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From: jsdy@hadron.UUCP (Joseph S. D. Yao)
Newsgroups: comp.lang.c
Subject: Re: CTRL(x)
Message-ID: <624@hadron.UUCP>
Date: Sun, 23-Nov-86 16:59:32 EST
Article-I.D.: hadron.624
Posted: Sun Nov 23 16:59:32 1986
Date-Received: Mon, 24-Nov-86 21:52:13 EST
References: <4880@brl-smoke.ARPA> <1319@sunybcs.UUCP> <614@hadron.UUCP> <170@haddock.UUCP>
Reply-To: jsdy@hadron.UUCP (Joseph S. D. Yao)
Organization: Hadron, Inc., Fairfax, VA
Lines: 33
Summary: Commentary on commentary; request for history.

In article <170@haddock.UUCP> karl@haddock.UUCP (Karl Heuer) writes:
>In article <614@hadron.UUCP> jsdy@hadron.UUCP (Joseph S. D. Yao) writes:
>>The XOR, (x^0100), will not generally work.  Use (x&037).
>True if you want the domain of the function to include lowercase.  I never
>do; e.g. I claim that the proper name for EOT is "^D" rather than "^d".

Your privilege.  My definition of control char, umpteen years ago,
just said that no bits not in the lower five were clear.  Said
nothing about "proper" names for them (othere than NUL, EOT, etc.).
Most people make a control-d without hitting the shift key.

Further, Control-ESC is ESC, not '['; and Control-TAB is TAB, not
'I'.  Yes, people are unlikely to do this in C code.  But that's
part of the reason I reacted as I did.

>allowing the use of CTRL('?') for DEL, which is a widely (though by no means
>universally) accepted notation.

My surprise.  I'd thought that Berkeley introduced this notation.
At any rate I'd never heard or seen it before 2BSD.  (My experience
before that had covered a variety of hardware, software, and
documentation.)  If anyone has a VERIFIABLE pre-BSD reference for
use of ^?, I'd appreciate your MAILing to me.  Summary will be
posted.  (I can't remember any non-BSD-derived version of the Unix(R)
operating systems that use this, just to stick my neck out further.)
This cute (x^0100) trick is the first reason I'd ever seen for '^?'
to mean DEL; so I have learned something new today.  (I guess I'd
assumed that with someone's screwy keyboard you could generate DEL
as a Control-?.)
-- 

	Joe Yao		hadron!jsdy@seismo.{CSS.GOV,ARPA,UUCP}
			jsdy@hadron.COM (not yet domainised)