Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!mit-eddie!genrad!decvax!ima!haddock!karl From: karl@haddock.UUCP (Karl Heuer) Newsgroups: comp.lang.c Subject: Re: is it really necessary for character values to be positive? Message-ID: <289@haddock.UUCP> Date: Wed, 24-Dec-86 16:05:18 EST Article-I.D.: haddock.289 Posted: Wed Dec 24 16:05:18 1986 Date-Received: Wed, 24-Dec-86 21:38:16 EST References: <39@houligan.UUCP> Reply-To: karl@haddock.ISC.COM.UUCP (Karl Heuer) Organization: Interactive Systems, Boston Lines: 15 Summary: yes In article <39@houligan.UUCP> dave@murphy.UUCP writes: >Summary: invent an 8-bit character set and then let some of them be negative Suppose I am using such a system, and one of the characters -- call it '@' -- has a negative value. The following program will not work: main() { int c; ... c = getchar(); ... if (c == '@') ... } Note that getchar() returns an UNSIGNED char on success; this is to guarantee that none of them compare equal to EOF. Thus, any printing character that I want to enclose in single quotes had better be positive, or it becomes VERY awkward to use. Please don't suggest that getchar() should return a signed char and that '\377' should be reserved. It won't work. Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint