Change browse-url advice for older releases

[elpher.git] / elpher.el

diff --git a/elpher.el b/elpher.el
index f2a8188..f94b33f 100644 (file)
--- a/elpher.el
+++ b/elpher.el
@@ -1,13 +1,28 @@
-;;; elpher.el --- A friendly gopher and gemini client  -*- lexical-binding:t -*-
-
-;; Copyright (C) 2019-2020 Tim Vaughan
+;;; elpher.el --- A friendly gopher and gemini client  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2021 Jens Östlund <jostlund@gmail.com>
+;; Copyright (C) 2021 F. Jason Park <jp@neverwas.me>
+;; Copyright (C) 2021 Christopher Brannon <chris@the-brannons.com>
+;; Copyright (C) 2021 Omar Polo <op@omarpolo.com>
+;; Copyright (C) 2021 Noodles! <nnoodle@chiru.no>
+;; Copyright (C) 2020-2021 Alex Schroeder <alex@gnu.org>
+;; Copyright (C) 2020 Zhiwei Chen <chenzhiwei03@kuaishou.com>
+;; Copyright (C) 2020 condy0919 <condy0919@gmail.com>
+;; Copyright (C) 2020 Alexis <flexibeast@gmail.com>
+;; Copyright (C) 2020 Étienne Deparis <etienne@depar.is>
+;; Copyright (C) 2020 Simon Nicolussi <sinic@sinic.name>
+;; Copyright (C) 2020 Michel Alexandre Salim <michel@michel-slm.name>
+;; Copyright (C) 2020 Koushk Roy <kroy@twilio.com>
+;; Copyright (C) 2020 Vee <vee@vnsf.xyz>
+;; Copyright (C) 2020 Simon South <simon@simonsouth.net>
+;; Copyright (C) 2019-2020 Tim Vaughan <plugd@thelambdalab.xyz>

 
 ;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
 ;; Created: 11 April 2019
 
 ;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
 ;; Created: 11 April 2019

-;; Version: 2.9.1
+;; Version: 2.11.0

 ;; Keywords: comm gopher
 ;; Keywords: comm gopher

-;; Homepage: http://thelambdalab.xyz/elpher
-;; Package-Requires: ((emacs "26.2"))
+;; Homepage: https://alexschroeder.ch/cgit/elpher
+;; Package-Requires: ((emacs "27.1"))

 
 ;; This file is not part of GNU Emacs.
 
 
 ;; This file is not part of GNU Emacs.
 


@@ -48,7 +63,7 @@
 
 ;; Elpher is under active development.  Any suggestions for
 ;; improvements are welcome, and can be made on the official
 
 ;; 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/.
+;; project page, https://alexschroeder.ch/cgit/elpher.

 
 ;;; Code:
 
 
 ;;; Code:
 


@@ -63,15 +78,32 @@
 (require 'url-util)
 (require 'subr-x)
 (require 'dns)
 (require 'url-util)
 (require 'subr-x)
 (require 'dns)

-(require 'ansi-color)

 (require 'nsm)
 (require 'gnutls)
 (require 'nsm)
 (require 'gnutls)

-
+(require 'socks)
+
+;;; ANSI colors or XTerm colors
+
+(or (require 'xterm-color nil t)
+    (require 'ansi-color))
+
+(defalias 'elpher-color-filter-apply
+  (if (fboundp 'xterm-color-filter)
+      (lambda (s)
+        (let ((xterm-color-render nil))
+          (xterm-color-filter s)))
+    'ansi-color-filter-apply)
+  "A function to filter out ANSI escape sequences.")
+(defalias 'elpher-color-apply
+  (if (fboundp 'xterm-color-filter)
+      'xterm-color-filter
+    'ansi-color-apply)
+  "A function to apply ANSI escape sequences.")

 
 ;;; Global constants
 ;;
 
 
 ;;; Global constants
 ;;
 

-(defconst elpher-version "2.9.1"
+(defconst elpher-version "2.11.0"

   "Current version of elpher.")
 
 (defconst elpher-margin-width 6
   "Current version of elpher.")
 
 (defconst elpher-margin-width 6


@@ -100,6 +132,19 @@
   "Association list from types to getters, renderers, margin codes and index faces.")
 
 
   "Association list from types to getters, renderers, margin codes and index faces.")
 
 

+;;; Internal variables
+;;
+
+;; buffer-local
+(defvar elpher--gemini-page-headings nil
+  "List of headings on the page.")
+
+(defvar elpher--gemini-page-links nil
+  "List of links on the page.")
+
+(defvar elpher--gemini-page-links-cache (make-hash-table :test 'equal)
+  "Hash of addresses and page links.")
+

 ;;; Customization group
 ;;
 
 ;;; Customization group
 ;;
 


@@ -111,7 +156,7 @@
 
 (defcustom elpher-open-urls-with-eww nil
   "If non-nil, open URL selectors using eww.
 
 (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."
+Otherwise, use the system browser via the `browse-url' function."

   :type '(boolean))
 
 (defcustom elpher-use-header t
   :type '(boolean))
 
 (defcustom elpher-use-header t


@@ -120,8 +165,9 @@ Otherwise, use the system browser via the BROWSE-URL function."
 
