Merging upstream version 1.12~rc1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 415 insertions, 326 deletions

diff --git a/doc/plzip.1 b/doc/plzip.1
index 3985e5b..7f16c55 100644
--- a/doc/plzip.1
+++ b/doc/plzip.1
@@ -1,32 +1,33 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.49.2.
-.TH PLZIP "1" "January 2024" "plzip 1.11" "User Commands"
+.TH PLZIP "1" "November 2024" "plzip 1.12-rc1" "User Commands"
 .SH NAME
 plzip \- reduces the size of files
 .SH SYNOPSIS
 .B plzip
 [\fI\,options\/\fR] [\fI\,files\/\fR]
 .SH DESCRIPTION
-Plzip is a massively parallel (multi\-threaded) implementation of lzip,
-compatible with lzip 1.4 or newer. Plzip uses the compression library lzlib.
+Plzip is a massively parallel (multi\-threaded) implementation of lzip. Plzip
+uses the compression library lzlib.
 .PP
 Lzip is a lossless data compressor with a user interface similar to the one
-of gzip or bzip2. Lzip uses a simplified form of the 'Lempel\-Ziv\-Markov
-chain\-Algorithm' (LZMA) stream format to maximize interoperability. The
-maximum dictionary size is 512 MiB so that any lzip file can be decompressed
-on 32\-bit machines. Lzip provides accurate and robust 3\-factor integrity
-checking. Lzip can compress about as fast as gzip (lzip \fB\-0\fR) or compress most
-files more than bzip2 (lzip \fB\-9\fR). Decompression speed is intermediate between
-gzip and bzip2. Lzip is better than gzip and bzip2 from a data recovery
-perspective. Lzip has been designed, written, and tested with great care to
-replace gzip and bzip2 as the standard general\-purpose compressed format for
-Unix\-like systems.
+of gzip or bzip2. Lzip uses a simplified form of LZMA (Lempel\-Ziv\-Markov
+chain\-Algorithm) designed to achieve complete interoperability between
+implementations. The maximum dictionary size is 512 MiB so that any lzip
+file can be decompressed on 32\-bit machines. Lzip provides accurate and
+robust 3\-factor integrity checking. 'lzip \fB\-0\fR' compresses about as fast as
+gzip, while 'lzip \fB\-9\fR' compresses most files more than bzip2. Decompression
+speed is intermediate between gzip and bzip2. Lzip provides better data
+recovery capabilities than gzip and bzip2. Lzip has been designed, written,
+and tested with great care to replace gzip and bzip2 as general\-purpose
+compressed format for Unix\-like systems.
 .PP
 Plzip can compress/decompress large files on multiprocessor machines much
 faster than lzip, at the cost of a slightly reduced compression ratio (0.4
 to 2 percent larger compressed files). Note that the number of usable
 threads is limited by file size; on files larger than a few GB plzip can use
-hundreds of processors, but on files of only a few MB plzip is no faster
-than lzip.
+hundreds of processors, but on files smaller than 1 MiB plzip is no faster
+than lzip (even at compression level \fB\-0\fR).
+The number of threads defaults to the number of processors.
 .SH OPTIONS
 .TP
 \fB\-h\fR, \fB\-\-help\fR
@@ -132,8 +133,8 @@ License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
 There is NO WARRANTY, to the extent permitted by law.
-Using lzlib 1.14
-Using LZ_API_VERSION = 1014
+Using lzlib 1.15\-rc1
+Using LZ_API_VERSION = 1015
 .SH "SEE ALSO"
 The full documentation for
 .B plzip
diff --git a/doc/plzip.info b/doc/plzip.info
index becd133..a12b06a 100644
--- a/doc/plzip.info
+++ b/doc/plzip.info
@@ -11,21 +11,22 @@ File: plzip.info,  Node: Top,  Next: Introduction,  Up: (dir)
 Plzip Manual
 ************
 
-This manual is for Plzip (version 1.11, 21 January 2024).
+This manual is for Plzip (version 1.12-rc1, 19 November 2024).
 
 * Menu:
 
-* Introduction::           Purpose and features of plzip
-* Output::                 Meaning of plzip's output
-* Invoking plzip::         Command-line interface
-* Program design::         Internal structure of plzip
-* Memory requirements::    Memory required to compress and decompress
-* Minimum file sizes::     Minimum file sizes required for full speed
-* File format::            Detailed format of the compressed file
-* Trailing data::          Extra data appended to the file
-* Examples::               A small tutorial with examples
-* Problems::               Reporting bugs
-* Concept index::          Index of concepts
+* Introduction::         Purpose and features of plzip
+* Output::               Meaning of plzip's output
+* Invoking plzip::       Command-line interface
+* Argument syntax::      By convention, options start with a hyphen
+* File format::          Detailed format of the compressed file
+* Program design::       Internal structure of plzip
+* Memory requirements::  Memory required to compress and decompress
+* Minimum file sizes::   Minimum file sizes required for full speed
+* Trailing data::        Extra data appended to the file
+* Examples::             A small tutorial with examples
+* Problems::             Reporting bugs
+* Concept index::        Index of concepts
 
 
    Copyright (C) 2009-2024 Antonio Diaz Diaz.
@@ -39,27 +40,27 @@ File: plzip.info,  Node: Introduction,  Next: Output,  Prev: Top,  Up: Top
 1 Introduction
 **************
 
-Plzip is a massively parallel (multi-threaded) implementation of lzip,
-compatible with lzip 1.4 or newer. Plzip uses the compression library lzlib.
+Plzip is a massively parallel (multi-threaded) implementation of lzip.
+Plzip uses the compression library lzlib.
 
