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://alexschroeder.ch/cgit/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, https://alexschroeder.ch/cgit/elpher.
84 ;;; ANSI colors or XTerm colors
86 (or (require 'xterm-color nil t)
87 (require 'ansi-color))
89 (defalias 'elpher-color-filter-apply
90 (if (fboundp 'xterm-color-filter)
92 (let ((xterm-color-render nil))
93 (xterm-color-filter s)))
94 'ansi-color-filter-apply)
95 "A function to filter out ANSI escape sequences.")
96 (defalias 'elpher-color-apply
97 (if (fboundp 'xterm-color-filter)
100 "A function to apply ANSI escape sequences.")
105 (defconst elpher-version "2.11.0"
106 "Current version of elpher.")
108 (defconst elpher-margin-width 6
109 "Width of left-hand margin used when rendering indicies.")
111 (defconst elpher-type-map
112 '(((gopher ?0) elpher-get-gopher-page elpher-render-text "txt" elpher-text)
113 ((gopher ?1) elpher-get-gopher-page elpher-render-index "/" elpher-index)
114 ((gopher ?4) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
115 ((gopher ?5) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
116 ((gopher ?7) elpher-get-gopher-query-page elpher-render-index "?" elpher-search)
117 ((gopher ?9) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
118 ((gopher ?g) elpher-get-gopher-page elpher-render-image "img" elpher-image)
119 ((gopher ?p) elpher-get-gopher-page elpher-render-image "img" elpher-image)
120 ((gopher ?I) elpher-get-gopher-page elpher-render-image "img" elpher-image)
121 ((gopher ?d) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
122 ((gopher ?P) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
123 ((gopher ?s) elpher-get-gopher-page elpher-render-download "snd" elpher-binary)
124 ((gopher ?h) elpher-get-gopher-page elpher-render-html "htm" elpher-html)
125 (gemini elpher-get-gemini-page elpher-render-gemini "gem" elpher-gemini)
126 (finger elpher-get-finger-page elpher-render-text "txt" elpher-text)
127 (telnet elpher-get-telnet-page nil "tel" elpher-telnet)
128 (other-url elpher-get-other-url-page nil "url" elpher-other-url)
129 ((special start) elpher-get-start-page nil)
130 ((special history) elpher-get-history-page nil)
131 ((special history-all) elpher-get-history-all-page nil))
132 "Association list from types to getters, renderers, margin codes and index faces.")
135 ;;; Internal variables
139 (defvar elpher--gemini-page-headings nil
140 "List of headings on the page.")
143 ;;; Customization group
147 "A gopher and gemini client."
148 :group 'applications)
150 ;; General appearance and customizations
152 (defcustom elpher-open-urls-with-eww nil
153 "If non-nil, open URL selectors using eww.
154 Otherwise, use the system browser via the `browse-url' function."
157 (defcustom elpher-use-header t
158 "If non-nil, display current page information in buffer header."
161 (defcustom elpher-auto-disengage-TLS nil
162 "If non-nil, automatically disengage TLS following an unsuccessful connection.
163 While enabling this may seem convenient, it is also potentially
164 dangerous as it allows switching from an encrypted channel back to
165 plain text without user input."
168 (defcustom elpher-connection-timeout 5
169 "Specifies the number of seconds to wait for a network connection to time out."
172 (defcustom elpher-filter-ansi-from-text nil
173 "If non-nil, filter ANSI escape sequences from text.
174 The default behaviour is to use the ansi-color package to interpret these
178 (defcustom elpher-certificate-directory
179 (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
180 "Specify the name of the directory where client certificates will be stored.
181 These certificates may be used for establishing authenticated TLS connections."
184 (defcustom elpher-openssl-command "openssl"
185 "The command used to launch openssl when generating TLS client certificates."
188 (defcustom elpher-default-url-type "gopher"
189 "Default URL type (i.e. scheme) to assume if not explicitly given."
190 :type '(choice (const "gopher")
193 (defcustom elpher-gemini-TLS-cert-checks nil
194 "If non-nil, verify gemini server TLS certs using the default security level.
195 Otherwise, certificate verification is disabled.
197 This defaults to off because it is standard practice for Gemini servers
198 to use self-signed certificates, meaning that most servers provide what
199 EMACS considers to be an invalid certificate."
202 (defcustom elpher-gemini-max-fill-width 80
203 "Specify the maximum default width (in columns) of text/gemini documents.
204 The actual width used is the minimum of this value and the window width at
205 the time when the text is rendered."
208 (defcustom elpher-gemini-link-string "→ "
209 "Specify the string used to indicate links when rendering gemini maps.
213 (defcustom elpher-gemini-bullet-string "•"
214 "Specify the string used for bullets when rendering gemini maps."
217 (defcustom elpher-ipv4-always nil
218 "If non-nil, elpher will always use IPv4 to establish network connections.
219 This can be useful when browsing from a computer that supports IPv6, because
220 some servers which do not support IPv6 can take a long time to time-out."
223 (defcustom elpher-socks-always nil
224 "If non-nil, elpher will establish network connections over a SOCKS proxy.
225 Otherwise, the SOCKS proxy is only used for connections to onion services."
228 (defcustom elpher-number-links nil
229 "If non-nil, number links in pages when rendering.
230 Links can be followed numerically by pressing `M' and entering by the link number."
233 ;; Face customizations
235 (defgroup elpher-faces nil
236 "Elpher face customizations."
239 (defface elpher-index
240 '((t :inherit font-lock-keyword-face))
241 "Face used for directory type directory records.")
245 "Face used for text type directory records.")
248 '((t :inherit default))
249 "Face used for info type directory records.")
251 (defface elpher-image
252 '((t :inherit font-lock-string-face))
253 "Face used for image type directory records.")
255 (defface elpher-search
256 '((t :inherit warning))
257 "Face used for search type directory records.")
260 '((t :inherit font-lock-comment-face))
261 "Face used for html type directory records.")
263 (defface elpher-gemini
264 '((t :inherit font-lock-constant-face))
265 "Face used for Gemini type directory records.")
267 (defface elpher-other-url
268 '((t :inherit font-lock-comment-face))
269 "Face used for other URL type links records.")
271 (defface elpher-telnet
272 '((t :inherit font-lock-function-name-face))
273 "Face used for telnet type directory records.")
275 (defface elpher-binary
276 '((t :inherit font-lock-doc-face))
277 "Face used for binary type directory records.")
279 (defface elpher-unknown
280 '((t :inherit error))
281 "Face used for directory records with unknown/unsupported types.")
283 (defface elpher-margin-key
285 "Face used for directory margin key.")
287 (defface elpher-margin-brackets
288 '((t :inherit shadow))
289 "Face used for brackets around directory margin key.")
291 (defface elpher-gemini-heading1
292 '((t :inherit bold :height 1.8))
293 "Face used for gemini heading level 1.")
295 (defface elpher-gemini-heading2
296 '((t :inherit bold :height 1.5))
297 "Face used for gemini heading level 2.")
299 (defface elpher-gemini-heading3
300 '((t :inherit bold :height 1.2))
301 "Face used for gemini heading level 3.")
303 (defface elpher-gemini-preformatted
304 '((t :inherit fixed-pitch))
305 "Face used for pre-formatted gemini text blocks.")
307 (defface elpher-gemini-quoted
308 '((t :inherit font-lock-doc-face))
309 "Face used for gemini quoted texts.")
316 ;; An elpher "address" object is either a url object or a symbol.
317 ;; Symbol addresses are "special", corresponding to pages generated
318 ;; dynamically for and by elpher. All others represent pages which
319 ;; rely on content retrieved over the network.
321 (defun elpher-address-from-url (url-string)
322 "Create a ADDRESS object corresponding to the given URL-STRING."
