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: http://thelambdalab.xyz/elpher
25 ;; Package-Requires: ((emacs "26.2"))
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, gopher://thelambdalab.xyz/1/projects/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 "2.10.2"
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 '()
140 "Interval variable containing list of headings on page.")
142 (defvar elpher--gemini-page-links '()
143 "Internal variable containing list of links on page.")
145 (defvar elpher--gemini-page-links-cache (make-hash-table :test 'equal)
146 "Internal variable containing 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 dangerous as it
169 allows switching from an encrypted channel back to plain text without user input."
172 (defcustom elpher-connection-timeout 5
173 "Specifies the number of seconds to wait for a network connection to time out."
176 (defcustom elpher-filter-ansi-from-text nil
177 "If non-nil, filter ANSI escape sequences from text.
178 The default behaviour is to use the ansi-color package to interpret these
182 (defcustom elpher-certificate-directory
183 (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
184 "Specify the name of the directory where client certificates will be stored.
185 These certificates may be used for establishing authenticated TLS connections."
188 (defcustom elpher-openssl-command "openssl"
189 "The command used to launch openssl when generating TLS client certificates."
192 (defcustom elpher-default-url-type "gopher"
193 "Default URL type (i.e. schema) to assume if not explicitly given."
194 :type '(choice (const "gopher")
197 (defcustom elpher-gemini-TLS-cert-checks nil
198 "If non-nil, verify gemini server TLS certs using the default security level.
199 Otherwise, certificate verification is disabled.
201 This defaults to off because it is standard practice for Gemini servers
202 to use self-signed certificates, meaning that most servers provide what
203 EMACS considers to be an invalid certificate."
206 (defcustom elpher-gemini-max-fill-width 80
207 "Specify the maximum default width (in columns) of text/gemini documents.
208 The actual width used is the minimum of this value and the window width at
209 the time when the text is rendered."
212 (defcustom elpher-gemini-link-string "→ "
213 "Specify the string used to indicate links when rendering gemini maps.
217 (defcustom elpher-gemini-bullet-string "•"
218 "Specify the string used for bullets when rendering gemini maps."
221 (defcustom elpher-bookmarks-file (locate-user-emacs-file "elpher-bookmarks")
222 "Specify the name of the file where elpher bookmarks will be saved."
225 (defcustom elpher-ipv4-always nil
226 "If non-nil, elpher will always use IPv4 to establish network connections.
227 This can be useful when browsing from a computer that supports IPv6, because
228 some servers which do not support IPv6 can take a long time to time-out."
231 (defcustom elpher-socks-always nil
232 "If non-nil, elpher will establish network connections over a SOCKS proxy.
233 Otherwise, the SOCKS proxy is only used for connections to onion services."
236 (defcustom elpher-gemini-number-links nil
237 "If non-nil, number links in gemini pages when rendering.
238 Links can be accessed by pressing `v' ('visit') followed by the link number."
241 ;; Face customizations
243 (defgroup elpher-faces nil
244 "Elpher face customizations."
247 (defface elpher-index
248 '((t :inherit font-lock-keyword-face))
249 "Face used for directory type directory records.")
253 "Face used for text type directory records.")
256 '((t :inherit default))
257 "Face used for info type directory records.")
259 (defface elpher-image
260 '((t :inherit font-lock-string-face))
261 "Face used for image type directory records.")
263 (defface elpher-search
264 '((t :inherit warning))
265 "Face used for search type directory records.")
268 '((t :inherit font-lock-comment-face))
269 "Face used for html type directory records.")
271 (defface elpher-gemini
272 '((t :inherit font-lock-constant-face))
273 "Face used for Gemini type directory records.")
275 (defface elpher-other-url
276 '((t :inherit font-lock-comment-face))
277 "Face used for other URL type links records.")
279 (defface elpher-telnet
280 '((t :inherit font-lock-function-name-face))
281 "Face used for telnet type directory records.")
283 (defface elpher-binary
284 '((t :inherit font-lock-doc-face))
285 "Face used for binary type directory records.")
287 (defface elpher-unknown
288 '((t :inherit error))
289 "Face used for directory records with unknown/unsupported types.")
291 (defface elpher-margin-key
293 "Face used for directory margin key.")
295 (defface elpher-margin-brackets
296 '((t :inherit shadow))
297 "Face used for brackets around directory margin key.")
299 (defface elpher-gemini-heading1
300 '((t :inherit bold :height 1.8))
301 "Face used for gemini heading level 1.")
303 (defface elpher-gemini-heading2
304 '((t :inherit bold :height 1.5))
305 "Face used for gemini heading level 2.")
307 (defface elpher-gemini-heading3
308 '((t :inherit bold :height 1.2))
309 "Face used for gemini heading level 3.")
311 (defface elpher-gemini-preformatted
312 '((t :inherit fixed-pitch))
313 "Face used for pre-formatted gemini text blocks.")
315 (defface elpher-gemini-quoted
316 '((t :inherit font-lock-doc-face))
317 "Face used for gemini quoted texts.")
324 ;; An elpher "address" object is either a url object or a symbol.
325 ;; Symbol addresses are "special", corresponding to pages generated
326 ;; dynamically for and by elpher. All others represent pages which
327 ;; rely on content retrieved over the network.
329 (defun elpher-address-from-url (url-string)
330 "Create a ADDRESS object corresponding to the given URL-STRING."
331 (let ((data (match-data))) ; Prevent parsing clobbering match data
333 (let ((url (url-generic-parse-url url-string)))
334 (unless (and (not (url-fullness url)) (url-type url))
335 (setf (url-fullness url) t)
336 (setf (url-filename url)
337 (url-unhex-string (url-filename url)))
338 (unless (url-type url)
339 (setf (url-type url) elpher-default-url-type))
340 (unless (url-host url)
341 (let ((p (split-string (url-filename url) "/" nil nil)))
342 (setf (url-host url) (car p))
343 (setf (url-filename url)
345 (concat "/" (mapconcat #'identity (cdr p) "/"))
347 (when (or (equal "gopher" (url-type url))
348 (equal "gophers" (url-type url)))
350 (when (or (equal (url-filename url) "")
351 (equal (url-filename url) "/"))
352 (setf (url-filename url) "/1")))
353 (when (equal "gemini" (url-type url))
355 (if (equal (url-filename url) "")
356 (setf (url-filename url) "/"))))
357 (elpher-remove-redundant-ports url))
358 (set-match-data data))))
360 (defun elpher-remove-redundant-ports (address)
361 "Remove redundant port specifiers from ADDRESS.
362 Here 'redundant' means that the specified port matches the default
363 for that protocol, eg 70 for gopher."
364 (if (and (not (elpher-address-special-p address))
365 (eq (url-portspec address) ; (url-port) is too slow!
366 (pcase (url-type address)
368 ((or "gopher" "gophers") 70)
371 (setf (url-portspec address) nil))
374 (defun elpher-make-gopher-address (type selector host port &optional tls)
375 "Create an ADDRESS object using gopher directory record attributes.
376 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
377 If the optional attribute TLS is non-nil, the address will be marked as
378 requiring gopher-over-TLS."
380 ((equal type ?i) nil)
381 ((and (equal type ?h)
382 (string-prefix-p "URL:" selector))
383 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
385 (elpher-address-from-url
388 ":" (number-to-string port))))
390 (elpher-address-from-url
391 (concat "gopher" (if tls "s" "")
393 ":" (number-to-string port)
397 (defun elpher-make-special-address (type)
398 "Create an ADDRESS object corresponding to the given special address symbol TYPE."
401 (defun elpher-address-to-url (address)
402 "Get string representation of ADDRESS, or nil if ADDRESS is special."
403 (if (elpher-address-special-p address)
405 (url-encode-url (url-recreate-url address))))
407 (defun elpher-address-type (address)
408 "Retrieve type of ADDRESS object.
409 This is used to determine how to retrieve and render the document the
410 address refers to, via the table `elpher-type-map'."
411 (if (symbolp address)
412 (list 'special address)
413 (let ((protocol (url-type address)))
414 (cond ((or (equal protocol "gopher")
415 (equal protocol "gophers"))
417 (if (member (url-filename address) '("" "/"))
419 (string-to-char (substring (url-filename address) 1)))))
420 ((equal protocol "gemini")
422 ((equal protocol "telnet")
424 ((equal protocol "finger")
428 (defun elpher-address-protocol (address)
429 "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
430 (if (symbolp address)
434 (defun elpher-address-filename (address)
435 "Retrieve the filename component of ADDRESS.
436 For gopher addresses this is a combination of the selector type and selector."
437 (if (symbolp address)
439 (url-filename address)))
441 (defun elpher-address-host (address)
442 "Retrieve host from ADDRESS object."
445 (defun elpher-address-user (address)
446 "Retrieve user from ADDRESS object."
449 (defun elpher-address-port (address)
450 "Retrieve port from ADDRESS object.
