printf "%s\n\n" ,  $_
  foreach
    #  extract the sorted complete URL list
    map { $_->[0] }

    #  sort on massged host name or the complete url
    sort { $a->[1] cmp $b->[1] || $a->[0] cmp $b->[0] }

      #  set up for extracting the complete URL & sortkeys
      map { #  extract host/domain components in reverse order
            my @host =
              reverse split '\.'
                 , ( split '/' , substr($_ , index($_, '://') + 3) )[0];

            [ #  current URL
              $_

            , #  put domain at front; everything else afterwords
              #  ----
              #  poo.koo -> poo.koo
              #  web.poo.koo:80 -> poo.koo:80.www
              #  rand.web.poo.koo -> poo.koo.web.rand
              #  ----
              (scalar @host > 1 ? $host[1] . '.' : '')
              . $host[0]
              . ( scalar @host < 3 ? '' : '.' . join('.' , @host[2..$#host]) )
            ]
          } keys %url;