1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
| | ;;; mailcap.el --- MIME media types configuration -*- lexical-binding: t -*-
;; Copyright (C) 1998-2024 Free Software Foundation, Inc.
;; Author: William M. Perry <wmperry@aventail.com>
;; Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news, mail, multimedia
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; Provides configuration of MIME media types from directly from Lisp
;; and via the usual mailcap mechanism (RFC 1524). Deals with
;; mime.types similarly.
;;; Code:
(require 'cl-lib)
(autoload 'mail-header-parse-content-type "mail-parse")
(defgroup mailcap nil
"Definition of viewers for MIME types."
:version "21.1"
:group 'mime)
(defcustom mailcap-prefer-mailcap-viewers t
"If non-nil, prefer viewers specified in ~/.mailcap.
If nil, the most specific viewer will be chosen, even if there is
a general override in ~/.mailcap. For instance, if /etc/mailcap
has an entry for \"image/gif\", that one will be chosen even if
you have an entry for \"image/*\" in your ~/.mailcap file."
:type 'boolean)
(defvar mailcap-parse-args-syntax-table
(let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
(modify-syntax-entry ?' "\"" table)
(modify-syntax-entry ?` "\"" table)
(modify-syntax-entry ?{ "(" table)
(modify-syntax-entry ?} ")" table)
table)
"A syntax table for parsing SGML attributes.")
(defvar mailcap-print-command
(mapconcat #'identity
(cons (if (boundp 'lpr-command)
lpr-command
"lpr")
(when (boundp 'lpr-switches)
(if (stringp lpr-switches)
(list lpr-switches)
lpr-switches)))
" ")
"Shell command (including switches) used to print PostScript files.")
(defun mailcap--get-user-mime-data (sym)
(let ((val (default-value sym))
res)
(dolist (entry val)
(push (list (cdr (assq 'viewer entry))
(cdr (assq 'type entry))
(cdr (assq 'test entry)))
res))
(nreverse res)))
(defun mailcap--set-user-mime-data (sym val)
(let (res)
(pcase-dolist (`(,viewer ,type ,test) val)
(push `((viewer . ,viewer)
(type . ,type)
,@(when test `((test . ,test))))
res))
(set-default sym (nreverse res))))
(defcustom mailcap-user-mime-data nil
"A list of viewers preferred for different MIME types.
The elements of the list are lists of the following structure
(VIEWER MIME-TYPE TEST)
where VIEWER is either a Lisp command, e.g., a major mode, or a
string containing a shell command for viewing files of the
defined MIME-TYPE. In case of a shell command, %s will be
replaced with the file.
MIME-TYPE is a regular expression being matched against the
actual MIME type. It is implicitly surrounded with ^ and $.
TEST is a Lisp form which is evaluated in order to test if the
entry should be chosen. The `test' entry is optional.
When selecting a viewer for a given MIME type, the first viewer
in this list with a matching MIME-TYPE and successful TEST is
selected. Only if none matches, the standard `mailcap-mime-data'
is consulted."
:version "26.1"
:type '(repeat
(list
(choice (function :tag "Function or mode")
(string :tag "Shell command"))
(regexp :tag "MIME Type")
(sexp :tag "Test (optional)")))
:get #'mailcap--get-user-mime-data
:set #'mailcap--set-user-mime-data)
;; Postpone using defcustom for this as it's so big and we essentially
;; have to have two copies of the data around then. Perhaps just
;; customize the Lisp viewers and rely on the normal configuration
;; files for the rest? -- fx
(defvar mailcap-mime-data
`(("application"
("vnd\\.ms-excel"
(viewer . "gnumeric %s")
(test . (getenv "DISPLAY"))
(type . "application/vnd\\.ms-excel"))
("octet-stream"
(viewer . mailcap-save-binary-file)
(non-viewer . t)
(type . "application/octet-stream"))
("dvi"
(viewer . "xdvi -safer %s")
(test . (eq window-system 'x))
("needsx11")
(type . "application/dvi")
("print" . "dvips -qRP %s"))
("dvi"
(viewer . "dvitty %s")
(test . (not (getenv "DISPLAY")))
(type . "application/dvi")
("print" . "dvips -qRP %s"))
("emacs-lisp"
(viewer . mailcap-maybe-eval)
(type . "application/emacs-lisp"))
("x-emacs-lisp"
(viewer . mailcap-maybe-eval)
(type . "application/x-emacs-lisp"))
("x-tar"
(viewer . mailcap-save-binary-file)
(non-viewer . t)
(type . "application/x-tar"))
("x-latex"
(viewer . tex-mode)
(type . "application/x-latex"))
("x-tex"
(viewer . tex-mode)
(type . "application/x-tex"))
("latex"
(viewer . tex-mode)
(type . "application/latex"))
("tex"
(viewer . tex-mode)
(type . "application/tex"))
("texinfo"
(viewer . texinfo-mode)
(type . "application/tex"))
("zip"
(viewer . mailcap-save-binary-file)
(non-viewer . t)
(type . "application/zip")
("copiousoutput"))
("pdf"
(viewer . doc-view-mode)
(type . "application/pdf")
(test . window-system))
("pdf"
(viewer . pdf-view-mode)
(type . "application/pdf")
(test . window-system))
("pdf"
(viewer . "gv -safer %s")
(type . "application/pdf")
(test . window-system)
("print" . ,(concat "pdf2ps %s - | " mailcap-print-command)))
("pdf"
(viewer . "gpdf %s")
