lisp/gnus/mailcap.el

   1 ;;; mailcap.el --- MIME media types configuration
   2
   3 ;; Copyright (C) 1998-2012 Free Software Foundation, Inc.
   4
   5 ;; Author: William M. Perry <wmperry@aventail.com>
   6 ;;      Lars Magne Ingebrigtsen <larsi@gnus.org>
   7 ;; Keywords: news, mail, multimedia
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Provides configuration of MIME media types from directly from Lisp
  27 ;; and via the usual mailcap mechanism (RFC 1524).  Deals with
  28 ;; mime.types similarly.
  29
  30 ;;; Code:
  31
  32 (eval-when-compile (require 'cl))
  33 (autoload 'mail-header-parse-content-type "mail-parse")
  34
  35 ;; `mm-delete-duplicates' is an alias for `delete-dups' in Emacs 22.
  36 (defalias 'mailcap-delete-duplicates
  37   (if (fboundp 'delete-dups)
  38       'delete-dups
  39     (autoload 'mm-delete-duplicates "mm-util")
  40     'mm-delete-duplicates))
  41
  42 ;; `mailcap-replace-in-string' is an alias like `gnus-replace-in-string'.
  43 (eval-and-compile
  44   (cond
  45    ((fboundp 'replace-regexp-in-string)
  46     (defun mailcap-replace-in-string  (string regexp newtext &optional literal)
  47       "Replace all matches for REGEXP with NEWTEXT in STRING.
  48 If LITERAL is non-nil, insert NEWTEXT literally.  Return a new
  49 string containing the replacements.
  50 This is a compatibility function for different Emacsen."
  51       (replace-regexp-in-string regexp newtext string nil literal)))
  52    ((fboundp 'replace-in-string)
  53     (defalias 'mailcap-replace-in-string 'replace-in-string))))
  54
  55 (defgroup mailcap nil
  56   "Definition of viewers for MIME types."
  57   :version "21.1"
  58   :group 'mime)
  59
  60 (defvar mailcap-parse-args-syntax-table
  61   (let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
  62     (modify-syntax-entry ?' "\"" table)
  63     (modify-syntax-entry ?` "\"" table)
  64     (modify-syntax-entry ?{ "(" table)
  65     (modify-syntax-entry ?} ")" table)
  66     table)
  67   "A syntax table for parsing SGML attributes.")
  68
  69 (eval-and-compile
  70   (when (featurep 'xemacs)
  71     (condition-case nil
  72         (require 'lpr)
  73       (error nil))))
  74
  75 (defvar mailcap-print-command
  76   (mapconcat 'identity
  77              (cons (if (boundp 'lpr-command)
  78                        lpr-command
  79                      "lpr")
  80                    (when (boundp 'lpr-switches)
  81                      (if (stringp lpr-switches)
  82                          (list lpr-switches)
  83                        lpr-switches)))
  84              " ")
  85   "Shell command (including switches) used to print PostScript files.")
  86
  87 ;; Postpone using defcustom for this as it's so big and we essentially
  88 ;; have to have two copies of the data around then.  Perhaps just
  89 ;; customize the Lisp viewers and rely on the normal configuration
  90 ;; files for the rest?  -- fx
  91 (defvar mailcap-mime-data
  92   `(("application"
  93      ("vnd\\.ms-excel"
  94       (viewer . "gnumeric %s")
  95       (test   . (getenv "DISPLAY"))
  96       (type . "application/vnd.ms-excel"))
  97      ("x-x509-ca-cert"
  98       (viewer . ssl-view-site-cert)
  99       (test . (fboundp 'ssl-view-site-cert))
 100       (type . "application/x-x509-ca-cert"))
 101      ("x-x509-user-cert"
 102       (viewer . ssl-view-user-cert)
 103       (test . (fboundp 'ssl-view-user-cert))
 104       (type . "application/x-x509-user-cert"))
 105      ("octet-stream"
 106       (viewer . mailcap-save-binary-file)
 107       (non-viewer . t)
 108       (type . "application/octet-stream"))
 109      ("dvi"
 110       (viewer . "xdvi -safer %s")
 111       (test   . (eq window-system 'x))
 112       ("needsx11")
 113       (type   . "application/dvi")
 114       ("print" . "dvips -qRP %s"))
 115      ("dvi"
 116       (viewer . "dvitty %s")
 117       (test   . (not (getenv "DISPLAY")))
 118       (type   . "application/dvi")
 119       ("print" . "dvips -qRP %s"))
 120      ("emacs-lisp"
 121       (viewer . mailcap-maybe-eval)
 122       (type   . "application/emacs-lisp"))
 123      ("x-emacs-lisp"
 124       (viewer . mailcap-maybe-eval)
 125       (type   . "application/x-emacs-lisp"))
 126      ("x-tar"
 127       (viewer . mailcap-save-binary-file)
 128       (non-viewer . t)
 129       (type   . "application/x-tar"))
 130      ("x-latex"
 131       (viewer . tex-mode)
 132       (test   . (fboundp 'tex-mode))
 133       (type   . "application/x-latex"))
 134      ("x-tex"
 135       (viewer . tex-mode)
 136       (test   . (fboundp 'tex-mode))
 137       (type   . "application/x-tex"))
 138      ("latex"
 139       (viewer . tex-mode)
 140       (test   . (fboundp 'tex-mode))
 141       (type   . "application/latex"))
 142      ("tex"
 143       (viewer . tex-mode)
 144       (test   . (fboundp 'tex-mode))
 145       (type   . "application/tex"))
 146      ("texinfo"
 147       (viewer . texinfo-mode)
 148       (test   . (fboundp 'texinfo-mode))
 149       (type   . "application/tex"))
