Java™ Application Development on Linux - Dator

8.2 Source Control: Whys and Hows191Enter cvs—the Concurrent Versioning System. It’s a versioning system,allowing you to retrieve copies of the source based on either date parameters(e.g., last Tuesday) or the labels that you create. It’s concurrent because itsupports multiple simultaneous users.You may have used a versioning system before that let multiple programmerswork with a set of files. Often such systems will “lock” a file while oneuser is using it, keeping others from modifying it. CVS doesn’t work thatway—or doesn’t have to. Rather it allows users to each modify the same file(truly concurrent), and then reconciles the changes when those changes aremade permanent.To explain all this, it would be best to set down some terminology, as usedby CVS.repositoryThe master copy of the source.sandboxA developer’s local copy of the source.checkoutThe process of acquiring a copy of the source (one or more pieces) fromthe repository.commitThe process of adding the changes from your sandbox into the repository.updateThe process of revising your sandbox with changes that have occurred inthe repository since you last updated or created your sandbox. When you“update” your sandbox, other developers’ changes that have been committedto the repository are merged into your source sandbox.tagtagAs a noun, is a special label that you create to mark a milestone in yoursource repository; you can return to that milestone by checking out a copyof the source with that tag.As a verb, refers to creating a tag in the source repository.