yii\caching\FileCache::gcRecursive PHP Method

    protected function gcRecursive($path, $expiredOnly)
    {
        if (($handle = opendir($path)) !== false) {
            while (($file = readdir($handle)) !== false) {
                if ($file[0] === '.') {
                    continue;
                }
                $fullPath = $path . DIRECTORY_SEPARATOR . $file;
                if (is_dir($fullPath)) {
                    $this->gcRecursive($fullPath, $expiredOnly);
                    if (!$expiredOnly) {
                        if (!@rmdir($fullPath)) {
                            $error = error_get_last();
                            Yii::warning("Unable to remove directory '{$fullPath}': {$error['message']}", __METHOD__);
                        }
                    }
                } elseif (!$expiredOnly || $expiredOnly && @filemtime($fullPath) < time()) {
                    if (!@unlink($fullPath)) {
                        $error = error_get_last();
                        Yii::warning("Unable to remove file '{$fullPath}': {$error['message']}", __METHOD__);
                    }
                }
            }
            closedir($handle);
        }
    }