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 pbzip2(1)                                                         pbzip2(1)




 NAME
      pbzip2  -  parallel bzip2 file compressor, v1.1.8

 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
      decompressed 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
      supported 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)





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 pbzip2(1)                                                         pbzip2(1)




      -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 processors.

 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




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 pbzip2(1)                                                         pbzip2(1)




      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
      "second*.txt" in that directory.

      Example 4: tar cf myfile.tar.bz2 --use-compress-prog=pbzip2
      dir_to_compress/
      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
      supported) with the default file block size of 900k and default BWT
      block size of 900k.  TAR is collecting all of the files from the
      "directory_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
      decompressed 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.

 SEE ALSO
      bzip2(1) gzip(1) lzip(1) rzip(1) zip(1)





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 pbzip2(1)                                                         pbzip2(1)




 AUTHOR
      Jeff Gilchrist

      http://compression.ca


















































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