(type . "application/pdf")
("print" . ,(concat "pdftops %s - | " mailcap-print-command))
(test . (eq window-system 'x)))
("pdf"
(viewer . "xpdf %s")
(type . "application/pdf")
("print" . ,(concat "pdftops %s - | " mailcap-print-command))
(test . (eq window-system 'x)))
("pdf"
(viewer . ,(concat "pdftotext %s -"))
(type . "application/pdf")
("print" . ,(concat "pdftops %s - | " mailcap-print-command))
("copiousoutput"))
("postscript"
(viewer . "gv -safer %s")
(type . "application/postscript")
(test . window-system)
("print" . ,(concat mailcap-print-command " %s"))
("needsx11"))
("postscript"
(viewer . "ghostview -dSAFER %s")
(type . "application/postscript")
(test . (eq window-system 'x))
("print" . ,(concat mailcap-print-command " %s"))
("needsx11"))
("postscript"
(viewer . "ps2ascii %s")
(type . "application/postscript")
(test . (not (getenv "DISPLAY")))
("print" . ,(concat mailcap-print-command " %s"))
("copiousoutput"))
("sieve"
(viewer . sieve-mode)
(type . "application/sieve"))
("pgp-keys"
(viewer . "gpg --import --interactive --verbose")
(type . "application/pgp-keys")
("needsterminal")))
("audio"
("x-mpeg"
(viewer . "maplay %s")
(type . "audio/x-mpeg"))
(".*"
(viewer . "showaudio")
(type . "audio/*")))
("message"
("rfc-*822"
(viewer . mm-view-message)
(test . (and (featurep 'gnus)
(gnus-alive-p)))
(type . "message/rfc822"))
("rfc-*822"
(viewer . vm-mode)
(type . "message/rfc822"))
("rfc-*822"
(viewer . view-mode)
(type . "message/rfc822")))
("image"
("x-xwd"
(viewer . "xwud -in %s")
(type . "image/x-xwd")
("compose" . "xwd -frame > %s")
(test . (eq window-system 'x))
("needsx11"))
("x11-dump"
(viewer . "xwud -in %s")
(type . "image/x-xwd")
("compose" . "xwd -frame > %s")
(test . (eq window-system 'x))
("needsx11"))
("windowdump"
(viewer . "xwud -in %s")
(type . "image/x-xwd")
("compose" . "xwd -frame > %s")
(test . (eq window-system 'x))
("needsx11"))
(".*"
(viewer . "display %s")
(type . "image/*")
(test . (eq window-system 'x))
("needsx11")))
("text"
("plain"
(viewer . view-mode)
(type . "text/plain"))
("plain"
(viewer . fundamental-mode)
(type . "text/plain"))
("enriched"
(viewer . enriched-decode)
(type . "text/enriched"))
("dns"
(viewer . dns-mode)
(type . "text/dns")))
("video"
("mpeg"
(viewer . "mpeg_play %s")
(type . "video/mpeg")
(test . (eq window-system 'x))
("needsx11")))
("x-world"
("x-vrml"
(viewer . "webspace -remote %s -URL %u")
(type . "x-world/x-vrml")
("description"
"VRML document")))
("archive"
("tar"
(viewer . tar-mode)
(type . "archive/tar"))))
"The mailcap structure is an assoc list of assoc lists.
1st assoc list is keyed on the major content-type
2nd assoc list is keyed on the minor content-type (which can be a regexp)
Which looks like:
-----------------
((\"application\"
(\"postscript\" . <info>))
(\"text\"
(\"plain\" . <info>)))
Where <info> is another assoc list of the various information
related to the mailcap RFC 1524. This is keyed on the lowercase
attribute name (viewer, test, etc). This looks like:
((viewer . VIEWERINFO)
(test . TESTINFO)
(xxxx . \"STRING\")
FLAG)
Where VIEWERINFO specifies how the content-type is viewed. Can be
a string, in which case it is run through a shell, with appropriate
parameters, or a symbol, in which case the symbol must name a function
of zero arguments which is called in a buffer holding the MIME part's
content.
TESTINFO is a test for the viewer's applicability, or nil. If nil, it
means the viewer is always valid. If it is a Lisp function, it is
called with a list of items from any extra fields from the
Content-Type header as argument to return a boolean value for the
validity. Otherwise, if it is a non-function Lisp symbol or list
whose car is a symbol, it is `eval'uated to yield the validity. If it
is a string or list of strings, it represents a shell command to run
to return a true or false shell value for the validity.
The last matching entry in this structure takes precedence over
preceding entries.")
(put 'mailcap-mime-data 'risky-local-variable t)
(defvar mailcap--computed-mime-data nil
"Computed version of the mailcap data incorporating all sources.
Same format as `mailcap-mime-data'.")
(defcustom mailcap-download-directory nil
"Directory to which `mailcap-save-binary-file' downloads files by default.
nil means your home directory."
:type '(choice (const :tag "Home directory" nil)
directory))
(defvar mailcap-poor-system-types
'(ms-dos windows-nt)
"Systems that don't have a Unix-like directory hierarchy.")
;;;
;;; Utility functions
;;;
(defun mailcap-save-binary-file ()
(goto-char (point-min))
(unwind-protect
(let ((file (read-file-name
"Filename to save as: "
(or mailcap-download-directory "~/")))
(require-final-newline nil))
(write-region (point-min) (point-max) file))
(kill-buffer (current-buffer))))
(defvar mailcap-maybe-eval-warning
"*** WARNING ***
This MIME part contains untrusted and possibly harmful content.
