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Date:      Wed, 19 Feb 2003 10:14:20 +0100
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 
Message-ID:  <86890.1045646060@critter.freebsd.dk>
In-Reply-To: Your message of "Wed, 19 Feb 2003 00:59:46 PST." <20030219003725.W240-100000@mammoth.eat.frenchfries.net> 

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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.

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