 150      ("zip"
 151       (viewer . mailcap-save-binary-file)
 152       (non-viewer . t)
 153       (type   . "application/zip")
 154       ("copiousoutput"))
 155      ("pdf"
 156       (viewer . "gv -safer %s")
 157       (type . "application/pdf")
 158       (test . window-system)
 159       ("print" . ,(concat "pdf2ps %s - | " mailcap-print-command)))
 160      ("pdf"
 161       (viewer . "gpdf %s")
 162       (type . "application/pdf")
 163       ("print" . ,(concat "pdftops %s - | " mailcap-print-command))
 164       (test . (eq window-system 'x)))
 165      ("pdf"
 166       (viewer . "xpdf %s")
 167       (type . "application/pdf")
 168       ("print" . ,(concat "pdftops %s - | " mailcap-print-command))
 169       (test . (eq window-system 'x)))
 170      ("pdf"
 171       (viewer . ,(concat "pdftotext %s -"))
 172       (type   . "application/pdf")
 173       ("print" . ,(concat "pdftops %s - | " mailcap-print-command))
 174       ("copiousoutput"))
 175      ("postscript"
 176       (viewer . "gv -safer %s")
 177       (type . "application/postscript")
 178       (test   . window-system)
 179       ("print" . ,(concat mailcap-print-command " %s"))
 180       ("needsx11"))
 181      ("postscript"
 182       (viewer . "ghostview -dSAFER %s")
 183       (type . "application/postscript")
 184       (test   . (eq window-system 'x))
 185       ("print" . ,(concat mailcap-print-command " %s"))
 186       ("needsx11"))
 187      ("postscript"
 188       (viewer . "ps2ascii %s")
 189       (type . "application/postscript")
 190       (test . (not (getenv "DISPLAY")))
 191       ("print" . ,(concat mailcap-print-command " %s"))
 192       ("copiousoutput"))
 193      ("sieve"
 194       (viewer . sieve-mode)
 195       (test   . (fboundp 'sieve-mode))
 196       (type   . "application/sieve"))
 197      ("pgp-keys"
 198       (viewer . "gpg --import --interactive --verbose")
 199       (type   . "application/pgp-keys")
 200       ("needsterminal")))
 201     ("audio"
 202      ("x-mpeg"
 203       (viewer . "maplay %s")
 204       (type   . "audio/x-mpeg"))
 205      (".*"
 206       (viewer . "showaudio")
 207       (type   . "audio/*")))
 208     ("message"
 209      ("rfc-*822"
 210       (viewer . mm-view-message)
 211       (test   . (and (featurep 'gnus)
 212                      (gnus-alive-p)))
 213       (type   . "message/rfc822"))
 214      ("rfc-*822"
 215       (viewer . vm-mode)
 216       (test   . (fboundp 'vm-mode))
 217       (type   . "message/rfc822"))
 218      ("rfc-*822"
 219       (viewer . w3-mode)
 220       (test   . (fboundp 'w3-mode))
 221       (type   . "message/rfc822"))
 222      ("rfc-*822"
 223       (viewer . view-mode)
 224       (type   . "message/rfc822")))
 225     ("image"
 226      ("x-xwd"
 227       (viewer  . "xwud -in %s")
 228       (type    . "image/x-xwd")
 229       ("compose" . "xwd -frame > %s")
 230       (test    . (eq window-system 'x))
 231       ("needsx11"))
 232      ("x11-dump"
 233       (viewer . "xwud -in %s")
 234       (type . "image/x-xwd")
 235       ("compose" . "xwd -frame > %s")
 236       (test   . (eq window-system 'x))
 237       ("needsx11"))
 238      ("windowdump"
 239       (viewer . "xwud -in %s")
 240       (type . "image/x-xwd")
 241       ("compose" . "xwd -frame > %s")
 242       (test   . (eq window-system 'x))
 243       ("needsx11"))
 244      (".*"
 245       (viewer . "display %s")
 246       (type . "image/*")
 247       (test   . (eq window-system 'x))
 248       ("needsx11"))
 249      (".*"
 250       (viewer . "ee %s")
 251       (type . "image/*")
 252       (test   . (eq window-system 'x))
 253       ("needsx11")))
 254     ("text"
 255      ("plain"
 256       (viewer  . w3-mode)
 257       (test    . (fboundp 'w3-mode))
 258       (type    . "text/plain"))
 259      ("plain"
 260       (viewer  . view-mode)
 261       (test    . (fboundp 'view-mode))
 262       (type    . "text/plain"))
 263      ("plain"
 264       (viewer  . fundamental-mode)
 265       (type    . "text/plain"))
 266      ("enriched"
 267       (viewer . enriched-decode)
 268       (test   . (fboundp 'enriched-decode))
 269       (type   . "text/enriched"))
 270      ("html"
 271       (viewer . mm-w3-prepare-buffer)
 272       (test   . (fboundp 'w3-prepare-buffer))
 273       (type   . "text/html"))
 274      ("dns"
 275       (viewer . dns-mode)
 276       (test   . (fboundp 'dns-mode))
 277       (type   . "text/dns")))
 278     ("video"
 279      ("mpeg"
 280       (viewer . "mpeg_play %s")
 281       (type   . "video/mpeg")
 282       (test   . (eq window-system 'x))
 283       ("needsx11")))
 284     ("x-world"
 285      ("x-vrml"
 286       (viewer  . "webspace -remote %s -URL %u")
 287       (type    . "x-world/x-vrml")
 288       ("description"
 289        "VRML document")))
 290     ("archive"
 291      ("tar"
 292       (viewer . tar-mode)
 293       (type . "archive/tar")
 294       (test . (fboundp 'tar-mode)))))
 295   "The mailcap structure is an assoc list of assoc lists.