If you evaluate the Emacs Lisp code contained in it, a lot of nasty
things can happen. Please examine the code very carefully before you
instruct Emacs to evaluate it. You can browse the buffer containing
the code using \\[scroll-other-window].
If you are unsure what to do, please answer \"no\"."
"Text of warning message displayed by `mailcap-maybe-eval'.
Make sure that this text consists only of few text lines. Otherwise,
Gnus might fail to display all of it.")
(defun mailcap-maybe-eval ()
"Maybe evaluate a buffer of Emacs Lisp code."
(let ((lisp-buffer (current-buffer)))
(goto-char (point-min))
(when
(save-window-excursion
(delete-other-windows)
(let ((buffer (generate-new-buffer "*Warning*")))
(unwind-protect
(with-current-buffer buffer
(insert (substitute-command-keys
mailcap-maybe-eval-warning))
(goto-char (point-min))
(display-buffer buffer)
(yes-or-no-p "This is potentially dangerous emacs-lisp code, evaluate it? "))
(kill-buffer buffer))))
(eval-buffer (current-buffer)))
(when (buffer-live-p lisp-buffer)
(with-current-buffer lisp-buffer
(emacs-lisp-mode)))))
;;;
;;; The mailcap parser
;;;
(defun mailcap-replace-regexp (regexp to-string)
;; Quiet replace-regexp.
(goto-char (point-min))
(while (re-search-forward regexp nil t)
(replace-match to-string t nil)))
(defvar mailcap-parsed-p nil)
(defun mailcap-parse-mailcaps (&optional path force)
"Parse out all the mailcaps specified in a path string PATH.
Components of PATH are separated by the `path-separator' character
appropriate for this system. If FORCE, re-parse even if already
parsed. If PATH is omitted, use the value of environment variable
MAILCAPS if set; otherwise (on Unix) use the path from RFC 1524, plus
/usr/local/etc/mailcap."
(interactive (list nil t))
(when (or (not mailcap-parsed-p)
force)
(cond
(path nil)
((getenv "MAILCAPS")
(setq path (getenv "MAILCAPS")))
((memq system-type mailcap-poor-system-types)
(setq path '(("~/.mailcap" user)
("~/mail.cap" user)
("~/etc/mail.cap" user))))
(t
(setq path
;; This is per RFC 1524, specifically with /usr before
;; /usr/local.
'(("~/.mailcap" user)
("/etc/mailcap" system)
("/usr/etc/mailcap" system)
("/usr/local/etc/mailcap" system)))))
(when (stringp path)
(setq path (mapcar #'list (split-string path path-separator t))))
(when (or (null mailcap--computed-mime-data)
(seq-some (lambda (f)
(file-has-changed-p (car f) 'mail-parse-mailcaps))
path))
;; Clear out all old data.
(setq mailcap--computed-mime-data nil)
;; Add the Emacs-distributed defaults (which will be used as
;; fallbacks). Do it this way instead of just copying the list,
;; since entries are destructively modified.
(cl-loop for (major . minors) in mailcap-mime-data
do (cl-loop for (minor . entry) in minors
do (mailcap-add-mailcap-entry major minor entry)))
;; The ~/.mailcap entries will end up first in the resulting data.
(dolist (spec (reverse path))
(let ((source (cadr spec))
(file-name (car spec)))
(when (and (file-readable-p file-name)
(file-regular-p file-name))
(mailcap-parse-mailcap file-name source)))))
(setq mailcap-parsed-p t)))
(defun mailcap-parse-mailcap (fname &optional source)
"Parse out the mailcap file specified by FNAME.
If SOURCE, mark the entry with this as the source."
(let (major ; The major mime type (image/audio/etc)
minor ; The minor mime type (gif, basic, etc)
save-pos ; Misc saved positions used in parsing
viewer ; How to view this mime type
info ; Misc info about this mime type
)
(with-temp-buffer
(insert-file-contents fname)
(set-syntax-table mailcap-parse-args-syntax-table)
(mailcap-replace-regexp "#.*" "") ; Remove all comments
(mailcap-replace-regexp "\\\\[ \t]*\n" " ") ; And collapse spaces
(mailcap-replace-regexp "\n+" "\n") ; And blank lines
(goto-char (point-max))
(skip-chars-backward " \t\n")
(delete-region (point) (point-max))
(while (not (bobp))
(skip-chars-backward " \t\n")
(beginning-of-line)
(setq save-pos (point)
info nil)
(skip-chars-forward "^/; \t\n")
(downcase-region save-pos (point))
(setq major (buffer-substring save-pos (point)))
(skip-chars-forward " \t")
(setq minor "")
(when (eq (char-after) ?/)
(forward-char)
(skip-chars-forward " \t")
(setq save-pos (point))
(skip-chars-forward "^; \t\n")
(downcase-region save-pos (point))
(setq minor
(cond
((eq ?* (or (char-after save-pos) 0)) ".*")
((= (point) save-pos) ".*")
(t (regexp-quote (buffer-substring save-pos (point)))))))
(skip-chars-forward " \t")
;;; Got the major/minor chunks, now for the viewers/etc
;;; The first item _must_ be a viewer, according to the
;;; RFC for mailcap files (#1524)
(setq viewer "")
(when (eq (char-after) ?\;)
(forward-char)
(skip-chars-forward " \t")
(setq save-pos (point))
(skip-chars-forward "^;\n")
;; skip \;
(while (eq (char-before) ?\\)
(delete-char -1)
(forward-char)
(skip-chars-forward "^;\n"))
(if (eq (or (char-after save-pos) 0) ?')
