Updated package header.
[elpher.git] / elpher.el
index 12ef1c8..8e2e48e 100644 (file)
--- a/elpher.el
+++ b/elpher.el
@@ -1,10 +1,10 @@
-;;; elpher.el --- Full-featured gopher client.
+;;; elpher.el --- A friendly gopher client.
 
 ;; Copyright (C) 2019 Tim Vaughan
 
 ;; Author: Tim Vaughan <tgvaughan@gmail.com>
 ;; Created: 11 April 2019
-;; Version: 1.0.0
+;; Version: 1.4.3
 ;; Keywords: comm gopher
 ;; Homepage: https://github.com/tgvaughan/elpher
 ;; Package-Requires: ((emacs "25"))
 
 ;;; Commentary:
 
-;; Elpher aims to provide a full-featured gopher client for GNU Emacs.
-;; It supports:
+;; Elpher aims to provide a practical and friendly gopher client
+;; for GNU Emacs.  It supports:
 
-;; - intuitive keyboard and mouse-driven browsing,
+;; - an intuitive keyboard and mouse-driven interface,
+;; - followable web and gopher links in plain text,
 ;; - caching of visited sites (both content and cursor position),
 ;; - pleasant and configurable colouring of Gopher directories,
 ;; - direct visualisation of image files,
 ;; - (m)enu key support, similar to Emacs' info browser,
-;; - clickable web and gopher links in plain text.
-
-;; The caching mechanism works by maintaining a hierarchy of visited
-;; pages rather than a linear history, meaning that it is quick and
-;; easy to navigate this history.
+;; - a simple bookmark management system,
+;; - support for TLS.
 
 ;; To launch Elpher, simply use 'M-x elpher'.  This will open a start
 ;; page containing information on key bindings and suggested starting
 ;; points for your gopher exploration.
 
-;; Faces, caching options and start page can be configured via
-;; the Elpher customization group in Applications.
+;; Further instructions can be found in the Elpher info manual.
+
+;; Elpher is under active development, and any suggestions for
+;; improvements are welcome!
 
 ;;; Code:
 
 (provide 'elpher)
+(require 'seq)
+(require 'pp)
+(require 'shr)
 
 ;;; Global constants
 ;;
 
-(defconst elpher-version "1.0.0"
+(defconst elpher-version "1.4.3"
   "Current version of elpher.")
 
 (defconst elpher-margin-width 6
   (mapconcat
    'identity
    (list "i\tfake\tfake\t1"
-         "i--------------------------------------------\tfake\tfake\t1"
-         "i           Elpher Gopher Client             \tfake\tfake\t1"
-         (format "i              version %s\tfake\tfake\t1" elpher-version)
-         "i--------------------------------------------\tfake\tfake\t1"
+         "i     --------------------------------------------\tfake\tfake\t1"
+         "i                Elpher Gopher Client             \tfake\tfake\t1"
+         (format "i                   version %s\tfake\tfake\t1" elpher-version)
+         "i     --------------------------------------------\tfake\tfake\t1"
          "i\tfake\tfake\t1"
-         "iBasic usage:\tfake\tfake\t1"
+         "iUsage:\tfake\tfake\t1"
          "i\tfake\tfake\t1"
-         "i - tab/shift-tab: next/prev directory entry on current page\tfake\tfake\t1"
-         "i - RET/mouse-1: open directory entry under cursor\tfake\tfake\t1"
-         "i - m: select a directory entry by name (autocompletes)\tfake\tfake\t1"
-         "i - u: return to parent directory entry\tfake\tfake\t1"
-         "i - g: go to a particular page\tfake\tfake\t1"
+         "i - tab/shift-tab: next/prev item on current page\tfake\tfake\t1"
+         "i - RET/mouse-1: open item under cursor\tfake\tfake\t1"
+         "i - m: select an item on current page by name (autocompletes)\tfake\tfake\t1"
+         "i - u: return to parent\tfake\tfake\t1"
+         "i - O: visit the root menu of the current server\tfake\tfake\t1"
+         "i - g: go to a particular gopher address\tfake\tfake\t1"
+         "i - i/I: info on item under cursor or current page\tfake\tfake\t1"
+         "i - c/C: copy URL representation of item under cursor or current page\tfake\tfake\t1"
+         "i - a/A: bookmark the item under cursor or current page\tfake\tfake\t1"
+         "i - x/X: remove bookmark for item under cursor or current page\tfake\tfake\t1"
+         "i - B: visit the bookmarks page\tfake\tfake\t1"
          "i - r: redraw current page (using cached contents if available)\tfake\tfake\t1"
          "i - R: reload current page (regenerates cache)\tfake\tfake\t1"
-         "i - d: download directory entry under cursor\tfake\tfake\t1"
+         "i - T: toggle TLS mode\tfake\tfake\t1"
+         "i - d/D: download item under cursor or current page\tfake\tfake\t1"
          "i - w: display the raw server response for the current page\tfake\tfake\t1"
+         "i - S: set an explicit character coding system (default is to autodetect)\tfake\tfake\t1"
          "i\tfake\tfake\t1"
-         "iPlaces to start exploring Gopherspace:\tfake\tfake\t1"
+         "iWhere to start exploring Gopherspace:\tfake\tfake\t1"
          "i\tfake\tfake\t1"
-         "1Floodgap Systems Gopher Server\t\tgopher.floodgap.com\t70"
+         "1Floodgap Systems Gopher Server\t/\tgopher.floodgap.com\t70"
          "i\tfake\tfake\t1"
          "iAlternatively, select the following item and enter some\tfake\tfake\t1"
          "isearch terms:\tfake\tfake\t1"
          "i\tfake\tfake\t1"
          "7Veronica-2 Gopher Search Engine\t/v2/vs\tgopher.floodgap.com\t70"
-         ".")
+         ".\r\n")
    "\r\n")
   "Source for elpher start page.")
 
 (defconst elpher-type-map
-  '((?0 elpher-get-text-node "T" elpher-text)
+  '((?0 elpher-get-text-node "txt" elpher-text)
     (?1 elpher-get-index-node "/" elpher-index)
-    (?g elpher-get-image-node "im" elpher-image)
-    (?p elpher-get-image-node "im" elpher-image)
-    (?I elpher-get-image-node "im" elpher-image)
-    (?4 elpher-get-node-download "B" elpher-binary)
-    (?5 elpher-get-node-download "B" elpher-binary)
-    (?9 elpher-get-node-download "B" elpher-binary)
-    (?7 elpher-get-search-node "?" elpher-search))
+    (?4 elpher-get-node-download "bin" elpher-binary)
+    (?5 elpher-get-node-download "bin" elpher-binary)
+    (?7 elpher-get-search-node "?" elpher-search)
+    (?8 elpher-get-telnet-node "tel" elpher-telnet)
+    (?9 elpher-get-node-download "bin" elpher-binary)
+    (?g elpher-get-image-node "img" elpher-image)
+    (?p elpher-get-image-node "img" elpher-image)
+    (?I elpher-get-image-node "img" elpher-image)
+    (?d elpher-get-node-download "doc" elpher-binary)
+    (?h elpher-get-url-node "web" elpher-url)
+    (bookmarks elpher-get-bookmarks-node "#" elpher-index)
+    (start elpher-get-start-node "#" elpher-index))
   "Association list from types to getters, margin codes and index faces.")
 
