1. /proc/version – This file stores a string which identifies the kernel version. It includes the contents of /proc/sys/kernel/ostype, /proc/sys/kernel/osrelease and /proc/sys/kernel/version.

You can also use the following command for the same purpose:

1. uname command – Display name and information about current kernel.
2. Package manager such as rpm/yum or apt-get provides output information about the kernel.

How to find the kernel version using uname command

Open the Terminal application and type the following command to show you Linux system kernel version:
uname -r
Sample outputs:

2.6.32-431.1.2.el6.x86_64

Where,

• 2.6.32 – Linux kernel version.
• 431.1.2 – Distro specific number for bug and security fixes.

Here is another output from my Ubuntu based server:
uname -r
Sample outputs:

3.2.0-51-generic

The following command gives a little more information about Linux kernel and machine type:
uname -mrs
Sample outputs:

Linux 3.2.0-51-generic x86_64

A list uname command line options

  -a, --all                print all information, in the following order, except omit -p and -i if unknown:
  -s, --kernel-name        print the kernel name
  -n, --nodename           print the network node hostname
  -r, --kernel-release     print the kernel release
  -v, --kernel-version     print the kernel version
  -m, --machine            print the machine hardware name
  -p, --processor          print the processor type or "unknown"
  -i, --hardware-platform  print the hardware platform or "unknown"
  -o, --operating-system   print the operating system

How to check kernel version using /proc/version file

Use the cat command to look at /proc/version file:

## display my linux kernel version ##
cat /proc/version

Related media

This tutorial is also available in a quick video format:

Conclusion

This page explained several ways to check kernel version in Linux terminal application. It is important that you keep your Linux kernel updated to avoid security problems.