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1998-04-27
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LZOP(1) LZOP(1)
NNNNAAAAMMMMEEEE
lzop - compress or expand files
AAAABBBBSSSSTTTTRRRRAAAACCCCTTTT
llllzzzzoooopppp is a file compressor very similar to ggggzzzziiiipppp. llllzzzzoooopppp
favors speed over compression ratio.
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
llllzzzzoooopppp [ _c_o_m_m_a_n_d ] [ _o_p_t_i_o_n_s ] [ _f_i_l_e_n_a_m_e ... ]
llllzzzzoooopppp [----ddddxxxxlllltttthhhhIIIIVVVVLLLL11119999] [----qqqqvvvvccccffffFFFFnnnnNNNNkkkkUUUU] [----oooo _f_i_l_e] [----pppp[_p_a_t_h]]
[----SSSS _s_u_f_f_i_x] [_f_i_l_e_n_a_m_e ...]
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
llllzzzzoooopppp reduces the size of the named files. Whenever
possible, each file is compressed into one with the
extension ....llllzzzzoooo, 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. In particular, it will
ignore directories and symbolic links.
If the compressed file name is too long for its file
system, llllzzzzoooopppp truncates it.
Compressed files can be restored to their original form
using llllzzzzoooopppp ----dddd. llllzzzzoooopppp ----dddd takes a list of files on its
command line and decompresses each file whose name ends
with ....llllzzzzoooo and which begins with the correct magic number
to an uncompressed file without the original extension.
llllzzzzoooopppp ----dddd also recognizes the special extension ....ttttzzzzoooo as
shorthand for ....ttttaaaarrrr....llllzzzzoooo. When compressing, lzop uses the
....ttttzzzzoooo extension if necessary instead of truncating a file
with a ....ttttaaaarrrr extension.
llllzzzzoooopppp stores the original file name, mode and time stamp in
the compressed file. These can be used when decompressing
the file with the ----dddd option. This is useful when the
compressed file name was truncated or when the time stamp
was not preserved after a file transfer.
llllzzzzoooopppp 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 ----nnnn, ----NNNN, --------nnnnoooo----mmmmooooddddeeee and --------nnnnoooo----ttttiiiimmmmeeee for more
information.
llllzzzzoooopppp always keeps original files unchanged unless you use
the option ----UUUU.
llllzzzzoooopppp uses the _L_Z_O _d_a_t_a _c_o_m_p_r_e_s_s_i_o_n _l_i_b_r_a_r_y for compression
services. The amount of compression obtained depends on
the size of the input and the distribution of common
1998-04-27 lzop 1.00 1
LZOP(1) LZOP(1)
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 ggggzzzziiiipppp, but compression
ratio is worse.
CCCCOOOOMMMMPPPPRRRREEEESSSSSSSSIIIIOOOONNNN LLLLEEEEVVVVEEEELLLLSSSS
lzop offers the following compression levels of the LZO1X
algorithm:
-3 the default level offers pretty fast compression.
Note that -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 ----9999 can be
somewhat slow
Decompression is _v_e_r_y fast for all compression levels.
MMMMAAAAIIIINNNN CCCCOOOOMMMMMMMMAAAANNNNDDDD
If no other command is given then lzop defaults to
compression.
-#, --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:
1998-04-27 lzop 1.00 2
LZOP(1) LZOP(1)
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=_F_L_A_G_S
List each compressed file in a format similar to
llllssss ----llllnnnn.
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 then quit.
--version
Version. Display the version number then quit.
Note that ----tttt has priority over ----dddd, ----llll over ----tttt, and so on.
OOOOPPPPTTTTIIIIOOOONNNNSSSS
1998-04-27 lzop 1.00 3
LZOP(1) LZOP(1)
-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 _F_I_L_E, --output=_F_I_L_E
Write output to the file _F_I_L_E. If there are several
input files, the output consists of a sequence of
independently (de)compressed members.
-p, -p_D_I_R, --path=_D_I_R
Write output files into the directory _D_I_R instead of
the directory determined by the input file. If _D_I_R is
omitted, then write to the current working directory.
-f, --force
Force lzop to
- overwrite existing files
- compress from stdin even if it seems a terminal
- compress to stdout even if it seems a terminal
- allow option -c in combination with -U
Using ----ffff two or more times forces things like
- compress files that already have a .lzo suffix
- 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).
