pbzip2
(1)
Name
pbzip2 - parallel bzip2 file compressor, v1.1.6
Synopsis
pbzip2 [ -123456789 ] [ -b#cdfhklm#p#qrS#tvVz ] [ filenames
... ]
Description
User Commands 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-sort-
ing 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 compat-
ible 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: autode-
tect)
SunOS 5.11 Last change: 1
User Commands pbzip2(1)
-q,--quiet
Quiet mode (default)
-r,--read
Read entire input file into RAM and split between pro-
cessors
-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 - forbid-
den)
If no file names are given, pbzip2 compresses or decom-
presses 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 can-
not be split between processors.
EXAMPLES
Example 1: pbzip2 myfile.tar
SunOS 5.11 Last change: 2
User Commands pbzip2(1)
This example will compress the file "myfile.tar" into the
compressed file "myfile.tar.bz2". It will use the autode-
tected # 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 autode-
tected # 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 proces-
sors 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_com-
press/" 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 autode-
tected # 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
SunOS 5.11 Last change: 3
User Commands pbzip2(1)
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 com-
pressing 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://compres-
sion.ca/pbzip2/.
SunOS 5.11 Last change: 4