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From: cd5340@mars.njit.edu (David Charlap)
Newsgroups: comp.lang.pascal
Subject: Re: CTRL-Characters
Message-ID: <1991Mar28.082147.28971@njitgw.njit.edu>
Date: 28 Mar 91 08:21:47 GMT
References: <1991Mar27.160905.1962@cs.mcgill.ca> <1991Mar27.161213.2100@cs.mcgill.ca>
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In article <1991Mar27.161213.2100@cs.mcgill.ca> storm@cs.mcgill.ca (Marc WANDSCHNEIDER) writes:
>
>
>How do I make a PASCAL program recognize CTRL characters (or ALT characters 
>for that matter).  Ie I want the following:
>
>     IF CH = CTRL-G then 
>          BEGIN 
>           blahblahb
>	  END;

Simple. Ctrl-Codes are ascii values 1-31 representing ^A-^_.  Note
that certain special keys "map" onto other Control codes.  For
example: ^M=<Return>=Ascii 13, ^I=<Tab>=Ascii 9, ^[=<Esc>=Ascii 27,
etc.  So, your example would be:

Var
	Ch : Char;
...
	If Ch = #7 then.....

To scan for an Alt-Key, you need to use Turbo Pascal's extended
scan codes.  If the character read is ASCII-0  (#0), then the
key pressed is a special "extended" key.  The next "Character" read
will be the extended key code.  Consult the chart in the back of
your manual for the extended codes.  It's on page 424 in the Turbo
Pascal 5.0 reference guide.
--
David Charlap                   "Invention is the mother of necessity"
cd5340@mars.njit.edu            "Necessity is a mother"
Operators are standing by	"mother!" - Daffy Duck