(setq viewer (progn
(narrow-to-region (1+ save-pos) (point))
(goto-char (point-min))
(prog1
(read (current-buffer))
(goto-char (point-max))
(widen))))
(setq viewer (buffer-substring save-pos (point)))))
(setq save-pos (point))
(end-of-line)
(unless (equal viewer "")
(setq info (nconc (list (cons 'viewer viewer)
(cons 'type (concat major "/"
(if (string= minor ".*")
"*" minor))))
(mailcap-parse-mailcap-extras save-pos (point))))
(mailcap-mailcap-entry-passes-test info)
;; Record where the data came from.
(when source
(setq info (nconc info (list (cons 'source source)))))
(mailcap-add-mailcap-entry major minor info))
(beginning-of-line)))))
(defun mailcap-parse-mailcap-extras (st nd)
"Grab all the extra stuff from a mailcap entry."
(let (
name ; From name=
value ; its value
results ; Assoc list of results
name-pos ; Start of XXXX= position
val-pos ; Start of value position
done ; Found end of \'d ;s?
)
(save-restriction
(narrow-to-region st nd)
(goto-char (point-min))
(skip-chars-forward " \n\t;")
(while (not (eobp))
(setq done nil)
(setq name-pos (point))
(skip-chars-forward "^ \n\t=;")
(downcase-region name-pos (point))
(setq name (buffer-substring name-pos (point)))
(skip-chars-forward " \t\n")
(if (not (eq (char-after (point)) ?=)) ; There is no value
(setq value t)
(skip-chars-forward " \t\n=")
(setq val-pos (point))
(if (memq (char-after val-pos) '(?\" ?'))
(progn
(setq val-pos (1+ val-pos))
(condition-case nil
(progn
(forward-sexp 1)
(backward-char 1))
(error (goto-char (point-max)))))
(while (not done)
(skip-chars-forward "^;")
(if (eq (char-after (1- (point))) ?\\ )
(progn
(subst-char-in-region (1- (point)) (point) ?\\ ? )
(skip-chars-forward ";"))
(setq done t))))
(setq value (buffer-substring val-pos (point))))
;; `test' as symbol, others like "copiousoutput" and "needsx11" as
;; strings
(push (cons (if (string-equal name "test") 'test name) value) results)
(skip-chars-forward " \";\n\t"))
results)))
(defun mailcap-mailcap-entry-passes-test (info)
"Replace the test clause of INFO itself with a boolean for some cases.
This function supports only `test -n $DISPLAY' and `test -z $DISPLAY',
replaces them with t or nil. As for others or if INFO has an interactive
spec (needsterm, needsterminal, or needsx11) but DISPLAY is not set,
the test clause will be unchanged."
(let ((test (assq 'test info)) ; The test clause
status)
(setq status (and test (split-string (cdr test) " ")))
(if (and (or (assoc "needsterm" info)
(assoc "needsterminal" info)
(assoc "needsx11" info))
(not (getenv "DISPLAY")))
(setq status nil)
(cond
((and (equal (nth 0 status) "test")
(equal (nth 1 status) "-n")
(or (equal (nth 2 status) "$DISPLAY")
(equal (nth 2 status) "\"$DISPLAY\"")))
(setq status (if (getenv "DISPLAY") t nil)))
((and (equal (nth 0 status) "test")
(equal (nth 1 status) "-z")
(or (equal (nth 2 status) "$DISPLAY")
(equal (nth 2 status) "\"$DISPLAY\"")))
(setq status (if (getenv "DISPLAY") nil t)))
(test nil)
(t nil)))
(and test (listp test) (setcdr test status))))
;;;
;;; The action routines.
;;;
(defun mailcap-possible-viewers (major minor)
"Return a list of possible viewers from MAJOR for minor type MINOR."
(let ((result nil))
(pcase-dolist (`(,type . ,attrs) major)
(when (or (equal type minor)
(and minor
(string-match (concat "^" type "$") minor)))
(push attrs result)))
(nreverse result)))
(defun mailcap-unescape-mime-test (test type-info)
(let (save-pos save-chr subst)
(cond
((symbolp test) test)
((and (listp test) (symbolp (car test))) test)
((or (stringp test)
(and (listp test) (stringp (car test))
(setq test (mapconcat #'identity test " "))))
(with-temp-buffer
(insert test)
(goto-char (point-min))
(while (not (eobp))
(skip-chars-forward "^%")
(if (/= (- (point)
(progn (skip-chars-backward "\\\\")
(point)))
0) ; It is an escaped %
(progn
(delete-char 1)
(skip-chars-forward "%."))
(setq save-pos (point))
(skip-chars-forward "%")
(setq save-chr (char-after (point)))
;; Escapes:
;; %s: name of a file for the body data
;; %t: content-type
;; %{<parameter name}: value of parameter in mailcap entry
;; %n: number of sub-parts for multipart content-type
;; %F: a set of content-type/filename pairs for multiparts
(cond
((null save-chr) nil)
((= save-chr ?t)
(delete-region save-pos (progn (forward-char 1) (point)))
(insert (or (cdr (assq 'type type-info)) "\"\"")))
((memq save-chr '(?M ?n ?F))
(delete-region save-pos (progn (forward-char 1) (point)))
(insert "\"\""))
((= save-chr ?{)
(forward-char 1)
(skip-chars-forward "^}")
(downcase-region (+ 2 save-pos) (point))
(setq subst (buffer-substring (+ 2 save-pos) (point)))
(delete-region save-pos (1+ (point)))
(insert (or (cdr (assoc subst type-info)) "\"\"")))
(t nil))))
(buffer-string)))
(t (error "Bad value to mailcap-unescape-mime-test: %s" test)))))
(defvar mailcap-viewer-test-cache nil)
(defun mailcap-viewer-passes-test (viewer-info type-info)
"Return non-nil if viewer specified by VIEWER-INFO passes its test clause.
Also return non-nil if it has no test clause. TYPE-INFO is an argument
to supply to the test."
(let* ((test-info (assq 'test viewer-info))
(test (cdr test-info))
(otest test)
(viewer (cdr (assq 'viewer viewer-info)))
(default-directory (expand-file-name "~/"))
status cache result)
(cond ((not (or (stringp viewer) (fboundp viewer)))
nil) ; Non-existent Lisp function
((null test-info) t) ; No test clause
((setq cache (assoc test mailcap-viewer-test-cache))
(cadr cache))
(t
(setq
result
(cond
((not test) nil) ; Already failed test
((eq test t) t) ; Already passed test
((functionp test) ; Lisp function as test
(funcall test type-info))
((and (symbolp test) ; Lisp variable as test
(boundp test))
(symbol-value test))
((and (listp test) ; List to be eval'd
(symbolp (car test)))
(eval test t))
(t
(setq test (mailcap-unescape-mime-test test type-info)
test (list shell-file-name nil nil nil
shell-command-switch test)
status (apply #'call-process test))
(eq 0 status))))
(push (list otest result) mailcap-viewer-test-cache)
result))))
(defun mailcap-add-mailcap-entry (major minor info &optional storage)
"Add handler INFO for mime type MAJOR/MINOR to STORAGE.
MAJOR and MINOR should be strings. MINOR is treated as a regexp
in later lookups, and, therefore, you may need to escape it
appropriately.
The format of INFO is described in `mailcap-mime-data'.
STORAGE should be a symbol referring to a variable. The value of
this variable should have the same format as `mailcap-mime-data'.
STORAGE defaults to `mailcap--computed-mime-data'.
None of this is enforced."
(let* ((storage (or storage 'mailcap--computed-mime-data))
(major-entry (assoc major (symbol-value storage)))
(new-minor-entry (cons minor info))
minor-entry)
(cond
((null major-entry)
;; Add a new major entry containing the new minor entry.
(setf major-entry (list major new-minor-entry))
(push major-entry (symbol-value storage)))
((and (setf minor-entry (assoc minor major-entry))
(not (assq 'test info))
(not (assq 'test minor-entry))
(equal (assq 'viewer info)
(assq 'viewer minor-entry)))
;; Replace a previous MINOR entry if it and the entry to be
;; added both do *not* have a ‘test’ associated in their info
;; alist and both use the same ‘viewer’ command. This ignores
;; other fields in the previous entryʼs info alist: they will be
;; lost when the info alist in the cdr of the previous entry is
;; replaced with the new INFO alist.
(setf (cdr minor-entry) info))
(t
;; Add the new minor entry to the existing major entry.
(push new-minor-entry (cdr major-entry))))))
(defun mailcap-add (type viewer &optional test)
"Add VIEWER as a handler for TYPE.
If TEST is not given, it defaults to t."
(let ((tl (split-string type "/")))
(when (or (not (car tl))
(not (cadr tl)))
(error "%s is not a valid MIME type" type))
(let ((entry
`((viewer . ,viewer)
(test . ,(if test test t))
(type . ,type))))
;; Store it.
(mailcap-add-mailcap-entry (car tl) (cadr tl) entry
'mailcap-user-mime-data)
;; Make it available for usage.
(mailcap-add-mailcap-entry (car tl) (cadr tl) entry))))
;;;
;;; The main whabbo
;;;
(defun mailcap-viewer-lessp (x y)
"Return t if viewer X is more desirable than viewer Y."
(let ((x-wild (string-match "[*?]" (or (cdr-safe (assq 'type x)) "")))
(y-wild (string-match "[*?]" (or (cdr-safe (assq 'type y)) "")))
(x-lisp (not (stringp (or (cdr-safe (assq 'viewer x)) ""))))
(y-lisp (not (stringp (or (cdr-safe (assq 'viewer y)) "")))))
(cond
((and x-wild (not y-wild))
nil)
((and (not x-wild) y-wild)
t)
((and (not y-lisp) x-lisp)
t)
(t nil))))
(defun mailcap-select-preferred-viewer (type-info)
"Return an applicable viewer entry from `mailcap-user-mime-data'."
(let ((info (mapcar (lambda (a) (cons (symbol-name (car a))
(cdr a)))
(cdr type-info)))
viewer)
(dolist (entry mailcap-user-mime-data)
(when (and (null viewer)
(string-match (concat "^" (cdr (assq 'type entry)) "$")
(car type-info))
(mailcap-viewer-passes-test entry info))
(setq viewer entry)))
viewer))
(defun mailcap-mime-info (string &optional request no-decode)
"Get the MIME viewer command for STRING, return nil if none found.
