I'm not entirelt sure that the rcs command I use here is original or a
cisco wrapper, but the principal remains the same...


(defun rcs-check-out-file ()
  (interactive)
  ;;; check for clearcase environment
  (if (file-exists-p (concat (buffer-file-name) "@@/main/LATEST"))
      (progn
        (shell-command (concat "cleartool co -nc " (buffer-file-name)))
        (revert-buffer t (not (buffer-modified-p)))
      )
    ;;; else  (check for RCS environment)
    (if (file-exists-p "./RCS")
        (progn
          (shell-command (concat "co -l " (buffer-file-name)))
          (revert-buffer t (not (buffer-modified-p)))
          )
    ;;; else (check for CVS environment)
      (if (file-exists-p "./CVS")
          (progn
            (shell-command (concat "chmod u+w " (buffer-file-name)))
            (revert-buffer t (not (buffer-modified-p)))
            )
        )
      )
    )
  )

(define-key global-map "\C-c\C-o" 'rcs-check-out-file)