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From: ddc@druak.UUCP (CusterDD)
Newsgroups: net.unix-wizards
Subject: Unsigned and Bitwise Operators
Message-ID: <638@druak.UUCP>
Date: Mon, 25-Jun-84 15:59:48 EDT
Article-I.D.: druak.638
Posted: Mon Jun 25 15:59:48 1984
Date-Received: Thu, 28-Jun-84 01:45:26 EDT
Organization: AT&T Information Systems Laboratories, Denver
Lines: 30

<munch>

The following program always reports -1 is negative, -1 is positive
on UNIX 5.05 running on VAX-11/780, 3B20 and 3B2.
I used the cc compiler

=============
#include <stdio.h>

main()
{
	char	foo;
	unsigned char ufoo;
	
	foo = ufoo = 1;
	if ((-1 | foo) < 0) printf("-1 is negative");
	if ((-1 | ufoo) > 0) printf("-1 is positive");
}
==============

If the ufoo test were to read:
	if ((-1 | ufoo) < 0) printf("-1 is positive");
then the printf would not be executed.

David Custer
AT&T Information Systems Labs
(303) 538-3517
{druak | druky | druxp}!ddc

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