1 ;;; elpher.el --- A friendly gopher and gemini client -*- lexical-binding: t -*-
3 ;; Copyright (C) 2021 Jens Östlund <jostlund@gmail.com>
4 ;; Copyright (C) 2021 F. Jason Park <jp@neverwas.me>
5 ;; Copyright (C) 2021 Christopher Brannon <chris@the-brannons.com>
6 ;; Copyright (C) 2021 Omar Polo <op@omarpolo.com>
7 ;; Copyright (C) 2021 Noodles! <nnoodle@chiru.no>
8 ;; Copyright (C) 2020-2021 Alex Schroeder <alex@gnu.org>
9 ;; Copyright (C) 2020 Zhiwei Chen <chenzhiwei03@kuaishou.com>
10 ;; Copyright (C) 2020 condy0919 <condy0919@gmail.com>
11 ;; Copyright (C) 2020 Alexis <flexibeast@gmail.com>
12 ;; Copyright (C) 2020 Étienne Deparis <etienne@depar.is>
13 ;; Copyright (C) 2020 Simon Nicolussi <sinic@sinic.name>
14 ;; Copyright (C) 2020 Michel Alexandre Salim <michel@michel-slm.name>
15 ;; Copyright (C) 2020 Koushk Roy <kroy@twilio.com>
16 ;; Copyright (C) 2020 Vee <vee@vnsf.xyz>
17 ;; Copyright (C) 2020 Simon South <simon@simonsouth.net>
18 ;; Copyright (C) 2019-2021 Tim Vaughan <plugd@thelambdalab.xyz>
20 ;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
21 ;; Created: 11 April 2019
23 ;; Keywords: comm gopher
24 ;; Homepage: https://thelambdalab.xyz/elpher
25 ;; Package-Requires: ((emacs "27.1"))
27 ;; This file is not part of GNU Emacs.
29 ;; This program is free software: you can redistribute it and/or modify
30 ;; it under the terms of the GNU General Public License as published by
31 ;; the Free Software Foundation, either version 3 of the License, or
32 ;; (at your option) any later version.
34 ;; This program is distributed in the hope that it will be useful,
35 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
36 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 ;; GNU General Public License for more details.
39 ;; You should have received a copy of the GNU General Public License
40 ;; along with this file. If not, see <http://www.gnu.org/licenses/>.
44 ;; Elpher aims to provide a practical and friendly gopher and gemini
45 ;; client for GNU Emacs. It supports:
47 ;; - intuitive keyboard and mouse-driven browsing,
48 ;; - out-of-the-box compatibility with evil-mode,
49 ;; - clickable web and gopher links *in plain text*,
50 ;; - caching of visited sites,
51 ;; - pleasant and configurable colouring of Gopher directories,
52 ;; - direct visualisation of image files,
53 ;; - gopher connections using TLS encryption,
54 ;; - the fledgling Gemini protocol,
55 ;; - the greybeard Finger protocol.
57 ;; To launch Elpher, simply use 'M-x elpher'. This will open a start
58 ;; page containing information on key bindings and suggested starting
59 ;; points for your gopher exploration.
61 ;; Full instructions can be found in the Elpher info manual.
63 ;; Elpher is under active development. Any suggestions for
64 ;; improvements are welcome, and can be made on the official project
65 ;; page, gopher://thelambdalab.xyz/1/projects/elpher, or via the
66 ;; project mailing list at https://lists.sr.ht/~michel-slm/elpher.
87 (defconst elpher-version "3.0.0"
88 "Current version of elpher.")
90 (defconst elpher-margin-width 6
91 "Width of left-hand margin used when rendering indicies.")
93 (defconst elpher-type-map
94 '(((gopher ?0) elpher-get-gopher-page elpher-render-text "txt" elpher-text)
95 ((gopher ?1) elpher-get-gopher-page elpher-render-index "/" elpher-index)
96 ((gopher ?4) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
97 ((gopher ?5) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
98 ((gopher ?7) elpher-get-gopher-query-page elpher-render-index "?" elpher-search)
99 ((gopher ?9) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
100 ((gopher ?g) elpher-get-gopher-page elpher-render-image "img" elpher-image)
101 ((gopher ?p) elpher-get-gopher-page elpher-render-image "img" elpher-image)
102 ((gopher ?I) elpher-get-gopher-page elpher-render-image "img" elpher-image)
103 ((gopher ?d) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
104 ((gopher ?P) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
105 ((gopher ?s) elpher-get-gopher-page elpher-render-download "snd" elpher-binary)
106 ((gopher ?h) elpher-get-gopher-page elpher-render-html "htm" elpher-html)
107 (gemini elpher-get-gemini-page elpher-render-gemini "gem" elpher-gemini)
108 (finger elpher-get-finger-page elpher-render-text "txt" elpher-text)
109 (telnet elpher-get-telnet-page nil "tel" elpher-telnet)
110 (other-url elpher-get-other-url-page nil "url" elpher-other-url)
111 ((special start) elpher-get-start-page nil "E" elpher-index)
112 ((special bookmarks) elpher-get-bookmarks-page nil "E" elpher-index)
113 ((special history) elpher-get-history-page nil "E" elpher-index)
114 ((special visited-pages) elpher-get-visited-pages-page nil "E" elpher-index))
115 "Association list from types to getters, renderers, margin codes and index faces.")
118 ;;; Declarations to avoid compiler warnings.
122 (declare-function ansi-color-filter-apply "ansi-color")
123 (declare-function ansi-color-apply "ansi-color")
124 (declare-function bookmark-store "bookmark")
125 (declare-function org-link-store-props "ol")
126 (declare-function org-link-set-parameters "ol")
127 (defvar ansi-color-context)
128 (defvar bookmark-make-record-function)
129 (defvar mu4e~view-beginning-of-url-regexp)
130 (defvar thing-at-point-uri-schemes)
131 (defvar xterm-color-preserve-properties))
134 ;;; Customization group
138 "A gopher and gemini client."
139 :group 'applications)
141 ;; General appearance and customizations
143 (defcustom elpher-open-urls-with-eww nil
144 "If non-nil, open URL selectors using eww.
145 Otherwise, use the system browser via the `browse-url' function."
148 (defcustom elpher-use-header t
149 "If non-nil, display current page information in buffer header."
152 (defcustom elpher-auto-disengage-TLS nil
153 "If non-nil, automatically disengage TLS following an unsuccessful connection.
154 While enabling this may seem convenient, it is also potentially
155 dangerous as it allows switching from an encrypted channel back to
156 plain text without user input."
159 (defcustom elpher-connection-timeout 5
160 "Specifies the number of seconds to wait for a network connection to time out."
163 (defcustom elpher-filter-ansi-from-text nil
164 "If non-nil, filter ANSI escape sequences from text.
165 The default behaviour is to use the ansi-color package to interpret these
169 (defcustom elpher-certificate-directory
170 (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
171 "Specify the name of the directory where client certificates will be stored.
172 These certificates may be used for establishing authenticated TLS connections."
175 (defcustom elpher-openssl-command "openssl"
176 "The command used to launch openssl when generating TLS client certificates."
179 (defcustom elpher-default-url-type "gopher"
180 "Default URL type (i.e. scheme) to assume if not explicitly given."
181 :type '(choice (const "gopher")
184 (defcustom elpher-gemini-TLS-cert-checks nil
185 "If non-nil, verify gemini server TLS certs using the default security level.
186 Otherwise, certificate verification is disabled.
188 This defaults to off because it is standard practice for Gemini servers
189 to use self-signed certificates, meaning that most servers provide what
190 EMACS considers to be an invalid certificate."
193 (defcustom elpher-gemini-max-fill-width 80
194 "Specify the maximum default width (in columns) of text/gemini documents.
195 The actual width used is the minimum of this value and the window width at
196 the time when the text is rendered."
199 (defcustom elpher-gemini-link-string "→ "
200 "Specify the string used to indicate links when rendering gemini maps.
204 (defcustom elpher-gemini-bullet-string "•"
205 "Specify the string used for bullets when rendering gemini maps."
208 (defcustom elpher-ipv4-always nil
209 "If non-nil, elpher will always use IPv4 to establish network connections.
210 This can be useful when browsing from a computer that supports IPv6, because
211 some servers which do not support IPv6 can take a long time to time-out."
214 (defcustom elpher-socks-always nil
215 "If non-nil, elpher will establish network connections over a SOCKS proxy.
216 Otherwise, the SOCKS proxy is only used for connections to onion services."
219 (defcustom elpher-use-emacs-bookmark-menu nil
220 "If non-nil, elpher will only use the native Emacs bookmark menu.
221 Otherwise, \\[elpher-show-bookmarks] will visit a special elpher bookmark
222 page within which all of the standard elpher keybindings are active."
225 ;; Face customizations
227 (defgroup elpher-faces nil
228 "Elpher face customizations."
231 (defface elpher-index
232 '((t :inherit font-lock-keyword-face))
233 "Face used for directory type directory records.")
237 "Face used for text type directory records.")
240 '((t :inherit default))
241 "Face used for info type directory records.")
243 (defface elpher-image
244 '((t :inherit font-lock-string-face))
245 "Face used for image type directory records.")
247 (defface elpher-search
248 '((t :inherit warning))
249 "Face used for search type directory records.")
252 '((t :inherit font-lock-comment-face))
253 "Face used for html type directory records.")
255 (defface elpher-gemini
256 '((t :inherit font-lock-constant-face))
257 "Face used for Gemini type directory records.")
259 (defface elpher-other-url
260 '((t :inherit font-lock-comment-face))
261 "Face used for other URL type links records.")
263 (defface elpher-telnet
264 '((t :inherit font-lock-function-name-face))
265 "Face used for telnet type directory records.")
267 (defface elpher-binary
268 '((t :inherit font-lock-doc-face))
269 "Face used for binary type directory records.")
271 (defface elpher-unknown
272 '((t :inherit error))
273 "Face used for directory records with unknown/unsupported types.")
275 (defface elpher-margin-key
277 "Face used for directory margin key.")
279 (defface elpher-margin-brackets
280 '((t :inherit shadow))
281 "Face used for brackets around directory margin key.")
283 (defface elpher-gemini-heading1
284 '((t :inherit bold :height 1.8))
285 "Face used for gemini heading level 1.")
287 (defface elpher-gemini-heading2
288 '((t :inherit bold :height 1.5))
289 "Face used for gemini heading level 2.")
