dd4f667e70
https://bugzilla.tianocore.org/show_bug.cgi?id=1201 Update Brotli to the latest version 1.0.6 https://github.com/google/brotli Verify VS2017, GCC5 build. Verify Decompression boot functionality. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Liming Gao <liming.gao@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com>
108 lines
3.5 KiB
Markdown
108 lines
3.5 KiB
Markdown
brotli(1) -- brotli, unbrotli - compress or decompress files
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================================================================
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SYNOPSIS
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--------
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`brotli` [*OPTION|FILE*]...
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`unbrotli` is equivalent to `brotli --decompress`
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DESCRIPTION
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-----------
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`brotli` is a generic-purpose lossless compression algorithm that compresses
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data using a combination of a modern variant of the **LZ77** algorithm, Huffman
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coding and 2-nd order context modeling, with a compression ratio comparable to
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the best currently available general-purpose compression methods. It is similar
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in speed with deflate but offers more dense compression.
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`brotli` command line syntax similar to `gzip (1)` and `zstd (1)`.
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Unlike `gzip (1)`, source files are preserved by default. It is possible to
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remove them after processing by using the `--rm` _option_.
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Arguments that look like "`--name`" or "`--name=value`" are _options_. Every
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_option_ has a short form "`-x`" or "`-x value`". Multiple short form _options_
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could be coalesced:
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* "`--decompress --stdout --suffix=.b`" works the same as
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* "`-d -s -S .b`" and
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* "`-dsS .b`"
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`brotli` has 3 operation modes:
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* default mode is compression;
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* `--decompress` option activates decompression mode;
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* `--test` option switches to integrity test mode; this option is equivalent to
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"`--decompress --stdout`" except that the decompressed data is discarded
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instead of being written to standard output.
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Every non-option argument is a _file_ entry. If no _files_ are given or _file_
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is "`-`", `brotli` reads from standard input. All arguments after "`--`" are
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_file_ entries.
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Unless `--stdout` or `--output` is specified, _files_ are written to a new file
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whose name is derived from the source _file_ name:
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* when compressing, a suffix is appended to the source filename to
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get the target filename
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* when decompressing, a suffix is removed from the source filename to
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get the target filename
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Default suffix is `.br`, but it could be specified with `--suffix` option.
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Conflicting or duplicate _options_ are not allowed.
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OPTIONS
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-------
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* `-#`:
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compression level (0-9); bigger values cause denser, but slower compression
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* `-c`, `--stdout`:
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write on standard output
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* `-d`, `--decompress`:
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decompress mode
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* `-f`, `--force`:
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force output file overwrite
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* `-h`, `--help`:
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display this help and exit
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* `-j`, `--rm`:
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remove source file(s); `gzip (1)`-like behaviour
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* `-k`, `--keep`:
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keep source file(s); `zstd (1)`-like behaviour
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* `-n`, `--no-copy-stat`:
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do not copy source file(s) attributes
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* `-o FILE`, `--output=FILE`
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output file; valid only if there is a single input entry
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* `-q NUM`, `--quality=NUM`:
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compression level (0-11); bigger values cause denser, but slower compression
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* `-t`, `--test`:
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test file integrity mode
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* `-v`, `--verbose`:
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increase output verbosity
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* `-w NUM`, `--lgwin=NUM`:
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set LZ77 window size (0, 10-24) (default: 22); window size is
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`(2**NUM - 16)`; 0 lets compressor decide over the optimal value; bigger
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windows size improve density; decoder might require up to window size
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memory to operate
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* `-S SUF`, `--suffix=SUF`:
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output file suffix (default: `.br`)
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* `-V`, `--version`:
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display version and exit
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* `-Z`, `--best`:
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use best compression level (default); same as "`-q 11`"
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SEE ALSO
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--------
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`brotli` file format is defined in
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[RFC 7932](https://www.ietf.org/rfc/rfc7932.txt).
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`brotli` is open-sourced under the
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[MIT License](https://opensource.org/licenses/MIT).
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Mailing list: https://groups.google.com/forum/#!forum/brotli
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BUGS
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----
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Report bugs at: https://github.com/google/brotli/issues
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