XZ Utils for Debian =================== Contents: 1. Differences from standard XZ Utils 2. History 3. LZMA Utils compatibility 4. Configuration Differences from standard XZ Utils ---------------------------------- * The soname of standard liblzma was bumped to 5.0.0, while Debian liblzma remains at 2.0.0. * Some corners of the liblzma API (like layout of reserved fields) have therefore been maintained at an older version in Debian liblzma. Pre-compiled applications built against liblzma on other distributions are likely not to work on this version of Debian if an additional compatibility library is not installed. See /usr/share/doc/liblzma2/README.Debian for details. History ------- XZ Utils should have been called LZMA Utils 4.42, but it came too late. The old .lzma file format has some problems, worst of which is the lack of magic number, but it gets enough use to still need to be supported. See /usr/share/doc/xz-utils/history.txt.gz for the full story. LZMA Utils compatibility ------------------------ To support old scripts and muscle memory, XZ Utils can emulate the legacy LZMA Utils interface. To use this feature, you can install some subset of the following list of symbolic links to your $PATH. lzma, unlzma, lzcat -> /usr/bin/xz lzgrep, lzegrep, lzfgrep -> /usr/bin/xzgrep lzless -> /usr/bin/xzless lzmore -> /usr/bin/xzmore lzdiff, lzcmp -> /usr/bin/xzdiff To allow administrators to keep the old lzma package, the xz-utils package does not provide those links itself. If you would like XZ Utils to provide these commands by default for all users, install the xz-lzma package. Configuration ------------- The memory usage of xz can vary from a few hundred kilobytes to several gigabytes depending on the compression settings. If you would like xz to automatically scale down its settings while compressing to decrease memory usage, you can declare so by adding an option like the following to your environment (e.g., in ~/.profile): XZ_DEFAULTS=--memlimit-compress=256MiB export XZ_DEFAULTS See the "Memory usage" section of the xz(1) manual page for details. -- Jonathan Nieder Mon, 25 Oct 2010 12:29:25 -0500