Here's yum list installed php
[root@server1 ~]# yum list installed php
Loaded plugins: fastestmirror, priorities, protectbase, replace
Loading mirror speeds from cached hostfile
* base: mirror.sanctuaryhost.com
* extras: mirror.cisp.com
* mratwork-epel: mirror.steadfast.net
* mratwork-ius-stable: ord.mirror.rackspace.com
* mratwork-remi-php56: mirrors.mediatemple.net
* updates: centos.chi.host-engine.com
0 packages excluded due to repository protections
Error: No matching Packages to list
[root@server1 ~]#