-;;; elpher.el --- Full-featured gopher client.
+;;; elpher.el --- A friendly gopher and gemini client -*- lexical-binding:t -*-
-;; Copyright (C) 2019 Tim Vaughan
+;; Copyright (C) 2019-2020 Tim Vaughan
-;; Author: Tim Vaughan <tgvaughan@gmail.com>
+;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
;; Created: 11 April 2019
-;; Version: 1.1.0
+;; Version: 2.10.2
;; Keywords: comm gopher
-;; Homepage: https://github.com/tgvaughan/elpher
-;; Package-Requires: ((emacs "25"))
+;; Homepage: http://thelambdalab.xyz/elpher
+;; Package-Requires: ((emacs "26.2"))
;; This file is not part of GNU Emacs.
;;; Commentary:
-;; Elpher aims to provide a full-featured gopher client for GNU Emacs.
-;; It supports:
+;; Elpher aims to provide a practical and friendly gopher and gemini
+;; client for GNU Emacs. It supports:
;; - intuitive keyboard and mouse-driven browsing,
-;; - caching of visited sites (both content and cursor position),
+;; - out-of-the-box compatibility with evil-mode,
+;; - clickable web and gopher links *in plain text*,
+;; - caching of visited sites,
;; - 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.
-
-;; Visited pages are stored as a hierarchy rather than a linear history,
-;; meaning that navigation between these pages is quick and easy.
+;; - a simple bookmark management system,
+;; - gopher connections using TLS encryption,
+;; - the fledgling Gemini protocol,
+;; - the greybeard Finger protocol.
;; 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.
+;; Full instructions can be found in the Elpher info manual.
+
+;; Elpher is under active development. Any suggestions for
+;; improvements are welcome, and can be made on the official
+;; project page, gopher://thelambdalab.xyz/1/projects/elpher/.
;;; Code:
(provide 'elpher)
+;;; Dependencies
+;;
+
+(require 'seq)
+(require 'pp)
+(require 'shr)
+(require 'url-util)
+(require 'subr-x)
+(require 'dns)
+(require 'ansi-color)
+(require 'nsm)
+(require 'gnutls)
+
+
;;; Global constants
;;
-(defconst elpher-version "1.1.0"
+(defconst elpher-version "2.10.2"
"Current version of elpher.")
(defconst elpher-margin-width 6
"Width of left-hand margin used when rendering indicies.")
-(defconst elpher-start-index
- (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"
- "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 - O: visit the root directory of the current server\tfake\tfake\t1"
- "i - g: go to a particular 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 - w: display the raw server response for the current page\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "iPlaces to start exploring Gopherspace:\tfake\tfake\t1"
- "i\tfake\tfake\t1"
- "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)
- (?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))
- "Association list from types to getters, margin codes and index faces.")
+ '(((gopher ?0) elpher-get-gopher-page elpher-render-text "txt" elpher-text)
+ ((gopher ?1) elpher-get-gopher-page elpher-render-index "/" elpher-index)
+ ((gopher ?4) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
+ ((gopher ?5) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
+ ((gopher ?7) elpher-get-gopher-query-page elpher-render-index "?" elpher-search)
+ ((gopher ?9) elpher-get-gopher-page elpher-render-download "bin" elpher-binary)
+ ((gopher ?g) elpher-get-gopher-page elpher-render-image "img" elpher-image)
+ ((gopher ?p) elpher-get-gopher-page elpher-render-image "img" elpher-image)
+ ((gopher ?I) elpher-get-gopher-page elpher-render-image "img" elpher-image)
+ ((gopher ?d) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
+ ((gopher ?P) elpher-get-gopher-page elpher-render-download "doc" elpher-binary)
+ ((gopher ?s) elpher-get-gopher-page elpher-render-download "snd" elpher-binary)
+ ((gopher ?h) elpher-get-gopher-page elpher-render-html "htm" elpher-html)
+ (gemini elpher-get-gemini-page elpher-render-gemini "gem" elpher-gemini)
+ (finger elpher-get-finger-page elpher-render-text "txt" elpher-text)
+ (telnet elpher-get-telnet-page nil "tel" elpher-telnet)
+ (other-url elpher-get-other-url-page nil "url" elpher-other-url)
+ ((special bookmarks) elpher-get-bookmarks-page nil "/" elpher-index)
+ ((special start) elpher-get-start-page nil))
+ "Association list from types to getters, renderers, margin codes and index faces.")
;;; Customization group
;;
(defgroup elpher nil
- "A gopher client."
+ "A gopher and gemini client."
:group 'applications)
+;; General appearance and customizations
+
+(defcustom elpher-open-urls-with-eww nil
+ "If non-nil, open URL selectors using eww.
+Otherwise, use the system browser via the BROWSE-URL function."
+ :type '(boolean))
+
+(defcustom elpher-use-header t
+ "If non-nil, display current page 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))
+
+(defcustom elpher-connection-timeout 5
+ "Specifies the number of seconds to wait for a network connection to time out."
+ :type '(integer))
+
+(defcustom elpher-filter-ansi-from-text nil
+ "If non-nil, filter ANSI escape sequences from text.
+The default behaviour is to use the ansi-color package to interpret these
+sequences."
+ :type '(boolean))
+
+(defcustom elpher-certificate-directory
+ (file-name-as-directory (locate-user-emacs-file "elpher-certificates"))
+ "Specify the name of the directory where client certificates will be stored.
+These certificates may be used for establishing authenticated TLS connections."
+ :type '(directory))
+
+(defcustom elpher-openssl-command "openssl"
+ "The command used to launch openssl when generating TLS client certificates."
+ :type '(file))
+
+(defcustom elpher-gemini-TLS-cert-checks nil
+ "If non-nil, verify gemini server TLS certs using the default security level.
+Otherwise, certificate verification is disabled.
+
+This defaults to off because it is standard practice for Gemini servers
+to use self-signed certificates, meaning that most servers provide what
+EMACS considers to be an invalid certificate."
+ :type '(boolean))
+
+(defcustom elpher-gemini-max-fill-width 80
+ "Specify the maximum default width (in columns) of text/gemini documents.
+The actual width used is the minimum of this value and the window width at
+the time when the text is rendered."
+ :type '(integer))
+
+(defcustom elpher-gemini-link-string "→ "
+ "Specify the string used to indicate links when rendering gemini maps.
+May be empty."
+ :type '(string))
+
+(defcustom elpher-gemini-bullet-string "•"
+ "Specify the string used for bullets when rendering gemini maps."
+ :type '(string))
+
+(defcustom elpher-bookmarks-file (locate-user-emacs-file "elpher-bookmarks")
+ "Specify the name of the file where elpher bookmarks will be saved."
+ :type '(file))
+
+(defcustom elpher-ipv4-always nil
+ "If non-nil, elpher will always use IPv4 to establish network connections.
+This can be useful when browsing from a computer that supports IPv6, because
+some servers which do not support IPv6 can take a long time to time-out."
+ :type '(boolean))
+
;; Face customizations
+(defgroup elpher-faces nil
+ "Elpher face customizations."
+ :group 'elpher)
+
(defface elpher-index
- '((t :inherit org-drawer))
+ '((t :inherit font-lock-keyword-face))
"Face used for directory type directory records.")
(defface elpher-text
- '((t :inherit org-tag))
+ '((t :inherit bold))
"Face used for text type directory records.")
(defface elpher-info
- '((t :inherit org-default))
+ '((t :inherit default))
"Face used for info type directory records.")
(defface elpher-image
- '((t :inherit org-level-4))
+ '((t :inherit font-lock-string-face))
"Face used for image type directory records.")
(defface elpher-search
- '((t :inherit org-level-5))
+ '((t :inherit warning))
"Face used for search type directory records.")
-(defface elpher-url
- '((t :inherit org-level-6))
- "Face used for url type directory records.")
+(defface elpher-html
+ '((t :inherit font-lock-comment-face))
+ "Face used for html type directory records.")
+
+(defface elpher-gemini
+ '((t :inherit font-lock-constant-face))
+ "Face used for Gemini type directory records.")
+
+(defface elpher-other-url
+ '((t :inherit font-lock-comment-face))
+ "Face used for other URL type links records.")
+
+(defface elpher-telnet
+ '((t :inherit font-lock-function-name-face))
+ "Face used for telnet type directory records.")
(defface elpher-binary
- '((t :inherit org-level-7))
+ '((t :inherit font-lock-doc-face))
"Face used for binary type directory records.")
(defface elpher-unknown
- '((t :inherit org-warning))
+ '((t :inherit error))
"Face used for directory records with unknown/unsupported types.")
(defface elpher-margin-key
- '((t :inherit org-tag))
+ '((t :inherit bold))
"Face used for directory margin key.")
(defface elpher-margin-brackets
- '((t :inherit org-special-keyword))
+ '((t :inherit shadow))
"Face used for brackets around directory margin key.")
-;; Other customizations
+(defface elpher-gemini-heading1
+ '((t :inherit bold :height 1.8))
+ "Face used for gemini heading level 1.")
-(defcustom elpher-open-urls-with-eww nil
- "If non-nil, open URL selectors using eww.
-Otherwise, use the system browser via the BROWSE-URL function."
- :type '(boolean))
+(defface elpher-gemini-heading2
+ '((t :inherit bold :height 1.5))
+ "Face used for gemini heading level 2.")
-(defcustom elpher-buttonify-urls-in-directories nil
- "If non-nil, turns URLs matched in directories into clickable buttons."
- :type '(boolean))
+(defface elpher-gemini-heading3
+ '((t :inherit bold :height 1.2))
+ "Face used for gemini heading level 3.")
-(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))
+(defface elpher-gemini-preformatted
+ '((t :inherit fixed-pitch))
+ "Face used for pre-formatted gemini text blocks.")
;;; Model
;;
;; 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-address-selector (address)
- "Retrieve selector from ADDRESS."
