MyNews 调用栏目信息（缓存方式）

function getCategorys () {
	global $mysql, $cfg_cache_category;
	$cache = SYSPATH . "/data/cache/categorys.php";
	if (!file_exists($cache) || (time() - filemtime($cache)) > $cfg_cache_category) {
		$categorys = array();
		$arrays = $mysql->getArrays("SELECT id, fid, name, url FROM my_category");
		if (!empty($arrays)) {
			foreach ($arrays as $v) {
				$categorys[$v['id']] = $v;
			}
			unset($arrays);
			unset($v);
		}
		$fp = fopen($cache, 'w');
		if ($fp) {
			fwrite($fp, serialize($categorys));
			fclose($fp);
		} else {
			httpError(500, "写入栏目缓存文件失败");
		}
		unset($categorys);
	}
	$fp = fopen($cache, 'r');
	if ($fp) {
		$array = unserialize(fread($fp, filesize($cache)));
		return $array;
		unset($array);
	} else {
		httpError(500, "读取栏目缓存文件失败");
	}
}