security and php

Dear gentlemen/madams, I am a system administrator and currently we are playing to migrate all our CGI (written in C) to php! But playing a little with php i got worried about how services that need to keep username/password are handled by php, for instance: All our CGI programs execute sql queries to a mysql server, they contains the user name and password in order to login into the database. Since these programs need only to be executed its read flags are turned off. I need such a funcionality with php, but how can this be done? PHP scripts not owned by the user that runs the web server are required to have the read flag for all tuned on, ok? this makes its contents readable by all my system users, right ? So how to put user name/password information into such script in order to get it accessing mysql, but without allowing any other user to get into its contents and reading login/password information ? Thanks a lot for your time and cooperation.