| XZ Utils for Debian |
| =================== |
| |
| Contents: |
| 1. History |
| 2. Differences from standard XZ Utils |
| 3. LZMA Utils compatibility |
| 4. Configuration |
| |
| 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. |
| |
| Differences from standard XZ Utils |
| ---------------------------------- |
| |
| The Debian package modifies liblzma to produce a more readable build |
| log and to avoid breakage when a binary links indirectly to liblzma |
| from Debian 6.0 (squeeze) and 7.0 (wheezy) at the same time. |
| |
| Patches applied: |
| |
| silent-rules: |
| build: Use AM_SILENT_RULES if requested. |
| |
| xz-block-list: |
| xz: Remove support for the --block-list option. |
| |
| abi-liblzma2-compat, configure-liblzma2-compat: |
| liblzma: Do not check reserved space past the historical end of |
| the lzma_stream structure if liblzma.so.2 is loaded in the same |
| process image. Likewise when building statically. |
| (See bug #649522.) |
| |
| 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 |
| |
| If you would like XZ Utils to provide these commands by default for |
| all users, use "update-alternatives --config lzma". |
| |
| 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 <jrnieder@gmail.com> Sat, 18 Aug 2012 03:18:42 -0700 |
