public static function getJsonConfigFilename()
    {
        $scanDir = getenv('BARTLETT_SCAN_DIR');
        if ($scanDir) {
            $dirs = explode(PATH_SEPARATOR, $scanDir);

            foreach ($dirs as $scanDir) {
                $filename = $scanDir . DIRECTORY_SEPARATOR . getenv('BARTLETTRC');
                if (file_exists($filename) && is_file($filename)) {
                    return realpath($filename);
                }
            }
        }
        return false;
    }