bzip3/bzip3.1.in

.TH @TRANSFORMED_PACKAGE_NAME@ 1 "@MAN_DATE@" "version v@VERSION@"
.
.SH NAME
@TRANSFORMED_PACKAGE_NAME@ \- an efficient statistical file compressor and spiritual successor
to bzip2

.SH SYNOPSIS
.B @TRANSFORMED_PACKAGE_NAME@
.RB [ " \-BbcdehftV " ]
[
.I "filenames \&..."
]
.
.P
.B bz3cat
is equivalent to
.B @TRANSFORMED_PACKAGE_NAME@ \-dc
.P
.B bunzip3
is equivalent to
.B @TRANSFORMED_PACKAGE_NAME@ \-d
.SH DESCRIPTION
Compress or decompress a file using run length encoding and Lempel Ziv
prediction, followed by the Burrows-Wheeler transform and arithmetic
coding.
.B @TRANSFORMED_PACKAGE_NAME@,
like its ancestor
.B bzip2,
excels at compressing text or source code.

The command-line options are deliberately very similar to
those of
.B bzip2,
but they are not identical.
.PP
.B @TRANSFORMED_PACKAGE_NAME@
expects at most two filenames intertwined with flags.
.B @TRANSFORMED_PACKAGE_NAME@
will by default not overwrite existing files.
If this behaviour is intended, use the \-f flag.

If no file names are specified,
.B @TRANSFORMED_PACKAGE_NAME@
will compress from standard input to standard output, refusing
to output binary data to a terminal. The \-e flag (encode) is implied.

.B bunzip3
(or,
.B @TRANSFORMED_PACKAGE_NAME@ \-d
equivalently) decompresses data from standard input to the standard
output, refusing to read from a terminal.

If two files are specified, the first one is used in place of
standard input, and the second one is used in place of standard
output.

If the \-c flag is present, @TRANSFORMED_PACKAGE_NAME@ will read from the specified
file and output data to standard output instead. Otherwise, if decoding,
.B @TRANSFORMED_PACKAGE_NAME@
will try to guess the decompressed filename by removing the
.I .bz3
extension. If not present, an error will be reported. If encoding,
the output filename will be generated by appending the
.I .bz3
extension to the input filename.

.SH OPTIONS
.TP
.B \-B --batch
Enable batch mode. By default,
.B @TRANSFORMED_PACKAGE_NAME@
will error if more than two files are passed, and the two files specified
are always treated as input and output. The batch mode makes
.B @TRANSFORMED_PACKAGE_NAME@
treat every file as input, so for example
.I @TRANSFORMED_PACKAGE_NAME@ -Bd *.bz3
will decompress all
.I .bz3
files in the current directory.
.TP
.B \-b --block N
Set the block size to N mebibytes. The minimum is 1MiB, the maximum is
511MiB.
.TP
.B \-c --stdout
Force writing output data to the standard output if one file is
specified.
.TP
.B \-d --decode
Force decompression.
.TP
.B \-e/-z --encode
Force compression (default behaviour).
.TP
.B \-f --force
Overwrite existing files.
.TP
.B \-h --help
Display a help message and exit.
.TP
.B \-j --jobs N
Set the amount of parallel worker threads that process one block each.
.TP
.B \--rm
Remove the input files after successful compression or decompression. This is
silently ignored if output is stdout.
.TP
.B \-k --keep
Keep (don't delete) the input files. Set by default, provided only
for compatibility with other compressors.
.TP
.B \-v --verbose
Set verbose output mode to see compression statistics.
.TP
.B \-V --version
Display version information and exit.
.TP
.B \-t --test
Verify the validity of compressed blocks.
.TP
.B \--
Treat all subsequent arguments as file names, even if they start with
a dash. This is so you can handle files with names beginning with a dash.
.SH FILE FORMAT

Compression is performed as long as the input block is longer
than 64 bytes. Otherwise, it's coded as a literal block. In all
other cases, the compressed data is written to the file. The
file format has constant overhead of 9 bytes per file and from
9 to 17 bytes per block. Random data is coded so that expansion
is generally under 0.8%.

.B @TRANSFORMED_PACKAGE_NAME@
uses 32-bit CRC to ensure that the decompressed version of a file is
identical to the original. This guards against corruption of the
compressed data. 

.SH MEMORY MANAGEMENT

The \-b flag sets the block size in mebibytes (MiB). The default is 16
MiB. Compression and decompression memory usage can be estimated as:

       6 x block size

Larger block sizes usually give rapidly diminishing returns.
It is also important to appreciate that the decompression memory
requirement is set at compression time by the choice of block size.
In general, try and use the largest block size memory constraints allow,
since that maximises the compression achieved.  Compression and
decompression speed are virtually unaffected by block size.

.SH AUTHOR
Kamila Szewczyk, kspalaiologos@gmail.com.

https://github.com/kspalaiologos/bzip3

Thanks to: Ilya Grebnov, Benjamin Strachan, Caleb Maclennan, Ilya Muravyov,
package maintainers - Leah Neukirchen, Grigory Kirillov, Maciej Barc, 
Robert Schutz, Petr Pisar, Przemyslaw Skibinski, Shun Sakai and others.
Also everyone who sent patches, helped with portability problems, encouraged
me to work on bzip3 and lent me machines for performance tests.

.SH "SEE ALSO"
\fBbzip2(1)\fR, \fBbz3less(1)\fR, \fBbz3more(1)\fR, \fBbz3grep(1)\fR, \fBbunzip3(1)\fR