-;;; elopher.el --- gopher client
+;;; elopher.el --- elisp gopher client
;;; Commentary:
-;; Simple gopher client in elisp.
+;; An elisp gopher client.
;;; Code:
"Width of left-hand margin used when rendering indicies.")
(defconst elopher-start-index
- (string-join
+ (mapconcat
+ 'identity
(list "i\tfake\tfake\t1"
"i--------------------------------------------\tfake\tfake\t1"
"i Elopher Gopher Client \tfake\tfake\t1"
"i--------------------------------------------\tfake\tfake\t1"
"i\tfake\tfake\t1"
"iBasic usage:\tfake\tfake\t1"
- "i - tab/shift-tab: next/prev directory entry\tfake\tfake\t1"
- "i - RET/mouse-1: open directory entry\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 - u: return to parent directory entry\tfake\tfake\t1"
- "i - g: go to a particular site\tfake\tfake\t1"
- "i - r: reload current page\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"
- "1Super-Dimensional Fortress\t\tsdf.org\t70"
"i\tfake\tfake\t1"
- "iTest entries:\tfake\tfake\t1"
- "pXKCD comic image\t/fun/xkcd/comics/2130/2137/text_entry.png\tgopher.floodgap.com\t70"
- "1Test server\t\tlocalhost\t70"
+ "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 elopher start page.")
;;; Customization group
;;
(defgroup elopher nil
- "A simple gopher client."
+ "A gopher client."
:group 'applications)
-(defcustom elopher-index-face '(foreground-color . "cyan")
+(defface elopher-index
+ '((((background dark)) :foreground "deep sky blue")
+ (((background light)) :foreground "blue"))
"Face used for index records.")
-(defcustom elopher-text-face '(foreground-color . "white")
+
+(defface elopher-text
+ '((((background dark)) :foreground "white")
+ (((background light)) :weight bold))
"Face used for text records.")
-(defcustom elopher-info-face '(foreground-color . "gray")
+
+(defface elopher-info '()
"Face used for info records.")
-(defcustom elopher-image-face '(foreground-color . "green")
+
+(defface elopher-image
+ '((((background dark)) :foreground "green")
+ (t :foreground "dark green"))
"Face used for image records.")
-(defcustom elopher-unknown-face '(foreground-color . "red")
+
+(defface elopher-search
+ '((((background light)) :foreground "orange")
+ (((background dark)) :foreground "dark orange"))
+ "Face used for search records.")
+
+(defface elopher-url
+ '((((background dark)) :foreground "yellow")
+ (((background light)) :foreground "dark red"))
+ "Face used for url records.")
+
+(defface elopher-binary
+ '((t :foreground "magenta"))
+ "Face used for binary records.")
+
+(defface elopher-unknown
+ '((t :foreground "red"))
"Face used for unknown record types.")
+(defface elopher-margin-key
+ '((((background dark)) :foreground "white"))
+ "Face used for margin key.")
+
+(defface elopher-margin-brackets
+ '((t :foreground "blue"))
+ "Face used for brackets around margin key.")
+
+(defcustom elopher-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))
+
;;; Model
;;
;; Address
(defun elopher-make-address (selector host port)
+ "Create an address of a gopher object with SELECTOR, HOST and PORT."
(list selector host port))
(defun elopher-address-selector (address)
+ "Retrieve selector from ADDRESS."
(car address))
(defun elopher-address-host (address)
+ "Retrieve host from ADDRESS."
(cadr address))
(defun elopher-address-port (address)
+ "Retrieve port from ADDRESS."
(caddr address))
;; Node
(defun elopher-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.
+
+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))
(defun elopher-node-parent (node)
+ "Retrieve the parent node of NODE."
(elt node 0))
(defun elopher-node-address (node)
+ "Retrieve the address of NODE."
(elt node 1))
(defun elopher-node-getter (node)
+ "Retrieve the preferred getter function of NODE."
(elt node 2))
(defun elopher-node-content (node)
+ "Retrieve the cached content of NODE, or nil if none exists."
(elt node 3))
(defun elopher-node-pos (node)
+ "Retrieve the cached cursor position for NODE, or nil if none exists."
(elt node 4))
(defun elopher-set-node-content (node content)
+ "Set the content cache of NODE to CONTENT."
