lisp/mail/rnews.el

   1 ;;; rnews.el --- USENET news reader for gnu emacs
   2
   3 ;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc.
   4
   5 ;; This file is part of GNU Emacs.
   6
   7 ;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation; either version 1, or (at your option)
  10 ;; any later version.
  11
  12 ;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  19 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 ;; Created Sun Mar 10,1985 at 21:35:01 ads and sundar@hernes.ai.mit.edu
  22 ;; Should do the point pdl stuff sometime
  23 ;; finito except pdl.... Sat Mar 16,1985 at 06:43:44
  24 ;; lets keep the summary stuff out until we get it working ..
  25 ;;      sundar@hermes.ai.mit.edu Wed Apr 10,1985 at 16:32:06
  26 ;; hack slash maim. mly@prep.ai.mit.edu Thu 18 Apr, 1985 06:11:14
  27 ;; modified to correct reentrance bug, to not bother with groups that
  28 ;;   received no new traffic since last read completely, to find out
  29 ;;   what traffic a group has available much more quickly when
  30 ;;   possible, to do some completing reads for group names - should
  31 ;;   be much faster...
  32 ;;      KING@KESTREL.arpa, Thu Mar 13 09:03:28 1986
  33 ;; made news-{next,previous}-group skip groups with no new messages; and
  34 ;; added checking for unsubscribed groups to news-add-news-group
  35 ;;      tower@prep.ai.mit.edu Jul 18 1986
  36 ;; bound rmail-output to C-o; and changed header-field commands binding to
  37 ;; agree with the new C-c C-f usage in sendmail
  38 ;;      tower@prep Sep  3 1986
  39 ;; added news-rotate-buffer-body
  40 ;;      tower@prep Oct 17 1986
  41 ;; made messages more user friendly, cleanuped news-inews
  42 ;; move posting and mail code to new file rnewpost.el
  43 ;;      tower@prep Oct 29 1986
  44 ;; added caesar-region, rename news-caesar-buffer-body, hacked accordingly
  45 ;;      tower@prep Nov 21 1986
  46 ;; added tower@prep 22 Apr 87
  47 (require 'mail-utils)
  48
  49 (autoload 'rmail-output "rmailout"
  50   "Append this message to Unix mail file named FILE-NAME."
  51   t)
  52
  53 (autoload 'news-reply "rnewspost"
  54   "Compose and post a reply to the current article on USENET.
  55 While composing the reply, use \\[mail-yank-original] to yank the original
  56 message into it."
  57   t)
  58
  59 (autoload 'news-mail-other-window "rnewspost"
  60   "Send mail in another window.
  61 While composing the message, use \\[mail-yank-original] to yank the
  62 original message into it."
  63   t)
  64
  65 (autoload 'news-post-news "rnewspost"
  66   "Begin editing a new USENET news article to be posted."
  67   t)
  68
  69 (autoload 'news-mail-reply "rnewspost"
  70   "Mail a reply to the author of the current article.
  71 While composing the reply, use \\[mail-yank-original] to yank the original
  72 message into it."
  73   t)
  74
  75 (defvar news-group-hook-alist nil
  76   "Alist of (GROUP-REGEXP . HOOK) pairs.
  77 Just before displaying a message, each HOOK is called
  78 if its GROUP-REGEXP matches the current newsgroup name.")
  79
  80 (defvar rmail-last-file (expand-file-name "~/mbox.news"))
  81
  82 ;Now in paths.el.
  83 ;(defvar news-path "/usr/spool/news/"
  84 ;  "The root directory below which all news files are stored.")
  85
  86 (defvar news-startup-file "$HOME/.newsrc" "Contains ~/.newsrc")
  87 (defvar news-certification-file "$HOME/.news-dates" "Contains ~/.news-dates")
  88
  89 ;; random headers that we decide to ignore.
  90 (defvar news-ignored-headers
  91   "^Path:\\|^Posting-Version:\\|^Article-I.D.:\\|^Expires:\\|^Date-Received:\\|^References:\\|^Control:\\|^Xref:\\|^Lines:\\|^Posted:\\|^Relay-Version:\\|^Message-ID:\\|^Nf-ID:\\|^Nf-From:\\|^Approved:\\|^Sender:"
  92   "All random fields within the header of a message.")
  93
  94 (defvar news-mode-map nil)
  95 (defvar news-read-first-time-p t)
  96 ;; Contains the (dotified) news groups of which you are a member.
  97 (defvar news-user-group-list nil)
  98
  99 (defvar news-current-news-group nil)
 100 (defvar news-current-group-begin nil)
 101 (defvar news-current-group-end  nil)
 102 (defvar news-current-certifications nil
 103         "An assoc list of a group name and the time at which it is
 104 known that the group had no new traffic")
 105 (defvar news-current-certifiable nil
 106         "The time when the directory we are now working on was written")
 107
 108 (defvar news-message-filter nil
 109   "User specifiable filter function that will be called during
 110 formatting of the news file")
 111
 112 ;(defvar news-mode-group-string "Starting-Up"
 113 ;  "Mode line group name info is held in this variable")
 114 (defvar news-list-of-files nil
 115   "Global variable in which we store the list of files
 116 associated with the current newsgroup")
 117 (defvar news-list-of-files-possibly-bogus nil
 118   "variable indicating we only are guessing at which files are available.
