On Thu, 2007-10-18 at 17:34 -0700, Garrick Staples wrote:

On Thu, Oct 18, 2007 at 08:07:46PM -0400, Jerry Geis alleged:

...

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.

Is each instance of "some_program" spawned from the same parent? If not, the PPID of the child can be used to differentiate between the children.

You don't. At least not by using system().

Use fork() and exec() and you will have the child pid.

Unfortunately (maybe), the environment that is provided by the system call (the command interpreter is invoked - /etc/profile, /etc/bashrc et al may come into play) is not established with fork and the exec* family of commands. Programming effort may be needed if this is important.

Changing the invocation to some variation of

"/bin/bash some_params some_program &"

might do the trick when using the fork/exec combo.

<snip sig stuff>

-- Bill