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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 15:34:49 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 15:34:49 +0000
commit7421b48c7505faa0415b255b34538c44093ec1fa (patch)
treee12893016048b34824da8a78e7f448946e42e2ab /doc/plzip.info
parentAdding debian version 1.0~rc1-3. (diff)
downloadplzip-7421b48c7505faa0415b255b34538c44093ec1fa.tar.xz
plzip-7421b48c7505faa0415b255b34538c44093ec1fa.zip
Merging upstream version 1.0.
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to 'doc/plzip.info')
-rw-r--r--doc/plzip.info76
1 files changed, 43 insertions, 33 deletions
diff --git a/doc/plzip.info b/doc/plzip.info
index bf22e32..2070f4f 100644
--- a/doc/plzip.info
+++ b/doc/plzip.info
@@ -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