dpkg Command in Debian.md

The dpkg command in Linux is the low-level package manager for Debian-based distributions like Ubuntu. It is used to install, remove, and manage .deb packages. Here's a list of common dpkg commands, along with example outputs:

1. Install a .deb package:

sudo dpkg -i <package_name>.deb

Example:

sudo dpkg -i mypackage.deb

Output:

Selecting previously unselected package mypackage.
(Reading database ... 12345 files and directories currently installed.)
Preparing to unpack mypackage.deb ...
Unpacking mypackage (1.0) ...
Setting up mypackage (1.0) ...

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2. Remove an installed package:

sudo dpkg -r <package_name>

Example:

sudo dpkg -r mypackage

Output:

(Reading database ... 12345 files and directories currently installed.)
Removing mypackage (1.0) ...

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3. Purge (remove) an installed package and its configuration files:

sudo dpkg -P <package_name>

Example:

sudo dpkg -P mypackage

Output:

(Reading database ... 12345 files and directories currently installed.)
Purging mypackage (1.0) ...

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4. List all installed packages:

dpkg -l

Example:

dpkg -l

Output:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Configured/Unpacked/Failed-Config/Half-Installed
|/ Error?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                   Version                Architecture            Description
+++-======================-======================-======================-=======================================================
ii  bash                   5.0-6ubuntu1.1         amd64                  GNU Bourne Again SHell
ii  libc6                  2.31-0ubuntu9.9        amd64                  GNU C Library: Shared libraries

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5. Show information about a specific package:

dpkg -s <package_name>

Example:

dpkg -s bash

Output:

Package: bash
Status: install ok installed
Priority: important
Section: shells
Installed-Size: 1168
Maintainer: Ubuntu Developers <[email protected]>
Architecture: amd64
Version: 5.0-6ubuntu1.1
Depends: libc6 (>= 2.17)
Description: GNU Bourne Again SHell

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6. List files installed by a specific package:

dpkg -L <package_name>

Example:

dpkg -L bash

Output:

/.
/usr
/usr/bin
/usr/bin/bash
/usr/share
/usr/share/man
/usr/share/man/man1
/usr/share/man/man1/bash.1.gz

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7. List the package that installed a specific file:

dpkg -S <file_name>

Example:

dpkg -S /usr/bin/bash

Output:

bash: /usr/bin/bash

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8. Check for missing dependencies (after using dpkg -i to install a package):

sudo dpkg --configure -a

Example:

sudo dpkg --configure -a

Output:

(Reading database ... 12345 files and directories currently installed.)
Setting up mypackage (1.0) ...

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9. Fix broken dependencies:

sudo apt-get install -f

(Although apt-get is not a dpkg command, it can be used to fix broken dependencies after dpkg operations.)

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10. Check the status of the package database:

dpkg --audit

Example:

dpkg --audit

Output:

dpkg: error: could not open package info file '/var/lib/dpkg/status': No such file or directory

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11. List all available dpkg options (help):

dpkg --help

Output:

Usage: dpkg [option...] <package_file...>
Options:
  -?, --help            Show this help message
  -D, --debug           Enable debugging output
  -i, --install         Install the package(s)
  -r, --remove          Remove the package(s)
  -P, --purge           Purge the package(s)
  -L, --listfiles       List files installed by package
  -S, --search          Search for a package owning a file
  -s, --status          Show package information

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