code.delx.au - gnu-emacs/blob - lisp/info.el

   1 ;;; info.el --- info package for Emacs.
   2
   3 ;; Copyright (C) 1985, 1986, 1992, 1993, 1994 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: help
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Commentary:
  25
  26 ;;; Note that nowadays we expect info files to be made using makeinfo.
  27
  28 ;;; Code:
  29
  30 (defvar Info-history nil
  31   "List of info nodes user has visited.
  32 Each element of list is a list (FILENAME NODENAME BUFFERPOS).")
  33
  34 (defvar Info-enable-edit nil
  35   "*Non-nil means the \\<Info-mode-map>\\[Info-edit] command in Info can edit the current node.
  36 This is convenient if you want to write info files by hand.
  37 However, we recommend that you not do this.
  38 It is better to write a Texinfo file and generate the Info file from that,
  39 because that gives you a printed manual as well.")
  40
  41 (defvar Info-enable-active-nodes t
  42   "Non-nil allows Info to execute Lisp code associated with nodes.
  43 The Lisp code is executed when the node is selected.")
  44
  45 (defvar Info-default-directory-list nil
  46   "List of default directories to search for Info documentation files.
  47 This value is used as the default for `Info-directory-list'.  It is set
  48 in paths.el.")
  49
  50 (defvar Info-fontify t
  51   "*Non-nil enables highlighting and fonts in Info nodes.")
  52
  53 (defvar Info-directory-list
  54   (let ((path (getenv "INFOPATH"))
  55         (sep (if (eq system-type 'ms-dos) ";" ":"))
  56         (sibling (expand-file-name "../info/" (invocation-directory))))
  57     (if path
  58         (let ((list nil)
  59               idx)
  60           (while (> (length path) 0)
  61             (setq idx (or (string-match sep path) (length path))
  62                   list (cons (substring path 0 idx) list)
  63                   path (substring path (min (1+ idx)
  64                                             (length path)))))
  65           (nreverse list))
  66       (if (or (member sibling Info-default-directory-list)
  67               (not (file-exists-p sibling))
  68               ;; On MS-DOS, we use movable executables always,
  69               ;; and we must always find the Info dir at run time.
  70               (if (eq system-type 'ms-dos)
  71                   nil
  72                 ;; Use invocation-directory for Info only if we used it for
  73                 ;; exec-directory also.
  74                 (not (string= exec-directory
  75                               (expand-file-name "../lib-src/"
  76                                                 (invocation-directory))))))
  77           Info-default-directory-list
  78         (reverse (cons sibling (cdr (reverse Info-default-directory-list)))))))
  79   "List of directories to search for Info documentation files.
  80 nil means not yet initialized.  In this case, Info uses the environment
  81 variable INFOPATH to initialize it, or `Info-default-directory-list'
  82 if there is no INFOPATH variable in the environment.
  83 The last element of `Info-default-directory-list' is the directory
  84 where Emacs installs the Info files that come with it.
  85 If Emacs finds it has been installed elsewhere, or not yet installed,
  86 it replaces that element with the directory that its Info files are in.")
  87
  88 (defvar Info-current-file nil
  89   "Info file that Info is now looking at, or nil.")
  90
  91 (defvar Info-current-subfile nil
  92   "Info subfile that is actually in the *info* buffer now,
  93 or nil if current info file is not split into subfiles.")
  94
  95 (defvar Info-current-node nil
  96   "Name of node that Info is now looking at, or nil.")
  97
  98 (defvar Info-tag-table-marker (make-marker)
  99   "Marker pointing at beginning of current Info file's tag table.
 100 Marker points nowhere if file has no tag table.")
 101
 102 (defvar Info-current-file-completions nil
 103   "Cached completion list for current Info file.")
 104
 105 (defvar Info-index-alternatives nil
 106   "List of possible matches for last Info-index command.")
 107
 108 (defvar Info-standalone nil
 109   "Non-nil if Emacs was started solely as an Info browser.")
 110
 111 (defvar Info-suffix-list '( (".info.Z"  . "uncompress")
 112                             (".info.Y"  . "unyabba")
 113                             (".info.gz" . "gunzip")
 114                             (".info.z"  . "gunzip")
 115                             (".info"    . nil)
 116                             (".Z"       . "uncompress")
 117                             (".Y"       . "unyabba")
 118                             (".gz"      . "gunzip")
 119                             (".z"       . "gunzip")
 120                             (""         . nil))
 121   "List of file name suffixes and associated decoding commands.
 122 Each entry should be (SUFFIX . STRING); the file is given to
 123 the command as standard input.  If STRING is nil, no decoding is done.
 124 Because the SUFFIXes are tried in order, the empty string should
 125 be last in the list.")
 126
 127 (defun info-insert-file-contents (filename &optional visit)
 128   "Insert the contents of an info file in the current buffer.
 129 Do the right thing if the file has been compressed or zipped."
 130   (let ((tail Info-suffix-list)
 131         fullname decoder)
 132     (if (file-exists-p filename)
 133         (progn
 134           (while (and tail
 135                       (not (string-match
 136                             (concat (regexp-quote (car (car tail))) "$")
 137                             filename)))
 138             (setq tail (cdr tail)))
 139           (setq fullname filename
 140                 decoder (cdr (car tail))))
 141       (while (and tail
 142                   (not (file-exists-p (concat filename (car (car tail))))))
 143         (setq tail (cdr tail)))
 144       (setq fullname (concat filename (car (car tail)))
 145             decoder (cdr (car tail)))
 146       ;; check for conflict with jka-compr
 147       (if (and (featurep 'jka-compr)
 148                (jka-compr-installed-p)
 149                (jka-compr-get-compression-info (concat filename
 150                                                        (car (car tail)))))
 151           (setq decoder nil))
 152       (or tail
 153           (error "Can't find %s or any compressed version of it!" filename)))
 154     (insert-file-contents fullname visit)
 155     (if decoder
 156         (let ((buffer-read-only nil))
 157           (shell-command-on-region (point-min) (point-max) decoder t)))))
 158
 159 ;;;###autoload
 160 (defun info (&optional file)
 161   "Enter Info, the documentation browser.
 162 Optional argument FILE specifies the file to examine;
 163 the default is the top-level directory of Info.
 164
 165 In interactive use, a prefix argument directs this command
 166 to read a file name from the minibuffer."
 167   (interactive (if current-prefix-arg
 168                    (list (read-file-name "Info file name: " nil nil t))))
 169   (if file
 170       (Info-goto-node (concat "(" file ")"))
 171     (if (get-buffer "*info*")
 172         (switch-to-buffer "*info*")
 173       (Info-directory))))
 174
 175 ;;;###autoload
 176 (defun info-standalone ()
 177   "Run Emacs as a standalone Info reader.
 178 Usage:  emacs -f info-standalone [filename]
 179 In standalone mode, \\<Info-mode-map>\\[Info-exit] exits Emacs itself."
 180   (setq Info-standalone t)
 181   (if (and command-line-args-left
 182            (not (string-match "^-" (car command-line-args-left))))
 183       (condition-case err
 184           (progn
 185             (info (car command-line-args-left))
 186             (setq command-line-args-left (cdr command-line-args-left)))
 187         (error (send-string-to-terminal
 188                 (format "%s\n" (if (eq (car-safe err) 'error)
 189                                    (nth 1 err) err)))
 190                (save-buffers-kill-emacs)))
 191     (info)))
 192
 193 ;; Go to an info node specified as separate filename and nodename.
 194 ;; no-going-back is non-nil if recovering from an error in this function;
 195 ;; it says do not attempt further (recursive) error recovery.
 196 (defun Info-find-node (filename nodename &optional no-going-back)
 197   ;; Convert filename to lower case if not found as specified.
 198   ;; Expand it.
 199   (if filename
 200       (let (temp temp-downcase found)
 201         (setq filename (substitute-in-file-name filename))
 202         (if (string= (downcase (file-name-nondirectory filename)) "dir")
 203             (setq found t)
 204           (let ((dirs (if (string-match "^\\./" filename)
 205                           ;; If specified name starts with `./'
 206                           ;; then just try current directory.
 207                           '("./")
 208                         Info-directory-list)))
 209             ;; Search the directory list for file FILENAME.
 210             (while (and dirs (not found))
 211               (setq temp (expand-file-name filename (car dirs)))
 212               (setq temp-downcase
 213                     (expand-file-name (downcase filename) (car dirs)))
 214               ;; Try several variants of specified name.
