linux 下利用FORK生成子进程，从而可以多客户端访问服务器等基本例程，在linux环境下分别编译两个文件，在不同窗口运行一个服务器端，运行多个客户端，即可看到效果-Under linux use FORK generate child processes, which can be more than the Client Access server and other basic routines, respectively, in the linux environment to compile two documents in different windows to run a server, running multiple clients, you can see the effect