    Lzip is a lossless data compressor with a user interface similar to the
-one of gzip or bzip2. Lzip uses a simplified form of the 'Lempel-Ziv-Markov
-chain-Algorithm' (LZMA) stream format to maximize interoperability. The
-maximum dictionary size is 512 MiB so that any lzip file can be decompressed
-on 32-bit machines. Lzip provides accurate and robust 3-factor integrity
-checking. Lzip can compress about as fast as gzip (lzip -0) or compress most
-files more than bzip2 (lzip -9). Decompression speed is intermediate between
-gzip and bzip2. Lzip is better than gzip and bzip2 from a data recovery
-perspective. Lzip has been designed, written, and tested with great care to
-replace gzip and bzip2 as the standard general-purpose compressed format for
-Unix-like systems.
+one of gzip or bzip2. Lzip uses a simplified form of LZMA (Lempel-Ziv-Markov
+chain-Algorithm) designed to achieve complete interoperability between
+implementations. The maximum dictionary size is 512 MiB so that any lzip
+file can be decompressed on 32-bit machines. Lzip provides accurate and
+robust 3-factor integrity checking. 'lzip -0' compresses about as fast as
+gzip, while 'lzip -9' compresses most files more than bzip2. Decompression
+speed is intermediate between gzip and bzip2. Lzip provides better data
+recovery capabilities than gzip and bzip2. Lzip has been designed, written,
+and tested with great care to replace gzip and bzip2 as general-purpose
+compressed format for Unix-like systems.
 
    Plzip can compress/decompress large files on multiprocessor machines much
 faster than lzip, at the cost of a slightly reduced compression ratio (0.4
 to 2 percent larger compressed files). Note that the number of usable
 threads is limited by file size; on files larger than a few GB plzip can use
-hundreds of processors, but on files of only a few MB plzip is no faster
-than lzip. *Note Minimum file sizes::.
+hundreds of processors, but on files smaller than 1 MiB plzip is no faster
+than lzip (even at compression level -0). *Note Minimum file sizes::.
 
    For creation and manipulation of compressed tar archives tarlz can be
 more efficient than using tar and plzip because tarlz is able to keep the
@@ -96,9 +97,9 @@ makes it safer than compressors returning ambiguous warning values (like
 gzip) when it is used as a back end for other programs like tar or zutils.
 
    Plzip automatically uses for each file the largest dictionary size that
-does not exceed neither the file size nor the limit given. Keep in mind
-that the decompression memory requirement is affected at compression time
-by the choice of dictionary size limit. *Note Memory requirements::.
+does not exceed neither the file size nor the limit given. The dictionary
+size used for decompression is the same dictionary size used for
+compression. *Note Memory requirements::.
 
    When compressing, plzip replaces every file given in the command line
 with a compressed version of itself, with the name "original_name.lz". When
@@ -174,7 +175,7 @@ have been compressed. Decompressed is used to refer to data which have
 undergone the process of decompression.
 
 
-File: plzip.info,  Node: Invoking plzip,  Next: Program design,  Prev: Output,  Up: Top
+File: plzip.info,  Node: Invoking plzip,  Next: Argument syntax,  Prev: Output,  Up: Top
 
 3 Invoking plzip
 ****************
@@ -189,8 +190,7 @@ means standard input. It can be mixed with other FILES and is read just
 once, the first time it appears in the command line. Remember to prepend
 './' to any file name beginning with a hyphen, or use '--'.
 
-   plzip supports the following options: *Note Argument syntax:
-(arg_parser)Argument syntax.
+plzip supports the following options: *Note Argument syntax::.
 
 '-h'
 '--help'
@@ -235,7 +235,8 @@ once, the first time it appears in the command line. Remember to prepend
      status 1. If a file fails to decompress, or is a terminal, plzip exits
      immediately with error status 2 without decompressing the rest of the
      files. A terminal is considered an uncompressed file, and therefore
-     invalid.
+     invalid. A multimember file with one or more empty members is accepted
+     if redirected to standard input.
 
 '-f'
 '--force'
@@ -259,7 +260,8 @@ once, the first time it appears in the command line. Remember to prepend
      '-v', the dictionary size, the number of members in the file, and the
      amount of trailing data (if any) are also printed. With '-vv', the
      positions and sizes of each member in multimember files are also
-     printed.
+     printed. A multimember file with one or more empty members is accepted
+     if redirected to standard input.
 
      If any file is damaged, does not exist, can't be opened, or is not
      regular, the final exit status is > 0. '-lq' can be used to check
@@ -278,8 +280,8 @@ once, the first time it appears in the command line. Remember to prepend
 '-n N'
 '--threads=N'
      Set the maximum number of worker threads, overriding the system's
-     default. Valid values range from 1 to "as many as your system can
-     support". If this option is not used, plzip tries to detect the number
+     default. Valid values range from 1 to as many as your system can
+     support. If this option is not used, plzip tries to detect the number
      of processors in the system and use it as default value. When
      compressing on a 32 bit system, plzip tries to limit the memory use to
      under 2.22 GiB (4 worker threads at level -9) by reducing the number
@@ -338,7 +340,8 @@ once, the first time it appears in the command line. Remember to prepend
      fails the test, does not exist, can't be opened, or is a terminal,
      plzip continues testing the rest of the files. A final diagnostic is
      shown at verbosity level 1 or higher if any file fails the test when
-     testing multiple files.
+     testing multiple files. A multimember file with one or more empty
+     members is accepted if redirected to standard input.
 
 '-v'
 '--verbose'
@@ -368,6 +371,7 @@ once, the first time it appears in the command line. Remember to prepend
      '-s64MiB -m273'
 
      Level   Dictionary size (-s)   Match length limit (-m)
+     ------------------------------------------------------
      -0      64 KiB                 16 bytes
      -1      1 MiB                  5 bytes
      -2      1.5 MiB                6 bytes
@@ -387,7 +391,7 @@ once, the first time it appears in the command line. Remember to prepend
      When decompressing, testing, or listing, allow trailing data whose
      first bytes are so similar to the magic bytes of a lzip header that
      they can be confused with a corrupt header. Use this option if a file
-     triggers a "corrupt header" error and the cause is not indeed a
+     triggers a 'corrupt header' error and the cause is not indeed a
      corrupt header.
 
