Tribblix: manual page: plzip.1

PLZIP(1) User Commands PLZIP(1)

NAME

plzip - reduces the size of files

SYNOPSIS

plzip [options] [files]

DESCRIPTION

Plzip is a massively parallel (multi-threaded) implementation of
lzip. Plzip uses the compression library lzlib.

Lzip is a lossless data compressor with a user interface similar to
the one of gzip or bzip2. Lzip uses a simplified form of LZMA
(Lempel-Ziv-Markov chain-Algorithm) designed to achieve complete
interoperability between implementations. The maximum dictionary size
is 512 MiB so that any lzip file can be decompressed on 32-bit
machines. Lzip provides accurate and robust 3-factor integrity
checking. 'lzip -0' compresses about as fast as gzip, while 'lzip -9'
compresses most files more than bzip2. Decompression speed is
intermediate between gzip and bzip2. Lzip provides better data
recovery capabilities than gzip and bzip2. Lzip has been designed,
written, and tested with great care to replace gzip and bzip2 as
general-purpose compressed format for Unix-like systems.

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
smaller than 1 MiB plzip is no faster than lzip (not even at
compression level -0). The number of threads defaults to the number
of processors.

OPTIONS

-h, --help
display this help and exit

-V, --version
output version information and exit

-a, --trailing-error
exit with error status if trailing data

-B, --data-size=<bytes>
set size of input data blocks [2x8=16 MiB]

-c, --stdout
write to standard output, keep input files

-d, --decompress
decompress, test compressed file integrity

-f, --force
overwrite existing output files

-F, --recompress
force re-compression of compressed files

-k, --keep
keep (don't delete) input files

-l, --list
print (un)compressed file sizes

-m, --match-length=<bytes>
set match length limit in bytes [36]

-n, --threads=<n>
set number of (de)compression threads [2]

-o, --output=<file>
write to <file>, keep input files

-q, --quiet
suppress all messages

-s, --dictionary-size=<bytes>
set dictionary size limit in bytes [8 MiB]

-t, --test
test compressed file integrity

-v, --verbose
be verbose (a 2nd -v gives more)

-0 .. -9
set compression level [default 6]

--fast alias for -0

--best alias for -9

--loose-trailing
allow trailing data seeming corrupt header

--in-slots=<n>
number of 1 MiB input packets buffered [4]

--out-slots=<n>
number of 1 MiB output packets buffered [64]

--check-lib
compare version of lzlib.h with liblz.{a,so}

If no file names are given, or if a file is '-', plzip compresses or
decompresses from standard input to standard output. Numbers may be
followed by a multiplier: k = kB = 10^3 = 1000, Ki = KiB = 2^10 =
1024, M = 10^6, Mi = 2^20, G = 10^9, Gi = 2^30, etc... Dictionary
sizes 12 to 29 are interpreted as powers of two, meaning 2^12 to 2^29
bytes.

The bidimensional parameter space of LZMA can't be mapped to a linear
scale optimal for all files. If your files are large, very
repetitive, etc, you may need to use the options --dictionary-size
and --match-length directly to achieve optimal performance.

To extract all the files from archive 'foo.tar.lz', use the commands
'tar -xf foo.tar.lz' or 'plzip -cd foo.tar.lz | tar -xf -'.

Exit status: 0 for a normal exit, 1 for environmental problems (file
not found, invalid command-line options, I/O errors, etc), 2 to
indicate a corrupt or invalid input file, 3 for an internal
consistency error (e.g., bug) which caused plzip to panic.

REPORTING BUGS

Report bugs to lzip-bug@nongnu.org
Plzip home page: http://www.nongnu.org/lzip/plzip.html

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