Reads a sequence of 8-bit bytes from standard input; compresses them using LZW compression with 12-bit codewords; and writes the results to standard output.

Reads a sequence of bit encoded using LZW compression with 12-bit codewords from standard input; expands them; and writes the results to standard output.

Sample client that calls compress() if the command-line argument is "-" an expand() if it is "+".