Lunzip(1) decompressor for the lzip format


lunzip [,options/] [,files/]


Lunzip is a decompressor for the lzip format. It is written in C and its small size makes it well suited for embedded devices or software installers that need to decompress files but don't need compression capabilities. Lunzip is fully compatible with lzip-1.4 or newer.

Lunzip provides a 'low memory' mode able to decompress any file using as little memory as 50 kB, irrespective of the dictionary size used to compress the file. To activate it, specify the size of the output buffer with the '--buffer-size' option and lunzip will use the decompressed file as dictionary for distances beyond the buffer size. Of course, the smaller the buffer size used in relation to the dictionary size, the more accesses to disk are needed and the slower the decompression is. This 'low memory' mode only works when decompressing to a regular file and is intended for systems without enough memory (RAM + swap) to keep the whole dictionary at once.


-h, --help
display this help and exit
-V, --version
output version information and exit
-a, --trailing-error
exit with error status if trailing data
-c, --stdout
write to standard output, keep input files
-d, --decompress
decompress (this is the default)
-f, --force
overwrite existing output files
-k, --keep
keep (don't delete) input files
-o, --output=<file>
if reading standard input, write to <file>
-q, --quiet
suppress all messages
-t, --test
test compressed file integrity
-u, --buffer-size=<bytes>
set output buffer size in bytes
-v, --verbose
be verbose (a 2nd -v gives more)

If no file names are given, or if a file is '-', lunzip decompresses from standard input to standard output. Numbers may be followed by a multiplier: k = kB = 10^3 = 1000, Ki = KiB = 2^10 = 1024, M = 10^6, Mi = 2^20, G = 10^9, Gi = 2^30, etc...

Exit status: 0 for a normal exit, 1 for environmental problems (file not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or invalid input file, 3 for an internal consistency error (eg, bug) which caused lunzip to panic.


Report bugs to [email protected]
Lunzip home page:


Copyright © 2016 Antonio Diaz Diaz. License GPLv2+: GNU GPL version 2 or later <>
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.