    Description

    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.

    When compressing, plzip divides the input file into chunks and
    compresses as many chunks simultaneously as worker threads are chosen,
    creating a multimember compressed file.

    When decompressing, plzip decompresses as many members simultaneously as
    worker threads are chosen. Files that were compressed with lzip will not
    be decompressed faster than using lzip (unless the "-b" option was used)
    because lzip usually produces single-member files, which can't be
    decompressed in parallel.

    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 lzip format provides very safe integrity checking and some data
         recovery means. The lziprecover program can repair bit-flip errors
         (one of the most common forms of data corruption) in lzip files,
         and provides data recovery capabilities, including error-checked
         merging of damaged copies of a file.

       * The lzip format is as simple as possible (but not simpler). The
         lzip manual provides the source code of a simple decompressor along
         with a detailed explanation of how it works, so that with the only
         help of the lzip manual it would be possible for a digital
         archaeologist to extract the data from a lzip file long after
         quantum computers eventually render LZMA obsolete.

       * Additionally the lzip reference implementation is copylefted, which
         guarantees that it will remain free forever.

    A nice feature of the lzip format is that a corrupt byte is easier to
    repair the nearer it is from the beginning of the file. Therefore, with
    the help of lziprecover, losing an entire archive just because of a
    corrupt byte near the beginning is a thing of the past.

    Plzip uses the same well-defined exit status values used by lzip and
    bzip2, which makes it safer than compressors returning ambiguous warning
    values (like gzip) when it is used as a back end for other programs like
    tar or zutils.

    Plzip will automatically use the smallest possible dictionary size for
    each file without exceeding the given limit. Keep in mind that the
    decompression memory requirement is affected at compression time by the
    choice of dictionary size limit.

    When compressing, plzip replaces every file given in the command line
    with a compressed version of itself, with the name "original_name.lz".
    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

    (De)compressing a file is much like copying or moving it; therefore plzip
    preserves the access and modification dates, permissions, and, when
    possible, ownership of the file just as "cp -p" does. (If the user ID or
    the group ID can't be duplicated, the file permission bits S_ISUID and
    S_ISGID are cleared).

    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.

    Copyright (C) 2009-2017 Antonio Diaz Diaz.

    This file is free documentation: you have unlimited permission to copy,
    distribute and modify it.

    The file Makefile.in is a data file used by configure to produce the
    Makefile. It has the same copyright owner and permissions that configure
    itself.