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) 2019-2020 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 ;; - a simple bookmark management system,
54 ;; - gopher connections using TLS encryption,
55 ;; - the fledgling Gemini protocol,
56 ;; - the greybeard Finger protocol.
58 ;; To launch Elpher, simply use 'M-x elpher'. This will open a start
59 ;; page containing information on key bindings and suggested starting
60 ;; points for your gopher exploration.
62 ;; Full instructions can be found in the Elpher info manual.
64 ;; Elpher is under active development. Any suggestions for
65 ;; improvements are welcome, and can be made on the official
66 ;; project page, https://alexschroeder.ch/cgit/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.")
97 (defalias 'elpher-color-apply
98 (if (fboundp 'xterm-color-filter)
101 "A function to apply ANSI escape sequences.")
106 (defconst elpher-version "2.11.0"
107 "Current version of elpher.")
109 (defconst elpher-margin-width 6
110 "Width of left-hand margin used when rendering indicies.")
112 (defconst elpher-type-map
113 '(((gopher ?0) elpher-get-gopher-page elpher-render-text "txt" elpher-text)
114 ((gopher ?1) elpher-get-gopher-page elpher-render-index "/" elpher-index)
115 ((gopher ?4) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
116 ((gopher ?5) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
117 ((gopher ?7) elpher-get-gopher-query-page elpher-render-index "?" elpher-search)
118 ((gopher ?9) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
119 ((gopher ?g) elpher-get-gopher-page elpher-render-image "img" elpher-image)
120 ((gopher ?p) elpher-get-gopher-page elpher-render-image "img" elpher-image)
121 ((gopher ?I) elpher-get-gopher-page elpher-render-image "img" elpher-image)
122 ((gopher ?d) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
123 ((gopher ?P) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
124 ((gopher ?s) elpher-get-gopher-page elpher-render-download "snd" elpher-binary)
125 ((gopher ?h) elpher-get-gopher-page elpher-render-html "htm" elpher-html)
126 (gemini elpher-get-gemini-page elpher-render-gemini "gem" elpher-gemini)
127 (finger elpher-get-finger-page elpher-render-text "txt" elpher-text)
128 (telnet elpher-get-telnet-page nil "tel" elpher-telnet)
129 (other-url elpher-get-other-url-page nil "url" elpher-other-url)
130 ((special bookmarks) elpher-get-bookmarks-page nil "/" elpher-index)
131 ((special start) elpher-get-start-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.")
142 (defvar elpher--gemini-page-links nil
143 "List of links on the page.")
145 (defvar elpher--gemini-page-links-cache (make-hash-table :test 'equal)
146 "Hash of addresses and page links.")
148 ;;; Customization group
152 "A gopher and gemini client."
153 :group 'applications)
155 ;; General appearance and customizations
157 (defcustom elpher-open-urls-with-eww nil
158 "If non-nil, open URL selectors using eww.
159 Otherwise, use the system browser via the `browse-url' function."
162 (defcustom elpher-use-header t
163 "If non-nil, display current page information in buffer header."
166 (defcustom elpher-auto-disengage-TLS nil
167 "If non-nil, automatically disengage TLS following an unsuccessful connection.
168 While enabling this may seem convenient, it is also potentially
169 dangerous as it allows switching from an encrypted channel back to
170 plain text without user input."
173 (defcustom elpher-connection-timeout 5
174 "Specifies the number of seconds to wait for a network connection to time out."
177 (defcustom elpher-filter-ansi-from-text nil
178 "If non-nil, filter ANSI escape sequences from text.
179 The default behaviour is to use the ansi-color package to interpret these
183 (defcustom elpher-certificate-directory
184 (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
185 "Specify the name of the directory where client certificates will be stored.
186 These certificates may be used for establishing authenticated TLS connections."
189 (defcustom elpher-openssl-command "openssl"
190 "The command used to launch openssl when generating TLS client certificates."
193 (defcustom elpher-default-url-type "gopher"
194 "Default URL type (i.e. scheme) to assume if not explicitly given."
195 :type '(choice (const "gopher")
198 (defcustom elpher-gemini-TLS-cert-checks nil
199 "If non-nil, verify gemini server TLS certs using the default security level.
200 Otherwise, certificate verification is disabled.
202 This defaults to off because it is standard practice for Gemini servers
203 to use self-signed certificates, meaning that most servers provide what
204 EMACS considers to be an invalid certificate."
207 (defcustom elpher-gemini-max-fill-width 80
208 "Specify the maximum default width (in columns) of text/gemini documents.
209 The actual width used is the minimum of this value and the window width at
210 the time when the text is rendered."
213 (defcustom elpher-gemini-link-string "→ "
214 "Specify the string used to indicate links when rendering gemini maps.
218 (defcustom elpher-gemini-bullet-string "•"
219 "Specify the string used for bullets when rendering gemini maps."
222 (defcustom elpher-bookmarks-file (locate-user-emacs-file "elpher-bookmarks")
223 "Specify the name of the file where elpher bookmarks will be saved."
226 (defcustom elpher-ipv4-always nil
227 "If non-nil, elpher will always use IPv4 to establish network connections.
228 This can be useful when browsing from a computer that supports IPv6, because
229 some servers which do not support IPv6 can take a long time to time-out."
232 (defcustom elpher-socks-always nil
233 "If non-nil, elpher will establish network connections over a SOCKS proxy.
234 Otherwise, the SOCKS proxy is only used for connections to onion services."
237 (defcustom elpher-gemini-number-links nil
238 "If non-nil, number links in gemini pages when rendering.
239 Links can be accessed by pressing `v' ('visit') followed by the link number."
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 (setf (url-filename url)
338 (url-unhex-string (url-filename url)))
339 (unless (url-type url)
340 (setf (url-type url) elpher-default-url-type))
341 (unless (url-host url)
342 (let ((p (split-string (url-filename url) "/" nil nil)))
343 (setf (url-host url) (car p))
344 (setf (url-filename url)
346 (concat "/" (mapconcat #'identity (cdr p) "/"))
348 (when (or (equal "gopher" (url-type url))
349 (equal "gophers" (url-type url)))
351 (when (or (equal (url-filename url) "")
352 (equal (url-filename url) "/"))
353 (setf (url-filename url) "/1")))
354 (when (equal "gemini" (url-type url))
356 (if (equal (url-filename url) "")
357 (setf (url-filename url) "/"))))
358 (elpher-remove-redundant-ports url))
359 (set-match-data data))))
361 (defun elpher-remove-redundant-ports (address)
362 "Remove redundant port specifiers from ADDRESS.
363 Here 'redundant' means that the specified port matches the default
364 for that protocol, eg 70 for gopher."
365 (if (and (not (elpher-address-special-p address))
366 (eq (url-portspec address) ; (url-port) is too slow!
367 (pcase (url-type address)
369 ((or "gopher" "gophers") 70)
372 (setf (url-portspec address) nil))
375 (defun elpher-make-gopher-address (type selector host port &optional tls)
376 "Create an ADDRESS object using gopher directory record attributes.
377 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
378 If the optional attribute TLS is non-nil, the address will be marked as
379 requiring gopher-over-TLS."
381 ((equal type ?i) nil)
382 ((and (equal type ?h)
383 (string-prefix-p "URL:" selector))
384 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
386 (elpher-address-from-url
389 ":" (number-to-string port))))
391 (elpher-address-from-url
392 (concat "gopher" (if tls "s" "")
394 ":" (number-to-string port)
398 (defun elpher-make-special-address (type)
399 "Create an ADDRESS object corresponding to the given special address symbol TYPE."
402 (defun elpher-address-to-url (address)
403 "Get string representation of ADDRESS, or nil if ADDRESS is special."
404 (if (elpher-address-special-p address)
406 (url-encode-url (url-recreate-url address))))
408 (defun elpher-address-type (address)
409 "Retrieve type of ADDRESS object.
410 This is used to determine how to retrieve and render the document the
411 address refers to, via the table `elpher-type-map'."
412 (if (symbolp address)
413 (list 'special address)
414 (let ((protocol (url-type address)))
415 (cond ((or (equal protocol "gopher")
416 (equal protocol "gophers"))
418 (if (member (url-filename address) '("" "/"))
420 (string-to-char (substring (url-filename address) 1)))))
421 ((equal protocol "gemini")
423 ((equal protocol "telnet")
425 ((equal protocol "finger")
429 (defun elpher-address-protocol (address)
430 "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
431 (if (symbolp address)
435 (defun elpher-address-filename (address)
436 "Retrieve the filename component of ADDRESS.
437 For gopher addresses this is a combination of the selector type and selector."
438 (if (symbolp address)
440 (url-filename address)))
442 (defun elpher-address-host (address)
443 "Retrieve host from ADDRESS object."
446 (defun elpher-address-user (address)
447 "Retrieve user from ADDRESS object."
450 (defun elpher-address-port (address)
451 "Retrieve port from ADDRESS object.
452 If no address is defined, returns 0. (This is for compatibility with the URL library.)"
453 (if (symbolp address)
457 (defun elpher-address-special-p (address)
458 "Return non-nil if ADDRESS object is special (e.g. start page, bookmarks page)."
