minilzip1

Usage

Overview

Minilzip is a test program for the compression library lzlib. Minilzip is not intended to be installed because lzip has more features, but minilzip is well tested and you can use it as your main compressor if so you wish.

Lzip is a lossless data compressor with a user interface similar to the one of gzip or bzip2. Lzip uses a simplified form of LZMA (Lempel-Ziv-Markov chain-Algorithm) and is 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.

Options

-h

display usage help and exit

--help

display full help and exit

-V, --version

output version information and exit

-a, --trailing-error

exit with error status if trailing data

-b, --member-size=<bytes>

set member size limit of multimember files

-c, --stdout

write to standard output, keep input files

-d, --decompress

decompress, test compressed file integrity

-f, --force

overwrite existing output files

-F, --recompress

force re-compression of compressed files

-k, --keep

keep (don't delete) input files

-m, --match-length=<bytes>

set match length limit in bytes [36]

-o, --output=<file>

write to <file>, keep input files

-q, --quiet

suppress all messages

-s, --dictionary-size=<bytes>

set dictionary size limit in bytes [8 MiB]

-S, --volume-size=<bytes>

set volume size limit in bytes

-t, --test

test compressed file integrity

-v, --verbose

be verbose (a 2nd -v gives more)

-0 .. -9

set compression level [default 6]

--loose-trailing

allow trailing data seeming corrupt header

--check-lib

compare version of lzlib.h with liblz.{a,so}

If no file names are given, or if a file is '-', minilzip compresses or decompresses from standard input to standard output. Numbers may contain underscore separators between groups of digits and may be followed by a SI or binary multiplier: 1_234_567kB, 4KiB. Dictionary sizes 12 to 29 are interpreted as powers of two, meaning 2^12 to 2^29 bytes.

The bidimensional parameter space of LZMA can't be mapped to a linear scale optimal for all files. If your files are large, very repetitive, etc, you may need to use the options --dictionary-size and --match-length directly to achieve optimal performance.

To extract all the files from archive 'foo.tar.lz', use the commands 'tar -xf foo.tar.lz' or 'minilzip -cd foo.tar.lz | tar -xf -'.

The ideas embodied in lzlib are due to (at least) the following people: 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), Igor Pavlov (for putting all the above together in LZMA), and Julian Seward (for bzip2's CLI).

Exit status

0 for a normal exit, 1 for environmental problems (file not found, invalid command-line options, I/O errors, etc), 2 to indicate a corrupt or invalid input file, 3 for an internal consistency error (e.g., bug) which caused minilzip to panic.