Check the version a GNU/Linux distribution from the command line
To display the version of the currently installed GNU/Linux distribution, run:
$ lsb_release -a
The shell should display something like:
Distributor ID: Trisquel Description: Trisquel GNU/Linux Nabia (10.0.1) Release: 10.0.1 Codename: nabia
lsb_release to display all information available: the distributor’s ID as well as a description, the release number and the code name of the currently installed distribution.
$ man lsb_release to see all options.