461 (defun elpher-address-gopher-p (address)
462 "Return non-nill if ADDRESS object is a gopher address."
463 (and (not (elpher-address-special-p address))
464 (member (elpher-address-protocol address) '("gopher gophers"))))
466 (defun elpher-gopher-address-selector (address)
467 "Retrieve gopher selector from ADDRESS object."
468 (if (member (url-filename address) '("" "/"))
470 (url-unhex-string (substring (url-filename address) 2))))
475 (defvar elpher-content-cache (make-hash-table :test 'equal))
476 (defvar elpher-pos-cache (make-hash-table :test 'equal))
478 (defun elpher-get-cached-content (address)
479 "Retrieve the cached content for ADDRESS, or nil if none exists."
480 (gethash address elpher-content-cache))
482 (defun elpher-cache-content (address content)
483 "Set the content cache for ADDRESS to CONTENT."
484 (puthash address content elpher-content-cache))
486 (defun elpher-get-cached-pos (address)
487 "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
488 (gethash address elpher-pos-cache))
490 (defun elpher-cache-pos (address pos)
491 "Set the cursor position cache for ADDRESS to POS."
492 (puthash address pos elpher-pos-cache))
497 (defun elpher-make-page (display-string address)
498 "Create a page with DISPLAY-STRING and ADDRESS."
499 (list display-string address))
501 (defun elpher-page-display-string (page)
502 "Retrieve the display string corresponding to PAGE."
505 (defun elpher-page-address (page)
506 "Retrieve the address corresponding to PAGE."
509 (defun elpher-page-set-address (page new-address)
510 "Set the address corresponding to PAGE to NEW-ADDRESS."
511 (setcar (cdr page) new-address))
513 (defvar elpher-current-page nil) ; buffer local
514 (defvar elpher-history nil) ; buffer local
516 (defun elpher-visit-page (page &optional renderer no-history)
517 "Visit PAGE using its own renderer or RENDERER, if non-nil.
518 Additionally, push PAGE onto the stack of previously-visited pages,
519 unless NO-HISTORY is non-nil."
521 (elpher-process-cleanup)
522 (unless (or no-history
523 (equal (elpher-page-address elpher-current-page)
524 (elpher-page-address page)))
525 (push elpher-current-page elpher-history))
526 (setq-local elpher-current-page page)
527 (let* ((address (elpher-page-address page))
528 (type (elpher-address-type address))
529 (type-record (cdr (assoc type elpher-type-map)))
533 (funcall (car type-record)
537 (setq page-links (gethash address elpher--gemini-page-links-cache))
539 (setq elpher--gemini-page-links page-links)))
540 (elpher-visit-previous-page)
542 (`(gopher ,type-char)
543 (error "Unsupported gopher selector type '%c' for '%s'"
544 type-char (elpher-address-to-url address)))
546 (error "Unsupported address type '%S' for '%s'"
547 other (elpher-address-to-url address)))))))
549 (defun elpher-visit-previous-page ()
550 "Visit the previous page in the history."
551 (let ((previous-page (pop elpher-history)))
553 (elpher-visit-page previous-page nil t)
554 (error "No previous page"))))
556 (defun elpher-reload-current-page ()
557 "Reload the current page, discarding any existing cached content."
558 (elpher-cache-content (elpher-page-address elpher-current-page) nil)
559 (elpher-visit-page elpher-current-page))
561 (defun elpher-save-pos ()
562 "Save the current position of point to the current page."
563 (when elpher-current-page
564 (elpher-cache-pos (elpher-page-address elpher-current-page) (point))))
566 (defun elpher-restore-pos ()
567 "Restore the position of point to that cached in the current page."
568 (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
571 (goto-char (point-min)))))
574 ;;; Buffer preparation
577 (defvar elpher-buffer-name "*elpher*"
578 "The default name of the Elpher buffer.")
580 (defun elpher-update-header ()
581 "If `elpher-use-header' is true, display current page info in window header."
582 (if elpher-use-header
583 (let* ((display-string (elpher-page-display-string elpher-current-page))
584 (address (elpher-page-address elpher-current-page))
585 (tls-string (if (and (not (elpher-address-special-p address))
586 (member (elpher-address-protocol address)
587 '("gophers" "gemini")))
590 (header (concat display-string
591 (propertize tls-string 'face 'bold))))
592 (setq header-line-format header))))
594 (defmacro elpher-with-clean-buffer (&rest args)
595 "Evaluate ARGS with a clean *elpher* buffer as current."
596 `(with-current-buffer elpher-buffer-name
597 (unless (eq major-mode 'elpher-mode)
598 ;; avoid resetting buffer-local variables
600 (let ((inhibit-read-only t))
601 (setq-local network-security-level
602 (default-value 'network-security-level))
604 (elpher-update-header)
607 (defun elpher-buffer-message (string &optional line)
608 "Replace first line in elpher buffer with STRING.
609 If LINE is non-nil, replace that line instead."
610 (with-current-buffer elpher-buffer-name
611 (let ((inhibit-read-only t))
612 (goto-char (point-min))
615 (let ((data (match-data)))
618 (re-search-forward "^.*$")
619 (replace-match string))
620 (set-match-data data))))))
626 (defvar elpher-user-coding-system nil
627 "User-specified coding system to use for decoding text responses.")
629 (defun elpher-decode (string)
630 "Decode STRING using autodetected or user-specified coding system."
631 (decode-coding-string string
632 (if elpher-user-coding-system
633 elpher-user-coding-system
634 (detect-coding-string string t))))
636 (defun elpher-preprocess-text-response (string)
637 "Preprocess text selector response contained in STRING.
638 This involes decoding the character representation, and clearing
639 away CRs and any terminating period."
640 (elpher-decode (replace-regexp-in-string "\n\\.\n$" "\n"
641 (replace-regexp-in-string "\r" "" string))))
644 ;;; Network error reporting
647 (defun elpher-network-error (address error)
648 "Display ERROR message following unsuccessful negotiation with ADDRESS.
649 ERROR can be either an error object or a string."
650 (elpher-with-clean-buffer
651 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
652 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
653 (if (stringp error) error (error-message-string error)) "\n"
654 (propertize "\n----------------\n\n" 'face 'error)
655 "Press 'u' to return to the previous page.")))
658 ;;; General network communication
661 (defvar elpher-network-timer nil
662 "Timer used for network connections.")
664 (defvar elpher-use-tls nil
665 "If non-nil, use TLS to communicate with gopher servers.")
667 (defvar elpher-client-certificate nil
668 "If non-nil, contains client certificate details to use for TLS connections.")
670 (defun elpher-process-cleanup ()
671 "Immediately shut down any extant elpher process and timers."
672 (let ((p (get-process "elpher-process")))
673 (if p (delete-process p)))
674 (if (timerp elpher-network-timer)
675 (cancel-timer elpher-network-timer)))
677 (defun elpher-get-host-response (address default-port query-string response-processor
678 &optional use-tls force-ipv4)
679 "Generic function for retrieving data from ADDRESS.
681 When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
682 QUERY-STRING is a string sent to the host specified by ADDRESS to
683 illicet a response. This response is passed as an argument to the
684 function RESPONSE-PROCESSOR.
686 If non-nil, USE-TLS specifies that the connection is to be made over
687 TLS. If set to gemini, the certificate verification will be disabled
688 unless `elpher-gemini-TLS-cert-checks' is non-nil.
690 If non-nil, FORCE-IPV4 causes the network connection to be made over
691 ipv4 only. (The default behaviour when this is not set depends on
692 the host operating system and the local network capabilities."
693 (if (and use-tls (not (gnutls-available-p)))
694 (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
695 (unless (< (elpher-address-port address) 65536)
696 (error "Cannot establish network connection: port number > 65536"))
697 (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
698 (setq-local network-security-level 'low)
699 (setq-local gnutls-verify-error nil))
701 (let* ((kill-buffer-query-functions nil)
702 (port (elpher-address-port address))
703 (service (if (> port 0) port default-port))
704 (host (elpher-address-host address))
705 (socks (or elpher-socks-always (string-suffix-p ".onion" host)))
706 (response-string-parts nil)
709 (timer (run-at-time elpher-connection-timeout nil
711 (elpher-process-cleanup)
713 ; Try again with IPv4
714 ((not (or force-ipv4 socks))
715 (message "Connection timed out. Retrying with IPv4.")
716 (elpher-get-host-response address default-port
721 (not (eq use-tls 'gemini))
722 (or elpher-auto-disengage-TLS
724 "TLS connetion failed. Disable TLS mode and retry? ")))
725 (setq elpher-use-tls nil)
726 (elpher-get-host-response address default-port
731 (elpher-network-error address "Connection time-out."))))))
732 (gnutls-params (list :type 'gnutls-x509pki :hostname host
733 :keylist (elpher-get-current-keylist address)))
734 (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
735 (make-network-process :name "elpher-process"
737 :family (and force-ipv4 'ipv4)
743 (cons 'gnutls-x509pki
744 (apply #'gnutls-boot-parameters
746 (setq elpher-network-timer timer)
747 (set-process-coding-system proc 'binary 'binary)
748 (set-process-query-on-exit-flag proc nil)
749 (elpher-buffer-message (concat "Connecting to " host "..."
