From: Francis Cianfrocca <garbagecat10@...>
Date: 2007-05-28T21:27:21+09:00
Subject: Re: Killing sons (Linux)

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On 5/28/07, Ohad Lutzky <lutzky@gmail.com> wrote:
>
>
> Now, my system also allows a 'kill' command, intended to stop the job in
> progress. This has been causing me a lot of trouble, and I suddenly
> (after quite a while the system has been in production, how embarassing)
> realized why - the PID I'm keeping is of the daemon fork. Killing it
> doesn't kill all of its sons - it causes bash to get reparented to init!
>
> Any idea of a clean, quick way to fix this?



Make your parent process the leader of its own process group with
setpgid(0,0). When you fork, add each child to the parent's process group
with setpgid(0, getppid()). If you fork subchildren, make sure they get
added to the same process group. Now, to send a signal to the whole group,
send it to (0 - pid), where pid is that of the parent. If you want them all
to die without killing the leader, use a signal whose default behavior is
terminate-process and ignore it in the parent.

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