 '--in-slots=N'
@@ -421,6 +425,7 @@ and may be followed by a multiplier and an optional 'B' for "byte".
    Table of SI and binary prefixes (unit multipliers):
 
 Prefix   Value                      |   Prefix   Value
+----------------------------------------------------------------------
 k        kilobyte   (10^3 = 1000)   |   Ki       kibibyte  (2^10 = 1024)
 M        megabyte   (10^6)          |   Mi       mebibyte  (2^20)
 G        gigabyte   (10^9)          |   Gi       gibibyte  (2^30)
@@ -439,9 +444,131 @@ corrupt or invalid input file, 3 for an internal consistency error (e.g.,
 bug) which caused plzip to panic.
 
 
-File: plzip.info,  Node: Program design,  Next: Memory requirements,  Prev: Invoking plzip,  Up: Top
+File: plzip.info,  Node: Argument syntax,  Next: File format,  Prev: Invoking plzip,  Up: Top
 
-4 Internal structure of plzip
+4 Syntax of command-line arguments
+**********************************
+
+POSIX recommends these conventions for command-line arguments.
+
+   * A command-line argument is an option if it begins with a hyphen ('-').
+
+   * Option names are single alphanumeric characters.
+
+   * Certain options require an argument.
+
+   * An option and its argument may or may not appear as separate tokens.
+     (In other words, the whitespace separating them is optional, unless the
+     argument is the empty string). Thus, '-o foo' and '-ofoo' are
+     equivalent.
+
+   * One or more options without arguments, followed by at most one option
+     that takes an argument, may follow a hyphen in a single token. Thus,
+     '-abc' is equivalent to '-a -b -c'.
+
+   * Options typically precede other non-option arguments.
+
+   * The argument '--' terminates all options; any following arguments are
+     treated as non-option arguments, even if they begin with a hyphen.
+
+   * A token consisting of a single hyphen character is interpreted as an
+     ordinary non-option argument. By convention, it is used to specify
+     standard input, standard output, or a file named '-'.
+
+GNU adds "long options" to these conventions:
+
+   * A long option consists of two hyphens ('--') followed by a name made
+     of alphanumeric characters and hyphens. Option names are typically one
+     to three words long, with hyphens to separate words. Abbreviations can
+     be used for the long option names as long as the abbreviations are
+     unique.
+
+   * A long option and its argument may or may not appear as separate
+     tokens. In the latter case they must be separated by an equal sign '='.
+     Thus, '--foo bar' and '--foo=bar' are equivalent.
+
+The syntax of options with an optional argument is
+'-<short_option><argument>' (without whitespace), or
+'--<long_option>=<argument>'.
+
+
+File: plzip.info,  Node: File format,  Next: Program design,  Prev: Argument syntax,  Up: Top
+
+5 File format
+*************
+
+Perfection is reached, not when there is no longer anything to add, but
+when there is no longer anything to take away.
+-- Antoine de Saint-Exupery
+
+   In the diagram below, a box like this:
+
++---+
+|   | <-- the vertical bars might be missing
++---+
+
+   represents one byte; a box like this:
+
++==============+
+|              |
++==============+
+
+   represents a variable number of bytes.
+
+A lzip file consists of one or more independent "members" (compressed data
+sets). The members simply appear one after another in the file, with no
+additional information before, between, or after them. Each member can
+encode in compressed form up to 16 EiB - 1 byte of uncompressed data. The
+size of a multimember file is unlimited. Empty members (data size = 0) are
+not allowed in multimember files.
+
+   Each member has the following structure:
+
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| ID string | VN | DS | LZMA stream | CRC32 |   Data size   |  Member size  |
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+   All multibyte values are stored in little endian order.
+
+'ID string (the "magic" bytes)'
+     A four byte string, identifying the lzip format, with the value "LZIP"
+     (0x4C, 0x5A, 0x49, 0x50).
+
+'VN (version number, 1 byte)'
+     Just in case something needs to be modified in the future. 1 for now.
+
+'DS (coded dictionary size, 1 byte)'
+     The dictionary size is calculated by taking a power of 2 (the base
+     size) and subtracting from it a fraction between 0/16 and 7/16 of the
+     base size.
+     Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).
+     Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
+     from the base size to obtain the dictionary size.
+     Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB
+     Valid values for dictionary size range from 4 KiB to 512 MiB.
+
+'LZMA stream'
+     The LZMA stream, terminated by an 'End Of Stream' marker. Uses default
+     values for encoder properties. *Note Stream format: (lzip)Stream
+     format, for a complete description.
+
+'CRC32 (4 bytes)'
+     Cyclic Redundancy Check (CRC) of the original uncompressed data.
+
+'Data size (8 bytes)'
+     Size of the original uncompressed data.
+
+'Member size (8 bytes)'
+     Total size of the member, including header and trailer. This field acts
+     as a distributed index, improves the checking of stream integrity, and
+     facilitates the safe recovery of undamaged members from multimember
+     files. Lzip limits the member size to 2 PiB to prevent the data size
+     field from overflowing.
+
+
+File: plzip.info,  Node: Program design,  Next: Memory requirements,  Prev: File format,  Up: Top
+
+6 Internal structure of plzip
 *****************************
 
 When compressing, plzip divides the input file into chunks and compresses as
@@ -456,8 +583,8 @@ because lzip usually produces single-member files, which can't be
 decompressed in parallel.
 
    For each input file, a splitter thread and several worker threads are
-created, acting the main thread as muxer (multiplexer) thread. A "packet
-courier" takes care of data transfers among threads and limits the maximum
+created, acting the main thread as muxer (multiplexer) thread. A 'packet
+courier' takes care of data transfers among threads and limits the maximum
 number of data blocks (packets) being processed simultaneously.
 
    The splitter reads data blocks from the input file, and distributes them
@@ -486,7 +613,7 @@ only limited by the number of processors available and by I/O speed.
 
