The Design And Implementation Of Linux-based Real-time Network Communication Software

As a sort of instant message transmitting method, the real-time network communications based on the Internet or other wired or wireless networks have been flourished since the beginning of pervasive computing, or informally named "post-PC dominant epoch" . In this thesis, a real-time network communication system (named "MyComm" ) based on Linux, but platform independent, is investigated.In order to improve and extend the existing real-time network communication software, either made in China or abroad, it is necessary to develop a real-time communications software for Linux desktop. On this basis, the Concurrent Versions System (CVS), usually employed in the development of large- or middle-scale commercial software, is used to develop MyComm system. After completing the overall design for both the server and the client, the author has implemented fundamental real-time communications functions, such as real-time message transmitting, the management of current user and user' s friend, etc. The major research and characteristics related to the realization of MyComm are, only ANSI C/C++ and some system calls of MySQL and QT are used so as to embody the thought of OS-free; the real-time response and network security issues are resolved by the introduction of mulit-thread and daemon programming mode, as well as the conversion of a clear text signal to a coded form in the data domain of UDP packet; in order to provide a friendly user interface, a series of shell-based system management commands in the server and skin-based programming techniques in the client are developed based on QT development tools; to solve the hardware dependent configuration problem, all system files are packed into a RPM file which can be automatically installed, avoiding revise and recompile "makefile" manually, therefore, making the software upgrade and distribution much easier.Based on the developed MyComm client software and the analysis ofthe popular real-time network communication software, OICQ, the first OICQ version under the Linux-XWindow environment, which can communicate with the server of Tencent OICQ successfully and smoothly, is implemented and distributed on the Internet.