291 (defface elpher-gemini-heading3
292 '((t :inherit bold :height 1.2))
293 "Face used for gemini heading level 3.")
295 (defface elpher-gemini-preformatted
296 '((t :inherit fixed-pitch))
297 "Face used for pre-formatted gemini text blocks.")
299 (defface elpher-gemini-quoted
300 '((t :inherit font-lock-doc-face))
301 "Face used for gemini quoted texts.")
308 ;; An elpher "address" object is either a url object or a symbol.
309 ;; Symbol addresses are "special", corresponding to pages generated
310 ;; dynamically for and by elpher. All others represent pages which
311 ;; rely on content retrieved over the network.
313 (defun elpher-address-from-url (url-string)
314 "Create a ADDRESS object corresponding to the given URL-STRING."
315 (let ((data (match-data))) ; Prevent parsing clobbering match data
317 (let ((url (url-generic-parse-url url-string)))
318 (unless (and (not (url-fullness url)) (url-type url))
319 (setf (url-fullness url) t)
320 (unless (url-type url)
321 (setf (url-type url) elpher-default-url-type))
322 (unless (url-host url)
323 (let ((p (split-string (url-filename url) "/" nil nil)))
324 (setf (url-host url) (car p))
325 (setf (url-filename url)
327 (concat "/" (mapconcat #'identity (cdr p) "/"))
329 (when (or (equal "gopher" (url-type url))
330 (equal "gophers" (url-type url)))
332 (when (or (equal (url-filename url) "")
333 (equal (url-filename url) "/"))
334 (setf (url-filename url) "/1")))
335 (when (equal "gemini" (url-type url))
337 (if (equal (url-filename url) "")
338 (setf (url-filename url) "/"))))
339 (elpher-remove-redundant-ports url))
340 (set-match-data data))))
342 (defun elpher-remove-redundant-ports (address)
343 "Remove redundant port specifiers from ADDRESS.
344 Here 'redundant' means that the specified port matches the default
345 for that protocol, eg 70 for gopher."
346 (if (and (not (elpher-address-special-p address))
347 (eq (url-portspec address) ; (url-port) is too slow!
348 (pcase (url-type address)
350 ((or "gopher" "gophers") 70)
353 (setf (url-portspec address) nil))
356 (defun elpher-make-gopher-address (type selector host port &optional tls)
357 "Create an ADDRESS object using gopher directory record attributes.
358 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
359 If the optional attribute TLS is non-nil, the address will be marked as
360 requiring gopher-over-TLS."
362 ((equal type ?i) nil)
363 ((and (equal type ?h)
364 (string-prefix-p "URL:" selector))
365 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
367 (elpher-address-from-url
370 ":" (number-to-string port))))
372 (elpher-address-from-url
373 (concat "gopher" (if tls "s" "")
375 ":" (number-to-string port)
379 (defun elpher-make-special-address (type)
380 "Create an ADDRESS object corresponding to the given special address symbol TYPE."
383 (defun elpher-address-to-url (address)
384 "Get string representation of ADDRESS, or nil if ADDRESS is special."
385 (if (elpher-address-special-p address)
387 (url-encode-url (url-recreate-url address))))
389 (defun elpher-address-type (address)
390 "Retrieve type of ADDRESS object.
391 This is used to determine how to retrieve and render the document the
392 address refers to, via the table `elpher-type-map'."
393 (if (symbolp address)
394 (list 'special address)
395 (let ((protocol (url-type address)))
396 (cond ((or (equal protocol "gopher")
397 (equal protocol "gophers"))
399 (if (member (url-filename address) '("" "/"))
401 (string-to-char (substring (url-filename address) 1)))))
402 ((equal protocol "gemini")
404 ((equal protocol "telnet")
406 ((equal protocol "finger")
410 (defun elpher-address-protocol (address)
411 "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
412 (if (symbolp address)
416 (defun elpher-address-filename (address)
417 "Retrieve the filename component of ADDRESS.
418 For gopher addresses this is a combination of the selector type and selector."
419 (if (symbolp address)
421 (url-unhex-string (url-filename address))))
423 (defun elpher-address-host (address)
424 "Retrieve host from ADDRESS object."
427 (defun elpher-address-user (address)
428 "Retrieve user from ADDRESS object."
431 (defun elpher-address-port (address)
432 "Retrieve port from ADDRESS object.
433 If no address is defined, returns 0. (This is for compatibility with the URL library.)"
434 (if (symbolp address)
438 (defun elpher-address-special-p (address)
439 "Return non-nil if ADDRESS object is special (e.g. start page page)."
442 (defun elpher-address-gopher-p (address)
443 "Return non-nill if ADDRESS object is a gopher address."
444 (and (not (elpher-address-special-p address))
445 (member (elpher-address-protocol address) '("gopher" "gophers"))))
447 (defun elpher-gopher-address-selector (address)
448 "Retrieve gopher selector from ADDRESS object."
449 (if (member (url-filename address) '("" "/"))
451 (url-unhex-string (substring (url-filename address) 2))))
456 (defvar elpher-content-cache (make-hash-table :test 'equal))
457 (defvar elpher-pos-cache (make-hash-table :test 'equal))
459 (defun elpher-get-cached-content (address)
460 "Retrieve the cached content for ADDRESS, or nil if none exists."
461 (gethash address elpher-content-cache))
463 (defun elpher-cache-content (address content)
464 "Set the content cache for ADDRESS to CONTENT."
465 (puthash address content elpher-content-cache))
467 (defun elpher-get-cached-pos (address)
468 "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
469 (gethash address elpher-pos-cache))
471 (defun elpher-cache-pos (address pos)
472 "Set the cursor position cache for ADDRESS to POS."
473 (puthash address pos elpher-pos-cache))
478 (defun elpher-make-page (display-string address)
479 "Create a page with DISPLAY-STRING and ADDRESS."
480 (list display-string address))
482 (defun elpher-make-start-page ()
483 "Create the start page."
484 (elpher-make-page "Elpher Start Page"
485 (elpher-make-special-address 'start)))
487 (defun elpher-page-display-string (page)
488 "Retrieve the display string corresponding to PAGE."
491 (defun elpher-page-address (page)
492 "Retrieve the address corresponding to PAGE."
495 (defun elpher-page-set-address (page new-address)
496 "Set the address corresponding to PAGE to NEW-ADDRESS."
497 (setcar (cdr page) new-address))
499 (defvar elpher-current-page nil
500 "The current page for this Elpher buffer.")
502 (defvar elpher-history nil
503 "The local history stack for this Elpher buffer.
504 This variable is used by `elpher-back' and
505 `elpher-show-history'.")
507 (defvar elpher-visited-pages nil
508 "The global history for all Elpher buffers.
509 This variable is used by `elpher-show-visited-pages'.")
511 (defun elpher-visit-page (page &optional renderer no-history)
512 "Visit PAGE using its own renderer or RENDERER, if non-nil.
513 Additionally, push PAGE onto the history stack and the list of
514 previously-visited pages,unless NO-HISTORY is non-nil."
516 (elpher-process-cleanup)
518 (unless (equal (elpher-page-address elpher-current-page)
519 (elpher-page-address page))
520 (push elpher-current-page elpher-history)
521 (unless (or (elpher-address-special-p (elpher-page-address page))
522 (and elpher-visited-pages
523 (equal page (car elpher-visited-pages))))
524 (push page elpher-visited-pages))))
525 (setq-local elpher-current-page page)
526 (let* ((address (elpher-page-address page))
527 (type (elpher-address-type address))
528 (type-record (cdr (assoc type elpher-type-map))))
530 (funcall (car type-record)
534 (elpher-visit-previous-page)
536 (`(gopher ,type-char)
537 (error "Unsupported gopher selector type '%c' for '%s'"
538 type-char (elpher-address-to-url address)))
540 (error "Unsupported address type '%S' for '%s'"
541 other (elpher-address-to-url address)))))))
543 (defun elpher-visit-previous-page ()
544 "Visit the previous page in the history."
545 (let ((previous-page (pop elpher-history)))
547 (elpher-visit-page previous-page nil t)
548 (error "No previous page"))))
550 (defun elpher-reload-current-page ()
551 "Reload the current page, discarding any existing cached content."
552 (elpher-cache-content (elpher-page-address elpher-current-page) nil)
553 (elpher-visit-page elpher-current-page))
555 (defun elpher-save-pos ()
556 "Save the current position of point to the current page."
557 (when elpher-current-page
558 (elpher-cache-pos (elpher-page-address elpher-current-page) (point))))
560 (defun elpher-restore-pos ()
561 "Restore the position of point to that cached in the current page."
562 (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
565 (goto-char (point-min)))))
568 ;;; Buffer preparation
571 (defvar elpher-buffer-name "*elpher*"
572 "The default name of the Elpher buffer.")
574 (defun elpher-update-header ()
575 "If `elpher-use-header' is true, display current page info in window header."
576 (if elpher-use-header
577 (let* ((display-string (elpher-page-display-string elpher-current-page))
578 (address (elpher-page-address elpher-current-page))
579 (tls-string (if (and (not (elpher-address-special-p address))
580 (member (elpher-address-protocol address)
581 '("gophers" "gemini")))
584 (header (concat display-string
585 (propertize tls-string 'face 'bold))))
586 (setq header-line-format header))))
588 (defmacro elpher-with-clean-buffer (&rest args)
589 "Evaluate ARGS with a clean *elpher* buffer as current."
590 (declare (debug (body))) ;; Allow edebug to step through body
591 `(with-current-buffer elpher-buffer-name
592 (unless (eq major-mode 'elpher-mode)
593 ;; avoid resetting buffer-local variables
595 (let ((inhibit-read-only t)
596 (ansi-color-context nil)) ;; clean ansi interpreter state
597 (setq-local network-security-level
598 (default-value 'network-security-level))
600 (elpher-update-header)
603 (defun elpher-buffer-message (string &optional line)
604 "Replace first line in elpher buffer with STRING.
605 If LINE is non-nil, replace that line instead."
606 (with-current-buffer elpher-buffer-name
607 (let ((inhibit-read-only t))
608 (goto-char (point-min))
611 (let ((data (match-data)))
614 (re-search-forward "^.*$")
615 (replace-match string))
616 (set-match-data data))))))
622 (defvar elpher-user-coding-system nil
623 "User-specified coding system to use for decoding text responses.")
625 (defun elpher-decode (string)
626 "Decode STRING using autodetected or user-specified coding system."
