1 ;;; elpher.el --- A friendly gopher client. -*- lexical-binding:t -*-
3 ;; Copyright (C) 2019 Tim Vaughan
5 ;; Author: Tim Vaughan <tgvaughan@gmail.com>
6 ;; Created: 11 April 2019
8 ;; Keywords: comm gopher
9 ;; Homepage: http://thelambdalab.xyz/elpher
10 ;; Package-Requires: ((emacs "26"))
12 ;; This file is not part of GNU Emacs.
14 ;; This program is free software: you can redistribute it and/or modify
15 ;; it under the terms of the GNU General Public License as published by
16 ;; the Free Software Foundation, either version 3 of the License, or
17 ;; (at your option) any later version.
19 ;; This program is distributed in the hope that it will be useful,
20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 ;; GNU General Public License for more details.
24 ;; You should have received a copy of the GNU General Public License
25 ;; along with this file. If not, see <http://www.gnu.org/licenses/>.
29 ;; Elpher aims to provide a practical and friendly gopher client
30 ;; for GNU Emacs. It supports:
32 ;; - intuitive keyboard and mouse-driven browsing,
33 ;; - out-of-the-box compatibility with evil-mode,
34 ;; - clickable web and gopher links *in plain text*,
35 ;; - caching of visited sites,
36 ;; - pleasant and configurable colouring of Gopher directories,
37 ;; - direct visualisation of image files,
38 ;; - a simple bookmark management system,
39 ;; - connections using TLS encryption,
40 ;; - support for the fledgling Gemini protocol.
42 ;; To launch Elpher, simply use 'M-x elpher'. This will open a start
43 ;; page containing information on key bindings and suggested starting
44 ;; points for your gopher exploration.
46 ;; Full instructions can be found in the Elpher info manual.
48 ;; Elpher is under active development. Any suggestions for
49 ;; improvements are welcome, and can be made on the official
50 ;; project page, gopher://thelambdalab.xyz/1/projects/elpher/.
70 (defconst elpher-version "2.4.4"
71 "Current version of elpher.")
73 (defconst elpher-margin-width 6
74 "Width of left-hand margin used when rendering indicies.")
76 (defconst elpher-type-map
77 '(((gopher ?0) elpher-get-gopher-node elpher-render-text "txt" elpher-text)
78 ((gopher ?1) elpher-get-gopher-node elpher-render-index "/" elpher-index)
79 ((gopher ?4) elpher-get-gopher-node elpher-render-download "bin" elpher-binary)
80 ((gopher ?5) elpher-get-gopher-node elpher-render-download "bin" elpher-binary)
81 ((gopher ?7) elpher-get-gopher-query-node elpher-render-index "?" elpher-search)
82 ((gopher ?9) elpher-get-gopher-node elpher-render-download "bin" elpher-binary)
83 ((gopher ?g) elpher-get-gopher-node elpher-render-image "img" elpher-image)
84 ((gopher ?p) elpher-get-gopher-node elpher-render-image "img" elpher-image)
85 ((gopher ?I) elpher-get-gopher-node elpher-render-image "img" elpher-image)
86 ((gopher ?d) elpher-get-gopher-node elpher-render-download "doc" elpher-binary)
87 ((gopher ?P) elpher-get-gopher-node elpher-render-download "doc" elpher-binary)
88 ((gopher ?s) elpher-get-gopher-node elpher-render-download "snd" elpher-binary)
89 ((gopher ?h) elpher-get-gopher-node elpher-render-html "htm" elpher-html)
90 (gemini elpher-get-gemini-node elpher-render-gemini "gem" elpher-gemini)
91 (telnet elpher-get-telnet-node nil "tel" elpher-telnet)
92 (other-url elpher-get-other-url-node nil "url" elpher-other-url)
93 ((special bookmarks) elpher-get-bookmarks-node nil "/" elpher-index)
94 ((special start) elpher-get-start-node nil))
95 "Association list from types to getters, renderers, margin codes and index faces.")
98 ;;; Customization group
103 :group 'applications)
105 ;; Face customizations
107 (defface elpher-index
108 '((t :inherit font-lock-keyword-face))
109 "Face used for directory type directory records.")
113 "Face used for text type directory records.")
116 '((t :inherit default))
117 "Face used for info type directory records.")
119 (defface elpher-image
120 '((t :inherit font-lock-string-face))
121 "Face used for image type directory records.")
123 (defface elpher-search
124 '((t :inherit warning))
125 "Face used for search type directory records.")
128 '((t :inherit font-lock-comment-face))
129 "Face used for html type directory records.")
131 (defface elpher-gemini
132 '((t :inherit font-lock-regexp-grouping-backslash))
133 "Face used for html type directory records.")
135 (defface elpher-other-url
136 '((t :inherit font-lock-comment-face))
137 "Face used for other URL type links records.")
139 (defface elpher-telnet
140 '((t :inherit font-lock-function-name-face))
141 "Face used for telnet type directory records.")
143 (defface elpher-binary
144 '((t :inherit font-lock-doc-face))
145 "Face used for binary type directory records.")
147 (defface elpher-unknown
148 '((t :inherit error))
149 "Face used for directory records with unknown/unsupported types.")
151 (defface elpher-margin-key
153 "Face used for directory margin key.")
155 (defface elpher-margin-brackets
156 '((t :inherit shadow))
157 "Face used for brackets around directory margin key.")
159 ;; Other customizations
161 (defcustom elpher-open-urls-with-eww nil
162 "If non-nil, open URL selectors using eww.
163 Otherwise, use the system browser via the BROWSE-URL function."
166 (defcustom elpher-buttonify-urls-in-directories t
167 "If non-nil, turns URLs matched in directories into clickable buttons."
170 (defcustom elpher-use-header t
171 "If non-nil, display current node information in buffer header."
174 (defcustom elpher-auto-disengage-TLS nil
175 "If non-nil, automatically disengage TLS following an unsuccessful connection.
176 While enabling this may seem convenient, it is also potentially dangerous as it
177 allows switching from an encrypted channel back to plain text without user input."
180 (defcustom elpher-connection-timeout 5
181 "Specifies the number of seconds to wait for a network connection to time out."
189 ;; An elpher "address" object is either a url object or a symbol.
190 ;; Symbol addresses are "special", corresponding to pages generated
191 ;; dynamically for and by elpher. All others represent pages which
192 ;; rely on content retrieved over the network.
194 (defun elpher-address-from-url (url-string)
195 "Create a ADDRESS object corresponding to the given URL-STRING."
