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-rw-r--r--src/xz/xz.1469
1 files changed, 316 insertions, 153 deletions
diff --git a/src/xz/xz.1 b/src/xz/xz.1
index 73ca6ef..5b880e8 100644
--- a/src/xz/xz.1
+++ b/src/xz/xz.1
@@ -1,12 +1,10 @@
'\" t
+.\" SPDX-License-Identifier: 0BSD
.\"
.\" Authors: Lasse Collin
.\" Jia Tan
.\"
-.\" This file has been put into the public domain.
-.\" You can do whatever you want with this file.
-.\"
-.TH XZ 1 "2023-07-17" "Tukaani" "XZ Utils"
+.TH XZ 1 "2024-04-08" "Tukaani" "XZ Utils"
.
.SH NAME
xz, unxz, xzcat, lzma, unlzma, lzcat \- Compress or decompress .xz and .lzma files
@@ -801,8 +799,6 @@ in the single-threaded mode.
It may vary slightly between
.B xz
versions.
-Memory requirements of some of the future multithreaded modes may
-be dramatically higher than that of the single-threaded mode.
.IP \(bu 3
DecMem contains the decompressor memory requirements.
That is, the compression settings determine
@@ -811,6 +807,15 @@ The exact decompressor memory usage is slightly more than
the LZMA2 dictionary size, but the values in the table
have been rounded up to the next full MiB.
.RE
+.IP ""
+Memory requirements of the multi-threaded mode are
+significantly higher than that of the single-threaded mode.
+With the default value of
+.BR \-\-block\-size ,
+each thread needs 3*3*DictSize plus CompMem or DecMem.
+For example, four threads with preset
+.B \-6
+needs 660\(en670\ MiB of memory.
.TP
.BR \-e ", " \-\-extreme
Use a slower variant of the selected compression preset level
@@ -902,50 +907,90 @@ Using
.I size
less than the LZMA2 dictionary size is waste of RAM
because then the LZMA2 dictionary buffer will never get fully used.
-The sizes of the blocks are stored in the block headers,
-which a future version of
-.B xz
-will use for multi-threaded decompression.
+In multi-threaded mode,
+the sizes of the blocks are stored in the block headers.
+This size information is required for multi-threaded decompression.
.IP ""
In single-threaded mode no block splitting is done by default.
Setting this option doesn't affect memory usage.
No size information is stored in block headers,
thus files created in single-threaded mode
won't be identical to files created in multi-threaded mode.
-The lack of size information also means that a future version of
+The lack of size information also means that
.B xz
won't be able decompress the files in multi-threaded mode.
.TP
-.BI \-\-block\-list= sizes
+.BI \-\-block\-list= items
When compressing to the
.B .xz
-format, start a new block after
+format, start a new block with an optional custom filter chain after
the given intervals of uncompressed data.
.IP ""
-The uncompressed
-.I sizes
-of the blocks are specified as a comma-separated list.
-Omitting a size (two or more consecutive commas) is a shorthand
-to use the size of the previous block.
+The
+.I items
+are a comma-separated list.
+Each item consists of an optional filter chain number
+between 0 and 9 followed by a colon
+.RB ( : )
+and a required size of uncompressed data.
+Omitting an item (two or more consecutive commas) is a
+shorthand to use the size and filters of the previous item.
.IP ""
If the input file is bigger than the sum of
-.IR sizes ,
-the last value in
-.I sizes
-is repeated until the end of the file.
+the sizes in
+.IR items ,
+the last item is repeated until the end of the file.
A special value of
.B 0
-may be used as the last value to indicate that
+may be used as the last size to indicate that
the rest of the file should be encoded as a single block.
.IP ""
-If one specifies
-.I sizes
-that exceed the encoder's block size
+An alternative filter chain for each block can be
+specified in combination with the
+.BI \-\-filters1= filters
+\&...\&
+.BI \-\-filters9= filters
+options.
+These options define filter chains with an identifier
+between 1\(en9.
+Filter chain 0 can be used to refer to the default filter chain,
+which is the same as not specifying a filter chain.
+The filter chain identifier can be used before the uncompressed
+size, followed by a colon
+.RB ( : ).