627 (decode-coding-string string
628 (if elpher-user-coding-system
629 elpher-user-coding-system
630 (detect-coding-string string t))))
632 (defun elpher-preprocess-text-response (string)
633 "Preprocess text selector response contained in STRING.
634 This involes decoding the character representation, and clearing
635 away CRs and any terminating period."
636 (elpher-decode (replace-regexp-in-string "\n\\.\n$" "\n"
637 (replace-regexp-in-string "\r" "" string))))
641 (defconst elpher-url-regex
642 "\\([a-zA-Z]+\\)://\\([a-zA-Z0-9.-]*[a-zA-Z0-9-]\\|\\[[a-zA-Z0-9:]+\\]\\)\\(:[0-9]+\\)?\\(/\\([0-9a-zA-Z_~?/@|:.%#=&-]*[0-9a-zA-Z_~?/@|#-]\\)?\\)?"
643 "Regexp used to locate and buttonify URLs in text files loaded by elpher.")
645 (defun elpher-buttonify-urls (string)
646 "Turn substrings which look like urls in STRING into clickable buttons."
649 (goto-char (point-min))
650 (while (re-search-forward elpher-url-regex nil t)
651 (let ((page (elpher-make-page (substring-no-properties (match-string 0))
652 (elpher-address-from-url (match-string 0)))))
653 (make-text-button (match-beginning 0)
656 'action #'elpher-click-link
658 'help-echo #'elpher--page-button-help
662 ;;; ANSI colors or XTerm colors (application and filtering)
664 (or (require 'xterm-color nil t)
665 (require 'ansi-color))
667 (defalias 'elpher-color-filter-apply
668 (if (fboundp 'xterm-color-filter)
670 (let ((_xterm-color-render nil))
671 (xterm-color-filter s)))
672 #'ansi-color-filter-apply)
673 "A function to filter out ANSI escape sequences.")
675 (defalias 'elpher-color-apply
676 (if (fboundp 'xterm-color-filter)
679 "A function to apply ANSI escape sequences.")
681 ;;; Processing text for display
683 (defun elpher-process-text-for-display (string)
684 "Perform any desired processing of STRING prior to display as text.
685 Currently includes buttonifying URLs and processing ANSI escape codes."
686 (elpher-buttonify-urls (if elpher-filter-ansi-from-text
687 (elpher-color-filter-apply string)
688 (elpher-color-apply string))))
691 ;;; Network error reporting
694 (defun elpher-network-error (address error)
695 "Display ERROR message following unsuccessful negotiation with ADDRESS.
696 ERROR can be either an error object or a string."
697 (elpher-with-clean-buffer
698 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
699 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
700 (if (stringp error) error (error-message-string error)) "\n"
701 (propertize "\n----------------\n\n" 'face 'error)
702 "Press 'u' to return to the previous page.")))
705 ;;; General network communication
708 (defvar elpher-network-timer nil
709 "Timer used for network connections.")
711 (defvar elpher-use-tls nil
712 "If non-nil, use TLS to communicate with gopher servers.")
714 (defvar elpher-client-certificate nil
715 "If non-nil, contains client certificate details to use for TLS connections.")
717 (defun elpher-process-cleanup ()
718 "Immediately shut down any extant elpher process and timers."
719 (let ((p (get-process "elpher-process")))
720 (if p (delete-process p)))
721 (if (timerp elpher-network-timer)
722 (cancel-timer elpher-network-timer)))
724 (defun elpher-make-network-timer (thunk)
725 "Create a timer to run the THUNK after `elpher-connection-timeout' seconds.
726 This is just a wraper around `run-at-time' which additionally sets the
727 buffer-local variable `elpher-network-timer' to allow
728 `elpher-process-cleanup' to also clear the timer."
729 (let ((timer (run-at-time elpher-connection-timeout nil thunk)))
730 (setq-local elpher-network-timer timer)
733 (defun elpher-get-host-response (address default-port query-string response-processor
734 &optional use-tls force-ipv4)
735 "Generic function for retrieving data from ADDRESS.
737 When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
738 QUERY-STRING is a string sent to the host specified by ADDRESS to
739 illicet a response. This response is passed as an argument to the
740 function RESPONSE-PROCESSOR.
742 If non-nil, USE-TLS specifies that the connection is to be made over
743 TLS. If set to gemini, the certificate verification will be disabled
744 unless `elpher-gemini-TLS-cert-checks' is non-nil.
746 If non-nil, FORCE-IPV4 causes the network connection to be made over
747 ipv4 only. (The default behaviour when this is not set depends on
748 the host operating system and the local network capabilities.)"
749 (if (and use-tls (not (gnutls-available-p)))
750 (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
751 (unless (< (elpher-address-port address) 65536)
752 (error "Cannot establish network connection: port number > 65536"))
753 (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
754 (setq-local network-security-level 'low)
755 (setq-local gnutls-verify-error nil))
757 (let* ((kill-buffer-query-functions nil)
758 (port (elpher-address-port address))
759 (host (elpher-address-host address))
760 (service (if (> port 0) port default-port))
761 (response-string-parts nil)
764 (socks (or elpher-socks-always (string-suffix-p ".onion" host)))
765 (gnutls-params (list :type 'gnutls-x509pki
768 (elpher-get-current-keylist address)))
769 (timer (elpher-make-network-timer
771 (elpher-process-cleanup)
773 ; Try again with IPv4
774 ((not (or force-ipv4 socks))
775 (message "Connection timed out. Retrying with IPv4.")
776 (elpher-get-host-response address default-port
781 (not (eq use-tls 'gemini))
782 (or elpher-auto-disengage-TLS
784 "TLS connetion failed. Disable TLS mode and retry? ")))
785 (setq elpher-use-tls nil)
786 (elpher-get-host-response address default-port
791 (elpher-network-error address "Connection time-out."))))))
792 (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
793 (make-network-process :name "elpher-process"
795 :family (and force-ipv4 'ipv4)
801 (cons 'gnutls-x509pki
802 (apply #'gnutls-boot-parameters
804 (setq elpher-network-timer timer)
805 (set-process-coding-system proc 'binary 'binary)
806 (set-process-query-on-exit-flag proc nil)
807 (elpher-buffer-message (concat "Connecting to " host "..."
808 " (press 'u' to abort)"))
809 (set-process-filter proc
810 (lambda (_proc string)
814 (setq bytes-received (+ bytes-received (length string)))
815 (let ((new-hkbytes-received (/ bytes-received 102400)))
816 (when (> new-hkbytes-received hkbytes-received)
817 (setq hkbytes-received new-hkbytes-received)
818 (elpher-buffer-message
820 (number-to-string (/ hkbytes-received 10.0))
823 (setq response-string-parts
824 (cons string response-string-parts))))
825 (set-process-sentinel proc
828 (cancel-timer timer))
829 (condition-case the-error
831 ((string-prefix-p "open" event) ; request URL
832 (elpher-buffer-message
833 (concat "Connected to " host ". Receiving data..."
834 " (press 'u' to abort)"))
835 (let ((inhibit-eol-conversion t))
836 (process-send-string proc query-string)))
837 ((string-prefix-p "deleted" event)) ; do nothing
838 ((and (not response-string-parts)
839 (not (or elpher-ipv4-always force-ipv4 socks)))
840 ; Try again with IPv4
841 (message "Connection failed. Retrying with IPv4.")
842 (elpher-get-host-response address default-port
846 (response-string-parts
847 (elpher-with-clean-buffer
848 (insert "Data received. Rendering..."))
849 (funcall response-processor
850 (apply #'concat (reverse response-string-parts)))
851 (elpher-restore-pos))
853 (error "No response from server")))
855 (elpher-network-error address the-error)))))
857 (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
858 (funcall (process-sentinel proc) proc "open\n")))
860 (elpher-process-cleanup)
861 (error "Error initiating connection to server")))))
864 ;;; Client-side TLS Certificate Management
867 (defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
868 "Generate a key and a self-signed client TLS certificate using openssl.
870 The Common Name field of the certificate is set to COMMON-NAME. The
871 arguments KEY-FILE and CERT-FILE should contain the absolute paths of
872 the key and certificate files to write.
874 If TEMPORARY is non-nil, the certificate will be given an exporation
875 period of one day, and the key and certificate files will be deleted
876 when the certificate is no longer needed for the current session.
878 Otherwise, the certificate will be given a 100 year expiration period
879 and the files will not be deleted.
881 The function returns a list containing the current host name, the
882 temporary flag, and the key and cert file names in the form required
883 by `gnutls-boot-parameters`."
884 (let ((exp-key-file (expand-file-name key-file))
885 (exp-cert-file (expand-file-name cert-file)))
888 (call-process elpher-openssl-command nil nil nil
889 "req" "-x509" "-newkey" "rsa:2048"
890 "-days" (if temporary "1" "36500")
892 "-subj" (concat "/CN=" common-name)
893 "-keyout" exp-key-file
894 "-out" exp-cert-file)
895 (list (elpher-address-host (elpher-page-address elpher-current-page))
896 temporary exp-key-file exp-cert-file))
898 (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
899 (error "Program 'openssl', required for certificate generation, not found")))))
901 (defun elpher-generate-throwaway-certificate ()
902 "Generate and return details of a throwaway certificate.
903 The key and certificate files will be deleted when they are no
904 longer needed for this session."
905 (let* ((file-base (make-temp-name "elpher"))
906 (key-file (concat temporary-file-directory file-base ".key"))
907 (cert-file (concat temporary-file-directory file-base ".crt")))
908 (elpher-generate-certificate file-base key-file cert-file t)))
910 (defun elpher-generate-persistent-certificate (file-base common-name)
911 "Generate and return details of a persistent certificate.
912 The argument FILE-BASE is used as the base for the key and certificate
913 files, while COMMON-NAME specifies the common name field of the
916 The key and certificate files are written to in `elpher-certificate-directory'."
917 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
918 (cert-file (concat elpher-certificate-directory file-base ".crt")))
919 (elpher-generate-certificate common-name key-file cert-file)))
921 (defun elpher-get-existing-certificate (file-base)
922 "Return a certificate object corresponding to an existing certificate.
923 It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
924 the directory `elpher-certificate-directory'."
925 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
926 (cert-file (concat elpher-certificate-directory file-base ".crt")))
927 (list (elpher-address-host (elpher-page-address elpher-current-page))
929 (expand-file-name key-file)
930 (expand-file-name cert-file))))
932 (defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
933 "Install a key+certificate file pair in `elpher-certificate-directory'.
