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.
85 ;;; ANSI colors or XTerm colors
87 (or (require 'xterm-color nil t)
88 (require 'ansi-color))
90 (defalias 'elpher-color-filter-apply
91 (if (fboundp 'xterm-color-filter)
93 (let ((_xterm-color-render nil))
94 (xterm-color-filter s)))
95 #'ansi-color-filter-apply)
96 "A function to filter out ANSI escape sequences.")
98 (defalias 'elpher-color-apply
99 (if (fboundp 'xterm-color-filter)
102 "A function to apply ANSI escape sequences.")
107 (defconst elpher-version "3.0.0"
108 "Current version of elpher.")
110 (defconst elpher-margin-width 6
111 "Width of left-hand margin used when rendering indicies.")
113 (defconst elpher-type-map
114 '(((gopher ?0) elpher-get-gopher-page elpher-render-text "txt" elpher-text)
115 ((gopher ?1) elpher-get-gopher-page elpher-render-index "/" elpher-index)
116 ((gopher ?4) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
117 ((gopher ?5) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
118 ((gopher ?7) elpher-get-gopher-query-page elpher-render-index "?" elpher-search)
119 ((gopher ?9) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
120 ((gopher ?g) elpher-get-gopher-page elpher-render-image "img" elpher-image)
121 ((gopher ?p) elpher-get-gopher-page elpher-render-image "img" elpher-image)
122 ((gopher ?I) elpher-get-gopher-page elpher-render-image "img" elpher-image)
123 ((gopher ?d) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
124 ((gopher ?P) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
125 ((gopher ?s) elpher-get-gopher-page elpher-render-download "snd" elpher-binary)
126 ((gopher ?h) elpher-get-gopher-page elpher-render-html "htm" elpher-html)
127 (gemini elpher-get-gemini-page elpher-render-gemini "gem" elpher-gemini)
128 (finger elpher-get-finger-page elpher-render-text "txt" elpher-text)
129 (telnet elpher-get-telnet-page nil "tel" elpher-telnet)
130 (other-url elpher-get-other-url-page nil "url" elpher-other-url)
131 ((special start) elpher-get-start-page nil "E" elpher-index)
132 ((special bookmarks) elpher-get-bookmarks-page nil "E" elpher-index)
133 ((special history) elpher-get-history-page nil "E" elpher-index)
134 ((special visited-pages) elpher-get-visited-pages-page nil "E" elpher-index))
135 "Association list from types to getters, renderers, margin codes and index faces.")
138 ;;; Declarations to avoid compiler warnings.
142 (declare-function ansi-color-filter-apply "ansi-color")
143 (declare-function ansi-color-apply "ansi-color")
144 (declare-function bookmark-store "bookmark")
145 (declare-function org-link-store-props "ol")
146 (declare-function org-link-set-parameters "ol")
147 (defvar ansi-color-context)
148 (defvar bookmark-make-record-function)
149 (defvar mu4e~view-beginning-of-url-regexp)
150 (defvar thing-at-point-uri-schemes))
153 ;;; Customization group
157 "A gopher and gemini client."
158 :group 'applications)
160 ;; General appearance and customizations
162 (defcustom elpher-open-urls-with-eww nil
163 "If non-nil, open URL selectors using eww.
164 Otherwise, use the system browser via the `browse-url' function."
167 (defcustom elpher-use-header t
168 "If non-nil, display current page information in buffer header."
171 (defcustom elpher-auto-disengage-TLS nil
172 "If non-nil, automatically disengage TLS following an unsuccessful connection.
173 While enabling this may seem convenient, it is also potentially
174 dangerous as it allows switching from an encrypted channel back to
175 plain text without user input."
178 (defcustom elpher-connection-timeout 5
179 "Specifies the number of seconds to wait for a network connection to time out."
182 (defcustom elpher-filter-ansi-from-text nil
183 "If non-nil, filter ANSI escape sequences from text.
184 The default behaviour is to use the ansi-color package to interpret these
188 (defcustom elpher-certificate-directory
189 (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
190 "Specify the name of the directory where client certificates will be stored.
191 These certificates may be used for establishing authenticated TLS connections."
194 (defcustom elpher-openssl-command "openssl"
195 "The command used to launch openssl when generating TLS client certificates."
198 (defcustom elpher-default-url-type "gopher"
199 "Default URL type (i.e. scheme) to assume if not explicitly given."
200 :type '(choice (const "gopher")
203 (defcustom elpher-gemini-TLS-cert-checks nil
204 "If non-nil, verify gemini server TLS certs using the default security level.
205 Otherwise, certificate verification is disabled.
207 This defaults to off because it is standard practice for Gemini servers
208 to use self-signed certificates, meaning that most servers provide what
209 EMACS considers to be an invalid certificate."
212 (defcustom elpher-gemini-max-fill-width 80
213 "Specify the maximum default width (in columns) of text/gemini documents.
214 The actual width used is the minimum of this value and the window width at
215 the time when the text is rendered."
218 (defcustom elpher-gemini-link-string "→ "
219 "Specify the string used to indicate links when rendering gemini maps.
223 (defcustom elpher-gemini-bullet-string "•"
224 "Specify the string used for bullets when rendering gemini maps."
227 (defcustom elpher-ipv4-always nil
228 "If non-nil, elpher will always use IPv4 to establish network connections.
229 This can be useful when browsing from a computer that supports IPv6, because
230 some servers which do not support IPv6 can take a long time to time-out."
233 (defcustom elpher-socks-always nil
234 "If non-nil, elpher will establish network connections over a SOCKS proxy.
235 Otherwise, the SOCKS proxy is only used for connections to onion services."
238 ;; Face customizations
240 (defgroup elpher-faces nil
241 "Elpher face customizations."
244 (defface elpher-index
245 '((t :inherit font-lock-keyword-face))
246 "Face used for directory type directory records.")
250 "Face used for text type directory records.")
253 '((t :inherit default))
254 "Face used for info type directory records.")
256 (defface elpher-image
257 '((t :inherit font-lock-string-face))
258 "Face used for image type directory records.")
260 (defface elpher-search
261 '((t :inherit warning))
262 "Face used for search type directory records.")
265 '((t :inherit font-lock-comment-face))
266 "Face used for html type directory records.")
268 (defface elpher-gemini
269 '((t :inherit font-lock-constant-face))
270 "Face used for Gemini type directory records.")
272 (defface elpher-other-url
273 '((t :inherit font-lock-comment-face))
274 "Face used for other URL type links records.")
276 (defface elpher-telnet
277 '((t :inherit font-lock-function-name-face))
278 "Face used for telnet type directory records.")
280 (defface elpher-binary
281 '((t :inherit font-lock-doc-face))
282 "Face used for binary type directory records.")
284 (defface elpher-unknown
285 '((t :inherit error))
286 "Face used for directory records with unknown/unsupported types.")
288 (defface elpher-margin-key
290 "Face used for directory margin key.")
292 (defface elpher-margin-brackets
293 '((t :inherit shadow))
294 "Face used for brackets around directory margin key.")
296 (defface elpher-gemini-heading1
297 '((t :inherit bold :height 1.8))
298 "Face used for gemini heading level 1.")
300 (defface elpher-gemini-heading2
301 '((t :inherit bold :height 1.5))
302 "Face used for gemini heading level 2.")
304 (defface elpher-gemini-heading3
305 '((t :inherit bold :height 1.2))
306 "Face used for gemini heading level 3.")
308 (defface elpher-gemini-preformatted
309 '((t :inherit fixed-pitch))
310 "Face used for pre-formatted gemini text blocks.")
312 (defface elpher-gemini-quoted
313 '((t :inherit font-lock-doc-face))
314 "Face used for gemini quoted texts.")
321 ;; An elpher "address" object is either a url object or a symbol.
322 ;; Symbol addresses are "special", corresponding to pages generated
323 ;; dynamically for and by elpher. All others represent pages which
324 ;; rely on content retrieved over the network.
326 (defun elpher-address-from-url (url-string)
327 "Create a ADDRESS object corresponding to the given URL-STRING."
328 (let ((data (match-data))) ; Prevent parsing clobbering match data
330 (let ((url (url-generic-parse-url url-string)))
331 (unless (and (not (url-fullness url)) (url-type url))
332 (setf (url-fullness url) t)
333 (unless (url-type url)
334 (setf (url-type url) elpher-default-url-type))
335 (unless (url-host url)
336 (let ((p (split-string (url-filename url) "/" nil nil)))
337 (setf (url-host url) (car p))
338 (setf (url-filename url)
340 (concat "/" (mapconcat #'identity (cdr p) "/"))
342 (when (or (equal "gopher" (url-type url))
343 (equal "gophers" (url-type url)))
345 (when (or (equal (url-filename url) "")
346 (equal (url-filename url) "/"))
347 (setf (url-filename url) "/1")))
348 (when (equal "gemini" (url-type url))
350 (if (equal (url-filename url) "")
351 (setf (url-filename url) "/"))))
352 (elpher-remove-redundant-ports url))
353 (set-match-data data))))
355 (defun elpher-remove-redundant-ports (address)
356 "Remove redundant port specifiers from ADDRESS.
357 Here 'redundant' means that the specified port matches the default
358 for that protocol, eg 70 for gopher."
359 (if (and (not (elpher-address-special-p address))
360 (eq (url-portspec address) ; (url-port) is too slow!
361 (pcase (url-type address)
363 ((or "gopher" "gophers") 70)
366 (setf (url-portspec address) nil))
369 (defun elpher-make-gopher-address (type selector host port &optional tls)
370 "Create an ADDRESS object using gopher directory record attributes.
371 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
372 If the optional attribute TLS is non-nil, the address will be marked as
373 requiring gopher-over-TLS."
