[gnus] / lisp / nntp.el

;;; nntp.el --- nntp access for Gnus
;;; Copyright (C) 1987-90,92-97 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
;; Keywords: news

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Commentary:

;;; Code:

(require 'nnheader)
(require 'nnoo)
(require 'gnus-util)

(nnoo-declare nntp)

(eval-and-compile
  (unless (fboundp 'open-network-stream)
    (require 'tcp)))

(eval-when-compile (require 'cl))

(defvoo nntp-address nil
  "Address of the physical nntp server.")

(defvoo nntp-port-number "nntp"
  "Port number on the physical nntp server.")

(defvoo nntp-server-opened-hook '(nntp-send-mode-reader)
  "*Hook used for sending commands to the server at startup.
The default value is `nntp-send-mode-reader', which makes an innd
server spawn an nnrpd server.  Another useful function to put in this
hook might be `nntp-send-authinfo', which will prompt for a password
to allow posting from the server.  Note that this is only necessary to
do on servers that use strict access control.")

(defvoo nntp-authinfo-function 'nntp-send-authinfo
  "Function used to send AUTHINFO to the server.")

(defvoo nntp-server-action-alist
  '(("nntpd 1\\.5\\.11t"
     (remove-hook 'nntp-server-opened-hook 'nntp-send-mode-reader))
    ("NNRP server Netscape"
     (setq nntp-server-list-active-group nil)))
  "Alist of regexps to match on server types and actions to be taken.
For instance, if you want Gnus to beep every time you connect
to innd, you could say something like:

\(setq nntp-server-action-alist
       '((\"innd\" (ding))))

You probably don't want to do that, though.")

(defvoo nntp-open-connection-function 'nntp-open-network-stream
  "*Function used for connecting to a remote system.
It will be called with the buffer to output in.

Two pre-made functions are `nntp-open-network-stream', which is the
default, and simply connects to some port or other on the remote
system (see nntp-port-number).  The other are `nntp-open-rlogin',
which does an rlogin on the remote system, and then does a telnet to
the NNTP server available there (see nntp-rlogin-parameters) and
`nntp-open-telnet' which telnets to a remote system, logs in and does
the same.")

(defvoo nntp-rlogin-program "rsh"
  "*Program used to log in on remote machines.
The default is \"rsh\", but \"ssh\" is a popular alternative.")

(defvoo nntp-rlogin-parameters '("telnet" "-8" "${NNTPSERVER:=news}" "nntp")
  "*Parameters to `nntp-open-login'.
That function may be used as `nntp-open-connection-function'.  In that
case, this list will be used as the parameter list given to rsh.")

(defvoo nntp-rlogin-user-name nil
  "*User name on remote system when using the rlogin connect method.")

(defvoo nntp-telnet-parameters '("exec" "telnet" "-8" "${NNTPSERVER:=news}" "nntp")
  "*Parameters to `nntp-open-telnet'.
That function may be used as `nntp-open-connection-function'.  In that
case, this list will be executed as a command after logging in
via telnet.")

(defvoo nntp-telnet-user-name nil
  "User name to log in via telnet with.")

(defvoo nntp-telnet-passwd nil
  "Password to use to log in via telnet with.")

(defvoo nntp-open-telnet-envuser nil
  "*If non-nil, telnet session (client and server both) will support the ENVIRON option and not prompt for login name.")

(defvoo nntp-telnet-shell-prompt "bash\\|\$ *\r?$\\|> *\r?"
  "*Regular expression to match the shell prompt on the remote machine.")

(defvoo nntp-telnet-command "telnet"
  "Command used to start telnet.")

(defvoo nntp-telnet-switches '("-8")
  "Switches given to the telnet command.")

(defvoo nntp-end-of-line "\r\n"
  "String to use on the end of lines when talking to the NNTP server.
This is \"\\r\\n\" by default, but should be \"\\n\" when
using rlogin or telnet to communicate with the server.")

(defvoo nntp-large-newsgroup 50
  "*The number of the articles which indicates a large newsgroup.
If the number of the articles is greater than the value, verbose
messages will be shown to indicate the current status.")

(defvoo nntp-maximum-request 400
  "*The maximum number of the requests sent to the NNTP server at one time.
If Emacs hangs up while retrieving headers, set the variable to a
lower value.")

(defvoo nntp-nov-is-evil nil
  "*If non-nil, nntp will never attempt to use XOVER when talking to the server.")

(defvoo nntp-xover-commands '("XOVER" "XOVERVIEW")
  "*List of strings that are used as commands to fetch NOV lines from a server.
The strings are tried in turn until a positive response is gotten.  If
none of the commands are successful, nntp will just grab headers one
by one.")

(defvoo nntp-nov-gap 5
  "*Maximum allowed gap between two articles.
If the gap between two consecutive articles is bigger than this
variable, split the XOVER request into two requests.")

