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
65 ;; project page, gopher://thelambdalab.xyz/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 history) elpher-get-history-page nil "E" elpher-index)
133 ((special visited-pages) elpher-get-visited-pages-page nil "E" elpher-index))
134 "Association list from types to getters, renderers, margin codes and index faces.")
137 ;;; Internal variables
141 (defvar elpher--gemini-page-headings nil
142 "List of headings on the page.")
145 ;;; Declarations to avoid compiler warnings.
149 (defvar bookmark-make-record-function)
150 (declare-function bookmark-store "bookmark")
151 (declare-function org-link-store-props "ol")
152 (declare-function org-link-set-parameters "ol")
153 (defvar thing-at-point-uri-schemes)
154 (defvar mu4e~view-beginning-of-url-regexp))
157 ;;; Customization group
161 "A gopher and gemini client."
162 :group 'applications)
164 ;; General appearance and customizations
166 (defcustom elpher-open-urls-with-eww nil
167 "If non-nil, open URL selectors using eww.
168 Otherwise, use the system browser via the `browse-url' function."
171 (defcustom elpher-use-header t
172 "If non-nil, display current page information in buffer header."
175 (defcustom elpher-auto-disengage-TLS nil
176 "If non-nil, automatically disengage TLS following an unsuccessful connection.
177 While enabling this may seem convenient, it is also potentially
178 dangerous as it allows switching from an encrypted channel back to
179 plain text without user input."
182 (defcustom elpher-connection-timeout 5
183 "Specifies the number of seconds to wait for a network connection to time out."
186 (defcustom elpher-filter-ansi-from-text nil
187 "If non-nil, filter ANSI escape sequences from text.
188 The default behaviour is to use the ansi-color package to interpret these
192 (defcustom elpher-certificate-directory
193 (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
194 "Specify the name of the directory where client certificates will be stored.
195 These certificates may be used for establishing authenticated TLS connections."
198 (defcustom elpher-openssl-command "openssl"
199 "The command used to launch openssl when generating TLS client certificates."
202 (defcustom elpher-default-url-type "gopher"
203 "Default URL type (i.e. scheme) to assume if not explicitly given."
204 :type '(choice (const "gopher")
207 (defcustom elpher-gemini-TLS-cert-checks nil
208 "If non-nil, verify gemini server TLS certs using the default security level.
209 Otherwise, certificate verification is disabled.
211 This defaults to off because it is standard practice for Gemini servers
212 to use self-signed certificates, meaning that most servers provide what
213 EMACS considers to be an invalid certificate."
216 (defcustom elpher-gemini-max-fill-width 80
217 "Specify the maximum default width (in columns) of text/gemini documents.
218 The actual width used is the minimum of this value and the window width at
219 the time when the text is rendered."
222 (defcustom elpher-gemini-link-string "→ "
223 "Specify the string used to indicate links when rendering gemini maps.
227 (defcustom elpher-gemini-bullet-string "•"
228 "Specify the string used for bullets when rendering gemini maps."
231 (defcustom elpher-ipv4-always nil
232 "If non-nil, elpher will always use IPv4 to establish network connections.
233 This can be useful when browsing from a computer that supports IPv6, because
234 some servers which do not support IPv6 can take a long time to time-out."
237 (defcustom elpher-socks-always nil
238 "If non-nil, elpher will establish network connections over a SOCKS proxy.
239 Otherwise, the SOCKS proxy is only used for connections to onion services."
242 ;; Face customizations
244 (defgroup elpher-faces nil
245 "Elpher face customizations."
248 (defface elpher-index
249 '((t :inherit font-lock-keyword-face))
250 "Face used for directory type directory records.")
254 "Face used for text type directory records.")
257 '((t :inherit default))
258 "Face used for info type directory records.")
260 (defface elpher-image
261 '((t :inherit font-lock-string-face))
262 "Face used for image type directory records.")
264 (defface elpher-search
265 '((t :inherit warning))
266 "Face used for search type directory records.")
269 '((t :inherit font-lock-comment-face))
270 "Face used for html type directory records.")
272 (defface elpher-gemini
273 '((t :inherit font-lock-constant-face))
274 "Face used for Gemini type directory records.")
276 (defface elpher-other-url
277 '((t :inherit font-lock-comment-face))
278 "Face used for other URL type links records.")
280 (defface elpher-telnet
281 '((t :inherit font-lock-function-name-face))
282 "Face used for telnet type directory records.")
284 (defface elpher-binary
285 '((t :inherit font-lock-doc-face))
286 "Face used for binary type directory records.")
288 (defface elpher-unknown
289 '((t :inherit error))
290 "Face used for directory records with unknown/unsupported types.")
292 (defface elpher-margin-key
294 "Face used for directory margin key.")
296 (defface elpher-margin-brackets
297 '((t :inherit shadow))
298 "Face used for brackets around directory margin key.")
300 (defface elpher-gemini-heading1
301 '((t :inherit bold :height 1.8))
302 "Face used for gemini heading level 1.")
304 (defface elpher-gemini-heading2
305 '((t :inherit bold :height 1.5))
306 "Face used for gemini heading level 2.")
308 (defface elpher-gemini-heading3
309 '((t :inherit bold :height 1.2))
310 "Face used for gemini heading level 3.")
312 (defface elpher-gemini-preformatted
313 '((t :inherit fixed-pitch))
314 "Face used for pre-formatted gemini text blocks.")
316 (defface elpher-gemini-quoted
317 '((t :inherit font-lock-doc-face))
318 "Face used for gemini quoted texts.")
325 ;; An elpher "address" object is either a url object or a symbol.
326 ;; Symbol addresses are "special", corresponding to pages generated
327 ;; dynamically for and by elpher. All others represent pages which
328 ;; rely on content retrieved over the network.
330 (defun elpher-address-from-url (url-string)
331 "Create a ADDRESS object corresponding to the given URL-STRING."
332 (let ((data (match-data))) ; Prevent parsing clobbering match data
334 (let ((url (url-generic-parse-url url-string)))
335 (unless (and (not (url-fullness url)) (url-type url))
336 (setf (url-fullness url) t)
337 (unless (url-type url)
338 (setf (url-type url) elpher-default-url-type))
339 (unless (url-host url)
340 (let ((p (split-string (url-filename url) "/" nil nil)))
341 (setf (url-host url) (car p))
342 (setf (url-filename url)
344 (concat "/" (mapconcat #'identity (cdr p) "/"))
346 (when (or (equal "gopher" (url-type url))
347 (equal "gophers" (url-type url)))
349 (when (or (equal (url-filename url) "")
350 (equal (url-filename url) "/"))
351 (setf (url-filename url) "/1")))
352 (when (equal "gemini" (url-type url))
354 (if (equal (url-filename url) "")
355 (setf (url-filename url) "/"))))
356 (elpher-remove-redundant-ports url))
357 (set-match-data data))))
359 (defun elpher-remove-redundant-ports (address)
360 "Remove redundant port specifiers from ADDRESS.
361 Here 'redundant' means that the specified port matches the default
362 for that protocol, eg 70 for gopher."
363 (if (and (not (elpher-address-special-p address))
364 (eq (url-portspec address) ; (url-port) is too slow!
365 (pcase (url-type address)
367 ((or "gopher" "gophers") 70)
370 (setf (url-portspec address) nil))
373 (defun elpher-make-gopher-address (type selector host port &optional tls)
374 "Create an ADDRESS object using gopher directory record attributes.
375 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
376 If the optional attribute TLS is non-nil, the address will be marked as
377 requiring gopher-over-TLS."
379 ((equal type ?i) nil)
380 ((and (equal type ?h)
381 (string-prefix-p "URL:" selector))
382 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
384 (elpher-address-from-url
387 ":" (number-to-string port))))
389 (elpher-address-from-url
390 (concat "gopher" (if tls "s" "")
392 ":" (number-to-string port)
396 (defun elpher-make-special-address (type)
397 "Create an ADDRESS object corresponding to the given special address symbol TYPE."
400 (defun elpher-make-start-page ()
401 "Create the start page."
402 (elpher-make-page "Elpher Start Page"
403 (elpher-make-special-address 'start)))
405 (defun elpher-address-to-url (address)
406 "Get string representation of ADDRESS, or nil if ADDRESS is special."
407 (if (elpher-address-special-p address)
409 (url-encode-url (url-recreate-url address))))
411 (defun elpher-address-type (address)
412 "Retrieve type of ADDRESS object.
413 This is used to determine how to retrieve and render the document the
414 address refers to, via the table `elpher-type-map'."
415 (if (symbolp address)
416 (list 'special address)
417 (let ((protocol (url-type address)))
418 (cond ((or (equal protocol "gopher")
419 (equal protocol "gophers"))
421 (if (member (url-filename address) '("" "/"))
423 (string-to-char (substring (url-filename address) 1)))))
424 ((equal protocol "gemini")
426 ((equal protocol "telnet")
428 ((equal protocol "finger")
432 (defun elpher-address-protocol (address)
433 "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
434 (if (symbolp address)
438 (defun elpher-address-filename (address)
439 "Retrieve the filename component of ADDRESS.
440 For gopher addresses this is a combination of the selector type and selector."
441 (if (symbolp address)
443 (url-unhex-string (url-filename address))))
445 (defun elpher-address-host (address)
446 "Retrieve host from ADDRESS object."
