1.3.2 Committing your changes

When you have checked that the compiler is still compilable you decide to make a new version of backend.c. This will store your new backend.c in the repository and make it available to anyone else who is using that same repository.

$ cvs commit backend.c

CVS starts an editor, to allow you to enter a log message. You type in “Added an optimization pass.”, save the temporary file, and exit the editor.

The environment variable $CVSEDITOR determines which editor is started. If $CVSEDITOR is not set, then if the environment variable $EDITOR is set, it will be used. If both $CVSEDITOR and $EDITOR are not set then there is a default which will vary with your operating system, for example vi for unix or notepad for Windows NT/95.

In addition, CVS checks the $VISUAL environment variable. Opinions vary on whether this behavior is desirable and whether future releases of CVS should check $VISUAL or ignore it. You will be OK either way if you make sure that $VISUAL is either unset or set to the same thing as $EDITOR.

When CVS starts the editor, it includes a list of files which are modified. For the CVS client, this list is based on comparing the modification time of the file against the modification time that the file had when it was last gotten or updated. Therefore, if a file’s modification time has changed but its contents have not, it will show up as modified. The simplest way to handle this is simply not to worry about it—if you proceed with the commit CVS will detect that the contents are not modified and treat it as an unmodified file. The next update will clue CVS in to the fact that the file is unmodified, and it will reset its stored timestamp so that the file will not show up in future editor sessions.

If you want to avoid starting an editor you can specify the log message on the command line using the ‘-m’ flag instead, like this:

$ cvs commit -m "Added an optimization pass" backend.c