emacs - 如何使用emacs/elisp获取当前缓冲区信息的开始/结束？

我有以下代码运行figlet，其输入范围为。
如何修改此代码以检查是否未指定b或e，将b设置为当前缓冲区的开始，而e为当前缓冲区的结束？

(defun figlet-region (&optional b e)
  (interactive "r")
  (shell-command-on-region b e "/opt/local/bin/figlet" (current-buffer) t)
  (comment-region (mark) (point)))
(global-set-key (kbd "C-c C-x") 'figlet-region)

添加

肖恩(Sean)帮助我得到了这个问题的答案

(defun figlet-region (&optional b e)
  (interactive)
  (let ((b (if mark-active (min (point) (mark)) (point-min)))
        (e (if mark-active (max (point) (mark)) (point-max))))
   (shell-command-on-region b e "/opt/local/bin/figlet" (current-buffer) t)
  (comment-region (mark) (point))))
(global-set-key (kbd "C-c C-x") 'figlet-region)

最佳答案

像这样:

(defun figlet-region (&optional b e)
  (interactive "r")
  (shell-command-on-region
   (or b (point-min))
   (or e (point-max))
   "/opt/local/bin/figlet" (current-buffer) t)
  (comment-region (mark) (point)))

但是请注意，以交互方式运行此命令时，将始终设置b和e。

您也可以这样做:

(require 'cl)

(defun* figlet-region (&optional (b (point-min)) (e (point-max)))
  # your original function body here
    )

编辑:

因此，我想您的意思是即使该区域处于非 Activity 状态，您也希望能够以交互方式运行该命令？然后，这可能会为您工作:

(defun figlet-region ()
  (interactive)
  (let ((b (if mark-active (min (point) (mark)) (point-min)))
        (e (if mark-active (max (point) (mark)) (point-max))))
    # ... rest of your original function body ...
      ))

关于emacs - 如何使用emacs/elisp获取当前缓冲区信息的开始/结束？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/3569501/