Function: utf-7-encode

utf-7-encode is a byte-compiled function defined in utf-7.el.gz.

Signature

(utf-7-encode FROM TO IMAP)

Documentation

Encode bytes between FROM and TO to UTF-7.

ESC and SKIP-CHARS are adjusted for the normal and IMAP versions.

Source Code

;; Defined in /usr/src/emacs/lisp/international/utf-7.el.gz
(defun utf-7-encode (from to imap)
  "Encode bytes between FROM and TO to UTF-7.
ESC and SKIP-CHARS are adjusted for the normal and IMAP versions."
  (let* ((old-buf (current-buffer))
	 (esc (if imap ?& ?+))
	 ;; These are characters which can be encoded asis.
	 (skip-chars (if imap
			 "\t\n\r\x20-\x25\x27-\x7e" ; rfc2060
		       ;; This includes the rfc2152 optional set.
		       ;; Perhaps it shouldn't (like iconv).
		       "\t\n\r -*,-[]-}"))
	 (not-skip-chars (format "^%s%c" skip-chars esc)))
    (set-buffer (generate-new-buffer " *temp*"))
    (if (stringp from)
	(insert from)
      (insert-buffer-substring old-buf from to))
    (goto-char (point-min))
    (while (not (eobp))
      (skip-chars-forward skip-chars)
      (if (eq esc (char-after))
	  (progn (forward-char)
		 (insert ?-))
	(unless (eobp)
	  (insert esc)
	  (let ((p (point)))
	    (skip-chars-forward not-skip-chars)
	    (save-restriction
	      ;; encode-coding-region doesn't preserve point
	      (narrow-to-region p (point))
	      (encode-coding-region p (point-max) 'utf-16be)
	      (base64-encode-region p (point-max))
	      (if imap
		  (subst-char-in-region p (point-max) ?/ ?,))
	      (goto-char p)
	      ;; As I read the RFC, this isn't correct, but it's
	      ;; consistent with iconv, at least regarding `='.
	      (skip-chars-forward "^= \t\n")
	      (delete-region (point) (point-max))))
          ;; RFC2060 stipulates that all names MUST end in US-ASCII (i.e.
          ;; a name that ends with a Unicode octet MUST end with a "-").
	  (if (or imap (not (eobp)))
	    (insert ?-)))))
    nil))