 119 Not currently used.")
 120
 121 ;; association list in which we store lists of the form
 122 ;; (pointified-group-name (first last old-last))
 123 (defvar news-group-article-assoc nil)
 124
 125 (defvar news-current-message-number 0 "Displayed Article Number")
 126 (defvar news-total-current-group 0 "Total no of messages in group")
 127
 128 (defvar news-unsubscribe-groups ())
 129 (defvar news-point-pdl () "List of visited news messages.")
 130 (defvar news-no-jumps-p t)
 131 (defvar news-buffer () "Buffer into which news files are read.")
 132
 133 (defmacro news-push (item ref)
 134   (list 'setq ref (list 'cons item ref)))
 135
 136 (defmacro news-cadr (x) (list 'car (list 'cdr x)))
 137 (defmacro news-cdar (x) (list 'cdr (list 'car x)))
 138 (defmacro news-caddr (x) (list 'car (list 'cdr (list 'cdr x))))
 139 (defmacro news-cadar (x) (list 'car (list 'cdr (list 'car x))))
 140 (defmacro news-caadr (x) (list 'car (list 'car (list 'cdr x))))
 141 (defmacro news-cdadr (x) (list 'cdr (list 'car (list 'cdr x))))
 142
 143 (defmacro news-wins (pfx index)
 144   (` (file-exists-p (concat (, pfx) "/" (int-to-string (, index))))))
 145
 146 (defvar news-max-plausible-gap 2
 147         "* In an rnews directory, the maximum possible gap size.
 148 A gap is a sequence of missing messages between two messages that exist.
 149 An empty file does not contribute to a gap -- it ends one.")
 150
 151 (defun news-find-first-and-last (prefix base)
 152   (and (news-wins prefix base)
 153        (cons (news-find-first-or-last prefix base -1)
 154              (news-find-first-or-last prefix base 1))))
 155
 156 (defmacro news-/ (a1 a2)
 157 ;; a form of / that guarantees that (/ -1 2) = 0
 158   (if (zerop (/ -1 2))
 159       (` (/ (, a1) (, a2)))
 160     (` (if (< (, a1) 0)
 161            (- (/ (- (, a1)) (, a2)))
 162          (/ (, a1) (, a2))))))
 163
 164 (defun news-find-first-or-last (pfx base dirn)
 165   ;; first use powers of two to find a plausible ceiling
 166   (let ((original-dir dirn))
 167     (while (news-wins pfx (+ base dirn))
 168       (setq dirn (* dirn 2)))
 169     (setq dirn (news-/ dirn 2))
 170     ;; Then use a binary search to find the high water mark
 171     (let ((offset (news-/ dirn 2)))
 172       (while (/= offset 0)
 173         (if (news-wins pfx (+ base dirn offset))
 174             (setq dirn (+ dirn offset)))
 175         (setq offset (news-/ offset 2))))
 176     ;; If this high-water mark is bogus, recurse.
 177     (let ((offset (* news-max-plausible-gap original-dir)))
 178       (while (and (/= offset 0) (not (news-wins pfx (+ base dirn offset))))
 179         (setq offset (- offset original-dir)))
 180       (if (= offset 0)
 181           (+ base dirn)
 182         (news-find-first-or-last pfx (+ base dirn offset) original-dir)))))
 183
 184 (defun rnews ()
 185 "Read USENET news for groups for which you are a member and add or
 186 delete groups.
 187 You can reply to articles posted and send articles to any group.
 188
 189 Type \\[describe-mode] once reading news to get a list of rnews commands."
 190   (interactive)
 191   (let ((last-buffer (buffer-name)))
 192     (make-local-variable 'rmail-last-file)
 193     (switch-to-buffer (setq news-buffer (get-buffer-create "*news*")))
 194     (news-mode)
 195     (setq news-buffer-save last-buffer)
 196     (setq buffer-read-only nil)
 197     (erase-buffer)
 198     (setq buffer-read-only t)
 199     (set-buffer-modified-p t)
 200     (sit-for 0)
 201     (message "Getting new USENET news...")
 202     (news-set-mode-line)
 203     (news-get-certifications)
 204     (news-get-new-news)))
 205
 206 (defun news-group-certification (group)
 207   (cdr-safe (assoc group news-current-certifications)))
 208
 209
 210 (defun news-set-current-certifiable ()
 211   ;; Record the date that corresponds to the directory you are about to check
 212   (let ((file (concat news-path
 213                       (string-subst-char ?/ ?. news-current-news-group))))
 214     (setq news-current-certifiable
 215           (nth 5 (file-attributes
 216                   (or (file-symlink-p file) file))))))
 217
 218 (defun news-get-certifications ()
 219   ;; Read the certified-read file from last session
 220   (save-excursion
 221     (save-window-excursion
 222       (setq news-current-certifications
 223             (car-safe
 224              (condition-case var
 225                  (let*
 226                      ((file (substitute-in-file-name news-certification-file))
 227                       (buf (find-file-noselect file)))
 228                    (and (file-exists-p file)
 229                         (progn
 230                           (switch-to-buffer buf 'norecord)
 231                           (unwind-protect
 232                               (read-from-string (buffer-string))
 233                             (kill-buffer buf)))))
 234                (error nil)))))))
 235
 236 (defun news-write-certifications ()
 237   ;; Write a certification file.
 238   ;; This is an assoc list of group names with doubletons that represent
 239   ;; mod times of the directory when group is read completely.
