This is Bzip2/libbz2; a program and library for lossless, block-sorting data compression.

This document pertains to the Bzip2 feature development effort hosted on GitLab.com.

The documentation here may differ from that on the Bzip2 1.0.x project page maintained by Mark Wielaard onsourceware.org.

Copyright (C) 1996-2010 Julian Seward [email protected]

Copyright (C) 2019-2020 Federico Mena Quintero [email protected]

Copyright (C) 2021 Micah Snyder.

Please read the WARNING, DISCLAIMER and PATENTS sections in this file for important information.

This program is released under the terms of the license contained in the COPYING file.

This version is fully compatible with the previous public releases.

Complete documentation is available in Postscript form (manual.ps), PDF (manual.pdf) or HTML (manual.html). A plain-text version of the manual page is available as bzip2.txt.

There is a code of conduct for contributors to Bzip2/libbz2. Please see the code-of-conduct.md file.

The Bzip2 project is hosted on GitLab for feature development work. It can be found at https://gitlab.com/bzip2/bzip2

Changes to be included in the next feature version are committed to the master branch.

Feature releases are maintained in release/* branches.

Long-term feature and experimental development will occur in feature branches. Feature branches are unstable. Feature branches may be rebased and force- pushed on occasion to keep them up-to-date and to resolve merge conflicts.

The rustify branch is a feature branch that represents an effort to gradually port Bzip2 to Rust.

Please report bugs via GitLab Issues.

Before you create a new issue, please verify that no one else has already reported the same issue.

Please see the COMPILING.md file for details. This includes instructions for building using Meson or CMake.

This program and library (attempts to) compress data by performing several non-trivial transformations on it. Unless you are 100% familiar with all the algorithms contained herein, and with the consequences of modifying them, you should NOT meddle with the compression or decompression machinery. Incorrect changes can and very likely will lead to disastrous loss of data.

Please contact the maintainers if you want to modify the algorithms.

I TAKE NO RESPONSIBILITY FOR ANY LOSS OF DATA ARISING FROM THE USE OF THIS PROGRAM/LIBRARY, HOWSOEVER CAUSED.

Every compression of a file implies an assumption that the compressed file can be decompressed to reproduce the original. Great efforts in design, coding and testing have been made to ensure that this program works correctly.

However, the complexity of the algorithms, and, in particular, the presence of various special cases in the code which occur with very low but non-zero probability make it impossible to rule out the possibility of bugs remaining in the program.

DO NOT COMPRESS ANY DATA WITH THIS PROGRAM UNLESS YOU ARE PREPARED TO ACCEPT THE POSSIBILITY, HOWEVER SMALL, THAT THE DATA WILL NOT BE RECOVERABLE.

That is not to say this program is inherently unreliable. Indeed, I very much hope the opposite is true. Bzip2/libbz2 has been carefully constructed and extensively tested.

To the best of my knowledge, Bzip2/libbz2 does not use any patented algorithms. However, I do not have the resources to carry out a patent search. Therefore I cannot give any guarantee of the above statement.

As of June 2021, Micah Snyder is the maintainer of Bzip2/libbz2 for feature development work (I.e. versions 1.1+).

The Bzip2 feature development project is hosted on GitLab and can be found at https://gitlab.com/bzip2/bzip2

Bzip2 version 1.0 is maintained by Mark Wielaard at Sourceware and can be found at https://sourceware.org/git/?p=bzip2.git

Thanks to Julian Seward, the original author of Bzip2/libbz2, for creating the program and making it a very compelling alternative to previous compression programs back in the early 2000's. Thanks to Julian also for letting Federico, Mark, and Micah carry on with the maintainership of the program.