如何检查Emacs中是否存在当前缓冲区？

Question

我想编写一个函数,如果已经存在一个给定缓冲区名称,它将采取行动.例如:

(if (buffer-exists "my-buffer-name")
    ; do something
 )

elisp是否有一个函数来检查是否存在类似于我的"缓冲存在"函数的缓冲区的存在？

谢谢

Answer 1

从文档:

(get-buffer name)

Return the buffer named name (a string).
If there is no live buffer named name, return nil.
name may also be a buffer; if so, the value is that buffer.

(get-buffer-create name)

Return the buffer named name, or create such a buffer and return it.
A new buffer is created if there is no live buffer named name.
If name starts with a space, the new buffer does not keep undo information.
If name is a buffer instead of a string, then it is the value returned.
The value is never nil.

Answer 2

这就是我做的:

(when (get-buffer "*scratch*")
  (kill-buffer "*scratch*"))

这将检查缓冲区划痕.如果有这样的事情,就杀掉它.如果没有,什么都不做.

Answer 3

不确定这个谓词出现的版本，但现在 Emacs 有buffer-live-p：

buffer-live-p is a built-in function in `buffer.c'.

(buffer-live-p OBJECT)

Return non-nil if OBJECT is a buffer which has not been killed.
Value is nil if OBJECT is not a buffer or if it has been killed.

Answer 4

如果你想定义你的假设函数如上，这有效：

(defun buffer-exists (bufname)   (not (eq nil (get-buffer bufname))))

我使用它*scratch*在启动时自动关闭缓冲区，因此我不必在我的缓冲区列表中循环它，如下所示：

(defun buffer-exists (bufname) (not (eq nil (get-buffer bufname))))
(if (buffer-exists "*scratch*")  (kill-buffer "*scratch*"))