323 (let ((data (match-data))) ; Prevent parsing clobbering match data
325 (let ((url (url-generic-parse-url url-string)))
326 (unless (and (not (url-fullness url)) (url-type url))
327 (setf (url-fullness url) t)
328 (unless (url-type url)
329 (setf (url-type url) elpher-default-url-type))
330 (unless (url-host url)
331 (let ((p (split-string (url-filename url) "/" nil nil)))
332 (setf (url-host url) (car p))
333 (setf (url-filename url)
335 (concat "/" (mapconcat #'identity (cdr p) "/"))
337 (when (or (equal "gopher" (url-type url))
338 (equal "gophers" (url-type url)))
340 (when (or (equal (url-filename url) "")
341 (equal (url-filename url) "/"))
342 (setf (url-filename url) "/1")))
343 (when (equal "gemini" (url-type url))
345 (if (equal (url-filename url) "")
346 (setf (url-filename url) "/"))))
347 (elpher-remove-redundant-ports url))
348 (set-match-data data))))
350 (defun elpher-remove-redundant-ports (address)
351 "Remove redundant port specifiers from ADDRESS.
352 Here 'redundant' means that the specified port matches the default
353 for that protocol, eg 70 for gopher."
354 (if (and (not (elpher-address-special-p address))
355 (eq (url-portspec address) ; (url-port) is too slow!
356 (pcase (url-type address)
358 ((or "gopher" "gophers") 70)
361 (setf (url-portspec address) nil))
364 (defun elpher-make-gopher-address (type selector host port &optional tls)
365 "Create an ADDRESS object using gopher directory record attributes.
366 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
367 If the optional attribute TLS is non-nil, the address will be marked as
368 requiring gopher-over-TLS."
370 ((equal type ?i) nil)
371 ((and (equal type ?h)
372 (string-prefix-p "URL:" selector))
373 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
375 (elpher-address-from-url
378 ":" (number-to-string port))))
380 (elpher-address-from-url
381 (concat "gopher" (if tls "s" "")
383 ":" (number-to-string port)
387 (defun elpher-make-special-address (type)
388 "Create an ADDRESS object corresponding to the given special address symbol TYPE."
391 (defun elpher-make-start-page ()
392 "Create the start page."
393 (elpher-make-page "Elpher Start Page"
394 (elpher-make-special-address 'start)))
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-page-display-string (page)
496 "Retrieve the display string corresponding to PAGE."
499 (defun elpher-page-address (page)
500 "Retrieve the address corresponding to PAGE."
503 (defun elpher-page-set-address (page new-address)
504 "Set the address corresponding to PAGE to NEW-ADDRESS."
505 (setcar (cdr page) new-address))
507 (defvar elpher-current-page nil
508 "The current page for this Elpher buffer.")
510 (defvar elpher-history nil
511 "The local history for this Elpher buffer.
512 This variable is used by `elpher-back' and
513 `elpher-show-history'.")
515 (defvar elpher-history-all nil
516 "The global history for all Elpher buffers.
517 This variable is used by `elpher-show-history-all'.")
519 (defun elpher-visit-page (page &optional renderer no-history)
520 "Visit PAGE using its own renderer or RENDERER, if non-nil.
521 Additionally, push PAGE onto the stack of previously-visited pages,
522 unless NO-HISTORY is non-nil."
524 (elpher-process-cleanup)
525 (elpher-reset-link-number-counter)
526 (unless (or no-history
527 (equal (elpher-page-address elpher-current-page)
528 (elpher-page-address page)))
529 (push elpher-current-page elpher-history)
530 (push elpher-current-page elpher-history-all))
531 (setq-local elpher-current-page page)
532 (let* ((address (elpher-page-address page))
533 (type (elpher-address-type address))
534 (type-record (cdr (assoc type elpher-type-map)))
537 (funcall (car type-record)
541 (elpher-visit-previous-page)
543 (`(gopher ,type-char)
544 (error "Unsupported gopher selector type '%c' for '%s'"
545 type-char (elpher-address-to-url address)))
547 (error "Unsupported address type '%S' for '%s'"
548 other (elpher-address-to-url address)))))))
550 (defun elpher-visit-previous-page ()
551 "Visit the previous page in the history."
552 (let ((previous-page (pop elpher-history)))
554 (elpher-visit-page previous-page nil t)
555 (error "No previous page"))))
557 (defun elpher-reload-current-page ()
558 "Reload the current page, discarding any existing cached content."
559 (elpher-cache-content (elpher-page-address elpher-current-page) nil)
560 (elpher-visit-page elpher-current-page))
562 (defun elpher-save-pos ()
563 "Save the current position of point to the current page."
564 (when elpher-current-page
565 (elpher-cache-pos (elpher-page-address elpher-current-page) (point))))
567 (defun elpher-restore-pos ()
568 "Restore the position of point to that cached in the current page."
569 (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
572 (goto-char (point-min)))))
575 ;;; Buffer preparation
578 (defvar elpher-buffer-name "*elpher*"
579 "The default name of the Elpher buffer.")
581 (defun elpher-update-header ()
582 "If `elpher-use-header' is true, display current page info in window header."
583 (if elpher-use-header
584 (let* ((display-string (elpher-page-display-string elpher-current-page))
585 (address (elpher-page-address elpher-current-page))
586 (tls-string (if (and (not (elpher-address-special-p address))
587 (member (elpher-address-protocol address)
588 '("gophers" "gemini")))
591 (header (concat display-string
592 (propertize tls-string 'face 'bold))))
593 (setq header-line-format header))))
595 (defmacro elpher-with-clean-buffer (&rest args)
596 "Evaluate ARGS with a clean *elpher* buffer as current."
597 `(with-current-buffer elpher-buffer-name
598 (unless (eq major-mode 'elpher-mode)
599 ;; avoid resetting buffer-local variables
601 (let ((inhibit-read-only t))
602 (setq-local network-security-level
603 (default-value 'network-security-level))
605 (elpher-update-header)
608 (defun elpher-buffer-message (string &optional line)
609 "Replace first line in elpher buffer with STRING.
610 If LINE is non-nil, replace that line instead."
611 (with-current-buffer elpher-buffer-name
612 (let ((inhibit-read-only t))
613 (goto-char (point-min))
616 (let ((data (match-data)))
619 (re-search-forward "^.*$")
620 (replace-match string))
621 (set-match-data data))))))
627 (defvar elpher-user-coding-system nil
628 "User-specified coding system to use for decoding text responses.")
630 (defun elpher-decode (string)
631 "Decode STRING using autodetected or user-specified coding system."
632 (decode-coding-string string
633 (if elpher-user-coding-system
634 elpher-user-coding-system
635 (detect-coding-string string t))))
637 (defun elpher-preprocess-text-response (string)
638 "Preprocess text selector response contained in STRING.
639 This involes decoding the character representation, and clearing
640 away CRs and any terminating period."
641 (elpher-decode (replace-regexp-in-string "\n\\.\n$" "\n"
642 (replace-regexp-in-string "\r" "" string))))
645 ;;; Network error reporting
648 (defun elpher-network-error (address error)
649 "Display ERROR message following unsuccessful negotiation with ADDRESS.
650 ERROR can be either an error object or a string."
651 (elpher-with-clean-buffer
652 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
653 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
654 (if (stringp error) error (error-message-string error)) "\n"
655 (propertize "\n----------------\n\n" 'face 'error)
656 "Press 'u' to return to the previous page.")))
659 ;;; General network communication
662 (defvar elpher-network-timer nil
663 "Timer used for network connections.")
665 (defvar elpher-use-tls nil
666 "If non-nil, use TLS to communicate with gopher servers.")
668 (defvar elpher-client-certificate nil
669 "If non-nil, contains client certificate details to use for TLS connections.")
671 (defun elpher-process-cleanup ()
672 "Immediately shut down any extant elpher process and timers."
673 (let ((p (get-process "elpher-process")))
674 (if p (delete-process p)))
675 (if (timerp elpher-network-timer)
676 (cancel-timer elpher-network-timer)))
678 (defun elpher-get-host-response (address default-port query-string response-processor
679 &optional use-tls force-ipv4)
680 "Generic function for retrieving data from ADDRESS.
682 When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
683 QUERY-STRING is a string sent to the host specified by ADDRESS to
684 illicet a response. This response is passed as an argument to the
685 function RESPONSE-PROCESSOR.
687 If non-nil, USE-TLS specifies that the connection is to be made over
688 TLS. If set to gemini, the certificate verification will be disabled
689 unless `elpher-gemini-TLS-cert-checks' is non-nil.
691 If non-nil, FORCE-IPV4 causes the network connection to be made over
692 ipv4 only. (The default behaviour when this is not set depends on
693 the host operating system and the local network capabilities.)"
