
How to get $_SERVER["DOCUMENT_ROOT"] on IIS :