-;;; elpher.el --- A friendly gopher client. -*- lexical-binding:t -*-
+;;; elpher.el --- A friendly gopher client -*- lexical-binding:t -*-
;; Copyright (C) 2019 Tim Vaughan
-;; Author: Tim Vaughan <tgvaughan@gmail.com>
+;; Author: Tim Vaughan <timv@ughan.xyz>
;; Created: 11 April 2019
-;; Version: 2.4.4
+;; Version: 2.7.3
;; Keywords: comm gopher
;; Homepage: http://thelambdalab.xyz/elpher
;; Package-Requires: ((emacs "26"))
;; - direct visualisation of image files,
;; - a simple bookmark management system,
;; - connections using TLS encryption,
-;; - support for the fledgling Gemini protocol.
+;; - 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
(require 'url-util)
(require 'subr-x)
(require 'dns)
+(require 'ansi-color)
+(require 'nsm)
;;; Global constants
;;
-(defconst elpher-version "2.4.4"
+(defconst elpher-version "2.7.3"
"Current version of elpher.")
(defconst elpher-margin-width 6
((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)
"A gopher 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-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-bookmarks-file (locate-user-emacs-file "elpher-bookmarks")
+ "Specify the name of the file where elpher bookmarks will be saved."
+ :type '(file))
+
;; Face customizations
+(defgroup elpher-faces nil
+ "Elpher face customizations."
+ :group 'elpher)
+
(defface elpher-index
'((t :inherit font-lock-keyword-face))
"Face used for directory type directory records.")
(defface elpher-gemini
'((t :inherit font-lock-regexp-grouping-backslash))
- "Face used for html type directory records.")
+ "Face used for Gemini type directory records.")
(defface elpher-other-url
'((t :inherit font-lock-comment-face))
'((t :inherit shadow))
"Face used for brackets around directory margin key.")
-;; Other 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-buttonify-urls-in-directories t
- "If non-nil, turns URLs matched in directories into clickable buttons."
- :type '(boolean))
-
-(defcustom elpher-use-header t
- "If non-nil, display current page information in buffer header."
- :type '(boolean))
+(defface elpher-gemini-heading1
+ '((t :inherit bold :height 1.8))
+ "Face used for gemini heading level 1.")
-(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))
+(defface elpher-gemini-heading2
+ '((t :inherit bold :height 1.5))
+ "Face used for gemini heading level 2.")
+(defface elpher-gemini-heading3
+ '((t :inherit bold :height 1.2))
+ "Face used for gemini heading level 3.")
;;; Model
;;
'gemini)
((equal protocol "telnet")
'telnet)
+ ((equal protocol "finger")
+ 'finger)
(t 'other-url)))))
(defun elpher-address-protocol (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 object.
If no address is defined, returns 0. (This is for compatibility with the URL library.)"
;; Page
(defun elpher-make-page (display-string address)
+ "Create a page with DISPLAY-STRING and ADDRESS."
(list display-string address))
(defun elpher-page-display-string (page)
+ "Retrieve the display string corresponding to PAGE."
(elt page 0))
(defun elpher-page-address (page)
+ "Retrieve the address corresponding to PAGE."
(elt page 1))
+(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)
(defvar elpher-history nil)
(let ((previous-page (pop elpher-history)))
(if previous-page
(elpher-visit-page previous-page nil t)
- (error "No previous page."))))
+ (error "No previous page"))))
(defun elpher-reload-current-page ()
"Reload the current page, discarding any existing cached content."
(list 'with-current-buffer "*elpher*"
'(elpher-mode)
(append (list 'let '((inhibit-read-only t))
+ '(setq-local network-security-level
+ (default-value 'network-security-level))
'(erase-buffer)
'(elpher-update-header))
args)))
(let* ((kill-buffer-query-functions nil)
(port (elpher-address-port address))
(host (elpher-address-host address))
- (selector-string "")
+ (selector-string-parts nil)
(proc (open-network-stream "elpher-process"
nil
(if force-ipv4 (dns-query host) host)
(set-process-filter proc
(lambda (_proc string)
(cancel-timer timer)
- (setq selector-string
- (concat selector-string string))))
+ (setq selector-string-parts
+ (cons string selector-string-parts))))
(set-process-sentinel proc
(lambda (_proc event)
(condition-case the-error
"\r\n"))))
(t
(cancel-timer timer)
- (funcall renderer selector-string)
+ (funcall renderer (apply #'concat
+ (reverse selector-string-parts)))
(elpher-restore-pos)))
(error
(elpher-network-error address the-error))))))
(if type-map-entry
(let* ((margin-code (elt type-map-entry 2))
(face (elt type-map-entry 3))
- (page (elpher-make-page display-string address)))
+ (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-page page
'action #'elpher-click-link
(elpher-insert-margin)
(let ((propertized-display-string
(propertize display-string 'face 'elpher-info)))
- (insert (if elpher-buttonify-urls-in-directories
- (elpher-buttonify-urls propertized-display-string)
- propertized-display-string))))
+ (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
(defconst elpher-url-regex
"\\([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 buttniofy URLs in text files loaded by elpher.")