 (defcustom elpher-auto-disengage-TLS nil
   "If non-nil, automatically disengage TLS following an unsuccessful connection.
 
 (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."
+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
   :type '(boolean))
 
 (defcustom elpher-connection-timeout 5


@@ -144,6 +190,11 @@ These certificates may be used for establishing authenticated TLS connections."
   "The command used to launch openssl when generating TLS client certificates."
   :type '(file))
 
   "The command used to launch openssl when generating TLS client certificates."
   :type '(file))
 

+(defcustom elpher-default-url-type "gopher"
+  "Default URL type (i.e. scheme) to assume if not explicitly given."
+  :type '(choice (const "gopher")
+                 (const "gemini")))
+

 (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.
 (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.


@@ -178,6 +229,16 @@ 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))
 
 some servers which do not support IPv6 can take a long time to time-out."
   :type '(boolean))
 

+(defcustom elpher-socks-always nil
+  "If non-nil, elpher will establish network connections over a SOCKS proxy.
+Otherwise, the SOCKS proxy is only used for connections to onion services."
+  :type '(boolean))
+
+(defcustom elpher-gemini-number-links nil
+  "If non-nil, number links in gemini pages when rendering.
+Links can be accessed by pressing `v' ('visit') followed by the link number."
+  :type '(boolean))
+

 ;; Face customizations
 
 (defgroup elpher-faces nil
 ;; Face customizations
 
 (defgroup elpher-faces nil


@@ -209,7 +270,7 @@ some servers which do not support IPv6 can take a long time to time-out."
   "Face used for html type directory records.")
 
 (defface elpher-gemini
   "Face used for html type directory records.")
 
 (defface elpher-gemini

-  '((t :inherit font-lock-regexp-grouping-backslash))
+  '((t :inherit font-lock-constant-face))

   "Face used for Gemini type directory records.")
 
 (defface elpher-other-url
   "Face used for Gemini type directory records.")
 
 (defface elpher-other-url


@@ -252,6 +313,10 @@ some servers which do not support IPv6 can take a long time to time-out."
   '((t :inherit fixed-pitch))
   "Face used for pre-formatted gemini text blocks.")
 
   '((t :inherit fixed-pitch))
   "Face used for pre-formatted gemini text blocks.")
 

+(defface elpher-gemini-quoted
+  '((t :inherit font-lock-doc-face))
+  "Face used for gemini quoted texts.")
+

 ;;; Model
 ;;
 
 ;;; Model
 ;;
 


@@ -272,13 +337,17 @@ some servers which do not support IPv6 can take a long time to time-out."
             (setf (url-filename url)
                   (url-unhex-string (url-filename url)))
             (unless (url-type url)
             (setf (url-filename url)
                   (url-unhex-string (url-filename url)))
             (unless (url-type url)

-              (setf (url-type url) "gopher"))
+              (setf (url-type url) elpher-default-url-type))
+            (unless (url-host url)
+              (let ((p (split-string (url-filename url) "/" nil nil)))
+                (setf (url-host url) (car p))
+                (setf (url-filename url)
+                      (if (cdr p)
+                          (concat "/" (mapconcat #'identity (cdr p) "/"))
+                        ""))))

             (when (or (equal "gopher" (url-type url))
                       (equal "gophers" (url-type url)))
               ;; Gopher defaults
             (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 (or (equal (url-filename url) "")
                         (equal (url-filename url) "/"))
                 (setf (url-filename url) "/1")))


@@ -441,8 +510,8 @@ If no address is defined, returns 0.  (This is for compatibility with the URL li
   "Set the address corresponding to PAGE to NEW-ADDRESS."
   (setcar (cdr 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)
+(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.
 
 (defun elpher-visit-page (page &optional renderer no-history)
   "Visit PAGE using its own renderer or RENDERER, if non-nil.


@@ -454,15 +523,20 @@ unless NO-HISTORY is non-nil."
               (equal (elpher-page-address elpher-current-page)
                      (elpher-page-address page)))
     (push elpher-current-page elpher-history))
               (equal (elpher-page-address elpher-current-page)
                      (elpher-page-address page)))
     (push elpher-current-page elpher-history))

-  (setq elpher-current-page page)
+  (setq-local elpher-current-page page)

   (let* ((address (elpher-page-address page))
          (type (elpher-address-type address))
   (let* ((address (elpher-page-address page))
          (type (elpher-address-type address))

-         (type-record (cdr (assoc type elpher-type-map))))
+         (type-record (cdr (assoc type elpher-type-map)))
+         (page-links nil))

     (if type-record
     (if type-record

-        (funcall (car type-record)
-                 (if renderer
-                     renderer
-                   (cadr type-record)))
+        (progn
+          (funcall (car type-record)
+                   (if renderer
+                       renderer
+                     (cadr type-record)))
+          (setq page-links (gethash address elpher--gemini-page-links-cache))
+          (if page-links
+              (setq elpher--gemini-page-links page-links)))

       (elpher-visit-previous-page)
       (pcase type
         (`(gopher ,type-char)
       (elpher-visit-previous-page)
       (pcase type
         (`(gopher ,type-char)


@@ -478,7 +552,7 @@ unless NO-HISTORY is non-nil."
     (if previous-page
         (elpher-visit-page previous-page nil t)
       (error "No previous page"))))
     (if previous-page
         (elpher-visit-page previous-page nil t)
       (error "No previous page"))))