375 ((equal type ?i) nil)
376 ((and (equal type ?h)
377 (string-prefix-p "URL:" selector))
378 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
380 (elpher-address-from-url
383 ":" (number-to-string port))))
385 (elpher-address-from-url
386 (concat "gopher" (if tls "s" "")
388 ":" (number-to-string port)
392 (defun elpher-make-special-address (type)
393 "Create an ADDRESS object corresponding to the given special address symbol TYPE."
396 (defun elpher-address-to-url (address)
397 "Get string representation of ADDRESS, or nil if ADDRESS is special."
398 (if (elpher-address-special-p address)
400 (url-encode-url (url-recreate-url address))))
402 (defun elpher-address-type (address)
403 "Retrieve type of ADDRESS object.
404 This is used to determine how to retrieve and render the document the
405 address refers to, via the table `elpher-type-map'."
406 (if (symbolp address)
407 (list 'special address)
408 (let ((protocol (url-type address)))
409 (cond ((or (equal protocol "gopher")
410 (equal protocol "gophers"))
412 (if (member (url-filename address) '("" "/"))
414 (string-to-char (substring (url-filename address) 1)))))
415 ((equal protocol "gemini")
417 ((equal protocol "telnet")
419 ((equal protocol "finger")
423 (defun elpher-address-protocol (address)
424 "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
425 (if (symbolp address)
429 (defun elpher-address-filename (address)
430 "Retrieve the filename component of ADDRESS.
431 For gopher addresses this is a combination of the selector type and selector."
432 (if (symbolp address)
434 (url-unhex-string (url-filename address))))
436 (defun elpher-address-host (address)
437 "Retrieve host from ADDRESS object."
440 (defun elpher-address-user (address)
441 "Retrieve user from ADDRESS object."
444 (defun elpher-address-port (address)
445 "Retrieve port from ADDRESS object.
446 If no address is defined, returns 0. (This is for compatibility with the URL library.)"
447 (if (symbolp address)
451 (defun elpher-address-special-p (address)
452 "Return non-nil if ADDRESS object is special (e.g. start page page)."
455 (defun elpher-address-gopher-p (address)
456 "Return non-nill if ADDRESS object is a gopher address."
457 (and (not (elpher-address-special-p address))
458 (member (elpher-address-protocol address) '("gopher" "gophers"))))
460 (defun elpher-gopher-address-selector (address)
461 "Retrieve gopher selector from ADDRESS object."
462 (if (member (url-filename address) '("" "/"))
464 (url-unhex-string (substring (url-filename address) 2))))
469 (defvar elpher-content-cache (make-hash-table :test 'equal))
470 (defvar elpher-pos-cache (make-hash-table :test 'equal))
472 (defun elpher-get-cached-content (address)
473 "Retrieve the cached content for ADDRESS, or nil if none exists."
474 (gethash address elpher-content-cache))
476 (defun elpher-cache-content (address content)
477 "Set the content cache for ADDRESS to CONTENT."
478 (puthash address content elpher-content-cache))
480 (defun elpher-get-cached-pos (address)
481 "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
482 (gethash address elpher-pos-cache))
484 (defun elpher-cache-pos (address pos)
485 "Set the cursor position cache for ADDRESS to POS."
486 (puthash address pos elpher-pos-cache))
491 (defun elpher-make-page (display-string address)
492 "Create a page with DISPLAY-STRING and ADDRESS."
493 (list display-string address))
495 (defun elpher-make-start-page ()
496 "Create the start page."
497 (elpher-make-page "Elpher Start Page"
498 (elpher-make-special-address 'start)))
500 (defun elpher-page-display-string (page)
501 "Retrieve the display string corresponding to PAGE."
504 (defun elpher-page-address (page)
505 "Retrieve the address corresponding to PAGE."
508 (defun elpher-page-set-address (page new-address)
509 "Set the address corresponding to PAGE to NEW-ADDRESS."
510 (setcar (cdr page) new-address))
512 (defvar elpher-current-page nil
513 "The current page for this Elpher buffer.")
515 (defvar elpher-history nil
516 "The local history stack for this Elpher buffer.
517 This variable is used by `elpher-back' and
518 `elpher-show-history'.")
520 (defvar elpher-visited-pages nil
521 "The global history for all Elpher buffers.
522 This variable is used by `elpher-show-visited-pages'.")
524 (defun elpher-visit-page (page &optional renderer no-history)
525 "Visit PAGE using its own renderer or RENDERER, if non-nil.
526 Additionally, push PAGE onto the history stack and the list of
527 previously-visited pages,unless NO-HISTORY is non-nil."
529 (elpher-process-cleanup)
531 (unless (equal (elpher-page-address elpher-current-page)
532 (elpher-page-address page))
533 (push elpher-current-page elpher-history)
534 (unless (or (elpher-address-special-p (elpher-page-address page))
535 (and elpher-visited-pages
536 (equal page (car elpher-visited-pages))))
537 (push page elpher-visited-pages))))
538 (setq-local elpher-current-page page)
539 (let* ((address (elpher-page-address page))
540 (type (elpher-address-type address))
541 (type-record (cdr (assoc type elpher-type-map))))
543 (funcall (car type-record)
547 (elpher-visit-previous-page)
549 (`(gopher ,type-char)
550 (error "Unsupported gopher selector type '%c' for '%s'"
551 type-char (elpher-address-to-url address)))
553 (error "Unsupported address type '%S' for '%s'"
554 other (elpher-address-to-url address)))))))
556 (defun elpher-visit-previous-page ()
557 "Visit the previous page in the history."
558 (let ((previous-page (pop elpher-history)))
560 (elpher-visit-page previous-page nil t)
561 (error "No previous page"))))
563 (defun elpher-reload-current-page ()
564 "Reload the current page, discarding any existing cached content."
565 (elpher-cache-content (elpher-page-address elpher-current-page) nil)
566 (elpher-visit-page elpher-current-page))
568 (defun elpher-save-pos ()
569 "Save the current position of point to the current page."
570 (when elpher-current-page
571 (elpher-cache-pos (elpher-page-address elpher-current-page) (point))))
573 (defun elpher-restore-pos ()
574 "Restore the position of point to that cached in the current page."
575 (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
578 (goto-char (point-min)))))
581 ;;; Buffer preparation
584 (defvar elpher-buffer-name "*elpher*"
585 "The default name of the Elpher buffer.")
587 (defun elpher-update-header ()
588 "If `elpher-use-header' is true, display current page info in window header."
589 (if elpher-use-header
590 (let* ((display-string (elpher-page-display-string elpher-current-page))
591 (address (elpher-page-address elpher-current-page))
592 (tls-string (if (and (not (elpher-address-special-p address))
593 (member (elpher-address-protocol address)
594 '("gophers" "gemini")))
597 (header (concat display-string
598 (propertize tls-string 'face 'bold))))
599 (setq header-line-format header))))
601 (defmacro elpher-with-clean-buffer (&rest args)
602 "Evaluate ARGS with a clean *elpher* buffer as current."
603 `(with-current-buffer elpher-buffer-name
604 (unless (eq major-mode 'elpher-mode)
605 ;; avoid resetting buffer-local variables
607 (let ((inhibit-read-only t)
608 (ansi-color-context nil)) ;; clean ansi interpreter state
609 (setq-local network-security-level
610 (default-value 'network-security-level))
612 (elpher-update-header)
615 (defun elpher-buffer-message (string &optional line)
616 "Replace first line in elpher buffer with STRING.
617 If LINE is non-nil, replace that line instead."
618 (with-current-buffer elpher-buffer-name
619 (let ((inhibit-read-only t))
620 (goto-char (point-min))
623 (let ((data (match-data)))
626 (re-search-forward "^.*$")
627 (replace-match string))
628 (set-match-data data))))))
634 (defvar elpher-user-coding-system nil
635 "User-specified coding system to use for decoding text responses.")
637 (defun elpher-decode (string)
638 "Decode STRING using autodetected or user-specified coding system."
639 (decode-coding-string string
640 (if elpher-user-coding-system
641 elpher-user-coding-system
642 (detect-coding-string string t))))
644 (defun elpher-preprocess-text-response (string)
645 "Preprocess text selector response contained in STRING.
646 This involes decoding the character representation, and clearing
647 away CRs and any terminating period."
648 (elpher-decode (replace-regexp-in-string "\n\\.\n$" "\n"
649 (replace-regexp-in-string "\r" "" string))))
652 ;;; Network error reporting
655 (defun elpher-network-error (address error)
656 "Display ERROR message following unsuccessful negotiation with ADDRESS.
657 ERROR can be either an error object or a string."
658 (elpher-with-clean-buffer
659 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
660 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
661 (if (stringp error) error (error-message-string error)) "\n"
662 (propertize "\n----------------\n\n" 'face 'error)
663 "Press 'u' to return to the previous page.")))
666 ;;; General network communication
669 (defvar elpher-network-timer nil
670 "Timer used for network connections.")
672 (defvar elpher-use-tls nil
673 "If non-nil, use TLS to communicate with gopher servers.")
675 (defvar elpher-client-certificate nil
676 "If non-nil, contains client certificate details to use for TLS connections.")
678 (defun elpher-process-cleanup ()
679 "Immediately shut down any extant elpher process and timers."
680 (let ((p (get-process "elpher-process")))
681 (if p (delete-process p)))
682 (if (timerp elpher-network-timer)
683 (cancel-timer elpher-network-timer)))
685 (defun elpher-make-network-timer (thunk)
686 "Creates a timer to run the THUNK after `elpher-connection-timeout' seconds.
687 This is just a wraper around `run-at-time' which additionally sets the
688 buffer-local variable `elpher-network-timer' to allow
689 `elpher-process-cleanup' to also clear the timer."
690 (let ((timer (run-at-time elpher-connection-timeout nil thunk)))
691 (setq-local elpher-network-timer timer)
694 (defun elpher-get-host-response (address default-port query-string response-processor
695 &optional use-tls force-ipv4)
696 "Generic function for retrieving data from ADDRESS.
