License Part II and Quick start

Using lbzip2 should be straightforward for most of users because it is fully compatible with bzip2. Additionally, lbzip2 usage is very similar to other compressors, like gzip and xz, so users of these programs should have no problems using lbzip2.

There’s a chance that lbzip2 is already installed in your system. You can check this by running:

If lbzip2 is not installed then system shell will print something like “command not found”. Otherwise version of installed lbzip2 will be printed. The latest released version of lbzip2 is 2.5. It’s recommended to use the latest version if possible. If you can’t upgrade lbzip2 installed in your system then you can build and install a local copy.

lbzip2 is shipped with number of operating systems. It is recommended to use packaging management software of your system to install system version of lbzip2. If you can’t or don’t want to do this, you can compile lbzip2 from sources.

This document presents only basic usage of lbzip2. More advanced usage, including all available options, is described in detail in the manual. You are encouraged to see the manual if this document doesn’t give enough information.

File compression

To compress a single file you can simply run:

This command will replace file_name with its compressed form – file_name.bz2. The original file will be deleted upon successful compression. You can keep it by specifying --keep parameter (-k in short):

lbzip2 doesn’t output any logging information during normal operation. Error messages are printed only on failure, but also warnings can be printed in some cases too. More verbose logging can be turned on by specifying --verbose option (-v in short):

lbzip2 doesn’t output any logging information during normal operation. Error messages are printed only on failure, but also warnings can be printed in some cases too. More verbose logging can be turned on by specifying --verbose option (-v in short):

If no file names are given as command line arguments then lbzip2 works in filter mode. This means that lbzip2 will compress or decompress data from standard input to standard output. For example:

To extract all files just skip the files-to-be-extracted part.

The above commands will use lbzip2 only if bzip2 is not installed or tar was configured to work with lbzip2. Otherwise you can pass an additional --use-compress-program option to tar to make it use lbzip2, for example:

lbzip2 works well with pipes, so you can redirect standard streams to a pipe. The following example concatenates several compressed files, sorts them and writes merged output to a single file.

 

License

lbzip2 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.

lbzip2 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.

A copy of the GNU General Public License is included below.

The GNU General Public License is a free, copyleft license for
software and other kinds of works.

The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom to
share and change all versions of a program–to make sure it remains free
software for all its users. We, the Free Software Foundation, use the
GNU General Public License for most of our software; it applies also to
any other work released this way by its authors. You can apply it to
your programs, too.

When we speak of free software, we are referring to freedom, not
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To protect your rights, we need to prevent others from denying you
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FAQ

What does it mean that lbzip2 is a block compressor?

It means that if file being compressed is big enough lbzip2 will internally divide it into blocks of data and compresses them independently. This allows number of blocks to be processed in parallel, as well as makes it possible to recover data from partially damaged .bz2 files. It does not mean that lbzip2 can compress only block devices, nor that input file size must be multiply of block size.

Why progress estimation doesn’t work with pipes?

Knowledge of input file length is necessary for lbzip2 to be able to estimate current progress and predict ETA. lbzip2 uses fstat(2) system call to obtain this information. When processing files which size is not available, such as pipes, named FIFO queues, or some special devices) lbzip2 has no way of measuring progress.

Does lbzip2 support non-regular files?

Yes, lbzip2 should work correctly with almost any kind of files. This includes regular disk files, pipes, block devices, character devices, FIFOs, network sockets, UNIX-domain sockets, streams and any other special files, as long as they support read(2) and/or write(2) system calls. Files don’t need to support random access system calls, like lseek(2) or pread(2).

Note that when you execute lbzip2 from shell you probably will only be able to open named files and pipes. For example, lbzip2 won’t open any network connections on its own, but it should work with network sockets if you pass it as one of three standard file descriptors.

How can I enable progress indicator by default?

By default lbzip2 doesn’t display any information about files it processes. This behavior follows what bzip2 does. Progress measurement can be useful, especially when processing large files.

You can pass any arguments to lbzip2 via it’s environmental variable LBZIP2. Simply add a line such as this to your shell configuration file:

For more information about environmental variables and options accepted by lbzip2, see the manual page.

