#!/usr/bin/ruby
require 'rubygems'
require 'zip/zip'
require 'fileutils'

include Zip

def saveFile (name, data)
  i, new_name = 0, name
  while File.exist?(new_name) do
    return if File.size(new_name) == data.size && File.read(new_name).eql? data
    new_name = "#{i+=1}_#{name}"
  end

  File.write(new_name, data) # might require some of my custom code, not sure :)
end

Zip::ZipInputStream::open('test.zip') do |io|
  saveFile(entry.name, io.read) while (entry = io.get_next_entry)
end