698 When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
699 QUERY-STRING is a string sent to the host specified by ADDRESS to
700 illicet a response. This response is passed as an argument to the
701 function RESPONSE-PROCESSOR.
703 If non-nil, USE-TLS specifies that the connection is to be made over
704 TLS. If set to gemini, the certificate verification will be disabled
705 unless `elpher-gemini-TLS-cert-checks' is non-nil.
707 If non-nil, FORCE-IPV4 causes the network connection to be made over
708 ipv4 only. (The default behaviour when this is not set depends on
709 the host operating system and the local network capabilities.)"
710 (if (and use-tls (not (gnutls-available-p)))
711 (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
712 (unless (< (elpher-address-port address) 65536)
713 (error "Cannot establish network connection: port number > 65536"))
714 (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
715 (setq-local network-security-level 'low)
716 (setq-local gnutls-verify-error nil))
718 (let* ((kill-buffer-query-functions nil)
719 (port (elpher-address-port address))
720 (host (elpher-address-host address))
721 (service (if (> port 0) port default-port))
722 (response-string-parts nil)
725 (socks (or elpher-socks-always (string-suffix-p ".onion" host)))
726 (gnutls-params (list :type 'gnutls-x509pki
729 (elpher-get-current-keylist address)))
730 (timer (elpher-make-network-timer
732 (elpher-process-cleanup)
734 ; Try again with IPv4
735 ((not (or force-ipv4 socks))
736 (message "Connection timed out. Retrying with IPv4.")
737 (elpher-get-host-response address default-port
742 (not (eq use-tls 'gemini))
743 (or elpher-auto-disengage-TLS
745 "TLS connetion failed. Disable TLS mode and retry? ")))
746 (setq elpher-use-tls nil)
747 (elpher-get-host-response address default-port
752 (elpher-network-error address "Connection time-out."))))))
753 (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
754 (make-network-process :name "elpher-process"
756 :family (and force-ipv4 'ipv4)
762 (cons 'gnutls-x509pki
763 (apply #'gnutls-boot-parameters
765 (setq elpher-network-timer timer)
766 (set-process-coding-system proc 'binary 'binary)
767 (set-process-query-on-exit-flag proc nil)
768 (elpher-buffer-message (concat "Connecting to " host "..."
769 " (press 'u' to abort)"))
770 (set-process-filter proc
771 (lambda (_proc string)
775 (setq bytes-received (+ bytes-received (length string)))
776 (let ((new-hkbytes-received (/ bytes-received 102400)))
777 (when (> new-hkbytes-received hkbytes-received)
778 (setq hkbytes-received new-hkbytes-received)
779 (elpher-buffer-message
781 (number-to-string (/ hkbytes-received 10.0))
784 (setq response-string-parts
785 (cons string response-string-parts))))
786 (set-process-sentinel proc
789 (cancel-timer timer))
790 (condition-case the-error
792 ((string-prefix-p "open" event) ; request URL
793 (elpher-buffer-message
794 (concat "Connected to " host ". Receiving data..."
795 " (press 'u' to abort)"))
796 (let ((inhibit-eol-conversion t))
797 (process-send-string proc query-string)))
798 ((string-prefix-p "deleted" event)) ; do nothing
799 ((and (not response-string-parts)
800 (not (or elpher-ipv4-always force-ipv4 socks)))
801 ; Try again with IPv4
802 (message "Connection failed. Retrying with IPv4.")
803 (elpher-get-host-response address default-port
807 (response-string-parts
808 (elpher-with-clean-buffer
809 (insert "Data received. Rendering..."))
810 (funcall response-processor
811 (apply #'concat (reverse response-string-parts)))
812 (elpher-restore-pos))
814 (error "No response from server")))
816 (elpher-network-error address the-error)))))
818 (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
819 (funcall (process-sentinel proc) proc "open\n")))
821 (elpher-process-cleanup)
822 (error "Error initiating connection to server")))))
825 ;;; Client-side TLS Certificate Management
828 (defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
829 "Generate a key and a self-signed client TLS certificate using openssl.
831 The Common Name field of the certificate is set to COMMON-NAME. The
832 arguments KEY-FILE and CERT-FILE should contain the absolute paths of
833 the key and certificate files to write.
835 If TEMPORARY is non-nil, the certificate will be given an exporation
836 period of one day, and the key and certificate files will be deleted
837 when the certificate is no longer needed for the current session.
839 Otherwise, the certificate will be given a 100 year expiration period
840 and the files will not be deleted.
842 The function returns a list containing the current host name, the
843 temporary flag, and the key and cert file names in the form required
844 by `gnutls-boot-parameters`."
845 (let ((exp-key-file (expand-file-name key-file))
846 (exp-cert-file (expand-file-name cert-file)))
849 (call-process elpher-openssl-command nil nil nil
850 "req" "-x509" "-newkey" "rsa:2048"
851 "-days" (if temporary "1" "36500")
853 "-subj" (concat "/CN=" common-name)
854 "-keyout" exp-key-file
855 "-out" exp-cert-file)
856 (list (elpher-address-host (elpher-page-address elpher-current-page))
857 temporary exp-key-file exp-cert-file))
859 (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
860 (error "Program 'openssl', required for certificate generation, not found")))))
862 (defun elpher-generate-throwaway-certificate ()
863 "Generate and return details of a throwaway certificate.
864 The key and certificate files will be deleted when they are no
865 longer needed for this session."
866 (let* ((file-base (make-temp-name "elpher"))
867 (key-file (concat temporary-file-directory file-base ".key"))
868 (cert-file (concat temporary-file-directory file-base ".crt")))
869 (elpher-generate-certificate file-base key-file cert-file t)))
871 (defun elpher-generate-persistent-certificate (file-base common-name)
872 "Generate and return details of a persistent certificate.
873 The argument FILE-BASE is used as the base for the key and certificate
874 files, while COMMON-NAME specifies the common name field of the
877 The key and certificate files are written to in `elpher-certificate-directory'."
878 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
879 (cert-file (concat elpher-certificate-directory file-base ".crt")))
880 (elpher-generate-certificate common-name key-file cert-file)))
882 (defun elpher-get-existing-certificate (file-base)
883 "Return a certificate object corresponding to an existing certificate.
884 It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
885 the directory `elpher-certificate-directory'."
886 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
887 (cert-file (concat elpher-certificate-directory file-base ".crt")))
888 (list (elpher-address-host (elpher-page-address elpher-current-page))
890 (expand-file-name key-file)
891 (expand-file-name cert-file))))
893 (defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
894 "Install a key+certificate file pair in `elpher-certificate-directory'.
895 The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
896 certificate files to install. The argument FILE-BASE is used as the
897 base for the installed key and certificate files."
898 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
899 (cert-file (concat elpher-certificate-directory file-base ".crt")))
900 (if (or (file-exists-p key-file)
901 (file-exists-p cert-file))
902 (error "A certificate with base name %s is already installed" file-base))
903 (copy-file key-file-src key-file)
904 (copy-file cert-file-src cert-file)
905 (list (elpher-address-host (elpher-page-address elpher-current-page))
907 (expand-file-name key-file)
908 (expand-file-name cert-file))))
910 (defun elpher-list-existing-certificates ()
911 "Return a list of the persistent certificates in `elpher-certificate-directory'."
912 (unless (file-directory-p elpher-certificate-directory)
913 (make-directory elpher-certificate-directory))
916 (file-name-sans-extension file))
917 (directory-files elpher-certificate-directory nil "\\.key$")))
919 (defun elpher-forget-current-certificate ()
920 "Causes any current certificate to be forgotten.)
921 In the case of throwaway certificates, the key and certificate files
924 (when elpher-client-certificate
925 (unless (and (called-interactively-p 'any)
926 (not (y-or-n-p (concat "Really forget client certificate? "
927 "(Throwaway certificates will be deleted.)"))))
928 (when (cadr elpher-client-certificate)
929 (delete-file (elt elpher-client-certificate 2))
930 (delete-file (elt elpher-client-certificate 3)))
931 (setq elpher-client-certificate nil)
932 (if (called-interactively-p 'any)
933 (message "Client certificate forgotten.")))))
935 (defun elpher-get-current-keylist (address)
936 "Retrieve the `gnutls-boot-parameters'-compatable keylist.
938 This is obtained from the client certificate described by
939 `elpher-current-certificate', if one is available and the host for
940 that certificate matches the host in ADDRESS.
942 If `elpher-current-certificate' is non-nil, and its host name doesn't
943 match that of ADDRESS, the certificate is forgotten."
944 (if elpher-client-certificate
945 (if (string= (car elpher-client-certificate)
946 (elpher-address-host address))
947 (list (cddr elpher-client-certificate))
948 (elpher-forget-current-certificate)
949 (message "Disabling client certificate for new host")
954 ;;; Gopher selector retrieval
957 (defun elpher-get-gopher-response (address renderer)
958 "Get response string from gopher server at ADDRESS and render using RENDERER."
959 (elpher-get-host-response address 70
960 (concat (elpher-gopher-address-selector address) "\r\n")
962 (or (string= (elpher-address-protocol address) "gophers")
965 (defun elpher-get-gopher-page (renderer)
966 "Getter function for gopher pages.
967 The RENDERER procedure is used to display the contents of the page
968 once they are retrieved from the gopher server."
969 (let* ((address (elpher-page-address elpher-current-page))
970 (content (elpher-get-cached-content address)))
971 (if (and content (funcall renderer nil))
972 (elpher-with-clean-buffer
974 (elpher-restore-pos))
975 (elpher-with-clean-buffer
976 (insert "LOADING... (use 'u' to cancel)\n"))
977 (condition-case the-error
978 (elpher-get-gopher-response address renderer)
980 (elpher-network-error address the-error))))))
984 (defun elpher-insert-index (string)
985 "Insert the index corresponding to STRING into the current buffer."
986 ;; Should be able to split directly on CRLF, but some non-conformant
987 ;; LF-only servers sadly exist, hence the following.
