1LZOP(1)                                                                LZOP(1)
2
3
4

NAME

6       lzop - compress or expand files
7

ABSTRACT

9       lzop is a file compressor very similar to gzip.  lzop favors speed over
10       compression ratio.
11

SYNOPSIS

13       lzop [ command ] [ options ] [ filename ...  ]
14
15       lzop [-dxlthIVL19] [-qvcfFnNPkU] [-o file] [-p[path]] [-S suffix]
16       [filename ...]
17

DESCRIPTION

19       lzop reduces the size of the named files. Whenever possible, each file
20       is compressed into one with the extension .lzo, while keeping the same
21       ownership modes, access and modification times. If no files are
22       specified, or if a file name is "-", lzop tries to compress the
23       standard input to the standard output. lzop will only attempt to
24       compress regular files or symbolic links to regular files.  In
25       particular, it will ignore directories.
26
27       If the compressed file name is too long for its file system, lzop
28       truncates it.
29
30       Compressed files can be restored to their original form using lzop -d.
31       lzop -d takes a list of files on its command line and decompresses each
32       file whose name ends with .lzo and which begins with the correct magic
33       number to an uncompressed file without the original extension. lzop -d
34       also recognizes the special extension .tzo as shorthand for .tar.lzo.
35       When compressing, lzop uses the .tzo extension if necessary instead of
36       truncating a file with a .tar extension.
37
38       lzop stores the original file name, mode and time stamp in the
39       compressed file. These can be used when decompressing the file with the
40       -d option. This is useful when the compressed file name was truncated
41       or when the time stamp was not preserved after a file transfer.
42
43       lzop preserves the ownership, mode and time stamp of files when
44       compressing. When decompressing lzop restores the mode and time stamp
45       if present in the compressed files.  See the options -n, -N, --no-mode
46       and --no-time for more information.
47
48       lzop always keeps original files unchanged unless you use the option
49       -U.
50
51       lzop uses the LZO data compression library for compression services.
52       The amount of compression obtained depends on the size of the input and
53       the distribution of common substrings.  Typically, text such as source
54       code or English is compressed into 40-50% of the original size, and
55       large files usually compress much better than small ones. Compression
56       and decompression speed is generally much faster than that achieved by
57       gzip, but compression ratio is worse.
58
59   COMPRESSION LEVELS
60       lzop offers the following compression levels of the LZO1X algorithm:
61
62       -3  the default level offers pretty fast compression.  -2, -3, -4, -5
63           and -6 are currently all equivalent - this may change in a future
64           release.
65
66       -1, --fast
67           can be even a little bit faster in some cases - but most times you
68           won't notice the difference
69
70       -7, -8, -9, --best
71           these compression levels are mainly intended for generating pre-
72           compressed data - especially -9 can be somewhat slow
73
74       Decompression is very fast for all compression levels, and
75       decompression speed is not affected by the compression level.
76

MAIN COMMAND

78       If no other command is given then lzop defaults to compression (using
79       compression level -3).
80
81       -#, --fast, --best
82           Regulate the speed of compression using the specified digit #,
83           where -1 or --fast indicates the fastest compression method (less
84           compression) and -9 or --best indicates the slowest compression
85           method (best compression). The default compression level is -3.
86
87       -d, --decompress, --uncompress
88           Decompress. Each file will be placed into same the directory as the
89           compressed file.
90
91       -x, --extract
92           Extract compressed files to the current working directory. This is
93           the same as '-dPp'.
94
95       -t, --test
96           Test. Check the compressed file integrity.
97
98       -l, --list
99           For each compressed file, list the following fields:
100
101             method: compression method
102             compressed: size of the compressed file
103             uncompr.: size of the uncompressed file
104             ratio: compression ratio
105             uncompressed_name: name of the uncompressed file
106
107           In combination with the --verbose option, the following fields are
108           also displayed:
109
110             date & time: time stamp for the uncompressed file
111
112           With --name, the uncompressed name, date and time are those stored
113           within the compress file if present.
114
115           With --verbose, the size totals and compression ratio for all files
116           is also displayed. With --quiet, the title and totals lines are not
117           displayed.
118
119           Note that lzop defines compression ratio as compressed_size /
120           uncompressed_size.
121
122       --ls, --ls=FLAGS
123           List each compressed file in a format similar to ls -ln.
124
125           The following flags are currently honoured:
126             F  Append a '*' for executable files.
127             G  Inhibit display of group information.
128             Q  Enclose file names in double quotes.
129
130       --info
131           For each compressed file, list the internal header fields.
132
133       -I, --sysinfo
134           Display information about the system and quit.
135
136       -L, --license
137           Display the lzop license and quit.
138
139       -h, -H, --help
140           Display a help screen and quit.
141
142       -V  Version. Display the version number and compilation options and
143           quit.
144
145       --version
146           Version. Display the version number and quit.
147