 296 1st assoc list is keyed on the major content-type
 297 2nd assoc list is keyed on the minor content-type (which can be a regexp)
 298
 299 Which looks like:
 300 -----------------
 301  ((\"application\"
 302    (\"postscript\" . <info>))
 303   (\"text\"
 304    (\"plain\" . <info>)))
 305
 306 Where <info> is another assoc list of the various information
 307 related to the mailcap RFC 1524.  This is keyed on the lowercase
 308 attribute name (viewer, test, etc).  This looks like:
 309  ((viewer . VIEWERINFO)
 310   (test   . TESTINFO)
 311   (xxxx   . \"STRING\")
 312   FLAG)
 313
 314 Where VIEWERINFO specifies how the content-type is viewed.  Can be
 315 a string, in which case it is run through a shell, with
 316 appropriate parameters, or a symbol, in which case the symbol is
 317 `funcall'ed, with the buffer as an argument.
 318
 319 TESTINFO is a test for the viewer's applicability, or nil.  If nil, it
 320 means the viewer is always valid.  If it is a Lisp function, it is
 321 called with a list of items from any extra fields from the
 322 Content-Type header as argument to return a boolean value for the
 323 validity.  Otherwise, if it is a non-function Lisp symbol or list
 324 whose car is a symbol, it is `eval'led to yield the validity.  If it
 325 is a string or list of strings, it represents a shell command to run
 326 to return a true or false shell value for the validity.")
 327 (put 'mailcap-mime-data 'risky-local-variable t)
 328
 329 (defcustom mailcap-download-directory nil
 330   "*Directory to which `mailcap-save-binary-file' downloads files by default.
 331 nil means your home directory."
 332   :type '(choice (const :tag "Home directory" nil)
 333                  directory)
 334   :group 'mailcap)
 335
 336 (defvar mailcap-poor-system-types
 337   '(ms-dos windows-nt)
 338   "Systems that don't have a Unix-like directory hierarchy.")
 339
 340 ;;;
 341 ;;; Utility functions
 342 ;;;
 343
 344 (defun mailcap-save-binary-file ()
 345   (goto-char (point-min))
 346   (unwind-protect
 347       (let ((file (read-file-name
 348                    "Filename to save as: "
 349                    (or mailcap-download-directory "~/")))
 350             (require-final-newline nil))
 351         (write-region (point-min) (point-max) file))
 352     (kill-buffer (current-buffer))))
 353
 354 (defvar mailcap-maybe-eval-warning
 355   "*** WARNING ***
 356
 357 This MIME part contains untrusted and possibly harmful content.
 358 If you evaluate the Emacs Lisp code contained in it, a lot of nasty
 359 things can happen.  Please examine the code very carefully before you
 360 instruct Emacs to evaluate it.  You can browse the buffer containing
 361 the code using \\[scroll-other-window].
 362
 363 If you are unsure what to do, please answer \"no\"."
 364   "Text of warning message displayed by `mailcap-maybe-eval'.
 365 Make sure that this text consists only of few text lines.  Otherwise,
 366 Gnus might fail to display all of it.")
 367
 368 (defun mailcap-maybe-eval ()
 369   "Maybe evaluate a buffer of Emacs Lisp code."
 370   (let ((lisp-buffer (current-buffer)))
 371     (goto-char (point-min))
 372     (when
 373         (save-window-excursion
 374           (delete-other-windows)
 375           (let ((buffer (get-buffer-create (generate-new-buffer-name
 376                                             "*Warning*"))))
 377             (unwind-protect
 378                 (with-current-buffer buffer
 379                   (insert (substitute-command-keys
 380                            mailcap-maybe-eval-warning))
 381                   (goto-char (point-min))
 382                   (display-buffer buffer)
 383                   (yes-or-no-p "This is potentially dangerous emacs-lisp code, evaluate it? "))
 384               (kill-buffer buffer))))
 385       (eval-buffer (current-buffer)))
 386     (when (buffer-live-p lisp-buffer)
 387       (with-current-buffer lisp-buffer
 388         (emacs-lisp-mode)))))
 389
 390
 391 ;;;
 392 ;;; The mailcap parser
 393 ;;;
 394
 395 (defun mailcap-replace-regexp (regexp to-string)
 396   ;; Quiet replace-regexp.
 397   (goto-char (point-min))
 398   (while (re-search-forward regexp nil t)
 399     (replace-match to-string t nil)))
 400
 401 (defvar mailcap-parsed-p nil)
 402
 403 (defun mailcap-parse-mailcaps (&optional path force)
 404   "Parse out all the mailcaps specified in a path string PATH.
 405 Components of PATH are separated by the `path-separator' character
 406 appropriate for this system.  If FORCE, re-parse even if already
 407 parsed.  If PATH is omitted, use the value of environment variable
 408 MAILCAPS if set; otherwise (on Unix) use the path from RFC 1524, plus
 409 /usr/local/etc/mailcap."
 410   (interactive (list nil t))
 411   (when (or (not mailcap-parsed-p)
 412             force)
 413     (cond
 414      (path nil)
 415      ((getenv "MAILCAPS") (setq path (getenv "MAILCAPS")))
 416      ((memq system-type mailcap-poor-system-types)
 417       (setq path '("~/.mailcap" "~/mail.cap" "~/etc/mail.cap")))
 418      (t (setq path
 419               ;; This is per RFC 1524, specifically
 420               ;; with /usr before /usr/local.
 421               '("~/.mailcap" "/etc/mailcap" "/usr/etc/mailcap"
 422                 "/usr/local/etc/mailcap"))))
 423     (let ((fnames (reverse
 424                    (if (stringp path)
 425                        (split-string path path-separator t)
 426                      path)))
 427           fname)
 428       (while fnames
 429         (setq fname (car fnames))
 430         (if (and (file-readable-p fname)
 431                  (file-regular-p fname))
 432             (mailcap-parse-mailcap fname))
 433         (setq fnames (cdr fnames))))
 434       (setq mailcap-parsed-p t)))
 435
 436 (defun mailcap-parse-mailcap (fname)
 437   "Parse out the mailcap file specified by FNAME."
