LZW Implementation in Go

This is a small implementation of the LZW compression algorithm in Go. It implements both the compression and decompression sides and can be used with the predefined flags outlined in the Usage section.

Note: this is a small version meant to learn how LZW worked. It doesn't work for long text files because when the dictionary exceeds 256, it can't convert the bytes (2^8 = 256) properly. Full implementations account for this and provide more bits after the overflow.

Installation

Pull the repo down from the github page.

git clone github.com/jmwoliver/lzw-go

Then navigate to the lzw-go directory and build the file.

cd lzw-go
go build main.go

Now an executable has been built and can be run.

./main <...flags...>

Usage

After building the project, you can run the following command (note: this currently only works on .txt files):

./main -file /path/to/text/file.txt -compress

Once that command has been run, it will generate a compressed.lzw file in the output directory. You can see the compressed contents of this file with:

cat ./output/compressed.lzw

After compressing, you can then decompress the compressed.lzw file (note: this command only works on .lzw files):

./main -file ./output/compressed.lzw -decompress

Once you have done this, you can see the newly generated, decompressed file in decompressed.txt in the output directory:

cat ./output/decompressed.txt

Bada bing bada boom! Well isn't that neat, it's the same as the original!

It's also fun to see the size changes by looking at the byte values on the original file and the files generated.

ls -l /path/to/text/file.txt
ls -l ./output/compressed.lzw
ls -l ./output/decompressed.txt

That's it, hope you enjoy!

License

MIT