From: Nobuyoshi Nakada <nobu@...>
Date: 2007-07-29T08:38:11+09:00
Subject: Re: checking if machine is 64-bit

Hi,

At Sun, 29 Jul 2007 02:42:46 +0900,
Suraj Kurapati wrote in [ruby-talk:262297]:
> I am checking if the machine is 64-bit by doing this:
> 
>   require 'rbconfig'
>   is_machine_64_bit = ( Config::CONFIG["arch"] =~ /64/ )
> 
> Is there a better way?

Depends on the purpose.

If you are trying to compile an extension library:

  is_machine_64_bit = check_sizeof("int") == 64

  is_machine_64_bit = try_static_assert("sizeof int == 64")

or, better in C source(s):

  #if SIZEOF_VOIDP == 8

Otherwise, if you want to know the current running platform is
64bit:

  is_machine_64_bit = [0].pack("i!").size == 8

Note that all of the above check for the size of int.

-- 
Nobu Nakada