Path: utzoo!attcan!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.questions
Subject: Re: Can the output to a terminal be monitored?
Message-ID: <1990Jun3.011111.1589@virtech.uucp>
Date: 3 Jun 90 01:11:11 GMT
References: <2784@syma.sussex.ac.uk> <270@demott.COM>
Reply-To: cpcahil@virtech.UUCP (Conor P. Cahill)
Organization: Virtual Technologies Inc., Sterling VA
Lines: 23

In article <270@demott.COM> kdq@demott.COM (Kevin D. Quitt) writes:
>    Is there a way that I (as root) can "tap into" a user to monitor
>terminal activity?  I specifcally would like to do this for the modem line.

Not in software (unless you modify the software running on that port to 
dump the data to a log file that you tail).  

If what you want to do is to be able to abitrarily "tap" into a data line
you must do it with hardware.  This can be done in several ways including

	1. a data line analyzer that captures all the data
	2. a poor-mans data capture which uses a second serial port on
	   your system and a special cable that wires TXD from the modem
	   port to RXD on the second serial port.  You can then tail this
	   serial port whenever you want.  Be sure that you do not have a
	   getty running on the port and that if the second port requires
	   DCD to be high you should loop DTR back to DCD.


-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170