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LZOP(1)								       LZOP(1)

NAME
       lzop - compress or expand files

ABSTRACT
       lzop is a file compressor very similar to gzip.	lzop favors speed over
       compression ratio.

SYNOPSIS
       lzop [ command ]	[ options ] [ filename ...  ]

       lzop [-dxlthIVL19] [-qvcfFnNPkU]	[-o file] [-p[path]] [-S suffix]
       [filename ...]

DESCRIPTION
       lzop reduces the	size of	the named files. Whenever possible, each file
       is compressed into one with the extension .lzo, while keeping the same
       ownership modes,	access and modification	times. If no files are
       specified, or if	a file name is "-", lzop tries to compress the
       standard	input to the standard output. lzop will	only attempt to
       compress	regular	files or symbolic links	to regular files.  In
       particular, it will ignore directories.

       If the compressed file name is too long for its file system, lzop
       truncates it.

       Compressed files	can be restored	to their original form using lzop -d.
       lzop -d takes a list of files on	its command line and decompresses each
       file whose name ends with .lzo and which	begins with the	correct	magic
       number to an uncompressed file without the original extension. lzop -d
       also recognizes the special extension .tzo as shorthand for .tar.lzo.
       When compressing, lzop uses the .tzo extension if necessary instead of
       truncating a file with a	.tar extension.

       lzop stores the original	file name, mode	and time stamp in the
       compressed file.	These can be used when decompressing the file with the
       -d option. This is useful when the compressed file name was truncated
       or when the time	stamp was not preserved	after a	file transfer.

       lzop preserves the ownership, mode and time stamp of files when
       compressing. When decompressing lzop restores the mode and time stamp
       if present in the compressed files.  See	the options -n,	-N, --no-mode
       and --no-time for more information.

       lzop always keeps original files	unchanged unless you use the option
       -U.

       lzop uses the LZO data compression library for compression services.
       The amount of compression obtained depends on the size of the input and
       the distribution	of common substrings.  Typically, text such as source
       code or English is compressed into 40-50% of the	original size, and
       large files usually compress much better	than small ones. Compression
       and decompression speed is generally much faster	than that achieved by
       gzip, but compression ratio is worse.

   COMPRESSION LEVELS
       lzop offers the following compression levels of the LZO1X algorithm:

       -3  the default level offers pretty fast	compression.  -2, -3, -4, -5
	   and -6 are currently	all equivalent - this may change in a future
	   release.

       -1, --fast
	   can be even a little	bit faster in some cases - but most times you
	   won't notice	the difference

       -7, -8, -9, --best
	   these compression levels are	mainly intended	for generating pre-
	   compressed data - especially	-9 can be somewhat slow

       Decompression is	very fast for all compression levels, and
       decompression speed is not affected by the compression level.

MAIN COMMAND
       If no other command is given then lzop defaults to compression (using
       compression level -3).

       -#, --fast, --best
	   Regulate the	speed of compression using the specified digit #,
	   where -1 or --fast indicates	the fastest compression	method (less
	   compression)	and -9 or --best indicates the slowest compression
	   method (best	compression). The default compression level is -3.

       -d, --decompress, --uncompress
	   Decompress. Each file will be placed	into same the directory	as the
	   compressed file.

       -x, --extract
	   Extract compressed files to the current working directory. This is
	   the same as '-dPp'.

       -t, --test
	   Test. Check the compressed file integrity.

       -l, --list
	   For each compressed file, list the following	fields:

	     method: compression method
	     compressed: size of the compressed	file
	     uncompr.: size of the uncompressed	file
	     ratio: compression	ratio
	     uncompressed_name:	name of	the uncompressed file

	   In combination with the --verbose option, the following fields are
	   also	displayed:

	     date & time: time stamp for the uncompressed file

	   With	--name,	the uncompressed name, date and	time are those stored
	   within the compress file if present.

	   With	--verbose, the size totals and compression ratio for all files
	   is also displayed. With --quiet, the	title and totals lines are not
	   displayed.

	   Note	that lzop defines compression ratio as compressed_size /
	   uncompressed_size.

       --ls, --ls=FLAGS
	   List	each compressed	file in	a format similar to ls -ln.

	   The following flags are currently honoured:
	     F	Append a '*' for executable files.
	     G	Inhibit	display	of group information.
	     Q	Enclose	file names in double quotes.

       --info
	   For each compressed file, list the internal header fields.

       -I, --sysinfo
	   Display information about the system	and quit.

       -L, --license
	   Display the lzop license and	quit.