-      
+

 (defun elpher-reload-current-page ()
   "Reload the current page, discarding any existing cached content."
   (elpher-cache-content (elpher-page-address elpher-current-page) nil)
 (defun elpher-reload-current-page ()
   "Reload the current page, discarding any existing cached content."
   (elpher-cache-content (elpher-page-address elpher-current-page) nil)


@@ -500,6 +574,9 @@ unless NO-HISTORY is non-nil."
 ;;; Buffer preparation
 ;;
 
 ;;; 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
 (defun elpher-update-header ()
   "If `elpher-use-header' is true, display current page info in window header."
   (if elpher-use-header


@@ -516,19 +593,21 @@ unless NO-HISTORY is non-nil."
 
 (defmacro elpher-with-clean-buffer (&rest args)
   "Evaluate ARGS with a clean *elpher* buffer as current."
 
 (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))
-                      '(setq-local network-security-level
-                                   (default-value 'network-security-level))
-                      '(erase-buffer)
-                      '(elpher-update-header))
-                args)))
+  `(with-current-buffer elpher-buffer-name
+     (unless (eq major-mode 'elpher-mode)
+       ;; avoid resetting buffer-local variables
+       (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."
 
 (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*"
+  (with-current-buffer elpher-buffer-name

     (let ((inhibit-read-only t))
       (goto-char (point-min))
       (if line
     (let ((inhibit-read-only t))
       (goto-char (point-min))
       (if line


@@ -558,7 +637,7 @@ If LINE is non-nil, replace that line instead."
   "Preprocess text selector response contained in STRING.
 This involes decoding the character representation, and clearing
 away CRs and any terminating period."
   "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$" "\n"
+  (elpher-decode (replace-regexp-in-string "\n\\.\n$" "\n"

                                            (replace-regexp-in-string "\r" "" string))))
 
 
                                            (replace-regexp-in-string "\r" "" string))))
 
 


@@ -616,36 +695,23 @@ the host operating system and the local network capabilities."
     (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))
     (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))
+      (setq-local network-security-level 'low)
+      (setq-local gnutls-verify-error nil))

     (condition-case nil
         (let* ((kill-buffer-query-functions nil)
                (port (elpher-address-port address))
     (condition-case nil
         (let* ((kill-buffer-query-functions nil)
                (port (elpher-address-port address))

+               (service (if (> port 0) port default-port))

                (host (elpher-address-host address))
                (host (elpher-address-host address))

+               (socks (or elpher-socks-always (string-suffix-p ".onion" host)))

                (response-string-parts nil)
                (bytes-received 0)
                (hkbytes-received 0)
                (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
                (timer (run-at-time elpher-connection-timeout nil
                                    (lambda ()
                                      (elpher-process-cleanup)
                                      (cond
                                         ; Try again with IPv4

-                                      ((not force-ipv4)
+                                      ((not (or force-ipv4 socks))

                                        (message "Connection timed out.  Retrying with IPv4.")
                                        (elpher-get-host-response address default-port
                                                                  query-string
                                        (message "Connection timed out.  Retrying with IPv4.")
                                        (elpher-get-host-response address default-port
                                                                  query-string


@@ -662,8 +728,24 @@ the host operating system and the local network capabilities."
                                                                  response-processor
                                                                  nil force-ipv4))
                                       (t
                                                                  response-processor
                                                                  nil force-ipv4))
                                       (t

-                                       (elpher-network-error address "Connection time-out.")))))))
+                                       (elpher-network-error address "Connection time-out."))))))
+               (gnutls-params (list :type 'gnutls-x509pki :hostname host
+                                    :keylist (elpher-get-current-keylist address)))
+               (proc (if socks (socks-open-network-stream "elpher-process" nil host service)
+                       (make-network-process :name "elpher-process"
+                                             :host host
+                                             :family (and force-ipv4 'ipv4)
+                                             :service service
+                                             :buffer nil
+                                             :nowait t
+                                             :tls-parameters
+                                             (and use-tls
+                                                  (cons 'gnutls-x509pki
+                                                        (apply #'gnutls-boot-parameters
+                                                               gnutls-params)))))))

           (setq elpher-network-timer timer)
           (setq elpher-network-timer timer)

+          (set-process-coding-system proc 'binary 'binary)
+          (set-process-query-on-exit-flag proc nil)

           (elpher-buffer-message (concat "Connecting to " host "..."
                                          " (press 'u' to abort)"))
           (set-process-filter proc
           (elpher-buffer-message (concat "Connecting to " host "..."
                                          " (press 'u' to abort)"))
           (set-process-filter proc


@@ -676,10 +758,10 @@ the host operating system and the local network capabilities."
                                   (when (> new-hkbytes-received hkbytes-received)
                                     (setq hkbytes-received new-hkbytes-received)
                                     (elpher-buffer-message
                                   (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)))
+                                     (concat "("
+                                             (number-to-string (/ hkbytes-received 10.0))
+                                             " MB read)")
+                                     1)))

                                 (setq response-string-parts
                                       (cons string response-string-parts))))
           (set-process-sentinel proc
                                 (setq response-string-parts
                                       (cons string response-string-parts))))
           (set-process-sentinel proc


