Merge remote-tracking branch 'refs/remotes/lz4/dev' into dev

4 files changed, 462 insertions, 259 deletions

diff --git a/programs/Makefile b/programs/Makefile
index 9939a44..ffbcbf1 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -27,6 +27,17 @@
 # lz4c32: Same as lz4c, but forced to compile in 32-bits mode
 # ##########################################################################
 
+# Version numbers
+LIBVER_SRC := ../lib/lz4.h
+LIBVER_MAJOR_SCRIPT:=`sed -n '/define LZ4_VERSION_MAJOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < $(LIBVER_SRC)`
+LIBVER_MINOR_SCRIPT:=`sed -n '/define LZ4_VERSION_MINOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < $(LIBVER_SRC)`
+LIBVER_PATCH_SCRIPT:=`sed -n '/define LZ4_VERSION_RELEASE/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < $(LIBVER_SRC)`
+LIBVER_SCRIPT:= $(LIBVER_MAJOR_SCRIPT).$(LIBVER_MINOR_SCRIPT).$(LIBVER_PATCH_SCRIPT)
+LIBVER_MAJOR := $(shell echo $(LIBVER_MAJOR_SCRIPT))
+LIBVER_MINOR := $(shell echo $(LIBVER_MINOR_SCRIPT))
+LIBVER_PATCH := $(shell echo $(LIBVER_PATCH_SCRIPT))
+LIBVER  := $(shell echo $(LIBVER_SCRIPT))
+
 DESTDIR ?=
 PREFIX  ?= /usr/local
 BINDIR  := $(PREFIX)/bin
@@ -34,14 +45,18 @@ MANDIR  := $(PREFIX)/share/man/man1
 LZ4DIR  := ../lib
 VOID    := /dev/null
 
-CFLAGS  ?= -O3   # allows custom optimization flags. For example : CFLAGS="-O2 -g" make
-CFLAGS  += -g -Wall -Wextra -Wundef -Wcast-qual -Wcast-align -Wshadow \
+CPPFLAGS+= -I$(LZ4DIR) -DXXH_NAMESPACE=LZ4_
+CFLAGS  ?= -O3
+DEBUGFLAGS:=-g -Wall -Wextra -Wundef -Wcast-qual -Wcast-align -Wshadow \
            -Wswitch-enum -Wdeclaration-after-statement -Wstrict-prototypes \
-		   -Wpointer-arith -Wstrict-aliasing=1
+           -Wpointer-arith -Wstrict-aliasing=1
 CFLAGS  += $(MOREFLAGS)
-CPPFLAGS:= -I$(LZ4DIR) -DXXH_NAMESPACE=LZ4_
 FLAGS    = $(CFLAGS) $(CPPFLAGS) $(LDFLAGS)
 
+LZ4_VERSION=$(LIBVER)
+MD2ROFF  =ronn
+MD2ROFF_FLAGS  = --roff --warnings --manual="User Commands" --organization="lz4 $(LZ4_VERSION)"
+
 
 # Define *.exe as extension for Windows systems
 ifneq (,$(filter Windows%,$(OS)))
@@ -54,17 +69,18 @@ endif
 
 default: lz4-release
 
+lz4-release: $(LZ4DIR)/lz4.o $(LZ4DIR)/lz4hc.o $(LZ4DIR)/lz4frame.o $(LZ4DIR)/xxhash.o bench.o lz4io.o lz4cli.o datagen.o
+	$(CC) $(FLAGS) $^ -o lz4$(EXT)
+
 all: lz4 lz4c
 
 all32: CFLAGS+=-m32
 all32: all
 
-lz4: $(LZ4DIR)/lz4.o $(LZ4DIR)/lz4hc.o $(LZ4DIR)/lz4frame.o $(LZ4DIR)/xxhash.o bench.o lz4io.o lz4cli.o datagen.o
-	$(CC) $(FLAGS) $^ -o $@$(EXT)
-
-lz4-release: CFLAGS := -O3
-lz4-release: lz4
+lz4: CFLAGS += $(DEBUGFLAGS)
+lz4: lz4-release
 
+lz4c: CFLAGS += $(DEBUGFLAGS)
 lz4c  : $(LZ4DIR)/lz4.o $(LZ4DIR)/lz4hc.o $(LZ4DIR)/lz4frame.o $(LZ4DIR)/xxhash.o bench.o lz4io.o lz4cli.c datagen.o
 	$(CC) $(FLAGS) -DENABLE_LZ4C_LEGACY_OPTIONS $^ -o $@$(EXT)
 