988 (let ((str-processed (elpher-preprocess-text-response string)))
989 (dolist (line (split-string str-processed "\n"))
991 (unless (= (length line) 0)
992 (let* ((type (elt line 0))
993 (fields (split-string (substring line 1) "\t"))
994 (display-string (elt fields 0))
995 (selector (elt fields 1))
996 (host (elt fields 2))
997 (port (if (elt fields 3)
998 (string-to-number (elt fields 3))
1000 (address (elpher-make-gopher-address type selector host port)))
1001 (elpher-insert-index-record display-string address)))))))
1003 (defun elpher-insert-margin (&optional type-name)
1004 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
1007 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
1009 (propertize "[" 'face 'elpher-margin-brackets)
1010 (propertize type-name 'face 'elpher-margin-key)
1011 (propertize "]" 'face 'elpher-margin-brackets))))
1013 (insert (make-string elpher-margin-width ?\s))))
1015 (defun elpher--page-button-help (_window buffer pos)
1016 "Function called by Emacs to generate mouse-over text.
1017 The arguments specify the BUFFER and the POS within the buffer of the item
1018 for which help is required. The function returns the help to be
1019 displayed. The _WINDOW argument is currently unused."
1020 (with-current-buffer buffer
1021 (let ((button (button-at pos)))
1023 (let* ((page (button-get button 'elpher-page))
1024 (address (elpher-page-address page)))
1025 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
1027 (elpher-address-to-url address))))))))
1029 (defun elpher-insert-index-record (display-string &optional address)
1030 "Function to insert an index record into the current buffer.
1031 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
1032 If ADDRESS is not supplied or nil the record is rendered as an
1033 'information' line."
1034 (let* ((type (if address (elpher-address-type address) nil))
1035 (type-map-entry (cdr (assoc type elpher-type-map))))
1037 (let* ((margin-code (elt type-map-entry 2))
1038 (face (elt type-map-entry 3))
1039 (filtered-display-string (elpher-color-filter-apply display-string))
1040 (page (elpher-make-page filtered-display-string address)))
1041 (elpher-insert-margin margin-code)
1042 (insert-text-button filtered-display-string
1045 'action #'elpher-click-link
1047 'help-echo #'elpher--page-button-help))
1049 ('nil ;; Information
1050 (elpher-insert-margin)
1051 (let ((propertized-display-string
1052 (propertize display-string 'face 'elpher-info)))
1053 (insert (elpher-process-text-for-display propertized-display-string))))
1054 (`(gopher ,selector-type) ;; Unknown
1055 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
1056 (insert (propertize display-string
1057 'face 'elpher-unknown)))))
1060 (defun elpher-click-link (button)
1061 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
1062 (let ((page (button-get button 'elpher-page)))
1063 (elpher-visit-page page)))
1065 (defun elpher-render-index (data &optional _mime-type-string)
1066 "Render DATA as an index. MIME-TYPE-STRING is unused."
1067 (elpher-with-clean-buffer
1070 (elpher-insert-index data)
1071 (elpher-cache-content (elpher-page-address elpher-current-page)
1076 (defconst elpher-url-regex
1077 "\\([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_~?/@|#-]\\)?\\)?"
1078 "Regexp used to locate and buttonify URLs in text files loaded by elpher.")
1080 (defun elpher-buttonify-urls (string)
1081 "Turn substrings which look like urls in STRING into clickable buttons."
1084 (goto-char (point-min))
1085 (while (re-search-forward elpher-url-regex nil t)
1086 (let ((page (elpher-make-page (substring-no-properties (match-string 0))
1087 (elpher-address-from-url (match-string 0)))))
1088 (make-text-button (match-beginning 0)
1091 'action #'elpher-click-link
1093 'help-echo #'elpher--page-button-help
1097 (defun elpher-process-text-for-display (string)
1098 "Perform any desired processing of STRING prior to display as text.
1099 Currently includes buttonifying URLs and processing ANSI escape codes."
1100 (elpher-buttonify-urls (if elpher-filter-ansi-from-text
1101 (elpher-color-filter-apply string)
1102 (elpher-color-apply string))))
1104 (defun elpher-render-text (data &optional _mime-type-string)
1105 "Render DATA as text. MIME-TYPE-STRING is unused."
1106 (elpher-with-clean-buffer
1109 (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
1110 (elpher-cache-content
1111 (elpher-page-address elpher-current-page)
1116 (defun elpher-render-image (data &optional _mime-type-string)
1117 "Display DATA as image. MIME-TYPE-STRING is unused."
1120 (if (display-images-p)
1122 (let ((image (create-image
1125 (elpher-with-clean-buffer
1126 (insert-image image)
1127 (elpher-restore-pos))))
1128 (elpher-render-download data))))
1130 ;; Search retrieval and rendering
1132 (defun elpher-get-gopher-query-page (renderer)
1133 "Getter for gopher addresses requiring input.
1134 The response is rendered using the rendering function RENDERER."
1135 (let* ((address (elpher-page-address elpher-current-page))
1136 (content (elpher-get-cached-content address))
1138 (if (and content (funcall renderer nil))
1139 (elpher-with-clean-buffer
1141 (elpher-restore-pos)
1142 (message "Displaying cached search results. Reload to perform a new search."))
1144 (let* ((query-string (read-string "Query: "))
1145 (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
1146 (search-address (elpher-make-gopher-address ?1
1148 (elpher-address-host address)
1149 (elpher-address-port address)
1150 (equal (elpher-address-type address) "gophers"))))
1153 (elpher-with-clean-buffer
1154 (insert "LOADING RESULTS... (use 'u' to cancel)"))
1155 (elpher-get-gopher-response search-address renderer))
1157 (elpher-visit-previous-page))))))
1159 ;; Raw server response rendering
1161 (defun elpher-render-raw (data &optional mime-type-string)
1162 "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
1165 (elpher-with-clean-buffer
1166 (when mime-type-string
1167 (insert "MIME type specified by server: '" mime-type-string "'\n"))
1169 (goto-char (point-min)))
1170 (message "Displaying raw server response. Reload or redraw to return to standard view.")))
1172 ;; File save "rendering"
1174 (defun elpher-render-download (data &optional _mime-type-string)
1175 "Save DATA to file. MIME-TYPE-STRING is unused."
1178 (let* ((address (elpher-page-address elpher-current-page))
1179 (selector (if (elpher-address-gopher-p address)
1180 (elpher-gopher-address-selector address)
1181 (elpher-address-filename address))))
1182 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1183 (let* ((filename-proposal (file-name-nondirectory selector))
1184 (filename (read-file-name "Download complete. Save file as: "
1186 (if (> (length filename-proposal) 0)
1189 (let ((coding-system-for-write 'binary))
1190 (with-temp-file filename
1192 (message (format "Saved to file %s." filename))))))
1196 (defun elpher-render-html (data &optional _mime-type-string)
1197 "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
1198 (elpher-with-clean-buffer
1201 (let ((dom (with-temp-buffer
1203 (libxml-parse-html-region (point-min) (point-max)))))
1204 (shr-insert-document dom)))))
1206 ;; Gemini page retrieval
1208 (defvar elpher-gemini-redirect-chain)
1210 (defun elpher-get-gemini-response (address renderer)
1211 "Get response string from gemini server at ADDRESS and render using RENDERER."
1212 (elpher-get-host-response address 1965
1213 (concat (elpher-address-to-url address) "\r\n")
1214 (lambda (response-string)
1215 (elpher-process-gemini-response response-string renderer))
1218 (defun elpher-parse-gemini-response (response)
1219 "Parse the RESPONSE string and return a list of components.
1220 The list is of the form (code meta body). A response of nil implies
1221 that the response was malformed."
1222 (let ((header-end-idx (string-match "\r\n" response)))
1224 (let ((header (string-trim (substring response 0 header-end-idx)))
1225 (body (substring response (+ header-end-idx 2))))
1226 (if (>= (length header) 2)
1227 (let ((code (substring header 0 2))
1228 (meta (string-trim (substring header 2))))
1229 (list code meta body))
1230 (error "Malformed response: No response status found in header %s" header)))
1231 (error "Malformed response: No CRLF-delimited header found in response %s" response))))
1233 (defun elpher-process-gemini-response (response-string renderer)
1234 "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
1235 (let ((response-components (elpher-parse-gemini-response response-string)))
1236 (let ((response-code (elt response-components 0))
1237 (response-meta (elt response-components 1))
1238 (response-body (elt response-components 2)))
1239 (pcase (elt response-code 0)
1240 (?1 ; Input required
1241 (elpher-with-clean-buffer
1242 (insert "Gemini server is requesting input."))
1243 (let* ((query-string
1244 (if (eq (elt response-code 1) ?1)
1245 (read-passwd (concat response-meta ": "))
1246 (read-string (concat response-meta ": "))))
1247 (query-address (seq-copy (elpher-page-address elpher-current-page)))
1248 (old-fname (url-filename query-address)))
1249 (setf (url-filename query-address)
1250 (concat old-fname "?" (url-build-query-string `((,query-string)))))
1251 (elpher-get-gemini-response query-address renderer)))
1252 (?2 ; Normal response
1253 (funcall renderer response-body response-meta))
1255 (message "Following redirect to %s" response-meta)
1256 (if (>= (length elpher-gemini-redirect-chain) 5)
1257 (error "More than 5 consecutive redirects followed"))
1258 (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
1259 (if (member redirect-address elpher-gemini-redirect-chain)
1260 (error "Redirect loop detected"))
1261 (if (not (string= (elpher-address-protocol redirect-address)
1263 (error "Server tried to automatically redirect to non-gemini URL: %s"
1265 (elpher-page-set-address elpher-current-page redirect-address)
1266 (add-to-list 'elpher-gemini-redirect-chain redirect-address)
1267 (elpher-get-gemini-response redirect-address renderer)))
1268 (?4 ; Temporary failure
1269 (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
1270 response-code response-meta))
1271 (?5 ; Permanent failure
1272 (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
1273 response-code response-meta))
1274 (?6 ; Client certificate required
1275 (elpher-with-clean-buffer
1276 (if elpher-client-certificate
1277 (insert "Gemini server does not recognise the provided TLS certificate:\n\n")
1278 (insert "Gemini server is requesting a valid TLS certificate:\n\n"))
1280 (elpher-gemini-insert-text response-meta))
1281 (let ((chosen-certificate (elpher-choose-client-certificate)))
1282 (unless chosen-certificate
1283 (error "Gemini server requires a client certificate and none was provided"))
1284 (setq elpher-client-certificate chosen-certificate))
1285 (elpher-with-clean-buffer)
1286 (elpher-get-gemini-response (elpher-page-address elpher-current-page) renderer))
1288 (error "Gemini server response unknown: %s %s"
1289 response-code response-meta))))))
1291 (defun elpher--read-answer-polyfill (question answers)
1292 "Polyfill for `read-answer' in Emacs 26.1.
