lzip/plzip
1
0
Fork 0
Code Issues Activity

Adding upstream version 1.0.

Browse source 
Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-02-24 03:59:17 +01:00
parent d49eb8d954
commit 4bce01c02a
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
10 changed files with 162 additions and 109 deletions
Download patch file Download diff file Expand all files Collapse all files

63
doc/plzip.texinfo
View file

@ -6,8 +6,8 @@
@finalout
@c %**end of header
@set UPDATED 8 March 2013
@set VERSION 1.0-rc1
@set UPDATED 29 May 2013
@set VERSION 1.0
@dircategory Data Compression
@direntry
@ -35,12 +35,12 @@
This manual is for Plzip (version @value{VERSION}, @value{UPDATED}).
@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
@end menu
@sp 1
@ -57,13 +57,18 @@ to copy, distribute and modify it.
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
@ -92,15 +97,16 @@ file from that of the compressed file as follows:
@end multitable
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.
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, etc).
@ -109,11 +115,6 @@ Therefore, if the data you are going to compress is important, give the
you verify the compressed file with a command like
@w{@samp{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.
@node Program Design
@chapter Program Design
@ -289,6 +290,12 @@ Table of SI and binary prefixes (unit multipliers):
@item Y @tab yottabyte (10^24) @tab | @tab Yi @tab yobibyte (2^80)
@end multitable
@sp 1
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.
@node File Format
@chapter File Format
@ -349,7 +356,7 @@ Valid values for dictionary size range from 4KiB to 512MiB.
@item Lzma stream
The lzma stream, finished by an end of stream marker. Uses default values
for encoder properties.
for encoder properties. See the lzip manual for a full description.
@item CRC32 (4 bytes)
CRC of the uncompressed original data.
@ -359,8 +366,8 @@ Size of the uncompressed original data.
@item 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.
as a distributed index, allows the verification of stream integrity, and
facilitates safe recovery of undamaged members from multi-member files.
@end table