Index: lisp/files.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/files.el,v
retrieving revision 1.927
diff -c -B -w -r1.927 files.el
*** lisp/files.el	31 Aug 2007 13:29:34 -0000	1.927
--- lisp/files.el	9 Sep 2007 20:42:43 -0000
***************
*** 5407,5412 ****
--- 5407,5503 ----
  	  (t
  	   (apply operation arguments)))))
  
+ 
+ ;; Symbolic modes and read-file-modes.
+ 
+ (defun char-to-who (char)
+   "Convert CHAR to a who-mask from a symbolic mode notation.
+ CHAR is in [ugoa] and represents the users on which rights are applied."
+   (cond ((= char ?u) #o4700)
+ 	((= char ?g) #o2070)
+ 	((= char ?o) #o1007)
+ 	((= char ?a) #o7777)
+ 	(t (error "%c: bad `who' character" char))))
+ 
+ (defun char-to-right (char &optional from)
+   "Convert CHAR to a right-mask from a symbolic mode notation.
+ CHAR is in [rwxXstugo] and represents a right.
+ If CHAR is in [Xugo], the value is extracted from FROM (or 0 if nil)."
+   (or from (setq from 0))
+   (cond ((= char ?r) #o0444)
+ 	((= char ?w) #o0222)
+ 	((= char ?x) #o0111)
+ 	((= char ?s) #o1000)
+ 	((= char ?t) #o6000)
+ 	;; Rights relative to the previous file modes.
+ 	((= char ?X) (if (= (logand from #o111) 0) 0 #o0111))
+ 	((= char ?u) (let ((uright (logand #o4700 from)))
+ 		       (+ uright (/ uright #o10) (/ uright #o100))))
+ 	((= char ?g) (let ((gright (logand #o2070 from)))
+ 		       (+ gright (/ gright #o10) (* gright #o10))))
+ 	((= char ?o) (let ((oright (logand #o1007 from)))
+ 		       (+ oright (* oright #o10) (* oright #o100))))
+ 	(t (error "%c: bad right character" char))))
+ 
+ (defun right-string-to-number (rights who-mask &optional from)
+   "Convert a right string to a right-mask from a symbolic modes notation.
+ RIGHTS is the right string, it should match \"([+=-][rwxXstugo]+)+\".
+ WHO-MASK is the mask number of the users on which the rights are to be applied.
+ FROM (or 0 if nil) is the orginal modes of the file to be chmod'ed."
+   (let* ((num-rights (or from 0))
+ 	 (list-rights (string-to-list rights))
+ 	 (op (pop list-rights)))
+     (while (memq op '(?+ ?- ?=))
+       (let ((num-right 0)
+ 	    char-right)
+ 	(while (memq (setq char-right (pop list-rights))
+ 		     '(?r ?w ?x ?X ?s ?t ?u ?g ?o))
+ 	  (setq num-right
+ 		(logior num-right (char-to-right char-right num-rights))))
+ 	(setq num-right (logand who-mask num-right)
+ 	      num-rights
+ 	      (cond ((= op ?+) (logior num-rights num-right))
+ 		    ((= op ?-) (logand num-rights (lognot num-right)))
+ 		    (t (logior (logand num-rights (lognot who-mask)) num-right)))
+ 	      op char-right)))
+     num-rights))
+ 
+ (defun symbolic-file-modes-to-number (modes &optional from)
+   "Convert symbolic file modes to numeric file modes.
+ MODES is the string to convert, it should match
+ \"[ugoa]*([+-=][rwxXstugo]+)+,...\".
+ See (info \"(coreutils)File permissions\") for more information on this
+ notation.
+ FROM (or 0 if nil) is the orginal modes of the file to be chmod'ed."
+   (save-match-data
+     (let ((case-fold-search nil)
+ 	  (num-modes (or from 0)))
+       (while (/= (string-to-char modes) 0)
+ 	(if (string-match "^\\([ugoa]*\\)\\([+=-][rwxXstugo]+\\)+\\(,\\|\\)" modes)
+ 	    (let ((num-who (apply 'logior 0
+ 				  (mapcar 'char-to-who (match-string 1 modes)))))
+ 	      (when (= num-who 0)
+ 		(setq num-who (default-file-modes)))
+ 	      (setq num-modes
+ 		    (right-string-to-number (substring modes (match-end 1))
+ 					    num-who num-modes)
+ 		    modes (substring modes (match-end 3))))
+ 	  (error "Parse error in modes near %s" (substring modes 0))))
+       num-modes)))
+ 
+ (defun read-file-modes (&optional prompt orig-file)
+   "Read file modes in octal or symbolic notation.
+ PROMPT is used as the prompt, default to `File modes (octal or symbolic): '.
+ ORIG-FILE is the original file of which modes will be change."
+   (let* ((modes (or (if orig-file (file-modes orig-file) 0)
+ 		    (error "File not found")))
+ 	 (value (read-string (or prompt "File modes (octal or symbolic): "))))
+     (save-match-data
+       (if (string-match "^[0-7]+" value)
+ 	  (string-to-number value 8)
+ 	(symbolic-file-modes-to-number value modes)))))
+ 
+ 
  (define-key ctl-x-map "\C-f" 'find-file)
  (define-key ctl-x-map "\C-r" 'find-file-read-only)
  (define-key ctl-x-map "\C-v" 'find-alternate-file)
Index: src/fileio.c
===================================================================
RCS file: /sources/emacs/emacs/src/fileio.c,v
retrieving revision 1.590
diff -c -B -w -r1.590 fileio.c
*** src/fileio.c	29 Aug 2007 05:27:58 -0000	1.590
--- src/fileio.c	9 Sep 2007 20:42:46 -0000
***************
*** 3435,3441 ****
    return make_number (st.st_mode & 07777);
  }
  
! DEFUN ("set-file-modes", Fset_file_modes, Sset_file_modes, 2, 2, 0,
         doc: /* Set mode bits of file named FILENAME to MODE (an integer).
  Only the 12 low bits of MODE are used.  */)
    (filename, mode)
--- 3435,3443 ----
    return make_number (st.st_mode & 07777);
  }
  
! DEFUN ("set-file-modes", Fset_file_modes, Sset_file_modes, 2, 2,
!        "(let ((file (read-file-name \"File: \")))			\
! 	  (list file (read-file-modes nil file)))",
         doc: /* Set mode bits of file named FILENAME to MODE (an integer).
  Only the 12 low bits of MODE are used.  */)
    (filename, mode)