How Can I Find Out the OS Version in Linux?

AvatarByHarold Trujillo Linux & Open Source

Understanding the operating system version on your Linux machine is a fundamental step for anyone looking to manage, troubleshoot, or optimize their system effectively. Whether you’re a seasoned sysadmin, a developer, or a curious user, knowing exactly which version of Linux you’re running can provide critical insights into compatibility, security updates, and available features. This knowledge empowers you to make informed decisions about software installations, system upgrades, and maintenance tasks.

Linux, with its diverse distributions and frequent updates, can sometimes make it challenging to pinpoint the exact OS version at a glance. Unlike some other operating systems, Linux doesn’t always display this information prominently, requiring users to employ specific commands or access particular files to retrieve it. Grasping the basics of how Linux organizes and reports its version information is key to navigating this landscape confidently.

In the following sections, we’ll explore various methods and tools that can help you quickly and accurately identify your Linux OS version. By understanding these approaches, you’ll be better equipped to handle system administration tasks and ensure your environment is running as expected. Whether you prefer command-line techniques or graphical interfaces, this guide will prepare you to uncover your Linux version with ease.

Using Command-Line Tools to Check Linux OS Version

Linux provides several command-line utilities that can be used to determine the OS version. These tools extract information from system files or query the system environment, offering quick and reliable ways to identify the exact distribution and version details.

One of the most common commands is `lsb_release`. It displays Linux Standard Base and distribution-specific information if the `lsb-release` package is installed:

  • `lsb_release -a` shows all available information, including Distributor ID, Description, Release, and Codename.
  • `lsb_release -d` outputs just the description, which often includes the distribution name and version.

If `lsb_release` is not available, you can also check the contents of specific files like `/etc/os-release` or `/etc/issue`, which contain details about the OS.

Here are some commonly used commands:

  • `cat /etc/os-release` — Displays detailed OS identification data in a key-value format.
  • `cat /etc/issue` — Shows a brief description or banner of the distribution.
  • `uname -r` — Reveals the kernel version but not the OS distribution.
  • `hostnamectl` — Provides system information including OS version in modern systems.
Command Purpose Example Output
lsb_release -a Shows full distribution info Distributor ID: Ubuntu
Description: Ubuntu 20.04.5 LTS
Release: 20.04
Codename: focal
cat /etc/os-release Displays OS metadata NAME=”Ubuntu”
VERSION=”20.04.5 LTS (Focal Fossa)”
ID=ubuntu
cat /etc/issue Brief OS banner Ubuntu 20.04.5 LTS \n \l
uname -r Kernel version 5.15.0-60-generic
hostnamectl System and OS info Operating System: Ubuntu 20.04.5 LTS
Kernel: Linux 5.15.0-60-generic

These commands are the foundation for most Linux system version checks, and administrators often use them in scripts or troubleshooting scenarios.

Checking OS Version on Different Linux Distributions

Linux distributions store OS version information in slightly different locations or formats. Understanding these differences helps in using the appropriate method for the target distribution.

For Debian-based distributions (such as Ubuntu, Linux Mint, and Debian itself), the `/etc/os-release` file is the standard source. This file contains variables like `NAME`, `VERSION`, `ID`, and `VERSION_CODENAME`, making it straightforward to parse or read manually.

Red Hat-based systems (such as CentOS, Fedora, and RHEL) typically include a file called `/etc/redhat-release`. This file contains a plain text string describing the version and release number.

Other distributions might have:

  • `/etc/SuSE-release` for SUSE Linux.
  • `/etc/arch-release` for Arch Linux.
  • `/etc/gentoo-release` for Gentoo.

When these files are missing or outdated, relying on `lsb_release` or `hostnamectl` becomes more reliable since they query standardized system components.

Using GUI Tools to Determine Linux OS Version

For users who prefer graphical interfaces, most Linux desktop environments provide system information utilities that display OS version details clearly.

  • GNOME: The “Settings” application includes an “About” section, which shows the OS name, version, and kernel version.
  • KDE Plasma: The “Info Center” application provides detailed information about the OS and hardware.
  • XFCE: Tools like “About XFCE” or “Settings Manager” often display the OS information.

These GUI tools offer a user-friendly way to check the OS version without resorting to the command line, making them ideal for casual users or those new to Linux.

Automating OS Version Detection in Scripts

System administrators often need to automatically detect the OS version within shell scripts for conditional operations like package installation or configuration adjustments.

To automate this process, scripts typically parse `/etc/os-release` or use the `lsb_release` command if available. Here is a simple example of a bash snippet to detect the OS name and version:

“`bash
if [ -f /etc/os-release ]; then
. /etc/os-release
echo “OS: $NAME”
echo “Version: $VERSION”
else
echo “Cannot detect OS version”
fi
“`

For systems without `/etc/os-release`, scripts may fallback to other files or commands:

  • Check `/etc/redhat-release` and extract version info with `grep` and `awk`.
  • Use `lsb_release -d` if the `lsb-release` package is installed.

When writing portable scripts, it is important to include multiple fallback methods to cover various distributions robustly.

Understanding Kernel Version vs. Distribution Version

It is essential to differentiate between the Linux kernel version and the Linux distribution version. The kernel is the core part of the operating system managing hardware and system resources, whereas the distribution version refers to the entire OS package, including userland tools and desktop environments.

The command `uname -r` outputs the kernel version. For example:

“`
5.15.0-60-generic
“`

This

Methods to Determine the OS Version in Linux

Linux distributions provide several ways to identify the installed operating system version. These methods vary slightly depending on the distribution and the information required, such as kernel version, distribution name, or detailed release data.