- (car address))
+;; An elpher "address" object is either a url object or a symbol.
+;; Symbol addresses are "special", corresponding to pages generated
+;; dynamically for and by elpher. All others represent pages which
+;; rely on content retrieved over the network.
+
+(defun elpher-address-from-url (url-string)
+ "Create a ADDRESS object corresponding to the given URL-STRING."
+ (let ((data (match-data))) ; Prevent parsing clobbering match data
+ (unwind-protect
+ (let ((url (url-generic-parse-url url-string)))
+ (unless (and (not (url-fullness url)) (url-type url))
+ (setf (url-fullness url) t)
+ (setf (url-filename url)
+ (url-unhex-string (url-filename url)))
+ (unless (url-type url)
+ (setf (url-type url) "gopher"))
+ (when (or (equal "gopher" (url-type url))
+ (equal "gophers" (url-type url)))
+ ;; Gopher defaults
+ (unless (url-host url)
+ (setf (url-host url) (url-filename url))
+ (setf (url-filename url) ""))
+ (when (or (equal (url-filename url) "")
+ (equal (url-filename url) "/"))
+ (setf (url-filename url) "/1")))
+ (when (equal "gemini" (url-type url))
+ ;; Gemini defaults
+ (if (equal (url-filename url) "")
+ (setf (url-filename url) "/"))))
+ (elpher-remove-redundant-ports url))
+ (set-match-data data))))
+
+(defun elpher-remove-redundant-ports (address)
+ "Remove redundant port specifiers from ADDRESS.
+Here 'redundant' means that the specified port matches the default
+for that protocol, eg 70 for gopher."
+ (if (and (not (elpher-address-special-p address))
+ (eq (url-portspec address) ; (url-port) is too slow!
+ (pcase (url-type address)
+ ("gemini" 1965)
+ ((or "gopher" "gophers") 70)
+ ("finger" 79)
+ (_ -1))))
+ (setf (url-portspec address) nil))
+ address)
+
+(defun elpher-make-gopher-address (type selector host port &optional tls)
+ "Create an ADDRESS object using gopher directory record attributes.
+The basic attributes include: TYPE, SELECTOR, HOST and PORT.
+If the optional attribute TLS is non-nil, the address will be marked as
+requiring gopher-over-TLS."
+ (cond
+ ((equal type ?i) nil)
+ ((and (equal type ?h)
+ (string-prefix-p "URL:" selector))
+ (elpher-address-from-url (elt (split-string selector "URL:") 1)))
+ ((equal type ?8)
+ (elpher-address-from-url
+ (concat "telnet"
+ "://" host
+ ":" (number-to-string port))))
+ (t
+ (elpher-address-from-url
+ (concat "gopher" (if tls "s" "")
+ "://" host
+ ":" (number-to-string port)
+ "/" (string type)
+ selector)))))
+
+(defun elpher-make-special-address (type)
+ "Create an ADDRESS object corresponding to the given special address symbol TYPE."
+ type)
+
+(defun elpher-address-to-url (address)
+ "Get string representation of ADDRESS, or nil if ADDRESS is special."
+ (if (elpher-address-special-p address)
+ nil
+ (url-encode-url (url-recreate-url address))))
+
+(defun elpher-address-type (address)
+ "Retrieve type of ADDRESS object.
+This is used to determine how to retrieve and render the document the
+address refers to, via the table `elpher-type-map'."
+ (if (symbolp address)
+ (list 'special address)
+ (let ((protocol (url-type address)))
+ (cond ((or (equal protocol "gopher")
+ (equal protocol "gophers"))
+ (list 'gopher
+ (if (member (url-filename address) '("" "/"))
+ ?1
+ (string-to-char (substring (url-filename address) 1)))))
+ ((equal protocol "gemini")
+ 'gemini)
+ ((equal protocol "telnet")
+ 'telnet)
+ ((equal protocol "finger")
+ 'finger)
+ (t 'other-url)))))
+
+(defun elpher-address-protocol (address)
+ "Retrieve the transport protocol for ADDRESS. This is nil for special addresses."
+ (if (symbolp address)
+ nil
+ (url-type address)))
+
+(defun elpher-address-filename (address)
+ "Retrieve the filename component of ADDRESS.
+For gopher addresses this is a combination of the selector type and selector."
+ (if (symbolp address)
+ nil
+ (url-filename address)))
(defun elpher-address-host (address)
- "Retrieve host from ADDRESS."
- (cadr address))
+ "Retrieve host from ADDRESS object."
+ (url-host address))
+
+(defun elpher-address-user (address)
+ "Retrieve user from ADDRESS object."
+ (url-user address))
(defun elpher-address-port (address)
- "Retrieve port from ADDRESS."
- (caddr address))
+ "Retrieve port from ADDRESS object.
+If no address is defined, returns 0. (This is for compatibility with the URL library.)"
+ (if (symbolp address)
+ 0
+ (url-port address)))
+
+(defun elpher-address-special-p (address)
+ "Return non-nil if ADDRESS object is special (e.g. start page, bookmarks page)."
+ (symbolp address))
+
+(defun elpher-address-gopher-p (address)
+ "Return non-nill if ADDRESS object is a gopher address."
+ (and (not (elpher-address-special-p address))
+ (member (elpher-address-protocol address) '("gopher gophers"))))
-;; Node
+(defun elpher-gopher-address-selector (address)
+ "Retrieve gopher selector from ADDRESS object."
+ (if (member (url-filename address) '("" "/"))
+ ""
+ (url-unhex-string (substring (url-filename address) 2))))
-(defun elpher-make-node (parent address getter &optional content pos)
- "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.
+;; Cache
-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))
+(defvar elpher-content-cache (make-hash-table :test 'equal))
+(defvar elpher-pos-cache (make-hash-table :test 'equal))
-(defun elpher-node-parent (node)
- "Retrieve the parent node of NODE."
- (elt node 0))
+(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-address (node)
- "Retrieve the address of NODE."
- (elt node 1))
+(defun elpher-cache-content (address content)
+ "Set the content cache for ADDRESS to CONTENT."
+ (puthash address content elpher-content-cache))
-(defun elpher-node-getter (node)
- "Retrieve the preferred getter function of NODE."
- (elt node 2))
+(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-node-content (node)
- "Retrieve the cached content of NODE, or nil if none exists."
- (elt node 3))
+(defun elpher-cache-pos (address pos)
+ "Set the cursor position cache for ADDRESS to POS."
+ (puthash address pos elpher-pos-cache))
-(defun elpher-node-pos (node)
- "Retrieve the cached cursor position for NODE, or nil if none exists."
- (elt node 4))
-(defun elpher-set-node-content (node content)
- "Set the content cache of NODE to CONTENT."
- (setcar (nthcdr 3 node) content))
+;; Page
-(defun elpher-set-node-pos (node pos)
- "Set the cursor position cache of NODE to POS."
- (setcar (nthcdr 4 node) pos))
+(defun elpher-make-page (display-string address)
+ "Create a page with DISPLAY-STRING and ADDRESS."
+ (list display-string address))
-;; Node graph traversal
+(defun elpher-page-display-string (page)
+ "Retrieve the display string corresponding to PAGE."
+ (elt page 0))
-(defvar elpher-current-node nil)
+(defun elpher-page-address (page)
+ "Retrieve the address corresponding to PAGE."
+ (elt page 1))
-(defun elpher-visit-node (node &optional getter)
- "Visit NODE using its own getter or GETTER, if non-nil."
+(defun elpher-page-set-address (page new-address)
+ "Set the address corresponding to PAGE to NEW-ADDRESS."
+ (setcar (cdr page) new-address))
+
+(defvar elpher-current-page nil) ; buffer local
+(defvar elpher-history nil) ; buffer local
+
+(defun elpher-visit-page (page &optional renderer no-history)
+ "Visit PAGE using its own renderer or RENDERER, if non-nil.
+Additionally, push PAGE onto the stack of previously-visited pages,
+unless NO-HISTORY is non-nil."
(elpher-save-pos)
(elpher-process-cleanup)
- (setq elpher-current-node node)
- (if getter
- (funcall getter)
- (funcall (elpher-node-getter node))))
-
-(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))))
+ (unless (or no-history
+ (equal (elpher-page-address elpher-current-page)
+ (elpher-page-address page)))
+ (push elpher-current-page elpher-history))
+ (setq elpher-current-page page)
+ (let* ((address (elpher-page-address page))
+ (type (elpher-address-type address))
+ (type-record (cdr (assoc type elpher-type-map))))
+ (if type-record
+ (funcall (car type-record)
+ (if renderer
+ renderer
+ (cadr type-record)))
+ (elpher-visit-previous-page)
+ (pcase type
+ (`(gopher ,type-char)
+ (error "Unsupported gopher selector type '%c' for '%s'"
+ type-char (elpher-address-to-url address)))
+ (other
+ (error "Unsupported address type '%S' for '%s'"
+ other (elpher-address-to-url address)))))))
+
+(defun elpher-visit-previous-page ()
+ "Visit the previous page in the history."
+ (let ((previous-page (pop elpher-history)))
+ (if previous-page
+ (elpher-visit-page previous-page nil t)
+ (error "No previous page"))))
-(defun elpher-reload-current-node ()
- "Reload the current node, discarding any existing cached content."
- (elpher-set-node-content elpher-current-node nil)
- (elpher-visit-node elpher-current-node))
+(defun elpher-reload-current-page ()
+ "Reload the current page, discarding any existing cached content."
+ (elpher-cache-content (elpher-page-address elpher-current-page) nil)
+ (elpher-visit-page elpher-current-page))
(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))))
+ "Save the current position of point to the current page."
+ (when elpher-current-page
+ (elpher-cache-pos (elpher-page-address elpher-current-page) (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)))
+ "Restore the position of point to that cached in the current page."
