23.7.10.1 General Options
Emacs normally does not save backup files for source files that are
maintained with version control. If you want to make backup files even
for files that use version control, set the variable
vc-make-backup-files
to a non-nil
value.
Normally the work file exists all the time, whether it is locked or
not. If you set vc-keep-workfiles
to nil
, then checking
in a new version with C-x v v deletes the work file; but any
attempt to visit the file with Emacs creates it again. (With CVS, work
files are always kept.)
Editing a version-controlled file through a symbolic link can be
dangerous. It bypasses the version control system—you can edit the
file without locking it, and fail to check your changes in. Also,
your changes might overwrite those of another user. To protect against
this, VC checks each symbolic link that you visit, to see if it points
to a file under version control.
The variable vc-follow-symlinks
controls what to do when a
symbolic link points to a version-controlled file. If it is nil
,
VC only displays a warning message. If it is t
, VC automatically
follows the link, and visits the real file instead, telling you about
this in the echo area. If the value is ask
(the default), VC
asks you each time whether to follow the link.
If vc-suppress-confirm
is non-nil
, then C-x v v
and C-x v i can save the current buffer without asking, and
C-x v u also operates without asking for confirmation. (This
variable does not affect C-x v c; that operation is so drastic
that it should always ask for confirmation.)
VC mode does much of its work by running the shell commands for RCS,
CVS and SCCS. If vc-command-messages
is non-nil
, VC
displays messages to indicate which shell commands it runs, and
additional messages when the commands finish.
You can specify additional directories to search for version control
programs by setting the variable vc-path
. These directories
are searched before the usual search path. It is rarely necessary to
set this variable, because VC normally finds the proper files
automatically.