196 (let ((data (match-data))) ; Prevent parsing clobbering match data
198 (let ((url (url-generic-parse-url url-string)))
199 (unless (and (not (url-fullness url)) (url-type url))
200 (setf (url-fullness url) t)
201 (setf (url-filename url)
202 (url-unhex-string (url-filename url)))
203 (unless (url-type url)
204 (setf (url-type url) "gopher"))
205 (when (or (equal "gopher" (url-type url))
206 (equal "gophers" (url-type url)))
208 (unless (url-host url)
209 (setf (url-host url) (url-filename url))
210 (setf (url-filename url) ""))
211 (when (or (equal (url-filename url) "")
212 (equal (url-filename url) "/"))
213 (setf (url-filename url) "/1")))
214 (when (equal "gemini" (url-type url))
216 (if (equal (url-filename url) "")
217 (setf (url-filename url) "/"))))
219 (set-match-data data))))
221 (defun elpher-make-gopher-address (type selector host port &optional tls)
222 "Create an ADDRESS object using gopher directory record attributes.
223 The basic attributes include: TYPE, SELECTOR, HOST and PORT.
224 If the optional attribute TLS is non-nil, the address will be marked as
225 requiring gopher-over-TLS."
227 ((and (equal type ?h)
228 (string-prefix-p "URL:" selector))
229 (elpher-address-from-url (elt (split-string selector "URL:") 1)))
231 (elpher-address-from-url
234 ":" (number-to-string port))))
236 (elpher-address-from-url
237 (concat "gopher" (if tls "s" "")
239 ":" (number-to-string port)
243 (defun elpher-make-special-address (type)
244 "Create an ADDRESS object corresponding to the given special page symbol TYPE."
247 (defun elpher-address-to-url (address)
248 "Get string representation of ADDRESS, or nil if ADDRESS is special."
249 (if (not (elpher-address-special-p address))
250 (url-encode-url (url-recreate-url address))
253 (defun elpher-address-type (address)
254 "Retrieve type of ADDRESS object.
255 This is used to determine how to retrieve and render the document the
256 address refers to, via the table `elpher-type-map'."
257 (if (symbolp address)
258 (list 'special address)
259 (let ((protocol (url-type address)))
260 (cond ((or (equal protocol "gopher")
261 (equal protocol "gophers"))
263 (if (member (url-filename address) '("" "/"))
265 (string-to-char (substring (url-filename address) 1)))))
266 ((equal protocol "gemini")
268 ((equal protocol "telnet")
272 (defun elpher-address-protocol (address)
273 "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
274 (if (symbolp address)
278 (defun elpher-address-filename (address)
279 "Retrieve the filename component of ADDRESS.
280 For gopher addresses this is a combination of the selector type and selector."
281 (if (symbolp address)
283 (url-filename address)))
285 (defun elpher-address-host (address)
286 "Retrieve host from ADDRESS object."
289 (defun elpher-address-port (address)
290 "Retrieve port from ADDRESS object.
291 If no address is defined, returns 0. (This is for compatibility with the URL library.)"
292 (if (symbolp address)
296 (defun elpher-address-special-p (address)
297 "Return non-nil if ADDRESS object is special (e.g. start page, bookmarks page)."
300 (defun elpher-address-gopher-p (address)
301 "Return non-nill if ADDRESS object is a gopher address."
302 (and (not (elpher-address-special-p address))
303 (member (elpher-address-protocol address) '("gopher gophers"))))
305 (defun elpher-gopher-address-selector (address)
306 "Retrieve gopher selector from ADDRESS object."
307 (if (member (url-filename address) '("" "/"))
309 (substring (url-filename address) 2)))
313 (defun elpher-make-node (display-string address &optional parent)
314 "Create a node in the page hierarchy.
316 DISPLAY-STRING records the display string used for the page.
318 ADDRESS specifies the address object of the page.
320 The optional PARENT specifies the parent node in the hierarchy.
321 This is set every time the node is visited, so while it forms
322 an important part of the node data there is no need to set it
324 (list display-string address parent))
326 (defun elpher-node-display-string (node)
327 "Retrieve the display string of NODE."
330 (defun elpher-node-address (node)
331 "Retrieve the ADDRESS object of NODE."
334 (defun elpher-node-parent (node)
335 "Retrieve the parent node of NODE."
338 (defun elpher-set-node-parent (node parent)
339 "Set the parent node of NODE to be PARENT."
340 (setcar (cdr (cdr node)) parent))
344 (defvar elpher-content-cache (make-hash-table :test 'equal))
345 (defvar elpher-pos-cache (make-hash-table :test 'equal))
347 (defun elpher-get-cached-content (address)
348 "Retrieve the cached content for ADDRESS, or nil if none exists."
349 (gethash address elpher-content-cache))
351 (defun elpher-cache-content (address content)
352 "Set the content cache for ADDRESS to CONTENT."
353 (puthash address content elpher-content-cache))
355 (defun elpher-get-cached-pos (address)
356 "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
357 (gethash address elpher-pos-cache))
359 (defun elpher-cache-pos (address pos)
360 "Set the cursor position cache for ADDRESS to POS."
361 (puthash address pos elpher-pos-cache))
363 ;; Node graph traversal
365 (defvar elpher-current-node nil)
367 (defun elpher-visit-node (node &optional renderer preserve-parent)
368 "Visit NODE using its own renderer or RENDERER, if non-nil.
369 Additionally, set the parent of NODE to `elpher-current-node',
370 unless PRESERVE-PARENT is non-nil."
372 (elpher-process-cleanup)
373 (unless preserve-parent
374 (if (and (elpher-node-parent elpher-current-node)
375 (equal (elpher-node-address elpher-current-node)
376 (elpher-node-address node)))
377 (elpher-set-node-parent node (elpher-node-parent elpher-current-node))
378 (elpher-set-node-parent node elpher-current-node)))
379 (setq elpher-current-node node)
380 (let* ((address (elpher-node-address node))
381 (type (elpher-address-type address))
382 (type-record (cdr (assoc type elpher-type-map))))
384 (funcall (car type-record)
388 (elpher-visit-parent-node)
390 (`(gopher ,type-char)
391 (error "Unsupported gopher selector type '%c' for '%s'"
392 type-char (elpher-address-to-url address)))
394 (error "Unsupported address type '%S' for '%s'"
395 other (elpher-address-to-url address)))))))
397 (defun elpher-visit-parent-node ()
398 "Visit the parent of the current node."
399 (let ((parent-node (elpher-node-parent elpher-current-node)))
401 (elpher-visit-node parent-node nil t))))
403 (defun elpher-reload-current-node ()
404 "Reload the current node, discarding any existing cached content."
405 (elpher-cache-content (elpher-node-address elpher-current-node) nil)
406 (elpher-visit-node elpher-current-node))
408 (defun elpher-save-pos ()
409 "Save the current position of point to the current node."
410 (when elpher-current-node
411 (elpher-cache-pos (elpher-node-address elpher-current-node) (point))))
413 (defun elpher-restore-pos ()
414 "Restore the position of point to that cached in the current node."
415 (let ((pos (elpher-get-cached-pos (elpher-node-address elpher-current-node))))
418 (goto-char (point-min)))))
421 ;;; Buffer preparation
424 (defun elpher-update-header ()
425 "If `elpher-use-header' is true, display current node info in window header."