@@ -696,7 +778,7 @@ the host operating system and the local network capabilities."
                                           (process-send-string proc query-string)))
                                        ((string-prefix-p "deleted" event)) ; do nothing
                                        ((and (not response-string-parts)
                                           (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)))
+                                             (not (or elpher-ipv4-always force-ipv4 socks)))

                                         ; Try again with IPv4
                                         (message "Connection failed. Retrying with IPv4.")
                                         (elpher-get-host-response address default-port
                                         ; Try again with IPv4
                                         (message "Connection failed. Retrying with IPv4.")
                                         (elpher-get-host-response address default-port


@@ -712,7 +794,10 @@ the host operating system and the local network capabilities."
                                        (t
                                         (error "No response from server")))
                                     (error
                                        (t
                                         (error "No response from server")))
                                     (error

-                                     (elpher-network-error address the-error))))))
+                                     (elpher-network-error address the-error)))))
+          (when socks
+            (if use-tls (apply #'gnutls-negotiate :process proc gnutls-params))
+            (funcall (process-sentinel proc) proc "open\n")))

       (error
        (error "Error initiating connection to server")))))
 
       (error
        (error "Error initiating connection to server")))))
 


@@ -763,8 +848,8 @@ longer needed for this session."
          (cert-file (concat temporary-file-directory file-base ".crt")))
     (elpher-generate-certificate file-base key-file cert-file t)))
 
          (cert-file (concat temporary-file-directory file-base ".crt")))
     (elpher-generate-certificate file-base key-file cert-file t)))
 

-(defun elpher-generate-permanent-certificate (file-base common-name)
-  "Generate and return details of a persistant certificate.
+(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 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.


@@ -803,11 +888,13 @@ base for the installed key and certificate files."
           (expand-file-name cert-file))))
 
 (defun elpher-list-existing-certificates ()
           (expand-file-name cert-file))))
 
 (defun elpher-list-existing-certificates ()

-  "Return a list of the persistant certificates in `elpher-certificate-directory'."
+  "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))
   (mapcar
    (lambda (file)
      (file-name-sans-extension file))

-   (directory-files elpher-certificate-directory nil "\.key$")))
+   (directory-files elpher-certificate-directory nil "\\.key$")))

 
 (defun elpher-forget-current-certificate ()
   "Causes any current certificate to be forgotten.)
 
 (defun elpher-forget-current-certificate ()
   "Causes any current certificate to be forgotten.)


@@ -929,7 +1016,7 @@ If ADDRESS is not supplied or nil the record is rendered as an
     (if type-map-entry
         (let* ((margin-code (elt type-map-entry 2))
                (face (elt type-map-entry 3))
     (if 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))
+               (filtered-display-string (elpher-color-filter-apply display-string))

                (page (elpher-make-page filtered-display-string address)))
           (elpher-insert-margin margin-code)
           (insert-text-button filtered-display-string
                (page (elpher-make-page filtered-display-string address)))
           (elpher-insert-margin margin-code)
           (insert-text-button filtered-display-string


@@ -967,7 +1054,7 @@ If ADDRESS is not supplied or nil the record is rendered as an
 ;; Text rendering
 
 (defconst elpher-url-regex
 ;; Text rendering
 
 (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\-_~?/@|#]\\)?\\)?"
+  "\\([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)
   "Regexp used to locate and buttinofy URLs in text files loaded by elpher.")
 
 (defun elpher-buttonify-urls (string)


@@ -978,24 +1065,24 @@ If ADDRESS is not supplied or nil the record is rendered as an
     (while (re-search-forward elpher-url-regex nil t)
       (let ((page (elpher-make-page (substring-no-properties (match-string 0))
                                     (elpher-address-from-url (match-string 0)))))
     (while (re-search-forward elpher-url-regex nil t)
       (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-page  page
-                            'action #'elpher-click-link
-                            'follow-link t
-                            'help-echo #'elpher--page-button-help
-                            'face 'button)))
+        (make-text-button (match-beginning 0)
+                          (match-end 0)
+                          'elpher-page  page
+                          'action #'elpher-click-link
+                          'follow-link t
+                          'help-echo #'elpher--page-button-help
+                          'face 'button)))

     (buffer-string)))
 
 (defconst elpher-ansi-regex "\x1b\\[[^m]*m"
     (buffer-string)))
 
 (defconst elpher-ansi-regex "\x1b\\[[^m]*m"

-  "Wildly incomplete regexp used to strip out some troublesome ANSI escape sequences.")
+  "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
 
 (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))))
+                             (elpher-color-filter-apply string)
+                           (elpher-color-apply string))))

 
 (defun elpher-render-text (data &optional _mime-type-string)
   "Render DATA as text.  MIME-TYPE-STRING is unused."
 
 (defun elpher-render-text (data &optional _mime-type-string)
   "Render DATA as text.  MIME-TYPE-STRING is unused."


