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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-06 11:38:56 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-06 11:38:56 +0000
commit31b59bd727f04865b68022d5416ce0b00819c7f6 (patch)
tree94326ede22d252496e3e7b93cae629dc9209ca7c /README
parentAdding upstream version 1.5~pre1. (diff)
downloadclzip-31b59bd727f04865b68022d5416ce0b00819c7f6.tar.xz
clzip-31b59bd727f04865b68022d5416ce0b00819c7f6.zip
Adding upstream version 1.5~pre2.upstream/1.5_pre2
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
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Description
-Clzip is a lossless data compressor based on the LZMA algorithm, with
-very safe integrity checking and a user interface similar to the one of
-gzip or bzip2. Clzip decompresses almost as fast as gzip and compresses
-better than bzip2, which makes it well suited for software distribution
-and data archiving.
+Clzip is a lossless data compressor with a user interface similar to the
+one of gzip or bzip2. Clzip decompresses almost as fast as gzip and
+compresses more than bzip2, which makes it well suited for software
+distribution and data archiving. Clzip is a clean implementation of the
+LZMA algorithm.
-Clzip uses the same well-defined exit status values used by bzip2, which
-makes it safer when used in pipes or scripts than compressors returning
-ambiguous warning values, like gzip.
+Clzip 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.
Clzip uses the lzip file format; the files produced by clzip are fully
-compatible with lzip-1.4 or newer. Clzip is in fact a C language version
-of lzip, intended for embedded devices or systems lacking a C++
-compiler.
+compatible with lzip-1.4 or newer, and can be rescued with lziprecover.
+Clzip is in fact a C language version of lzip, intended for embedded
+devices or systems lacking a C++ compiler.
+
+The lzip file format is designed for long-term data archiving and
+provides very safe integrity checking. The member trailer stores 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 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 clzip (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.
If you ever need to recover data from a damaged lzip file, try the
-lziprecover program.
+lziprecover program. Lziprecover makes lzip files resistant to bit-flip
+(one of the most common forms of data corruption), and provides data
+recovery capabilities, including error-checked merging of damaged copies
+of a file.
Clzip replaces every file given in the command line with a compressed
version of itself, with the name "original_name.lz". Each compressed
@@ -50,18 +66,6 @@ without exceeding the given limit. Keep in mind that the decompression
memory requirement is affected at compression time by the choice of
dictionary size limit.
-As a self-check for your protection, clzip stores in the member 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 clzip (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.
-
Clzip implements a simplified version of the LZMA (Lempel-Ziv-Markov
chain-Algorithm) algorithm. The high compression of LZMA comes from
combining two basic, well-proven compression ideas: sliding dictionaries