You need to use the uname command to print certain system information such as:
- Linux Kernel version and name.
- Print the Unix machine hardware name.
- Find out about server processor type.
- Display the operating system and more.
uname command to display the Linux or Unix kernel version
This command works under all Linux distributions and other UNIX-like operating systems such as FreeBSD, OpenBSD, Solaris, HP UX, OS X and friends. Type the following command to see running kernel version:
$ uname -r
Output taken from Linux based system:
2.6.22-14-generic
Where,
- 2 : Kernel version
- 6 : The major revision of the kernel
- 22 : The minor revision of the kernel
- 14 : Immediate fixing / bug fixing for critical error
- generic : Distribution specific sting. For example, Redhat appends string such as EL5 to indicate RHEL 5 kernel.
Another common usage is as follows:
$ uname -mrsn
Output taken from Linux:
Linux moon.nixcraft.in 2.6.18-53.1.4.el5 x86_64
Here is another output from RHEL 8:
Outputs from my OS X Unix desktop
$ uname -a Darwin desktop01 13.0.0 Darwin Kernel Version 13.0.0: Thu Sep 19 22:22:27 PDT 2013; root:xnu-2422.1.72~6/RELEASE_X86_64 x86_64
Outputs from OpenBSD Unix server
$ uname -mrs OpenBSD 5.4 amd64
For example, at the prompt, I type the following on AIX unix to print OS name:
uname
Sample outputs:
AIX
Common uname options
| Option | Description |
|---|---|
| -a | Behave as though the options -m, -n, -r, -s, and -v were specified. |
| -i | Write the kernel ident to standard output. |
| -K | Write the FreeBSD version of the kernel. |
| -m | Displays the machine ID number of the hardware running the system. |
| -n | Write the name of the system/node to standard output. |
| -o | This is a synonym for the -s option, for compatibility with other systems. |
| -p | Displays the architecture of the system processor. |
| -r | Displays the release number of the operating system. |
| -s | Write the name of the operating system implementation to standard output. |
| -v | Write the version level of this release of the operating system to standard output. |
How to find the kernel version with /proc/version file (Linux only command)
You can also obtain kernel version from /proc/version file by using cat command as follows:
$ less /proc/version
$ more /proc/version
$ cat /proc/version
Sample outputs:
Linux version 2.6.18-53.1.4.el5 (brewbuilder@hs20-bc2-3.build.redhat.com) (gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)) #1 SMP Wed Nov 14 10:37:27 EST 2007
Related media
See how to use uname and other commands to find the kernel version on Linux or Unix-like oses:
Video 01: Find The Linux/Unix Kernel Version Command Tutorial
Package management tools (Linux only command)
You can list all installed kernel and its version with the following command under RHEL / CentOS / Suse / Fedora Linux :
$ rpm -q kernel
Output:
kernel-2.6.18-53.el5 kernel-2.6.18-53.1.4.el5
If you are using Debian / Ubuntu, try:
$ dpkg --list | grep linux-image
Output:
ii linux-image 2.6.22.14.21 Generic Linux kernel image. rc linux-image-2.6.20-15-generic 2.6.20-15.27 Linux kernel image for version 2.6.20 on x86/ ii linux-image-2.6.20-16-generic 2.6.20-16.32 Linux kernel image for version 2.6.20 on x86/ ii linux-image-2.6.22-14-generic 2.6.22-14.47 Linux kernel image for version 2.6.22 on x86/ ii linux-image-generic 2.6.22.14.21 Generic Linux kernel image
Conclusion
We have shown you how to find the version of the Unix and Linux kernel running on your server/desktop/laptop/workstion from the command line. See uname man page here and here for more info.
- How To Find Out FreeBSD Version and Patch Level Number
- How To Find Which Linux Kernel Version Is Installed On My System
- Find Linux / UNIX Kernel Version Command
- How To Find Out If 32 or 64 bit Unix OS Installed On Server
- Linux: Find If Processor (CPU) is 64 bit / 32 bit [long mode ~ lm]
- List or Check Installed Linux Kernels
- Find Linux Kernel Version Command
- Linux Command: Show Linux Version
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Use the following command line: uname -r