 240   (save-excursion
 241     (save-window-excursion
 242       (with-output-to-temp-buffer
 243           "*CeRtIfIcAtIoNs*"
 244           (print news-current-certifications))
 245       (let ((buf (get-buffer "*CeRtIfIcAtIoNs*")))
 246         (switch-to-buffer buf)
 247         (write-file (substitute-in-file-name news-certification-file))
 248         (kill-buffer buf)))))
 249
 250 (defun news-set-current-group-certification ()
 251   (let ((cgc (assoc news-current-news-group news-current-certifications)))
 252     (if cgc (setcdr cgc news-current-certifiable)
 253       (news-push (cons news-current-news-group news-current-certifiable)
 254                  news-current-certifications))))
 255
 256 (defun news-set-minor-modes ()
 257   "Creates a minor mode list that has group name, total articles,
 258 and attribute for current article."
 259   (setq news-minor-modes (list (cons 'foo
 260                                      (concat news-current-message-number
 261                                              "/"
 262                                              news-total-current-group
 263                                              (news-get-attribute-string)))))
 264   ;; Detect Emacs versions 18.16 and up, which display
 265   ;; directly from news-minor-modes by using a list for mode-name.
 266   (or (boundp 'minor-mode-alist)
 267       (setq minor-modes news-minor-modes)))
 268
 269 (defun news-set-message-counters ()
 270   "Scan through current news-groups filelist to figure out how many messages
 271 are there. Set counters for use with minor mode display."
 272     (if (null news-list-of-files)
 273         (setq news-current-message-number 0)))
 274
 275 (if news-mode-map
 276     nil
 277   (setq news-mode-map (make-keymap))
 278   (suppress-keymap news-mode-map)
 279   (define-key news-mode-map "." 'beginning-of-buffer)
 280   (define-key news-mode-map " " 'scroll-up)
 281   (define-key news-mode-map "\177" 'scroll-down)
 282   (define-key news-mode-map "n" 'news-next-message)
 283   (define-key news-mode-map "c" 'news-make-link-to-message)
 284   (define-key news-mode-map "p" 'news-previous-message)
 285   (define-key news-mode-map "j" 'news-goto-message)
 286   (define-key news-mode-map "q" 'news-exit)
 287   (define-key news-mode-map "e" 'news-exit)
 288   (define-key news-mode-map "\ej" 'news-goto-news-group)
 289   (define-key news-mode-map "\en" 'news-next-group)
 290   (define-key news-mode-map "\ep" 'news-previous-group)
 291   (define-key news-mode-map "l" 'news-list-news-groups)
 292   (define-key news-mode-map "?" 'describe-mode)
 293   (define-key news-mode-map "g" 'news-get-new-news)
 294   (define-key news-mode-map "f" 'news-reply)
 295   (define-key news-mode-map "m" 'news-mail-other-window)
 296   (define-key news-mode-map "a" 'news-post-news)
 297   (define-key news-mode-map "r" 'news-mail-reply)
 298   (define-key news-mode-map "o" 'news-save-item-in-file)
 299   (define-key news-mode-map "\C-o" 'rmail-output)
 300   (define-key news-mode-map "t" 'news-show-all-headers)
 301   (define-key news-mode-map "x" 'news-force-update)
 302   (define-key news-mode-map "A" 'news-add-news-group)
 303   (define-key news-mode-map "u" 'news-unsubscribe-current-group)
 304   (define-key news-mode-map "U" 'news-unsubscribe-group)
 305   (define-key news-mode-map "\C-c\C-r" 'news-caesar-buffer-body))
 306
 307 (defun news-mode ()
 308   "News Mode is used by M-x rnews for reading USENET Newsgroups articles.
 309 New readers can find additional help in newsgroup: news.announce.newusers .
 310 All normal editing commands are turned off.
 311 Instead, these commands are available:
 312
 313 .       move point to front of this news article (same as Meta-<).
 314 Space   scroll to next screen of this news article.
 315 Delete  scroll down previous page of this news article.
 316 n       move to next news article, possibly next group.
 317 p       move to previous news article, possibly previous group.
 318 j       jump to news article specified by numeric position.
 319 M-j     jump to news group.
 320 M-n     goto next news group.
 321 M-p     goto previous news group.
 322 l       list all the news groups with current status.
 323 ?       print this help message.
 324 C-c C-r caesar rotate all letters by 13 places in the article's body (rot13).
 325 g       get new USENET news.
 326 f       post a reply article to USENET.
 327 a       post an original news article.
 328 A       add a newsgroup.
 329 o       save the current article in the named file (append if file exists).
 330 C-o     output this message to a Unix-format mail file (append it).
 331 c       \"copy\" (actually link) current or prefix-arg msg to file.
 332         warning: target directory and message file must be on same device
 333                 (UNIX magic)
 334 t       show all the headers this news article originally had.
 335 q       quit reading news after updating .newsrc file.
 336 e       exit updating .newsrc file.
 337 m       mail a news article.  Same as C-x 4 m.
 338 x       update last message seen to be the current message.
 339 r       mail a reply to this news article.  Like m but initializes some fields.
 340 u       unsubscribe from current newsgroup.
 341 U       unsubscribe from specified newsgroup."
 342   (interactive)
 343   (kill-all-local-variables)
 344   (make-local-variable 'news-read-first-time-p)
 345   (setq news-read-first-time-p t)
 346   (make-local-variable 'news-current-news-group)
 347 ;  (setq news-current-news-group "??")
