Problem with PHP and MySQL libraries - need library names.

I am currently in charge of a set of servers (SuSE 9.2 OS) running, among other things, PHP and MySQL. As of version 5, PHP no longer includes the client libraries for MySQL with its packages, as they used to do. The result of this is that, after I upgraded one of these servers from PHP4 to PHP5, I lost access to our MySQL databases.

Does anyone know the names of the client libraries that PHP needs to connect to MySQL? I know there has to be one or more copies of the libraries on the system, since it previously had a working PHP4 installation which would have included the libraries in question. I simply do not know where they were installed (the installation was done by my predecessor in the position) nor the name of the files to search for. If anyone can suggest one or more names I can do a search on, I would be grateful.

Thank you for your consideration,
EnderX