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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 /README
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 'README')
-rw-r--r--README30
1 files changed, 18 insertions, 12 deletions
diff --git a/README b/README
index 3f1d72b..a2c9a34 100644
--- a/README
+++ b/README
@@ -3,13 +3,18 @@ Description
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
@@ -29,15 +34,16 @@ corresponding uncompressed files. Integrity testing of concatenated
compressed files is also supported.
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.
Copyright (C) 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.