Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!mailrus!nrl-cmf!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: Signedness of chars
Message-ID: <7413@brl-smoke.ARPA>
Date: 4 Mar 88 13:05:40 GMT
References: <23209@ucbvax.BERKELEY.EDU>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 13

In article <23209@ucbvax.BERKELEY.EDU> hilfingr@tully.Berkeley.EDU.berkeley.edu (Paul Hilfinger) writes:
>Does anyone know of widely-used programs that depend on the type
>`char' being signed?  That is, how many programs would break if
>`unsigned char' and `char' were the same type?

A large number of PDP-11 UNIX programs were in this category, for example
much of the GPS-based PWB/Graphics.  By now, I think the version in use here
has all these bugs fixed.  (NOT the AT&T way, which was to use #ifdef u3b2
rather than change the code to work portably.)

The most common portability error in this regard is
	char c;
	while ((c = getchar()) != EOF)
		...