如何让Emacs自动写入只读文件?

向添加呼叫 chmod 在里面 before-save-hook 这将是实现这一目标的干净方法。没有任何设置可以更改以避免权限检查。

根据后续问题,听起来您希望文件在打开时自动更改为可写。这段代码的作用是:

(defun change-file-permissions-to-writable ()
  "to be run from find-file-hook, change write permissions"
  (when (not (file-writable-p buffer-file-name))
    (chmod buffer-file-name (file-modes-symbolic-to-number "u+w" (nth 8 (file-attributes buffer-file-name))))
    (if (not (file-writable-p buffer-file-name))
        (message "Unable to make file writable."))))

(add-hook 'find-file-hook 'change-file-permissions-to-writable)

注意:当我在我的Windows机器上测试它时,文件权限直到我尝试保存缓冲区时才出现,但它按预期工作。我个人对这个定制感到不安,但这是你的emacs。:)

我同意Trey的观点,即在写时普遍使用chmod是有风险的——只读文件出于某种原因是只读的,imho。这里有一种方法可以在每个缓冲区的基础上具体地重写内容。它不太理想,因为它覆盖了 file-writable-p 在缓冲区的使用寿命内(或者至少在切换之前 my-override-mode-on-save 回到nil),但是它让你在一个文件一个文件的基础上做出一个有意识的决定(有点;它实际上是一个缓冲区一个缓冲区的基础,这是相当相似的)。当然,由于您希望在访问文件时自动切换只读标志,因此您可能对这种区别不感兴趣。尽管如此,它还是在这里;尽情享受它,或者随意忽略它。

(make-variable-buffer-local
 (defvar my-override-mode-on-save nil
   "Can be set to automatically ignore read-only mode of a file when saving."))

(defadvice file-writable-p (around my-overide-file-writeable-p act)
  "override file-writable-p if `my-override-mode-on-save' is set."
  (setq ad-return-value (or
                         my-override-mode-on-save
                         ad-do-it)))

(defun my-override-toggle-read-only ()
  "Toggle buffer's read-only status, keeping `my-override-mode-on-save' in sync."
  (interactive)
  (setq my-override-mode-on-save (not my-override-mode-on-save))
  (toggle-read-only))

P.S.感谢Trey ad-return-value 中的指针 other SO question .

因为我发现经常提醒我要编辑一个我没有权限的文件很有用,所以当我在缓冲区中打开一个文件时,我想强迫自己主动地使缓冲区可写。 C-x q . 然而,用手打开它却很乏味,所以我建议 save-buffer 如果密码无法写入,则提示我输入密码。我完全建议你把这段话写进 .emacs

(defadvice save-buffer (around save-buffer-as-root-around activate)
  "Use sudo to save the current buffer."
  (interactive "p")
  (if (and (buffer-file-name) (not (file-writable-p (buffer-file-name))))
      (let ((buffer-file-name (format "/sudo::%s" buffer-file-name)))
    ad-do-it)
    ad-do-it))

因为某种原因,我不能确定特雷·杰克逊 solution 无法在Windows下的GNU Emacs 25.2上工作: file-modes-rights-to-number 打电话来 文件模式对数字的权限 失败。 如果有人遇到同样的问题,他可以使用一个不那么优雅但有效的解决方案来替换块:

(chmod buffer-file-name (file-modes-symbolic-to-number "u+w" (nth 8 (file-attributes buffer-file-name))))

用块:

(cond ((or (eq system-type 'ms-dos) (eq system-type 'windows-nt))
              (progn
                (shell-command-to-string (concat "attrib -R " (buffer-file-name (current-buffer))))
                (message "Setting file and buffer to writeable (%s style)" system-type)
              ))
           ((eq system-type 'gnu/linux)
              (progn
              (shell-command-to-string (concat "chmod u+w " (buffer-file-name (current-buffer))))
              (message "Setting file and buffer to writeable (%s style)" system-type)
             ))
           (t (message "file permission change not handle for OS %s" system-type))               
)