750 " (press 'u' to abort)"))
751 (set-process-filter proc
752 (lambda (_proc string)
756 (setq bytes-received (+ bytes-received (length string)))
757 (let ((new-hkbytes-received (/ bytes-received 102400)))
758 (when (> new-hkbytes-received hkbytes-received)
759 (setq hkbytes-received new-hkbytes-received)
760 (elpher-buffer-message
762 (number-to-string (/ hkbytes-received 10.0))
765 (setq response-string-parts
766 (cons string response-string-parts))))
767 (set-process-sentinel proc
770 (cancel-timer timer))
771 (condition-case the-error
773 ((string-prefix-p "open" event) ; request URL
774 (elpher-buffer-message
775 (concat "Connected to " host ". Receiving data..."
776 " (press 'u' to abort)"))
777 (let ((inhibit-eol-conversion t))
778 (process-send-string proc query-string)))
779 ((string-prefix-p "deleted" event)) ; do nothing
780 ((and (not response-string-parts)
781 (not (or elpher-ipv4-always force-ipv4 socks)))
782 ; Try again with IPv4
783 (message "Connection failed. Retrying with IPv4.")
784 (elpher-get-host-response address default-port
788 (response-string-parts
789 (elpher-with-clean-buffer
790 (insert "Data received. Rendering..."))
791 (funcall response-processor
792 (apply #'concat (reverse response-string-parts)))
793 (elpher-restore-pos))
795 (error "No response from server")))
797 (elpher-network-error address the-error)))))
799 (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
800 (funcall (process-sentinel proc) proc "open\n")))
802 (error "Error initiating connection to server")))))
805 ;;; Client-side TLS Certificate Management
808 (defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
809 "Generate a key and a self-signed client TLS certificate using openssl.
811 The Common Name field of the certificate is set to COMMON-NAME. The
812 arguments KEY-FILE and CERT-FILE should contain the absolute paths of
813 the key and certificate files to write.
815 If TEMPORARY is non-nil, the certificate will be given an exporation
816 period of one day, and the key and certificate files will be deleted
817 when the certificate is no longer needed for the current session.
819 Otherwise, the certificate will be given a 100 year expiration period
820 and the files will not be deleted.
822 The function returns a list containing the current host name, the
823 temporary flag, and the key and cert file names in the form required
824 by `gnutls-boot-parameters`."
825 (let ((exp-key-file (expand-file-name key-file))
826 (exp-cert-file (expand-file-name cert-file)))
829 (call-process elpher-openssl-command nil nil nil
830 "req" "-x509" "-newkey" "rsa:2048"
831 "-days" (if temporary "1" "36500")
833 "-subj" (concat "/CN=" common-name)
834 "-keyout" exp-key-file
835 "-out" exp-cert-file)
836 (list (elpher-address-host (elpher-page-address elpher-current-page))
837 temporary exp-key-file exp-cert-file))
839 (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
840 (error "Program 'openssl', required for certificate generation, not found")))))
842 (defun elpher-generate-throwaway-certificate ()
843 "Generate and return details of a throwaway certificate.
844 The key and certificate files will be deleted when they are no
845 longer needed for this session."
846 (let* ((file-base (make-temp-name "elpher"))
847 (key-file (concat temporary-file-directory file-base ".key"))
848 (cert-file (concat temporary-file-directory file-base ".crt")))
849 (elpher-generate-certificate file-base key-file cert-file t)))
851 (defun elpher-generate-persistent-certificate (file-base common-name)
852 "Generate and return details of a persistent certificate.
853 The argument FILE-BASE is used as the base for the key and certificate
854 files, while COMMON-NAME specifies the common name field of the
857 The key and certificate files are written to in `elpher-certificate-directory'."
858 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
859 (cert-file (concat elpher-certificate-directory file-base ".crt")))
860 (elpher-generate-certificate common-name key-file cert-file)))
862 (defun elpher-get-existing-certificate (file-base)
863 "Return a certificate object corresponding to an existing certificate.
864 It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
865 the directory `elpher-certificate-directory'."
866 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
867 (cert-file (concat elpher-certificate-directory file-base ".crt")))
868 (list (elpher-address-host (elpher-page-address elpher-current-page))
870 (expand-file-name key-file)
871 (expand-file-name cert-file))))
873 (defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
874 "Install a key+certificate file pair in `elpher-certificate-directory'.
875 The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
876 certificate files to install. The argument FILE-BASE is used as the
877 base for the installed key and certificate files."
878 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
879 (cert-file (concat elpher-certificate-directory file-base ".crt")))
880 (if (or (file-exists-p key-file)
881 (file-exists-p cert-file))
882 (error "A certificate with base name %s is already installed" file-base))
883 (copy-file key-file-src key-file)
884 (copy-file cert-file-src cert-file)
885 (list (elpher-address-host (elpher-page-address elpher-current-page))
887 (expand-file-name key-file)
888 (expand-file-name cert-file))))
890 (defun elpher-list-existing-certificates ()
891 "Return a list of the persistent certificates in `elpher-certificate-directory'."
892 (unless (file-directory-p elpher-certificate-directory)
893 (make-directory elpher-certificate-directory))
896 (file-name-sans-extension file))
897 (directory-files elpher-certificate-directory nil "\\.key$")))
899 (defun elpher-forget-current-certificate ()
900 "Causes any current certificate to be forgotten.)
901 In the case of throwaway certificates, the key and certificate files
904 (when elpher-client-certificate
905 (unless (and (called-interactively-p 'any)
906 (not (y-or-n-p (concat "Really forget client certificate? "
907 "(Throwaway certificates will be deleted.)"))))
908 (when (cadr elpher-client-certificate)
909 (delete-file (elt elpher-client-certificate 2))
910 (delete-file (elt elpher-client-certificate 3)))
911 (setq elpher-client-certificate nil)
912 (if (called-interactively-p 'any)
913 (message "Client certificate forgotten.")))))
915 (defun elpher-get-current-keylist (address)
916 "Retrieve the `gnutls-boot-parameters'-compatable keylist.
918 This is obtained from the client certificate described by
919 `elpher-current-certificate', if one is available and the host for
920 that certificate matches the host in ADDRESS.
922 If `elpher-current-certificate' is non-nil, and its host name doesn't
923 match that of ADDRESS, the certificate is forgotten."
924 (if elpher-client-certificate
925 (if (string= (car elpher-client-certificate)
926 (elpher-address-host address))
927 (list (cddr elpher-client-certificate))
928 (elpher-forget-current-certificate)
929 (message "Disabling client certificate for new host")
934 ;;; Gopher selector retrieval
937 (defun elpher-get-gopher-response (address renderer)
938 "Get response string from gopher server at ADDRESS and render using RENDERER."
939 (elpher-get-host-response address 70
940 (concat (elpher-gopher-address-selector address) "\r\n")
942 (or (string= (elpher-address-protocol address) "gophers")
945 (defun elpher-get-gopher-page (renderer)
946 "Getter function for gopher pages.
947 The RENDERER procedure is used to display the contents of the page
948 once they are retrieved from the gopher server."
949 (let* ((address (elpher-page-address elpher-current-page))
950 (content (elpher-get-cached-content address)))
951 (if (and content (funcall renderer nil))
952 (elpher-with-clean-buffer
954 (elpher-restore-pos))
955 (elpher-with-clean-buffer
956 (insert "LOADING... (use 'u' to cancel)\n"))
957 (condition-case the-error
958 (elpher-get-gopher-response address renderer)
960 (elpher-network-error address the-error))))))
964 (defun elpher-insert-index (string)
965 "Insert the index corresponding to STRING into the current buffer."
966 ;; Should be able to split directly on CRLF, but some non-conformant
967 ;; LF-only servers sadly exist, hence the following.
968 (let ((str-processed (elpher-preprocess-text-response string)))
969 (dolist (line (split-string str-processed "\n"))
971 (unless (= (length line) 0)
972 (let* ((type (elt line 0))
973 (fields (split-string (substring line 1) "\t"))
974 (display-string (elt fields 0))
975 (selector (elt fields 1))
976 (host (elt fields 2))
977 (port (if (elt fields 3)
978 (string-to-number (elt fields 3))
980 (address (elpher-make-gopher-address type selector host port)))
981 (elpher-insert-index-record display-string address)))))))
983 (defun elpher-insert-margin (&optional type-name)
984 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
987 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
989 (propertize "[" 'face 'elpher-margin-brackets)
990 (propertize type-name 'face 'elpher-margin-key)
991 (propertize "]" 'face 'elpher-margin-brackets))))
993 (insert (make-string elpher-margin-width ?\s))))
995 (defun elpher--page-button-help (_window buffer pos)
996 "Function called by Emacs to generate mouse-over text.
997 The arguments specify the BUFFER and the POS within the buffer of the item
998 for which help is required. The function returns the help to be
999 displayed. The _WINDOW argument is currently unused."
1000 (with-current-buffer buffer
1001 (let ((button (button-at pos)))
1003 (let* ((page (button-get button 'elpher-page))
1004 (address (elpher-page-address page)))
1005 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
1007 (elpher-address-to-url address))))))))
1009 (defun elpher-insert-index-record (display-string &optional address)
1010 "Function to insert an index record into the current buffer.