@@ -1028,9 +1115,9 @@ Currently includes buttonifying URLs and processing ANSI escape codes."
 (defun elpher-get-gopher-query-page (renderer)
   "Getter for gopher addresses requiring input.
 The response is rendered using the rendering function RENDERER."
 (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))
+  (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)
     (if (and content (funcall renderer nil))
         (elpher-with-clean-buffer
          (insert content)


@@ -1051,7 +1138,7 @@ The response is rendered using the rendering function RENDERER."
             (elpher-get-gopher-response search-address renderer))
         (if aborted
             (elpher-visit-previous-page))))))
             (elpher-get-gopher-response search-address renderer))
         (if aborted
             (elpher-visit-previous-page))))))

- 
+

 ;; Raw server response rendering
 
 (defun elpher-render-raw (data &optional mime-type-string)
 ;; Raw server response rendering
 
 (defun elpher-render-raw (data &optional mime-type-string)


@@ -1184,19 +1271,24 @@ that the response was malformed."
          (error "Gemini server response unknown: %s %s"
                 response-code response-meta))))))
 
          (error "Gemini server response unknown: %s %s"
                 response-code response-meta))))))
 

+(unless (fboundp 'read-answer)
+  (defun read-answer (question answers)
+    "Backfill for the new read-answer code."
+    (completing-read question (mapcar 'identity answers))))
+

 (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")
 (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")

-                          ("persistant" ?p
-                           "generate new or use existing persistant certificate")
+                          ("persistent" ?p
+                           "generate new or use existing persistent certificate")

                           ("abort" ?a
                            "stop immediately")))
       ("throwaway"
        (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))
                           ("abort" ?a
                            "stop immediately")))
       ("throwaway"
        (setq elpher-client-certificate (elpher-generate-throwaway-certificate)))

-      ("persistant"
+      ("persistent"

        (let* ((existing-certificates (elpher-list-existing-certificates))
               (file-base (completing-read
                           "Nickname for new or existing certificate (autocompletes, empty response aborts): "
        (let* ((existing-certificates (elpher-list-existing-certificates))
               (file-base (completing-read
                           "Nickname for new or existing certificate (autocompletes, empty response aborts): "


@@ -1218,7 +1310,7 @@ that the response was malformed."
                                                 file-base)))
                   (message "New key and self-signed certificate written to %s"
                            elpher-certificate-directory)
                                                 file-base)))
                   (message "New key and self-signed certificate written to %s"
                            elpher-certificate-directory)

-                  (elpher-generate-permanent-certificate file-base common-name)))
+                  (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)))
                ("install"
                 (let* ((cert-file (read-file-name "Certificate file: " nil nil t))
                        (key-file (read-file-name "Key file: " nil nil t)))


@@ -1237,8 +1329,8 @@ that the response was malformed."
     (condition-case the-error
         (if (and content (funcall renderer nil))
             (elpher-with-clean-buffer
     (condition-case the-error
         (if (and content (funcall renderer nil))
             (elpher-with-clean-buffer

-              (insert content)
-              (elpher-restore-pos))
+             (insert content)
+             (elpher-restore-pos))

           (elpher-with-clean-buffer
            (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
           (setq elpher-gemini-redirect-chain nil)
           (elpher-with-clean-buffer
            (insert "LOADING GEMINI... (use 'u' to cancel)\n"))
           (setq elpher-gemini-redirect-chain nil)


@@ -1343,11 +1435,12 @@ treatment that a separate function is warranted."
          (address (elpher-address-from-gemini-url url))
          (type (if address (elpher-address-type address) nil))
          (type-map-entry (cdr (assoc type elpher-type-map))))
          (address (elpher-address-from-gemini-url url))
          (type (if address (elpher-address-type address) nil))
          (type-map-entry (cdr (assoc type elpher-type-map))))

+    (setq elpher--gemini-page-links (append elpher--gemini-page-links `(,address)))

     (when display-string
       (insert elpher-gemini-link-string)
       (if type-map-entry
           (let* ((face (elt type-map-entry 3))
     (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))
+                 (filtered-display-string (elpher-color-filter-apply display-string))

                  (page (elpher-make-page filtered-display-string address)))
             (insert-text-button filtered-display-string
                                 'face face
                  (page (elpher-make-page filtered-display-string address)))
             (insert-text-button filtered-display-string
                                 'face face


@@ -1357,61 +1450,87 @@ treatment that a separate function is warranted."
                                 'help-echo #'elpher--page-button-help))
         (insert (propertize display-string 'face 'elpher-unknown)))
       (insert "\n"))))
                                 '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)
 (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))))
+    (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 (if (display-graphic-p)
+                            (/ (* fill-column
+                                  (font-get (font-spec :name (face-font 'default)) :size))
+                               (font-get (font-spec :name (face-font face)) :size)) fill-column)))
+      (setq elpher--gemini-page-headings (cons (cons header (point))
+                                               elpher--gemini-page-headings))

       (unless (display-graphic-p)
         (insert (make-string level ?#) " "))
       (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"))))
+      (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
 
 (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)))
+width defined by `elpher-gemini-max-fill-width'."
+  (string-match "\\(^[ \t]*\\)\\(\\*[ \t]+\\|>[ \t]*\\)?" text-line)
+  (let* ((line-prefix (match-string 2 text-line))
+         (processed-text-line
+          (if line-prefix
+              (cond ((string-prefix-p "*" line-prefix)
+                     (concat
+                      (replace-regexp-in-string "\\*"
+                                                elpher-gemini-bullet-string
+                                                (match-string 0 text-line))
+                      (substring text-line (match-end 0))))
+                    ((string-prefix-p ">" line-prefix)
+                     (propertize text-line 'face 'elpher-gemini-quoted))
+                    (t text-line))
+            text-line))
+         (adaptive-fill-mode t))