 438   (let (major                           ; The major mime type (image/audio/etc)
 439         minor                           ; The minor mime type (gif, basic, etc)
 440         save-pos                        ; Misc saved positions used in parsing
 441         viewer                          ; How to view this mime type
 442         info                            ; Misc info about this mime type
 443         )
 444     (with-temp-buffer
 445       (insert-file-contents fname)
 446       (set-syntax-table mailcap-parse-args-syntax-table)
 447       (mailcap-replace-regexp "#.*" "") ; Remove all comments
 448       (mailcap-replace-regexp "\\\\[ \t]*\n" " ") ; And collapse spaces
 449       (mailcap-replace-regexp "\n+" "\n") ; And blank lines
 450       (goto-char (point-max))
 451       (skip-chars-backward " \t\n")
 452       (delete-region (point) (point-max))
 453       (while (not (bobp))
 454         (skip-chars-backward " \t\n")
 455         (beginning-of-line)
 456         (setq save-pos (point)
 457               info nil)
 458         (skip-chars-forward "^/; \t\n")
 459         (downcase-region save-pos (point))
 460         (setq major (buffer-substring save-pos (point)))
 461         (skip-chars-forward " \t")
 462         (setq minor "")
 463         (when (eq (char-after) ?/)
 464           (forward-char)
 465           (skip-chars-forward " \t")
 466           (setq save-pos (point))
 467           (skip-chars-forward "^; \t\n")
 468           (downcase-region save-pos (point))
 469           (setq minor
 470                 (cond
 471                  ((eq ?* (or (char-after save-pos) 0)) ".*")
 472                  ((= (point) save-pos) ".*")
 473                  (t (regexp-quote (buffer-substring save-pos (point)))))))
 474         (skip-chars-forward " \t")
 475         ;;; Got the major/minor chunks, now for the viewers/etc
 476         ;;; The first item _must_ be a viewer, according to the
 477         ;;; RFC for mailcap files (#1524)
 478         (setq viewer "")
 479         (when (eq (char-after) ?\;)
 480           (forward-char)
 481           (skip-chars-forward " \t")
 482           (setq save-pos (point))
 483           (skip-chars-forward "^;\n")
 484           ;; skip \;
 485           (while (eq (char-before) ?\\)
 486             (backward-delete-char 1)
 487             (forward-char)
 488             (skip-chars-forward "^;\n"))
 489           (if (eq (or (char-after save-pos) 0) ?')
 490               (setq viewer (progn
 491                              (narrow-to-region (1+ save-pos) (point))
 492                              (goto-char (point-min))
 493                              (prog1
 494                                  (read (current-buffer))
 495                                (goto-char (point-max))
 496                                (widen))))
 497             (setq viewer (buffer-substring save-pos (point)))))
 498         (setq save-pos (point))
 499         (end-of-line)
 500         (unless (equal viewer "")
 501           (setq info (nconc (list (cons 'viewer viewer)
 502                                   (cons 'type (concat major "/"
 503                                                       (if (string= minor ".*")
 504                                                           "*" minor))))
 505                             (mailcap-parse-mailcap-extras save-pos (point))))
 506           (mailcap-mailcap-entry-passes-test info)
 507           (mailcap-add-mailcap-entry major minor info))
 508         (beginning-of-line)))))
 509
 510 (defun mailcap-parse-mailcap-extras (st nd)
 511   "Grab all the extra stuff from a mailcap entry."
 512   (let (
 513         name                            ; From name=
 514         value                           ; its value
 515         results                         ; Assoc list of results
 516         name-pos                        ; Start of XXXX= position
 517         val-pos                         ; Start of value position
 518         done                            ; Found end of \'d ;s?
 519         )
 520     (save-restriction
 521       (narrow-to-region st nd)
 522       (goto-char (point-min))
 523       (skip-chars-forward " \n\t;")
 524       (while (not (eobp))
 525         (setq done nil)
 526         (setq name-pos (point))
 527         (skip-chars-forward "^ \n\t=;")
 528         (downcase-region name-pos (point))
 529         (setq name (buffer-substring name-pos (point)))
 530         (skip-chars-forward " \t\n")
 531         (if (not (eq (char-after (point)) ?=)) ; There is no value
 532             (setq value t)
 533           (skip-chars-forward " \t\n=")
 534           (setq val-pos (point))
 535           (if (memq (char-after val-pos) '(?\" ?'))
 536               (progn
 537                 (setq val-pos (1+ val-pos))
 538                 (condition-case nil
 539                     (progn
 540                       (forward-sexp 1)
 541                       (backward-char 1))
 542                   (error (goto-char (point-max)))))
 543             (while (not done)
 544               (skip-chars-forward "^;")
 545               (if (eq (char-after (1- (point))) ?\\ )
 546                   (progn
 547                     (subst-char-in-region (1- (point)) (point) ?\\ ? )
 548                     (skip-chars-forward ";"))
 549                 (setq done t))))
 550           (setq value (buffer-substring val-pos (point))))
 551         ;; `test' as symbol, others like "copiousoutput" and "needsx11" as
 552         ;; strings
 553         (setq results (cons (cons (if (string-equal name "test")
 554                                       'test
 555                                     name)
 556                                   value) results))
 557         (skip-chars-forward " \";\n\t"))
 558       results)))
 559
 560 (defun mailcap-mailcap-entry-passes-test (info)
 561   "Return non-nil if mailcap entry INFO passes its test clause.
