Linux: Finding What Distro We Are Using

scottalanmiller

A very common task of both system administrators and of automation scripts is to attempt to determine exactly what operating system (or distribution / distro in Linux parlance) and version number we are running. There is no standard terminology for this as there is no common system component that defines what is the OS, what version it is and so forth. So distro maintainers have turned to a relatively simplistic text file methodology that handles this for us. Simple, but effective. Nearly every Linux-based distro, and certainly all enterprise server ones, use the same standard pattern for storing the operating system name and version information to make it as easy as is reasonable for us to identify what kind of system we are running on. This is especially important to know this as it will often be the first place that we look when logging into a new machine for the first time.

Sadly, things are just a tiny bit different for each major distro. But knowing the basics should always make it very easy to find.

CentOS, RHEL and Fedora

cat /etc/redhat-release

Suse

cat /etc/SuSE-release

Debian

cat /etc/debian_version

Arch Linux

cat /etc/arch-release

Gentoo

cat /etc/gentoo-release

Slackware

cat /etc/slackware-version

There are some attempts at making some standard tools so that you can query the same thing on many different distros. These are not catching on universally, however. But some that you can always try are...

cat /etc/os-release
cat /etc/lsb-release

Part of a series on Linux Systems Administration by Scott Alan Miller

Dashrender

I'm confused - wouldn't you have to know what distro you're using to run those commands.

i.e. you can't run the

 cat /etc/gentoo-release

command on Ubuntu, can you? and if you can, can you run it on another Linux family line?

JaredBusch

@Dashrender said in Linux: Finding What Distro We Are Using:

I'm confused - wouldn't you have to know what distro you're using to run those commands.

i.e. you can't run the
 cat /etc/gentoo-release
command on Ubuntu, can you? and if you can, can you run it on another Linux family line?

Of course you can. You simply get an error that there is no file.

the command is cat the parameter is the path and file name.

JaredBusch

root@jaredweb:[~] $ cat /etc/gentoo-release
cat: /etc/gentoo-release: No such file or directory
root@jaredweb:[~] $ cat /etc/redhat-release
CentOS Linux release 7.3.1611 (Core)
root@jaredweb:[~] $

scottalanmiller

@Dashrender said in Linux: Finding What Distro We Are Using:

I'm confused - wouldn't you have to know what distro you're using to run those commands.

i.e. you can't run the
 cat /etc/gentoo-release
command on Ubuntu, can you? and if you can, can you run it on another Linux family line?

You have to know what to look for and look for it. Same with anything. How do you know that you are on Windows? You rely on look and feel, knowing ahead of time what it is. If you make a Linux desktop look just like Windows and answer to Windows commands, how would you determine that it is really Windows?

It's harder than it sounds.

You also have to know that it is Linux, what if it was AIX or HP-UX? At some point you just have to know what things look like and poke around.

A simple solution for Linux machines is to do this...

ls /etc/ | grep release

scottalanmiller

You can do this as well:

cat /etc/*release

And see the output of every file with the name all at once. But you might get more than you wanted.

thwr

Most distros will also give you a hint when opening a session (SSH, bash, getty etc). But it's nice to see such a summary, thanks.

JaredBusch

@scottalanmiller said in Linux: Finding What Distro We Are Using:

You can do this as well:
cat /etc/*release
And see the output of every file with the name all at once. But you might get more than you wanted.

For exampels, CentOS 7 has 4 files that match.

root@jaredweb:[~] $ ls /etc/*release
/etc/centos-release  /etc/os-release  /etc/redhat-release  /etc/system-release

It would output this disaster

root@jaredweb:[~] $ cat /etc/*release
CentOS Linux release 7.3.1611 (Core)
NAME="CentOS Linux"
VERSION="7 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="7"
PRETTY_NAME="CentOS Linux 7 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:7"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"

CentOS Linux release 7.3.1611 (Core)
CentOS Linux release 7.3.1611 (Core)

JaredBusch

What can be done if you do not want to rely on a maybe like

cat /etc/os-release
cat /etc/lsb-release

Is to write your own if/then script to find the data you need.

momurda

@Dashrender Yes that is generally true. However you usually are only going to have 2 options, redhat_release or debian as those are by far the two most common in use in any business environment.
also the os-release seems to be very new for distros. It is not in my centOS 6.6 or 6.8 but is in my debian 8+, but not in a debian 5 server i have.
typing
cat /etc/os then tab complete will get you possibilities with os in etc dir. If os-release isnt there it isnt.
so you can cat /etc/r then tab complete to see redhat-release

stacksofplates

/proc/version usually has pertinent information across most systems.

Edit: I looked closer. It's just the OS name (RHEL/Ubuntu) and kernel version. Never mind.