10.8.1 How ECB identifies the VC-backend of a dir

ECB tries all functions added as identify-backend-funtions to the option ecb-vc-supported-backends until one of them returns not nil but a symbol which identifies the backend (e.g. CVS). After this check ECB stores the result of this check (i.e. either the identified backend or the fact that the directory is not managed by a VC-system) for that directory in a special cache, so the identify-backend-process will be performed only once per directory. If for a directory a VC-backend could be identified ECB stores not only the backend itself for that directory but also the associated check-state-function defined in ecb-vc-supported-backends (see Checking the state).

You can add arbitrary functions to this options as long as they get one directory-argument and return either nil or a backend-symbol. Per default ECB offers the following functions to identify the VC-backend CVS, RCS, SCCS, Git, Monotone or Subversion³⁷:

ecb-vc-dir-managed-by-CVS DIRECTORY

Return CVS if DIRECTORY is managed by CVS. nil if not.

ecb-vc-dir-managed-by-RCS DIRECTORY

Return RCS if DIRECTORY is managed by RCS. nil if not.

ecb-vc-dir-managed-by-SCCS DIRECTORY

Return SCCS if DIRECTORY is managed by SCCS. nil if not.

ecb-vc-dir-managed-by-MTN DIRECTORY

return MTN if directory is managed by Monotone. nil if not.

ecb-vc-dir-managed-by-BZR DIRECTORY

return BZR if directory is managed by Bazaar. nil if not.

ecb-vc-dir-managed-by-GIT DIRECTORY

Return GIT if directory is managed by Git. nil if not. Because with Git only the top-most directory of a source-tree has a subdir .git this function tries recursively upwards if there is a .git-subdir.

ecb-vc-dir-managed-by-SVN DIRECTORY

Return SVN if DIRECTORY is managed by Subversion. nil if not. Returns always nil if the library vc-svn.el can not be found.

If ECB should support another VC-backend than CVS, RCS, SCCS, Monotone, Git or Subversion you have to write your own identify-backend-funtion for the used VC-backend (e.g. Clearcase)!