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 the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; Note that nowadays we expect info files to be made using makeinfo.
  28
  29 ;;; Code:
  30
  31 (defvar Info-history nil
  32   "List of info nodes user has visited.
  33 Each element of list is a list (FILENAME NODENAME BUFFERPOS).")
  34
  35 (defvar Info-enable-edit nil
  36   "*Non-nil means the \\<Info-mode-map>\\[Info-edit] command in Info can edit the current node.
  37 This is convenient if you want to write info files by hand.
  38 However, we recommend that you not do this.
  39 It is better to write a Texinfo file and generate the Info file from that,
  40 because that gives you a printed manual as well.")
  41
  42 (defvar Info-enable-active-nodes t
  43   "Non-nil allows Info to execute Lisp code associated with nodes.
  44 The Lisp code is executed when the node is selected.")
  45
  46 (defvar Info-fontify t
  47   "*Non-nil enables highlighting and fonts in Info nodes.")
  48
  49 (defvar Info-fontify-maximum-menu-size 30000
  50   "*Maximum size of menu to fontify if `Info-fontify' is non-nil.")
  51
  52 (defvar Info-directory-list
  53   (let ((path (getenv "INFOPATH"))
  54         ;; This is for older Emacs versions
  55         ;; which might get this info.el from the Texinfo distribution.
  56         (path-separator (if (boundp 'path-separator) path-separator
  57                           (if (eq system-type 'ms-dos) ";" ":")))
  58         (source (expand-file-name "info/" source-directory))
  59         (sibling (if installation-directory
  60                      (expand-file-name "info/" installation-directory)))
  61         alternative)
  62     (if path
  63         (let ((list nil)
  64               idx)
  65           (while (> (length path) 0)
  66             (setq idx (or (string-match path-separator path) (length path))
  67                   list (cons (substring path 0 idx) list)
  68                   path (substring path (min (1+ idx)
  69                                             (length path)))))
  70           (nreverse list))
  71       (if (and sibling (file-exists-p sibling))
  72           (setq alternative sibling)
  73         (setq alternative source))
  74       (if (or (member alternative Info-default-directory-list)
  75               (not (file-exists-p alternative))
  76               ;; On DOS/NT, we use movable executables always,
  77               ;; and we must always find the Info dir at run time.
  78               (if (or (eq system-type 'ms-dos) (eq system-type 'windows-nt))
  79                   nil
  80                 ;; Use invocation-directory for Info only if we used it for
  81                 ;; exec-directory also.
  82                 (not (string= exec-directory
  83                               (expand-file-name "lib-src/"
  84                                                 installation-directory)))))
  85           Info-default-directory-list
  86         (reverse (cons alternative
  87                        (cdr (reverse Info-default-directory-list)))))))
  88   "List of directories to search for Info documentation files.
  89 nil means not yet initialized.  In this case, Info uses the environment
  90 variable INFOPATH to initialize it, or `Info-default-directory-list'
  91 if there is no INFOPATH variable in the environment.
  92 The last element of `Info-default-directory-list' is the directory
  93 where Emacs installs the Info files that come with it.
  94
  95 If you run the Emacs executable from the `src' directory in the Emacs
  96 source tree, the `info' directory in the source tree is used as the last
  97 element, in place of the installation Info directory.  This is useful
  98 when you run a version of Emacs without installing it.")
  99
 100 (defvar Info-additional-directory-list nil
 101   "List of additional directories to search for Info documentation files.
 102 These directories are not searched for merging the `dir' file.")
 103
 104 (defvar Info-current-file nil
 105   "Info file that Info is now looking at, or nil.
 106 This is the name that was specified in Info, not the actual file name.
 107 It doesn't contain directory names or file name extensions added by Info.")
 108
 109 (defvar Info-current-subfile nil
 110   "Info subfile that is actually in the *info* buffer now,
 111 or nil if current info file is not split into subfiles.")