 215               (catch 'foundit
 216                 (mapcar
 217                  (function
 218                   (lambda (x)
 219                     (if (file-exists-p (concat temp (car x)))
 220                         (progn
 221                           (setq found temp)
 222                           (throw 'foundit nil)))
 223                     (if (file-exists-p (concat temp-downcase (car x)))
 224                         (progn
 225                           (setq found temp-downcase)
 226                           (throw 'foundit nil)))))
 227                  Info-suffix-list))
 228               (setq dirs (cdr dirs)))))
 229         (if found
 230             (setq filename found)
 231           (error "Info file %s does not exist" filename))))
 232   ;; Record the node we are leaving.
 233   (if (and Info-current-file (not no-going-back))
 234       (setq Info-history
 235             (cons (list Info-current-file Info-current-node (point))
 236                   Info-history)))
 237   ;; Go into info buffer.
 238   (switch-to-buffer "*info*")
 239   (buffer-disable-undo (current-buffer))
 240   (or (eq major-mode 'Info-mode)
 241       (Info-mode))
 242   (widen)
 243   (setq Info-current-node nil)
 244   (unwind-protect
 245       (progn
 246         ;; Switch files if necessary
 247         (or (null filename)
 248             (equal Info-current-file filename)
 249             (let ((buffer-read-only nil))
 250               (setq Info-current-file nil
 251                     Info-current-subfile nil
 252                     Info-current-file-completions nil
 253                     Info-index-alternatives nil
 254                     buffer-file-name nil)
 255               (erase-buffer)
 256               (if (eq filename t)
 257                   (Info-insert-dir)
 258                 (info-insert-file-contents filename t)
 259                 (setq default-directory (file-name-directory filename)))
 260               (set-buffer-modified-p nil)
 261               ;; See whether file has a tag table.  Record the location if yes.
 262               (set-marker Info-tag-table-marker nil)
 263               (goto-char (point-max))
 264               (forward-line -8)
 265               (or (equal nodename "*")
 266                   (not (search-forward "\^_\nEnd tag table\n" nil t))
 267                   (let (pos)
 268                     ;; We have a tag table.  Find its beginning.
 269                     ;; Is this an indirect file?
 270                     (search-backward "\nTag table:\n")
 271                     (setq pos (point))
 272                     (if (save-excursion
 273                           (forward-line 2)
 274                           (looking-at "(Indirect)\n"))
 275                         ;; It is indirect.  Copy it to another buffer
 276                         ;; and record that the tag table is in that buffer.
 277                         (save-excursion
 278                           (let ((buf (current-buffer)))
 279                             (set-buffer (get-buffer-create " *info tag table*"))
 280                             (buffer-disable-undo (current-buffer))
 281                             (setq case-fold-search t)
 282                             (erase-buffer)
 283                             (insert-buffer-substring buf)
 284                             (set-marker Info-tag-table-marker
 285                                         (match-end 0))))
 286                       (set-marker Info-tag-table-marker pos))))
 287               (setq Info-current-file
 288                     (if (eq filename t) "dir"
 289                       (file-name-sans-versions buffer-file-name)))))
 290         (if (equal nodename "*")
 291             (progn (setq Info-current-node nodename)
 292                    (Info-set-mode-line))
 293           ;; Search file for a suitable node.
 294           (let ((guesspos (point-min))
 295                 (regexp (concat "Node: *" (regexp-quote nodename) " *[,\t\n\177]")))
 296             ;; First get advice from tag table if file has one.
 297             ;; Also, if this is an indirect info file,
 298             ;; read the proper subfile into this buffer.
 299             (if (marker-position Info-tag-table-marker)
 300                 (save-excursion
 301                   (set-buffer (marker-buffer Info-tag-table-marker))
 302                   (goto-char Info-tag-table-marker)
 303                   (if (re-search-forward regexp nil t)
 304                       (progn
 305                         (setq guesspos (read (current-buffer)))
 306                         ;; If this is an indirect file,
 307                         ;; determine which file really holds this node
 308                         ;; and read it in.
 309                         (if (not (eq (current-buffer) (get-buffer "*info*")))
 310                             (setq guesspos
 311                                   (Info-read-subfile guesspos))))
 312                     (error "No such node: \"%s\"" nodename))))
 313             (goto-char (max (point-min) (- guesspos 1000)))
 314             ;; Now search from our advised position (or from beg of buffer)
 315             ;; to find the actual node.
 316             (catch 'foo
 317               (while (search-forward "\n\^_" nil t)
 318                 (forward-line 1)
 319                 (let ((beg (point)))
 320                   (forward-line 1)
 321                   (if (re-search-backward regexp beg t)
 322                       (throw 'foo t))))
 323               (error "No such node: %s" nodename)))
 324           (Info-select-node)))
 325     ;; If we did not finish finding the specified node,
 326     ;; go back to the previous one.
 327     (or Info-current-node no-going-back (null Info-history)
 328         (let ((hist (car Info-history)))
 329           (setq Info-history (cdr Info-history))
 330           (Info-find-node (nth 0 hist) (nth 1 hist) t)
 331           (goto-char (nth 2 hist)))))
 332   (goto-char (point-min)))
 333
 334 ;; Cache the contents of the (virtual) dir file, once we have merged
 335 ;; it for the first time, so we can save time subsequently.
 336 (defvar Info-dir-contents nil)
 337
 338 ;; Cache for the directory we decided to use for the default-directory
 339 ;; of the merged dir text.
 340 (defvar Info-dir-contents-directory nil)
 341
 342 ;; Record the file attributes of all the files from which we
 343 ;; constructed Info-dir-contents.
 344 (defvar Info-dir-file-attributes nil)
 345
 346 ;; Construct the Info directory node by merging the files named `dir'
 347 ;; from various directories.  Set the *info* buffer's
 348 ;; default-directory to the first directory we actually get any text
 349 ;; from.
 350 (defun Info-insert-dir ()
 351   (if (and Info-dir-contents Info-dir-file-attributes
 352            ;; Verify that none of the files we used has changed
 353            ;; since we used it.
 354            (eval (cons 'and
 355                        (mapcar '(lambda (elt)
 356                                   (let ((curr (file-attributes (car elt))))
 357                                     ;; Don't compare the access time.
 358                                     (if curr (setcar (nthcdr 4 curr) 0))
 359                                     (setcar (nthcdr 4 (cdr elt)) 0)
 360                                     (equal (cdr elt) curr)))
 361                                Info-dir-file-attributes))))
 362       (insert Info-dir-contents)
 363     (let ((dirs Info-directory-list)
 364           buffers buffer others nodes dirs-done)
 365
 366       (setq Info-dir-file-attributes nil)
 367
 368       ;; Search the directory list for the directory file.
 369       (while dirs
 370         (let ((truename (file-truename (expand-file-name (car dirs)))))
 371           (or (member truename dirs-done)
 372               (member (directory-file-name truename) dirs-done)
 373               ;; Try several variants of specified name.
 374               ;; Try upcasing, appending `.info', or both.
 375               (let* (file
 376                      (attrs
 377                       (or
 378                        (progn (setq file (expand-file-name "dir" truename))
 379                               (file-attributes file))
 380                        (progn (setq file (expand-file-name "DIR" truename))
 381                               (file-attributes file))
 382                        (progn (setq file (expand-file-name "dir.info" truename))
 383                               (file-attributes file))
 384                        (progn (setq file (expand-file-name "DIR.INFO" truename))
 385                               (file-attributes file)))))
 386                 (setq dirs-done
 387                       (cons truename
 388                             (cons (directory-file-name truename)
 389                                   dirs-done)))
 390                 (if attrs
 391                     (save-excursion
 392                       (or buffers
 393                           (message "Composing main Info directory..."))
 394                       (set-buffer (generate-new-buffer "info dir"))
 395                       (insert-file-contents file)
 396                       (setq buffers (cons (current-buffer) buffers)
 397                             Info-dir-file-attributes
 398                             (cons (cons file attrs)
 399                                   Info-dir-file-attributes))))))
 400           (setq dirs (cdr dirs))))
 401
 402       (or buffers
 403           (error "Can't find the info directory node"))
 404       ;; Distinguish the dir file that comes with Emacs from all the
 405       ;; others.  Yes, that is really what this is supposed to do.
 406       ;; If it doesn't work, fix it.
 407       (setq buffer (car buffers)
 408             others (cdr buffers))
 409
 410       ;; Insert the entire original dir file as a start; use its
 411       ;; default directory as the default directory for the whole
 412       ;; concatenation.
 413       (insert-buffer buffer)
 414       (setq Info-dir-contents-directory (save-excursion
 415                                           (set-buffer buffer)
 416                                           default-directory))
 417
 418       ;; Look at each of the other buffers one by one.
 419       (while others
 420         (let ((other (car others)))
 421           ;; In each, find all the menus.
 422           (save-excursion
 423             (set-buffer other)
 424             (goto-char (point-min))
 425             ;; Find each menu, and add an elt to NODES for it.
