diff options
Diffstat (limited to 'README')
| -rw-r--r-- | README | 43 |
1 files changed, 23 insertions, 20 deletions
@@ -1,16 +1,18 @@ +See the file INSTALL for compilation and installation instructions. + Description Lzip is a lossless data compressor with a user interface similar to the one -of gzip or bzip2. Lzip uses a simplified form of the 'Lempel-Ziv-Markov -chain-Algorithm' (LZMA) stream format to maximize interoperability. The -maximum dictionary size is 512 MiB so that any lzip file can be decompressed -on 32-bit machines. Lzip provides accurate and robust 3-factor integrity -checking. 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. 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. +of gzip or bzip2. Lzip uses a simplified form of LZMA (Lempel-Ziv-Markov +chain-Algorithm) designed to achieve complete interoperability between +implementations. The maximum dictionary size is 512 MiB so that any lzip +file can be decompressed on 32-bit machines. Lzip provides accurate and +robust 3-factor integrity checking. 'lzip -0' compresses about as fast as +gzip, while 'lzip -9' compresses most files more than bzip2. Decompression +speed is intermediate between gzip and bzip2. Lzip provides better data +recovery capabilities than gzip and bzip2. Lzip has been designed, written, +and tested with great care to replace gzip and bzip2 as general-purpose +compressed format for Unix-like systems. For compressing/decompressing large files on multiprocessor machines plzip can be much faster than lzip at the cost of a slightly reduced compression @@ -23,11 +25,10 @@ alignment between tar members and lzip members. 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 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 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 @@ -91,7 +92,6 @@ 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 compressed output in volumes of a given size, even when reading from standard input. -This allows the direct creation of multivolume compressed tar archives. Lzip is able to compress and decompress streams of unlimited size by automatically creating multimember output. The members so created are large, @@ -101,10 +101,10 @@ In spite of its name (Lempel-Ziv-Markov chain-Algorithm), LZMA is not a concrete algorithm; it is more like "any algorithm using the LZMA coding scheme". For example, the option '-0' of lzip uses the scheme in almost the simplest way possible; issuing the longest match it can find, or a literal -byte if it can't find a match. Inversely, a much more elaborated way of -finding coding sequences of minimum size than the one currently used by lzip -could be developed, and the resulting sequence could also be coded using the -LZMA coding scheme. +byte if it can't find a match. Inversely, a more elaborate way of finding +coding sequences of minimum size than the one currently used by lzip could +be developed, and the resulting sequence could also be coded using the LZMA +coding scheme. Lzip currently implements two variants of the LZMA algorithm: fast (used by option '-0') and normal (used by all other compression levels). @@ -121,6 +121,9 @@ 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). +Lzip uses Arg_parser for command-line argument parsing: +http://www.nongnu.org/arg-parser/arg_parser.html + 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. |