 File: plzip.info,  Node: Memory requirements,  Next: Minimum file sizes,  Prev: Program design,  Up: Top
 
-5 Memory required to compress and decompress
+7 Memory required to compress and decompress
 ********************************************
 
 The amount of memory required *per worker thread* for decompression or
@@ -520,6 +647,7 @@ The following table shows the memory required *per thread* for compression
 at a given level, using the default data size for each level:
 
 Level   Memory required
+------------------------
 -0      4.875 MiB
 -1      17.75 MiB
 -2      26.625 MiB
@@ -532,9 +660,9 @@ Level   Memory required
 -9      568 MiB
 
 
-File: plzip.info,  Node: Minimum file sizes,  Next: File format,  Prev: Memory requirements,  Up: Top
+File: plzip.info,  Node: Minimum file sizes,  Next: Trailing data,  Prev: Memory requirements,  Up: Top
 
-6 Minimum file sizes required for full compression speed
+8 Minimum file sizes required for full compression speed
 ********************************************************
 
 When compressing, plzip divides the input file into chunks and compresses
@@ -569,85 +697,9 @@ Level
 -9           128 MiB   256 MiB   512 MiB   1 GiB     4 GiB     16 GiB
 
 
-File: plzip.info,  Node: File format,  Next: Trailing data,  Prev: Minimum file sizes,  Up: Top
-
-7 File format
-*************
-
-Perfection is reached, not when there is no longer anything to add, but
-when there is no longer anything to take away.
--- Antoine de Saint-Exupery
-
-
-   In the diagram below, a box like this:
-
-+---+
-|   | <-- the vertical bars might be missing
-+---+
-
-   represents one byte; a box like this:
-
-+==============+
-|              |
-+==============+
-
-   represents a variable number of bytes.
-
-
-   A lzip file consists of one or more independent "members" (compressed
-data sets). The members simply appear one after another in the file, with no
-additional information before, between, or after them. Each member can
-encode in compressed form up to 16 EiB - 1 byte of uncompressed data. The
-size of a multimember file is unlimited.
-
-   Each member has the following structure:
-
-+--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-| ID string | VN | DS | LZMA stream | CRC32 |   Data size   |  Member size  |
-+--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-
-   All multibyte values are stored in little endian order.
-
-'ID string (the "magic" bytes)'
-     A four byte string, identifying the lzip format, with the value "LZIP"
-     (0x4C, 0x5A, 0x49, 0x50).
-
-'VN (version number, 1 byte)'
-     Just in case something needs to be modified in the future. 1 for now.
+File: plzip.info,  Node: Trailing data,  Next: Examples,  Prev: Minimum file sizes,  Up: Top
 
-'DS (coded dictionary size, 1 byte)'
-     The dictionary size is calculated by taking a power of 2 (the base
-     size) and subtracting from it a fraction between 0/16 and 7/16 of the
-     base size.
-     Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).
-     Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
-     from the base size to obtain the dictionary size.
-     Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB
-     Valid values for dictionary size range from 4 KiB to 512 MiB.
-
-'LZMA stream'
-     The LZMA stream, finished by an "End Of Stream" marker. Uses default
-     values for encoder properties. *Note Stream format: (lzip)Stream
-     format, for a complete description.
-
-'CRC32 (4 bytes)'
-     Cyclic Redundancy Check (CRC) of the original uncompressed data.
-
-'Data size (8 bytes)'
-     Size of the original uncompressed data.
-
-'Member size (8 bytes)'
-     Total size of the member, including header and trailer. This field acts
-     as a distributed index, improves the checking of stream integrity, and
-     facilitates the safe recovery of undamaged members from multimember
-     files. Lzip limits the member size to 2 PiB to prevent the data size
-     field from overflowing.
-
-
-
-File: plzip.info,  Node: Trailing data,  Next: Examples,  Prev: File format,  Up: Top
-
-8 Extra data appended to the file
+9 Extra data appended to the file
 *********************************
 
 Sometimes extra data are found appended to a lzip file after the last
@@ -657,7 +709,7 @@ member. Such trailing data may be:
      example when writing to a tape. It is safe to append any amount of
      padding zero bytes to a lzip file.
 
-   * Useful data added by the user; an "End Of File" string (to check that
+   * Useful data added by the user; an 'End Of File' string (to check that
      the file has not been truncated), a cryptographically secure hash, a
      description of file contents, etc. It is safe to append any amount of
      text to a lzip file as long as none of the first four bytes of the
@@ -693,8 +745,8 @@ where a file containing trailing data must be rejected, the option
 
 File: plzip.info,  Node: Examples,  Next: Problems,  Prev: Trailing data,  Up: Top
 
-9 A small tutorial with examples
-********************************
+10 A small tutorial with examples
+*********************************
 
 WARNING! Even if plzip is bug-free, other causes may result in a corrupt
 compressed file (bugs in the system libraries, memory errors, etc).
@@ -706,38 +758,32 @@ comparing the compressed file with the original because the corruption
 happens before plzip compresses the RAM contents, resulting in a valid
 compressed file containing wrong data.
 
-
 Example 1: Extract all the files from archive 'foo.tar.lz'.
 
        tar -xf foo.tar.lz
      or
        plzip -cd foo.tar.lz | tar -xf -
 
-
 Example 2: Replace a regular file with its compressed version 'file.lz' and
 show the compression ratio.
 
      plzip -v file
 
-
 Example 3: Like example 2 but the created 'file.lz' has a block size of
 1 MiB. The compression ratio is not shown.
 
      plzip -B 1MiB file
 
-
 Example 4: Restore a regular file from its compressed version 'file.lz'. If
 the operation is successful, 'file.lz' is removed.
 
      plzip -d file.lz
 
-
 Example 5: Check the integrity of the compressed file 'file.lz' and show
 status.
 
      plzip -tv file.lz
 
-
 Example 6: The right way of concatenating the decompressed output of two or
 more compressed files. *Note Trailing data::.
 
@@ -746,19 +792,16 @@ more compressed files. *Note Trailing data::.
      Do this instead
        plzip -cd file1.lz file2.lz file3.lz
 
-
 Example 7: Decompress 'file.lz' partially until 10 KiB of decompressed data
 are produced.
 
      plzip -cd file.lz | dd bs=1024 count=10
 
-
 Example 8: Decompress 'file.lz' partially from decompressed byte at offset
 10000 to decompressed byte at offset 14999 (5000 bytes are produced).
 
      plzip -cd file.lz | dd bs=1000 skip=10 count=5
 
-
 Example 9: Compress a whole device in /dev/sdc and send the output to
 'file.lz'.
 
