From: Ben Giddings <bg-rubytalk@...>
Date: 2005-08-19T01:38:47+09:00
Subject: Re: Idiomatic ruby version of this code?

def switch_endings(current_ending, new_ending)
  files = Dir.glob("*.#{current_ending}") do |filename|
    File.rename(filename, filename.gsub(/\.#{current_ending}$/, 
".#{new_ending}"))
  end
end

As for doing both renames at the same time (i.e. swapping the various 
endings) you can't really do that without using a third temporary ending, 
so you could do:

switch_endings("mp3", "mp3foo")
switch_endings("temp", "mp3")
switch_endings("mp3foo", "temp")

Ben