From: Daniel Berger <Daniel.Berger@...>
Date: 2006-02-16T02:47:58+09:00
Subject: Re: pack("l"), 64 bit question

Yukihiro Matsumoto wrote:
> List-Unsubscribe: <mailto:ruby-talk-ctl@ruby-lang.org?body=unsubscribe>
> 
> Hi,
> 
> In message "Re: pack("l"), 64 bit question"
>     on Thu, 16 Feb 2006 01:50:34 +0900, Daniel Berger <Daniel.Berger@qwest.com> writes:
> 
> |Ruby 1.8.4
> |Solaris 10
> |
> |Is this correct?
> |
> |# 32 bit
> |irb(main):002:0> [-1].pack("l")
> |=> "\377\377\377\377"
> |irb(main):003:0> "\377\377\377\377".unpack("l")
> |=> [-1]
> |
> |# 64 bit
> |irb(main):002:0> [-1].pack("l")
> |=> "\377\377\377\377"
> |irb(main):003:0> "\377\377\377\377".unpack("l")
> |=> [4294967295]
> 
> Hmm, unpack("l") should have returned negative value unless "_" suffix
> is supplied.
> 
> 							matz.
> 

Here's some more info that may or may not be useful:

# 64 bit
irb(main):004:0> "\377\377\377\377".unpack("l_")
=> [nil]
irb(main):005:0> [-1].pack("l_")
=> "\377\377\377\377\377\377\377\377"
irb(main):006:0> "\377\377\377\377\377\377\377\377".unpack("l_")
=> [-1]

Regards,

Dan