Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!ucsd!ames!haven!adm!smoke!ibd!heilpern
From: heilpern@ibd.BRL.MIL (Mark A. Heilpern )
Newsgroups: comp.unix.questions
Subject: Re: Help on control keys
Message-ID: <235@ibd.BRL.MIL>
Date: 3 Jan 89 14:28:39 GMT
References: <893@husc6.harvard.edu>
Reply-To: heilpern@brl.arpa (Mark A. Heilpern (IBD) <heilpern>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 43

In article <893@husc6.harvard.edu> yylu@walsh.UUCP (Ya Yan Lu) writes:

>     I am concerning the following program.  Is it possible to put some
>control characters in an ascii file, so that whenever I read that file 
>by cat or more, it actually runs a program? When cat or more are used, the 
>control keys in a file usually have some effect, but I am not so clear 
>what they really are.
>     Thanks for any help.

Define program. If you are refering to a 'graphics' type of display, yes.
It is not possible, however, to give a code that tells cat to execute the
command rather than print it. {Unless you feel like rewriting /bin/cat.
If you do, there is a genereic source of the 'normal' cat in comp.sources.}

To create a graphics display that is catted, there are two basic options.
Just like your old instructor from school, I will explain the hard one first.


1) 	a) get out the manual for your terminal and thoroughly study all
	   Control codes and escape codes for graphics/movement.

	b) decide what you want to do and use 'cat >file' and start giving
	   the codes to do what you want the screen to do. [You will not
	   be able to give ^D, kill chars, etc., and the screen may start
	   performing these results, so don't be discouraged if you can
	   no longer see waht you are typeing. Just remember to use ^D on
	   a line by itself to end input.

	c) cat the file and observe. Do Not Use More, as this will pause
	   in unwanted areas.


2) [easy?]
	a) write a program using curses to perform your desired functions.

	b) run this program with redirected output: $ program > catfile

	c) cat catfile and the same display should be seen.

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