dpkg-licenses

A command line tool which lists the licenses of all installed packages in a Debian-based system (like Ubuntu)

How it works

Almost every package in Debian contains a copyright file in /usr/share/doc/<packagename>/copyright. Unfortunately, this file was initially a plain-text file without a specified format, not even specified what it should contain. In 2012, Debian tried to change this by specifying a machine-readable format (http://dep.debian.net/deps/dep5/). Until now, this specification is not a requirement, and many developers don't care about it, so that reading out the licenses of all packages is still a pain. But in business, there is a regular demand for such license information.

A google search showed me that until now nobody tried to parse these files or found another approach to lists the licenses:

dpkg-licenses tries to read these well-formatted licenses file and has multiple fallbacks for the case that it isn't well-formatted. You can probably imagine how hard it is to read a license from a unformatted plain-text file.

Feel free to try this tool. Any suggestions are welcome.

Sample output

$ ./dpkg-licenses
St  Name             Version               Arch   Description                                   Licenses
--  ----             -------               ----   -----------                                   --------
ii  accountsservice  0.6.35-0ubuntu7.2     amd64  query and manipulate user account informatio  GPL-2+ GPL-3+
ii  acl              2.2.52-1              amd64  Access control list utilities                 GPL LGPL-2.1
ii  acpi-support     0.142                 amd64  scripts for handling many ACPI events         GPL-2+
ii  acpid            1:2.0.21-1ubuntu2     amd64  Advanced Configuration and Power Interface e  GPL-2
ii  adduser          3.113+nmu3ubuntu3     all    add and remove users and groups               GPL-2
ii  alsa-base        1.0.25+dfsg-0ubuntu4  all    ALSA driver configuration files               GPL-2
ii  alsa-utils       1.0.27.2-1ubuntu2     amd64  Utilities for configuring and using ALSA      GPL-2
ii  anacron          2.3-20ubuntu1         amd64  cron-like program that doesn't go by time     GPL-2

CSV format

To get parsable format without shortened fields, use --csv (-c) flag:

$ ./dpkg-licenses -c
"St","Name","Version","Arch","Description","Licenses"
"ii","accountsservice","0.6.35-0ubuntu7.2","amd64","query and manipulate user account information","GPL-2+ GPL-3+"
"ii","acl","2.2.52-1","amd64","Access control list utilities","GPL LGPL-2.1"
"ii","acpid","1:2.0.21-1ubuntu2","amd64","Advanced Configuration and Power Interface event daemon","GPL-2"
...

Output quality

The output quality on an average workspace Ubuntu installation looks like this:

$ ./dpkg-licenses >output.txt 2>errors.txt
$ cat output.txt | cut -c135- | wc -l
2230
$ cat output.txt | cut -c135- | grep unknown | wc -l
228

Interpretation: 2230 installed packages, success rate of tool is 1−(228/2230) = 90%

However, there is still a lot of garbage:

ii  autoconf          2.69-6                      all    automatic configure script builder                   GFDL-1.3+ GPL-2+ GPL-2+ with Autoconf exception GPL-3+ GPL-3+ with Autoconf exception GPL-3+ with Texinfo exception MIT-X-Consortium no-modification other permissive permissive-long-disclaimer permissive-short-disclaimer permissive-without-disclaimer permissive-without-notices-or-disclaimer
ii  bc                1.06.95-8ubuntu1            amd64  GNU bc arbitrary precision calculator language       GPL-2.0+ GPL-2.0+ with Texinfo exception permissive X11 and public-domain
ii  cron              3.0pl1-124ubuntu2           amd64  process scheduling daemon                            Artistic GPL-2+ ISC Paul Vixie's license Paul Vixie's license and GPL-2+ and ISC
ii  fonts-opensymbol  2:102.6+LibO4.2.8-0ubuntu3  all    OpenSymbol TrueType font                             Apache-2.0 BSD-3-clause BSD-4-clause CDDL-1.0 CDDL-1.0 | GPPL-2 GPL GPL-1 GPL-2 GPL-2+ GPL-2 | LGPL-2.1 | MPL-1.1 LGPL LGPL-2+ LGPL2+ LGPL-2.1 LGPL-2 | Apache-2.0 LGPL-3 LGPL | Apache-2.0 MIT MIT/X MPL-1.1 MPL-1.1 | GPL-2 | LGPL-2 MPL-1.1 | GPL-3+ | LGPL-3+ MPL-1.1 | LGPL-2.1 MPL 1.1 | LGPL-2+ | GPL-2+ MPL-2.0 other PSF-2 public-domain W3C Zlib
ii  ghostscript       9.10~dfsg-0ubuntu10.4       amd64  interpreter for the PostScript language and for PDF  AFPL AFPL~AFPL AGPL-3+ Apache-2.0 BSD-3-Clause BSD-3-Clause~Adobe Expat Expat~Ghostgum Expat~SunSoft Expat~SunSoft with SunSoft exception GAP~configure GPL GPL-2+ GPL-2+ or AFPL~AFPL GPL-2+ with Autoconf exception GPL-2+ with Libtool exception GPL-2+~you GPL-2+~you or AFPL GPL-2+~you or AFPL~AFPL GPL-3+ GPL-3+~Artifex GPL~CUPS GPL~LIPS GPL~URW GPL~URW with font exception icclib LGPL-2.1+ LGPL-2.1+ and LGPL-2.1+~program-in-file LGPL-2.1~pcl3 LGPL-2.1+~program-in-file NTP~Lucent NTP~Open NTP~WSU other PD Unicode UNKNOWN ZLIB

Copyright

Copyright 2016 Daniel Alder, https://github.com/daald

dpkg-licenses was written by Daniel Alder, https://github.com/daald

dpkg-licenses is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

dpkg-licenses is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with dpkg-licenses.  If not, see <http://www.gnu.org/licenses/>.