 
 ;; Face customizations
 
 (defface elpher-index
-  '((((background dark)) :foreground "deep sky blue")
-    (((background light)) :foreground "blue"))
-  "Face used for index records.")
+  '((t :inherit font-lock-keyword-face))
+  "Face used for directory type directory records.")
 
 (defface elpher-text
-  '((((background dark)) :foreground "white")
-    (((background light)) :weight bold))
-  "Face used for text records.")
+  '((t :inherit bold))
+  "Face used for text type directory records.")
 
-(defface elpher-info '()
-  "Face used for info records.")
+(defface elpher-info
+  '((t :inherit default))
+  "Face used for info type directory records.")
 
 (defface elpher-image
-  '((((background dark)) :foreground "green")
-    (t :foreground "dark green"))
-  "Face used for image records.")
+  '((t :inherit font-lock-string-face))
+  "Face used for image type directory records.")
 
 (defface elpher-search
-  '((((background light)) :foreground "orange")
-    (((background dark)) :foreground "dark orange"))
-  "Face used for search records.")
+  '((t :inherit warning))
+  "Face used for search type directory records.")
 
 (defface elpher-url
-  '((((background dark)) :foreground "yellow")
-    (((background light)) :foreground "dark red"))
-  "Face used for url records.")
+  '((t :inherit font-lock-comment-face))
+  "Face used for url type directory records.")
+
+(defface elpher-telnet
+  '((t :inherit font-lock-function-name-face))
+  "Face used for telnet type directory records.")
 
 (defface elpher-binary
-  '((t :foreground "magenta"))
-  "Face used for binary records.")
+  '((t :inherit font-lock-doc-face))
+  "Face used for binary type directory records.")
 
 (defface elpher-unknown
-  '((t :foreground "red"))
-  "Face used for unknown record types.")
+  '((t :inherit error))
+  "Face used for directory records with unknown/unsupported types.")
 
 (defface elpher-margin-key
-  '((((background dark)) :foreground "white"))
-  "Face used for margin key.")
+  '((t :inherit bold))
+  "Face used for directory margin key.")
 
 (defface elpher-margin-brackets
-  '((t :foreground "blue"))
-  "Face used for brackets around margin key.")
+  '((t :inherit shadow))
+  "Face used for brackets around directory margin key.")
 
 ;; Other customizations
 
 Otherwise, use the system browser via the BROWSE-URL function."
   :type '(boolean))
 
+(defcustom elpher-buttonify-urls-in-directories nil
+  "If non-nil, turns URLs matched in directories into clickable buttons."
+  :type '(boolean))
+
 (defcustom elpher-cache-images nil
   "If non-nil, cache images in memory in the same way as other content."
   :type '(boolean))
 
-(defcustom elpher-start-address nil
-  "If nil, the default start directory is shown when Elpher is started.
-Otherwise, a list containing the selector, host and port of a directory to
-use as the start page."
-  :type '(list string string integer))
+(defcustom elpher-use-header t
+  "If non-nil, display current node information in buffer header."
+  :type '(boolean))
+
+(defcustom elpher-auto-disengage-TLS nil
+  "If non-nil, automatically disengage TLS following an unsuccessful connection.
+While enabling this may seem convenient, it is also potentially dangerous as it
+allows switching from an encrypted channel back to plain text without user input."
+  :type '(boolean))
 
 
 ;;; Model
@@ -182,119 +206,198 @@ use as the start page."
 
 ;; Address
 
-(defun elpher-make-address (selector host port)
-  "Create an address of a gopher object with SELECTOR, HOST and PORT."
-  (list selector host port))
+(defun elpher-make-address (type &optional selector host port use-tls)
+  "Create an address of a gopher object with TYPE, SELECTOR, HOST and PORT.
+Although selector host and port are optional, they are only omitted for
+special address types, such as 'start for the start page.
+
+Setting the USE-TLS parameter to non-nil causes Elpher to engage TLS mode
+before attempting to connect to the server."
+  (if use-tls
+      (list type selector host port 'tls)
+    (list type selector host port)))
+
+(defun elpher-address-type (address)
+  "Retrieve type from ADDRESS."
+  (elt address 0))
 
 (defun elpher-address-selector (address)
   "Retrieve selector from ADDRESS."
-  (car address))
+  (elt address 1))
 
 (defun elpher-address-host (address)
   "Retrieve host from ADDRESS."
-  (cadr address))
+  (elt address 2))
 
 (defun elpher-address-port (address)
   "Retrieve port from ADDRESS."
-  (caddr address))
+  (elt address 3))
+
+(defun elpher-address-use-tls-p (address)
+  "Return non-nil if ADDRESS is marked as needing TLS."
+  (elt address 4))
+
+(defun elpher-address-special-p (address)
+  "Return non-nil if ADDRESS is special (e.g. start page, bookmarks page)."
+  (not (elpher-address-host address)))
 
 ;; Node
 
-(defun elpher-make-node (parent address getter &optional content pos)
+(defun elpher-make-node (display-string address &optional parent)
   "Create a node in the gopher page hierarchy.
 
-PARENT specifies the parent of the node, ADDRESS specifies the address of
-the gopher page, GETTER provides the getter function used to obtain this
-page.
+DISPLAY-STRING records the display string used for the page.
 
-The optional arguments CONTENT and POS can be used to fill the cached
-content and cursor position fields of the node."
-  (list parent address getter content pos))
+ADDRESS specifies the address of the gopher page.
 
-(defun elpher-node-parent (node)
-  "Retrieve the parent node of NODE."
+The optional PARENT specifies the parent node in the hierarchy.
+This is set every time the node is visited, so while it forms
+an important part of the node data there is no need to set it
+initially."
+  (list display-string address parent))
+
+(defun elpher-node-display-string (node)
+  "Retrieve the display string of NODE."
   (elt node 0))
 
 (defun elpher-node-address (node)
   "Retrieve the address of NODE."
   (elt node 1))
 
-(defun elpher-node-getter (node)
-  "Retrieve the preferred getter function of NODE."
+(defun elpher-node-parent (node)
+  "Retrieve the parent node of NODE."
   (elt node 2))
 
-(defun elpher-node-content (node)
-  "Retrieve the cached content of NODE, or nil if none exists."
-  (elt node 3))
+(defun elpher-set-node-parent (node parent)
+  "Set the parent node of NODE to be PARENT."
+  (setcar (cdr (cdr node)) parent))
+
+;; Cache
+
+(defvar elpher-content-cache (make-hash-table :test 'equal))
+(defvar elpher-pos-cache (make-hash-table :test 'equal))
+
+(defun elpher-get-cached-content (address)
+  "Retrieve the cached content for ADDRESS, or nil if none exists."
+  (gethash address elpher-content-cache))
 
-(defun elpher-node-pos (node)
-  "Retrieve the cached cursor position for NODE, or nil if none exists."
-  (elt node 4))
+(defun elpher-cache-content (address content)
+  "Set the content cache for ADDRESS to CONTENT."
+  (puthash address content elpher-content-cache))
 
-(defun elpher-set-node-content (node content)
-  "Set the content cache of NODE to CONTENT."
-  (setcar (nthcdr 3 node) content))
+(defun elpher-get-cached-pos (address)
+  "Retrieve the cached cursor position for ADDRESS, or nil if none exists."
+  (gethash address elpher-pos-cache))
 