+ (let ((pos (elpher-get-cached-pos (elpher-page-address elpher-current-page))))
(if pos
(goto-char pos)
(goto-char (point-min)))))
+
;;; Buffer preparation
;;
+(defvar elpher-buffer-name "*elpher*"
+ "The default name of the Elpher buffer.")
+
+(defun elpher-update-header ()
+ "If `elpher-use-header' is true, display current page info in window header."
+ (if elpher-use-header
+ (let* ((display-string (elpher-page-display-string elpher-current-page))
+ (address (elpher-page-address elpher-current-page))
+ (tls-string (if (and (not (elpher-address-special-p address))
+ (member (elpher-address-protocol address)
+ '("gophers" "gemini")))
+ " [TLS encryption]"
+ ""))
+ (header (concat display-string
+ (propertize tls-string 'face 'bold))))
+ (setq header-line-format header))))
+
(defmacro elpher-with-clean-buffer (&rest args)
"Evaluate ARGS with a clean *elpher* buffer as current."
- (list 'with-current-buffer "*elpher*"
- '(elpher-mode)
- (append (list 'let '((inhibit-read-only t))
- '(erase-buffer))
- args)))
+ `(with-current-buffer elpher-buffer-name
+ (unless (eq major-mode 'elpher-mode)
+ (elpher-mode))
+ (let ((inhibit-read-only t))
+ (setq-local network-security-level
+ (default-value 'network-security-level))
+ (erase-buffer)
+ (elpher-update-header)
+ ,@args)))
+
+(defun elpher-buffer-message (string &optional line)
+ "Replace first line in elpher buffer with STRING.
+If LINE is non-nil, replace that line instead."
+ (with-current-buffer elpher-buffer-name
+ (let ((inhibit-read-only t))
+ (goto-char (point-min))
+ (if line
+ (forward-line line))
+ (let ((data (match-data)))
+ (unwind-protect
+ (progn
+ (re-search-forward "^.*$")
+ (replace-match string))
+ (set-match-data data))))))
+
+
+;;; Text Processing
+;;
+
+(defvar elpher-user-coding-system nil
+ "User-specified coding system to use for decoding text responses.")
+
+(defun elpher-decode (string)
+ "Decode STRING using autodetected or user-specified coding system."
+ (decode-coding-string string
+ (if elpher-user-coding-system
+ elpher-user-coding-system
+ (detect-coding-string string t))))
+
+(defun elpher-preprocess-text-response (string)
+ "Preprocess text selector response contained in STRING.
+This involes decoding the character representation, and clearing
+away CRs and any terminating period."
+ (elpher-decode (replace-regexp-in-string "\n\.\n$" "\n"
+ (replace-regexp-in-string "\r" "" string))))
+
+
+;;; Network error reporting
+;;
+
+(defun elpher-network-error (address error)
+ "Display ERROR message following unsuccessful negotiation with ADDRESS.
+ERROR can be either an error object or a string."
+ (elpher-with-clean-buffer
+ (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
+ "When attempting to retrieve " (elpher-address-to-url address) ":\n"
+ (if (stringp error) error (error-message-string error)) "\n"
+ (propertize "\n----------------\n\n" 'face 'error)
+ "Press 'u' to return to the previous page.")))
-;;; Index rendering
+
+;;; General network communication
+;;
+
+(defvar elpher-network-timer nil
+ "Timer used for network connections.")
+
+(defvar elpher-use-tls nil
+ "If non-nil, use TLS to communicate with gopher servers.")
+
+(defvar elpher-client-certificate nil
+ "If non-nil, contains client certificate details to use for TLS connections.")
+
+(defun elpher-process-cleanup ()
+ "Immediately shut down any extant elpher process and timers."
+ (let ((p (get-process "elpher-process")))
+ (if p (delete-process p)))
+ (if (timerp elpher-network-timer)
+ (cancel-timer elpher-network-timer)))
+
+(defun elpher-get-host-response (address default-port query-string response-processor
+ &optional use-tls force-ipv4)
+ "Generic function for retrieving data from ADDRESS.
+
+When ADDRESS lacks a specific port, DEFAULT-PORT is used instead.
+QUERY-STRING is a string sent to the host specified by ADDRESS to
+illicet a response. This response is passed as an argument to the
+function RESPONSE-PROCESSOR.
+
+If non-nil, USE-TLS specifies that the connection is to be made over
+TLS. If set to gemini, the certificate verification will be disabled
+unless `elpher-gemini-TLS-cert-checks' is non-nil.
+
+If non-nil, FORCE-IPV4 causes the network connection to be made over
+ipv4 only. (The default behaviour when this is not set depends on
+the host operating system and the local network capabilities."
+ (if (and use-tls (not (gnutls-available-p)))
+ (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
+ (unless (< (elpher-address-port address) 65536)
+ (error "Cannot establish network connection: port number > 65536"))
+ (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
+ (setq-local network-security-level 'low))
+ (condition-case nil
+ (let* ((kill-buffer-query-functions nil)
+ (port (elpher-address-port address))
+ (host (elpher-address-host address))
+ (response-string-parts nil)
+ (bytes-received 0)
+ (hkbytes-received 0)
+ (proc (make-network-process :name "elpher-process"
+ :host host
+ :family (and force-ipv4 'ipv4)
+ :service (if (> port 0) port default-port)
+ :buffer nil
+ :coding 'binary
+ :noquery t
+ :nowait t
+ :tls-parameters
+ (and use-tls
+ (cons 'gnutls-x509pki
+ (gnutls-boot-parameters
+ :type 'gnutls-x509pki
+ :hostname host
+ :keylist
+ (elpher-get-current-keylist address))))))
+ (timer (run-at-time elpher-connection-timeout nil
+ (lambda ()
+ (elpher-process-cleanup)
+ (cond
+ ; Try again with IPv4
+ ((not force-ipv4)
+ (message "Connection timed out. Retrying with IPv4.")
+ (elpher-get-host-response address default-port
+ query-string
+ response-processor
+ use-tls t))
+ ((and use-tls
+ (not (eq use-tls 'gemini))
+ (or elpher-auto-disengage-TLS
+ (y-or-n-p
+ "TLS connetion failed. Disable TLS mode and retry? ")))
+ (setq elpher-use-tls nil)
+ (elpher-get-host-response address default-port
+ query-string
+ response-processor
+ nil force-ipv4))
+ (t
+ (elpher-network-error address "Connection time-out.")))))))
+ (setq elpher-network-timer timer)
+ (elpher-buffer-message (concat "Connecting to " host "..."
+ " (press 'u' to abort)"))
+ (set-process-filter proc
+ (lambda (_proc string)
+ (when timer
+ (cancel-timer timer)
+ (setq timer nil))
+ (setq bytes-received (+ bytes-received (length string)))
+ (let ((new-hkbytes-received (/ bytes-received 102400)))
+ (when (> new-hkbytes-received hkbytes-received)
+ (setq hkbytes-received new-hkbytes-received)
+ (elpher-buffer-message
+ (concat "("
+ (number-to-string (/ hkbytes-received 10.0))
+ " MB read)")
+ 1)))
+ (setq response-string-parts
+ (cons string response-string-parts))))
+ (set-process-sentinel proc
+ (lambda (proc event)
+ (when timer
+ (cancel-timer timer))
+ (condition-case the-error
+ (cond
+ ((string-prefix-p "open" event) ; request URL
+ (elpher-buffer-message
+ (concat "Connected to " host ". Receiving data..."
+ " (press 'u' to abort)"))
+ (let ((inhibit-eol-conversion t))
+ (process-send-string proc query-string)))
+ ((string-prefix-p "deleted" event)) ; do nothing
+ ((and (not response-string-parts)
+ (not (or elpher-ipv4-always force-ipv4)))
+ ; Try again with IPv4
+ (message "Connection failed. Retrying with IPv4.")
+ (elpher-get-host-response address default-port
+ query-string
+ response-processor
+ use-tls t))
+ (response-string-parts
+ (elpher-with-clean-buffer
+ (insert "Data received. Rendering..."))
+ (funcall response-processor
+ (apply #'concat (reverse response-string-parts)))
+ (elpher-restore-pos))
+ (t
+ (error "No response from server")))
+ (error
+ (elpher-network-error address the-error))))))
+ (error
+ (error "Error initiating connection to server")))))
+
+
+;;; Client-side TLS Certificate Management
;;
+(defun elpher-generate-certificate (common-name key-file cert-file &optional temporary)
+ "Generate a key and a self-signed client TLS certificate using openssl.
+
+The Common Name field of the certificate is set to COMMON-NAME. The
+arguments KEY-FILE and CERT-FILE should contain the absolute paths of
+the key and certificate files to write.
+
+If TEMPORARY is non-nil, the certificate will be given an exporation
+period of one day, and the key and certificate files will be deleted
+when the certificate is no longer needed for the current session.
+
+Otherwise, the certificate will be given a 100 year expiration period
+and the files will not be deleted.
+
+The function returns a list containing the current host name, the
+temporary flag, and the key and cert file names in the form required
+by `gnutls-boot-parameters`."
+ (let ((exp-key-file (expand-file-name key-file))
+ (exp-cert-file (expand-file-name cert-file)))
+ (condition-case nil
+ (progn
+ (call-process elpher-openssl-command nil nil nil
+ "req" "-x509" "-newkey" "rsa:2048"
+ "-days" (if temporary "1" "36500")
+ "-nodes"
+ "-subj" (concat "/CN=" common-name)
+ "-keyout" exp-key-file
+ "-out" exp-cert-file)
+ (list (elpher-address-host (elpher-page-address elpher-current-page))
+ temporary exp-key-file exp-cert-file))
+ (error
+ (message "Check that openssl is installed, or customize `elpher-openssl-command`.")
+ (error "Program 'openssl', required for certificate generation, not found")))))
+
+(defun elpher-generate-throwaway-certificate ()
+ "Generate and return details of a throwaway certificate.
