As support was added to libstdf to read compressed files, the request came up to read LZW compressed files. Many may be familiar with this compression algorithm via the classical UNIX programs compress and uncompress which manipulate files named with a .Z extension, or perhaps the usage of LZW in compressing GIF/TIFF image data.

Unable to locate a decent library with an API comparable to that of zlib or libbzip2, I decided to write my own from scratch. liblzw is the result.

Since I ripped the compression algorithms out of the public-domain package ncompress (google for ncompress-4.2.4.tar.gz as it no longer has a homepage), I've also released liblzw into the public-domain for people to do with as they will. Just please send me bugfixes as you find them :).

One last note for those of you coming late to the party; all existing patents on the LZW algorithm have expired world-wide. So LZW is now patent free (whoopee!).

The current implementation supports the open/read/close functions since that is all I require at this time for reading files in libstdf. Maybe if there's interest, more features can be added.

0.1.2

• Bundle testsuite
• Fix liblzw.pc.in file as pointed out by Tester A.

0.1.1

• Fix buffer underflow bug CVE-2006-1168

0.1

• Proof of concept which can open/read files

You can find plenty of info on the LZW algorithm (just use Google), but for fun, here's some helpful links.

• LZW Wikipedia Entry
• LZW Data Compression by Mark Nelson
• LZW Encoding Discussion and Implementation by Michael Dipperstein
• LZW NIST Reference Page