linux UDP例子，展示了UDP端口对端口的应用-linux udp demo，show how to use udp port-to-port communicaton

在基于linux下实现聊天的功能，群聊和私聊都可以实现。(To achieve the function of chat, group chat and private chat can be achieved)

主要是一些TCP、UDP的网络编程，学习Linux的可以尝试(Kalman filter is used to obtain more stable signals from random signals, which are generally used in aerial vehicles.)