+The key and certificate files will be deleted when they are no
+longer needed for this session."
+ (let* ((file-base (make-temp-name "elpher"))
+ (key-file (concat temporary-file-directory file-base ".key"))
+ (cert-file (concat temporary-file-directory file-base ".crt")))
+ (elpher-generate-certificate file-base key-file cert-file t)))
+
+(defun elpher-generate-persistent-certificate (file-base common-name)
+ "Generate and return details of a persistent certificate.
+The argument FILE-BASE is used as the base for the key and certificate
+files, while COMMON-NAME specifies the common name field of the
+certificate.
+
+The key and certificate files are written to in `elpher-certificate-directory'."
+ (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
+ (cert-file (concat elpher-certificate-directory file-base ".crt")))
+ (elpher-generate-certificate common-name key-file cert-file)))
+
+(defun elpher-get-existing-certificate (file-base)
+ "Return a certificate object corresponding to an existing certificate.
+It is assumed that the key files FILE-BASE.key and FILE-BASE.crt exist in
+the directory `elpher-certificate-directory'."
+ (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
+ (cert-file (concat elpher-certificate-directory file-base ".crt")))
+ (list (elpher-address-host (elpher-page-address elpher-current-page))
+ nil
+ (expand-file-name key-file)
+ (expand-file-name cert-file))))
+
+(defun elpher-install-and-use-existing-certificate (key-file-src cert-file-src file-base)
+ "Install a key+certificate file pair in `elpher-certificate-directory'.
+The strings KEY-FILE-SRC and CERT-FILE-SRC are the existing key and
+certificate files to install. The argument FILE-BASE is used as the
+base for the installed key and certificate files."
+ (let* ((key-file (concat elpher-certificate-directory file-base ".key"))
+ (cert-file (concat elpher-certificate-directory file-base ".crt")))
+ (if (or (file-exists-p key-file)
+ (file-exists-p cert-file))
+ (error "A certificate with base name %s is already installed" file-base))
+ (copy-file key-file-src key-file)
+ (copy-file cert-file-src cert-file)
+ (list (elpher-address-host (elpher-page-address elpher-current-page))
+ nil
+ (expand-file-name key-file)
+ (expand-file-name cert-file))))
+
+(defun elpher-list-existing-certificates ()
+ "Return a list of the persistent certificates in `elpher-certificate-directory'."
+ (unless (file-directory-p elpher-certificate-directory)
+ (make-directory elpher-certificate-directory))
+ (mapcar
+ (lambda (file)
+ (file-name-sans-extension file))
+ (directory-files elpher-certificate-directory nil "\.key$")))
+
+(defun elpher-forget-current-certificate ()
+ "Causes any current certificate to be forgotten.)
+In the case of throwaway certificates, the key and certificate files
+are also deleted."
+ (interactive)
+ (when elpher-client-certificate
+ (unless (and (called-interactively-p 'any)
+ (not (y-or-n-p (concat "Really forget client certificate? "
+ "(Throwaway certificates will be deleted.)"))))
+ (when (cadr elpher-client-certificate)
+ (delete-file (elt elpher-client-certificate 2))
+ (delete-file (elt elpher-client-certificate 3)))
+ (setq elpher-client-certificate nil)
+ (if (called-interactively-p 'any)
+ (message "Client certificate forgotten.")))))
+
+(defun elpher-get-current-keylist (address)
+ "Retrieve the `gnutls-boot-parameters'-compatable keylist.
+
+This is obtained from the client certificate described by
+`elpher-current-certificate', if one is available and the host for
+that certificate matches the host in ADDRESS.
+
+If `elpher-current-certificate' is non-nil, and its host name doesn't
+match that of ADDRESS, the certificate is forgotten."
+ (if elpher-client-certificate
+ (if (string= (car elpher-client-certificate)
+ (elpher-address-host address))
+ (list (cddr elpher-client-certificate))
+ (elpher-forget-current-certificate)
+ (message "Disabling client certificate for new host")
+ nil)
+ nil))
+
+
+;;; Gopher selector retrieval
+;;
+
+(defun elpher-get-gopher-response (address renderer)
+ "Get response string from gopher server at ADDRESS and render using RENDERER."
+ (elpher-get-host-response address 70
+ (concat (elpher-gopher-address-selector address) "\r\n")
+ renderer
+ (or (string= (elpher-address-protocol address) "gophers")
+ elpher-use-tls)))
+
+(defun elpher-get-gopher-page (renderer)
+ "Getter function for gopher pages.
+The RENDERER procedure is used to display the contents of the page
+once they are retrieved from the gopher server."
+ (let* ((address (elpher-page-address elpher-current-page))
+ (content (elpher-get-cached-content address)))
+ (if (and content (funcall renderer nil))
+ (elpher-with-clean-buffer
+ (insert content)
+ (elpher-restore-pos))
+ (elpher-with-clean-buffer
+ (insert "LOADING... (use 'u' to cancel)\n"))
+ (condition-case the-error
+ (elpher-get-gopher-response address renderer)
+ (error
+ (elpher-network-error address the-error))))))
+
+;; Index rendering
+
(defun elpher-insert-index (string)
"Insert the index corresponding to STRING into the current buffer."
;; Should be able to split directly on CRLF, but some non-conformant
;; LF-only servers sadly exist, hence the following.
- (let* ((str-no-period (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string))
- (str-no-cr (replace-regexp-in-string "\r" "" str-no-period)))
- (dolist (line (split-string str-no-cr "\n"))
- (unless (= (length line) 0)
- (elpher-insert-index-record line)))))
+ (let ((str-processed (elpher-preprocess-text-response string)))
+ (dolist (line (split-string str-processed "\n"))
+ (ignore-errors
+ (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-gopher-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."
(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))
- (type-map-entry (alist-get type elpher-type-map)))
+(defun elpher--page-button-help (_window buffer pos)
+ "Function called by Emacs to generate mouse-over text.
+The arguments specify the BUFFER and the POS within the buffer of the item
+for which help is required. The function returns the help to be
+displayed. The _WINDOW argument is currently unused."
+ (with-current-buffer buffer
+ (let ((button (button-at pos)))
+ (when button
+ (let* ((page (button-get button 'elpher-page))
+ (address (elpher-page-address page)))
+ (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
+ address
+ (elpher-address-to-url address))))))))
+
+(defun elpher-insert-index-record (display-string &optional address)
+ "Function to insert an index record into the current buffer.
+The contents of the record are dictated by DISPLAY-STRING and ADDRESS.
+If ADDRESS is not supplied or nil the record is rendered as an
+'information' line."
+ (let* ((type (if address (elpher-address-type address) nil))
+ (type-map-entry (cdr (assoc 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 2))
+ (face (elt type-map-entry 3))
+ (filtered-display-string (ansi-color-filter-apply display-string))
+ (page (elpher-make-page filtered-display-string address)))
(elpher-insert-margin margin-code)
- (insert-text-button display-string
+ (insert-text-button filtered-display-string
'face face
- 'elpher-node (elpher-make-node elpher-current-node
- address
- getter)
+ 'elpher-page page
'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--page-button-help))
(pcase type
- (?i (elpher-insert-margin) ;; Information
- (insert (propertize
- (if elpher-buttonify-urls-in-directories
- (elpher-buttonify-urls display-string)
- 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))))
- (tp (elpher-insert-margin (concat (char-to-string tp) "?"))
- (insert (propertize display-string
- 'face 'elpher-unknown-face)))))
+ ('nil ;; Information
+ (elpher-insert-margin)
+ (let ((propertized-display-string
+ (propertize display-string 'face 'elpher-info)))
+ (insert (elpher-process-text-for-display propertized-display-string))))
+ (`(gopher ,selector-type) ;; Unknown
+ (elpher-insert-margin (concat (char-to-string selector-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 ((page (button-get button 'elpher-page)))
+ (elpher-visit-page page)))
-;;; Selector retrieval (all kinds)
-;;
-
-(defun elpher-process-cleanup ()
- "Immediately shut down any extant elpher process."
- (let ((p (get-process "elpher-process")))
- (if p (delete-process p))))
-
-(defvar elpher-selector-string)
-
-(defun elpher-get-selector (address after)
- "Retrieve selector specified by ADDRESS, then execute AFTER.
-The result is stored as a string in the variable ‘elpher-selector-string’."
- (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")))
-
-;; 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)))
- (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))))))))
+(defun elpher-render-index (data &optional _mime-type-string)
+ "Render DATA as an index. MIME-TYPE-STRING is unused."
+ (elpher-with-clean-buffer
+ (if (not data)
+ t
+ (elpher-insert-index data)
+ (elpher-cache-content (elpher-page-address elpher-current-page)
+ (buffer-string)))))
-;; Text retrieval
+;; Text rendering
(defconst elpher-url-regex
- "\\(https?\\|gopher\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
+ "\\([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\-_~?/@|#]\\)?\\)?"
"Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
(defun elpher-buttonify-urls (string)
(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 ((page (elpher-make-page (substring-no-properties (match-string 0))
+ (elpher-address-from-url (match-string 0)))))
(make-text-button (match-beginning 0)
(match-end 0)
- 'elpher-url url
- 'action #'elpher-click-url
+ 'elpher-page page
+ 'action #'elpher-click-link
'follow-link t
- 'help-echo (format "mouse-1, RET: open url %s" url)))))
+ 'help-echo #'elpher--page-button-help
+ 'face 'button)))
(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)))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos)))
- (progn
- (elpher-with-clean-buffer
- (insert "LOADING TEXT..."))
- (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))))))))))
+(defconst elpher-ansi-regex "\x1b\\[[^m]*m"
+ "Wildly incomplete regexp used to strip out some troublesome ANSI escape sequences.")
+
+(defun elpher-process-text-for-display (string)
+ "Perform any desired processing of STRING prior to display as text.
+Currently includes buttonifying URLs and processing ANSI escape codes."
+ (elpher-buttonify-urls (if elpher-filter-ansi-from-text
+ (ansi-color-filter-apply string)
+ (ansi-color-apply string))))
+
+(defun elpher-render-text (data &optional _mime-type-string)
+ "Render DATA as text. MIME-TYPE-STRING is unused."
+ (elpher-with-clean-buffer
+ (if (not data)
+ t
+ (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
+ (elpher-cache-content
+ (elpher-page-address elpher-current-page)
+ (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)))
- (if content
+(defun elpher-render-image (data &optional _mime-type-string)
+ "Display DATA as image. MIME-TYPE-STRING is unused."
+ (if (not data)
+ nil
+ (if (display-images-p)
(progn
- (elpher-with-clean-buffer
- (insert-image content)
- (elpher-restore-pos)))
- (if (display-images-p)
- (progn
+ (let ((image (create-image
+ data
+ nil t)))
(elpher-with-clean-buffer
- (insert "LOADING IMAGE..."))
- (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)
- nil t)))
- (elpher-with-clean-buffer
- (insert-image image)
- (elpher-restore-pos))
- (if elpher-cache-images
- (elpher-set-node-content 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))
- (if content
- (progn
- (elpher-with-clean-buffer
- (insert content)
- (elpher-restore-pos))
- (message "Displaying cached search results. Reload to perform a new search."))
+ (insert-image image)
+ (elpher-restore-pos))))
+ (elpher-render-download data))))
+
+;; Search retrieval and rendering
+
+(defun elpher-get-gopher-query-page (renderer)
+ "Getter for gopher addresses requiring input.
+The response is rendered using the rendering function RENDERER."
+ (let* ((address (elpher-page-address elpher-current-page))
+ (content (elpher-get-cached-content address))
+ (aborted t))
+ (if (and content (funcall renderer nil))
+ (elpher-with-clean-buffer
+ (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))))
+ (query-selector (concat (elpher-gopher-address-selector address) "\t" query-string))
+ (search-address (elpher-make-gopher-address ?1
+ query-selector
+ (elpher-address-host address)
+ (elpher-address-port address)
+ (equal (elpher-address-type address) "gophers"))))
(setq aborted nil)
+
(elpher-with-clean-buffer
- (insert "LOADING RESULTS..."))
- (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))))))
+ (insert "LOADING RESULTS... (use 'u' to cancel)"))
+ (elpher-get-gopher-response search-address renderer))
(if aborted
- (elpher-visit-parent-node))))))
-
-;; Raw server response retrieval
+ (elpher-visit-previous-page))))))
+
+;; Raw server response rendering
-(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)))
+(defun elpher-render-raw (data &optional mime-type-string)
+ "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
+ (if (not data)
+ nil
(elpher-with-clean-buffer
- (insert "LOADING RAW SERVER RESPONSE..."))
- (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))))))
- (progn
+ (when mime-type-string
+ (insert "MIME type specified by server: '" mime-type-string "'\n"))
+ (insert data)
+ (goto-char (point-min)))
+ (message "Displaying raw server response. Reload or redraw to return to standard view.")))
+
+;; File save "rendering"
+
+(defun elpher-render-download (data &optional _mime-type-string)
+ "Save DATA to file. MIME-TYPE-STRING is unused."
+ (if (not data)
+ nil
+ (let* ((address (elpher-page-address elpher-current-page))
+ (selector (if (elpher-address-gopher-p address)
+ (elpher-gopher-address-selector address)
+ (elpher-address-filename address))))
+ (elpher-visit-previous-page) ; Do first in case of non-local exits.
+ (let* ((filename-proposal (file-name-nondirectory selector))
+ (filename (read-file-name "Download complete. Save file as: "
+ nil nil nil
+ (if (> (length filename-proposal) 0)
+ filename-proposal
+ "download.file"))))
+ (let ((coding-system-for-write 'binary))
+ (with-temp-file filename
+ (insert data)))
+ (message (format "Saved to file %s." filename))))))
+
+;; HTML rendering
+
+(defun elpher-render-html (data &optional _mime-type-string)
+ "Render DATA as HTML using shr. MIME-TYPE-STRING is unused."
+ (elpher-with-clean-buffer
+ (if (not data)
+ t
+ (let ((dom (with-temp-buffer
+ (insert data)
+ (libxml-parse-html-region (point-min) (point-max)))))
+ (shr-insert-document dom)))))
+
+;; Gemini page retrieval
+
+(defvar elpher-gemini-redirect-chain)
+
+(defun elpher-get-gemini-response (address renderer)
+ "Get response string from gemini server at ADDRESS and render using RENDERER."
+ (elpher-get-host-response address 1965
+ (concat (elpher-address-to-url address) "\r\n")
+ (lambda (response-string)
+ (elpher-process-gemini-response response-string renderer))
+ 'gemini))
+
+(defun elpher-parse-gemini-response (response)
+ "Parse the RESPONSE string and return a list of components.
+The list is of the form (code meta body). A response of nil implies
+that the response was malformed."
+ (let ((header-end-idx (string-match "\r\n" response)))
+ (if header-end-idx
+ (let ((header (string-trim (substring response 0 header-end-idx)))
+ (body (substring response (+ header-end-idx 2))))
+ (if (>= (length header) 2)
+ (let ((code (substring header 0 2))
+ (meta (string-trim (substring header 2))))
+ (list code meta body))
+ (error "Malformed response: No response status found in header %s" header)))
+ (error "Malformed response: No CRLF-delimited header found in response %s" response))))
+
+(defun elpher-process-gemini-response (response-string renderer)
+ "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
+ (let ((response-components (elpher-parse-gemini-response response-string)))
+ (let ((response-code (elt response-components 0))
+ (response-meta (elt response-components 1))
+ (response-body (elt response-components 2)))
+ (pcase (elt response-code 0)
+ (?1 ; Input required
+ (elpher-with-clean-buffer
+ (insert "Gemini server is requesting input."))
+ (let* ((query-string
+ (if (eq (elt response-code 1) ?1)
+ (read-passwd (concat response-meta ": "))
+ (read-string (concat response-meta ": "))))
+ (query-address (seq-copy (elpher-page-address elpher-current-page)))
+ (old-fname (url-filename query-address)))
+ (setf (url-filename query-address)
+ (concat old-fname "?" (url-build-query-string `((,query-string)))))
+ (elpher-get-gemini-response query-address renderer)))
+ (?2 ; Normal response
+ (funcall renderer response-body response-meta))
+ (?3 ; Redirect
+ (message "Following redirect to %s" response-meta)
+ (if (>= (length elpher-gemini-redirect-chain) 5)
+ (error "More than 5 consecutive redirects followed"))
+ (let ((redirect-address (elpher-address-from-gemini-url response-meta)))
+ (if (member redirect-address elpher-gemini-redirect-chain)
+ (error "Redirect loop detected"))
+ (if (not (string= (elpher-address-protocol redirect-address)
+ "gemini"))
+ (error "Server tried to automatically redirect to non-gemini URL: %s"
+ response-meta))
+ (elpher-page-set-address elpher-current-page redirect-address)
+ (add-to-list 'elpher-gemini-redirect-chain redirect-address)
+ (elpher-get-gemini-response redirect-address renderer)))
+ (?4 ; Temporary failure
+ (error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
+ response-code response-meta))
+ (?5 ; Permanent failure
+ (error "Gemini server reports PERMANENT FAILURE for this request: %s %s"
+ response-code response-meta))
+ (?6 ; Client certificate required
+ (elpher-with-clean-buffer
+ (if elpher-client-certificate
+ (insert "Gemini server does not recognise the provided TLS certificate:\n\n")
+ (insert "Gemini server is requesting a valid TLS certificate:\n\n"))
+ (auto-fill-mode 1)
+ (elpher-gemini-insert-text response-meta))
+ (let ((chosen-certificate (elpher-choose-client-certificate)))
+ (unless chosen-certificate
+ (error "Gemini server requires a client certificate and none was provided"))
+ (setq elpher-client-certificate chosen-certificate))
+ (elpher-with-clean-buffer)
+ (elpher-get-gemini-response (elpher-page-address elpher-current-page) renderer))
+ (_other
+ (error "Gemini server response unknown: %s %s"
+ response-code response-meta))))))
+
+(defun elpher-choose-client-certificate ()
+ "Prompt for a client certificate to use to establish a TLS connection."
+ (let* ((read-answer-short t))
+ (pcase (read-answer "What do you want to do? "
+ '(("throwaway" ?t
+ "generate and use throw-away certificate")
+ ("persistent" ?p
+ "generate new or use existing persistent certificate")
+ ("abort" ?a
+ "stop immediately")))
+ ("throwaway"
+ (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
+ ("persistent"
+ (let* ((existing-certificates (elpher-list-existing-certificates))
+ (file-base (completing-read
+ "Nickname for new or existing certificate (autocompletes, empty response aborts): "
+ existing-certificates)))
+ (if (string-empty-p (string-trim file-base))
+ nil
+ (if (member file-base existing-certificates)
+ (setq elpher-client-certificate
+ (elpher-get-existing-certificate file-base))
+ (pcase (read-answer "Generate new certificate or install externally-generated one? "
+ '(("new" ?n
+ "generate new certificate")
+ ("install" ?i
+ "install existing certificate")
+ ("abort" ?a
+ "stop immediately")))
+ ("new"
+ (let ((common-name (read-string "Common Name field for new certificate: "
+ file-base)))
+ (message "New key and self-signed certificate written to %s"
+ elpher-certificate-directory)
+ (elpher-generate-persistent-certificate file-base common-name)))
+ ("install"
+ (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
+ (key-file (read-file-name "Key file: " nil nil t)))
+ (message "Key and certificate installed in %s for future use"
+ elpher-certificate-directory)
+ (elpher-install-and-use-existing-certificate key-file
+ cert-file
+ file-base)))
+ ("abort" nil))))))
+ ("abort" nil))))
+
+(defun elpher-get-gemini-page (renderer)
+ "Getter which retrieves and renders a Gemini page and renders it using RENDERER."