426 (if elpher-use-header
427 (let* ((display-string (elpher-node-display-string elpher-current-node))
428 (address (elpher-node-address elpher-current-node))
429 (tls-string (if (and (not (elpher-address-special-p address))
430 (member (elpher-address-protocol address)
431 '("gophers" "gemini")))
434 (header (concat display-string
435 (propertize tls-string 'face 'bold))))
436 (setq header-line-format header))))
438 (defmacro elpher-with-clean-buffer (&rest args)
439 "Evaluate ARGS with a clean *elpher* buffer as current."
440 (list 'with-current-buffer "*elpher*"
442 (append (list 'let '((inhibit-read-only t))
444 '(elpher-update-header))
451 (defvar elpher-user-coding-system nil
452 "User-specified coding system to use for decoding text responses.")
454 (defun elpher-decode (string)
455 "Decode STRING using autodetected or user-specified coding system."
456 (decode-coding-string string
457 (if elpher-user-coding-system
458 elpher-user-coding-system
459 (detect-coding-string string t))))
461 (defun elpher-preprocess-text-response (string)
462 "Preprocess text selector response contained in STRING.
463 This involes decoding the character representation, and clearing
464 away CRs and any terminating period."
465 (elpher-decode (replace-regexp-in-string "\n\.\n$" "\n"
466 (replace-regexp-in-string "\r" "" string))))
469 ;;; Network error reporting
472 (defun elpher-network-error (address error)
473 "Display ERROR message following unsuccessful negotiation with ADDRESS.
474 ERROR can be either an error object or a string."
475 (elpher-with-clean-buffer
476 (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
477 "When attempting to retrieve " (elpher-address-to-url address) ":\n"
478 (if (stringp error) error (error-message-string error)) "\n"
479 (propertize "\n----------------\n\n" 'face 'error)
480 "Press 'u' to return to the previous page.")))
483 ;;; Gopher selector retrieval
486 (defvar elpher-network-timer nil
487 "Timer used for network connections.")
489 (defun elpher-process-cleanup ()
490 "Immediately shut down any extant elpher process and timers."
491 (let ((p (get-process "elpher-process")))
492 (if p (delete-process p)))
493 (if (timerp elpher-network-timer)
494 (cancel-timer elpher-network-timer)))
496 (defvar elpher-use-tls nil
497 "If non-nil, use TLS to communicate with gopher servers.")
499 (defun elpher-get-selector (address renderer &optional force-ipv4)
500 "Retrieve selector specified by ADDRESS, then render it using RENDERER.
501 If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
503 (when (equal (elpher-address-protocol address) "gophers")
504 (if (gnutls-available-p)
505 (when (not elpher-use-tls)
506 (setq elpher-use-tls t)
507 (message "Engaging TLS gopher mode."))
508 (error "Cannot retrieve TLS gopher selector: GnuTLS not available")))
509 (unless (< (elpher-address-port address) 65536)
510 (error "Cannot retrieve gopher selector: port number > 65536"))
512 (let* ((kill-buffer-query-functions nil)
513 (port (elpher-address-port address))
514 (host (elpher-address-host address))
516 (proc (open-network-stream "elpher-process"
518 (if force-ipv4 (dns-query host) host)
519 (if (> port 0) port 70)
520 :type (if elpher-use-tls 'tls 'plain)
522 (timer (run-at-time elpher-connection-timeout
525 (pcase (process-status proc)
527 (if (and (not (equal (elpher-address-protocol address)
530 (or elpher-auto-disengage-TLS
531 (yes-or-no-p "Could not establish encrypted connection. Disable TLS mode?")))
533 (message "Disabling TLS mode.")
534 (setq elpher-use-tls nil)
535 (elpher-get-selector address renderer))
536 (elpher-network-error address "Could not establish encrypted connection")))
538 (elpher-process-cleanup)
540 (message "Connection timed out. Retrying with IPv4 address.")
541 (elpher-get-selector address renderer t))))))))
542 (setq elpher-network-timer timer)
543 (set-process-coding-system proc 'binary)
544 (set-process-filter proc
545 (lambda (_proc string)
547 (setq selector-string
548 (concat selector-string string))))
549 (set-process-sentinel proc
550 (lambda (_proc event)
551 (condition-case the-error
553 ((string-prefix-p "deleted" event))
554 ((string-prefix-p "open" event)
555 (let ((inhibit-eol-conversion t))
558 (concat (elpher-gopher-address-selector address)
562 (funcall renderer selector-string)
563 (elpher-restore-pos)))
565 (elpher-network-error address the-error))))))
567 (error "Error initiating connection to server"))))
569 (defun elpher-get-gopher-node (renderer)
570 "Getter function for gopher nodes.
571 The RENDERER procedure is used to display the contents of the node
572 once they are retrieved from the gopher server."
573 (let* ((address (elpher-node-address elpher-current-node))
574 (content (elpher-get-cached-content address)))
575 (if (and content (funcall renderer nil))
576 (elpher-with-clean-buffer
578 (elpher-restore-pos))
579 (elpher-with-clean-buffer
580 (insert "LOADING... (use 'u' to cancel)"))
581 (condition-case the-error
582 (elpher-get-selector address renderer)
584 (elpher-network-error address the-error))))))
588 (defun elpher-insert-index (string)
589 "Insert the index corresponding to STRING into the current buffer."
590 ;; Should be able to split directly on CRLF, but some non-conformant
591 ;; LF-only servers sadly exist, hence the following.
592 (let ((str-processed (elpher-preprocess-text-response string)))
593 (dolist (line (split-string str-processed "\n"))
595 (unless (= (length line) 0)
596 (let* ((type (elt line 0))
597 (fields (split-string (substring line 1) "\t"))
598 (display-string (elt fields 0))
599 (selector (elt fields 1))
600 (host (elt fields 2))
601 (port (if (elt fields 3)
602 (string-to-number (elt fields 3))
604 (address (elpher-make-gopher-address type selector host port)))
605 (elpher-insert-index-record display-string address)))))))
607 (defun elpher-insert-margin (&optional type-name)
608 "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
611 (insert (format (concat "%" (number-to-string (- elpher-margin-width 1)) "s")
613 (propertize "[" 'face 'elpher-margin-brackets)
614 (propertize type-name 'face 'elpher-margin-key)
615 (propertize "]" 'face 'elpher-margin-brackets))))
617 (insert (make-string elpher-margin-width ?\s))))
619 (defun elpher-node-button-help (node)
620 "Return a string containing the help text for a button corresponding to NODE."
621 (let ((address (elpher-node-address node)))
622 (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
624 (elpher-address-to-url address)))))
626 (defun elpher-insert-index-record (display-string &optional address)
627 "Function to insert an index record into the current buffer.