@@ -79,6 +95,18 @@ clean:
 	@echo Cleaning completed
 
 
+lz4.1: lz4.1.md
+	cat $^ | $(MD2ROFF) $(MD2ROFF_FLAGS) | sed -n '/^\.\\\".*/!p' > $@
+
+man: lz4.1
+
+clean-man:
+	rm lz4.1
+
+preview-man: clean-man man
+	man ./lz4.1
+
+
 #------------------------------------------------------------------------
 #make install is validated only for Linux, OSX, kFreeBSD, Hurd and
 #FreeBSD targets
diff --git a/programs/lz4.1 b/programs/lz4.1
index 2c94033..48c988a 100644
--- a/programs/lz4.1
+++ b/programs/lz4.1
@@ -1,251 +1,206 @@
-\."
-\." 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
diff --git a/programs/lz4.1.md b/programs/lz4.1.md
new file mode 100644
index 0000000..83a08b6
--- /dev/null
+++ b/programs/lz4.1.md
@@ -0,0 +1,217 @@
+lz4(1) -- lz4, unlz4, lz4cat - Compress or decompress .lz4 files
+================================================================
+
+SYNOPSIS
+--------
+
+`lz4` [*OPTIONS*] [-|INPUT-FILE] <OUTPUT-FILE>
+
+`unlz4` is equivalent to `lz4 -d`
+
+`lz4cat` is equivalent to `lz4 -dcfm`
+
+When writing scripts that need to decompress files,
+it is recommended to always use the name `lz4` with appropriate arguments
+(`lz4 -d` or `lz4 -dc`) instead of the names `unlz4` and `lz4cat`.
+
+
+DESCRIPTION
+-----------
+
+`lz4` is an extremely fast lossless compression algorithm,
+based on **byte-aligned LZ77** family of compression scheme.
+`lz4` 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 `.lz4` format.
+
+### Difference between lz4 and gzip
+
+`lz4` supports a command line syntax similar _but not identical_ to `gzip(1)`.
+Differences are :
+
+  * `lz4` preserves original files
+  * `lz4` compresses a single file by default (see `-m` for multiple files)
+  * `lz4 file1 file2` means : compress file1 _into_ file2
+  * `lz4` shows real-time notification statistics
+     during compression or decompression of a single file
+     (use `-q` to silent them)
+  * If no destination name is provided, result is sent to `stdout`
+    _except if stdout is the console_.
+  * If no destination name is provided, __and__ if `stdout` is the console,
+    `file` is compressed into `file.lz4`.
+  * As a consequence of previous rules, note the following example :
+    `lz4 file | consumer` sends compressed data to `consumer` through `stdout`,
+    hence it does _not_ create any `file.lz4`.
+
+Default behaviors can be modified by opt-in commands, detailed below.
+
+  * `lz4 -m` makes it possible to provide multiple input filenames,
+    which will be compressed into files using suffix `.lz4`.
+    Progress notifications are also disabled by default.
+    This mode has a behavior which more closely mimics `gzip` command line,
+    with the main difference being that source files are preserved by default.
+  * It's possible to opt-in to erase source files
+    on successful compression or decompression, using `--rm` command.
+  * Consequently, `lz4 -m --rm` behaves the same as `gzip`.
+
+### Concatenation of .lz4 files
+
+It is possible to concatenate `.lz4` files as is.
+`lz4` will decompress such files as if they were a single `.lz4` file.
+For example:
+    lz4 file1  > foo.lz4
+    lz4 file2 >> foo.lz4
+
+then
+    lz4cat foo.lz4
+
+is equivalent to :
+    cat file1 file2
+
+
+OPTIONS
+-------
+
+### Short commands concatenation
+
+In some cases, some options can be expressed using short command `-x`
+or long command `--long-word`.
+Short commands can be concatenated together.
+For example, `-d -c` is equivalent to `-dc`.
+Long commands cannot be concatenated.
+They must be clearly separated by a space.
+
+### Multiple commands
+
+When multiple contradictory commands are issued on a same command line,
+only the latest one will be applied.
+
+### Operation mode
+
+* `-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, `unlz4` implies `--decompress`),
+  nor from the input file name
+  (for example, a file extension `.lz4` implies  `--decompress` by default).
+  `-z` can also be used to force compression of an already compressed
+  `.lz4` file.
+
+* `-d` `--decompress` `--uncompress`:
+  Decompress.
+  `--decompress` is also the default operation when the input filename has an
+  `.lz4` extension.
+
+* `-t` `--test`:
+  Test the integrity of compressed `.lz4` files.