934 The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
935 certificate files to install. The argument FILE-BASE is used as the
936 base for the installed key and certificate files."
937 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
938 (cert-file (concat elpher-certificate-directory file-base ".crt")))
939 (if (or (file-exists-p key-file)
940 (file-exists-p cert-file))
941 (error "A certificate with base name %s is already installed" file-base))
942 (copy-file key-file-src key-file)
943 (copy-file cert-file-src cert-file)
944 (list (elpher-address-host (elpher-page-address elpher-current-page))
946 (expand-file-name key-file)
947 (expand-file-name cert-file))))
949 (defun elpher-list-existing-certificates ()
950 "Return a list of the persistent certificates in `elpher-certificate-directory'."
951 (unless (file-directory-p elpher-certificate-directory)
952 (make-directory elpher-certificate-directory))
955 (file-name-sans-extension file))
956 (directory-files elpher-certificate-directory nil "\\.key$")))
958 (defun elpher-forget-current-certificate ()
959 "Causes any current certificate to be forgotten.)
960 In the case of throwaway certificates, the key and certificate files
963 (when elpher-client-certificate
964 (unless (and (called-interactively-p 'any)
965 (not (y-or-n-p (concat "Really forget client certificate? "
966 "(Throwaway certificates will be deleted.)"))))
967 (when (cadr elpher-client-certificate)
968 (delete-file (elt elpher-client-certificate 2))
969 (delete-file (elt elpher-client-certificate 3)))
970 (setq elpher-client-certificate nil)
971 (if (called-interactively-p 'any)
972 (message "Client certificate forgotten.")))))
974 (defun elpher-get-current-keylist (address)
975 "Retrieve the `gnutls-boot-parameters'-compatable keylist.
977 This is obtained from the client certificate described by
978 `elpher-current-certificate', if one is available and the host for
979 that certificate matches the host in ADDRESS.
981 If `elpher-current-certificate' is non-nil, and its host name doesn't
982 match that of ADDRESS, the certificate is forgotten."
983 (if elpher-client-certificate
984 (if (string= (car elpher-client-certificate)
985 (elpher-address-host address))
986 (list (cddr elpher-client-certificate))
987 (elpher-forget-current-certificate)
988 (message "Disabling client certificate for new host")
993 ;;; Gopher selector retrieval
996 (defun elpher-get-gopher-response (address renderer)
997 "Get response string from gopher server at ADDRESS and render using RENDERER."
998 (elpher-get-host-response address 70
999 (concat (elpher-gopher-address-selector address) "\r\n")
1001 (or (string= (elpher-address-protocol address) "gophers")
1004 (defun elpher-get-gopher-page (renderer)
1005 "Getter function for gopher pages.
1006 The RENDERER procedure is used to display the contents of the page
1007 once they are retrieved from the gopher server."
1008 (let* ((address (elpher-page-address elpher-current-page))
1009 (content (elpher-get-cached-content address)))
1010 (if (and content (funcall renderer nil))
1011 (elpher-with-clean-buffer
1013 (elpher-restore-pos))
1014 (elpher-with-clean-buffer
1015 (insert "LOADING... (use 'u' to cancel)\n"))
1016 (condition-case the-error
1017 (elpher-get-gopher-response address renderer)
1019 (elpher-network-error address the-error))))))
1023 (defun elpher-insert-index (string)
1024 "Insert the index corresponding to STRING into the current buffer."
1025 ;; Should be able to split directly on CRLF, but some non-conformant
1026 ;; LF-only servers sadly exist, hence the following.
1027 (let ((str-processed (elpher-preprocess-text-response string)))
1028 (dolist (line (split-string str-processed "\n"))
1030 (unless (= (length line) 0)
1031 (let* ((type (elt line 0))
1032 (fields (split-string (substring line 1) "\t"))
1033 (display-string (elt fields 0))
1034 (selector (elt fields 1))
1035 (host (elt fields 2))
1036 (port (if (elt fields 3)
1037 (string-to-number (elt fields 3))
1039 (address (elpher-make-gopher-address type selector host port)))
1040 (elpher-insert-index-record display-string address)))))))
1042 (defun elpher-insert-margin (&optional type-name)
1043 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
1046 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
1048 (propertize "[" 'face 'elpher-margin-brackets)
1049 (propertize type-name 'face 'elpher-margin-key)
1050 (propertize "]" 'face 'elpher-margin-brackets))))
1052 (insert (make-string elpher-margin-width ?\s))))
1054 (defun elpher--page-button-help (_window buffer pos)
1055 "Function called by Emacs to generate mouse-over text.
1056 The arguments specify the BUFFER and the POS within the buffer of the item
1057 for which help is required. The function returns the help to be
1058 displayed. The _WINDOW argument is currently unused."
1059 (with-current-buffer buffer
1060 (let ((button (button-at pos)))
1062 (let* ((page (button-get button 'elpher-page))
1063 (address (elpher-page-address page)))
1064 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
1066 (elpher-address-to-url address))))))))
1068 (defun elpher-insert-index-record (display-string &optional address)
1069 "Function to insert an index record into the current buffer.
1070 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
1071 If ADDRESS is not supplied or nil the record is rendered as an
1072 'information' line."
1073 (let* ((type (if address (elpher-address-type address) nil))
1074 (type-map-entry (cdr (assoc type elpher-type-map))))
1076 (let* ((margin-code (elt type-map-entry 2))
1077 (face (elt type-map-entry 3))
1078 (filtered-display-string (elpher-color-filter-apply display-string))
1079 (page (elpher-make-page filtered-display-string address)))
1080 (elpher-insert-margin margin-code)
1081 (insert-text-button filtered-display-string
1084 'action #'elpher-click-link
1086 'help-echo #'elpher--page-button-help))
1088 ('nil ;; Information
1089 (elpher-insert-margin)
1090 (let ((propertized-display-string
1091 (propertize display-string 'face 'elpher-info)))
1092 (insert (elpher-process-text-for-display propertized-display-string))))
1093 (`(gopher ,selector-type) ;; Unknown
1094 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
1095 (insert (propertize display-string
1096 'face 'elpher-unknown)))))
1099 (defun elpher-click-link (button)
1100 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
1101 (let ((page (button-get button 'elpher-page)))
1102 (elpher-visit-page page)))
1104 (defun elpher-render-index (data &optional _mime-type-string)
1105 "Render DATA as an index. MIME-TYPE-STRING is unused."
1106 (elpher-with-clean-buffer
1109 (elpher-insert-index data)
1110 (elpher-cache-content (elpher-page-address elpher-current-page)
1115 (defun elpher-render-text (data &optional _mime-type-string)
1116 "Render DATA as text. MIME-TYPE-STRING is unused."
1117 (elpher-with-clean-buffer
1120 (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
1121 (elpher-cache-content
1122 (elpher-page-address elpher-current-page)
1127 (defun elpher-render-image (data &optional _mime-type-string)
1128 "Display DATA as image. MIME-TYPE-STRING is unused."
1131 (if (display-images-p)
1133 (let ((image (create-image
1136 (elpher-with-clean-buffer
1137 (insert-image image)
1138 (elpher-restore-pos))))
1139 (elpher-render-download data))))
1141 ;; Search retrieval and rendering
1143 (defun elpher-get-gopher-query-page (renderer)
1144 "Getter for gopher addresses requiring input.
1145 The response is rendered using the rendering function RENDERER."
1146 (let* ((address (elpher-page-address elpher-current-page))
1147 (content (elpher-get-cached-content address))
1149 (if (and content (funcall renderer nil))
1150 (elpher-with-clean-buffer
1152 (elpher-restore-pos)
1153 (message "Displaying cached search results. Reload to perform a new search."))
1155 (let* ((query-string (read-string "Query: "))
1156 (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
1157 (search-address (elpher-make-gopher-address ?1
1159 (elpher-address-host address)
1160 (elpher-address-port address)
1161 (equal (elpher-address-type address) "gophers"))))
1164 (elpher-with-clean-buffer
1165 (insert "LOADING RESULTS... (use 'u' to cancel)"))
1166 (elpher-get-gopher-response search-address renderer))
1168 (elpher-visit-previous-page))))))
1170 ;; Raw server response rendering
1172 (defun elpher-render-raw (data &optional mime-type-string)
1173 "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
1176 (elpher-with-clean-buffer
1177 (when mime-type-string
1178 (insert "MIME type specified by server: '" mime-type-string "'\n"))
1180 (goto-char (point-min)))
1181 (message "Displaying raw server response. Reload or redraw to return to standard view.")))
1183 ;; File save "rendering"
1185 (defun elpher-render-download (data &optional _mime-type-string)
1186 "Save DATA to file. MIME-TYPE-STRING is unused."
1189 (let* ((address (elpher-page-address elpher-current-page))
1190 (selector (if (elpher-address-gopher-p address)
1191 (elpher-gopher-address-selector address)
1192 (elpher-address-filename address))))
1193 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1194 (let* ((filename-proposal (file-name-nondirectory selector))
1195 (filename (read-file-name "Download complete. Save file as: "
1197 (if (> (length filename-proposal) 0)
1200 (let ((coding-system-for-write 'binary))
1201 (with-temp-file filename
1203 (message (format "Saved to file %s." filename))))))
1207 (defun elpher-render-html (data &optional _mime-type-string)
1208 "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
1209 (elpher-with-clean-buffer
1212 (let ((dom (with-temp-buffer
1214 (libxml-parse-html-region (point-min) (point-max)))))
1215 (shr-insert-document dom)))))
1217 ;; Gemini page retrieval
1219 (defvar elpher-gemini-redirect-chain)
1221 (defun elpher-get-gemini-response (address renderer)
1222 "Get response string from gemini server at ADDRESS and render using RENDERER."
1223 (elpher-get-host-response address 1965
1224 (concat (elpher-address-to-url address) "\r\n")
1225 (lambda (response-string)
1226 (elpher-process-gemini-response response-string renderer))
1229 (defun elpher-parse-gemini-response (response)
1230 "Parse the RESPONSE string and return a list of components.
1231 The list is of the form (code meta body). A response of nil implies
1232 that the response was malformed."