+ (let* ((address (elpher-page-address elpher-current-page))
+ (content (elpher-get-cached-content address)))
+ (condition-case the-error
+ (if (and content (funcall renderer nil))
+ (elpher-with-clean-buffer
+ (insert content)
+ (elpher-restore-pos))
+ (elpher-with-clean-buffer
+ (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
+ (setq elpher-gemini-redirect-chain nil)
+ (elpher-get-gemini-response address renderer))
+ (error
+ (elpher-network-error address the-error)))))
+
+(defun elpher-render-gemini (body &optional mime-type-string)
+ "Render gemini response BODY with rendering MIME-TYPE-STRING."
+ (if (not body)
+ t
+ (let* ((mime-type-string* (if (or (not mime-type-string)
+ (string-empty-p mime-type-string))
+ "text/gemini; charset=utf-8"
+ mime-type-string))
+ (mime-type-split (split-string mime-type-string* ";" t))
+ (mime-type (string-trim (car mime-type-split)))
+ (parameters (mapcar (lambda (s)
+ (let ((key-val (split-string s "=")))
+ (list (downcase (string-trim (car key-val)))
+ (downcase (string-trim (cadr key-val))))))
+ (cdr mime-type-split))))
+ (when (string-prefix-p "text/" mime-type)
+ (setq body (decode-coding-string
+ body
+ (if (assoc "charset" parameters)
+ (intern (cadr (assoc "charset" parameters)))
+ 'utf-8)))
+ (setq body (replace-regexp-in-string "\r" "" body)))
+ (pcase mime-type
+ ((or "text/gemini" "")
+ (elpher-render-gemini-map body parameters))
+ ("text/html"
+ (elpher-render-html body))
+ ((pred (string-prefix-p "text/"))
+ (elpher-render-gemini-plain-text body parameters))
+ ((pred (string-prefix-p "image/"))
+ (elpher-render-image body))
+ (_other
+ (elpher-render-download body))))))
+
+(defun elpher-gemini-get-link-url (link-line)
+ "Extract the url portion of LINK-LINE, a gemini map file link line.
+Returns nil in the event that the contents of the line following the
+=> prefix are empty."
+ (let ((l (split-string (substring link-line 2))))
+ (if l
+ (string-trim (elt l 0))
+ nil)))
+
+(defun elpher-gemini-get-link-display-string (link-line)
+ "Extract the display string portion of LINK-LINE, a gemini map file link line.
+Returns the url portion in the event that the display-string portion is empty."
+ (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))
+ (idx (string-match "[ \t]" rest)))
+ (string-trim (if idx
+ (substring rest (+ idx 1))
+ rest))))
+
+(defun elpher-collapse-dot-sequences (filename)
+ "Collapse dot sequences in FILENAME.
+For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
+ (let* ((path (split-string filename "/"))
+ (path-reversed-normalized
+ (seq-reduce (lambda (a b)
+ (cond ((and a (equal b "..") (cdr a)))
+ ((and (not a) (equal b "..")) a) ;leading .. are dropped
+ ((equal b ".") a)
+ (t (cons b a))))
+ path nil)))
+ (string-join (reverse path-reversed-normalized) "/")))
+
+(defun elpher-address-from-gemini-url (url)
+ "Extract address from URL with defaults as per gemini map files.
+While there's obviously some redundancy here between this function and
+`elpher-address-from-url', gemini map file URLs require enough special
+treatment that a separate function is warranted."
+ (let ((address (url-generic-parse-url url))
+ (current-address (elpher-page-address elpher-current-page)))
+ (unless (and (url-type address) (not (url-fullness address))) ;avoid mangling mailto: urls
+ (setf (url-fullness address) t)
+ (if (url-host address) ;if there is an explicit host, filenames are absolute
+ (if (string-empty-p (url-filename address))
+ (setf (url-filename address) "/")) ;ensure empty filename is marked as absolute
+ (setf (url-host address) (url-host current-address))
+ (setf (url-port address) (url-port current-address))
+ (unless (string-prefix-p "/" (url-filename address)) ;deal with relative links
+ (setf (url-filename address)
+ (concat (file-name-directory (url-filename current-address))
+ (url-filename address)))))
+ (unless (url-type address)
+ (setf (url-type address) "gemini"))
+ (when (equal (url-type address) "gemini")
+ (setf (url-filename address)
+ (elpher-collapse-dot-sequences (url-filename address)))))
+ (elpher-remove-redundant-ports address)))
+
+(defun elpher-gemini-insert-link (link-line)
+ "Insert link described by LINK-LINE into a text/gemini document."
+ (let* ((url (elpher-gemini-get-link-url link-line))
+ (display-string (elpher-gemini-get-link-display-string link-line))
+ (address (elpher-address-from-gemini-url url))
+ (type (if address (elpher-address-type address) nil))
+ (type-map-entry (cdr (assoc type elpher-type-map))))
+ (when display-string
+ (insert elpher-gemini-link-string)
+ (if type-map-entry
+ (let* ((face (elt type-map-entry 3))
+ (filtered-display-string (ansi-color-filter-apply display-string))
+ (page (elpher-make-page filtered-display-string address)))
+ (insert-text-button filtered-display-string
+ 'face face
+ 'elpher-page page
+ 'action #'elpher-click-link
+ 'follow-link t
+ 'help-echo #'elpher--page-button-help))
+ (insert (propertize display-string 'face 'elpher-unknown)))
+ (insert "\n"))))
+
+(defun elpher-gemini-insert-header (header-line)
+ "Insert header described by HEADER-LINE into a text/gemini document.
+The gemini map file line describing the header is given
+by HEADER-LINE."
+ (when (string-match "^\\(#+\\)[ \t]*" header-line)
+ (let* ((level (length (match-string 1 header-line)))
+ (header (substring header-line (match-end 0)))
+ (face (pcase level
+ (1 'elpher-gemini-heading1)
+ (2 'elpher-gemini-heading2)
+ (3 'elpher-gemini-heading3)
+ (_ 'default)))
+ (fill-column (/ (* fill-column
+ (font-get (font-spec :name (face-font 'default)) :size))
+ (font-get (font-spec :name (face-font face)) :size))))
+ (unless (display-graphic-p)
+ (insert (make-string level ?#) " "))
+ (insert (propertize header 'face face))
+ (newline))))
+
+(defun elpher-gemini-insert-text (text-line)
+ "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
+This function uses Emacs' auto-fill to wrap text sensibly to a maximum
+width defined by elpher-gemini-max-fill-width."
+ (string-match "\\(^[ \t]*\\)\\(\*[ \t]+\\|>[ \t]*\\)?" text-line)
+ (let* ((processed-text-line (if (match-string 2 text-line)
+ (concat
+ (replace-regexp-in-string "\*"
+ elpher-gemini-bullet-string
+ (match-string 0 text-line))
+ (substring text-line (match-end 0)))
+ text-line))
+ (adaptive-fill-mode nil)
+ (fill-prefix (if (match-string 2 text-line)
+ (replace-regexp-in-string "[>\*]" " " (match-string 0 text-line))
+ nil)))
+ (insert (elpher-process-text-for-display processed-text-line))
+ (newline)))
+
+(defun elpher-render-gemini-map (data _parameters)
+ "Render DATA as a gemini map file, PARAMETERS is currently unused."
+ (elpher-with-clean-buffer
+ (let ((preformatted nil))
+ (auto-fill-mode 1)
+ (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
+ (dolist (line (split-string data "\n"))
+ (cond
+ ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
+ (preformatted (insert (elpher-process-text-for-display
+ (propertize line 'face 'elpher-gemini-preformatted))
+ "\n"))
+ ((string-prefix-p "=>" line) (elpher-gemini-insert-link line))
+ ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
+ (t (elpher-gemini-insert-text line)))))
+ (elpher-cache-content
+ (elpher-page-address elpher-current-page)
+ (buffer-string))))
+
+(defun elpher-render-gemini-plain-text (data _parameters)
+ "Render DATA as plain text file. PARAMETERS is currently unused."
+ (elpher-with-clean-buffer
+ (insert (elpher-process-text-for-display data))
+ (elpher-cache-content
+ (elpher-page-address elpher-current-page)
+ (buffer-string))))
+
+
+;; Finger page connection
+
+(defun elpher-get-finger-page (renderer)
+ "Opens a finger connection to the current page address.
+The result is rendered using RENDERER."
+ (let* ((address (elpher-page-address elpher-current-page))
+ (content (elpher-get-cached-content address)))
+ (if (and content (funcall renderer nil))
(elpher-with-clean-buffer
- (insert elpher-start-index))
- (goto-char (point-min)))))
- (message "Displaying raw server response. Reload or redraw to return to standard view."))
-
-;; File export retrieval
-
-(defvar elpher-download-filename)
-
-(defun elpher-get-node-download ()
- "Getter which retrieves the current node and writes the result to a file."
- (let* ((address (elpher-node-address elpher-current-node))
- (selector (elpher-address-selector address)))
- (elpher-visit-parent-node) ; Do first in case of non-local exits.