628 The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
629 If ADDRESS is not supplied or nil the record is rendered as an
631 (let* ((type (if address (elpher-address-type address) nil))
632 (type-map-entry (cdr (assoc type elpher-type-map))))
634 (let* ((margin-code (elt type-map-entry 2))
635 (face (elt type-map-entry 3))
636 (node (elpher-make-node display-string address)))
637 (elpher-insert-margin margin-code)
638 (insert-text-button display-string
641 'action #'elpher-click-link
643 'help-echo (elpher-node-button-help node)))
645 ((or '(gopher ?i) 'nil) ;; Information
646 (elpher-insert-margin)
647 (let ((propertized-display-string
648 (propertize display-string 'face 'elpher-info)))
649 (insert (if elpher-buttonify-urls-in-directories
650 (elpher-buttonify-urls propertized-display-string)
651 propertized-display-string))))
652 (`(gopher ,selector-type) ;; Unknown
653 (elpher-insert-margin (concat (char-to-string selector-type) "?"))
654 (insert (propertize display-string
655 'face 'elpher-unknown)))))
658 (defun elpher-click-link (button)
659 "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
660 (let ((node (button-get button 'elpher-node)))
661 (elpher-visit-node node)))
663 (defun elpher-render-index (data &optional _mime-type-string)
664 "Render DATA as an index. MIME-TYPE-STRING is unused."
665 (elpher-with-clean-buffer
668 (elpher-insert-index data)
669 (elpher-cache-content (elpher-node-address elpher-current-node)
674 (defconst elpher-url-regex
675 "\\([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\-_~?/@|#]\\)?\\)?"
676 "Regexp used to locate and buttniofy URLs in text files loaded by elpher.")
678 (defun elpher-buttonify-urls (string)
679 "Turn substrings which look like urls in STRING into clickable buttons."
682 (goto-char (point-min))
683 (while (re-search-forward elpher-url-regex nil t)
684 (let ((node (elpher-make-node (substring-no-properties (match-string 0))
685 (elpher-address-from-url (match-string 0)))))
686 (make-text-button (match-beginning 0)
689 'action #'elpher-click-link
691 'help-echo (elpher-node-button-help node)
695 (defun elpher-render-text (data &optional _mime-type-string)
696 "Render DATA as text. MIME-TYPE-STRING is unused."
697 (elpher-with-clean-buffer
700 (insert (elpher-buttonify-urls (elpher-preprocess-text-response data)))
701 (elpher-cache-content
702 (elpher-node-address elpher-current-node)
707 (defun elpher-render-image (data &optional _mime-type-string)
708 "Display DATA as image. MIME-TYPE-STRING is unused."
711 (if (display-images-p)
713 (let ((image (create-image
716 (elpher-with-clean-buffer
718 (elpher-restore-pos))))
719 (elpher-render-download data))))
721 ;; Search retrieval and rendering
723 (defun elpher-get-gopher-query-node (renderer)
724 "Getter for gopher addresses requiring input.
725 The response is rendered using the rendering function RENDERER."
726 (let* ((address (elpher-node-address elpher-current-node))
727 (content (elpher-get-cached-content address))
729 (if (and content (funcall renderer nil))
730 (elpher-with-clean-buffer
733 (message "Displaying cached search results. Reload to perform a new search."))
735 (let* ((query-string (read-string "Query: "))
736 (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
737 (search-address (elpher-make-gopher-address ?1
739 (elpher-address-host address)
740 (elpher-address-port address)
741 (equal (elpher-address-type address) "gophers"))))
744 (elpher-with-clean-buffer
745 (insert "LOADING RESULTS... (use 'u' to cancel)"))
746 (elpher-get-selector search-address renderer))
748 (elpher-visit-parent-node))))))
750 ;; Raw server response rendering
752 (defun elpher-render-raw (data &optional mime-type-string)
753 "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
756 (elpher-with-clean-buffer
757 (when mime-type-string
758 (insert "MIME type specified by server: '" mime-type-string "'\n"))
760 (goto-char (point-min)))
761 (message "Displaying raw server response. Reload or redraw to return to standard view.")))
763 ;; File save "rendering"
765 (defun elpher-render-download (data &optional _mime-type-string)
766 "Save DATA to file. MIME-TYPE-STRING is unused."
769 (let* ((address (elpher-node-address elpher-current-node))
770 (selector (elpher-gopher-address-selector address)))
771 (elpher-visit-parent-node) ; Do first in case of non-local exits.
772 (let* ((filename-proposal (file-name-nondirectory selector))
773 (filename (read-file-name "Download complete. Save file as: "
775 (if (> (length filename-proposal) 0)
778 (let ((coding-system-for-write 'binary))
779 (with-temp-file filename
781 (message (format "Saved to file %s." filename))))))
785 (defun elpher-render-html (data &optional _mime-type-string)
786 "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
787 (elpher-with-clean-buffer
790 (let ((dom (with-temp-buffer
792 (libxml-parse-html-region (point-min) (point-max)))))
793 (shr-insert-document dom)))))
795 ;; Gemini node retrieval
797 (defvar elpher-gemini-redirect-chain)
799 (defun elpher-get-gemini-response (address renderer &optional force-ipv4)
800 "Retrieve gemini ADDRESS, then render using RENDERER.
801 If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
803 (if (not (gnutls-available-p))
804 (error "Cannot establish gemini connection: GnuTLS not available")
805 (unless (< (elpher-address-port address) 65536)
806 (error "Cannot establish gemini connection: port number > 65536"))
808 (let* ((kill-buffer-query-functions nil)
809 (port (elpher-address-port address))
810 (host (elpher-address-host address))
812 (proc (open-network-stream "elpher-process"
814 (if force-ipv4 (dns-query host) host)
815 (if (> port 0) port 1965)
818 (timer (run-at-time elpher-connection-timeout nil
820 (elpher-process-cleanup)
822 ; Try again with IPv4
823 (message "Connection timed out. Retrying with IPv4.")
824 (elpher-get-gemini-response address renderer t))))))
825 (setq elpher-network-timer timer)
826 (set-process-coding-system proc 'binary)
827 (set-process-filter proc
828 (lambda (_proc string)
830 (setq response-string
831 (concat response-string string))))
832 (set-process-sentinel proc
834 (condition-case the-error
836 ((string-prefix-p "open" event) ; request URL
837 (let ((inhibit-eol-conversion t))
840 (concat (elpher-address-to-url address)
842 ((string-prefix-p "deleted" event)) ; do nothing
843 ((and (string-empty-p response-string)
845 ; Try again with IPv4
846 (message "Connection failed. Retrying with IPv4.")
848 (elpher-get-gemini-response address renderer t))
850 (funcall #'elpher-process-gemini-response
853 (elpher-restore-pos)))
855 (elpher-network-error address the-error))))))
857 (error "Error initiating connection to server")))))
859 (defun elpher-parse-gemini-response (response)
860 "Parse the RESPONSE string and return a list of components.