+For example, if one specifies
+.B \-\-block\-list=1:2MiB,3:2MiB,2:4MiB,,2MiB,0:4MiB
+then blocks will be created using:
+.RS
+.IP \(bu 3
+The filter chain specified by
+.B \-\-filters1
+and 2 MiB input
+.IP \(bu 3
+The filter chain specified by
+.B \-\-filters3
+and 2 MiB input
+.IP \(bu 3
+The filter chain specified by
+.B \-\-filters2
+and 4 MiB input
+.IP \(bu 3
+The filter chain specified by
+.B \-\-filters2
+and 4 MiB input
+.IP \(bu 3
+The default filter chain and 2 MiB input
+.IP \(bu 3
+The default filter chain and 4 MiB input for every block until
+end of input.
+.RE
+.IP ""
+If one specifies a size that exceeds the encoder's block size
(either the default value in threaded mode or
the value specified with \fB\-\-block\-size=\fIsize\fR),
the encoder will create additional blocks while
keeping the boundaries specified in
-.IR sizes .
+.IR items .
For example, if one specifies
.B \-\-block\-size=10MiB
.B \-\-block\-list=5MiB,10MiB,8MiB,12MiB,24MiB
@@ -1262,6 +1307,15 @@ meet this condition,
but files compressed in single-threaded mode don't even if
.BI \-\-block\-size= size
has been used.
+.IP ""
+The default value for
+.I threads
+is
+.BR 0 .
+In
+.B xz
+5.4.x and older the default is
+.BR 1 .
.
.SS "Custom compressor filter chains"
A custom filter chain allows specifying
@@ -1295,22 +1349,37 @@ in the chain.
Depending on the filter, this limitation is either inherent to
the filter design or exists to prevent security issues.
.PP
-A custom filter chain is specified by using one or more
-filter options in the order they are wanted in the filter chain.
-That is, the order of filter options is significant!
+A custom filter chain can be specified in two different ways.
+The options
+.BI \-\-filters= filters
+and
+.BI \-\-filters1= filters
+\&...\&
+.BI \-\-filters9= filters
+allow specifying an entire filter chain in one option using the
+liblzma filter string syntax.
+Alternatively, a filter chain can be specified by using one or more
+individual filter options in the order they are wanted in the filter chain.
+That is, the order of the individual filter options is significant!
When decoding raw streams
.RB ( \-\-format=raw ),
-the filter chain is specified in the same order as
+the filter chain must be specified in the same order as
it was specified when compressing.
-.PP
-Filters take filter-specific
+Any individual filter or preset options specified before the full
+chain option
+(\fB\-\-filters=\fIfilters\fR)
+will be forgotten.
+Individual filters specified after the full chain option will reset the
+filter chain.
+.PP
+Both the full and individual filter options take filter-specific
.I options
as a comma-separated list.
Extra commas in
.I options
are ignored.
-Every option has a default value, so you need to
-specify only those you want to change.
+Every option has a default value, so
+specify those you want to change.
.PP
To see the whole filter chain and
.IR options ,
@@ -1321,6 +1390,45 @@ use
twice).
This works also for viewing the filter chain options used by presets.
.TP
+.BI \-\-filters= filters
+Specify the full filter chain or a preset in a single option.
+Each filter can be separated by spaces or two dashes
+.RB ( \-\- ).
+.I filters
+may need to be quoted on the shell command line so it is
+parsed as a single option.
+To denote
+.IR options ,
+use
+.B :
+or
+.BR = .
+A preset can be prefixed with a
+.B \-
+and followed with zero or more flags.
+The only supported flag is
+.B e
+to apply the same options as
+.BR \-\-extreme .
+.TP
+\fB\-\-filters1\fR=\fIfilters\fR ... \fB\-\-filters9\fR=\fIfilters
+Specify up to nine additional filter chains that can be used with
+.BR \-\-block\-list .
+.IP ""
+For example, when compressing an archive with executable files
+followed by text files, the executable part could use a filter
+chain with a BCJ filter and the text part only the LZMA2 filter.
+.TP
+.B \-\-filters-help
+Display a help message describing how to specify presets and
+custom filter chains in the
+.B \-\-filters
+and
+.BI \-\-filters1= filters
+\&...\&
+.BI \-\-filters9= filters
+options, and exit successfully.