What’s the recommended way of using lbzip2 with GNU tar?

GNU tar has built-in support for lbzip2. This means it will use lbzip2 for compression and decompression of bz2 tarballs provided that bzip2 is not installed.

To use lbzip2 no matter if bzip2 is installed or not, you need to configure it at build time or use --use-compress-program option. For more information see GNU tar documentation about using lbzip2 with GNU tar.

How can I concatenate compressed files?

To concatenate files while recompressing them you can run:

Files in bz2 format can be simply concatenated without decompression, so it is also possible to concatenate them directly – just use the cat utility:

The second solution may be faster, but be aware that it is also less portable. While lbzip2 and recent versions of bzip2 will be able to decompress the resulting file, other software may have problems. In particular the following software is known not to support concatenated streams: libbzip2 (all versions), bzip2 older than version 0.9.0, Apache Commons Compress.

lbzip2 -> parallel bzip2 compression utility

The latest released version of lbzip2 is 2.5. You can see its release notes or download it.

If you don’t know what is lbzip2 then keep reading this introduction. If you are looking for examples how to use it then you should read quick start.

If you need help, found a bug or want to request a feature then you can contact lbzip2 maintainer. Any feedback is welcome too.

Introduction

lbzip2 is a free, multi-threaded compression utility with support for bzip2 compressed file format.

lbzip2 can process standard bz2 files in parallel. It uses POSIX threading model (pthreads), which allows it to take full advantage of symmetric multiprocessing (SMP) systems. It has been proven to scale linearly, even to over one hundred processor cores.

lbzip2 is fully compatible with bzip2 – both at file format and command line level. Files created by lbzip2 can be decompressed by all versions of bzip2 and other software supporting bz2 format. lbzip2 can decompress any bz2 files in parallel. All bzip2 command-line options are also accepted by lbzip2. This makes lbzip2 a drop-in replacement for bzip2.

lbzip2 is portable. It was successfully compiled and ran on wide variety of operating systems and on multiple hardware architectures. It is included in most popular GNU/Linux distributions.

Quality is essential. It was achieved by careful design and thorough testing. lbzip2 test suite consists of more than 300,000 test cases, which are ran on several system architectures before every release. The code is checked using different static analysis tools.

Download

The latest version of lbzip2 is 2.5. For older versions, see below.

lbzip2 is released in form of source code only – lbzip2 authors themselves don’t provide pre-built binaries. You can either download source tarball of released versions of lbzip2 (recommended), or check out development branch.

Before trying to compile lbzip2 from source you should consider checking repositories of your operating system distribution. A number of systems ships packaged lbzip2 binaries. For many others lbzip2 is available from external repositories. See below.

Source code

You can download source tarball of the latest released version here: lbzip2-2.5.tar.gz, or in bz2 format: lbzip2-2.5.tar.bz2. Downloadable tarballs of older releases are listed at the botton of this page.

For instructions how to build lbzip2 from source code unpack sources and read the INSTALL file included there. lbzip2 uses GNU build system, so compilation and installation usually boils down to the following sequence:

Development snapshots

lbzip2 uses Git for source configuration management. Full source code of all versions of lbzip2 is available in the Git repository on GitHub.

The repository is accessible through Git native protocol at git://github.com/kjn/lbzip2.git or more securely, through HTTPS at https://github.com/kjn/lbzip2.git. There is also a Subversion mirror available at https://github.com/kjn/lbzip2.

Git repositories don’t contain any bundled third-party code, pre-built binaries or autogenerated files. To build lbzip2 from Git you need to generate bootstrap it first. During this process a few source files are generated, others are copied from Gnulib. You need a few additional software dependencies. See BOOTSTRAP file for more information.

Pre-built binaries

lbzip2 is part of a number of operating systems. The following list includes distributions for which lbzip2 is known to be packaged. It can be either included in official repositories or available from third parties.

Please note that neither these distributions nor lbzip2 packages provided by them are supported or endorsed by lbzip2 authors; this list is provided merely for users’ convenience.