CODEWITHSUNDEEP
emacs
Alan
Alan

Reputation: 2178

emacs: calling chmod causes "file is no longer readable" warning

I'm writing a function designed to make whatever file is in the current buffer writable without being prompted for its name or for the mode (which I always want to be 644). I also want the buffer to be refreshed automatically to reflect the fact that its contents are now writable.

I have the following code in my .emacs file:

;; from http://www.stokebloke.com/wordpress/2008/04/17/emacs-refresh-f5-key/
(defun refresh-file ()
  "Refresh the buffer from the disk (prompt if modified)."
  (interactive)
  (revert-buffer t (not (buffer-modified-p)) t))

(defun my-make-writable ()
   "make file writable to owner"
   (interactive)
   (chmod buffer-file-name 644)
   (refresh-file))

However, when I execute the function, emacs displays the following error message in the minibuffer:

File filename no longer readable

This is rather unnerving. However, I can still execute a "chmod" command to make the file readable and writable.

What can I do to make my function work correctly?

Upvotes: 0

Views: 94

Answers (1)

Vatine
Vatine

Reputation: 21258

The unix permission bits are expressed in octal and you are feeding in a decimal number.

You are setting the file mode to 1204 (that is, "sticky-bit, user can write, group has no permissions, everyone else can read). If you use (chmod buffer-file-name #o644) or (chmod buffer-file-name 420) you will probably get the result you are expecting.

Upvotes: 4

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