Learning DCOM

Appendix D. Hello, Universe!

This appendix captures the basic code that makes up a simple distributed system using COM, for people who like to see all essential components of a technology in one place. Some programmers learn best with all the code at hand, and if you belong to this group, this appendix may be helpful because it’s a short summary, mostly mirroring Chapter 3, and Chapter 4. The source code from this appendix is in the Hello directory of the files on the O’Reilly FTP site. You can take this appendix as an abbreviated summary for building simple distributed components, but you must read the whole book in order to obtain the necessary knowledge you need to build real distributed systems using COM. Having said that, let’s say “Hello, Universe!”

To uphold the Kernighan and Ritchie tradition, we’ll create a distributed system to print a message similar to the classic “Hello, World!” program. Unlike the original Kernighan and Ritchie example, which operates within a single process, our example will break not only the process barrier but also the machine barrier. In our application, a client program can print the “Hello, Universe!” message in a remote console on a totally different machine. In other words, a client simply calls a method that is implemented by a remote server, and the server prints the message “Hello, Universe!” on the server machine’s console.

Tip

Throughout this simple example, C++ comments that start with the symbol [Chapter] indicate that the immediate and ...