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NNTP-Posting-Date: Sun, 11 Mar 2012 08:02:59 -0500
Message-ID: <4F5CB0C8.2C88@mindspring.com>
Date: Sun, 11 Mar 2012 09:03:52 -0500
From: pete <pfiland@mindspring.com>
Reply-To: pfiland@mindspring.com
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Subject: Re: Method to test a program against different C implementations
References: <jji27a$d4e$1@nnrp.ngi.it> <jji6up$68s$1@online.de>
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Xref: csiph.com comp.lang.c:18531

Joachim Schmitz wrote:
> 
> pozz wrote:
> > We perfectly know that C implementations can be very different in
> > terms of:
> > - number of bits per byte
> 
> #include <limits.h>
>  and use CHAR_BIT
> 
> > - number of bytes per int
> 
> sizeof(int);
> 
> > - number of bytes per long
> 
> sizeof(long)
> 
> > - signed or unsigned char
> 
> #include <limits.h>
> and look at CHAR_BIT, CHAR_MAX and CHAR_MIN
> 
> > - negative number implementation (two's or one's complement)

    
#include <stdio.h>

    fputs("Negative numbers are ", stdout);
    switch (-1 & 3) {
        case 1: puts ("sign and magnitude.");
                break;
        case 2: puts ("one's complement.");
                break;
        case 3 : puts("two's complement.");
                break;
        default : puts("something strange.");
                break;
    }

> > - big or little endian or others
> 
> http://c-faq.com/misc/endiantest.html
> 
> <snip>
> 
> Bye, Jojo

-- 
pete