 348   (make-local-variable 'news-current-group-begin)
 349   (setq news-current-group-begin 0)
 350   (make-local-variable 'news-current-message-number)
 351   (setq news-current-message-number 0)
 352   (make-local-variable 'news-total-current-group)
 353   (make-local-variable 'news-buffer-save)
 354   (make-local-variable 'version-control)
 355   (setq version-control 'never)
 356   (make-local-variable 'news-point-pdl)
 357 ;  This breaks it.  I don't have time to figure out why. -- RMS
 358 ;  (make-local-variable 'news-group-article-assoc)
 359   (setq major-mode 'news-mode)
 360   (if (boundp 'minor-mode-alist)
 361       ;; Emacs versions 18.16 and up.
 362       (setq mode-name '("NEWS" news-minor-modes))
 363     ;; Earlier versions display minor-modes via a special mechanism.
 364     (setq mode-name "NEWS"))
 365   (news-set-mode-line)
 366   (set-syntax-table text-mode-syntax-table)
 367   (use-local-map news-mode-map)
 368   (setq local-abbrev-table text-mode-abbrev-table)
 369   (run-hooks 'news-mode-hook))
 370
 371 (defun string-subst-char (new old string)
 372   (let (index)
 373     (setq old (regexp-quote (char-to-string old))
 374           string (substring string 0))
 375     (while (setq index (string-match old string))
 376       (aset string index new)))
 377   string)
 378
 379 ;; update read message number
 380 (defmacro news-update-message-read (ngroup nno)
 381   (list 'setcar
 382         (list 'news-cdadr
 383               (list 'assoc ngroup 'news-group-article-assoc))
 384         nno))
 385
 386 (defun news-parse-range (number-string)
 387   "Parse string representing range of numbers of he form <a>-<b>
 388 to a list (a . b)"
 389   (let ((n (string-match "-" number-string)))
 390     (if n
 391         (cons (string-to-int (substring number-string 0 n))
 392               (string-to-int (substring number-string (1+ n))))
 393       (setq n (string-to-int number-string))
 394       (cons n n))))
 395
 396 ;(defun is-in (elt lis)
 397 ;  (catch 'foo
 398 ;    (while lis
 399 ;      (if (equal (car lis) elt)
 400 ;         (throw 'foo t)
 401 ;       (setq lis (cdr lis))))))
 402
 403 (defun news-get-new-news ()
 404   "Get new USENET news, if there is any for the current user."
 405   (interactive)
 406   (if (not (null news-user-group-list))
 407       (news-update-newsrc-file))
 408   (setq news-group-article-assoc ())
 409   (setq news-user-group-list ())
 410   (message "Looking up %s file..." news-startup-file)
 411   (let ((file (substitute-in-file-name news-startup-file))
 412         (temp-user-groups ()))
 413     (save-excursion
 414       (let ((newsrcbuf (find-file-noselect file))
 415             start end endofline tem)
 416         (set-buffer newsrcbuf)
 417         (goto-char 0)
 418         (while (search-forward ": " nil t)
 419           (setq end (point))
 420           (beginning-of-line)
 421           (setq start (point))
 422           (end-of-line)
 423           (setq endofline (point))
 424           (setq tem (buffer-substring start (- end 2)))
 425           (let ((range (news-parse-range
 426                         (buffer-substring end endofline))))
 427             (if (assoc tem news-group-article-assoc)
 428                 (message "You are subscribed twice to %s; I ignore second"
 429                          tem)
 430               (setq temp-user-groups (cons tem temp-user-groups)
 431                     news-group-article-assoc
 432                     (cons (list tem (list (car range)
 433                                           (cdr range)
 434                                           (cdr range)))
 435                           news-group-article-assoc)))))
 436         (kill-buffer newsrcbuf)))
 437     (setq temp-user-groups (nreverse temp-user-groups))
 438     (message "Prefrobnicating...")
 439     (switch-to-buffer news-buffer)
 440     (setq news-user-group-list temp-user-groups)
 441     (while (and temp-user-groups
 442                 (not (news-read-files-into-buffer
 443                       (car temp-user-groups) nil)))
 444       (setq temp-user-groups (cdr temp-user-groups)))
 445     (if (null temp-user-groups)
 446         (message "No news is good news.")
 447       (message ""))))
 448
 449 (defun news-list-news-groups ()
 450   "Display all the news groups to which you belong."
 451   (interactive)
 452   (with-output-to-temp-buffer "*Newsgroups*"
 453     (save-excursion
 454       (set-buffer standard-output)
 455       (insert
 456         "News Group        Msg No.       News Group        Msg No.\n")
 457       (insert
 458         "-------------------------       -------------------------\n")
 459       (let ((temp news-user-group-list)
 460             (flag nil))
 461         (while temp
 462           (let ((item (assoc (car temp) news-group-article-assoc)))
 463             (insert (car item))
 464             (indent-to (if flag 52 20))
 465             (insert (int-to-string (news-cadr (news-cadr item))))
 466             (if flag
 467                 (insert "\n")
 468               (indent-to 33))
 469             (setq temp (cdr temp) flag (not flag))))))))
 470
 471 ;; Mode line hack
 472 (defun news-set-mode-line ()
 473   "Set mode line string to something useful."
 474   (setq mode-line-process
 475         (concat " "
 476                 (if (integerp news-current-message-number)
 477                     (int-to-string news-current-message-number)
 478                  "??")
