PhpBrew\Config::initDirectories PHP Method

    public static function initDirectories($buildName = null)
    {
        $dirs = array();
        $dirs[] = self::getRoot();
        $dirs[] = self::getHome();
        $dirs[] = self::getVariantsDir();
        $dirs[] = self::getBuildDir();
        $dirs[] = self::getCacheDir();
        $dirs[] = self::getDistFileDir();
        $dirs[] = self::getRegistryDir();
        if ($buildName) {
            $dirs[] = self::getCurrentBuildDir($buildName);
            $dirs[] = self::getCurrentBuildDir($buildName) . DIRECTORY_SEPARATOR . 'ext';
            $dirs[] = self::getInstallPrefix($buildName) . DIRECTORY_SEPARATOR . 'var' . DIRECTORY_SEPARATOR . 'db';
        }
        foreach ($dirs as $dir) {
            if (!file_exists($dir)) {
                mkdir($dir, 0755, true);
            }
        }
        $write = array();
        $write[] = self::getHome();
        $write[] = self::getVariantsDir();
        $write[] = self::getBuildDir();
        $write[] = self::getCacheDir();
        $write[] = self::getDistFileDir();
        $write[] = self::getRegistryDir();
        foreach ($write as $dir) {
            if (!is_writable($dir)) {
                throw new Exception("{$dir} is not writable, please fix the folder permissions.");
            }
        }
    }