XZ Utils

XZ Utils

XZ Utils

XZ Utils is free general-purpose data compression software with high compression ratio. XZ Utils were written for POSIX-like systems, but also work on some not-so-POSIX systems. XZ Utils are the successor to LZMA Utils.

The core of the XZ Utils compression code is based on LZMA SDK, but it has been modified quite a lot to be suitable for XZ Utils. The primary compression algorithm is currently LZMA2, which is used inside the .xz container format. With typical files, XZ Utils create 30 % smaller output than gzip and 15 % smaller output than bzip2.

XZ Utils consist of several components:

• liblzma is a compression library with API similar to that of zlib.
• xz is a command line tool with syntax similar to that of gzip.
• xzdec is a decompression-only tool smaller than the full-featured xz tool.
• A set of shell scripts (xzgrep, xzdiff, etc.) have been adapted from gzip to ease viewing, grepping, and comparing compressed files.
• Emulation of command line tools of LZMA Utils eases transition from LZMA Utils to XZ Utils.

While liblzma has a zlib-like API, liblzma doesn't include any file I/O functions. A separate I/O library is planned, which would abstract handling of .gz, .bz2, and .xz files with an easy to use API.