$ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux testing (stretch) Release: testing Codename: stretch
$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.4 LTS Release: 14.04 Codename: trusty
In case when you don't have
lsb_release installed you may want to try some guessing, for example, there is a file
/etc/issue that often contains distribution name. For example, on ubuntu:
$ cat /etc/issue Ubuntu 12.04.5 LTS \n \l
Don't use file
/etc/debian_version because its contents do not match distribution name!
Note that this will also work on non-Debian-family distributions like Fedora, RHEL, or openSUSE — but that
lsb_release may not be installed.