- (let* ((filename-proposal (file-name-nondirectory selector))
- (filename (read-file-name "Save file as: "
- nil nil nil
- (if (> (length filename-proposal) 0)
- filename-proposal
- "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)))))))))
-
-
-;;; Navigation procedures
+ (insert content)
+ (elpher-restore-pos))
+ (elpher-with-clean-buffer
+ (insert "LOADING... (use 'u' to cancel)\n"))
+ (condition-case the-error
+ (let* ((kill-buffer-query-functions nil)
+ (user (let ((filename (elpher-address-filename address)))
+ (if (> (length filename) 1)
+ (substring filename 1)
+ (elpher-address-user address)))))
+ (elpher-get-host-response address 79
+ (concat user "\r\n")
+ renderer))
+ (error
+ (elpher-network-error address the-error))))))
+
+
+;; Telnet page connection
+
+(defun elpher-get-telnet-page (renderer)
+ "Opens a telnet connection to the current page address (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-previous-page)
+ (error "Command not supported for telnet URLs"))
+ (let* ((address (elpher-page-address elpher-current-page))
+ (host (elpher-address-host address))
+ (port (elpher-address-port address)))
+ (elpher-visit-previous-page)
+ (if (> port 0)
+ (telnet host port)
+ (telnet host))))
+
+
+;; Other URL page opening
+
+(defun elpher-get-other-url-page (renderer)
+ "Getter which attempts to open the URL specified by the current page (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-previous-page)
+ (error "Command not supported for general URLs"))
+ (let* ((address (elpher-page-address elpher-current-page))
+ (url (elpher-address-to-url address)))
+ (progn
+ (elpher-visit-previous-page) ; Do first in case of non-local exits.
+ (message "Opening URL...")
+ (if elpher-open-urls-with-eww
+ (browse-web url)
+ (browse-url url)))))
+
+
+;; Start page page retrieval
+
+(defun elpher-get-start-page (renderer)
+ "Getter which displays the start page (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-previous-page)
+ (error "Command not supported for start page"))
+ (elpher-with-clean-buffer
+ (insert " --------------------------------------------\n"
+ " Elpher Gopher and Gemini Client \n"
+ " version " elpher-version "\n"
+ " --------------------------------------------\n"
+ "\n"
+ "Default bindings:\n"
+ "\n"
+ " - TAB/Shift-TAB: next/prev item on current page\n"
+ " - RET/mouse-1: open item under cursor\n"
+ " - m: select an item on current page by name (autocompletes)\n"
+ " - u/mouse-3/U: return to previous page or to the start page\n"
+ " - o/O: visit different selector or the root menu of the current server\n"
+ " - g: go to a particular address (gopher, gemini, finger)\n"
+ " - d/D: download item under cursor or current page\n"
+ " - i/I: info on item under cursor or current page\n"
+ " - c/C: copy URL representation of item under cursor or current page\n"
+ " - a/A: bookmark the item under cursor or current page\n"
+ " - x/X: remove bookmark for item under cursor or current page\n"
+ " - B: visit the bookmarks page\n"
+ " - r: redraw current page (using cached contents if available)\n"
+ " - R: reload current page (regenerates cache)\n"
+ " - S: set character coding system for gopher (default is to autodetect)\n"
+ " - T: toggle TLS gopher mode\n"
+ " - F: forget/discard current TLS client certificate\n"
+ " - .: display the raw server response for the current page\n"
+ "\n"
+ "Start your exploration of gopher space and gemini:\n")
+ (elpher-insert-index-record "Floodgap Systems Gopher Server"
+ (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
+ (elpher-insert-index-record "Project Gemini home page"
+ (elpher-address-from-url "gemini://gemini.circumlunar.space/"))
+ (insert "\n"
+ "Alternatively, select a search engine and enter some search terms:\n")
+ (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"
+ (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
+ (elpher-insert-index-record "Gemini Search Engine (GUS)"
+ (elpher-address-from-url "gemini://gus.guru/search"))
+ (insert "\n"
+ "This page contains your bookmarked sites (also visit with B):\n")
+ (elpher-insert-index-record "Your Bookmarks" 'bookmarks)
+ (insert "\n"
+ "For Elpher release news or to leave feedback, visit:\n")
+ (elpher-insert-index-record "The Elpher Project Page"
+ (elpher-make-gopher-address ?1
+ "/projects/elpher/"
+ "thelambdalab.xyz"
+ 70))
+ (insert "\n"
+ "** Refer to the ")
+ (let ((help-string "RET,mouse-1: Open Elpher info manual (if available)"))
+ (insert-text-button "Elpher info manual"
+ 'face 'link
+ 'action (lambda (_)
+ (interactive)
+ (info "(elpher)"))
+ 'follow-link t
+ 'help-echo help-string))
+ (insert " for the full documentation. **\n")
+ (insert (propertize
+ (concat " (This should be available if you have installed Elpher using\n"
+ " MELPA. Otherwise you will have to install the manual yourself.)\n")
+ 'face 'shadow))
+ (elpher-restore-pos)))
+
+;; Bookmarks page page retrieval
+
+(defun elpher-get-bookmarks-page (renderer)
+ "Getter to load and display the current bookmark list (RENDERER must be nil)."
+ (when renderer
+ (elpher-visit-previous-page)
+ (error "Command not supported for bookmarks page"))
+ (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-address-from-url (elpher-bookmark-url 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 ")
+ (let ((filename elpher-bookmarks-file)
+ (help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
+ (insert-text-button filename
+ 'face 'link
+ 'action (lambda (_)
+ (interactive)
+ (find-file filename))
+ 'follow-link t
+ 'help-echo help-string))
+ (insert "\n")
+ (elpher-restore-pos)))
+
+
+;;; Bookmarks
+;;
+
+(defun elpher-make-bookmark (display-string url)
+ "Make an elpher bookmark.
+DISPLAY-STRING determines how the bookmark will appear in the
+bookmark list, while URL is the url of the entry."
+ (list display-string url))
+
+(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-url (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 elpher-bookmarks-file
+ (erase-buffer)
+ (insert "; Elpher bookmarks file\n\n"
+ "; Bookmarks are stored as a list of (label URL) items.\n"
+ "; Feel free to edit by hand, but take care to ensure\n"
+ "; the list structure remains intact.\n\n")
+ (pp bookmarks (current-buffer))))
+
+(defun elpher-load-bookmarks ()
+ "Get the list of bookmarks from the users's bookmark file."
+ (let ((bookmarks
+ (with-temp-buffer
+ (ignore-errors
+ (insert-file-contents elpher-bookmarks-file)
+ (goto-char (point-min))
+ (read (current-buffer))))))
+ (if (and bookmarks (listp (cadar bookmarks)))
+ (progn
+ (message "Reading old bookmark file. (Will be updated on write.)")
+ (mapcar (lambda (old-bm)
+ (list (car old-bm)
+ (elpher-address-to-url (apply #'elpher-make-gopher-address
+ (cadr old-bm)))))
+ bookmarks))
+ bookmarks)))
+
+(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))
+ (url (elpher-address-to-url address)))
+ (let ((existing-bookmark (rassoc (list url) bookmarks)))
+ (if existing-bookmark
+ (elpher-set-bookmark-display-string existing-bookmark display-string)
+ (push (elpher-make-bookmark display-string url) bookmarks)))
+ (elpher-save-bookmarks bookmarks)))
+
+(defun elpher-remove-address-bookmark (address)
+ "Remove any bookmark to ADDRESS."
+ (let ((url (elpher-address-to-url address)))
+ (elpher-save-bookmarks
+ (seq-filter (lambda (bookmark)
+ (not (equal (elpher-bookmark-url bookmark) url)))
+ (elpher-load-bookmarks)))))
+
+;;; Interactive procedures
;;
(defun elpher-next-link ()
(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."
+(defun elpher-go (host-or-url)
+ "Go to a particular gopher site HOST-OR-URL.
+When run interactively HOST-OR-URL is read from the minibuffer."
+ (interactive "sGopher or Gemini URL: ")
+ (let* ((cleaned-host-or-url (string-trim host-or-url))
+ (address (elpher-address-from-url cleaned-host-or-url))
+ (page (elpher-make-page cleaned-host-or-url address)))
+ (switch-to-buffer elpher-buffer-name)
+ (elpher-visit-page page)
+ nil))
+
+(defun elpher-go-current ()
+ "Go to a particular site read from the minibuffer, initialized with the current URL."
(interactive)
- (switch-to-buffer "*elpher*")
- (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 ((address (elpher-page-address elpher-current-page)))
+ (if (elpher-address-special-p address)
+ (error "Command invalid for this page")
+ (let ((url (read-string "Gopher or Gemini URL: " (elpher-address-to-url address))))
+ (elpher-visit-page (elpher-make-page url (elpher-address-from-url url)))))))
+
+(defun elpher-redraw ()
"Redraw current page."
(interactive)
- (if elpher-current-node
- (elpher-visit-node elpher-current-node)
- (message "No current site.")))
+ (elpher-visit-page elpher-current-page))
-(defun elpher-reload ()
+(defun elpher-reload ()
"Reload current page."
(interactive)
- (if elpher-current-node
- (elpher-reload-current-node)
- (message "No current site.")))
+ (elpher-reload-current-page))
+
+(defun elpher-toggle-tls ()
+ "Toggle TLS encryption mode for gopher."
+ (interactive)
+ (setq elpher-use-tls (not elpher-use-tls))
+ (if elpher-use-tls
+ (if (gnutls-available-p)
+ (message "TLS gopher mode enabled. (Will not affect current page until reload.)")
+ (setq elpher-use-tls nil)
+ (error "Cannot enable TLS gopher mode: GnuTLS not available"))
+ (message "TLS gopher 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)
- (if elpher-current-node
- (elpher-visit-node elpher-current-node
- #'elpher-get-node-raw)
- (message "No current site.")))
+ (if (elpher-address-special-p (elpher-page-address elpher-current-page))
+ (error "This page was not generated by a server")
+ (elpher-visit-page elpher-current-page
+ #'elpher-render-raw)))
(defun elpher-back ()
"Go to previous site."
(interactive)
- (if (elpher-node-parent elpher-current-node)
- (elpher-visit-parent-node)
- (message "No previous site.")))
+ (elpher-visit-previous-page))
+
+(defun elpher-back-to-start ()
+ "Go all the way back to the start page."
