redis和memcache列出所有key

//redis
$redis = new Redis();
$redis->connect("host", "port");
$redis->select(0);  //redis默认有0-15 16个数据库 此处选择0
$redis->dbsize();   //返回有多少个key
$keys = $redis->keys("*"); //使用通配符列出所有key
var_dump($keys);

//memcache
$servers = array(array("host1", "port1"), array("host2", "port2"));
$mem = new Memcache();
$mem->addServer("host1", "port1");
$mem->addServer("host2", "port2");
$all_items = $memcache->getExtendedStats('items');
$options = array("host1:port1","host2:port2");
foreach($servers as $server){
  $option = $server[0] . ":" . $server[1];
    if(isset($all_items[$option]['items'])) {
      $items = $all_items[$option]['items'];
        foreach ($items as $number => $item) {
        $str = $memcache->getExtendedStats('cachedump', $number, 0);
        $line  = $str[$option];
        if(is_array($line) && count($line) > 0){
          foreach ($line as $key=>$value) {
            $keys[] = $key;
          }
        }
      }
    }
}

var_dump($keys);