CentOS show version number 2017-06-30 05:13
In CentOS, run the following command will get the version number.
cat /etc/centos-release
In my environment the output is like following.
CentOS release 6.8 (Final)
To show the detail info of system use uname -a.
[root@virtual ~]# uname -a
Linux virtual 2.6.32-042stab123.3 #1 SMP Fri May 5 12:29:05 MSK 2017 i686 i686 i386 GNU/Linux
EOF