prg1_1.c : 简单的网络编程实例。该实例是一个客户端程序，它首先连接到一个标准时间服务器上，从服务器读取当前时间，然后显示时间。-prg1_1.c : simple network programming examples. The example is a client program, it is first connected to a standard time on the server, from the server to read the current time, and then show time.