do
local f_user_agent = Field.new("http.user_agent")

local file = io.open("luawrite.txt", "w")

--local function init_listener()
local tap = Listener.new("http")

local counter = 0
local ua_table={}
function tap.packet(pinfo, tvb)


local ua=  f_user_agent()
if ua then
local ua_index = tostring(ua)
local ua_value = ua_table[ua_index] or 0
ua_table[ua_index] = ua_value + 1
counter=counter+1
end
--file:write("Counter: \t" .. counter .."  "..ua_index.. "\n")
end


function tap.draw(t)
file:write("Counter: \t" .. counter .. "\n")
for ua_content,num in pairs(ua_table) do
file:write(ua_content.."\t"..num.."\n")
end
end
--retap_packets()
end