 426             (while (re-search-forward "^\\* Menu:" nil t)
 427               (let (beg nodename end)
 428                 (forward-line 1)
 429                 (setq beg (point))
 430                 (search-backward "\n\^_")
 431                 (search-forward "Node: ")
 432                 (setq nodename (Info-following-node-name))
 433                 (search-forward "\n\^_" nil 'move)
 434                 (beginning-of-line)
 435                 (setq end (point))
 436                 (setq nodes (cons (list nodename other beg end) nodes))))))
 437         (setq others (cdr others)))
 438       ;; Add to the main menu a menu item for each other node.
 439       (re-search-forward "^\\* Menu:")
 440       (forward-line 1)
 441       (let ((menu-items '("top"))
 442             (nodes nodes)
 443             (case-fold-search t)
 444             (end (save-excursion (search-forward "\^_" nil t) (point))))
 445         (while nodes
 446           (let ((nodename (car (car nodes))))
 447             (save-excursion
 448               (or (member (downcase nodename) menu-items)
 449                   (re-search-forward (concat "^\\* "
 450                                              (regexp-quote nodename)
 451                                              "::")
 452                                      end t)
 453                   (progn
 454                     (insert "* " nodename "::" "\n")
 455                     (setq menu-items (cons nodename menu-items))))))
 456           (setq nodes (cdr nodes))))
 457       ;; Now take each node of each of the other buffers
 458       ;; and merge it into the main buffer.
 459       (while nodes
 460         (let ((nodename (car (car nodes))))
 461           (goto-char (point-min))
 462           ;; Find the like-named node in the main buffer.
 463           (if (re-search-forward (concat "\n\^_.*\n.*Node: "
 464                                          (regexp-quote nodename)
 465                                          "[,\n\t]")
 466                                  nil t)
 467               (progn
 468                 (search-forward "\n\^_" nil 'move)
 469                 (beginning-of-line))
 470             ;; If none exists, add one.
 471             (goto-char (point-max))
 472             (insert "\^_\nFile: dir\tnode: " nodename "\n\n* Menu:\n\n"))
 473           ;; Merge the text from the other buffer's menu
 474           ;; into the menu in the like-named node in the main buffer.
 475           (apply 'insert-buffer-substring (cdr (car nodes)))
 476           (insert "\n"))
 477         (setq nodes (cdr nodes)))
 478       ;; Kill all the buffers we just made.
 479       (while buffers
 480         (kill-buffer (car buffers))
 481         (setq buffers (cdr buffers)))
 482       (message "Composing main Info directory...done"))
 483     (setq Info-dir-contents (buffer-string)))
 484   (setq default-directory Info-dir-contents-directory))
 485
 486 (defun Info-read-subfile (nodepos)
 487   (set-buffer (marker-buffer Info-tag-table-marker))
 488   (goto-char (point-min))
 489   (search-forward "\n\^_")
 490   (let (lastfilepos
 491         lastfilename)
 492     (forward-line 2)
 493     (catch 'foo
 494       (while (not (looking-at "\^_"))
 495         (if (not (eolp))
 496             (let ((beg (point))
 497                   thisfilepos thisfilename)
 498               (search-forward ": ")
 499               (setq thisfilename  (buffer-substring beg (- (point) 2)))
 500               (setq thisfilepos (read (current-buffer)))
 501               ;; read in version 19 stops at the end of number.
 502               ;; Advance to the next line.
 503               (forward-line 1)
 504               (if (> thisfilepos nodepos)
 505                   (throw 'foo t))
 506               (setq lastfilename thisfilename)
 507               (setq lastfilepos thisfilepos))
 508           (forward-line 1))))
 509     (set-buffer (get-buffer "*info*"))
 510     (or (equal Info-current-subfile lastfilename)
 511         (let ((buffer-read-only nil))
 512           (setq buffer-file-name nil)
 513           (widen)
 514           (erase-buffer)
 515           (info-insert-file-contents lastfilename)
 516           (set-buffer-modified-p nil)
 517           (setq Info-current-subfile lastfilename)))
 518     (goto-char (point-min))
 519     (search-forward "\n\^_")
 520     (+ (- nodepos lastfilepos) (point))))
 521
 522 ;; Select the info node that point is in.
 523 (defun Info-select-node ()
 524   (save-excursion
 525    ;; Find beginning of node.
 526    (search-backward "\n\^_")
 527    (forward-line 2)
 528    ;; Get nodename spelled as it is in the node.
 529    (re-search-forward "Node:[ \t]*")
 530    (setq Info-current-node
 531          (buffer-substring (point)
 532                            (progn
 533                             (skip-chars-forward "^,\t\n")
 534                             (point))))
 535    (Info-set-mode-line)
 536    ;; Find the end of it, and narrow.
 537    (beginning-of-line)
 538    (let (active-expression)
 539      (narrow-to-region (point)
 540                        (if (re-search-forward "\n[\^_\f]" nil t)
 541                            (prog1
 542                             (1- (point))
 543                             (if (looking-at "[\n\^_\f]*execute: ")
 544                                 (progn
 545                                   (goto-char (match-end 0))
 546                                   (setq active-expression
 547                                         (read (current-buffer))))))
 548                          (point-max)))
 549      (if Info-enable-active-nodes (eval active-expression))
 550      (if Info-fontify (Info-fontify-node))
 551      (run-hooks 'Info-selection-hook))))
 552
 553 (defun Info-set-mode-line ()
 554   (setq mode-line-buffer-identification
 555         (concat
 556          "Info:  ("
 557          (if Info-current-file
 558              (file-name-nondirectory Info-current-file)
 559            "")
 560          ")"
 561          (or Info-current-node ""))))
 562 \f
 563 ;; Go to an info node specified with a filename-and-nodename string
 564 ;; of the sort that is found in pointers in nodes.
 565
 566 (defun Info-goto-node (nodename)
 567   "Go to info node named NAME.  Give just NODENAME or (FILENAME)NODENAME."
 568   (interactive (list (Info-read-node-name "Goto node: ")))
 569   (let (filename)
 570     (string-match "\\s *\\((\\s *\\([^\t)]*\\)\\s *)\\s *\\|\\)\\(.*\\)"
 571                   nodename)
 572     (setq filename (if (= (match-beginning 1) (match-end 1))
 573                        ""
 574                      (substring nodename (match-beginning 2) (match-end 2)))
 575           nodename (substring nodename (match-beginning 3) (match-end 3)))
 576     (let ((trim (string-match "\\s *\\'" filename)))
 577       (if trim (setq filename (substring filename 0 trim))))
 578     (let ((trim (string-match "\\s *\\'" nodename)))
 579       (if trim (setq nodename (substring nodename 0 trim))))
 580     (Info-find-node (if (equal filename "") nil filename)
 581                     (if (equal nodename "") "Top" nodename))))
 582
 583 (defun Info-read-node-name (prompt &optional default)
 584   (let* ((completion-ignore-case t)
 585          (nodename (completing-read prompt (Info-build-node-completions))))
 586     (if (equal nodename "")
 587         (or default
 588             (Info-read-node-name prompt))
 589       nodename)))
 590
 591 (defun Info-build-node-completions ()
 592   (or Info-current-file-completions
 593       (let ((compl nil))
 594         (save-excursion
 595           (save-restriction
 596             (if (marker-buffer Info-tag-table-marker)
 597                 (progn
 598                   (set-buffer (marker-buffer Info-tag-table-marker))
 599                   (widen)
 600                   (goto-char Info-tag-table-marker)
 601                   (while (re-search-forward "\nNode: \\(.*\\)\177" nil t)
 602                     (setq compl
 603                           (cons (list (buffer-substring (match-beginning 1)
 604                                                         (match-end 1)))
 605                                 compl))))
 606               (widen)
 607               (goto-char (point-min))
 608               (while (search-forward "\n\^_" nil t)
 609                 (forward-line 1)
 610                 (let ((beg (point)))
 611                   (forward-line 1)
 612                   (if (re-search-backward "Node: *\\([^,\n]*\\) *[,\n\t]"
 613                                           beg t)
 614                       (setq compl
 615                             (cons (list (buffer-substring (match-beginning 1)
 616                                                           (match-end 1)))
 617                                   compl))))))))
 618         (setq Info-current-file-completions compl))))
 619 \f
 620 (defun Info-restore-point (hl)
 621   "If this node has been visited, restore the point value when we left."
 622   (while hl
 623     (if (and (equal (nth 0 (car hl)) Info-current-file)
 624              (equal (nth 1 (car hl)) Info-current-node))
 625         (progn
 626           (goto-char (nth 2 (car hl)))
 627           (setq hl nil))                ;terminate the while at next iter
 628       (setq hl (cdr hl)))))
 629 \f
 630 (defvar Info-last-search nil
 631   "Default regexp for \\<Info-mode-map>\\[Info-search] command to search for.")