Expects a complete content-type header line as its argument.
Second argument REQUEST specifies what information to return. If it is
nil or the empty string, the viewer (second field of the mailcap
entry) will be returned. If it is a string, then the mailcap field
corresponding to that string will be returned (print, description,
whatever). If a number, then all the information for this specific
viewer is returned. If `all', then all possible viewers for
this type is returned.
If NO-DECODE is non-nil, don't decode STRING."
;; NO-DECODE avoids calling `mail-header-parse-content-type' from
;; `mail-parse.el'
(let (
major ; Major encoding (text, etc)
minor ; Minor encoding (html, etc)
info ; Other info
major-info ; (assoc major mailcap--computed-mime-data)
viewers ; Possible viewers
passed ; Viewers that passed the test
viewer ; The one and only viewer
ctl)
(save-excursion
(setq ctl
(if no-decode
(list (or string "text/plain"))
(mail-header-parse-content-type (or string "text/plain"))))
;; Check if there's a user-defined viewer from `mailcap-user-mime-data'.
(setq viewer (mailcap-select-preferred-viewer ctl))
(if viewer
(setq passed (list viewer))
;; None found, so heuristically select some applicable viewer
;; from `mailcap--computed-mime-data'.
(mailcap-parse-mailcaps nil t)
(setq major (split-string (car ctl) "/"))
(setq minor (cadr major)
major (car major))
(when (setq major-info (cdr (assoc major mailcap--computed-mime-data)))
(when (setq viewers (mailcap-possible-viewers major-info minor))
(setq info (mapcar (lambda (a)
(cons (symbol-name (car a)) (cdr a)))
(cdr ctl)))
(dolist (entry viewers)
(when (mailcap-viewer-passes-test entry info)
(push entry passed)))
(setq passed (sort (nreverse passed) #'mailcap-viewer-lessp))
;; When we want to prefer entries from the user's
;; ~/.mailcap file, then we filter out the system entries
;; and see whether we have anything left.
(when mailcap-prefer-mailcap-viewers
(when-let* ((user-entries
(seq-filter (lambda (elem)
(eq (cdr (assq 'source elem)) 'user))
passed)))
(setq passed user-entries)))
(setq viewer (car passed))))
(when (and (stringp (cdr (assq 'viewer viewer)))
passed)
(setq viewer (car passed))))
(cond
((and (null viewer) (not (equal major "default")) request)
(mailcap-mime-info "default" request no-decode))
((or (null request) (equal request ""))
(mailcap-unescape-mime-test (cdr (assq 'viewer viewer)) info))
((stringp request)
(mailcap-unescape-mime-test
(cdr-safe (assoc request viewer)) info))
((eq request 'all)
passed)
(t
;; MUST make a copy *sigh*, else we modify mailcap--computed-mime-data
(setq viewer (copy-sequence viewer))
(let ((view (assq 'viewer viewer))
(test (assq 'test viewer)))
(if view (setcdr view (mailcap-unescape-mime-test (cdr view) info)))
(if test (setcdr test (mailcap-unescape-mime-test (cdr test) info))))
viewer)))))
;;;
;;; Experimental MIME-types parsing
;;;
(defvar mailcap-mime-extensions
'(("" . "text/plain")
(".1" . "text/plain") ;; Manual pages
(".3" . "text/plain")
(".8" . "text/plain")
(".abs" . "audio/x-mpeg")
(".aif" . "audio/aiff")
(".aifc" . "audio/aiff")
(".aiff" . "audio/aiff")
(".ano" . "application/x-annotator")
(".au" . "audio/ulaw")
(".avi" . "video/x-msvideo")
(".bcpio" . "application/x-bcpio")
(".bin" . "application/octet-stream")
(".cdf" . "application/x-netcdr")
(".cpio" . "application/x-cpio")
(".csh" . "application/x-csh")
(".css" . "text/css")
(".dvi" . "application/x-dvi")
(".diff" . "text/x-patch")
(".dpatch". "text/x-patch")
(".el" . "application/emacs-lisp")
(".eps" . "application/postscript")
(".etx" . "text/x-setext")
(".exe" . "application/octet-stream")
(".fax" . "image/x-fax")
(".gif" . "image/gif")
(".hdf" . "application/x-hdf")
(".hqx" . "application/mac-binhex40")
(".htm" . "text/html")
(".html" . "text/html")
(".icon" . "image/x-icon")
(".ief" . "image/ief")
(".jpg" . "image/jpeg")
(".macp" . "image/x-macpaint")
(".man" . "application/x-troff-man")
(".me" . "application/x-troff-me")
(".mif" . "application/mif")
(".mov" . "video/quicktime")
(".movie" . "video/x-sgi-movie")
(".mp2" . "audio/x-mpeg")
(".mp3" . "audio/x-mpeg")
(".mp2a" . "audio/x-mpeg2")
(".mpa" . "audio/x-mpeg")
(".mpa2" . "audio/x-mpeg2")
(".mpe" . "video/mpeg")
(".mpeg" . "video/mpeg")
(".mpega" . "audio/x-mpeg")
(".mpegv" . "video/mpeg")
(".mpg" . "video/mpeg")
(".mpv" . "video/mpeg")
(".ms" . "application/x-troff-ms")
(".nc" . "application/x-netcdf")
(".nc" . "application/x-netcdf")
(".oda" . "application/oda")