449 (defun elpher-address-user (address)
450 "Retrieve user from ADDRESS object."
453 (defun elpher-address-port (address)
454 "Retrieve port from ADDRESS object.
455 If no address is defined, returns 0. (This is for compatibility with the URL library.)"
456 (if (symbolp address)
460 (defun elpher-address-special-p (address)
461 "Return non-nil if ADDRESS object is special (e.g. start page page)."
464 (defun elpher-address-gopher-p (address)
465 "Return non-nill if ADDRESS object is a gopher address."
466 (and (not (elpher-address-special-p address))
467 (member (elpher-address-protocol address) '("gopher" "gophers"))))
469 (defun elpher-gopher-address-selector (address)
470 "Retrieve gopher selector from ADDRESS object."
471 (if (member (url-filename address) '("" "/"))
473 (url-unhex-string (substring (url-filename address) 2))))
478 (defvar elpher-content-cache (make-hash-table :test 'equal))
479 (defvar elpher-pos-cache (make-hash-table :test 'equal))
481 (defun elpher-get-cached-content (address)
482 "Retrieve the cached content for ADDRESS, or nil if none exists."
483 (gethash address elpher-content-cache))
485 (defun elpher-cache-content (address content)
486 "Set the content cache for ADDRESS to CONTENT."
487 (puthash address content elpher-content-cache))
489 (defun elpher-get-cached-pos (address)
490 "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
491 (gethash address elpher-pos-cache))
493 (defun elpher-cache-pos (address pos)
494 "Set the cursor position cache for ADDRESS to POS."
495 (puthash address pos elpher-pos-cache))
500 (defun elpher-make-page (display-string address)
501 "Create a page with DISPLAY-STRING and ADDRESS."
502 (list display-string address))
504 (defun elpher-page-display-string (page)
505 "Retrieve the display string corresponding to PAGE."
508 (defun elpher-page-address (page)
509 "Retrieve the address corresponding to PAGE."
512 (defun elpher-page-set-address (page new-address)
513 "Set the address corresponding to PAGE to NEW-ADDRESS."
514 (setcar (cdr page) new-address))
516 (defvar elpher-current-page nil
517 "The current page for this Elpher buffer.")
519 (defvar elpher-history nil
520 "The local history stack for this Elpher buffer.
521 This variable is used by `elpher-back' and
522 `elpher-show-history'.")
524 (defvar elpher-visited-pages nil
525 "The global history for all Elpher buffers.
526 This variable is used by `elpher-show-visited-pages'.")
528 (defun elpher-visit-page (page &optional renderer no-history)
529 "Visit PAGE using its own renderer or RENDERER, if non-nil.
530 Additionally, push PAGE onto the history stack and the list of
531 previously-visited pages,unless NO-HISTORY is non-nil."
533 (elpher-process-cleanup)
535 (unless (equal (elpher-page-address elpher-current-page)
536 (elpher-page-address page))
537 (push elpher-current-page elpher-history)
538 (unless (or (elpher-address-special-p (elpher-page-address page))
539 (and elpher-visited-pages
540 (equal page (car elpher-visited-pages))))
541 (push page elpher-visited-pages))))
542 (setq-local elpher-current-page page)
543 (let* ((address (elpher-page-address page))
544 (type (elpher-address-type address))
545 (type-record (cdr (assoc type elpher-type-map))))
547 (funcall (car type-record)
551 (elpher-visit-previous-page)
553 (`(gopher ,type-char)
554 (error "Unsupported gopher selector type '%c' for '%s'"
555 type-char (elpher-address-to-url address)))
557 (error "Unsupported address type '%S' for '%s'"
558 other (elpher-address-to-url address)))))))
560 (defun elpher-visit-previous-page ()
561 "Visit the previous page in the history."
562 (let ((previous-page (pop elpher-history)))
564 (elpher-visit-page previous-page nil t)
565 (error "No previous page"))))
567 (defun elpher-reload-current-page ()
568 "Reload the current page, discarding any existing cached content."
569 (elpher-cache-content (elpher-page-address elpher-current-page) nil)
570 (elpher-visit-page elpher-current-page))
572 (defun elpher-save-pos ()
573 "Save the current position of point to the current page."
574 (when elpher-current-page
575 (elpher-cache-pos (elpher-page-address elpher-current-page) (point))))
577 (defun elpher-restore-pos ()
578 "Restore the position of point to that cached in the current page."
579 (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
582 (goto-char (point-min)))))
585 ;;; Buffer preparation
588 (defvar elpher-buffer-name "*elpher*"
589 "The default name of the Elpher buffer.")
591 (defun elpher-update-header ()
592 "If `elpher-use-header' is true, display current page info in window header."
593 (if elpher-use-header
594 (let* ((display-string (elpher-page-display-string elpher-current-page))
595 (address (elpher-page-address elpher-current-page))
596 (tls-string (if (and (not (elpher-address-special-p address))
597 (member (elpher-address-protocol address)
598 '("gophers" "gemini")))
601 (header (concat display-string
602 (propertize tls-string 'face 'bold))))
603 (setq header-line-format header))))
605 (defmacro elpher-with-clean-buffer (&rest args)
606 "Evaluate ARGS with a clean *elpher* buffer as current."
607 `(with-current-buffer elpher-buffer-name
608 (unless (eq major-mode 'elpher-mode)
609 ;; avoid resetting buffer-local variables
611 (let ((inhibit-read-only t))
612 (setq-local network-security-level
613 (default-value 'network-security-level))
615 (elpher-update-header)
618 (defun elpher-buffer-message (string &optional line)
619 "Replace first line in elpher buffer with STRING.
620 If LINE is non-nil, replace that line instead."
621 (with-current-buffer elpher-buffer-name
622 (let ((inhibit-read-only t))
623 (goto-char (point-min))
626 (let ((data (match-data)))
629 (re-search-forward "^.*$")
630 (replace-match string))
631 (set-match-data data))))))
637 (defvar elpher-user-coding-system nil
638 "User-specified coding system to use for decoding text responses.")
640 (defun elpher-decode (string)
641 "Decode STRING using autodetected or user-specified coding system."
642 (decode-coding-string string
643 (if elpher-user-coding-system
644 elpher-user-coding-system
645 (detect-coding-string string t))))
647 (defun elpher-preprocess-text-response (string)
648 "Preprocess text selector response contained in STRING.
649 This involes decoding the character representation, and clearing
650 away CRs and any terminating period."
651 (elpher-decode (replace-regexp-in-string "\n\\.\n$" "\n"
652 (replace-regexp-in-string "\r" "" string))))
655 ;;; Network error reporting
658 (defun elpher-network-error (address error)
659 "Display ERROR message following unsuccessful negotiation with ADDRESS.
660 ERROR can be either an error object or a string."
661 (elpher-with-clean-buffer
662 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
663 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
664 (if (stringp error) error (error-message-string error)) "\n"
665 (propertize "\n----------------\n\n" 'face 'error)
666 "Press 'u' to return to the previous page.")))
669 ;;; General network communication
672 (defvar elpher-network-timer nil
673 "Timer used for network connections.")
675 (defvar elpher-use-tls nil
676 "If non-nil, use TLS to communicate with gopher servers.")
678 (defvar elpher-client-certificate nil
679 "If non-nil, contains client certificate details to use for TLS connections.")
681 (defun elpher-process-cleanup ()
682 "Immediately shut down any extant elpher process and timers."
683 (let ((p (get-process "elpher-process")))
684 (if p (delete-process p)))
685 (if (timerp elpher-network-timer)
686 (cancel-timer elpher-network-timer)))
688 (defun elpher-get-host-response (address default-port query-string response-processor
689 &optional use-tls force-ipv4)
690 "Generic function for retrieving data from ADDRESS.
692 When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
693 QUERY-STRING is a string sent to the host specified by ADDRESS to
694 illicet a response. This response is passed as an argument to the
695 function RESPONSE-PROCESSOR.
697 If non-nil, USE-TLS specifies that the connection is to be made over
698 TLS. If set to gemini, the certificate verification will be disabled
699 unless `elpher-gemini-TLS-cert-checks' is non-nil.
701 If non-nil, FORCE-IPV4 causes the network connection to be made over
702 ipv4 only. (The default behaviour when this is not set depends on
703 the host operating system and the local network capabilities.)"
704 (if (and use-tls (not (gnutls-available-p)))
705 (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
706 (unless (< (elpher-address-port address) 65536)
707 (error "Cannot establish network connection: port number > 65536"))
708 (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
709 (setq-local network-security-level 'low)
710 (setq-local gnutls-verify-error nil))
712 (let* ((kill-buffer-query-functions nil)
713 (port (elpher-address-port address))
714 (service (if (> port 0) port default-port))
715 (host (elpher-address-host address))
716 (socks (or elpher-socks-always (string-suffix-p ".onion" host)))
717 (response-string-parts nil)
720 (timer (run-at-time elpher-connection-timeout nil
722 (elpher-process-cleanup)
724 ; Try again with IPv4
725 ((not (or force-ipv4 socks))
726 (message "Connection timed out. Retrying with IPv4.")
727 (elpher-get-host-response address default-port
732 (not (eq use-tls 'gemini))
733 (or elpher-auto-disengage-TLS
735 "TLS connetion failed. Disable TLS mode and retry? ")))
736 (setq elpher-use-tls nil)
737 (elpher-get-host-response address default-port
742 (elpher-network-error address "Connection time-out."))))))