1293 QUESTION is a string containing a question, and ANSWERS
1294 is a list of possible answers."
1295 (completing-read question (mapcar 'identity answers)))
1297 (if (fboundp 'read-answer)
1298 (defalias 'elpher-read-answer 'read-answer)
1299 (defalias 'elpher-read-answer 'elpher--read-answer-polyfill))
1301 (defun elpher-choose-client-certificate ()
1302 "Prompt for a client certificate to use to establish a TLS connection."
1303 (let* ((read-answer-short t))
1304 (pcase (read-answer "What do you want to do? "
1306 "generate and use throw-away certificate")
1308 "generate new or use existing persistent certificate")
1310 "stop immediately")))
1312 (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
1314 (let* ((existing-certificates (elpher-list-existing-certificates))
1315 (file-base (completing-read
1316 "Nickname for new or existing certificate (autocompletes, empty response aborts): "
1317 existing-certificates)))
1318 (if (string-empty-p (string-trim file-base))
1320 (if (member file-base existing-certificates)
1321 (setq elpher-client-certificate
1322 (elpher-get-existing-certificate file-base))
1323 (pcase (read-answer "Generate new certificate or install externally-generated one? "
1325 "generate new certificate")
1327 "install existing certificate")
1329 "stop immediately")))
1331 (let ((common-name (read-string "Common Name field for new certificate: "
1333 (message "New key and self-signed certificate written to %s"
1334 elpher-certificate-directory)
1335 (elpher-generate-persistent-certificate file-base common-name)))
1337 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
1338 (key-file (read-file-name "Key file: " nil nil t)))
1339 (message "Key and certificate installed in %s for future use"
1340 elpher-certificate-directory)
1341 (elpher-install-and-use-existing-certificate key-file
1347 (defun elpher-get-gemini-page (renderer)
1348 "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
1349 (let* ((address (elpher-page-address elpher-current-page))
1350 (content (elpher-get-cached-content address)))
1351 (condition-case the-error
1352 (if (and content (funcall renderer nil))
1353 (elpher-with-clean-buffer
1355 (elpher-restore-pos))
1356 (elpher-with-clean-buffer
1357 (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
1358 (setq elpher-gemini-redirect-chain nil)
1359 (elpher-get-gemini-response address renderer))
1361 (elpher-network-error address the-error)))))
1363 (defun elpher-render-gemini (body &optional mime-type-string)
1364 "Render gemini response BODY with rendering MIME-TYPE-STRING."
1367 (let* ((mime-type-string* (if (or (not mime-type-string)
1368 (string-empty-p mime-type-string))
1369 "text/gemini; charset=utf-8"
1371 (mime-type-split (split-string mime-type-string* ";" t))
1372 (mime-type (string-trim (car mime-type-split)))
1373 (parameters (mapcar (lambda (s)
1374 (let ((key-val (split-string s "=")))
1375 (list (downcase (string-trim (car key-val)))
1376 (downcase (string-trim (cadr key-val))))))
1377 (cdr mime-type-split))))
1378 (when (string-prefix-p "text/" mime-type)
1379 (setq body (decode-coding-string
1381 (if (assoc "charset" parameters)
1382 (intern (cadr (assoc "charset" parameters)))
1384 (setq body (replace-regexp-in-string "\r" "" body)))
1386 ((or "text/gemini" "")
1387 (elpher-render-gemini-map body parameters))
1389 (elpher-render-html body))
1390 ((pred (string-prefix-p "text/"))
1391 (elpher-render-gemini-plain-text body parameters))
1392 ((pred (string-prefix-p "image/"))
1393 (elpher-render-image body))
1395 (elpher-render-download body))))))
1397 (defun elpher-gemini-get-link-url (link-line)
1398 "Extract the url portion of LINK-LINE, a gemini map file link line.
1399 Returns nil in the event that the contents of the line following the
1400 => prefix are empty."
1401 (let ((l (split-string (substring link-line 2))))
1403 (string-trim (elt l 0))
1406 (defun elpher-gemini-get-link-display-string (link-line)
1407 "Extract the display string portion of LINK-LINE, a gemini map file link line.
1408 Returns the url portion in the event that the display-string portion is empty."
1409 (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
1410 (idx (string-match "[ \t]" rest)))
1411 (string-trim (if idx
1412 (substring rest (+ idx 1))
1415 (defun elpher-collapse-dot-sequences (filename)
1416 "Collapse dot sequences in FILENAME.
1417 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
1418 (let* ((path (split-string filename "/"))
1419 (path-reversed-normalized
1420 (seq-reduce (lambda (a b)
1421 (cond ((and a (equal b "..") (cdr a)))
1422 ((and (not a) (equal b "..")) a) ;leading .. are dropped
1426 (string-join (reverse path-reversed-normalized) "/")))
1428 (defun elpher-address-from-gemini-url (url)
1429 "Extract address from URL with defaults as per gemini map files.
1430 While there's obviously some redundancy here between this function and
1431 `elpher-address-from-url', gemini map file URLs require enough special
1432 treatment that a separate function is warranted."
1433 (let ((address (url-generic-parse-url url))
1434 (current-address (elpher-page-address elpher-current-page)))
1435 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
1436 (setf (url-fullness address) t)
1437 (if (url-host address) ;if there is an explicit host, filenames are absolute
1438 (if (string-empty-p (url-filename address))
1439 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
1440 (setf (url-host address) (url-host current-address))
1441 (setf (url-port address) (url-port current-address))
1442 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1443 (setf (url-filename address)
1444 (concat (file-name-directory (url-filename current-address))
1445 (url-filename address)))))
1446 (unless (url-type address)
1447 (setf (url-type address) "gemini"))
1448 (when (equal (url-type address) "gemini")
1449 (setf (url-filename address)
1450 (elpher-collapse-dot-sequences (url-filename address)))))
1451 (elpher-remove-redundant-ports address)))
1453 (defun elpher-gemini-insert-link (link-line)
1454 "Insert link described by LINK-LINE into a text/gemini document."
1455 (let* ((url (elpher-gemini-get-link-url link-line))
1456 (display-string (elpher-gemini-get-link-display-string link-line))
1457 (address (elpher-address-from-gemini-url url))
1458 (type (if address (elpher-address-type address) nil))
1459 (type-map-entry (cdr (assoc type elpher-type-map))))
1460 (when display-string
1461 (insert elpher-gemini-link-string)
1463 (let* ((face (elt type-map-entry 3))
1464 (filtered-display-string (elpher-color-filter-apply display-string))
1465 (page (elpher-make-page filtered-display-string address)))
1466 (insert-text-button filtered-display-string
1469 'action #'elpher-click-link
1471 'help-echo #'elpher--page-button-help))
1472 (insert (propertize display-string 'face 'elpher-unknown)))
1475 (defvar elpher--gemini-page-headings nil
1476 "List of headings on the page.")
1478 (defun elpher-gemini-insert-header (header-line)
1479 "Insert header described by HEADER-LINE into a text/gemini document.
1480 The gemini map file line describing the header is given
1482 (when (string-match "^\\(#+\\)[ \t]*" header-line)
1483 (let* ((level (length (match-string 1 header-line)))
1484 (header (substring header-line (match-end 0)))
1486 (1 'elpher-gemini-heading1)
1487 (2 'elpher-gemini-heading2)
1488 (3 'elpher-gemini-heading3)
1490 (fill-column (if (display-graphic-p)
1492 (font-get (font-spec :name (face-font 'default)) :size))
1493 (font-get (font-spec :name (face-font face)) :size)) fill-column)))
1494 (setq elpher--gemini-page-headings (cons (cons header (point))
1495 elpher--gemini-page-headings))
1496 (unless (display-graphic-p)
1497 (insert (make-string level ?#) " "))
1498 (insert (propertize header 'face face))
1501 (defun elpher-gemini-insert-text (text-line)
1502 "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
1503 This function uses Emacs' auto-fill to wrap text sensibly to a maximum
1504 width defined by `elpher-gemini-max-fill-width'."
1505 (string-match "\\(^[ \t]*\\)\\(\\*[ \t]+\\|>[ \t]*\\)?" text-line)
1506 (let* ((line-prefix (match-string 2 text-line))
1507 (processed-text-line
1509 (cond ((string-prefix-p "*" line-prefix)
1511 (replace-regexp-in-string "\\*"
1512 elpher-gemini-bullet-string
1513 (match-string 0 text-line))
1514 (substring text-line (match-end 0))))
1515 ((string-prefix-p ">" line-prefix)
1516 (propertize text-line 'face 'elpher-gemini-quoted))
1519 (adaptive-fill-mode t)
1520 ;; fill-prefix is important for adaptive-fill-mode: without
1521 ;; it, multi-line list items are not indented correct
1522 (fill-prefix (if (match-string 2 text-line)
1523 (replace-regexp-in-string "[>\*]" " " (match-string 0 text-line))
1525 (insert (elpher-process-text-for-display processed-text-line))
1528 (defun elpher-render-gemini-map (data _parameters)
1529 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1530 (elpher-with-clean-buffer
1531 (setq elpher--gemini-page-headings nil)
1532 (let ((preformatted nil))
1534 (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
1535 (dolist (line (split-string data "\n"))
1537 ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
1538 (preformatted (insert (elpher-process-text-for-display
1539 (propertize line 'face 'elpher-gemini-preformatted))
1541 ((string-prefix-p "=>" line)
1542 (elpher-gemini-insert-link line))
1543 ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
1544 (t (elpher-gemini-insert-text line)))))
1545 (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))
1546 (elpher-cache-content
1547 (elpher-page-address elpher-current-page)
1550 (defun elpher-render-gemini-plain-text (data _parameters)
1551 "Render DATA as plain text file. PARAMETERS is currently unused."
