We can run following command from shell to check extenstion available on server but make sure that you have logged in as root user.
root@server [~]# /scripts/phpextensionmgr list
It will give followings result.
root@server [~]# /scripts/phpextensionmgr list
Available Extensions:
EAccelerator
IonCubeLoader
Zendopt
SourceGuardian
PHPSuHosin
