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Pixz (pronounced 'pixie') is a parallel, indexing version of XZ. The existing XZ Utils ( http://tukaani.org/xz/ ) provide great compression in the .xz file format, but they have two significant problems: * They are single-threaded, while most users nowadays have multi-core computers. * The .xz files they produce are just one big block of compressed data, rather than a collection of smaller blocks. This makes random access to the original data impossible. With pixz, both these problems are solved. The most useful commands: $ pixz foo.tar foo.tpxz # Compress and index a tarball, multi-core $ pixz -l foo.tpxz # Very quickly list the contents of the compressed tarball $ pixz -d foo.tpxz foo.tar # Decompress it, multi-core $ pixz -x dir/file < foo.tpxz | tar x # Very quickly extract a file, multi-core. # Also verifies that contents match index. $ tar -Ipixz -cf foo.tpxz foo # Create a tarball using pixz for multi-core compression $ pixz bar bar.xz # Compress a non-tarball, multi-core $ pixz -d bar.xz bar # Decompress it, multi-core Specifying input and output: $ pixz < foo.tar > foo.tpxz # Same as 'pixz foo.tar foo.tpxz' $ pixz -i foo.tar -o foo.tpxz # Ditto. These both work for -x, -d and -l too, eg: $ pixz -x -i foo.tpxz -o foo.tar file1 file2 ... # Extract the files from foo.tpxz into foo.tar $ pixz foo.tar # Compress it to foo.tpxz, removing the original $ pixz -d foo.tpxz # Extract it to foo.tar, removing the original Other flags: $ pixz -1 foo.tar # Faster, worse compression $ pixz -9 foo.tar # Better, slower compression $ pixz -t foo.tar # Compress but don't treat it as a tarball (don't index it) $ pixz -d -t foo.tpxz # Decompress foo, don't check that contents match index $ pixz -l -t foo.tpxz # List the xz blocks instead of files WARNING: Running pixz without the -t flag will cause it to treat the input as a tarball, as long as it looks vaguely tarball-like. This means if the file starts with at least 1024 zero bytes, pixz will assume it's empty, and truncate the output! If your input files aren't tarballs, run with -t or face possible data-loss. Compare to: plzip * About equally complex, efficient * lzip format seems less-used * Version 1 is theoretically indexable...I think ChopZip * Python, much simpler * More flexible, supports arbitrary compression programs * Uses streams instead of blocks, not indexable * Splits input and then combines output, much higher disk usage pxz * Simpler code * Uses OpenMP instead of pthreads * Uses streams instead of blocks, not indexable * Uses temp files and doesn't combine them until the whole file is compressed, high disk/memory usage Comparable tools for other compression algorithms: pbzip2 * Not indexable * Appears slow * bzip2 algorithm is non-ideal pigz * Not indexable dictzip * Not parallel Requirements: * libarchive 2.8 or later * liblzma 4.999.9-beta-212 or later (from the xz distribution)