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-\."
-\." lz4.1: This is a manual page for 'lz4' program. This file is part of the
-\." lz4 <http://www.lz4.org/> project.
-\." Author: Yann Collet
-\."
-.
-\." No hyphenation
-.hy 0
-.nr HY 0
-.
-.TH lz4 "1" "2015-03-21" "lz4" "User Commands"
-.SH NAME
-\fBlz4, unlz4, lz4cat\fR \- Compress or decompress .lz4 files
-
-.SH SYNOPSIS
-.TP 5
-\fBlz4\fR [\fBOPTIONS\fR] [-|INPUT-FILE] <OUTPUT-FILE>
-.PP
-.B unlz4
-is equivalent to
-.BR "lz4 \-d"
-.br
-.B lz4cat
-is equivalent to
-.BR "lz4 \-dcfm"
-.br
-.PP
-When writing scripts that need to decompress files,
-it is recommended to always use the name
-.B lz4
-with appropriate arguments
-.RB ( "lz4 \-d"
-or
-.BR "lz4 \-dc" )
-instead of the names
-.B unlz4
-and
-.BR lz4cat .
-
-
-.SH DESCRIPTION
-.PP
-\fBlz4\fR is an extremely fast lossless compression algorithm,
-based on \fBbyte-aligned LZ77\fR family of compression scheme.
-\fBlz4\fR offers compression speeds of 400 MB/s per core, linearly scalable with multi-core CPUs.
-It features an extremely fast decoder, with speed in multiple GB/s per core,
-typically reaching RAM speed limit on multi-core systems.
-The native file format is the
-.B .lz4
-format.
-
-.B lz4
-supports a command line syntax similar \fIbut not identical\fR to
-.BR gzip (1).
-Differences are :
- \fBlz4\fR preserves original files
- \fBlz4\fR compresses a single file by default (use \fB-m\fR for multiple files)
- \fBlz4 file1 file2\fR means : compress file1 \fIinto\fR file2
- When no destination name is provided, compressed file name receives a \fB.lz4\fR suffix
- When no destination name is provided, if \fBstdout\fR is \fInot\fR the console, it becomes the output (like a silent \fB-c\fR)
- Therefore \fBlz4 file > /dev/null\fR will not create \fBfile.lz4\fR
- \fBlz4 file\fR shows real-time statistics during compression (use \fB-q\fR to silent them)
-
-Default behaviors can be modified by opt-in commands, described below.
-\fBlz4 --quiet --multiple\fR more closely mimics \fBgzip\fR behavior.
-
-.SS "Concatenation of .lz4 files"
-It is possible to concatenate
-.B .lz4
-files as is.
-.B lz4
-will decompress such files as if they were a single
-.B .lz4
-file. For example:
- lz4 file1 > foo.lz4
- lz4 file2 >> foo.lz4
- then
- lz4cat foo.lz4
- is equivalent to :
- cat file1 file2
-
-.PP
-
-.SH OPTIONS
+.
+.TH "LZ4" "1" "November 2016" "lz4 1.7.4" "User Commands"
+.
+.SH "NAME"
+\fBlz4\fR \- lz4, unlz4, lz4cat \- Compress or decompress \.lz4 files
+.
+.SH "SYNOPSIS"
+\fBlz4\fR [\fIOPTIONS\fR] [\-|INPUT\-FILE] \fIOUTPUT\-FILE\fR
+.
+.P
+\fBunlz4\fR is equivalent to \fBlz4 \-d\fR
+.
+.P
+\fBlz4cat\fR is equivalent to \fBlz4 \-dcfm\fR
+.
+.P
+When writing scripts that need to decompress files, it is recommended to always use the name \fBlz4\fR with appropriate arguments (\fBlz4 \-d\fR or \fBlz4 \-dc\fR) instead of the names \fBunlz4\fR and \fBlz4cat\fR\.
+.
+.SH "DESCRIPTION"
+\fBlz4\fR is an extremely fast lossless compression algorithm, based on \fBbyte\-aligned LZ77\fR family of compression scheme\. \fBlz4\fR offers compression speeds of 400 MB/s per core, linearly scalable with multi\-core CPUs\. It features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limit on multi\-core systems\. The native file format is the \fB\.lz4\fR format\.