743 (gnutls-params (list :type 'gnutls-x509pki :hostname host
744 :keylist (elpher-get-current-keylist address)))
745 (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
746 (make-network-process :name "elpher-process"
748 :family (and force-ipv4 'ipv4)
754 (cons 'gnutls-x509pki
755 (apply #'gnutls-boot-parameters
757 (setq elpher-network-timer timer)
758 (set-process-coding-system proc 'binary 'binary)
759 (set-process-query-on-exit-flag proc nil)
760 (elpher-buffer-message (concat "Connecting to " host "..."
761 " (press 'u' to abort)"))
762 (set-process-filter proc
763 (lambda (_proc string)
767 (setq bytes-received (+ bytes-received (length string)))
768 (let ((new-hkbytes-received (/ bytes-received 102400)))
769 (when (> new-hkbytes-received hkbytes-received)
770 (setq hkbytes-received new-hkbytes-received)
771 (elpher-buffer-message
773 (number-to-string (/ hkbytes-received 10.0))
776 (setq response-string-parts
777 (cons string response-string-parts))))
778 (set-process-sentinel proc
781 (cancel-timer timer))
782 (condition-case the-error
784 ((string-prefix-p "open" event) ; request URL
785 (elpher-buffer-message
786 (concat "Connected to " host ". Receiving data..."
787 " (press 'u' to abort)"))
788 (let ((inhibit-eol-conversion t))
789 (process-send-string proc query-string)))
790 ((string-prefix-p "deleted" event)) ; do nothing
791 ((and (not response-string-parts)
792 (not (or elpher-ipv4-always force-ipv4 socks)))
793 ; Try again with IPv4
794 (message "Connection failed. Retrying with IPv4.")
795 (elpher-get-host-response address default-port
799 (response-string-parts
800 (elpher-with-clean-buffer
801 (insert "Data received. Rendering..."))
802 (funcall response-processor
803 (apply #'concat (reverse response-string-parts)))
804 (elpher-restore-pos))
806 (error "No response from server")))
808 (elpher-network-error address the-error)))))
810 (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
811 (funcall (process-sentinel proc) proc "open\n")))
813 (error "Error initiating connection to server")))))
816 ;;; Client-side TLS Certificate Management
819 (defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
820 "Generate a key and a self-signed client TLS certificate using openssl.
822 The Common Name field of the certificate is set to COMMON-NAME. The
823 arguments KEY-FILE and CERT-FILE should contain the absolute paths of
824 the key and certificate files to write.
826 If TEMPORARY is non-nil, the certificate will be given an exporation
827 period of one day, and the key and certificate files will be deleted
828 when the certificate is no longer needed for the current session.
830 Otherwise, the certificate will be given a 100 year expiration period
831 and the files will not be deleted.
833 The function returns a list containing the current host name, the
834 temporary flag, and the key and cert file names in the form required
835 by `gnutls-boot-parameters`."
836 (let ((exp-key-file (expand-file-name key-file))
837 (exp-cert-file (expand-file-name cert-file)))
840 (call-process elpher-openssl-command nil nil nil
841 "req" "-x509" "-newkey" "rsa:2048"
842 "-days" (if temporary "1" "36500")
844 "-subj" (concat "/CN=" common-name)
845 "-keyout" exp-key-file
846 "-out" exp-cert-file)
847 (list (elpher-address-host (elpher-page-address elpher-current-page))
848 temporary exp-key-file exp-cert-file))
850 (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
851 (error "Program 'openssl', required for certificate generation, not found")))))
853 (defun elpher-generate-throwaway-certificate ()
854 "Generate and return details of a throwaway certificate.
855 The key and certificate files will be deleted when they are no
856 longer needed for this session."
857 (let* ((file-base (make-temp-name "elpher"))
858 (key-file (concat temporary-file-directory file-base ".key"))
859 (cert-file (concat temporary-file-directory file-base ".crt")))
860 (elpher-generate-certificate file-base key-file cert-file t)))
862 (defun elpher-generate-persistent-certificate (file-base common-name)
863 "Generate and return details of a persistent certificate.
864 The argument FILE-BASE is used as the base for the key and certificate
865 files, while COMMON-NAME specifies the common name field of the
868 The key and certificate files are written to in `elpher-certificate-directory'."
869 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
870 (cert-file (concat elpher-certificate-directory file-base ".crt")))
871 (elpher-generate-certificate common-name key-file cert-file)))
873 (defun elpher-get-existing-certificate (file-base)
874 "Return a certificate object corresponding to an existing certificate.
875 It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
876 the directory `elpher-certificate-directory'."
877 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
878 (cert-file (concat elpher-certificate-directory file-base ".crt")))
879 (list (elpher-address-host (elpher-page-address elpher-current-page))
881 (expand-file-name key-file)
882 (expand-file-name cert-file))))
884 (defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
885 "Install a key+certificate file pair in `elpher-certificate-directory'.
886 The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
887 certificate files to install. The argument FILE-BASE is used as the
888 base for the installed key and certificate files."
889 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
890 (cert-file (concat elpher-certificate-directory file-base ".crt")))
891 (if (or (file-exists-p key-file)
892 (file-exists-p cert-file))
893 (error "A certificate with base name %s is already installed" file-base))
894 (copy-file key-file-src key-file)
895 (copy-file cert-file-src cert-file)
896 (list (elpher-address-host (elpher-page-address elpher-current-page))
898 (expand-file-name key-file)
899 (expand-file-name cert-file))))
901 (defun elpher-list-existing-certificates ()
902 "Return a list of the persistent certificates in `elpher-certificate-directory'."
903 (unless (file-directory-p elpher-certificate-directory)
904 (make-directory elpher-certificate-directory))
907 (file-name-sans-extension file))
908 (directory-files elpher-certificate-directory nil "\\.key$")))
910 (defun elpher-forget-current-certificate ()
911 "Causes any current certificate to be forgotten.)
912 In the case of throwaway certificates, the key and certificate files
915 (when elpher-client-certificate
916 (unless (and (called-interactively-p 'any)
917 (not (y-or-n-p (concat "Really forget client certificate? "
918 "(Throwaway certificates will be deleted.)"))))
919 (when (cadr elpher-client-certificate)
920 (delete-file (elt elpher-client-certificate 2))
921 (delete-file (elt elpher-client-certificate 3)))
922 (setq elpher-client-certificate nil)
923 (if (called-interactively-p 'any)
924 (message "Client certificate forgotten.")))))
926 (defun elpher-get-current-keylist (address)
927 "Retrieve the `gnutls-boot-parameters'-compatable keylist.
929 This is obtained from the client certificate described by
930 `elpher-current-certificate', if one is available and the host for
931 that certificate matches the host in ADDRESS.
933 If `elpher-current-certificate' is non-nil, and its host name doesn't
934 match that of ADDRESS, the certificate is forgotten."
935 (if elpher-client-certificate
936 (if (string= (car elpher-client-certificate)
937 (elpher-address-host address))
938 (list (cddr elpher-client-certificate))
939 (elpher-forget-current-certificate)
940 (message "Disabling client certificate for new host")
945 ;;; Gopher selector retrieval
948 (defun elpher-get-gopher-response (address renderer)
949 "Get response string from gopher server at ADDRESS and render using RENDERER."
950 (elpher-get-host-response address 70
951 (concat (elpher-gopher-address-selector address) "\r\n")
953 (or (string= (elpher-address-protocol address) "gophers")
956 (defun elpher-get-gopher-page (renderer)
957 "Getter function for gopher pages.
958 The RENDERER procedure is used to display the contents of the page
959 once they are retrieved from the gopher server."
960 (let* ((address (elpher-page-address elpher-current-page))
961 (content (elpher-get-cached-content address)))
962 (if (and content (funcall renderer nil))
963 (elpher-with-clean-buffer
965 (elpher-restore-pos))
966 (elpher-with-clean-buffer
967 (insert "LOADING... (use 'u' to cancel)\n"))
968 (condition-case the-error
969 (elpher-get-gopher-response address renderer)
971 (elpher-network-error address the-error))))))
975 (defun elpher-insert-index (string)
976 "Insert the index corresponding to STRING into the current buffer."
977 ;; Should be able to split directly on CRLF, but some non-conformant
978 ;; LF-only servers sadly exist, hence the following.
979 (let ((str-processed (elpher-preprocess-text-response string)))
980 (dolist (line (split-string str-processed "\n"))
982 (unless (= (length line) 0)
983 (let* ((type (elt line 0))
984 (fields (split-string (substring line 1) "\t"))
985 (display-string (elt fields 0))
986 (selector (elt fields 1))
987 (host (elt fields 2))
988 (port (if (elt fields 3)
989 (string-to-number (elt fields 3))
991 (address (elpher-make-gopher-address type selector host port)))
992 (elpher-insert-index-record display-string address)))))))
994 (defun elpher-insert-margin (&optional type-name)
995 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
998 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
1000 (propertize "[" 'face 'elpher-margin-brackets)
1001 (propertize type-name 'face 'elpher-margin-key)
1002 (propertize "]" 'face 'elpher-margin-brackets))))
1004 (insert (make-string elpher-margin-width ?\s))))
1006 (defun elpher--page-button-help (_window buffer pos)
1007 "Function called by Emacs to generate mouse-over text.