     (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
     (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))
+   (setq elpher--gemini-page-headings nil)
+   (let ((preformatted nil)
+         (link-counter 1))

      (auto-fill-mode 1)
      (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
      (auto-fill-mode 1)
      (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))

+     (setq elpher--gemini-page-links '())

      (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"))
      (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)
+         (progn
+           (if elpher-gemini-number-links
+               (insert
+                (concat
+                 "["
+                 (number-to-string link-counter)
+                 "] ")))
+           (setq link-counter (1+ link-counter))
+           (elpher-gemini-insert-link line)))

         ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
         (t (elpher-gemini-insert-text line)))))
         ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
         (t (elpher-gemini-insert-text line)))))

+   (setq elpher--gemini-page-headings (nreverse elpher--gemini-page-headings))

    (elpher-cache-content
     (elpher-page-address elpher-current-page)
    (elpher-cache-content
     (elpher-page-address elpher-current-page)

-    (buffer-string))))
+    (buffer-string))
+   (puthash
+    (elpher-page-address elpher-current-page)
+    elpher--gemini-page-links
+    elpher--gemini-page-links-cache)))

 
 (defun elpher-render-gemini-plain-text (data _parameters)
   "Render DATA as plain text file.  PARAMETERS is currently unused."
 
 (defun elpher-render-gemini-plain-text (data _parameters)
   "Render DATA as plain text file.  PARAMETERS is currently unused."


@@ -1502,6 +1621,7 @@ The result is rendered using RENDERER."
            " - 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"
            " - 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"

+           " - v: visit a numbered link on a gemini page\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"
            " - 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"


@@ -1524,8 +1644,8 @@ The result is rendered using RENDERER."
            "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))
            "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"))
+   (elpher-insert-index-record "Gemini Search Engine (geminispace.info)"
+                               (elpher-address-from-url "gemini://geminispace.info/search"))

    (insert "\n"
            "This page contains your bookmarked sites (also visit with B):\n")
    (elpher-insert-index-record "Your Bookmarks" 'bookmarks)
    (insert "\n"
            "This page contains your bookmarked sites (also visit with B):\n")
    (elpher-insert-index-record "Your Bookmarks" 'bookmarks)


@@ -1587,7 +1707,7 @@ The result is rendered using RENDERER."
                          'help-echo help-string))
    (insert "\n")
    (elpher-restore-pos)))
                          'help-echo help-string))
    (insert "\n")
    (elpher-restore-pos)))

-  
+

 
 ;;; Bookmarks
 ;;
 
 ;;; Bookmarks
 ;;


@@ -1597,7 +1717,7 @@ The result is rendered using RENDERER."
 DISPLAY-STRING determines how the bookmark will appear in the
 bookmark list, while URL is the url of the entry."
   (list display-string url))
 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-bookmark-display-string (bookmark)
   "Get the display string of BOOKMARK."
   (elt bookmark 0))


@@ -1613,6 +1733,9 @@ bookmark list, while URL is the url of the entry."
 (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."
 (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."

+  (let ((bookmark-dir (file-name-directory elpher-bookmarks-file)))
+    (unless (file-directory-p bookmark-dir)
+      (make-directory bookmark-dir)))

   (with-temp-file elpher-bookmarks-file
     (erase-buffer)
     (insert "; Elpher bookmarks file\n\n"
   (with-temp-file elpher-bookmarks-file
     (erase-buffer)
     (insert "; Elpher bookmarks file\n\n"


@@ -1658,6 +1781,128 @@ If ADDRESS is already bookmarked, update the label only."
                    (not (equal (elpher-bookmark-url bookmark) url)))
                  (elpher-load-bookmarks)))))
 
                    (not (equal (elpher-bookmark-url bookmark) url)))
                  (elpher-load-bookmarks)))))
 