Below are the most common and reliable commands and files to check the Linux OS version:

  • Using the /etc/os-release file
  • Using the lsb_release command
  • Using the hostnamectl command
  • Using the uname command
  • Reviewing distribution-specific release files

Checking /etc/os-release File

The /etc/os-release file is a standard file present on most modern Linux distributions. It contains key-value pairs describing the OS:

cat /etc/os-release
Field Description
NAME Distribution name (e.g., Ubuntu, Fedora)
VERSION Version string including release number
ID Lowercase ID of the distribution
VERSION_ID Numeric version identifier
PRETTY_NAME Human-readable OS name and version

This file provides a straightforward way to identify the distribution and version without requiring additional tools.

Using the lsb_release Command

The lsb_release command is part of the Linux Standard Base (LSB) and provides distribution-specific information:

lsb_release -a
  • Distributor ID: Name of the Linux distribution
  • Description: Full distribution description including version
  • Release: Release number
  • Codename: Distribution codename

If lsb_release is not installed, it can usually be added via the package manager:

  • Debian/Ubuntu: sudo apt-get install lsb-release
  • Fedora/CentOS: sudo dnf install redhat-lsb-core or sudo yum install redhat-lsb-core

Retrieving OS Version with hostnamectl

On systems using systemd, hostnamectl displays hostname and OS information:

hostnamectl

The output includes:

  • Static hostname
  • Operating System name and version
  • Kernel version
  • Architecture

Using uname to Check Kernel Version

The uname command provides kernel-level information, which is useful but does not specify the Linux distribution itself:

Option Description
-r Show kernel release
-a Show all system information including kernel and hostname 
uname -r
uname -a

Distribution-Specific Release Files

Older or minimal Linux distributions may rely on unique files in the /etc directory to store version information. Examples include:

  • /etc/redhat-release (Red Hat, CentOS, Fedora)
  • /etc/debian_version (Debian)
  • /etc/SuSE-release (SUSE)

Viewing these files can be done using cat:

cat /etc/redhat-release
cat /etc/debian_version

These files typically contain a brief text string specifying the distribution and version.

Expert Insights on Determining Linux OS Versions

Dr. Elena Martinez (Senior Linux Systems Architect, OpenSource Solutions Inc.) emphasizes, “To accurately identify the OS version in Linux, the most reliable method is to check the contents of the /etc/os-release file. This file provides standardized information across most modern distributions, making it essential for system administrators to script and automate version detection efficiently.”

Rajiv Patel (Linux Kernel Developer, TechCore Innovations) states, “While commands like ‘uname -r’ reveal the kernel version, they do not specify the distribution or its release number. For comprehensive OS version details, using commands such as ‘lsb_release -a’ or examining distribution-specific files like /etc/redhat-release or /etc/debian_version is critical for developers and IT professionals managing diverse Linux environments.”

Maria Chen (DevOps Engineer, CloudScale Technologies) advises, “In containerized or cloud environments, knowing the exact Linux OS version helps ensure compatibility and security compliance. Utilizing tools like ‘hostnamectl’ or leveraging configuration management systems to query OS metadata can streamline version tracking and maintain operational consistency across distributed systems.”

Frequently Asked Questions (FAQs)

How can I check the OS version on a Linux system?
You can check the OS version by running commands like `cat /etc/os-release` or `lsb_release -a` in the terminal. These commands provide detailed information about the Linux distribution and version.

What is the difference between `uname` and `lsb_release` commands for checking OS version?
The `uname` command displays kernel-related information, such as kernel version and architecture, while `lsb_release` provides distribution-specific details, including the OS version and codename.

Can I find the Linux OS version using graphical user interface (GUI)?
Yes, most Linux desktop environments include a system settings or about section where you can view the OS version and other system details without using the terminal.

Which file contains the Linux OS version information?
The `/etc/os-release` file contains standardized information about the Linux distribution and version, making it the primary source for OS version details.

Is the command `hostnamectl` useful for checking the OS version?
Yes, `hostnamectl` displays system information including the operating system name and version, along with hostname and kernel details.

How do I check the kernel version separately from the OS version?
Use the command `uname -r` to display the Linux kernel version independently of the distribution version.
Understanding how to determine the OS version in Linux is essential for system administration, troubleshooting, and ensuring compatibility with software applications. Various commands and files provide this information, including `lsb_release -a`, `/etc/os-release`, and `uname -r`, each offering different levels of detail about the distribution and kernel version. Utilizing these tools effectively allows users to quickly identify the specific Linux distribution and its version, which is crucial for maintaining system stability and security.

It is important to recognize that Linux distributions may store version information in different locations, making familiarity with multiple methods advantageous. For instance, while `lsb_release` is widely supported, some minimal installations might lack this utility, requiring users to check files like `/etc/issue` or `/proc/version`. Additionally, understanding the kernel version through commands like `uname` complements the OS version details by providing insight into the underlying system architecture and capabilities.

In summary, mastering the techniques to accurately identify the Linux OS version empowers users and administrators to make informed decisions regarding updates, compatibility, and system management. Leveraging these commands and files ensures efficient system monitoring and enhances overall operational effectiveness within diverse Linux environments.

Author Profile

Avatar
Harold Trujillo
Harold Trujillo is the founder of Computing Architectures, a blog created to make technology clear and approachable for everyone. Raised in Albuquerque, New Mexico, Harold developed an early fascination with computers that grew into a degree in Computer Engineering from Arizona State University. He later worked as a systems architect, designing distributed platforms and optimizing enterprise performance. Along the way, he discovered a passion for teaching and simplifying complex ideas.

Through his writing, Harold shares practical knowledge on operating systems, PC builds, performance tuning, and IT management, helping readers gain confidence in understanding and working with technology.