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Signed-off-by: Daniel Baumann <daniel@debian.org>
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doc/plzip.info
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@ -1,5 +1,4 @@
This is plzip.info, produced by makeinfo version 4.13 from
plzip.texinfo.
This is plzip.info, produced by makeinfo version 4.13+ from plzip.texi.
INFO-DIR-SECTION Data Compression
START-INFO-DIR-ENTRY
@ -12,7 +11,7 @@ File: plzip.info, Node: Top, Next: Introduction, Up: (dir)
Plzip Manual
************
This manual is for Plzip (version 1.1, 17 September 2013).
This manual is for Plzip (version 1.2-pre1, 20 January 2014).
* Menu:
@ -24,7 +23,7 @@ This manual is for Plzip (version 1.1, 17 September 2013).
* Concept index:: Index of concepts
Copyright (C) 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Antonio Diaz Diaz.
This manual is free documentation: you have unlimited permission to
copy, distribute and modify it.
@ -41,12 +40,9 @@ the one of lzip, bzip2 or gzip.
Plzip can compress/decompress large files on multiprocessor machines
much faster than lzip, at the cost of a slightly reduced compression
ratio. On files large enough (several GB), plzip can use hundreds of
processors. On files of only a few MB it is better to use lzip.
Plzip uses the same well-defined exit status values used by lzip and
bzip2, which makes it safer when used in pipes or scripts than
compressors returning ambiguous warning values, like gzip.
ratio. Note that the number of usable threads is limited by file size,
so 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.
Plzip uses the lzip file format; the files produced by plzip are
fully compatible with lzip-1.4 or newer, and can be rescued with
@ -71,12 +67,27 @@ lziprecover program. Lziprecover makes lzip files resistant to bit-flip
recovery capabilities, including error-checked merging of damaged copies
of a file.
Plzip replaces every file given in the command line with a compressed
version of itself, with the name "original_name.lz". Each compressed
file has the same modification date, permissions, and, when possible,
ownership as the corresponding original, so that these properties can be
correctly restored at decompression time. Plzip is able to read from
some types of non regular files if the `--stdout' option is specified.
Plzip uses the same well-defined exit status values used by lzip and
bzip2, which makes it safer than compressors returning ambiguous warning
values (like gzip) when it is used as a back end for tar or zutils.
When compressing, plzip replaces every file given in the command line
with a compressed version of itself, with the name "original_name.lz".
When decompressing, plzip attempts to guess the name for the
decompressed file from that of the compressed file as follows:
filename.lz becomes filename
filename.tlz becomes filename.tar
anyothername becomes anyothername.out
(De)compressing a file is much like copying or moving it; therefore
plzip preserves the access and modification dates, permissions, and,
when possible, ownership of the file just as "cp -p" does. (If the user
ID or the group ID can't be duplicated, the file permission bits
S_ISUID and S_ISGID are cleared).
Plzip is able to read from some types of non regular files if the
'--stdout' option is specified.
If no file names are specified, plzip compresses (or decompresses)
from standard input to standard output. In this case, plzip will
@ -88,19 +99,12 @@ two or more compressed files. The result is the concatenation of the
corresponding uncompressed files. Integrity testing of concatenated
compressed files is also supported.
When decompressing, plzip attempts to guess the name for the
decompressed file from that of the compressed file as follows:
filename.lz becomes filename
filename.tlz becomes filename.tar
anyothername becomes anyothername.out
WARNING! Even if plzip is bug-free, other causes may result in a
corrupt compressed file (bugs in the system libraries, memory errors,
etc). Therefore, if the data you are going to compress is important,
give the `--keep' option to plzip and do not remove the original file
give the '--keep' option to plzip and do not remove the original file
until you verify the compressed file with a command like
`plzip -cd file.lz | cmp file -'.
'plzip -cd file.lz | cmp file -'.

