Reading a ZIP file in PHP

I'm looking for a way to open a zip file, and decompress a text file that's in it, allowing it to be opened and parsed. I've found several very useful ones, but they use a specialized library for it. Believe me, if I could use that library, I would, but there's no way my host would install it, and unfortunately, switching hosts is not an option(not my decision).

I need something that will allow me to do the above, but without installing anything on the server besides a php script.

Help...
Please, someone....
:o(