451 If no address is defined, returns 0. (This is for compatibility with the URL library.)"
452 (if (symbolp address)
456 (defun elpher-address-special-p (address)
457 "Return non-nil if ADDRESS object is special (e.g. start page, bookmarks page)."
460 (defun elpher-address-gopher-p (address)
461 "Return non-nill if ADDRESS object is a gopher address."
462 (and (not (elpher-address-special-p address))
463 (member (elpher-address-protocol address) '("gopher gophers"))))
465 (defun elpher-gopher-address-selector (address)
466 "Retrieve gopher selector from ADDRESS object."
467 (if (member (url-filename address) '("" "/"))
469 (url-unhex-string (substring (url-filename address) 2))))
474 (defvar elpher-content-cache (make-hash-table :test 'equal))
475 (defvar elpher-pos-cache (make-hash-table :test 'equal))
477 (defun elpher-get-cached-content (address)
478 "Retrieve the cached content for ADDRESS, or nil if none exists."
479 (gethash address elpher-content-cache))
481 (defun elpher-cache-content (address content)
482 "Set the content cache for ADDRESS to CONTENT."
483 (puthash address content elpher-content-cache))
485 (defun elpher-get-cached-pos (address)
486 "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
487 (gethash address elpher-pos-cache))
489 (defun elpher-cache-pos (address pos)
490 "Set the cursor position cache for ADDRESS to POS."
491 (puthash address pos elpher-pos-cache))
496 (defun elpher-make-page (display-string address)
497 "Create a page with DISPLAY-STRING and ADDRESS."
498 (list display-string address))
500 (defun elpher-page-display-string (page)
501 "Retrieve the display string corresponding to PAGE."
504 (defun elpher-page-address (page)
505 "Retrieve the address corresponding to PAGE."
508 (defun elpher-page-set-address (page new-address)
509 "Set the address corresponding to PAGE to NEW-ADDRESS."
510 (setcar (cdr page) new-address))
512 (defvar elpher-current-page nil) ; buffer local
513 (defvar elpher-history nil) ; buffer local
515 (defun elpher-visit-page (page &optional renderer no-history)
516 "Visit PAGE using its own renderer or RENDERER, if non-nil.
517 Additionally, push PAGE onto the stack of previously-visited pages,
518 unless NO-HISTORY is non-nil."
520 (elpher-process-cleanup)
521 (unless (or no-history
522 (equal (elpher-page-address elpher-current-page)
523 (elpher-page-address page)))
524 (push elpher-current-page elpher-history))
525 (setq-local elpher-current-page page)
526 (let* ((address (elpher-page-address page))
527 (type (elpher-address-type address))
528 (type-record (cdr (assoc type elpher-type-map)))
532 (funcall (car type-record)
536 (setq page-links (gethash address elpher--gemini-page-links-cache))
538 (setq elpher--gemini-page-links page-links)))
539 (elpher-visit-previous-page)
541 (`(gopher ,type-char)
542 (error "Unsupported gopher selector type '%c' for '%s'"
543 type-char (elpher-address-to-url address)))
545 (error "Unsupported address type '%S' for '%s'"
546 other (elpher-address-to-url address)))))))
548 (defun elpher-visit-previous-page ()
549 "Visit the previous page in the history."
550 (let ((previous-page (pop elpher-history)))
552 (elpher-visit-page previous-page nil t)
553 (error "No previous page"))))
555 (defun elpher-reload-current-page ()
556 "Reload the current page, discarding any existing cached content."
557 (elpher-cache-content (elpher-page-address elpher-current-page) nil)
558 (elpher-visit-page elpher-current-page))
560 (defun elpher-save-pos ()
561 "Save the current position of point to the current page."
562 (when elpher-current-page
563 (elpher-cache-pos (elpher-page-address elpher-current-page) (point))))
565 (defun elpher-restore-pos ()
566 "Restore the position of point to that cached in the current page."
567 (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
570 (goto-char (point-min)))))
573 ;;; Buffer preparation
576 (defvar elpher-buffer-name "*elpher*"
577 "The default name of the Elpher buffer.")
579 (defun elpher-update-header ()
580 "If `elpher-use-header' is true, display current page info in window header."
581 (if elpher-use-header
582 (let* ((display-string (elpher-page-display-string elpher-current-page))
583 (address (elpher-page-address elpher-current-page))
584 (tls-string (if (and (not (elpher-address-special-p address))
585 (member (elpher-address-protocol address)
586 '("gophers" "gemini")))
589 (header (concat display-string
590 (propertize tls-string 'face 'bold))))
591 (setq header-line-format header))))
593 (defmacro elpher-with-clean-buffer (&rest args)
594 "Evaluate ARGS with a clean *elpher* buffer as current."
595 `(with-current-buffer elpher-buffer-name
596 (unless (eq major-mode 'elpher-mode)
597 ;; avoid resetting buffer-local variables
599 (let ((inhibit-read-only t))
600 (setq-local network-security-level
601 (default-value 'network-security-level))
603 (elpher-update-header)
606 (defun elpher-buffer-message (string &optional line)
607 "Replace first line in elpher buffer with STRING.
608 If LINE is non-nil, replace that line instead."
609 (with-current-buffer elpher-buffer-name
610 (let ((inhibit-read-only t))
611 (goto-char (point-min))
614 (let ((data (match-data)))
617 (re-search-forward "^.*$")
618 (replace-match string))
619 (set-match-data data))))))
625 (defvar elpher-user-coding-system nil
626 "User-specified coding system to use for decoding text responses.")
628 (defun elpher-decode (string)
629 "Decode STRING using autodetected or user-specified coding system."
630 (decode-coding-string string
631 (if elpher-user-coding-system
632 elpher-user-coding-system
633 (detect-coding-string string t))))
635 (defun elpher-preprocess-text-response (string)
636 "Preprocess text selector response contained in STRING.
637 This involes decoding the character representation, and clearing
638 away CRs and any terminating period."
639 (elpher-decode (replace-regexp-in-string "\n\.\n$" "\n"
640 (replace-regexp-in-string "\r" "" string))))
643 ;;; Network error reporting
646 (defun elpher-network-error (address error)
647 "Display ERROR message following unsuccessful negotiation with ADDRESS.
648 ERROR can be either an error object or a string."
649 (elpher-with-clean-buffer
650 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
651 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
652 (if (stringp error) error (error-message-string error)) "\n"
653 (propertize "\n----------------\n\n" 'face 'error)
654 "Press 'u' to return to the previous page.")))
657 ;;; General network communication
660 (defvar elpher-network-timer nil
661 "Timer used for network connections.")
663 (defvar elpher-use-tls nil
664 "If non-nil, use TLS to communicate with gopher servers.")
666 (defvar elpher-client-certificate nil
667 "If non-nil, contains client certificate details to use for TLS connections.")
669 (defun elpher-process-cleanup ()
670 "Immediately shut down any extant elpher process and timers."
671 (let ((p (get-process "elpher-process")))
672 (if p (delete-process p)))
673 (if (timerp elpher-network-timer)
674 (cancel-timer elpher-network-timer)))
676 (defun elpher-get-host-response (address default-port query-string response-processor
677 &optional use-tls force-ipv4)
678 "Generic function for retrieving data from ADDRESS.
680 When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
681 QUERY-STRING is a string sent to the host specified by ADDRESS to
682 illicet a response. This response is passed as an argument to the
683 function RESPONSE-PROCESSOR.
685 If non-nil, USE-TLS specifies that the connection is to be made over
686 TLS. If set to gemini, the certificate verification will be disabled
687 unless `elpher-gemini-TLS-cert-checks' is non-nil.
689 If non-nil, FORCE-IPV4 causes the network connection to be made over
690 ipv4 only. (The default behaviour when this is not set depends on
691 the host operating system and the local network capabilities."
692 (if (and use-tls (not (gnutls-available-p)))
693 (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
694 (unless (< (elpher-address-port address) 65536)
695 (error "Cannot establish network connection: port number > 65536"))
696 (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
697 (setq-local network-security-level 'low)
698 (setq-local gnutls-verify-error nil))
700 (let* ((kill-buffer-query-functions nil)
701 (port (elpher-address-port address))
702 (service (if (> port 0) port default-port))
703 (host (elpher-address-host address))
704 (socks (or elpher-socks-always (string-suffix-p ".onion" host)))
705 (response-string-parts nil)
708 (timer (run-at-time elpher-connection-timeout nil
710 (elpher-process-cleanup)
712 ; Try again with IPv4
713 ((not (or force-ipv4 socks))
714 (message "Connection timed out. Retrying with IPv4.")
715 (elpher-get-host-response address default-port
720 (not (eq use-tls 'gemini))
721 (or elpher-auto-disengage-TLS
723 "TLS connetion failed. Disable TLS mode and retry? ")))
724 (setq elpher-use-tls nil)
725 (elpher-get-host-response address default-port
730 (elpher-network-error address "Connection time-out."))))))