-(defun elpher-set-node-pos (node pos)
-  "Set the cursor position cache of NODE to POS."
-  (setcar (nthcdr 4 node) pos))
+(defun elpher-cache-pos (address pos)
+  "Set the cursor position cache for ADDRESS to POS."
+  (puthash address pos elpher-pos-cache))
 
 ;; Node graph traversal
 
-(defvar elpher-current-node)
+(defvar elpher-current-node nil)
 
-(defun elpher-visit-node (node &optional getter)
-  "Visit NODE using its own getter or GETTER, if non-nil."
+(defun elpher-visit-node (node &optional getter preserve-parent)
+  "Visit NODE using its own getter or GETTER, if non-nil.
+Additionally, set the parent of NODE to `elpher-current-node',
+unless PRESERVE-PARENT is non-nil."
   (elpher-save-pos)
   (elpher-process-cleanup)
+  (unless preserve-parent
+    (if (and (elpher-node-parent elpher-current-node)
+             (equal (elpher-node-address elpher-current-node)
+                    (elpher-node-address node)))
+        (elpher-set-node-parent node (elpher-node-parent elpher-current-node))
+      (elpher-set-node-parent node elpher-current-node)))
   (setq elpher-current-node node)
   (if getter
       (funcall getter)
-    (funcall (elpher-node-getter node))))
+    (let* ((address (elpher-node-address node))
+           (type (elpher-address-type address)))
+      (funcall (car (alist-get type elpher-type-map))))))
 
 (defun elpher-visit-parent-node ()
   "Visit the parent of the current node."
   (let ((parent-node (elpher-node-parent elpher-current-node)))
     (when parent-node
-      (elpher-visit-node parent-node))))
+      (elpher-visit-node parent-node nil t))))
       
 (defun elpher-reload-current-node ()
   "Reload the current node, discarding any existing cached content."
-  (elpher-set-node-content elpher-current-node nil)
+  (elpher-cache-content (elpher-node-address elpher-current-node) nil)
   (elpher-visit-node elpher-current-node))
 
 (defun elpher-save-pos ()
   "Save the current position of point to the current node."
   (when elpher-current-node
-    (elpher-set-node-pos elpher-current-node (point))))
+    (elpher-cache-pos (elpher-node-address elpher-current-node) (point))))
 
 (defun elpher-restore-pos ()
   "Restore the position of point to that cached in the current node."
-  (let ((pos (elpher-node-pos elpher-current-node)))
+  (let ((pos (elpher-get-cached-pos (elpher-node-address elpher-current-node))))
     (if pos
         (goto-char pos)
       (goto-char (point-min)))))
 
+
 ;;; Buffer preparation
 ;;
 
+(defun elpher-update-header ()
+  "If `elpher-use-header' is true, display current node info in window header."
+  (if elpher-use-header
+      (setq header-line-format (elpher-node-display-string elpher-current-node))))
+
 (defmacro elpher-with-clean-buffer (&rest args)
   "Evaluate ARGS with a clean *elpher* buffer as current."
-  (list 'progn
-        '(switch-to-buffer "*elpher*")
+  (list 'with-current-buffer "*elpher*"
         '(elpher-mode)
         (append (list 'let '((inhibit-read-only t))
-                      '(erase-buffer))
+                      '(erase-buffer)
+                      '(elpher-update-header))
                 args)))
 
+
+;;; Text Processing
+;;
+
+(defvar elpher-user-coding-system nil
+  "User-specified coding system to use for decoding text responses.")
+
+(defun elpher-decode (string)
+  "Decode STRING using autodetected or user-specified coding system."
+  (decode-coding-string string
+                        (if elpher-user-coding-system
+                            elpher-user-coding-system
+                          (detect-coding-string string t))))
+
+(defun elpher-preprocess-text-response (string)
+  "Preprocess text selector response contained in STRING.
+This involes decoding the character representation, and clearing
+away CRs and any terminating period."
+  (elpher-decode (replace-regexp-in-string "\n\.\n$" "\n"
+                                           (replace-regexp-in-string "\r" "" string))))
+
 ;;; Index rendering
 ;;
 
 (defun elpher-insert-index (string)
   "Insert the index corresponding to STRING into the current buffer."
-  (dolist (line (split-string string "\r\n"))
-    (unless (= (length line) 0)
-      (elpher-insert-index-record line))))
+  ;; Should be able to split directly on CRLF, but some non-conformant
+  ;; LF-only servers sadly exist, hence the following.
+  (let ((str-processed (elpher-preprocess-text-response string)))
+    (dolist (line (split-string str-processed "\n"))
+      (unless (= (length line) 0)
+        (let* ((type (elt line 0))
+               (fields (split-string (substring line 1) "\t"))
+               (display-string (elt fields 0))
+               (selector (elt fields 1))
+               (host (elt fields 2))
+               (port (if (elt fields 3)
+                         (string-to-number (elt fields 3))
+                       nil))
+               (address (elpher-make-address type selector host port)))
+          (elpher-insert-index-record display-string address))))))
 
 (defun elpher-insert-margin (&optional type-name)
   "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
@@ -308,48 +411,53 @@ content and cursor position fields of the node."
         (insert " "))
     (insert (make-string elpher-margin-width ?\s))))
 
-(defun elpher-insert-index-record (line)
-  "Insert the index record corresponding to LINE into the current buffer."
-  (let* ((type (elt line 0))
-         (fields (split-string (substring line 1) "\t"))
-         (display-string (elt fields 0))
-         (selector (elt fields 1))
-         (host (elt fields 2))
-         (port (elt fields 3))
-         (address (elpher-make-address selector host port))
+(defun elpher-node-button-help (node)
+  "Return a string containing the help text for a button corresponding to NODE."
+  (let ((address (elpher-node-address node)))
+    (if (eq (elpher-address-type address) ?h)
+        (let ((url (cadr (split-string (elpher-address-selector address) "URL:"))))
+          (format "mouse-1, RET: open url '%s'" url))
+      (format "mouse-1, RET: open '%s' on %s port %s"
+              (elpher-address-selector address)
+              (elpher-address-host address)
+              (elpher-address-port address)))))
+
+
+(defun elpher-insert-index-record (display-string address)
+  "Function to insert an index record into the current buffer.
+The contents of the record are dictated by DISPLAY-STRING and ADDRESS."
+  (let* ((type (elpher-address-type address))
          (type-map-entry (alist-get type elpher-type-map)))
     (if type-map-entry
-        (let ((getter (car type-map-entry))
-              (margin-code (cadr type-map-entry))
-              (face (caddr type-map-entry)))
+        (let* ((margin-code (elt type-map-entry 1))
+               (face (elt type-map-entry 2))
+               (node (elpher-make-node display-string address)))
           (elpher-insert-margin margin-code)
           (insert-text-button display-string
                               'face face
-                              'elpher-node (elpher-make-node elpher-current-node
-                                                               address
-                                                               getter)
+                              'elpher-node node
                               'action #'elpher-click-link
                               'follow-link t
-                              'help-echo (format "mouse-1, RET: open %s on %s port %s"
-                                                 selector host port)))
+                              'help-echo (elpher-node-button-help node)))
       (pcase type
-        (?i (elpher-insert-margin) ; Information
-            (insert (propertize display-string
-                                'face 'elpher-info)))
-        (?h (elpher-insert-margin "W") ; Web link
-            (let ((url (elt (split-string selector "URL:") 1)))
-              (insert-text-button display-string
-                                  'face 'elpher-url
-                                  'elpher-url url
-                                  'action #'elpher-click-url
-                                  'follow-link t
-                                  'help-echo (format "mouse-1, RET: open url %s" url))))
-        (?.) ; Occurs at end of index, can safely ignore.
-        (tp (elpher-insert-margin (concat (char-to-string tp) "?"))
-            (insert (propertize display-string
-                                'face 'elpher-unknown-face)))))
+        (?i ;; Information
+         (elpher-insert-margin)
+         (insert (propertize
+                  (if elpher-buttonify-urls-in-directories
+                      (elpher-buttonify-urls display-string)
+                    display-string)
+                  'face 'elpher-info)))
+        (other ;; Unknown
+         (elpher-insert-margin (concat (char-to-string type) "?"))
+         (insert (propertize display-string
+                             'face 'elpher-unknown)))))
     (insert "\n")))
 
