🚀 go-pugleaf

There is a feature of GNU Emacs, enabled by default, which makes a
very convenient vehicle for Trojan horses.  The facility is described
in the 'file variables' section of the info tree, and lets you execute
any Emacs Lisp code when a file is loaded into a buffer.  As a benign
example, the following code, which I found the end of file written by
a Scheme application, will format the file, destroy itself, and save
the file, all when you first open the file:

;;; Local Variables:
;;; mode: scheme
;;; eval: (save-excursion (goto-char (point-min)) (kill-line 3))
;;; eval: (save-excursion (goto-char (point-min)) (replace-regexp "[ \n]*)" ")")
)
;;; eval: (indent-region (point-min) (point-max) nil)
;;; eval: (progn (kill-line -3) (delete-backward-char 1) (save-buffer))
;;; End:

Given Emacs' capability to start processes, write files, etc., a
Trojan horse using this feature can obviously be used to do great
damage to people who have the habit of using Emacs as a file browser.

Shouldn't this feature be protected in some way, e.g., by asking the
user permission to execute such code (if it is more than just setting
a major mode)?

--Guido van Rossum, CWI, Amsterdam <guido@cwi.nl>
"He used to be a euphemism, now he's just a friend"