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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 15:08:12 +0000
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+This is plzip.info, produced by makeinfo version 4.13 from
+plzip.texinfo.
+
+INFO-DIR-SECTION Data Compression
+START-INFO-DIR-ENTRY
+* Plzip: (plzip). Parallel version of the lzip data compressor
+END-INFO-DIR-ENTRY
+
+
+File: plzip.info, Node: Top, Next: Introduction, Up: (dir)
+
+Plzip Manual
+************
+
+This manual is for Plzip (version 0.1, 5 December 2009).
+
+* Menu:
+
+* Introduction:: Purpose and features of plzip
+* Invoking Plzip:: Command line interface
+* File Format:: Detailed format of the compressed file
+* Problems:: Reporting bugs
+* Concept Index:: Index of concepts
+
+
+ Copyright (C) 2008, 2009 Antonio Diaz Diaz.
+
+ This manual is free documentation: you have unlimited permission to
+copy, distribute and modify it.
+
+
+File: plzip.info, Node: Introduction, Next: Invoking Plzip, Prev: Top, Up: Top
+
+1 Introduction
+**************
+
+Plzip is a parallel version of the lzip data compressor. Currently only
+compression is performed in parallel. Parallel decompression is planned
+to be implemented soon.
+
+ Lzip is a lossless data compressor based on the LZMA algorithm, with
+very safe integrity checking and a user interface similar to the one of
+gzip or bzip2. Lzip decompresses almost as fast as gzip and compresses
+better than bzip2, which makes it well suited for software distribution
+and data archiving.
+
+ Plzip replaces every file given in the command line with a compressed
+version of itself, with the name "original_name.lz". Each compressed
+file has the same modification date, permissions, and, when possible,
+ownership as the corresponding original, so that these properties can be
+correctly restored at decompression time. Plzip is able to read from
+some types of non regular files if the `--stdout' option is specified.
+
+ If no file names are specified, plzip compresses (or decompresses)
+from standard input to standard output. In this case, plzip will
+decline to write compressed output to a terminal, as this would be
+entirely incomprehensible and therefore pointless.
+
+ Plzip will correctly decompress a file which is the concatenation of
+two or more compressed files. The result is the concatenation of the
+corresponding uncompressed files. Integrity testing of concatenated
+compressed files is also supported.
+
+ When decompressing, plzip attempts to guess the name for the
+decompressed file from that of the compressed file as follows:
+
+filename.lz becomes filename
+filename.tlz becomes filename.tar
+anyothername becomes anyothername.out
+
+ As a self-check for your protection, plzip stores in the member
+trailer the 32-bit CRC of the original data and the size of the
+original data, to make sure that the decompressed version of the data
+is identical to the original. This guards against corruption of the
+compressed data, and against undetected bugs in plzip (hopefully very
+unlikely). The chances of data corruption going undetected are
+microscopic, less than one chance in 4000 million for each member
+processed. Be aware, though, that the check occurs upon decompression,
+so it can only tell you that something is wrong. It can't help you
+recover the original uncompressed data.
+
+ Return values: 0 for a normal exit, 1 for environmental problems
+(file not found, invalid flags, I/O errors, etc), 2 to indicate a
+corrupt or invalid input file, 3 for an internal consistency error (eg,
+bug) which caused plzip to panic.
+
+
+File: plzip.info, Node: Invoking Plzip, Next: File Format, Prev: Introduction, Up: Top
+
+2 Invoking Plzip
+****************
+
+The format for running plzip is:
+
+ plzip [OPTIONS] [FILES]
+
+ Plzip supports the following options:
+
+`--help'
+`-h'
+ Print an informative help message describing the options and exit.
+
+`--version'
+`-V'
+ Print the version number of plzip on the standard output and exit.
+
+`--stdout'
+`-c'
+ Compress or decompress to standard output. Needed when reading
+ from a named pipe (fifo) or from a device.
+
+`--decompress'
+`-d'
+ Decompress.
+
+`--force'
+`-f'
+ Force overwrite of output file.
+
+`--keep'
+`-k'
+ Keep (don't delete) input files during compression or
+ decompression.
+
+`--match-length=LENGTH'
+`-m LENGTH'
+ Set the match length limit in bytes. Valid values range from 5 to
+ 273. Larger values usually give better compression ratios but
+ longer compression times.
+
+`--output=FILE'
+`-o FILE'
+ When reading from standard input and `--stdout' has not been
+ specified, use `FILE' as the virtual name of the uncompressed
+ file. This produces a file named `FILE' when decompressing, and a
+ file named `FILE.lz' when compressing.
+
+`--quiet'
+`-q'
+ Quiet operation. Suppress all messages.
+
+`--dictionary-size=SIZE'
+`-s SIZE'
+ Set the dictionary size limit in bytes. Valid values range from
+ 4KiB to 512MiB. Note that dictionary sizes are quantized. If the
+ specified size does not match one of the valid sizes, it will be
+ rounded upwards.
