Re: About using COPROC

[Peng Yu]

On Fri, Apr 2, 2021 at 4:11 PM Marco Ippolito <maroloccio@gmail.com> wrote:
>
> > But if I run the following script. I don't quite understand why the
> > following does not work but the previous one works? Could anybody help
> > explain coproc?
>
> The coproc ends and the file descriptors are closed. The array is unset.
>
> You are _racing_ your coproc.
>
> Try adding a `sleep` inside the coproc command group, before `seq`.
>
> Does it work then?

By adding a longer sleep time, the following script works. But why the
coprocess is not halt to wait for its output to be taken? This
behavior is counterintuitive.

coproc {
sleep 2
seq 3
}

sleep 1
while IFS= read -r -u "${COPROC[0]}" line; do
    builtin printf '%s\n' "$line"
done

-- 
Regards,
Peng