I want to write a script that outputs the license for every software package installed on my system.

Using dpkg --get-selections I am able to get list of everything installed. However, I don't see a way to get the license information for each package. For example, I can use aptitude show to get the properties of each package, but that does not include the license:

$ aptitude show apache2

Package: apache2

State: installed

Automatically installed: no

Version: 2.2.14-5ubuntu8.6

Priority: optional

Section: httpd

Maintainer: Ubuntu Developers <[email protected]>

Uncompressed Size: 36.9k

Depends: apache2-mpm-worker (= 2.2.14-5ubuntu8.6) | apache2-mpm-prefork (= 2.2.14-5ubuntu8.6) | apache2-mpm-event (= 2.2.14-5ubuntu8.6) | apache2-mpm-itk (= 2.2.14-5ubuntu8.6),

         apache2.2-common (= 2.2.14-5ubuntu8.6)

Provided by: apache2-mpm-event, apache2-mpm-itk, apache2-mpm-prefork, apache2-mpm-worker

Description: Apache HTTP Server metapackage

 The Apache Software Foundation's goal is to build a secure, efficient and extensible HTTP server as standards-compliant open source software. The result has long been the

 number one web server on the Internet. 



 It features support for HTTPS, virtual hosting, CGI, SSI, IPv6, easy scripting and database integration, request/response filtering, many flexible authentication schemes, and

 more.

Homepage: http://httpd.apache.org/

Is there a third-party repository that correlates the license to each package?

It sounds painful to download every source package and inspect it for licensing information, but maybe that's the best way.