elisp中是否有类似fopen的函数

Question

我知道insert-file-contents惯用语：

(defun read-lines (filePath)
  (with-temp-buffer
    (insert-file-contents filePath)
    (split-string (buffer-string) "\n" t)))

但是，有一种更自然的方式来逐行读取文件而不一次读取整个文件吗？我正在寻找类似fopen / fread的功能。

Answer 1

我认为在emacs中处理文件的自然方法是将文件加载到缓冲区中，然后可以逐行处理它。还要看一下ergoemacs中的this answer in emacs stackexchange和this blog post

例如：

ELISP> (find-file "foo.txt")
#<buffer foo.txt>
ELISP> (goto-char 1)
1 (#o1, #x1, ?\C-a)
ELISP> (while (not (eobp))
  (print (current-line-contents))
  (forward-line 1))

为了不获取属性，您可以在此时使用Thing函数：

ELISP> (goto-char 1)
1 (#o1, #x1, ?\C-a)
ELISP> (while (not (eobp))
         (print (thing-at-point 'line t))
         (forward-line 1))

"line 1
"

"line 2
"

"line 3
"

"line 4
"

nil

如果您需要为speed reasons try使用临时缓冲区，请执行以下操作：

 (with-temp-buffer
         (insert-file-contents "./foo.txt")
         (while (not (eobp))
           (print (thing-at-point 'line t))
           (forward-line 1)))