694 (if (and use-tls (not (gnutls-available-p)))
695 (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
696 (unless (< (elpher-address-port address) 65536)
697 (error "Cannot establish network connection: port number > 65536"))
698 (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
699 (setq-local network-security-level 'low)
700 (setq-local gnutls-verify-error nil))
702 (let* ((kill-buffer-query-functions nil)
703 (port (elpher-address-port address))
704 (service (if (> port 0) port default-port))
705 (host (elpher-address-host address))
706 (socks (or elpher-socks-always (string-suffix-p ".onion" host)))
707 (response-string-parts nil)
710 (timer (run-at-time elpher-connection-timeout nil
712 (elpher-process-cleanup)
714 ; Try again with IPv4
715 ((not (or force-ipv4 socks))
716 (message "Connection timed out. Retrying with IPv4.")
717 (elpher-get-host-response address default-port
722 (not (eq use-tls 'gemini))
723 (or elpher-auto-disengage-TLS
725 "TLS connetion failed. Disable TLS mode and retry? ")))
726 (setq elpher-use-tls nil)
727 (elpher-get-host-response address default-port
732 (elpher-network-error address "Connection time-out."))))))
733 (gnutls-params (list :type 'gnutls-x509pki :hostname host
734 :keylist (elpher-get-current-keylist address)))
735 (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
736 (make-network-process :name "elpher-process"
738 :family (and force-ipv4 'ipv4)
744 (cons 'gnutls-x509pki
745 (apply #'gnutls-boot-parameters
747 (setq elpher-network-timer timer)
748 (set-process-coding-system proc 'binary 'binary)
749 (set-process-query-on-exit-flag proc nil)
750 (elpher-buffer-message (concat "Connecting to " host "..."
751 " (press 'u' to abort)"))
752 (set-process-filter proc
753 (lambda (_proc string)
757 (setq bytes-received (+ bytes-received (length string)))
758 (let ((new-hkbytes-received (/ bytes-received 102400)))
759 (when (> new-hkbytes-received hkbytes-received)
760 (setq hkbytes-received new-hkbytes-received)
761 (elpher-buffer-message
763 (number-to-string (/ hkbytes-received 10.0))
766 (setq response-string-parts
767 (cons string response-string-parts))))
768 (set-process-sentinel proc
771 (cancel-timer timer))
772 (condition-case the-error
774 ((string-prefix-p "open" event) ; request URL
775 (elpher-buffer-message
776 (concat "Connected to " host ". Receiving data..."
777 " (press 'u' to abort)"))
778 (let ((inhibit-eol-conversion t))
779 (process-send-string proc query-string)))
780 ((string-prefix-p "deleted" event)) ; do nothing
781 ((and (not response-string-parts)
782 (not (or elpher-ipv4-always force-ipv4 socks)))
783 ; Try again with IPv4
784 (message "Connection failed. Retrying with IPv4.")
785 (elpher-get-host-response address default-port
789 (response-string-parts
790 (elpher-with-clean-buffer
791 (insert "Data received. Rendering..."))
792 (funcall response-processor
793 (apply #'concat (reverse response-string-parts)))
794 (elpher-restore-pos))
796 (error "No response from server")))
798 (elpher-network-error address the-error)))))
800 (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
801 (funcall (process-sentinel proc) proc "open\n")))
803 (error "Error initiating connection to server")))))
806 ;;; Client-side TLS Certificate Management
809 (defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
810 "Generate a key and a self-signed client TLS certificate using openssl.
812 The Common Name field of the certificate is set to COMMON-NAME. The
813 arguments KEY-FILE and CERT-FILE should contain the absolute paths of
814 the key and certificate files to write.
816 If TEMPORARY is non-nil, the certificate will be given an exporation
817 period of one day, and the key and certificate files will be deleted
818 when the certificate is no longer needed for the current session.
820 Otherwise, the certificate will be given a 100 year expiration period
821 and the files will not be deleted.
823 The function returns a list containing the current host name, the
824 temporary flag, and the key and cert file names in the form required
825 by `gnutls-boot-parameters`."
826 (let ((exp-key-file (expand-file-name key-file))
827 (exp-cert-file (expand-file-name cert-file)))
830 (call-process elpher-openssl-command nil nil nil
831 "req" "-x509" "-newkey" "rsa:2048"
832 "-days" (if temporary "1" "36500")
834 "-subj" (concat "/CN=" common-name)
835 "-keyout" exp-key-file
836 "-out" exp-cert-file)
837 (list (elpher-address-host (elpher-page-address elpher-current-page))
838 temporary exp-key-file exp-cert-file))
840 (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
841 (error "Program 'openssl', required for certificate generation, not found")))))
843 (defun elpher-generate-throwaway-certificate ()
844 "Generate and return details of a throwaway certificate.
845 The key and certificate files will be deleted when they are no
846 longer needed for this session."
847 (let* ((file-base (make-temp-name "elpher"))
848 (key-file (concat temporary-file-directory file-base ".key"))
849 (cert-file (concat temporary-file-directory file-base ".crt")))
850 (elpher-generate-certificate file-base key-file cert-file t)))
852 (defun elpher-generate-persistent-certificate (file-base common-name)
853 "Generate and return details of a persistent certificate.
854 The argument FILE-BASE is used as the base for the key and certificate
855 files, while COMMON-NAME specifies the common name field of the
858 The key and certificate files are written to in `elpher-certificate-directory'."
859 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
860 (cert-file (concat elpher-certificate-directory file-base ".crt")))
861 (elpher-generate-certificate common-name key-file cert-file)))
863 (defun elpher-get-existing-certificate (file-base)
864 "Return a certificate object corresponding to an existing certificate.
865 It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
866 the directory `elpher-certificate-directory'."
867 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
868 (cert-file (concat elpher-certificate-directory file-base ".crt")))
869 (list (elpher-address-host (elpher-page-address elpher-current-page))
871 (expand-file-name key-file)
872 (expand-file-name cert-file))))
874 (defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
875 "Install a key+certificate file pair in `elpher-certificate-directory'.
876 The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
877 certificate files to install. The argument FILE-BASE is used as the
878 base for the installed key and certificate files."
879 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
880 (cert-file (concat elpher-certificate-directory file-base ".crt")))
881 (if (or (file-exists-p key-file)
882 (file-exists-p cert-file))
883 (error "A certificate with base name %s is already installed" file-base))
884 (copy-file key-file-src key-file)
885 (copy-file cert-file-src cert-file)
886 (list (elpher-address-host (elpher-page-address elpher-current-page))
888 (expand-file-name key-file)
889 (expand-file-name cert-file))))
891 (defun elpher-list-existing-certificates ()
892 "Return a list of the persistent certificates in `elpher-certificate-directory'."
893 (unless (file-directory-p elpher-certificate-directory)
894 (make-directory elpher-certificate-directory))
897 (file-name-sans-extension file))
898 (directory-files elpher-certificate-directory nil "\\.key$")))
900 (defun elpher-forget-current-certificate ()
901 "Causes any current certificate to be forgotten.)
902 In the case of throwaway certificates, the key and certificate files
905 (when elpher-client-certificate
906 (unless (and (called-interactively-p 'any)
907 (not (y-or-n-p (concat "Really forget client certificate? "
908 "(Throwaway certificates will be deleted.)"))))
909 (when (cadr elpher-client-certificate)
910 (delete-file (elt elpher-client-certificate 2))
911 (delete-file (elt elpher-client-certificate 3)))
912 (setq elpher-client-certificate nil)
913 (if (called-interactively-p 'any)
914 (message "Client certificate forgotten.")))))
916 (defun elpher-get-current-keylist (address)
917 "Retrieve the `gnutls-boot-parameters'-compatable keylist.
919 This is obtained from the client certificate described by
920 `elpher-current-certificate', if one is available and the host for
921 that certificate matches the host in ADDRESS.
923 If `elpher-current-certificate' is non-nil, and its host name doesn't
924 match that of ADDRESS, the certificate is forgotten."