 632
 633 (defun Info-search (regexp)
 634   "Search for REGEXP, starting from point, and select node it's found in."
 635   (interactive "sSearch (regexp): ")
 636   (if (equal regexp "")
 637       (setq regexp Info-last-search)
 638     (setq Info-last-search regexp))
 639   (let ((found ()) current
 640         (onode Info-current-node)
 641         (ofile Info-current-file)
 642         (opoint (point))
 643         (osubfile Info-current-subfile))
 644     (save-excursion
 645       (save-restriction
 646         (widen)
 647         (if (null Info-current-subfile)
 648             (progn (re-search-forward regexp) (setq found (point)))
 649           (condition-case err
 650               (progn (re-search-forward regexp) (setq found (point)))
 651             (search-failed nil)))))
 652     (if (not found) ;can only happen in subfile case -- else would have erred
 653         (unwind-protect
 654             (let ((list ()))
 655               (set-buffer (marker-buffer Info-tag-table-marker))
 656               (goto-char (point-min))
 657               (search-forward "\n\^_\nIndirect:")
 658               (save-restriction
 659                 (narrow-to-region (point)
 660                                   (progn (search-forward "\n\^_")
 661                                          (1- (point))))
 662                 (goto-char (point-min))
 663                 (search-forward (concat "\n" osubfile ": "))
 664                 (beginning-of-line)
 665                 (while (not (eobp))
 666                   (re-search-forward "\\(^.*\\): [0-9]+$")
 667                   (goto-char (+ (match-end 1) 2))
 668                   (setq list (cons (cons (read (current-buffer))
 669                                          (buffer-substring (match-beginning 1)
 670                                                            (match-end 1)))
 671                                    list))
 672                   (goto-char (1+ (match-end 0))))
 673                 (setq list (nreverse list)
 674                       current (car (car list))
 675                       list (cdr list)))
 676               (while list
 677                 (message "Searching subfile %s..." (cdr (car list)))
 678                 (Info-read-subfile (car (car list)))
 679                 (setq list (cdr list))
 680                 (goto-char (point-min))
 681                 (if (re-search-forward regexp nil t)
 682                     (setq found (point) list ())))
 683               (if found
 684                   (message "")
 685                 (signal 'search-failed (list regexp))))
 686           (if (not found)
 687               (progn (Info-read-subfile opoint)
 688                      (goto-char opoint)
 689                      (Info-select-node)))))
 690     (widen)
 691     (goto-char found)
 692     (Info-select-node)
 693     (or (and (equal onode Info-current-node)
 694              (equal ofile Info-current-file))
 695         (setq Info-history (cons (list ofile onode opoint)
 696                                  Info-history)))))
 697 \f
 698 ;; Extract the value of the node-pointer named NAME.
 699 ;; If there is none, use ERRORNAME in the error message;
 700 ;; if ERRORNAME is nil, just return nil.
 701 (defun Info-extract-pointer (name &optional errorname)
 702   (save-excursion
 703    (goto-char (point-min))
 704    (forward-line 1)
 705    (if (re-search-backward (concat name ":") nil t)
 706        (progn
 707          (goto-char (match-end 0))
 708          (Info-following-node-name))
 709      (if (eq errorname t)
 710          nil
 711        (error (concat "Node has no " (capitalize (or errorname name))))))))
 712
 713 ;; Return the node name in the buffer following point.
 714 ;; ALLOWEDCHARS, if non-nil, goes within [...] to make a regexp
 715 ;; saying which chas may appear in the node name.
 716 (defun Info-following-node-name (&optional allowedchars)
 717   (skip-chars-forward " \t")
 718   (buffer-substring
 719    (point)
 720    (progn
 721      (while (looking-at (concat "[" (or allowedchars "^,\t\n") "]"))
 722        (skip-chars-forward (concat (or allowedchars "^,\t\n") "("))
 723        (if (looking-at "(")
 724            (skip-chars-forward "^)")))
 725      (skip-chars-backward " ")
 726      (point))))
 727
 728 (defun Info-next ()
 729   "Go to the next node of this node."
 730   (interactive)
 731   (Info-goto-node (Info-extract-pointer "next")))
 732
 733 (defun Info-prev ()
 734   "Go to the previous node of this node."
 735   (interactive)
 736   (Info-goto-node (Info-extract-pointer "prev[ious]*" "previous")))
 737
 738 (defun Info-up ()
 739   "Go to the superior node of this node."
 740   (interactive)
 741   (Info-goto-node (Info-extract-pointer "up"))
 742   (Info-restore-point Info-history))
 743
 744 (defun Info-last ()
 745   "Go back to the last node visited."
 746   (interactive)
 747   (or Info-history
 748       (error "This is the first Info node you looked at"))
 749   (let (filename nodename opoint)
 750     (setq filename (car (car Info-history)))
 751     (setq nodename (car (cdr (car Info-history))))
 752     (setq opoint (car (cdr (cdr (car Info-history)))))
 753     (setq Info-history (cdr Info-history))
 754     (Info-find-node filename nodename)
 755     (setq Info-history (cdr Info-history))
 756     (goto-char opoint)))
 757
 758 (defun Info-directory ()
 759   "Go to the Info directory node."
 760   (interactive)
 761   (Info-find-node "dir" "top"))
 762 \f
 763 (defun Info-follow-reference (footnotename)
 764   "Follow cross reference named NAME to the node it refers to.
 765 NAME may be an abbreviation of the reference name."
 766   (interactive
 767    (let ((completion-ignore-case t)
 768          completions default alt-default (start-point (point)) str i bol eol)
 769      (save-excursion
 770        ;; Store end and beginning of line.
 771        (end-of-line)
 772        (setq eol (point))
 773        (beginning-of-line)
 774        (setq bol (point))
 775
 776        (goto-char (point-min))
 777        (while (re-search-forward "\\*note[ \n\t]*\\([^:]*\\):" nil t)
 778          (setq str (buffer-substring
 779                     (match-beginning 1)
 780                     (1- (point))))
 781          ;; See if this one should be the default.
 782          (and (null default)
 783               (<= (match-beginning 0) start-point)
 784               (<= start-point (point))
 785               (setq default t))
 786          ;; See if this one should be the alternate default.
 787          (and (null alt-default)
 788               (and (<= bol (match-beginning 0))
 789                    (<= (point) eol))
 790               (setq alt-default t))
 791          (setq i 0)
 792          (while (setq i (string-match "[ \n\t]+" str i))
 793            (setq str (concat (substring str 0 i) " "
 794                              (substring str (match-end 0))))
 795            (setq i (1+ i)))
 796          ;; Record as a completion and perhaps as default.
 797          (if (eq default t) (setq default str))
 798          (if (eq alt-default t) (setq alt-default str))
 799          (setq completions
 800                (cons (cons str nil)
 801                      completions))))
 802      ;; If no good default was found, try an alternate.
 803      (or default
 804          (setq default alt-default))
 805      ;; If only one cross-reference found, then make it default.
 806      (if (eq (length completions) 1)
 807          (setq default (car (car completions))))
 808      (if completions
 809          (let ((input (completing-read (if default
 810                                            (concat "Follow reference named: ("
 811                                                    default ") ")
 812                                          "Follow reference named: ")
 813                                        completions nil t)))
 814            (list (if (equal input "")
 815                      default input)))
 816        (error "No cross-references in this node"))))
 817   (let (target beg i (str (concat "\\*note " footnotename)))
 818     (while (setq i (string-match " " str i))
 819       (setq str (concat (substring str 0 i) "[ \t\n]+" (substring str (1+ i))))
 820       (setq i (+ i 6)))
 821     (save-excursion
 822       (goto-char (point-min))
 823       (or (re-search-forward str nil t)
 824           (error "No cross-reference named %s" footnotename))
 825       (goto-char (+ (match-beginning 0) 5))
 826       (setq target
 827             (Info-extract-menu-node-name "Bad format cross reference" t)))
 828     (while (setq i (string-match "[ \t\n]+" target i))
 829       (setq target (concat (substring target 0 i) " "
 830                            (substring target (match-end 0))))
 831       (setq i (+ i 1)))
 832     (Info-goto-node target)))
 833
 834 (defun Info-extract-menu-node-name (&optional errmessage multi-line)
 835   (skip-chars-forward " \t\n")
 836   (let ((beg (point))
 837         str i)
 838     (skip-chars-forward "^:")
 839     (forward-char 1)
 840     (setq str
 841           (if (looking-at ":")
 842               (buffer-substring beg (1- (point)))
 843             (skip-chars-forward " \t\n")
 844             (Info-following-node-name (if multi-line "^.,\t" "^.,\t\n"))))
 845     (while (setq i (string-match "\n" str i))
 846       (aset str i ?\ ))
 847     str))
 848
 849 ;; No one calls this.