(setcar (nthcdr 3 node) content))
(defun elopher-set-node-pos (node pos)
+ "Set the cursor position cache of NODE to POS."
(setcar (nthcdr 4 node) pos))
(defun elopher-save-pos ()
+ "Save the current position of point to the current node."
(when elopher-current-node
(elopher-set-node-pos elopher-current-node (point))))
(defun elopher-restore-pos ()
+ "Restore the position of point to that cached in the current node."
(let ((pos (elopher-node-pos elopher-current-node)))
(if pos
(goto-char pos)
(defvar elopher-current-node)
-(defun elopher-visit-node (node)
+(defun elopher-visit-node (node &optional getter)
+ "Visit NODE using its own getter or GETTER, if non-nil."
(elopher-save-pos)
- (elopher-prepare-buffer)
+ (elopher-process-cleanup)
(setq elopher-current-node node)
- (funcall (elopher-node-getter node)))
+ (if getter
+ (funcall getter)
+ (funcall (elopher-node-getter node))))
(defun elopher-visit-parent-node ()
+ "Visit the parent of the current node."
(let ((parent-node (elopher-node-parent elopher-current-node)))
(when parent-node
(elopher-visit-node parent-node))))
(defun elopher-reload-current-node ()
+ "Reload the current node, discarding any existing cached content."
(elopher-set-node-content elopher-current-node nil)
(elopher-visit-node elopher-current-node))
-
;;; Buffer preparation
;;
-(defun elopher-prepare-buffer ()
- (switch-to-buffer "*elopher*")
- (elopher-mode)
- (let ((inhibit-read-only t))
- (erase-buffer)))
-
+(defmacro elopher-with-clean-buffer (&rest args)
+ "Evaluate ARGS with a clean *elopher* buffer as current."
+ (list 'progn
+ '(switch-to-buffer "*elopher*")
+ '(elopher-mode)
+ (append (list 'let '((inhibit-read-only t))
+ '(erase-buffer))
+ args)))
;;; Index rendering
;;
(defun elopher-insert-index (string)
- "Inserts the index corresponding to STRING into the current buffer."
+ "Insert the index corresponding to STRING into the current buffer."
(dolist (line (split-string string "\r\n"))
- (unless (string-empty-p line)
+ (unless (= (length line) 0)
(elopher-insert-index-record line))))
(defun elopher-insert-margin (&optional type-name)
(progn
(insert (format (concat "%" (number-to-string (- elopher-margin-width 1)) "s")
(concat
- (propertize "[" 'face '(foreground-color . "blue"))
- (propertize type-name 'face '(foreground-color . "white"))
- (propertize "]" 'face '(foreground-color . "blue")))))
+ (propertize "[" 'face 'elopher-margin-brackets)
+ (propertize type-name 'face 'elopher-margin-key)
+ (propertize "]" 'face 'elopher-margin-brackets))))
(insert " "))
(insert (make-string elopher-margin-width ?\s))))
+(defvar elopher-type-map
+ '((?0 elopher-get-text-node "T" elopher-text)
+ (?1 elopher-get-index-node "/" elopher-index)
+ (?g elopher-get-image-node "im" elopher-image)
+ (?p elopher-get-image-node "im" elopher-image)
+ (?I elopher-get-image-node "im" elopher-image)
+ (?4 elopher-get-node-download "B" elopher-binary)
+ (?5 elopher-get-node-download "B" elopher-binary)
+ (?9 elopher-get-node-download "B" elopher-binary)
+ (?7 elopher-get-search-node "?" elopher-search))
+ "Association list from types to getters, margin codes and index faces.")
+
(defun elopher-insert-index-record (line)
- "Inserts the index record corresponding to LINE into the current buffer."