@@ -769,7 +812,7 @@ Example 9: Compress a whole device in /dev/sdc and send the output to
 
 File: plzip.info,  Node: Problems,  Next: Concept index,  Prev: Examples,  Up: Top
 
-10 Reporting bugs
+11 Reporting bugs
 *****************
 
 There are probably bugs in plzip. There are certainly errors and omissions
@@ -790,6 +833,7 @@ Concept index
 
 * Menu:
 
+* argument syntax:                       Argument syntax.           (line 6)
 * bugs:                                  Problems.                  (line 6)
 * examples:                              Examples.                  (line 6)
 * file format:                           File format.               (line 6)
@@ -809,21 +853,22 @@ Concept index
 
 Tag Table:
 Node: Top217
-Node: Introduction1156
-Node: Output5934
-Node: Invoking plzip7497
-Ref: --trailing-error8372
-Ref: --data-size8610
-Node: Program design19519
-Node: Memory requirements21818
-Node: Minimum file sizes23503
-Node: File format25506
-Ref: coded-dict-size26945
-Node: Trailing data28195
-Node: Examples30531
-Ref: concat-example31964
-Node: Problems32721
-Node: Concept index33276
+Node: Introduction1207
+Node: Output5956
+Node: Invoking plzip7519
+Ref: --trailing-error8365
+Ref: --data-size8603
+Node: Argument syntax19941
+Node: File format21886
+Ref: coded-dict-size23386
+Node: Program design24637
+Node: Memory requirements26933
+Node: Minimum file sizes28643
+Node: Trailing data30648
+Node: Examples32991
+Ref: concat-example34420
+Node: Problems35174
+Node: Concept index35729
 
 End Tag Table
 
diff --git a/doc/plzip.texi b/doc/plzip.texi
index 323fad1..5ff39da 100644
--- a/doc/plzip.texi
+++ b/doc/plzip.texi
@@ -6,8 +6,8 @@
 @finalout
 @c %**end of header
 
-@set UPDATED 21 January 2024
-@set VERSION 1.11
+@set UPDATED 19 November 2024
+@set VERSION 1.12-rc1
 
 @dircategory Compression
 @direntry
@@ -36,17 +36,18 @@
 This manual is for Plzip (version @value{VERSION}, @value{UPDATED}).
 
 @menu
-* Introduction::           Purpose and features of plzip
-* Output::                 Meaning of plzip's output
-* Invoking plzip::         Command-line interface
-* Program design::         Internal structure of plzip
-* Memory requirements::    Memory required to compress and decompress
-* Minimum file sizes::     Minimum file sizes required for full speed
-* File format::            Detailed format of the compressed file
-* Trailing data::          Extra data appended to the file
-* Examples::               A small tutorial with examples
-* Problems::               Reporting bugs
-* Concept index::          Index of concepts
+* Introduction::         Purpose and features of plzip
+* Output::               Meaning of plzip's output
+* Invoking plzip::       Command-line interface
+* Argument syntax::      By convention, options start with a hyphen
+* File format::          Detailed format of the compressed file
+* Program design::       Internal structure of plzip
+* Memory requirements::  Memory required to compress and decompress
+* Minimum file sizes::   Minimum file sizes required for full speed
+* Trailing data::        Extra data appended to the file
+* Examples::             A small tutorial with examples
+* Problems::             Reporting bugs
+* Concept index::        Index of concepts
 @end menu
 
 @sp 1
@@ -61,30 +62,29 @@ distribute, and modify it.
 @chapter Introduction
 @cindex introduction
 
-@uref{http://www.nongnu.org/lzip/plzip.html,,Plzip}
-is a massively parallel (multi-threaded) implementation of lzip,
-compatible with lzip 1.4 or newer. Plzip uses the compression library
+@uref{http://www.nongnu.org/lzip/plzip.html,,Plzip} is a massively parallel
+(multi-threaded) implementation of lzip. Plzip uses the compression library
 @uref{http://www.nongnu.org/lzip/lzlib.html,,lzlib}.
 
 @uref{http://www.nongnu.org/lzip/lzip.html,,Lzip}
 is a lossless data compressor with a user interface similar to the one
-of gzip or bzip2. Lzip uses a simplified form of the 'Lempel-Ziv-Markov
-chain-Algorithm' (LZMA) stream format to maximize interoperability. The
-maximum dictionary size is 512 MiB so that any lzip file can be decompressed
-on 32-bit machines. Lzip provides accurate and robust 3-factor integrity
-checking. Lzip can compress about as fast as gzip @w{(lzip -0)} or compress most
-files more than bzip2 @w{(lzip -9)}. Decompression speed is intermediate between
-gzip and bzip2. Lzip is better than gzip and bzip2 from a data recovery
-perspective. Lzip has been designed, written, and tested with great care to
-replace gzip and bzip2 as the standard general-purpose compressed format for
-Unix-like systems.
+of gzip or bzip2. Lzip uses a simplified form of LZMA (Lempel-Ziv-Markov
+chain-Algorithm) designed to achieve complete interoperability between
+implementations. The maximum dictionary size is 512 MiB so that any lzip
+file can be decompressed on 32-bit machines. Lzip provides accurate and
+robust 3-factor integrity checking. @w{@samp{lzip -0}} compresses about as fast as
+gzip, while @w{@samp{lzip -9}} compresses most files more than bzip2. Decompression
+speed is intermediate between gzip and bzip2. Lzip provides better data
+recovery capabilities than gzip and bzip2. Lzip has been designed, written,
+and tested with great care to replace gzip and bzip2 as general-purpose
+compressed format for Unix-like systems.
 
 Plzip can compress/decompress large files on multiprocessor machines much
 faster than lzip, at the cost of a slightly reduced compression ratio (0.4
 to 2 percent larger compressed files). Note that the number of usable
 threads is limited by file size; on files larger than a few GB plzip can use
-hundreds of processors, but on files of only a few MB plzip is no faster
-than lzip. @xref{Minimum file sizes}.
+hundreds of processors, but on files smaller than @w{1 MiB} plzip is no faster
+than lzip (even at compression level -0). @xref{Minimum file sizes}.
 