-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
1998-04-27 lzop 1.00 4
LZOP(1) LZOP(1)
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.
--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 _._s_u_f, --suffix=_._s_u_f
Use suffix _._s_u_f instead of _._l_z_o. The suffix must not
contain multiple dots and special characters like '+'
or '*', and suffixes other than _._l_z_o 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. Beware. Use this option to make lzop
behave like ggggzzzziiiipppp. Note that ----kkkk overrides ----UUUU.
--no-stdin
Do not try to read standard input. This option is
necessary in cron jobs (which do not have a
controlling terminal). A file name "-" will still
override this option.
--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 --------lllliiiisssstttt or --------tttteeeesssstttt.
-v, --verbose
Verbose. Display the name for each file compressed or
decompressed. Multiple ----vvvv can be used to increase the
verbosity of some commands like --------lllliiiisssstttt or --------tttteeeesssstttt.
-- 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.
1998-04-27 lzop 1.00 5
LZOP(1) LZOP(1)
OOOOTTTTHHHHEEEERRRR OOOOPPPPTTTTIIIIOOOONNNNSSSS
--no-color
Do not use any color escape sequences.
--mono
Assume a mono ANSI terminal. This is the default under
UNIX.
--color
Assume a color ANSI terminal or try full-screen
access. This is the default under DOS and in a Linux
virtual console.
--intro
Try to display that nice intro sequence then quit.
Needs full-screen access.
--filter=_N_U_M_B_E_R
Rarely useful. Preprocess data with a special
"multimedia" filter before compressing in order to
improve compression ratio. _N_U_M_B_E_R 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 old versions
as lzop now uses a checksum by default. This option
may get removed in a future release.
AAAADDDDVVVVAAAANNNNCCCCEEEEDDDD UUUUSSSSAAAAGGGGEEEE
lzop allows you to deal with your files in many flexible
ways. Here are some usage examples:
ssssiiiinnnngggglllleeee ffffiiiilllleeee mmmmooooddddeeee:::: 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
1998-04-27 lzop 1.00 6
LZOP(1) LZOP(1)
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
ppppiiiippppeeee mmmmooooddddeeee:::: (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
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
ssssttttddddoooouuuutttt mmmmooooddddeeee:::: (de)compress to stdout
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
aaaarrrrcccchhhhiiiivvvveeee mmmmooooddddeeee:::: compress/extract multiple files into a
single archive file
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
1998-04-27 lzop 1.00 7
LZOP(1) LZOP(1)
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 or zip. The latest version of GNU tar supports
the --------uuuusssseeee----ccccoooommmmpppprrrreeeessssssss----pppprrrrooooggggrrrraaaammmm====llllzzzzoooopppp option to invoke lzop
transparently. lzop is designed as a complement to tar,
not as a replacement.
EEEENNNNVVVVIIIIRRRROOOONNNNMMMMEEEENNNNTTTT
The environment variable LLLLZZZZOOOOPPPP 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.
Note that not all options are valid in the environment
variable - lzop will tell you.
SSSSEEEEEEEE AAAALLLLSSSSOOOO
ggggzzzziiiipppp(1), ttttaaaarrrr(1), bbbbzzzziiiipppp2222(1)
Precompiled binaries for some platforms should be
available from the lzop home page soon.
see http://wildsau.idv.uni-linz.ac.at/mfx/lzop.html
lzop uses the LZO data compression library for compression
services.
see http://wildsau.idv.uni-linz.ac.at/mfx/lzo.html
DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
Exit status is normally 0; if an error occurs, exit status
1998-04-27 lzop 1.00 8
LZOP(1) LZOP(1)
is 1. If a warning occurs, exit status is 2.
llllzzzzoooopppp''''ssss diagnostics are intended to be self-explanatory.
BBBBUUUUGGGGSSSS
Please report all bugs immediately to the author.
AAAAUUUUTTTTHHHHOOOORRRR
markus.oberhumer@jk.uni-linz.ac.at
CCCCOOOOPPPPYYYYRRRRIIIIGGGGHHHHTTTT
lzop and the LZO library are Copyright (C) 1996, 1997,
1998 by Markus Franz Xaver Johannes Oberhumer.
lzop and the LZO library are distributed under the terms
of the GNU General Public License (GPL).
1998-04-27 lzop 1.00 9
LZOP(1) LZOP(1)
1998-04-27 lzop 1.00 10