1011 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
1012 If ADDRESS is not supplied or nil the record is rendered as an
1013 'information' line."
1014 (let* ((type (if address (elpher-address-type address) nil))
1015 (type-map-entry (cdr (assoc type elpher-type-map))))
1017 (let* ((margin-code (elt type-map-entry 2))
1018 (face (elt type-map-entry 3))
1019 (filtered-display-string (elpher-color-filter-apply display-string))
1020 (page (elpher-make-page filtered-display-string address)))
1021 (elpher-insert-margin margin-code)
1022 (insert-text-button filtered-display-string
1025 'action #'elpher-click-link
1027 'help-echo #'elpher--page-button-help))
1029 ('nil ;; Information
1030 (elpher-insert-margin)
1031 (let ((propertized-display-string
1032 (propertize display-string 'face 'elpher-info)))
1033 (insert (elpher-process-text-for-display propertized-display-string))))
1034 (`(gopher ,selector-type) ;; Unknown
1035 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
1036 (insert (propertize display-string
1037 'face 'elpher-unknown)))))
1040 (defun elpher-click-link (button)
1041 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
1042 (let ((page (button-get button 'elpher-page)))
1043 (elpher-visit-page page)))
1045 (defun elpher-render-index (data &optional _mime-type-string)
1046 "Render DATA as an index. MIME-TYPE-STRING is unused."
1047 (elpher-with-clean-buffer
1050 (elpher-insert-index data)
1051 (elpher-cache-content (elpher-page-address elpher-current-page)
1056 (defconst elpher-url-regex
1057 "\\([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_~?/@|#-]\\)?\\)?"
1058 "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
1060 (defun elpher-buttonify-urls (string)
1061 "Turn substrings which look like urls in STRING into clickable buttons."
1064 (goto-char (point-min))
1065 (while (re-search-forward elpher-url-regex nil t)
1066 (let ((page (elpher-make-page (substring-no-properties (match-string 0))
1067 (elpher-address-from-url (match-string 0)))))
1068 (make-text-button (match-beginning 0)
1071 'action #'elpher-click-link
1073 'help-echo #'elpher--page-button-help
1077 (defconst elpher-ansi-regex "\x1b\\[[^m]*m"
1078 "Incomplete regexp used to strip out some troublesome ANSI escape sequences.")
1080 (defun elpher-process-text-for-display (string)
1081 "Perform any desired processing of STRING prior to display as text.
1082 Currently includes buttonifying URLs and processing ANSI escape codes."
1083 (elpher-buttonify-urls (if elpher-filter-ansi-from-text
1084 (elpher-color-filter-apply string)
1085 (elpher-color-apply string))))
1087 (defun elpher-render-text (data &optional _mime-type-string)
1088 "Render DATA as text. MIME-TYPE-STRING is unused."
1089 (elpher-with-clean-buffer
1092 (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
1093 (elpher-cache-content
1094 (elpher-page-address elpher-current-page)
1099 (defun elpher-render-image (data &optional _mime-type-string)
1100 "Display DATA as image. MIME-TYPE-STRING is unused."
1103 (if (display-images-p)
1105 (let ((image (create-image
1108 (elpher-with-clean-buffer
1109 (insert-image image)
1110 (elpher-restore-pos))))
1111 (elpher-render-download data))))
1113 ;; Search retrieval and rendering
1115 (defun elpher-get-gopher-query-page (renderer)
1116 "Getter for gopher addresses requiring input.
1117 The response is rendered using the rendering function RENDERER."
1118 (let* ((address (elpher-page-address elpher-current-page))
1119 (content (elpher-get-cached-content address))
1121 (if (and content (funcall renderer nil))
1122 (elpher-with-clean-buffer
1124 (elpher-restore-pos)
1125 (message "Displaying cached search results. Reload to perform a new search."))
1127 (let* ((query-string (read-string "Query: "))
1128 (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
1129 (search-address (elpher-make-gopher-address ?1
1131 (elpher-address-host address)
1132 (elpher-address-port address)
1133 (equal (elpher-address-type address) "gophers"))))
1136 (elpher-with-clean-buffer
1137 (insert "LOADING RESULTS... (use 'u' to cancel)"))
1138 (elpher-get-gopher-response search-address renderer))
1140 (elpher-visit-previous-page))))))
1142 ;; Raw server response rendering
1144 (defun elpher-render-raw (data &optional mime-type-string)
1145 "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
1148 (elpher-with-clean-buffer
1149 (when mime-type-string
1150 (insert "MIME type specified by server: '" mime-type-string "'\n"))
1152 (goto-char (point-min)))
1153 (message "Displaying raw server response. Reload or redraw to return to standard view.")))
1155 ;; File save "rendering"
1157 (defun elpher-render-download (data &optional _mime-type-string)
1158 "Save DATA to file. MIME-TYPE-STRING is unused."
1161 (let* ((address (elpher-page-address elpher-current-page))
1162 (selector (if (elpher-address-gopher-p address)
1163 (elpher-gopher-address-selector address)
1164 (elpher-address-filename address))))
1165 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1166 (let* ((filename-proposal (file-name-nondirectory selector))
1167 (filename (read-file-name "Download complete. Save file as: "
1169 (if (> (length filename-proposal) 0)
1172 (let ((coding-system-for-write 'binary))
1173 (with-temp-file filename
1175 (message (format "Saved to file %s." filename))))))
1179 (defun elpher-render-html (data &optional _mime-type-string)
1180 "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
1181 (elpher-with-clean-buffer
1184 (let ((dom (with-temp-buffer
1186 (libxml-parse-html-region (point-min) (point-max)))))
1187 (shr-insert-document dom)))))
1189 ;; Gemini page retrieval
1191 (defvar elpher-gemini-redirect-chain)
1193 (defun elpher-get-gemini-response (address renderer)
1194 "Get response string from gemini server at ADDRESS and render using RENDERER."
1195 (elpher-get-host-response address 1965
1196 (concat (elpher-address-to-url address) "\r\n")
1197 (lambda (response-string)
1198 (elpher-process-gemini-response response-string renderer))
1201 (defun elpher-parse-gemini-response (response)
1202 "Parse the RESPONSE string and return a list of components.
1203 The list is of the form (code meta body). A response of nil implies
1204 that the response was malformed."
1205 (let ((header-end-idx (string-match "\r\n" response)))
1207 (let ((header (string-trim (substring response 0 header-end-idx)))
1208 (body (substring response (+ header-end-idx 2))))
1209 (if (>= (length header) 2)
1210 (let ((code (substring header 0 2))
1211 (meta (string-trim (substring header 2))))
1212 (list code meta body))
1213 (error "Malformed response: No response status found in header %s" header)))
1214 (error "Malformed response: No CRLF-delimited header found in response %s" response))))
1216 (defun elpher-process-gemini-response (response-string renderer)
1217 "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
1218 (let ((response-components (elpher-parse-gemini-response response-string)))
1219 (let ((response-code (elt response-components 0))
1220 (response-meta (elt response-components 1))
1221 (response-body (elt response-components 2)))
1222 (pcase (elt response-code 0)
1223 (?1 ; Input required
1224 (elpher-with-clean-buffer
1225 (insert "Gemini server is requesting input."))
1226 (let* ((query-string
1227 (if (eq (elt response-code 1) ?1)
1228 (read-passwd (concat response-meta ": "))
1229 (read-string (concat response-meta ": "))))
1230 (query-address (seq-copy (elpher-page-address elpher-current-page)))
1231 (old-fname (url-filename query-address)))
1232 (setf (url-filename query-address)
1233 (concat old-fname "?" (url-build-query-string `((,query-string)))))
1234 (elpher-get-gemini-response query-address renderer)))
1235 (?2 ; Normal response
1236 (funcall renderer response-body response-meta))
1238 (message "Following redirect to %s" response-meta)
1239 (if (>= (length elpher-gemini-redirect-chain) 5)
1240 (error "More than 5 consecutive redirects followed"))
1241 (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
1242 (if (member redirect-address elpher-gemini-redirect-chain)
1243 (error "Redirect loop detected"))
1244 (if (not (string= (elpher-address-protocol redirect-address)
1246 (error "Server tried to automatically redirect to non-gemini URL: %s"
1248 (elpher-page-set-address elpher-current-page redirect-address)
1249 (add-to-list 'elpher-gemini-redirect-chain redirect-address)
1250 (elpher-get-gemini-response redirect-address renderer)))
1251 (?4 ; Temporary failure
1252 (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
1253 response-code response-meta))
1254 (?5 ; Permanent failure
1255 (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
1256 response-code response-meta))
1257 (?6 ; Client certificate required
1258 (elpher-with-clean-buffer
1259 (if elpher-client-certificate
1260 (insert "Gemini server does not recognise the provided TLS certificate:\n\n")
1261 (insert "Gemini server is requesting a valid TLS certificate:\n\n"))
1263 (elpher-gemini-insert-text response-meta))
1264 (let ((chosen-certificate (elpher-choose-client-certificate)))
1265 (unless chosen-certificate
1266 (error "Gemini server requires a client certificate and none was provided"))
1267 (setq elpher-client-certificate chosen-certificate))
1268 (elpher-with-clean-buffer)
1269 (elpher-get-gemini-response (elpher-page-address elpher-current-page) renderer))
1271 (error "Gemini server response unknown: %s %s"
1272 response-code response-meta))))))
1274 (unless (fboundp 'read-answer)
1275 (defun read-answer (question answers)
1276 "Backfill for the new read-answer code."
