From owner-freebsd-hackers  Wed Feb 19  1:14:24 2003
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B134337B401
	for <hackers@FreeBSD.ORG>; Wed, 19 Feb 2003 01:14:23 -0800 (PST)
Received: from phk.freebsd.dk (phk.freebsd.dk [212.242.86.175])
	by mx1.FreeBSD.org (Postfix) with ESMTP id BBE5143F85
	for <hackers@FreeBSD.ORG>; Wed, 19 Feb 2003 01:14:22 -0800 (PST)
	(envelope-from phk@phk.freebsd.dk)
Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163])
	by phk.freebsd.dk (8.12.6/8.12.6) with ESMTP id h1J9EL6E090211;
	Wed, 19 Feb 2003 09:14:21 GMT
	(envelope-from phk@phk.freebsd.dk)
Received: from critter.freebsd.dk (localhost [127.0.0.1])
	by critter.freebsd.dk (8.12.6/8.12.6) with ESMTP id h1J9EKOx086891;
	Wed, 19 Feb 2003 10:14:20 +0100 (CET)
	(envelope-from phk@phk.freebsd.dk)
To: Paul Herman <pherman@frenchfries.net>
Cc: Peter Jeremy <peterjeremy@optushome.com.au>,
	FreeBSD Hackers <hackers@FreeBSD.ORG>
Subject: Re: arc4random() range 
From: phk@phk.freebsd.dk
In-Reply-To: Your message of "Wed, 19 Feb 2003 00:59:46 PST."
             <20030219003725.W240-100000@mammoth.eat.frenchfries.net> 
Date: Wed, 19 Feb 2003 10:14:20 +0100
Message-ID: <86890.1045646060@critter.freebsd.dk>
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG

In message <20030219003725.W240-100000@mammoth.eat.frenchfries.net>, Paul Herma
n writes:
>>
>> >  EXAMPLES
>> >  The following produces a drop-in replacement for the traditional
>> >  random() and rand() functions using arc4random():
>> >      #define arc4random31()   (arc4random() & 0x7FFFFFFF)
>>
>> Not good.  Only true on 32 bit archs.
>
>Heh?
>
>random(3) produces numbers between 0 and RAND_MAX on my alpha.
>random(3) produces numbers between 0 and RAND_MAX on my i386.

Well, I'm right in principle but wrong in current practice, at
the very least make it:

#define arc4random31()   (arc4random() & RAND_MAX)

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message