Re: ISO-8859-1 encoded file names and UTF-8

[Kenichi Handa <handa@m17n.org>]

In article <E18xXbY-0005rn-00@fencepost.gnu.org>, Richard Stallman <rms@gnu.org> writes:
>     So, I wanted to hear other people's opinions about which is
>     better; enhancing the existing rename-file directly (perhaps
>     by making use of the prefix argument), or making a new
>     command recode-file-name.

> It should be a new command.

I've just installed the attached change.

---
Ken'ichi HANDA
handa@m17n.org
2003-03-26  Kenichi Handa  <handa@etlken2>

	* files.el (recode-file-name): New function.

Index: files.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/files.el,v
retrieving revision 1.643
retrieving revision 1.644
diff -u -c -r1.643 -r1.644
cvs server: conflicting specifications of output style
*** files.el	14 Mar 2003 22:36:57 -0000	1.643
--- files.el	26 Mar 2003 04:42:29 -0000	1.644
***************
*** 766,771 ****
--- 766,823 ----
  	(setq newname (expand-file-name tem (file-name-directory newname)))
  	(setq count (1- count))))
      newname))
+ 
+ (defun recode-file-name (file coding new-coding &optional ok-if-already-exists)
+   "Change the encoding of FILE's name from CODING to NEW-CODING.
+ The value is a new name of FILE.
+ Signals a `file-already-exists' error if a file of the new name
+ already exists unless optional third argument OK-IF-ALREADY-EXISTS
+ is non-nil.  A number as third arg means request confirmation if
+ the new name already exists.  This is what happens in interactive
+ use with M-x."
+   (interactive
+    (let ((default-coding (or file-name-coding-system
+ 			     default-file-name-coding-system))
+ 	 (filename (read-file-name "Recode filename: " nil nil t))
+ 	 from-coding to-coding)
+      (if (and default-coding
+ 	      ;; We provide the default coding only when it seems that
+ 	      ;; the filename is correctly decoded by the default
+ 	      ;; coding.
+ 	      (let ((charsets (find-charset-string filename)))
+ 		(and (not (memq 'eight-bit-control charsets))
+ 		     (not (memq 'eight-bit-graphic charsets)))))
+ 	 (setq from-coding (read-coding-system
+ 			    (format "Recode filename %s from (default %s): "
+ 				    filename default-coding)
+ 			    default-coding))
+        (setq from-coding (read-coding-system
+ 			  (format "Recode filename %s from: " filename))))
+      
+      ;; We provide the default coding only when a user is going to
+      ;; change the encoding not from the default coding.
+      (if (eq from-coding default-coding)
+ 	 (setq to-coding (read-coding-system
+ 			  (format "Recode filename %s from %s to: "
+ 				  filename from-coding)))
+        (setq to-coding (read-coding-system
+ 			(format "Recode filename %s from %s to (default %s): "
+ 				filename from-coding default-coding)
+ 			default-coding)))
+      (list filename from-coding to-coding)))
+ 
+   (let* ((default-coding (or file-name-coding-system
+ 			     default-file-name-coding-system))
+ 	 ;; FILE should have been decoded by DEFAULT-CODING.
+ 	 (encoded (encode-coding-string file default-coding))
+ 	 (newname (decode-coding-string encoded coding))
+ 	 (new-encoded (encode-coding-string newname new-coding))
+ 	 ;; Suppress further encoding.
+ 	 (file-name-coding-system nil)
+ 	 (default-file-name-coding-system nil)
+ 	 (locale-coding-system nil))
+     (rename-file encoded new-encoded ok-if-already-exists)
+     newname))
  \f
  (defun switch-to-buffer-other-window (buffer &optional norecord)
    "Select buffer BUFFER in another window.
Index: NEWS
===================================================================
RCS file: /cvsroot/emacs/emacs/etc/NEWS,v
retrieving revision 1.799
retrieving revision 1.800
diff -u -c -r1.799 -r1.800
cvs server: conflicting specifications of output style
*** NEWS	8 Mar 2003 02:13:59 -0000	1.799
--- NEWS	26 Mar 2003 04:45:00 -0000	1.800
***************
*** 138,143 ****
--- 138,146 ----
  ** The new command `revert-buffer-with-coding-system' (C-x RET r)
  revisits the current file using a coding system that you specify.
  
+ ** The new command `recode-file-name' changes the encoding of the name
+ of a file.
+ 
  ---
  ** `ps-print' can now print characters from the mule-unicode charsets.