+.
+.SS "Difference between lz4 and gzip"
+\fBlz4\fR supports a command line syntax similar \fIbut not identical\fR to \fBgzip(1)\fR\. Differences are :
+.
+.IP "\(bu" 4
+\fBlz4\fR preserves original files
+.
+.IP "\(bu" 4
+\fBlz4\fR compresses a single file by default (see \fB\-m\fR for multiple files)
+.
+.IP "\(bu" 4
+\fBlz4 file1 file2\fR means : compress file1 \fIinto\fR file2
+.
+.IP "\(bu" 4
+\fBlz4\fR shows real\-time notification statistics during compression or decompression of a single file (use \fB\-q\fR to silent them)
+.
+.IP "\(bu" 4
+If no destination name is provided, result is sent to \fBstdout\fR \fIexcept if stdout is the console\fR\.
+.
+.IP "\(bu" 4
+If no destination name is provided, \fBand\fR if \fBstdout\fR is the console, \fBfile\fR is compressed into \fBfile\.lz4\fR\.
+.
+.IP "\(bu" 4
+As a consequence of previous rules, note the following example : \fBlz4 file | consumer\fR sends compressed data to \fBconsumer\fR through \fBstdout\fR, hence it does \fInot\fR create any \fBfile\.lz4\fR\.
+.
+.IP "" 0
+.
+.P
+Default behaviors can be modified by opt\-in commands, detailed below\.
+.
+.IP "\(bu" 4
+\fBlz4 \-m\fR makes it possible to provide multiple input filenames, which will be compressed into files using suffix \fB\.lz4\fR\. Progress notifications are also disabled by default\. This mode has a behavior which more closely mimics \fBgzip\fR command line, with the main difference being that source files are preserved by default\.
+.
+.IP "\(bu" 4
+It\'s possible to opt\-in to erase source files on successful compression or decompression, using \fB\-\-rm\fR command\.
+.
+.IP "\(bu" 4
+Consequently, \fBlz4 \-m \-\-rm\fR behaves the same as \fBgzip\fR\.
+.
+.IP "" 0
+.
+.SS "Concatenation of \.lz4 files"
+It is possible to concatenate \fB\.lz4\fR files as is\. \fBlz4\fR will decompress such files as if they were a single \fB\.lz4\fR file\. For example: lz4 file1 > foo\.lz4 lz4 file2 >> foo\.lz4
+.
+.P
+then lz4cat foo\.lz4
+.
+.P
+is equivalent to : cat file1 file2
+.
+.SH "OPTIONS"
.
.SS "Short commands concatenation"
-In some cases, some options can be expressed using short command
-.B "-x"
-or long command
-.B "--long-word" .
-Short commands can be concatenated together. For example,
-.B "-d -c"
-is equivalent to
-.B "-dc" .
-Long commands cannot be concatenated.
-They must be clearly separated by a space.
+In some cases, some options can be expressed using short command \fB\-x\fR or long command \fB\-\-long\-word\fR\. Short commands can be concatenated together\. For example, \fB\-d \-c\fR is equivalent to \fB\-dc\fR\. Long commands cannot be concatenated\. They must be clearly separated by a space\.
+.
.SS "Multiple commands"
-When multiple contradictory commands are issued on a same command line,
-only the latest one will be applied.
+When multiple contradictory commands are issued on a same command line, only the latest one will be applied\.
.
.SS "Operation mode"
+.
.TP
-.BR \-z ", " \-\-compress
-Compress.
-This is the default operation mode
-when no operation mode option is specified ,
-no other operation mode is implied from the command name
-(for example,
-.B unlz4
-implies
-.B \-\-decompress ),
-nor from the input file name
-(for example, a file extension
-.B .lz4
-implies
-.B \-\-decompress
-by default).
-.B -z
-can also be used to force compression of an already compressed
-.B .lz4
-file.
-.TP
-.BR \-d ", " \-\-decompress ", " \-\-uncompress
-Decompress.
