Question

So basically what i need is:

pid = fork();
if (pid == -1)
   exit(1);

if (pid == 0)
{
   // do stuff in child
}
else
{
   // ONLY do stuff while child is running
}

would I need to create a tmp file right before the child exits saying that it is no longer running so the parent knows the child has exited when that file exists, or is there a simpler way to do this?

Answer 1

You can use waitpid to know if a child process is still running:

int status;
if (waitpid(pid, &status, WNOHANG) == 0) {
    // still running
}

With WNOHANG, waitpid returns immediately so that the program can do something else.

When you have nothing to do other than waiting for the child process to terminate, call waitpid without WNOHANG.