 850 ;;(defun Info-menu-item-sequence (list)
 851 ;;  (while list
 852 ;;    (Info-menu (car list))
 853 ;;    (setq list (cdr list))))
 854
 855 (defun Info-complete-menu-item (string predicate action)
 856   (let ((case-fold-search t))
 857     (cond ((eq action nil)
 858            (let (completions
 859                  (pattern (concat "\n\\* \\("
 860                                   (regexp-quote string)
 861                                   "[^:\t\n]*\\):")))
 862              (save-excursion
 863                (set-buffer Info-complete-menu-buffer)
 864                (goto-char (point-min))
 865                (while (re-search-forward pattern nil t)
 866                  (setq completions (cons (cons (format "%s"
 867                                                        (buffer-substring
 868                                                         (match-beginning 1)
 869                                                         (match-end 1)))
 870                                                (match-beginning 1))
 871                                          completions))))
 872              (try-completion string completions predicate)))
 873           ((eq action t)
 874            (let (completions
 875                  (pattern (concat "\n\\* \\("
 876                                   (regexp-quote string)
 877                                   "[^:\t\n]*\\):")))
 878              (save-excursion
 879                (set-buffer Info-complete-menu-buffer)
 880                (goto-char (point-min))
 881                (while (re-search-forward pattern nil t)
 882                  (setq completions (cons (cons (format "%s"
 883                                                        (buffer-substring
 884                                                         (match-beginning 1)
 885                                                         (match-end 1)))
 886                                                (match-beginning 1))
 887                                          completions))))
 888              (all-completions string completions predicate)))
 889           (t
 890            (save-excursion
 891              (set-buffer Info-complete-menu-buffer)
 892              (goto-char (point-min))
 893              (re-search-forward (concat "\n\\* "
 894                                         (regexp-quote string)
 895                                         ":")
 896                                 nil t))))))
 897
 898
 899 (defun Info-menu (menu-item)
 900   "Go to node for menu item named (or abbreviated) NAME.
 901 Completion is allowed, and the menu item point is on is the default."
 902   (interactive
 903    (let ((completions '())
 904          ;; If point is within a menu item, use that item as the default
 905          (default nil)
 906          (p (point))
 907          (last nil))
 908      (save-excursion
 909        (goto-char (point-min))
 910        (if (not (search-forward "\n* menu:" nil t))
 911            (error "No menu in this node"))
 912        (setq beg (point))
 913        (and (< (point) p)
 914             (save-excursion
 915               (goto-char p)
 916               (end-of-line)
 917               (re-search-backward "\n\\* \\([^:\t\n]*\\):" beg t)
 918               (setq default (format "%s" (buffer-substring
 919                                           (match-beginning 1)
 920                                           (match-end 1)))))))
 921      (let ((item nil))
 922        (while (null item)
 923          (setq item (let ((completion-ignore-case t)
 924                           (Info-complete-menu-buffer (current-buffer)))
 925                       (completing-read (if default
 926                                            (format "Menu item (default %s): "
 927                                                    default)
 928                                            "Menu item: ")
 929                                        'Info-complete-menu-item nil t)))
 930          ;; we rely on the fact that completing-read accepts an input
 931          ;; of "" even when the require-match argument is true and ""
 932          ;; is not a valid possibility
 933          (if (string= item "")
 934              (if default
 935                  (setq item default)
 936                  ;; ask again
 937                  (setq item nil))))
 938        (list item))))
 939   ;; there is a problem here in that if several menu items have the same
 940   ;; name you can only go to the node of the first with this command.
 941   (Info-goto-node (Info-extract-menu-item menu-item)))
 942
 943 (defun Info-extract-menu-item (menu-item)
 944   (setq menu-item (regexp-quote menu-item))
 945   (save-excursion
 946     (goto-char (point-min))
 947     (or (search-forward "\n* menu:" nil t)
 948         (error "No menu in this node"))
 949     (or (re-search-forward (concat "\n\\* " menu-item ":") nil t)
 950         (re-search-forward (concat "\n\\* " menu-item) nil t)
 951         (error "No such item in menu"))
 952     (beginning-of-line)
 953     (forward-char 2)
 954     (Info-extract-menu-node-name)))
 955
 956 ;; If COUNT is nil, use the last item in the menu.
 957 (defun Info-extract-menu-counting (count)
 958   (save-excursion
 959     (goto-char (point-min))
 960     (or (search-forward "\n* menu:" nil t)
 961         (error "No menu in this node"))
 962     (if count
 963         (or (search-forward "\n* " nil t count)
 964             (error "Too few items in menu"))
 965       (while (search-forward "\n* " nil t)
 966         nil))
 967     (Info-extract-menu-node-name)))
 968
 969 (defun Info-nth-menu-item ()
 970   "Go to the node of the Nth menu item.
 971 N is the digit argument used to invoke this command."
 972   (interactive)
 973   (Info-goto-node
 974    (Info-extract-menu-counting
 975     (- (aref (this-command-keys) (1- (length (this-command-keys)))) ?0))))
 976
 977 (defun Info-top-node ()
 978   "Go to the Top node of this file."
 979   (interactive)
 980   (Info-goto-node "Top"))
 981
 982 (defun Info-final-node ()
 983   "Go to the final node in this file."
 984   (interactive)
 985   (Info-goto-node "Top")
 986   (let (Info-history)
 987     ;; Go to the last node in the menu of Top.
 988     (Info-goto-node (Info-extract-menu-counting nil))
 989     ;; If the last node in the menu is not last in pointer structure,
 990     ;; move forward until we can't go any farther.
 991     (while (Info-forward-node t t) nil)
 992     ;; Then keep moving down to last subnode, unless we reach an index.
 993     (while (and (not (string-match "\\<index\\>" Info-current-node))
 994                 (save-excursion (search-forward "\n* Menu:" nil t)))
 995       (Info-goto-node (Info-extract-menu-counting nil)))))
 996
 997 (defun Info-forward-node (&optional not-down no-error)
 998   "Go forward one node, considering all nodes as forming one sequence."
 999   (interactive)
1000   (goto-char (point-min))
1001   (forward-line 1)
1002   ;; three possibilities, in order of priority:
1003   ;;     1. next node is in a menu in this node (but not in an index)
1004   ;;     2. next node is next at same level
1005   ;;     3. next node is up and next
1006   (cond ((and (not not-down)
1007               (save-excursion (search-forward "\n* menu:" nil t))
1008               (not (string-match "\\<index\\>" Info-current-node)))
1009          (Info-goto-node (Info-extract-menu-counting 1))
1010          t)
1011         ((save-excursion (search-backward "next:" nil t))
1012          (Info-next)
1013          t)
1014         ((and (save-excursion (search-backward "up:" nil t))
1015               (not (equal (downcase (Info-extract-pointer "up")) "top")))
1016          (let ((old-node Info-current-node))
1017            (Info-up)
1018            (let (Info-history success)
1019              (unwind-protect
1020                  (setq success (Info-forward-node t no-error))
1021                (or success (Info-goto-node old-node))))))
1022         (no-error nil)
1023         (t (error "No pointer forward from this node"))))
1024
1025 (defun Info-backward-node ()
1026   "Go backward one node, considering all nodes as forming one sequence."
1027   (interactive)
1028   (let ((prevnode (Info-extract-pointer "prev[ious]*" t))
1029         (upnode (Info-extract-pointer "up" t)))
1030     (cond ((and upnode (string-match "(" upnode))
1031            (error "First node in file"))
1032           ((and upnode (or (null prevnode)
1033                            (equal (downcase prevnode) (downcase upnode))))
1034            (Info-up))
1035           (prevnode
1036            ;; If we move back at the same level,
1037            ;; go down to find the last subnode*.
1038            (Info-prev)
1039            (let (Info-history)
1040              (while (and (not (string-match "\\<index\\>" Info-current-node))
1041                          (save-excursion (search-forward "\n* Menu:" nil t)))
1042                (Info-goto-node (Info-extract-menu-counting nil)))))
1043           (t
1044            (error "No pointer backward from this node")))))
1045
1046 (defun Info-exit ()
1047   "Exit Info by selecting some other buffer."
1048   (interactive)
1049   (if Info-standalone
1050       (save-buffers-kill-emacs)
1051     (switch-to-buffer (prog1 (other-buffer (current-buffer))
1052                         (bury-buffer (current-buffer))))))
1053
1054 (defun Info-next-menu-item ()
1055   (interactive)
1056   (save-excursion
1057     (forward-line -1)
1058     (search-forward "\n* menu:" nil t)
1059     (or (search-forward "\n* " nil t)
1060         (error "No more items in menu"))
1061     (Info-goto-node (Info-extract-menu-node-name))))
1062
1063 (defun Info-last-menu-item ()
1064   (interactive)
1065   (save-excursion
1066     (forward-line 1)
1067     (search-backward "\n* menu:" nil t)
1068     (or (search-backward "\n* " nil t)
1069         (error "No previous items in menu"))
1070     (Info-goto-node (Info-extract-menu-node-name))))
1071
1072 (defmacro Info-no-error (&rest body)
1073   (list 'condition-case nil (cons 'progn (append body '(t))) '(error nil)))
1074
1075 (defun Info-next-preorder ()
1076   "Go to the next node, popping up a level if there is none."
