一、安装

1. 获取最新的redis的扩展的链接，获取方式见如何安装PHP扩展

   # memcached-2.2.0这个版本php7，php5都可以使用
   pecl install https://pecl.php.net/get/memcached-2.2.0.tgz

二、可能的错误

1. 错误提示： memcached support requires libmemcached，需要先安装 libmemcached 软件

   wget https://launchpad.net/libmemcached/1.0/1.0.18/+download/libmemcached-1.0.18.tar.gz
   tar -zxvf libmemcached-1.0.18.tar.gz
   # 要带有--enable-sasl参数，不然安装php扩展的时候会报错：no, libmemcached sasl support is not enabled
   ./configure --prefix=/lnmp/libmemcached1.0 --enable-sasl
   make
   make install

2. 错误提示：configure: error: no, sasl.h is not available. Run configure with --disable-memcached-sasl to disable this check

   yum install cyrus-sasl-devel