+ "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
(defun elpher-buttonify-urls (string)
"Turn substrings which look like urls in STRING into clickable buttons."
'face 'button)))
(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-buttonify-urls (elpher-preprocess-text-response data)))
+ (insert (elpher-process-text-for-display (elpher-preprocess-text-response data)))
(elpher-cache-content
(elpher-page-address elpher-current-page)
(buffer-string)))))
"Retrieve gemini ADDRESS, then render using RENDERER.
If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
to ADDRESS."
+ (unless elpher-gemini-TLS-cert-checks
+ (setq-local network-security-level 'low))
(if (not (gnutls-available-p))
(error "Cannot establish gemini connection: GnuTLS not available")
(unless (< (elpher-address-port address) 65536)
(let* ((kill-buffer-query-functions nil)
(port (elpher-address-port address))
(host (elpher-address-host address))
- (response-string "")
+ (response-string-parts nil)
(proc (open-network-stream "elpher-process"
nil
(if force-ipv4 (dns-query host) host)
(set-process-coding-system proc 'binary)
(set-process-filter proc
(lambda (_proc string)
- (cancel-timer timer)
- (setq response-string
- (concat response-string string))))
+ (when timer
+ (cancel-timer timer)
+ (setq timer nil))
+ (setq response-string-parts
+ (cons string response-string-parts))))
(set-process-sentinel proc
(lambda (proc event)
(condition-case the-error
(concat (elpher-address-to-url address)
"\r\n"))))
((string-prefix-p "deleted" event)) ; do nothing
- ((and (string-empty-p response-string)
+ ((and (not response-string-parts)
(not force-ipv4))
; Try again with IPv4
(message "Connection failed. Retrying with IPv4.")
(elpher-get-gemini-response address renderer t))
(t
(funcall #'elpher-process-gemini-response
- response-string
+ (apply #'concat (reverse response-string-parts))
renderer)
(elpher-restore-pos)))
(error
"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
(_other
(error "Unsupported MIME type %S" mime-type))))))
-(defun elpher-gemini-get-link-url (line)
- "Extract the url portion of LINE, a gemini map file link line."
- (string-trim (elt (split-string (substring line 2)) 0)))
-
-(defun elpher-gemini-get-link-display-string (line)
- "Extract the display string portion of LINE, a gemini map file link line."
- (let* ((rest (string-trim (elt (split-string line "=>") 1)))
+(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)))
- (if idx
- (string-trim (substring rest (+ idx 1)))
- "")))
+ (string-trim (if idx
+ (substring rest (+ idx 1))
+ rest))))
(defun elpher-collapse-dot-sequences (filename)
"Collapse dot sequences in FILENAME.
(elpher-collapse-dot-sequences (url-filename address)))))
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 "→ ")
+ (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 page)))
+ (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))))
+ (unless (display-graphic-p)
+ (insert (make-string level ?#) " "))
+ (insert (propertize header 'face
+ (pcase level
+ (1 'elpher-gemini-heading1)
+ (2 'elpher-gemini-heading2)
+ (3 'elpher-gemini-heading3)
+ (_ 'default)))
+ "\n"))))
+
(defun elpher-render-gemini-map (data _parameters)
"Render DATA as a gemini map file, PARAMETERS is currently unused."