731 (gnutls-params (list :type 'gnutls-x509pki :hostname host
732 :keylist (elpher-get-current-keylist address)))
733 (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
734 (make-network-process :name "elpher-process"
736 :family (and force-ipv4 'ipv4)
742 (cons 'gnutls-x509pki
743 (apply #'gnutls-boot-parameters
745 (setq elpher-network-timer timer)
746 (set-process-coding-system proc 'binary 'binary)
747 (set-process-query-on-exit-flag proc nil)
748 (elpher-buffer-message (concat "Connecting to " host "..."
749 " (press 'u' to abort)"))
750 (set-process-filter proc
751 (lambda (_proc string)
755 (setq bytes-received (+ bytes-received (length string)))
756 (let ((new-hkbytes-received (/ bytes-received 102400)))
757 (when (> new-hkbytes-received hkbytes-received)
758 (setq hkbytes-received new-hkbytes-received)
759 (elpher-buffer-message
761 (number-to-string (/ hkbytes-received 10.0))
764 (setq response-string-parts
765 (cons string response-string-parts))))
766 (set-process-sentinel proc
769 (cancel-timer timer))
770 (condition-case the-error
772 ((string-prefix-p "open" event) ; request URL
773 (elpher-buffer-message
774 (concat "Connected to " host ". Receiving data..."
775 " (press 'u' to abort)"))
776 (let ((inhibit-eol-conversion t))
777 (process-send-string proc query-string)))
778 ((string-prefix-p "deleted" event)) ; do nothing
779 ((and (not response-string-parts)
780 (not (or elpher-ipv4-always force-ipv4 socks)))
781 ; Try again with IPv4
782 (message "Connection failed. Retrying with IPv4.")
783 (elpher-get-host-response address default-port
787 (response-string-parts
788 (elpher-with-clean-buffer
789 (insert "Data received. Rendering..."))
790 (funcall response-processor
791 (apply #'concat (reverse response-string-parts)))
792 (elpher-restore-pos))
794 (error "No response from server")))
796 (elpher-network-error address the-error)))))
798 (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
799 (funcall (process-sentinel proc) proc "open\n")))
801 (error "Error initiating connection to server")))))
804 ;;; Client-side TLS Certificate Management
807 (defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
808 "Generate a key and a self-signed client TLS certificate using openssl.
810 The Common Name field of the certificate is set to COMMON-NAME. The
811 arguments KEY-FILE and CERT-FILE should contain the absolute paths of
812 the key and certificate files to write.
814 If TEMPORARY is non-nil, the certificate will be given an exporation
815 period of one day, and the key and certificate files will be deleted
816 when the certificate is no longer needed for the current session.
818 Otherwise, the certificate will be given a 100 year expiration period
819 and the files will not be deleted.
821 The function returns a list containing the current host name, the
822 temporary flag, and the key and cert file names in the form required
823 by `gnutls-boot-parameters`."
824 (let ((exp-key-file (expand-file-name key-file))
825 (exp-cert-file (expand-file-name cert-file)))
828 (call-process elpher-openssl-command nil nil nil
829 "req" "-x509" "-newkey" "rsa:2048"
830 "-days" (if temporary "1" "36500")
832 "-subj" (concat "/CN=" common-name)
833 "-keyout" exp-key-file
834 "-out" exp-cert-file)
835 (list (elpher-address-host (elpher-page-address elpher-current-page))
836 temporary exp-key-file exp-cert-file))
838 (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
839 (error "Program 'openssl', required for certificate generation, not found")))))
841 (defun elpher-generate-throwaway-certificate ()
842 "Generate and return details of a throwaway certificate.
843 The key and certificate files will be deleted when they are no
844 longer needed for this session."
845 (let* ((file-base (make-temp-name "elpher"))
846 (key-file (concat temporary-file-directory file-base ".key"))
847 (cert-file (concat temporary-file-directory file-base ".crt")))
848 (elpher-generate-certificate file-base key-file cert-file t)))
850 (defun elpher-generate-persistent-certificate (file-base common-name)
851 "Generate and return details of a persistent certificate.
852 The argument FILE-BASE is used as the base for the key and certificate
853 files, while COMMON-NAME specifies the common name field of the
856 The key and certificate files are written to in `elpher-certificate-directory'."
857 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
858 (cert-file (concat elpher-certificate-directory file-base ".crt")))
859 (elpher-generate-certificate common-name key-file cert-file)))
861 (defun elpher-get-existing-certificate (file-base)
862 "Return a certificate object corresponding to an existing certificate.
863 It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
864 the directory `elpher-certificate-directory'."
865 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
866 (cert-file (concat elpher-certificate-directory file-base ".crt")))
867 (list (elpher-address-host (elpher-page-address elpher-current-page))
869 (expand-file-name key-file)
870 (expand-file-name cert-file))))
872 (defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
873 "Install a key+certificate file pair in `elpher-certificate-directory'.
874 The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
875 certificate files to install. The argument FILE-BASE is used as the
876 base for the installed key and certificate files."
877 (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
878 (cert-file (concat elpher-certificate-directory file-base ".crt")))
879 (if (or (file-exists-p key-file)
880 (file-exists-p cert-file))
881 (error "A certificate with base name %s is already installed" file-base))
882 (copy-file key-file-src key-file)
883 (copy-file cert-file-src cert-file)
884 (list (elpher-address-host (elpher-page-address elpher-current-page))
886 (expand-file-name key-file)
887 (expand-file-name cert-file))))
889 (defun elpher-list-existing-certificates ()
890 "Return a list of the persistent certificates in `elpher-certificate-directory'."
891 (unless (file-directory-p elpher-certificate-directory)
892 (make-directory elpher-certificate-directory))
895 (file-name-sans-extension file))
896 (directory-files elpher-certificate-directory nil "\\.key$")))
898 (defun elpher-forget-current-certificate ()
899 "Causes any current certificate to be forgotten.)
900 In the case of throwaway certificates, the key and certificate files
903 (when elpher-client-certificate
904 (unless (and (called-interactively-p 'any)
905 (not (y-or-n-p (concat "Really forget client certificate? "
906 "(Throwaway certificates will be deleted.)"))))
907 (when (cadr elpher-client-certificate)
908 (delete-file (elt elpher-client-certificate 2))
909 (delete-file (elt elpher-client-certificate 3)))
910 (setq elpher-client-certificate nil)
911 (if (called-interactively-p 'any)
912 (message "Client certificate forgotten.")))))
914 (defun elpher-get-current-keylist (address)
915 "Retrieve the `gnutls-boot-parameters'-compatable keylist.
917 This is obtained from the client certificate described by
918 `elpher-current-certificate', if one is available and the host for
919 that certificate matches the host in ADDRESS.
921 If `elpher-current-certificate' is non-nil, and its host name doesn't
922 match that of ADDRESS, the certificate is forgotten."
923 (if elpher-client-certificate
924 (if (string= (car elpher-client-certificate)
925 (elpher-address-host address))
926 (list (cddr elpher-client-certificate))
927 (elpher-forget-current-certificate)
928 (message "Disabling client certificate for new host")
933 ;;; Gopher selector retrieval
936 (defun elpher-get-gopher-response (address renderer)
937 "Get response string from gopher server at ADDRESS and render using RENDERER."
938 (elpher-get-host-response address 70
939 (concat (elpher-gopher-address-selector address) "\r\n")
941 (or (string= (elpher-address-protocol address) "gophers")
944 (defun elpher-get-gopher-page (renderer)
945 "Getter function for gopher pages.
946 The RENDERER procedure is used to display the contents of the page
947 once they are retrieved from the gopher server."
948 (let* ((address (elpher-page-address elpher-current-page))
949 (content (elpher-get-cached-content address)))
950 (if (and content (funcall renderer nil))
951 (elpher-with-clean-buffer
953 (elpher-restore-pos))
954 (elpher-with-clean-buffer
955 (insert "LOADING... (use 'u' to cancel)\n"))
956 (condition-case the-error
957 (elpher-get-gopher-response address renderer)
959 (elpher-network-error address the-error))))))
963 (defun elpher-insert-index (string)
964 "Insert the index corresponding to STRING into the current buffer."
965 ;; Should be able to split directly on CRLF, but some non-conformant
966 ;; LF-only servers sadly exist, hence the following.
967 (let ((str-processed (elpher-preprocess-text-response string)))
968 (dolist (line (split-string str-processed "\n"))
970 (unless (= (length line) 0)
971 (let* ((type (elt line 0))
972 (fields (split-string (substring line 1) "\t"))
973 (display-string (elt fields 0))
974 (selector (elt fields 1))
975 (host (elt fields 2))
976 (port (if (elt fields 3)
977 (string-to-number (elt fields 3))
979 (address (elpher-make-gopher-address type selector host port)))
980 (elpher-insert-index-record display-string address)))))))
982 (defun elpher-insert-margin (&optional type-name)
983 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
986 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
988 (propertize "[" 'face 'elpher-margin-brackets)
989 (propertize type-name 'face 'elpher-margin-key)
990 (propertize "]" 'face 'elpher-margin-brackets))))
992 (insert (make-string elpher-margin-width ?\s))))
994 (defun elpher--page-button-help (_window buffer pos)
995 "Function called by Emacs to generate mouse-over text.