+
+`--test'
+`-t'
+ Check integrity of the specified file(s), but don't decompress
+ them. This really performs a trial decompression and throws away
+ the result. Use `-tvv' or `-tvvv' to see information about the
+ file.
+
+`--verbose'
+`-v'
+ Verbose mode. Show the compression ratio for each file processed.
+ Further -v's increase the verbosity level.
+
+`-1 .. -9'
+ Set the compression parameters (dictionary size and match length
+ limit) as shown in the table below. Note that `-9' can be much
+ slower than `-1'. These options have no effect when decompressing.
+
+ Level Dictionary size Match length limit
+ -1 1MiB 10 bytes
+ -2 1MiB 12 bytes
+ -3 1MiB 17 bytes
+ -4 2MiB 26 bytes
+ -5 4MiB 44 bytes
+ -6 8MiB 80 bytes
+ -7 16MiB 108 bytes
+ -8 16MiB 163 bytes
+ -9 32MiB 273 bytes
+
+`--fast'
+`--best'
+ Aliases for GNU gzip compatibility.
+
+
+
+ Numbers given as arguments to options may be followed by a multiplier
+and an optional `B' for "byte".
+
+ Table of SI and binary prefixes (unit multipliers):
+
+Prefix Value | Prefix Value
+k kilobyte (10^3 = 1000) | Ki kibibyte (2^10 = 1024)
+M megabyte (10^6) | Mi mebibyte (2^20)
+G gigabyte (10^9) | Gi gibibyte (2^30)
+T terabyte (10^12) | Ti tebibyte (2^40)
+P petabyte (10^15) | Pi pebibyte (2^50)
+E exabyte (10^18) | Ei exbibyte (2^60)
+Z zettabyte (10^21) | Zi zebibyte (2^70)
+Y yottabyte (10^24) | Yi yobibyte (2^80)
+
+
+File: plzip.info, Node: File Format, Next: Problems, Prev: Invoking Plzip, Up: Top
+
+3 File Format
+*************
+
+In the diagram below, a box like this:
++---+
+| | <-- the vertical bars might be missing
++---+
+
+ represents one byte; a box like this:
++==============+
+| |
++==============+
+
+ represents a variable number of bytes.
+
+
+ A lzip file consists of a series of "members" (compressed data sets).
+The members simply appear one after another in the file, with no
+additional information before, between, or after them.
+
+ Each member has the following structure:
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| ID string | VN | DS | Lzma stream | CRC32 | Data size | Member size |
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+ All multibyte values are stored in little endian order.
+
+`ID string'
+ A four byte string, identifying the member type, with the value
+ "LZIP".
+
+`VN (version number, 1 byte)'
+ Just in case something needs to be modified in the future. Valid
+ values are 0 and 1. Version 0 files have only one member and lack
+ `Member size'.
+
+`DS (coded dictionary size, 1 byte)'
+ Bits 4-0 contain the base 2 logarithm of the base dictionary size.
+ Bits 7-5 contain the number of "wedges" to substract from the base
+ dictionary size to obtain the dictionary size. The size of a wedge
+ is (base dictionary size / 16).
+ Valid values for dictionary size range from 4KiB to 512MiB.
+
+`Lzma stream'
+ The lzma stream, finished by an end of stream marker. Uses default
+ values for encoder properties.
+
+`CRC32 (4 bytes)'
+ CRC of the uncompressed original data.
+
+`Data size (8 bytes)'
+ Size of the uncompressed original data.
+
+`Member size (8 bytes)'
+ Total size of the member, including header and trailer. This
+ facilitates safe recovery of undamaged members from multimember
+ files.
+
+
+
+File: plzip.info, Node: Problems, Next: Concept Index, Prev: File Format, Up: Top
+
+4 Reporting Bugs
+****************
+
+There are probably bugs in plzip. There are certainly errors and
+omissions in this manual. If you report them, they will get fixed. If
+you don't, no one will ever know about them and they will remain unfixed
+for all eternity, if not longer.
+
+ If you find a bug in plzip, please send electronic mail to
+<lzip-bug@nongnu.org>. Include the version number, which you can find
+by running `plzip --version'.
+
+
+File: plzip.info, Node: Concept Index, Prev: Problems, Up: Top
+
+Concept Index
+*************
+
+
+* Menu:
+
+* bugs: Problems. (line 6)
+* file format: File Format. (line 6)
+* getting help: Problems. (line 6)
+* introduction: Introduction. (line 6)
+* invoking: Invoking Plzip. (line 6)
+* options: Invoking Plzip. (line 6)
+* usage: Invoking Plzip. (line 6)
+* version: Invoking Plzip. (line 6)
+
+
+
+Tag Table:
+Node: Top227
+Node: Introduction750
+Node: Invoking Plzip3401
+Node: File Format6746
+Node: Problems8702
+Node: Concept Index9231
+
+End Tag Table