925 (if elpher-client-certificate
926 (if (string= (car elpher-client-certificate)
927 (elpher-address-host address))
928 (list (cddr elpher-client-certificate))
929 (elpher-forget-current-certificate)
930 (message "Disabling client certificate for new host")
935 ;;; Gopher selector retrieval
938 (defun elpher-get-gopher-response (address renderer)
939 "Get response string from gopher server at ADDRESS and render using RENDERER."
940 (elpher-get-host-response address 70
941 (concat (elpher-gopher-address-selector address) "\r\n")
943 (or (string= (elpher-address-protocol address) "gophers")
946 (defun elpher-get-gopher-page (renderer)
947 "Getter function for gopher pages.
948 The RENDERER procedure is used to display the contents of the page
949 once they are retrieved from the gopher server."
950 (let* ((address (elpher-page-address elpher-current-page))
951 (content (elpher-get-cached-content address)))
952 (if (and content (funcall renderer nil))
953 (elpher-with-clean-buffer
955 (elpher-restore-pos))
956 (elpher-with-clean-buffer
957 (insert "LOADING... (use 'u' to cancel)\n"))
958 (condition-case the-error
959 (elpher-get-gopher-response address renderer)
961 (elpher-network-error address the-error))))))
965 (defun elpher-insert-index (string)
966 "Insert the index corresponding to STRING into the current buffer."
967 ;; Should be able to split directly on CRLF, but some non-conformant
968 ;; LF-only servers sadly exist, hence the following.
969 (let ((str-processed (elpher-preprocess-text-response string)))
970 (dolist (line (split-string str-processed "\n"))
972 (unless (= (length line) 0)
973 (let* ((type (elt line 0))
974 (fields (split-string (substring line 1) "\t"))
975 (display-string (elt fields 0))
976 (selector (elt fields 1))
977 (host (elt fields 2))
978 (port (if (elt fields 3)
979 (string-to-number (elt fields 3))
981 (address (elpher-make-gopher-address type selector host port)))
982 (elpher-insert-index-record display-string address)))))))
984 (defun elpher-insert-margin (&optional type-name)
985 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
988 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
990 (propertize "[" 'face 'elpher-margin-brackets)
991 (propertize type-name 'face 'elpher-margin-key)
992 (propertize "]" 'face 'elpher-margin-brackets))))
994 (insert (make-string elpher-margin-width ?\s))))
996 (defun elpher--page-button-help (_window buffer pos)
997 "Function called by Emacs to generate mouse-over text.
998 The arguments specify the BUFFER and the POS within the buffer of the item
999 for which help is required. The function returns the help to be
1000 displayed. The _WINDOW argument is currently unused."
1001 (with-current-buffer buffer
1002 (let ((button (button-at pos)))
1004 (let* ((page (button-get button 'elpher-page))
1005 (address (elpher-page-address page)))
1006 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
1008 (elpher-address-to-url address))))))))
1010 (defvar elpher--link-number-counter 0)
1011 (defun elpher-reset-link-number-counter ()
1012 (setq-local elpher--link-number-counter 0))
1014 (defun elpher--insert-text-button (label &rest properties)
1015 "Inserts a potentially-numbered button into the current buffer.
1016 The text for the button is provided by LABEL, while the button
1017 properties in PROPERTIES are as per `insert-text-button'."
1019 (if elpher-number-links
1020 (setq-local elpher--link-number-counter (+ elpher--link-number-counter 1)))
1021 (let ((pref (if elpher-number-links
1022 (concat "[" (number-to-string elpher--link-number-counter) "] ")
1024 (apply #'insert-text-button (cons (concat pref label) properties))))
1026 (defun elpher-insert-index-record (display-string &optional address)
1027 "Function to insert an index record into the current buffer.
1028 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
1029 If ADDRESS is not supplied or nil the record is rendered as an
1030 'information' line."
1031 (let* ((type (if address (elpher-address-type address) nil))
1032 (type-map-entry (cdr (assoc type elpher-type-map))))
1034 (let* ((margin-code (elt type-map-entry 2))
1035 (face (elt type-map-entry 3))
1036 (filtered-display-string (elpher-color-filter-apply display-string))
1037 (page (elpher-make-page filtered-display-string address)))
1038 (elpher-insert-margin margin-code)
1039 (elpher--insert-text-button filtered-display-string
1042 'action #'elpher-click-link
1044 'help-echo #'elpher--page-button-help))
1046 ('nil ;; Information
1047 (elpher-insert-margin)
1048 (let ((propertized-display-string
1049 (propertize display-string 'face 'elpher-info)))
1050 (insert (elpher-process-text-for-display propertized-display-string))))
1051 (`(gopher ,selector-type) ;; Unknown
1052 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
1053 (insert (propertize display-string
1054 'face 'elpher-unknown)))))
1057 (defun elpher-click-link (button)
1058 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
1059 (let ((page (button-get button 'elpher-page)))
1060 (elpher-visit-page page)))
1062 (defun elpher-render-index (data &optional _mime-type-string)
1063 "Render DATA as an index. MIME-TYPE-STRING is unused."
1064 (elpher-with-clean-buffer
1067 (elpher-insert-index data)
1068 (elpher-cache-content (elpher-page-address elpher-current-page)
1073 (defconst elpher-url-regex
1074 "\\([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_~?/@|#-]\\)?\\)?"
1075 "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
1077 (defun elpher-buttonify-urls (string)
1078 "Turn substrings which look like urls in STRING into clickable buttons."
1081 (goto-char (point-min))
1082 (while (re-search-forward elpher-url-regex nil t)
1083 (let ((page (elpher-make-page (substring-no-properties (match-string 0))
1084 (elpher-address-from-url (match-string 0)))))
1085 (make-text-button (match-beginning 0)
1088 'action #'elpher-click-link
1090 'help-echo #'elpher--page-button-help
1094 (defconst elpher-ansi-regex "\x1b\\[[^m]*m"
1095 "Incomplete regexp used to strip out some troublesome ANSI escape sequences.")
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 (unless (fboundp 'read-answer)
1292 (defun read-answer (question answers)
1293 "Backfill for the new read-answer code."
1294 (completing-read question (mapcar 'identity answers))))
1296 (defun elpher-choose-client-certificate ()
1297 "Prompt for a client certificate to use to establish a TLS connection."
1298 (let* ((read-answer-short t))
1299 (pcase (read-answer "What do you want to do? "
1301 "generate and use throw-away certificate")
1303 "generate new or use existing persistent certificate")
1305 "stop immediately")))
1307 (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
1309 (let* ((existing-certificates (elpher-list-existing-certificates))
1310 (file-base (completing-read
1311 "Nickname for new or existing certificate (autocompletes, empty response aborts): "
1312 existing-certificates)))
1313 (if (string-empty-p (string-trim file-base))
1315 (if (member file-base existing-certificates)
1316 (setq elpher-client-certificate
1317 (elpher-get-existing-certificate file-base))
1318 (pcase (read-answer "Generate new certificate or install externally-generated one? "
1320 "generate new certificate")
1322 "install existing certificate")
1324 "stop immediately")))
1326 (let ((common-name (read-string "Common Name field for new certificate: "
1328 (message "New key and self-signed certificate written to %s"
1329 elpher-certificate-directory)
1330 (elpher-generate-persistent-certificate file-base common-name)))
1332 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
1333 (key-file (read-file-name "Key file: " nil nil t)))
1334 (message "Key and certificate installed in %s for future use"
1335 elpher-certificate-directory)
1336 (elpher-install-and-use-existing-certificate key-file
1342 (defun elpher-get-gemini-page (renderer)
1343 "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
1344 (let* ((address (elpher-page-address elpher-current-page))
1345 (content (elpher-get-cached-content address)))
1346 (condition-case the-error
1347 (if (and content (funcall renderer nil))
1348 (elpher-with-clean-buffer
1350 (elpher-restore-pos))
1351 (elpher-with-clean-buffer
1352 (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
1353 (setq elpher-gemini-redirect-chain nil)
1354 (elpher-get-gemini-response address renderer))
1356 (elpher-network-error address the-error)))))
1358 (defun elpher-render-gemini (body &optional mime-type-string)
1359 "Render gemini response BODY with rendering MIME-TYPE-STRING."
