;; Author: Tim Vaughan <tgvaughan@gmail.com>
;; Created: 11 April 2019
-;; Version: 1.2.3
+;; Version: 1.4.3
;; Keywords: comm gopher
;; Homepage: https://github.com/tgvaughan/elpher
;; Package-Requires: ((emacs "25"))
;;; Commentary:
-;; Elpher aims to provide a practical 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 interface,
+;; - 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,
-;; - a simple bookmark management system.
-
-;; 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,
+;; - 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 and other options 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:
;;; Global constants
;;
-(defconst elpher-version "1.2.3"
+(defconst elpher-version "1.4.3"
"Current version of elpher.")
(defconst elpher-margin-width 6
"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 menu or item\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 - 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"
"iWhere to start exploring Gopherspace:\tfake\tfake\t1"
"i\tfake\tfake\t1"
"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)
- (?4 elpher-get-node-download "B" elpher-binary)
- (?5 elpher-get-node-download "B" elpher-binary)
+ (?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 "?" elpher-telnet)
- (?9 elpher-get-node-download "B" elpher-binary)
- (?g elpher-get-image-node "im" elpher-image)
- (?p elpher-get-image-node "im" elpher-image)
- (?I elpher-get-image-node "im" elpher-image)
- (?d elpher-get-node-download "d" elpher-binary)
- (?h elpher-get-url-node "W" elpher-url)
+ (?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.")
"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
;;
;; Address
-(defun elpher-make-address (type &optional 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."
- (list type selector host port))
+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."
"Retrieve port from 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)))
args)))
-;;; Index rendering
+;;; 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)
- "Clear away CRs and terminating period from STRING."
- (replace-regexp-in-string "\n\.\n$" "\n"
- (replace-regexp-in-string "\r" ""
- string)))
+ "Preprocess text selector response contained in STRING.
+This involes decoding the character representation, and clearing
+away CRs and any terminating period."
+ (elpher-decode (replace-regexp-in-string "\n\.\n$" "\n"
+ (replace-regexp-in-string "\r" "" string))))
+
+;;; Index rendering
+;;
(defun elpher-insert-index (string)
"Insert the index corresponding to STRING into the current buffer."
(host (elt fields 2))
(port (if (elt fields 3)
(string-to-number (elt fields 3))
- nil)))
- (elpher-insert-index-record display-string type selector host port))))))
+ 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."
(elpher-address-host address)
(elpher-address-port address)))))
-(defun elpher-insert-index-record (display-string type selector host port)
+
+(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 TYPE, DISPLAY-STRING, SELECTOR, HOST
-and PORT."
- (let ((address (elpher-make-address type selector host port))
- (type-map-entry (alist-get type elpher-type-map)))
+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* ((margin-code (elt type-map-entry 1))
(face (elt type-map-entry 2))
(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 "")
- (condition-case nil
- (progn
- (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"
+ (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
- (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.")))))
+ (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
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 (string= protocol "gopher")
+ (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))
(selector (if (> (length type-and-selector) 1)
(substring type-and-selector 2)
""))
- (address (elpher-make-address type selector host port)))
+ (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)
(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)
"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
(dolist (bookmark bookmarks)
(let ((display-string (elpher-bookmark-display-string bookmark))
(address (elpher-bookmark-address bookmark)))
- (elpher-insert-index-record display-string
- (elpher-address-type address)
- (elpher-address-selector address)
- (elpher-address-host address)
- (elpher-address-port address))))
+ (elpher-insert-index-record display-string address)))
(insert "No bookmarks found.\n")))
(insert "\n-----------------------\n\n"
"- u: return to previous page\n"
(switch-to-buffer "*elpher*")
(elpher-visit-node node)))
-(defun elpher-redraw ()
+(defun elpher-redraw ()
"Redraw current page."
(interactive)
(if elpher-current-node
(elpher-visit-node elpher-current-node)
(message "No current site.")))
-(defun elpher-reload ()
+(defun elpher-reload ()
"Reload current page."
(interactive)
(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 raw server response for current page."
(interactive)
#'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."
(let ((link-map nil)
(defun elpher-bookmark-current ()
"Bookmark the current node."
(interactive)
- (unless (elpher-bookmarks-current-p)
- (let ((address (elpher-node-address elpher-current-node))
- (display-string (read-string "Bookmark display string: "
- (elpher-node-display-string elpher-current-node))))
- (elpher-add-address-bookmark address display-string)
- (message "Bookmark added."))))
+ (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."
(if button
(let* ((node (button-get button 'elpher-node))
(address (elpher-node-address node))
- (display-string (read-string "Bookmark display string: "
- (elpher-node-display-string node))))
- (elpher-add-address-bookmark address display-string)
- (elpher-reload-bookmarks)
- (message "Bookmark added."))
+ (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)
- (unless (elpher-bookmarks-current-p)
- (elpher-remove-address-bookmark (elpher-node-address elpher-current-node))
- (message "Bookmark removed.")))
+ (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."
(error "No link selected"))))
(defun elpher-bookmarks ()
- "Visit bookmarks."
+ "Visit bookmarks page."
(interactive)
(switch-to-buffer "*elpher*")
(elpher-visit-node
- (elpher-make-node "Bookmarks" (elpher-make-address 'bookmarks))))
+ (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 address
+ (if (not (elpher-address-special-p address))
(message "`%s' on %s port %s"
(elpher-address-selector address)
(elpher-address-host address)
(defun elpher-get-address-url (address)
"Get URL representation of ADDRESS."
- (concat "gopher://"
- (elpher-address-host address)
- (let ((port (elpher-address-port address)))
- (if (equal port 70)
- ""
- (format ":%d" port)))
- "/" (string (elpher-address-type address))
- (elpher-address-selector 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 address
- (let ((url (elpher-get-address-url address)))
- (message url)
- (kill-new url))
- (error (format "Cannot represent %s as URL" (elpher-node-display-string 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)
(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
;;
(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 "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 "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 'motion map
(kbd "TAB") 'elpher-next-link
(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 "D") 'elpher-download-current
(kbd "m") 'elpher-jump
(kbd "i") 'elpher-info-link
(kbd "I") 'elpher-info-current
(kbd "A") 'elpher-bookmark-current
(kbd "x") 'elpher-unbookmark-link
(kbd "X") 'elpher-unbookmark-current
- (kbd "B") 'elpher-bookmarks))
+ (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))
The Lambda Lab / projects / elpher.git / blobdiff