用pipe实现远程控制系统中的popen函数功能。参数f_des[0]从管道中读数据，f_des[1]向管道中写数据。通过管道实现父子进程间的通信。服务器可以向多个用户提供服务。-Remote control system with a pipe in the popen functionality. Parameter f_des [0] read data from the pipe, f_des [1] write data to the pipeline. Father and son through the pipeline to achieve inter-process communication. Server can provide services to multiple users.