locate-user-emacs-file

locate-user-emacs-file is a compiled Lisp function in `files.el'.

(locate-user-emacs-file NEW-NAME &optional OLD-NAME)

Return an absolute per-user Emacs-specific file name.
If NEW-NAME exists in `user-emacs-directory', return it.
Else if OLD-NAME is non-nil and ~/OLD-NAME exists, return ~/OLD-NAME.
Else return NEW-NAME in `user-emacs-directory', creating the
directory if it does not exist.