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Diffstat (limited to 'README')
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@@ -6,17 +6,50 @@ the one of lzip, bzip2 or gzip. Pdlzip uses the lzip file format; the files produced by pdlzip are (hope)fully compatible with lzip-1.4 or newer. Pdlzip is in fact a "public domain" version of the lzip data compressor, intended for those -who can't distribute GPL licensed Free Software. +who can't distribute (or even use) GPL licensed Free Software. + +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 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. Pdlzip is also able to decompress legacy lzma-alone (.lzma) files. +Lzma-alone is a very bad format. If you keep any lzma-alone files, it is +advisable to recompress them to lzip format. Pdlzip is written in C. -Pdlzip includes public domain compression code from the LZMA SDK written -by Igor Pavlov. +Pdlzip includes public domain (de)compression code from the LZMA SDK +(Software Development Kit) written by Igor Pavlov. + +I would not write non-copylefted software unless it is too simple to be +worth copylefting it, but one of the uses of the lzip format is the +interchange of information, and it is therefore desirable that even the +users of the most non-free platforms can share lzip files with everybody +else. -Copyright (C) 2010, 2011, 2012, 2013 Antonio Diaz Diaz. +Copyright (C) 2010-2015 Antonio Diaz Diaz. This file is free documentation: you have unlimited permission to copy, distribute and modify it. |