wshdbg - A Debugger for CGI Applications

This contribution discusses wshdbg, an interactive, remote debugger for CGI applications written in pure or derived Tcl-based environments such as wshdbg. The discussion covers a short overview of the wshdbg environment and an analysis of current techniques and impediments of CGI debugging. The debugger presented consists of a client-server architecture, where the server is running on the same host as the Web browser, while the client is included in the CGI application that needs to be debugged. The resulting environment does not provide the level of sophistication known from typical source level debuggers, yet it presents a significant step forward compared to typical CGI debugging techniques which rely on tracing the execution by many log or debug messages. The system has been in operational use in the last two years and proved to be a great help in debugging large Web-based applications, allowing high-level software engineering for Web applications on nearly the same level as it is being done in traditional software development.