Applied Software Project Management

Version Control with Subversion

The purpose of a version control system is to bring a project's source code under control.^[*] The main element of the version control system is the repository , a database or directory that contains each of the files that make up the system. Bringing a group of files under control means that someone can pick a point at any time in the history of the project and see exactly what those files looked like at the time. It is always possible to find the latest version of any file by retrieving it from the repository. Changing a file will not unexpectedly overwrite any previous changes to that file; any change can be rolled back, so no work will accidentally be overwritten. Modern version control systems can identify exactly what changed between two different versions of a file, and allow the team to roll back those changes—even if they were made a long time ago, and the affected files have had many modifications since then.

This is very important for source code. When source code files are stored in a shared folder, for example, it is easy for changes to be lost when more than one programmer is working on the software. Even a single programmer, working on source code that resides in a folder on his computer, can run into problems. He might make a large change, only to realize that he needs to roll it back. Or he may find that he's got several copies of the code on his hard drive and laptop, and that each of them contains a different set of changes that ...