1008 The arguments specify the BUFFER and the POS within the buffer of the item
1009 for which help is required. The function returns the help to be
1010 displayed. The _WINDOW argument is currently unused."
1011 (with-current-buffer buffer
1012 (let ((button (button-at pos)))
1014 (let* ((page (button-get button 'elpher-page))
1015 (address (elpher-page-address page)))
1016 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
1018 (elpher-address-to-url address))))))))
1020 (defun elpher-insert-index-record (display-string &optional address)
1021 "Function to insert an index record into the current buffer.
1022 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
1023 If ADDRESS is not supplied or nil the record is rendered as an
1024 'information' line."
1025 (let* ((type (if address (elpher-address-type address) nil))
1026 (type-map-entry (cdr (assoc type elpher-type-map))))
1028 (let* ((margin-code (elt type-map-entry 2))
1029 (face (elt type-map-entry 3))
1030 (filtered-display-string (elpher-color-filter-apply display-string))
1031 (page (elpher-make-page filtered-display-string address)))
1032 (elpher-insert-margin margin-code)
1033 (insert-text-button filtered-display-string
1036 'action #'elpher-click-link
1038 'help-echo #'elpher--page-button-help))
1040 ('nil ;; Information
1041 (elpher-insert-margin)
1042 (let ((propertized-display-string
1043 (propertize display-string 'face 'elpher-info)))
1044 (insert (elpher-process-text-for-display propertized-display-string))))
1045 (`(gopher ,selector-type) ;; Unknown
1046 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
1047 (insert (propertize display-string
1048 'face 'elpher-unknown)))))
1051 (defun elpher-click-link (button)
1052 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
1053 (let ((page (button-get button 'elpher-page)))
1054 (elpher-visit-page page)))
1056 (defun elpher-render-index (data &optional _mime-type-string)
1057 "Render DATA as an index. MIME-TYPE-STRING is unused."
1058 (elpher-with-clean-buffer
1061 (elpher-insert-index data)
1062 (elpher-cache-content (elpher-page-address elpher-current-page)
1067 (defconst elpher-url-regex
1068 "\\([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_~?/@|#-]\\)?\\)?"
1069 "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
1071 (defun elpher-buttonify-urls (string)
1072 "Turn substrings which look like urls in STRING into clickable buttons."
1075 (goto-char (point-min))
1076 (while (re-search-forward elpher-url-regex nil t)
1077 (let ((page (elpher-make-page (substring-no-properties (match-string 0))
1078 (elpher-address-from-url (match-string 0)))))
1079 (make-text-button (match-beginning 0)
1082 'action #'elpher-click-link
1084 'help-echo #'elpher--page-button-help
1088 (defconst elpher-ansi-regex "\x1b\\[[^m]*m"
1089 "Incomplete regexp used to strip out some troublesome ANSI escape sequences.")
1091 (defun elpher-process-text-for-display (string)
1092 "Perform any desired processing of STRING prior to display as text.
1093 Currently includes buttonifying URLs and processing ANSI escape codes."
1094 (elpher-buttonify-urls (if elpher-filter-ansi-from-text
1095 (elpher-color-filter-apply string)
1096 (elpher-color-apply string))))
1098 (defun elpher-render-text (data &optional _mime-type-string)
1099 "Render DATA as text. MIME-TYPE-STRING is unused."
1100 (elpher-with-clean-buffer
1103 (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
1104 (elpher-cache-content
1105 (elpher-page-address elpher-current-page)
1110 (defun elpher-render-image (data &optional _mime-type-string)
1111 "Display DATA as image. MIME-TYPE-STRING is unused."
1114 (if (display-images-p)
1116 (let ((image (create-image
1119 (elpher-with-clean-buffer
1120 (insert-image image)
1121 (elpher-restore-pos))))
1122 (elpher-render-download data))))
1124 ;; Search retrieval and rendering
1126 (defun elpher-get-gopher-query-page (renderer)
1127 "Getter for gopher addresses requiring input.
1128 The response is rendered using the rendering function RENDERER."
1129 (let* ((address (elpher-page-address elpher-current-page))
1130 (content (elpher-get-cached-content address))
1132 (if (and content (funcall renderer nil))
1133 (elpher-with-clean-buffer
1135 (elpher-restore-pos)
1136 (message "Displaying cached search results. Reload to perform a new search."))
1138 (let* ((query-string (read-string "Query: "))
1139 (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
1140 (search-address (elpher-make-gopher-address ?1
1142 (elpher-address-host address)
1143 (elpher-address-port address)
1144 (equal (elpher-address-type address) "gophers"))))
1147 (elpher-with-clean-buffer
1148 (insert "LOADING RESULTS... (use 'u' to cancel)"))
1149 (elpher-get-gopher-response search-address renderer))
1151 (elpher-visit-previous-page))))))
1153 ;; Raw server response rendering
1155 (defun elpher-render-raw (data &optional mime-type-string)
1156 "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
1159 (elpher-with-clean-buffer
1160 (when mime-type-string
1161 (insert "MIME type specified by server: '" mime-type-string "'\n"))
1163 (goto-char (point-min)))
1164 (message "Displaying raw server response. Reload or redraw to return to standard view.")))
1166 ;; File save "rendering"
1168 (defun elpher-render-download (data &optional _mime-type-string)
1169 "Save DATA to file. MIME-TYPE-STRING is unused."
1172 (let* ((address (elpher-page-address elpher-current-page))
1173 (selector (if (elpher-address-gopher-p address)
1174 (elpher-gopher-address-selector address)
1175 (elpher-address-filename address))))
1176 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1177 (let* ((filename-proposal (file-name-nondirectory selector))
1178 (filename (read-file-name "Download complete. Save file as: "
1180 (if (> (length filename-proposal) 0)
1183 (let ((coding-system-for-write 'binary))
1184 (with-temp-file filename
1186 (message (format "Saved to file %s." filename))))))
1190 (defun elpher-render-html (data &optional _mime-type-string)
1191 "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
1192 (elpher-with-clean-buffer
1195 (let ((dom (with-temp-buffer
1197 (libxml-parse-html-region (point-min) (point-max)))))
1198 (shr-insert-document dom)))))
1200 ;; Gemini page retrieval
1202 (defvar elpher-gemini-redirect-chain)
1204 (defun elpher-get-gemini-response (address renderer)
1205 "Get response string from gemini server at ADDRESS and render using RENDERER."
1206 (elpher-get-host-response address 1965
1207 (concat (elpher-address-to-url address) "\r\n")
1208 (lambda (response-string)
1209 (elpher-process-gemini-response response-string renderer))
1212 (defun elpher-parse-gemini-response (response)
1213 "Parse the RESPONSE string and return a list of components.
1214 The list is of the form (code meta body). A response of nil implies
1215 that the response was malformed."
1216 (let ((header-end-idx (string-match "\r\n" response)))
1218 (let ((header (string-trim (substring response 0 header-end-idx)))
1219 (body (substring response (+ header-end-idx 2))))
1220 (if (>= (length header) 2)
1221 (let ((code (substring header 0 2))
1222 (meta (string-trim (substring header 2))))
1223 (list code meta body))
1224 (error "Malformed response: No response status found in header %s" header)))
1225 (error "Malformed response: No CRLF-delimited header found in response %s" response))))
1227 (defun elpher-process-gemini-response (response-string renderer)
1228 "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
1229 (let ((response-components (elpher-parse-gemini-response response-string)))
1230 (let ((response-code (elt response-components 0))
1231 (response-meta (elt response-components 1))
1232 (response-body (elt response-components 2)))
1233 (pcase (elt response-code 0)
1234 (?1 ; Input required
1235 (elpher-with-clean-buffer
1236 (insert "Gemini server is requesting input."))
1237 (let* ((query-string
1238 (if (eq (elt response-code 1) ?1)
1239 (read-passwd (concat response-meta ": "))
1240 (read-string (concat response-meta ": "))))
1241 (query-address (seq-copy (elpher-page-address elpher-current-page)))
1242 (old-fname (url-filename query-address)))
1243 (setf (url-filename query-address)
1244 (concat old-fname "?" (url-build-query-string `((,query-string)))))
1245 (elpher-get-gemini-response query-address renderer)))
1246 (?2 ; Normal response
1247 (funcall renderer response-body response-meta))
1249 (message "Following redirect to %s" response-meta)
1250 (if (>= (length elpher-gemini-redirect-chain) 5)
1251 (error "More than 5 consecutive redirects followed"))
1252 (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
1253 (if (member redirect-address elpher-gemini-redirect-chain)
1254 (error "Redirect loop detected"))
1255 (if (not (string= (elpher-address-protocol redirect-address)
1257 (error "Server tried to automatically redirect to non-gemini URL: %s"
1259 (elpher-page-set-address elpher-current-page redirect-address)
1260 (add-to-list 'elpher-gemini-redirect-chain redirect-address)
1261 (elpher-get-gemini-response redirect-address renderer)))
1262 (?4 ; Temporary failure
1263 (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
1264 response-code response-meta))
1265 (?5 ; Permanent failure
1266 (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
1267 response-code response-meta))
1268 (?6 ; Client certificate required
1269 (elpher-with-clean-buffer
1270 (if elpher-client-certificate
1271 (insert "Gemini server does not recognise the provided TLS certificate:\n\n")
1272 (insert "Gemini server is requesting a valid TLS certificate:\n\n"))
1274 (elpher-gemini-insert-text response-meta))
1275 (let ((chosen-certificate (elpher-choose-client-certificate)))
1276 (unless chosen-certificate
1277 (error "Gemini server requires a client certificate and none was provided"))
1278 (setq elpher-client-certificate chosen-certificate))
1279 (elpher-with-clean-buffer)
1280 (elpher-get-gemini-response (elpher-page-address elpher-current-page) renderer))
1282 (error "Gemini server response unknown: %s %s"
1283 response-code response-meta))))))
1285 (defun elpher--read-answer-polyfill (question answers)
1286 "Polyfill for `read-answer' in Emacs 26.1.