861 The list is of the form (code meta body). A response of nil implies
862 that the response was malformed."
863 (let ((header-end-idx (string-match "\r\n" response)))
865 (let ((header (string-trim (substring response 0 header-end-idx)))
866 (body (substring response (+ header-end-idx 2))))
867 (if (>= (length header) 2)
868 (let ((code (substring header 0 2))
869 (meta (string-trim (substring header 2))))
870 (list code meta body))
871 (error "Malformed response: No response status found in header %s" header)))
872 (error "Malformed response: No CRLF-delimited header found"))))
874 (defun elpher-process-gemini-response (response-string renderer)
875 "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
876 (let ((response-components (elpher-parse-gemini-response response-string)))
877 (let ((response-code (elt response-components 0))
878 (response-meta (elt response-components 1))
879 (response-body (elt response-components 2)))
880 (pcase (elt response-code 0)
882 (elpher-with-clean-buffer
883 (insert "Gemini server is requesting input."))
884 (let* ((query-string (read-string (concat response-meta ": ")))
885 (url (elpher-address-to-url (elpher-node-address elpher-current-node)))
886 (query-address (elpher-address-from-url (concat url "?" query-string))))
887 (elpher-get-gemini-response query-address renderer)))
888 (?2 ; Normal response
889 (funcall renderer response-body response-meta))
891 (message "Following redirect to %s" response-meta)
892 (if (>= (length elpher-gemini-redirect-chain) 5)
893 (error "More than 5 consecutive redirects followed"))
894 (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
895 (if (member redirect-address elpher-gemini-redirect-chain)
896 (error "Redirect loop detected"))
897 (if (not (string= (elpher-address-protocol redirect-address)
899 (error "Server tried to automatically redirect to non-gemini URL: %s"
901 (add-to-list 'elpher-gemini-redirect-chain redirect-address)
902 (elpher-get-gemini-response redirect-address renderer)))
903 (?4 ; Temporary failure
904 (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
905 response-code response-meta))
906 (?5 ; Permanent failure
907 (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
908 response-code response-meta))
909 (?6 ; Client certificate required
910 (error "Gemini server requires client certificate (unsupported at this time)"))
912 (error "Gemini server response unknown: %s %s"
913 response-code response-meta))))))
915 (defun elpher-get-gemini-node (renderer)
916 "Getter which retrieves and renders a Gemini node and renders it using RENDERER."
917 (let* ((address (elpher-node-address elpher-current-node))
918 (content (elpher-get-cached-content address)))
919 (condition-case the-error
920 (if (and content (funcall renderer nil))
921 (elpher-with-clean-buffer
923 (elpher-restore-pos))
924 (elpher-with-clean-buffer
925 (insert "LOADING GEMINI... (use 'u' to cancel)"))
926 (setq elpher-gemini-redirect-chain nil)
927 (elpher-get-gemini-response address renderer))
929 (elpher-network-error address the-error)))))
932 (defun elpher-render-gemini (body &optional mime-type-string)
933 "Render gemini response BODY with rendering MIME-TYPE-STRING."
936 (let* ((mime-type-string* (if (or (not mime-type-string)
937 (string-empty-p mime-type-string))
938 "text/gemini; charset=utf-8"
940 (mime-type-split (split-string mime-type-string* ";" t))
941 (mime-type (string-trim (car mime-type-split)))
942 (parameters (mapcar (lambda (s)
943 (let ((key-val (split-string s "=")))
944 (list (downcase (string-trim (car key-val)))
945 (downcase (string-trim (cadr key-val))))))
946 (cdr mime-type-split))))
947 (when (string-prefix-p "text/" mime-type)
948 (setq body (decode-coding-string
950 (if (assoc "charset" parameters)
951 (intern (cadr (assoc "charset" parameters)))
953 (setq body (replace-regexp-in-string "\r" "" body)))
955 ((or "text/gemini" "")
956 (elpher-render-gemini-map body parameters))
958 (elpher-render-html body))
959 ((pred (string-prefix-p "text/"))
960 (elpher-render-gemini-plain-text body parameters))
961 ((pred (string-prefix-p "image/"))
962 (elpher-render-image body))
964 (error "Unsupported MIME type %S" mime-type))))))
966 (defun elpher-gemini-get-link-url (line)
967 "Extract the url portion of LINE, a gemini map file link line."
968 (string-trim (elt (split-string (substring line 2)) 0)))
970 (defun elpher-gemini-get-link-display-string (line)
971 "Extract the display string portion of LINE, a gemini map file link line."
972 (let* ((rest (string-trim (elt (split-string line "=>") 1)))
973 (idx (string-match "[ \t]" rest)))
975 (string-trim (substring rest (+ idx 1)))
978 (defun elpher-collapse-dot-sequences (filename)
979 "Collapse dot sequences in FILENAME.
980 For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
981 (let* ((path (split-string filename "/"))
982 (path-reversed-normalized
983 (seq-reduce (lambda (a b)
984 (cond ((and a (equal b "..") (cdr a)))
985 ((and (not a) (equal b "..")) a) ;leading .. are dropped
989 (string-join (reverse path-reversed-normalized) "/")))
991 (defun elpher-address-from-gemini-url (url)
992 "Extract address from URL with defaults as per gemini map files."
993 (let ((address (url-generic-parse-url url)))
994 (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
995 (setf (url-fullness address) t)
996 (if (url-host address) ;if there is an explicit host, filenames are absolute
997 (if (string-empty-p (url-filename address))
998 (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
999 (setf (url-host address) (url-host (elpher-node-address elpher-current-node)))
1000 (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
1001 (setf (url-filename address)
1002 (concat (file-name-directory
1003 (url-filename (elpher-node-address elpher-current-node)))
1004 (url-filename address)))))
1005 (unless (url-type address)
1006 (setf (url-type address) "gemini"))
1007 (if (equal (url-type address) "gemini")
1008 (setf (url-filename address)
1009 (elpher-collapse-dot-sequences (url-filename address)))))
1012 (defun elpher-render-gemini-map (data _parameters)
1013 "Render DATA as a gemini map file, PARAMETERS is currently unused."
1014 (elpher-with-clean-buffer
1015 (dolist (line (split-string data "\n"))
1016 (if (string-prefix-p "=>" line)
1017 (let* ((url (elpher-gemini-get-link-url line))
1018 (display-string (elpher-gemini-get-link-display-string line))
1019 (address (elpher-address-from-gemini-url url)))
1020 (if (> (length display-string) 0)
1021 (elpher-insert-index-record display-string address)
1022 (elpher-insert-index-record url address)))
1023 (elpher-insert-index-record line)))
1024 (elpher-cache-content
1025 (elpher-node-address elpher-current-node)
1028 (defun elpher-render-gemini-plain-text (data _parameters)
1029 "Render DATA as plain text file. PARAMETERS is currently unused."