+  The decompressed data is discarded.
+  No files are created nor removed.
+
+* `-b#`:
+  Benchmark mode, using `#` compression level.
+
+### Operation modifiers
+
+* `-#`:
+  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.
+
+* `-f` `--[no-]force`:
+  This option has several effects:
+
+  If the target file already exists, overwrite it without prompting.
+
+  When used with `--decompress` and `lz4` cannot recognize the type of
+  the source file, copy the source file as is to standard output.
+  This allows `lz4cat --force` to be used like `cat (1)` for files
+  that have not been compressed with `lz4`.
+
+* `-c` `--stdout` `--to-stdout`:
+  Force write to standard output, even if it is the console.
+
+* `-m` `--multiple`:
+  Multiple input files.
+  Compressed file names will be appended a `.lz4` suffix.
+  This mode also reduces notification level.
+  `lz4 -m` has a behavior equivalent to `gzip -k`
+  (it preserves source files by default).
+
+* `-r` :
+  operate recursively on directories.
+  This mode also sets `-m` (multiple input files).
+
+* `-B#`:
+  Block size \[4-7\](default : 7)<br/>
+  `-B4`= 64KB ; `-B5`= 256KB ; `-B6`= 1MB ; `-B7`= 4MB
+
+* `-BD`:
+  Block Dependency (improves compression ratio on small blocks)
+
+* `--[no-]frame-crc`:
+  Select frame checksum (default:enabled)
+
+* `--[no-]content-size`:
+  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.
+
+* `--[no-]sparse`:
+  Sparse mode support (default:enabled on file, disabled on stdout)
+
+* `-l`:
+  Use Legacy format (typically for Linux Kernel compression)<br/>
+  Note : `-l` is not compatible with `-m` (`--multiple`) nor `-r`
+
+### Other options
+
+* `-v` `--verbose`:
+  Verbose mode
+
+* `-q` `--quiet`:
+  Suppress warnings and real-time statistics;
+  specify twice to suppress errors too
+
+* `-h` `-H` `--help`:
+  Display help/long help and exit
+
+* `-V` `--version`:
+  Display Version number and exit
+
+* `-k` `--keep`:
+  Preserve source files (default behavior)
+
+* `--rm` :
+  Delete source files on successful compression or decompression
+
+
+### Benchmark mode
+
+* `-b#`:
+  Benchmark file(s), using # compression level
+
+* `-e#`:
+  Benchmark multiple compression levels, from b# to e# (included)
+
+* `-i#`:
+  Minimum evaluation in seconds \[1-9\] (default : 3)
+
+
+BUGS
+----
+
+Report bugs at: https://github.com/lz4/lz4/issues
+
+
+AUTHOR
+------
+
+Yann Collet
diff --git a/programs/lz4cli.c b/programs/lz4cli.c
index 71378aa..46c2f1b 100644
--- a/programs/lz4cli.c
+++ b/programs/lz4cli.c
@@ -78,7 +78,7 @@
 ******************************/
 #define COMPRESSOR_NAME "LZ4 command line interface"
 #define AUTHOR "Yann Collet"
-#define WELCOME_MESSAGE "*** %s %i-bits v%s, by %s ***\n", COMPRESSOR_NAME, (int)(sizeof(void*)*8), LZ4_VERSION_STRING, AUTHOR
+#define WELCOME_MESSAGE "*** %s %i-bits v%s, by %s ***\n", COMPRESSOR_NAME, (int)(sizeof(void*)*8), LZ4_versionString(), AUTHOR
 #define LZ4_EXTENSION ".lz4"
 #define LZ4CAT "lz4cat"
 #define UNLZ4 "unlz4"
@@ -129,19 +129,20 @@ int LZ4IO_compressFilename_Legacy(const char* input_filename, const char* output
 *****************************/
 static int usage(const char* exeName)
 {
-    DISPLAY( "Usage :\n");
-    DISPLAY( "      %s [arg] [input] [output]\n", exeName);
+    DISPLAY( "Usage : \n");
+    DISPLAY( "      %s [arg] [input] [output] \n", exeName);
     DISPLAY( "\n");
-    DISPLAY( "input   : a filename\n");
+    DISPLAY( "input   : a filename \n");
     DISPLAY( "          with no FILE, or when FILE is - or %s, read standard input\n", stdinmark);
-    DISPLAY( "Arguments :\n");
+    DISPLAY( "Arguments : \n");
     DISPLAY( " -1     : Fast compression (default) \n");
     DISPLAY( " -9     : High compression \n");
     DISPLAY( " -d     : decompression (default for %s extension)\n", LZ4_EXTENSION);
-    DISPLAY( " -z     : force compression\n");
+    DISPLAY( " -z     : force compression \n");
     DISPLAY( " -f     : overwrite output without prompting \n");
+    DISPLAY( " -k     : preserve source files(s)  (default) \n");
     DISPLAY( "--rm    : remove source file(s) after successful de/compression \n");
-    DISPLAY( " -h/-H  : display help/long help and exit\n");
+    DISPLAY( " -h/-H  : display help/long help and exit \n");
     return 0;
 }
 