1277 (completing-read question (mapcar 'identity answers))))
1279 (defun elpher-choose-client-certificate ()
1280 "Prompt for a client certificate to use to establish a TLS connection."
1281 (let* ((read-answer-short t))
1282 (pcase (read-answer "What do you want to do? "
1284 "generate and use throw-away certificate")
1286 "generate new or use existing persistent certificate")
1288 "stop immediately")))
1290 (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
1292 (let* ((existing-certificates (elpher-list-existing-certificates))
1293 (file-base (completing-read
1294 "Nickname for new or existing certificate (autocompletes, empty response aborts): "
1295 existing-certificates)))
1296 (if (string-empty-p (string-trim file-base))
1298 (if (member file-base existing-certificates)
1299 (setq elpher-client-certificate
1300 (elpher-get-existing-certificate file-base))
1301 (pcase (read-answer "Generate new certificate or install externally-generated one? "
1303 "generate new certificate")
1305 "install existing certificate")
1307 "stop immediately")))
1309 (let ((common-name (read-string "Common Name field for new certificate: "
1311 (message "New key and self-signed certificate written to %s"
1312 elpher-certificate-directory)
1313 (elpher-generate-persistent-certificate file-base common-name)))
1315 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
1316 (key-file (read-file-name "Key file: " nil nil t)))
1317 (message "Key and certificate installed in %s for future use"
1318 elpher-certificate-directory)
1319 (elpher-install-and-use-existing-certificate key-file
1325 (defun elpher-get-gemini-page (renderer)
1326 "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
1327 (let* ((address (elpher-page-address elpher-current-page))
1328 (content (elpher-get-cached-content address)))
1329 (condition-case the-error
1330 (if (and content (funcall renderer nil))
1331 (elpher-with-clean-buffer
1333 (elpher-restore-pos))
1334 (elpher-with-clean-buffer
1335 (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
1336 (setq elpher-gemini-redirect-chain nil)
1337 (elpher-get-gemini-response address renderer))
1339 (elpher-network-error address the-error)))))
1341 (defun elpher-render-gemini (body &optional mime-type-string)
1342 "Render gemini response BODY with rendering MIME-TYPE-STRING."
1345 (let* ((mime-type-string* (if (or (not mime-type-string)
1346 (string-empty-p mime-type-string))
1347 "text/gemini; charset=utf-8"
1349 (mime-type-split (split-string mime-type-string* ";" t))
1350 (mime-type (string-trim (car mime-type-split)))
1351 (parameters (mapcar (lambda (s)
1352 (let ((key-val (split-string s "=")))
1353 (list (downcase (string-trim (car key-val)))
1354 (downcase (string-trim (cadr key-val))))))
1355 (cdr mime-type-split))))
1356 (when (string-prefix-p "text/" mime-type)
1357 (setq body (decode-coding-string
1359 (if (assoc "charset" parameters)
1360 (intern (cadr (assoc "charset" parameters)))
1362 (setq body (replace-regexp-in-string "\r" "" body)))
1364 ((or "text/gemini" "")
1365 (elpher-render-gemini-map body parameters))
1367 (elpher-render-html body))
1368 ((pred (string-prefix-p "text/"))
1369 (elpher-render-gemini-plain-text body parameters))
1370 ((pred (string-prefix-p "image/"))
1371 (elpher-render-image body))
1373 (elpher-render-download body))))))
1375 (defun elpher-gemini-get-link-url (link-line)
1376 "Extract the url portion of LINK-LINE, a gemini map file link line.
1377 Returns nil in the event that the contents of the line following the
1378 => prefix are empty."
1379 (let ((l (split-string (substring link-line 2))))
1381 (string-trim (elt l 0))
1384 (defun elpher-gemini-get-link-display-string (link-line)
1385 "Extract the display string portion of LINK-LINE, a gemini map file link line.
1386 Returns the url portion in the event that the display-string portion is empty."
1387 (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
1388 (idx (string-match "[ \t]" rest)))
1389 (string-trim (if idx
1390 (substring rest (+ idx 1))
1393 (defun elpher-collapse-dot-sequences (filename)
1394 "Collapse dot sequences in FILENAME.
1395 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
1396 (let* ((path (split-string filename "/"))
1397 (path-reversed-normalized
1398 (seq-reduce (lambda (a b)
1399 (cond ((and a (equal b "..") (cdr a)))
1400 ((and (not a) (equal b "..")) a) ;leading .. are dropped
1404 (string-join (reverse path-reversed-normalized) "/")))
1406 (defun elpher-address-from-gemini-url (url)
1407 "Extract address from URL with defaults as per gemini map files.
1408 While there's obviously some redundancy here between this function and
1409 `elpher-address-from-url', gemini map file URLs require enough special
1410 treatment that a separate function is warranted."
1411 (let ((address (url-generic-parse-url url))
1412 (current-address (elpher-page-address elpher-current-page)))
1413 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
1414 (setf (url-fullness address) t)
1415 (if (url-host address) ;if there is an explicit host, filenames are absolute
1416 (if (string-empty-p (url-filename address))
1417 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
1418 (setf (url-host address) (url-host current-address))
1419 (setf (url-port address) (url-port current-address))
1420 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1421 (setf (url-filename address)
1422 (concat (file-name-directory (url-filename current-address))
1423 (url-filename address)))))
1424 (unless (url-type address)
1425 (setf (url-type address) "gemini"))
1426 (when (equal (url-type address) "gemini")
1427 (setf (url-filename address)
1428 (elpher-collapse-dot-sequences (url-filename address)))))
1429 (elpher-remove-redundant-ports address)))
1431 (defun elpher-gemini-insert-link (link-line)
1432 "Insert link described by LINK-LINE into a text/gemini document."
1433 (let* ((url (elpher-gemini-get-link-url link-line))
1434 (display-string (elpher-gemini-get-link-display-string link-line))
1435 (address (elpher-address-from-gemini-url url))
1436 (type (if address (elpher-address-type address) nil))
1437 (type-map-entry (cdr (assoc type elpher-type-map))))
1438 (setq elpher--gemini-page-links (append elpher--gemini-page-links `(,address)))
1439 (when display-string
1440 (insert elpher-gemini-link-string)
1442 (let* ((face (elt type-map-entry 3))
1443 (filtered-display-string (elpher-color-filter-apply display-string))
1444 (page (elpher-make-page filtered-display-string address)))
1445 (insert-text-button filtered-display-string
1448 'action #'elpher-click-link
1450 'help-echo #'elpher--page-button-help))
1451 (insert (propertize display-string 'face 'elpher-unknown)))
1454 (defun elpher-gemini-insert-header (header-line)
1455 "Insert header described by HEADER-LINE into a text/gemini document.
1456 The gemini map file line describing the header is given
1458 (when (string-match "^\\(#+\\)[ \t]*" header-line)
1459 (let* ((level (length (match-string 1 header-line)))
1460 (header (substring header-line (match-end 0)))
1462 (1 'elpher-gemini-heading1)
1463 (2 'elpher-gemini-heading2)
1464 (3 'elpher-gemini-heading3)
1466 (fill-column (if (display-graphic-p)
1468 (font-get (font-spec :name (face-font 'default)) :size))
1469 (font-get (font-spec :name (face-font face)) :size)) fill-column)))
1470 (setq elpher--gemini-page-headings (cons (cons header (point))
1471 elpher--gemini-page-headings))
1472 (unless (display-graphic-p)
1473 (insert (make-string level ?#) " "))
1474 (insert (propertize header 'face face))
1477 (defun elpher-gemini-insert-text (text-line)
1478 "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
1479 This function uses Emacs' auto-fill to wrap text sensibly to a maximum
1480 width defined by `elpher-gemini-max-fill-width'."
1481 (string-match "\\(^[ \t]*\\)\\(\\*[ \t]+\\|>[ \t]*\\)?" text-line)
1482 (let* ((line-prefix (match-string 2 text-line))
1483 (processed-text-line
1485 (cond ((string-prefix-p "*" line-prefix)
1487 (replace-regexp-in-string "\\*"
1488 elpher-gemini-bullet-string
1489 (match-string 0 text-line))
1490 (substring text-line (match-end 0))))
1491 ((string-prefix-p ">" line-prefix)
1492 (propertize text-line 'face 'elpher-gemini-quoted))
1495 (adaptive-fill-mode t))
1496 (insert (elpher-process-text-for-display processed-text-line))
1499 (defun elpher-render-gemini-map (data _parameters)
1500 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1501 (elpher-with-clean-buffer
1502 (setq elpher--gemini-page-headings nil)
1503 (let ((preformatted nil)
1506 (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
1507 (setq elpher--gemini-page-links '())
1508 (dolist (line (split-string data "\n"))
1510 ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
1511 (preformatted (insert (elpher-process-text-for-display
1512 (propertize line 'face 'elpher-gemini-preformatted))
1514 ((string-prefix-p "=>" line)
1516 (if elpher-gemini-number-links
1520 (number-to-string link-counter)
1522 (setq link-counter (1+ link-counter))
1523 (elpher-gemini-insert-link line)))
1524 ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
1525 (t (elpher-gemini-insert-text line)))))
1526 (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))
1527 (elpher-cache-content
1528 (elpher-page-address elpher-current-page)
1531 (elpher-page-address elpher-current-page)
1532 elpher--gemini-page-links
1533 elpher--gemini-page-links-cache)))
1535 (defun elpher-render-gemini-plain-text (data _parameters)
1536 "Render DATA as plain text file. PARAMETERS is currently unused."
