Implicit killing of subprocesses

[René Neumann <lists@xxxxxxxxx>]

Hi,

I have a question regarding if and when subprocesses are killed when
exiting a shell script.

My case: I want to pipe the output of a longrunning process (here:
dbus-monitor) through some evaluation. As it does not read from stdin, I
can't simply close it by sending EOF.

When I use

coproc dbus-monitor
while read -p line; do ... done

the dbus-monitor process lurks around after the script finishes
(breaking or returning from the loop).

When I use

dbus-monitor | while read -p line; do ... done

it does not (i.e. it gets killed).

My questions now are:

- Can I build on the process being killed when exiting the loop (in the
second case)? Or does it only work in some cases?

- Is it intentional that coprocs don't get killed and I have to make it
by hand? (Which is hard if you have "coproc dbus-monitor | grep ...", as
$! only holds the grep).

Thanks and regards,
René