1552 (elpher-with-clean-buffer
1553 (insert (elpher-process-text-for-display data))
1554 (elpher-cache-content
1555 (elpher-page-address elpher-current-page)
1559 ;; Finger page connection
1561 (defun elpher-get-finger-page (renderer)
1562 "Opens a finger connection to the current page address.
1563 The result is rendered using RENDERER."
1564 (let* ((address (elpher-page-address elpher-current-page))
1565 (content (elpher-get-cached-content address)))
1566 (if (and content (funcall renderer nil))
1567 (elpher-with-clean-buffer
1569 (elpher-restore-pos))
1570 (elpher-with-clean-buffer
1571 (insert "LOADING... (use 'u' to cancel)\n"))
1572 (condition-case the-error
1573 (let* ((kill-buffer-query-functions nil)
1574 (user (let ((filename (elpher-address-filename address)))
1575 (if (> (length filename) 1)
1576 (substring filename 1)
1577 (elpher-address-user address)))))
1578 (elpher-get-host-response address 79
1579 (concat user "\r\n")
1582 (elpher-network-error address the-error))))))
1585 ;; Telnet page connection
1587 (defun elpher-get-telnet-page (renderer)
1588 "Opens a telnet connection to the current page address (RENDERER must be nil)."
1590 (elpher-visit-previous-page)
1591 (error "Command not supported for telnet URLs"))
1592 (let* ((address (elpher-page-address elpher-current-page))
1593 (host (elpher-address-host address))
1594 (port (elpher-address-port address)))
1595 (elpher-visit-previous-page)
1601 ;; Other URL page opening
1603 (defun elpher-get-other-url-page (renderer)
1604 "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
1606 (elpher-visit-previous-page)
1607 (error "Command not supported for general URLs"))
1608 (let* ((address (elpher-page-address elpher-current-page))
1609 (url (elpher-address-to-url address)))
1611 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1612 (message "Opening URL...")
1613 (if elpher-open-urls-with-eww
1615 (browse-url url)))))
1618 ;; Start page retrieval
1620 (defun elpher-get-start-page (renderer)
1621 "Getter which displays the start page (RENDERER must be nil)."
1623 (elpher-visit-previous-page)
1624 (error "Command not supported for start page"))
1625 (elpher-with-clean-buffer
1626 (insert " --------------------------------------------\n"
1627 " Elpher Gopher and Gemini Client \n"
1628 " version " elpher-version "\n"
1629 " --------------------------------------------\n"
1631 "Default bindings:\n"
1633 " - TAB/Shift-TAB: next/prev item on current page\n"
1634 " - RET/mouse-1: open item under cursor\n"
1635 " - m: select an item on current page by name (autocompletes)\n"
1636 " - u/mouse-3/U: return to previous page or to the start page\n"
1637 " - g: go to a particular address (gopher, gemini, finger)\n"
1638 " - o/O: open a different address selector or the root menu of the current server\n"
1639 " - d/D: download item under cursor or current page\n"
1640 " - i/I: info on item under cursor or current page\n"
1641 " - c/C: copy URL representation of item under cursor or current page\n"
1642 " - a/A: bookmark the item under cursor or current page\n"
1643 " - B: list all bookmarks\n"
1644 " - s/S: show current history stack or all previously visted pages\n"
1645 " - r: redraw current page (using cached contents if available)\n"
1646 " - R: reload current page (regenerates cache)\n"
1647 " - !: set character coding system for gopher (default is to autodetect)\n"
1648 " - T: toggle TLS gopher mode\n"
1649 " - F: forget/discard current TLS client certificate\n"
1650 " - .: display the raw server response for the current page\n"
1652 "Start your exploration of gopher space and gemini:\n")
1653 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1654 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1655 (elpher-insert-index-record "Project Gemini home page"
1656 (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
1658 "Alternatively, select a search engine and enter some search terms:\n")
1659 (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
1660 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1661 (elpher-insert-index-record "Gemini Search Engine (geminispace.info)"
1662 (elpher-address-from-url "gemini://geminispace.info/search"))
1664 "Your bookmarks are stored in your ")
1665 (let ((help-string "RET,mouse-1: Open Emacs bookmark list"))
1666 (insert-text-button "Emacs bookmark list"
1670 (call-interactively #'elpher-open-bookmarks))
1672 'help-echo help-string))
1675 "(Bookmarks from legacy elpher-bookmarks files will be automatically imported.)\n"
1678 "The gopher home of the Elpher project is here:\n")
1679 (elpher-insert-index-record "The Elpher Project Page"
1680 (elpher-make-gopher-address ?1
1684 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1686 "The following info documentation is available:\n"
1688 (insert-text-button "Elpher Manual"
1694 'help-echo help-string)
1696 (insert-text-button "Changes introduced by the latest release"
1700 (info "(elpher)News"))
1702 'help-echo help-string))
1705 (concat " (These documents should be available if you have installed Elpher \n"
1706 " using MELPA. Otherwise you may have to install the manual yourself.)\n")
1708 (elpher-restore-pos)))
1710 ;; History page retrieval
1712 (defun elpher-show-history ()
1713 "Show the current contents of elpher's history stack.
1714 Use \\[elpher-show-visited-pages] to see the entire history.
1715 This is rendered using `elpher-get-history-page' via `elpher-type-map'."
1718 (elpher-make-page "Current History Stack"
1719 (elpher-make-special-address 'history))))
1721 (defun elpher-show-visited-pages ()
1722 "Show the all the pages you've visited using Elpher.
1723 Use \\[elpher-show-history] to see just the current history stack.
1724 This is rendered using `elpher-get-visited-pages-page' via `elpher-type-map'."
1727 (elpher-make-page "Elpher Visted Pages"
1728 (elpher-make-special-address 'visited-pages))))
1730 (defun elpher-get-history-page (renderer)
1731 "Getter which displays the history page (RENDERER must be nil)."
1733 (elpher-visit-previous-page)
1734 (error "Command not supported for history page"))
1735 (elpher-display-history-links elpher-history "Current history stack"))
1737 (defun elpher-get-visited-pages-page (renderer)
1738 "Getter which displays the list of visited pages (RENDERER must be nil)."
1740 (elpher-visit-previous-page)
1741 (error "Command not supported for history page"))
1742 (elpher-display-history-links
1743 (seq-filter (lambda (page)
1744 (not (elpher-address-special-p (elpher-page-address page))))
1745 elpher-visited-pages)
1746 "All visited pages"))
1748 (defun elpher-display-history-links (pages title)
1749 "Show all PAGES in an Elpher buffer with a given TITLE."
1750 (let* ((title-line (concat "---- " title " ----"))
1751 (footer-line (make-string (length title-line) ?-)))
1752 (elpher-with-clean-buffer
1753 (insert title-line "\n\n")
1755 (dolist (page pages)
1757 (let ((display-string (elpher-page-display-string page))
1758 (address (elpher-page-address page)))
1759 (elpher-insert-index-record display-string address))))
1760 (insert "No history items found.\n"))
1761 (insert "\n" footer-line "\n"
1762 "Select an entry or press 'u' to return to the previous page.")
1763 (elpher-restore-pos))))
1768 ;; This code allows Elpher to use the standard Emacs bookmarks: `C-x r
1769 ;; m' to add a bookmark, `C-x r l' to list bookmarks (which is where
1770 ;; you can anotate bookmarks!), `C-x r b' to jump to a bookmark, and
1771 ;; so on. See the Bookmarks section in the Emacs info manual for more.
1773 (defvar elpher-bookmark-link nil
1774 "Prefer bookmarking a link or the current page.
1775 Bind this variable dynamically, or set it to t.
1776 If you set it to t, the commands \\[bookmark-set-no-overwrite]
1777 and \\[elpher-set-bookmark-no-overwrite] do the same thing.")
1779 (defun elpher-bookmark-make-record ()
1780 "Return a bookmark record.
1781 If `elpher-bookmark-link' is non-nil and point is on a link button,
1782 return a bookmark record for that link. Otherwise, return a bookmark
1783 record for the current elpher page."
1784 (let* ((button (and elpher-bookmark-link (button-at (point))))
1786 (button-get button 'elpher-page)
1787 elpher-current-page))
1788 (address (elpher-page-address page))
1789 (url (elpher-address-to-url address))
1790 (display-string (elpher-page-display-string page))
1791 (pos (if button nil (point))))
1792 (if (elpher-address-special-p address)
1793 (error "Cannot bookmark %s" display-string)
1795 (defaults . (,display-string))
1798 (handler . elpher-bookmark-jump)))))
1801 (defun elpher-bookmark-jump (bookmark)
1802 "Handler used to open a bookmark using elpher.
1803 The argument BOOKMARK is a bookmark record passed to the function.
1804 This handler is responsible for loading the bookmark in some buffer,
1805 then making that buffer the current buffer. It should not switch
1807 (let* ((url (cdr (assq 'location bookmark)))
1808 (cleaned-url (string-trim url))
1809 (address (elpher-address-from-url cleaned-url))
1810 (page (elpher-make-page cleaned-url address)))
1811 (elpher-with-clean-buffer
1812 (elpher-visit-page page))
1813 (set-buffer (get-buffer elpher-buffer-name))
1816 (defun elpher-bookmark-link ()
1817 "Bookmark the link at point.
