Pragmatic Version Control Using CVS

Author: Dave Thomas and Andy Hunt

ISBN: 0974514004

Publisher: The Pragmatic Programmers

Reviewed by: Dean Wilson

While the presence of a version control system doesn't mean that all is well with a project its absence is often a warning sign of bad practises. Pragmatic Version Control with CVS provides the fundamentals required to ensure your project has a least the basics covered.

Firstly let's discuss what this book isn't, comprehensive and for experienced CVS users; unless you want something to hand to your less experienced co-workers. The book focuses on teaching the essentials of CVS, the commands used on a daily basis to, ideally, an audience new to the benefits and principles of revision control and usage of CVS.

The first two chapters explain the why and how of version control, beginning with an explanation of why you would want to store a project under revision control through to an introduction of the terminology and principles. These early chapters provide a clear and concise guide that is accessible to people with no previous experience in this area. In a bold move Chapter two explains the basic concepts behind merging and branching, something which too many articles on CVS leave to the footnote and closing paragraphs.

Chapter three contains the first hands on interaction with CVS, it explains how to install a CVS server on both Windows and Unix machines before taking the reader through a simple exercise in using the day-to-day functionality. It also differentiates itself from most writing on the subject by deliberately causing conflicts and showing you have to resolve them. This part of the chapter shouldn't be overlooked: the tendency to use real world examples, warts and all, makes the book a lot more useful.

Chapter three is extremely clear and easy to follow. If you have coders unfamiliar with CVS who need the 20 second guide then this chapter alone justifies the cost of the book. It's worth noting this chapter covers all the basic, common tasks using the command line. This ensures you understand what's going on under the hood, it doesn't focus on tools such as TortoiseCVS that, while making CVS easier to use, hide all the working parts and stop you forming the mental framework required to debug and fix any problems that may arise in casual usage.

Chapters five, six and seven cover CVS in more detail, chapter five, 'Accessing the Repository', contains what you'd expect from the title. However only the most common approaches are covered, SSH and pserver. This is followed by details of the related environmental variables, $CVSROOT and $CVS_RSH. These are used to specify the transport and repository locations and receive adequate attention. While this isn't as comprehensive as other sources these two mechanisms should suit most people.

The next two chapters take a more recipe based approach and expand upon the basics covered in chapter three. They provide a closer look at the common CVS tasks and explain the best practises and trade-offs involved. While most of the book should be read sequentially these two chapters are likely to be flicked to and referenced once CVS usage becomes the norm in the project and the user gains confidence with the checkout, update and commit cycle. Each recipe is self-contained and avoids unnecessary cross-referencing to make them easy to scan and digest in future rereads.

The final three chapters discuss how to set up your project in CVS, chapter eight explains one potential structure for your projects, detailing the directory layouts and providing an explanation of the different types and purposes of stored content that should steer CVS newbies away from the horror of trying to rename files and directories once the project has begun.

Dividing the project into modules, systems and sub-projects is covered in chapter nine, the advice in this chapter goes beyond just the commands required and explains some of the potential pitfalls you'll encounter when working in large projects or when checking out to a central build box. The final chapter of the book continues the theme and provides help and advice on integration with third party code and its place in both your project and revision system.

Appendix A provides what amounts to copies of the man pages for some of the CVS commands. This is followed by an index of the recipes covered in earlier chapters. Appendix B covers further resources but doesn't surprise you with anything beyond what a Google search would return.

If you are new to revision control in general or CVS in particular this book is an excellent place to start; clear, hands on, and need I say it, pragmatic in its coverage. The book's few negatives include its focus on the more common usages, if you want to use the more esoteric functionality, such as kerberos authentication or the scripting hooks in CVSROOT, then you'll be better off with the on-line docs or a different book such as Essential CVS by Jennifer Vesperman.