Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!ico!auto-trol!robwah
From: robwah@auto-trol.UUCP (Robert Wahl)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How can I disable Control-C ?
Message-ID: <186@auto-trol.UUCP>
Date: 15 Jun 89 18:20:08 GMT
References: <216100099@trsvax> <1553@cod.NOSC.MIL> <1241@ethz.UUCP>
Reply-To: robwah@auto-trol.UUCP (Robert Wahl)
Organization: Auto-trol Technology, Denver
Lines: 20

In article <1241@ethz.UUCP> zu@bernina.UUCP (Urs Zurbuchen) writes:
>If you write a little program which intercepts to Ctrl-Break (Ctrl-C)
>handler as a device driver and have it included in the Config.Sys file,
>no user would be able to stop the machine with a ^C. Well, at least I
>think, I didn't test it. Anybody volunteering to write it ? :-)

Not so.  The interrupts dealing with keyboard input will still respond
to Ctrl-C.  The only way to get sure control over Ctrl-C is to replace
all of these interrupts.  (And even then, as someone pointed out, some
programs will still replace YOUR interrupts.  Hypothetically, interrupts
should cascade, so that user-defined interrupts would call the interrupts
they replace; but such clean encapsulation doesn't always exist, and most
programs never consider the existence/desirability of TSR programs.)

A good discussion of Ctrl-C handling is given in "Crafting C Tools" (I
think that's the name), where the authors begin by replacing some of
the standard interrupts to correct some of IBM's serious design errors.
(Insert favorite IBM flame here.)  =:->
-- 
Rob Wahl  =:->  {...!ncar!ico!auto-trol!robwah}