+ (interactive)
+ (setq elpher-current-page nil)
+ (setq elpher-history nil)
+ (let ((start-page (elpher-make-page "Elpher Start Page"
+ (elpher-make-special-address 'start))))
+ (elpher-visit-page start-page)))
(defun elpher-download ()
"Download the link at point."
(interactive)
(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."))))
+ (let ((page (button-get button 'elpher-page)))
+ (if (elpher-address-special-p (elpher-page-address page))
+ (error "Cannot download %s"
+ (elpher-page-display-string page))
+ (elpher-visit-page (button-get button 'elpher-page)
+ #'elpher-render-download)))
+ (error "No link selected"))))
+
+(defun elpher-download-current ()
+ "Download the current page."
+ (interactive)
+ (if (elpher-address-special-p (elpher-page-address elpher-current-page))
+ (error "Cannot download %s"
+ (elpher-page-display-string elpher-current-page))
+ (elpher-visit-page (elpher-make-page
+ (elpher-page-display-string elpher-current-page)
+ (elpher-page-address elpher-current-page))
+ #'elpher-render-download
+ t)))
(defun elpher-build-link-map ()
- "Build alist mapping link names to destination nodes in current buffer."
+ "Build alist mapping link names to destination pages in current buffer."
(let ((link-map nil)
(b (next-button (point-min) t)))
(while b
- (add-to-list 'link-map (cons (button-label b) b))
+ (push (cons (button-label b) b) link-map)
(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 "Directory entry/link (tab to autocomplete): "
+ (completing-read "Directory item/link: "
link-map nil t))))
(if (and key (> (length key) 0))
(let ((b (cdr (assoc key link-map))))
(defun elpher-root-dir ()
"Visit root of current server."
(interactive)
- (let ((address (elpher-node-address elpher-current-node)))
- (if address
- (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 "" host port)))
- (elpher-visit-node (elpher-make-node elpher-current-node
- root-address
- #'elpher-get-index-node)))
- (message "Already at root directory of current server.")))
- (message "Command invalid for Elpher start page."))))
+ (let ((address (elpher-page-address elpher-current-page)))
+ (if (not (elpher-address-special-p address))
+ (if (or (member (url-filename address) '("/" ""))
+ (and (elpher-address-gopher-p address)
+ (= (length (elpher-gopher-address-selector address)) 0)))
+ (error "Already at root directory of current server")
+ (let ((address-copy (elpher-address-from-url
+ (elpher-address-to-url address))))
+ (setf (url-filename address-copy) "")
+ (elpher-go (elpher-address-to-url address-copy))))
+ (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
+
+(defun elpher-bookmarks-current-p ()
+ "Return non-nil if current page is a bookmarks page."
+ (equal (elpher-address-type (elpher-page-address elpher-current-page))
+ '(special bookmarks)))
+
+(defun elpher-reload-bookmarks ()
+ "Reload bookmarks if current page is a bookmarks page."
+ (if (elpher-bookmarks-current-p)
+ (elpher-reload-current-page)))
+
+(defun elpher-bookmark-current ()
+ "Bookmark the current page."
+ (interactive)
+ (let ((address (elpher-page-address elpher-current-page))
+ (display-string (elpher-page-display-string elpher-current-page)))
+ (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* ((page (button-get button 'elpher-page))
+ (address (elpher-page-address page))
+ (display-string (elpher-page-display-string page)))
+ (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 page."
+ (interactive)
+ (let ((address (elpher-page-address elpher-current-page)))
+ (when (and (not (elpher-address-special-p address))
+ (y-or-n-p "Really remove bookmark for the current page? "))
+ (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
+ (when (y-or-n-p "Really remove bookmark for this link? ")
+ (let ((page (button-get button 'elpher-page)))
+ (elpher-remove-address-bookmark (elpher-page-address page))
+ (elpher-reload-bookmarks)
+ (message "Bookmark removed.")))
+ (error "No link selected"))))
+
+(defun elpher-bookmarks ()
+ "Visit bookmarks page."
+ (interactive)
+ (switch-to-buffer elpher-buffer-name)
+ (elpher-visit-page
+ (elpher-make-page "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
+
+(defun elpher-info-page (page)
+ "Display information on PAGE."
+ (let ((display-string (elpher-page-display-string page))
+ (address (elpher-page-address page)))
+ (if (elpher-address-special-p address)
+ (message "Special page: %s" display-string)
+ (message "%s" (elpher-address-to-url address)))))
+
+(defun elpher-info-link ()
+ "Display information on page corresponding to link at point."
+ (interactive)
+ (let ((button (button-at (point))))
+ (if button
+ (elpher-info-page (button-get button 'elpher-page))
+ (error "No item selected"))))
+
+(defun elpher-info-current ()
+ "Display information on current page."
+ (interactive)
+ (elpher-info-page elpher-current-page))
+
+(defun elpher-copy-page-url (page)
+ "Copy URL representation of address of PAGE to `kill-ring'."
+ (let ((address (elpher-page-address page)))
+ (if (elpher-address-special-p address)
+ (error (format "Cannot represent %s as URL" (elpher-page-display-string page)))
+ (let ((url (elpher-address-to-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-page-url (button-get button 'elpher-page))
+ (error "No item selected"))))
+
+(defun elpher-copy-current-url ()
+ "Copy URL of current page to `kill-ring'."
+ (interactive)
+ (elpher-copy-page-url elpher-current-page))
+
+(defun elpher-set-gopher-coding-system ()
+ "Specify an explicit character coding system for gopher selectors."
+ (interactive)
+ (let ((system (read-coding-system "Set coding system to use for gopher (default is to autodetect): " nil)))
+ (setq elpher-user-coding-system system)
+ (if system
+ (message "Gopher coding system fixed to %s. (Reload to see effect)." system)
+ (message "Gopher coding system set to autodetect. (Reload to see effect)."))))
+
;;; Mode and keymap
;;
(let ((map (make-sparse-keymap)))
(define-key map (kbd "TAB") 'elpher-next-link)
(define-key map (kbd "<backtab>") 'elpher-prev-link)
+ (define-key map (kbd "C-M-i") 'elpher-prev-link)
(define-key map (kbd "u") 'elpher-back)
+ (define-key map (kbd "U") 'elpher-back-to-start)
+ (define-key map [mouse-3] 'elpher-back)
(define-key map (kbd "O") 'elpher-root-dir)
(define-key map (kbd "g") 'elpher-go)
+ (define-key map (kbd "o") 'elpher-go-current)
(define-key map (kbd "r") 'elpher-redraw)
(define-key map (kbd "R") 'elpher-reload)
- (define-key map (kbd "w") 'elpher-view-raw)
+ (define-key map (kbd "T") 'elpher-toggle-tls)
+ (define-key map (kbd ".") 'elpher-view-raw)
(define-key map (kbd "d") 'elpher-download)
- (define-key map (kbd "m") 'elpher-menu)
- (when (fboundp 'evil-define-key)
- (evil-define-key 'normal map
+ (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-gopher-coding-system)
+ (define-key map (kbd "F") 'elpher-forget-current-certificate)
+ (when (fboundp 'evil-define-key*)
+ (evil-define-key* 'motion map
(kbd "TAB") 'elpher-next-link
- (kbd "C-]") 'elpher-follow-current-link
+ (kbd "C-") 'elpher-follow-current-link
(kbd "C-t") 'elpher-back
(kbd "u") 'elpher-back
- (kbd "O") 'elpher-root-dir
+ (kbd "U") 'elpher-back-to-start
+ [mouse-3] 'elpher-back
(kbd "g") 'elpher-go
+ (kbd "o") 'elpher-go-current
(kbd "r") 'elpher-redraw
(kbd "R") 'elpher-reload
- (kbd "w") 'elpher-view-raw
+ (kbd "T") 'elpher-toggle-tls
+ (kbd ".") '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-gopher-coding-system
+ (kbd "F") 'elpher-forget-current-certificate))
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'."
+ (setq-local elpher-current-page nil)
+ (setq-local elpher-history nil)
+ (setq-local elpher-buffer-name (buffer-name)))
+
+(when (fboundp 'evil-set-initial-state)
+ (evil-set-initial-state 'elpher-mode 'motion))
;;; Main start procedure
;;
;;;###autoload
-(defun elpher ()
- "Start elpher with default landing page."
- (interactive)
- (if (get-buffer "*elpher*")
- (switch-to-buffer "*elpher*")
- (switch-to-buffer "*elpher*")
- (setq elpher-current-node nil)
- (let ((start-node (elpher-make-node nil
- elpher-start-address
- #'elpher-get-index-node)))
- (elpher-visit-node start-node)))
- "Started Elpher.") ; Otherwise (elpher) evaluates to start page string.
+(defun elpher (&optional arg)
+ "Start elpher with default landing page.
+The buffer used for Elpher sessions is determined by the value of
+‘elpher-buffer-name’. If there is already an Elpher session active in
+that buffer, Emacs will simply switch to it. Otherwise, a new session
+will begin. A numeric prefix arg (as in ‘C-u 42 M-x elpher RET’)
+switches to the session with that number, creating it if necessary. A
+nonnumeric prefix arg means to create a new session. Returns the
+buffer selected (or created)."
+ (interactive "P")
+ (let* ((name (default-value 'elpher-buffer-name))
+ (buf (cond ((numberp arg)
+ (get-buffer-create (format "%s<%d>" name arg)))
+ (arg
+ (generate-new-buffer name))
+ (t
+ (get-buffer-create name)))))
+ (pop-to-buffer-same-window buf)
+ (unless (buffer-modified-p)
+ (let ((elpher-buffer-name (buffer-name)); for elpher-with-clean-buffer
+ (start-page (elpher-make-page "Elpher Start Page"
+ (elpher-make-special-address 'start))))
+ (elpher-visit-page start-page))
+ "Started Elpher."))) ; Otherwise (elpher) evaluates to start page string.
;;; elpher.el ends here