lisp/gnus/mm-url.el

   1 ;;; mm-url.el --- a wrapper of url functions/commands for Gnus
   2
   3 ;; Copyright (C) 2001-2015 Free Software Foundation, Inc.
   4
   5 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;; Some code is stolen from w3 and url packages. Some are moved from
  25 ;; nnweb.
  26
  27 ;; TODO: Support POST, cookie.
  28
  29 ;;; Code:
  30
  31 (eval-when-compile (require 'cl))
  32
  33 (require 'mm-util)
  34 (require 'gnus)
  35
  36 (defvar url-current-object)
  37 (defvar url-package-name)
  38 (defvar url-package-version)
  39
  40 (defgroup mm-url nil
  41   "A wrapper of url package and external url command for Gnus."
  42   :group 'gnus)
  43
  44 (defcustom mm-url-use-external (not
  45                                 (condition-case nil
  46                                     (require 'url)
  47                                   (error nil)))
  48   "*If non-nil, use external grab program `mm-url-program'."
  49   :version "22.1"
  50   :type 'boolean
  51   :group 'mm-url)
  52
  53 (defvar mm-url-predefined-programs
  54   '((wget "wget" "--user-agent=mm-url" "-q" "-O" "-")
  55     (w3m  "w3m" "-dump_source")
  56     (lynx "lynx" "-source")
  57     (curl "curl" "--silent" "--user-agent" "mm-url" "--location")))
  58
  59 (defcustom mm-url-program
  60   (cond
  61    ((executable-find "wget") 'wget)
  62    ((executable-find "w3m") 'w3m)
  63    ((executable-find "lynx") 'lynx)
  64    ((executable-find "curl") 'curl)
  65    (t "GET"))
  66   "The url grab program.
  67 Likely values are `wget', `w3m', `lynx' and `curl'."
  68   :version "22.1"
  69   :type '(choice
  70           (symbol :tag "wget" wget)
  71           (symbol :tag "w3m" w3m)
  72           (symbol :tag "lynx" lynx)
  73           (symbol :tag "curl" curl)
  74           (string :tag "other"))
  75   :group 'mm-url)
  76
  77 (defcustom mm-url-arguments nil
  78   "The arguments for `mm-url-program'."
  79   :version "22.1"
  80   :type '(repeat string)
  81   :group 'mm-url)
  82
  83 \f
  84 ;;; Internal variables
  85
  86 ;; Stolen from w3.
  87 (defvar mm-url-html-entities
  88   '(
  89     ;;(excl        .  33)
  90     (quot        .  34)
  91     ;;(num         .  35)
  92     ;;(dollar      .  36)
  93     ;;(percent     .  37)
  94     (amp         .  38)
  95     (rsquo       .  39)                 ; should be U+8217
  96     ;;(apos        .  39)
  97     ;;(lpar        .  40)
  98     ;;(rpar        .  41)
  99     ;;(ast         .  42)
 100     ;;(plus        .  43)
 101     ;;(comma       .  44)
 102     ;;(period      .  46)
 103     ;;(colon       .  58)
 104     ;;(semi        .  59)
 105     (lt          .  60)
 106     ;;(equals      .  61)
 107     (gt          .  62)
 108     ;;(quest       .  63)
 109     ;;(commat      .  64)
 110     ;;(lsqb        .  91)
 111     ;;(rsqb        .  93)
 112     (uarr        .  94)                 ; should be U+8593
 113     ;;(lowbar      .  95)
 114     (lsquo       .  96)                 ; should be U+8216
 115     (lcub        . 123)
 116     ;;(verbar      . 124)
 117     (rcub        . 125)
 118     (tilde       . 126)
 119     (nbsp        . 160)
 120     (iexcl       . 161)
 121     (cent        . 162)
 122     (pound       . 163)
 123     (curren      . 164)
 124     (yen         . 165)
 125     (brvbar      . 166)
 126     (sect        . 167)
 127     (uml         . 168)
 128     (copy        . 169)
 129     (ordf        . 170)
 130     (laquo       . 171)
 131     (not         . 172)
 132     (shy         . 173)
 133     (reg         . 174)
 134     (macr        . 175)
 135     (deg         . 176)
 136     (plusmn      . 177)
 137     (sup2        . 178)
 138     (sup3        . 179)
 139     (acute       . 180)
 140     (micro       . 181)
 141     (para        . 182)