 112
 113 (defvar Info-current-node nil
 114   "Name of node that Info is now looking at, or nil.")
 115
 116 (defvar Info-tag-table-marker (make-marker)
 117   "Marker pointing at beginning of current Info file's tag table.
 118 Marker points nowhere if file has no tag table.")
 119
 120 (defvar Info-current-file-completions nil
 121   "Cached completion list for current Info file.")
 122
 123 (defvar Info-index-alternatives nil
 124   "List of possible matches for last Info-index command.")
 125
 126 (defvar Info-standalone nil
 127   "Non-nil if Emacs was started solely as an Info browser.")
 128
 129 (defvar Info-suffix-list
 130   (if (eq system-type 'ms-dos)
 131       '( (".gz"      . "gunzip")
 132          (".z"       . "gunzip")
 133          (".inf"     . nil)
 134          (""         . nil))
 135     '( (".info.Z"  . "uncompress")
 136        (".info.Y"  . "unyabba")
 137        (".info.gz" . "gunzip")
 138        (".info.z"  . "gunzip")
 139        (".info"    . nil)
 140        (".Z"       . "uncompress")
 141        (".Y"       . "unyabba")
 142        (".gz"      . "gunzip")
 143        (".z"       . "gunzip")
 144        (""         . nil)))
 145   "List of file name suffixes and associated decoding commands.
 146 Each entry should be (SUFFIX . STRING); the file is given to
 147 the command as standard input.  If STRING is nil, no decoding is done.
 148 Because the SUFFIXes are tried in order, the empty string should
 149 be last in the list.")
 150
 151 ;; Concatenate SUFFIX onto FILENAME.  SUFFIX should start with a dot.
 152 ;; First, on ms-dos, delete some of the extension in FILENAME
 153 ;; to make room.
 154 (defun info-insert-file-contents-1 (filename suffix)
 155   (if (not (eq system-type 'ms-dos))
 156       (concat filename suffix)
 157     (let* ((sans-exts (file-name-sans-extension filename))
 158            ;; How long is the extension in FILENAME (not counting the dot).
 159            (ext-len (max 0 (- (length filename) (length sans-exts) 1)))
 160            ext-left)
 161       ;; SUFFIX starts with a dot.  If FILENAME already has one,
 162       ;; get rid of the one in SUFFIX (unless suffix is empty).
 163       (or (and (<= ext-len 0)
 164                (not (eq (aref filename (1- (length filename))) ?.)))
 165           (= (length suffix) 0)
 166           (setq suffix (substring suffix 1)))
 167       ;; How many chars of that extension should we keep?
 168       (setq ext-left (min ext-len (max 0 (- 3 (length suffix)))))
 169       ;; Get rid of the rest of the extension, and add SUFFIX.
 170       (concat (substring filename 0 (- (length filename)
 171                                        (- ext-len ext-left)))
 172               suffix))))
 173
 174 (defun info-insert-file-contents (filename &optional visit)
 175   "Insert the contents of an info file in the current buffer.
 176 Do the right thing if the file has been compressed or zipped."
 177   (let ((tail Info-suffix-list)
 178         fullname decoder)
 179     (if (file-exists-p filename)
 180         ;; FILENAME exists--see if that name contains a suffix.
 181         ;; If so, set DECODE accordingly.
 182         (progn
 183           (while (and tail
 184                       (not (string-match
 185                             (concat (regexp-quote (car (car tail))) "$")
 186                             filename)))
 187             (setq tail (cdr tail)))
 188           (setq fullname filename
 189                 decoder (cdr (car tail))))
 190       ;; Try adding suffixes to FILENAME and see if we can find something.
 191       (while (and tail
 192                   (not (file-exists-p (info-insert-file-contents-1
 193                                        filename (car (car tail))))))
 194         (setq tail (cdr tail)))
 195       ;; If we found a file with a suffix, set DECODER according to the suffix
 196       ;; and set FULLNAME to the file's actual name.
