From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2004-02-19T02:04:53+09:00
Subject: Re: Ruby 1.8.1: Unexpected "pack" result

On Wed, 18 Feb 2004, Ara.T.Howard wrote:

<snip>

this version is even more informative...

~ > cat int_max.rb

  require 'tmpdir'
  require 'ftools'

  c_prog = <<-code
    #include <limits.h>
    main(){int i = INT_MAX; write(1,&i,sizeof(int));}
  code

  tmp = Dir::tmpdir

  a_c = File.join tmp, 'a.c'
  a_out = File.join tmp, 'a.out'
  out = File.join tmp, 'out'

  open(a_c, 'w'){|f| f.write c_prog}
  system "cc #{ a_c } -o #{ a_out }"
  system "#{ a_out } > #{ out }"

  int_max = IO.read(out).unpack('i').first

  p(int_max)
  p((2 ** 31) - 1)
  p("%032.32b" % int_max)

  p(0xFFFFFFFF)
  p((2 ** 32) - 1)
  p("%032.32b" % 0xFFFFFFFF)


  File.rm_f a_c
  File.rm_f a_out
  File.rm_f out



-a
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