996 The arguments specify the BUFFER and the POS within the buffer of the item
997 for which help is required. The function returns the help to be
998 displayed. The _WINDOW argument is currently unused."
999 (with-current-buffer buffer
1000 (let ((button (button-at pos)))
1002 (let* ((page (button-get button 'elpher-page))
1003 (address (elpher-page-address page)))
1004 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
1006 (elpher-address-to-url address))))))))
1008 (defun elpher-insert-index-record (display-string &optional address)
1009 "Function to insert an index record into the current buffer.
1010 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
1011 If ADDRESS is not supplied or nil the record is rendered as an
1012 'information' line."
1013 (let* ((type (if address (elpher-address-type address) nil))
1014 (type-map-entry (cdr (assoc type elpher-type-map))))
1016 (let* ((margin-code (elt type-map-entry 2))
1017 (face (elt type-map-entry 3))
1018 (filtered-display-string (elpher-color-filter-apply display-string))
1019 (page (elpher-make-page filtered-display-string address)))
1020 (elpher-insert-margin margin-code)
1021 (insert-text-button filtered-display-string
1024 'action #'elpher-click-link
1026 'help-echo #'elpher--page-button-help))
1028 ('nil ;; Information
1029 (elpher-insert-margin)
1030 (let ((propertized-display-string
1031 (propertize display-string 'face 'elpher-info)))
1032 (insert (elpher-process-text-for-display propertized-display-string))))
1033 (`(gopher ,selector-type) ;; Unknown
1034 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
1035 (insert (propertize display-string
1036 'face 'elpher-unknown)))))
1039 (defun elpher-click-link (button)
1040 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
1041 (let ((page (button-get button 'elpher-page)))
1042 (elpher-visit-page page)))
1044 (defun elpher-render-index (data &optional _mime-type-string)
1045 "Render DATA as an index. MIME-TYPE-STRING is unused."
1046 (elpher-with-clean-buffer
1049 (elpher-insert-index data)
1050 (elpher-cache-content (elpher-page-address elpher-current-page)
1055 (defconst elpher-url-regex
1056 "\\([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\-_~?/@|#]\\)?\\)?"
1057 "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
1059 (defun elpher-buttonify-urls (string)
1060 "Turn substrings which look like urls in STRING into clickable buttons."
1063 (goto-char (point-min))
1064 (while (re-search-forward elpher-url-regex nil t)
1065 (let ((page (elpher-make-page (substring-no-properties (match-string 0))
1066 (elpher-address-from-url (match-string 0)))))
1067 (make-text-button (match-beginning 0)
1070 'action #'elpher-click-link
1072 'help-echo #'elpher--page-button-help
1076 (defconst elpher-ansi-regex "\x1b\\[[^m]*m"
1077 "Wildly incomplete regexp used to strip out some troublesome ANSI escape sequences.")
1079 (defun elpher-process-text-for-display (string)
1080 "Perform any desired processing of STRING prior to display as text.
1081 Currently includes buttonifying URLs and processing ANSI escape codes."
1082 (elpher-buttonify-urls (if elpher-filter-ansi-from-text
1083 (elpher-color-filter-apply string)
1084 (elpher-color-apply string))))
1086 (defun elpher-render-text (data &optional _mime-type-string)
1087 "Render DATA as text. MIME-TYPE-STRING is unused."
1088 (elpher-with-clean-buffer
1091 (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
1092 (elpher-cache-content
1093 (elpher-page-address elpher-current-page)
1098 (defun elpher-render-image (data &optional _mime-type-string)
1099 "Display DATA as image. MIME-TYPE-STRING is unused."
1102 (if (display-images-p)
1104 (let ((image (create-image
1107 (elpher-with-clean-buffer
1108 (insert-image image)
1109 (elpher-restore-pos))))
1110 (elpher-render-download data))))
1112 ;; Search retrieval and rendering
1114 (defun elpher-get-gopher-query-page (renderer)
1115 "Getter for gopher addresses requiring input.
1116 The response is rendered using the rendering function RENDERER."
1117 (let* ((address (elpher-page-address elpher-current-page))
1118 (content (elpher-get-cached-content address))
1120 (if (and content (funcall renderer nil))
1121 (elpher-with-clean-buffer
1123 (elpher-restore-pos)
1124 (message "Displaying cached search results. Reload to perform a new search."))
1126 (let* ((query-string (read-string "Query: "))
1127 (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
1128 (search-address (elpher-make-gopher-address ?1
1130 (elpher-address-host address)
1131 (elpher-address-port address)
1132 (equal (elpher-address-type address) "gophers"))))
1135 (elpher-with-clean-buffer
1136 (insert "LOADING RESULTS... (use 'u' to cancel)"))
1137 (elpher-get-gopher-response search-address renderer))
1139 (elpher-visit-previous-page))))))
1141 ;; Raw server response rendering
1143 (defun elpher-render-raw (data &optional mime-type-string)
1144 "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
1147 (elpher-with-clean-buffer
1148 (when mime-type-string
1149 (insert "MIME type specified by server: '" mime-type-string "'\n"))
1151 (goto-char (point-min)))
1152 (message "Displaying raw server response. Reload or redraw to return to standard view.")))
1154 ;; File save "rendering"
1156 (defun elpher-render-download (data &optional _mime-type-string)
1157 "Save DATA to file. MIME-TYPE-STRING is unused."
1160 (let* ((address (elpher-page-address elpher-current-page))
1161 (selector (if (elpher-address-gopher-p address)
1162 (elpher-gopher-address-selector address)
1163 (elpher-address-filename address))))
1164 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1165 (let* ((filename-proposal (file-name-nondirectory selector))
1166 (filename (read-file-name "Download complete. Save file as: "
1168 (if (> (length filename-proposal) 0)
1171 (let ((coding-system-for-write 'binary))
1172 (with-temp-file filename
1174 (message (format "Saved to file %s." filename))))))
1178 (defun elpher-render-html (data &optional _mime-type-string)
1179 "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
1180 (elpher-with-clean-buffer
1183 (let ((dom (with-temp-buffer
1185 (libxml-parse-html-region (point-min) (point-max)))))
1186 (shr-insert-document dom)))))
1188 ;; Gemini page retrieval
1190 (defvar elpher-gemini-redirect-chain)
1192 (defun elpher-get-gemini-response (address renderer)
1193 "Get response string from gemini server at ADDRESS and render using RENDERER."
1194 (elpher-get-host-response address 1965
1195 (concat (elpher-address-to-url address) "\r\n")
1196 (lambda (response-string)
1197 (elpher-process-gemini-response response-string renderer))
1200 (defun elpher-parse-gemini-response (response)
1201 "Parse the RESPONSE string and return a list of components.
1202 The list is of the form (code meta body). A response of nil implies
1203 that the response was malformed."
1204 (let ((header-end-idx (string-match "\r\n" response)))
1206 (let ((header (string-trim (substring response 0 header-end-idx)))
1207 (body (substring response (+ header-end-idx 2))))
1208 (if (>= (length header) 2)
1209 (let ((code (substring header 0 2))
1210 (meta (string-trim (substring header 2))))
1211 (list code meta body))
1212 (error "Malformed response: No response status found in header %s" header)))
1213 (error "Malformed response: No CRLF-delimited header found in response %s" response))))
1215 (defun elpher-process-gemini-response (response-string renderer)
1216 "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
1217 (let ((response-components (elpher-parse-gemini-response response-string)))
1218 (let ((response-code (elt response-components 0))
1219 (response-meta (elt response-components 1))
1220 (response-body (elt response-components 2)))
1221 (pcase (elt response-code 0)
1222 (?1 ; Input required
1223 (elpher-with-clean-buffer
1224 (insert "Gemini server is requesting input."))
1225 (let* ((query-string
1226 (if (eq (elt response-code 1) ?1)
1227 (read-passwd (concat response-meta ": "))
1228 (read-string (concat response-meta ": "))))
1229 (query-address (seq-copy (elpher-page-address elpher-current-page)))
1230 (old-fname (url-filename query-address)))
1231 (setf (url-filename query-address)
1232 (concat old-fname "?" (url-build-query-string `((,query-string)))))
1233 (elpher-get-gemini-response query-address renderer)))
1234 (?2 ; Normal response
1235 (funcall renderer response-body response-meta))
1237 (message "Following redirect to %s" response-meta)
1238 (if (>= (length elpher-gemini-redirect-chain) 5)
1239 (error "More than 5 consecutive redirects followed"))
1240 (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
1241 (if (member redirect-address elpher-gemini-redirect-chain)
1242 (error "Redirect loop detected"))
1243 (if (not (string= (elpher-address-protocol redirect-address)
1245 (error "Server tried to automatically redirect to non-gemini URL: %s"
1247 (elpher-page-set-address elpher-current-page redirect-address)
1248 (add-to-list 'elpher-gemini-redirect-chain redirect-address)
1249 (elpher-get-gemini-response redirect-address renderer)))
1250 (?4 ; Temporary failure
1251 (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
1252 response-code response-meta))
1253 (?5 ; Permanent failure
1254 (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
1255 response-code response-meta))
1256 (?6 ; Client certificate required
1257 (elpher-with-clean-buffer
1258 (if elpher-client-certificate
1259 (insert "Gemini server does not recognise the provided TLS certificate:\n\n")
1260 (insert "Gemini server is requesting a valid TLS certificate:\n\n"))
1262 (elpher-gemini-insert-text response-meta))
1263 (let ((chosen-certificate (elpher-choose-client-certificate)))
1264 (unless chosen-certificate
1265 (error "Gemini server requires a client certificate and none was provided"))
1266 (setq elpher-client-certificate chosen-certificate))
1267 (elpher-with-clean-buffer)
1268 (elpher-get-gemini-response (elpher-page-address elpher-current-page) renderer))
1270 (error "Gemini server response unknown: %s %s"
1271 response-code response-meta))))))
1273 (defun elpher-choose-client-certificate ()
1274 "Prompt for a client certificate to use to establish a TLS connection."
