如何檢查Emacs中是否存在當前緩衝區？

Question

我想編寫一個函數，該函數在給定緩衝區名稱已經存在的情況下會採取行動。例如：

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

是否elisp的有將檢查對類似我如何由一個緩衝的存在功能「緩衝-存在」功能呢？

感謝

Answer 1

從documentation：

 
(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

如果您想將其定義爲上述假想的功能，這個工程：

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

我使用它來自動關閉*scratch*緩衝區啓動時，所以我不必循環訪問我的緩衝區列表，如下所示：

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

Answer 3

這是我做過什麼：

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

此檢查的緩衝區劃傷。如果有這樣的事情，就殺了它。 如果不是，則什麼也不做。

Answer 4

不知道這個版本出現了謂詞，但是現在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.