+(defun elpher-click-link (button)
+  "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
+  (let ((node (button-get button 'elpher-node)))
+    (elpher-visit-node node)))
+
 
 ;;; Selector retrieval (all kinds)
 ;;
@@ -359,184 +467,222 @@ content and cursor position fields of the node."
   (let ((p (get-process "elpher-process")))
     (if p (delete-process p))))
 
+(defvar elpher-use-tls nil
+  "If non-nil, use TLS to communicate with gopher servers.")
+
 (defvar elpher-selector-string)
 
-(defun elpher-get-selector (address after)
+(defun elpher-get-selector (address after &optional propagate-error)
   "Retrieve selector specified by ADDRESS, then execute AFTER.
-The result is stored as a string in the variable ‘elpher-selector-string’."
+The result is stored as a string in the variable ‘elpher-selector-string’.
+
+Usually errors result in an error page being displayed.  This is only
+appropriate if the selector is to be directly viewed.  If PROPAGATE-ERROR
+is non-nil, this message is not displayed.  Instead, the error propagates
+up to the calling function."
   (setq elpher-selector-string "")
-  (make-network-process
-   :name "elpher-process"
-   :host (elpher-address-host address)
-   :service (elpher-address-port address)
-   :filter (lambda (proc string)
-             (setq elpher-selector-string (concat elpher-selector-string string)))
-   :sentinel after)
-  (process-send-string "elpher-process"
-                       (concat (elpher-address-selector address) "\n")))
+  (when (elpher-address-use-tls-p address)
+      (if (gnutls-available-p)
+          (when (not elpher-use-tls)
+            (setq elpher-use-tls t)
+            (message "Engaging TLS mode."))
+        (error "Cannot retrieve TLS selector: GnuTLS not available")))
+  (condition-case the-error
+      (let* ((kill-buffer-query-functions nil)
+             (proc (open-network-stream "elpher-process"
+                                       nil
+                                       (elpher-address-host address)
+                                       (elpher-address-port address)
+                                       :type (if elpher-use-tls 'tls 'plain))))
+        (set-process-coding-system proc 'binary)
+        (set-process-filter proc
+                            (lambda (proc string)
+                              (setq elpher-selector-string
+                                    (concat elpher-selector-string string))))
+        (set-process-sentinel proc after)
+        (process-send-string proc
+                             (concat (elpher-address-selector address) "\n")))
+    (error
+     (if (and (consp the-error)
+              (eq (car the-error) 'gnutls-error)
+              (not (elpher-address-use-tls-p address))
+              (or elpher-auto-disengage-TLS
+                  (yes-or-no-p "Could not establish encrypted connection.  Disable TLS mode? ")))
+         (progn
+           (message "Disengaging TLS mode.")
+           (setq elpher-use-tls nil)
+           (elpher-get-selector address after))
+       (elpher-process-cleanup)
+       (if propagate-error
+           (error the-error)
+         (elpher-with-clean-buffer
+          (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
+                  "Failed to connect to " (elpher-get-address-url address) ".\n"
+                  (propertize "\n----------------\n\n" 'face 'error)
+                  "Press 'u' to return to the previous page.")))))))
 
 ;; Index retrieval
 
 (defun elpher-get-index-node ()
   "Getter which retrieves the current node contents as an index."
-  (let ((content (elpher-node-content elpher-current-node))
-        (address (elpher-node-address elpher-current-node)))
+  (let* ((address (elpher-node-address elpher-current-node))
+         (content (elpher-get-cached-content address)))
     (if content
         (progn
           (elpher-with-clean-buffer
-           (insert content))
-          (elpher-restore-pos))
-      (if address
-          (progn
-            (elpher-with-clean-buffer
-             (insert "LOADING DIRECTORY..."))
-            (elpher-get-selector address
-                                  (lambda (proc event)
-                                    (unless (string-prefix-p "deleted" event)
-                                      (elpher-with-clean-buffer
-                                       (elpher-insert-index elpher-selector-string))
-                                      (elpher-restore-pos)
-                                      (elpher-set-node-content elpher-current-node
-                                                                (buffer-string))))))
-        (progn
-          (elpher-with-clean-buffer
-           (elpher-insert-index elpher-start-index))
-          (elpher-restore-pos)
-          (elpher-set-node-content elpher-current-node
-                                    (buffer-string)))))))
+           (insert content)
+           (elpher-restore-pos)))
+      (elpher-with-clean-buffer
+       (insert "LOADING DIRECTORY... (use 'u' to cancel)"))
+      (elpher-get-selector address
+                           (lambda (proc event)
+                             (unless (string-prefix-p "deleted" event)
+                               (elpher-with-clean-buffer
+                                (elpher-insert-index elpher-selector-string)
+                                (elpher-restore-pos)
+                                (elpher-cache-content
+                                 (elpher-node-address elpher-current-node)
+                                 (buffer-string)))))))))
 
 ;; Text retrieval
 
 (defconst elpher-url-regex
-  "\\(https?\\|gopher\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
+  "\\([a-zA-Z]+\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
   "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
 
+(defun elpher-make-node-from-matched-url (&optional string)
+  "Convert most recent `elpher-url-regex' match to a node.
+
+If STRING is non-nil, this is given as an argument to all `match-string'
+calls, as is necessary if the match is performed by `string-match'."
+  (let ((url (match-string 0 string))
+        (protocol (downcase (match-string 1 string))))
+    (if (or (string= protocol "gopher")
+            (string= protocol "gophers"))
+        (let* ((host (match-string 2 string))
+               (port (if (> (length (match-string 3 string))  1)
+                         (string-to-number (substring (match-string 3 string) 1))
+                       70))
+               (type-and-selector (match-string 4 string))
+               (type (if (> (length type-and-selector) 1)
+                         (elt type-and-selector 1)
+                       ?1))
+               (selector (if (> (length type-and-selector) 1)
+                             (substring type-and-selector 2)
+                           ""))
+               (use-tls (string= protocol "gophers"))
+               (address (elpher-make-address type selector host port use-tls)))
+          (elpher-make-node url address))
+      (let* ((host (match-string 2 string))
+             (port (if (> (length (match-string 3 string)) 1)
+                       (string-to-number (substring (match-string 3 string) 1))
+                     70))
+             (selector (concat "URL:" url))
+             (address (elpher-make-address ?h selector host port)))
+        (elpher-make-node url address)))))
+
+
 (defun elpher-buttonify-urls (string)
   "Turn substrings which look like urls in STRING into clickable buttons."
   (with-temp-buffer
     (insert string)
     (goto-char (point-min))
     (while (re-search-forward elpher-url-regex nil t)
-      (let ((url (match-string 0))
-            (protocol (downcase (match-string 1))))
-        (if (string= protocol "gopher")
-            (let* ((host (match-string 2))
-                   (port 70)
-                   (type-and-selector (match-string 4))
-                   (type (if (> (length type-and-selector) 1)
-                             (elt type-and-selector 1)
-                           ?1))
-                   (selector (if (> (length type-and-selector) 1)
-                                 (substring type-and-selector 2)
-                               ""))
-                   (address (elpher-make-address selector host port))
-                   (getter (car (alist-get type elpher-type-map))))
-              (make-text-button (match-beginning 0)
-                                (match-end 0)
-                                'elpher-node (elpher-make-node elpher-current-node
-                                                                 address
-                                                                 getter)
-                                'action #'elpher-click-link
-                                'follow-link t
-                                'help-echo (format "mouse-1, RET: open %s on %s port %s"
-                                                   selector host port)))
+        (let ((node (elpher-make-node-from-matched-url)))
           (make-text-button (match-beginning 0)
                             (match-end 0)
-                            'elpher-url url
-                            'action #'elpher-click-url
+                            'elpher-node  node
+                            'action #'elpher-click-link
                             'follow-link t
-                            'help-echo (format "mouse-1, RET: open url %s" url)))))
+                            'help-echo (elpher-node-button-help node))))
     (buffer-string)))
 