1077   (interactive)
1078   (cond ((Info-no-error (Info-next-menu-item))  )
1079         ((Info-no-error (Info-up))              (forward-line 1))
1080         (t                                      (error "No more nodes"))))
1081
1082 (defun Info-last-preorder ()
1083   "Go to the last node, popping up a level if there is none."
1084   (interactive)
1085   (cond ((Info-no-error (Info-last-menu-item))  )
1086         ((Info-no-error (Info-up))              (forward-line -1))
1087         (t                                      (error "No previous nodes"))))
1088
1089 (defun Info-scroll-up ()
1090   "Read the next screen.  If end of buffer is visible, go to next entry."
1091   (interactive)
1092   (if (pos-visible-in-window-p (point-max))
1093       (Info-next-preorder)
1094     (scroll-up)))
1095
1096 (defun Info-scroll-down ()
1097   "Read the previous screen.  If start of buffer is visible, go to last entry."
1098   (interactive)
1099   (if (pos-visible-in-window-p (point-min))
1100       (Info-last-preorder)
1101     (scroll-down)))
1102
1103 (defun Info-next-reference ()
1104   "Move cursor to the next cross-reference or menu item in the node."
1105   (interactive)
1106   (let ((pat "\\*note[ \n\t]*\\([^:]*\\):\\|^\\* .*:")
1107         (old-pt (point)))
1108     (or (eobp) (forward-char 1))
1109     (or (re-search-forward pat nil t)
1110         (progn
1111           (goto-char (point-min))
1112           (or (re-search-forward pat nil t)
1113               (progn
1114                 (goto-char old-pt)
1115                 (error "No cross references in this node")))))
1116     (goto-char (match-beginning 0))
1117     (if (looking-at "\\* Menu:")
1118         (Info-next-reference))))
1119
1120 (defun Info-prev-reference ()
1121   "Move cursor to the previous cross-reference or menu item in the node."
1122   (interactive)
1123   (let ((pat "\\*note[ \n\t]*\\([^:]*\\):\\|^\\* .*:")
1124         (old-pt (point)))
1125     (or (re-search-backward pat nil t)
1126         (progn
1127           (goto-char (point-max))
1128           (or (re-search-backward pat nil t)
1129               (progn
1130                 (goto-char old-pt)
1131                 (error "No cross references in this node")))))
1132     (goto-char (match-beginning 0))
1133     (if (looking-at "\\* Menu:")
1134         (Info-prev-reference))))
1135
1136 (defun Info-index (topic)
1137   "Look up a string in the index for this file.
1138 The index is defined as the first node in the top-level menu whose
1139 name contains the word \"Index\", plus any immediately following
1140 nodes whose names also contain the word \"Index\".
1141 If there are no exact matches to the specified topic, this chooses
1142 the first match which is a case-insensitive substring of a topic.
1143 Use the `,' command to see the other matches.
1144 Give a blank topic name to go to the Index node itself."
1145   (interactive "sIndex topic: ")
1146   (let ((orignode Info-current-node)
1147         (rnode nil)
1148         (pattern (format "\n\\* \\([^\n:]*%s[^\n:]*\\):[ \t]*\\([^.\n]*\\)\\.[ t]*\\([0-9]*\\)"
1149                          (regexp-quote topic)))
1150         node)
1151     (Info-goto-node "Top")
1152     (or (search-forward "\n* menu:" nil t)
1153         (error "No index"))
1154     (or (re-search-forward "\n\\* \\(.*\\<Index\\>\\)" nil t)
1155         (error "No index"))
1156     (goto-char (match-beginning 1))
1157     (let ((Info-keeping-history nil))
1158       (Info-goto-node (Info-extract-menu-node-name)))
1159     (or (equal topic "")
1160         (let ((matches nil)
1161               (exact nil)
1162               (Info-keeping-history nil)
1163               found)
1164           (while
1165               (progn
1166                 (goto-char (point-min))
1167                 (while (re-search-forward pattern nil t)
1168                   (setq matches
1169                         (cons (list (buffer-substring (match-beginning 1)
1170                                                       (match-end 1))
1171                                     (buffer-substring (match-beginning 2)
1172                                                       (match-end 2))
1173                                     Info-current-node
1174                                     (string-to-int (concat "0"
1175                                                            (buffer-substring
1176                                                             (match-beginning 3)
1177                                                             (match-end 3)))))
1178                               matches)))
1179                 (and (setq node (Info-extract-pointer "next" t))
1180                      (string-match "\\<Index\\>" node)))
1181             (Info-goto-node node))
1182           (or matches
1183               (progn
1184                 (Info-last)
1185                 (error "No \"%s\" in index" topic)))
1186           ;; Here it is a feature that assoc is case-sensitive.
1187           (while (setq found (assoc topic matches))
1188             (setq exact (cons found exact)
1189                   matches (delq found matches)))
1190           (setq Info-index-alternatives (nconc exact (nreverse matches)))
1191           (Info-index-next 0)))))
1192
1193 (defun Info-index-next (num)
1194   "Go to the next matching index item from the last `i' command."
1195   (interactive "p")
1196   (or Info-index-alternatives
1197       (error "No previous `i' command in this file"))
1198   (while (< num 0)
1199     (setq num (+ num (length Info-index-alternatives))))
1200   (while (> num 0)
1201     (setq Info-index-alternatives
1202           (nconc (cdr Info-index-alternatives)
1203                  (list (car Info-index-alternatives)))
1204           num (1- num)))
1205   (Info-goto-node (nth 1 (car Info-index-alternatives)))
1206   (if (> (nth 3 (car Info-index-alternatives)) 0)
1207       (forward-line (nth 3 (car Info-index-alternatives)))
1208     (forward-line 3)  ; don't search in headers
1209     (let ((name (car (car Info-index-alternatives))))
1210       (if (or (re-search-forward (format
1211                                   "\\(Function\\|Command\\): %s\\( \\|$\\)"
1212                                   (regexp-quote name)) nil t)
1213               (search-forward (format "`%s'" name) nil t)
1214               (and (string-match "\\`.*\\( (.*)\\)\\'" name)
1215                    (search-forward
1216                     (format "`%s'" (substring name 0 (match-beginning 1)))
1217                     nil t))
1218               (search-forward name nil t))
1219           (beginning-of-line)
1220         (goto-char (point-min)))))
1221   (message "Found \"%s\" in %s.  %s"
1222            (car (car Info-index-alternatives))
1223            (nth 2 (car Info-index-alternatives))
1224            (if (cdr Info-index-alternatives)
1225                "(Press `,' for more)"
1226              "(Only match)")))
1227
1228 (defun Info-undefined ()
1229   "Make command be undefined in Info."
1230   (interactive)
1231   (ding))
1232
1233 (defun Info-help ()
1234   "Enter the Info tutorial."
1235   (interactive)
1236   (delete-other-windows)
1237   (Info-find-node "info"
1238                   (if (< (window-height) 23)
1239                       "Help-Small-Screen"
1240                     "Help")))
1241
1242 (defun Info-summary ()
1243   "Display a brief summary of all Info commands."
1244   (interactive)
1245   (save-window-excursion
1246     (switch-to-buffer "*Help*")
1247     (erase-buffer)
1248     (insert (documentation 'Info-mode))
1249     (goto-char (point-min))
1250     (let (ch flag)
1251       (while (progn (setq flag (not (pos-visible-in-window-p (point-max))))
1252                     (message (if flag "Type Space to see more"
1253                                "Type Space to return to Info"))
1254                     (if (not (eq ?\  (setq ch (read-event))))
1255                         (progn (setq unread-command-events (list ch)) nil)
1256                       flag))
1257         (scroll-up)))
1258     (bury-buffer "*Help*")))
1259 \f
1260 (defun Info-get-token (pos start all &optional errorstring)
1261   "Return the token around POS,
1262 POS must be somewhere inside the token
1263 START is a regular expression which will match the
1264     beginning of the tokens delimited string
1265 ALL is a regular expression with a single
1266     parenthized subpattern which is the token to be
1267     returned. E.g. '{\(.*\)}' would return any string
1268     enclosed in braces around POS.
1269 SIG optional fourth argument, controls action on no match
1270     nil: return nil
1271     t: beep
1272     a string: signal an error, using that string."
