// Get the path of the configuration file $fname = JPATH_CONFIGURATION.DS.'configuration.php'; // clear cache $cache = JFactory::getCache(); $cache->clean(); // Update the credentials with the new settings $config =& JFactory::getConfig(); $config->setValue('config.custom_var', 'xxx'); // Get the config registry in PHP class format and write it to configuation.php jimport('joomla.filesystem.file'); if (!JFile::write($fname, $config->toString('PHP', 'config', array('class' => 'JConfig')))) { die(JText::_('ERRORCONFIGFILE')); }

global $mainframe; $mainframe->getCfg('custom_var');