1287 QUESTION is a string containing a question, and ANSWERS
1288 is a list of possible answers."
1289 (completing-read question (mapcar 'identity answers)))
1291 (if (fboundp 'read-answer)
1292 (defalias 'elpher-read-answer 'read-answer)
1293 (defalias 'elpher-read-answer 'elpher--read-answer-polyfill))
1295 (defun elpher-choose-client-certificate ()
1296 "Prompt for a client certificate to use to establish a TLS connection."
1297 (let* ((read-answer-short t))
1298 (pcase (read-answer "What do you want to do? "
1300 "generate and use throw-away certificate")
1302 "generate new or use existing persistent certificate")
1304 "stop immediately")))
1306 (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
1308 (let* ((existing-certificates (elpher-list-existing-certificates))
1309 (file-base (completing-read
1310 "Nickname for new or existing certificate (autocompletes, empty response aborts): "
1311 existing-certificates)))
1312 (if (string-empty-p (string-trim file-base))
1314 (if (member file-base existing-certificates)
1315 (setq elpher-client-certificate
1316 (elpher-get-existing-certificate file-base))
1317 (pcase (read-answer "Generate new certificate or install externally-generated one? "
1319 "generate new certificate")
1321 "install existing certificate")
1323 "stop immediately")))
1325 (let ((common-name (read-string "Common Name field for new certificate: "
1327 (message "New key and self-signed certificate written to %s"
1328 elpher-certificate-directory)
1329 (elpher-generate-persistent-certificate file-base common-name)))
1331 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
1332 (key-file (read-file-name "Key file: " nil nil t)))
1333 (message "Key and certificate installed in %s for future use"
1334 elpher-certificate-directory)
1335 (elpher-install-and-use-existing-certificate key-file
1341 (defun elpher-get-gemini-page (renderer)
1342 "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
1343 (let* ((address (elpher-page-address elpher-current-page))
1344 (content (elpher-get-cached-content address)))
1345 (condition-case the-error
1346 (if (and content (funcall renderer nil))
1347 (elpher-with-clean-buffer
1349 (elpher-restore-pos))
1350 (elpher-with-clean-buffer
1351 (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
1352 (setq elpher-gemini-redirect-chain nil)
1353 (elpher-get-gemini-response address renderer))
1355 (elpher-network-error address the-error)))))
1357 (defun elpher-render-gemini (body &optional mime-type-string)
1358 "Render gemini response BODY with rendering MIME-TYPE-STRING."
1361 (let* ((mime-type-string* (if (or (not mime-type-string)
1362 (string-empty-p mime-type-string))
1363 "text/gemini; charset=utf-8"
1365 (mime-type-split (split-string mime-type-string* ";" t))
1366 (mime-type (string-trim (car mime-type-split)))
1367 (parameters (mapcar (lambda (s)
1368 (let ((key-val (split-string s "=")))
1369 (list (downcase (string-trim (car key-val)))
1370 (downcase (string-trim (cadr key-val))))))
1371 (cdr mime-type-split))))
1372 (when (string-prefix-p "text/" mime-type)
1373 (setq body (decode-coding-string
1375 (if (assoc "charset" parameters)
1376 (intern (cadr (assoc "charset" parameters)))
1378 (setq body (replace-regexp-in-string "\r" "" body)))
1380 ((or "text/gemini" "")
1381 (elpher-render-gemini-map body parameters))
1383 (elpher-render-html body))
1384 ((pred (string-prefix-p "text/"))
1385 (elpher-render-gemini-plain-text body parameters))
1386 ((pred (string-prefix-p "image/"))
1387 (elpher-render-image body))
1389 (elpher-render-download body))))))
1391 (defun elpher-gemini-get-link-url (link-line)
1392 "Extract the url portion of LINK-LINE, a gemini map file link line.
1393 Returns nil in the event that the contents of the line following the
1394 => prefix are empty."
1395 (let ((l (split-string (substring link-line 2))))
1397 (string-trim (elt l 0))
1400 (defun elpher-gemini-get-link-display-string (link-line)
1401 "Extract the display string portion of LINK-LINE, a gemini map file link line.
1402 Returns the url portion in the event that the display-string portion is empty."
1403 (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
1404 (idx (string-match "[ \t]" rest)))
1405 (string-trim (if idx
1406 (substring rest (+ idx 1))
1409 (defun elpher-collapse-dot-sequences (filename)
1410 "Collapse dot sequences in FILENAME.
1411 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
1412 (let* ((path (split-string filename "/"))
1413 (path-reversed-normalized
1414 (seq-reduce (lambda (a b)
1415 (cond ((and a (equal b "..") (cdr a)))
1416 ((and (not a) (equal b "..")) a) ;leading .. are dropped
1420 (string-join (reverse path-reversed-normalized) "/")))
1422 (defun elpher-address-from-gemini-url (url)
1423 "Extract address from URL with defaults as per gemini map files.
1424 While there's obviously some redundancy here between this function and
1425 `elpher-address-from-url', gemini map file URLs require enough special
1426 treatment that a separate function is warranted."
1427 (let ((address (url-generic-parse-url url))
1428 (current-address (elpher-page-address elpher-current-page)))
1429 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
1430 (setf (url-fullness address) t)
1431 (if (url-host address) ;if there is an explicit host, filenames are absolute
1432 (if (string-empty-p (url-filename address))
1433 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
1434 (setf (url-host address) (url-host current-address))
1435 (setf (url-port address) (url-port current-address))
1436 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1437 (setf (url-filename address)
1438 (concat (file-name-directory (url-filename current-address))
1439 (url-filename address)))))
1440 (unless (url-type address)
1441 (setf (url-type address) "gemini"))
1442 (when (equal (url-type address) "gemini")
1443 (setf (url-filename address)
1444 (elpher-collapse-dot-sequences (url-filename address)))))
1445 (elpher-remove-redundant-ports address)))
1447 (defun elpher-gemini-insert-link (link-line)
1448 "Insert link described by LINK-LINE into a text/gemini document."
1449 (let* ((url (elpher-gemini-get-link-url link-line))
1450 (display-string (elpher-gemini-get-link-display-string link-line))
1451 (address (elpher-address-from-gemini-url url))
1452 (type (if address (elpher-address-type address) nil))
1453 (type-map-entry (cdr (assoc type elpher-type-map))))
1454 (when display-string
1455 (insert elpher-gemini-link-string)
1457 (let* ((face (elt type-map-entry 3))
1458 (filtered-display-string (elpher-color-filter-apply display-string))
1459 (page (elpher-make-page filtered-display-string address)))
1460 (insert-text-button filtered-display-string
1463 'action #'elpher-click-link
1465 'help-echo #'elpher--page-button-help))
1466 (insert (propertize display-string 'face 'elpher-unknown)))
1469 (defun elpher-gemini-insert-header (header-line)
1470 "Insert header described by HEADER-LINE into a text/gemini document.
1471 The gemini map file line describing the header is given
1473 (when (string-match "^\\(#+\\)[ \t]*" header-line)
1474 (let* ((level (length (match-string 1 header-line)))
1475 (header (substring header-line (match-end 0)))
1477 (1 'elpher-gemini-heading1)
1478 (2 'elpher-gemini-heading2)
1479 (3 'elpher-gemini-heading3)
1481 (fill-column (if (display-graphic-p)
1483 (font-get (font-spec :name (face-font 'default)) :size))
1484 (font-get (font-spec :name (face-font face)) :size)) fill-column)))
1485 (setq elpher--gemini-page-headings (cons (cons header (point))
1486 elpher--gemini-page-headings))
1487 (unless (display-graphic-p)
1488 (insert (make-string level ?#) " "))
1489 (insert (propertize header 'face face))
1492 (defun elpher-gemini-insert-text (text-line)
1493 "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
1494 This function uses Emacs' auto-fill to wrap text sensibly to a maximum
1495 width defined by `elpher-gemini-max-fill-width'."
