TIOCCDTR (bug|feature)

[ron%brl-bmd at sri-unix.UUCP]

From:      Ron Natalie <ron at brl-bmd>

On our system write is Setuid.  It checks the "execute" bits
of the terminal it is planning to write on to see if the user
wants to receive messages.   A later modification caused the
user to enter a message that gets printed to the invoker of
write when the x bits on the terminal are off.   (in addition
our write prefaces each sent line with the tty name of the sender
(and from time to time various non printing characters such as
backspace, return, and escape have been blocked, depending on
the mood of our user community).

-Ron