How to Check OS Version in Linux Command line

I am a new Linux system user. How do I check os version in linux command line?

Linux is a free and open source operating system. There are many variants of Linux out there. They are typically called Linux distribution. Suse, OpenSUSE, Debian, Ubuntu, CentOS, Arch, Fedora, RHEL all are common Linux distribution names. Knowing your os version and name can be very useful for security patches.

Check os version in Linux

The procedure to find os name and version on Linux:

1. Open the terminal application (bash shell)
2. For remote server login using the ssh: ssh user@server-name
3. Type any one of the following command to find os name and version in Linux:
   cat /etc/os-release
   lsb_release -a
   hostnamectl
4. Type the following command to find Linux kernel version:
   uname -r

Let us see all examples in detailed.

/etc/os-release file

Type the following cat command:
$ cat /etc/os-release
Sample outputs:

NAME="Ubuntu"
VERSION="17.10 (Artful Aardvark)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 17.10"
VERSION_ID="17.10"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=artful
UBUNTU_CODENAME=artful

lsb_release command

The lsb_release command gives LSB (Linux Standard Base) and distribution-specific information on the CLI. The syntax is:
$ lsb_release -a
Sample outputs:

LSB Version:	:core-4.1-amd64:core-4.1-noarch
Distributor ID:	CentOS
Description:	CentOS Linux release 7.4.1708 (Core) 
Release:	7.4.1708
Codename:	Core

hostnamectl command

Use hostnamectl command to query and change the system hostname and related settings. Just type the following command to check OS name and Linux kernel version:
$ hostnamectl
Sample outputs:

   Static hostname: nixcraft-www-42
         Icon name: computer-vm
           Chassis: vm
        Machine ID: beb217fbb4324b7d9959f78c279e6599
           Boot ID: 10f00cc5ca614b518a84d1793d0134bc
    Virtualization: qemu
  Operating System: Ubuntu 16.04.3 LTS
            Kernel: Linux 4.10.0-42-generic
      Architecture: x86-64

Read : 12 Best Web Browsers for Ubuntu in 2019

uname command

Just print Linux kernel version, run:
$ uname -r
Sample outputs:

Another option is to type the following command:
$ cat /proc/version
Sample outputs:

Linux version 3.10.0-693.11.6.el7.x86_64 (mockbuild@x86-041.build.eng.bos.redhat.com) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) ) #1 SMP Thu Dec 28 14:23:39 EST 2017

/etc/issue file

Use more command/less command as follows:
$ cat /etc/issue
$ more /etc/issue
$ less /etc/issue

Getting help

You can also view the manual page on uname using the following command:
$ man hostnamectl
$ man uname
$ man cat