-(defun elpher-process-text (string)
-  "Remove CRs and trailing period from the gopher text document STRING."
-  (let* ((chopped-str (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string))
-         (cleaned-str (replace-regexp-in-string "\r" "" chopped-str)))
-    (elpher-buttonify-urls cleaned-str)))
-
 (defun elpher-get-text-node ()
   "Getter which retrieves the current node contents as a text document."
-  (let ((content (elpher-node-content elpher-current-node))
-        (address (elpher-node-address elpher-current-node)))
+  (let* ((address (elpher-node-address elpher-current-node))
+         (content (elpher-get-cached-content address)))
     (if content
         (progn
           (elpher-with-clean-buffer
-           (insert content))
-          (elpher-restore-pos))
+           (insert content)
+           (elpher-restore-pos)))
       (progn
         (elpher-with-clean-buffer
-         (insert "LOADING TEXT..."))
+         (insert "LOADING TEXT... (use 'u' to cancel)"))
         (elpher-get-selector address
                               (lambda (proc event)
                                 (unless (string-prefix-p "deleted" event)
                                   (elpher-with-clean-buffer
-                                   (insert (elpher-process-text elpher-selector-string)))
-                                  (elpher-restore-pos)
-                                  (elpher-set-node-content elpher-current-node
-                                                            (buffer-string)))))))))
+                                   (insert (elpher-buttonify-urls
+                                            (elpher-preprocess-text-response
+                                             elpher-selector-string)))
+                                   (elpher-restore-pos)
+                                   (elpher-cache-content
+                                    (elpher-node-address elpher-current-node)
+                                    (buffer-string))))))))))
 
 ;; Image retrieval
 
 (defun elpher-get-image-node ()
   "Getter which retrieves the current node contents as an image to view."
-  (let ((content (elpher-node-content elpher-current-node))
-        (address (elpher-node-address elpher-current-node)))
+  (let* ((address (elpher-node-address elpher-current-node))
+         (content (elpher-get-cached-content address)))
     (if content
         (progn
           (elpher-with-clean-buffer
-           (insert-image content))
-          (setq cursor-type nil)
-          (elpher-restore-pos))
+           (insert-image content)
+           (elpher-restore-pos)))
       (if (display-images-p)
           (progn
             (elpher-with-clean-buffer
-             (insert "LOADING IMAGE..."))
+             (insert "LOADING IMAGE... (use 'u' to cancel)"))
             (elpher-get-selector address
                                  (lambda (proc event)
                                    (unless (string-prefix-p "deleted" event)
                                      (let ((image (create-image
-                                                   (encode-coding-string elpher-selector-string
-                                                                         'no-conversion)
+                                                   elpher-selector-string
                                                    nil t)))
                                        (elpher-with-clean-buffer
-                                        (insert-image image))
-                                       (setq cursor-type nil)
-                                       (elpher-restore-pos)
+                                        (insert-image image)
+                                        (elpher-restore-pos))
                                        (if elpher-cache-images
-                                           (elpher-set-node-content elpher-current-node
-                                                                    image)))))))
+                                           (elpher-cache-content
+                                            (elpher-node-address elpher-current-node)
+                                            image)))))))
         (elpher-get-node-download)))))
 
 ;; Search retrieval
 
 (defun elpher-get-search-node ()
   "Getter which submits a search query to the address of the current node."
-  (let ((content (elpher-node-content elpher-current-node))
-        (address (elpher-node-address elpher-current-node))
-        (aborted t))
+  (let* ((address (elpher-node-address elpher-current-node))
+         (content (elpher-get-cached-content address))
+         (aborted t))
     (if content
         (progn
           (elpher-with-clean-buffer
-           (insert content))
-          (elpher-restore-pos)
+           (insert content)
+           (elpher-restore-pos))
           (message "Displaying cached search results.  Reload to perform a new search."))
       (unwind-protect
           (let* ((query-string (read-string "Query: "))
                  (query-selector (concat (elpher-address-selector address) "\t" query-string))
-                 (search-address (elpher-make-address query-selector
-                                                       (elpher-address-host address)
-                                                       (elpher-address-port address))))
+                 (search-address (elpher-make-address ?1
+                                                      query-selector
+                                                      (elpher-address-host address)
+                                                      (elpher-address-port address))))
             (setq aborted nil)
             (elpher-with-clean-buffer
-             (insert "LOADING RESULTS..."))
+             (insert "LOADING RESULTS... (use 'u' to cancel)"))
             (elpher-get-selector search-address
                                   (lambda (proc event)
                                     (unless (string-prefix-p "deleted" event)
                                       (elpher-with-clean-buffer
                                        (elpher-insert-index elpher-selector-string))
                                       (goto-char (point-min))
-                                      (elpher-set-node-content elpher-current-node
-                                                                (buffer-string))))))
+                                      (elpher-cache-content
+                                       (elpher-node-address elpher-current-node)
+                                       (buffer-string))))))
         (if aborted
             (elpher-visit-parent-node))))))
 
