(defun get-file-from-buffer-other-window ()
  "Load a file into another window referenced by the string on the current line"
  (interactive)

  ;; get the filename and lineno
  (setq vals (get-fileline))
  (print vals)

  ;; load the filename into the next window and goto linenumber
  (switch-to-buffer-other-window (find-file-noselect (nth 0 vals)))
  (goto-line (nth 1 vals))
)

(defun display-on-side (buffer &optional not-this-window frame)
  (let* ((window (or (minibuffer-selected-window)
                     (selected-window)))
         (display-buffer-function nil)
         (pop-up-windows nil))
    (with-selected-window (or window (error "display-on-side"))
      (when (one-window-p t)
        (split-window-horizontally))
      (display-buffer buffer not-this-window frame))))

(setq display-buffer-function 'display-on-side)

;; unit test, should open in the same side window.
(display-buffer (get-buffer-create "*foo*"))
(display-buffer (get-buffer-create "*bar*"))