由于新版wordpress不支持默认源的php5.4，所以必须升级。。。

1、删除旧版本php
yum list installed | grep php
yum remove php
yum remove php-*

2、安装第三方更新源
rpm -Uvh https://mirror.webtatic.com/yum/el7/epel-release.rpm
rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm

3、安装php7.2
yum install php72w mod_php72w php72w-bcmath php72w-cli php72w-common php72w-devel php72w-gd php72w-mbstring php72w-mysqlnd php72w-pdo php72w-pear php72w-process php72w-xml php72w-xmlrpc
如果是apache服务器还要安装mod_php72w

4、查看版本
php -v