 For creation and manipulation of compressed tar archives
 @uref{http://www.nongnu.org/lzip/manual/tarlz_manual.html,,tarlz} can be more
@@ -132,9 +132,9 @@ makes it safer than compressors returning ambiguous warning values (like
 gzip) when it is used as a back end for other programs like tar or zutils.
 
 Plzip automatically uses for each file the largest dictionary size that does
-not exceed neither the file size nor the limit given. Keep in mind that the
-decompression memory requirement is affected at compression time by the
-choice of dictionary size limit. @xref{Memory requirements}.
+not exceed neither the file size nor the limit given. The dictionary size
+used for decompression is the same dictionary size used for compression.
+@xref{Memory requirements}.
 
 When compressing, plzip replaces every file given in the command line
 with a compressed version of itself, with the name "original_name.lz".
@@ -235,11 +235,8 @@ argument means standard input. It can be mixed with other @var{files} and is
 read just once, the first time it appears in the command line. Remember to
 prepend @file{./} to any file name beginning with a hyphen, or use @samp{--}.
 
-plzip supports the following
-@uref{http://www.nongnu.org/arg-parser/manual/arg_parser_manual.html#Argument-syntax,,options}:
-@ifnothtml
-@xref{Argument syntax,,,arg_parser}.
-@end ifnothtml
+@noindent
+plzip supports the following options: @xref{Argument syntax}.
 
 @table @code
 @item -h
@@ -286,7 +283,8 @@ already exists and @option{--force} has not been specified, plzip continues
 decompressing the rest of the files and exits with error status 1. If a file
 fails to decompress, or is a terminal, plzip exits immediately with error
 status 2 without decompressing the rest of the files. A terminal is
-considered an uncompressed file, and therefore invalid.
+considered an uncompressed file, and therefore invalid. A multimember file
+with one or more empty members is accepted if redirected to standard input.
 
 @item -f
 @itemx --force
@@ -295,7 +293,7 @@ Force overwrite of output files.
 @item -F
 @itemx --recompress
 When compressing, force re-compression of files whose name already has
-the @samp{.lz} or @samp{.tlz} suffix.
+the @file{.lz} or @file{.tlz} suffix.
 
 @item -k
 @itemx --keep
@@ -309,7 +307,8 @@ even for multimember files. If more than one file is given, a final line
 containing the cumulative sizes is printed. With @option{-v}, the dictionary
 size, the number of members in the file, and the amount of trailing data (if
 any) are also printed. With @option{-vv}, the positions and sizes of each
-member in multimember files are also printed.
+member in multimember files are also printed. A multimember file with one or
+more empty members is accepted if redirected to standard input.
 
 If any file is damaged, does not exist, can't be opened, or is not regular,
 the final exit status is @w{> 0}. @option{-lq} can be used to check quickly
@@ -327,7 +326,7 @@ times.
 @item -n @var{n}
 @itemx --threads=@var{n}
 Set the maximum number of worker threads, overriding the system's default.
-Valid values range from 1 to "as many as your system can support". If this
+Valid values range from 1 to as many as your system can support. If this
 option is not used, plzip tries to detect the number of processors in the
 system and use it as default value. When compressing on a @w{32 bit} system,
 plzip tries to limit the memory use to under @w{2.22 GiB} (4 worker threads
@@ -353,10 +352,10 @@ to @option{-c}. @option{-o} has no effect when testing or listing.
 
 In order to keep backward compatibility with plzip versions prior to 1.9,
 when compressing from standard input and no other file names are given, the
-extension @samp{.lz} is appended to @var{file} unless it already ends in
-@samp{.lz} or @samp{.tlz}. This feature will be removed in a future version
+extension @file{.lz} is appended to @var{file} unless it already ends in
+@file{.lz} or @file{.tlz}. This feature will be removed in a future version
 of plzip. Meanwhile, redirection may be used instead of @option{-o} to write
-the compressed output to a file without the extension @samp{.lz} in its
+the compressed output to a file without the extension @file{.lz} in its
 name: @w{@samp{plzip < file > foo}}.
 
 @item -q
@@ -386,7 +385,8 @@ together with @option{-v} to see information about the files. If a file
 fails the test, does not exist, can't be opened, or is a terminal, plzip
 continues testing the rest of the files. A final diagnostic is shown at
 verbosity level 1 or higher if any file fails the test when testing multiple
-files.
+files. A multimember file with one or more empty members is accepted if
+redirected to standard input.
 
 @item -v
 @itemx --verbose
@@ -416,7 +416,7 @@ given, the last setting is used. For example @w{@option{-9 -s64MiB}} is
 equivalent to @w{@option{-s64MiB -m273}}
 
 @multitable {Level} {Dictionary size (-s)} {Match length limit (-m)}
-@item Level @tab Dictionary size (-s) @tab Match length limit (-m)
+@headitem Level @tab Dictionary size (-s) @tab Match length limit (-m)
 @item -0 @tab 64 KiB @tab  16 bytes
 @item -1 @tab  1 MiB @tab   5 bytes
 @item -2 @tab  1.5 MiB @tab   6 bytes
@@ -437,7 +437,7 @@ Aliases for GNU gzip compatibility.
 When decompressing, testing, or listing, allow trailing data whose first
 bytes are so similar to the magic bytes of a lzip header that they can
 be confused with a corrupt header. Use this option if a file triggers a
-"corrupt header" error and the cause is not indeed a corrupt header.
+'corrupt header' error and the cause is not indeed a corrupt header.
 
 @item --in-slots=@var{n}
 Number of @w{1 MiB} input packets buffered per worker thread when
@@ -474,7 +474,7 @@ and may be followed by a multiplier and an optional @samp{B} for "byte".
 Table of SI and binary prefixes (unit multipliers):
 
 @multitable {Prefix} {kilobyte   (10^3 = 1000)} {|} {Prefix} {kibibyte  (2^10 = 1024)}
-@item Prefix @tab Value               @tab | @tab Prefix @tab Value
+@headitem Prefix @tab Value           @tab | @tab Prefix @tab Value
 @item k @tab kilobyte   (10^3 = 1000) @tab | @tab Ki @tab kibibyte  (2^10 = 1024)
 @item M @tab megabyte   (10^6)        @tab | @tab Mi @tab mebibyte  (2^20)
 @item G @tab gigabyte   (10^9)        @tab | @tab Gi @tab gibibyte  (2^30)
@@ -494,6 +494,148 @@ indicate a corrupt or invalid input file, 3 for an internal consistency
 error (e.g., bug) which caused plzip to panic.
 