       -h, -H, --help
	   Display a help screen and quit.

       -V  Version. Display the	version	number and compilation options and
	   quit.

       --version
	   Version. Display the	version	number and quit.

OPTIONS
       -c, --stdout, --to-stdout
	   Write output	on standard output. If there are several input files,
	   the output consists of a sequence of	independently (de)compressed
	   members. To obtain better compression, concatenate all input	files
	   before compressing them.

       -o FILE,	--output=FILE
	   Write output	to the file FILE. If there are several input files,
	   the output consists of a sequence of	independently (de)compressed
	   members.

       -p, -pDIR, --path=DIR
	   Write output	files into the directory DIR instead of	the directory
	   determined by the input file. If DIR	is omitted, then write to the
	   current working directory.

       -f, --force
	   Force lzop to

	    - overwrite	existing files
	    - (de-)compress from stdin even if it seems	a terminal
	    - (de-)compress to stdout even if it seems a terminal
	    - allow option -c in combination with -U

	   Using -f two	or more	times forces things like

	    - compress files that already have a .lzo suffix
	    - try to decompress	files that do not have a valid suffix
	    - try to handle compressed files with unknown header flags

	   Use with care.

       -F, --no-checksum
	   Do not store	or verify a checksum of	the uncompressed file when
	   compressing or decompressing.  This speeds up the operation of lzop
	   a little bit	(especially when decompressing), but as	unnoticed data
	   corruption can happen in case of damaged compressed files the usage
	   of this option is not generally recommended.	 Also, a checksum is
	   always stored when compressing with one of the slow compression
	   levels (-7, -8 or -9), regardless of	this option.

       -n, --no-name
	   When	decompressing, do not restore the original file	name if
	   present (remove only	the lzop suffix	from the compressed file
	   name). This option is the default under UNIX.

       -N, --name
	   When	decompressing, restore the original file name if present. This
	   option is useful on systems which have a limit on file name length.
	   If the original name	saved in the compressed	file is	not suitable
	   for its file	system,	a new name is constructed from the original
	   one to make it legal.  This option is the default under DOS,
	   Windows and OS/2.

       -P  When	decompressing, restore the original path and file name if
	   present.  When compressing, store the relative (and cleaned)	path
	   name.  This option is mainly	useful when using archive mode - see
	   usage examples below.

       --no-mode
	   When	decompressing, do not restore the original mode	(permissions)
	   saved in the	compressed file.

       --no-time
	   When	decompressing, do not restore the original time	stamp saved in
	   the compressed file.

       -S .suf,	--suffix=.suf
	   Use suffix .suf instead of .lzo. The	suffix must not	contain
	   multiple dots and special characters	like '+' or '*', and suffixes
	   other than .lzo should be avoided to	avoid confusion	when files are
	   transferred to other	systems.

       -k, --keep
	   Do not delete input files. This is the default.

       -U, --unlink, --delete
	   Delete input	files after succesfull compression or decompression.
	   Use this option to make lzop	behave like gzip and bzip2.  Note that
	   explicitly giving -k	overrides -U.

       --crc32
	   Use a crc32 checksum	instead	of a adler32 checksum.

       --no-warn
	   Suppress all	warnings.

       --ignore-warn
	   Suppress all	warnings, and never exit with exit status 2.

       -q, --quiet, --silent
	   Suppress all	warnings and decrease the verbosity of some commands
	   like	--list or --test.

       -v, --verbose
	   Verbose. Display the	name for each file compressed or decompressed.
	   Multiple -v can be used to increase the verbosity of	some commands
	   like	--list or --test.

       --  Specifies that this is the end of the options. Any file name	after
	   -- will not be interpreted as an option even	if it starts with a
	   hyphen.

OTHER OPTIONS
       --no-stdin
	   Do not try to read standard input (but a file name "-" will still
	   override this option).  In old versions of lzop, this option	was
	   necessary when used in cron jobs (which do not have a controlling
	   terminal).

       --filter=NUMBER
	   Rarely useful.  Preprocess data with	a special "multimedia" filter
	   before compressing in order to improve compression ratio.  NUMBER
	   must	be a decimal number from 1 to 16, inclusive.  Using a filter
	   slows down both compression and decompression quite a bit, and the
	   compression ratio usually doesn't improve much either...  More
	   effective filters may be added in the future, though.

	   You can try --filter=1 with data like 8-bit sound samples,
	   --filter=2 with 16-bit samples or depth-16 images, etc.