1496 (string-match "\\(^[ \t]*\\)\\(\\*[ \t]+\\|>[ \t]*\\)?" text-line)
1497 (let* ((line-prefix (match-string 2 text-line))
1498 (processed-text-line
1500 (cond ((string-prefix-p "*" line-prefix)
1502 (replace-regexp-in-string "\\*"
1503 elpher-gemini-bullet-string
1504 (match-string 0 text-line))
1505 (substring text-line (match-end 0))))
1506 ((string-prefix-p ">" line-prefix)
1507 (propertize text-line 'face 'elpher-gemini-quoted))
1510 (adaptive-fill-mode t)
1511 ;; fill-prefix is important for adaptive-fill-mode: without
1512 ;; it, multi-line list items are not indented correct
1513 (fill-prefix (if (match-string 2 text-line)
1514 (replace-regexp-in-string "[>\*]" " " (match-string 0 text-line))
1516 (insert (elpher-process-text-for-display processed-text-line))
1519 (defun elpher-render-gemini-map (data _parameters)
1520 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1521 (elpher-with-clean-buffer
1522 (setq elpher--gemini-page-headings nil)
1523 (let ((preformatted nil))
1525 (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
1526 (dolist (line (split-string data "\n"))
1528 ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
1529 (preformatted (insert (elpher-process-text-for-display
1530 (propertize line 'face 'elpher-gemini-preformatted))
1532 ((string-prefix-p "=>" line)
1533 (elpher-gemini-insert-link line))
1534 ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
1535 (t (elpher-gemini-insert-text line)))))
1536 (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))
1537 (elpher-cache-content
1538 (elpher-page-address elpher-current-page)
1541 (defun elpher-render-gemini-plain-text (data _parameters)
1542 "Render DATA as plain text file. PARAMETERS is currently unused."
1543 (elpher-with-clean-buffer
1544 (insert (elpher-process-text-for-display data))
1545 (elpher-cache-content
1546 (elpher-page-address elpher-current-page)
1550 ;; Finger page connection
1552 (defun elpher-get-finger-page (renderer)
1553 "Opens a finger connection to the current page address.
1554 The result is rendered using RENDERER."
1555 (let* ((address (elpher-page-address elpher-current-page))
1556 (content (elpher-get-cached-content address)))
1557 (if (and content (funcall renderer nil))
1558 (elpher-with-clean-buffer
1560 (elpher-restore-pos))
1561 (elpher-with-clean-buffer
1562 (insert "LOADING... (use 'u' to cancel)\n"))
1563 (condition-case the-error
1564 (let* ((kill-buffer-query-functions nil)
1565 (user (let ((filename (elpher-address-filename address)))
1566 (if (> (length filename) 1)
1567 (substring filename 1)
1568 (elpher-address-user address)))))
1569 (elpher-get-host-response address 79
1570 (concat user "\r\n")
1573 (elpher-network-error address the-error))))))
1576 ;; Telnet page connection
1578 (defun elpher-get-telnet-page (renderer)
1579 "Opens a telnet connection to the current page address (RENDERER must be nil)."
1581 (elpher-visit-previous-page)
1582 (error "Command not supported for telnet URLs"))
1583 (let* ((address (elpher-page-address elpher-current-page))
1584 (host (elpher-address-host address))
1585 (port (elpher-address-port address)))
1586 (elpher-visit-previous-page)
1592 ;; Other URL page opening
1594 (defun elpher-get-other-url-page (renderer)
1595 "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
1597 (elpher-visit-previous-page)
1598 (error "Command not supported for general URLs"))
1599 (let* ((address (elpher-page-address elpher-current-page))
1600 (url (elpher-address-to-url address)))
1602 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1603 (message "Opening URL...")
1604 (if elpher-open-urls-with-eww
1606 (browse-url url)))))
1609 ;; Start page retrieval
1611 (defun elpher-get-start-page (renderer)
1612 "Getter which displays the start page (RENDERER must be nil)."
1614 (elpher-visit-previous-page)
1615 (error "Command not supported for start page"))
1616 (elpher-with-clean-buffer
1617 (insert " --------------------------------------------\n"
1618 " Elpher Gopher and Gemini Client \n"
1619 " version " elpher-version "\n"
1620 " --------------------------------------------\n"
1622 "Default bindings:\n"
1624 " - TAB/Shift-TAB: next/prev item on current page\n"
1625 " - RET/mouse-1: open item under cursor\n"
1626 " - m: select an item on current page by name (autocompletes)\n"
1627 " - u/mouse-3/U: return to previous page or to the start page\n"
1628 " - g: go to a particular address (gopher, gemini, finger)\n"
1629 " - o/O: open a different address selector or the root menu of the current server\n"
1630 " - d/D: download item under cursor or current page\n"
1631 " - i/I: info on item under cursor or current page\n"
1632 " - c/C: copy URL representation of item under cursor or current page\n"
1633 " - a/A: bookmark the item under cursor or current page\n"
1634 " - B: list all bookmarks\n"
1635 " - s/S: show current history stack or all previously visted pages\n"
1636 " - r: redraw current page (using cached contents if available)\n"
1637 " - R: reload current page (regenerates cache)\n"
1638 " - !: set character coding system for gopher (default is to autodetect)\n"
1639 " - T: toggle TLS gopher mode\n"
1640 " - F: forget/discard current TLS client certificate\n"
1641 " - .: display the raw server response for the current page\n"
1643 "Start your exploration of gopher space and gemini:\n")
1644 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1645 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1646 (elpher-insert-index-record "Project Gemini home page"
1647 (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
1649 "Alternatively, select a search engine and enter some search terms:\n")
1650 (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
1651 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1652 (elpher-insert-index-record "Gemini Search Engine (geminispace.info)"
1653 (elpher-address-from-url "gemini://geminispace.info/search"))
1655 "Your bookmarks are stored in your ")
1656 (let ((help-string "RET,mouse-1: Open Emacs bookmark list"))
1657 (insert-text-button "Emacs bookmark list"
1661 (call-interactively #'elpher-open-bookmarks))
1663 'help-echo help-string))
1666 "(Bookmarks from legacy elpher-bookmarks files will be automatically imported.)\n"
1669 "For Elpher release news or to leave feedback, visit:\n")
1670 (elpher-insert-index-record "The Elpher Project Page"
1671 (elpher-make-gopher-address ?1
1677 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1678 (insert-text-button "Elpher info manual"
1684 'help-echo help-string))
1685 (insert " for the full documentation. **\n")
1687 (concat " (This should be available if you have installed Elpher using\n"
1688 " MELPA. Otherwise you will have to install the manual yourself.)\n")
1690 (elpher-restore-pos)))
1692 ;; History page retrieval
1694 (defun elpher-show-history ()
1695 "Show the current contents of elpher's history stack.
1696 Use \\[elpher-show-visited-pages] to see the entire history.
1697 This is rendered using `elpher-get-history-page' via `elpher-type-map'."
1700 (elpher-make-page "Current History Stack"
1701 (elpher-make-special-address 'history))))
1703 (defun elpher-show-visited-pages ()
1704 "Show the all the pages you've visited using Elpher.
1705 Use \\[elpher-show-history] to see just the current history stack.
1706 This is rendered using `elpher-get-visited-pages-page' via `elpher-type-map'."
1709 (elpher-make-page "Elpher Visted Pages"
1710 (elpher-make-special-address 'visited-pages))))
1712 (defun elpher-get-history-page (renderer)
1713 "Getter which displays the history page (RENDERER must be nil)."
1715 (elpher-visit-previous-page)
1716 (error "Command not supported for history page"))
1717 (elpher-display-history-links elpher-history "Current history stack"))
1719 (defun elpher-get-visited-pages-page (renderer)
1720 "Getter which displays the list of visited pages (RENDERER must be nil)."
1722 (elpher-visit-previous-page)
1723 (error "Command not supported for history page"))
1724 (elpher-display-history-links
1725 (seq-filter (lambda (page)
1726 (not (elpher-address-special-p (elpher-page-address page))))
1727 elpher-visited-pages)
1728 "All visited pages"))
1730 (defun elpher-display-history-links (pages title)
1731 "Show all PAGES in an Elpher buffer with a given TITLE."
1732 (let* ((title-line (concat "---- " title " ----"))
1733 (footer-line (make-string (length title-line) ?-)))
1734 (elpher-with-clean-buffer
1735 (insert title-line "\n\n")
1737 (dolist (page pages)
1739 (let ((display-string (elpher-page-display-string page))
1740 (address (elpher-page-address page)))
1741 (elpher-insert-index-record display-string address))))
1742 (insert "No history items found.\n"))
1743 (insert "\n" footer-line "\n"
1744 "Select and entry or press 'u' to return to the previous page.")
1745 (elpher-restore-pos))))
1750 ;; This code allows Elpher to use the standard Emacs bookmarks: `C-x r
1751 ;; m' to add a bookmark, `C-x r l' to list bookmarks (which is where
1752 ;; you can anotate bookmarks!), `C-x r b' to jump to a bookmark, and
1753 ;; so on. See the Bookmarks section in the Emacs info manual for more.
1755 (defvar elpher-bookmark-link nil
1756 "Prefer bookmarking a link or the current page.
1757 Bind this variable dynamically, or set it to t.
1758 If you set it to t, the commands \\[bookmark-set-no-overwrite]
1759 and \\[elpher-set-bookmark-no-overwrite] do the same thing.")
1761 (defun elpher-bookmark-make-record ()
1762 "Return a bookmark record.
1763 If `elpher-bookmark-link' is non-nil and point is on a link button,
1764 return a bookmark record for that link. Otherwise, return a bookmark
1765 record for the current elpher page."