1275 (let* ((read-answer-short t))
1276 (pcase (read-answer "What do you want to do? "
1278 "generate and use throw-away certificate")
1280 "generate new or use existing persistent certificate")
1282 "stop immediately")))
1284 (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
1286 (let* ((existing-certificates (elpher-list-existing-certificates))
1287 (file-base (completing-read
1288 "Nickname for new or existing certificate (autocompletes, empty response aborts): "
1289 existing-certificates)))
1290 (if (string-empty-p (string-trim file-base))
1292 (if (member file-base existing-certificates)
1293 (setq elpher-client-certificate
1294 (elpher-get-existing-certificate file-base))
1295 (pcase (read-answer "Generate new certificate or install externally-generated one? "
1297 "generate new certificate")
1299 "install existing certificate")
1301 "stop immediately")))
1303 (let ((common-name (read-string "Common Name field for new certificate: "
1305 (message "New key and self-signed certificate written to %s"
1306 elpher-certificate-directory)
1307 (elpher-generate-persistent-certificate file-base common-name)))
1309 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
1310 (key-file (read-file-name "Key file: " nil nil t)))
1311 (message "Key and certificate installed in %s for future use"
1312 elpher-certificate-directory)
1313 (elpher-install-and-use-existing-certificate key-file
1319 (defun elpher-get-gemini-page (renderer)
1320 "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
1321 (let* ((address (elpher-page-address elpher-current-page))
1322 (content (elpher-get-cached-content address)))
1323 (condition-case the-error
1324 (if (and content (funcall renderer nil))
1325 (elpher-with-clean-buffer
1327 (elpher-restore-pos))
1328 (elpher-with-clean-buffer
1329 (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
1330 (setq elpher-gemini-redirect-chain nil)
1331 (elpher-get-gemini-response address renderer))
1333 (elpher-network-error address the-error)))))
1335 (defun elpher-render-gemini (body &optional mime-type-string)
1336 "Render gemini response BODY with rendering MIME-TYPE-STRING."
1339 (let* ((mime-type-string* (if (or (not mime-type-string)
1340 (string-empty-p mime-type-string))
1341 "text/gemini; charset=utf-8"
1343 (mime-type-split (split-string mime-type-string* ";" t))
1344 (mime-type (string-trim (car mime-type-split)))
1345 (parameters (mapcar (lambda (s)
1346 (let ((key-val (split-string s "=")))
1347 (list (downcase (string-trim (car key-val)))
1348 (downcase (string-trim (cadr key-val))))))
1349 (cdr mime-type-split))))
1350 (when (string-prefix-p "text/" mime-type)
1351 (setq body (decode-coding-string
1353 (if (assoc "charset" parameters)
1354 (intern (cadr (assoc "charset" parameters)))
1356 (setq body (replace-regexp-in-string "\r" "" body)))
1358 ((or "text/gemini" "")
1359 (elpher-render-gemini-map body parameters))
1361 (elpher-render-html body))
1362 ((pred (string-prefix-p "text/"))
1363 (elpher-render-gemini-plain-text body parameters))
1364 ((pred (string-prefix-p "image/"))
1365 (elpher-render-image body))
1367 (elpher-render-download body))))))
1369 (defun elpher-gemini-get-link-url (link-line)
1370 "Extract the url portion of LINK-LINE, a gemini map file link line.
1371 Returns nil in the event that the contents of the line following the
1372 => prefix are empty."
1373 (let ((l (split-string (substring link-line 2))))
1375 (string-trim (elt l 0))
1378 (defun elpher-gemini-get-link-display-string (link-line)
1379 "Extract the display string portion of LINK-LINE, a gemini map file link line.
1380 Returns the url portion in the event that the display-string portion is empty."
1381 (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
1382 (idx (string-match "[ \t]" rest)))
1383 (string-trim (if idx
1384 (substring rest (+ idx 1))
1387 (defun elpher-collapse-dot-sequences (filename)
1388 "Collapse dot sequences in FILENAME.
1389 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
1390 (let* ((path (split-string filename "/"))
1391 (path-reversed-normalized
1392 (seq-reduce (lambda (a b)
1393 (cond ((and a (equal b "..") (cdr a)))
1394 ((and (not a) (equal b "..")) a) ;leading .. are dropped
1398 (string-join (reverse path-reversed-normalized) "/")))
1400 (defun elpher-address-from-gemini-url (url)
1401 "Extract address from URL with defaults as per gemini map files.
1402 While there's obviously some redundancy here between this function and
1403 `elpher-address-from-url', gemini map file URLs require enough special
1404 treatment that a separate function is warranted."
1405 (let ((address (url-generic-parse-url url))
1406 (current-address (elpher-page-address elpher-current-page)))
1407 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
1408 (setf (url-fullness address) t)
1409 (if (url-host address) ;if there is an explicit host, filenames are absolute
1410 (if (string-empty-p (url-filename address))
1411 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
1412 (setf (url-host address) (url-host current-address))
1413 (setf (url-port address) (url-port current-address))
1414 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1415 (setf (url-filename address)
1416 (concat (file-name-directory (url-filename current-address))
1417 (url-filename address)))))
1418 (unless (url-type address)
1419 (setf (url-type address) "gemini"))
1420 (when (equal (url-type address) "gemini")
1421 (setf (url-filename address)
1422 (elpher-collapse-dot-sequences (url-filename address)))))
1423 (elpher-remove-redundant-ports address)))
1425 (defun elpher-gemini-insert-link (link-line)
1426 "Insert link described by LINK-LINE into a text/gemini document."
1427 (let* ((url (elpher-gemini-get-link-url link-line))
1428 (display-string (elpher-gemini-get-link-display-string link-line))
1429 (address (elpher-address-from-gemini-url url))
1430 (type (if address (elpher-address-type address) nil))
1431 (type-map-entry (cdr (assoc type elpher-type-map))))
1432 (setq elpher--gemini-page-links (append elpher--gemini-page-links `(,address)))
1433 (when display-string
1434 (insert elpher-gemini-link-string)
1436 (let* ((face (elt type-map-entry 3))
1437 (filtered-display-string (elpher-color-filter-apply display-string))
1438 (page (elpher-make-page filtered-display-string address)))
1439 (insert-text-button filtered-display-string
1442 'action #'elpher-click-link
1444 'help-echo #'elpher--page-button-help))
1445 (insert (propertize display-string 'face 'elpher-unknown)))
1448 (defun elpher-gemini-insert-header (header-line)
1449 "Insert header described by HEADER-LINE into a text/gemini document.
1450 The gemini map file line describing the header is given
1452 (when (string-match "^\\(#+\\)[ \t]*" header-line)
1453 (let* ((level (length (match-string 1 header-line)))
1454 (header (substring header-line (match-end 0)))
1456 (1 'elpher-gemini-heading1)
1457 (2 'elpher-gemini-heading2)
1458 (3 'elpher-gemini-heading3)
1460 (fill-column (if (display-graphic-p)
1462 (font-get (font-spec :name (face-font 'default)) :size))
1463 (font-get (font-spec :name (face-font face)) :size)) fill-column)))
1464 (setq elpher--gemini-page-headings (cons (cons header (point))
1465 elpher--gemini-page-headings))
1466 (unless (display-graphic-p)
1467 (insert (make-string level ?#) " "))
1468 (insert (propertize header 'face face))
1471 (defun elpher-gemini-insert-text (text-line)
1472 "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
1473 This function uses Emacs' auto-fill to wrap text sensibly to a maximum
1474 width defined by elpher-gemini-max-fill-width."