1362 (let* ((mime-type-string* (if (or (not mime-type-string)
1363 (string-empty-p mime-type-string))
1364 "text/gemini; charset=utf-8"
1366 (mime-type-split (split-string mime-type-string* ";" t))
1367 (mime-type (string-trim (car mime-type-split)))
1368 (parameters (mapcar (lambda (s)
1369 (let ((key-val (split-string s "=")))
1370 (list (downcase (string-trim (car key-val)))
1371 (downcase (string-trim (cadr key-val))))))
1372 (cdr mime-type-split))))
1373 (when (string-prefix-p "text/" mime-type)
1374 (setq body (decode-coding-string
1376 (if (assoc "charset" parameters)
1377 (intern (cadr (assoc "charset" parameters)))
1379 (setq body (replace-regexp-in-string "\r" "" body)))
1381 ((or "text/gemini" "")
1382 (elpher-render-gemini-map body parameters))
1384 (elpher-render-html body))
1385 ((pred (string-prefix-p "text/"))
1386 (elpher-render-gemini-plain-text body parameters))
1387 ((pred (string-prefix-p "image/"))
1388 (elpher-render-image body))
1390 (elpher-render-download body))))))
1392 (defun elpher-gemini-get-link-url (link-line)
1393 "Extract the url portion of LINK-LINE, a gemini map file link line.
1394 Returns nil in the event that the contents of the line following the
1395 => prefix are empty."
1396 (let ((l (split-string (substring link-line 2))))
1398 (string-trim (elt l 0))
1401 (defun elpher-gemini-get-link-display-string (link-line)
1402 "Extract the display string portion of LINK-LINE, a gemini map file link line.
1403 Returns the url portion in the event that the display-string portion is empty."
1404 (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
1405 (idx (string-match "[ \t]" rest)))
1406 (string-trim (if idx
1407 (substring rest (+ idx 1))
1410 (defun elpher-collapse-dot-sequences (filename)
1411 "Collapse dot sequences in FILENAME.
1412 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
1413 (let* ((path (split-string filename "/"))
1414 (path-reversed-normalized
1415 (seq-reduce (lambda (a b)
1416 (cond ((and a (equal b "..") (cdr a)))
1417 ((and (not a) (equal b "..")) a) ;leading .. are dropped
1421 (string-join (reverse path-reversed-normalized) "/")))
1423 (defun elpher-address-from-gemini-url (url)
1424 "Extract address from URL with defaults as per gemini map files.
1425 While there's obviously some redundancy here between this function and
1426 `elpher-address-from-url', gemini map file URLs require enough special
1427 treatment that a separate function is warranted."
1428 (let ((address (url-generic-parse-url url))
1429 (current-address (elpher-page-address elpher-current-page)))
1430 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
1431 (setf (url-fullness address) t)
1432 (if (url-host address) ;if there is an explicit host, filenames are absolute
1433 (if (string-empty-p (url-filename address))
1434 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
1435 (setf (url-host address) (url-host current-address))
1436 (setf (url-port address) (url-port current-address))
1437 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1438 (setf (url-filename address)
1439 (concat (file-name-directory (url-filename current-address))
1440 (url-filename address)))))
1441 (unless (url-type address)
1442 (setf (url-type address) "gemini"))
1443 (when (equal (url-type address) "gemini")
1444 (setf (url-filename address)
1445 (elpher-collapse-dot-sequences (url-filename address)))))
1446 (elpher-remove-redundant-ports address)))
1448 (defun elpher-gemini-insert-link (link-line)
1449 "Insert link described by LINK-LINE into a text/gemini document."
1450 (let* ((url (elpher-gemini-get-link-url link-line))
1451 (display-string (elpher-gemini-get-link-display-string link-line))
1452 (address (elpher-address-from-gemini-url url))
1453 (type (if address (elpher-address-type address) nil))
1454 (type-map-entry (cdr (assoc type elpher-type-map))))
1455 (when display-string
1456 (insert elpher-gemini-link-string)
1458 (let* ((face (elt type-map-entry 3))
1459 (filtered-display-string (elpher-color-filter-apply display-string))
1460 (page (elpher-make-page filtered-display-string address)))
1461 (elpher--insert-text-button filtered-display-string
1464 'action #'elpher-click-link
1466 'help-echo #'elpher--page-button-help))
1467 (insert (propertize display-string 'face 'elpher-unknown)))
1470 (defun elpher-gemini-insert-header (header-line)
1471 "Insert header described by HEADER-LINE into a text/gemini document.
1472 The gemini map file line describing the header is given
1474 (when (string-match "^\\(#+\\)[ \t]*" header-line)
1475 (let* ((level (length (match-string 1 header-line)))
1476 (header (substring header-line (match-end 0)))
1478 (1 'elpher-gemini-heading1)
1479 (2 'elpher-gemini-heading2)
1480 (3 'elpher-gemini-heading3)
1482 (fill-column (if (display-graphic-p)
1484 (font-get (font-spec :name (face-font 'default)) :size))
1485 (font-get (font-spec :name (face-font face)) :size)) fill-column)))
1486 (setq elpher--gemini-page-headings (cons (cons header (point))
1487 elpher--gemini-page-headings))
1488 (unless (display-graphic-p)
1489 (insert (make-string level ?#) " "))
1490 (insert (propertize header 'face face))
1493 (defun elpher-gemini-insert-text (text-line)
1494 "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
1495 This function uses Emacs' auto-fill to wrap text sensibly to a maximum
1496 width defined by `elpher-gemini-max-fill-width'."
1497 (string-match "\\(^[ \t]*\\)\\(\\*[ \t]+\\|>[ \t]*\\)?" text-line)
1498 (let* ((line-prefix (match-string 2 text-line))
1499 (processed-text-line
1501 (cond ((string-prefix-p "*" line-prefix)
1503 (replace-regexp-in-string "\\*"
1504 elpher-gemini-bullet-string
1505 (match-string 0 text-line))
1506 (substring text-line (match-end 0))))
1507 ((string-prefix-p ">" line-prefix)
1508 (propertize text-line 'face 'elpher-gemini-quoted))
1511 (adaptive-fill-mode t)
1512 ;; fill-prefix is important for adaptive-fill-mode: without
1513 ;; it, multi-line list items are not indented correct
1514 (fill-prefix (if (match-string 2 text-line)
1515 (replace-regexp-in-string "[>\*]" " " (match-string 0 text-line))
1517 (insert (elpher-process-text-for-display processed-text-line))
1520 (defun elpher-render-gemini-map (data _parameters)
1521 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1522 (elpher-with-clean-buffer
1523 (setq elpher--gemini-page-headings nil)
1524 (let ((preformatted nil))
1526 (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
1527 (dolist (line (split-string data "\n"))
1529 ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
1530 (preformatted (insert (elpher-process-text-for-display
1531 (propertize line 'face 'elpher-gemini-preformatted))
1533 ((string-prefix-p "=>" line)
1534 (elpher-gemini-insert-link line))
1535 ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
1536 (t (elpher-gemini-insert-text line)))))
1537 (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))
1538 (elpher-cache-content
1539 (elpher-page-address elpher-current-page)
1542 (defun elpher-render-gemini-plain-text (data _parameters)
1543 "Render DATA as plain text file. PARAMETERS is currently unused."
1544 (elpher-with-clean-buffer
1545 (insert (elpher-process-text-for-display data))
1546 (elpher-cache-content
1547 (elpher-page-address elpher-current-page)
1551 ;; Finger page connection
1553 (defun elpher-get-finger-page (renderer)
1554 "Opens a finger connection to the current page address.
1555 The result is rendered using RENDERER."
1556 (let* ((address (elpher-page-address elpher-current-page))
1557 (content (elpher-get-cached-content address)))
1558 (if (and content (funcall renderer nil))
1559 (elpher-with-clean-buffer
1561 (elpher-restore-pos))
1562 (elpher-with-clean-buffer
1563 (insert "LOADING... (use 'u' to cancel)\n"))
1564 (condition-case the-error
1565 (let* ((kill-buffer-query-functions nil)
1566 (user (let ((filename (elpher-address-filename address)))
1567 (if (> (length filename) 1)
1568 (substring filename 1)
1569 (elpher-address-user address)))))
1570 (elpher-get-host-response address 79
1571 (concat user "\r\n")
1574 (elpher-network-error address the-error))))))
1577 ;; Telnet page connection
1579 (defun elpher-get-telnet-page (renderer)
1580 "Opens a telnet connection to the current page address (RENDERER must be nil)."