 562 Also return non-nil if no test clause is present."
 563   (let ((test (assq 'test info))        ; The test clause
 564         status)
 565     (setq status (and test (split-string (cdr test) " ")))
 566     (if (and (or (assoc "needsterm" info)
 567                  (assoc "needsterminal" info)
 568                  (assoc "needsx11" info))
 569              (not (getenv "DISPLAY")))
 570         (setq status nil)
 571       (cond
 572        ((and (equal (nth 0 status) "test")
 573              (equal (nth 1 status) "-n")
 574              (or (equal (nth 2 status) "$DISPLAY")
 575                  (equal (nth 2 status) "\"$DISPLAY\"")))
 576         (setq status (if (getenv "DISPLAY") t nil)))
 577        ((and (equal (nth 0 status) "test")
 578              (equal (nth 1 status) "-z")
 579              (or (equal (nth 2 status) "$DISPLAY")
 580                  (equal (nth 2 status) "\"$DISPLAY\"")))
 581         (setq status (if (getenv "DISPLAY") nil t)))
 582        (test nil)
 583        (t nil)))
 584     (and test (listp test) (setcdr test status))))
 585
 586 ;;;
 587 ;;; The action routines.
 588 ;;;
 589
 590 (defun mailcap-possible-viewers (major minor)
 591   "Return a list of possible viewers from MAJOR for minor type MINOR."
 592   (let ((exact '())
 593         (wildcard '()))
 594     (while major
 595       (cond
 596        ((equal (car (car major)) minor)
 597         (setq exact (cons (cdr (car major)) exact)))
 598        ((and minor (string-match (concat "^" (car (car major)) "$") minor))
 599         (setq wildcard (cons (cdr (car major)) wildcard))))
 600       (setq major (cdr major)))
 601     (nconc exact wildcard)))
 602
 603 (defun mailcap-unescape-mime-test (test type-info)
 604   (let (save-pos save-chr subst)
 605     (cond
 606      ((symbolp test) test)
 607      ((and (listp test) (symbolp (car test))) test)
 608      ((or (stringp test)
 609           (and (listp test) (stringp (car test))
 610                (setq test (mapconcat 'identity test " "))))
 611       (with-temp-buffer
 612         (insert test)
 613         (goto-char (point-min))
 614         (while (not (eobp))
 615           (skip-chars-forward "^%")
 616           (if (/= (- (point)
 617                      (progn (skip-chars-backward "\\\\")
 618                             (point)))
 619                   0)                    ; It is an escaped %
 620               (progn
 621                 (delete-char 1)
 622                 (skip-chars-forward "%."))
 623             (setq save-pos (point))
 624             (skip-chars-forward "%")
 625             (setq save-chr (char-after (point)))
 626             ;; Escapes:
 627             ;; %s: name of a file for the body data
 628             ;; %t: content-type
 629             ;; %{<parameter name}: value of parameter in mailcap entry
 630             ;; %n: number of sub-parts for multipart content-type
 631             ;; %F: a set of content-type/filename pairs for multiparts
 632             (cond
 633              ((null save-chr) nil)
 634              ((= save-chr ?t)
 635               (delete-region save-pos (progn (forward-char 1) (point)))
 636               (insert (or (cdr (assq 'type type-info)) "\"\"")))
 637              ((memq save-chr '(?M ?n ?F))
 638               (delete-region save-pos (progn (forward-char 1) (point)))
 639               (insert "\"\""))
 640              ((= save-chr ?{)
 641               (forward-char 1)
 642               (skip-chars-forward "^}")
 643               (downcase-region (+ 2 save-pos) (point))
 644               (setq subst (buffer-substring (+ 2 save-pos) (point)))
 645               (delete-region save-pos (1+ (point)))
 646               (insert (or (cdr (assoc subst type-info)) "\"\"")))
 647              (t nil))))
 648         (buffer-string)))
 649      (t (error "Bad value to mailcap-unescape-mime-test: %s" test)))))
 650
 651 (defvar mailcap-viewer-test-cache nil)
 652
 653 (defun mailcap-viewer-passes-test (viewer-info type-info)
 654   "Return non-nil if viewer specified by VIEWER-INFO passes its test clause.
 655 Also return non-nil if it has no test clause.  TYPE-INFO is an argument
 656 to supply to the test."
 657   (let* ((test-info (assq 'test viewer-info))
 658          (test (cdr test-info))
 659          (otest test)
 660          (viewer (cdr (assoc 'viewer viewer-info)))
 661          (default-directory (expand-file-name "~/"))
 662          status parsed-test cache result)
 663     (cond ((setq cache (assoc test mailcap-viewer-test-cache))
 664            (cadr cache))
 665           ((not test-info) t)           ; No test clause
 666           (t
 667            (setq
 668             result
 669             (cond
 670              ((not test) nil)           ; Already failed test
 671              ((eq test t) t)            ; Already passed test
 672              ((functionp test)          ; Lisp function as test
 673               (funcall test type-info))
 674              ((and (symbolp test)       ; Lisp variable as test
 675                    (boundp test))
 676               (symbol-value test))
 677              ((and (listp test)         ; List to be eval'd
 678                    (symbolp (car test)))
 679               (eval test))
 680              (t
 681               (setq test (mailcap-unescape-mime-test test type-info)
 682                     test (list shell-file-name nil nil nil
 683                                shell-command-switch test)
 684                     status (apply 'call-process test))
 685               (eq 0 status))))
 686            (push (list otest result) mailcap-viewer-test-cache)
 687            result))))
 688
 689 (defun mailcap-add-mailcap-entry (major minor info)
 690   (let ((old-major (assoc major mailcap-mime-data)))
 691     (if (null old-major)                ; New major area
 692         (setq mailcap-mime-data
 693               (cons (cons major (list (cons minor info)))
 694                     mailcap-mime-data))
 695       (let ((cur-minor (assoc minor old-major)))
 696         (cond
 697          ((or (null cur-minor)          ; New minor area, or
 698               (assq 'test info))        ; Has a test, insert at beginning
 699           (setcdr old-major (cons (cons minor info) (cdr old-major))))
 700          ((and (not (assq 'test info))  ; No test info, replace completely
 701                (not (assq 'test cur-minor))
 702                (equal (assq 'viewer info)  ; Keep alternative viewer
 703                       (assq 'viewer cur-minor)))
 704           (setcdr cur-minor info))
 705          (t
 706           (setcdr old-major (cons (cons minor info) (cdr old-major))))))
 707       )))
 708
 709 (defun mailcap-add (type viewer &optional test)
 710   "Add VIEWER as a handler for TYPE.
