generate_bin_symlink (Gem::Installer)

    # File lib/rubygems/installer.rb, line 374
      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, 'bin', 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