On 6/4/19 4:34 PM, mwnx wrote:
> Thanks for the explanation. In view of the change you describe,
> there is another behaviour that I think might qualify as a bug. I'll
> give you my actual use case first.
>
> I simply want to make sure all processes running inside a given
> subshell are killed on exit. To that means, I set up the following
> trap in the shell (and potentially, its subshells and so on):
>
> trap 'kill $(jobs -p) &>/dev/null || true; wait' EXIT
>
> This was working fine in bash 4.x, despite `jobs -p` not returning
> the process ID of process substitutions. But now that `wait` (with
> no arguments) waits for process substitutions in addition to
> "ordinary" foreground and background processes, the situation is
> asymmetric, leading to my subshells freezing when killed while a
> process substitution is running.
Not quite. `wait' without arguments waits for the last process
substitution, and the pid of that process is available in $! for the
cases you care about. If you are sure that your script hasn't started
any asynchronous processes since the last process substitution, you
can use $! directly. Otherwise, you can capture it into a variable
and use it in the `kill' command.
You should also ensure that you're using bash-5.0 with patch 4 applied,
since that is relevant to this issue.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