 197       (setq fullname (info-insert-file-contents-1 filename (car (car tail)))
 198             decoder (cdr (car tail)))
 199       (or tail
 200           (error "Can't find %s or any compressed version of it" filename)))
 201     ;; check for conflict with jka-compr
 202     (if (and (featurep 'jka-compr)
 203              (jka-compr-installed-p)
 204              (jka-compr-get-compression-info fullname))
 205         (setq decoder nil))
 206     (insert-file-contents fullname visit)
 207     (if decoder
 208         (let ((buffer-read-only nil)
 209               (default-directory (or (file-name-directory fullname)
 210                                      default-directory)))
 211           (call-process-region (point-min) (point-max) decoder t t)))))
 212
 213 ;;;###autoload (add-hook 'same-window-buffer-names "*info*")
 214
 215 ;;;###autoload
 216 (defun info (&optional file)
 217   "Enter Info, the documentation browser.
 218 Optional argument FILE specifies the file to examine;
 219 the default is the top-level directory of Info.
 220
 221 In interactive use, a prefix argument directs this command
 222 to read a file name from the minibuffer.
 223
 224 The search path for Info files is in the variable `Info-directory-list'.
 225 The top-level Info directory is made by combining all the files named `dir'
 226 in all the directories in that path."
 227   (interactive (if current-prefix-arg
 228                    (list (read-file-name "Info file name: " nil nil t))))
 229   (if file
 230       (Info-goto-node (concat "(" file ")"))
 231     (if (get-buffer "*info*")
 232         (pop-to-buffer "*info*")
 233       (Info-directory))))
 234
 235 ;;;###autoload
 236 (defun info-standalone ()
 237   "Run Emacs as a standalone Info reader.
 238 Usage:  emacs -f info-standalone [filename]
 239 In standalone mode, \\<Info-mode-map>\\[Info-exit] exits Emacs itself."
 240   (setq Info-standalone t)
 241   (if (and command-line-args-left
 242            (not (string-match "^-" (car command-line-args-left))))
 243       (condition-case err
 244           (progn
 245             (info (car command-line-args-left))
 246             (setq command-line-args-left (cdr command-line-args-left)))
 247         (error (send-string-to-terminal
 248                 (format "%s\n" (if (eq (car-safe err) 'error)
 249                                    (nth 1 err) err)))
 250                (save-buffers-kill-emacs)))
 251     (info)))
 252
 253 ;; Go to an info node specified as separate filename and nodename.
 254 ;; no-going-back is non-nil if recovering from an error in this function;
 255 ;; it says do not attempt further (recursive) error recovery.
 256 (defun Info-find-node (filename nodename &optional no-going-back)
 257   ;; Convert filename to lower case if not found as specified.
 258   ;; Expand it.
 259   (if filename
 260       (let (temp temp-downcase found)
 261         (setq filename (substitute-in-file-name filename))
 262         (if (string= (downcase (file-name-nondirectory filename)) "dir")
 263             (setq found t)
 264           (let ((dirs (if (string-match "^\\./" filename)
 265                           ;; If specified name starts with `./'
 266                           ;; then just try current directory.
 267                           '("./")
 268                         (if (file-name-absolute-p filename)
 269                             ;; No point in searching for an
 270                             ;; absolute file name
 271                             '(nil)
 272                           (if Info-additional-directory-list
 273                               (append Info-directory-list
 274                                       Info-additional-directory-list)
 275                             Info-directory-list)))))
 276             ;; Search the directory list for file FILENAME.
 277             (while (and dirs (not found))
 278               (setq temp (expand-file-name filename (car dirs)))
 279               (setq temp-downcase
 280                     (expand-file-name (downcase filename) (car dirs)))
 281               ;; Try several variants of specified name.