1582 (elpher-visit-previous-page)
1583 (error "Command not supported for telnet URLs"))
1584 (let* ((address (elpher-page-address elpher-current-page))
1585 (host (elpher-address-host address))
1586 (port (elpher-address-port address)))
1587 (elpher-visit-previous-page)
1593 ;; Other URL page opening
1595 (defun elpher-get-other-url-page (renderer)
1596 "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
1598 (elpher-visit-previous-page)
1599 (error "Command not supported for general URLs"))
1600 (let* ((address (elpher-page-address elpher-current-page))
1601 (url (elpher-address-to-url address)))
1603 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1604 (message "Opening URL...")
1605 (if elpher-open-urls-with-eww
1607 (browse-url url)))))
1610 ;; Start page page retrieval
1612 (defun elpher-get-start-page (renderer)
1613 "Getter which displays the start page (RENDERER must be nil)."
1615 (elpher-visit-previous-page)
1616 (error "Command not supported for start page"))
1617 (elpher-with-clean-buffer
1618 (insert " --------------------------------------------\n"
1619 " Elpher Gopher and Gemini Client \n"
1620 " version " elpher-version "\n"
1621 " --------------------------------------------\n"
1623 "Default bindings:\n"
1625 " - TAB/Shift-TAB: next/prev item on current page\n"
1626 " - RET/mouse-1: open item under cursor\n"
1627 " - m/M: select an item on current page by name (autocompletes) or number\n"
1628 " - u/mouse-3/U: return to previous page or to the start page\n"
1629 " - o/O: visit different selector or the root menu of the current server\n"
1630 " - g: go to a particular address (gopher, gemini, finger)\n"
1631 " - d/D: download item under cursor or current page\n"
1632 " - i/I: info on item under cursor or current page\n"
1633 " - c/C: copy URL representation of item under cursor or current page\n"
1634 " - a/A: bookmark the item under cursor or current page\n"
1635 " - B: list all bookmarks\n"
1636 " - s/S: show history of current buffer or for all buffers\n"
1637 " - r: redraw current page (using cached contents if available)\n"
1638 " - R: reload current page (regenerates cache)\n"
1639 " - !: set character coding system for gopher (default is to autodetect)\n"
1640 " - T: toggle TLS gopher mode\n"
1641 " - F: forget/discard current TLS client certificate\n"
1642 " - .: display the raw server response for the current page\n"
1644 "Start your exploration of gopher space and gemini:\n")
1645 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1646 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1647 (elpher-insert-index-record "Project Gemini home page"
1648 (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
1650 "Alternatively, select a search engine and enter some search terms:\n")
1651 (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
1652 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1653 (elpher-insert-index-record "Gemini Search Engine (geminispace.info)"
1654 (elpher-address-from-url "gemini://geminispace.info/search"))
1656 "For Elpher release news or to leave feedback, visit:\n")
1657 (elpher-insert-index-record "The Elpher Project Page"
1658 (elpher-make-gopher-address ?1
1664 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1665 (elpher--insert-text-button "Elpher info manual"
1671 'help-echo help-string))
1672 (insert " for the full documentation. **\n")
1674 (concat " (This should be available if you have installed Elpher using\n"
1675 " MELPA. Otherwise you will have to install the manual yourself.)\n")
1677 (elpher-restore-pos)))
1679 ;; History page retrieval
1681 (defun elpher-history ()
1682 "Show the history of pages leading to the current page in this buffer.
1683 Use \\[elpher-history-all] to see the entire history.
1684 This is rendered using `elpher-get-history-page' via `elpher-type-map'."
1687 (elpher-make-page "Elpher History Page"
1688 (elpher-make-special-address 'history))))
1690 (defun elpher-history-all ()
1691 "Show the all the pages you've visited using Elpher.
1692 Use \\[elpher-history] to see just the history for the current buffer.
1693 This is rendered using `elpher-get-history-all-page' via `elpher-type-map'."
1696 (elpher-make-page "Elpher History Of All Seen Pages"
1697 (elpher-make-special-address 'history-all))))
1699 (defun elpher-get-history-page (renderer)
1700 "Getter which displays the history page (RENDERER must be nil)."
1702 (elpher-visit-previous-page)
1703 (error "Command not supported for history page"))
1704 (elpher-show-history elpher-history))
1706 (defun elpher-get-history-all-page (renderer)
1707 "Getter which displays the history page (RENDERER must be nil)."
1709 (elpher-visit-previous-page)
1710 (error "Command not supported for history page"))
1711 (elpher-show-history elpher-history-all))
1713 (defun elpher-show-history (pages)
1714 "Show all PAGES in the Elpher buffer."
1715 (elpher-with-clean-buffer
1716 (insert "---- Visited link history ----\n\n")
1718 (dolist (page pages)
1720 (let ((display-string (elpher-page-display-string page))
1721 (address (elpher-page-address page)))
1722 (elpher-insert-index-record display-string address))))
1723 (insert "No history items found.\n"))
1724 (insert "\n----------------------------")))
1729 ;; This code allows Elpher to use the standard Emacs bookmarks: `C-x r
1730 ;; m' to add a bookmark, `C-x r l' to list bookmarks (which is where
1731 ;; you can anotate bookmarks!), `C-x r b' to jump to a bookmark, and
1732 ;; so on. See the Bookmarks section in the Emacs info manual for more.
1734 (defvar elpher-bookmark-link nil
1735 "Prefer bookmarking a link or the current page.
1736 Bind this variable dynamically, or set it to t.
1737 If you set it to t, the commands \\[bookmark-set-no-overwrite]
1738 and \\[elpher-set-bookmark-no-overwrite] do the same thing.")
1740 (defun elpher-bookmark-make-record ()
1741 "Return a bookmark record.
1742 If `elpher-bookmark-link' is non-nil and point is on a link button,
1743 return a bookmark record for that link. Otherwise, return a bookmark
1744 record for the current elpher page."
1745 (let* ((button (and elpher-bookmark-link (button-at (point))))
1747 (button-get button 'elpher-page)
1748 elpher-current-page))
1749 (address (elpher-page-address page))
1750 (url (elpher-address-to-url address))
1751 (display-string (elpher-page-display-string page))
1752 (pos (if button nil (point))))
1753 (if (elpher-address-special-p address)
1754 (error "Cannot bookmark %s" display-string)
1756 (defaults . (,display-string))
1759 (handler . elpher-bookmark-jump)))))
1762 (defun elpher-bookmark-jump (bookmark)
1763 "Go to a particular BOOKMARK."
1764 (let* ((url (cdr (assq 'location bookmark))))
1767 (defun elpher-set-bookmark-no-overwrite ()
1768 "Bookmark the link at point.
1769 To bookmark the current page, use \\[bookmark-set-no-overwrite]."
1771 (let ((elpher-bookmark-link t))
1772 (bookmark-set-no-overwrite)))
1774 (defun elpher-bookmark-import (file)
1775 "Import Elpher bookmarks file FILE into Emacs bookmarks."
1776 (interactive (list (if (and (boundp 'elpher-bookmarks-file)
1777 (file-readable-p elpher-bookmarks-file))
1778 elpher-bookmarks-file
1779 (read-file-name "Old Elpher bookmarks: "
1780 user-emacs-directory nil t
1781 "elpher-bookmarks"))))
1783 (dolist (bookmark (with-temp-buffer
1784 (insert-file-contents file)
1785 (read (current-buffer))))
1786 (let* ((display-string (car bookmark))
1787 (url (cadr bookmark))
1788 (record `(,display-string
1790 (handler . elpher-bookmark-jump))))
1791 (bookmark-store display-string (cdr record) t)))
1799 ;; Avoid byte compilation warnings.
1801 (declare-function org-link-store-props "ol")
1802 (declare-function org-link-set-parameters "ol"))
1804 (defun elpher-org-export-link (link description format protocol)
1805 "Export a LINK with DESCRIPTION for the given PROTOCOL and FORMAT.
1807 FORMAT is an Org export backend. DESCRIPTION may be nil. PROTOCOL may be one
1808 of gemini, gopher or finger."
