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[Lzip-bug] Plzip 1.7 released

From: Antonio Diaz Diaz
Subject: [Lzip-bug] Plzip 1.7 released
Date: Mon, 12 Feb 2018 16:56:22 +0100
User-agent: Mozilla/5.0 (X11; U; Linux i586; en-US; rv: Gecko/20110420 SeaMonkey/2.0.14

I am pleased to announce the release of plzip 1.7.

Plzip is a massively parallel (multi-threaded) lossless data compressor based on the lzlib compression library, with a user interface similar to the one of lzip, bzip2 or gzip.

Plzip can compress/decompress large files on multiprocessor machines much faster than lzip, at the cost of a slightly reduced compression ratio (0.4 to 2 percent larger compressed files). Note that the number of usable threads is limited by file size; on files larger than a few GB plzip can use hundreds of processors, but on files of only a few MB plzip is no faster than lzip.

Plzip uses the lzip file format; the files produced by plzip are fully compatible with lzip-1.4 or newer, and can be rescued with lziprecover.

The lzip file format is designed for data sharing and long-term archiving, taking into account both data integrity and decoder availability.

The homepage is at http://www.nongnu.org/lzip/plzip.html

The sources can be downloaded from http://download.savannah.gnu.org/releases/lzip/plzip/

The sha256sums are:
70697c1b1f76e8e85ecbd7d1cb96eb545e52972dfbf76fb34b9a3f4c87e559dd plzip-1.7.tar.lz 95e22cdd98eb2f41bf4fb169530a5945aad2fec20c2e2284d597e77972baf2b7 plzip-1.7.tar.gz

This release is also GPG signed. You can download the signature by appending '.sig' to the URL. If the 'gpg --verify' command fails because you don't have the required public key, then run this command to import it:

  gpg --keyserver keys.gnupg.net --recv-keys 8FE99503132D7742

Key fingerprint = 1D41 C14B 272A 2219 A739  FA4F 8FE9 9503 132D 7742

Changes in version 1.7:

* When compressing on a 32 bit system, plzip now tries to limit the memory use to under 2.22 GiB (4 worker threads at level -9) by reducing the number of threads below the system's default.

  * The option '--loose-trailing', has been added.

* The test used by plzip to discriminate trailing data from a corrupt header in multimember regular (seekable) files has been improved to a Hamming distance (HD) of 3, and the 3 bit flips must happen in different magic bytes for the test to fail. As a consequence some kinds of files no longer can be appended to a lzip file as trailing data unless the '--loose-trailing' option is used when decompressing.
Lzlib 1.10 or newer is required for this test to work on non-seekable files.
Lziprecover can be used to remove conflicting trailing data from a file.

* The 'bits/byte' ratio has been replaced with the inverse compression ratio in the output.

* The progress of decompression is now shown at verbosity level 2 (-vv) or higher.

  * Progress of (de)compression is only shown if stderr is a terminal.

* A second '.lz' extension is no longer added to the argument of '-o' if it already ends in '.lz' or '.tlz'.

* The dictionary size is now shown at verbosity level 4 (-vvvv) when decompressing or testing.

* The new chapter "Meaning of plzip's output", and a block diagram of plzip have been added to the manual.

Please send bug reports and suggestions to address@hidden

Antonio Diaz, plzip co-author and maintainer.

If you are distributing software in xz format, please consider using lzip instead. See http://www.nongnu.org/lzip/lzip_benchmark.html#xz1 and http://www.nongnu.org/lzip/xz_inadequate.html

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