 142     (middot      . 183)
 143     (cedil       . 184)
 144     (sup1        . 185)
 145     (ordm        . 186)
 146     (raquo       . 187)
 147     (frac14      . 188)
 148     (frac12      . 189)
 149     (frac34      . 190)
 150     (iquest      . 191)
 151     (Agrave      . 192)
 152     (Aacute      . 193)
 153     (Acirc       . 194)
 154     (Atilde      . 195)
 155     (Auml        . 196)
 156     (Aring       . 197)
 157     (AElig       . 198)
 158     (Ccedil      . 199)
 159     (Egrave      . 200)
 160     (Eacute      . 201)
 161     (Ecirc       . 202)
 162     (Euml        . 203)
 163     (Igrave      . 204)
 164     (Iacute      . 205)
 165     (Icirc       . 206)
 166     (Iuml        . 207)
 167     (ETH         . 208)
 168     (Ntilde      . 209)
 169     (Ograve      . 210)
 170     (Oacute      . 211)
 171     (Ocirc       . 212)
 172     (Otilde      . 213)
 173     (Ouml        . 214)
 174     (times       . 215)
 175     (Oslash      . 216)
 176     (Ugrave      . 217)
 177     (Uacute      . 218)
 178     (Ucirc       . 219)
 179     (Uuml        . 220)
 180     (Yacute      . 221)
 181     (THORN       . 222)
 182     (szlig       . 223)
 183     (agrave      . 224)
 184     (aacute      . 225)
 185     (acirc       . 226)
 186     (atilde      . 227)
 187     (auml        . 228)
 188     (aring       . 229)
 189     (aelig       . 230)
 190     (ccedil      . 231)
 191     (egrave      . 232)
 192     (eacute      . 233)
 193     (ecirc       . 234)
 194     (euml        . 235)
 195     (igrave      . 236)
 196     (iacute      . 237)
 197     (icirc       . 238)
 198     (iuml        . 239)
 199     (eth         . 240)
 200     (ntilde      . 241)
 201     (ograve      . 242)
 202     (oacute      . 243)
 203     (ocirc       . 244)
 204     (otilde      . 245)
 205     (ouml        . 246)
 206     (divide      . 247)
 207     (oslash      . 248)
 208     (ugrave      . 249)
 209     (uacute      . 250)
 210     (ucirc       . 251)
 211     (uuml        . 252)
 212     (yacute      . 253)
 213     (thorn       . 254)
 214     (yuml        . 255)
 215
 216     ;; Special handling of these
 217     (frac56      . "5/6")
 218     (frac16      . "1/6")
 219     (frac45      . "4/5")
 220     (frac35      . "3/5")
 221     (frac25      . "2/5")
 222     (frac15      . "1/5")
 223     (frac23      . "2/3")
 224     (frac13      . "1/3")
 225     (frac78      . "7/8")
 226     (frac58      . "5/8")
 227     (frac38      . "3/8")
 228     (frac18      . "1/8")
 229
 230     ;; The following 5 entities are not mentioned in the HTML 2.0
 231     ;; standard, nor in any other HTML proposed standard of which I
 232     ;; am aware.  I am not even sure they are ISO entity names.  ***
 233     ;; Hence, some arrangement should be made to give a bad HTML
 234     ;; message when they are seen.
 235     (ndash       .  45)
 236     (mdash       .  45)
 237     (emsp        .  32)
 238     (ensp        .  32)
 239     (sim         . 126)
 240     (le          . "<=")
 241     (agr         . "alpha")
 242     (rdquo       . "''")
 243     (ldquo       . "``")
 244     (trade       . "(TM)")
 245     ;; To be done
 246     ;; (shy      . ????) ; soft hyphen
 247     )
 248   "*An assoc list of entity names and how to actually display them.")
 249
 250 (defconst mm-url-unreserved-chars
 251   '(
 252     ?a ?b ?c ?d ?e ?f ?g ?h ?i ?j ?k ?l ?m ?n ?o ?p ?q ?r ?s ?t ?u ?v ?w ?x ?y ?z
 253     ?A ?B ?C ?D ?E ?F ?G ?H ?I ?J ?K ?L ?M ?N ?O ?P ?Q ?R ?S ?T ?U ?V ?W ?X ?Y ?Z
 254     ?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9
 255     ?- ?_ ?. ?! ?~ ?* ?' ?\( ?\))
 256   "A list of characters that are _NOT_ reserved in the URL spec.
 257 This is taken from RFC 2396.")
 258
 259 (defun mm-url-load-url ()
 260   "Load `url-insert-file-contents'."
