Top 29 APT Commands Every Linux User Should Know

APT (Advanced Package Tool) is a powerful package management system used in Debian-based Linux distributions such as Ubuntu, Kali Linux, and Raspberry Pi OS. It simplifies package installation, removal, and updates while automatically resolving dependencies, making it an essential tool for managing software on Linux systems.

This guide provides an in-depth look at APT, including its syntax, commands, and advanced usage.

APT Command Syntax

APT commands follow a simple syntax:

apt [options] [package_name]

The options define the operation to be performed, such as installing, removing, updating, or upgrading packages.

Managing Packages with APT

1. Update the package list
2. Check for upgradable packages
3. Upgrade all installed packages
4. Perform a full system upgrade
5. Upgrade the system while handling dependency changes
6. Install a package
7. Remove a package while keeping configuration files
8. Remove a package along with its configuration files
9. Reinstall a package
10. Remove unused dependencies
11. Clean the APT cache
12. Search for a package
13. Show detailed package information
14. List all installed packages
15. Check package dependencies
16. Check reverse dependencies
17. View package source information
18. Download a package without installing it
19. Fetch the source code of a package
20. Check package changelog
21. Fix broken dependencies
22. Force reconfiguration of installed packages
23. Unlock APT when another process is using it
24. Search for a package
25. Show package details
26. Check package dependencies
27. List reverse dependencies
28. View available package names
29. Check package policy

1. Update the package list

apt update

This command refreshes the local package index, allowing APT to fetch the latest available versions from repositories.

2. Check for upgradable packages

apt list --upgradable

Displays a list of installed packages that have newer versions available.

3. Upgrade all installed packages

apt upgrade -y

Updates all installed packages to their latest versions without removing obsolete ones.

4. Perform a full system upgrade (including dependency changes and obsolete package removals)

apt full-upgrade -y

This command upgrades packages and removes outdated or unnecessary dependencies.

5. Upgrade the system while handling dependency changes

apt dist-upgrade -y

Similar to full-upgrade, but it also considers changes in package dependencies and removes conflicting packages if necessary.

6. Install a package

apt install package_name -y

Installs the specified package and its dependencies.

7. Remove a package while keeping configuration files

apt remove package_name -y

Uninstalls the package but retains its configuration files in case you reinstall it later.

8. Remove a package along with its configuration files

apt remove --purge package_name -y

Completely removes the package and its configuration files.

9. Reinstall a package

apt reinstall package_name

Useful if a package is corrupted or needs to be restored to its default state.

10. Remove unused dependencies

apt autoremove -y

Uninstalls packages that were automatically installed as dependencies but are no longer needed.

11. Clean the APT cache

apt autoclean

Deletes outdated package files from the cache, freeing up disk space.

12. Search for a package

apt search package_name

Lists packages that match the specified keyword.

13. Show detailed package information

apt show package_name

Displays information such as version, dependencies, and maintainer.

14. List all installed packages

apt list --installed

Shows all packages currently installed on the system.

15. Check package dependencies

apt depends package_name

Displays a list of required dependencies for the specified package.

16. Check reverse dependencies (which packages depend on this package)

apt rdepends package_name

Lists other packages that depend on the specified package.

17. View package source information

apt showsrc package_name

Retrieves details about the source package from which a binary package is built.

18. Download a package without installing it

apt download package_name

Fetches the package file but does not install it.

19. Fetch the source code of a package

apt source package_name

Downloads the source code for the specified package.

20. Check package changelog

apt changelog package_name

Displays the version history and changes made to the package.

21. Fix broken dependencies

apt --fix-broken install

Repairs package dependency issues by installing missing dependencies.

22. Force reconfiguration of installed packages

dpkg --configure -a

This command is useful when installation processes are interrupted.

23. Unlock APT when another process is using it

rm /var/lib/dpkg/lock
rm /var/lib/dpkg/lock-frontend

This can resolve issues where APT is locked due to an incomplete or interrupted operation.

24. Search for a package

apt-cache search package_name

Searches for available packages.

25. Show package details

apt-cache show package_name

Displays detailed package information.

26. Check package dependencies

apt-cache depends package_name

Lists the dependencies of a package.

27. List reverse dependencies

apt-cache rdepends package_name

Shows which packages depend on a given package.

28. View available package names

apt-cache pkgnames

Lists all available package names in the repositories.

29. Check package policy (installed vs available versions)

apt-cache policy package_name

Displays the installed version and available versions of a package.

Conclusion

APT is an indispensable tool for managing software on Debian-based systems. Understanding its commands helps ensure a well-maintained and optimized system. Whether you’re updating packages, installing new software, or troubleshooting dependency issues, APT provides a comprehensive and efficient way to manage your Linux environment.