1818 To bookmark the current page, use \\[elpher-bookmark-current]."
1820 (let ((elpher-bookmark-link t))
1821 (bookmark-set-no-overwrite)))
1823 (defun elpher-bookmark-current ()
1824 "Bookmark the current page.
1825 To bookmark the link at point use \\[elpher-bookmark-link]."
1827 (call-interactively #'bookmark-set-no-overwrite))
1829 (defun elpher-bookmark-import (file)
1830 "Import legacy Elpher bookmarks file FILE into Emacs bookmarks."
1831 (interactive (list (if (and (boundp 'elpher-bookmarks-file)
1832 (file-readable-p elpher-bookmarks-file))
1833 elpher-bookmarks-file
1834 (read-file-name "Old Elpher bookmarks: "
1835 user-emacs-directory nil t
1836 "elpher-bookmarks"))))
1838 (dolist (bookmark (with-temp-buffer
1839 (insert-file-contents file)
1840 (read (current-buffer))))
1841 (let* ((display-string (car bookmark))
1842 (url (cadr bookmark))
1843 (record `(,display-string
1845 (handler . elpher-bookmark-jump))))
1846 (bookmark-store display-string (cdr record) t)))
1849 (defun elpher-open-bookmarks ()
1850 "Display the current list of elpher bookmarks.
1851 This is just a call to `bookmark-bmenu-list', but we also check for a legacy
1852 bookmark file and offer to import it."
1854 (let ((old-bookmarks-file (or (and (boundp 'elpher-bookmarks-file)
1855 elpher-bookmarks-file)
1856 (locate-user-emacs-file "elpher-bookmarks"))))
1857 (when (and (file-readable-p old-bookmarks-file)
1858 (y-or-n-p (concat "Legacy elpher-bookmarks file \""
1860 "\" found. Import now?")))
1861 (elpher-bookmark-import old-bookmarks-file)
1862 (rename-file old-bookmarks-file (concat old-bookmarks-file "-legacy"))))
1863 (call-interactively #'bookmark-bmenu-list))
1865 (defun elpher-get-bookmarks-page (renderer)
1866 "Getter which displays the history page (RENDERER must be nil)."
1868 (elpher-visit-previous-page)
1869 (error "Command not supported for bookmarks page"))
1870 (let* ((names (seq-filter (lambda (name)
1871 (let ((record (bookmark-get-bookmark-record name)))
1873 (eq (alist-get 'handler record) 'elpher-bookmark-jump)
1875 (bookmark-all-names))))
1876 (elpher-with-clean-buffer
1877 (insert " ---- Elpher Bookmarks ---- \n\n")
1879 (dolist (name names)
1881 (let* ((url (alist-get 'location (bookmark-get-bookmark-record name)))
1882 (address (elpher-address-from-url url)))
1883 (elpher-insert-index-record name address))))
1884 (insert "No bookmarked pages found.\n"))
1885 (insert "\n --------------------------\n\n"
1886 "Select an entry or press 'u' to return to the previous page.")
1887 (elpher-restore-pos))))
1889 (defun elpher-show-bookmarks ()
1890 "Show elpher bookmarks."
1893 (elpher-make-page "Elpher Bookmarks"
1894 (elpher-make-special-address 'bookmarks))))
1901 (defun elpher-org-export-link (link description format protocol)
1902 "Export a LINK with DESCRIPTION for the given PROTOCOL and FORMAT.
1904 FORMAT is an Org export backend. DESCRIPTION may be nil. PROTOCOL may be one
1905 of gemini, gopher or finger."
1906 (let* ((url (if (equal protocol "elpher")
1907 (string-remove-prefix "elpher:" link)
1908 (format "%s:%s" protocol link)))
1909 (desc (or description url)))
1911 (`gemini (format "=> %s %s" url desc))
1912 (`html (format "<a href=\"%s\">%s</a>" url desc))
1913 (`latex (format "\\href{%s}{%s}" url desc))
1914 (_ (if (not description)
1916 (format "%s (%s)" desc url))))))
1918 (defun elpher-org-store-link ()
1919 "Store link to an `elpher' page in Org."
1920 (when (eq major-mode 'elpher-mode)
1921 (let* ((url (elpher-info-current))
1922 (desc (car elpher-current-page))
1924 ((string-prefix-p "gemini:" url) "gemini")
1925 ((string-prefix-p "gopher:" url) "gopher")
1926 ((string-prefix-p "finger:" url) "finger")
1928 (when (equal "elpher" protocol)
1929 ;; Weird link. Or special inner link?
1930 (setq url (concat "elpher:" url)))
1931 (org-link-store-props :type protocol :link url :description desc)
1934 (defun elpher-org-follow-link (link protocol)
1935 "Visit a LINK for the given PROTOCOL.
1937 PROTOCOL may be one of gemini, gopher or finger. This method also
1938 supports the old protocol elpher, where the link is self-contained."
1939 (let ((url (if (equal protocol "elpher")
1940 (string-remove-prefix "elpher:" link)
1941 (format "%s:%s" protocol link))))
1944 (defun elpher-org-mode-integration ()
1945 "Set up `elpher' integration for `org-mode'."
1946 (org-link-set-parameters
1948 :store #'elpher-org-store-link
1949 :export (lambda (link description format _plist)
1950 (elpher-org-export-link link description format "elpher"))
1951 :follow (lambda (link _arg) (elpher-org-follow-link link "elpher")))
1952 (org-link-set-parameters
1954 :export (lambda (link description format _plist)
1955 (elpher-org-export-link link description format "gemini"))
1956 :follow (lambda (link _arg) (elpher-org-follow-link link "gemini")))
1957 (org-link-set-parameters
1959 :export (lambda (link description format _plist)
1960 (elpher-org-export-link link description format "gopher"))
1961 :follow (lambda (link _arg) (elpher-org-follow-link link "gopher")))
1962 (org-link-set-parameters
1964 :export (lambda (link description format _plist)
1965 (elpher-org-export-link link description format "finger"))
1966 :follow (lambda (link _arg) (elpher-org-follow-link link "finger"))))
1968 (add-hook 'org-mode-hook #'elpher-org-mode-integration)
1973 (defun elpher-browse-url-elpher (url &rest _args)
1974 "Browse URL using Elpher. This function is used by `browse-url'."
1975 (interactive (browse-url-interactive-arg "Elpher URL: "))
1978 ;; Use elpher to open gopher, finger and gemini links
1979 ;; For recent version of `browse-url' package
1980 (if (boundp 'browse-url-default-handlers)
1982 'browse-url-default-handlers
1983 '("^\\(gopher\\|finger\\|gemini\\)://" . elpher-browse-url-elpher))
1984 ;; Patch `browse-url-browser-function' for older ones. The value of
1985 ;; that variable is `browse-url-default-browser' by default, so
1986 ;; that's the function that gets advised.
1987 (advice-add browse-url-browser-function :before-while
1988 (lambda (url &rest _args)
1989 "Handle gemini, gopher, and finger schemes using Elpher."
1990 (let ((scheme (downcase (car (split-string url ":" t)))))
1991 (if (member scheme '("gemini" "gopher" "finger"))
1992 ;; `elpher-go' always returns nil, which will stop the
1993 ;; advice chain here in a before-while
1995 ;; chain must continue, then return t.
1998 ;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
1999 (with-eval-after-load 'thingatpt
2000 (add-to-list 'thing-at-point-uri-schemes "gemini://"))
2004 ;; Make mu4e aware of the gemini world
2005 (setq mu4e~view-beginning-of-url-regexp
2006 "\\(?:https?\\|gopher\\|finger\\|gemini\\)://\\|mailto:")
2008 ;;; Interactive procedures
2011 (defun elpher-next-link ()
2012 "Move point to the next link on the current page."
2016 (defun elpher-prev-link ()
2017 "Move point to the previous link on the current page."
2019 (backward-button 1))
2021 (defun elpher-follow-current-link ()
2022 "Open the link or url at point."
2027 (defun elpher-go (host-or-url)
2028 "Go to a particular gopher site HOST-OR-URL.
2029 When run interactively HOST-OR-URL is read from the minibuffer."
2030 (interactive "sGopher or Gemini URL: ")
2031 (let* ((cleaned-host-or-url (string-trim host-or-url))
2032 (address (elpher-address-from-url cleaned-host-or-url))
2033 (page (elpher-make-page cleaned-host-or-url address)))
2034 (switch-to-buffer elpher-buffer-name)
2035 (elpher-with-clean-buffer
2036 (elpher-visit-page page))
2039 (defun elpher-go-current ()
2040 "Go to a particular site read from the minibuffer, initialized with the current URL."
2042 (let ((address (elpher-page-address elpher-current-page)))
2043 (let ((url (read-string "Gopher or Gemini URL: "
2044 (unless (elpher-address-special-p address)
2045 (elpher-address-to-url address)))))
2046 (elpher-visit-page (elpher-make-page url (elpher-address-from-url url))))))
2048 (defun elpher-redraw ()
2049 "Redraw current page."
2051 (elpher-visit-page elpher-current-page))
2053 (defun elpher-reload ()
2054 "Reload current page."
2056 (elpher-reload-current-page))
2058 (defun elpher-toggle-tls ()
2059 "Toggle TLS encryption mode for gopher."
2061 (setq elpher-use-tls (not elpher-use-tls))
2063 (if (gnutls-available-p)
2064 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
2065 (setq elpher-use-tls nil)
2066 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
2067 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
2069 (defun elpher-view-raw ()
2070 "View raw server response for current page."
2072 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2073 (error "This page was not generated by a server")
2074 (elpher-visit-page elpher-current-page
2075 #'elpher-render-raw)))
2077 (defun elpher-back ()
2078 "Go to previous site."
