Linux distributions overview (Ubuntu, CentOS, Fedora) in Linux CLI - Commands & Configuration

Introduction

Linux distributions are different versions of the Linux operating system. Each distribution has its own features and tools. Ubuntu, CentOS, and Fedora are popular choices that serve different needs for users and servers.

When you want a user-friendly desktop experience with lots of software support, choose Ubuntu.

When you need a stable and secure server environment for business, CentOS is a good choice.

When you want the latest Linux features and software for testing or development, Fedora is suitable.

Commands

This command shows detailed information about the Linux distribution you are using. It helps you identify if you are on Ubuntu, CentOS, Fedora, or another distro.

Terminal

lsb_release -a

Expected Output

No LSB modules are available.

Distributor ID: Ubuntu

Description:    Ubuntu 22.04.2 LTS

Release:        22.04

Codename:       jammy

→

-a - Show all available distribution information

This command shows the CentOS version if you are using CentOS. It reads the release file specific to CentOS.

Terminal

cat /etc/centos-release

Expected Output

CentOS Linux release 7.9.2009 (Core)

This command shows the Fedora version if you are using Fedora. It reads the release file specific to Fedora.

Terminal

cat /etc/fedora-release

Expected Output

Fedora release 38 (Thirty Eight)

Key Concept

If you remember nothing else, remember: each Linux distribution has its own way to show its version and purpose, so use the right command to check which one you have.

Common Mistakes

Trying to use 'cat /etc/centos-release' on Ubuntu or Fedora systems.

The file does not exist on those systems, so the command fails.

Use 'lsb_release -a' for Ubuntu or 'cat /etc/fedora-release' for Fedora to check the version.

Assuming all Linux distributions use the same package manager.

Ubuntu uses apt, CentOS uses yum or dnf, Fedora uses dnf, so commands differ.

Learn the package manager for your distribution before installing software.

Summary

Use 'lsb_release -a' to find detailed info on Ubuntu and many other distros.

Use 'cat /etc/centos-release' to check CentOS version.

Use 'cat /etc/fedora-release' to check Fedora version.

Practice

1. Which Linux distribution is known for being beginner-friendly and suitable for general use?

easy

A. Ubuntu

B. CentOS

C. Fedora

D. Arch Linux

Solution

1. Step 1: Understand beginner-friendly distributions

   Ubuntu is widely recognized for its ease of use and beginner-friendly interface.

2. Step 2: Compare with other distributions

   CentOS is more server-focused and Fedora targets advanced users, so they are less beginner-friendly.

3. Final Answer:

   Ubuntu -> Option A

4. Quick Check:

   Beginner-friendly = Ubuntu [OK]

Hint: Ubuntu = beginner-friendly, CentOS = servers, Fedora = advanced [OK]

Common Mistakes:

• Confusing CentOS as beginner-friendly
• Thinking Fedora is for beginners
• Choosing Arch Linux which is advanced

2. Which command correctly installs a package on CentOS using the default package manager?

easy

A. apt-get install httpd

B. pacman -S httpd

C. dnf install httpd

D. yum install httpd

Solution

1. Step 1: Identify CentOS package manager

   CentOS traditionally uses yum as its package manager.

2. Step 2: Check command syntax

   yum install httpd is the correct syntax to install the Apache web server on CentOS.

3. Final Answer:

   yum install httpd -> Option D

4. Quick Check:

   CentOS uses yum = yum install [OK]

Hint: CentOS uses yum, Ubuntu uses apt, Fedora uses dnf [OK]

Common Mistakes:

• Using apt-get on CentOS
• Using pacman which is for Arch Linux
• Confusing dnf as default on CentOS

3. What will be the output of the command cat /etc/os-release | grep '^ID=' on a Fedora system?

medium

A. ID=fedora

B. ID=centos

C. ID=ubuntu

D. ID=debian

Solution

1. Step 1: Understand /etc/os-release file

   This file contains identification info about the Linux distribution, including the ID field.

2. Step 2: Recognize Fedora's ID value

   Fedora's ID in this file is fedora, so the grep command outputs ID=fedora.

3. Final Answer:

   ID=fedora -> Option A

4. Quick Check:

   Fedora ID = fedora [OK]

Hint: Fedora's ID in os-release is 'fedora' [OK]

Common Mistakes:

• Assuming ID=ubuntu on Fedora
• Confusing CentOS and Fedora IDs
• Not using grep correctly

4. You try to update packages on Fedora using yum update but get an error. What is the likely cause?

medium

A. CentOS commands work on Fedora without changes

B. You need to run 'apt-get update' instead

C. Fedora uses 'dnf' instead of 'yum' for package management

D. You must use 'pacman' on Fedora

Solution

1. Step 1: Identify Fedora's package manager

   Fedora uses dnf as its default package manager, replacing yum.

2. Step 2: Understand error cause

   Using yum update on Fedora may fail because yum is deprecated or not installed by default.

3. Final Answer:

   Fedora uses 'dnf' instead of 'yum' for package management -> Option C

4. Quick Check:

   Fedora package manager = dnf [OK]

Hint: Fedora uses dnf, not yum, for updates [OK]

Common Mistakes:

• Trying apt-get on Fedora
• Assuming CentOS commands always work
• Using pacman which is Arch Linux's manager

5. You want to set up a stable web server environment with long-term support and minimal updates. Which Linux distribution should you choose?

hard

A. Ubuntu

B. CentOS

C. Fedora

D. Debian Testing

Solution

1. Step 1: Understand stability and support needs

   Stable web servers require long-term support and minimal frequent updates to avoid disruptions.

2. Step 2: Match distribution to requirements

   CentOS is known for its stability and long-term support, making it ideal for servers.

3. Step 3: Compare other options

   Fedora is cutting-edge and updates often; Ubuntu is user-friendly but less stable long-term; Debian Testing is unstable.

4. Final Answer:

   CentOS -> Option B

5. Quick Check:

   Stable server = CentOS [OK]

Hint: Choose CentOS for stable, long-term server setups [OK]

Common Mistakes:

• Choosing Fedora for stability
• Assuming Ubuntu is best for servers
• Picking Debian Testing for production