1475 (string-match "\\(^[ \t]*\\)\\(\*[ \t]+\\|>[ \t]*\\)?" text-line)
1476 (let* ((line-prefix (match-string 2 text-line))
1477 (processed-text-line
1479 (cond ((string-prefix-p "*" line-prefix)
1481 (replace-regexp-in-string "\*"
1482 elpher-gemini-bullet-string
1483 (match-string 0 text-line))
1484 (substring text-line (match-end 0))))
1485 ((string-prefix-p ">" line-prefix)
1486 (propertize text-line 'face 'elpher-gemini-quoted))
1489 (adaptive-fill-mode nil))
1490 (insert (elpher-process-text-for-display processed-text-line))
1493 (defun elpher-render-gemini-map (data _parameters)
1494 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1495 (elpher-with-clean-buffer
1496 (setq elpher--gemini-page-headings nil)
1497 (let ((preformatted nil)
1500 (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
1501 (setq elpher--gemini-page-links '())
1502 (dolist (line (split-string data "\n"))
1504 ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
1505 (preformatted (insert (elpher-process-text-for-display
1506 (propertize line 'face 'elpher-gemini-preformatted))
1508 ((string-prefix-p "=>" line)
1510 (if elpher-gemini-number-links
1514 (number-to-string link-counter)
1516 (setq link-counter (1+ link-counter))
1517 (elpher-gemini-insert-link line)))
1518 ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
1519 (t (elpher-gemini-insert-text line)))))
1520 (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))
1521 (elpher-cache-content
1522 (elpher-page-address elpher-current-page)
1525 (elpher-page-address elpher-current-page)
1526 elpher--gemini-page-links
1527 elpher--gemini-page-links-cache)))
1529 (defun elpher-render-gemini-plain-text (data _parameters)
1530 "Render DATA as plain text file. PARAMETERS is currently unused."
1531 (elpher-with-clean-buffer
1532 (insert (elpher-process-text-for-display data))
1533 (elpher-cache-content
1534 (elpher-page-address elpher-current-page)
1538 ;; Finger page connection
1540 (defun elpher-get-finger-page (renderer)
1541 "Opens a finger connection to the current page address.
1542 The result is rendered using RENDERER."
1543 (let* ((address (elpher-page-address elpher-current-page))
1544 (content (elpher-get-cached-content address)))
1545 (if (and content (funcall renderer nil))
1546 (elpher-with-clean-buffer
1548 (elpher-restore-pos))
1549 (elpher-with-clean-buffer
1550 (insert "LOADING... (use 'u' to cancel)\n"))
1551 (condition-case the-error
1552 (let* ((kill-buffer-query-functions nil)
1553 (user (let ((filename (elpher-address-filename address)))
1554 (if (> (length filename) 1)
1555 (substring filename 1)
1556 (elpher-address-user address)))))
1557 (elpher-get-host-response address 79
1558 (concat user "\r\n")
1561 (elpher-network-error address the-error))))))
1564 ;; Telnet page connection
1566 (defun elpher-get-telnet-page (renderer)
1567 "Opens a telnet connection to the current page address (RENDERER must be nil)."
1569 (elpher-visit-previous-page)
1570 (error "Command not supported for telnet URLs"))
1571 (let* ((address (elpher-page-address elpher-current-page))
1572 (host (elpher-address-host address))
1573 (port (elpher-address-port address)))
1574 (elpher-visit-previous-page)
1580 ;; Other URL page opening
1582 (defun elpher-get-other-url-page (renderer)
1583 "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
1585 (elpher-visit-previous-page)
1586 (error "Command not supported for general URLs"))
1587 (let* ((address (elpher-page-address elpher-current-page))
1588 (url (elpher-address-to-url address)))
1590 (elpher-visit-previous-page) ; Do first in case of non-local exits.
1591 (message "Opening URL...")
1592 (if elpher-open-urls-with-eww
1594 (browse-url url)))))
1597 ;; Start page page retrieval
1599 (defun elpher-get-start-page (renderer)
1600 "Getter which displays the start page (RENDERER must be nil)."
1602 (elpher-visit-previous-page)
1603 (error "Command not supported for start page"))
1604 (elpher-with-clean-buffer
1605 (insert " --------------------------------------------\n"
1606 " Elpher Gopher and Gemini Client \n"
1607 " version " elpher-version "\n"
1608 " --------------------------------------------\n"
1610 "Default bindings:\n"
1612 " - TAB/Shift-TAB: next/prev item on current page\n"
1613 " - RET/mouse-1: open item under cursor\n"
1614 " - m: select an item on current page by name (autocompletes)\n"
1615 " - u/mouse-3/U: return to previous page or to the start page\n"
1616 " - o/O: visit different selector or the root menu of the current server\n"
1617 " - g: go to a particular address (gopher, gemini, finger)\n"
1618 " - v: visit a numbered link on a gemini page\n"
1619 " - d/D: download item under cursor or current page\n"
1620 " - i/I: info on item under cursor or current page\n"
1621 " - c/C: copy URL representation of item under cursor or current page\n"
1622 " - a/A: bookmark the item under cursor or current page\n"
1623 " - x/X: remove bookmark for item under cursor or current page\n"
1624 " - B: visit the bookmarks page\n"
1625 " - r: redraw current page (using cached contents if available)\n"
1626 " - R: reload current page (regenerates cache)\n"
1627 " - S: set character coding system for gopher (default is to autodetect)\n"
1628 " - T: toggle TLS gopher mode\n"
1629 " - F: forget/discard current TLS client certificate\n"
1630 " - .: display the raw server response for the current page\n"
1632 "Start your exploration of gopher space and gemini:\n")
1633 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1634 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1635 (elpher-insert-index-record "Project Gemini home page"
1636 (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
1638 "Alternatively, select a search engine and enter some search terms:\n")
1639 (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
1640 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1641 (elpher-insert-index-record "Gemini Search Engine"
1642 (elpher-address-from-url "gemini://geminispace.info"))
1644 "This page contains your bookmarked sites (also visit with B):\n")
1645 (elpher-insert-index-record "Your Bookmarks" 'bookmarks)
1647 "For Elpher release news or to leave feedback, visit:\n")
1648 (elpher-insert-index-record "The Elpher Project Page"
1649 (elpher-make-gopher-address ?1
1655 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1656 (insert-text-button "Elpher info manual"
1662 'help-echo help-string))
1663 (insert " for the full documentation. **\n")
1665 (concat " (This should be available if you have installed Elpher using\n"
1666 " MELPA. Otherwise you will have to install the manual yourself.)\n")
1668 (elpher-restore-pos)))
1670 ;; Bookmarks page page retrieval
1672 (defun elpher-get-bookmarks-page (renderer)
1673 "Getter to load and display the current bookmark list (RENDERER must be nil)."
1675 (elpher-visit-previous-page)
1676 (error "Command not supported for bookmarks page"))
1677 (elpher-with-clean-buffer
1678 (insert "---- Bookmark list ----\n\n")
1679 (let ((bookmarks (elpher-load-bookmarks)))
1681 (dolist (bookmark bookmarks)
1682 (let ((display-string (elpher-bookmark-display-string bookmark))
1683 (address (elpher-address-from-url (elpher-bookmark-url bookmark))))
1684 (elpher-insert-index-record display-string address)))
1685 (insert "No bookmarks found.\n")))
1686 (insert "\n-----------------------\n"
1688 "- u: return to previous page\n"
1689 "- x: delete selected bookmark\n"
1690 "- a: rename selected bookmark\n"
1692 "Bookmarks are stored in the file ")
1693 (let ((filename elpher-bookmarks-file)
1694 (help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
1695 (insert-text-button filename
1699 (find-file filename))
1701 'help-echo help-string))
1703 (elpher-restore-pos)))
1709 (defun elpher-make-bookmark (display-string url)
1710 "Make an elpher bookmark.
1711 DISPLAY-STRING determines how the bookmark will appear in the
1712 bookmark list, while URL is the url of the entry."
1713 (list display-string url))
1715 (defun elpher-bookmark-display-string (bookmark)
1716 "Get the display string of BOOKMARK."
1719 (defun elpher-set-bookmark-display-string (bookmark display-string)
1720 "Set the display string of BOOKMARK to DISPLAY-STRING."
1721 (setcar bookmark display-string))
1723 (defun elpher-bookmark-url (bookmark)
1724 "Get the address for BOOKMARK."
1727 (defun elpher-save-bookmarks (bookmarks)
1728 "Record the bookmark list BOOKMARKS to the user's bookmark file.
1729 Beware that this completely replaces the existing contents of the file."
1730 (let ((bookmark-dir (file-name-directory elpher-bookmarks-file)))
1731 (unless (file-directory-p bookmark-dir)
1732 (make-directory bookmark-dir)))
1733 (with-temp-file elpher-bookmarks-file
1735 (insert "; Elpher bookmarks file\n\n"
1736 "; Bookmarks are stored as a list of (label URL) items.\n"
1737 "; Feel free to edit by hand, but take care to ensure\n"
1738 "; the list structure remains intact.\n\n")
1739 (pp bookmarks (current-buffer))))
1741 (defun elpher-load-bookmarks ()
1742 "Get the list of bookmarks from the users's bookmark file."
