一、引言 Web服务、FTP服务、邮件服务等是Internet应用中最常见的服务。如果在一台主机固定的IP地址和端口号上向外提供以上的服务,该主机便成了一台Web服务器、FTP服务器或邮件服务器,能够接收和处理来自客户端的请求。在某些应用中,可能要向自己的客户群提供以上的服务,同时还要对各服务的运行状态进行实时控制,如笔者曾经开发的考试 I. Introduction Web services, FTP services, mail services, etc. are the most common Internet services. If the above service is provided outwards on a fixed host IP address and port number, the host becomes a web server, FTP server, or mail server that can receive and process requests from clients. In some applications, it may be necessary to provide these services to their own customer base, as well as to provide real-time control over the running status of each service. For exams that I have developed