How to Use the Command 'apt-get' (with examples)

The apt-get command is a powerful tool used in Debian-based Linux distributions like Debian and Ubuntu for managing software packages. It allows users to install, update, upgrade, and remove packages from their system with ease. Using apt-get helps keep the system up to date with the latest software releases and security patches. It’s crucial for maintaining the stability and performance of the system.

Although apt-get is being gradually replaced by apt for interactive use in recent versions of Ubuntu, it remains an essential command-line utility for scripting and automating package management tasks.

Update the list of available packages and versions

Code:

apt-get update

Motivation:
Running apt-get update is the first step in managing packages on a Debian-based system. It refreshes the list of available packages from the official repositories, ensuring the user has access to the latest versions and updates.

Explanation:

• apt-get: Invokes the package management tool.
• update: A subcommand that tells apt-get to update the local package database. This updates the list of available packages and their latest versions from all the repositories listed in /etc/apt/sources.list.

Example Output:

Hit:1 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://archive.ubuntu.com/ubuntu focal-updates InRelease
...
Reading package lists... Done

Install a package, or update it to the latest available version

Code:

apt-get install package

Motivation:
When you want to install a new application or update an existing one, you use the apt-get install command. This ensures your system has the desired software at its latest version.

Explanation:

• apt-get: The package management utility.
• install: This subcommand initiates the installation of the specified package(s).
• package: Replace this placeholder with the actual package name you wish to install. For instance, apt-get install vim to install the Vim text editor.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
...
After this operation, 50.5 MB of additional disk space will be used.
Do you want to continue? [Y/n]

Remove a package

Code:

apt-get remove package

Motivation:
If you no longer need a package or want to free up system resources, you can use apt-get remove to uninstall it. This will remove the package files but leave configuration files for future use.

Explanation:

• apt-get: Calls the package management tool.
• remove: The subcommand used to delete the specified package.
• package: Replace with the desired package name, such as apt-get remove vim.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  package
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
After this operation, 12.3 MB disk space will be freed.
Do you want to continue? [Y/n]

Remove a package and its configuration files

Code:

apt-get purge package

Motivation:
If you fully intend to get rid of a package and its configuration files, apt-get purge will do just that. This is useful for a clean slate when reinstalling a package or ensuring no remnants are left behind.

Explanation:

• apt-get: Invokes the command-line package manager.
• purge: A more thorough removal command than remove, including configuration and list files.
• package: Placeholder for the actual package name, such as apt-get purge vim.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be purged:
  package
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
After this operation, 13.1 MB disk space will be freed.
Do you want to continue? [Y/n]

Upgrade all installed packages to their newest available versions

Code:

apt-get upgrade

Motivation:
Keeping the system up to date with the latest software patches is crucial for security and performance. Running apt-get upgrade ensures all installed packages are updated if there are newer versions available.

Explanation:

• apt-get: The package manager tool.
• upgrade: Subcommand that upgrades all installed packages if there are newer versions available.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  package1 package2 package3
...
After this operation, 5.1 MB of additional disk space will be used.
Do you want to continue? [Y/n]

Clean the local repository

Code:

apt-get autoclean

Motivation:
This command is useful for tidying up the local repository cache by removing outdated package files that cannot be downloaded anymore. This helps reclaim disk space without affecting the ability to reinstall any packages currently installed.

Explanation:

• apt-get: Executes the package manager.
• autoclean: Removes package files from interrupted downloads that could no longer be downloaded, offering some disk space relief.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
Del package_1 1.0-1 [680 kB]
Del package_2 2.4-1 [1,024 kB]
...

Remove all packages that are no longer needed

Code:

apt-get autoremove

Motivation:
After removing packages, some unnecessary dependencies might linger. apt-get autoremove finds and deletes these packages, optimizing system resources.

Explanation:

• apt-get: Calls the package manager.
• autoremove: Subcommand that removes packages installed as dependencies that are no longer used by any installed package.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  package1 package2 package3
...
After this operation, 45.6 MB disk space will be freed.
Do you want to continue? [Y/n]

Upgrade installed packages, remove obsolete packages, and install additional packages to meet new dependencies

Code:

apt-get dist-upgrade

Motivation:
apt-get dist-upgrade is the most comprehensive upgrade command. It not only upgrades packages like apt-get upgrade but also resolves changes in dependencies by removing obsolete packages and installing new ones, making it suitable for major system updates.

Explanation:

• apt-get: Invokes the package managing tool.
• dist-upgrade: Subcommand that goes beyond upgrading, handling dependency changes comprehensively through package additions or removals as needed.

Example Output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  package1 package2
The following NEW packages will be installed:
  package4
The following packages will be REMOVED:
  obsolete-package
...
After this operation, 10.6 MB of additional disk space will be used.
Do you want to continue? [Y/n]

Conclusion:

The apt-get command is a versatile tool for managing software packages on Debian-based Linux distributions. It is essential for installing, updating, upgrading, and removing packages, thus maintaining system stability and performance. While more recent versions of Ubuntu suggest using apt for interactive use, apt-get remains crucial for script-based or automated package management tasks. By understanding and utilizing each of its functionalities, users can finely control their system’s software landscape.