-.B --decompress
-is also the default operation when the input filename has an
-.B .lz4
-extension.
-.TP
-.BR \-t ", " \-\-test
-Test the integrity of compressed
-.B .lz4
-files.
-The decompressed data is discarded.
-No files are created nor removed.
-
-.TP
-.BR \-b#
-Benchmark mode, using # compression level.
-
+\fB\-z\fR \fB\-\-compress\fR
+Compress\. This is the default operation mode when no operation mode option is specified, no other operation mode is implied from the command name (for example, \fBunlz4\fR implies \fB\-\-decompress\fR), nor from the input file name (for example, a file extension \fB\.lz4\fR implies \fB\-\-decompress\fR by default)\. \fB\-z\fR can also be used to force compression of an already compressed \fB\.lz4\fR file\.
+.
+.TP
+\fB\-d\fR \fB\-\-decompress\fR \fB\-\-uncompress\fR
+Decompress\. \fB\-\-decompress\fR is also the default operation when the input filename has an \fB\.lz4\fR extension\.
+.
+.TP
+\fB\-t\fR \fB\-\-test\fR
+Test the integrity of compressed \fB\.lz4\fR files\. The decompressed data is discarded\. No files are created nor removed\.
+.
+.TP
+\fB\-b#\fR
+Benchmark mode, using \fB#\fR compression level\.
.
.SS "Operation modifiers"
+.
+.TP
+\fB\-#\fR
+Compression level, with # being any value from 1 to 16\. Higher values trade compression speed for compression ratio\. Values above 16 are considered the same as 16\. Recommended values are 1 for fast compression (default), and 9 for high compression\. Speed/compression trade\-off will vary depending on data to compress\. Decompression speed remains fast at all settings\.
+.
.TP
-.B \-#
- compression level, with # being any value from 1 to 16.
- Higher values trade compression speed for compression ratio.
- Values above 16 are considered the same as 16.
- Recommended values are 1 for fast compression (default), and 9 for high compression.
- Speed/compression trade-off will vary depending on data to compress.
- Decompression speed remains fast at all settings.
-
-.TP
-.BR \-f ", " --[no-]force
- This option has several effects:
-.RS
-.IP \(bu 3
-If the target file already exists,
-overwrite it without prompting.
-.IP \(bu 3
-When used with
-.B \-\-decompress
-and
-.B lz4
-cannot recognize the type of the source file,
-copy the source file as is to standard output.
-This allows
-.B lz4cat
-.B \-\-force
-to be used like
-.BR cat (1)
-for files that have not been compressed with
-.BR lz4 .
-.RE
-
-.TP
-.BR \-c ", " \--stdout ", " \--to-stdout
- force write to standard output, even if it is the console
-
-.TP
-.BR \-m ", " \--multiple
- Multiple file names.
- By default, the second filename is used as the destination filename for the compressed file.
- With
-.B -m
-, it is possible to specify any number of input filenames. Each of them will be compressed
-independently, and the resulting name of each compressed file will be
-.B filename.lz4
-.
-
-.TP
-.B \-B#
- block size [4-7](default : 7)
- B4= 64KB ; B5= 256KB ; B6= 1MB ; B7= 4MB
-.TP
-.B \-BD
- block dependency (improves compression ratio on small blocks)
-.TP
-.B \--[no-]frame-crc
- select frame checksum (default:enabled)
-.TP
-.B \--[no-]content-size
- header includes original size (default:not present)
- Note : this option can only be activated when the original size can be determined,
-hence for a file. It won't work with unknown source size, such as stdin or pipe.
-.TP
-.B \--[no-]sparse
- sparse mode support (default:enabled on file, disabled on stdout)
-.TP
-.B \-l
- use Legacy format (typically used for Linux Kernel compression)
- note : \fB-l\fR is not compatible with \fB-m\fR (\fB--multiple\fR)
+\fB\-f\fR \fB\-\-[no\-]force\fR
+This option has several effects:
+.
+.IP
+If the target file already exists, overwrite it without prompting\.
+.
