oh ok, that seems what I want (except I don't want to read from stdin when
there is no tty, just assume a negative answer, but that's trivial).
I am still wondering,  what can be a way to simulate the situation of a
script launched by cron, where there is no tty and no other mean for read
to connect to a terminal?
thanks!

Pier Paolo Grassi


Il giorno sab 7 gen 2023 alle ore 18:31 Roman Perepelitsa <
roman.perepelitsa@gmail.com> ha scritto:

> On Sat, Jan 7, 2023 at 6:22 PM Pier Paolo Grassi <pierpaolog@gmail.com>
> wrote:
> >
> > Thanks, but i don't _always_ redirect stdin.
>
> The code will still work (except for the corner case I mentioned).
>
> Upon further thinking, the following should work in all cases:
>
>     if [[ -n $TTY ]]; then
>       # There is a terminal. Read from it.
>       read -k1
>     else
>       # There is no terminal. Read from stdin.
>       read -k1 -u0
>     fi
>
> Roman.
>