1746 (insert-file-contents elpher-bookmarks-file)
1747 (goto-char (point-min))
1748 (read (current-buffer))))))
1749 (if (and bookmarks (listp (cadar bookmarks)))
1751 (message "Reading old bookmark file. (Will be updated on write.)")
1752 (mapcar (lambda (old-bm)
1754 (elpher-address-to-url (apply #'elpher-make-gopher-address
1759 (defun elpher-add-address-bookmark (address display-string)
1760 "Save a bookmark for ADDRESS with label DISPLAY-STRING.)))
1761 If ADDRESS is already bookmarked, update the label only."
1762 (let ((bookmarks (elpher-load-bookmarks))
1763 (url (elpher-address-to-url address)))
1764 (let ((existing-bookmark (rassoc (list url) bookmarks)))
1765 (if existing-bookmark
1766 (elpher-set-bookmark-display-string existing-bookmark display-string)
1767 (push (elpher-make-bookmark display-string url) bookmarks)))
1768 (elpher-save-bookmarks bookmarks)))
1770 (defun elpher-remove-address-bookmark (address)
1771 "Remove any bookmark to ADDRESS."
1772 (let ((url (elpher-address-to-url address)))
1773 (elpher-save-bookmarks
1774 (seq-filter (lambda (bookmark)
1775 (not (equal (elpher-bookmark-url bookmark) url)))
1776 (elpher-load-bookmarks)))))
1781 (defun elpher-org-link-store ()
1782 "Store link to an `elpher' page in org-mode."
1783 (when (eq major-mode 'elpher-mode)
1784 (let ((link (concat "elpher:" (elpher-info-current)))
1785 (desc (car elpher-current-page)))
1786 (org-link-store-props :type "elpher"
1791 (defun elpher-org-link-follow (link _args)
1792 "Follow an `elpher' link in an `org' buffer."
1794 (message (concat "Got link: " link))
1796 (string-match-p "^gemini://.+" link)
1797 (string-match-p "^gopher://.+" link)
1798 (string-match-p "^finger://.+" link))
1799 (elpher-go (string-remove-prefix "elpher:" link))))
1801 (with-eval-after-load "org"
1802 ;; Use `org-link-set-parameters' if defined (org-mode 9+)
1803 (if (fboundp 'org-link-set-parameters)
1804 (org-link-set-parameters "elpher"
1805 :store #'elpher-org-link-store
1806 :follow #'elpher-org-link-follow)
1807 (org-add-link-type "mu4e" 'elpher-org-link-follow)
1808 (add-hook 'org-store-link-functions 'elpher-org-link-store)))
1810 (defun browse-url-elpher (url &rest _args)
1811 "Browse URL. This function is used by `browse-url'."
1812 (interactive (browse-url-interactive-arg "Elpher URL: "))
1815 (with-eval-after-load "browse-url"
1816 ;; Use elpher to open gopher, finger and gemini links
1817 (when (boundp 'browse-url-default-handlers)
1818 (add-to-list 'browse-url-default-handlers
1819 '("^\\(gopher\\|finger\\|gemini\\)://" . browse-url-elpher)))
1820 ;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
1821 (add-to-list 'thing-at-point-uri-schemes "gemini://"))
1823 ;;; Interactive procedures
1826 (defun elpher-next-link ()
1827 "Move point to the next link on the current page."
1831 (defun elpher-prev-link ()
1832 "Move point to the previous link on the current page."
1834 (backward-button 1))
1836 (defun elpher-follow-current-link ()
1837 "Open the link or url at point."
1842 (defun elpher-go (host-or-url)
1843 "Go to a particular gopher site HOST-OR-URL.
1844 When run interactively HOST-OR-URL is read from the minibuffer."
1845 (interactive "sGopher or Gemini URL: ")
1846 (let* ((cleaned-host-or-url (string-trim host-or-url))
1847 (address (elpher-address-from-url cleaned-host-or-url))
1848 (page (elpher-make-page cleaned-host-or-url address)))
1849 (switch-to-buffer elpher-buffer-name)
1850 (elpher-visit-page page)
1853 (defun elpher-go-current ()
1854 "Go to a particular site read from the minibuffer, initialized with the current URL."
1856 (let ((address (elpher-page-address elpher-current-page)))
1857 (if (elpher-address-special-p address)
1858 (error "Command invalid for this page")
1859 (let ((url (read-string "Gopher or Gemini URL: " (elpher-address-to-url address))))
1860 (elpher-visit-page (elpher-make-page url (elpher-address-from-url url)))))))
1862 (defun elpher-visit-gemini-numbered-link (n)
1863 "Visit link designated by a number."
1864 (interactive "nLink number: ")
1865 (if (or (> n (length elpher--gemini-page-links))
1867 (user-error "Invalid link number"))
1868 (let ((address (nth (1- n) elpher--gemini-page-links)))
1869 (elpher-go (url-recreate-url address))))
1871 (defun elpher-redraw ()
1872 "Redraw current page."
1874 (elpher-visit-page elpher-current-page))
1876 (defun elpher-reload ()
1877 "Reload current page."
1879 (elpher-reload-current-page))
1881 (defun elpher-toggle-tls ()
1882 "Toggle TLS encryption mode for gopher."
1884 (setq elpher-use-tls (not elpher-use-tls))
1886 (if (gnutls-available-p)
1887 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
1888 (setq elpher-use-tls nil)
1889 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
1890 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
1892 (defun elpher-view-raw ()
1893 "View raw server response for current page."
1895 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
1896 (error "This page was not generated by a server")
1897 (elpher-visit-page elpher-current-page
1898 #'elpher-render-raw)))
1900 (defun elpher-back ()
1901 "Go to previous site."
1903 (elpher-visit-previous-page))
1905 (defun elpher-back-to-start ()
1906 "Go all the way back to the start page."
1908 (setq-local elpher-current-page nil)
1909 (setq-local elpher-history nil)
1910 (let ((start-page (elpher-make-page "Elpher Start Page"
1911 (elpher-make-special-address 'start))))
1912 (elpher-visit-page start-page)))
1914 (defun elpher-download ()
1915 "Download the link at point."
1917 (let ((button (button-at (point))))
1919 (let ((page (button-get button 'elpher-page)))
1920 (if (elpher-address-special-p (elpher-page-address page))
1921 (error "Cannot download %s"
1922 (elpher-page-display-string page))
1923 (elpher-visit-page (button-get button 'elpher-page)
1924 #'elpher-render-download)))
1925 (error "No link selected"))))
1927 (defun elpher-download-current ()
1928 "Download the current page."
1930 (if (elpher-address-special-p (elpher-page-address elpher-current-page))
1931 (error "Cannot download %s"
1932 (elpher-page-display-string elpher-current-page))
1933 (elpher-visit-page (elpher-make-page
1934 (elpher-page-display-string elpher-current-page)
1935 (elpher-page-address elpher-current-page))
1936 #'elpher-render-download
1939 (defun elpher-build-link-map ()
1940 "Build alist mapping link names to destination pages in current buffer."
1941 (let ((link-map nil)
1942 (b (next-button (point-min) t)))
1944 (push (cons (button-label b) b) link-map)
1945 (setq b (next-button (button-start b))))
1948 (defun elpher-jump ()
1949 "Select a directory entry by name. Similar to the info browser (m)enu command."
1951 (let* ((link-map (elpher-build-link-map)))
1953 (let ((key (let ((completion-ignore-case t))
1954 (completing-read "Directory item/link: "
1956 (if (and key (> (length key) 0))
1957 (let ((b (cdr (assoc key link-map))))
1958 (goto-char (button-start b))
1959 (button-activate b)))))))
1961 (defun elpher-root-dir ()
1962 "Visit root of current server."
1964 (let ((address (elpher-page-address elpher-current-page)))
1965 (if (not (elpher-address-special-p address))
1966 (if (or (member (url-filename address) '("/" ""))
1967 (and (elpher-address-gopher-p address)
1968 (= (length (elpher-gopher-address-selector address)) 0)))
1969 (error "Already at root directory of current server")
1970 (let ((address-copy (elpher-address-from-url
1971 (elpher-address-to-url address))))
1972 (setf (url-filename address-copy) "")
1973 (elpher-go (elpher-address-to-url address-copy))))
1974 (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
1976 (defun elpher-bookmarks-current-p ()
1977 "Return non-nil if current page is a bookmarks page."
1978 (equal (elpher-address-type (elpher-page-address elpher-current-page))
1979 '(special bookmarks)))
1981 (defun elpher-reload-bookmarks ()
1982 "Reload bookmarks if current page is a bookmarks page."
1983 (if (elpher-bookmarks-current-p)
1984 (elpher-reload-current-page)))
1986 (defun elpher-bookmark-current ()
1987 "Bookmark the current page."
1989 (let ((address (elpher-page-address elpher-current-page))
1990 (display-string (elpher-page-display-string elpher-current-page)))
1991 (if (not (elpher-address-special-p address))
1992 (let ((bookmark-display-string (read-string "Bookmark display string: "
1994 (elpher-add-address-bookmark address bookmark-display-string)
1995 (message "Bookmark added."))