 479                 "/"
 480                 (if (integerp news-current-group-end)
 481                     (int-to-string news-current-group-end)
 482                   news-current-group-end)))
 483   (setq mode-line-buffer-identification
 484         (concat "NEWS: "
 485                 news-current-news-group
 486                 ;; Enough spaces to pad group name to 17 positions.
 487                 (substring "                 "
 488                            0 (max 0 (- 17 (length news-current-news-group))))))
 489   (set-buffer-modified-p t)
 490   (sit-for 0))
 491
 492 (defun news-goto-news-group (gp)
 493   "Takes a string and goes to that news group."
 494   (interactive (list (completing-read "NewsGroup: "
 495                                       news-group-article-assoc)))
 496   (message "Jumping to news group %s..." gp)
 497   (news-select-news-group gp)
 498   (message "Jumping to news group %s... done." gp))
 499
 500 (defun news-select-news-group (gp)
 501   (let ((grp (assoc gp news-group-article-assoc)))
 502     (if (null grp)
 503         (error "Group %s not subscribed to" gp)
 504       (progn
 505         (news-update-message-read news-current-news-group
 506                                   (news-cdar news-point-pdl))
 507         (news-read-files-into-buffer  (car grp) nil)
 508         (news-set-mode-line)))))
 509
 510 (defun news-goto-message (arg)
 511   "Goes to the article ARG in current newsgroup."
 512   (interactive "p")
 513   (if (null current-prefix-arg)
 514       (setq arg (read-no-blanks-input "Go to article: " "")))
 515   (news-select-message arg))
 516
 517 (defun news-select-message (arg)
 518   (if (stringp arg) (setq arg (string-to-int arg)))
 519   (let ((file (concat news-path
 520                       (string-subst-char ?/ ?. news-current-news-group)
 521                       "/" arg)))
 522     (if (file-exists-p file)
 523         (let ((buffer-read-only ()))
 524           (if (= arg
 525                  (or (news-cadr (memq (news-cdar news-point-pdl) news-list-of-files))
 526                      0))
 527               (setcdr (car news-point-pdl) arg))
 528           (setq news-current-message-number arg)
 529           (news-read-in-file file)
 530           (news-set-mode-line))
 531       (error "Article %d nonexistent" arg))))
 532
 533 (defun news-force-update ()
 534   "updates the position of last article read in the current news group"
 535   (interactive)
 536   (setcdr (car news-point-pdl) news-current-message-number)
 537   (message "Updated to %d" news-current-message-number))
 538
 539 (defun news-next-message (arg)
 540   "Move ARG messages forward within one newsgroup.
 541 Negative ARG moves backward.
 542 If ARG is 1 or -1, moves to next or previous newsgroup if at end."
 543   (interactive "p")
 544   (let ((no (+ arg news-current-message-number)))
 545     (if (or (< no news-current-group-begin)
 546             (> no news-current-group-end))
 547         (cond ((= arg 1)
 548                (news-set-current-group-certification)
 549                (news-next-group))
 550               ((= arg -1)
 551                (news-previous-group))
 552               (t (error "Article out of range")))
 553       (let ((plist (news-get-motion-lists
 554                      news-current-message-number
 555                      news-list-of-files)))
 556         (if (< arg 0)
 557             (news-select-message (nth (1- (- arg)) (car (cdr plist))))
 558           (news-select-message (nth (1- arg) (car plist))))))))
 559
 560 (defun news-previous-message (arg)
 561   "Move ARG messages backward in current newsgroup.
 562 With no arg or arg of 1, move one message
 563 and move to previous newsgroup if at beginning.
 564 A negative ARG means move forward."
 565   (interactive "p")
 566   (news-next-message (- arg)))
 567
 568 (defun news-move-to-group (arg)
 569   "Given arg move forward or backward to a new newsgroup."
 570   (let ((cg news-current-news-group))
 571     (let ((plist (news-get-motion-lists cg news-user-group-list))
 572           ngrp)
 573       (if (< arg 0)
 574           (or (setq ngrp (nth (1- (- arg)) (news-cadr plist)))
 575               (error "No previous news groups"))
 576         (or (setq ngrp (nth arg (car plist)))
 577             (error "No more news groups")))
 578       (news-select-news-group ngrp))))
 579
 580 (defun news-next-group ()
 581   "Moves to the next user group."
 582   (interactive)
 583 ;  (message "Moving to next group...")
 584   (news-move-to-group 0)
 585   (while (null news-list-of-files)
 586     (news-move-to-group 0)))
 587 ;  (message "Moving to next group... done.")
 588
 589 (defun news-previous-group ()
 590   "Moves to the previous user group."
 591   (interactive)
 592 ;  (message "Moving to previous group...")
 593   (news-move-to-group -1)
 594   (while (null news-list-of-files)
 595     (news-move-to-group -1)))
 596 ;  (message "Moving to previous group... done.")
 597
 598 (defun news-get-motion-lists (arg listy)
 599   "Given a msgnumber/group this will return a list of two lists;
 600 one for moving forward and one for moving backward."
 601   (let ((temp listy)
 602         (result ()))
 603     (catch 'out
 604       (while temp
 605         (if (equal (car temp) arg)
 606             (throw 'out (cons (cdr temp) (list result)))
 607           (setq result (nconc (list (car temp)) result))
 608           (setq temp (cdr temp)))))))
 609
 610 ;; miscellaneous io routines
 611 (defun news-read-in-file (filename)
 612   (erase-buffer)
 613   (let ((start (point)))
 614   (insert-file-contents filename)
 615   (news-convert-format)
 616   ;; Run each hook that applies to the current newsgroup.
