brotli.1

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Author : Eugene Kliuchnikov
Date : 2018-02-26 09:04:36
Hash : 35e69fc7
Message : New feature: "Large Window Brotli" (#640) * New feature: "Large Window Brotli" By setting special encoder/decoder flag it is now possible to extend LZ-window up to 30 bits; though produced stream will not be RFC7932 compliant. Added new dictionary generator - "DSH". It combines speed of "Sieve" and quality of "DM". Plus utilities to prepare train corpora (remove unique strings). Improved compression ratio: now two sub-blocks could be stitched: the last copy command could be extended to span the next sub-block. Fixed compression ineffectiveness caused by floating numbers rounding and wrong cost heuristic. Other C changes: - combined / moved `context.h` to `common` - moved transforms to `common` - unified some aspects of code formatting - added an abstraction for encoder (static) dictionary - moved default allocator/deallocator functions to `common` brotli CLI: - window size is auto-adjusted if not specified explicitly Java: - added "eager" decoding both to JNI wrapper and pure decoder - huge speed-up of `DictionaryData` initialization * Add dictionaryless compressed dictionary * Fix `sources.lst` * Fix `sources.lst` and add a note that `libtool` is also required. * Update setup.py * Fix `EagerStreamTest` * Fix BUILD file * Add missing `libdivsufsort` dependency * Fix "unused parameter" warning.

docs/brotli.1

.TH "BROTLI" "1" "February 2018" "brotli 1.0.0" "User commands"
.SH "NAME"
\fBbrotli\fR \- brotli, unbrotli \- compress or decompress files
.SH SYNOPSIS
.P
\fBbrotli\fP [\fIOPTION|FILE\fR]\.\.\.
.P
\fBunbrotli\fP is equivalent to \fBbrotli \-\-decompress\fP
.SH DESCRIPTION
.P
\fBbrotli\fP is a generic\-purpose lossless compression algorithm that compresses
data using a combination of a modern variant of the \fBLZ77\fR algorithm, Huffman
coding and 2\-nd order context modeling, with a compression ratio comparable to
the best currently available general\-purpose compression methods\. It is similar
in speed with deflate but offers more dense compression\.
.P
\fBbrotli\fP command line syntax similar to \fBgzip (1)\fP and \fBzstd (1)\fP\|\.
Unlike \fBgzip (1)\fP, source files are preserved by default\. It is possible to
remove them after processing by using the \fB\-\-rm\fP \fIoption\fR\|\.
.P
Arguments that look like "\fB\-\-name\fP" or "\fB\-\-name=value\fP" are \fIoptions\fR\|\. Every
\fIoption\fR has a short form "\fB\-x\fP" or "\fB\-x value\fP"\. Multiple short form \fIoptions\fR
could be coalesced:
.RS 0
.IP \(bu 2
"\fB\-\-decompress \-\-stdout \-\-suffix=\.b\fP" works the same as
.IP \(bu 2
"\fB\-d \-s \-S \.b\fP" and
.IP \(bu 2
"\fB\-dsS \.b\fP"

.RE
.P
\fBbrotli\fP has 3 operation modes:
.RS 0
.IP \(bu 2
default mode is compression;
.IP \(bu 2
\fB\-\-decompress\fP option activates decompression mode;
.IP \(bu 2
\fB\-\-test\fP option switches to integrity test mode; this option is equivalent to
"\fB\-\-decompress \-\-stdout\fP" except that the decompressed data is discarded
instead of being written to standard output\.

.RE
.P
Every non\-option argument is a \fIfile\fR entry\. If no \fIfiles\fR are given or \fIfile\fR
is "\fB\-\fP", \fBbrotli\fP reads from standard input\. All arguments after "\fB\-\-\fP" are
\fIfile\fR entries\.
.P
Unless \fB\-\-stdout\fP or \fB\-\-output\fP is specified, \fIfiles\fR are written to a new file
whose name is derived from the source \fIfile\fR name:
.RS 0
.IP \(bu 2
when compressing, a suffix is appended to the source filename to
get the target filename
.IP \(bu 2
when decompressing, a suffix is removed from the source filename to
get the target filename

.RE
.P
Default suffix is \fB\|\.br\fP, but it could be specified with \fB\-\-suffix\fP option\.
.P
Conflicting or duplicate \fIoptions\fR are not allowed\.
.SH OPTIONS
.RS 0
.IP \(bu 2
\fB\-#\fP:
  compression level (0\-9); bigger values cause denser, but slower compression
.IP \(bu 2
\fB\-c\fP, \fB\-\-stdout\fP:
  write on standard output
.IP \(bu 2
\fB\-d\fP, \fB\-\-decompress\fP:
  decompress mode
.IP \(bu 2
\fB\-f\fP, \fB\-\-force\fP:
  force output file overwrite
.IP \(bu 2
\fB\-h\fP, \fB\-\-help\fP:
  display this help and exit
.IP \(bu 2
\fB\-j\fP, \fB\-\-rm\fP:
  remove source file(s); \fBgzip (1)\fP\-like behaviour
.IP \(bu 2
\fB\-k\fP, \fB\-\-keep\fP:
  keep source file(s); \fBzstd (1)\fP\-like behaviour
.IP \(bu 2
\fB\-n\fP, \fB\-\-no\-copy\-stat\fP:
  do not copy source file(s) attributes
.IP \(bu 2
\fB\-o FILE\fP, \fB\-\-output=FILE\fP
  output file; valid only if there is a single input entry
.IP \(bu 2
\fB\-q NUM\fP, \fB\-\-quality=NUM\fP:
  compression level (0\-11); bigger values cause denser, but slower compression
.IP \(bu 2
\fB\-t\fP, \fB\-\-test\fP:
  test file integrity mode
.IP \(bu 2
\fB\-v\fP, \fB\-\-verbose\fP:
  increase output verbosity
.IP \(bu 2
\fB\-w NUM\fP, \fB\-\-lgwin=NUM\fP:
  set LZ77 window size (0, 10\-24) (default: 22); window size is
  \fB(2**NUM \- 16)\fP; 0 lets compressor decide over the optimal value; bigger
  windows size improve density; decoder might require up to window size
  memory to operate
.IP \(bu 2
\fB\-S SUF\fP, \fB\-\-suffix=SUF\fP:
  output file suffix (default: \fB\|\.br\fP)
.IP \(bu 2
\fB\-V\fP, \fB\-\-version\fP:
  display version and exit
.IP \(bu 2
\fB\-Z\fP, \fB\-\-best\fP:
  use best compression level (default); same as "\fB\-q 11\fP"

.RE
.SH SEE ALSO
.P
\fBbrotli\fP file format is defined in
RFC 7932 \fIhttps://www\.ietf\.org/rfc/rfc7932\.txt\fR\|\.
.P
\fBbrotli\fP is open\-sourced under the
MIT License \fIhttps://opensource\.org/licenses/MIT\fR\|\.
.P
Mailing list: https://groups\.google\.com/forum/#!forum/brotli
.SH BUGS
.P
Report bugs at: https://github\.com/google/brotli/issues

kc3-lang/brotli/docs/brotli.1

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kc3-lang/brotli /docs/brotli.1