-;;; elopher.el --- gopher client
+;;; elopher.el --- elisp gopher client
;;; Commentary:
-;; Simple gopher client in elisp.
+;; An elisp gopher client.
;;; Code:
-;; (defvar elopher-mode-map nil "Keymap for gopher client.")
-;; (define-key elopher-mode-map (kbd "p") 'elopher-quit)
+;;; Global constants
+;;
-;; (define-derived-mode elopher-mode special-mode "elopher"
-;; "Major mode for elopher, an elisp gopher client.")
+(defconst elopher-version "1.0.0"
+ "Current version of elopher.")
-(defvar my-marker nil)
+(defconst elopher-margin-width 6
+ "Width of left-hand margin used when rendering indicies.")
-(defun my-filter (proc string)
- (with-current-buffer (get-buffer "*elopher*")
- (let ((marker (process-mark proc)))
- (if (not (marker-position marker))
- (set-marker marker 0 (current-buffer)))
- (save-excursion
- (goto-char marker)
- (insert (propertize string 'face '(foreground-color . "yellow")))
- (set-marker marker (point))))))
-
+(defconst elopher-start-index
+ (mapconcat
+ 'identity
+ (list "i\tfake\tfake\t1"
+ "i--------------------------------------------\tfake\tfake\t1"
+ "i Elopher Gopher Client \tfake\tfake\t1"
+ (format "i version %s\tfake\tfake\t1" elopher-version)
+ "i--------------------------------------------\tfake\tfake\t1"
+ "i\tfake\tfake\t1"
+ "iBasic usage:\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 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")
+ "Source for elopher start page.")
-(defun elopher ()
- "Start gopher client."
+
+;;; Customization group
+;;
+
+(defgroup elopher nil
+ "A gopher client."
+ :group 'applications)
+
+(defface elopher-index
+ '((((background dark)) :foreground "deep sky blue")
+ (((background light)) :foreground "blue"))
+ "Face used for index records.")
+
+(defface elopher-text
+ '((((background dark)) :foreground "white")
+ (((background light)) :weight bold))
+ "Face used for text records.")
+
+(defface elopher-info '()
+ "Face used for info records.")
+
+(defface elopher-image
+ '((((background dark)) :foreground "green")
+ (t :foreground "dark green"))
+ "Face used for image records.")
+
+(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)
+ (list selector host port))
+
+(defun elopher-address-selector (address)
+ (car address))
+
+(defun elopher-address-host (address)
+ (cadr address))
+
+(defun elopher-address-port (address)
+ (caddr address))
+
+;; Node
+
+(defun elopher-make-node (parent address getter &optional content pos)
+ (list parent address getter content pos))
+
+(defun elopher-node-parent (node)
+ (elt node 0))
+
+(defun elopher-node-address (node)
+ (elt node 1))
+
+(defun elopher-node-getter (node)
+ (elt node 2))
+
+(defun elopher-node-content (node)
+ (elt node 3))
+
+(defun elopher-node-pos (node)
+ (elt node 4))
+
+(defun elopher-set-node-content (node content)
+ (setcar (nthcdr 3 node) content))
+
+(defun elopher-set-node-pos (node pos)
+ (setcar (nthcdr 4 node) pos))
+
+(defun elopher-save-pos ()
+ (when elopher-current-node
+ (elopher-set-node-pos elopher-current-node (point))))
+
+(defun elopher-restore-pos ()
+ (let ((pos (elopher-node-pos elopher-current-node)))
+ (if pos
+ (goto-char pos)
+ (goto-char (point-min)))))
+
+;; Node graph traversal
+
+(defvar elopher-current-node)
+
+(defun elopher-visit-node (node &optional getter)
+ "Visit NODE using its own getter or GETTER, if non-nil."
+ (elopher-save-pos)
+ (elopher-process-cleanup)
+ (setq elopher-current-node node)
+ (if getter
+ (funcall getter)
+ (funcall (elopher-node-getter node))))
+
+(defun elopher-visit-parent-node ()
+ (let ((parent-node (elopher-node-parent elopher-current-node)))
+ (when parent-node
+ (elopher-visit-node parent-node))))
+
+(defun elopher-reload-current-node ()
+ (elopher-set-node-content elopher-current-node nil)
+ (elopher-visit-node elopher-current-node))
+
+;;; Buffer preparation
+;;
+
+(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)
+ "Insert the index corresponding to STRING into the current buffer."