+ "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))
- (address (elopher-make-address (elt fields 1) (elt fields 2) (elt fields 3)))
- (help-string (format "mouse-1, RET: open %s on %s port %s"
- (elopher-address-selector address)
- (elopher-address-host address)
- (elopher-address-port address))))
- (pcase type
- (?i (elopher-insert-margin)
- (insert (propertize display-string
- 'face elopher-info-face)))
- (?0 (elopher-insert-margin "T")
+ (selector (elt fields 1))
+ (host (elt fields 2))
+ (port (elt fields 3))
+ (address (elopher-make-address selector host port))
+ (type-map-entry (alist-get type elopher-type-map)))
+ (if type-map-entry
+ (let ((getter (car type-map-entry))
+ (margin-code (cadr type-map-entry))
+ (face (caddr type-map-entry)))
+ (elopher-insert-margin margin-code)
(insert-text-button display-string
- 'face elopher-text-face
+ 'face face
'elopher-node (elopher-make-node elopher-current-node
address
- #'elopher-get-text-node)
+ getter)
'action #'elopher-click-link
'follow-link t
- 'help-echo help-string))
- (?1 (elopher-insert-margin "/")
- (insert-text-button display-string
- 'face elopher-index-face
- 'elopher-node (elopher-make-node elopher-current-node
- address
- #'elopher-get-index-node)
- 'action #'elopher-click-link
- 'follow-link t
- 'help-echo help-string))
- (?.) ; Occurs at end of index, can safely ignore.
- (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
- (insert (propertize display-string
- 'face elopher-unknown-face))))
+ 'help-echo (format "mouse-1, RET: open %s on %s port %s"
+ selector host port)))
+ (pcase type
+ (?i (elopher-insert-margin) ; Information
+ (insert (propertize display-string
+ 'face 'elopher-info)))
+ (?h (elopher-insert-margin "W") ; Web link
+ (let ((url (elt (split-string selector "URL:") 1)))
+ (insert-text-button display-string
+ 'face 'elopher-url
+ 'elopher-url url
+ 'action #'elopher-click-url
+ 'follow-link t
+ 'help-echo (format "mouse-1, RET: open url %s" url))))
+ (?.) ; Occurs at end of index, can safely ignore.
+ (tp (elopher-insert-margin (concat (char-to-string tp) "?"))
+ (insert (propertize display-string
+ 'face 'elopher-unknown-face)))))
(insert "\n")))
;;; Selector retrieval (all kinds)
;;
+(defun elopher-process-cleanup ()
+ "Immediately shut down any extant elopher process."
+ (let ((p (get-process "elopher-process")))
+ (if p (delete-process p))))
+
(defvar elopher-selector-string)
(defun elopher-get-selector (address after)
+ "Retrieve selector specified by ADDRESS, then execute AFTER.
+The result is stored as a string in the variable elopher-selector-string."
(setq elopher-selector-string "")
- (let ((p (get-process "elopher-process")))
- (if p (delete-process p)))
(make-network-process
:name "elopher-process"
:host (elopher-address-host address)
(address (elopher-node-address elopher-current-node)))
(if content
(progn
- (let ((inhibit-read-only t))
- (insert content))
+ (elopher-with-clean-buffer
+ (insert content))
(elopher-restore-pos))
(if address
- (elopher-get-selector address
- (lambda (proc event)
- (let ((inhibit-read-only t))
- (elopher-insert-index elopher-selector-string))
- (elopher-restore-pos)
- (elopher-set-node-content elopher-current-node
- (buffer-string))))
+ (progn
+ (elopher-with-clean-buffer
+ (insert "LOADING DIRECTORY..."))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (unless (string-prefix-p "deleted" event)
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-selector-string))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string))))))
(progn
- (let ((inhibit-read-only t))
- (elopher-insert-index elopher-start-index))
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-start-index))
(elopher-restore-pos)
(elopher-set-node-content elopher-current-node
(buffer-string)))))))
;; Text retrieval
-(defun elopher-strip-CRs (string)
- (replace-regexp-in-string "\r" "" string))
+(defconst elopher-url-regex "\\(https?\\|gopher\\)://\\([a-zA-Z0-9.\-]+\\)\\(?3::[0-9]+\\)?\\(?4:/[^ \r\n\t(),]*\\)?"
+ "Regexp used to locate and buttinofy URLs in text files loaded by elopher.")
+
+(defun elopher-buttonify-urls (string)
+ "Turn substrings which look like urls in STRING into clickable buttons."