(defvoo nntp-connection-timeout nil
  "*Number of seconds to wait before an nntp connection times out.
If this variable is nil, which is the default, no timers are set.")

(defvoo nntp-prepare-server-hook nil
  "*Hook run before a server is opened.
If can be used to set up a server remotely, for instance.  Say you
have an account at the machine \"other.machine\".  This machine has
access to an NNTP server that you can't access locally.  You could
then use this hook to rsh to the remote machine and start a proxy NNTP
server there that you can connect to.  See also `nntp-open-connection-function'")

(defvoo nntp-warn-about-losing-connection t
  "*If non-nil, beep when a server closes connection.")

(defvoo nntp-coding-system-for-read 'binary
  "*Coding system to read from NNTP.")

(defvoo nntp-coding-system-for-write 'binary
    "*Coding system to write to NNTP.")

\f

;;; Internal variables.

(defvar nntp-have-messaged nil)

(defvar nntp-process-wait-for nil)
(defvar nntp-process-to-buffer nil)
(defvar nntp-process-callback nil)
(defvar nntp-process-decode nil)
(defvar nntp-process-start-point nil)
(defvar nntp-inside-change-function nil)
(defvoo nntp-last-command-time nil)
(defvoo nntp-last-command nil)

(defvar nntp-connection-list nil)

(defvoo nntp-server-type nil)
(defvoo nntp-connection-alist nil)
(defvoo nntp-status-string "")
(defconst nntp-version "nntp 5.0")
(defvoo nntp-inhibit-erase nil)
(defvoo nntp-inhibit-output nil)

(defvoo nntp-server-xover 'try)
(defvoo nntp-server-list-active-group 'try)

(eval-and-compile
  (autoload 'nnmail-read-passwd "nnmail"))

\f

;;; Internal functions.

(defsubst nntp-send-string (process string)
  "Send STRING to PROCESS."
  (setq nntp-last-command-time (current-time)
        nntp-last-command string)
  (process-send-string process (concat string nntp-end-of-line)))

(defsubst nntp-wait-for (process wait-for buffer &optional decode discard)
  "Wait for WAIT-FOR to arrive from PROCESS."
  (save-excursion
    (set-buffer (process-buffer process))
    (goto-char (point-min))
    (while (or (not (memq (char-after (point)) '(?2 ?3 ?4 ?5)))
               (looking-at "480"))
      (when (looking-at "480")
        (nntp-handle-authinfo process))
      (nntp-accept-process-output process)
      (goto-char (point-min)))
    (prog1
        (if (looking-at "[45]")
            (progn
              (nntp-snarf-error-message)
              nil)
          (goto-char (point-max))
          (let ((limit (point-min)))
            (while (not (re-search-backward wait-for limit t))
              (nntp-accept-process-output process)
              ;; We assume that whatever we wait for is less than 1000
              ;; characters long.
              (setq limit (max (- (point-max) 1000) (point-min)))
              (goto-char (point-max))))
          (nntp-decode-text (not decode))
          (unless discard
            (save-excursion
              (set-buffer buffer)
              (goto-char (point-max))
              (insert-buffer-substring (process-buffer process))
              ;; Nix out "nntp reading...." message.
              (when nntp-have-messaged
                (setq nntp-have-messaged nil)
                (message ""))
              t)))
      (unless discard
        (erase-buffer)))))

(defsubst nntp-find-connection (buffer)
  "Find the connection delivering to BUFFER."
  (let ((alist nntp-connection-alist)
        (buffer (if (stringp buffer) (get-buffer buffer) buffer))
        process entry)
    (while (setq entry (pop alist))
      (when (eq buffer (cadr entry))
        (setq process (car entry)
              alist nil)))
    (when process
      (if (memq (process-status process) '(open run))
          process
        (when (buffer-name (process-buffer process))
          (kill-buffer (process-buffer process)))
        (setq nntp-connection-alist (delq entry nntp-connection-alist))
        nil))))

(defsubst nntp-find-connection-entry (buffer)
  "Return the entry for the connection to BUFFER."
  (assq (nntp-find-connection buffer) nntp-connection-alist))

(defun nntp-find-connection-buffer (buffer)
  "Return the process connection buffer tied to BUFFER."
  (let ((process (nntp-find-connection buffer)))
    (when process
      (process-buffer process))))

(defsubst nntp-retrieve-data (command address port buffer
                                      &optional wait-for callback decode)
  "Use COMMAND to retrieve data into BUFFER from PORT on ADDRESS."
  (let ((process (or (nntp-find-connection buffer)
                     (nntp-open-connection buffer))))
    (if (not process)
        (nnheader-report 'nntp "Couldn't open connection to %s" address)
      (unless (or nntp-inhibit-erase nnheader-callback-function)
        (save-excursion
          (set-buffer (process-buffer process))
          (erase-buffer)))
      (when command
        (nntp-send-string process command))
      (cond
       ((eq callback 'ignore)
        t)
       ((and callback wait-for)
        (save-excursion
    &