mel-q.el

   1 ;;;
   2 ;;; $Id: mel-q.el,v 2.0 1995/09/11 11:33:47 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       (catch 'tag
 110         (let (b e str)
 111           (while t
 112             (beginning-of-line) (setq b (point))
 113             (end-of-line)       (setq e (point))
 114             (if (< b e)
 115                 (progn
 116                   (setq str (buffer-substring b e))
 117                   (delete-region b e)
 118                   (insert (quoted-printable-encode-string str))
 119                   ))
 120             (if (eobp)
 121                 (throw 'tag nil)
 122               )
 123             (forward-char 1)
 124             )))
 125       )))
 126
 127 (defun quoted-printable-internal-decode-region (beg end)
 128   (save-excursion
 129     (save-restriction
 130       (narrow-to-region beg end)
 131       (goto-char (point-min))
 132       (while (re-search-forward "=\n" nil t)
 133         (replace-match "")
 134         )
 135       (goto-char (point-min))
 136       (let (b e str)
 137         (while (re-search-forward quoted-printable-octet-regexp nil t)
 138           (setq b (match-beginning 0))
 139           (setq e (match-end 0))
 140           (setq str (buffer-substring b e))
 141           (delete-region b e)
 142           (insert (quoted-printable-decode-string str))
 143           ))
 144       )))
 145
 146 (cond ((boundp 'MULE)
 147        (define-program-coding-system
 148          nil (car quoted-printable-external-encoder) *noconv*)
 149        (define-program-coding-system
 150          nil (car quoted-printable-external-decoder) *noconv*)
 151        )
 152       ((boundp 'NEMACS)
 153        (define-program-kanji-code
 154          nil (car quoted-printable-external-encoder) 0)
 155        (define-program-kanji-code
 156          nil (car quoted-printable-external-decoder) 0)
 157        ))
 158
 159 (defun quoted-printable-external-encode-region (beg end)
 160   (save-excursion
 161     (apply (function call-process-region)
 162            beg end (car quoted-printable-external-encoder)
 163            t t nil (cdr quoted-printable-external-encoder))
 164     ))
 165
 166 (defun quoted-printable-external-decode-region (beg end)
 167   (save-excursion
 168     (apply (function call-process-region)
 169            beg end (car quoted-printable-external-decoder)
 170            t t nil (cdr quoted-printable-external-decoder))
 171     ))
 172
 173 (defun quoted-printable-encode-region (beg end)
 174   (interactive "r")
 175   (if (and quoted-printable-internal-encoding-limit
 176            (> (- end beg) quoted-printable-internal-encoding-limit))
 177       (quoted-printable-external-encode-region beg end)
 178     (quoted-printable-internal-encode-region beg end)
 179     ))
 180
 181 (defun quoted-printable-decode-region (beg end)
 182   (interactive "r")
 183   (if (and quoted-printable-internal-decoding-limit
 184            (> (- end beg) quoted-printable-internal-decoding-limit))
 185       (quoted-printable-external-decode-region beg end)
 186     (quoted-printable-internal-decode-region beg end)
 187     ))
 188
 189
 190 ;;; @ Q-encoding encode/decode string
 191 ;;;
 192
 193 (defun q-encoding-encode-string-for-text (str)
 194   (mapconcat (function
 195               (lambda (chr)
 196                 (cond ((eq chr 32) "_")
 197                       ((or (< chr 32) (< 126 chr) (eq chr ?=))
 198                        (quoted-printable-quote-char chr)
 199                        )
 200                       (t (char-to-string chr))
 201                       )))
 202              str ""))
 203
 204 (defun q-encoding-encode-string-for-comment (str)
 205   (mapconcat (function
 206               (lambda (chr)
 207                 (cond ((eq chr 32) "_")
 208                       ((or (< chr 32) (< 126 chr)
 209                            (memq chr '(?= ?\( ?\) ?\\))
 210                            )
 211                        (quoted-printable-quote-char chr)
 212                        )
 213                       (t (char-to-string chr))
 214                       )))
 215              str ""))
 216
 217 (defun q-encoding-encode-string-for-phrase (str)
 218   (mapconcat (function
 219               (lambda (chr)
 220                 (cond ((eq chr 32) "_")
 221                       ((or (and (<= ?A chr)(<= chr ?Z))
 222                            (and (<= ?a chr)(<= chr ?z))
 223                            (and (<= ?0 chr)(<= chr ?9))
 224                            (memq chr '(?! ?* ?+ ?- ?/))
 225                            )
 226                        (char-to-string chr)
 227                        )
 228                       (t (quoted-printable-quote-char chr))
 229                       )))
 230              str ""))
 231
 232 (defun q-encoding-encode-string (str &optional mode)
 233   (cond ((eq mode 'text)
 234          (q-encoding-encode-string-for-text str)
 235          )
 236         ((eq mode 'comment)
 237          (q-encoding-encode-string-for-comment str)
 238          )
 239         (t
 240          (q-encoding-encode-string-for-phrase str)
 241          )))
 242
 243 (defun q-encoding-decode-string (str)
 244   (let (q h l)
 245     (mapconcat (function
 246                 (lambda (chr)
 247                   (cond ((eq chr ?_) " ")
 248                         ((eq chr ?=)
 249                          (setq q t)
 250                          "")
 251                         (q (setq h (cond ((<= ?a chr) (+ (- chr ?a) 10))
 252                                          ((<= ?A chr) (+ (- chr ?A) 10))
 253                                          ((<= ?0 chr) (- chr ?0))
 254                                          ))
 255                            (setq q nil)
 256                            "")
 257                         (h (setq l (cond ((<= ?a chr) (+ (- chr ?a) 10))
 258                                          ((<= ?A chr) (+ (- chr ?A) 10))
 259                                          ((<= ?0 chr) (- chr ?0))
 260                                          ))
 261                            (prog1
 262                                (char-to-string (logior (ash h 4) l))
 263                              (setq h nil)
 264                              )
 265                            )
 266                         (t (char-to-string chr))
 267                         )))
 268                str "")))
 269
 270
 271 ;;; @@ etc
 272 ;;;
 273
 274 (defun q-encoding-encoded-length (string &optional mode)
 275   (let ((l 0)(i 0)(len (length string)) chr)
 276     (while (< i len)
 277       (setq chr (elt string i))
 278       (if (string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))
 279           (setq l (+ l 1))
 280         (setq l (+ l 3))
 281         )
 282       (setq i (+ i 1)) )
 283     l))
 284
 285
 286 ;;; @ end
 287 ;;;
 288
 289 (provide 'mel-q)