How do I determine what the Redhat Linux system I have is?
To determine the version and update, look at the version information as follows...
$ lsb_release -a
LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1-noarch
Distributor ID: RedHatEnterpriseServer
Description: Red Hat Enterprise Linux Server release 5.2 (Tikanga)
The "Release:" line shows this is a version 5, update 2 machine.