1537 (elpher-with-clean-buffer
1538 (insert (elpher-process-text-for-display data))
1539 (elpher-cache-content
1540 (elpher-page-address elpher-current-page)
1544 ;; Finger page connection
1546 (defun elpher-get-finger-page (renderer)
1547 "Opens a finger connection to the current page address.
1548 The result is rendered using RENDERER."
1549 (let* ((address (elpher-page-address elpher-current-page))
1550 (content (elpher-get-cached-content address)))
1551 (if (and content (funcall renderer nil))
1552 (elpher-with-clean-buffer
1554 (elpher-restore-pos))
1555 (elpher-with-clean-buffer
1556 (insert "LOADING... (use 'u' to cancel)\n"))
1557 (condition-case the-error
1558 (let* ((kill-buffer-query-functions nil)
1559 (user (let ((filename (elpher-address-filename address)))
1560 (if (> (length filename) 1)
1561 (substring filename 1)
1562 (elpher-address-user address)))))
1563 (elpher-get-host-response address 79
1564 (concat user "\r\n")
1567 (elpher-network-error address the-error))))))
1570 ;; Telnet page connection
1572 (defun elpher-get-telnet-page (renderer)
1573 "Opens a telnet connection to the current page address (RENDERER must be nil)."
1575 (elpher-visit-previous-page)
1576 (error "Command not supported for telnet URLs"))
1577 (let* ((address (elpher-page-address elpher-current-page))
1578 (host (elpher-address-host address))
1579 (port (elpher-address-port address)))
1580 (elpher-visit-previous-page)
1586 ;; Other URL page opening
1588 (defun elpher-get-other-url-page (renderer)
1589 "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
1591 (elpher-visit-previous-page)
1592 (error "Command not supported for general URLs"))
1593 (let* ((address (elpher-page-address elpher-current-page))
1594 (url (elpher-address-to-url address)))
1596 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1597 (message "Opening URL...")
1598 (if elpher-open-urls-with-eww
1600 (browse-url url)))))
1603 ;; Start page page retrieval
1605 (defun elpher-get-start-page (renderer)
1606 "Getter which displays the start page (RENDERER must be nil)."
1608 (elpher-visit-previous-page)
1609 (error "Command not supported for start page"))
1610 (elpher-with-clean-buffer
1611 (insert " --------------------------------------------\n"
1612 " Elpher Gopher and Gemini Client \n"
1613 " version " elpher-version "\n"
1614 " --------------------------------------------\n"
1616 "Default bindings:\n"
1618 " - TAB/Shift-TAB: next/prev item on current page\n"
1619 " - RET/mouse-1: open item under cursor\n"
1620 " - m: select an item on current page by name (autocompletes)\n"
1621 " - u/mouse-3/U: return to previous page or to the start page\n"
1622 " - o/O: visit different selector or the root menu of the current server\n"
1623 " - g: go to a particular address (gopher, gemini, finger)\n"
1624 " - v: visit a numbered link on a gemini page\n"
1625 " - d/D: download item under cursor or current page\n"
1626 " - i/I: info on item under cursor or current page\n"
1627 " - c/C: copy URL representation of item under cursor or current page\n"
1628 " - a/A: bookmark the item under cursor or current page\n"
1629 " - x/X: remove bookmark for item under cursor or current page\n"
1630 " - B: visit the bookmarks page\n"
1631 " - r: redraw current page (using cached contents if available)\n"
1632 " - R: reload current page (regenerates cache)\n"
1633 " - S: set character coding system for gopher (default is to autodetect)\n"
1634 " - T: toggle TLS gopher mode\n"
1635 " - F: forget/discard current TLS client certificate\n"
1636 " - .: display the raw server response for the current page\n"
1638 "Start your exploration of gopher space and gemini:\n")
1639 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1640 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1641 (elpher-insert-index-record "Project Gemini home page"
1642 (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
1644 "Alternatively, select a search engine and enter some search terms:\n")
1645 (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
1646 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1647 (elpher-insert-index-record "Gemini Search Engine (geminispace.info)"
1648 (elpher-address-from-url "gemini://geminispace.info/search"))
1650 "This page contains your bookmarked sites (also visit with B):\n")
1651 (elpher-insert-index-record "Your Bookmarks" 'bookmarks)
1653 "For Elpher release news or to leave feedback, visit:\n")
1654 (elpher-insert-index-record "The Elpher Project Page"
1655 (elpher-make-gopher-address ?1
1661 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1662 (insert-text-button "Elpher info manual"
1668 'help-echo help-string))
1669 (insert " for the full documentation. **\n")
1671 (concat " (This should be available if you have installed Elpher using\n"
1672 " MELPA. Otherwise you will have to install the manual yourself.)\n")
1674 (elpher-restore-pos)))
1676 ;; Bookmarks page page retrieval
1678 (defun elpher-get-bookmarks-page (renderer)
1679 "Getter to load and display the current bookmark list (RENDERER must be nil)."
1681 (elpher-visit-previous-page)
1682 (error "Command not supported for bookmarks page"))
1683 (elpher-with-clean-buffer
1684 (insert "---- Bookmark list ----\n\n")
1685 (let ((bookmarks (elpher-load-bookmarks)))
1687 (dolist (bookmark bookmarks)
1688 (let ((display-string (elpher-bookmark-display-string bookmark))
1689 (address (elpher-address-from-url (elpher-bookmark-url bookmark))))
1690 (elpher-insert-index-record display-string address)))
1691 (insert "No bookmarks found.\n")))
1692 (insert "\n-----------------------\n"
1694 "- u: return to previous page\n"
1695 "- x: delete selected bookmark\n"
1696 "- a: rename selected bookmark\n"
1698 "Bookmarks are stored in the file ")
1699 (let ((filename elpher-bookmarks-file)
1700 (help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
1701 (insert-text-button filename
1705 (find-file filename))
1707 'help-echo help-string))
1709 (elpher-restore-pos)))
1715 (defun elpher-make-bookmark (display-string url)
1716 "Make an elpher bookmark.
1717 DISPLAY-STRING determines how the bookmark will appear in the
1718 bookmark list, while URL is the url of the entry."
1719 (list display-string url))
1721 (defun elpher-bookmark-display-string (bookmark)
1722 "Get the display string of BOOKMARK."
1725 (defun elpher-set-bookmark-display-string (bookmark display-string)
1726 "Set the display string of BOOKMARK to DISPLAY-STRING."
1727 (setcar bookmark display-string))
1729 (defun elpher-bookmark-url (bookmark)
1730 "Get the address for BOOKMARK."
1733 (defun elpher-save-bookmarks (bookmarks)
1734 "Record the bookmark list BOOKMARKS to the user's bookmark file.
1735 Beware that this completely replaces the existing contents of the file."
1736 (let ((bookmark-dir (file-name-directory elpher-bookmarks-file)))
1737 (unless (file-directory-p bookmark-dir)
1738 (make-directory bookmark-dir)))
1739 (with-temp-file elpher-bookmarks-file
1741 (insert "; Elpher bookmarks file\n\n"
1742 "; Bookmarks are stored as a list of (label URL) items.\n"
1743 "; Feel free to edit by hand, but take care to ensure\n"
1744 "; the list structure remains intact.\n\n")
1745 (pp bookmarks (current-buffer))))
1747 (defun elpher-load-bookmarks ()
1748 "Get the list of bookmarks from the users's bookmark file."
1752 (insert-file-contents elpher-bookmarks-file)
1753 (goto-char (point-min))
1754 (read (current-buffer))))))
1755 (if (and bookmarks (listp (cadar bookmarks)))
1757 (message "Reading old bookmark file. (Will be updated on write.)")
1758 (mapcar (lambda (old-bm)
1760 (elpher-address-to-url (apply #'elpher-make-gopher-address
1765 (defun elpher-add-address-bookmark (address display-string)
1766 "Save a bookmark for ADDRESS with label DISPLAY-STRING.)))
1767 If ADDRESS is already bookmarked, update the label only."
1768 (let ((bookmarks (elpher-load-bookmarks))
1769 (url (elpher-address-to-url address)))
1770 (let ((existing-bookmark (rassoc (list url) bookmarks)))
1771 (if existing-bookmark
1772 (elpher-set-bookmark-display-string existing-bookmark display-string)
1773 (push (elpher-make-bookmark display-string url) bookmarks)))
1774 (elpher-save-bookmarks bookmarks)))
1776 (defun elpher-remove-address-bookmark (address)
1777 "Remove any bookmark to ADDRESS."
