mel-q.el

   1 ;;;
   2 ;;; $Id: mel-q.el,v 1.8 1995/08/27 19:29:17 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 ((or (< chr 32) (< 126 chr) (eq chr ?=))
  52                          (if (>= i 73)
  53                              (progn
  54                                (setq i 0)
  55                                (concat "=\n" (quoted-printable-quote-char chr))
  56                                )
  57                            (progn
  58                              (setq i (+ i 3))
  59                              (quoted-printable-quote-char chr)
  60                              )))
  61                         (t (if (>= i 75)
  62                                (progn
  63                                  (setq i 0)
  64                                  (concat "=\n" (char-to-string chr))
  65                                  )
  66                              (progn
  67                                (setq i (1+ i))
  68                                (char-to-string chr)
  69                                )))
  70                         )))
  71                str "")))
  72
  73 (defun quoted-printable-decode-string (str)
  74   (let (q h l)
  75     (mapconcat (function
  76                 (lambda (chr)
  77                   (cond ((eq chr ?=)
  78                          (setq q t)
  79                          "")
  80                         (q (setq h
  81                                  (cond ((<= ?a chr) (+ (- chr ?a) 10))
  82                                        ((<= ?A chr) (+ (- chr ?A) 10))
  83                                        ((<= ?0 chr) (- chr ?0))
  84                                        ))
  85                            (setq q nil)
  86                            "")
  87                         (h (setq l (cond ((<= ?a chr) (+ (- chr ?a) 10))
  88                                          ((<= ?A chr) (+ (- chr ?A) 10))
  89                                          ((<= ?0 chr) (- chr ?0))
  90                                          ))
  91                            (prog1
  92                                (char-to-string (logior (ash h 4) l))
  93                              (setq h nil)
  94                              )
  95                            )
  96                         (t (char-to-string chr))
  97                         )))
  98                str "")))
  99
 100
 101 ;;; @@ Quoted-Printable encode/decode region
 102 ;;;
 103
 104 (defun quoted-printable-internal-encode-region (beg end)
 105   (save-excursion
 106     (save-restriction
 107       (narrow-to-region beg end)
 108       (goto-char (point-min))
 109       (while (re-search-forward "^.*$" nil t)
 110         (replace-match
 111          (quoted-printable-encode-string
 112           (buffer-substring (match-beginning 0)(match-end 0))
 113           ))
 114         ))))
 115
 116 (defun quoted-printable-internal-decode-region (beg end)
 117   (save-excursion
 118     (save-restriction
 119       (narrow-to-region beg end)
 120       (goto-char (point-min))
 121       (while (re-search-forward "=\n" nil t)
 122         (replace-match "")
 123         )
 124       (goto-char (point-min))
 125       (let (b e str)
 126         (while (re-search-forward quoted-printable-octet-regexp nil t)
 127           (setq b (match-beginning 0))
 128           (setq e (match-end 0))
 129           (setq str (buffer-substring b e))
 130           (delete-region b e)
 131           (insert (quoted-printable-decode-string str))
 132           ))
 133       )))
 134
 135 (cond ((boundp 'MULE)
 136        (define-program-coding-system
 137          nil (car quoted-printable-external-encoder) *noconv*)
 138        (define-program-coding-system
 139          nil (car quoted-printable-external-decoder) *noconv*)
 140        )
 141       ((boundp 'NEMACS)
 142        (define-program-kanji-code
 143          nil (car quoted-printable-external-encoder) 0)
 144        (define-program-kanji-code
 145          nil (car quoted-printable-external-decoder) 0)
 146        ))
 147
 148 (defun quoted-printable-external-encode-region (beg end)
 149   (save-excursion
 150     (apply (function call-process-region)
 151            beg end (car quoted-printable-external-encoder)
 152            t t nil (cdr quoted-printable-external-encoder))
 153     ))
 154
 155 (defun quoted-printable-external-decode-region (beg end)
 156   (save-excursion
 157     (apply (function call-process-region)
 158            beg end (car quoted-printable-external-decoder)
