From: Pit Capitain <pit@...>
Date: 2006-07-14T07:46:33+09:00
Subject: Re: challenge

ara.t.howard@noaa.gov schrieb:
> wow.  learn something every day!
> 
>   ~ > cat a.rb
>   class File
>     def File.open(*a) 42 end
>   end
> 
>   p File.open(__FILE__)
> 
>   class << File; self; end.class_eval do
>     remove_method :open
>   end
> 
>   p File.open(__FILE__)
> 
> 
> 
>   ~ > ruby a.rb
>   42
>   #<File:a.rb>
> 
> 
> i wasn't aware remove_method had this 'stacklike' quality.

Ara, I just called

   p open_m

and noticed that "open" wasn't a method of class "File", but of class 
"IO"! So to get back to the normal behaviour it was enough to remove the 
new method of class "File".

This is even shorter:

   class << File
     remove_method :open
   end

The "class_eval" part isn't necessary.

Regards,
Pit