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LZOP(1) 							       LZOP(1)

       lzop - compress or expand files

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

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

       lzop [-dxlthIVL19] [-qvcfFnNkU] [-o file] [-p[path]] [-S suffix] [file
       name ...]

       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 speci
       fied, or if a file name is "-", lzop tries to compress the standard
       input to the standard output. lzop will only attempt to compress regu
       lar 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 trun
       cates 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 com
       pressed 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 com
       pressing. 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

       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.


       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

       -1, --fast
	   can be even a little bit faster in some cases - but most times you
	   wont 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 decompres
       sion speed is not affected by the compression level.

       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 -dNp.

       -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

	   Note that lzop defines compression ratio as compressed_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.

	   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

	   Version. Display the version number and quit.

       Commands are listed in increasing priority here, i.e.  -t has priority
       over -d, -l over -t, and so on.

       -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

       -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, Win
	   dows 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.

	   When decompressing, do not restore the original mode (permissions)
	   saved in the compressed file.

	   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 multi
	   ple 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.

	   Use a crc32 checksum instead of a adler32 checksum.

	   Suppress all warnings.

	   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

	   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

	   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 doesnt 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, --fil
	   ter=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.

	   Do not use any color escape sequences.

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

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

       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 (possibly huge) backups.
	  Requires GNU tar or a compatible version which accpets the
	  --use-compress-program=XXX option.

       single file mode: individually (de)compress each file
	   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

	   lzop -d a.c.lzo	-> restore a.c
	   lzop -df a.c.lzo	-> restore a.c, overwrite if already exists
	   lzop -d *.lzo

	   lzop -l a.c.lzo
	   lzop -l *.lzo
	   lzop -lv *.lzo	-> be verbose

	   lzop -t a.c.lzo
	   lzop -tq *.lzo	-> be quiet

       pipe mode: (de)compress from stdin to stdout
	   lzop < a.c > y.lzo
	   cat a.c  lzop > y.lzo
	   tar -cf - *.c  lzop > y.tar.lzo     -> create a compressed tar file

	   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

	   lzop -l < y.lzo
	   cat y.lzo  lzop -l

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

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

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

       archive mode: compress/extract multiple files into a single archive
	   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

	   lzop -dN sources.lzo
	   lzop -x ../src/sources.lzo		-> extract to current directory
	   lzop -x -p/tmp < ../src/sources.lzo	-> extract to /tmp directory

	   lzop -lNv sources.lzo

	   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 sup
       ports the --use-compress-program=lzop option to invoke lzop transpar
       ently.  lzop is designed as a complement to tar, not as a replacement.

       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:	      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.

       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/

       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

       lzops diagnostics are intended to be self-explanatory.

       Please report all problems immediately to the author.

       Markus Franz Xaver Johannes Oberhumer 

       lzop and the LZO library are Copyright (C) 1996, 1997, 1998, 1999,
       2000, 2001, 2002, 2003 by Markus Franz Xaver Johannes Oberhumer.

       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 check the GNU GPL FAQ at
       http://www.gnu.org/licenses/gpl-faq.html about possible implications.

lzop 1.01			  2003-04-27			       LZOP(1)

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