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 was initially started by the "reproducible builds" Debian project and now being developed as part of the (wider) “Reproducible Builds” initiative. It is meant to be able to quickly understand why two builds of the same package produce different outputs. diffoscope was previously named debbindiff.

See the COMMAND-LINE EXAMPLES section further below to get you started, as well as more detailed explanations of all the command-line options. The same information is also available in /usr/share/doc/diffoscope/README.rst or similar.

Exit status

Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.

Command-line examples

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

If you have enough RAM, you can improve performance by running:

$ TMPDIR=/run/shm bin/diffoscope very-big-input-0/ very-big-input-1/

By default this allowed to use up half of RAM; for more add something like:

tmpfs   /run/shm    tmpfs   size=80%    0   0

to your /etc/fstab; see man mount for details.

External dependencies

diffoscope requires Python 3 and the following modules available on PyPI: libarchive-c, python-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, Mattia Rizzolo, Ximin Luo, Helmut Grohne, Holger Levsen, 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>

For more instructions, see CONTRIBUTING.rst in this directory.

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 <https://www.gnu.org/licenses/>.

See also

• <https://diffoscope.org/>
• <https://wiki.debian.org/ReproducibleBuilds>