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Diffstat (limited to 'README')
| -rw-r--r-- | README | 52 |
1 files changed, 28 insertions, 24 deletions
@@ -1,27 +1,28 @@ Description Lzip is a lossless data compressor with a user interface similar to the -one of gzip or bzip2. Lzip can compress about as fast as gzip (lzip -0), +one of gzip or bzip2. Lzip can compress about as fast as gzip (lzip -0) or compress most files more than bzip2 (lzip -9). Decompression speed is intermediate between gzip and bzip2. Lzip is better than gzip and bzip2 -from a data recovery perspective. +from a data recovery perspective. Lzip has been designed, written and +tested with great care to replace gzip and bzip2 as the standard +general-purpose compressed format for unix-like systems. -The lzip file format is designed for data sharing and long-term -archiving, taking into account both data integrity and decoder -availability: +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 + 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. + 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. @@ -33,13 +34,12 @@ corrupt byte near the beginning is a thing of the past. Lzip uses the same well-defined exit status values used by bzip2, which makes it safer than compressors returning ambiguous warning values (like -gzip) when it is used as a back end for other programs like tar or -zutils. +gzip) when it is used as a back end for other programs like tar or zutils. -Lzip will automatically use the smallest possible dictionary size for -each file 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. +Lzip will automatically use for each file the largest dictionary size +that does not exceed neither the file size nor the limit given. Keep in +mind that the decompression memory requirement is affected at +compression time by the choice of dictionary size limit. The amount of memory required for compression is about 1 or 2 times the dictionary size limit (1 if input file size is less than dictionary size @@ -59,22 +59,22 @@ anyothername becomes anyothername.out (De)compressing a file is much like copying or moving it; therefore lzip preserves the access and modification dates, permissions, and, when -possible, ownership of the file just as "cp -p" does. (If the user ID or +possible, ownership of the file just as 'cp -p' does. (If the user ID or the group ID can't be duplicated, the file permission bits S_ISUID and S_ISGID are cleared). Lzip is able to read from some types of non regular files if the -"--stdout" option is specified. +'--stdout' option is specified. If no file names are specified, lzip compresses (or decompresses) from standard input to standard output. In this case, lzip will decline to write compressed output to a terminal, as this would be entirely incomprehensible and therefore pointless. -Lzip will correctly decompress a file which is the concatenation of two -or more compressed files. The result is the concatenation of the -corresponding decompressed files. Integrity testing of concatenated -compressed files is also supported. +Lzip will correctly decompress a file which is the concatenation of two or +more compressed files. The result is the concatenation of the corresponding +decompressed files. Integrity testing of concatenated compressed files is +also supported. Lzip can produce multimember files, and lziprecover can safely recover the undamaged members in case of file damage. Lzip can also split the @@ -110,8 +110,12 @@ the definition of Markov chains), G.N.N. Martin (for the definition of range encoding), Igor Pavlov (for putting all the above together in LZMA), and Julian Seward (for bzip2's CLI). +LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may never +have been compressed. Decompressed is used to refer to data which have +undergone the process of decompression. -Copyright (C) 2008-2018 Antonio Diaz Diaz. + +Copyright (C) 2008-2019 Antonio Diaz Diaz. This file is free documentation: you have unlimited permission to copy, distribute and modify it. |