diffoscope
==========

diffoscope will try to get to the bottom of what makes files or
directories different. It will recursively unpack archives of many kinds
and transform various binary formats into more human readable form to
compare them. It can compare two tarballs, ISO images, or PDF just as
easily.

It can be scripted through error codes, and a report can be produced
with the detected differences. The report can be text or HTML.
When no type of report has been selected, diffoscope defaults
to write a text report on the standard output.

diffoscope is developed as part of the `“reproducible builds” Debian
project <https://wiki.debian.org/ReproducibleBuilds>`_.
It is meant to be able to quickly understand why two builds of the same
package produce different outputs. diffoscope was previously named
debbindiff.

Example
-------

To compare two files in-depth and produce an HTML report, run something like::

    $ bin/diffoscope --html output.html build1.changes build2.changes

diffoscope will exit with 0 if there's no differences and 1 if there
are.

*diffoscope* can also compare non-existent files::

    $ bin/diffoscope /nonexistent archive.zip

To get all possible options, run::

    $ bin/diffoscope --help

External dependencies
---------------------

diffoscope requires Python 3 and the following modules available on PyPI:
`libarchive-c <https://pypi.python.org/pypi/libarchive-c>`_,
`python-magic <https://pypi.python.org/pypi/python-magic>`_.

Optionally, the following modules will enhance it:

* ``tlsh`` is used to recognize file renames.
  It is build from `tlsh source
  <https://github.com/trendmicro/tlsh>`_.
  Available on Debian as ``python3-tlsh``.
* ``python-debian`` is used to inspect Debian control files.
  It is available on `PyPI <https://pypi.python.org/pypi/python-debian>`_.
* ``rpm-python`` is used to inspect RPM files.
  It is built from `rpm
  <http://rpm.org/>`_.
  Available on Debian and Fedora as ``python3-rpm``.
* ``Magic-file-extension`` can be used instead of
  ``python-magic``. It is built from `file
  <http://www.darwinsys.com/file/>`_.
  Available on Debian and Fedora as ``python3-magic``.

The various comparators rely on external commands being available. To
get a list of them, please run::

    $ bin/diffoscope --list-tools

Contributors
------------

Lunar, Reiner Herrmann, Chris Lamb, Helmut Grohne, Holger Levsen,
Mattia Rizzolo, Daniel Kahn Gillmor, Paul Gevers, Peter De Wachter,
Yasushi SHOJI, Clemens Lang, Ed Maste, Joachim Breitner, Mike McQuaid.
Baptiste Daroussin, Levente Polyak.

Contact
-------

Please report bugs and send patches through the Debian bug tracking
system against the diffoscope package:
<https://bugs.debian.org/src:diffoscope>

Join the users and developers mailing-list:
<https://lists.reproducible-builds.org/listinfo/diffoscope>

diffoscope website is at <https://diffoscope.org/>

License
-------

diffoscope 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.

diffoscope 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 diffoscope.  If not, see <http://www.gnu.org/licenses/>.