+.TP
\fB\-\-lzma1\fR[\fB=\fIoptions\fR]
.PD 0
.TP
@@ -1704,6 +1812,8 @@ and
\fB\-\-ia64\fR[\fB=\fIoptions\fR]
.TP
\fB\-\-sparc\fR[\fB=\fIoptions\fR]
+.TP
+\fB\-\-riscv\fR[\fB=\fIoptions\fR]
.PD
Add a branch/call/jump (BCJ) filter to the filter chain.
These filters can be used only as a non-last filter
@@ -1762,6 +1872,7 @@ ARM64;4;4096-byte alignment is best
PowerPC;4;Big endian only
IA-64;16;Itanium
SPARC;4;
+RISC-V;2;
.TE
.RE
.RE
@@ -1770,14 +1881,38 @@ Since the BCJ-filtered data is usually compressed with LZMA2,
the compression ratio may be improved slightly if
the LZMA2 options are set to match the
alignment of the selected BCJ filter.
-For example, with the IA-64 filter, it's good to set
-.B pb=4
-or even
+Examples:
+.RS
+.IP \(bu 3
+IA-64 filter has 16-byte alignment so
.B pb=4,lp=4,lc=0
+is good
with LZMA2 (2^4=16).
-The x86 filter is an exception;
-it's usually good to stick to LZMA2's default
-four-byte alignment when compressing x86 executables.
+.IP \(bu 3
+RISC-V code has 2-byte or 4-byte alignment
+depending on whether the file contains
+16-bit compressed instructions (the C extension).
+When 16-bit instructions are used,
+.B pb=2,lp=1,lc=3
+or
+.B pb=1,lp=1,lc=3
+is good.
+When 16-bit instructions aren't present,
+.B pb=2,lp=2,lc=2
+is the best.
+.B readelf \-h
+can be used to check if "RVC"
+appears on the "Flags" line.
+.IP \(bu 3
+ARM64 is always 4-byte aligned so
+.B pb=2,lp=2,lc=2
+is the best.
+.IP \(bu 3
+The x86 filter is an exception.
+It's usually good to stick to LZMA2's defaults
+.RB ( pb=2,lp=0,lc=3 )
+when compressing x86 executables.
+.RE
.IP ""
All BCJ filters support the same
.IR options :
@@ -1954,107 +2089,14 @@ easier to parse by other programs.
Currently
.B \-\-robot
is supported only together with
-.BR \-\-version ,
+.BR \-\-list ,
+.BR \-\-filters\-help ,
.BR \-\-info\-memory ,
and
-.BR \-\-list .
+.BR \-\-version .
It will be supported for compression and
decompression in the future.
.
-.SS Version
-.B "xz \-\-robot \-\-version"
-prints the version number of
-.B xz
-and liblzma in the following format:
-.PP
-.BI XZ_VERSION= XYYYZZZS
-.br
-.BI LIBLZMA_VERSION= XYYYZZZS
-.TP
-.I X
-Major version.
-.TP
-.I YYY
-Minor version.
-Even numbers are stable.
-Odd numbers are alpha or beta versions.
-.TP
-.I ZZZ
-Patch level for stable releases or
-just a counter for development releases.
-.TP
-.I S
-Stability.
-0 is alpha, 1 is beta, and 2 is stable.
-.I S
-should be always 2 when
-.I YYY
-is even.
-.PP
-.I XYYYZZZS
-are the same on both lines if
-.B xz
-and liblzma are from the same XZ Utils release.
-.PP
-Examples: 4.999.9beta is
-.B 49990091
-and
-5.0.0 is
-.BR 50000002 .
-.
-.SS "Memory limit information"
-.B "xz \-\-robot \-\-info\-memory"
-prints a single line with multiple tab-separated columns:
-.IP 1. 4
-Total amount of physical memory (RAM) in bytes.
-.IP 2. 4
-Memory usage limit for compression in bytes
-.RB ( \-\-memlimit\-compress ).
-A special value of
-.B 0
-indicates the default setting
-which for single-threaded mode is the same as no limit.