1273   (save-excursion
1274     (goto-char pos)
1275     (re-search-backward start (max (point-min) (- pos 200)) 'yes)
1276     (let (found)
1277       (while (and (re-search-forward all (min (point-max) (+ pos 200)) 'yes)
1278                   (not (setq found (and (<= (match-beginning 0) pos)
1279                                         (> (match-end 0) pos))))))
1280       (if (and found (<= (match-beginning 0) pos)
1281                (> (match-end 0) pos))
1282           (buffer-substring (match-beginning 1) (match-end 1))
1283         (cond ((null errorstring)
1284                nil)
1285               ((eq errorstring t)
1286                (beep)
1287                nil)
1288               (t
1289                (error "No %s around position %d" errorstring pos)))))))
1290
1291 (defun Info-mouse-follow-nearest-node (click)
1292   "\\<Info-mode-map>Follow a node reference near point.
1293 Like \\[Info-menu], \\[Info-follow-reference], \\[Info-next], \\[Info-prev] or \\[Info-up] command, depending on where you click.
1294 At end of the node's text, moves to the next node, or up if none."
1295   (interactive "e")
1296   (let* ((start (event-start click))
1297          (window (car start))
1298          (pos (car (cdr start))))
1299     (select-window window)
1300     (goto-char pos))
1301   (and (not (Info-try-follow-nearest-node))
1302        (save-excursion (forward-line 1) (eobp))
1303        (Info-next-preorder)))
1304
1305 (defun Info-follow-nearest-node ()
1306   "\\<Info-mode-map>Follow a node reference near point.
1307 Like \\[Info-menu], \\[Info-follow-reference], \\[Info-next], \\[Info-prev] or \\[Info-up] command, depending on where point is.
1308 If no reference to follow, moves to the next node, or up if none."
1309   (interactive)
1310   (or (Info-try-follow-nearest-node)
1311       (Info-next-preorder)))
1312
1313 ;; Common subroutine.
1314 (defun Info-try-follow-nearest-node ()
1315   "Follow a node reference near point.  Return non-nil if successful."
1316   (let (node)
1317     (cond
1318      ((setq node (Info-get-token (point) "\\*note[ \n]"
1319                                  "\\*note[ \n]\\([^:]*\\):"))
1320       (Info-follow-reference node))
1321      ((setq node (Info-get-token (point) "\\* " "\\* \\([^:]*\\)::"))
1322       (Info-goto-node node))
1323      ((setq node (Info-get-token (point) "\\* " "\\* \\([^:]*\\):"))
1324       (Info-menu node))
1325      ((setq node (Info-get-token (point) "Up: " "Up: \\([^,\n\t]*\\)"))
1326       (Info-goto-node node))
1327      ((setq node (Info-get-token (point) "Next: " "Next: \\([^,\n\t]*\\)"))
1328       (Info-goto-node node))
1329      ((setq node (Info-get-token (point) "File: " "File: \\([^,\n\t]*\\)"))
1330       (Info-goto-node "Top"))
1331      ((setq node (Info-get-token (point) "Prev: " "Prev: \\([^,\n\t]*\\)"))
1332       (Info-goto-node node)))
1333     node))
1334 \f
1335 (defvar Info-mode-map nil
1336   "Keymap containing Info commands.")
1337 (if Info-mode-map
1338     nil
1339   (setq Info-mode-map (make-keymap))
1340   (suppress-keymap Info-mode-map)
1341   (define-key Info-mode-map "." 'beginning-of-buffer)
1342   (define-key Info-mode-map " " 'Info-scroll-up)
1343   (define-key Info-mode-map "\C-m" 'Info-follow-nearest-node)
1344   (define-key Info-mode-map "\t" 'Info-next-reference)
1345   (define-key Info-mode-map "\e\t" 'Info-prev-reference)
1346   (define-key Info-mode-map "1" 'Info-nth-menu-item)
1347   (define-key Info-mode-map "2" 'Info-nth-menu-item)
1348   (define-key Info-mode-map "3" 'Info-nth-menu-item)
1349   (define-key Info-mode-map "4" 'Info-nth-menu-item)
1350   (define-key Info-mode-map "5" 'Info-nth-menu-item)
1351   (define-key Info-mode-map "6" 'Info-nth-menu-item)
1352   (define-key Info-mode-map "7" 'Info-nth-menu-item)
1353   (define-key Info-mode-map "8" 'Info-nth-menu-item)
1354   (define-key Info-mode-map "9" 'Info-nth-menu-item)
1355   (define-key Info-mode-map "0" 'undefined)
1356   (define-key Info-mode-map "?" 'Info-summary)
1357   (define-key Info-mode-map "]" 'Info-forward-node)
1358   (define-key Info-mode-map "[" 'Info-backward-node)
1359   (define-key Info-mode-map "<" 'Info-top-node)
1360   (define-key Info-mode-map ">" 'Info-final-node)
1361   (define-key Info-mode-map "b" 'beginning-of-buffer)
1362   (define-key Info-mode-map "d" 'Info-directory)
1363   (define-key Info-mode-map "e" 'Info-edit)
1364   (define-key Info-mode-map "f" 'Info-follow-reference)
1365   (define-key Info-mode-map "g" 'Info-goto-node)
1366   (define-key Info-mode-map "h" 'Info-help)
1367   (define-key Info-mode-map "i" 'Info-index)
1368   (define-key Info-mode-map "l" 'Info-last)
1369   (define-key Info-mode-map "m" 'Info-menu)
1370   (define-key Info-mode-map "n" 'Info-next)
1371   (define-key Info-mode-map "p" 'Info-prev)
1372   (define-key Info-mode-map "q" 'Info-exit)
1373   (define-key Info-mode-map "s" 'Info-search)
1374   (define-key Info-mode-map "t" 'Info-top-node)
1375   (define-key Info-mode-map "u" 'Info-up)
1376   (define-key Info-mode-map "," 'Info-index-next)
1377   (define-key Info-mode-map "\177" 'Info-scroll-down)
1378   (define-key Info-mode-map [mouse-2] 'Info-mouse-follow-nearest-node)
1379   )
1380 \f
1381 ;; Info mode is suitable only for specially formatted data.
1382 (put 'info-mode 'mode-class 'special)
1383
1384 (defun Info-mode ()
1385   "\\<Info-mode-map>
1386 Info mode provides commands for browsing through the Info documentation tree.
1387 Documentation in Info is divided into \"nodes\", each of which discusses
1388 one topic and contains references to other nodes which discuss related
1389 topics.  Info has commands to follow the references and show you other nodes.
1390
1391 \\[Info-help]   Invoke the Info tutorial.
1392
1393 Selecting other nodes:
1394 \\[Info-next]   Move to the \"next\" node of this node.
1395 \\[Info-prev]   Move to the \"previous\" node of this node.
1396 \\[Info-up]     Move \"up\" from this node.
1397 \\[Info-menu]   Pick menu item specified by name (or abbreviation).
1398         Picking a menu item causes another node to be selected.
1399 \\[Info-directory]      Go to the Info directory node.
1400 \\[Info-follow-reference]       Follow a cross reference.  Reads name of reference.
1401 \\[Info-last]   Move to the last node you were at.
1402 \\[Info-index]  Look up a topic in this file's Index and move to that node.
1403 \\[Info-index-next]     (comma) Move to the next match from a previous `i' command.
1404
1405 Moving within a node:
1406 \\[Info-scroll-up]      Normally, scroll forward a full screen.  If the end of the buffer is
1407 already visible, try to go to the next menu entry, or up if there is none.
1408 \\[Info-scroll-down]  Normally, scroll backward.  If the beginning of the buffer is
1409 already visible, try to go to the previous menu entry, or up if there is none.
1410 \\[beginning-of-buffer] Go to beginning of node.
1411
1412 Advanced commands:
1413 \\[Info-exit]   Quit Info: reselect previously selected buffer.
1414 \\[Info-edit]   Edit contents of selected node.
1415 1       Pick first item in node's menu.
1416 2, 3, 4, 5   Pick second ... fifth item in node's menu.
1417 \\[Info-goto-node]      Move to node specified by name.
1418         You may include a filename as well, as (FILENAME)NODENAME.
1419 \\[universal-argument] \\[info] Move to new Info file with completion.
1420 \\[Info-search] Search through this Info file for specified regexp,
1421         and select the node in which the next occurrence is found.
1422 \\[Info-next-preorder]  Next-preorder; that is, try to go to the next menu item,
1423         and if that fails try to move up, and if that fails, tell user
1424         he/she is done reading.
1425 \\[Info-next-reference] Move cursor to next cross-reference or menu item.
1426 \\[Info-prev-reference] Move cursor to previous cross-reference or menu item."
