Newsgroups: comp.lang.c
Path: utzoo!utgpu!jarvis.csri.toronto.edu!dgp.toronto.edu!hugh
From: hugh@dgp.toronto.edu ("D. Hugh Redelmeier")
Subject: Re: Trigraphs -- some numbers
Message-ID: <8805271448.AA09761@explorer.dgp.toronto.edu>
Organization: University of Toronto, CSRI
References: <847@fig.bbn.com>
Date:	Fri, 27 May 88 09:28:42 EDT

In article <847@fig.bbn.com> rsalz@bbn.com (Rich Salz) writes:
>I logged on to the machine that has our Sun3.2 sources and did
>	find . -type f -print | xargs fgrep '??' >/tmp/tri
>	vi /tmp/tri	# to remove comments, etc.

Ah, but trigraphs are converted in comments too!  Consider the following:

/* This comment ends only if trigraphs are handled correctly *??/
/

>Most uses fall into these two types:
>	printf("%s", ptr ? ptr->field : "???");
>	static char tty[] = "/dev/tty??";

Notice that ??" is not a trigraph, so these examples are no problem.
I recently checked about 15000 lines of my own code, and found only
one (accidental) trigraph.  It was in a comment, and treating it as a
trigraph had no effect:

	/* no value will be greater than 10 (really???) */

Hugh Redelmeier
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