; run perl on the current region, updating the region
(defun perl-replace-region (start end)     
  "Apply perl command to region"
  (interactive "r")
  (shell-command-on-region start end 
                           (read-from-minibuffer "Replace region command: " '("perl -pe \"\"" . 11 ))
                           t
                           t
                           )
  (exchange-point-and-mark)
  )

; run perl on the current buffer, updating the buffer
(defun perl-replace-buffer ()    
  "Apply perl command to buffer"
  (interactive)
  (let ((ptline (count-lines (point-min) (point)))
        (ptcol (current-column))
        (markline 0)
        (markcol  0)
        (command (read-from-minibuffer "Replace buffer command: " '("perl -pe \"\"" . 11 ))))
    (exchange-point-and-mark)
    (setq markline (count-lines (point-min) (point)))
    (setq markcol  (current-column))
    (mark-whole-buffer)
    (let ((new-start (region-beginning))
          (new-end   (region-end)))
      (shell-command-on-region  new-start new-end command t t )
      )
    (goto-line markline)
    (move-to-column markcol)
    (exchange-point-and-mark)
    (goto-line ptline)
    (move-to-column ptcol)
    )
  )