One basic application of Internet environment is to copy documents from one computer to another distant one, while the File Transfer Protocol (FTP) is the most widely-used document transfer protocol on the Internet. FTP adopts the client-server mode. The object of this task is to design a FTP server program and a FTP client program.
This article mainly focuses on how to design and concretely realize the programs of FTP server and client through the method of software engineering. The procedures follow the way which is from the top to the bottom. This article could be divided into several chapters, including the analysis of FTP protocol, the analysis of demands, program design and practical function design, with a detailed introduction of the analysis, design and realization of FTP programs.This largely according with programming criterion, this FTP program is equipped with a couple of functions involving the initiation and closure of FTP links, uploading and downloading files, the judgement of user’s logging status, automatically altering Jumping catalogs and the output of file catalogs.