dpkg: Listing installed packages

Written by Benjamin Cane on 2011-08-27

If you want to check what packages are installed on a debian based machine you can use dpkg.

slize:~# dpkg --list  
Desired=Unknown/Install/Remove/Purge/Hold  
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend  
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)  
||/ Name Version Description  
+++-===========================================  
ii adduser 3.110 add and remove users and groups  
ii apache2 2.2.9-10+lenny7 Apache HTTP Server metapackage  
ii apache2-mpm-prefork 2.2.9-10+lenny7 Apache HTTP Server - traditional non-threaded model

Or if you are looking for a specific package you can put the name after the command.

slize:~# dpkg --list apache2  
Desired=Unknown/Install/Remove/Purge/Hold  
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend  
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)  
||/ Name Version Description  
+++-=============================================================-ii  
apache2 2.2.9-10+lenny7 Apache HTTP Server metapackage

Picture of Benjamin Cane

Benjamin's specialty is keeping the lights on for mission critical systems. He is currently building applications that enable high concurrency financial transactions.

Recently Benjamin published his first book; Red Hat Enterprise Linux Troubleshooting Guide. In addition to writing, he has several Open Source projects focused on making Ops easier. These projects include Automatron, a project enabling auto-healing infrastructure for the masses.


Publications

Identify, capture and resolve common issues faced by Red Hat Enterprise Linux administrators using best practices and advanced troubleshooting techniques

What people are saying:
Excellent, excellent resource for practical guidance on how to troubleshoot a wide variety of problems on Red Hat Linux. I particularly enjoyed how the author made sure to provide solid background and practical examples. I have a lot of experience on Red Hat but still came away with some great practical tools to add to my toolkit. - Amazon Review