-.IP 3. 4
-Memory usage limit for decompression in bytes
-.RB ( \-\-memlimit\-decompress ).
-A special value of
-.B 0
-indicates the default setting
-which for single-threaded mode is the same as no limit.
-.IP 4. 4
-Since
-.B xz
-5.3.4alpha:
-Memory usage for multi-threaded decompression in bytes
-.RB ( \-\-memlimit\-mt\-decompress ).
-This is never zero because a system-specific default value
-shown in the column 5
-is used if no limit has been specified explicitly.
-This is also never greater than the value in the column 3
-even if a larger value has been specified with
-.BR \-\-memlimit\-mt\-decompress .
-.IP 5. 4
-Since
-.B xz
-5.3.4alpha:
-A system-specific default memory usage limit
-that is used to limit the number of threads
-when compressing with an automatic number of threads
-.RB ( \-\-threads=0 )
-and no memory usage limit has been specified
-.RB ( \-\-memlimit\-compress ).
-This is also used as the default value for
-.BR \-\-memlimit\-mt\-decompress .
-.IP 6. 4
-Since
-.B xz
-5.3.4alpha:
-Number of available processor threads.
-.PP
-In the future, the output of
-.B "xz \-\-robot \-\-info\-memory"
-may have more columns, but never more than a single line.
-.
.SS "List mode"
.B "xz \-\-robot \-\-list"
uses tab-separated output.
@@ -2339,6 +2381,127 @@ Future versions may add new line types and
new columns can be added to the existing line types,
but the existing columns won't be changed.
.
+.SS "Filters help"
+.B "xz \-\-robot \-\-filters-help"
+prints the supported filters in the following format:
+.PP
+\fIfilter\fB:\fIoption\fB=<\fIvalue\fB>,\fIoption\fB=<\fIvalue\fB>\fR...
+.TP
+.I filter
+Name of the filter
+.TP
+.I option
+Name of a filter specific option
+.TP
+.I value
+Numeric
+.I value
+ranges appear as
+\fB<\fImin\fB\-\fImax\fB>\fR.
+String
+.I value
+choices are shown within
+.B "< >"
+and separated by a
+.B |
+character.
+.PP
+Each filter is printed on its own line.
+.
+.SS "Memory limit information"
+.B "xz \-\-robot \-\-info\-memory"
+prints a single line with multiple tab-separated columns:
+.IP 1. 4
+Total amount of physical memory (RAM) in bytes.
+.IP 2. 4
+Memory usage limit for compression in bytes
+.RB ( \-\-memlimit\-compress ).
+A special value of
+.B 0
+indicates the default setting
+which for single-threaded mode is the same as no limit.
+.IP 3. 4
+Memory usage limit for decompression in bytes
+.RB ( \-\-memlimit\-decompress ).
+A special value of
+.B 0
+indicates the default setting
+which for single-threaded mode is the same as no limit.
+.IP 4. 4
+Since
+.B xz
+5.3.4alpha:
+Memory usage for multi-threaded decompression in bytes
+.RB ( \-\-memlimit\-mt\-decompress ).
+This is never zero because a system-specific default value
+shown in the column 5
+is used if no limit has been specified explicitly.
+This is also never greater than the value in the column 3
+even if a larger value has been specified with
+.BR \-\-memlimit\-mt\-decompress .
+.IP 5. 4
+Since
+.B xz
+5.3.4alpha:
+A system-specific default memory usage limit
+that is used to limit the number of threads
+when compressing with an automatic number of threads
+.RB ( \-\-threads=0 )
+and no memory usage limit has been specified
+.RB ( \-\-memlimit\-compress ).
+This is also used as the default value for
+.BR \-\-memlimit\-mt\-decompress .
+.IP 6. 4
+Since
+.B xz
+5.3.4alpha:
+Number of available processor threads.
+.PP
+In the future, the output of
+.B "xz \-\-robot \-\-info\-memory"
+may have more columns, but never more than a single line.
+.
+.SS Version
+.B "xz \-\-robot \-\-version"
+prints the version number of
+.B xz
+and liblzma in the following format:
+.PP
+.BI XZ_VERSION= XYYYZZZS
+.br
+.BI LIBLZMA_VERSION= XYYYZZZS
+.TP
+.I X
+Major version.
