Path: utzoo!attcan!uunet!mcsun!unido!pbinfo!fillg1
From: fillg1@uni-paderborn.de (Michael Illgner)
Newsgroups: comp.std.c
Subject: Re: Casting pointers
Keywords: Pointers, casting
Message-ID: <1990Oct2.123350.20527@uni-paderborn.de>
Date: 2 Oct 90 12:33:50 GMT
References: <1990Sep29.201144.23113@maths.tcd.ie>
Organization: Uni-GH Paderborn, West Germany
Lines: 39

in tim@maths.tcd.ie (Timothy Murphy) writes:

>I recently came across the following problem,
>when temporarily 'borrowing' od from Unix to Mac.
>Consider a program like this.

>#include <stdio.h>

>char *buf = "abc";

>main()
>{
>  int *n = (int*) buf;
>  printf("%d", *n);
>}

>Should this always work?
>On the Mac, with THINK C,
>it only works if buf has an even address.
>Otherwise it bombs out.
>Is that a bug, according to standard C?

>-- 

>Timothy Murphy  

>e-mail: tim@maths.tcd.ie

I think it is a problem with the Macs 680X0 processor. Larger objects like
integer number are aligned at even addresses, and if they are accessed at
an odd address, the processor raises an exception.


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