+ (with-temp-buffer
+ (insert string)
+ (goto-char (point-min))
+ (while (re-search-forward elopher-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 (elopher-make-address selector host port))
+ (getter (car (alist-get type elopher-type-map))))
+ (make-text-button (match-beginning 0)
+ (match-end 0)
+ 'elopher-node (elopher-make-node elopher-current-node
+ address
+ getter)
+ 'action #'elopher-click-link
+ 'follow-link t
+ 'help-echo (format "mouse-1, RET: open %s on %s port %s"
+ selector host port)))
+ (make-text-button (match-beginning 0)
+ (match-end 0)
+ 'elopher-url url
+ 'action #'elopher-click-url
+ 'follow-link t
+ 'help-echo (format "mouse-1, RET: open url %s" url)))))
+ (buffer-string)))
+
+(defun elopher-process-text (string)
+ (let* ((chopped-str (replace-regexp-in-string "\r\n\.\r\n$" "\r\n" string))
+ (cleaned-str (replace-regexp-in-string "\r" "" chopped-str)))
+ (elopher-buttonify-urls cleaned-str)))
(defun elopher-get-text-node ()
(let ((content (elopher-node-content elopher-current-node))
(address (elopher-node-address elopher-current-node)))
(if content
(progn
- (let ((inhibit-read-only t))
- (insert content))
+ (elopher-with-clean-buffer
+ (insert content))
(elopher-restore-pos))
+ (progn
+ (elopher-with-clean-buffer
+ (insert "LOADING TEXT..."))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (unless (string-prefix-p "deleted" event)
+ (elopher-with-clean-buffer
+ (insert (elopher-process-text elopher-selector-string)))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string)))))))))
+
+;; Image retrieval
+
+(defun elopher-get-image-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (elopher-with-clean-buffer
+ (insert-image content))
+ (setq cursor-type nil)
+ (elopher-restore-pos))
+ (progn
+ (elopher-with-clean-buffer
+ (insert "LOADING IMAGE..."))
+ (elopher-get-selector address
+ (lambda (proc event)
+ (unless (string-prefix-p "deleted" event)
+ (let ((image (create-image
+ (string-as-unibyte elopher-selector-string)
+ nil t)))
+ (elopher-with-clean-buffer
+ (insert-image image))
+ (setq cursor-type nil)
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ image)))))))))
+
+;; Search retrieval
+
+(defun elopher-get-search-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node))
+ (aborted t))
+ (if content
+ (progn
+ (elopher-with-clean-buffer
+ (insert content))
+ (elopher-restore-pos)
+ (message "Displaying cached search results. Reload to perform a new search."))
+ (unwind-protect
+ (let* ((query-string (read-string "Query: "))
+ (query-selector (concat (elopher-address-selector address) "\t" query-string))
+ (search-address (elopher-make-address query-selector
+ (elopher-address-host address)
+ (elopher-address-port address))))
+ (setq aborted nil)
+ (elopher-with-clean-buffer
+ (insert "LOADING RESULTS..."))
+ (elopher-get-selector search-address
+ (lambda (proc event)
+ (unless (string-prefix-p "deleted" event)
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-selector-string))
+ (goto-char (point-min))
+ (elopher-set-node-content elopher-current-node
+ (buffer-string))))))
+ (if aborted
+ (elopher-visit-parent-node))))))
+
+;; Raw server response retrieval
+
+(defun elopher-get-node-raw ()
+ (let* ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (elopher-with-clean-buffer
+ (insert "LOADING RAW SERVER RESPONSE..."))
+ (if address
+ (elopher-get-selector address
+ (lambda (proc event)
+ (unless (string-prefix-p "deleted" event)
+ (elopher-with-clean-buffer
+ (insert elopher-selector-string))
+ (goto-char (point-min)))))
+ (progn
+ (elopher-with-clean-buffer
+ (insert elopher-start-index))
+ (goto-char (point-min)))))
+ (message "Displaying raw server response. Reload or redraw to return to standard view."))
+
+;; File export retrieval
+
+(defvar elopher-download-filename)
+
+(defun elopher-get-node-download ()
+ (let* ((address (elopher-node-address elopher-current-node))
+ (selector (elopher-address-selector address)))
+ (elopher-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 elopher-download-filename filename)
(elopher-get-selector address
(lambda (proc event)
- (let ((inhibit-read-only t))
- (insert (elopher-strip-CRs elopher-selector-string)))
- (elopher-restore-pos)
- (elopher-set-node-content elopher-current-node
- (buffer-string)))))))
+ (let ((coding-system-for-write 'binary))
+ (with-temp-file elopher-download-filename
+ (insert elopher-selector-string)
+ (message (format "Download complate, saved to file %s."