1233 (let ((header-end-idx (string-match "\r\n" response)))
1235 (let ((header (string-trim (substring response 0 header-end-idx)))
1236 (body (substring response (+ header-end-idx 2))))
1237 (if (>= (length header) 2)
1238 (let ((code (substring header 0 2))
1239 (meta (string-trim (substring header 2))))
1240 (list code meta body))
1241 (error "Malformed response: No response status found in header %s" header)))
1242 (error "Malformed response: No CRLF-delimited header found in response %s" response))))
1244 (defun elpher-process-gemini-response (response-string renderer)
1245 "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
1246 (let ((response-components (elpher-parse-gemini-response response-string)))
1247 (let ((response-code (elt response-components 0))
1248 (response-meta (elt response-components 1))
1249 (response-body (elt response-components 2)))
1250 (pcase (elt response-code 0)
1251 (?1 ; Input required
1252 (elpher-with-clean-buffer
1253 (insert "Gemini server is requesting input."))
1254 (let* ((query-string
1255 (if (eq (elt response-code 1) ?1)
1256 (read-passwd (concat response-meta ": "))
1257 (read-string (concat response-meta ": "))))
1258 (query-address (seq-copy (elpher-page-address elpher-current-page)))
1259 (old-fname (url-filename query-address)))
1260 (setf (url-filename query-address)
1261 (concat old-fname "?" (url-build-query-string `((,query-string)))))
1262 (elpher-get-gemini-response query-address renderer)))
1263 (?2 ; Normal response
1264 (funcall renderer response-body response-meta))
1266 (message "Following redirect to %s" response-meta)
1267 (if (>= (length elpher-gemini-redirect-chain) 5)
1268 (error "More than 5 consecutive redirects followed"))
1269 (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
1270 (if (member redirect-address elpher-gemini-redirect-chain)
1271 (error "Redirect loop detected"))
1272 (if (not (string= (elpher-address-protocol redirect-address)
1274 (error "Server tried to automatically redirect to non-gemini URL: %s"
1276 (elpher-page-set-address elpher-current-page redirect-address)
1277 (add-to-list 'elpher-gemini-redirect-chain redirect-address)
1278 (elpher-get-gemini-response redirect-address renderer)))
1279 (?4 ; Temporary failure
1280 (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
1281 response-code response-meta))
1282 (?5 ; Permanent failure
1283 (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
1284 response-code response-meta))
1285 (?6 ; Client certificate required
1286 (elpher-with-clean-buffer
1287 (if elpher-client-certificate
1288 (insert "Gemini server does not recognise the provided TLS certificate:\n\n")
1289 (insert "Gemini server is requesting a valid TLS certificate:\n\n"))
1291 (elpher-gemini-insert-text response-meta))
1292 (let ((chosen-certificate (elpher-choose-client-certificate)))
1293 (unless chosen-certificate
1294 (error "Gemini server requires a client certificate and none was provided"))
1295 (setq elpher-client-certificate chosen-certificate))
1296 (elpher-with-clean-buffer)
1297 (elpher-get-gemini-response (elpher-page-address elpher-current-page) renderer))
1299 (error "Gemini server response unknown: %s %s"
1300 response-code response-meta))))))
1302 (defun elpher--read-answer-polyfill (question answers)
1303 "Polyfill for `read-answer' in Emacs 26.1.
1304 QUESTION is a string containing a question, and ANSWERS
1305 is a list of possible answers."
1306 (completing-read question (mapcar 'identity answers)))
1308 (if (fboundp 'read-answer)
1309 (defalias 'elpher-read-answer 'read-answer)
1310 (defalias 'elpher-read-answer 'elpher--read-answer-polyfill))
1312 (defun elpher-choose-client-certificate ()
1313 "Prompt for a client certificate to use to establish a TLS connection."
1314 (let* ((read-answer-short t))
1315 (pcase (read-answer "What do you want to do? "
1317 "generate and use throw-away certificate")
1319 "generate new or use existing persistent certificate")
1321 "stop immediately")))
1323 (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
1325 (let* ((existing-certificates (elpher-list-existing-certificates))
1326 (file-base (completing-read
1327 "Nickname for new or existing certificate (autocompletes, empty response aborts): "
1328 existing-certificates)))
1329 (if (string-empty-p (string-trim file-base))
1331 (if (member file-base existing-certificates)
1332 (setq elpher-client-certificate
1333 (elpher-get-existing-certificate file-base))
1334 (pcase (read-answer "Generate new certificate or install externally-generated one? "
1336 "generate new certificate")
1338 "install existing certificate")
1340 "stop immediately")))
1342 (let ((common-name (read-string "Common Name field for new certificate: "
1344 (message "New key and self-signed certificate written to %s"
1345 elpher-certificate-directory)
1346 (elpher-generate-persistent-certificate file-base common-name)))
1348 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
1349 (key-file (read-file-name "Key file: " nil nil t)))
1350 (message "Key and certificate installed in %s for future use"
1351 elpher-certificate-directory)
1352 (elpher-install-and-use-existing-certificate key-file
1358 (defun elpher-get-gemini-page (renderer)
1359 "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
1360 (let* ((address (elpher-page-address elpher-current-page))
1361 (content (elpher-get-cached-content address)))
1362 (condition-case the-error
1363 (if (and content (funcall renderer nil))
1364 (elpher-with-clean-buffer
1366 (elpher-restore-pos))
1367 (elpher-with-clean-buffer
1368 (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
1369 (setq elpher-gemini-redirect-chain nil)
1370 (elpher-get-gemini-response address renderer))
1372 (elpher-network-error address the-error)))))
1374 (defun elpher-render-gemini (body &optional mime-type-string)
1375 "Render gemini response BODY with rendering MIME-TYPE-STRING."
1378 (let* ((mime-type-string* (if (or (not mime-type-string)
1379 (string-empty-p mime-type-string))
1380 "text/gemini; charset=utf-8"
1382 (mime-type-split (split-string mime-type-string* ";" t))
1383 (mime-type (string-trim (car mime-type-split)))
1384 (parameters (mapcar (lambda (s)
1385 (let ((key-val (split-string s "=")))
1386 (list (downcase (string-trim (car key-val)))
1387 (downcase (string-trim (cadr key-val))))))
1388 (cdr mime-type-split))))
1389 (when (string-prefix-p "text/" mime-type)
1390 (setq body (decode-coding-string
1392 (if (assoc "charset" parameters)
1393 (intern (cadr (assoc "charset" parameters)))
1395 (setq body (replace-regexp-in-string "\r" "" body)))
1397 ((or "text/gemini" "")
1398 (elpher-render-gemini-map body parameters))
1400 (elpher-render-html body))
1401 ((pred (string-prefix-p "text/"))
1402 (elpher-render-gemini-plain-text body parameters))
1403 ((pred (string-prefix-p "image/"))
1404 (elpher-render-image body))
1406 (elpher-render-download body))))))
1408 (defun elpher-gemini-get-link-url (link-line)
1409 "Extract the url portion of LINK-LINE, a gemini map file link line.
1410 Returns nil in the event that the contents of the line following the
1411 => prefix are empty."
1412 (let ((l (split-string (substring link-line 2))))
1414 (string-trim (elt l 0))
1417 (defun elpher-gemini-get-link-display-string (link-line)
1418 "Extract the display string portion of LINK-LINE, a gemini map file link line.
1419 Returns the url portion in the event that the display-string portion is empty."
1420 (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
1421 (idx (string-match "[ \t]" rest)))
1422 (string-trim (if idx
1423 (substring rest (+ idx 1))
1426 (defun elpher-collapse-dot-sequences (filename)
1427 "Collapse dot sequences in FILENAME.
1428 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
1429 (let* ((path (split-string filename "/"))
1430 (path-reversed-normalized
1431 (seq-reduce (lambda (a b)
1432 (cond ((and a (equal b "..") (cdr a)))
1433 ((and (not a) (equal b "..")) a) ;leading .. are dropped
1437 (string-join (reverse path-reversed-normalized) "/")))
1439 (defun elpher-address-from-gemini-url (url)
1440 "Extract address from URL with defaults as per gemini map files.
1441 While there's obviously some redundancy here between this function and
1442 `elpher-address-from-url', gemini map file URLs require enough special
1443 treatment that a separate function is warranted."
1444 (let ((address (url-generic-parse-url url))
1445 (current-address (elpher-page-address elpher-current-page)))
1446 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
1447 (setf (url-fullness address) t)
1448 (if (url-host address) ;if there is an explicit host, filenames are absolute
1449 (if (string-empty-p (url-filename address))
1450 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
1451 (setf (url-host address) (url-host current-address))
1452 (setf (url-port address) (url-port current-address))
1453 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1454 (setf (url-filename address)
1455 (concat (file-name-directory (url-filename current-address))
1456 (url-filename address)))))
1457 (unless (url-type address)
1458 (setf (url-type address) "gemini"))
1459 (when (equal (url-type address) "gemini")
1460 (setf (url-filename address)
1461 (elpher-collapse-dot-sequences (url-filename address)))))
1462 (elpher-remove-redundant-ports address)))
1464 (defun elpher-gemini-insert-link (link-line)
1465 "Insert link described by LINK-LINE into a text/gemini document."
1466 (let* ((url (elpher-gemini-get-link-url link-line))
1467 (display-string (elpher-gemini-get-link-display-string link-line))
1468 (address (elpher-address-from-gemini-url url))
1469 (type (if address (elpher-address-type address) nil))
1470 (type-map-entry (cdr (assoc type elpher-type-map))))
1471 (when display-string
1472 (insert elpher-gemini-link-string)
1474 (let* ((face (elt type-map-entry 3))
1475 (filtered-display-string (elpher-color-filter-apply display-string))
1476 (page (elpher-make-page filtered-display-string address)))
1477 (insert-text-button filtered-display-string
1480 'action #'elpher-click-link
1482 'help-echo #'elpher--page-button-help))
1483 (insert (propertize display-string 'face 'elpher-unknown)))
1486 (defvar elpher--gemini-page-headings nil
1487 "List of headings on the page.")
1489 (defun elpher-gemini-insert-header (header-line)
1490 "Insert header described by HEADER-LINE into a text/gemini document.
