def generate_bin_symlink(filename, bindir)
    if Gem.win_platform? then
      alert_warning "Unable to use symlinks on Windows, installing wrapper"
      generate_bin_script filename, bindir
      return
    end

    src = File.join gem_dir, spec.bindir, filename
    dst = File.join bindir, formatted_program_filename(filename)

    if File.exist? dst then
      if File.symlink? dst then
        link = File.readlink(dst).split File::SEPARATOR
        cur_version = Gem::Version.create(link[-3].sub(/^.*-/, ''))
        return if spec.version < cur_version
      end
      File.unlink dst
    end

    FileUtils.symlink src, dst, :verbose => Gem.configuration.really_verbose
  end
#
Creates the symlinks to run the applications in the gem.  Moves
the symlink if the gem being installed has a newer version.