PIGZ man page on Archlinux

Printed from http://www.polarhome.com/service/man/?qf=PIGZ&af=0&tf=2&of=Archlinux

PIGZ(1)								       PIGZ(1)

NAME
       pigz, unpigz - compress or expand files

SYNOPSIS
       pigz  [ -cdfhikKlLnNqrRtTz0..9,11 ] [ -b blocksize ] [ -p threads ] [ -S suffix
       ] [ name ...  ]
       unpigz [ -cfhikKlLnNqrRtTz ] [ -b blocksize ] [ -p threads ] [ -S  suf‐
       fix ] [ name ...	 ]

DESCRIPTION
       Pigz  compresses	 using	threads to make use of multiple processors and
       cores.  The input is broken up into 128 KB chunks with each  compressed
       in  parallel.  The individual check value for each chunk is also calcu‐
       lated in parallel.  The compressed data is written in order to the out‐
       put, and a combined check value is calculated from the individual check
       values.

       The compressed data format generated is in the gzip, zlib,  or  single-
       entry zip format using the deflate compression method.  The compression
       produces partial raw deflate streams which are concatenated by a single
       write thread and wrapped with the appropriate header and trailer, where
       the trailer contains the combined check value.

       Each partial raw deflate stream is terminated by an empty stored	 block
       (using  the  Z_SYNC_FLUSH option of zlib), in order to end that partial
       bit stream at a byte boundary.  That allows the partial streams	to  be
       concatenated simply as sequences of bytes.  This adds a very small four
       to five byte overhead to the output for each input chunk.

       The default input block size is 128K, but can be changed	 with  the  -b
       option.	The number of compress threads is set by default to the number
       of online processors, which can be changed using the -p option.	Speci‐
       fying -p 1 avoids the use of threads entirely.

       The  input blocks, while compressed independently, have the last 32K of
       the previous block loaded as a preset dictionary to preserve  the  com‐
       pression	 effectiveness	of  deflating in a single thread.  This can be
       turned off using the -i or --independent option, so that the blocks can
       be  decompressed independently for partial error recovery or for random
       access.

       Decompression can't be parallelized, at	least  not  without  specially
       prepared	 deflate  streams  for that purpose.  As a result, pigz uses a
       single thread (the main thread)	for  decompression,  but  will	create
       three  other threads for reading, writing, and check calculation, which
       can speed up decompression under some circumstances.   Parallel	decom‐
       pression	 can  be turned off by specifying one process ( -dp 1 or -tp 1
       ).

       Compressed files can be restored to their original form using  pigz  -d
       or unpigz.

OPTIONS
       -# --fast --best
	      Regulate	the  speed of compression using the specified digit #,
	      where -1 or --fast  indicates  the  fastest  compression	method
	      (less  compression)  and -9 or --best indicates the slowest com‐
	      pression method (best compression).  -0 is no compression.   -11
	      gives  a few percent better compression at a severe cost in exe‐
	      cution time.  The default is -6.

       -b --blocksize mmm
	      Set compression block size to mmmK (default 128KiB).

       -c --stdout --to-stdout
	      Write all processed output to stdout (won't delete).

       -d --decompress --uncompress
	      Decompress the compressed input.

       -f --force
	      Force overwrite, compress .gz, links, and to terminal.

       -h --help
	      Display a help screen and quit.

       -i --independent
	      Compress blocks independently for damage recovery.

       -k --keep
	      Do not delete original file after processing.

       -K --zip
	      Compress to PKWare zip (.zip) single entry format.

       -l --list
	      List the contents of the compressed input.

       -L --license
	      Display the pigz license and quit.

       -n --no-name
	      Do not store or restore file name in/from header.

       -N --name
	      Store/restore file name and mod time in/from header.

       -p --processes n
	      Allow up to n processes (default is the number of online proces‐
	      sors)

       -q --quiet --silent
	      Print no messages, even on error.

       -r --recursive
	      Process the contents of all subdirectories.

       -R --rsyncable
	      Input-determined block locations for rsync.

       -S --suffix .sss
	      Use suffix .sss instead of .gz (for compression).

       -t --test
	      Test the integrity of the compressed input.

       -T --no-time
	      Do not store or restore mod time in/from header.

       -v --verbose
	      Provide more verbose output.

       -V --version
	      Show the version of pigz.

       -z --zlib
	      Compress to zlib (.zz) instead of gzip format.

       --     All  arguments  after  "--" are treated as file names (for names
	      that start with "-")

       These options are unique to the -11 compression level:

       -F --first
	      Do iterations first, before block split (default is last).

       -I, --iterations n
	      Number of iterations for optimization (default 15).

       -M, --maxsplits n
	      Maximum number of split blocks (default 15).

       -O --oneblock
	      Do not split into smaller blocks (default is block splitting).

COPYRIGHT NOTICE
       This software is provided 'as-is', without any express or implied  war‐
       ranty.	In  no	event  will  the author be held liable for any damages
       arising from the use of this software.

       Copyright (C) 2007, 2008, 2009,	2010,  2011,  2012,  2013  Mark	 Adler
       <madler@alumni.caltech.edu>

				     local			       PIGZ(1)
[top]

List of man pages available for Archlinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net