Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cme!cam!coleman
From: coleman@cam.nist.gov (Sean Sheridan Coleman X5672)
Newsgroups: comp.unix.internals
Subject: How to determine if a process has access to tty port
Keywords: repost
Message-ID: <6764@fs1.cam.nist.gov>
Date: 23 Jan 91 03:10:26 GMT
Organization: National Institute of Standards & Technology, Gaithersburg, MD
Lines: 21


I want to be able to determine if another process has control
of an RS232 port on a Alm Board on a Sun4. I am writing a 
program to gather data from a device that is connected via
RS-232. I want to deny access to the program if another program
is accessing the port currently. 

I want to know (1) how to tell if a port is being used
currently for a login port. ie.. some has log in using the port
(2) how to tell if a process has control of a port for out going
communication such as kermit?

I use a simplistic tty driver for comunicating to the  ports.
Is there something I should add to the driver code to allow
other programs to do what I have asked about above?

Thanks

Sean Coleman
NIST
coleman@bldrdoc.gov