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@@ -1,54 +1,37 @@ 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. - -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 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 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. - - * 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. +purpose. Studying its source code is a good first step to understand how +lzip works. Lzd is written in C++. + +The source code 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 code. Lzd is compliant with the +lzip specification; it checks the 3 integrity factors. + +The source code 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 correctly decompresses 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 checked. 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), Andrei 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) 2013-2024 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 -itself. +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 itself. |