mel-q.el

   1 ;;;
   2 ;;; $Id: mel-q.el,v 1.5 1995/06/26 05:56:39 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           (replace-match (quoted-printable-decode-string str))
 131           ))
 132       )))
 133
 134 (cond ((boundp 'MULE)
 135        (define-program-coding-system
 136          nil (car quoted-printable-external-encoder) *noconv*)
 137        (define-program-coding-system
 138          nil (car quoted-printable-external-decoder) *noconv*)
 139        )
 140       ((boundp 'NEMACS)
 141        (define-program-kanji-code
 142          nil (car quoted-printable-external-encoder) 0)
 143        (define-program-kanji-code
 144          nil (car quoted-printable-external-decoder) 0)
 145        ))
 146
 147 (defun quoted-printable-external-encode-region (beg end)
 148   (save-excursion
 149     (apply (function call-process-region)
 150            beg end (car quoted-printable-external-encoder)
 151            t t nil (cdr quoted-printable-external-encoder))
 152     ))
 153
 154 (defun quoted-printable-external-decode-region (beg end)
 155   (save-excursion
 156     (apply (function call-process-region)
 157            beg end (car quoted-printable-external-decoder)
 158            t t nil (cdr quoted-printable-external-decoder))
 159     ))
 160
 161 (defun quoted-printable-encode-region (beg end)
 162   (interactive "r")
 163   (if (and quoted-printable-internal-encoding-limit
 164            (> (- end beg) quoted-printable-internal-encoding-limit))
 165       (quoted-printable-external-encode-region beg end)
 166     (quoted-printable-internal-encode-region beg end)
 167     ))
 168
 169 (defun quoted-printable-decode-region (beg end)
 170   (interactive "r")
 171   (if (and quoted-printable-internal-decoding-limit
 172            (> (- end beg) quoted-printable-internal-decoding-limit))
 173       (quoted-printable-external-decode-region beg end)
 174     (quoted-printable-internal-decode-region beg end)
 175     ))
 176
 177
 178 ;;; @ Q-encoding encode/decode string
 179 ;;;
 180
 181 (defun q-encoding-encode-string-for-text (str)
 182   (mapconcat (function
 183               (lambda (chr)
 184                 (cond ((eq chr 32) "_")
 185                       ((or (< chr 32) (< 126 chr) (eq chr ?=))
 186                        (quoted-printable-quote-char chr)
 187                        )
 188                       (t (char-to-string chr))
 189                       )))
 190              str ""))
 191
 192 (defun q-encoding-encode-string-for-comment (str)
 193   (mapconcat (function
 194               (lambda (chr)
 195                 (cond ((eq chr 32) "_")
 196                       ((or (< chr 32) (< 126 chr)
 197                            (memq chr '(?= ?\( ?\) ?\\))
 198                            )
 199                        (quoted-printable-quote-char chr)
 200                        )
 201                       (t (char-to-string chr))
 202                       )))
 203              str ""))
 204
 205 (defun q-encoding-encode-string-for-phrase (str)
 206   (mapconcat (function
 207               (lambda (chr)
 208                 (cond ((or (and (<= ?A chr)(<= chr ?Z))
 209                            (and (<= ?a chr)(<= chr ?z))
 210                            (and (<= ?0 chr)(<= chr ?9))
 211                            (memq chr '(?! ?* ?+ ?- ?/))
 212                            )
 213                        (char-to-string chr)
 214                        )
 215                       (t (quoted-printable-quote-char chr))
 216                       )))
 217              str ""))
 218
 219 (defun q-encoding-encode-string (str &optional mode)
 220   (cond ((eq mode 'text)
 221          (q-encoding-encode-string-for-text str)
 222          )
 223         ((eq mode 'comment)
 224          (q-encoding-encode-string-for-comment str)
 225          )
 226         ((eq mode 'phrase)
 227          (q-encoding-encode-string-for-phrase str)
 228          )
 229         (t (quoted-printable-encode-string 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 'qprint)