1491 The gemini map file line describing the header is given
1493 (when (string-match "^\\(#+\\)[ \t]*" header-line)
1494 (let* ((level (length (match-string 1 header-line)))
1495 (header (substring header-line (match-end 0)))
1497 (1 'elpher-gemini-heading1)
1498 (2 'elpher-gemini-heading2)
1499 (3 'elpher-gemini-heading3)
1501 (fill-column (if (display-graphic-p)
1503 (font-get (font-spec :name (face-font 'default)) :size))
1504 (font-get (font-spec :name (face-font face)) :size)) fill-column)))
1505 (setq elpher--gemini-page-headings (cons (cons header (point))
1506 elpher--gemini-page-headings))
1507 (unless (display-graphic-p)
1508 (insert (make-string level ?#) " "))
1509 (insert (propertize header 'face face))
1512 (defun elpher-gemini-insert-text (text-line)
1513 "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
1514 This function uses Emacs' auto-fill to wrap text sensibly to a maximum
1515 width defined by `elpher-gemini-max-fill-width'."
1516 (string-match "\\(^[ \t]*\\)\\(\\*[ \t]+\\|>[ \t]*\\)?" text-line)
1517 (let* ((line-prefix (match-string 2 text-line))
1518 (processed-text-line
1520 (cond ((string-prefix-p "*" line-prefix)
1522 (replace-regexp-in-string "\\*"
1523 elpher-gemini-bullet-string
1524 (match-string 0 text-line))
1525 (substring text-line (match-end 0))))
1526 ((string-prefix-p ">" line-prefix)
1527 (propertize text-line 'face 'elpher-gemini-quoted))
1530 (adaptive-fill-mode t)
1531 ;; fill-prefix is important for adaptive-fill-mode: without
1532 ;; it, multi-line list items are not indented correct
1533 (fill-prefix (if (match-string 2 text-line)
1534 (replace-regexp-in-string "[>\*]" " " (match-string 0 text-line))
1536 (insert (elpher-process-text-for-display processed-text-line))
1539 (defun elpher-render-gemini-map (data _parameters)
1540 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1541 (elpher-with-clean-buffer
1542 (setq elpher--gemini-page-headings nil)
1543 (let ((preformatted nil))
1545 (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
1546 (dolist (line (split-string data "\n"))
1548 ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
1549 (preformatted (insert (elpher-process-text-for-display
1550 (propertize line 'face 'elpher-gemini-preformatted))
1552 ((string-prefix-p "=>" line)
1553 (elpher-gemini-insert-link line))
1554 ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
1555 (t (elpher-gemini-insert-text line)))))
1556 (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))
1557 (elpher-cache-content
1558 (elpher-page-address elpher-current-page)
1561 (defun elpher-render-gemini-plain-text (data _parameters)
1562 "Render DATA as plain text file. PARAMETERS is currently unused."
1563 (elpher-with-clean-buffer
1564 (insert (elpher-process-text-for-display data))
1565 (elpher-cache-content
1566 (elpher-page-address elpher-current-page)
1570 ;; Finger page connection
1572 (defun elpher-get-finger-page (renderer)
1573 "Opens a finger connection to the current page address.
1574 The result is rendered using RENDERER."
1575 (let* ((address (elpher-page-address elpher-current-page))
1576 (content (elpher-get-cached-content address)))
1577 (if (and content (funcall renderer nil))
1578 (elpher-with-clean-buffer
1580 (elpher-restore-pos))
1581 (elpher-with-clean-buffer
1582 (insert "LOADING... (use 'u' to cancel)\n"))
1583 (condition-case the-error
1584 (let* ((kill-buffer-query-functions nil)
1585 (user (let ((filename (elpher-address-filename address)))
1586 (if (> (length filename) 1)
1587 (substring filename 1)
1588 (elpher-address-user address)))))
1589 (elpher-get-host-response address 79
1590 (concat user "\r\n")
1593 (elpher-network-error address the-error))))))
1596 ;; Telnet page connection
1598 (defun elpher-get-telnet-page (renderer)
1599 "Opens a telnet connection to the current page address (RENDERER must be nil)."
1601 (elpher-visit-previous-page)
1602 (error "Command not supported for telnet URLs"))
1603 (let* ((address (elpher-page-address elpher-current-page))
1604 (host (elpher-address-host address))
1605 (port (elpher-address-port address)))
1606 (elpher-visit-previous-page)
1612 ;; Other URL page opening
1614 (defun elpher-get-other-url-page (renderer)
1615 "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
1617 (elpher-visit-previous-page)
1618 (error "Command not supported for general URLs"))
1619 (let* ((address (elpher-page-address elpher-current-page))
1620 (url (elpher-address-to-url address)))
1622 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1623 (message "Opening URL...")
1624 (if elpher-open-urls-with-eww
1626 (browse-url url)))))
1629 ;; Start page retrieval
1631 (defun elpher-get-start-page (renderer)
1632 "Getter which displays the start page (RENDERER must be nil)."
1634 (elpher-visit-previous-page)
1635 (error "Command not supported for start page"))
1636 (elpher-with-clean-buffer
1637 (insert " --------------------------------------------\n"
1638 " Elpher Gopher and Gemini Client \n"
1639 " version " elpher-version "\n"
1640 " --------------------------------------------\n"
1642 "Default bindings:\n"
1644 " - TAB/Shift-TAB: next/prev item on current page\n"
1645 " - RET/mouse-1: open item under cursor\n"
1646 " - m: select an item on current page by name (autocompletes)\n"
1647 " - u/mouse-3/U: return to previous page or to the start page\n"
1648 " - g: go to a particular address (gopher, gemini, finger)\n"
1649 " - o/O: open a different address selector or the root menu of the current server\n"
1650 " - d/D: download item under cursor or current page\n"
1651 " - i/I: info on item under cursor or current page\n"
1652 " - c/C: copy URL representation of item under cursor or current page\n"
1653 " - a/A: bookmark the item under cursor or current page\n"
1654 " - B: list all bookmarks\n"
1655 " - s/S: show current history stack or all previously visted pages\n"
1656 " - r: redraw current page (using cached contents if available)\n"
1657 " - R: reload current page (regenerates cache)\n"
1658 " - !: set character coding system for gopher (default is to autodetect)\n"
1659 " - T: toggle TLS gopher mode\n"
1660 " - F: forget/discard current TLS client certificate\n"
1661 " - .: display the raw server response for the current page\n"
1663 "Start your exploration of gopher space and gemini:\n")
1664 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1665 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1666 (elpher-insert-index-record "Project Gemini home page"
1667 (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
1669 "Alternatively, select a search engine and enter some search terms:\n")
1670 (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
1671 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1672 (elpher-insert-index-record "Gemini Search Engine (geminispace.info)"
1673 (elpher-address-from-url "gemini://geminispace.info/search"))
1675 "Your bookmarks are stored in your ")
1676 (let ((help-string "RET,mouse-1: Open bookmark list"))
1677 (insert-text-button "bookmark list"
1681 (call-interactively #'elpher-show-bookmarks))
1683 'help-echo help-string))
1686 "(Bookmarks from legacy elpher-bookmarks files will be automatically imported.)\n"
1689 "The gopher home of the Elpher project is here:\n")
1690 (elpher-insert-index-record "The Elpher Project Page"
1691 (elpher-make-gopher-address ?1
1695 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1697 "The following info documentation is available:\n"
1699 (insert-text-button "Elpher Manual"
1705 'help-echo help-string)
1707 (insert-text-button "Changes introduced by the latest release"
1711 (info "(elpher)News"))
1713 'help-echo help-string))
1716 (concat "(These documents should be available if you have installed Elpher \n"
1717 " using MELPA. Otherwise you may have to install the manual yourself.)\n")
1719 (elpher-restore-pos)))
1721 ;; History page retrieval
1723 (defun elpher-show-history ()
1724 "Show the current contents of elpher's history stack.
1725 Use \\[elpher-show-visited-pages] to see the entire history.
1726 This is rendered using `elpher-get-history-page' via `elpher-type-map'."
1729 (elpher-make-page "Current History Stack"
1730 (elpher-make-special-address 'history))))
1732 (defun elpher-show-visited-pages ()
1733 "Show the all the pages you've visited using Elpher.
1734 Use \\[elpher-show-history] to see just the current history stack.
1735 This is rendered using `elpher-get-visited-pages-page' via `elpher-type-map'."
1738 (elpher-make-page "Elpher Visted Pages"
1739 (elpher-make-special-address 'visited-pages))))
1741 (defun elpher-get-history-page (renderer)
1742 "Getter which displays the history page (RENDERER must be nil)."
1744 (elpher-visit-previous-page)
1745 (error "Command not supported for history page"))
1746 (elpher-display-history-links elpher-history "Current history stack"))
1748 (defun elpher-get-visited-pages-page (renderer)
1749 "Getter which displays the list of visited pages (RENDERER must be nil)."
1751 (elpher-visit-previous-page)
1752 (error "Command not supported for history page"))
1753 (elpher-display-history-links
1754 (seq-filter (lambda (page)
1755 (not (elpher-address-special-p (elpher-page-address page))))
1756 elpher-visited-pages)
1757 "All visited pages"))
1759 (defun elpher-display-history-links (pages title)
1760 "Show all PAGES in an Elpher buffer with a given TITLE."
1761 (let* ((title-line (concat " ---- " title " ----"))
1762 (footer-line (make-string (length title-line) ?-)))
1763 (elpher-with-clean-buffer
1764 (insert title-line "\n\n")
1766 (dolist (page pages)
1768 (let ((display-string (elpher-page-display-string page))
1769 (address (elpher-page-address page)))
1770 (elpher-insert-index-record display-string address))))
1771 (insert "No history items found.\n"))
1772 (insert "\n " footer-line "\n"
1773 "Select an entry or press 'u' to return to the previous page.")
1774 (elpher-restore-pos))))
1779 ;; This code allows Elpher to use the standard Emacs bookmarks: `C-x r
1780 ;; m' to add a bookmark, `C-x r l' to list bookmarks (which is where
1781 ;; you can anotate bookmarks!), `C-x r b' to jump to a bookmark, and
1782 ;; so on. See the Bookmarks section in the Emacs info manual for more.
1784 (defvar elpher-bookmark-link nil
1785 "Prefer bookmarking a link or the current page.
1786 Bind this variable dynamically, or set it to t.
1787 If you set it to t, the commands \\[bookmark-set-no-overwrite]
1788 and \\[elpher-set-bookmark-no-overwrite] do the same thing.")
1790 (defun elpher-bookmark-make-record ()
1791 "Return a bookmark record.
1792 If `elpher-bookmark-link' is non-nil and point is on a link button,
1793 return a bookmark record for that link. Otherwise, return a bookmark
1794 record for the current elpher page."
