What is a linux package manager

When using Linux a popular method of installing software is to make use of a Package Manager, but Package Managers can help users accomplish a number of tasks. In this post, we'll take a deeper look into Linux Package Managers.

what are package managers in linux?

In Linux Package Managers are essentially software applications that help users to: Search, Download, Install, Remove and Update software applications on their computer operating system. These can be either Command Line tools or a complete Graphical User Interface application.

Experienced Linux users will very rarely download software from websites or any other location. The primary reasons for this included aspects as ease of use, security and the fact that most Linux distributions have a list of sources where users can download free open source software packages.

These package sources are referred to as repositories. Using a package manager users will automatically download the appropriate, package from a configured repository, install it and complete all the required configuration tasks. There is no need to for the user to click through a wizard screen or hunt down configuration settings. If packages version are updated within package repository, the package manager will update each package to its latest version whenever it is requested by the user to do so.

What is a package?

In Linux a package is a compressed software archive file that contains all the files that comes with a software application delivers any kind of functionality, this can be any kind of command line utility,GUI application or a software library.

A package may consist of a binary executable, configuration file and other software dependencies. Common types of Linux packages include .deb, .rpm, and .tgz. Linux packages don't usually contain the dependencies necessary to install them, therefore Linux distributions use package managers to automatically read dependencies files and download the packages needed before proceeding with the installation.

The package usually includes a manifest of dependencies that must be satisfied for a software application to execute as expected on any give Linux computer.

Common Package Managers in Linux include:

• dpkg (Debian Package Manager)
• APT (Advanced Package Tool)
• rpm (RedHat Package Manager)
• yum (Yellowdog Update Modified)
• dnf (Dandified Yum)
• zypper
• flatpak
• pacman
• snap
• synaptic

Packages also contain scripts that need to be executed if a package is requested to be removed. Ensuring that everything that is associated with execution of package is cleared up.

How to use a package manager.

Using a package manager, is typically accomplished via the terminal window although it is becoming more popular for Package Managers to implement a GUI and most of the popular Linux Distros now provide User friendly interface to help users install software. These GUI, typically just provide a wrapper and automate the bash commands used to install using the command line.

For most novice users of Linux, the most common and popular package managers they are likely to first start using is the apt (Advanced Package Tool) because it is most widely shipped as the default Package Manager for users of Debian, Ubuntu and Mint.

We'll cover some of the basic commands of how to use apt in order to illustrate the ease of use of using a package manager in the terminal window

How to install a package

You can install a package as follows by specify a single package name or install many packages at once by listing all their names.

To install Flameshot - a popular free powerful open source screenshot software

sudo apt install flameshot

Find dependencies of a package

Once package has been installed you might want to understand which dependencies the package is making use of, you can list out the dependencies of a package using apt as follows

sudo apt depends flameshot

Search for package

It is highly likely that you will need to search for a package to perform a specific task. The apt package manager enables you to easily search for packages via the terminal.

In this case, I want to search for an image manipulation program, I can simply include the phrase in quotes and use the apt search facility

sudo apt search "image manipulation program"

View package details

You will often want to find and view details of package. In this example I want to view some details regarding the Flameshot package we installed earlier.

sudo apt show flameshot

Update System Packages

You will periodically want to check and ensure you are making use of the latest available packages, often package maintainers will release Bug Fixes and new additional features in packages and you will want to ensure you are able to make use of these

To download a list of packages from different repositories included on your system and updates them when there are new versions of packages and their dependencies.

sudo apt update

Upgrade System Packages

Often the above command will instruct you that new releases of packages are available, so to install new versions of all the packages on your system.

sudo apt upgrade

You will often want to execute both these commands at the same time, so you can run them both at the same time using

sudo apt update && sudo apt upgrade -y

Remove packages

To remove packages from your system.

sudo apt remove flameshot

if you want to ensure all packages configuration and dependencies are removed at the same time you can use the purge switch

sudo apt remove flameshot --purge

Remove unused packages

Installing or upgrading packages will result in some dependencies not being required, you can clean up these unused dependencies after removing that particular package, it’s dependencies will remain on the system, therefore to remove them use autoremove as follows:

sudo apt autoremove

Summary

Learning how to use the Package Manager from the terminal window can help you to quickly, easily and efficiently install, update and remove packages on your system.