Sometimes we need to determine what version of our OS. Mostly for all unix, linux os we can do it with ‘uname’ command. for FreeBSD it works well and we can see directly what version our FreeBSD is, but for ubuntu and centos we can get it straight what we need because instead of display OS version its just will display the kernel version.
then i find out that we can use this command
1. cat /etc/issue
3. cat /etc/apt/sources.list (by seeing repository)
On debian u can use this command (in order)
1. cd /etc
2. ls | grep version
1. uname -a