1996 (error "Cannot bookmark %s" display-string))))
1998 (defun elpher-bookmark-link ()
1999 "Bookmark the link at point."
2001 (let ((button (button-at (point))))
2003 (let* ((page (button-get button 'elpher-page))
2004 (address (elpher-page-address page))
2005 (display-string (elpher-page-display-string page)))
2006 (if (not (elpher-address-special-p address))
2007 (let ((bookmark-display-string (read-string "Bookmark display string: "
2009 (elpher-add-address-bookmark address bookmark-display-string)
2010 (elpher-reload-bookmarks)
2011 (message "Bookmark added."))
2012 (error "Cannot bookmark %s" display-string)))
2013 (error "No link selected"))))
2015 (defun elpher-unbookmark-current ()
2016 "Remove bookmark for the current page."
2018 (let ((address (elpher-page-address elpher-current-page)))
2019 (when (and (not (elpher-address-special-p address))
2020 (y-or-n-p "Really remove bookmark for the current page? "))
2021 (elpher-remove-address-bookmark address)
2022 (message "Bookmark removed."))))
2024 (defun elpher-unbookmark-link ()
2025 "Remove bookmark for the link at point."
2027 (let ((button (button-at (point))))
2029 (when (y-or-n-p "Really remove bookmark for this link? ")
2030 (let ((page (button-get button 'elpher-page)))
2031 (elpher-remove-address-bookmark (elpher-page-address page))
2032 (elpher-reload-bookmarks)
2033 (message "Bookmark removed.")))
2034 (error "No link selected"))))
2037 (defun elpher-bookmarks ()
2038 "Visit bookmarks page."
2040 (switch-to-buffer elpher-buffer-name)
2042 (elpher-make-page "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
2044 (defun elpher-info-page (page)
2045 "Display information on PAGE."
2046 (let ((display-string (elpher-page-display-string page))
2047 (address (elpher-page-address page)))
2048 (if (elpher-address-special-p address)
2049 (message "Special page: %s" display-string)
2050 (message "%s" (elpher-address-to-url address)))))
2052 (defun elpher-info-link ()
2053 "Display information on page corresponding to link at point."
2055 (let ((button (button-at (point))))
2057 (elpher-info-page (button-get button 'elpher-page))
2058 (error "No item selected"))))
2060 (defun elpher-info-current ()
2061 "Display information on current page."
2063 (elpher-info-page elpher-current-page))
2065 (defun elpher-copy-page-url (page)
2066 "Copy URL representation of address of PAGE to `kill-ring'."
2067 (let ((address (elpher-page-address page)))
2068 (if (elpher-address-special-p address)
2069 (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
2070 (let ((url (elpher-address-to-url address)))
2071 (message "Copied \"%s\" to kill-ring/clipboard." url)
2074 (defun elpher-copy-link-url ()
2075 "Copy URL of item at point to `kill-ring'."
2077 (let ((button (button-at (point))))
2079 (elpher-copy-page-url (button-get button 'elpher-page))
2080 (error "No item selected"))))
2082 (defun elpher-copy-current-url ()
2083 "Copy URL of current page to `kill-ring'."
2085 (elpher-copy-page-url elpher-current-page))
2087 (defun elpher-set-gopher-coding-system ()
2088 "Specify an explicit character coding system for gopher selectors."
2090 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
2091 (setq elpher-user-coding-system system)
2093 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
2094 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
2100 (defvar elpher-mode-map
2101 (let ((map (make-sparse-keymap)))
2102 (define-key map (kbd "TAB") 'elpher-next-link)
2103 (define-key map (kbd "<backtab>") 'elpher-prev-link)
2104 (define-key map (kbd "C-M-i") 'elpher-prev-link)
2105 (define-key map (kbd "u") 'elpher-back)
2106 (define-key map (kbd "U") 'elpher-back-to-start)
2107 (define-key map [mouse-3] 'elpher-back)
2108 (define-key map (kbd "O") 'elpher-root-dir)
2109 (define-key map (kbd "g") 'elpher-go)
2110 (define-key map (kbd "o") 'elpher-go-current)
2111 (define-key map (kbd "r") 'elpher-redraw)
2112 (define-key map (kbd "R") 'elpher-reload)
2113 (define-key map (kbd "T") 'elpher-toggle-tls)
2114 (define-key map (kbd ".") 'elpher-view-raw)
2115 (define-key map (kbd "d") 'elpher-download)
2116 (define-key map (kbd "D") 'elpher-download-current)
2117 (define-key map (kbd "m") 'elpher-jump)
2118 (define-key map (kbd "i") 'elpher-info-link)
2119 (define-key map (kbd "I") 'elpher-info-current)
2120 (define-key map (kbd "c") 'elpher-copy-link-url)
2121 (define-key map (kbd "C") 'elpher-copy-current-url)
2122 (define-key map (kbd "a") 'elpher-bookmark-link)
2123 (define-key map (kbd "A") 'elpher-bookmark-current)
2124 (define-key map (kbd "x") 'elpher-unbookmark-link)
2125 (define-key map (kbd "X") 'elpher-unbookmark-current)
2126 (define-key map (kbd "B") 'elpher-bookmarks)
2127 (define-key map (kbd "S") 'elpher-set-gopher-coding-system)
2128 (define-key map (kbd "F") 'elpher-forget-current-certificate)
2129 (define-key map (kbd "v") 'elpher-visit-gemini-numbered-link)
2130 (when (fboundp 'evil-define-key*)
2131 (evil-define-key* 'motion map
2132 (kbd "TAB") 'elpher-next-link
2133 (kbd "C-") 'elpher-follow-current-link
2134 (kbd "C-t") 'elpher-back
2135 (kbd "u") 'elpher-back
2136 (kbd "-") 'elpher-back
2137 (kbd "^") 'elpher-back
2138 (kbd "U") 'elpher-back-to-start
2139 [mouse-3] 'elpher-back
2140 (kbd "o") 'elpher-go
2141 (kbd "O") 'elpher-go-current
2142 (kbd "r") 'elpher-redraw
2143 (kbd "R") 'elpher-reload
2144 (kbd "T") 'elpher-toggle-tls
2145 (kbd ".") 'elpher-view-raw
2146 (kbd "d") 'elpher-download
2147 (kbd "D") 'elpher-download-current
2148 (kbd "J") 'elpher-jump
2149 (kbd "i") 'elpher-info-link
2150 (kbd "I") 'elpher-info-current
2151 (kbd "c") 'elpher-copy-link-url
2152 (kbd "C") 'elpher-copy-current-url
2153 (kbd "a") 'elpher-bookmark-link
2154 (kbd "A") 'elpher-bookmark-current
2155 (kbd "x") 'elpher-unbookmark-link
2156 (kbd "X") 'elpher-unbookmark-current
2157 (kbd "B") 'elpher-bookmarks
2158 (kbd "S") 'elpher-set-gopher-coding-system
2159 (kbd "F") 'elpher-forget-current-certificate
2160 (kbd "v") 'elpher-visit-gemini-numbered-link))
2162 "Keymap for gopher client.")
2164 (define-derived-mode elpher-mode special-mode "elpher"
2165 "Major mode for elpher, an elisp gopher client.
2167 This mode is automatically enabled by the interactive
2168 functions which initialize the gopher client, namely
2169 `elpher', `elpher-go' and `elpher-bookmarks'."
2170 (setq-local elpher--gemini-page-headings nil)
2171 (setq-local elpher-current-page nil)
2172 (setq-local elpher-history nil)
2173 (setq-local elpher-buffer-name (buffer-name))
2175 (setq-local imenu-create-index-function
2177 elpher--gemini-page-headings)))
2179 (when (fboundp 'evil-set-initial-state)
2180 (evil-set-initial-state 'elpher-mode 'motion))
2183 ;;; Main start procedure
2187 (defun elpher (&optional arg)
2188 "Start elpher with default landing page.
2189 The buffer used for Elpher sessions is determined by the value of
2190 ‘elpher-buffer-name’. If there is already an Elpher session active in
2191 that buffer, Emacs will simply switch to it. Otherwise, a new session
2192 will begin. A numeric prefix arg (as in ‘C-u 42 M-x elpher RET’)
2193 switches to the session with that number, creating it if necessary. A
2194 nonnumeric prefix arg means to create a new session. Returns the
2195 buffer selected (or created)."
2197 (let* ((name (default-value 'elpher-buffer-name))
2198 (buf (cond ((numberp arg)
2199 (get-buffer-create (format "%s<%d>" name arg)))
2201 (generate-new-buffer name))
2203 (get-buffer-create name)))))
2204 (pop-to-buffer-same-window buf)
2205 (unless (buffer-modified-p)
2207 (let ((start-page (elpher-make-page "Elpher Start Page"
2208 (elpher-make-special-address 'start))))
2209 (elpher-visit-page start-page))
2210 "Started Elpher."))); Otherwise (elpher) evaluates to start page string.
2212 ;;; elpher.el ends here