1427   (kill-all-local-variables)
1428   (setq major-mode 'Info-mode)
1429   (setq mode-name "Info")
1430   (use-local-map Info-mode-map)
1431   (set-syntax-table text-mode-syntax-table)
1432   (setq local-abbrev-table text-mode-abbrev-table)
1433   (setq case-fold-search t)
1434   (setq buffer-read-only t)
1435   (make-local-variable 'Info-current-file)
1436   (make-local-variable 'Info-current-subfile)
1437   (make-local-variable 'Info-current-node)
1438   (make-local-variable 'Info-tag-table-marker)
1439   (make-local-variable 'Info-history)
1440   (make-local-variable 'Info-index-alternatives)
1441   (if (fboundp 'make-face)
1442       (progn
1443         (make-face 'info-node)
1444         (make-face 'info-menu-5)
1445         (make-face 'info-xref)
1446         (or (face-differs-from-default-p 'info-node)
1447             (if (face-differs-from-default-p 'bold-italic)
1448                 (copy-face 'bold-italic 'info-node)
1449               (copy-face 'bold 'info-node)))
1450         (or (face-differs-from-default-p 'info-menu-5)
1451             (set-face-underline-p 'info-menu-5 t))
1452         (or (face-differs-from-default-p 'info-xref)
1453             (copy-face 'bold 'info-xref)))
1454     (setq Info-fontify nil))
1455   (Info-set-mode-line)
1456   (run-hooks 'Info-mode-hook))
1457
1458 (defvar Info-edit-map nil
1459   "Local keymap used within `e' command of Info.")
1460 (if Info-edit-map
1461     nil
1462   (setq Info-edit-map (nconc (make-sparse-keymap) text-mode-map))
1463   (define-key Info-edit-map "\C-c\C-c" 'Info-cease-edit))
1464
1465 ;; Info-edit mode is suitable only for specially formatted data.
1466 (put 'info-edit-mode 'mode-class 'special)
1467
1468 (defun Info-edit-mode ()
1469   "Major mode for editing the contents of an Info node.
1470 Like text mode with the addition of `Info-cease-edit'
1471 which returns to Info mode for browsing.
1472 \\{Info-edit-map}"
1473   )
1474
1475 (defun Info-edit ()
1476   "Edit the contents of this Info node.
1477 Allowed only if variable `Info-enable-edit' is non-nil."
1478   (interactive)
1479   (or Info-enable-edit
1480       (error "Editing info nodes is not enabled"))
1481   (use-local-map Info-edit-map)
1482   (setq major-mode 'Info-edit-mode)
1483   (setq mode-name "Info Edit")
1484   (kill-local-variable 'mode-line-buffer-identification)
1485   (setq buffer-read-only nil)
1486   ;; Make mode line update.
1487   (set-buffer-modified-p (buffer-modified-p))
1488   (message (substitute-command-keys
1489              "Editing: Type \\<Info-edit-map>\\[Info-cease-edit] to return to info")))
1490
1491 (defun Info-cease-edit ()
1492   "Finish editing Info node; switch back to Info proper."
1493   (interactive)
1494   ;; Do this first, so nothing has changed if user C-g's at query.
1495   (and (buffer-modified-p)
1496        (y-or-n-p "Save the file? ")
1497        (save-buffer))
1498   (use-local-map Info-mode-map)
1499   (setq major-mode 'Info-mode)
1500   (setq mode-name "Info")
1501   (Info-set-mode-line)
1502   (setq buffer-read-only t)
1503   ;; Make mode line update.
1504   (set-buffer-modified-p (buffer-modified-p))
1505   (and (marker-position Info-tag-table-marker)
1506        (buffer-modified-p)
1507        (message "Tags may have changed.  Use Info-tagify if necessary")))
1508 \f
1509 (defun Info-find-emacs-command-nodes (command)
1510   "Return a list of locations documenting COMMAND in the Emacs Info manual.
1511 The locations are of the format used in Info-history, i.e.
1512 \(FILENAME NODENAME BUFFERPOS\)."
1513   (require 'info)
1514   (let ((where '())
1515         (cmd-desc (concat "^\\* " (regexp-quote (symbol-name command))
1516                           ":\\s *\\(.*\\)\\.$")))
1517     (save-excursion
1518       (Info-find-node "emacs" "Command Index")
1519       ;; Take the index node off the Info history.
1520       (setq Info-history (cdr Info-history))
1521       (goto-char (point-max))
1522       (while (re-search-backward cmd-desc nil t)
1523           (setq where (cons (list Info-current-file
1524                                   (buffer-substring
1525                                    (match-beginning 1)
1526                                    (match-end 1))
1527                                   0)
1528                             where)))
1529       where)))
1530
1531 ;;;###autoload
1532 (defun Info-goto-emacs-command-node (command)
1533   "Go to the Info node in the Emacs manual for command COMMAND.
1534 The command is found by looking up in Emacs manual's Command Index."
1535   (interactive "CFind documentation for command: ")
1536   (or (commandp command)
1537       (signal 'wrong-type-argument (list 'commandp command)))
1538   (let ((where (Info-find-emacs-command-nodes command)))
1539     (if where
1540         (let ((num-matches (length where)))
1541           ;; Get Info running, and pop to it in another window.
1542           (save-window-excursion
1543             (info))
1544           (pop-to-buffer "*info*")
1545           (Info-find-node (car (car where))
1546                           (car (cdr (car where))))
1547           (if (> num-matches 1)
1548               (progn
1549                 ;; Info-find-node already pushed (car where) onto
1550                 ;; Info-history.  Put the other nodes that were found on
1551                 ;; the history.
1552                 (setq Info-history (nconc (cdr where) Info-history))
1553                 (message (substitute-command-keys
1554                           "Found %d other entr%s.  Use \\[Info-last] to see %s.")
1555                          (1- num-matches)
1556                          (if (> num-matches 2) "ies" "y")
1557                          (if (> num-matches 2) "them" "it")))))
1558       (error "Couldn't find documentation for %s." command))))
1559
1560 ;;;###autoload
1561 (defun Info-goto-emacs-key-command-node (key)
1562   "Go to the Info node in the Emacs manual the command bound to KEY, a string.
1563 Interactively, if the binding is execute-extended-command, a command is read.
1564 The command is found by looking up in Emacs manual's Command Index."
1565   (interactive "kFind documentation for key:")
1566   (let ((command (key-binding key)))
1567     (cond ((null command)
1568            (message "%s is undefined" (key-description key)))
1569           ((and (interactive-p)
1570                 (eq command 'execute-extended-command))
1571            (Info-goto-emacs-command-node
1572             (read-command "Find documentation for command: ")))
1573           (t
1574            (Info-goto-emacs-command-node command)))))
1575 \f
1576 (defun Info-fontify-node ()
1577   (save-excursion
1578     (let ((buffer-read-only nil))
1579       (goto-char (point-min))
1580       (if (looking-at "^File: [^,: \t]+,?[ \t]+")
1581           (progn
1582             (goto-char (match-end 0))
1583             (while
1584                 (looking-at "[ \t]*[^:, \t\n]+:[ \t]+\\([^:,\t\n]+\\),?")
1585               (goto-char (match-end 0))
1586               (put-text-property (match-beginning 1) (match-end 1)
1587                                  'face 'info-xref)
1588               (put-text-property (match-beginning 1) (match-end 1)
1589                                  'mouse-face 'highlight))))
1590       (goto-char (point-min))
1591       (while (re-search-forward "\\*Note[ \n\t]+\\([^:]*\\):" nil t)
1592         (if (= (char-after (1- (match-beginning 0))) ?\") ; hack
1593             nil
1594           (put-text-property (match-beginning 1) (match-end 1)
1595                              'face 'info-xref)
1596           (put-text-property (match-beginning 1) (match-end 1)
1597                              'mouse-face 'highlight)))
1598       (goto-char (point-min))
1599       (if (and (search-forward "\n* Menu:" nil t)
1600                (not (string-match "\\<Index\\>" Info-current-node))
1601                ;; Don't take time to annotate huge menus
1602                (< (- (point-max) (point)) 30000))
1603           (let ((n 0))
1604             (while (re-search-forward "^\\* \\([^:\t\n]*\\):" nil t)
1605               (setq n (1+ n))
1606               (if (memq n '(5 9))   ; visual aids to help with 1-9 keys
1607                   (put-text-property (match-beginning 0)
1608                                      (1+ (match-beginning 0))
1609                                      'face 'info-menu-5))
1610               (put-text-property (match-beginning 1) (match-end 1)
1611                                  'face 'info-node)
1612               (put-text-property (match-beginning 1) (match-end 1)
1613                                  'mouse-face 'highlight))))
1614       (set-buffer-modified-p nil))))
1615
1616 (provide 'info)
1617
1618 ;;; info.el ends here