1030 (elpher-with-clean-buffer
1031 (insert (elpher-buttonify-urls data))
1032 (elpher-cache-content
1033 (elpher-node-address elpher-current-node)
1036 ;; Other URL node opening
1038 (defun elpher-get-other-url-node (renderer)
1039 "Getter which attempts to open the URL specified by the current node (RENDERER must be nil)."
1041 (elpher-visit-parent-node)
1042 (error "Command not supported for general URLs"))
1043 (let* ((address (elpher-node-address elpher-current-node))
1044 (url (elpher-address-to-url address)))
1046 (elpher-visit-parent-node) ; Do first in case of non-local exits.
1047 (message "Opening URL...")
1048 (if elpher-open-urls-with-eww
1050 (browse-url url)))))
1052 ;; Telnet node connection
1054 (defun elpher-get-telnet-node (renderer)
1055 "Opens a telnet connection to the current node address (RENDERER must be nil)."
1057 (elpher-visit-parent-node)
1058 (error "Command not supported for telnet URLs"))
1059 (let* ((address (elpher-node-address elpher-current-node))
1060 (host (elpher-address-host address))
1061 (port (elpher-address-port address)))
1062 (elpher-visit-parent-node)
1067 ;; Start page node retrieval
1069 (defun elpher-get-start-node (renderer)
1070 "Getter which displays the start page (RENDERER must be nil)."
1072 (elpher-visit-parent-node)
1073 (error "Command not supported for start page"))
1074 (elpher-with-clean-buffer
1075 (insert " --------------------------------------------\n"
1076 " Elpher Gopher Client \n"
1077 " version " elpher-version "\n"
1078 " --------------------------------------------\n"
1080 "Default bindings:\n"
1082 " - TAB/Shift-TAB: next/prev item on current page\n"
1083 " - RET/mouse-1: open item under cursor\n"
1084 " - m: select an item on current page by name (autocompletes)\n"
1085 " - u/mouse-3: return to previous page\n"
1086 " - o/O: visit different selector or the root menu of the current server\n"
1087 " - g: go to a particular gopher address\n"
1088 " - d/D: download item under cursor or current page\n"
1089 " - i/I: info on item under cursor or current page\n"
1090 " - c/C: copy URL representation of item under cursor or current page\n"
1091 " - a/A: bookmark the item under cursor or current page\n"
1092 " - x/X: remove bookmark for item under cursor or current page\n"
1093 " - B: visit the bookmarks page\n"
1094 " - r: redraw current page (using cached contents if available)\n"
1095 " - R: reload current page (regenerates cache)\n"
1096 " - S: set character coding system for gopher (default is to autodetect)\n"
1097 " - T: toggle TLS gopher mode\n"
1098 " - .: display the raw server response for the current page\n"
1100 "Start your exploration of gopher space:\n")
1101 (elpher-insert-index-record "Floodgap Systems Gopher Server"
1102 (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
1104 "Alternatively, select the following item and enter some search terms:\n")
1105 (elpher-insert-index-record "Veronica-2 Gopher Search Engine"
1106 (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
1108 "This page contains your bookmarked sites (also visit with B):\n")
1109 (elpher-insert-index-record "Your Bookmarks" 'bookmarks)
1111 "For Elpher release news or to leave feedback, visit:\n")
1112 (elpher-insert-index-record "The Elpher Project Page"
1113 (elpher-make-gopher-address ?1
1119 (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
1120 (insert-text-button "Elpher info manual"
1126 'help-echo help-string))
1127 (insert " for the full documentation. **\n")
1129 (concat " (This should be available if you have installed Elpher using\n"
1130 " MELPA. Otherwise you will have to install the manual yourself.)\n")
1132 (elpher-restore-pos)))
1134 ;; Bookmarks page node retrieval
1136 (defun elpher-get-bookmarks-node (renderer)
1137 "Getter to load and display the current bookmark list (RENDERER must be nil)."
1139 (elpher-visit-parent-node)
1140 (error "Command not supported for bookmarks page"))
1141 (elpher-with-clean-buffer
1142 (insert "---- Bookmark list ----\n\n")
1143 (let ((bookmarks (elpher-load-bookmarks)))
1145 (dolist (bookmark bookmarks)
1146 (let ((display-string (elpher-bookmark-display-string bookmark))
1147 (address (elpher-address-from-url (elpher-bookmark-url bookmark))))
1148 (elpher-insert-index-record display-string address)))
1149 (insert "No bookmarks found.\n")))
1150 (insert "\n-----------------------\n"
1152 "- u: return to previous page\n"
1153 "- x: delete selected bookmark\n"
1154 "- a: rename selected bookmark\n"
1156 "Bookmarks are stored in the file ")
1157 (let ((filename (locate-user-emacs-file "elpher-bookmarks"))
1158 (help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
1159 (insert-text-button filename
1163 (find-file filename))
1165 'help-echo help-string))
1167 (elpher-restore-pos)))
1173 (defun elpher-make-bookmark (display-string url)
1174 "Make an elpher bookmark.
1175 DISPLAY-STRING determines how the bookmark will appear in the
1176 bookmark list, while URL is the url of the entry."
1177 (list display-string url))
1179 (defun elpher-bookmark-display-string (bookmark)
1180 "Get the display string of BOOKMARK."
1183 (defun elpher-set-bookmark-display-string (bookmark display-string)
1184 "Set the display string of BOOKMARK to DISPLAY-STRING."
1185 (setcar bookmark display-string))
1187 (defun elpher-bookmark-url (bookmark)
1188 "Get the address for BOOKMARK."
1191 (defun elpher-save-bookmarks (bookmarks)
1192 "Record the bookmark list BOOKMARKS to the user's bookmark file.
1193 Beware that this completely replaces the existing contents of the file."
1194 (with-temp-file (locate-user-emacs-file "elpher-bookmarks")
1196 (insert "; Elpher bookmarks file\n\n"
1197 "; Bookmarks are stored as a list of (label URL) items.\n"
1198 "; Feel free to edit by hand, but take care to ensure\n"
1199 "; the list structure remains intact.\n\n")
1200 (pp bookmarks (current-buffer))))
1202 (defun elpher-load-bookmarks ()
1203 "Get the list of bookmarks from the users's bookmark file."
1207 (insert-file-contents (locate-user-emacs-file "elpher-bookmarks"))
1208 (goto-char (point-min))
1209 (read (current-buffer))))))
1210 (if (and bookmarks (listp (cadar bookmarks)))
1212 (message "Reading old bookmark file. (Will be updated on write.)")
1213 (mapcar (lambda (old-bm)
1215 (elpher-address-to-url (apply #'elpher-make-gopher-address
1220 (defun elpher-add-address-bookmark (address display-string)
1221 "Save a bookmark for ADDRESS with label DISPLAY-STRING.)))