(".patch" . "text/x-patch")
(".pbm" . "image/x-portable-bitmap")
(".pdf" . "application/pdf")
(".pgm" . "image/portable-graymap")
(".pict" . "image/pict")
(".png" . "image/png")
(".pnm" . "image/x-portable-anymap")
(".pod" . "text/plain")
(".ppm" . "image/portable-pixmap")
(".ps" . "application/postscript")
(".qt" . "video/quicktime")
(".ras" . "image/x-raster")
(".rgb" . "image/x-rgb")
(".rtf" . "application/rtf")
(".rtx" . "text/richtext")
(".sh" . "application/x-sh")
(".sit" . "application/x-stuffit")
(".siv" . "application/sieve")
(".snd" . "audio/basic")
(".soa" . "text/dns")
(".src" . "application/x-wais-source")
(".tar" . "archive/tar")
(".tcl" . "application/x-tcl")
(".tex" . "application/x-tex")
(".texi" . "application/texinfo")
(".tga" . "image/x-targa")
(".tif" . "image/tiff")
(".tiff" . "image/tiff")
(".tr" . "application/x-troff")
(".troff" . "application/x-troff")
(".tsv" . "text/tab-separated-values")
(".txt" . "text/plain")
(".vbs" . "video/mpeg")
(".vox" . "audio/basic")
(".vrml" . "x-world/x-vrml")
(".wav" . "audio/x-wav")
(".xls" . "application/vnd.ms-excel")
(".wrl" . "x-world/x-vrml")
(".xbm" . "image/xbm")
(".xpm" . "image/xpm")
(".xwd" . "image/windowdump")
(".zip" . "application/zip")
(".ai" . "application/postscript")
(".jpe" . "image/jpeg")
(".jpeg" . "image/jpeg")
(".webp" . "image/webp")
(".org" . "text/x-org"))
"An alist of file extensions and corresponding MIME content-types.
This exists for you to customize the information in Lisp. It is
merged with values from mailcap files by `mailcap-parse-mimetypes'.")
(defvar mailcap-mimetypes-parsed-p nil)
(defun mailcap-parse-mimetypes (&optional path force)
"Parse out all the mimetypes specified in a Unix-style path string PATH.
Components of PATH are separated by the `path-separator' character
appropriate for this system. If PATH is omitted, use the value of
environment variable MIMETYPES if set; otherwise use a default path.
If FORCE, re-parse even if already parsed."
(interactive (list nil t))
(when (or (not mailcap-mimetypes-parsed-p)
force)
(cond
(path nil)
((getenv "MIMETYPES") (setq path (getenv "MIMETYPES")))
((memq system-type mailcap-poor-system-types)
(setq path '("~/mime.typ" "~/etc/mime.typ")))
(t (setq path
;; mime.types seems to be the normal name, definitely so
;; on current GNUish systems. The search order follows
;; that for mailcap.
'("~/.mime.types"
"/etc/mime.types"
"/usr/etc/mime.types"
"/usr/local/etc/mime.types"
"/usr/local/www/conf/mime.types"
"~/.mime-types"
"/etc/mime-types"
"/usr/etc/mime-types"
"/usr/local/etc/mime-types"
"/usr/local/www/conf/mime-types"))))
(dolist (fname (reverse (if (stringp path)
(split-string path path-separator t)
path)))
(when (file-readable-p fname)
(mailcap-parse-mimetype-file fname)))
(setq mailcap-mimetypes-parsed-p t)))
(defun mailcap-parse-mimetype-file (fname)
"Parse out a mime-types file FNAME."
(let (type ; The MIME type for this line
extns ; The extensions for this line
save-pos ; Misc. saved buffer positions
save-extn)
(with-temp-buffer
(insert-file-contents fname)
(mailcap-replace-regexp "#.*" "")
(mailcap-replace-regexp "\n+" "\n")
(mailcap-replace-regexp "[ \t]+$" "")
(goto-char (point-max))
(skip-chars-backward " \t\n")
(delete-region (point) (point-max))
(goto-char (point-min))
(while (not (eobp))
(skip-chars-forward " \t\n")
(setq save-pos (point))
(skip-chars-forward "^ \t\n")
(downcase-region save-pos (point))
(setq type (buffer-substring save-pos (point)))
(while (not (eolp))
(skip-chars-forward " \t")
(setq save-pos (point))
(skip-chars-forward "^ \t\n")
(setq save-extn (buffer-substring save-pos (point)))
(push (cons (if (= (string-to-char save-extn) ?.)
save-extn (concat "." save-extn))
type)
extns))
(setq mailcap-mime-extensions (append extns mailcap-mime-extensions)
extns nil)))))
(defun mailcap-extension-to-mime (extn)
"Return the MIME content type of the file extensions EXTN."
(mailcap-parse-mimetypes)
(if (and (stringp extn)
(not (eq (string-to-char extn) ?.)))
(setq extn (concat "." extn)))
(cdr (assoc (downcase extn) mailcap-mime-extensions)))
(defun mailcap-file-name-to-mime-type (file-name)
"Return the MIME content type based on the FILE-NAME's extension.
For instance, \"foo.png\" will result in \"image/png\"."
(mailcap-extension-to-mime
(if (string-match "\\(\\.[^.]+\\)\\'" file-name)
(match-string 1 file-name)
"")))
;;;###autoload
(defun mailcap-mime-type-to-extension (mime-type)
"Return a file name extension based on a MIME-TYPE.
