From: Rob Biedenharn <Rob@...>
Date: 2007-12-28T13:36:37+09:00
Subject: Re: testing for 64-bit environment


On Dec 27, 2007, at 10:59 PM, Tom Metge wrote:

> in case anyone else is wondering, my solution:
>
> arch = `uname -i`
>
> tom
>
> On Dec 27, 2007, at 8:15 PM, Tom Metge wrote:
>
>> subject says it all- anyone know a way to determine if the host  
>> system is 64-bit?  i need to load a different module for different  
>> environments.
>>
>> thanks,
>> tom


I only have a 32-bit system to try, but the Pickaxe seems to indicate  
that Fixnum.size is the bytes in the machine representation of a Fixnum.

On my Intel MacBookPro:

irb> Object::PLATFORM
=> "universal-darwin9.0"
irb> 1.size
=> 4
irb> (2**30 - 1).class
=> Fixnum
irb> (2**30 - 1).size
=> 4
irb> (2**31 - 1).class
=> Bignum
irb> (2**31 - 1).size
=> 4
irb> (2**32 - 1).size
=> 4
irb> (2**33 - 1).size
=> 8
irb> (2**33 - 1).class
=> Bignum

Note that Fixnum can hold 31 bits (30 + sign bit) and Bignum jumps  
from 4 bytes to 8 bytes.

What do you get for 1.size on a 64-bit platform?

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com