OPTIONS

149       -c, --stdout, --to-stdout
150           Write output on standard output. If there are several input files,
151           the output consists of a sequence of independently (de)compressed
152           members. To obtain better compression, concatenate all input files
153           before compressing them.
154
155       -o FILE, --output=FILE
156           Write output to the file FILE. If there are several input files,
157           the output consists of a sequence of independently (de)compressed
158           members.
159
160       -p, -pDIR, --path=DIR
161           Write output files into the directory DIR instead of the directory
162           determined by the input file. If DIR is omitted, then write to the
163           current working directory.
164
165       -f, --force
166           Force lzop to
167
168            - overwrite existing files
169            - (de-)compress from stdin even if it seems a terminal
170            - (de-)compress to stdout even if it seems a terminal
171            - allow option -c in combination with -U
172
173           Using -f two or more times forces things like
174
175            - compress files that already have a .lzo suffix
176            - try to decompress files that do not have a valid suffix
177            - try to handle compressed files with unknown header flags
178
179           Use with care.
180
181       -F, --no-checksum
182           Do not store or verify a checksum of the uncompressed file when
183           compressing or decompressing.  This speeds up the operation of lzop
184           a little bit (especially when decompressing), but as unnoticed data
185           corruption can happen in case of damaged compressed files the usage
186           of this option is not generally recommended.  Also, a checksum is
187           always stored when compressing with one of the slow compression
188           levels (-7, -8 or -9), regardless of this option.
189
190       -n, --no-name
191           When decompressing, do not restore the original file name if
192           present (remove only the lzop suffix from the compressed file
193           name). This option is the default under UNIX.
194
195       -N, --name
196           When decompressing, restore the original file name if present. This
197           option is useful on systems which have a limit on file name length.
198           If the original name saved in the compressed file is not suitable
199           for its file system, a new name is constructed from the original
200           one to make it legal.  This option is the default under DOS,
201           Windows and OS/2.
202
203       -P  When decompressing, restore the original path and file name if
204           present.  When compressing, store the relative (and cleaned) path
205           name.  This option is mainly useful when using archive mode - see
206           usage examples below.
207
208       --no-mode
209           When decompressing, do not restore the original mode (permissions)
210           saved in the compressed file.
211
212       --no-time
213           When decompressing, do not restore the original time stamp saved in
214           the compressed file.
215
216       -S .suf, --suffix=.suf
217           Use suffix .suf instead of .lzo. The suffix must not contain
218           multiple dots and special characters like '+' or '*', and suffixes
219           other than .lzo should be avoided to avoid confusion when files are
220           transferred to other systems.
221
222       -k, --keep
223           Do not delete input files. This is the default.
224
225       -U, --unlink, --delete
226           Delete input files after succesfull compression or decompression.
227           Use this option to make lzop behave like gzip and bzip2.  Note that
228           explicitly giving -k overrides -U.
229
230       --crc32
231           Use a crc32 checksum instead of a adler32 checksum.
232
233       --no-warn
234           Suppress all warnings.
235
236       --ignore-warn
237           Suppress all warnings, and never exit with exit status 2.
238
239       -q, --quiet, --silent
240           Suppress all warnings and decrease the verbosity of some commands
241           like --list or --test.
242
243       -v, --verbose
244           Verbose. Display the name for each file compressed or decompressed.
245           Multiple -v can be used to increase the verbosity of some commands
246           like --list or --test.
247
248       --  Specifies that this is the end of the options. Any file name after
249           -- will not be interpreted as an option even if it starts with a
250           hyphen.
251

OTHER OPTIONS

253       --no-stdin
254           Do not try to read standard input (but a file name "-" will still
255           override this option).  In old versions of lzop, this option was
256           necessary when used in cron jobs (which do not have a controlling
257           terminal).
258
259       --filter=NUMBER
260           Rarely useful.  Preprocess data with a special "multimedia" filter
261           before compressing in order to improve compression ratio.  NUMBER
262           must be a decimal number from 1 to 16, inclusive.  Using a filter
263           slows down both compression and decompression quite a bit, and the
264           compression ratio usually doesn't improve much either...  More
265           effective filters may be added in the future, though.
266
267           You can try --filter=1 with data like 8-bit sound samples,
268           --filter=2 with 16-bit samples or depth-16 images, etc.
269
270           Un-filtering during decompression is handled automatically.
271
272       -C, --checksum
273           Deprecated. Only for compatibility with very old versions as lzop
274           now uses a checksum by default. This option will get removed in a
275           future release.
276
277       --no-color
278           Do not use any color escape sequences.
279
280       --mono
281           Assume a mono ANSI terminal. This is the default under UNIX (if
282           console support is compiled in).
283
284       --color
285           Assume a color ANSI terminal or try full-screen access. This is the
286           default under DOS and in a Linux virtual console (if console
287           support is compiled in).
288

