You have a non-Perl application, which we will call the "parent". From "parent", you call a Perl program, which we will call "A". From "A", you call another process, called "child". From "child", you call yet another process, which we call "grand child".

Now, "child" communicates with "parent". But now I am getting confused. You say that you do not want to lose the communication between "child" and "parent", however, you also want to kill "child". So, I am not certain which one you want to get rid of.

You also say you lose the communication if you exec "grand child", which isn't strange because an exec replaces the current process, it being "child". So, you use system and that works fine, but it leaves running processes behind. Well, of course that "works fine". Now you are not getting rid of "child", just as I said in my previous post. Because you are doing system, "child" will wait till "grand child" is finished before executing the next statement, which happens to be the exit. So.... "child" doesn't go away until "grand child" is finished. But isn't that exactly what you want? Because if "child" goes away your communication is broken anyway....

-- Abigail