For instance, `image/png' will result in `png'."
(intern (cadr (split-string (if (symbolp mime-type)
(symbol-name mime-type)
mime-type)
"/"))))
(defun mailcap-mime-types ()
"Return a list of MIME media types."
(mailcap-parse-mimetypes)
(delete-dups
(nconc
(mapcar #'cdr mailcap-mime-extensions)
(let (res type)
(dolist (data mailcap--computed-mime-data)
(dolist (info (cdr data))
(setq type (cdr (assq 'type (cdr info))))
(unless (string-search "*" type)
(push (string-replace "\\" "" type) res))))
(nreverse res)))))
;;;
;;; Useful supplementary functions
;;;
(defun mailcap-file-default-commands (files)
"Return a list of default commands for FILES."
(mailcap-parse-mailcaps)
(mailcap-parse-mimetypes)
(let* ((all-mime-type
;; All unique MIME types from file extensions
(delq nil
(delete-dups
(mapcar (lambda (file)
(mailcap-extension-to-mime
(file-name-extension file t)))
files))))
(all-mime-info
;; All MIME info lists
(delete-dups
(mapcar (lambda (mime-type)
(mailcap-mime-info mime-type 'all))
all-mime-type)))
(common-mime-info
;; Intersection of mime-infos from different mime-types;
;; or just the first MIME info for a single MIME type
(if (cdr all-mime-info)
(let (res)
(dolist (mi1 (car all-mime-info))
(dolist (mi2 (cdr all-mime-info))
(when (member mi1 mi2)
(push mi1 res))))
(nreverse res))
(car all-mime-info))))
;; Command strings from `viewer' field of the MIME info
(delete-dups
(let (res command)
(dolist (mime-info common-mime-info)
(setq command (cdr (assq 'viewer mime-info)))
(when (stringp command)
(push
(replace-regexp-in-string
;; Replace mailcap's `%s' placeholder
;; with dired's `?' placeholder
"%s" "?"
(replace-regexp-in-string
;; Remove the final filename placeholder
"[ \t\n]*\\('\\)?%s\\1?[ \t\n]*\\'" ""
command nil t)
nil t)
res)))
(nreverse res)))))
(defun mailcap--async-shell (command file)
"Asynchronously call MIME viewer shell COMMAND.
Replace %s in COMMAND with FILE, as per `mailcap-mime-data'.
Delete FILE once COMMAND exits."
(let ((buf (get-buffer-create " *mailcap shell*")))
(async-shell-command (format command file) buf)
(add-function :after (process-sentinel (get-buffer-process buf))
(lambda (proc _msg)
(when (memq (process-status proc) '(exit signal))
(delete-file file))))))
(defun mailcap-view-mime (type)
"View the data in the current buffer that has MIME type TYPE.
The variable `mailcap--computed-mime-data' determines the method
to use. If the method is a shell command string, erase the
current buffer after passing its contents to the shell command."
(let ((method (mailcap-mime-info type)))
(if (stringp method)
(let* ((ext (concat "." (cadr (split-string type "/"))))
(file (make-temp-file "emacs-mailcap" nil ext))
(coding-system-for-write 'binary))
(write-region nil nil file nil 'silent)
(delete-region (point-min) (point-max))
(mailcap--async-shell method file))
(funcall method))))
(defun mailcap-view-file (file)
"View FILE according to rules given by the mailcap system.
This normally involves executing some external program to display
the file.
See \"~/.mailcap\", `mailcap-mime-data' and related files and variables."
(interactive "fOpen file with mailcap: ")
(setq file (expand-file-name file))
(mailcap-parse-mailcaps)
(let ((command (mailcap-mime-info
(mailcap-extension-to-mime (file-name-extension file)))))
(if (functionp command)
;; command is a viewer function (a mode) expecting the file
;; contents to be in the current buffer.
(let ((buf (generate-new-buffer (file-name-nondirectory file))))
(set-buffer buf)
(insert-file-contents file)
(setq buffer-file-name file)
(funcall command)
(set-buffer-modified-p nil)
(pop-to-buffer buf))
;; command is a program to run with file as an argument.
(unless command
(error "No viewer for %s" (file-name-extension file)))
;; Remove quotes around the file name - we'll use shell-quote-argument.
(while (string-match "['\"]%s['\"]" command)
(setq command (replace-match "%s" t t command)))
(setq command (replace-regexp-in-string
"%s"
(shell-quote-argument (convert-standard-filename file))
command
nil t))
;; Handlers such as "gio open" and kde-open5 start viewer in background
;; and exit immediately. Avoid `start-process' since it assumes
;; :connection-type `pty' and kills children processes with SIGHUP
;; when temporary terminal session is finished (Bug#44824).
;; An alternative is `process-connection-type' let-bound to nil for
;; `start-process-shell-command' call (with no chance to report failure).
(make-process
:name "mailcap-view-file"
:connection-type 'pipe
:buffer nil ; "*Messages*" may be suitable for debugging
:sentinel (lambda (proc event)
(when (and (memq (process-status proc) '(exit signal))
(/= (process-exit-status proc) 0))
(message
"Command %s: %s."
(mapconcat #'identity (process-command proc) " ")
(substring event 0 -1))))
:command (list shell-file-name shell-command-switch command)))))
(provide 'mailcap)
;;; mailcap.el ends here
|