1795 (let* ((button (and elpher-bookmark-link (button-at (point))))
1797 (button-get button 'elpher-page)
1798 elpher-current-page))
1799 (address (elpher-page-address page))
1800 (url (elpher-address-to-url address))
1801 (display-string (elpher-page-display-string page))
1802 (pos (if button nil (point))))
1803 (if (elpher-address-special-p address)
1804 (error "Cannot bookmark %s" display-string)
1806 (defaults . (,display-string))
1809 (handler . elpher-bookmark-jump)))))
1812 (defun elpher-bookmark-jump (bookmark)
1813 "Handler used to open a bookmark using elpher.
1814 The argument BOOKMARK is a bookmark record passed to the function.
1815 This handler is responsible for loading the bookmark in some buffer,
1816 then making that buffer the current buffer. It should not switch
1818 (let* ((url (cdr (assq 'location bookmark)))
1819 (cleaned-url (string-trim url))
1820 (address (elpher-address-from-url cleaned-url))
1821 (page (elpher-make-page cleaned-url address)))
1822 (elpher-with-clean-buffer
1823 (elpher-visit-page page))
1824 (set-buffer (get-buffer elpher-buffer-name))
1827 (defun elpher-bookmark-link ()
1828 "Bookmark the link at point.
1829 To bookmark the current page, use \\[elpher-bookmark-current]."
1831 (let ((elpher-bookmark-link t))
1832 (bookmark-set-no-overwrite)))
1834 (defun elpher-bookmark-current ()
1835 "Bookmark the current page.
1836 To bookmark the link at point use \\[elpher-bookmark-link]."
1838 (call-interactively #'bookmark-set-no-overwrite))
1840 (defun elpher-bookmark-import (file)
1841 "Import legacy Elpher bookmarks file FILE into Emacs bookmarks."
1842 (interactive (list (if (and (boundp 'elpher-bookmarks-file)
1843 (file-readable-p elpher-bookmarks-file))
1844 elpher-bookmarks-file
1845 (read-file-name "Old Elpher bookmarks: "
1846 user-emacs-directory nil t
1847 "elpher-bookmarks"))))
1848 (dolist (bookmark (with-temp-buffer
1849 (insert-file-contents file)
1850 (read (current-buffer))))
1851 (let* ((display-string (car bookmark))
1852 (url (cadr bookmark))
1853 (record `(,display-string
1855 (handler . elpher-bookmark-jump))))
1856 (bookmark-store display-string (cdr record) t)))
1859 (defun elpher-get-bookmarks-page (renderer)
1860 "Getter which displays the history page (RENDERER must be nil)."
1862 (elpher-visit-previous-page)
1863 (error "Command not supported for bookmarks page"))
1864 (elpher-with-clean-buffer
1865 (insert " ---- Elpher Bookmarks ---- \n\n")
1866 (bookmark-maybe-load-default-file)
1867 (dolist (bookmark (bookmark-maybe-sort-alist))
1868 (when (eq #'elpher-bookmark-jump (alist-get 'handler (cdr bookmark)))
1869 (let* ((name (car bookmark))
1870 (url (alist-get 'location (cdr bookmark)))
1871 (address (elpher-address-from-url url)))
1872 (elpher-insert-index-record name address))))
1873 (when (<= (line-number-at-pos) 3)
1874 (insert "No bookmarked pages found.\n"))
1875 (insert "\n --------------------------\n\n"
1876 "Select an entry or press 'u' to return to the previous page.\n\n"
1877 "Bookmarks can be renamed or deleted via the ")
1878 (insert-text-button "Emacs bookmark menu"
1881 (call-interactively #'bookmark-bmenu-list))
1883 'help-echo "RET,mouse-1: open Emacs bookmark menu")
1884 (insert (substitute-command-keys
1885 ",\nwhich can also be opened from anywhere using '\\[bookmark-bmenu-list]'."))
1886 (elpher-restore-pos)))
1888 (defun elpher-show-bookmarks ()
1889 "Display the current list of elpher bookmarks.
1890 This will also check for a legacy bookmark file and offer to import it."
1892 (let ((old-bookmarks-file (or (and (boundp 'elpher-bookmarks-file)
1893 elpher-bookmarks-file)
1894 (locate-user-emacs-file "elpher-bookmarks"))))
1895 (when (and (file-readable-p old-bookmarks-file)
1896 (y-or-n-p (concat "Legacy elpher-bookmarks file \""
1898 "\" found. Import now?")))
1899 (elpher-bookmark-import old-bookmarks-file)
1900 (rename-file old-bookmarks-file (concat old-bookmarks-file "-legacy"))))
1901 (if elpher-use-emacs-bookmark-menu
1902 (call-interactively #'bookmark-bmenu-list)
1904 (elpher-make-page "Elpher Bookmarks"
1905 (elpher-make-special-address 'bookmarks)))))
1913 (defun elpher-org-export-link (link description format protocol)
1914 "Export a LINK with DESCRIPTION for the given PROTOCOL and FORMAT.
1916 FORMAT is an Org export backend. DESCRIPTION may be nil. PROTOCOL may be one
1917 of gemini, gopher or finger."
1918 (let* ((url (if (equal protocol "elpher")
1919 (string-remove-prefix "elpher:" link)
1920 (format "%s:%s" protocol link)))
1921 (desc (or description url)))
1923 (`gemini (format "=> %s %s" url desc))
1924 (`html (format "<a href=\"%s\">%s</a>" url desc))
1925 (`latex (format "\\href{%s}{%s}" url desc))
1926 (_ (if (not description)
1928 (format "%s (%s)" desc url))))))
1930 (defun elpher-org-store-link ()
1931 "Store link to an `elpher' page in Org."
1932 (when (eq major-mode 'elpher-mode)
1933 (let* ((url (elpher-info-current))
1934 (desc (car elpher-current-page))
1936 ((string-prefix-p "gemini:" url) "gemini")
1937 ((string-prefix-p "gopher:" url) "gopher")
1938 ((string-prefix-p "finger:" url) "finger")
1940 (when (equal "elpher" protocol)
1941 ;; Weird link. Or special inner link?
1942 (setq url (concat "elpher:" url)))
1943 (org-link-store-props :type protocol :link url :description desc)
1946 (defun elpher-org-follow-link (link protocol)
1947 "Visit a LINK for the given PROTOCOL.
1949 PROTOCOL may be one of gemini, gopher or finger. This method also
1950 supports the old protocol elpher, where the link is self-contained."
1951 (let ((url (if (equal protocol "elpher")
1952 (string-remove-prefix "elpher:" link)
1953 (format "%s:%s" protocol link))))
1956 (defun elpher-org-mode-integration ()
1957 "Set up `elpher' integration for `org-mode'."
1958 (org-link-set-parameters
1960 :store #'elpher-org-store-link
1961 :export (lambda (link description format _plist)
1962 (elpher-org-export-link link description format "elpher"))
1963 :follow (lambda (link _arg) (elpher-org-follow-link link "elpher")))
1964 (org-link-set-parameters
1966 :export (lambda (link description format _plist)
1967 (elpher-org-export-link link description format "gemini"))
1968 :follow (lambda (link _arg) (elpher-org-follow-link link "gemini")))
1969 (org-link-set-parameters
1971 :export (lambda (link description format _plist)
1972 (elpher-org-export-link link description format "gopher"))
1973 :follow (lambda (link _arg) (elpher-org-follow-link link "gopher")))
1974 (org-link-set-parameters
1976 :export (lambda (link description format _plist)
1977 (elpher-org-export-link link description format "finger"))
1978 :follow (lambda (link _arg) (elpher-org-follow-link link "finger"))))
1980 (add-hook 'org-mode-hook #'elpher-org-mode-integration)
1985 (defun elpher-browse-url-elpher (url &rest _args)
1986 "Browse URL using Elpher. This function is used by `browse-url'."
1987 (interactive (browse-url-interactive-arg "Elpher URL: "))
1990 ;; Use elpher to open gopher, finger and gemini links
1991 ;; For recent version of `browse-url' package
1992 (if (boundp 'browse-url-default-handlers)
1994 'browse-url-default-handlers
1995 '("^\\(gopher\\|finger\\|gemini\\)://" . elpher-browse-url-elpher))
1996 ;; Patch `browse-url-browser-function' for older ones. The value of
1997 ;; that variable is `browse-url-default-browser' by default, so
1998 ;; that's the function that gets advised.
1999 (advice-add browse-url-browser-function :before-while
2000 (lambda (url &rest _args)
2001 "Handle gemini, gopher, and finger schemes using Elpher."
2002 (let ((scheme (downcase (car (split-string url ":" t)))))
2003 (if (member scheme '("gemini" "gopher" "finger"))
2004 ;; `elpher-go' always returns nil, which will stop the
2005 ;; advice chain here in a before-while
2007 ;; chain must continue, then return t.
2010 ;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
2011 (with-eval-after-load 'thingatpt
2012 (add-to-list 'thing-at-point-uri-schemes "gemini://"))
2016 ;; Make mu4e aware of the gemini world
2017 (setq mu4e~view-beginning-of-url-regexp
2018 "\\(?:https?\\|gopher\\|finger\\|gemini\\)://\\|mailto:")
2020 ;;; Interactive procedures
2023 (defun elpher-next-link ()
2024 "Move point to the next link on the current page."
2028 (defun elpher-prev-link ()
2029 "Move point to the previous link on the current page."
2031 (backward-button 1))
2033 (defun elpher-follow-current-link ()
2034 "Open the link or url at point."
2039 (defun elpher-go (host-or-url)
2040 "Go to a particular gopher site HOST-OR-URL.
2041 When run interactively HOST-OR-URL is read from the minibuffer."
2042 (interactive "sGopher or Gemini URL: ")
2043 (let* ((cleaned-host-or-url (string-trim host-or-url))
2044 (address (elpher-address-from-url cleaned-host-or-url))
2045 (page (elpher-make-page cleaned-host-or-url address)))
2046 (switch-to-buffer elpher-buffer-name)
2047 (elpher-with-clean-buffer
2048 (elpher-visit-page page))
2051 (defun elpher-go-current ()
2052 "Go to a particular site read from the minibuffer, initialized with the current URL."
2054 (let ((address (elpher-page-address elpher-current-page)))
2055 (let ((url (read-string "Gopher or Gemini URL: "
2056 (unless (elpher-address-special-p address)
2057 (elpher-address-to-url address)))))
2058 (elpher-visit-page (elpher-make-page url (elpher-address-from-url url))))))
2060 (defun elpher-redraw ()
2061 "Redraw current page."