1766 (let* ((button (and elpher-bookmark-link (button-at (point))))
1768 (button-get button 'elpher-page)
1769 elpher-current-page))
1770 (address (elpher-page-address page))
1771 (url (elpher-address-to-url address))
1772 (display-string (elpher-page-display-string page))
1773 (pos (if button nil (point))))
1774 (if (elpher-address-special-p address)
1775 (error "Cannot bookmark %s" display-string)
1777 (defaults . (,display-string))
1780 (handler . elpher-bookmark-jump)))))
1783 (defun elpher-bookmark-jump (bookmark)
1784 "Go to a particular BOOKMARK."
1785 (let* ((url (cdr (assq 'location bookmark))))
1788 (defun elpher-bookmark-link ()
1789 "Bookmark the link at point.
1790 To bookmark the current page, use \\[elpher-bookmark-current]."
1792 (let ((elpher-bookmark-link t))
1793 (bookmark-set-no-overwrite)))
1795 (defun elpher-bookmark-current ()
1796 "Bookmark the current page.
1797 To bookmark the link at point use \\[elpher-bookmark-link]."
1799 (call-interactively #'bookmark-set-no-overwrite))
1801 (defun elpher-bookmark-import (file)
1802 "Import legacy Elpher bookmarks file FILE into Emacs bookmarks."
1803 (interactive (list (if (and (boundp 'elpher-bookmarks-file)
1804 (file-readable-p elpher-bookmarks-file))
1805 elpher-bookmarks-file
1806 (read-file-name "Old Elpher bookmarks: "
1807 user-emacs-directory nil t
1808 "elpher-bookmarks"))))
1810 (dolist (bookmark (with-temp-buffer
1811 (insert-file-contents file)
1812 (read (current-buffer))))
1813 (let* ((display-string (car bookmark))
1814 (url (cadr bookmark))
1815 (record `(,display-string
1817 (handler . elpher-bookmark-jump))))
1818 (bookmark-store display-string (cdr record) t)))
1821 (defun elpher-open-bookmarks ()
1822 "Display the current list of elpher bookmarks.
1823 This is just a call to `bookmark-bmenu-list', but we also check for a legacy
1824 bookmark file and offer to import it."
1826 (let ((old-bookmarks-file (or (and (boundp 'elpher-bookmarks-file)
1827 elpher-bookmarks-file)
1828 (locate-user-emacs-file "elpher-bookmarks"))))
1829 (when (and (file-readable-p old-bookmarks-file)
1830 (y-or-n-p (concat "Legacy elpher-bookmarks file \""
1832 "\" found. Import now?")))
1833 (elpher-bookmark-import old-bookmarks-file)
1834 (rename-file old-bookmarks-file (concat old-bookmarks-file "-legacy"))))
1835 (call-interactively #'bookmark-bmenu-list))
1843 (defun elpher-org-export-link (link description format protocol)
1844 "Export a LINK with DESCRIPTION for the given PROTOCOL and FORMAT.
1846 FORMAT is an Org export backend. DESCRIPTION may be nil. PROTOCOL may be one
1847 of gemini, gopher or finger."
1848 (let* ((url (if (equal protocol "elpher")
1849 (string-remove-prefix "elpher:" link)
1850 (format "%s:%s" protocol link)))
1851 (desc (or description url)))
1853 (`gemini (format "=> %s %s" url desc))
1854 (`html (format "<a href=\"%s\">%s</a>" url desc))
1855 (`latex (format "\\href{%s}{%s}" url desc))
1856 (_ (if (not description)
1858 (format "%s (%s)" desc url))))))
1860 (defun elpher-org-store-link ()
1861 "Store link to an `elpher' page in Org."
1862 (when (eq major-mode 'elpher-mode)
1863 (let* ((url (elpher-info-current))
1864 (desc (car elpher-current-page))
1866 ((string-prefix-p "gemini:" url) "gemini")
1867 ((string-prefix-p "gopher:" url) "gopher")
1868 ((string-prefix-p "finger:" url) "finger")
1870 (when (equal "elpher" protocol)
1871 ;; Weird link. Or special inner link?
1872 (setq url (concat "elpher:" url)))
1873 (org-link-store-props :type protocol :link url :description desc)
1876 (defun elpher-org-follow-link (link protocol)
1877 "Visit a LINK for the given PROTOCOL.
1879 PROTOCOL may be one of gemini, gopher or finger. This method also
1880 supports the old protocol elpher, where the link is self-contained."
1881 (let ((url (if (equal protocol "elpher")
1882 (string-remove-prefix "elpher:" link)
1883 (format "%s:%s" protocol link))))
1886 (defun elpher-org-mode-integration ()
1887 "Set up `elpher' integration for `org-mode'."
1888 (org-link-set-parameters
1890 :store #'elpher-org-store-link
1891 :export (lambda (link description format _plist)
1892 (elpher-org-export-link link description format "elpher"))
1893 :follow (lambda (link _arg) (elpher-org-follow-link link "elpher")))
1894 (org-link-set-parameters
1896 :export (lambda (link description format _plist)
1897 (elpher-org-export-link link description format "gemini"))
1898 :follow (lambda (link _arg) (elpher-org-follow-link link "gemini")))
1899 (org-link-set-parameters
1901 :export (lambda (link description format _plist)
1902 (elpher-org-export-link link description format "gopher"))
1903 :follow (lambda (link _arg) (elpher-org-follow-link link "gopher")))
1904 (org-link-set-parameters
1906 :export (lambda (link description format _plist)
1907 (elpher-org-export-link link description format "finger"))
1908 :follow (lambda (link _arg) (elpher-org-follow-link link "finger"))))
1910 (add-hook 'org-mode-hook #'elpher-org-mode-integration)
1915 (defun elpher-browse-url-elpher (url &rest _args)
1916 "Browse URL using Elpher. This function is used by `browse-url'."
1917 (interactive (browse-url-interactive-arg "Elpher URL: "))
1920 ;; Use elpher to open gopher, finger and gemini links
1921 ;; For recent version of `browse-url' package
1922 (if (boundp 'browse-url-default-handlers)
1924 'browse-url-default-handlers
1925 '("^\\(gopher\\|finger\\|gemini\\)://" . elpher-browse-url-elpher))
1926 ;; Patch `browse-url-browser-function' for older ones. The value of
1927 ;; that variable is `browse-url-default-browser' by default, so
1928 ;; that's the function that gets advised.
1929 (advice-add browse-url-browser-function :before-while
1930 (lambda (url &rest _args)
1931 "Handle gemini, gopher, and finger schemes using Elpher."
1932 (let ((scheme (downcase (car (split-string url ":" t)))))
1933 (if (member scheme '("gemini" "gopher" "finger"))
1934 ;; `elpher-go' always returns nil, which will stop the
1935 ;; advice chain here in a before-while
1937 ;; chain must continue, then return t.
1940 ;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
1941 (with-eval-after-load 'thingatpt
1942 (add-to-list 'thing-at-point-uri-schemes "gemini://"))
1946 ;; Make mu4e aware of the gemini world
1947 (setq mu4e~view-beginning-of-url-regexp
1948 "\\(?:https?\\|gopher\\|finger\\|gemini\\)://\\|mailto:")
1950 ;;; Interactive procedures
1953 (defun elpher-next-link ()
1954 "Move point to the next link on the current page."
1958 (defun elpher-prev-link ()
1959 "Move point to the previous link on the current page."
1961 (backward-button 1))
1963 (defun elpher-follow-current-link ()
1964 "Open the link or url at point."
1969 (defun elpher-go (host-or-url)
1970 "Go to a particular gopher site HOST-OR-URL.
1971 When run interactively HOST-OR-URL is read from the minibuffer."
1972 (interactive "sGopher or Gemini URL: ")
1973 (let* ((cleaned-host-or-url (string-trim host-or-url))
1974 (address (elpher-address-from-url cleaned-host-or-url))
1975 (page (elpher-make-page cleaned-host-or-url address)))
1976 (switch-to-buffer elpher-buffer-name)
1977 (elpher-with-clean-buffer
1978 (elpher-visit-page page))
1981 (defun elpher-go-current ()
1982 "Go to a particular site read from the minibuffer, initialized with the current URL."
1984 (let ((address (elpher-page-address elpher-current-page)))
1985 (let ((url (read-string "Gopher or Gemini URL: "
1986 (unless (elpher-address-special-p address)
1987 (elpher-address-to-url address)))))
1988 (elpher-visit-page (elpher-make-page url (elpher-address-from-url url))))))
1990 (defun elpher-redraw ()
1991 "Redraw current page."
1993 (elpher-visit-page elpher-current-page))
1995 (defun elpher-reload ()
1996 "Reload current page."
1998 (elpher-reload-current-page))
2000 (defun elpher-toggle-tls ()
2001 "Toggle TLS encryption mode for gopher."
2003 (setq elpher-use-tls (not elpher-use-tls))
2005 (if (gnutls-available-p)
2006 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
2007 (setq elpher-use-tls nil)
2008 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
2009 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
2011 (defun elpher-view-raw ()
2012 "View raw server response for current page."
2014 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2015 (error "This page was not generated by a server")
2016 (elpher-visit-page elpher-current-page
2017 #'elpher-render-raw)))
2019 (defun elpher-back ()
2020 "Go to previous site."
2022 (elpher-visit-previous-page))
2024 (defun elpher-back-to-start ()
2025 "Go all the way back to the start page."
2027 (setq-local elpher-current-page nil)
2028 (setq-local elpher-history nil)
2029 (elpher-visit-page (elpher-make-start-page)))
2031 (defun elpher-download ()
2032 "Download the link at point."
