30 Jan
2023
30 Jan
'23
8:30 p.m.
John Cowan <cowan(a)ccil.org> wrote:
On Mon, Jan 30, 2023 at 2:50 AM
<arnold(a)skeeve.com> wrote:
I don't see how. Input is from fd 0. fd 3 is open on the original terminal
device by init, so even if you closed fd 0, opening /dev/tty gets you fd 3
gets you the original tty.
Granted, someone could also redirect fd 3, but that's unlikely in most cases.
Arnold
What I really like is how in V8 - V10 /dev/tty
was a (sym)link to /dev/fd/3,
and init simply did one more dup call. That eliminated the special tty
device
driver and was a lovely generalization / simplification. It's too bad this
was never picked in the commercial Unixes or in Linux.
That's problematic. I often need to redirect 2>&1 in order to get a stream
of both output and error into a file or into less(1), without interfering
with *input* from the terminal, as for example a password.