2063 (elpher-visit-page elpher-current-page))
2065 (defun elpher-reload ()
2066 "Reload current page."
2068 (elpher-reload-current-page))
2070 (defun elpher-toggle-tls ()
2071 "Toggle TLS encryption mode for gopher."
2073 (setq elpher-use-tls (not elpher-use-tls))
2075 (if (gnutls-available-p)
2076 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
2077 (setq elpher-use-tls nil)
2078 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
2079 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
2081 (defun elpher-view-raw ()
2082 "View raw server response for current page."
2084 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2085 (error "This page was not generated by a server")
2086 (elpher-visit-page elpher-current-page
2087 #'elpher-render-raw)))
2089 (defun elpher-back ()
2090 "Go to previous site."
2092 (elpher-visit-previous-page))
2094 (defun elpher-back-to-start ()
2095 "Go all the way back to the start page."
2097 (setq-local elpher-current-page nil)
2098 (setq-local elpher-history nil)
2099 (elpher-visit-page (elpher-make-start-page)))
2101 (defun elpher-download ()
2102 "Download the link at point."
2104 (let ((button (button-at (point))))
2106 (let ((page (button-get button 'elpher-page)))
2107 (if (elpher-address-special-p (elpher-page-address page))
2108 (error "Cannot download %s"
2109 (elpher-page-display-string page))
2110 (elpher-visit-page (button-get button 'elpher-page)
2111 #'elpher-render-download)))
2112 (error "No link selected"))))
2114 (defun elpher-download-current ()
2115 "Download the current page."
2117 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2118 (error "Cannot download %s"
2119 (elpher-page-display-string elpher-current-page))
2120 (elpher-visit-page (elpher-make-page
2121 (elpher-page-display-string elpher-current-page)
2122 (elpher-page-address elpher-current-page))
2123 #'elpher-render-download
2126 (defun elpher--build-link-map ()
2127 "Build alist mapping link names to destination pages in current buffer."
2128 (let ((link-map nil)
2129 (b (next-button (point-min) t)))
2131 (push (cons (button-label b) b) link-map)
2132 (setq b (next-button (button-start b))))
2135 (defun elpher-jump ()
2136 "Select a directory entry by name. Similar to the info browser (m)enu command."
2138 (let* ((link-map (elpher--build-link-map)))
2140 (let ((key (let ((completion-ignore-case t))
2141 (completing-read "Directory item/link: "
2143 (if (and key (> (length key) 0))
2144 (let ((b (cdr (assoc key link-map))))
2145 (goto-char (button-start b))
2146 (button-activate b)))))))
2148 (defun elpher-root-dir ()
2149 "Visit root of current server."
2151 (let ((address (elpher-page-address elpher-current-page)))
2152 (if (not (elpher-address-special-p address))
2153 (if (or (member (url-filename address) '("/" ""))
2154 (and (elpher-address-gopher-p address)
2155 (= (length (elpher-gopher-address-selector address)) 0)))
2156 (error "Already at root directory of current server")
2157 (let ((address-copy (elpher-address-from-url
2158 (elpher-address-to-url address))))
2159 (setf (url-filename address-copy) "")
2160 (elpher-go (elpher-address-to-url address-copy))))
2161 (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
2163 (defun elpher-info-page (page)
2164 "Display information on PAGE."
2165 (let ((display-string (elpher-page-display-string page))
2166 (address (elpher-page-address page)))
2167 (if (elpher-address-special-p address)
2168 (message "Special page: %s" display-string)
2169 (message "%s" (elpher-address-to-url address)))))
2171 (defun elpher-info-link ()
2172 "Display information on page corresponding to link at point."
2174 (let ((button (button-at (point))))
2176 (elpher-info-page (button-get button 'elpher-page))
2177 (error "No item selected"))))
2179 (defun elpher-info-current ()
2180 "Display information on current page."
2182 (elpher-info-page elpher-current-page))
2184 (defun elpher-copy-page-url (page)
2185 "Copy URL representation of address of PAGE to `kill-ring'."
2186 (let ((address (elpher-page-address page)))
2187 (if (elpher-address-special-p address)
2188 (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
2189 (let ((url (elpher-address-to-url address)))
2190 (message "Copied \"%s\" to kill-ring/clipboard." url)
2193 (defun elpher-copy-link-url ()
2194 "Copy URL of item at point to `kill-ring'."
2196 (let ((button (button-at (point))))
2198 (elpher-copy-page-url (button-get button 'elpher-page))
2199 (error "No item selected"))))
2201 (defun elpher-copy-current-url ()
2202 "Copy URL of current page to `kill-ring'."
2204 (elpher-copy-page-url elpher-current-page))
2206 (defun elpher-set-gopher-coding-system ()
2207 "Specify an explicit character coding system for gopher selectors."
2209 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
2210 (setq elpher-user-coding-system system)
2212 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
2213 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
2219 (defvar elpher-mode-map
2220 (let ((map (make-sparse-keymap)))
2221 (define-key map (kbd "TAB") 'elpher-next-link)
2222 (define-key map (kbd "<backtab>") 'elpher-prev-link)
2223 (define-key map (kbd "C-M-i") 'elpher-prev-link)
2224 (define-key map (kbd "u") 'elpher-back)
2225 (define-key map (kbd "-") 'elpher-back)
2226 (define-key map (kbd "^") 'elpher-back)
2227 (define-key map [mouse-3] 'elpher-back)
2228 (define-key map (kbd "U") 'elpher-back-to-start)
2229 (define-key map (kbd "g") 'elpher-go)
2230 (define-key map (kbd "o") 'elpher-go-current)
2231 (define-key map (kbd "O") 'elpher-root-dir)
2232 (define-key map (kbd "s") 'elpher-show-history)
2233 (define-key map (kbd "S") 'elpher-show-visited-pages)
2234 (define-key map (kbd "r") 'elpher-redraw)
2235 (define-key map (kbd "R") 'elpher-reload)
2236 (define-key map (kbd "T") 'elpher-toggle-tls)
2237 (define-key map (kbd ".") 'elpher-view-raw)
2238 (define-key map (kbd "d") 'elpher-download)
2239 (define-key map (kbd "D") 'elpher-download-current)
2240 (define-key map (kbd "m") 'elpher-jump)
2241 (define-key map (kbd "i") 'elpher-info-link)
2242 (define-key map (kbd "I") 'elpher-info-current)
2243 (define-key map (kbd "c") 'elpher-copy-link-url)
2244 (define-key map (kbd "C") 'elpher-copy-current-url)
2245 (define-key map (kbd "a") 'elpher-bookmark-link)
2246 (define-key map (kbd "A") 'elpher-bookmark-current)
2247 (define-key map (kbd "B") 'elpher-show-bookmarks)
2248 (define-key map (kbd "!") 'elpher-set-gopher-coding-system)
2249 (define-key map (kbd "F") 'elpher-forget-current-certificate)
2250 (when (fboundp 'evil-define-key*)
2253 (kbd "TAB") 'elpher-next-link
2254 (kbd "C-") 'elpher-follow-current-link
2255 (kbd "C-t") 'elpher-back
2256 (kbd "u") 'elpher-back
2257 (kbd "-") 'elpher-back
2258 (kbd "^") 'elpher-back
2259 [mouse-3] 'elpher-back
2260 (kbd "U") 'elpher-back-to-start
2261 (kbd "g") 'elpher-go
2262 (kbd "o") 'elpher-go-current
2263 (kbd "O") 'elpher-root-dir
2264 (kbd "s") 'elpher-show-history
2265 (kbd "S") 'elpher-show-visited-pages
2266 (kbd "r") 'elpher-redraw
2267 (kbd "R") 'elpher-reload
2268 (kbd "T") 'elpher-toggle-tls
2269 (kbd ".") 'elpher-view-raw
2270 (kbd "d") 'elpher-download
2271 (kbd "D") 'elpher-download-current
2272 (kbd "m") 'elpher-jump
2273 (kbd "i") 'elpher-info-link
2274 (kbd "I") 'elpher-info-current
2275 (kbd "c") 'elpher-copy-link-url
2276 (kbd "C") 'elpher-copy-current-url
2277 (kbd "a") 'elpher-bookmark-link
2278 (kbd "A") 'elpher-bookmark-current
2279 (kbd "B") 'elpher-show-bookmarks
2280 (kbd "!") 'elpher-set-gopher-coding-system
2281 (kbd "F") 'elpher-forget-current-certificate))
2283 "Keymap for gopher client.")
2285 (define-derived-mode elpher-mode special-mode "elpher"
2286 "Major mode for elpher, an elisp gopher client.
2288 This mode is automatically enabled by the interactive
2289 functions which initialize the client, namely
2290 `elpher', and `elpher-go'."
2291 (setq-local elpher--gemini-page-headings nil)
2292 (setq-local elpher-current-page nil)
2293 (setq-local elpher-history nil)
2294 (setq-local elpher-buffer-name (buffer-name))
2295 (setq-local bookmark-make-record-function #'elpher-bookmark-make-record)
2296 (setq-local imenu-create-index-function (lambda () elpher--gemini-page-headings))
2297 (setq-local xterm-color-preserve-properties t))
2299 (when (fboundp 'evil-set-initial-state)
2300 (evil-set-initial-state 'elpher-mode 'motion))
2303 ;;; Main start procedure
2307 (defun elpher (&optional arg)
2308 "Start elpher with default landing page.
2309 The buffer used for Elpher sessions is determined by the value of
2310 ‘elpher-buffer-name’. If there is already an Elpher session active in
2311 that buffer, Emacs will simply switch to it. Otherwise, a new session
2312 will begin. A numeric prefix ARG (as in ‘\\[universal-argument] 42
2313 \\[execute-extended-command] elpher RET’) switches to the session with
2314 that number, creating it if necessary. A non numeric prefix ARG means
2315 to create a new session. Returns the buffer selected (or created)."
2317 (let* ((name (default-value 'elpher-buffer-name))
2318 (buf (cond ((numberp arg)
2319 (get-buffer-create (format "%s<%d>" name arg)))
2321 (generate-new-buffer name))
2323 (get-buffer-create name)))))
2324 (pop-to-buffer-same-window buf)
2325 (unless (buffer-modified-p)
2327 (elpher-visit-page (elpher-make-start-page))
2328 "Started Elpher."))); Otherwise (elpher) evaluates to start page string.
2330 ;;; elpher.el ends here