Re: how can we tell when a background process is finished?

[dave_the_m]

If we run system("program &");, is there a way to know when "program" has finished its execution?

No.
Instead, create a signal handler for SIGCHLD, then fork(), and do system("program") in the child.

Dave.

[integral]

Or you can do exec("program") in the child, saving another process, since system() incorporates a fork+exec.

[Anonymous Monk]

Thanks...do you know where I can find an example of this? I understand how to fork and then do system("program") in the child, but I'm not sure how to handle the "signal handler" for SIGCHLD. I think I will have to use waitpid()?

[DaWolf]

Take a look at perlmonkey's MP3 server with IO::Socket tutorial.
It explains in the fifth paragraph exactly what you're asking about processes.

Best regards,