mel-q.el

   1 ;;;
   2 ;;; $Id: mel-q.el,v 3.0 1995/11/02 03:48:01 morioka Exp $
   3 ;;;
   4
   5 ;;; @ constants
   6 ;;;
   7
   8 (defconst quoted-printable-hex-chars "0123456789ABCDEF")
   9 (defconst quoted-printable-octet-regexp
  10   (concat "=[" quoted-printable-hex-chars
  11           "][" quoted-printable-hex-chars "]"))
  12
  13
  14 ;;; @ variables
  15 ;;;
  16
  17 (defvar quoted-printable-external-encoder '("mmencode" "-q")
  18   "*list of quoted-printable encoder program name and its arguments.")
  19
  20 (defvar quoted-printable-external-decoder '("mmencode" "-q" "-u")
  21   "*list of quoted-printable decoder program name and its arguments.")
  22
  23 (defvar quoted-printable-internal-encoding-limit 10000
  24   "*limit size to use internal quoted-printable encoder.
  25 If size of input to encode is larger than this limit,
  26 external encoder is called.")
  27
  28 (defvar quoted-printable-internal-decoding-limit nil
  29   "*limit size to use internal quoted-printable decoder.
  30 If size of input to decode is larger than this limit,
  31 external decoder is called.")
  32
  33
  34 ;;; @ Quoted-Printable (Q-encode) encoder/decoder
  35 ;;;
  36
  37 (defun quoted-printable-quote-char (chr)
  38   (concat "="
  39           (char-to-string (elt quoted-printable-hex-chars (ash chr -4)))
  40           (char-to-string (elt quoted-printable-hex-chars (logand chr 15)))
  41           ))
  42
  43
  44 ;;; @@ Quoted-Printable encode/decode string
  45 ;;;
  46
  47 (defun quoted-printable-encode-string (str)
  48   (let ((i 0))
  49     (mapconcat (function
  50                 (lambda (chr)
  51                   (cond ((eq chr ?\n)
  52                          (setq i 0)
  53                          "\n")
  54                         ((or (< chr 32) (< 126 chr) (eq chr ?=))
  55                          (if (>= i 73)
  56                              (progn
  57                                (setq i 3)
  58                                (concat "=\n" (quoted-printable-quote-char chr))
  59                                )
  60                            (progn
  61                              (setq i (+ i 3))
  62                              (quoted-printable-quote-char chr)
  63                              )))
  64                         (t (if (>= i 75)
  65                                (progn
  66                                  (setq i 1)
  67                                  (concat "=\n" (char-to-string chr))
  68                                  )
  69                              (progn
  70                                (setq i (1+ i))
  71                                (char-to-string chr)
  72                                )))
  73                         )))
  74                str "")))
  75
  76 (defun quoted-printable-decode-string (str)
  77   (let (q h l)
  78     (mapconcat (function
  79                 (lambda (chr)
  80                   (cond ((eq chr ?=)
  81                          (setq q t)
  82                          "")
  83                         (q (setq h
  84                                  (cond ((<= ?a chr) (+ (- chr ?a) 10))
  85                                        ((<= ?A chr) (+ (- chr ?A) 10))
  86                                        ((<= ?0 chr) (- chr ?0))
  87                                        ))
  88                            (setq q nil)
  89                            "")
  90                         (h (setq l (cond ((<= ?a chr) (+ (- chr ?a) 10))
  91                                          ((<= ?A chr) (+ (- chr ?A) 10))
  92                                          ((<= ?0 chr) (- chr ?0))
  93                                          ))
  94                            (prog1
  95                                (char-to-string (logior (ash h 4) l))
  96                              (setq h nil)
  97                              )
  98                            )
  99                         (t (char-to-string chr))
 100                         )))
 101                str "")))
 102
 103
 104 ;;; @@ Quoted-Printable encode/decode region
 105 ;;;
 106
 107 (defun quoted-printable-internal-encode-region (beg end)
 108   (save-excursion
 109     (save-restriction
 110       (narrow-to-region beg end)
 111       (let ((str (buffer-substring beg end)))
 112         (delete-region beg end)
 113         (insert (quoted-printable-encode-string str))
 114         )
 115       (or (bolp)
 116           (insert "=\n")
 117           )
 118       )))
 119
 120 (defun quoted-printable-internal-decode-region (beg end)
 121   (save-excursion
 122     (save-restriction
 123       (narrow-to-region beg end)
 124       (goto-char (point-min))
 125       (while (re-search-forward "=\n" nil t)
 126         (replace-match "")
 127         )
 128       (goto-char (point-min))
 129       (let (b e str)
 130         (while (re-search-forward quoted-printable-octet-regexp nil t)
 131           (setq b (match-beginning 0))
 132           (setq e (match-end 0))
 133           (setq str (buffer-substring b e))
 134           (delete-region b e)
 135           (insert (quoted-printable-decode-string str))
 136           ))
 137       )))
 138
 139 (cond ((boundp 'MULE)
 140        (define-program-coding-system
 141          nil (car quoted-printable-external-encoder) *noconv*)
 142        (define-program-coding-system
 143          nil (car quoted-printable-external-decoder) *noconv*)
 144        )
 145       ((boundp 'NEMACS)
 146        (define-program-kanji-code
 147          nil (car quoted-printable-external-encoder) 0)
 148        (define-program-kanji-code
 149          nil (car quoted-printable-external-decoder) 0)
 150        ))
 151
 152 (defun quoted-printable-external-encode-region (beg end)
 153   (save-excursion
 154     (save-restriction
 155       (narrow-to-region beg end)
 156       (let ((selective-display nil) ;Disable ^M to nl translation.