1222 If ADDRESS is already bookmarked, update the label only."
1223 (let ((bookmarks (elpher-load-bookmarks))
1224 (url (elpher-address-to-url address)))
1225 (let ((existing-bookmark (rassoc (list url) bookmarks)))
1226 (if existing-bookmark
1227 (elpher-set-bookmark-display-string existing-bookmark display-string)
1228 (push (elpher-make-bookmark display-string url) bookmarks)))
1229 (elpher-save-bookmarks bookmarks)))
1231 (defun elpher-remove-address-bookmark (address)
1232 "Remove any bookmark to ADDRESS."
1233 (let ((url (elpher-address-to-url address)))
1234 (elpher-save-bookmarks
1235 (seq-filter (lambda (bookmark)
1236 (not (equal (elpher-bookmark-url bookmark) url)))
1237 (elpher-load-bookmarks)))))
1239 ;;; Interactive procedures
1242 (defun elpher-next-link ()
1243 "Move point to the next link on the current page."
1247 (defun elpher-prev-link ()
1248 "Move point to the previous link on the current page."
1250 (backward-button 1))
1252 (defun elpher-follow-current-link ()
1253 "Open the link or url at point."
1258 "Go to a particular gopher site read from the minibuffer."
1261 (let ((host-or-url (read-string "Gopher or Gemini URL: ")))
1262 (elpher-make-node host-or-url
1263 (elpher-address-from-url host-or-url)))))
1264 (switch-to-buffer "*elpher*")
1265 (elpher-visit-node node)))
1267 (defun elpher-go-current ()
1268 "Go to a particular site read from the minibuffer, initialized with the current URL."
1270 (let ((address (elpher-node-address elpher-current-node)))
1271 (if (elpher-address-special-p address)
1272 (error "Command invalid for this page")
1273 (let ((url (read-string "Gopher or Gemini URL: " (elpher-address-to-url address))))
1274 (elpher-visit-node (elpher-make-node url (elpher-address-from-url url)))))))
1276 (defun elpher-redraw ()
1277 "Redraw current page."
1279 (if elpher-current-node
1280 (elpher-visit-node elpher-current-node)
1281 (message "No current site.")))
1283 (defun elpher-reload ()
1284 "Reload current page."
1286 (if elpher-current-node
1287 (elpher-reload-current-node)
1288 (message "No current site.")))
1290 (defun elpher-toggle-tls ()
1291 "Toggle TLS encryption mode for gopher."
1293 (setq elpher-use-tls (not elpher-use-tls))
1295 (if (gnutls-available-p)
1296 (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
1297 (setq elpher-use-tls nil)
1298 (error "Cannot enable TLS gopher mode: GnuTLS not available"))
1299 (message "TLS gopher mode disabled. (Will not affect current page until reload.)")))
1301 (defun elpher-view-raw ()
1302 "View raw server response for current page."
1304 (if elpher-current-node
1305 (if (elpher-address-special-p (elpher-node-address elpher-current-node))
1306 (error "This page was not generated by a server")
1307 (elpher-visit-node elpher-current-node
1308 #'elpher-render-raw))
1309 (message "No current site.")))
1311 (defun elpher-back ()
1312 "Go to previous site."
1314 (if (elpher-node-parent elpher-current-node)
1315 (elpher-visit-parent-node)
1316 (error "No previous site")))
1318 (defun elpher-download ()
1319 "Download the link at point."
1321 (let ((button (button-at (point))))
1323 (let ((node (button-get button 'elpher-node)))
1324 (if (elpher-address-special-p (elpher-node-address node))
1325 (error "Cannot download %s"
1326 (elpher-node-display-string node))
1327 (elpher-visit-node (button-get button 'elpher-node)
1328 #'elpher-render-download)))
1329 (error "No link selected"))))
1331 (defun elpher-download-current ()
1332 "Download the current page."
1334 (if (elpher-address-special-p (elpher-node-address elpher-current-node))
1335 (error "Cannot download %s"
1336 (elpher-node-display-string elpher-current-node))
1337 (elpher-visit-node (elpher-make-node
1338 (elpher-node-display-string elpher-current-node)
1339 (elpher-node-address elpher-current-node)
1340 elpher-current-node)
1341 #'elpher-render-download
1344 (defun elpher-build-link-map ()
1345 "Build alist mapping link names to destination nodes in current buffer."
1346 (let ((link-map nil)
1347 (b (next-button (point-min) t)))
1349 (push (cons (button-label b) b) link-map)
1350 (setq b (next-button (button-start b))))
1353 (defun elpher-jump ()
1354 "Select a directory entry by name. Similar to the info browser (m)enu command."
1356 (let* ((link-map (elpher-build-link-map)))
1358 (let ((key (let ((completion-ignore-case t))
1359 (completing-read "Directory item/link: "
1361 (if (and key (> (length key) 0))
1362 (let ((b (cdr (assoc key link-map))))
1363 (goto-char (button-start b))
1364 (button-activate b)))))))
1366 (defun elpher-root-dir ()
1367 "Visit root of current server."
1369 (let ((address (elpher-node-address elpher-current-node)))
1370 (if (not (elpher-address-special-p address))
1371 (if (or (member (url-filename address) '("/" ""))
1372 (and (elpher-address-gopher-p address)
1373 (= (length (elpher-gopher-address-selector address)) 0)))
1374 (error "Already at root directory of current server")
1375 (let ((address-copy (elpher-address-from-url
1376 (elpher-address-to-url address))))
1377 (setf (url-filename address-copy) "")
1379 (elpher-make-node (elpher-address-to-url address-copy)
1381 (error "Command invalid for %s" (elpher-node-display-string elpher-current-node)))))
1383 (defun elpher-bookmarks-current-p ()
1384 "Return non-nil if current node is a bookmarks page."
1385 (equal (elpher-address-type (elpher-node-address elpher-current-node))
1386 '(special bookmarks)))
1388 (defun elpher-reload-bookmarks ()
1389 "Reload bookmarks if current node is a bookmarks page."
1390 (if (elpher-bookmarks-current-p)
1391 (elpher-reload-current-node)))
1393 (defun elpher-bookmark-current ()
1394 "Bookmark the current node."
1396 (let ((address (elpher-node-address elpher-current-node))
1397 (display-string (elpher-node-display-string elpher-current-node)))
1398 (if (not (elpher-address-special-p address))
1399 (let ((bookmark-display-string (read-string "Bookmark display string: "
1401 (elpher-add-address-bookmark address bookmark-display-string)
1402 (message "Bookmark added."))
1403 (error "Cannot bookmark %s" display-string))))
1405 (defun elpher-bookmark-link ()
1406 "Bookmark the link at point."
1408 (let ((button (button-at (point))))
1410 (let* ((node (button-get button 'elpher-node))
1411 (address (elpher-node-address node))
1412 (display-string (elpher-node-display-string node)))
1413 (if (not (elpher-address-special-p address))
1414 (let ((bookmark-display-string (read-string "Bookmark display string: "
1416 (elpher-add-address-bookmark address bookmark-display-string)
1417 (elpher-reload-bookmarks)
1418 (message "Bookmark added."))
