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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



 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,



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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



      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:









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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



            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



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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



          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.




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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



      -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




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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



      --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






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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



        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





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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



      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.




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 LZOP(1)                          lzop 1.03                          LZOP(1)
                                 2010-11-06



          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.


























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