 261   (unless (condition-case ()
 262               (progn
 263                 (require 'url-handlers)
 264                 (require 'url-parse)
 265                 (require 'url-vars))
 266             (error nil))
 267     (require 'url)))
 268
 269 ;;;###autoload
 270 (defun mm-url-insert-file-contents (url)
 271   "Insert file contents of URL.
 272 If `mm-url-use-external' is non-nil, use `mm-url-program'."
 273   (if mm-url-use-external
 274       (progn
 275         (if (string-match "^file:/+" url)
 276             (insert-file-contents (substring url (1- (match-end 0))))
 277           (mm-url-insert-file-contents-external url))
 278         (goto-char (point-min))
 279         (if (fboundp 'url-generic-parse-url)
 280             (setq url-current-object
 281                   (url-generic-parse-url url)))
 282         (list url (buffer-size)))
 283     (mm-url-load-url)
 284     (let ((name buffer-file-name)
 285           (url-request-extra-headers
 286            ;; ISTM setting a Connection header was a workaround for
 287            ;; older versions of url included with w3, but it does more
 288            ;; harm than good with the one shipped with Emacs. --ansel
 289            (if (not (and (boundp 'url-version)
 290                          (equal url-version "Emacs")))
 291                (list (cons "Connection" "Close"))))
 292           result)
 293       (setq result (url-insert-file-contents url))
 294       (save-excursion
 295         (goto-char (point-min))
 296         (while (re-search-forward "\r 1000\r ?" nil t)
 297           (replace-match "")))
 298       (setq buffer-file-name name)
 299       (if (and (fboundp 'url-generic-parse-url)
 300                (listp result))
 301           (setq url-current-object (url-generic-parse-url
 302                                     (car result))))
 303       result)))
 304
 305 ;;;###autoload
 306 (defun mm-url-insert-file-contents-external (url)
 307   "Insert file contents of URL using `mm-url-program'."
 308   (let (program args)
 309     (if (symbolp mm-url-program)
 310         (let ((item (cdr (assq mm-url-program mm-url-predefined-programs))))
 311           (setq program (car item)
 312                 args (append (cdr item) (list url))))
 313       (setq program mm-url-program
 314             args (append mm-url-arguments (list url))))
 315     (unless (eq 0 (apply 'call-process program nil t nil args))
 316       (error "Couldn't fetch %s" url))))
 317
 318 (defvar mm-url-timeout 30
 319   "The number of seconds before timing out an URL fetch.")
 320
 321 (defvar mm-url-retries 10
 322   "The number of retries after timing out when fetching an URL.")
 323
 324 (defun mm-url-insert (url &optional follow-refresh)
 325   "Insert the contents from an URL in the current buffer.
 326 If FOLLOW-REFRESH is non-nil, redirect refresh url in META."
 327   (let ((times mm-url-retries)
 328         (done nil)
 329         (first t)
 330         result)
 331     (while (and (not (zerop (decf times)))
 332                 (not done))
 333       (with-timeout (mm-url-timeout)
 334         (unless first
 335           (message "Trying again (%s)..." (- mm-url-retries times)))
 336         (setq first nil)
 337         (if follow-refresh
 338             (save-restriction
 339               (narrow-to-region (point) (point))
 340               (mm-url-insert-file-contents url)
 341               (goto-char (point-min))
 342               (when (re-search-forward
 343                      "<meta[ \t\r\n]*http-equiv=\"Refresh\"[^>]*URL=\\([^\"]+\\)\"" nil t)
 344                 (let ((url (match-string 1)))
 345                   (delete-region (point-min) (point-max))
 346                   (setq result (mm-url-insert url t)))))
 347           (setq result (mm-url-insert-file-contents url)))
 348         (setq done t)))
 349     result))
 350
 351 (defun mm-url-decode-entities ()
 352   "Decode all HTML entities."
 353   (goto-char (point-min))
 354   (while (re-search-forward "&\\(#[0-9]+\\|#x[0-9a-f]+\\|[a-z]+[0-9]*\\);"
 355                             nil t)
 356     (let* ((entity (match-string 1))
 357            (elem (if (eq (aref entity 0) ?\#)
 358                      (let ((c
 359                             ;; Hex number: &#x3212
 360                             (if (eq (aref entity 1) ?x)
 361                                 (string-to-number (substring entity 2)
 362                                                   16)
 363                               ;; Decimal number: &#23
 364                               (string-to-number (substring entity 1)))))
 365                        (setq c (or (cdr (assq c mm-extra-numeric-entities))
 366                                    (mm-ucs-to-char c)))
 367                        (if (mm-char-or-char-int-p c) c ?#))
 368                    (or (cdr (assq (intern entity)
 369                                   mm-url-html-entities))
 370                        ?#))))
 371       (unless (stringp elem)
 372         (setq elem (char-to-string elem)))
 373       (replace-match elem t t))))
 374
 375 (defun mm-url-decode-entities-nbsp ()
 376   "Decode all HTML entities and &nbsp; to a space."
