Centos6.8安装php5.6

1. 检查当前安装的PHP包

   yum list installed | grep php

   如果有安装的PHP包，先删除他们, 如:

   yum remove php.x86_64 php-cli.x86_64 php-common.x86_64

2. 配置安装包源:

   # Centos 5.X
   rpm -Uvh http://mirror.webtatic.com/yum/el5/latest.rpm
   # CentOs 6.x
   rpm -Uvh http://mirror.webtatic.com/yum/el6/latest.rpm
   # CentOs 7.X
   rpm -Uvh https://mirror.webtatic.com/yum/el7/epel-release.rpm
   rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm

   如果想删除上面安装的包，重新安装

   rpm -qa | grep webstatic
   rpm -e  [上面搜索到的包即可]

3. 执行安装

   yum -y install php56w.x86_64
   yum -y --enablerepo=webtatic install php56w-devel
   yum -y install php56w-pdo php56w-xml php56w-gd php56w-gd.x86_64 php56w-ldap.x86_64 php56w-mbstring.x86_64 php56w-mcrypt.x86_64 php56w-mysql.x86_64 php56w-pdo.x86_64 php56w-opcache.x86_64

4. 安装PHP FPM

   yum -y install php56w-fpm
   #设置php-fpm开机启动
   chkconfig php-fpm on
   #启动php-fpm
   /etc/init.d/php-fpm start

   注：如果想更换到php5.5或5.4版本, 直接把上面的56w换成55w或者54w就可以了