Some quick questions

[Stephen Masterman <floyd@animals.mit.edu>]

I have two completely unrelated questions.

First, I have strange problems with the 'write' command, and sometimes talk.
It complains about permissions, even if the person who I am trying to write
has typed 'mesg y'.  Does anyone know what the tty permissions should be?
I was going to change them to rw for other but then someone could just cat
a big file and redirect output to someone elses tty..?

Second, I am under the impression that there is a POSIX system call called
nanosleep() which allows a process to sleep an amount of time specified in
units of microseconds (don't know why its nanosleep and not microsleep).
Does anyone know what package this might be in?  I don't have a man page for
it so I assume I don't have the function.

Thanks.