(elpher-with-clean-buffer
- (dolist (line (split-string data "\n"))
- (if (string-prefix-p "=>" line)
- (let* ((url (elpher-gemini-get-link-url line))
- (display-string (elpher-gemini-get-link-display-string line))
- (address (elpher-address-from-gemini-url url)))
- (if (> (length display-string) 0)
- (elpher-insert-index-record display-string address)
- (elpher-insert-index-record url address)))
- (elpher-insert-index-record line)))
+ (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 line) "\n"))
+ ((string-prefix-p "=>" line) (elpher-gemini-insert-link line))
+ ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
+ (t (insert (elpher-process-text-for-display line)) (newline)))))
(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-buttonify-urls data))
+ (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 &optional force-ipv4)
+ "Opens a finger connection to the current page address and renders it 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 content)
+ (elpher-restore-pos))
+ (elpher-with-clean-buffer
+ (insert "LOADING... (use 'u' to cancel)"))
+ (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))))
+ (port (let ((given-port (elpher-address-port address)))
+ (if (> given-port 0) given-port 79)))
+ (host (elpher-address-host address))
+ (selector-string-parts nil)
+ (proc (open-network-stream "elpher-process"
+ nil
+ (if force-ipv4 (dns-query host) host)
+ port
+ :type 'plain
+ :nowait t))
+ (timer (run-at-time elpher-connection-timeout
+ nil
+ (lambda ()
+ (pcase (process-status proc)
+ ('connect
+ (elpher-process-cleanup)
+ (unless force-ipv4
+ (message "Connection timed out. Retrying with IPv4 address.")
+ (elpher-get-finger-page renderer t))))))))
+ (setq elpher-network-timer timer)
+ (set-process-coding-system proc 'binary)
+ (set-process-filter proc
+ (lambda (_proc string)
+ (cancel-timer timer)
+ (setq selector-string-parts
+ (cons string selector-string-parts))))
+ (set-process-sentinel proc
+ (lambda (_proc event)
+ (condition-case the-error
+ (cond
+ ((string-prefix-p "deleted" event))
+ ((string-prefix-p "open" event)
+ (let ((inhibit-eol-conversion t))
+ (process-send-string
+ proc
+ (concat user "\r\n"))))
+ (t
+ (cancel-timer timer)
+ (funcall renderer (apply #'concat
+ (reverse selector-string-parts)))
+ (elpher-restore-pos)))))))
+ (error
+ (elpher-network-error address the-error))))))
+
+
;; Other URL page opening
(defun elpher-get-other-url-page (renderer)
"- a: rename selected bookmark\n"
"\n"
"Bookmarks are stored in the file ")
- (let ((filename (locate-user-emacs-file "elpher-bookmarks"))
+ (let ((filename elpher-bookmarks-file)
(help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
(insert-text-button filename
'face 'link
(defun elpher-save-bookmarks (bookmarks)
"Record the bookmark list BOOKMARKS to the user's bookmark file.
Beware that this completely replaces the existing contents of the file."
- (with-temp-file (locate-user-emacs-file "elpher-bookmarks")
+ (with-temp-file elpher-boomarks-file
(erase-buffer)
(insert "; Elpher bookmarks file\n\n"
"; Bookmarks are stored as a list of (label URL) items.\n"
(let ((bookmarks
(with-temp-buffer
(ignore-errors
- (insert-file-contents (locate-user-emacs-file "elpher-bookmarks"))
+ (insert-file-contents elpher-bookmarks-file)
(goto-char (point-min))
(read (current-buffer))))))
(if (and bookmarks (listp (cadar bookmarks)))
(interactive)
(push-button))
-(defun elpher-go ()
- "Go to a particular gopher site read from the minibuffer."
- (interactive)
- (let ((page
- (let ((host-or-url (read-string "Gopher or Gemini URL: ")))
- (elpher-make-page host-or-url
- (elpher-address-from-url host-or-url)))))
+(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 ((page (elpher-make-page host-or-url
+ (elpher-address-from-url host-or-url))))
(switch-to-buffer "*elpher*")
- (elpher-visit-page page)))
+ (elpher-visit-page page)
+ '()))
(defun elpher-go-current ()
"Go to a particular site read from the minibuffer, initialized with the current URL."
(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-current-page)
+ (elpher-page-address elpher-current-page))
#'elpher-render-download
t)))
(let ((address-copy (elpher-address-from-url
(elpher-address-to-url address))))
(setf (url-filename address-copy) "")
- (elpher-visit-page
- (elpher-make-page (elpher-address-to-url address-copy)
- 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 ()