Provided by: lhasa_0.4.0-1build1_amd64 
NAME
lha - compression tool for .lzh archive files.
SYNOPSIS
lha [-]{lvtxep[q{num}][finv]}[w=<dir>] archive_file [file ...]
DESCRIPTION
lha is a tool for extracting .lzh archive files. It also supports variants of the .lzh
archive, such as .lzs and .pma.
This version of the lha tool is part of Lhasa, a free implementation of the .lzh format.
COMMAND SYNTAX
The lha tool has an unusual command syntax, compared to most other Unix commands. The
first parameter to the program specifies the command to perform and all additional
options. The second parameter specifies the path to the archive file to operate on.
Following this is a list of wildcard patterns to match against the filenames of the
archived files.
The first character of the command parameter specifies the command to perform, which is
one of the following:
-l List contents of the specified archive.
-v Verbosely list contents of the specified archive.
-t Test the integrity of the specified archive: decompress its contents and check the
CRC.
-e or -x
Extract archive. Files are extracted to the current working directory unless the
'w' option is specified.
-p Extract archive, sending decompressed files to stdout rather than writing them to
the filesystem as actual files. This is useful when used as part of a shell
pipeline.
OPTIONS
The remainder of the command parameter is used to specify additional options:
q[012] Quiet mode. Higher numbers suppress more output. Level 0 is normal operation. If no
number is specified, full suppression (level 2) is used. The quiet option also
turns on the force overwrite option ('f').
f Force overwrite of existing files: do not prompt.
i Ignore paths of archived files: extract all archived files to the same directory,
ignoring subdirectories.
n Do not perform any actual operations: instead, perform a dry run of the requested
operation and describe what would have been done on standard output.
v Verbose mode: causes extra information to be written to standard output.
w=dir Specify destination directory for extracting files. This must be the last option of
the first parameter.
COMPRESSION FORMATS
The following gives some basic description of the various different supported compression
formats (as listed when using the list command documented above). All formats are
variants on the LZSS compression algorithm.
-lz4- Uncompressed (stored) data, as used by the original LArc tool. This is not related
to the LZ4 compression algorithm of the same name.
-lz5-, -lzs-
Compression formats introduced with the original LArc tool. -lzs- uses a 2KiB
sliding window while -lz5- uses a 4KiB window.
-lhd- Directory entry. No data is stored, only headers.
-lh0- Uncompressed (stored) data, as used in LHarc and LHa.
-lh1- Compression algorithm introduced with LHarc. This uses a 4KiB sliding window with
dynamic Huffman encoding.
-lh4-, -lh5-, -lh6-, -lh7-
New algorithm introduced with LHa (aka LHarc v2.0). The original versions (-lh4-
and -lh5-) used 8KiB and 16KiB sliding window sizes, respectively. Later versions
introduced new variants with larger window sizes: -lh6- (64KiB) and -lh7- (128KiB).
-lhx- Variant on the -lh4- format listed above introduced by UNLHA32.dll that extends the
window size to 1MiB.
-lk7- Variant on the -lh4- format listed above that was introduced by the LHark tool (a
fork of LHa). This is actually named -lh7- within the archive files, but Lhasa
renames it internally to avoid clashing with the other algorithm of the same name.
Uses a 128KiB sliding window, with some minor improvement to the algorithm.
-pm0- Uncompressed (stored) data, as used by the PMarc tool.
-pm1- Algorithm used by version 1 of the PMarc tool.
-pm2- Algorithm used by version 2 of the PMarc tool.
UNSUPPORTED FORMATS
The following formats are not currently supported by Lhasa (but possibly will be in the
future):
-lh2-, -lh3-
These formats can be decompressed by LHa v2.0 but the tool could not actually
generate archives with these formats; they appear to have only been supported in
beta versions before the v2.0 release. As a result, few if any examples exist in
the wild.
-lh8-, -lh9-, -lha-, -lhb-, -lhc-, -lhe-
Extensions of the -lh4- format to even larger window sizes.
-pc1- Format generated by the PopCom! compression utility for CP/M.
If you encounter examples of these in the wild, please get in touch.
EXAMPLES
Here are some examples for how to invoke the program:
lha -v foobar.lzs
List the contents of the file foobar.lzs (producing verbose output).
lha -xf foobar.exe
Extract the contents of a self-extracting archive file named foobar.exe to the
current directory, overwriting existing files with the same names if they exist.
lha -xqw=/tmp foobar.lzh
Extract the contents of foobar.lzh to /tmp, overwriting any existing files found
there, and suppressing normal output (similar to how other Unix tools such as cp(1)
or tar(1) act silently by default).
SEE ALSO
unzip(1), tar(1), gzip(1), bzip2(1), xz(1), lzip(1)
HISTORY
The .lzh format originated with Kazuhiko Miki's MS-DOS archive tool, LArc, using the LZSS
algorithm developed by Haruhiko Okumura, and the .lzs filename extension. The container
format was reused for LHarc, by Haruyasu Yoshizaki (Yoshi), which used a new algorithm
named LZHUF and the .lzh extension. In later versions, LHarc was renamed to LHA and
extended with more effective compression algorithms.
Versions of the LHA tool were later ported to various different operating systems,
including the Amiga, Atari, MacOS, OS/2 and Unix. A tool for MSX-DOS named PMarc reused
the container format with a new compression algorithm (.pma extension).
The Unix version of the tool was developed by Masaru Oki, Nobutaka Watazaki and Tsugio
Okamoto, but was released under a software license that does not conform to the Free
Software or Open Source Definitions. Lhasa was developed as a drop-in replacement that is
Free Software and Open Source.
BUGS
The current version does not allow the creation of new archive files.
Some obscure compression algorithms are not currently supported (see the UNSUPPORTED
FORMATS section above).
The tool does not currently do text format conversion for non-ASCII filenames when listing
the contents of archives. Non-ASCII characters are replaced by a question mark.
AUTHOR
Lhasa was written and is maintained by Simon Howard.
COPYRIGHT
Copyright © 2011, 2012 Simon Howard.
Permission to use, copy, modify, and/or distribute this software for any purpose with or
without fee is hereby granted, provided that the above copyright notice and this
permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT
SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE
USE OR PERFORMANCE OF THIS SOFTWARE.
lha(1)