uname #sysadmin #troubleshooting - five4nets/Linux-Knowledgebase GitHub Wiki

🧠 Linux uname Command Tutorial

The uname command in Linux is used to display system information such as the kernel name, version, architecture, and more. It's a quick way to learn about the system you're working on—especially useful for troubleshooting, scripting, and system audits.

🧰 Basic Syntax

uname [OPTION]

If run without any options, uname displays the kernel name by default.

🔧 Common Options

Option Description
-a Show all system information
-s Kernel name
-n Network node hostname
-r Kernel release
-v Kernel version
-m Machine hardware name
-p Processor type (may return "unknown")
-i Hardware platform (may return "unknown")
-o Operating system

🧪 Examples

1. Show All System Information

uname -a

Displays everything: kernel name, hostname, kernel release, version, machine, processor, hardware platform, and OS.

2. Show Kernel Name

uname -s

3. Show Hostname

uname -n

4. Show Kernel Release

uname -r

5. Show Kernel Version

uname -v

6. Show Machine Architecture

uname -m

7. Show Processor Type

uname -p

8. Show Hardware Platform

uname -i

9. Show Operating System

uname -o

🧠 Use Cases

  • Scripting: Use uname -r to check kernel version before running kernel-specific commands.
  • Debugging: Use uname -a to provide full system info when reporting bugs.
  • Architecture Checks: Use uname -m or -p to determine if you're on a 32-bit or 64-bit system.

📚 References

Happy system sleuthing! 🕵️‍♀️

Let me know if you'd like a version that includes arch, hostname, or lsb_release for even deeper system insights!

From Grok

Tutorial: Using the Linux uname Command

The uname command in Linux is a simple yet powerful tool for retrieving system information, such as the operating system name, kernel version, hardware architecture, and more. This tutorial explains the uname command, its options, and provides multiple examples to demonstrate its usage.

What is the uname Command?

The uname (short for "Unix name") command displays system information about the Linux or Unix-like system you are running. It is a built-in utility available on most Linux distributions and is commonly used for scripting, system administration, and troubleshooting.

Prerequisites

  • A Linux system with access to a terminal.
  • The uname command (pre-installed on virtually all Linux distributions).
  • Basic familiarity with the Linux command line.

Basic Syntax

uname [option]
  • option: Flags that specify the type of system information to display (e.g., -a for all information).
  • Without options, uname displays only the operating system name (e.g., Linux).

Common Options

The uname command supports several options to retrieve specific system details:

  • -a or --all: Display all available system information.
  • -s or --kernel-name: Display the kernel name (default if no option is specified).
  • -n or --nodename: Display the network node hostname.
  • -r or --kernel-release: Display the kernel release version.
  • -v or --kernel-version: Display the kernel version.
  • -m or --machine: Display the machine hardware name (e.g., architecture like x86_64).
  • -p or --processor: Display the processor type (may be unknown on some systems).
  • -i or --hardware-platform: Display the hardware platform (may be unknown).
  • -o or --operating-system: Display the operating system name (e.g., GNU/Linux).
  • --help: Display help information.
  • --version: Display the uname version.

Examples with Explanations

Example 1: Display the Kernel Name

Retrieve the operating system kernel name.

uname

Explanation:

  • Without options, uname outputs the kernel name, typically Linux on Linux systems.
  • This is equivalent to uname -s.

Sample Output:

Linux

Example 2: Display All System Information

Show all available system details.

uname -a

Explanation:

  • The -a option displays all system information in the following order: kernel name, hostname, kernel release, kernel version, machine hardware name, processor type, hardware platform, and operating system.
  • Useful for getting a complete system overview.

Sample Output:

Linux ubuntu-server 5.15.0-73-generic #80~20.04.1-Ubuntu SMP Wed Jun 14 15:32:22 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Example 3: Display Kernel Release

Check the kernel release version.

uname -r

Explanation:

  • Outputs the kernel release version (e.g., 5.15.0-73-generic).
  • Useful for identifying the exact kernel version for troubleshooting or compatibility checks.

Sample Output:

5.15.0-73-generic

Example 4: Display Hostname

Retrieve the system’s network node hostname.

uname -n

Explanation:

  • Displays the hostname of the system, as set in the network configuration.
  • Useful for identifying the machine in a network.

Sample Output:

ubuntu-server

Example 5: Display Machine Hardware Name

Identify the system’s hardware architecture.

uname -m

Explanation:

  • Outputs the machine hardware name, such as x86_64 (64-bit) or arm (ARM architecture).
  • Useful for determining software compatibility.

Sample Output:

x86_64

Example 6: Combine Multiple Options

Display specific system details together.

uname -srm

Explanation:

  • Combines -s (kernel name), -r (kernel release), and -m (machine hardware name).
  • Outputs the kernel name, release, and architecture in a single command.

Sample Output:

Linux 5.15.0-73-generic x86_64

Example 7: Display Operating System

Show the operating system name.

uname -o

Explanation:

  • Outputs the operating system name, typically GNU/Linux on Linux systems.
  • Useful for scripts that need to identify the OS.

Sample Output:

GNU/Linux

Common Use Cases

  • System Identification: Use uname -a to gather comprehensive system details for documentation or support.
  • Scripting: Incorporate uname -r or uname -m in scripts to check kernel versions or architecture before installing software.
  • Troubleshooting: Verify system compatibility for drivers or applications using uname -m or uname -r.
  • Network Management: Use uname -n to confirm the system’s hostname in networked environments.

Tips and Best Practices

  • Use uname -a for a quick system overview when troubleshooting or reporting issues.
  • Combine uname with other commands (e.g., cat /etc/os-release) for more detailed OS information.
  • In scripts, parse uname output with tools like awk or cut for specific fields: 
    uname -r | cut -d'-' -f1
  • Be aware that -p and -i may return unknown on some systems, depending on hardware or kernel configuration.

Caveats

  • The output of uname is system-dependent and may vary slightly across Linux distributions or Unix-like systems (e.g., macOS, BSD).
  • Some options (e.g., -p, -i) may not provide meaningful output on all systems.
  • Requires no special permissions, but ensure you have terminal access.

References