Path: utzoo!attcan!uunet!usna!baldwin
From: baldwin@usna.MIL (J.D. Baldwin.)
Newsgroups: comp.lang.pascal
Subject: Re: disable ^C in Turbo Pascal
Message-ID: <364@usna.MIL>
Date: 14 Feb 90 00:41:23 GMT
References: <116500002@uxa.cso.uiuc.edu>
Reply-To: baldwin@cad.usna.mil (J.D. Baldwin.)
Organization: Canoe U.
Lines: 36

In article <116500002@uxa.cso.uiuc.edu>, bcs33424@uxa.cso.uiuc.edu writes:
>	I'm writing a password program in Turbo Pascal for friend's
>    computer.  The program is fine, but I can't disable control-C.
>    I've tried the break command under DOS, and the {C-}, {C+},      
>    {$U-}, and the {$U+} (the book I'm using is very vague).  With-
>    out the control-C disabled, the program has no real effect.
>    Is there something I missed?  Is there another compiler directive 
>    I could use?  Could the autoexec.bat be written so that, if
>    the password program is stopped by a ^C that it recalls the
>    password program, until it is ended normally?  

Yes, the Crt unit contains a variable CheckBreak : boolean.  Setting

          CheckBreak := false;

will have the desired effect.  N.B.:  the BREAK key *will* work normally
when you run the program from the Turbo editor!  You must run the .EXE file
to see any results from this.

There is no way I have heard to do what you desire with DOS, so your scheme
can be defeated easily enough by hitting BREAK *before* your program starts.
There are such things as security "drivers" (so to speak) that load from
your CONFIG.SYS file that cannot be defeated this way--you might look for
something like this on BBS's on simtel20 (but beware the data burglar who
carries a boot disk in his toolkit).

>    "The interests of the landlord always oppose the interests of 
>     every othewr class of society."  - David Ricardo

Like most statements so sweepingly general, this is patently false.
--
From the catapult of:               |+| "If anyone disagrees with anything I
   _, J. D. Baldwin, Comp Sci Dept  |+| say, I am quite prepared not only to
 __||____:::)=}-  U.S. Naval Academy|+| retract it, but also to deny under
 \      / baldwin@cad.usna.navy.mil |+| oath that I ever said it." --T. Lehrer
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