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============================================================================
lzop -- a real-time compressor
============================================================================
Author : Markus Franz Xaver Johannes Oberhumer
<markus.oberhumer@jk.uni-linz.ac.at>
http://www.infosys.tuwien.ac.at/Staff/lux/marco/lzop.html
Version : 0.94
Date : 15-Oct-1997
Introduction
------------
Welcome to the fourth public release of lzop.
lzop is a compressor similiar to gzip. Its main advantages over gzip
are much higher compression and decompression speed.
lzop was designed with the following goals in mind:
1) reliability
2) speed (both compression and decompression)
3) reasonable drop-in compatibility to gzip
4) portability
Short documentation
-------------------
General functionality and behaviour has been modelled very closely
after gzip. Due to lack of documentation at this time you are advised
to consult the gzip manual pages first.
The main differences between lzop and gzip are:
- Files compressed by lzop will have the suffix `.lzo'
- lzop does not store or verify a checksum when compressing and
decompressing a file by default.
You have to use the option `-C' if you want this behaviour.
- lzop does not delete the input file(s) by default.
You have to use the option `-U' if you want this behaviour.
Compression levels
------------------
lzop currently offers three compression levels of the LZO1X algorithm.
- the default level (`-5') offers pretty fast compression
- level `-1' can be even a little bit faster in some cases - but most
times you won't notice the difference
- level `-9' is mainly intended for generating pre-compressed data - it
is somewhat slow
Decompression is *very* fast for all levels.
Modes of operation
------------------
lzop allows you to deal with your files in many flexible ways:
- single file mode: individually (de-)compress each file
- pipe mode: (de-)compress from stdin to stdout
- stdout mode: (de-)compress to stdout
- archive mode: compress/extract multiple files into a single archive file
Here are some usage examples for each of the modes:
* single file mode (like gzip)
create
lzop a.c -> create a.c.lzo
lzop a.c b.c -> create a.c.lzo & b.c.lzo
lzop -U a.c b.c -> create a.c.lzo & b.c.lzo and delete a.c & b.c
lzop *.c
extract
lzop -d a.c.lzo -> restore a.c
lzop -df a.c.lzo -> restore a.c, overwrite if already exists
lzop -d *.lzo
list
lzop -l a.c.lzo
lzop -l *.lzo
lzop -lv *.lzo -> be verbose
test
lzop -t a.c.lzo
lzop -tq *.lzo -> be quiet
* pipe mode (like gzip)
create
lzop < a.c > y.lzo
cat a.c | lzop > y.lzo
tar -cf - *.c | lzop > y.tar.lzo -> create a compressed tar file
extract
lzop -d < y.lzo > a.c
lzop -d < y.tar.lzo | tar -xvf - -> extract a tar file
lzop -d < y.tar.lzo | tar -tvf - -> list a tar file
list
lzop -l < y.lzo
cat y.lzo | lzop -l
test
lzop -t < y.lzo
cat y.lzo | lzop -t
* stdout mode (like gzip)
create
lzop -c a.c > y.lzo
extract
lzop -dc y.lzo > a.c
lzop -dc y.tar.lzo | tar -tvf - -> list a tar file
* archive mode (similiar to zip/zoo/lha/rar)
create
lzop a.c b.c -o sources.lzo -> create an archive
lzop -c *.c > sources.lzo -> another way to create an archive
lzop -c *.h >> sources.lzo -> add files to archive
extract
lzop -dN sources.lzo
lzop -x ../src/sources.lzo -> extract to current directory
lzop -x -p/tmp < ../src/sources.lzo -> extract to /tmp directory
list
lzop -lNv sources.lzo
test
lzop -t sources.lzo
Related links
-------------
Precompiled binaries for some platforms will be available from
the lzop home page soon.
see http://www.infosys.tuwien.ac.at/Staff/lux/marco/lzop.html
lzop uses the LZO data compression library for compression services.
see http://www.infosys.tuwien.ac.at/Staff/lux/marco/lzo.html
The gzip home page can be found at http://www.gzip.org
The future
----------
- write some real documentation
- anything you find useful...
Copyright
---------
lzop is Copyright (C) 1996, 1997 Markus Franz Xaver Johannes Oberhumer
lzop is distributed under the terms of the GNU General Public License (GPL).
See the file COPYING.