 282               (let ((suffix-list Info-suffix-list))
 283                 (while (and suffix-list (not found))
 284                   (cond ((file-exists-p
 285                           (info-insert-file-contents-1
 286                            temp (car (car suffix-list))))
 287                          (setq found temp))
 288                         ((file-exists-p
 289                           (info-insert-file-contents-1
 290                            temp-downcase (car (car suffix-list))))
 291                          (setq found temp-downcase)))
 292                   (setq suffix-list (cdr suffix-list))))
 293               (setq dirs (cdr dirs)))))
 294         (if found
 295             (setq filename found)
 296           (error "Info file %s does not exist" filename))))
 297   ;; Record the node we are leaving.
 298   (if (and Info-current-file (not no-going-back))
 299       (setq Info-history
 300             (cons (list Info-current-file Info-current-node (point))
 301                   Info-history)))
 302   ;; Go into info buffer.
 303   (switch-to-buffer "*info*")
 304   (buffer-disable-undo (current-buffer))
 305   (or (eq major-mode 'Info-mode)
 306       (Info-mode))
 307   (widen)
 308   (setq Info-current-node nil)
 309   (unwind-protect
 310       (progn
 311         ;; Switch files if necessary
 312         (or (null filename)
 313             (equal Info-current-file filename)
 314             (let ((buffer-read-only nil))
 315               (setq Info-current-file nil
 316                     Info-current-subfile nil
 317                     Info-current-file-completions nil
 318                     Info-index-alternatives nil
 319                     buffer-file-name nil)
 320               (erase-buffer)
 321               (if (eq filename t)
 322                   (Info-insert-dir)
 323                 (info-insert-file-contents filename t)
 324                 (setq default-directory (file-name-directory filename)))
 325               (set-buffer-modified-p nil)
 326               ;; See whether file has a tag table.  Record the location if yes.
 327               (set-marker Info-tag-table-marker nil)
 328               (goto-char (point-max))
 329               (forward-line -8)
 330               ;; Use string-equal, not equal, to ignore text props.
 331               (or (string-equal nodename "*")
 332                   (not (search-forward "\^_\nEnd tag table\n" nil t))
 333                   (let (pos)
 334                     ;; We have a tag table.  Find its beginning.
 335                     ;; Is this an indirect file?
 336                     (search-backward "\nTag table:\n")
 337                     (setq pos (point))
 338                     (if (save-excursion
 339                           (forward-line 2)
 340                           (looking-at "(Indirect)\n"))
 341                         ;; It is indirect.  Copy it to another buffer
 342                         ;; and record that the tag table is in that buffer.
 343                         (save-excursion
 344                           (let ((buf (current-buffer)))
 345                             (set-buffer (get-buffer-create " *info tag table*"))
 346                             (buffer-disable-undo (current-buffer))
 347                             (setq case-fold-search t)
 348                             (erase-buffer)
 349                             (insert-buffer-substring buf)
 350                             (set-marker Info-tag-table-marker
 351                                         (match-end 0))))
 352                       (set-marker Info-tag-table-marker pos))))
 353               (setq Info-current-file
 354                     (if (eq filename t) "dir" filename))))
 355         ;; Use string-equal, not equal, to ignore text props.
 356         (if (string-equal nodename "*")
 357             (progn (setq Info-current-node nodename)
 358                    (Info-set-mode-line))
 359           ;; Search file for a suitable node.
 360           (let ((guesspos (point-min))
 361                 (regexp (concat "Node: *" (regexp-quote nodename) " *[,\t\n\177]")))
 362             ;; First get advice from tag table if file has one.
 363             ;; Also, if this is an indirect info file,
 364             ;; read the proper subfile into this buffer.
 365             (if (marker-position Info-tag-table-marker)
 366                 (save-excursion
 367                   (set-buffer (marker-buffer Info-tag-table-marker))
 368                   (goto-char Info-tag-table-marker)
 369                   (if (re-search-forward regexp nil t)
 370                       (progn
 371                         (setq guesspos (read (current-buffer)))
 372                         ;; If this is an indirect file,
 373                         ;; determine which file really holds this node
 374                         ;; and read it in.