+.IP
+When used with \fB\-\-decompress\fR and \fBlz4\fR cannot recognize the type of the source file, copy the source file as is to standard output\. This allows \fBlz4cat \-\-force\fR to be used like \fBcat (1)\fR for files that have not been compressed with \fBlz4\fR\.
+.
+.TP
+\fB\-c\fR \fB\-\-stdout\fR \fB\-\-to\-stdout\fR
+Force write to standard output, even if it is the console\.
+.
+.TP
+\fB\-m\fR \fB\-\-multiple\fR
+Multiple input files\. Compressed file names will be appended a \fB\.lz4\fR suffix\. This mode also reduces notification level\. \fBlz4 \-m\fR has a behavior equivalent to \fBgzip \-k\fR (it preserves source files by default)\.
+.
+.TP
+\fB\-r\fR
+operate recursively on directories\. This mode also sets \fB\-m\fR (multiple input files)\.
+.
+.TP
+\fB\-B#\fR
+Block size [4\-7](default : 7)
+.
+.br
+\fB\-B4\fR= 64KB ; \fB\-B5\fR= 256KB ; \fB\-B6\fR= 1MB ; \fB\-B7\fR= 4MB
+.
+.TP
+\fB\-BD\fR
+Block Dependency (improves compression ratio on small blocks)
+.
+.TP
+\fB\-\-[no\-]frame\-crc\fR
+Select frame checksum (default:enabled)
+.
+.TP
+\fB\-\-[no\-]content\-size\fR
+Header includes original size (default:not present)
+.
+.br
+Note : this option can only be activated when the original size can be determined, hence for a file\. It won\'t work with unknown source size, such as stdin or pipe\.
+.
+.TP
+\fB\-\-[no\-]sparse\fR
+Sparse mode support (default:enabled on file, disabled on stdout)
+.
+.TP
+\fB\-l\fR
+Use Legacy format (typically for Linux Kernel compression)
+.
+.br
+Note : \fB\-l\fR is not compatible with \fB\-m\fR (\fB\-\-multiple\fR) nor \fB\-r\fR
.
.SS "Other options"
+.
.TP
-.BR \-v ", " --verbose
- verbose mode
+\fB\-v\fR \fB\-\-verbose\fR
+Verbose mode
+.
.TP
-.BR \-q ", " --quiet
- suppress warnings and real-time statistics; specify twice to suppress errors too
+\fB\-q\fR \fB\-\-quiet\fR
+Suppress warnings and real\-time statistics; specify twice to suppress errors too
+.
.TP
-.B \-h/\-H ", " --help
- display help/long help and exit
+\fB\-h\fR \fB\-H\fR \fB\-\-help\fR
+Display help/long help and exit
+.
.TP
-.BR \-V ", " \--version
- display Version number and exit
+\fB\-V\fR \fB\-\-version\fR
+Display Version number and exit
+.
+.TP
+\fB\-k\fR \fB\-\-keep\fR
+Preserve source files (default behavior)
+.
.TP
-.BR \-k ", " \--keep
- Don't delete source file.
-This is default behavior anyway, so this option is just for compatibility with gzip/xz.
-
+\fB\-\-rm\fR
+Delete source files on successful compression or decompression
.
.SS "Benchmark mode"
+.
.TP
-.B \-b#
- benchmark file(s), using # compression level
+\fB\-b#\fR
+Benchmark file(s), using # compression level
+.
.TP
-.B \-e#
- benchmark multiple compression levels, from b# to e# (included)
+\fB\-e#\fR
+Benchmark multiple compression levels, from b# to e# (included)
+.
.TP
-.B \-i#
- minimum evaluation in seconds [1-9] (default : 3)
+\fB\-i#\fR
+Minimum evaluation in seconds [1\-9] (default : 3)
+.
.TP
-.B \-r
- operate recursively on directories
-
-
-.SH BUGS
-Report bugs at: https://github.com/Cyan4973/lz4/issues
-
-.SH AUTHOR
+\fB\-r\fR
+Operate recursively on directories
+.
+.SH "BUGS"
+Report bugs at: https://github\.com/lz4/lz4/issues
+.
+.SH "AUTHOR"
Yann Collet