@@ -544,17 +690,16 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
 
 (defun elpher-get-node-raw ()
   "Getter which retrieves the raw server response for the current node."
-  (let* ((content (elpher-node-content elpher-current-node))
-         (address (elpher-node-address elpher-current-node)))
+  (let ((address (elpher-node-address elpher-current-node)))
     (elpher-with-clean-buffer
-     (insert "LOADING RAW SERVER RESPONSE..."))
+     (insert "LOADING RAW SERVER RESPONSE... (use 'u' to cancel)"))
     (if address
         (elpher-get-selector address
                               (lambda (proc event)
                                 (unless (string-prefix-p "deleted" event)
                                   (elpher-with-clean-buffer
-                                   (insert elpher-selector-string))
-                                  (goto-char (point-min)))))
+                                   (insert elpher-selector-string)
+                                   (goto-char (point-min))))))
       (progn
         (elpher-with-clean-buffer
          (insert elpher-start-index))
@@ -578,16 +723,155 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
                                        "gopher.file"))))
       (message "Downloading...")
       (setq elpher-download-filename filename)
-      (elpher-get-selector address
-                            (lambda (proc event)
-                              (let ((coding-system-for-write 'binary))
-                                (with-temp-file elpher-download-filename
-                                  (insert elpher-selector-string)
-                                  (message (format "Download complate, saved to file %s."
-                                                   elpher-download-filename)))))))))
+      (condition-case the-error
+          (elpher-get-selector address
+                               (lambda (proc event)
+                                 (let ((coding-system-for-write 'binary))
+                                   (with-temp-file elpher-download-filename
+                                     (insert elpher-selector-string)
+                                     (message (format "Download complate, saved to file %s."
+                                                      elpher-download-filename)))))
+                               t)
+        (error
+         (error "Error downloading %s" elpher-download-filename))))))
+
+;; URL retrieval
+
+(defun elpher-insert-rendered-html (string)
+  "Use shr to insert rendered view of html STRING into current buffer."
+  (let ((dom (with-temp-buffer
+               (insert string)
+               (libxml-parse-html-region (point-min) (point-max)))))
+    (shr-insert-document dom)))
+
+(defun elpher-get-url-node ()
+  "Getter which attempts to open the URL specified by the current node."
+  (let* ((address (elpher-node-address elpher-current-node))
+         (selector (elpher-address-selector address)))
+    (let ((url (elt (split-string selector "URL:") 1)))
+      (if url
+          (progn
+            (elpher-visit-parent-node) ; Do first in case of non-local exits.
+            (message "Opening URL...")
+            (if elpher-open-urls-with-eww
+                (browse-web url)
+              (browse-url url)))
+        (let ((content (elpher-get-cached-content address)))
+          (if content
+              (progn
+                (elpher-with-clean-buffer
+                 (insert content)
+                 (elpher-restore-pos)))
+            (elpher-with-clean-buffer
+             (insert "LOADING HTML... (use 'u' to cancel)"))
+            (elpher-get-selector address
+                                 (lambda (proc event)
+                                   (unless (string-prefix-p "deleted" event)
+                                     (elpher-with-clean-buffer
+                                      (elpher-insert-rendered-html elpher-selector-string)
+                                      (goto-char (point-min))
+                                      (elpher-cache-content
+                                       (elpher-node-address elpher-current-node)
+                                       (buffer-string))))))))))))
+
+;; Telnet node connection
 
+(defun elpher-get-telnet-node ()
+  "Getter which opens a telnet connection to the server specified by the current node."
+  (let* ((address (elpher-node-address elpher-current-node))
+         (host (elpher-address-host address))
+         (port (elpher-address-port address)))
+    (elpher-visit-parent-node)
+    (telnet host port)))
+
+;; Start page node retrieval
+
+(defun elpher-get-start-node ()
+  "Getter which displays the start page."
+  (elpher-with-clean-buffer
+   (elpher-insert-index elpher-start-index)
+   (elpher-restore-pos)))
+
+;; Bookmarks page node retrieval
+
+(defun elpher-get-bookmarks-node ()
+  "Getter to load and display the current bookmark list."
+  (elpher-with-clean-buffer
+   (insert "---- Bookmark list ----\n\n")
+   (let ((bookmarks (elpher-load-bookmarks)))
+     (if bookmarks
+         (dolist (bookmark bookmarks)
+           (let ((display-string (elpher-bookmark-display-string bookmark))
+                 (address (elpher-bookmark-address bookmark)))
+             (elpher-insert-index-record display-string address)))
+       (insert "No bookmarks found.\n")))
+   (insert "\n-----------------------\n\n"
+           "- u: return to previous page\n"
+           "- x: delete selected bookmark\n"
+           "- a: rename selected bookmark\n\n"
+           "Bookmarks are stored in the file "
+           (locate-user-emacs-file "elpher-bookmarks"))
+   (elpher-restore-pos)))
+  
+
+;;; Bookmarks
+;;
 
-;;; Navigation procedures
+(defun elpher-make-bookmark (display-string address)
+  "Make an elpher bookmark.
+DISPLAY-STRING determines how the bookmark will appear in the
+bookmark list, while ADDRESS is the address of the entry."
+  (list display-string address))
+  
+(defun elpher-bookmark-display-string (bookmark)
+  "Get the display string of BOOKMARK."
+  (elt bookmark 0))
+
+(defun elpher-set-bookmark-display-string (bookmark display-string)
+  "Set the display string of BOOKMARK to DISPLAY-STRING."
+  (setcar bookmark display-string))
+
+(defun elpher-bookmark-address (bookmark)
+  "Get the address for BOOKMARK."
+  (elt bookmark 1))
+
+(defun elpher-save-bookmarks (bookmarks)
+  "Record the bookmark list BOOKMARKS to the user's bookmark file.
+Beware that this completely replaces the existing contents of the file."
+  (with-temp-file (locate-user-emacs-file "elpher-bookmarks")
+    (erase-buffer)
+    (insert "; Elpher gopher bookmarks file\n\n"
+            "; Bookmarks are stored as a list of (label (type selector host port))\n"
+            "; s-expressions, where type is stored as a character (i.e. 49 = ?1).\n"
+            "; Feel free to edit by hand, but ensure this structure remains intact.\n\n")
+    (pp bookmarks (current-buffer))))
+
+(defun elpher-load-bookmarks ()
+  "Get the list of bookmarks from the users's bookmark file."
+  (with-temp-buffer
+    (ignore-errors
+      (insert-file-contents (locate-user-emacs-file "elpher-bookmarks"))
+      (goto-char (point-min))
+      (read (current-buffer)))))
+
+(defun elpher-add-address-bookmark (address display-string)
+  "Save a bookmark for ADDRESS with label DISPLAY-STRING.
+If ADDRESS is already bookmarked, update the label only."
+  (let ((bookmarks (elpher-load-bookmarks)))
+    (let ((existing-bookmark (rassoc (list address) bookmarks)))
+      (if existing-bookmark
+          (elpher-set-bookmark-display-string existing-bookmark display-string)
+        (add-to-list 'bookmarks (elpher-make-bookmark display-string address))))
+    (elpher-save-bookmarks bookmarks)))
+
+(defun elpher-remove-address-bookmark (address)
+  "Remove any bookmark to ADDRESS."
+    (elpher-save-bookmarks
+     (seq-filter (lambda (bookmark)
+                   (not (equal (elpher-bookmark-address bookmark) address)))
+                 (elpher-load-bookmarks))))
+
+;;; Interactive procedures
 ;;
 
 (defun elpher-next-link ()
@@ -600,58 +884,71 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
   (interactive)
   (backward-button 1))
 
-(defun elpher-click-link (button)
-  "Function called when the gopher link BUTTON is activated (via mouse or keypress)."
-  (let ((node (button-get button 'elpher-node)))
-    (elpher-visit-node node)))
-
-(defun elpher-click-url (button)
-  "Function called when the url link BUTTON is activated (via mouse or keypress)."
-  (let ((url (button-get button 'elpher-url)))
-    (if elpher-open-urls-with-eww
-        (browse-web url)
-      (browse-url url))))
-
 (defun elpher-follow-current-link ()
   "Open the link or url at point."
   (interactive)
   (push-button))
 
