Add a file to a compressed tarfile

[Dennis Hotson]

Thanks Heiko, Thats really interesting..

To tell you the truth though, I'm not that familiar with the structure of
tar or gzip files. I've got a much better idea of how it works now though.
:D

I managed to get my function working... although it decompresses
everything and then compresses it back... Not the best, but good enough I
think.

Speed isn't a huge issue in my case anyway because this is for a web app
I'm writing... It's a directory tree which allows people to download and
upload files into/from directories as well as compressed archives.

Anyway.. thanks a lot for your help. I really appreciate it. Cheers mate!
:)