 617   (let ((hooks news-group-hook-alist))
 618     (while hooks
 619       (goto-char start)
 620       (if (string-match (car (car hooks)) news-group-name)
 621           (funcall (cdr (car hooks))))
 622       (setq hooks (cdr hooks))))
 623   (goto-char start)
 624   (forward-line 1)
 625   (if (eobp)
 626       (message "(Empty file?)")
 627     (goto-char start))))
 628
 629 (defun news-convert-format ()
 630   (save-excursion
 631     (save-restriction
 632       (let* ((start (point))
 633              (end (condition-case ()
 634                       (progn (search-forward "\n\n") (point))
 635                     (error nil)))
 636              has-from has-date)
 637        (cond (end
 638               (narrow-to-region start end)
 639               (goto-char start)
 640               (setq has-from (search-forward "\nFrom:" nil t))
 641               (cond ((and (not has-from) has-date)
 642                      (goto-char start)
 643                      (search-forward "\nDate:")
 644                      (beginning-of-line)
 645                      (kill-line) (kill-line)))
 646               (news-delete-headers start)
 647               (goto-char start)))))))
 648
 649 (defun news-show-all-headers ()
 650   "Redisplay current news item with all original headers"
 651   (interactive)
 652   (let (news-ignored-headers
 653         (buffer-read-only ()))
 654     (erase-buffer)
 655     (news-set-mode-line)
 656     (news-read-in-file
 657      (concat news-path
 658              (string-subst-char ?/ ?. news-current-news-group)
 659              "/" (int-to-string news-current-message-number)))))
 660
 661 (defun news-delete-headers (pos)
 662   (goto-char pos)
 663   (and (stringp news-ignored-headers)
 664        (while (re-search-forward news-ignored-headers nil t)
 665          (beginning-of-line)
 666          (delete-region (point)
 667                         (progn (re-search-forward "\n[^ \t]")
 668                                (forward-char -1)
 669                                (point))))))
 670
 671 (defun news-exit ()
 672   "Quit news reading session and update the .newsrc file."
 673   (interactive)
 674   (if (y-or-n-p "Do you really wanna quit reading news ? ")
 675       (progn (message "Updating %s..." news-startup-file)
 676              (news-update-newsrc-file)
 677              (news-write-certifications)
 678              (message "Updating %s... done" news-startup-file)
 679              (message "Now do some real work")
 680              (and (fboundp 'bury-buffer) (bury-buffer (current-buffer)))
 681              (switch-to-buffer news-buffer-save)
 682              (setq news-user-group-list ()))
 683     (message "")))
 684
 685 (defun news-update-newsrc-file ()
 686   "Updates the .newsrc file in the users home dir."
 687   (let ((newsrcbuf (find-file-noselect
 688                      (substitute-in-file-name news-startup-file)))
 689         (tem news-user-group-list)
 690         group)
 691     (save-excursion
 692       (if (not (null news-current-news-group))
 693           (news-update-message-read news-current-news-group
 694                                     (news-cdar news-point-pdl)))
 695       (set-buffer newsrcbuf)
 696       (while tem
 697         (setq group (assoc (car tem) news-group-article-assoc))
 698         (if (= (news-cadr (news-cadr group)) (news-caddr (news-cadr group)))
 699             nil
 700           (goto-char 0)
 701           (if (search-forward (concat (car group) ": ") nil t)
 702               (kill-line nil)
 703             (insert (car group) ": \n") (backward-char 1))
 704           (insert (int-to-string (car (news-cadr group))) "-"
 705                   (int-to-string (news-cadr (news-cadr group)))))
 706         (setq tem (cdr tem)))
 707      (while news-unsubscribe-groups
 708        (setq group (assoc (car news-unsubscribe-groups)
 709                           news-group-article-assoc))
 710        (goto-char 0)
 711        (if (search-forward (concat (car group) ": ") nil t)
 712            (progn
 713               (backward-char 2)
 714               (kill-line nil)
 715               (insert "! " (int-to-string (car (news-cadr group)))
 716                       "-" (int-to-string (news-cadr (news-cadr group))))))
 717        (setq news-unsubscribe-groups (cdr news-unsubscribe-groups)))
 718      (save-buffer)
 719      (kill-buffer (current-buffer)))))
 720
 721
 722 (defun news-unsubscribe-group (group)
 723   "Removes you from newgroup GROUP."
 724   (interactive (list (completing-read  "Unsubscribe from group: "
 725                                       news-group-article-assoc)))
 726   (news-unsubscribe-internal group))
 727
 728 (defun news-unsubscribe-current-group ()
 729   "Removes you from the newsgroup you are now reading."
 730   (interactive)
 731   (if (y-or-n-p "Do you really want to unsubscribe from this group ? ")
 732       (news-unsubscribe-internal news-current-news-group)))
 733
 734 (defun news-unsubscribe-internal (group)
 735   (let ((tem (assoc group news-group-article-assoc)))
 736     (if tem
 737         (progn
 738           (setq news-unsubscribe-groups (cons group news-unsubscribe-groups))
 739           (news-update-message-read group (news-cdar news-point-pdl))
 740           (if (equal group news-current-news-group)
 741               (news-next-group))
 742           (message ""))
 743       (error "Not subscribed to group: %s" group))))
 744
 745 (defun news-save-item-in-file (file)
 746   "Save the current article that is being read by appending to a file."