 711 If TEST is not given, it defaults to t."
 712   (let ((tl (split-string type "/")))
 713     (when (or (not (car tl))
 714               (not (cadr tl)))
 715       (error "%s is not a valid MIME type" type))
 716     (mailcap-add-mailcap-entry
 717      (car tl) (cadr tl)
 718      `((viewer . ,viewer)
 719        (test . ,(if test test t))
 720        (type . ,type)))))
 721
 722 ;;;
 723 ;;; The main whabbo
 724 ;;;
 725
 726 (defun mailcap-viewer-lessp (x y)
 727   "Return t if viewer X is more desirable than viewer Y."
 728   (let ((x-wild (string-match "[*?]" (or (cdr-safe (assq 'type x)) "")))
 729         (y-wild (string-match "[*?]" (or (cdr-safe (assq 'type y)) "")))
 730         (x-lisp (not (stringp (or (cdr-safe (assq 'viewer x)) ""))))
 731         (y-lisp (not (stringp (or (cdr-safe (assq 'viewer y)) "")))))
 732     (cond
 733      ((and x-wild (not y-wild))
 734       nil)
 735      ((and (not x-wild) y-wild)
 736       t)
 737      ((and (not y-lisp) x-lisp)
 738       t)
 739      (t nil))))
 740
 741 (defun mailcap-mime-info (string &optional request no-decode)
 742   "Get the MIME viewer command for STRING, return nil if none found.
 743 Expects a complete content-type header line as its argument.
 744
 745 Second argument REQUEST specifies what information to return.  If it is
 746 nil or the empty string, the viewer (second field of the mailcap
 747 entry) will be returned.  If it is a string, then the mailcap field
 748 corresponding to that string will be returned (print, description,
 749 whatever).  If a number, then all the information for this specific
 750 viewer is returned.  If `all', then all possible viewers for
 751 this type is returned.
 752
 753 If NO-DECODE is non-nil, don't decode STRING."
 754   ;; NO-DECODE avoids calling `mail-header-parse-content-type' from
 755   ;; `mail-parse.el'
 756   (let (
 757         major                           ; Major encoding (text, etc)
 758         minor                           ; Minor encoding (html, etc)
 759         info                            ; Other info
 760         save-pos                        ; Misc. position during parse
 761         major-info                      ; (assoc major mailcap-mime-data)
 762         minor-info                      ; (assoc minor major-info)
 763         test                            ; current test proc.
 764         viewers                         ; Possible viewers
 765         passed                          ; Viewers that passed the test
 766         viewer                          ; The one and only viewer
 767         ctl)
 768     (save-excursion
 769       (setq ctl
 770             (if no-decode
 771                 (list (or string "text/plain"))
 772               (mail-header-parse-content-type (or string "text/plain"))))
 773       (setq major (split-string (car ctl) "/"))
 774       (setq minor (cadr major)
 775             major (car major))
 776       (when (setq major-info (cdr (assoc major mailcap-mime-data)))
 777         (when (setq viewers (mailcap-possible-viewers major-info minor))
 778           (setq info (mapcar (lambda (a) (cons (symbol-name (car a))
 779                                                (cdr a)))
 780                              (cdr ctl)))
 781           (while viewers
 782             (if (mailcap-viewer-passes-test (car viewers) info)
 783                 (setq passed (cons (car viewers) passed)))
 784             (setq viewers (cdr viewers)))
 785           (setq passed (sort passed 'mailcap-viewer-lessp))
 786           (setq viewer (car passed))))
 787       (when (and (stringp (cdr (assq 'viewer viewer)))
 788                  passed)
 789         (setq viewer (car passed)))
 790       (cond
 791        ((and (null viewer) (not (equal major "default")) request)
 792         (mailcap-mime-info "default" request no-decode))
 793        ((or (null request) (equal request ""))
 794         (mailcap-unescape-mime-test (cdr (assq 'viewer viewer)) info))
 795        ((stringp request)
 796         (mailcap-unescape-mime-test
 797          (cdr-safe (assoc request viewer)) info))
 798        ((eq request 'all)
 799         passed)
 800        (t
 801         ;; MUST make a copy *sigh*, else we modify mailcap-mime-data
 802         (setq viewer (copy-sequence viewer))
 803         (let ((view (assq 'viewer viewer))
 804               (test (assq 'test viewer)))
 805           (if view (setcdr view (mailcap-unescape-mime-test (cdr view) info)))
 806           (if test (setcdr test (mailcap-unescape-mime-test (cdr test) info))))
 807         viewer)))))
 808
 809 ;;;
 810 ;;; Experimental MIME-types parsing
 811 ;;;
 812
 813 (defvar mailcap-mime-extensions
 814   '((""       . "text/plain")
 815     (".1"     . "text/plain")  ;; Manual pages
 816     (".3"     . "text/plain")
 817     (".8"     . "text/plain")
 818     (".abs"   . "audio/x-mpeg")
 819     (".aif"   . "audio/aiff")
