How to check OS and version in Linux

From time to time you end up in a machine running somewhere in the cloud and wonder what OS is running there. You know it's a flavour of Linux, but you don't know which one. Worry not my friend, this post will help you.

Kernel Version

If you want kernel version information, use uname(1).

$ uname -a
Linux localhost 4.4.0-101-generic #124-Ubuntu SMP Fri Nov 10 18:29:59 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

$ uname -a
Linux 10.0.2.15 4.13.15-300.fc27.x86_64 #1 SMP Tue Nov 21 21:10:22 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

Distribution Information

Information about the distribution varies depending on the distribution. If your distribution supports Linux Standard Base, then we can find that information using lsb_release. It can also be found from *-release files in /etc/ directory.

$ lsb_release -a
No LSB modules are available.
Distributor ID:  Ubuntu
Description:  Ubuntu 16.04.3 LTS
Release:  16.04
Codename:  xenial

On Fedora you may need to install lsb_release.

$ sudo yum install lsb_release -a
$ lsb_release -a
LSB Version:  :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID:  Fedora
Description:  Fedora release 27 (Twenty Seven)
Release:  27
Codename:  TwentySeven

Release files

Ubuntu has two release files /etc/lsb-release and /etc/os-release

$ cat /etc/*-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.3 LTS"
NAME="Ubuntu"
VERSION="16.04.3 LTS (Xenial Xerus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 16.04.3 LTS"
VERSION_ID="16.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
VERSION_CODENAME=xenial
UBUNTU_CODENAME=xenial

Fedoro has /etc/fedora-release, /etc/os-release, /etc/redhat-release, /etc/system-release

$ cat /etc/*-release
 sudo cat /etc/*release
Fedora release 27 (Twenty Seven)
NAME=Fedora
VERSION="27 (Cloud Edition)"
ID=fedora
VERSION_ID=27
PRETTY_NAME="Fedora 27 (Cloud Edition)"
ANSI_COLOR="0;34"
CPE_NAME="cpe:/o:fedoraproject:fedora:27"
HOME_URL="https://fedoraproject.org/"
SUPPORT_URL="https://fedoraproject.org/wiki/Communicating_and_getting_help"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=27
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=27
PRIVACY_POLICY_URL="https://fedoraproject.org/wiki/Legal:PrivacyPolicy"
VARIANT="Cloud Edition"
VARIANT_ID=cloud
Fedora release 27 (Twenty Seven)
Fedora release 27 (Twenty Seven)

Some extra places to look into for Ubuntu

$ cat /etc/issue.net
Ubuntu 16.04.3 LTS

$ cat /etc/debian_version
stretch/sid

Kernel Version

Distribution Information

Release files

Some extra places to look into for Ubuntu

References: