Package Management in Linux

Managing software on Linux is all about handling packages—installing, upgrading, deleting, and configuring them. Different Linux distributions use different tools for package management:

• Red Hat-based systems (like CentOS) use yum/dnf and RPM.

• Debian-based systems (like Ubuntu, Kali Linux) use apt.

Key Concepts

• Package: A bundle that contains a software program and everything it needs to run.

• Repositories: Warehouses where packages are stored.

• Package Manager: A tool that fetches, installs, and updates packages for you.

Red Hat-Based Systems

yum (Yellowdog Updater Modified)

yum is the main package management tool for Red Hat-based systems. It handles dependencies when installing, updating, or removing software packages.

Basic Commands:

• Install a package:

    sudo yum install nginx
  

• Remove a package:

    sudo yum remove nginx
  

• Upgrade a package:

    sudo yum upgrade <package-name>
  

• Update a package:

    sudo yum update <package-name>
  

Difference between update and upgrade:

• Upgrade: Deletes old packages.

• Update: Keeps old packages so you can roll back if needed.

Package Rollback:

• See package history:

    sudo yum history
  

• Undo or redo actions:

    sudo yum history undo <id>
    sudo yum history redo <id>
  

RPM (Redhat Package Manager)

RPM allows you to install, uninstall, and query individual software packages. However, it doesn't handle dependencies like yum does.

Basic Commands:

• Install a package:

    sudo rpm -i <package-name>
  

• Upgrade a package:

    sudo rpm -U <package-name>
  

• Remove a package:

    sudo rpm -evh <package-name>
  

• Query installed packages:

    sudo rpm -qa
  

• Get package info:

    sudo rpm -qi <package-name>
  

• Get config files info:

    sudo rpm -qc <package-name>
  

dnf (Dandified yum)

dnf is the newer version of yum, used in Red Hat/CentOS 8 and later.

Basic Commands:

• List available packages:

    sudo dnf list available
  

• List installed packages:

    sudo dnf list installed
  

• Install a package:

    sudo dnf install <package-name>
  

• Remove a package:

    sudo dnf remove <package-name>
  

• Upgrade a package:

    sudo dnf upgrade <package-name>
  

• Update a package:

    sudo dnf update <package-name>
  

Debian-Based Systems

apt (Advanced Packaging Tool)

apt is used for managing software on Debian-based systems like Ubuntu.

Key Concepts:

• APT Package Index: A catalog of all available software packages.

• Repositories: Servers on the internet that store software packages. These are listed in /etc/apt/sources.list and /etc/apt/sources.list.d.

Basic Commands:

• Update the package index:

    sudo apt update
  

• Install a package:

    sudo apt install <package-name>
  

• Remove a package:

    sudo apt remove <package-name>
  

• Remove dependencies:

    sudo apt autoremove
  

Summing It Up

• Install a package:

    sudo yum install nginx
    sudo dnf install nginx
    sudo apt install <package-name>
  

• Remove a package:

    sudo yum remove nginx
    sudo dnf remove nginx
    sudo apt remove <package-name>
  

• Upgrade/Update a package:

    sudo yum upgrade <package-name>
    sudo yum update <package-name>
    sudo dnf upgrade <package-name>
    sudo dnf update <package-name>
    sudo apt upgrade <package-name>
    sudo apt update
  

• Manage package history (for yum):

    sudo yum history
  

• Query packages (for rpm):

    sudo rpm -qa
    sudo rpm -qi <package-name>
    sudo rpm -qc <package-name>
  

Conclusion

Understanding package management is essential for effectively maintaining and managing a Linux system. Whether you are using Red Hat-based distributions like CentOS or Debian-based distributions like Ubuntu, knowing how to install, update, and remove software packages is fundamental. By mastering these tools and commands, you can ensure your system remains up-to-date, secure, and tailored to your needs.