2034 (let ((button (button-at (point))))
2036 (let ((page (button-get button 'elpher-page)))
2037 (if (elpher-address-special-p (elpher-page-address page))
2038 (error "Cannot download %s"
2039 (elpher-page-display-string page))
2040 (elpher-visit-page (button-get button 'elpher-page)
2041 #'elpher-render-download)))
2042 (error "No link selected"))))
2044 (defun elpher-download-current ()
2045 "Download the current page."
2047 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2048 (error "Cannot download %s"
2049 (elpher-page-display-string elpher-current-page))
2050 (elpher-visit-page (elpher-make-page
2051 (elpher-page-display-string elpher-current-page)
2052 (elpher-page-address elpher-current-page))
2053 #'elpher-render-download
2056 (defun elpher--build-link-map ()
2057 "Build alist mapping link names to destination pages in current buffer."
2058 (let ((link-map nil)
2059 (b (next-button (point-min) t)))
2061 (push (cons (button-label b) b) link-map)
2062 (setq b (next-button (button-start b))))
2065 (defun elpher-jump ()
2066 "Select a directory entry by name. Similar to the info browser (m)enu command."
2068 (let* ((link-map (elpher--build-link-map)))
2070 (let ((key (let ((completion-ignore-case t))
2071 (completing-read "Directory item/link: "
2073 (if (and key (> (length key) 0))
2074 (let ((b (cdr (assoc key link-map))))
2075 (goto-char (button-start b))
2076 (button-activate b)))))))
2078 (defun elpher-root-dir ()
2079 "Visit root of current server."
2081 (let ((address (elpher-page-address elpher-current-page)))
2082 (if (not (elpher-address-special-p address))
2083 (if (or (member (url-filename address) '("/" ""))
2084 (and (elpher-address-gopher-p address)
2085 (= (length (elpher-gopher-address-selector address)) 0)))
2086 (error "Already at root directory of current server")
2087 (let ((address-copy (elpher-address-from-url
2088 (elpher-address-to-url address))))
2089 (setf (url-filename address-copy) "")
2090 (elpher-go (elpher-address-to-url address-copy))))
2091 (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
2093 (defun elpher-info-page (page)
2094 "Display information on PAGE."
2095 (let ((display-string (elpher-page-display-string page))
2096 (address (elpher-page-address page)))
2097 (if (elpher-address-special-p address)
2098 (message "Special page: %s" display-string)
2099 (message "%s" (elpher-address-to-url address)))))
2101 (defun elpher-info-link ()
2102 "Display information on page corresponding to link at point."
2104 (let ((button (button-at (point))))
2106 (elpher-info-page (button-get button 'elpher-page))
2107 (error "No item selected"))))
2109 (defun elpher-info-current ()
2110 "Display information on current page."
2112 (elpher-info-page elpher-current-page))
2114 (defun elpher-copy-page-url (page)
2115 "Copy URL representation of address of PAGE to `kill-ring'."
2116 (let ((address (elpher-page-address page)))
2117 (if (elpher-address-special-p address)
2118 (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
2119 (let ((url (elpher-address-to-url address)))
2120 (message "Copied \"%s\" to kill-ring/clipboard." url)
2123 (defun elpher-copy-link-url ()
2124 "Copy URL of item at point to `kill-ring'."
2126 (let ((button (button-at (point))))
2128 (elpher-copy-page-url (button-get button 'elpher-page))
2129 (error "No item selected"))))
2131 (defun elpher-copy-current-url ()
2132 "Copy URL of current page to `kill-ring'."
2134 (elpher-copy-page-url elpher-current-page))
2136 (defun elpher-set-gopher-coding-system ()
2137 "Specify an explicit character coding system for gopher selectors."
2139 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
2140 (setq elpher-user-coding-system system)
2142 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
2143 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
2149 (defvar elpher-mode-map
2150 (let ((map (make-sparse-keymap)))
2151 (define-key map (kbd "TAB") 'elpher-next-link)
2152 (define-key map (kbd "<backtab>") 'elpher-prev-link)
2153 (define-key map (kbd "C-M-i") 'elpher-prev-link)
2154 (define-key map (kbd "u") 'elpher-back)
2155 (define-key map (kbd "-") 'elpher-back)
2156 (define-key map (kbd "^") 'elpher-back)
2157 (define-key map [mouse-3] 'elpher-back)
2158 (define-key map (kbd "U") 'elpher-back-to-start)
2159 (define-key map (kbd "g") 'elpher-go)
2160 (define-key map (kbd "o") 'elpher-go-current)
2161 (define-key map (kbd "O") 'elpher-root-dir)
2162 (define-key map (kbd "s") 'elpher-show-history)
2163 (define-key map (kbd "S") 'elpher-show-visited-pages)
2164 (define-key map (kbd "r") 'elpher-redraw)
2165 (define-key map (kbd "R") 'elpher-reload)
2166 (define-key map (kbd "T") 'elpher-toggle-tls)
2167 (define-key map (kbd ".") 'elpher-view-raw)
2168 (define-key map (kbd "d") 'elpher-download)
2169 (define-key map (kbd "D") 'elpher-download-current)
2170 (define-key map (kbd "m") 'elpher-jump)
2171 (define-key map (kbd "i") 'elpher-info-link)
2172 (define-key map (kbd "I") 'elpher-info-current)
2173 (define-key map (kbd "c") 'elpher-copy-link-url)
2174 (define-key map (kbd "C") 'elpher-copy-current-url)
2175 (define-key map (kbd "a") 'elpher-bookmark-link)
2176 (define-key map (kbd "A") 'elpher-bookmark-current)
2177 (define-key map (kbd "B") 'elpher-open-bookmarks)
2178 (define-key map (kbd "!") 'elpher-set-gopher-coding-system)
2179 (define-key map (kbd "F") 'elpher-forget-current-certificate)
2180 (when (fboundp 'evil-define-key*)
2183 (kbd "TAB") 'elpher-next-link
2184 (kbd "C-") 'elpher-follow-current-link
2185 (kbd "C-t") 'elpher-back
2186 (kbd "u") 'elpher-back
2187 (kbd "-") 'elpher-back
2188 (kbd "^") 'elpher-back
2189 [mouse-3] 'elpher-back
2190 (kbd "U") 'elpher-back-to-start
2191 (kbd "g") 'elpher-go
2192 (kbd "o") 'elpher-go-current
2193 (kbd "O") 'elpher-root-dir
2194 (kbd "s") 'elpher-show-history
2195 (kbd "S") 'elpher-show-visited-pages
2196 (kbd "r") 'elpher-redraw
2197 (kbd "R") 'elpher-reload
2198 (kbd "T") 'elpher-toggle-tls
2199 (kbd ".") 'elpher-view-raw
2200 (kbd "d") 'elpher-download
2201 (kbd "D") 'elpher-download-current
2202 (kbd "m") 'elpher-jump
2203 (kbd "i") 'elpher-info-link
2204 (kbd "I") 'elpher-info-current
2205 (kbd "c") 'elpher-copy-link-url
2206 (kbd "C") 'elpher-copy-current-url
2207 (kbd "a") 'elpher-bookmark-link
2208 (kbd "A") 'elpher-bookmark-current
2209 (kbd "B") 'elpher-open-bookmarks
2210 (kbd "!") 'elpher-set-gopher-coding-system
2211 (kbd "F") 'elpher-forget-current-certificate))
2213 "Keymap for gopher client.")
2215 (define-derived-mode elpher-mode special-mode "elpher"
2216 "Major mode for elpher, an elisp gopher client.
2218 This mode is automatically enabled by the interactive
2219 functions which initialize the client, namely
2220 `elpher', and `elpher-go'."
2221 (setq-local elpher--gemini-page-headings nil)
2222 (setq-local elpher-current-page nil)
2223 (setq-local elpher-history nil)
2224 (setq-local elpher-buffer-name (buffer-name))
2225 (setq-local bookmark-make-record-function #'elpher-bookmark-make-record)
2226 (setq-local imenu-create-index-function (lambda () elpher--gemini-page-headings)))
2228 (when (fboundp 'evil-set-initial-state)
2229 (evil-set-initial-state 'elpher-mode 'motion))
2232 ;;; Main start procedure
2236 (defun elpher (&optional arg)
2237 "Start elpher with default landing page.
2238 The buffer used for Elpher sessions is determined by the value of
2239 ‘elpher-buffer-name’. If there is already an Elpher session active in
2240 that buffer, Emacs will simply switch to it. Otherwise, a new session
2241 will begin. A numeric prefix ARG (as in ‘\\[universal-argument] 42
2242 \\[execute-extended-command] elpher RET’) switches to the session with
2243 that number, creating it if necessary. A non numeric prefix ARG means
2244 to create a new session. Returns the buffer selected (or created)."
2246 (let* ((name (default-value 'elpher-buffer-name))
2247 (buf (cond ((numberp arg)
2248 (get-buffer-create (format "%s<%d>" name arg)))
2250 (generate-new-buffer name))
2252 (get-buffer-create name)))))
2253 (pop-to-buffer-same-window buf)
2254 (unless (buffer-modified-p)
2256 (elpher-visit-page (elpher-make-start-page))
2257 "Started Elpher."))); Otherwise (elpher) evaluates to start page string.
2259 ;;; elpher.el ends here