+ (dolist (line (split-string string "\r\n"))
+ (unless (= (length line) 0)
+ (elopher-insert-index-record line))))
+
+(defun elopher-insert-margin (&optional type-name)
+ "Insert index margin, optionally containing the TYPE-NAME, into the current buffer."
+ (if type-name
+ (progn
+ (insert (format (concat "%" (number-to-string (- elopher-margin-width 1)) "s")
+ (concat
+ (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)
+ "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 (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 face
+ '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)))
+ (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 "")
+ (make-network-process
+ :name "elopher-process"
+ :host (elopher-address-host address)
+ :service (elopher-address-port address)
+ :filter (lambda (proc string)
+ (setq elopher-selector-string (concat elopher-selector-string string)))
+ :sentinel after)
+ (process-send-string "elopher-process"
+ (concat (elopher-address-selector address) "\n")))
+
+;; Index retrieval
+
+(defun elopher-get-index-node ()
+ (let ((content (elopher-node-content elopher-current-node))
+ (address (elopher-node-address elopher-current-node)))
+ (if content
+ (progn
+ (elopher-with-clean-buffer
+ (insert content))
+ (elopher-restore-pos))
+ (if address
+ (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
+ (elopher-with-clean-buffer
+ (elopher-insert-index elopher-start-index))
+ (elopher-restore-pos)
+ (elopher-set-node-content elopher-current-node
+ (buffer-string)))))))
+
+;; Text retrieval
+
+(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
+ (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 ((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 procedures
+;;
+
+(defun elopher-next-link ()
+ (interactive)
+ (forward-button 1))
+
+(defun elopher-prev-link ()
(interactive)
- (switch-to-buffer-other-window "*elopher*")
- (setq my-marker (make-marker))
- (erase-buffer)
- (make-process
- :name "date"
- :command (list "/bin/ls" "-l" "/")
- :filter #'my-filter))
+ (backward-button 1))
+
+(defun elopher-click-link (button)
+ (let ((node (button-get button 'elopher-node)))
+ (elopher-visit-node node)))
+
+(defun elopher-click-url (button)
+ (let ((url (button-get button 'elopher-url)))
+ (if elopher-open-urls-with-eww
+ (browse-web url)
+ (browse-url url))))
-(elopher)
-
- ;; (address (read-from-minibuffer "Address of gopher server: ")))
- ;; (message "Connecting to '%s' ..." address)
- ;; (erase-buffer)
- ;; (insert (propertize "Hello, world." 'face '(foreground-color . "red")))
- ;; (newline)
- ;; (insert (propertize "Hello, Tim." 'face '(foreground-color . "yellow"))))
+(defun elopher-follow-closest-link ()
+ (interactive)
+ (push-button))
-(defun elopher-quit ()
+(defun elopher-go ()
+ "Go to a particular gopher site."
(interactive)
- (kill-buffer "*elopher*"))
+ (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))))
-(start-process "ls" "*elopher*" "/bin/date")
+(defun elopher-redraw ()
+ "Redraw current page."
+ (interactive)
+ (elopher-visit-node elopher-current-node))
-;;; elopher.el ends here
+(defun elopher-reload ()
+ "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)
+ (if (elopher-node-parent elopher-current-node)
+ (elopher-visit-parent-node)
+ (message "No previous site.")))
-(list-processes)
+(defun elopher-download ()
+ "Download the link at point."
+ (interactive)
+ (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 "u") 'elopher-back)
+ (define-key map (kbd "g") 'elopher-go)
+ (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 "C-t") 'elopher-back
+ (kbd "u") 'elopher-back
+ (kbd "g") 'elopher-go
+ (kbd "r") 'elopher-reload
+ (kbd "w") 'elopher-view-raw
+ (kbd "d") 'elopher-download))
+ map)
+ "Keymap for gopher client.")
+
+(define-derived-mode elopher-mode special-mode "elopher"
+ "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
The Lambda Lab / projects / elpher.git / blobdiff