 (defun elpher-go ()
-  "Go to a particular gopher site."
+  "Go to a particular gopher site read from the minibuffer.
+The site may be specified via a URL or explicitly in terms of
+host, selector and port."
   (interactive)
-  (let* (
-         (hostname (read-string "Gopher host: "))
-         (selector (read-string "Selector (default none): " nil nil ""))
-         (port (read-string "Port (default 70): " nil nil 70))
-         (address (list selector hostname port)))
-    (elpher-visit-node
-     (elpher-make-node elpher-current-node
-                        address
-                        #'elpher-get-index-node))))
-
-(defun  elpher-redraw ()
+  (let ((node
+         (let ((host-or-url (read-string "Gopher host or URL: ")))
+           (if (string-match elpher-url-regex host-or-url)
+               (elpher-make-node-from-matched-url host-or-url)
+             (let ((selector (read-string "Selector (default none): " nil nil ""))
+                   (port-string (read-string "Port (default 70): " nil nil "70")))
+               (elpher-make-node (concat "gopher://" host-or-url
+                                         ":" port-string
+                                         "/1" selector)
+                                 (elpher-make-address ?1 selector host-or-url
+                                                      (string-to-number port-string))))))))
+    (switch-to-buffer "*elpher*")
+    (elpher-visit-node node)))
+
+(defun elpher-redraw ()
   "Redraw current page."
   (interactive)
-  (elpher-visit-node elpher-current-node))
+  (if elpher-current-node
+      (elpher-visit-node elpher-current-node)
+    (message "No current site.")))
 
-(defun  elpher-reload ()
+(defun elpher-reload ()
   "Reload current page."
   (interactive)
-  (elpher-reload-current-node))
+  (if elpher-current-node
+      (elpher-reload-current-node)
+    (message "No current site.")))
+
+(defun elpher-toggle-tls ()
+  "Toggle TLS encryption mode."
+  (interactive)
+  (setq elpher-use-tls (not elpher-use-tls))
+  (if elpher-use-tls
+      (if (gnutls-available-p)
+          (message "TLS mode enabled.  (Will not affect current page until reload.)")
+        (setq elpher-use-tls nil)
+        (error "Cannot enable TLS mode: GnuTLS not available"))
+    (message "TLS mode disabled.  (Will not affect current page until reload.)")))
 
 (defun elpher-view-raw ()
-  "View current page as plain text."
+  "View raw server response for current page."
   (interactive)
-  (elpher-visit-node elpher-current-node
-                      #'elpher-get-node-raw))
+  (if elpher-current-node
+      (if (elpher-address-special-p (elpher-node-address elpher-current-node))
+          (error "This page was not generated by a server")
+        (elpher-visit-node elpher-current-node
+                           #'elpher-get-node-raw))
+    (message "No current site.")))
 
 (defun elpher-back ()
   "Go to previous site."
   (interactive)
   (if (elpher-node-parent elpher-current-node)
       (elpher-visit-parent-node)
-    (message "No previous site.")))
+    (error "No previous site")))
 
 (defun elpher-download ()
   "Download the link at point."
@@ -659,11 +956,23 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
   (let ((button (button-at (point))))
     (if button
         (let ((node (button-get button 'elpher-node)))
-          (if node
-              (elpher-visit-node (button-get button 'elpher-node)
-                                 #'elpher-get-node-download)
-            (message "Can only download gopher links, not general URLs.")))
-      (message "No link selected."))))
+          (if (elpher-address-special-p (elpher-node-address node))
+              (error "Cannot download this link")
+            (elpher-visit-node (button-get button 'elpher-node)
+                               #'elpher-get-node-download)))
+      (error "No link selected"))))
+
+(defun elpher-download-current ()
+  "Download the current page."
+  (interactive)
+  (if (elpher-address-special-p (elpher-node-address elpher-current-node))
+      (error "Cannot download this page")
+    (elpher-visit-node (elpher-make-node
+                        (elpher-node-display-string elpher-current-node)
+                        (elpher-node-address elpher-current-node)
+                        elpher-current-node)
+                       #'elpher-get-node-download
+                       t)))
 
 (defun elpher-build-link-map ()
   "Build alist mapping link names to destination nodes in current buffer."
@@ -674,18 +983,176 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
       (setq b (next-button (button-start b))))
     link-map))
 
-(defun elpher-menu ()
+(defun elpher-jump ()
   "Select a directory entry by name.  Similar to the info browser (m)enu command."
   (interactive)
   (let* ((link-map (elpher-build-link-map)))
     (if link-map
         (let ((key (let ((completion-ignore-case t))
-                     (completing-read "Menu item: " link-map nil t))))
+                     (completing-read "Directory item/link: "
+                                      link-map nil t))))
           (if (and key (> (length key) 0))
               (let ((b (cdr (assoc key link-map))))
                 (goto-char (button-start b))
                 (button-activate b)))))))
 