 820     (".aifc"  . "audio/aiff")
 821     (".aiff"  . "audio/aiff")
 822     (".ano"   . "application/x-annotator")
 823     (".au"    . "audio/ulaw")
 824     (".avi"   . "video/x-msvideo")
 825     (".bcpio" . "application/x-bcpio")
 826     (".bin"   . "application/octet-stream")
 827     (".cdf"   . "application/x-netcdr")
 828     (".cpio"  . "application/x-cpio")
 829     (".csh"   . "application/x-csh")
 830     (".css"   . "text/css")
 831     (".dvi"   . "application/x-dvi")
 832     (".diff"  . "text/x-patch")
 833     (".dpatch". "test/x-patch")
 834     (".el"    . "application/emacs-lisp")
 835     (".eps"   . "application/postscript")
 836     (".etx"   . "text/x-setext")
 837     (".exe"   . "application/octet-stream")
 838     (".fax"   . "image/x-fax")
 839     (".gif"   . "image/gif")
 840     (".hdf"   . "application/x-hdf")
 841     (".hqx"   . "application/mac-binhex40")
 842     (".htm"   . "text/html")
 843     (".html"  . "text/html")
 844     (".icon"  . "image/x-icon")
 845     (".ief"   . "image/ief")
 846     (".jpg"   . "image/jpeg")
 847     (".macp"  . "image/x-macpaint")
 848     (".man"   . "application/x-troff-man")
 849     (".me"    . "application/x-troff-me")
 850     (".mif"   . "application/mif")
 851     (".mov"   . "video/quicktime")
 852     (".movie" . "video/x-sgi-movie")
 853     (".mp2"   . "audio/x-mpeg")
 854     (".mp3"   . "audio/x-mpeg")
 855     (".mp2a"  . "audio/x-mpeg2")
 856     (".mpa"   . "audio/x-mpeg")
 857     (".mpa2"  . "audio/x-mpeg2")
 858     (".mpe"   . "video/mpeg")
 859     (".mpeg"  . "video/mpeg")
 860     (".mpega" . "audio/x-mpeg")
 861     (".mpegv" . "video/mpeg")
 862     (".mpg"   . "video/mpeg")
 863     (".mpv"   . "video/mpeg")
 864     (".ms"    . "application/x-troff-ms")
 865     (".nc"    . "application/x-netcdf")
 866     (".nc"    . "application/x-netcdf")
 867     (".oda"   . "application/oda")
 868     (".patch" . "text/x-patch")
 869     (".pbm"   . "image/x-portable-bitmap")
 870     (".pdf"   . "application/pdf")
 871     (".pgm"   . "image/portable-graymap")
 872     (".pict"  . "image/pict")
 873     (".png"   . "image/png")
 874     (".pnm"   . "image/x-portable-anymap")
 875     (".pod"   . "text/plain")
 876     (".ppm"   . "image/portable-pixmap")
 877     (".ps"    . "application/postscript")
 878     (".qt"    . "video/quicktime")
 879     (".ras"   . "image/x-raster")
 880     (".rgb"   . "image/x-rgb")
 881     (".rtf"   . "application/rtf")
 882     (".rtx"   . "text/richtext")
 883     (".sh"    . "application/x-sh")
 884     (".sit"   . "application/x-stuffit")
 885     (".siv"   . "application/sieve")
 886     (".snd"   . "audio/basic")
 887     (".soa"   . "text/dns")
 888     (".src"   . "application/x-wais-source")
 889     (".tar"   . "archive/tar")
 890     (".tcl"   . "application/x-tcl")
 891     (".tex"   . "application/x-tex")
 892     (".texi"  . "application/texinfo")
 893     (".tga"   . "image/x-targa")
 894     (".tif"   . "image/tiff")
 895     (".tiff"  . "image/tiff")
 896     (".tr"    . "application/x-troff")
 897     (".troff" . "application/x-troff")
 898     (".tsv"   . "text/tab-separated-values")
 899     (".txt"   . "text/plain")
 900     (".vbs"   . "video/mpeg")
 901     (".vox"   . "audio/basic")
 902     (".vrml"  . "x-world/x-vrml")
 903     (".wav"   . "audio/x-wav")
 904     (".xls"   . "application/vnd.ms-excel")
 905     (".wrl"   . "x-world/x-vrml")
 906     (".xbm"   . "image/xbm")
 907     (".xpm"   . "image/xpm")
 908     (".xwd"   . "image/windowdump")
 909     (".zip"   . "application/zip")
 910     (".ai"    . "application/postscript")
 911     (".jpe"   . "image/jpeg")
 912     (".jpeg"  . "image/jpeg")
 913     (".org"   . "text/x-org"))
 914   "An alist of file extensions and corresponding MIME content-types.
 915 This exists for you to customize the information in Lisp.  It is
 916 merged with values from mailcap files by `mailcap-parse-mimetypes'.")
 917
 918 (defvar mailcap-mimetypes-parsed-p nil)
 919
 920 (defun mailcap-parse-mimetypes (&optional path force)
 921   "Parse out all the mimetypes specified in a Unix-style path string PATH.
 922 Components of PATH are separated by the `path-separator' character
 923 appropriate for this system.  If PATH is omitted, use the value of
 924 environment variable MIMETYPES if set; otherwise use a default path.
 925 If FORCE, re-parse even if already parsed."
 926   (interactive (list nil t))
 927   (when (or (not mailcap-mimetypes-parsed-p)
 928             force)
 929     (cond
 930      (path nil)
 931      ((getenv "MIMETYPES") (setq path (getenv "MIMETYPES")))
 932      ((memq system-type mailcap-poor-system-types)
 933       (setq path '("~/mime.typ" "~/etc/mime.typ")))
 934      (t (setq path
 935               ;; mime.types seems to be the normal name, definitely so
 936               ;; on current GNUish systems.  The search order follows
 937               ;; that for mailcap.
