Re: yes I'm root but want 444 files found readonly

[Dan Jacobson <jidanni@dman.ddts.net>]

>> $ su
>> # chmod 0 file
>> # chmod 444 otherfile
>> # emacs file otherfile
>> and the files are found without the "%%" readonly in the mode line.
>> 
>> OK, I'm root with the royal blood.  But that doesn't mean I don't want
>> to enjoy the same protection against altering my files all over the
>> place just like the other guy.  Sure wish there was an option in emacs
>> that would respect the hints from the file modes even if I'm root.  Or
>> what, do you expect me to do C-x C-q on each file?  Unfair.
>> 
>> Yes, for my mode 0 file the option could have a third etc. choice, not
>> only find-readonly, but also ask the user if he really wants to see it
>> etc.

>>>>> "J" == Jeff Sheinberg <jeffsh@erols.com> writes:

J> See below for a sample implementation.  IMO, there is no need for
J> prompting, since %% shows in the mode line, and C-x C-q will easily
J> toggle read-only off.

OK, hope the FSF folks implement something.

>> Also there's the case of 444 but not owned by root.  Here also I would
>> find-readonly. 

J> My version of Emacs (GNU Emacs 21.2.1) already finds files with
J> mode 444 read-only, just like versions 18, 19, and 20 did.

# ls -l index_en.html 
-r--r--r--    1 jidanni  jidanni      4018  6月 27 04:19 index_en.html
# emacs -q -nw index_en.html
[And I am free to go wreck the file any way I feel fit to, with not
the slightest beep to hold me back.  I feel nothing different than if
it were 666, 000, etc.]  [No I didn't try writing it, I just started
to type chars into its buffer and nothing about being read only was
mentioned.]
[Jeff's file:]
;;----------------------------------------------------------------------
;; Put buffer in read-only mode if there are no write bits set in the
;; file's mode.  This can occur when uid=0 edits a non-writable file.

(defun my-set-read-only-if-no-writeable-mode-bits ()
"This function is used to warn the super-user that the current buffer
has been set read-only because none of the file's write mode bits
are set."
(interactive)
(let* ((file (buffer-file-name))
(mode (file-modes file)))
(if mode
(progn
(if (and (not buffer-read-only)
(file-writable-p file)
(= (logand mode 146) 0)) ; 146 decimal is 222 octal.
(progn
(setq buffer-read-only t)
(ding)
(message "File's mode is %o, buffer set read-only, use `toggle-read-only' wisely!" mode))))))) 

(add-hook 'find-file-hooks 'my-set-read-only-if-no-writeable-mode-bits)

;; Put all buffers in `/usr/share/*' hierarchy in read-only mode.
(defun my-set-read-only-usr-share-files ()
"This function is used to warn the user that the current buffer has
been set read-only because the file being visited is in the
`/usr/share/*' hierarchy."
(interactive)
(let* ((dir "/usr/share/")
(len (- (length dir) 1)))
(if (and (not buffer-read-only)
(stringp buffer-file-truename)
(file-writable-p buffer-file-truename)
(fboundp 'compare-strings) ; keep emacs-19 happy
(eq t
(compare-strings dir 0 len buffer-file-truename 0 len)))
(progn
(setq buffer-read-only t)
(ding)
(message "Buffer %s set read-only, use `toggle-read-only' wisely!" (buffer-name))))))

(add-hook 'find-file-hooks 'my-set-read-only-usr-share-files)
;;----------------------------------------------------------------------
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