Learning GNU Emacs, 3rd Edition

Customizing VC

Some of the rules we've described earlier in the chapter for VC's behavior can be changed by setting certain Emacs variables related to VC mode. We'll go over a few of the most important here.

vc-handled-backends

This variable controls the set of version control systems used by VC, and the order in which they are found in the list controls the order in which they are attempted. It defaults to (RCS CVS SVN MCVS SCCS). If you remove values from the list, they won't be considered valid version control systems to use. If the list is empty, VC is disabled entirely.

vc-display-status

This variable displays a file's revision number and status on the mode line of each buffer visiting it, if this is non-nil. To avoid expensive queries of the master file, you may want to turn this variable off if you are running VC over very slow network links.

vc- backend -header

These variables provides lists of the headers to be inserted by vc-insert-headers when using the specified version control system. For example, the headers for CVS are in the variable vc-cvs-header. You can customize these lists if you like a different format for your version number headers.

vc-keep-workfiles

Normally, VC leaves a read-only copy of the work file in place whenever it performs a check-in. This feature is convenient because it means make and other tools always find work files where they expect to. If you're very tight on disk space, you can turn it off, but then you have to execute an explicit check-out ...