 747   (interactive "FSave item in file: ")
 748   (append-to-file (point-min) (point-max) file))
 749
 750 (defun news-get-pruned-list-of-files (gp-list end-file-no)
 751   "Given a news group it finds all files in the news group.
 752 The arg must be in slashified format.
 753 Using ls was found to be too slow in a previous version."
 754   (let
 755       ((answer
 756         (and
 757          (not (and end-file-no
 758                    (equal (news-set-current-certifiable)
 759                      (news-group-certification gp-list))
 760                    (setq news-list-of-files nil
 761                          news-list-of-files-possibly-bogus t)))
 762          (let* ((file-directory (concat news-path
 763                                         (string-subst-char ?/ ?. gp-list)))
 764                 tem
 765                 (last-winner
 766                  (and end-file-no
 767                       (news-wins file-directory end-file-no)
 768                       (news-find-first-or-last file-directory end-file-no 1))))
 769            (setq news-list-of-files-possibly-bogus t news-list-of-files nil)
 770            (if last-winner
 771                (progn
 772                  (setq news-list-of-files-possibly-bogus t
 773                        news-current-group-end last-winner)
 774                  (while (> last-winner end-file-no)
 775                    (news-push last-winner news-list-of-files)
 776                    (setq last-winner (1- last-winner)))
 777                  news-list-of-files)
 778              (if (or (not (file-directory-p file-directory))
 779                      (not (file-readable-p file-directory)))
 780                  nil
 781                (setq news-list-of-files
 782                      (condition-case error
 783                          (directory-files file-directory)
 784                        (file-error
 785                         (if (string= (nth 2 error) "permission denied")
 786                             (message "Newsgroup %s is read-protected"
 787                                      gp-list)
 788                           (signal 'file-error (cdr error)))
 789                         nil)))
 790                (setq tem news-list-of-files)
 791                (while tem
 792                  (if (or (not (string-match "^[0-9]*$" (car tem)))
 793                          ;; dont get confused by directories that look like numbers
 794                          (file-directory-p
 795                           (concat file-directory "/" (car tem)))
 796                          (<= (string-to-int (car tem)) end-file-no))
 797                      (setq news-list-of-files
 798                            (delq (car tem) news-list-of-files)))
 799                  (setq tem (cdr tem)))
 800                (if (null news-list-of-files)
 801                    (progn (setq news-current-group-end 0)
 802                           nil)
 803                  (setq news-list-of-files
 804                        (mapcar 'string-to-int news-list-of-files))
 805                  (setq news-list-of-files (sort news-list-of-files '<))
 806                  (setq news-current-group-end
 807                        (elt news-list-of-files
 808                             (1- (length news-list-of-files))))
 809                  news-list-of-files)))))))
 810     (or answer (progn (news-set-current-group-certification) nil))))
 811
 812 (defun news-read-files-into-buffer (group reversep)
 813   (let* ((files-start-end (news-cadr (assoc group news-group-article-assoc)))
 814          (start-file-no (car files-start-end))
 815          (end-file-no (news-cadr files-start-end))
 816          (buffer-read-only nil))
 817     (setq news-current-news-group group)
 818     (setq news-current-message-number nil)
 819     (setq news-current-group-end nil)
 820     (news-set-mode-line)
 821     (news-get-pruned-list-of-files group end-file-no)
 822     (news-set-mode-line)
 823     ;; @@ should be a lot smarter than this if we have to move
 824     ;; @@ around correctly.
 825     (setq news-point-pdl (list (cons (car files-start-end)
 826                                      (news-cadr files-start-end))))
 827     (if (null news-list-of-files)
 828         (progn (erase-buffer)
 829                (setq news-current-group-end end-file-no)
 830                (setq news-current-group-begin end-file-no)
 831                (setq news-current-message-number end-file-no)
 832                (news-set-mode-line)
 833 ;              (message "No new articles in " group " group.")
 834                nil)
 835       (setq news-current-group-begin (car news-list-of-files))
 836       (if reversep
 837           (setq news-current-message-number news-current-group-end)
 838         (if (> (car news-list-of-files) end-file-no)
 839             (setcdr (car news-point-pdl) (car news-list-of-files)))
 840         (setq news-current-message-number news-current-group-begin))
 841       (news-set-message-counters)
 842       (news-set-mode-line)
 843       (news-read-in-file (concat news-path
 844                                  (string-subst-char ?/ ?. group)
 845                                  "/"
 846                                  (int-to-string
 847                                    news-current-message-number)))
 848       (news-set-message-counters)
 849       (news-set-mode-line)
 850       t)))
 851
 852 (defun news-add-news-group (gp)
 853   "Resubscribe to or add a USENET news group named GROUP (a string)."
 854 ; @@ (completing-read ...)