1809 (let* ((url (if (equal protocol "elpher")
1810 (string-remove-prefix "elpher:" link)
1811 (format "%s:%s" protocol link)))
1812 (desc (or description url)))
1814 (`gemini (format "=> %s %s" url desc))
1815 (`html (format "<a href=\"%s\">%s</a>" url desc))
1816 (`latex (format "\\href{%s}{%s}" url desc))
1817 (_ (if (not description)
1819 (format "%s (%s)" desc url))))))
1821 (defun elpher-org-store-link ()
1822 "Store link to an `elpher' page in Org."
1823 (when (eq major-mode 'elpher-mode)
1824 (let* ((url (elpher-info-current))
1825 (desc (car elpher-current-page))
1827 ((string-prefix-p "gemini:" url) "gemini")
1828 ((string-prefix-p "gopher:" url) "gopher")
1829 ((string-prefix-p "finger:" url) "finger")
1831 (when (equal "elpher" protocol)
1832 ;; Weird link. Or special inner link?
1833 (setq url (concat "elpher:" url)))
1834 (org-link-store-props :type protocol :link url :description desc)
1837 (defun elpher-org-follow-link (link protocol)
1838 "Visit a LINK for the given PROTOCOL.
1840 PROTOCOL may be one of gemini, gopher or finger. This method also
1841 supports the old protocol elpher, where the link is self-contained."
1842 (let ((url (if (equal protocol "elpher")
1843 (string-remove-prefix "elpher:" link)
1844 (format "%s:%s" protocol link))))
1847 (with-eval-after-load 'org
1848 (org-link-set-parameters
1850 :store #'elpher-org-store-link
1851 :export (lambda (link description format _plist)
1852 (elpher-org-export-link link description format "elpher"))
1853 :follow (lambda (link _arg) (elpher-org-follow-link link "elpher")))
1854 (org-link-set-parameters
1856 :export (lambda (link description format _plist)
1857 (elpher-org-export-link link description format "gemini"))
1858 :follow (lambda (link _arg) (elpher-org-follow-link link "gemini")))
1859 (org-link-set-parameters
1861 :export (lambda (link description format _plist)
1862 (elpher-org-export-link link description format "gopher"))
1863 :follow (lambda (link _arg) (elpher-org-follow-link link "gopher")))
1864 (org-link-set-parameters
1866 :export (lambda (link description format _plist)
1867 (elpher-org-export-link link description format "finger"))
1868 :follow (lambda (link _arg) (elpher-org-follow-link link "finger"))))
1872 ;; Avoid byte compilation warnings.
1874 (defvar thing-at-point-uri-schemes))
1877 (defun elpher-browse-url-elpher (url &rest _args)
1878 "Browse URL using Elpher. This function is used by `browse-url'."
1879 (interactive (browse-url-interactive-arg "Elpher URL: "))
1882 ;; Use elpher to open gopher, finger and gemini links
1883 ;; For recent version of `browse-url' package
1884 (if (boundp 'browse-url-default-handlers)
1886 'browse-url-default-handlers
1887 '("^\\(gopher\\|finger\\|gemini\\)://" . elpher-browse-url-elpher))
1888 ;; Patch `browse-url-browser-function' for older ones. The value of
1889 ;; that variable is `browse-url-default-browser' by default, so
1890 ;; that's the function that gets advised.
1891 (advice-add browse-url-browser-function :before-while
1892 (lambda (url &rest _args)
1893 "Handle gemini, gopher, and finger schemes using Elpher."
1894 (let ((scheme (downcase (car (split-string url ":" t)))))
1895 (if (member scheme '("gemini" "gopher" "finger"))
1896 ;; `elpher-go' always returns nil, which will stop the
1897 ;; advice chain here in a before-while
1899 ;; chain must continue, then return t.
1902 ;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
1903 (with-eval-after-load 'thingatpt
1904 (add-to-list 'thing-at-point-uri-schemes "gemini://"))
1909 (defvar mu4e~view-beginning-of-url-regexp))
1911 (with-eval-after-load 'mu4e-view
1912 ;; Make mu4e aware of the gemini world
1913 (setq mu4e~view-beginning-of-url-regexp
1914 "\\(?:https?\\|gopher\\|finger\\|gemini\\)://\\|mailto:"))
1916 ;;; Interactive procedures
1919 (defun elpher-next-link ()
1920 "Move point to the next link on the current page."
1924 (defun elpher-prev-link ()
1925 "Move point to the previous link on the current page."
1927 (backward-button 1))
1929 (defun elpher-follow-current-link ()
1930 "Open the link or url at point."
1935 (defun elpher-go (host-or-url)
1936 "Go to a particular gopher site HOST-OR-URL.
1937 When run interactively HOST-OR-URL is read from the minibuffer."
1938 (interactive "sGopher or Gemini URL: ")
1939 (let* ((cleaned-host-or-url (string-trim host-or-url))
1940 (address (elpher-address-from-url cleaned-host-or-url))
1941 (page (elpher-make-page cleaned-host-or-url address)))
1942 (switch-to-buffer elpher-buffer-name)
1943 (elpher-with-clean-buffer
1944 (elpher-visit-page page))
1947 (defun elpher-go-current ()
1948 "Go to a particular site read from the minibuffer, initialized with the current URL."
1950 (let ((address (elpher-page-address elpher-current-page)))
1951 (let ((url (read-string "Gopher or Gemini URL: "
1952 (unless (elpher-address-special-p address)
1953 (elpher-address-to-url address)))))
1954 (elpher-visit-page (elpher-make-page url (elpher-address-from-url url))))))
1956 (defun elpher-redraw ()
1957 "Redraw current page."
1959 (elpher-visit-page elpher-current-page))
1961 (defun elpher-reload ()
1962 "Reload current page."
1964 (elpher-reload-current-page))
1966 (defun elpher-toggle-tls ()
1967 "Toggle TLS encryption mode for gopher."
1969 (setq elpher-use-tls (not elpher-use-tls))
1971 (if (gnutls-available-p)
1972 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
1973 (setq elpher-use-tls nil)
1974 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
1975 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
1977 (defun elpher-view-raw ()
1978 "View raw server response for current page."
1980 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
1981 (error "This page was not generated by a server")
1982 (elpher-visit-page elpher-current-page
1983 #'elpher-render-raw)))
1985 (defun elpher-back ()
1986 "Go to previous site."
1988 (elpher-visit-previous-page))
1990 (defun elpher-back-to-start ()
1991 "Go all the way back to the start page."
1993 (setq-local elpher-current-page nil)
1994 (setq-local elpher-history nil)
1995 (elpher-visit-page (elpher-make-start-page)))
1997 (defun elpher-download ()
1998 "Download the link at point."
2000 (let ((button (button-at (point))))
2002 (let ((page (button-get button 'elpher-page)))
2003 (if (elpher-address-special-p (elpher-page-address page))
2004 (error "Cannot download %s"
2005 (elpher-page-display-string page))
2006 (elpher-visit-page (button-get button 'elpher-page)
2007 #'elpher-render-download)))
2008 (error "No link selected"))))
2010 (defun elpher-download-current ()
2011 "Download the current page."
2013 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
2014 (error "Cannot download %s"
2015 (elpher-page-display-string elpher-current-page))
2016 (elpher-visit-page (elpher-make-page
2017 (elpher-page-display-string elpher-current-page)
2018 (elpher-page-address elpher-current-page))
2019 #'elpher-render-download
2022 (defun elpher-build-link-map ()
2023 "Build alist mapping link names to destination pages in current buffer."
2024 (let ((link-map nil)
2025 (b (next-button (point-min) t)))
2027 (push (cons (button-label b) b) link-map)
2028 (setq b (next-button (button-start b))))
2031 (defun elpher-jump ()
2032 "Select a directory entry by name. Similar to the info browser (m)enu command."
2034 (let* ((link-map (elpher-build-link-map)))
2036 (let ((key (let ((completion-ignore-case t))
2037 (completing-read "Directory item/link: "
2039 (if (and key (> (length key) 0))
2040 (let ((b (cdr (assoc key link-map))))
2041 (goto-char (button-start b))
2042 (button-activate b)))))))
2044 (defun elpher-jump-to-number (n)
2045 "Jump to directory entry number N."
