Re: FEATURE REQUEST : shell option to automatically terminate child processes on parent death

[Oğuz]

On Saturday, November 11, 2023, Corto Beau <corto.beau@laposte.net> wrote:

> Configuration Information [Automatically generated, do not change]:
> Machine: x86_64
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS: -g -O2
> uname output: Linux zinc 6.6.1-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 08 Nov
> 2023 16:05:38 +0000 x86_64 GNU/Linux
> Machine Type: x86_64-pc-linux-gnu
>
> Bash Version: 5.2 Patch
> Level: 21
> Release Status: release
>
> Description:
> Hi,
>
> I would like to suggest a new shell option to ensure child processes are
> automatically killed when the parent dies.
>
> Right now, it's already possible to emulate this feature by setting a trap
> to kill all child processes on exit (trap "kill 0" EXIT), but obviously it
> doesn't work if the process is terminated by a signal that cannot be caught
> (like SIGKILL).
>
> On Linux, it can be done by setting the PR_SET_PDEATHSIG flag to propagate
> the parent termination signal to the child, regardless of whether the
> signal can be caught or not.
>
> The rationale for this feature is that scripts spawning background
> processes to listen to various events (udev events, window manager events,
> etc) often leave orphan processes behind when terminated forcefully.
>
> I've attached a proof-of-concept patch.


I think it'd make more sense to implement this as a loadable builtin.


-- 
Oğuz