string = "http://w...content-available-to-author-only...u.org"
m = string.match(/^https?:\/\/(?:www\.)?([^.]+)\./i).captures
puts m[0]
string = "http://h...content-available-to-author-only...u.net"
m = string.match(/^https?:\/\/(?:www\.)?([^.]+)\./i).captures
puts m[0]
c3RyaW5nID0gImh0dHA6Ly93Li4uY29udGVudC1hdmFpbGFibGUtdG8tYXV0aG9yLW9ubHkuLi51Lm9yZyIKbSA9IHN0cmluZy5tYXRjaCgvXmh0dHBzPzpcL1wvKD86d3d3XC4pPyhbXi5dKylcLi9pKS5jYXB0dXJlcwpwdXRzIG1bMF0KCnN0cmluZyA9ICJodHRwOi8vaC4uLmNvbnRlbnQtYXZhaWxhYmxlLXRvLWF1dGhvci1vbmx5Li4udS5uZXQiCm0gPSBzdHJpbmcubWF0Y2goL15odHRwcz86XC9cLyg/Ond3d1wuKT8oW14uXSspXC4vaSkuY2FwdHVyZXMKcHV0cyBtWzBd