Parent PIDs

Sinope · 10-03-2004, 07:26 PM

When I run a program, is there a way I can specify a parent PID for that program? I want all of my X programs (yammi, thunderbird, various dockapps, etc) to be parented to .xsession.

trickykid · 10-03-2004, 07:50 PM

My first question is why? And no, well at least not that I know of. It all depends on how the program is designed to run, etc. But I'm still wondering why you'd want a parent PID for all your X related programs, etc.

Sinope · 10-04-2004, 06:22 PM

Why? Because when I end my X session, I sometimes have a bunch of programs floating around still running that chew up memory and sometimes interfere with new instances.

Tinkster · 10-04-2004, 06:34 PM

And having the PPID will change that how?

If a program is written badly and goes AWOL on
exit you won't benefit from all having the same PPID
because in that situation they probably won't respond
to a kill either ...

Cheers,
Tink

Sinope · 10-05-2004, 08:32 PM

Hmm... I thought that when a process is killed, all its child processes are killed as well. So right now i've got

Code:

init
  |-kdm---.xsession
  |               |-fluxbox---xterm---bash---vi
  |               `-xscreensaver
  `-juk

and when .xsession terminates i have:

Code:

init
  |-kdm
  `-juk

Blecch.

What I want is:

Code:

init
  `-kdm---.xsession
                  |-fluxbox
                  |-xterm--bash---vi
                  |-juk
                  `-xscreensaver

Not possible?

darthtux · 10-05-2004, 09:45 PM

For a process to be a child of a parent process, that parent has to spawn that process. I don't know of any way you can start a process and force it to attach itself to a parent.

I guess you could try to put everything you want to start in a ~/.xsession file to start when X does. But just starting a process once X is already started which seems to be what you want to do is not going to work.

btmiller · 10-05-2004, 11:46 PM

Besides, this won't work anyhow since children are definitely not killed when their parents exit.* Instead they are "adopted" by init, which will clean them up when they exit.

* Unless, in some situations, when you get an entire process group orphaned. See section 9.10 of W. Richard Stevens Advanced Programming the Unix Environment for all the gory details.