@@ -151,33 +152,33 @@ static int usage_advanced(const char* exeName)
     usage(exeName);
     DISPLAY( "\n");
     DISPLAY( "Advanced arguments :\n");
-    DISPLAY( " -V     : display Version number and exit\n");
-    DISPLAY( " -v     : verbose mode\n");
+    DISPLAY( " -V     : display Version number and exit \n");
+    DISPLAY( " -v     : verbose mode \n");
     DISPLAY( " -q     : suppress warnings; specify twice to suppress errors too\n");
     DISPLAY( " -c     : force write to standard output, even if it is the console\n");
     DISPLAY( " -t     : test compressed file integrity\n");
     DISPLAY( " -m     : multiple input files (implies automatic output filenames)\n");
 #ifdef UTIL_HAS_CREATEFILELIST
-    DISPLAY( " -r     : operate recursively on directories (sets also -m)\n");
+    DISPLAY( " -r     : operate recursively on directories (sets also -m) \n");
 #endif
     DISPLAY( " -l     : compress using Legacy format (Linux kernel compression)\n");
-    DISPLAY( " -B#    : Block size [4-7] (default : 7)\n");
-    DISPLAY( " -BD    : Block dependency (improve compression ratio)\n");
+    DISPLAY( " -B#    : Block size [4-7] (default : 7) \n");
+    DISPLAY( " -BD    : Block dependency (improve compression ratio) \n");
     /* DISPLAY( " -BX    : enable block checksum (default:disabled)\n");   *//* Option currently inactive */
-    DISPLAY( "--no-frame-crc : disable stream checksum (default:enabled)\n");
+    DISPLAY( "--no-frame-crc : disable stream checksum (default:enabled) \n");
     DISPLAY( "--content-size : compressed frame includes original size (default:not present)\n");
     DISPLAY( "--[no-]sparse  : sparse mode (default:enabled on file, disabled on stdout)\n");
-    DISPLAY( "Benchmark arguments :\n");
+    DISPLAY( "Benchmark arguments : \n");
     DISPLAY( " -b#    : benchmark file(s), using # compression level (default : 1) \n");
     DISPLAY( " -e#    : test all compression levels from -bX to # (default : 1)\n");
-    DISPLAY( " -i#    : minimum evaluation time in seconds (default : 3s)\n");
-    DISPLAY( " -B#    : cut file into independent blocks of size # bytes [32+]\n");
-    DISPLAY( "                      or predefined block size [4-7] (default: 7)\n");
+    DISPLAY( " -i#    : minimum evaluation time in seconds (default : 3s) \n");
+    DISPLAY( " -B#    : cut file into independent blocks of size # bytes [32+] \n");
+    DISPLAY( "                     or predefined block size [4-7] (default: 7) \n");
 #if defined(ENABLE_LZ4C_LEGACY_OPTIONS)
-    DISPLAY( "Legacy arguments :\n");
-    DISPLAY( " -c0    : fast compression\n");
-    DISPLAY( " -c1    : high compression\n");
-    DISPLAY( " -hc    : high compression\n");
+    DISPLAY( "Legacy arguments : \n");
+    DISPLAY( " -c0    : fast compression \n");
+    DISPLAY( " -c1    : high compression \n");
+    DISPLAY( " -hc    : high compression \n");
     DISPLAY( " -y     : overwrite output without prompting \n");
 #endif /* ENABLE_LZ4C_LEGACY_OPTIONS */
     EXTENDED_HELP;
@@ -548,7 +549,7 @@ int main(int argc, const char** argv)
     }
 
     /* No output filename ==> try to select one automatically (when possible) */
-    while (!output_filename) {
+    while ((!output_filename) && (multiple_inputs==0)) {
         if (!IS_CONSOLE(stdout)) { output_filename=stdoutmark; break; }   /* Default to stdout whenever possible (i.e. not a console) */
         if (mode == om_auto) {  /* auto-determine compression or decompression, based on file extension */
             size_t const inSize  = strlen(input_filename);
@@ -583,6 +584,8 @@ int main(int argc, const char** argv)
         break;
     }
 
+    if (!output_filename) output_filename = "*\\dummy^!//";
+
     /* Check if output is defined as console; trigger an error in this case */
     if (!strcmp(output_filename,stdoutmark) && IS_CONSOLE(stdout) && !forceStdout) {
         DISPLAYLEVEL(1, "refusing to write to console without -c\n");