[Complete Guide to Package Management in Ubuntu] Efficient Management Methods and Practical Use Cases

By 佐川 直弘 | Naohiro Sagawa (運営者)

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1. What is Package Management in Ubuntu?

The Basics of Package Management in Ubuntu

Ubuntu comes with a package management system that allows users to easily install, remove, and manage applications and tools. A package is a bundle that includes specific software, its dependencies, and configuration files. Efficient package management ensures system stability and security while facilitating development tasks and server operations.

The main functions of package management include:

• Installing and removing software:
  Using a package manager, you can install or remove software with simple commands.
• Managing dependencies:
  When installing software that depends on other packages, the package manager automatically resolves dependencies to ensure smooth operation.
• Version control:
  By managing package versions, you can keep your system up to date with the latest security patches and feature updates.

Why is Package Management Important?

Ubuntu is widely used as a server and desktop environment, with numerous open-source packages being updated daily. Efficient package management helps system administrators reduce security risks and maintain system stability. For developers and server administrators, managing packages properly is an essential task.

2. How to Check Installed Packages in Ubuntu

Using the apt Command

The apt command is one of the standard package management tools in Ubuntu. It allows you to install, update, remove, and check packages. The ability to list installed packages is particularly useful for system administrators.

Displaying Installed Packages

Run the following command to display all installed packages on your system:

sudo apt list --installed

The output includes a list of installed packages along with their versions and architectures. It also indicates whether a package was installed automatically. For example, you may see an output like this:

accountsservice/bionic,now 0.6.45-1ubuntu1 amd64 [installed,automatic]

Using the dpkg Command

The dpkg command provides more detailed information about installed packages, including descriptions and installation dates. Run the following command:

sudo dpkg-query -l

This command lists all installed packages with detailed information.

Using Snap and Flatpak

Snap and Flatpak are alternative package management systems that work differently from traditional deb packages. These require their own commands for package management.

• To list Snap packages:

snap list

• To list Flatpak packages:

flatpak list

These commands help manage packages that cannot be handled with traditional package managers.

3. How to Get Detailed Information About a Package

Using the apt-cache Command

If you need more details about a specific package, use the apt-cache command. This command provides information about package dependencies, versions, and descriptions.

Displaying Detailed Package Information

Run the following command to display details about a specific package:

apt-cache show package-name

For example, to view details about the nginx package, use:

apt-cache show nginx

This command displays details such as dependencies, versions, and descriptions.

4. How to Manage Packages Using a GUI

Using the Ubuntu Software Center

The “Ubuntu Software Center” is a graphical tool that allows users to manage packages without using commands. It is especially useful for beginners and those unfamiliar with the command line.

Checking Installed Packages via the Software Center

1. Open the Software Center
   From the desktop “Activities” menu, open “Ubuntu Software.”
2. Check Installed Packages
   Click the “Installed” tab to see a list of all installed packages.
3. View Package Details
   Click on a package to see details such as version, description, and installation date.