+ elopher-download-filename)))))))))
+
-;;; Navigation methods
+;;; Navigation procedures
;;
(defun elopher-next-link ()
(let ((node (button-get button 'elopher-node)))
(elopher-visit-node node)))
-(defun elopher-follow-closest-link ()
+(defun elopher-click-url (button)
+ (let ((url (button-get button 'elopher-url)))
+ (if elopher-open-urls-with-eww
+ (browse-web url)
+ (browse-url url))))
+
+(defun elopher-follow-current-link ()
+ "Open the link or url at point."
(interactive)
(push-button))
(defun elopher-go ()
"Go to a particular gopher site."
(interactive)
- (let* ((selector "")
- (hostname (read-from-minibuffer "Gopher host: "))
- (port 70)
+ (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)))
(elopher-visit-node
(elopher-make-node elopher-current-node
address
#'elopher-get-index-node))))
+(defun elopher-redraw ()
+ "Redraw current page."
+ (interactive)
+ (elopher-visit-node elopher-current-node))
+
(defun elopher-reload ()
- "Reload current site."
+ "Reload current page."
(interactive)
(elopher-reload-current-node))
+(defun elopher-view-raw ()
+ "View current page as plain text."
+ (interactive)
+ (elopher-visit-node elopher-current-node
+ #'elopher-get-node-raw))
+
(defun elopher-back ()
"Go to previous site."
(interactive)
(elopher-visit-parent-node)
(message "No previous site.")))
-;;; Main start procedure
-;;
-(defun elopher ()
- "Start elopher with default landing page."
+(defun elopher-download ()
+ "Download the link at point."
(interactive)
- (setq elopher-current-node nil)
- (let ((start-node (elopher-make-node nil nil #'elopher-get-index-node)))
- (elopher-visit-node start-node)))
-
+ (let ((button (button-at (point))))
+ (if button
+ (let ((node (button-get button 'elopher-node)))
+ (if node
+ (elopher-visit-node (button-get button 'elopher-node)
+ #'elopher-get-node-download)
+ (message "Can only download gopher links, not general URLs.")))
+ (message "No link selected."))))
;;; Mode and keymap
;;
(defvar elopher-mode-map
(let ((map (make-sparse-keymap)))
- (define-key map (kbd "<tab>") 'elopher-next-link)
- (define-key map (kbd "<S-tab>") 'elopher-prev-link)
+ (define-key map (kbd "TAB") 'elopher-next-link)
+ (define-key map (kbd "<backtab>") 'elopher-prev-link)
(define-key map (kbd "u") 'elopher-back)
(define-key map (kbd "g") 'elopher-go)
- (define-key map (kbd "r") 'elopher-reload)
- (when (require 'evil nil t)
+ (define-key map (kbd "r") 'elopher-redraw)
+ (define-key map (kbd "R") 'elopher-reload)
+ (define-key map (kbd "w") 'elopher-view-raw)
+ (define-key map (kbd "d") 'elopher-download)
+ (when (fboundp 'evil-define-key)
(evil-define-key 'normal map
- (kbd "C-]") 'elopher-follow-closest-link
+ (kbd "TAB") 'elopher-next-link
+ (kbd "C-]") 'elopher-follow-current-link
(kbd "C-t") 'elopher-back
(kbd "u") 'elopher-back
(kbd "g") 'elopher-go
- (kbd "r") 'elopher-reload))
+ (kbd "r") 'elopher-redraw
+ (kbd "R") 'elopher-reload
+ (kbd "w") 'elopher-view-raw
+ (kbd "d") 'elopher-download))
map)
"Keymap for gopher client.")
"Major mode for elopher, an elisp gopher client.")
+;;; Main start procedure
+;;
+
+(defun elopher ()
+ "Start elopher with default landing page."
+ (interactive)
+ (setq elopher-current-node nil)
+ (let ((start-node (elopher-make-node nil nil #'elopher-get-index-node)))
+ (elopher-visit-node start-node))
+ "Started Elopher.") ; Otherwise (elopher) evaluates to start page string.
+
;;; elopher.el ends here