+.TP
+.I YYY
+Minor version.
+Even numbers are stable.
+Odd numbers are alpha or beta versions.
+.TP
+.I ZZZ
+Patch level for stable releases or
+just a counter for development releases.
+.TP
+.I S
+Stability.
+0 is alpha, 1 is beta, and 2 is stable.
+.I S
+should be always 2 when
+.I YYY
+is even.
+.PP
+.I XYYYZZZS
+are the same on both lines if
+.B xz
+and liblzma are from the same XZ Utils release.
+.PP
+Examples: 4.999.9beta is
+.B 49990091
+and
+5.0.0 is
+.BR 50000002 .
+.
.SH "EXIT STATUS"
.TP
.B 0
@@ -2391,7 +2554,7 @@ is run by a script or tool, for example, GNU
.RS
.PP
.nf
-.ft CW
+.ft CR
XZ_OPT=\-2v tar caf foo.tar.xz foo
.ft R
.fi
@@ -2411,7 +2574,7 @@ scripts one may use something like this:
.RS
.PP
.nf
-.ft CW
+.ft CR
XZ_OPT=${XZ_OPT\-"\-7e"}
export XZ_OPT
.ft R
@@ -2669,7 +2832,7 @@ if compression is successful:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz foo
.ft R
.fi
@@ -2685,7 +2848,7 @@ even if decompression is successful:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-dk bar.xz
.ft R
.fi
@@ -2703,7 +2866,7 @@ and 5\ MiB, respectively):
.RS
.PP
.nf
-.ft CW
+.ft CR
tar cf \- baz | xz \-4e > baz.tar.xz
.ft R
.fi
@@ -2714,7 +2877,7 @@ to standard output with a single command:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-dcf a.txt b.txt.xz c.txt d.txt.lzma > abcd.txt
.ft R
.fi
@@ -2729,7 +2892,7 @@ can be used to parallelize compression of many files:
.RS
.PP
.nf
-.ft CW
+.ft CR
find . \-type f \e! \-name '*.xz' \-print0 \e
| xargs \-0r \-P4 \-n16 xz \-T1
.ft R
@@ -2769,7 +2932,7 @@ after compressing multiple files:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-\-robot \-\-list *.xz | awk '/^totals/{print $5\-$4}'
.ft R
.fi
@@ -2789,7 +2952,7 @@ option:
.RS
.PP
.nf
-.ft CW
+.ft CR
if ! eval "$(xz \-\-robot \-\-version 2> /dev/null)" ||
[ "$XZ_VERSION" \-lt 50000002 ]; then
echo "Your xz is too old."
@@ -2805,7 +2968,7 @@ but if a limit has already been set, don't increase it:
.RS
.PP
.nf
-.ft CW
+.ft CR
NEWLIM=$((123 << 20))\ \ # 123 MiB
OLDLIM=$(xz \-\-robot \-\-info\-memory | cut \-f3)
if [ $OLDLIM \-eq 0 \-o $OLDLIM \-gt $NEWLIM ]; then
@@ -2858,7 +3021,7 @@ can be modified to use a bigger dictionary:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-\-lzma2=preset=1,dict=32MiB foo.tar
.ft R
.fi
@@ -2886,7 +3049,7 @@ would use:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-vv \-\-lzma2=dict=192MiB big_foo.tar
.ft R
.fi
@@ -2916,7 +3079,7 @@ using about 100\ KiB of memory.
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-\-check=crc32 \-\-lzma2=preset=6e,dict=64KiB foo
.ft R
.fi
@@ -2944,7 +3107,7 @@ slightly (like 0.1\ %) smaller file than
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-\-lzma2=preset=6e,pb=0,lc=4 source_code.tar
.ft R
.fi
@@ -2957,7 +3120,7 @@ using the x86 BCJ filter:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-\-x86 \-\-lzma2 libfoo.so
.ft R
.fi
@@ -2992,7 +3155,7 @@ to LZMA2 to accommodate the three-byte alignment:
.RS
.PP
.nf
-.ft CW
+.ft CR
xz \-\-delta=dist=3 \-\-lzma2=pb=0 foo.tiff
.ft R
.fi