 
+@node Argument syntax
+@chapter Syntax of command-line arguments
+@cindex argument syntax
+
+POSIX recommends these conventions for command-line arguments.
+
+@itemize @bullet
+@item A command-line argument is an option if it begins with a hyphen
+(@samp{-}).
+
+@item Option names are single alphanumeric characters.
+
+@item Certain options require an argument.
+
+@item An option and its argument may or may not appear as separate tokens.
+(In other words, the whitespace separating them is optional, unless the
+argument is the empty string).
+Thus, @w{@option{-o foo}} and @option{-ofoo} are equivalent.
+
+@item One or more options without arguments, followed by at most one option
+that takes an argument, may follow a hyphen in a single token.
+Thus, @option{-abc} is equivalent to @w{@option{-a -b -c}}.
+
+@item Options typically precede other non-option arguments.
+
+@item The argument @samp{--} terminates all options; any following arguments
+are treated as non-option arguments, even if they begin with a hyphen.
+
+@item A token consisting of a single hyphen character is interpreted as an
+ordinary non-option argument. By convention, it is used to specify standard
+input, standard output, or a file named @samp{-}.
+@end itemize
+
+@noindent
+GNU adds @dfn{long options} to these conventions:
+
+@itemize @bullet
+@item A long option consists of two hyphens (@samp{--}) followed by a name
+made of alphanumeric characters and hyphens. Option names are typically one
+to three words long, with hyphens to separate words. Abbreviations can be
+used for the long option names as long as the abbreviations are unique.
+
+@item A long option and its argument may or may not appear as separate
+tokens. In the latter case they must be separated by an equal sign @samp{=}.
+Thus, @w{@option{--foo bar}} and @option{--foo=bar} are equivalent.
+@end itemize
+
+@noindent
+The syntax of options with an optional argument is
+@option{-<short_option><argument>} (without whitespace), or
+@option{--<long_option>=<argument>}.
+
+
+@node File format
+@chapter File format
+@cindex file format
+
+Perfection is reached, not when there is no longer anything to add, but
+when there is no longer anything to take away.@*
+--- Antoine de Saint-Exupery
+
+In the diagram below, a box like this:
+
+@verbatim
++---+
+|   | <-- the vertical bars might be missing
++---+
+@end verbatim
+
+represents one byte; a box like this:
+
+@verbatim
++==============+
+|              |
++==============+
+@end verbatim
+
+represents a variable number of bytes.
+
+@noindent
+A lzip file consists of one or more independent "members" (compressed data
+sets). The members simply appear one after another in the file, with no
+additional information before, between, or after them. Each member can
+encode in compressed form up to @w{16 EiB - 1 byte} of uncompressed data.
+The size of a multimember file is unlimited. Empty members (data size = 0)
+are not allowed in multimember files.
+
+Each member has the following structure:
+
+@verbatim
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| ID string | VN | DS | LZMA stream | CRC32 |   Data size   |  Member size  |
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+@end verbatim
+
+All multibyte values are stored in little endian order.
+
+@table @samp
+@item ID string (the "magic" bytes)
+A four byte string, identifying the lzip format, with the value "LZIP"
+(0x4C, 0x5A, 0x49, 0x50).
+
+@item VN (version number, 1 byte)
+Just in case something needs to be modified in the future. 1 for now.
+
+@anchor{coded-dict-size}
+@item DS (coded dictionary size, 1 byte)
+The dictionary size is calculated by taking a power of 2 (the base size)
+and subtracting from it a fraction between 0/16 and 7/16 of the base size.@*
+Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@*
+Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
+from the base size to obtain the dictionary size.@*
+Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB@*
+Valid values for dictionary size range from 4 KiB to 512 MiB.
+
+@item LZMA stream
+The LZMA stream, terminated by an 'End Of Stream' marker. Uses default values
+for encoder properties.
+@ifnothtml
+@xref{Stream format,,,lzip},
+@end ifnothtml
+@ifhtml
+See
+@uref{http://www.nongnu.org/lzip/manual/lzip_manual.html#Stream-format,,Stream format}
+@end ifhtml
+for a complete description.
+
+@item CRC32 (4 bytes)
+Cyclic Redundancy Check (CRC) of the original uncompressed data.
+
+@item Data size (8 bytes)
+Size of the original uncompressed data.
+
+@item Member size (8 bytes)
+Total size of the member, including header and trailer. This field acts
+as a distributed index, improves the checking of stream integrity, and
+facilitates the safe recovery of undamaged members from multimember files.
+Lzip limits the member size to @w{2 PiB} to prevent the data size field from
+overflowing.
+@end table
+
+
 @node Program design
 @chapter Internal structure of plzip
 @cindex program design
@@ -510,8 +652,8 @@ because lzip usually produces single-member files, which can't be
 decompressed in parallel.
 
 For each input file, a splitter thread and several worker threads are
-created, acting the main thread as muxer (multiplexer) thread. A "packet
-courier" takes care of data transfers among threads and limits the
+created, acting the main thread as muxer (multiplexer) thread. A 'packet
+courier' takes care of data transfers among threads and limits the
 maximum number of data blocks (packets) being processed simultaneously.
 
