Check Linux Ubuntu/Debian/Mint Version from Command Line
To check the version of Ubuntu just use the lsb_release command as shown below and you will be able to see the exact Ubuntu version you have installed.
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04 LTS
Release: 14.04
Codename: trusty
Tags:
linux, ubuntu, debian, mint, lineto, lsb_release, installed, lsb, modules, distributor, lts, codename, trusty,