'write', TIOCCDTR, and HP hang-up escape sequcences

[chris at umcp-cs.UUCP]

Here  at University of Maryland, we have a program called 'phone' which
will let  you  talk  to  up  to  8  people  simultaneously,  with  each
conversation  in  its own window (or, if your terminal does not support
windows, or if you don't like windows, on its  own  line).    This  was
originally  written  by  Jim  Rees (uw-beaver!jim) to use curses.  It's
similar to the VMS  phone  program.    I  hacked  at  it  for  multiple
conversations,  and  to  use  my  windows library.  It uses the CMU IPC
facility for 4.1BSD (and maybe 4.0; don't know).  This means that there
is  no  direct  connection  between  the  two users.  It does, however,
require the ability to write to the person's terminal to  annouce  that
someone  is  phoning.   I'm sure it could be rewritten to use 4.2-style
sockets, and a central phone server.  With  that  you  could  turn  off
writes  so  that no one can hang you up, yet still talk to other users.
Eventually perhaps inter-machine conversations will be common.

We're  willing to send source for it and for the windows library (which
I still plan to send to net.sources).  If you want it send me mail, and
I'll  pack  up and mail the phone source.  Note that the one I can send
will only work if you have CMU IPC.

				- Chris
-- 
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