mel-q.el

   1 ;;;
   2 ;;; $Id: mel-q.el,v 1.9 1995/09/09 05:14:23 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 (cond ((boundp 'MULE)
 128        (define-program-coding-system
 129          nil (car quoted-printable-external-encoder) *noconv*)
 130        (define-program-coding-system
 131          nil (car quoted-printable-external-decoder) *noconv*)
 132        )
 133       ((boundp 'NEMACS)
 134        (define-program-kanji-code
 135          nil (car quoted-printable-external-encoder) 0)
 136        (define-program-kanji-code
 137          nil (car quoted-printable-external-decoder) 0)
 138        ))
 139
 140 (defun quoted-printable-external-encode-region (beg end)
 141   (save-excursion
 142     (apply (function call-process-region)
 143            beg end (car quoted-printable-external-encoder)
 144            t t nil (cdr quoted-printable-external-encoder))
 145     ))
 146
 147 (defun quoted-printable-external-decode-region (beg end)
 148   (save-excursion
 149     (apply (function call-process-region)
 150            beg end (car quoted-printable-external-decoder)
 151            t t nil (cdr quoted-printable-external-decoder))
 152     ))
 153
 154 (defun quoted-printable-encode-region (beg end)
 155   (interactive "r")
 156   (if (and quoted-printable-internal-encoding-limit
 157            (> (- end beg) quoted-printable-internal-encoding-limit))
 158       (quoted-printable-external-encode-region beg end)
 159     (quoted-printable-internal-encode-region beg end)
 160     ))
 161
 162 (defun quoted-printable-decode-region (beg end)
 163   (interactive "r")
 164   (if (and quoted-printable-internal-decoding-limit
 165            (> (- end beg) quoted-printable-internal-decoding-limit))
 166       (quoted-printable-external-decode-region beg end)
 167     (quoted-printable-internal-decode-region beg end)
 168     ))
 169
 170
 171 ;;; @ Q-encoding encode/decode string
 172 ;;;
 173
 174 (defun q-encoding-encode-string-for-text (str)
 175   (mapconcat (function
 176               (lambda (chr)
 177                 (cond ((eq chr 32) "_")
 178                       ((or (< chr 32) (< 126 chr) (eq chr ?=))
 179                        (quoted-printable-quote-char chr)
 180                        )
 181                       (t (char-to-string chr))
 182                       )))
 183              str ""))
 184
 185 (defun q-encoding-encode-string-for-comment (str)
 186   (mapconcat (function
 187               (lambda (chr)
 188                 (cond ((eq chr 32) "_")
 189                       ((or (< chr 32) (< 126 chr)
 190                            (memq chr '(?= ?\( ?\) ?\\))
 191                            )
 192                        (quoted-printable-quote-char chr)
 193                        )
 194                       (t (char-to-string chr))
 195                       )))
 196              str ""))
 197
 198 (defun q-encoding-encode-string-for-phrase (str)
 199   (mapconcat (function
 200               (lambda (chr)
 201                 (cond ((eq chr 32) "_")
 202                       ((or (and (<= ?A chr)(<= chr ?Z))
 203                            (and (<= ?a chr)(<= chr ?z))
 204                            (and (<= ?0 chr)(<= chr ?9))
 205                            (memq chr '(?! ?* ?+ ?- ?/))
 206                            )
 207                        (char-to-string chr)
 208                        )
 209                       (t (quoted-printable-quote-char chr))
 210                       )))
 211              str ""))
 212
 213 (defun q-encoding-encode-string (str &optional mode)
 214   (cond ((eq mode 'text)
 215          (q-encoding-encode-string-for-text str)
 216          )
 217         ((eq mode 'comment)
 218          (q-encoding-encode-string-for-comment str)
 219          )
 220         (t
 221          (q-encoding-encode-string-for-phrase str)
 222          )))
 223
 224 (defun q-encoding-decode-string (str)
 225   (let (q h l)
 226     (mapconcat (function
 227                 (lambda (chr)
 228                   (cond ((eq chr ?_) " ")
 229                         ((eq chr ?=)
 230                          (setq q t)
 231                          "")
 232                         (q (setq h (cond ((<= ?a chr) (+ (- chr ?a) 10))
 233                                          ((<= ?A chr) (+ (- chr ?A) 10))
 234                                          ((<= ?0 chr) (- chr ?0))
 235                                          ))
 236                            (setq q nil)
 237                            "")
 238                         (h (setq l (cond ((<= ?a chr) (+ (- chr ?a) 10))
 239                                          ((<= ?A chr) (+ (- chr ?A) 10))
 240                                          ((<= ?0 chr) (- chr ?0))
 241                                          ))
 242                            (prog1
 243                                (char-to-string (logior (ash h 4) l))
 244                              (setq h nil)
 245                              )
 246                            )
 247                         (t (char-to-string chr))
 248                         )))
 249                str "")))
 250
 251
 252 ;;; @@ etc
 253 ;;;
 254
 255 (defun q-encoding-encoded-length (string &optional mode)
 256   (let ((l 0)(i 0)(len (length string)) chr)
 257     (while (< i len)
 258       (setq chr (elt string i))
 259       (if (string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))
 260           (setq l (+ l 1))
 261         (setq l (+ l 3))
 262         )
 263       (setq i (+ i 1)) )
 264     l))
 265
 266
 267 ;;; @ end
 268 ;;;
 269
 270 (provide 'mel-q)