 159            t t nil (cdr quoted-printable-external-decoder))
 160     ))
 161
 162 (defun quoted-printable-encode-region (beg end)
 163   (interactive "r")
 164   (if (and quoted-printable-internal-encoding-limit
 165            (> (- end beg) quoted-printable-internal-encoding-limit))
 166       (quoted-printable-external-encode-region beg end)
 167     (quoted-printable-internal-encode-region beg end)
 168     ))
 169
 170 (defun quoted-printable-decode-region (beg end)
 171   (interactive "r")
 172   (if (and quoted-printable-internal-decoding-limit
 173            (> (- end beg) quoted-printable-internal-decoding-limit))
 174       (quoted-printable-external-decode-region beg end)
 175     (quoted-printable-internal-decode-region beg end)
 176     ))
 177
 178
 179 ;;; @ Q-encoding encode/decode string
 180 ;;;
 181
 182 (defun q-encoding-encode-string-for-text (str)
 183   (mapconcat (function
 184               (lambda (chr)
 185                 (cond ((eq chr 32) "_")
 186                       ((or (< chr 32) (< 126 chr) (eq chr ?=))
 187                        (quoted-printable-quote-char chr)
 188                        )
 189                       (t (char-to-string chr))
 190                       )))
 191              str ""))
 192
 193 (defun q-encoding-encode-string-for-comment (str)
 194   (mapconcat (function
 195               (lambda (chr)
 196                 (cond ((eq chr 32) "_")
 197                       ((or (< chr 32) (< 126 chr)
 198                            (memq chr '(?= ?\( ?\) ?\\))
 199                            )
 200                        (quoted-printable-quote-char chr)
 201                        )
 202                       (t (char-to-string chr))
 203                       )))
 204              str ""))
 205
 206 (defun q-encoding-encode-string-for-phrase (str)
 207   (mapconcat (function
 208               (lambda (chr)
 209                 (cond ((eq chr 32) "_")
 210                       ((or (and (<= ?A chr)(<= chr ?Z))
 211                            (and (<= ?a chr)(<= chr ?z))
 212                            (and (<= ?0 chr)(<= chr ?9))
 213                            (memq chr '(?! ?* ?+ ?- ?/))
 214                            )
 215                        (char-to-string chr)
 216                        )
 217                       (t (quoted-printable-quote-char chr))
 218                       )))
 219              str ""))
 220
 221 (defun q-encoding-encode-string (str &optional mode)
 222   (cond ((eq mode 'text)
 223          (q-encoding-encode-string-for-text str)
 224          )
 225         ((eq mode 'comment)
 226          (q-encoding-encode-string-for-comment str)
 227          )
 228         (t
 229          (q-encoding-encode-string-for-phrase str)
 230          )))
 231
 232 (defun q-encoding-decode-string (str)
 233   (let (q h l)
 234     (mapconcat (function
 235                 (lambda (chr)
 236                   (cond ((eq chr ?_) " ")
 237                         ((eq chr ?=)
 238                          (setq q t)
 239                          "")
 240                         (q (setq h (cond ((<= ?a chr) (+ (- chr ?a) 10))
 241                                          ((<= ?A chr) (+ (- chr ?A) 10))
 242                                          ((<= ?0 chr) (- chr ?0))
 243                                          ))
 244                            (setq q nil)
 245                            "")
 246                         (h (setq l (cond ((<= ?a chr) (+ (- chr ?a) 10))
 247                                          ((<= ?A chr) (+ (- chr ?A) 10))
 248                                          ((<= ?0 chr) (- chr ?0))
 249                                          ))
 250                            (prog1
 251                                (char-to-string (logior (ash h 4) l))
 252                              (setq h nil)
 253                              )
 254                            )
 255                         (t (char-to-string chr))
 256                         )))
 257                str "")))
 258
 259
 260 ;;; @@ etc
 261 ;;;
 262
 263 (defun q-encoding-encoded-length (string &optional mode)
 264   (let ((l 0)(i 0)(len (length string)) chr)
 265     (while (< i len)
 266       (setq chr (elt string i))
 267       (if (string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))
 268           (setq l (+ l 1))
 269         (setq l (+ l 3))
 270         )
 271       (setq i (+ i 1)) )
 272     l))
 273
 274
 275 ;;; @ end
 276 ;;;
 277
 278 (provide 'mel-q)