1778 (let ((url (elpher-address-to-url address)))
1779 (elpher-save-bookmarks
1780 (seq-filter (lambda (bookmark)
1781 (not (equal (elpher-bookmark-url bookmark) url)))
1782 (elpher-load-bookmarks)))))
1789 ;; Avoid byte compilation warnings.
1791 (declare-function org-link-store-props "ol")
1792 (declare-function org-link-set-parameters "ol"))
1794 (defun elpher-org-export-link (link description format protocol)
1795 "Export a LINK with DESCRIPTION for the given PROTOCOL and FORMAT.
1797 FORMAT is an Org export backend. DESCRIPTION may be nil. PROTOCOL may be one
1798 of gemini, gopher or finger."
1799 (let* ((url (if (equal protocol "elpher")
1800 (string-remove-prefix "elpher:" link)
1801 (format "%s:%s" protocol link)))
1802 (desc (or description url)))
1804 (`gemini (format "=> %s %s" url desc))
1805 (`html (format "<a href=\"%s\">%s</a>" url desc))
1806 (`latex (format "\\href{%s}{%s}" url desc))
1807 (_ (if (not description)
1809 (format "%s (%s)" desc url))))))
1811 (defun elpher-org-store-link ()
1812 "Store link to an `elpher' page in Org."
1813 (when (eq major-mode 'elpher-mode)
1814 (let* ((url (elpher-info-current))
1815 (desc (car elpher-current-page))
1817 ((string-prefix-p "gemini:" url) "gemini")
1818 ((string-prefix-p "gopher:" url) "gopher")
1819 ((string-prefix-p "finger:" url) "finger")
1821 (when (equal "elpher" protocol)
1822 ;; Weird link. Or special inner link?
1823 (setq url (concat "elpher:" url)))
1824 (org-link-store-props :type protocol :link url :description desc)
1827 (defun elpher-org-follow-link (link protocol)
1828 "Visit a LINK for the given PROTOCOL.
1830 PROTOCOL may be one of gemini, gopher or finger. This method also
1831 supports the old protocol elpher, where the link is self-contained."
1832 (let ((url (if (equal protocol "elpher")
1833 (string-remove-prefix "elpher:" link)
1834 (format "%s:%s" protocol link))))
1837 (with-eval-after-load 'org
1838 (org-link-set-parameters
1840 :store #'elpher-org-store-link
1841 :export (lambda (link description format _plist)
1842 (elpher-org-export-link link description format "elpher"))
1843 :follow (lambda (link _arg) (elpher-org-follow-link link "elpher")))
1844 (org-link-set-parameters
1846 :export (lambda (link description format _plist)
1847 (elpher-org-export-link link description format "gemini"))
1848 :follow (lambda (link _arg) (elpher-org-follow-link link "gemini")))
1849 (org-link-set-parameters
1851 :export (lambda (link description format _plist)
1852 (elpher-org-export-link link description format "gopher"))
1853 :follow (lambda (link _arg) (elpher-org-follow-link link "gopher")))
1854 (org-link-set-parameters
1856 :export (lambda (link description format _plist)
1857 (elpher-org-export-link link description format "finger"))
1858 :follow (lambda (link _arg) (elpher-org-follow-link link "finger"))))
1862 ;; Avoid byte compilation warnings.
1864 (defvar thing-at-point-uri-schemes))
1867 (defun elpher-browse-url-elpher (url &rest _args)
1868 "Browse URL using Elpher. This function is used by `browse-url'."
1869 (interactive (browse-url-interactive-arg "Elpher URL: "))
1872 ;; Use elpher to open gopher, finger and gemini links
1873 ;; For recent version of `browse-url' package
1874 (if (boundp 'browse-url-default-handlers)
1876 'browse-url-default-handlers
1877 '("^\\(gopher\\|finger\\|gemini\\)://" . elpher-browse-url-elpher))
1878 ;; Patch `browse-url-browser-function' for older ones. The value of
1879 ;; that variable is `browse-url-default-browser' by default, so
1880 ;; that's the function that gets advised.
1881 (advice-add browse-url-browser-function :before-while
1882 (lambda (url &rest _args)
1883 "Handle gemini, gopher, and finger schemes using Elpher."
1884 (let ((scheme (downcase (car (split-string url ":" t)))))
1885 (if (member scheme '("gemini" "gopher" "finger"))
1886 ;; `elpher-go' always returns nil, which will stop the
1887 ;; advice chain here in a before-while
1889 ;; chain must continue, then return t.
1892 ;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
1893 (with-eval-after-load 'thingatpt
1894 (add-to-list 'thing-at-point-uri-schemes "gemini://"))
1899 (defvar mu4e~view-beginning-of-url-regexp))
1901 (with-eval-after-load 'mu4e-view
1902 ;; Make mu4e aware of the gemini world
1903 (setq mu4e~view-beginning-of-url-regexp
1904 "\\(?:https?\\|gopher\\|finger\\|gemini\\)://\\|mailto:"))
1906 ;;; Interactive procedures
1909 (defun elpher-next-link ()
1910 "Move point to the next link on the current page."
1914 (defun elpher-prev-link ()
1915 "Move point to the previous link on the current page."
1917 (backward-button 1))
1919 (defun elpher-follow-current-link ()
1920 "Open the link or url at point."
1925 (defun elpher-go (host-or-url)
1926 "Go to a particular gopher site HOST-OR-URL.
1927 When run interactively HOST-OR-URL is read from the minibuffer."
1928 (interactive "sGopher or Gemini URL: ")
1929 (let* ((cleaned-host-or-url (string-trim host-or-url))
1930 (address (elpher-address-from-url cleaned-host-or-url))
1931 (page (elpher-make-page cleaned-host-or-url address)))
1932 (switch-to-buffer elpher-buffer-name)
1933 (elpher-visit-page page)
1936 (defun elpher-go-current ()
1937 "Go to a particular site read from the minibuffer, initialized with the current URL."
1939 (let ((address (elpher-page-address elpher-current-page)))
1940 (let ((url (read-string "Gopher or Gemini URL: "
1941 (unless (elpher-address-special-p address)
1942 (elpher-address-to-url address)))))
1943 (elpher-visit-page (elpher-make-page url (elpher-address-from-url url))))))
1945 (defun elpher-visit-gemini-numbered-link (n)
1946 "Visit link designated by a number N."
1947 (interactive "nLink number: ")
1948 (if (or (> n (length elpher--gemini-page-links))
1950 (user-error "Invalid link number"))
1951 (let ((address (nth (1- n) elpher--gemini-page-links)))
1952 (elpher-go (url-recreate-url address))))
1954 (defun elpher-redraw ()
1955 "Redraw current page."
1957 (elpher-visit-page elpher-current-page))
1959 (defun elpher-reload ()
1960 "Reload current page."
1962 (elpher-reload-current-page))
1964 (defun elpher-toggle-tls ()
1965 "Toggle TLS encryption mode for gopher."
1967 (setq elpher-use-tls (not elpher-use-tls))
1969 (if (gnutls-available-p)
1970 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
1971 (setq elpher-use-tls nil)
1972 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
1973 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
1975 (defun elpher-view-raw ()
1976 "View raw server response for current page."
1978 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
1979 (error "This page was not generated by a server")
1980 (elpher-visit-page elpher-current-page
1981 #'elpher-render-raw)))
1983 (defun elpher-back ()
1984 "Go to previous site."
1986 (elpher-visit-previous-page))
1988 (defun elpher-back-to-start ()
1989 "Go all the way back to the start page."
1991 (setq-local elpher-current-page nil)
1992 (setq-local elpher-history nil)
1993 (let ((start-page (elpher-make-page "Elpher Start Page"
1994 (elpher-make-special-address 'start))))
1995 (elpher-visit-page 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-root-dir ()
2045 "Visit root of current server."
2047 (let ((address (elpher-page-address elpher-current-page)))
2048 (if (not (elpher-address-special-p address))
2049 (if (or (member (url-filename address) '("/" ""))
2050 (and (elpher-address-gopher-p address)
2051 (= (length (elpher-gopher-address-selector address)) 0)))
2052 (error "Already at root directory of current server")
2053 (let ((address-copy (elpher-address-from-url
2054 (elpher-address-to-url address))))
2055 (setf (url-filename address-copy) "")
2056 (elpher-go (elpher-address-to-url address-copy))))
2057 (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
2059 (defun elpher-bookmarks-current-p ()
2060 "Return non-nil if current page is a bookmarks page."
2061 (equal (elpher-address-type (elpher-page-address elpher-current-page))
2062 '(special bookmarks)))
2064 (defun elpher-reload-bookmarks ()
2065 "Reload bookmarks if current page is a bookmarks page."
2066 (if (elpher-bookmarks-current-p)
2067 (elpher-reload-current-page)))
2069 (defun elpher-bookmark-current ()
2070 "Bookmark the current page."
