Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!usc!chaph.usc.edu!phakt.usc.edu!tli
From: tli@phakt.usc.edu (Tony Li)
Newsgroups: comp.unix.internals
Subject: Re: Watch, Spy, whatever you wanna call it
Message-ID: <12448@chaph.usc.edu>
Date: 11 Oct 90 07:00:12 GMT
References: <29835@netnews.upenn.edu> <1990Oct2.022530.15042@celebr.uucp>
Sender: news@chaph.usc.edu
Distribution: na
Organization: University of Southern California, Los Angeles, CA
Lines: 21
Nntp-Posting-Host: phakt.usc.edu

In article <1990Oct2.022530.15042@celebr.uucp> jbm@celebr.uucp (John B.
Milton) writes: 

    Hmm. As far as I know, this has not been done for UNIX. This was available
    under TOPS/20, I think it was called ADVISE. 
    
Under Tops-20, the 'spy' program let you see output.  'advise' also
let you put stuff in the input buffer.  

Last spring, my operating systems lab class did a basic implementation
of this for SunOS 4.0.  The basic idea was to create a new device
which reached down into the bottom of the stream of the victim's
terminal session and installed a hook there.  Data was fed back
through the new device.  Needless to say, this is only one possible
design for this facility.  

-- 
Tony Li - USC Computer Science Department
Internet: tli@usc.edu Uucp: usc!tli
Thus spake the master programmer: "A well written program is its own
heaven; a poorly-written program its own hell."