 157             (mc-flag nil)      ;Mule
 158             (kanji-flag nil))  ;NEmacs
 159         (apply (function call-process-region)
 160                beg end (car quoted-printable-external-encoder)
 161                t t nil (cdr quoted-printable-external-encoder))
 162         )
 163       ;; for OS/2
 164       ;;   regularize line break code
 165       (goto-char (point-min))
 166       (while (re-search-forward "\r$" nil t)
 167         (replace-match "")
 168         )
 169       )))
 170
 171 (defun quoted-printable-external-decode-region (beg end)
 172   (save-excursion
 173     (let ((selective-display nil) ;Disable ^M to nl translation.
 174           (mc-flag nil)      ;Mule
 175           (kanji-flag nil))  ;NEmacs
 176       (apply (function call-process-region)
 177              beg end (car quoted-printable-external-decoder)
 178              t t nil (cdr quoted-printable-external-decoder))
 179       )))
 180
 181 (defun quoted-printable-encode-region (beg end)
 182   (interactive "r")
 183   (if (and quoted-printable-internal-encoding-limit
 184            (> (- end beg) quoted-printable-internal-encoding-limit))
 185       (quoted-printable-external-encode-region beg end)
 186     (quoted-printable-internal-encode-region beg end)
 187     ))
 188
 189 (defun quoted-printable-decode-region (beg end)
 190   (interactive "r")
 191   (if (and quoted-printable-internal-decoding-limit
 192            (> (- end beg) quoted-printable-internal-decoding-limit))
 193       (quoted-printable-external-decode-region beg end)
 194     (quoted-printable-internal-decode-region beg end)
 195     ))
 196
 197
 198 ;;; @ Q-encoding encode/decode string
 199 ;;;
 200
 201 (defun q-encoding-encode-string-for-text (str)
 202   (mapconcat (function
 203               (lambda (chr)
 204                 (cond ((eq chr 32) "_")
 205                       ((or (< chr 32) (< 126 chr) (eq chr ?=))
 206                        (quoted-printable-quote-char chr)
 207                        )
 208                       (t (char-to-string chr))
 209                       )))
 210              str ""))
 211
 212 (defun q-encoding-encode-string-for-comment (str)
 213   (mapconcat (function
 214               (lambda (chr)
 215                 (cond ((eq chr 32) "_")
 216                       ((or (< chr 32) (< 126 chr)
 217                            (memq chr '(?= ?\( ?\) ?\\))
 218                            )
 219                        (quoted-printable-quote-char chr)
 220                        )
 221                       (t (char-to-string chr))
 222                       )))
 223              str ""))
 224
 225 (defun q-encoding-encode-string-for-phrase (str)
 226   (mapconcat (function
 227               (lambda (chr)
 228                 (cond ((eq chr 32) "_")
 229                       ((or (and (<= ?A chr)(<= chr ?Z))
 230                            (and (<= ?a chr)(<= chr ?z))
 231                            (and (<= ?0 chr)(<= chr ?9))
 232                            (memq chr '(?! ?* ?+ ?- ?/))
 233                            )
 234                        (char-to-string chr)
 235                        )
 236                       (t (quoted-printable-quote-char chr))
 237                       )))
 238              str ""))
 239
 240 (defun q-encoding-encode-string (str &optional mode)
 241   (cond ((eq mode 'text)
 242          (q-encoding-encode-string-for-text str)
 243          )
 244         ((eq mode 'comment)
 245          (q-encoding-encode-string-for-comment str)
 246          )
 247         (t
 248          (q-encoding-encode-string-for-phrase str)
 249          )))
 250
 251 (defun q-encoding-decode-string (str)
 252   (let (q h l)
 253     (mapconcat (function
 254                 (lambda (chr)
 255                   (cond ((eq chr ?_) " ")
 256                         ((eq chr ?=)
 257                          (setq q t)
 258                          "")
 259                         (q (setq h (cond ((<= ?a chr) (+ (- chr ?a) 10))
 260                                          ((<= ?A chr) (+ (- chr ?A) 10))
 261                                          ((<= ?0 chr) (- chr ?0))
 262                                          ))
 263                            (setq q nil)
 264                            "")
 265                         (h (setq l (cond ((<= ?a chr) (+ (- chr ?a) 10))
 266                                          ((<= ?A chr) (+ (- chr ?A) 10))
 267                                          ((<= ?0 chr) (- chr ?0))
 268                                          ))
 269                            (prog1
 270                                (char-to-string (logior (ash h 4) l))
 271                              (setq h nil)
 272                              )
 273                            )
 274                         (t (char-to-string chr))
 275                         )))
 276                str "")))
 277
 278
 279 ;;; @@ etc
 280 ;;;
 281
 282 (defun q-encoding-encoded-length (string &optional mode)
 283   (let ((l 0)(i 0)(len (length string)) chr)
 284     (while (< i len)
 285       (setq chr (elt string i))
 286       (if (string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))
 287           (setq l (+ l 1))
 288         (setq l (+ l 3))
 289         )
 290       (setq i (+ i 1)) )
 291     l))
 292
 293
 294 ;;; @ end
 295 ;;;
 296
 297 (provide 'mel-q)