 The splitter reads data blocks from the input file, and distributes them
@@ -587,7 +729,7 @@ The following table shows the memory required @strong{per thread} for
 compression at a given level, using the default data size for each level:
 
 @multitable {Level} {Memory required}
-@item Level @tab Memory required
+@headitem Level @tab Memory required
 @item -0 @tab   4.875 MiB
 @item -1 @tab  17.75 MiB
 @item -2 @tab  26.625 MiB
@@ -638,96 +780,6 @@ data size for each level:
 @end multitable
 
 
-@node File format
-@chapter File format
-@cindex file format
-
-Perfection is reached, not when there is no longer anything to add, but
-when there is no longer anything to take away.@*
---- Antoine de Saint-Exupery
-
-@sp 1
-In the diagram below, a box like this:
-
-@verbatim
-+---+
-|   | <-- the vertical bars might be missing
-+---+
-@end verbatim
-
-represents one byte; a box like this:
-
-@verbatim
-+==============+
-|              |
-+==============+
-@end verbatim
-
-represents a variable number of bytes.
-
-@sp 1
-A lzip file consists of one or more independent "members" (compressed data
-sets). The members simply appear one after another in the file, with no
-additional information before, between, or after them. Each member can
-encode in compressed form up to @w{16 EiB - 1 byte} of uncompressed data.
-The size of a multimember file is unlimited.
-
-Each member has the following structure:
-
-@verbatim
-+--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-| ID string | VN | DS | LZMA stream | CRC32 |   Data size   |  Member size  |
-+--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-@end verbatim
-
-All multibyte values are stored in little endian order.
-
-@table @samp
-@item ID string (the "magic" bytes)
-A four byte string, identifying the lzip format, with the value "LZIP"
-(0x4C, 0x5A, 0x49, 0x50).
-
-@item VN (version number, 1 byte)
-Just in case something needs to be modified in the future. 1 for now.
-
-@anchor{coded-dict-size}
-@item DS (coded dictionary size, 1 byte)
-The dictionary size is calculated by taking a power of 2 (the base size)
-and subtracting from it a fraction between 0/16 and 7/16 of the base size.@*
-Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@*
-Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
-from the base size to obtain the dictionary size.@*
-Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB@*
-Valid values for dictionary size range from 4 KiB to 512 MiB.
-
-@item LZMA stream
-The LZMA stream, finished by an "End Of Stream" marker. Uses default values
-for encoder properties.
-@ifnothtml
-@xref{Stream format,,,lzip},
-@end ifnothtml
-@ifhtml
-See
-@uref{http://www.nongnu.org/lzip/manual/lzip_manual.html#Stream-format,,Stream format}
-@end ifhtml
-for a complete description.
-
-@item CRC32 (4 bytes)
-Cyclic Redundancy Check (CRC) of the original uncompressed data.
-
-@item Data size (8 bytes)
-Size of the original uncompressed data.
-
-@item Member size (8 bytes)
-Total size of the member, including header and trailer. This field acts
-as a distributed index, improves the checking of stream integrity, and
-facilitates the safe recovery of undamaged members from multimember files.
-Lzip limits the member size to @w{2 PiB} to prevent the data size field from
-overflowing.
-
-@end table
-
-
 @node Trailing data
 @chapter Extra data appended to the file
 @cindex trailing data
@@ -742,7 +794,7 @@ example when writing to a tape. It is safe to append any amount of
 padding zero bytes to a lzip file.
 
 @item
-Useful data added by the user; an "End Of File" string (to check that the
+Useful data added by the user; an 'End Of File' string (to check that the
 file has not been truncated), a cryptographically secure hash, a description
 of file contents, etc. It is safe to append any amount of text to a lzip
 file as long as none of the first four bytes of the text matches the
@@ -794,9 +846,8 @@ compression can only be detected by comparing the compressed file with the
 original because the corruption happens before plzip compresses the RAM
 contents, resulting in a valid compressed file containing wrong data.
 
-@sp 1
 @noindent
-Example 1: Extract all the files from archive @samp{foo.tar.lz}.
+Example 1: Extract all the files from archive @file{foo.tar.lz}.
 
 @example
   tar -xf foo.tar.lz
@@ -804,43 +855,38 @@ or
   plzip -cd foo.tar.lz | tar -xf -
 @end example
 
-@sp 1
 @noindent
-Example 2: Replace a regular file with its compressed version @samp{file.lz}
+Example 2: Replace a regular file with its compressed version @file{file.lz}
 and show the compression ratio.
 
 @example
 plzip -v file
 @end example
 
-@sp 1
 @noindent
-Example 3: Like example 2 but the created @samp{file.lz} has a block size of
+Example 3: Like example 2 but the created @file{file.lz} has a block size of
 @w{1 MiB}. The compression ratio is not shown.
 
 @example
 plzip -B 1MiB file
 @end example
 
-@sp 1
 @noindent
 Example 4: Restore a regular file from its compressed version
-@samp{file.lz}. If the operation is successful, @samp{file.lz} is removed.
+@file{file.lz}. If the operation is successful, @file{file.lz} is removed.
 
 @example
 plzip -d file.lz
 @end example
 
-@sp 1
 @noindent
-Example 5: Check the integrity of the compressed file @samp{file.lz} and
+Example 5: Check the integrity of the compressed file @file{file.lz} and
 show status.
 
 @example
 plzip -tv file.lz
 @end example
 
-@sp 1
 @anchor{concat-example}
 @noindent
 Example 6: The right way of concatenating the decompressed output of two or
@@ -853,28 +899,25 @@ Do this instead
   plzip -cd file1.lz file2.lz file3.lz
 @end example
 
-@sp 1
 @noindent
-Example 7: Decompress @samp{file.lz} partially until @w{10 KiB} of
+Example 7: Decompress @file{file.lz} partially until @w{10 KiB} of
 decompressed data are produced.
 
 @example
 plzip -cd file.lz | dd bs=1024 count=10
 @end example
 
-@sp 1
 @noindent
-Example 8: Decompress @samp{file.lz} partially from decompressed byte at
+Example 8: Decompress @file{file.lz} partially from decompressed byte at
 offset 10000 to decompressed byte at offset 14999 (5000 bytes are produced).
 
 @example
 plzip -cd file.lz | dd bs=1000 skip=10 count=5
 @end example
 
-@sp 1
 @noindent
 Example 9: Compress a whole device in /dev/sdc and send the output to
-@samp{file.lz}.
+@file{file.lz}.
 
 @example
   plzip -c /dev/sdc > file.lz