LZOP(1)
LZOP(1)
1mNAME0m
lzop - compress or expand files
1mABSTRACT0m
1mlzop 22mis a file compressor very similar to 1mgzip22m.
1mlzop 22mfavors speed over
compression ratio.
1mSYNOPSIS0m
1mlzop 22m[ 4mcommand24m ] [ 4moptions24m ] [ 4mfilename24m
... ]
1mlzop 22m[1m-dxlthIVL1922m] [1m-qvcfFnNPkU22m] [1m-o
4m22mfile24m] [1m-p22m[4mpath24m]] [1m-S 4m22msuffix24m]
[4mfilename24m ...]
1mDESCRIPTION0m
1mlzop 22mreduces the size of the named files. Whenever possible,
each file
is compressed into one with the extension 1m.lzo22m, 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,
1mlzop0m
truncates it.
Compressed files can be restored to their original form using
1mlzop -d22m.
1mlzop -d 22mtakes a list of files on its command line and
decompresses each
file whose name ends with 1m.lzo 22mand which begins with the
correct magic
number to an uncompressed file without the original extension.
1mlzop -d0m
also recognizes the special extension 1m.tzo 22mas shorthand for
1m.tar.lzo22m.
When compressing, lzop uses the 1m.tzo 22mextension if necessary
instead of
truncating a file with a 1m.tar 22mextension.
1mlzop 22mstores the original file name, mode and time stamp in
the
compressed file. These can be used when decompressing the file with
the
1m-d 22moption. This is useful when the compressed file name was
truncated
or when the time stamp was not preserved after a file transfer.
1mlzop 22mpreserves 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 1m-n22m,
1m-N22m, 1m--no-mode0m
and 1m--no-time 22mfor more information.
1mlzop 22malways keeps original files unchanged unless you use the
option
1m-U22m.
1mlzop 22muses the 4mLZO24m 4mdata24m 4mcompression24m
4mlibrary24m 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
1mgzip22m, but compression ratio is worse.
1mCOMPRESSION LEVELS0m
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 1m-9 22mcan be somewhat slow
Decompression is 4mvery24m fast for all compression levels, and
decompression speed is not affected by the compression level.
1mMAIN COMMAND0m
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
1m#22m,
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=4mFLAGS0m
List each compressed file in a format similar to 1mls -ln22m.
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.
1mOPTIONS0m
-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 4mFILE24m, --output=4mFILE0m
Write output to the file 4mFILE24m. If there are several input
files,
the output consists of a sequence of independently
(de)compressed
members.
-p, -p4mDIR24m, --path=4mDIR0m
Write output files into the directory 4mDIR24m instead of the
directory
determined by the input file. If 4mDIR24m 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 1m-f 22mtwo 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 1marchive mode
22m- 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 4m.suf24m, --suffix=4m.suf0m
Use suffix 4m.suf24m instead of 4m.lzo24m. The suffix must
not contain
multiple dots and special characters like '+' or '*', and
suffixes
other than 4m.lzo24m 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 successful compression or
decompression.
Use this option to make lzop behave like 1mgzip 22mand
1mbzip222m. Note that
explicitly giving 1m-k 22moverrides 1m-U22m.
--crc32
Use a crc32 checksum instead of an 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 1m--list 22mor 1m--test22m.
-v, --verbose
Verbose. Display the name for each file compressed or
decompressed.
Multiple 1m-v 22mcan be used to increase the verbosity of some
commands
like 1m--list 22mor 1m--test22m.
-- Specifies that this is the end of the options. Any file name
after
1m-- 22mwill not be interpreted as an option even if it starts
with a
hyphen.
1mOTHER OPTIONS0m
--no-stdin
Do not try to read standard input (but a file name "-" will
still
override this option). In old versions of 1mlzop22m, this
option was
necessary when used in cron jobs (which do not have a
controlling
terminal).
--filter=4mNUMBER0m
Rarely useful. Preprocess data with a special "multimedia"
filter
before compressing in order to improve compression ratio.
4mNUMBER0m
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).
1mADVANCED USAGE0m
lzop allows you to deal with your files in many flexible ways. Here
are
some usage examples:
1mbackup mode0m
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.
1msingle file mode: 22mindividually (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
1mpipe mode: 22m(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
1mstdout mode: 22m(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
1marchive mode: 22mcompress/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 1m--use-compress-program=lzop 22moption to invoke
lzop
transparently. lzop is designed as a complement to tar, not as a
replacement.
1mENVIRONMENT0m
The environment variable 1mLZOP 22mcan 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.
1mSEE ALSO0m
1mbzip222m(1), 1mgzip22m(1), 1mtar22m(1), 1mxz22m(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/
1mDIAGNOSTICS0m
Exit status is normally 0; if an error occurs, exit status is 1. If
a
warning occurs, exit status is 2 (unless option 1m--ignore-warn
22mis in
effect).
1mlzop's 22mdiagnostics are intended to be self-explanatory.
1mBUGS0m
No bugs are known. Please report all problems immediately to the
author.
1mAUTHOR0m
Markus Franz Xaver Johannes Oberhumer <markus@oberhumer.com>
http://www.oberhumer.com/opensource/lzop/
1mCOPYRIGHT0m
lzop and the LZO library are Copyright (C) 1996-2017 Markus Franz
Xaver
Oberhumer <markus@oberhumer.com>. 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 1.04 2017-08-10
LZOP(1)