2072 (let ((address (elpher-page-address elpher-current-page))
2073 (display-string (elpher-page-display-string elpher-current-page)))
2074 (if (not (elpher-address-special-p address))
2075 (let ((bookmark-display-string (read-string "Bookmark display string: "
2077 (elpher-add-address-bookmark address bookmark-display-string)
2078 (message "Bookmark added."))
2079 (error "Cannot bookmark %s" display-string))))
2081 (defun elpher-bookmark-link ()
2082 "Bookmark the link at point."
2084 (let ((button (button-at (point))))
2086 (let* ((page (button-get button 'elpher-page))
2087 (address (elpher-page-address page))
2088 (display-string (elpher-page-display-string page)))
2089 (if (not (elpher-address-special-p address))
2090 (let ((bookmark-display-string (read-string "Bookmark display string: "
2092 (elpher-add-address-bookmark address bookmark-display-string)
2093 (elpher-reload-bookmarks)
2094 (message "Bookmark added."))
2095 (error "Cannot bookmark %s" display-string)))
2096 (error "No link selected"))))
2098 (defun elpher-unbookmark-current ()
2099 "Remove bookmark for the current page."
2101 (let ((address (elpher-page-address elpher-current-page)))
2102 (when (and (not (elpher-address-special-p address))
2103 (y-or-n-p "Really remove bookmark for the current page? "))
2104 (elpher-remove-address-bookmark address)
2105 (message "Bookmark removed."))))
2107 (defun elpher-unbookmark-link ()
2108 "Remove bookmark for the link at point."
2110 (let ((button (button-at (point))))
2112 (when (y-or-n-p "Really remove bookmark for this link? ")
2113 (let ((page (button-get button 'elpher-page)))
2114 (elpher-remove-address-bookmark (elpher-page-address page))
2115 (elpher-reload-bookmarks)
2116 (message "Bookmark removed.")))
2117 (error "No link selected"))))
2120 (defun elpher-bookmarks ()
2121 "Visit bookmarks page."
2123 (switch-to-buffer elpher-buffer-name)
2125 (elpher-make-page "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
2127 (defun elpher-info-page (page)
2128 "Display information on PAGE."
2129 (let ((display-string (elpher-page-display-string page))
2130 (address (elpher-page-address page)))
2131 (if (elpher-address-special-p address)
2132 (message "Special page: %s" display-string)
2133 (message "%s" (elpher-address-to-url address)))))
2135 (defun elpher-info-link ()
2136 "Display information on page corresponding to link at point."
2138 (let ((button (button-at (point))))
2140 (elpher-info-page (button-get button 'elpher-page))
2141 (error "No item selected"))))
2143 (defun elpher-info-current ()
2144 "Display information on current page."
2146 (elpher-info-page elpher-current-page))
2148 (defun elpher-copy-page-url (page)
2149 "Copy URL representation of address of PAGE to `kill-ring'."
2150 (let ((address (elpher-page-address page)))
2151 (if (elpher-address-special-p address)
2152 (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
2153 (let ((url (elpher-address-to-url address)))
2154 (message "Copied \"%s\" to kill-ring/clipboard." url)
2157 (defun elpher-copy-link-url ()
2158 "Copy URL of item at point to `kill-ring'."
2160 (let ((button (button-at (point))))
2162 (elpher-copy-page-url (button-get button 'elpher-page))
2163 (error "No item selected"))))
2165 (defun elpher-copy-current-url ()
2166 "Copy URL of current page to `kill-ring'."
2168 (elpher-copy-page-url elpher-current-page))
2170 (defun elpher-set-gopher-coding-system ()
2171 "Specify an explicit character coding system for gopher selectors."
2173 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
2174 (setq elpher-user-coding-system system)
2176 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
2177 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
2183 (defvar elpher-mode-map
2184 (let ((map (make-sparse-keymap)))
2185 (define-key map (kbd "TAB") 'elpher-next-link)
2186 (define-key map (kbd "<backtab>") 'elpher-prev-link)
2187 (define-key map (kbd "C-M-i") 'elpher-prev-link)
2188 (define-key map (kbd "u") 'elpher-back)
2189 (define-key map (kbd "U") 'elpher-back-to-start)
2190 (define-key map [mouse-3] 'elpher-back)
2191 (define-key map (kbd "O") 'elpher-root-dir)
2192 (define-key map (kbd "g") 'elpher-go)
2193 (define-key map (kbd "o") 'elpher-go-current)
2194 (define-key map (kbd "r") 'elpher-redraw)
2195 (define-key map (kbd "R") 'elpher-reload)
2196 (define-key map (kbd "T") 'elpher-toggle-tls)
2197 (define-key map (kbd ".") 'elpher-view-raw)
2198 (define-key map (kbd "d") 'elpher-download)
2199 (define-key map (kbd "D") 'elpher-download-current)
2200 (define-key map (kbd "m") 'elpher-jump)
2201 (define-key map (kbd "i") 'elpher-info-link)
2202 (define-key map (kbd "I") 'elpher-info-current)
2203 (define-key map (kbd "c") 'elpher-copy-link-url)
2204 (define-key map (kbd "C") 'elpher-copy-current-url)
2205 (define-key map (kbd "a") 'elpher-bookmark-link)
2206 (define-key map (kbd "A") 'elpher-bookmark-current)
2207 (define-key map (kbd "x") 'elpher-unbookmark-link)
2208 (define-key map (kbd "X") 'elpher-unbookmark-current)
2209 (define-key map (kbd "B") 'elpher-bookmarks)
2210 (define-key map (kbd "S") 'elpher-set-gopher-coding-system)
2211 (define-key map (kbd "F") 'elpher-forget-current-certificate)
2212 (define-key map (kbd "v") 'elpher-visit-gemini-numbered-link)
2213 (when (fboundp 'evil-define-key*)
2216 (kbd "TAB") 'elpher-next-link
2217 (kbd "C-") 'elpher-follow-current-link
2218 (kbd "C-t") 'elpher-back
2219 (kbd "u") 'elpher-back
2220 (kbd "-") 'elpher-back
2221 (kbd "^") 'elpher-back
2222 (kbd "U") 'elpher-back-to-start
2223 [mouse-3] 'elpher-back
2224 (kbd "o") 'elpher-go
2225 (kbd "O") 'elpher-go-current
2226 (kbd "r") 'elpher-redraw
2227 (kbd "R") 'elpher-reload
2228 (kbd "T") 'elpher-toggle-tls
2229 (kbd ".") 'elpher-view-raw
2230 (kbd "d") 'elpher-download
2231 (kbd "D") 'elpher-download-current
2232 (kbd "J") 'elpher-jump
2233 (kbd "i") 'elpher-info-link
2234 (kbd "I") 'elpher-info-current
2235 (kbd "c") 'elpher-copy-link-url
2236 (kbd "C") 'elpher-copy-current-url
2237 (kbd "a") 'elpher-bookmark-link
2238 (kbd "A") 'elpher-bookmark-current
2239 (kbd "x") 'elpher-unbookmark-link
2240 (kbd "X") 'elpher-unbookmark-current
2241 (kbd "B") 'elpher-bookmarks
2242 (kbd "S") 'elpher-set-gopher-coding-system
2243 (kbd "F") 'elpher-forget-current-certificate
2244 (kbd "v") 'elpher-visit-gemini-numbered-link))
2246 "Keymap for gopher client.")
2248 (define-derived-mode elpher-mode special-mode "elpher"
2249 "Major mode for elpher, an elisp gopher client.
2251 This mode is automatically enabled by the interactive
2252 functions which initialize the gopher client, namely
2253 `elpher', `elpher-go' and `elpher-bookmarks'."
2254 (setq-local elpher--gemini-page-headings nil)
2255 (setq-local elpher-current-page nil)
2256 (setq-local elpher-history nil)
2257 (setq-local elpher-buffer-name (buffer-name))
2259 (setq-local imenu-create-index-function
2261 elpher--gemini-page-headings)))
2263 (when (fboundp 'evil-set-initial-state)
2264 (evil-set-initial-state 'elpher-mode 'motion))
2267 ;;; Main start procedure
2271 (defun elpher (&optional arg)
2272 "Start elpher with default landing page.
2273 The buffer used for Elpher sessions is determined by the value of
2274 ‘elpher-buffer-name’. If there is already an Elpher session active in
2275 that buffer, Emacs will simply switch to it. Otherwise, a new session
2276 will begin. A numeric prefix ARG (as in ‘\\[universal-argument] 42
2277 \\[execute-extended-command] elpher RET’) switches to the session with
2278 that number, creating it if necessary. A non numeric prefix ARG means
2279 to create a new session. Returns the buffer selected (or created)."
2281 (let* ((name (default-value 'elpher-buffer-name))
2282 (buf (cond ((numberp arg)
2283 (get-buffer-create (format "%s<%d>" name arg)))
2285 (generate-new-buffer name))
2287 (get-buffer-create name)))))
2288 (pop-to-buffer-same-window buf)
2289 (unless (buffer-modified-p)
2291 (let ((start-page (elpher-make-page
2293 (elpher-make-special-address 'start))))
2294 (elpher-visit-page start-page))
2295 "Started Elpher."))); Otherwise (elpher) evaluates to start page string.
2297 ;;; elpher.el ends here