Using 'flock' in GNU Pascal.

I am in the process of developing a CGI program using GNU Pascal. The CGI program is to be used in a Linux environment. It is a database CGI script and I would like to have one running process of the CGI script have exclusive write access. I was hoping that someone could provide me with an example, or a place where I can find further (detailed) information, of using the flock() function from the C library in a GNU Pascal program. I also need to know how to detect when a file is locked. A million thanks for your time and help. Sincerely, Chris Wood