Method check

/**
 * Checks for snooping outside of the file system root.
 *
 * @param   string  $path  A file system path to check.
 *
 * @return  string  A cleaned version of the path or exit on error.
 *
 * @throws  \Exception
 * @since   1.7.0
 */
public static function check($path)
{
    if (strpos($path, '..') !== false) {
        // Don't translate
        throw new \Exception(sprintf('%s() - Use of relative paths not permitted', __METHOD__));
    }
    $path = self::clean($path);
    if (JPATH_ROOT != '' && strpos($path, self::clean(JPATH_ROOT)) !== 0) {
        throw new \Exception(sprintf('%1$s() - Snooping out of bounds @ %2$s', __METHOD__, self::removeRoot($path)));
    }
    return $path;
}