nim_duilib/examples/proto_debuger/websocket_client.lua

require("string")
local file = io.open("writetest.txt", "w+")

function OnWebSocketData(data)
    if nil == file then
        print("open file writetest.txt fail")
    end
    file:write("OnUartData from lua " .. data)
    file:flush()
    showdata("dfasdfsddfasda" .. data.."\r\n")
end