GNU Cppi

GNU Cppi indents C preprocessor directives to reflect their nesting, among other regularizations.


Cppi is available on the main GNU download server (HTTPSHTTPFTP) and its mirrors; please use a mirror if possible.


Documentation for Cppi is available online, as is documentation for most GNU software. You may also find more information about Cppi by running info cppi or man cppi, or by looking at /usr/doc/cppi/, /usr/local/doc/cppi/, or similar directories on your system. A brief summary is available by running cppi --help.

Mailing lists

Cppi has one mailing list: <>.

This list is used to discuss all aspects of Cppi, including general discussion, user help, and enhancement requests, as well as bug reports.

Announcements about Cppi and most other GNU software are made on <>.

To subscribe to these or any GNU mailing lists, please send an empty mail with a Subject: header line of just “subscribe” to the relevant -request list. For example, to subscribe yourself to the GNU announcement list, you would send mail to <>. Or you can use the mailing list web interface.

Getting involved

Development of Cppi, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, it's a good idea to join the discussion mailing list (see above).

For development sources, bug and patch trackers, and other information, please see the Cppi project page at
Translating Cppi
To translate Cppi's messages into other languages, please see the Translation Project page for Cppi. If you have a new translation of the message strings, or updates to the existing strings, please have the changes made in this repository, otherwise they will not be incorporated into Cppi. For more information, see the Translation Project.
Cppi is currently being maintained by Jim Meyering. Please use the mailing list for contact.


Cppi 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.