Dpkg is a tool to install, build, remove and manage Debian packages. The primary and more user friendly front-end for dpkg is aptitude.
Important flags
-i = install
-r = Remove package but keep configuration
-P = Remove/Delete everything including configuration files
-l = List all installed packages, along with package version and short description
-S = Find what package owns the file
-s = Check if package is installed and status
-L, --listfiles = List files installed to your system from package-name
This will output every package installed so it is best paired with grep
[gitlab] (~) >>> dpkg -l|grep sudo
ii sudo 1.8.3p1-1ubuntu3.6 Provide limited super user privileges to specific users[solaris] (~) >>> sudo dpkg -l apache2
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Description
+++-=====================-=====================-==========================================================
ii apache2 2.2.14-5ubuntu8.11 Apache HTTP Server metapackage
[solaris] (~) >>> dpkg -L apache2
/.
/usr
/usr/share
/usr/share/bug
/usr/share/bug/apache2
/usr/share/bug/apache2/control
/usr/share/doc
/usr/share/bug/apache2/script
/usr/share/doc/apache2
[solaris] (~) >>> dpkg -S /usr/bin/dig
dnsutils: /usr/bin/dig[solaris] (~) >>> dpkg -s lsof | grep Status
Status: install ok installedIf you want to remove the configuration files as well make sure to user the -P (for purge) flag:
[gitlab] (~) >>> dpkg -r jwhois
(Reading database ... 102422 files and directories currently installed.)
Removing jwhois ...
Processing triggers for install-info ...
Processing triggers for man-db ...
[gitlab] (~) >>> grep whois /etc/
[gitlab] (~) >>> ls /etc/|grep whois
jwhois.conf
[gitlab] (~) >>> dpkg -P jwhois
(Reading database ... 102396 files and directories currently installed.)
Removing jwhois ...
Purging configuration files for jwhois ...
[gitlab] (~) >>> ls /etc/|grep whois
[gitlab] (~) >>> For the sanity of my <pre> code tags I added the -q (or quiet option)
[gitlab] (~/test) >>> wget -q http://mirrors.kernel.org/ubuntu/pool/universe/j/jwhois/jwhois_4.0-2_amd64.deb
[gitlab] (~/test) >>> dpkg -i jwhois_4.0-2_amd64.deb
Selecting previously unselected package jwhois.
(Reading database ... 102394 files and directories currently installed.)
Unpacking jwhois (from jwhois_4.0-2_amd64.deb) ...
Setting up jwhois (4.0-2) ...
Adding group `jwhois' (GID 111) ...
Done.
Processing triggers for man-db ...
Processing triggers for install-info ...Reconfigures packages after they have already been installed. Pass it the names of a package or packages to reconfigure. It will ask configuration questions, much like when the package was first installed.
15 Practical Examples of “dpkg commands” for Debian Based Distros