Funny you should mention that. I just spent a day implementing a LZW compressor in Perl. It took me a long time to do, I suspect because I am qutie thick, but mainly I was trying to do it by looking at C source code.

Kids, do not try this at home! The C program, which was meant to demonstrate clearly how it all worked was in fact horribly obfu. Linked lists everywhere, and ick. OTOH, it did run about 100 times faster than my Perl effort.

My little bit of agony was that I wasn't implementing the linked lists quite right. The first few lines were decompresing correctly, but as the program went further random garbage would appear, eventually obscuring the text. I was so close.

Many hours of shotgun debugging later, I threw out my pseudo-C code, and implemented a Perl version of a mathematical description of the LZW process. I nearly fell off my chair when it compiled and ran perfectly first time. I think that may be a lifetime first too.

So there is a moral to this story - don't do C, it ruins your style ;P

I would post the code, but Unisys are very clear that they will not tolerate even free versions to be distributed.

____________________
Jeremy
I didn't believe in evil until I dated it.

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