File: plzip.info, Node: Program design, Next: Invoking plzip, Prev: Introduction, Up: Top
@ -137,73 +141,78 @@ The format for running plzip is:
Plzip supports the following options:
`-h'
`--help'
'-h'
'--help'
Print an informative help message describing the options and exit.
`-V'
`--version'
'-V'
'--version'
Print the version number of plzip on the standard output and exit.
`-B BYTES'
`--data-size=BYTES'
'-B BYTES'
'--data-size=BYTES'
Set the input data block size in bytes. The input file will be
divided in chunks of this size before compression is performed.
Valid values range from 8 KiB to 1 GiB. Default value is two times
the dictionary size. Plzip will reduce the dictionary size if it
is larger than the chosen data size.
`-c'
`--stdout'
'-c'
'--stdout'
Compress or decompress to standard output. Needed when reading
from a named pipe (fifo) or from a device.
`-d'
`--decompress'
'-d'
'--decompress'
Decompress.
`-f'
`--force'
'-f'
'--force'
Force overwrite of output files.
`-F'
`--recompress'
Force recompression of files whose name already has the `.lz' or
`.tlz' suffix.
'-F'
'--recompress'
Force recompression of files whose name already has the '.lz' or
'.tlz' suffix.
`-k'
`--keep'
'-k'
'--keep'
Keep (don't delete) input files during compression or
decompression.
`-m BYTES'
`--match-length=BYTES'
'-m BYTES'
'--match-length=BYTES'
Set the match length limit in bytes. After a match this long is
found, the search is finished. Valid values range from 5 to 273.
Larger values usually give better compression ratios but longer
compression times.
`-n N'
`--threads=N'
'-n N'
'--threads=N'
Set the number of worker threads. 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. `plzip --help' shows the system's default
use it as default value. 'plzip --help' shows the system's default
value.
`-o FILE'
`--output=FILE'
When reading from standard input and `--stdout' has not been
specified, use `FILE' as the virtual name of the uncompressed
file. This produces a file named `FILE' when decompressing, and a
file named `FILE.lz' when compressing.
Note that the number of usable threads is limited to
ceil( file_size / data_size ) during compression (*note
--data-size::), and to the number of members in the input during
decompression.
`-q'
`--quiet'
'-o FILE'
'--output=FILE'
When reading from standard input and '--stdout' has not been
specified, use 'FILE' as the virtual name of the uncompressed
file. This produces a file named 'FILE' when decompressing, and a
file named 'FILE.lz' when compressing.
'-q'
'--quiet'
Quiet operation. Suppress all messages.
`-s BYTES'
`--dictionary-size=BYTES'
'-s BYTES'
'--dictionary-size=BYTES'
Set the dictionary size limit in bytes. Valid values range from 4
KiB to 512 MiB. Plzip will use the smallest possible dictionary
size for each member without exceeding this limit. Note that
@ -216,33 +225,33 @@ The format for running plzip is:
requirement is affected at compression time by the choice of
dictionary size limit.
`-t'
`--test'
'-t'
'--test'
Check integrity of the specified file(s), but don't decompress
them. This really performs a trial decompression and throws away
the result. Use it together with `-v' to see information about
the result. Use it together with '-v' to see information about
the file.
`-v'
`--verbose'
'-v'
'--verbose'
Verbose mode.
When compressing, show the compression ratio for each file
processed. A second -v shows the progress of compression.
processed. A second '-v' shows the progress of compression.
When decompressing or testing, further -v's (up to 4) increase the
verbosity level, showing status, compression ratio, decompressed
size, and compressed size.
`-1 .. -9'
'-1 .. -9'
Set the compression parameters (dictionary size and match length
limit) as shown in the table below. Note that `-9' can be much
slower than `-1'. These options have no effect when decompressing.
limit) as shown in the table below. Note that '-9' can be much
slower than '-1'. These options have no effect when decompressing.
The bidimensional parameter space of LZMA can't be mapped to a
linear scale optimal for all files. If your files are large, very
repetitive, etc, you may need to use the `--match-length' and
`--dictionary-size' options directly to achieve optimal
performance. For example, `-9m64' usually compresses executables
more (and faster) than `-9'.
repetitive, etc, you may need to use the '--match-length' and
'--dictionary-size' options directly to achieve optimal
performance. For example, '-9m64' usually compresses executables
more (and faster) than '-9'.
Level Dictionary size Match length limit
-1 1 MiB 5 bytes
@ -255,13 +264,13 @@ The format for running plzip is:
-8 24 MiB 132 bytes
-9 32 MiB 273 bytes
`--fast'
`--best'
'--fast'
'--best'
Aliases for GNU gzip compatibility.
Numbers given as arguments to options may be followed by a multiplier
and an optional `B' for "byte".
and an optional 'B' for "byte".
Table of SI and binary prefixes (unit multipliers):
@ -316,15 +325,15 @@ additional information before, between, or after them.
All multibyte values are stored in little endian order.
`ID string'
'ID string'
A four byte string, identifying the lzip format, with the value
"LZIP" (0x4C, 0x5A, 0x49, 0x50).
`VN (version number, 1 byte)'
'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)'
'DS (coded dictionary size, 1 byte)'
Lzip divides the distance between any two powers of 2 into 8
equally spaced intervals, named "wedges". The dictionary size is
calculated by taking a power of 2 (the base size) and substracting
@ -336,18 +345,18 @@ additional information before, between, or after them.
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'
'Lzma stream'
The lzma stream, finished by an end of stream marker. Uses default
values for encoder properties. See the lzip manual for a full
description.
`CRC32 (4 bytes)'
'CRC32 (4 bytes)'
CRC of the uncompressed original data.
`Data size (8 bytes)'
'Data size (8 bytes)'
Size of the uncompressed original data.
`Member size (8 bytes)'
'Member size (8 bytes)'
Total size of the member, including header and trailer. This field
acts as a distributed index, allows the verification of stream
integrity, and facilitates safe recovery of undamaged members from
@ -367,7 +376,7 @@ for all eternity, if not longer.
If you find a bug in plzip, please send electronic mail to
<lzip-bug@nongnu.org>. Include the version number, which you can find
by running `plzip --version'.
by running 'plzip --version'.

File: plzip.info, Node: Concept index, Prev: Problems, Up: Top
@ -391,13 +400,14 @@ Concept index

Tag Table:
Node: Top223
Node: Introduction871
Node: Program design4426
Node: Invoking plzip5480
Node: File format10864
Node: Problems13369
Node: Concept index13898
Node: Top221
Node: Introduction878
Node: Program design4650
Node: Invoking plzip5704
Ref: --data-size6149
Node: File format11300
Node: Problems13805
Node: Concept index14334

End Tag Table