 377   (let ((mm-url-html-entities (cons '(nbsp . 32) mm-url-html-entities)))
 378     (mm-url-decode-entities)))
 379
 380 (defun mm-url-decode-entities-string (string)
 381   (with-temp-buffer
 382     (insert string)
 383     (mm-url-decode-entities)
 384     (buffer-string)))
 385
 386 (defun mm-url-form-encode-xwfu (chunk)
 387   "Escape characters in a string for application/x-www-form-urlencoded.
 388 Blasphemous crap because someone didn't think %20 was good enough for encoding
 389 spaces.  Die Die Die."
 390   ;; This will get rid of the 'attributes' specified by the file type,
 391   ;; which are useless for an application/x-www-form-urlencoded form.
 392   (if (consp chunk)
 393       (setq chunk (cdr chunk)))
 394
 395   (mapconcat
 396    (lambda (char)
 397      (cond
 398       ((= char ?  ) "+")
 399       ((memq char mm-url-unreserved-chars) (char-to-string char))
 400       (t (upcase (format "%%%02x" char)))))
 401    (mm-encode-coding-string chunk
 402                             (if (fboundp 'find-coding-systems-string)
 403                                 (car (find-coding-systems-string chunk))
 404                               buffer-file-coding-system))
 405    ""))
 406
 407 (defun mm-url-encode-www-form-urlencoded (pairs)
 408   "Return PAIRS encoded for forms."
 409   (mapconcat
 410    (lambda (data)
 411      (concat (mm-url-form-encode-xwfu (car data)) "="
 412              (mm-url-form-encode-xwfu (cdr data))))
 413    pairs "&"))
 414
 415 (autoload 'mml-compute-boundary "mml")
 416
 417 (defun mm-url-encode-multipart-form-data (pairs &optional boundary)
 418   "Return PAIRS encoded in multipart/form-data."
 419   ;; RFC1867
 420   ;; Get a good boundary
 421   (unless boundary
 422     (setq boundary (mml-compute-boundary '())))
 423   (concat
 424    ;; Start with the boundary
 425    "--" boundary "\r\n"
 426    ;; Create name value pairs
 427    (mapconcat
 428     'identity
 429     ;; Delete any returned items that are empty
 430     (delq nil
 431           (mapcar (lambda (data)
 432                     (cond ((equal (car data) "file")
 433                            ;; For each pair
 434                            (format
 435                             ;; Encode the name
 436                             "Content-Disposition: form-data; name=%S; filename=%S\r\nContent-Type: text/plain; charset=utf-8\r\nContent-Transfer-Encoding: binary\r\n\r\n%s"
 437                             (cdr (assoc "name" (cdr data))) (cdr (assoc "filename" (cdr data)))
 438                             (cond ((stringp (cdr (assoc "filedata" (cdr data))))
 439                                    (cdr (assoc "filedata" (cdr data))))
 440                                   ((integerp (cdr (assoc "filedata" (cdr data))))
 441                                    (number-to-string (cdr (assoc "filedata" (cdr data))))))))
 442                           ((equal (car data) "submit")
 443                            "Content-Disposition: form-data; name=\"submit\"\r\n\r\nSubmit\r\n")
 444                           (t
 445                            (format
 446                             "Content-Disposition: form-data;name=%S\r\n\r\n%s\r\n"
 447                             (car data) (concat (mm-url-form-encode-xwfu (cdr data)))
 448                             ))))
 449                   pairs))
 450     ;; use the boundary as a separator
 451     (concat "\r\n--" boundary "\r\n"))
 452    ;; put a boundary at the end.
 453    "--" boundary "--\r\n"))
 454
 455 (defun mm-url-remove-markup ()
 456   "Remove all HTML markup, leaving just plain text."
 457   (goto-char (point-min))
 458   (while (search-forward "<!--" nil t)
 459     (delete-region (match-beginning 0)
 460                    (or (search-forward "-->" nil t)
 461                        (point-max))))
 462   (goto-char (point-min))
 463   (while (re-search-forward "<[^>]+>" nil t)
 464     (replace-match "" t t)))
 465
 466 (provide 'mm-url)
 467
 468 ;;; mm-url.el ends here