Java™ Application Development on Linux - Dator

8.2 Source Control: Whys and Hows195which will prompt you for a password. Having logged in once, you will notneed to log in again, even after reboots of your system, as CVS keeps thepassword (by default; it can be changed) in a file called .cvspass in your homedirectory. This makes using CVS with a remote repository (once you’ve loggedin as simple as if the repository were local). From here on, the commands willall look the same. If your repository is remote, CVS will use the password fromyour .cvspass file, without asking you for it.8.2.2 ImportAre you wanting to use CVS on an existing project? Have you already got yourproject at least partly underway? Let’s look at how to enter all those files intoCVS with a single command.Not every file that is in a working directory needs to be kept under sourcecontrol. Some, like .class files, are created from the .java source files. Othersmay be just scratch files that you don’t want to keep versioned.To automatically exclude certain files from ever being included in yourrepository, CVS uses a file called .cvsignore that lists filename patterns. Anyfilename matching a pattern will be ignored by all CVS commands.Here is a .cvsignore file that we recommend for Java developers:*.zip*.classThis will exclude any file whose name ends in .class or .zip. Note thatthe comparison is strictly based on a name, not the actual contents. CVSdoesn’t know what a “class” file is; it is only excluding a file based on its name.Certain files are not really source files and can’t be managed as such, butwe would still like to keep versions and a history of changes for them. A goodexample would be an image file. For example, you may have a corporate logoin a file called logo.jpg and at some point you may get a new or revised versionof that file. You can use CVS to track such files, but you need to tell CVSthat this is a binary file, so that CVS doesn’t try to do some special substitutionsthat it does on check-in and check-out. (More about those substitutions later.)For now, let’s just consider how to tell CVS which files are binary. We cando that on the command line when we create a new file, but for importing alot of files at once, and to avoid the need to remember doing that each time weadd a file, we can put patterns for binary filenames in a CVS file called.cvswrappers.