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Merging upstream version 1.0.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
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Daniel Baumann 2025-02-24 03:59:46 +01:00
parent 1834c3473d
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Signed by: daniel
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@ -12,16 +12,16 @@ File: plzip.info, Node: Top, Next: Introduction, Up: (dir)
Plzip Manual
************
This manual is for Plzip (version 1.0-rc1, 8 March 2013).
This manual is for Plzip (version 1.0, 29 May 2013).
* Menu:
* Introduction:: Purpose and features of plzip
* Program Design:: Internal structure of plzip
* Invoking Plzip:: Command line interface
* File Format:: Detailed format of the compressed file
* Problems:: Reporting bugs
* Concept Index:: Index of concepts
* Introduction:: Purpose and features of plzip
* Program Design:: Internal structure of plzip
* Invoking Plzip:: Command line interface
* File Format:: Detailed format of the compressed file
* Problems:: Reporting bugs
* Concept Index:: Index of concepts
Copyright (C) 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
@ -38,13 +38,19 @@ File: plzip.info, Node: Introduction, Next: Program Design, Prev: Top, Up: T
Plzip is a massively parallel (multi-threaded), lossless data compressor
based on the lzlib compression library, with very safe integrity
checking and a user interface similar to the one of bzip2, gzip or 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 lziprecover.
Plzip is intended for faster compression/decompression of big files
on multiprocessor machines, which makes it specially well suited for
distribution of big software files and large scale data archiving. On
files big enough, plzip can use hundreds of processors.
files big enough (several GB), plzip can use hundreds of processors.
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
lziprecover.
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.
Plzip replaces every file given in the command line with a compressed
version of itself, with the name "original_name.lz". Each compressed
@ -71,15 +77,16 @@ filename.tlz becomes filename.tar
anyothername becomes anyothername.out
As a self-check for your protection, plzip stores in the member
trailer the 32-bit CRC of the original data and the size of the
original data, to make sure that the decompressed version of the data
is identical to the original. This guards against corruption of the
compressed data, and against undetected bugs in plzip (hopefully very
unlikely). The chances of data corruption going undetected are
microscopic, less than one chance in 4000 million for each member
processed. Be aware, though, that the check occurs upon decompression,
so it can only tell you that something is wrong. It can't help you
recover the original uncompressed data.
trailer the 32-bit CRC of the original data, the size of the original
data and the size of the member. These values, together with the value
remaining in the range decoder and the end-of-stream marker, provide a
very safe 4 factor integrity checking which guarantees that the
decompressed version of the data is identical to the original. This
guards against corruption of the compressed data, and against
undetected bugs in plzip (hopefully very unlikely). The chances of data
corruption going undetected are microscopic. Be aware, though, that the
check occurs upon decompression, so it can only tell you that something
is wrong. It can't help you recover the original uncompressed data.
WARNING! Even if plzip is bug-free, other causes may result in a
corrupt compressed file (bugs in the system libraries, memory errors,
@ -88,11 +95,6 @@ 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 -'.
Return values: 0 for a normal exit, 1 for environmental problems
(file not found, invalid flags, I/O errors, etc), 2 to indicate a
corrupt or invalid input file, 3 for an internal consistency error (eg,
bug) which caused plzip to panic.

File: plzip.info, Node: Program Design, Next: Invoking Plzip, Prev: Introduction, Up: Top
@ -266,6 +268,12 @@ E exabyte (10^18) | Ei exbibyte (2^60)
Z zettabyte (10^21) | Zi zebibyte (2^70)
Y yottabyte (10^24) | Yi yobibyte (2^80)
Exit status: 0 for a normal exit, 1 for environmental problems (file
not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or
invalid input file, 3 for an internal consistency error (eg, bug) which
caused plzip to panic.

File: plzip.info, Node: File Format, Next: Problems, Prev: Invoking Plzip, Up: Top
@ -323,7 +331,8 @@ additional information before, between, or after them.
`Lzma stream'
The lzma stream, finished by an end of stream marker. Uses default
values for encoder properties.
values for encoder properties. See the lzip manual for a full
description.
`CRC32 (4 bytes)'
CRC of the uncompressed original data.
@ -333,8 +342,9 @@ additional information before, between, or after them.
`Member size (8 bytes)'
Total size of the member, including header and trailer. This field
acts as a distributed index, and facilitates safe recovery of
undamaged members from multi-member files.
acts as a distributed index, allows the verification of stream
integrity, and facilitates safe recovery of undamaged members from
multi-member files.

@ -375,12 +385,12 @@ Concept Index

Tag Table:
Node: Top223
Node: Introduction864
Node: Program Design4030
Node: Invoking Plzip5084
Node: File Format10093
Node: Problems12473
Node: Concept Index13002
Node: Introduction865
Node: Program Design4113
Node: Invoking Plzip5167
Node: File Format10416
Node: Problems12895
Node: Concept Index13424

End Tag Table