Leverage Lua to display a unique set of alphabetized urls on stdin:

#! /usr/bin/env lua
local sort = io.popen('sort -u', 'w')
for line in io.stdin:lines() do
  for url in string.gmatch(line, '(http[s]://.-)[%)%]%s\n]') do
  	url = string.gsub(url, '/$', '')
  	sort:write(url .. '\n')
  end
end
sort:close()