2080 (elpher-visit-previous-page))
2082 (defun elpher-back-to-start ()
2083 "Go all the way back to the start page."
2085 (setq-local elpher-current-page nil)
2086 (setq-local elpher-history nil)
2087 (elpher-visit-page (elpher-make-start-page)))
2089 (defun elpher-download ()
2090 "Download the link at point."
2092 (let ((button (button-at (point))))
2094 (let ((page (button-get button 'elpher-page)))
2095 (if (elpher-address-special-p (elpher-page-address page))
2096 (error "Cannot download %s"
2097 (elpher-page-display-string page))
2098 (elpher-visit-page (button-get button 'elpher-page)
2099 #'elpher-render-download)))
2100 (error "No link selected"))))
2102 (defun elpher-download-current ()
2103 "Download the current page."
2105 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2106 (error "Cannot download %s"
2107 (elpher-page-display-string elpher-current-page))
2108 (elpher-visit-page (elpher-make-page
2109 (elpher-page-display-string elpher-current-page)
2110 (elpher-page-address elpher-current-page))
2111 #'elpher-render-download
2114 (defun elpher--build-link-map ()
2115 "Build alist mapping link names to destination pages in current buffer."
2116 (let ((link-map nil)
2117 (b (next-button (point-min) t)))
2119 (push (cons (button-label b) b) link-map)
2120 (setq b (next-button (button-start b))))
2123 (defun elpher-jump ()
2124 "Select a directory entry by name. Similar to the info browser (m)enu command."
2126 (let* ((link-map (elpher--build-link-map)))
2128 (let ((key (let ((completion-ignore-case t))
2129 (completing-read "Directory item/link: "
2131 (if (and key (> (length key) 0))
2132 (let ((b (cdr (assoc key link-map))))
2133 (goto-char (button-start b))
2134 (button-activate b)))))))
2136 (defun elpher-root-dir ()
2137 "Visit root of current server."
2139 (let ((address (elpher-page-address elpher-current-page)))
2140 (if (not (elpher-address-special-p address))
2141 (if (or (member (url-filename address) '("/" ""))
2142 (and (elpher-address-gopher-p address)
2143 (= (length (elpher-gopher-address-selector address)) 0)))
2144 (error "Already at root directory of current server")
2145 (let ((address-copy (elpher-address-from-url
2146 (elpher-address-to-url address))))
2147 (setf (url-filename address-copy) "")
2148 (elpher-go (elpher-address-to-url address-copy))))
2149 (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
2151 (defun elpher-info-page (page)
2152 "Display information on PAGE."
2153 (let ((display-string (elpher-page-display-string page))
2154 (address (elpher-page-address page)))
2155 (if (elpher-address-special-p address)
2156 (message "Special page: %s" display-string)
2157 (message "%s" (elpher-address-to-url address)))))
2159 (defun elpher-info-link ()
2160 "Display information on page corresponding to link at point."
2162 (let ((button (button-at (point))))
2164 (elpher-info-page (button-get button 'elpher-page))
2165 (error "No item selected"))))
2167 (defun elpher-info-current ()
2168 "Display information on current page."
2170 (elpher-info-page elpher-current-page))
2172 (defun elpher-copy-page-url (page)
2173 "Copy URL representation of address of PAGE to `kill-ring'."
2174 (let ((address (elpher-page-address page)))
2175 (if (elpher-address-special-p address)
2176 (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
2177 (let ((url (elpher-address-to-url address)))
2178 (message "Copied \"%s\" to kill-ring/clipboard." url)
2181 (defun elpher-copy-link-url ()
2182 "Copy URL of item at point to `kill-ring'."
2184 (let ((button (button-at (point))))
2186 (elpher-copy-page-url (button-get button 'elpher-page))
2187 (error "No item selected"))))
2189 (defun elpher-copy-current-url ()
2190 "Copy URL of current page to `kill-ring'."
2192 (elpher-copy-page-url elpher-current-page))
2194 (defun elpher-set-gopher-coding-system ()
2195 "Specify an explicit character coding system for gopher selectors."
2197 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
2198 (setq elpher-user-coding-system system)
2200 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
2201 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
2207 (defvar elpher-mode-map
2208 (let ((map (make-sparse-keymap)))
2209 (define-key map (kbd "TAB") 'elpher-next-link)
2210 (define-key map (kbd "<backtab>") 'elpher-prev-link)
2211 (define-key map (kbd "C-M-i") 'elpher-prev-link)
2212 (define-key map (kbd "u") 'elpher-back)
2213 (define-key map (kbd "-") 'elpher-back)
2214 (define-key map (kbd "^") 'elpher-back)
2215 (define-key map [mouse-3] 'elpher-back)
2216 (define-key map (kbd "U") 'elpher-back-to-start)
2217 (define-key map (kbd "g") 'elpher-go)
2218 (define-key map (kbd "o") 'elpher-go-current)
2219 (define-key map (kbd "O") 'elpher-root-dir)
2220 (define-key map (kbd "s") 'elpher-show-history)
2221 (define-key map (kbd "S") 'elpher-show-visited-pages)
2222 (define-key map (kbd "r") 'elpher-redraw)
2223 (define-key map (kbd "R") 'elpher-reload)
2224 (define-key map (kbd "T") 'elpher-toggle-tls)
2225 (define-key map (kbd ".") 'elpher-view-raw)
2226 (define-key map (kbd "d") 'elpher-download)
2227 (define-key map (kbd "D") 'elpher-download-current)
2228 (define-key map (kbd "m") 'elpher-jump)
2229 (define-key map (kbd "i") 'elpher-info-link)
2230 (define-key map (kbd "I") 'elpher-info-current)
2231 (define-key map (kbd "c") 'elpher-copy-link-url)
2232 (define-key map (kbd "C") 'elpher-copy-current-url)
2233 (define-key map (kbd "a") 'elpher-bookmark-link)
2234 (define-key map (kbd "A") 'elpher-bookmark-current)
2235 (define-key map (kbd "B") 'elpher-show-bookmarks)
2236 ;; (define-key map (kbd "B") 'elpher-open-bookmarks)
2237 (define-key map (kbd "!") 'elpher-set-gopher-coding-system)
2238 (define-key map (kbd "F") 'elpher-forget-current-certificate)
2239 (when (fboundp 'evil-define-key*)
2242 (kbd "TAB") 'elpher-next-link
2243 (kbd "C-") 'elpher-follow-current-link
2244 (kbd "C-t") 'elpher-back
2245 (kbd "u") 'elpher-back
2246 (kbd "-") 'elpher-back
2247 (kbd "^") 'elpher-back
2248 [mouse-3] 'elpher-back
2249 (kbd "U") 'elpher-back-to-start
2250 (kbd "g") 'elpher-go
2251 (kbd "o") 'elpher-go-current
2252 (kbd "O") 'elpher-root-dir
2253 (kbd "s") 'elpher-show-history
2254 (kbd "S") 'elpher-show-visited-pages
2255 (kbd "r") 'elpher-redraw
2256 (kbd "R") 'elpher-reload
2257 (kbd "T") 'elpher-toggle-tls
2258 (kbd ".") 'elpher-view-raw
2259 (kbd "d") 'elpher-download
2260 (kbd "D") 'elpher-download-current
2261 (kbd "m") 'elpher-jump
2262 (kbd "i") 'elpher-info-link
2263 (kbd "I") 'elpher-info-current
2264 (kbd "c") 'elpher-copy-link-url
2265 (kbd "C") 'elpher-copy-current-url
2266 (kbd "a") 'elpher-bookmark-link
2267 (kbd "A") 'elpher-bookmark-current
2268 ;; (kbd "B") 'elpher-open-bookmarks
2269 (kbd "B") 'elpher-show-bookmarks
2270 (kbd "!") 'elpher-set-gopher-coding-system
2271 (kbd "F") 'elpher-forget-current-certificate))
2273 "Keymap for gopher client.")
2275 (define-derived-mode elpher-mode special-mode "elpher"
2276 "Major mode for elpher, an elisp gopher client.
2278 This mode is automatically enabled by the interactive
2279 functions which initialize the client, namely
2280 `elpher', and `elpher-go'."
2281 (setq-local elpher--gemini-page-headings nil)
2282 (setq-local elpher-current-page nil)
2283 (setq-local elpher-history nil)
2284 (setq-local elpher-buffer-name (buffer-name))
2285 (setq-local bookmark-make-record-function #'elpher-bookmark-make-record)
2286 (setq-local imenu-create-index-function (lambda () elpher--gemini-page-headings))
2287 (setq-local xterm-color-preserve-properties t))
2289 (when (fboundp 'evil-set-initial-state)
2290 (evil-set-initial-state 'elpher-mode 'motion))
2293 ;;; Main start procedure
2297 (defun elpher (&optional arg)
2298 "Start elpher with default landing page.
2299 The buffer used for Elpher sessions is determined by the value of
2300 ‘elpher-buffer-name’. If there is already an Elpher session active in
2301 that buffer, Emacs will simply switch to it. Otherwise, a new session
2302 will begin. A numeric prefix ARG (as in ‘\\[universal-argument] 42
2303 \\[execute-extended-command] elpher RET’) switches to the session with
2304 that number, creating it if necessary. A non numeric prefix ARG means
2305 to create a new session. Returns the buffer selected (or created)."
2307 (let* ((name (default-value 'elpher-buffer-name))
2308 (buf (cond ((numberp arg)
2309 (get-buffer-create (format "%s<%d>" name arg)))
2311 (generate-new-buffer name))
2313 (get-buffer-create name)))))
2314 (pop-to-buffer-same-window buf)
2315 (unless (buffer-modified-p)
2317 (elpher-visit-page (elpher-make-start-page))
2318 "Started Elpher."))); Otherwise (elpher) evaluates to start page string.
2320 ;;; elpher.el ends here