-- linkbot: fetches page titles for URLs posted in chat

function on_message(nick, channel, text)
  for url in text:gmatch("https?://[%w%.%-_~:/?#%[%]@!$&'%(%)%*%+,;%%=]+") do
    local ok, body = pcall(http.get, url)
    if ok and body then
      local title = body:match("<title[^>]*>([^<]+)</title>")
      if title then
        title = title:gsub("%s+", " "):gsub("^%s+", ""):gsub("%s+$", "")
        if #title > 0 and #title < 200 then
          irc.send(channel, "^ " .. title)
        end
      end
    end
  end
end