	   Un-filtering	during decompression is	handled	automatically.

       -C, --checksum
	   Deprecated. Only for	compatibility with very	old versions as	lzop
	   now uses a checksum by default. This	option will get	removed	in a
	   future release.

       --no-color
	   Do not use any color	escape sequences.

       --mono
	   Assume a mono ANSI terminal.	This is	the default under UNIX (if
	   console support is compiled in).

       --color
	   Assume a color ANSI terminal	or try full-screen access. This	is the
	   default under DOS and in a Linux virtual console (if	console
	   support is compiled in).

ADVANCED USAGE
       lzop allows you to deal with your files in many flexible	ways. Here are
       some usage examples:

       backup mode
	  tar --use-compress-program=lzop -cf archive.tar.lzo files..

	  This is the recommended mode for creating backups.
	  Requires GNU tar or a	compatible version which accepts the
	  '--use-compress-program=XXX' option.

       single file mode: individually (de)compress each	file
	 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: (de)compress from stdin to stdout
	 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

	 list
	   lzop	-l < y.lzo
	   cat y.lzo | lzop -l
	   lzop	-d < y.tar.lzo | tar -tvf -	-> list	a tar file

	 test
	   lzop	-t < y.lzo
	   cat y.lzo | lzop -t

       stdout mode: (de)compress to stdout
	 create
	   lzop	-c a.c > y.lzo

	 extract
	   lzop	-dc y.lzo > a.c
	   lzop	-dc y.tar.lzo |	tar -xvf -	-> extract a tar file

	 list
	   lzop	-dc y.tar.lzo |	tar -tvf -	-> list	a tar file

       archive mode: compress/extract multiple files into a single archive
       file
	 create
	   lzop	a.c b.c	-o sources.lzo		-> create an archive
	   lzop	-P src/*.c -o sources.lzo	-> create an archive, store path name
	   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
	   lzop	-tvv sources.lzo		-> be very verbose

       If you wish to create a single archive file with	multiple members so
       that members can	later be extracted independently, you should prefer a
       full-featured archiver such as tar. The latest version of GNU tar
       supports	the --use-compress-program=lzop	option to invoke lzop
       transparently.  lzop is designed	as a complement	to tar,	not as a
       replacement.

ENVIRONMENT
       The environment variable	LZOP can hold a	set of default options for
       lzop. These options are interpreted first and can be overwritten	by
       explicit	command	line parameters.  For example:

	   for sh/ksh/zsh:    LZOP="-1v	--name"; export	LZOP
	   for csh/tcsh:      setenv LZOP "-1v --name"
	   for DOS/Windows:   set LZOP=-1v --name

       On Vax/VMS, the name of the environment variable	is LZOP_OPT, to	avoid
       a conflict with the symbol set for invocation of	the program.

       Not all of the options are valid	in the environment variable - lzop
       will tell you.

SEE ALSO
       bzip2(1), gzip(1), tar(1)

       Precompiled binaries for	some platforms are available from the lzop
       home page.

	   see http://www.oberhumer.com/opensource/lzop/

       lzop uses the LZO data compression library for compression services.

	   see http://www.oberhumer.com/opensource/lzo/

DIAGNOSTICS
       Exit status is normally 0; if an	error occurs, exit status is 1.	If a
       warning occurs, exit status is 2	(unless	option --ignore-warn is	in
       effect).

       lzop's diagnostics are intended to be self-explanatory.

BUGS
       No bugs are known. Please report	all problems immediately to the
       author.

AUTHOR
       Markus Franz Xaver Johannes Oberhumer <markus@oberhumer.com>
       http://www.oberhumer.com/opensource/lzop/

COPYRIGHT
       lzop and	the LZO	library	are Copyright (C) 1996,	1997, 1998, 1999,
       2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010	by
       Markus Franz Xaver Johannes Oberhumer.  All Rights Reserved.

       lzop and	the LZO	library	are distributed	under the terms	of the GNU
       General Public License (GPL).

       Legal info: If want to integrate	lzop into your commercial
       (backup-)system please carefully	read the GNU GPL FAQ at
       http://www.gnu.org/licenses/gpl-faq.html	about possible implications.

lzop 1.03			  2010-11-06			       LZOP(1)

NAME | ABSTRACT | SYNOPSIS | DESCRIPTION | MAIN COMMAND | OPTIONS | OTHER OPTIONS | ADVANCED USAGE | ENVIRONMENT | SEE ALSO | DIAGNOSTICS | BUGS | AUTHOR | COPYRIGHT

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