Linux-based Pda E-mail Design And Realization

With the rapid development and gradual perfection of Linux, products with embedded Linux have received increasing attention from manufacturers and customers. The exploitation of PDA with Linux operating system is highly promising and practical.The author participates the project of PDA applied software with the Linux platform, which is provided by UESTC-ShuangXin union lab. Compared with PDA of the kind and PDA in other operating systems, this software is more carefully designed and developed strictly according to consumers' requirements. Therefore, it satisfies their needs for flexibility, efficiency, convenience, practicability and artistry.The author has fulfilled the exploitation of the E-mail Module. Users can receive and send text or MIME documents, handle emails easily and promptly. The module also offers such functions as identifying the user (by algorithm of MD5), forwarding answering emails, and supplying addresses. It is coded by C++, and designed graphical interfaces by FLTK.The thesis introduces embedded Linux system's present, future development, and some key technology.There are detailed analyzes on e-mail, from its appearance, system, form, working process to protocol (SMTP, POP3, MIME). In addition, the author discusses the client-server model, description of SOCKET (half-association, all-association) and its types and functions in network programming.The paper emphases this software's practicability, benefit, objective of e-mail module, and thinking, diagram of the main program module, exploring environment, and selection of instrument. The software contains SOCKET connection module, mail-sending module, and mail-receiving module. As the user-identification has been gradually employed in POP3 server, the paper analyzes the Base 64 and Quoted-Printable Coding, which are extensively used to handle the disordered codes in e-mails. The author debugged and compiled the program by tool of EMACS andMake. By connecting to server of SMTP and POP3, the software attains expectant requirement.