ADVANCED USAGE

290       lzop allows you to deal with your files in many flexible ways. Here are
291       some usage examples:
292
293       backup mode
294          tar --use-compress-program=lzop -cf archive.tar.lzo files..
295
296          This is the recommended mode for creating backups.
297          Requires GNU tar or a compatible version which accepts the
298          '--use-compress-program=XXX' option.
299
300       single file mode: individually (de)compress each file
301         create
302           lzop a.c             -> create a.c.lzo
303           lzop a.c b.c         -> create a.c.lzo & b.c.lzo
304           lzop -U a.c b.c      -> create a.c.lzo & b.c.lzo and delete a.c & b.c
305           lzop *.c
306
307         extract
308           lzop -d a.c.lzo      -> restore a.c
309           lzop -df a.c.lzo     -> restore a.c, overwrite if already exists
310           lzop -d *.lzo
311
312         list
313           lzop -l a.c.lzo
314           lzop -l *.lzo
315           lzop -lv *.lzo       -> be verbose
316
317         test
318           lzop -t a.c.lzo
319           lzop -tq *.lzo       -> be quiet
320
321       pipe mode: (de)compress from stdin to stdout
322         create
323           lzop < a.c > y.lzo
324           cat a.c | lzop > y.lzo
325           tar -cf - *.c | lzop > y.tar.lzo     -> create a compressed tar file
326
327         extract
328           lzop -d < y.lzo > a.c
329           lzop -d < y.tar.lzo | tar -xvf -     -> extract a tar file
330
331         list
332           lzop -l < y.lzo
333           cat y.lzo | lzop -l
334           lzop -d < y.tar.lzo | tar -tvf -     -> list a tar file
335
336         test
337           lzop -t < y.lzo
338           cat y.lzo | lzop -t
339
340       stdout mode: (de)compress to stdout
341         create
342           lzop -c a.c > y.lzo
343
344         extract
345           lzop -dc y.lzo > a.c
346           lzop -dc y.tar.lzo | tar -xvf -      -> extract a tar file
347
348         list
349           lzop -dc y.tar.lzo | tar -tvf -      -> list a tar file
350
351       archive mode: compress/extract multiple files into a single archive
352       file
353         create
354           lzop a.c b.c -o sources.lzo          -> create an archive
355           lzop -P src/*.c -o sources.lzo       -> create an archive, store path name
356           lzop -c *.c > sources.lzo            -> another way to create an archive
357           lzop -c *.h >> sources.lzo           -> add files to archive
358
359         extract
360           lzop -dN sources.lzo
361           lzop -x ../src/sources.lzo           -> extract to current directory
362           lzop -x -p/tmp < ../src/sources.lzo  -> extract to /tmp directory
363
364         list
365           lzop -lNv sources.lzo
366
367         test
368           lzop -t sources.lzo
369           lzop -tvv sources.lzo                -> be very verbose
370
371       If you wish to create a single archive file with multiple members so
372       that members can later be extracted independently, you should prefer a
373       full-featured archiver such as tar. The latest version of GNU tar
374       supports the --use-compress-program=lzop option to invoke lzop
375       transparently.  lzop is designed as a complement to tar, not as a
376       replacement.
377

ENVIRONMENT

379       The environment variable LZOP can hold a set of default options for
380       lzop. These options are interpreted first and can be overwritten by
381       explicit command line parameters.  For example:
382
383           for sh/ksh/zsh:    LZOP="-1v --name"; export LZOP
384           for csh/tcsh:      setenv LZOP "-1v --name"
385           for DOS/Windows:   set LZOP=-1v --name
386
387       On Vax/VMS, the name of the environment variable is LZOP_OPT, to avoid
388       a conflict with the symbol set for invocation of the program.
389
390       Not all of the options are valid in the environment variable - lzop
391       will tell you.
392

SEE ALSO

394       bzip2(1), gzip(1), tar(1)
395
396       Precompiled binaries for some platforms are available from the lzop
397       home page.
398
399           see http://www.oberhumer.com/opensource/lzop/
400
401       lzop uses the LZO data compression library for compression services.
402
403           see http://www.oberhumer.com/opensource/lzo/
404

DIAGNOSTICS

406       Exit status is normally 0; if an error occurs, exit status is 1. If a
407       warning occurs, exit status is 2 (unless option --ignore-warn is in
408       effect).
409
410       lzop's diagnostics are intended to be self-explanatory.
411

BUGS

413       No bugs are known. Please report all problems immediately to the
414       author.
415

AUTHOR

417       Markus Franz Xaver Johannes Oberhumer <markus@oberhumer.com>
418       http://www.oberhumer.com/opensource/lzop/
419
421       lzop and the LZO library are Copyright (C) 1996, 1997, 1998, 1999,
422       2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 by
423       Markus Franz Xaver Johannes Oberhumer.  All Rights Reserved.
424
425       lzop and the LZO library are distributed under the terms of the GNU
426       General Public License (GPL).
427
428       Legal info: If want to integrate lzop into your commercial
429       (backup-)system please carefully read the GNU GPL FAQ at
430       http://www.gnu.org/licenses/gpl-faq.html about possible implications.
431
432
433
434lzop 1.03                         2010-11-06                           LZOP(1)
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