Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!leah!bingvaxu!vu0310
From: vu0310@bingvaxu.cc.binghamton.edu (R. Kym Horsell)
Newsgroups: comp.lang.c
Subject: Re: Preprocessor macro to quote its argument
Message-ID: <3891@bingvaxu.cc.binghamton.edu>
Date: 25 Aug 90 18:03:41 GMT
References: <1112@mti.mti.com> <1114@mti.mti.com> <1990Aug20.012839.3545@zoo.toronto.edu> <11517@ogicse.ogi.edu> <1990Aug21.175138.24633@zoo.toronto.edu> <21594@grebyn.com>
Reply-To: vu0310@bingvaxu.cc.binghamton.edu.cc.binghamton.edu (R. Kym Horsell)
Organization: SUNY Binghamton, NY
Lines: 19

In article <21594@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes:
\\\
>(This is just off the top of my head, so please be gentle...)
>
>Why can't this work?
>
>#define CTRL(ch) ((* #ch) - 64)
>
>It's ANSI only. The single # places it's arg in double quotes, making a
>string, and the * returns the first byte of the string.

This is fine (and I think has been pointed out recently on this
newsgroup). A slight improvement may be

#define	CTRL(c)	((*#c)&037)

'though.

-Kym Horsell