[CentOS] program calls system() gettind PID - slightly off topic

Fri Oct 19 00:07:46 UTC 2007
Jerry Geis <geisj at pagestation.com>

I have a C program on centos. When I call system("some_program &");
how do I get the PID of the some_program?

I cant just list processes as there might be more than one some_program 
active.
I need to know the one that I just started.

Thanks,

Jerry