rakefile.rb

# this is how it would be invoked as a new task in the rakefile
# you can override the hashing function or exclude/include files 
revfiles :revfiles do |rev|
  rev.files_to_rev << './**/*.bmp'
end

revfiles.rb

require 'rake'
require 'digest/md5'
require 'albacore/support/albacore_helper'

class RevFiles
  extend AttrMethods
  include YAMLConfig

  attr_accessor :rev_function
  attr_array :files_to_rev
  
  def initialize
    super()
    @rev_function = Proc.new { |f| Digest::MD5.hexdigest(File.read(f))[0..6] }
    @files_to_rev = []
    @files_to_rev << './**/*.js'
    @files_to_rev << './**/*.png'
    @files_to_rev << './**/*.jpg'
    @files_to_rev << './**/*.gif'
    @files_to_rev << './**/*.css'
  end
    
  def execute
    files = FileList.new(@files_to_rev)
    files.each { |f|
      ext = File.extname(f)
      filename = File.basename(f,ext)
      dir = File.dirname(f)
      
      oldFiles = FileList.new("#{dir}/#{filename}.*#{ext}").exclude(f)
      oldFiles.each{|old| File.delete(old)}      
     
      new_filename = "#{filename}.#{@rev_function.call(f)}#{ext}"
      new_path = File.join(dir,new_filename)
      cp(f,new_path)
    }
    
  end


end