 938               '("~/.mime.types"
 939                 "/etc/mime.types"
 940                 "/usr/etc/mime.types"
 941                 "/usr/local/etc/mime.types"
 942                 "/usr/local/www/conf/mime.types"
 943                 "~/.mime-types"
 944                 "/etc/mime-types"
 945                 "/usr/etc/mime-types"
 946                 "/usr/local/etc/mime-types"
 947                 "/usr/local/www/conf/mime-types"))))
 948     (let ((fnames (reverse (if (stringp path)
 949                                (split-string path path-separator t)
 950                              path)))
 951           fname)
 952       (while fnames
 953         (setq fname (car fnames))
 954         (if (and (file-readable-p fname))
 955             (mailcap-parse-mimetype-file fname))
 956         (setq fnames (cdr fnames))))
 957     (setq mailcap-mimetypes-parsed-p t)))
 958
 959 (defun mailcap-parse-mimetype-file (fname)
 960   "Parse out a mime-types file FNAME."
 961   (let (type                            ; The MIME type for this line
 962         extns                           ; The extensions for this line
 963         save-pos                        ; Misc. saved buffer positions
 964         )
 965     (with-temp-buffer
 966       (insert-file-contents fname)
 967       (mailcap-replace-regexp "#.*" "")
 968       (mailcap-replace-regexp "\n+" "\n")
 969       (mailcap-replace-regexp "[ \t]+$" "")
 970       (goto-char (point-max))
 971       (skip-chars-backward " \t\n")
 972       (delete-region (point) (point-max))
 973       (goto-char (point-min))
 974       (while (not (eobp))
 975         (skip-chars-forward " \t\n")
 976         (setq save-pos (point))
 977         (skip-chars-forward "^ \t\n")
 978         (downcase-region save-pos (point))
 979         (setq type (buffer-substring save-pos (point)))
 980         (while (not (eolp))
 981           (skip-chars-forward " \t")
 982           (setq save-pos (point))
 983           (skip-chars-forward "^ \t\n")
 984           (setq extns (cons (buffer-substring save-pos (point)) extns)))
 985         (while extns
 986           (setq mailcap-mime-extensions
 987                 (cons
 988                  (cons (if (= (string-to-char (car extns)) ?.)
 989                            (car extns)
 990                          (concat "." (car extns))) type)
 991                  mailcap-mime-extensions)
 992                 extns (cdr extns)))))))
 993
 994 (defun mailcap-extension-to-mime (extn)
 995   "Return the MIME content type of the file extensions EXTN."
 996   (mailcap-parse-mimetypes)
 997   (if (and (stringp extn)
 998            (not (eq (string-to-char extn) ?.)))
 999       (setq extn (concat "." extn)))
1000   (cdr (assoc (downcase extn) mailcap-mime-extensions)))
1001
1002 ;; Unused?
1003 (defalias 'mailcap-command-p 'executable-find)
1004
1005 (defun mailcap-mime-types ()
1006   "Return a list of MIME media types."
1007   (mailcap-parse-mimetypes)
1008   (mailcap-delete-duplicates
1009    (nconc
1010     (mapcar 'cdr mailcap-mime-extensions)
1011     (apply
1012      'nconc
1013      (mapcar
1014       (lambda (l)
1015         (delq nil
1016               (mapcar
1017                (lambda (m)
1018                  (let ((type (cdr (assq 'type (cdr m)))))
1019                    (if (equal (cadr (split-string type "/"))
1020                               "*")
1021                        nil
1022                      type)))
1023                (cdr l))))
1024       mailcap-mime-data)))))
1025
1026 ;;;
1027 ;;; Useful supplementary functions
1028 ;;;
1029
1030 (defun mailcap-file-default-commands (files)
1031   "Return a list of default commands for FILES."
1032   (mailcap-parse-mailcaps)
1033   (mailcap-parse-mimetypes)
1034   (let* ((all-mime-type
1035           ;; All unique MIME types from file extensions
1036           (mailcap-delete-duplicates
1037            (mapcar (lambda (file)
1038                      (mailcap-extension-to-mime
1039                       (file-name-extension file t)))
1040                    files)))
1041          (all-mime-info
1042           ;; All MIME info lists
1043           (mailcap-delete-duplicates
1044            (mapcar (lambda (mime-type)
1045                      (mailcap-mime-info mime-type 'all))
1046                    all-mime-type)))
1047          (common-mime-info
1048           ;; Intersection of mime-infos from different mime-types;
1049           ;; or just the first MIME info for a single MIME type
1050           (if (cdr all-mime-info)
1051               (delq nil (mapcar (lambda (mi1)
1052                                   (unless (memq nil (mapcar
1053                                                      (lambda (mi2)
1054                                                        (member mi1 mi2))
1055                                                      (cdr all-mime-info)))
1056                                     mi1))
1057                                 (car all-mime-info)))
1058             (car all-mime-info)))
1059          (commands
1060           ;; Command strings from `viewer' field of the MIME info
1061           (mailcap-delete-duplicates
1062            (delq nil (mapcar (lambda (mime-info)
1063                                (let ((command (cdr (assoc 'viewer mime-info))))
1064                                  (if (stringp command)
1065                                      (mailcap-replace-in-string
1066                                       ;; Replace mailcap's `%s' placeholder
1067                                       ;; with dired's `?' placeholder
1068                                       (mailcap-replace-in-string
1069                                        ;; Remove the final filename placeholder
1070                                        command "[ \t\n]*\\('\\)?%s\\1?[ \t\n]*\\'" "" t)
1071                                       "%s" "?" t))))
1072                              common-mime-info)))))
1073     commands))
1074
1075 (provide 'mailcap)
1076
1077 ;;; mailcap.el ends here