2046 (interactive "nDirectory item/link number: ")
2047 (let* ((link-map (reverse (elpher-build-link-map))))
2049 (if (<= 1 n (length link-map))
2050 (let ((b (cdr (elt link-map (- n 1)))))
2051 (goto-char (button-start b))
2052 (button-activate b))
2053 (error "No link with that number.")))))
2055 (defun elpher-root-dir ()
2056 "Visit root of current server."
2058 (let ((address (elpher-page-address elpher-current-page)))
2059 (if (not (elpher-address-special-p address))
2060 (if (or (member (url-filename address) '("/" ""))
2061 (and (elpher-address-gopher-p address)
2062 (= (length (elpher-gopher-address-selector address)) 0)))
2063 (error "Already at root directory of current server")
2064 (let ((address-copy (elpher-address-from-url
2065 (elpher-address-to-url address))))
2066 (setf (url-filename address-copy) "")
2067 (elpher-go (elpher-address-to-url address-copy))))
2068 (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
2070 (defun elpher-info-page (page)
2071 "Display information on PAGE."
2072 (let ((display-string (elpher-page-display-string page))
2073 (address (elpher-page-address page)))
2074 (if (elpher-address-special-p address)
2075 (message "Special page: %s" display-string)
2076 (message "%s" (elpher-address-to-url address)))))
2078 (defun elpher-info-link ()
2079 "Display information on page corresponding to link at point."
2081 (let ((button (button-at (point))))
2083 (elpher-info-page (button-get button 'elpher-page))
2084 (error "No item selected"))))
2086 (defun elpher-info-current ()
2087 "Display information on current page."
2089 (elpher-info-page elpher-current-page))
2091 (defun elpher-copy-page-url (page)
2092 "Copy URL representation of address of PAGE to `kill-ring'."
2093 (let ((address (elpher-page-address page)))
2094 (if (elpher-address-special-p address)
2095 (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
2096 (let ((url (elpher-address-to-url address)))
2097 (message "Copied \"%s\" to kill-ring/clipboard." url)
2100 (defun elpher-copy-link-url ()
2101 "Copy URL of item at point to `kill-ring'."
2103 (let ((button (button-at (point))))
2105 (elpher-copy-page-url (button-get button 'elpher-page))
2106 (error "No item selected"))))
2108 (defun elpher-copy-current-url ()
2109 "Copy URL of current page to `kill-ring'."
2111 (elpher-copy-page-url elpher-current-page))
2113 (defun elpher-set-gopher-coding-system ()
2114 "Specify an explicit character coding system for gopher selectors."
2116 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
2117 (setq elpher-user-coding-system system)
2119 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
2120 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
2126 (defvar elpher-mode-map
2127 (let ((map (make-sparse-keymap)))
2128 (define-key map (kbd "TAB") 'elpher-next-link)
2129 (define-key map (kbd "<backtab>") 'elpher-prev-link)
2130 (define-key map (kbd "C-M-i") 'elpher-prev-link)
2131 (define-key map (kbd "u") 'elpher-back)
2132 (define-key map (kbd "-") 'elpher-back)
2133 (define-key map (kbd "^") 'elpher-back)
2134 (define-key map [mouse-3] 'elpher-back)
2135 (define-key map (kbd "U") 'elpher-back-to-start)
2136 (define-key map (kbd "O") 'elpher-root-dir)
2137 (define-key map (kbd "g") 'elpher-go)
2138 (define-key map (kbd "o") 'elpher-go-current)
2139 (define-key map (kbd "s") 'elpher-history)
2140 (define-key map (kbd "S") 'elpher-history-all)
2141 (define-key map (kbd "r") 'elpher-redraw)
2142 (define-key map (kbd "R") 'elpher-reload)
2143 (define-key map (kbd "T") 'elpher-toggle-tls)
2144 (define-key map (kbd ".") 'elpher-view-raw)
2145 (define-key map (kbd "d") 'elpher-download)
2146 (define-key map (kbd "D") 'elpher-download-current)
2147 (define-key map (kbd "m") 'elpher-jump)
2148 (define-key map (kbd "M") 'elpher-jump-to-number)
2149 (define-key map (kbd "i") 'elpher-info-link)
2150 (define-key map (kbd "I") 'elpher-info-current)
2151 (define-key map (kbd "c") 'elpher-copy-link-url)
2152 (define-key map (kbd "C") 'elpher-copy-current-url)
2153 (define-key map (kbd "a") 'elpher-set-bookmark-no-overwrite)
2154 (define-key map (kbd "A") 'bookmark-set-no-overwrite)
2155 (define-key map (kbd "B") 'bookmark-bmenu-list)
2156 (define-key map (kbd "!") 'elpher-set-gopher-coding-system)
2157 (define-key map (kbd "F") 'elpher-forget-current-certificate)
2158 (when (fboundp 'evil-define-key*)
2161 (kbd "TAB") 'elpher-next-link
2162 (kbd "C-") 'elpher-follow-current-link
2163 (kbd "C-t") 'elpher-back
2164 (kbd "u") 'elpher-back
2165 (kbd "-") 'elpher-back
2166 (kbd "^") 'elpher-back
2167 [mouse-3] 'elpher-back
2168 (kbd "U") 'elpher-back-to-start
2169 (kbd "o") 'elpher-go
2170 (kbd "O") 'elpher-go-current
2171 (kbd "r") 'elpher-redraw
2172 (kbd "R") 'elpher-reload
2173 (kbd "T") 'elpher-toggle-tls
2174 (kbd ".") 'elpher-view-raw
2175 (kbd "d") 'elpher-download
2176 (kbd "D") 'elpher-download-current
2177 (kbd "m") 'elpher-jump
2178 (kbd "M") 'elpher-jump-to-number
2179 (kbd "i") 'elpher-info-link
2180 (kbd "I") 'elpher-info-current
2181 (kbd "c") 'elpher-copy-link-url
2182 (kbd "C") 'elpher-copy-current-url
2183 (kbd "a") 'elpher-set-bookmark-no-overwrite
2184 (kbd "A") 'bookmark-set-no-overwrite
2185 (kbd "B") 'bookmark-bmenu-list
2186 (kbd "!") 'elpher-set-gopher-coding-system
2187 (kbd "F") 'elpher-forget-current-certificate))
2189 "Keymap for gopher client.")
2191 (define-derived-mode elpher-mode special-mode "elpher"
2192 "Major mode for elpher, an elisp gopher client.
2194 This mode is automatically enabled by the interactive
2195 functions which initialize the client, namely
2196 `elpher', and `elpher-go'."
2197 (setq-local elpher--gemini-page-headings nil)
2198 (setq-local elpher-current-page nil)
2199 (setq-local elpher-history nil)
2200 (setq-local elpher-buffer-name (buffer-name))
2201 (setq-local bookmark-make-record-function #'elpher-bookmark-make-record)
2202 (setq-local imenu-create-index-function #'elpher--gemini-page-headings))
2204 (when (fboundp 'evil-set-initial-state)
2205 (evil-set-initial-state 'elpher-mode 'motion))
2208 ;;; Main start procedure
2212 (defun elpher (&optional arg)
2213 "Start elpher with default landing page.
2214 The buffer used for Elpher sessions is determined by the value of
2215 ‘elpher-buffer-name’. If there is already an Elpher session active in
2216 that buffer, Emacs will simply switch to it. Otherwise, a new session
2217 will begin. A numeric prefix ARG (as in ‘\\[universal-argument] 42
2218 \\[execute-extended-command] elpher RET’) switches to the session with
2219 that number, creating it if necessary. A non numeric prefix ARG means
2220 to create a new session. Returns the buffer selected (or created)."
2222 (let* ((name (default-value 'elpher-buffer-name))
2223 (buf (cond ((numberp arg)
2224 (get-buffer-create (format "%s<%d>" name arg)))
2226 (generate-new-buffer name))
2228 (get-buffer-create name)))))
2229 (pop-to-buffer-same-window buf)
2230 (unless (buffer-modified-p)
2232 (elpher-visit-page (elpher-make-start-page))
2233 "Started Elpher."))); Otherwise (elpher) evaluates to start page string.
2235 ;;; elpher.el ends here