1419 (error "Cannot bookmark %s" display-string)))
1420 (error "No link selected"))))
1422 (defun elpher-unbookmark-current ()
1423 "Remove bookmark for the current node."
1425 (let ((address (elpher-node-address elpher-current-node)))
1426 (unless (elpher-address-special-p address)
1427 (elpher-remove-address-bookmark address)
1428 (message "Bookmark removed."))))
1430 (defun elpher-unbookmark-link ()
1431 "Remove bookmark for the link at point."
1433 (let ((button (button-at (point))))
1435 (let ((node (button-get button 'elpher-node)))
1436 (elpher-remove-address-bookmark (elpher-node-address node))
1437 (elpher-reload-bookmarks)
1438 (message "Bookmark removed."))
1439 (error "No link selected"))))
1441 (defun elpher-bookmarks ()
1442 "Visit bookmarks page."
1444 (switch-to-buffer "*elpher*")
1446 (elpher-make-node "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
1448 (defun elpher-info-node (node)
1449 "Display information on NODE."
1450 (let ((display-string (elpher-node-display-string node))
1451 (address (elpher-node-address node)))
1452 (if (elpher-address-special-p address)
1453 (message "Special page: %s" display-string)
1454 (message "%s" (elpher-address-to-url address)))))
1456 (defun elpher-info-link ()
1457 "Display information on node corresponding to link at point."
1459 (let ((button (button-at (point))))
1461 (elpher-info-node (button-get button 'elpher-node))
1462 (error "No item selected"))))
1464 (defun elpher-info-current ()
1465 "Display information on current node."
1467 (elpher-info-node elpher-current-node))
1469 (defun elpher-copy-node-url (node)
1470 "Copy URL representation of address of NODE to `kill-ring'."
1471 (let ((address (elpher-node-address node)))
1472 (if (elpher-address-special-p address)
1473 (error (format "Cannot represent %s as URL" (elpher-node-display-string node)))
1474 (let ((url (elpher-address-to-url address)))
1475 (message "Copied \"%s\" to kill-ring/clipboard." url)
1478 (defun elpher-copy-link-url ()
1479 "Copy URL of item at point to `kill-ring'."
1481 (let ((button (button-at (point))))
1483 (elpher-copy-node-url (button-get button 'elpher-node))
1484 (error "No item selected"))))
1486 (defun elpher-copy-current-url ()
1487 "Copy URL of current node to `kill-ring'."
1489 (elpher-copy-node-url elpher-current-node))
1491 (defun elpher-set-gopher-coding-system ()
1492 "Specify an explicit character coding system for gopher selectors."
1494 (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
1495 (setq elpher-user-coding-system system)
1497 (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
1498 (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
1504 (defvar elpher-mode-map
1505 (let ((map (make-sparse-keymap)))
1506 (define-key map (kbd "TAB") 'elpher-next-link)
1507 (define-key map (kbd "<backtab>") 'elpher-prev-link)
1508 (define-key map (kbd "u") 'elpher-back)
1509 (define-key map [mouse-3] 'elpher-back)
1510 (define-key map (kbd "O") 'elpher-root-dir)
1511 (define-key map (kbd "g") 'elpher-go)
1512 (define-key map (kbd "o") 'elpher-go-current)
1513 (define-key map (kbd "r") 'elpher-redraw)
1514 (define-key map (kbd "R") 'elpher-reload)
1515 (define-key map (kbd "T") 'elpher-toggle-tls)
1516 (define-key map (kbd ".") 'elpher-view-raw)
1517 (define-key map (kbd "d") 'elpher-download)
1518 (define-key map (kbd "D") 'elpher-download-current)
1519 (define-key map (kbd "m") 'elpher-jump)
1520 (define-key map (kbd "i") 'elpher-info-link)
1521 (define-key map (kbd "I") 'elpher-info-current)
1522 (define-key map (kbd "c") 'elpher-copy-link-url)
1523 (define-key map (kbd "C") 'elpher-copy-current-url)
1524 (define-key map (kbd "a") 'elpher-bookmark-link)
1525 (define-key map (kbd "A") 'elpher-bookmark-current)
1526 (define-key map (kbd "x") 'elpher-unbookmark-link)
1527 (define-key map (kbd "X") 'elpher-unbookmark-current)
1528 (define-key map (kbd "B") 'elpher-bookmarks)
1529 (define-key map (kbd "S") 'elpher-set-gopher-coding-system)
1530 (when (fboundp 'evil-define-key*)
1531 (evil-define-key* 'motion map
1532 (kbd "TAB") 'elpher-next-link
1533 (kbd "C-") 'elpher-follow-current-link
1534 (kbd "C-t") 'elpher-back
1535 (kbd "u") 'elpher-back
1536 [mouse-3] 'elpher-back
1537 (kbd "g") 'elpher-go
1538 (kbd "o") 'elpher-go-current
1539 (kbd "r") 'elpher-redraw
1540 (kbd "R") 'elpher-reload
1541 (kbd "T") 'elpher-toggle-tls
1542 (kbd ".") 'elpher-view-raw
1543 (kbd "d") 'elpher-download
1544 (kbd "D") 'elpher-download-current
1545 (kbd "m") 'elpher-jump
1546 (kbd "i") 'elpher-info-link
1547 (kbd "I") 'elpher-info-current
1548 (kbd "c") 'elpher-copy-link-url
1549 (kbd "C") 'elpher-copy-current-url
1550 (kbd "a") 'elpher-bookmark-link
1551 (kbd "A") 'elpher-bookmark-current
1552 (kbd "x") 'elpher-unbookmark-link
1553 (kbd "X") 'elpher-unbookmark-current
1554 (kbd "B") 'elpher-bookmarks
1555 (kbd "S") 'elpher-set-gopher-coding-system))
1557 "Keymap for gopher client.")
1559 (define-derived-mode elpher-mode special-mode "elpher"
1560 "Major mode for elpher, an elisp gopher client.
1562 This mode is automatically enabled by the interactive
1563 functions which initialize the gopher client, namely
1564 `elpher', `elpher-go' and `elpher-bookmarks'.")
1566 (when (fboundp 'evil-set-initial-state)
1567 (evil-set-initial-state 'elpher-mode 'motion))
1570 ;;; Main start procedure
1575 "Start elpher with default landing page."
1577 (if (get-buffer "*elpher*")
1578 (switch-to-buffer "*elpher*")
1579 (switch-to-buffer "*elpher*")
1580 (setq elpher-current-node nil)
1581 (let ((start-node (elpher-make-node "Elpher Start Page"
1582 (elpher-make-special-address 'start))))
1583 (elpher-visit-node start-node)))
1584 "Started Elpher.") ; Otherwise (elpher) evaluates to start page string.
1586 ;;; elpher.el ends here