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@@ -2,52 +2,60 @@ Description Lzd is a simplified decompressor for the lzip format with an educational purpose. Studying its source is a good first step to understand how lzip -works. It is not safe to use lzd for any real work. +works. -The source of lzd is used in the lzip manual as a reference decompressor -in the description of the lzip file format. Reading the lzip manual will -help you understand the source. +The source of lzd is used in the lzip manual as a reference decompressor in +the description of the lzip file format. Reading the lzip manual will help +you understand the source. Lzd is compliant with the lzip specification; it +verifies the 3 integrity factors. -Lzd decompresses from standard input to standard output. Lzd will -correctly decompress the concatenation of two or more compressed files. -The result is the concatenation of the corresponding decompressed data. -Integrity of such concatenated compressed input is also verified. +The source of lzd is also used as a reference in the description of the +media type 'application/lzip'. +See http://datatracker.ietf.org/doc/draft-diaz-lzip + +Lzd decompresses from standard input to standard output. It accepts (and +ignores) the option '-d' for compatibility with other lzip tools. In +particular, accepting the option '-d' allows lzd to be used as argument to +the option '--lz' of the tools from the zutils package. + +Lzd will correctly decompress the concatenation of two or more compressed +files. The result is the concatenation of the corresponding decompressed +data. Integrity of such concatenated compressed input is also verified. The lzip file format is designed for data sharing and long-term archiving, taking into account both data integrity and decoder availability: * The lzip format provides very safe integrity checking and some data - recovery means. The lziprecover program can repair bit flip errors - (one of the most common forms of data corruption) in lzip files, - and provides data recovery capabilities, including error-checked - merging of damaged copies of a file. - - * The lzip format is as simple as possible (but not simpler). The - lzip manual provides the source code of a simple decompressor - along with a detailed explanation of how it works, so that with - the only help of the lzip manual it would be possible for a - digital archaeologist to extract the data from a lzip file long - after quantum computers eventually render LZMA obsolete. + recovery means. The program lziprecover can repair bit flip errors + (one of the most common forms of data corruption) in lzip files, and + provides data recovery capabilities, including error-checked merging + of damaged copies of a file. + + * The lzip format is as simple as possible (but not simpler). The lzip + manual provides the source code of a simple decompressor along with a + detailed explanation of how it works, so that with the only help of the + lzip manual it would be possible for a digital archaeologist to extract + the data from a lzip file long after quantum computers eventually + render LZMA obsolete. * Additionally the lzip reference implementation is copylefted, which guarantees that it will remain free forever. -A nice feature of the lzip format is that a corrupt byte is easier to -repair the nearer it is from the beginning of the file. Therefore, with -the help of lziprecover, losing an entire archive just because of a -corrupt byte near the beginning is a thing of the past. +A nice feature of the lzip format is that a corrupt byte is easier to repair +the nearer it is from the beginning of the file. Therefore, with the help of +lziprecover, losing an entire archive just because of a corrupt byte near +the beginning is a thing of the past. The ideas embodied in lzd are due to (at least) the following people: -Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for -the definition of Markov chains), G.N.N. Martin (for the definition of -range encoding), and Igor Pavlov (for putting all the above together in -LZMA). +Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for the +definition of Markov chains), G.N.N. Martin (for the definition of range +encoding), and Igor Pavlov (for putting all the above together in LZMA). -Copyright (C) 2013-2019 Antonio Diaz Diaz. +Copyright (C) 2013-2021 Antonio Diaz Diaz. This file is free documentation: you have unlimited permission to copy, -distribute and modify it. +distribute, and modify it. The file Makefile.in is a data file used by configure to produce the Makefile. It has the same copyright owner and permissions that configure |