From: Dossy <dossy@...>
Date: 2002-09-19T07:18:50+09:00
Subject: Re: signed hex conversion

On 2002.09.19, akolarik@sonexis.com <akolarik@sonexis.com> wrote:
> > There's probably a better way, but:
> > 
> > [0xFFFFFFC4].pack("l").unpack("l")[0]   # => -60
> > 
> > -- Dossy
> 
> I definitely wouldn't have stumbled on that for a while ;-)
> Guess I'll have to check the doc to figure out what's going on there, but in
> the meantime it works!  
> Thanks a lot, 

The pack takes a Fixnum and converts it to a String of 4 bytes which
represents the value ("l" means long).  Then, we unpack the 4 bytes
as a signed long back into a Fixnum.  "L" would be unsigned.

#pack and #unpack are incredibly powerful.

-- Dossy

-- 
Dossy Shiobara                       mail: dossy@panoptic.com 
Panoptic Computer Network             web: http://www.panoptic.com/ 
  "He realized the fastest way to change is to laugh at your own
    folly -- then you can let go and quickly move on." (p. 70)