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Updated: July 2017
 
 

pbzip2 (1)

Name

pbzip2 - parallel bzip2 file compressor, v1.1.6

Synopsis

pbzip2 [ -123456789 ] [ -b#cdfhklm#p#qrS#tvVz ] [ filenames ...  ]

Description

pbzip2(1)                   General Commands Manual                  pbzip2(1)



NAME
       pbzip2  -  parallel bzip2 file compressor, v1.1.6

SYNOPSIS
       pbzip2 [ -123456789 ] [ -b#cdfhklm#p#qrS#tvVz ] [ filenames ...  ]

DESCRIPTION
       pbzip2  is  a  parallel  implementation of the bzip2 block-sorting file
       compressor that uses pthreads and achieves near-linear speedup  on  SMP
       machines.  The  output  of  this version is fully compatible with bzip2
       v1.0.2 or newer (ie: anything compressed  with  pbzip2  can  be  decom-
       pressed with bzip2).

       pbzip2  should  work  on  any system that has a pthreads compatible C++
       compiler (such as gcc). It has been tested on: Linux, Windows (cygwin),
       Solaris, Tru64/OSF1, HP-UX, and Irix.

       The  default settings for pbzip2 will work well in most cases. The only
       switch you will likely need to use is -d to decompress files and -p  to
       set  the  #  of  processors for pbzip2 to use if autodetect is not sup-
       ported on your system, or you want to use a specific # of CPUs.

OPTIONS
       -b#    Where # is block size in 100k steps (default 9 = 900k)

       -c, --stdout
              Output to standard out (stdout)

       -d,--decompress
              Decompress file

       -f,--force
              Force, overwrite existing output file

       -h,--help
              Print this help message

       -k,--keep
              Keep input file, do not delete

       -l,--loadavg
              Load average determines max number processors to use

       -m#    Where # is max memory usage in 1MB steps (default 100 = 100MB)

       -p#    Where # is the number of processors (default: autodetect)

       -q,--quiet
              Quiet mode (default)

       -r,--read
              Read entire input file into RAM and split between processors

       -S#    Child thread stack size in 1KB  steps  (default  stack  size  if
              unspecified)

       -t,--test
              Test compressed file integrity

       -v,--verbose
              Verbose mode

       -V     Display version info for pbzip2 then exit

       -z,--compress
              Compress file (default)

       -1,--fast ... -9,--best
              Set BWT block size to 100k .. 900k (default 900k).

       --ignore-trailing-garbage=#
              Ignore trailing garbage flag (1 - ignored; 0 - forbidden)

       If  no  file  names  are  given, pbzip2 compresses or decompresses from
       standard input to standard output.

FILE SIZES
       You should be able to compress files larger than 4GB with pbzip2.

       Files that are compressed with pbzip2 are broken  up  into  pieces  and
       each individual piece is compressed.  This is how pbzip2 runs faster on
       multiple CPUs since the pieces can be compressed  simultaneously.   The
       final  .bz2  file may be slightly larger than if it was compressed with
       the regular bzip2 program due to this file splitting (usually less than
       0.2%  larger).   Files  that  are compressed with pbzip2 will also gain
       considerable speedup when decompressed using pbzip2.

       Files that were compressed using bzip2 will not see speedup since bzip2
       packages the data into a single chunk that cannot be split between pro-
       cessors.

EXAMPLES
       Example 1: pbzip2 myfile.tar

       This example will compress the file "myfile.tar"  into  the  compressed
       file "myfile.tar.bz2". It will use the autodetected # of processors (or
       2 processors if autodetect not supported) with the default  file  block
       size of 900k and default BWT block size of 900k.

       Example 2: pbzip2 -b15k myfile.tar

       This  example  will  compress the file "myfile.tar" into the compressed
       file "myfile.tar.bz2". It will use the autodetected # of processors (or
       2  processors  if  autodetect  not supported) with a file block size of
       1500k and a BWT block size of 900k. The file "myfile.tar" will  not  be
       deleted after compression is finished.

       Example 3: pbzip2 -p4 -r -5 myfile.tar second*.txt

       This  example  will  compress the file "myfile.tar" into the compressed
       file "myfile.tar.bz2". It will use 4 processors with a BWT  block  size
       of  500k.  The file block size will be the size of "myfile.tar" divided
       by 4 (# of processors) so that the data will be split evenly among each
       processor.   This  requires  you have enough RAM for pbzip2 to read the
       entire file into memory for compression. Pbzip2 will then use the  same
       options  to  compress  all  other  files  that match the wildcard "sec-
       ond*.txt" in that directory.

       Example 4: tar cf myfile.tar.bz2 --use-compress-prog=pbzip2 dir_to_com-
       press/
       Example 4: tar -c directory_to_compress/ | pbzip2 -c > myfile.tar.bz2

       These  examples  will  compress the data being given to pbzip2 via pipe
       from TAR into the compressed file "myfile.tar.bz2".  It  will  use  the
       autodetected  #  of  processors (or 2 processors if autodetect not sup-
       ported) with the default file block size of 900k and default BWT  block
       size  of  900k.   TAR  is  collecting all of the files from the "direc-
       tory_to_compress/" directory and passing  the  data  to  pbzip2  as  it
       works.

       Example 5: pbzip2 -d -m500 myfile.tar.bz2

       This  example will decompress the file "myfile.tar.bz2" into the decom-
       pressed file "myfile.tar". It will use the autodetected # of processors
       (or 2 processors if autodetect not supported). It will use a maximum of
       500MB of memory for decompression.  The switches -b, -r, and -1..-9 are
       not valid for decompression.

       Example 6: pbzip2 -dc myfile.tar.bz2 | tar x

       This example will decompress and untar the file "myfile.tar.bz2" piping
       the output of the decompressing pbzip2 to tar.

       Example 7: pbzip2 -c < myfile.txt > myfile.txt.bz2

       This example will read myfile.txt from standard input compressing it to
       standard output which is redirected to to myfile.txt.bz2.


ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | compress/pbzip2  |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+
SEE ALSO
       bzip2(1) gzip(1) lzip(1) rzip(1) zip(1)

AUTHOR
       Jeff Gilchrist

       http://compression.ca



NOTES
       This     software     was    built    from    source    available    at
       https://java.net/projects/solaris-userland.   The  original   community
       source        was        downloaded        from         http://compres-
       sion.ca/pbzip2/pbzip2-1.1.6.tar.gz

       Further information about this software can be found on the open source
       community website at http://compression.ca/pbzip2/.



                                                                     pbzip2(1)