+;;; Integrations
+;;
+
+;;; Org
+
+;; Avoid byte compilation warnings.
+(eval-when-compile
+  (declare-function org-link-store-props "ol")
+  (declare-function org-link-set-parameters "ol"))
+
+(defun elpher-org-export-link (link description format protocol)
+  "Export a LINK with DESCRIPTION for the given PROTOCOL and FORMAT.
+
+FORMAT is an Org export backend.  DESCRIPTION may be nil.  PROTOCOL may be one
+of gemini, gopher or finger."
+  (let* ((url (if (equal protocol "elpher")
+                  (string-remove-prefix "elpher:" link)
+                (format "%s:%s" protocol link)))
+         (desc (or description url)))
+    (pcase format
+      (`gemini (format "=> %s %s" url desc))
+      (`html (format "<a href=\"%s\">%s</a>" url desc))
+      (`latex (format "\\href{%s}{%s}" url desc))
+      (_ (if (not description)
+             url
+           (format "%s (%s)" desc url))))))
+
+(defun elpher-org-store-link ()
+  "Store link to an `elpher' page in Org."
+  (when (eq major-mode 'elpher-mode)
+    (let* ((url (elpher-info-current))
+           (desc (car elpher-current-page))
+           (protocol (cond
+                      ((string-prefix-p "gemini:" url) "gemini")
+                      ((string-prefix-p "gopher:" url) "gopher")
+                      ((string-prefix-p "finger:" url) "finger")
+                      (t "elpher"))))
+      (when (equal "elpher" protocol)
+        ;; Weird link. Or special inner link?
+        (setq url (concat "elpher:" url)))
+      (org-link-store-props :type protocol :link url :description desc)
+      t)))
+
+(defun elpher-org-follow-link (link protocol)
+  "Visit a LINK for the given PROTOCOL.
+
+PROTOCOL may be one of gemini, gopher or finger.  This method also
+supports the old protocol elpher, where the link is self-contained."
+  (let ((url (if (equal protocol "elpher")
+                 (string-remove-prefix "elpher:" link)
+               (format "%s:%s" protocol link))))
+    (elpher-go url)))
+
+(with-eval-after-load 'org
+  (org-link-set-parameters
+   "elpher"
+   :store #'elpher-org-store-link
+   :export (lambda (link description format _plist)
+             (elpher-org-export-link link description format "elpher"))
+   :follow (lambda (link _arg) (elpher-org-follow-link link "elpher")))
+  (org-link-set-parameters
+   "gemini"
+   :export (lambda (link description format _plist)
+             (elpher-org-export-link link description format "gemini"))
+   :follow (lambda (link _arg) (elpher-org-follow-link link "gemini")))
+  (org-link-set-parameters
+   "gopher"
+   :export (lambda (link description format _plist)
+             (elpher-org-export-link link description format "gopher"))
+   :follow (lambda (link _arg) (elpher-org-follow-link link "gopher")))
+  (org-link-set-parameters
+   "finger"
+   :export (lambda (link description format _plist)
+             (elpher-org-export-link link description format "finger"))
+   :follow (lambda (link _arg) (elpher-org-follow-link link "finger"))))
+
+;;; Browse URL
+
+;; Avoid byte compilation warnings.
+(eval-when-compile
+  (defvar thing-at-point-uri-schemes))
+
+;;;###autoload
+(defun elpher-browse-url-elpher (url &rest _args)
+  "Browse URL using Elpher.  This function is used by `browse-url'."
+  (interactive (browse-url-interactive-arg "Elpher URL: "))
+  (elpher-go url))
+
+;; Use elpher to open gopher, finger and gemini links
+;; For recent version of `browse-url' package
+(if (boundp 'browse-url-default-handlers)
+    (add-to-list
+     'browse-url-default-handlers
+     '("^\\(gopher\\|finger\\|gemini\\)://" . elpher-browse-url-elpher))
+  ;; Patch `browse-url-browser-function' for older ones. The value of
+  ;; that variable is `browse-url-default-browser' by default, so
+  ;; that's the function that gets advised.
+  (advice-add browse-url-browser-function :before-while
+              (lambda (url &rest _args)
+               "Handle gemini, gopher, and finger schemes using Elpher."
+                (let ((scheme (downcase (car (split-string url ":" t)))))
+                  (if (member scheme '("gemini" "gopher" "finger"))
+                      ;; `elpher-go' always returns nil, which will stop the
+                      ;; advice chain here in a before-while
+                      (elpher-go url)
+                    ;; chain must continue, then return t.
+                    t)))))
+
+;; Register "gemini://" as a URI scheme so `browse-url' does the right thing
+(with-eval-after-load 'thingatpt
+  (add-to-list 'thing-at-point-uri-schemes "gemini://"))
+
+;;; Mu4e:
+
+(eval-when-compile
+  (defvar mu4e~view-beginning-of-url-regexp))
+
+(with-eval-after-load 'mu4e-view
+  ;; Make mu4e aware of the gemini world
+  (setq mu4e~view-beginning-of-url-regexp
+        "\\(?:https?\\|gopher\\|finger\\|gemini\\)://\\|mailto:"))
+

 ;;; Interactive procedures
 ;;
 
 ;;; Interactive procedures
 ;;
 


@@ -1676,6 +1921,7 @@ If ADDRESS is already bookmarked, update the label only."
   (interactive)
   (push-button))
 
   (interactive)
   (push-button))
 

+;;;###autoload

 (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."
 (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."


@@ -1683,7 +1929,7 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   (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)))
   (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*")
+    (switch-to-buffer elpher-buffer-name)

     (elpher-visit-page page)
     nil))
 
     (elpher-visit-page page)
     nil))
 


@@ -1691,10 +1937,19 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   "Go to a particular site read from the minibuffer, initialized with the current URL."
   (interactive)
   (let ((address (elpher-page-address elpher-current-page)))
   "Go to a particular site read from the minibuffer, initialized with the current URL."
   (interactive)
   (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)))))))
+    (let ((url (read-string "Gopher or Gemini URL: "
+                            (unless (elpher-address-special-p address)
+                              (elpher-address-to-url address)))))
+      (elpher-visit-page (elpher-make-page url (elpher-address-from-url url))))))
+
+(defun elpher-visit-gemini-numbered-link (n)
+  "Visit link designated by a number N."
+  (interactive "nLink number: ")
+  (if (or (> n (length elpher--gemini-page-links))
+          (< n 1))
+      (user-error "Invalid link number"))
+  (let ((address (nth (1- n) elpher--gemini-page-links)))
+    (elpher-go (url-recreate-url address))))

 
 (defun elpher-redraw ()
   "Redraw current page."
 