+(defun elpher-root-dir ()
+  "Visit root of current server."
+  (interactive)
+  (let* ((address (elpher-node-address elpher-current-node))
+         (host (elpher-address-host address)))
+    (if host
+        (let ((host (elpher-address-host address))
+              (selector (elpher-address-selector address))
+              (port (elpher-address-port address)))
+          (if (> (length selector) 0)
+              (let ((root-address (elpher-make-address ?1 "" host port)))
+                (elpher-visit-node
+                 (elpher-make-node (concat "gopher://" host
+                                           ":" (number-to-string port)
+                                           "/1/")
+                                   root-address)))
+            (error "Already at root directory of current server")))
+      (error "Command invalid for this page"))))
+
+(defun elpher-bookmarks-current-p ()
+  "Return non-nil if current node is a bookmarks page."
+  (eq (elpher-address-type (elpher-node-address elpher-current-node)) 'bookmarks))
+
+(defun elpher-reload-bookmarks ()
+  "Reload bookmarks if current node is a bookmarks page."
+  (if (elpher-bookmarks-current-p)
+      (elpher-reload-current-node)))
+
+(defun elpher-bookmark-current ()
+  "Bookmark the current node."
+  (interactive)
+  (let ((address (elpher-node-address elpher-current-node))
+        (display-string (elpher-node-display-string elpher-current-node)))
+    (if (not (elpher-address-special-p address))
+        (let ((bookmark-display-string (read-string "Bookmark display string: "
+                                                    display-string)))
+          (elpher-add-address-bookmark address bookmark-display-string)
+          (message "Bookmark added."))
+      (error "Cannot bookmark %s" display-string))))
+
+(defun elpher-bookmark-link ()
+  "Bookmark the link at point."
+  (interactive)
+  (let ((button (button-at (point))))
+    (if button
+        (let* ((node (button-get button 'elpher-node))
+               (address (elpher-node-address node))
+               (display-string (elpher-node-display-string node)))
+          (if (not (elpher-address-special-p address))
+              (let ((bookmark-display-string (read-string "Bookmark display string: "
+                                                          display-string)))
+                (elpher-add-address-bookmark address bookmark-display-string)
+                (elpher-reload-bookmarks)
+                (message "Bookmark added."))
+            (error "Cannot bookmark %s" display-string)))
+      (error "No link selected"))))
+
+(defun elpher-unbookmark-current ()
+  "Remove bookmark for the current node."
+  (interactive)
+  (let ((address (elpher-node-address elpher-current-node)))
+    (unless (elpher-address-special-p address)
+      (elpher-remove-address-bookmark address)
+      (message "Bookmark removed."))))
+
+(defun elpher-unbookmark-link ()
+  "Remove bookmark for the link at point."
+  (interactive)
+  (let ((button (button-at (point))))
+    (if button
+        (let ((node (button-get button 'elpher-node)))
+          (elpher-remove-address-bookmark (elpher-node-address node))
+          (elpher-reload-bookmarks)
+          (message "Bookmark removed."))
+      (error "No link selected"))))
+
+(defun elpher-bookmarks ()
+  "Visit bookmarks page."
+  (interactive)
+  (switch-to-buffer "*elpher*")
+  (elpher-visit-node
+   (elpher-make-node "Bookmarks Page" (elpher-make-address 'bookmarks))))
+
+(defun elpher-info-node (node)
+  "Display information on NODE."
+  (let ((display-string (elpher-node-display-string node))
+        (address (elpher-node-address node)))
+    (if (not (elpher-address-special-p address))
+        (message "`%s' on %s port %s"
+                (elpher-address-selector address)
+                (elpher-address-host address)
+                (elpher-address-port address))
+      (message "%s" display-string))))
+
+(defun elpher-info-link ()
+  "Display information on node corresponding to link at point."
+  (interactive)
+  (let ((button (button-at (point))))
+    (if button
+        (elpher-info-node (button-get button 'elpher-node))
+      (error "No item selected"))))
+  
+(defun elpher-info-current ()
+  "Display information on current node."
+  (interactive)
+  (elpher-info-node elpher-current-node))
+
+(defun elpher-get-address-url (address)
+  "Get URL representation of ADDRESS."
+  (let ((type (elpher-address-type address))
+        (selector (elpher-address-selector address))
+        (host (elpher-address-host address))
+        (port (elpher-address-port address)))
+    (if (and (equal type ?h)
+             (string-prefix-p "URL:" selector))
+        (elt (split-string selector "URL:") 1)
+      (concat "gopher"
+              (if (elpher-address-use-tls-p address) "s" "")
+              "://"
+              host
+              (if (equal port 70)
+                  ""
+                (format ":%d" port))
+              "/" (string type)
+              selector))))
+
+(defun elpher-copy-node-url (node)
+  "Copy URL representation of address of NODE to `kill-ring'."
+  (let ((address (elpher-node-address node)))
+    (if (elpher-address-special-p address)
+        (error (format "Cannot represent %s as URL" (elpher-node-display-string node)))
+      (let ((url (elpher-get-address-url address)))
+        (message "Copied \"%s\" to kill-ring/clipboard." url)
+        (kill-new url)))))
+
+(defun elpher-copy-link-url ()
+  "Copy URL of item at point to `kill-ring'."
+  (interactive)
+  (let ((button (button-at (point))))
+    (if button
+        (elpher-copy-node-url (button-get button 'elpher-node))
+      (error "No item selected"))))
+
+(defun elpher-copy-current-url ()
+  "Copy URL of current node to `kill-ring'."
+  (interactive)
+  (elpher-copy-node-url elpher-current-node))
+
+(defun elpher-set-coding-system ()
+  "Specify an explicit character coding system."
+  (interactive)
+  (let ((system (read-coding-system "Set coding system to use (default is to autodetect): " nil)))
+    (setq elpher-user-coding-system system)
+    (if system
+        (message "Coding system fixed to %s. (Reload to see effect)." system)
+      (message "Coding system set to autodetect. (Reload to see effect)."))))
+
 ;;; Mode and keymap
 ;;
 
@@ -694,30 +1161,62 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
     (define-key map (kbd "TAB") 'elpher-next-link)
     (define-key map (kbd "<backtab>") 'elpher-prev-link)
     (define-key map (kbd "u") 'elpher-back)
+    (define-key map (kbd "O") 'elpher-root-dir)
     (define-key map (kbd "g") 'elpher-go)
     (define-key map (kbd "r") 'elpher-redraw)
     (define-key map (kbd "R") 'elpher-reload)
+    (define-key map (kbd "T") 'elpher-toggle-tls)
     (define-key map (kbd "w") 'elpher-view-raw)
     (define-key map (kbd "d") 'elpher-download)
-    (define-key map (kbd "m") 'elpher-menu)
+    (define-key map (kbd "D") 'elpher-download-current)
+    (define-key map (kbd "m") 'elpher-jump)
+    (define-key map (kbd "i") 'elpher-info-link)
+    (define-key map (kbd "I") 'elpher-info-current)
+    (define-key map (kbd "c") 'elpher-copy-link-url)
+    (define-key map (kbd "C") 'elpher-copy-current-url)
+    (define-key map (kbd "a") 'elpher-bookmark-link)
+    (define-key map (kbd "A") 'elpher-bookmark-current)
+    (define-key map (kbd "x") 'elpher-unbookmark-link)
+    (define-key map (kbd "X") 'elpher-unbookmark-current)
+    (define-key map (kbd "B") 'elpher-bookmarks)
+    (define-key map (kbd "S") 'elpher-set-coding-system)
     (when (fboundp 'evil-define-key)
-      (evil-define-key 'normal map
+      (evil-define-key 'motion map
         (kbd "TAB") 'elpher-next-link
         (kbd "C-]") 'elpher-follow-current-link
         (kbd "C-t") 'elpher-back
         (kbd "u") 'elpher-back
+        (kbd "O") 'elpher-root-dir
         (kbd "g") 'elpher-go
         (kbd "r") 'elpher-redraw
         (kbd "R") 'elpher-reload
+        (kbd "T") 'elpher-toggle-tls
         (kbd "w") 'elpher-view-raw
         (kbd "d") 'elpher-download
-        (kbd "m") 'elpher-menu))
+        (kbd "D") 'elpher-download-current
+        (kbd "m") 'elpher-jump
+        (kbd "i") 'elpher-info-link
+        (kbd "I") 'elpher-info-current
+        (kbd "c") 'elpher-copy-link-url
+        (kbd "C") 'elpher-copy-current-url
+        (kbd "a") 'elpher-bookmark-link
+        (kbd "A") 'elpher-bookmark-current
+        (kbd "x") 'elpher-unbookmark-link
+        (kbd "X") 'elpher-unbookmark-current
+        (kbd "B") 'elpher-bookmarks
+        (kbd "S") 'elpher-set-coding-system))
     map)
   "Keymap for gopher client.")
 
 (define-derived-mode elpher-mode special-mode "elpher"
-  "Major mode for elpher, an elisp gopher client.")
+  "Major mode for elpher, an elisp gopher client.
+
+This mode is automatically enabled by the interactive
+functions which initialize the gopher client, namely
+`elpher', `elpher-go' and `elpher-bookmarks'.")
 
+(when (fboundp 'evil-set-initial-state)
+  (evil-set-initial-state 'elpher-mode 'motion))
 
 ;;; Main start procedure
 ;;
@@ -726,11 +1225,13 @@ The result is stored as a string in the variable ‘elpher-selector-string’."
 (defun elpher ()
   "Start elpher with default landing page."
   (interactive)
-  (setq elpher-current-node nil)
-  (let ((start-node (elpher-make-node nil
-                                      elpher-start-address
-                                      #'elpher-get-index-node)))
-    (elpher-visit-node start-node))
+  (if (get-buffer "*elpher*")
+      (switch-to-buffer "*elpher*")
+    (switch-to-buffer "*elpher*")
+    (setq elpher-current-node nil)
+    (let ((start-node (elpher-make-node "Elpher Start Page"
+                                        (elpher-make-address 'start))))
+      (elpher-visit-node start-node)))
   "Started Elpher.") ; Otherwise (elpher) evaluates to start page string.
 
 ;;; elpher.el ends here