TYPO3 Core

See configurationManager

/**
 * @var array
     */
    protected static $defaultConfiguration = NULL;

/**
 * @var array
     */
    protected static $localConfiguration = NULL;

/**
 * @var string Absolute path to typo3conf directory
     */
    protected $pathTypo3Conf = PATH_typo3conf;

/**
 * Writing to these configuration pathes is always allowed,
 * even if the requested sub path does not exist yet.
 *
 * @var array
     */
    protected $whiteListedLocalConfigurationPaths = array(
        'EXT/extConf',
        'EXTCONF',
        'INSTALL/wizardDone',
        'DB',
        'SYS/caching/cacheConfigurations',
    );

/**
 * Return default configuration array
 *
 * @return array
     */
    public function getDefaultConfiguration() {
        if (static::$defaultConfiguration === NULL) {
            static::$defaultConfiguration = require_once $this->getDefaultConfigurationFileLocation();
        }
        return static::$defaultConfiguration;
    }

/**
 * Get the file location of the default configuration file,
 * currently the path and filename.
 *
 * @return string
 * @access private
     */
    public function getDefaultConfigurationFileLocation() {
        return PATH_site . $this->defaultConfigurationFile;
    }

/**
 * Return local configuration array typo3conf/LocalConfiguration.php
 *
 * @return array Content array of local configuration file
     */
    public function getLocalConfiguration() {
        if (static::$localConfiguration === NULL) {
            static::$localConfiguration = require_once $this->getLocalConfigurationFileLocation();
        }
        return static::$localConfiguration;
    }