Debian Software Package Management(dpkg) in Linux

Debian Software Package Management(dpkg) is the low-level package management system used in Debian-based Linux operating systems. It installs, removes, configures, and manages software packages in the .deb format without handling dependencies automatically.

• Command-line tool for managing Debian (.deb) packages
• Installs and configures software directly on the filesystem
• Maintains a local database of installed packages
• Acts as the backend for higher-level tools like apt

Example: Listing the debian packages

dpkg -l

This command displays a list of all installed Debian packages on the system.

Output:

Key Features

1. Low-Level Package Control

• Directly installs, removes, and configures .deb packages
• Provides fine-grained control over individual package operations

2. Package Database Management

• Maintains a local record of installed packages
• Tracks the current state of each package on the system

3. System-Level Operation

• Interacts directly with the Linux filesystem
• Manages package-related configuration files and scripts

4. Backend for Higher-Level Tools

• Acts as the core engine for apt and similar tools
• Executes actual package installation and removal tasks

Syntax:

dpkg [options] action

• options: optional tags that modify the behavior of dpkg
• action: specifies what dpkg should do

Common dpkg Commands

1. Installing a stand-alone package

To install a package, -i flag is used. To install a stand-alone package using the Debian package.

Syntax:

sudo dpkg -i name_of_package.deb

Command:

sudo dpkg -i atom-amd64.deb

This command installs a standalone .deb package for Atom, an open-source text editor.

Output:

2. Removing a package

To remove a package, the -r flag is used with the dpkg command.

Syntax:

sudo dpkg -r name_of_package

Command:

sudo dpkg -r atom

This command is used to remove the Atom text editor package from the system while keeping its configuration files intact.

Output:

3. Purging a Package

The -P (purge) flag removes the package along with all configuration files.

Command:

sudo dpkg -P googler

This command completely removes the package and its configuration files from the system.

Output:

4. Finding a Specific Installed Package

To search for a particular package, the output of dpkg -l can be filtered using the grep command.

Command:

dpkg -l | grep atom

This command displays information only about the specified package if it is installed on the system.

Output:

5. Listing All Available dpkg Commands

To list all available options and commands supported by dpkg, the --help option is used.

Command:

dpkg -–help

This command displays a help menu containing all available dpkg commands and options.

Output:

• The following are the a few more options of dpkg:

6. View the content of a particular package

To view the content of the particular package -c flag is used

Command:

dpkg -c flashplugin-nonfree_3.2_i386.deb

This command lists all files that will be installed by the specified Debian package.

Output:

7. Printing the System Architecture

The --print-architecture option displays the system architecture

Command:

dpkg --print-architecture

This command outputs the system architecture, such as amd64, i386, or arm64.

Output:

8. Unpacking a Package

To unpack a package without configuring it, the --unpack flag is used.

Command:

dpkg --unpack flashplugin-nonfree_3.2_i386.deb

This command extracts the package files but does not configure the package.

Output:

• To configure it later:

Command:

dpkg --configure flashplugin-nonfree

Output:

9. Checking Whether a Package Is Installed

To check if a particular package is installed or not -s flag is used.

Command:

dpkg -s git

Output:

10. Reconfigure the installed package

To reconfigure the already installed package dpkg-reconfigure command is used

Command:

dpkg-reconfigure [package-name]

This command re-runs the configuration process for the specified package.

11. Locating Installed Package Files

The location of the installed package can be found using -L flag.

Syntax:

dpkg -L [package-name]

Command:

dpkg -L git

Output:

12. Checking for Package Issues

To check for partially installed or broken packages, the --audit option is used.

Command:

dpkg --audit

This command reports any issues related to package installation or configuration.

13. Clearing Available Package Information

To erase stored information about available packages, the --clear-avail option is used.

Command:

dpkg –-clear-avail

This command clears cached information about available packages from the system.

14. Display dpkg version

dpkg –version is used to display dpkg version information.

Command:

sudo dpkg --version

This command shows the current version of the Debian package manager installed on the system.

Output: