Emacs, switch active window

(global-set-key (kbd "C-x <up>") 'windmove-up)
(global-set-key (kbd "C-x <down>") 'windmove-down)
(global-set-key (kbd "C-x <right>") 'windmove-right)
(global-set-key (kbd "C-x <left>") 'windmove-left)

;; Windows Cycling
(defun windmove-up-cycle()
  (interactive)
  (condition-case nil (windmove-up)
    (error (condition-case nil (windmove-down)
         (error (condition-case nil (windmove-right) (error (condition-case nil (windmove-left) (error (windmove-up))))))))))

(defun windmove-down-cycle()
  (interactive)
  (condition-case nil (windmove-down)
    (error (condition-case nil (windmove-up)
         (error (condition-case nil (windmove-left) (error (condition-case nil (windmove-right) (error (windmove-down))))))))))

(defun windmove-right-cycle()
  (interactive)
  (condition-case nil (windmove-right)
    (error (condition-case nil (windmove-left)
         (error (condition-case nil (windmove-up) (error (condition-case nil (windmove-down) (error (windmove-right))))))))))

(defun windmove-left-cycle()
  (interactive)
  (condition-case nil (windmove-left)
    (error (condition-case nil (windmove-right)
         (error (condition-case nil (windmove-down) (error (condition-case nil (windmove-up) (error (windmove-left))))))))))

(global-set-key (kbd "C-x <up>") 'windmove-up-cycle)
(global-set-key (kbd "C-x <down>") 'windmove-down-cycle)
(global-set-key (kbd "C-x <right>") 'windmove-right-cycle)
(global-set-key (kbd "C-x <left>") 'windmove-left-cycle)