 855 ; @@ could be based on news library file ../active (slightly facist)
 856 ; @@ or (expensive to compute) all directories under the news spool directory
 857   (interactive "sAdd news group: ")
 858   (let ((file-dir (concat news-path (string-subst-char ?/ ?. gp))))
 859     (save-excursion
 860       (if (null (assoc gp news-group-article-assoc))
 861           (let ((newsrcbuf (find-file-noselect
 862                             (substitute-in-file-name news-startup-file))))
 863             (if (file-directory-p file-dir)
 864                 (progn
 865                   (switch-to-buffer newsrcbuf)
 866                   (goto-char 0)
 867                   (if (search-forward (concat gp "! ") nil t)
 868                       (progn
 869                         (message "Re-subscribing to group %s." gp)
 870                         ;;@@ news-unsubscribe-groups isn't being used
 871                         ;;(setq news-unsubscribe-groups
 872                         ;;    (delq gp news-unsubscribe-groups))
 873                         (backward-char 2)
 874                         (delete-char 1)
 875                         (insert ":"))
 876                     (progn
 877                       (message
 878                        "Added %s to your list of newsgroups." gp)
 879                       (end-of-buffer)
 880                       (insert gp ": 1-1\n")))
 881                   (search-backward gp nil t)
 882                   (let (start end endofline tem)
 883                     (search-forward ": " nil t)
 884                     (setq end (point))
 885                     (beginning-of-line)
 886                     (setq start (point))
 887                     (end-of-line)
 888                     (setq endofline (point))
 889                     (setq tem (buffer-substring start (- end 2)))
 890                     (let ((range (news-parse-range
 891                                   (buffer-substring end endofline))))
 892                       (setq news-group-article-assoc
 893                             (cons (list tem (list (car range)
 894                                                   (cdr range)
 895                                                   (cdr range)))
 896                                   news-group-article-assoc))))
 897                   (save-buffer)
 898                   (kill-buffer (current-buffer)))
 899               (message "Newsgroup %s doesn't exist." gp)))
 900         (message "Already subscribed to group %s." gp)))))
 901
 902 (defun news-make-link-to-message (number newname)
 903         "Forges a link to an rnews message numbered number (current if no arg)
 904 Good for hanging on to a message that might or might not be
 905 automatically deleted."
 906   (interactive "P
 907 FName to link to message: ")
 908   (add-name-to-file
 909    (concat news-path
 910            (string-subst-char ?/ ?. news-current-news-group)
 911            "/" (if number
 912                    (prefix-numeric-value number)
 913                  news-current-message-number))
 914    newname))
 915
 916 ;;; caesar-region written by phr@prep.ai.mit.edu  Nov 86
 917 ;;; modified by tower@prep Nov 86
 918 (defun caesar-region (&optional n)
 919   "Caesar rotation of region by N, default 13, for decrypting netnews."
 920   (interactive (if current-prefix-arg   ; Was there a prefix arg?
 921                    (list (prefix-numeric-value current-prefix-arg))
 922                  (list nil)))
 923   (cond ((not (numberp n)) (setq n 13))
 924         ((< n 0) (setq n (- 26 (% (- n) 26))))
 925         (t (setq n (% n 26))))          ;canonicalize N
 926   (if (not (zerop n))           ; no action needed for a rot of 0
 927       (progn
 928         (if (or (not (boundp 'caesar-translate-table))
 929                 (/= (aref caesar-translate-table ?a) (+ ?a n)))
 930             (let ((i 0) (lower "abcdefghijklmnopqrstuvwxyz") upper)
 931               (message "Building caesar-translate-table...")
 932               (setq caesar-translate-table (make-vector 256 0))
 933               (while (< i 256)
 934                 (aset caesar-translate-table i i)
 935                 (setq i (1+ i)))
 936               (setq lower (concat lower lower) upper (upcase lower) i 0)
 937               (while (< i 26)
 938                 (aset caesar-translate-table (+ ?a i) (aref lower (+ i n)))
 939                 (aset caesar-translate-table (+ ?A i) (aref upper (+ i n)))
 940                 (setq i (1+ i)))
 941               (message "Building caesar-translate-table... done")))
 942         (let ((from (region-beginning))
 943               (to (region-end))
 944               (i 0) str len)
 945           (setq str (buffer-substring from to))
 946           (setq len (length str))
 947           (while (< i len)
 948             (aset str i (aref caesar-translate-table (aref str i)))
 949             (setq i (1+ i)))
 950           (goto-char from)
 951           (kill-region from to)
 952           (insert str)))))
 953
 954 ;;; news-caesar-buffer-body written by paul@media-lab.mit.edu  Wed Oct 1, 1986
 955 ;;; hacked further by tower@prep.ai.mit.edu
 956 (defun news-caesar-buffer-body (&optional rotnum)
 957   "Caesar rotates all letters in the current buffer by 13 places.
 958 Used to encode/decode possibly offensive messages (commonly in net.jokes).
 959 With prefix arg, specifies the number of places to rotate each letter forward.
 960 Mail and USENET news headers are not rotated."
 961   (interactive (if current-prefix-arg   ; Was there a prefix arg?
 962                    (list (prefix-numeric-value current-prefix-arg))
 963                  (list nil)))
 964   (save-excursion
 965     (let ((buffer-status buffer-read-only))
 966       (setq buffer-read-only nil)
 967       ;; setup the region
 968       (set-mark (if (progn (goto-char (point-min))
 969                             (search-forward
 970                              (concat "\n"
 971                                      (if (equal major-mode 'news-mode)
 972                                          ""
 973                                        mail-header-separator)
 974                                      "\n") nil t))
 975                      (point)
 976                    (point-min)))
 977       (goto-char (point-max))
 978       (caesar-region rotnum)
 979       (setq buffer-read-only buffer-status))))
 980
 981 (provide 'rnews)
 982
 983 ;;; rnews.el ends here