 (defun elpher-redraw ()
   "Redraw current page."


@@ -1733,8 +1988,8 @@ When run interactively HOST-OR-URL is read from the minibuffer."
 (defun elpher-back-to-start ()
   "Go all the way back to the start page."
   (interactive)
 (defun elpher-back-to-start ()
   "Go all the way back to the start page."
   (interactive)

-  (setq elpher-current-page nil)
-  (setq elpher-history nil)
+  (setq-local elpher-current-page nil)
+  (setq-local elpher-history nil)

   (let ((start-page (elpher-make-page "Elpher Start Page"
                                       (elpher-make-special-address 'start))))
     (elpher-visit-page start-page)))
   (let ((start-page (elpher-make-page "Elpher Start Page"
                                       (elpher-make-special-address 'start))))
     (elpher-visit-page start-page)))


@@ -1861,10 +2116,11 @@ When run interactively HOST-OR-URL is read from the minibuffer."
             (message "Bookmark removed.")))
       (error "No link selected"))))
 
             (message "Bookmark removed.")))
       (error "No link selected"))))
 

+;;;###autoload

 (defun elpher-bookmarks ()
   "Visit bookmarks page."
   (interactive)
 (defun elpher-bookmarks ()
   "Visit bookmarks page."
   (interactive)

-  (switch-to-buffer "*elpher*")
+  (switch-to-buffer elpher-buffer-name)

   (elpher-visit-page
    (elpher-make-page "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
 
   (elpher-visit-page
    (elpher-make-page "Bookmarks Page" (elpher-make-special-address 'bookmarks))))
 


@@ -1883,7 +2139,7 @@ When run interactively HOST-OR-URL is read from the minibuffer."
     (if button
         (elpher-info-page (button-get button 'elpher-page))
       (error "No item selected"))))
     (if button
         (elpher-info-page (button-get button 'elpher-page))
       (error "No item selected"))))

-  
+

 (defun elpher-info-current ()
   "Display information on current page."
   (interactive)
 (defun elpher-info-current ()
   "Display information on current page."
   (interactive)


@@ -1953,34 +2209,39 @@ When run interactively HOST-OR-URL is read from the minibuffer."
     (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)
     (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)

+    (define-key map (kbd "v") 'elpher-visit-gemini-numbered-link)

     (when (fboundp 'evil-define-key*)
     (when (fboundp 'evil-define-key*)

-      (evil-define-key* 'motion map
-        (kbd "TAB") 'elpher-next-link
-        (kbd "C-") 'elpher-follow-current-link
-        (kbd "C-t") 'elpher-back
-        (kbd "u") 'elpher-back
-        (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 "T") 'elpher-toggle-tls
-        (kbd ".") '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 "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))
+      (evil-define-key*
+       'motion map
+       (kbd "TAB") 'elpher-next-link
+       (kbd "C-") 'elpher-follow-current-link
+       (kbd "C-t") 'elpher-back
+       (kbd "u") 'elpher-back
+       (kbd "-") 'elpher-back
+       (kbd "^") 'elpher-back
+       (kbd "U") 'elpher-back-to-start
+       [mouse-3] 'elpher-back
+       (kbd "o") 'elpher-go
+       (kbd "O") 'elpher-go-current
+       (kbd "r") 'elpher-redraw
+       (kbd "R") 'elpher-reload
+       (kbd "T") 'elpher-toggle-tls
+       (kbd ".") 'elpher-view-raw
+       (kbd "d") 'elpher-download
+       (kbd "D") 'elpher-download-current
+       (kbd "J") '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
+       (kbd "v") 'elpher-visit-gemini-numbered-link))

     map)
   "Keymap for gopher client.")
 
     map)
   "Keymap for gopher client.")
 


@@ -1989,7 +2250,15 @@ When run interactively HOST-OR-URL is read from the minibuffer."
 
 This mode is automatically enabled by the interactive
 functions which initialize the gopher client, namely
 
 This mode is automatically enabled by the interactive
 functions which initialize the gopher client, namely

-`elpher', `elpher-go' and `elpher-bookmarks'.")
+`elpher', `elpher-go' and `elpher-bookmarks'."
+  (setq-local elpher--gemini-page-headings nil)
+  (setq-local elpher-current-page nil)
+  (setq-local elpher-history nil)
+  (setq-local elpher-buffer-name (buffer-name))
+
+  (setq-local imenu-create-index-function
+              (lambda ()
+                elpher--gemini-page-headings)))

 
 (when (fboundp 'evil-set-initial-state)
   (evil-set-initial-state 'elpher-mode 'motion))
 
 (when (fboundp 'evil-set-initial-state)
   (evil-set-initial-state 'elpher-mode 'motion))


@@ -1999,17 +2268,30 @@ functions which initialize the gopher client, namely
 ;;
 
 ;;;###autoload
 ;;
 
 ;;;###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-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)))
-  "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 ‘\\[universal-argument] 42
+\\[execute-extended-command] elpher RET’) switches to the session with
+that number, creating it if necessary.  A non numeric 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)
+      (elpher-mode)
+      (let ((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
 
 ;;; elpher.el ends here