 375                         (if (not (eq (current-buffer) (get-buffer "*info*")))
 376                             (setq guesspos
 377                                   (Info-read-subfile guesspos))))
 378                     (error "No such node: %s" nodename))))
 379             (goto-char (max (point-min) (- guesspos 1000)))
 380             ;; Now search from our advised position (or from beg of buffer)
 381             ;; to find the actual node.
 382             (catch 'foo
 383               (while (search-forward "\n\^_" nil t)
 384                 (forward-line 1)
 385                 (let ((beg (point)))
 386                   (forward-line 1)
 387                   (if (re-search-backward regexp beg t)
 388                       (throw 'foo t))))
 389               (error "No such node: %s" nodename)))
 390           (Info-select-node)))
 391     ;; If we did not finish finding the specified node,
 392     ;; go back to the previous one.
 393     (or Info-current-node no-going-back (null Info-history)
 394         (let ((hist (car Info-history)))
 395           (setq Info-history (cdr Info-history))
 396           (Info-find-node (nth 0 hist) (nth 1 hist) t)
 397           (goto-char (nth 2 hist)))))
 398   (goto-char (point-min)))
 399
 400 ;; Cache the contents of the (virtual) dir file, once we have merged
 401 ;; it for the first time, so we can save time subsequently.
 402 (defvar Info-dir-contents nil)
 403
 404 ;; Cache for the directory we decided to use for the default-directory
 405 ;; of the merged dir text.
 406 (defvar Info-dir-contents-directory nil)
 407
 408 ;; Record the file attributes of all the files from which we
 409 ;; constructed Info-dir-contents.
 410 (defvar Info-dir-file-attributes nil)
 411
 412 ;; Construct the Info directory node by merging the files named `dir'
 413 ;; from various directories.  Set the *info* buffer's
 414 ;; default-directory to the first directory we actually get any text
 415 ;; from.
 416 (defun Info-insert-dir ()
 417   (if (and Info-dir-contents Info-dir-file-attributes
 418            ;; Verify that none of the files we used has changed
 419            ;; since we used it.
 420            (eval (cons 'and
 421                        (mapcar '(lambda (elt)
 422                                   (let ((curr (file-attributes (car elt))))
 423                                     ;; Don't compare the access time.
 424                                     (if curr (setcar (nthcdr 4 curr) 0))
 425                                     (setcar (nthcdr 4 (cdr elt)) 0)
 426                                     (equal (cdr elt) curr)))
 427                                Info-dir-file-attributes))))
 428       (insert Info-dir-contents)
 429     (let ((dirs Info-directory-list)
 430           buffers buffer others nodes dirs-done)
 431
 432       (setq Info-dir-file-attributes nil)
 433
 434       ;; Search the directory list for the directory file.
 435       (while dirs
 436         (let ((truename (file-truename (expand-file-name (car dirs)))))
 437           (or (member truename dirs-done)
 438               (member (directory-file-name truename) dirs-done)
 439               ;; Try several variants of specified name.
 440               ;; Try upcasing, appending `.info', or both.
 441               (let* (file
 442                      (attrs
 443                       (or
 444                        (progn (setq file (expand-file-name "dir" truename))
 445                               (file-attributes file))
 446                        (progn (setq file (expand-file-name "DIR" truename))
 447                               (file-attributes file))
 448                        (progn (setq file (expand-file-name "dir.info" truename))
 449                               (file-attributes file))
 450                        (progn (setq file (expand-file-name "DIR.INFO" truename))
 451                               (file-attributes file)))))
 452                 (setq dirs-done
 453                       (cons truename
 454                             (cons (directory-file-name truename)
 455                                   dirs-done)))
 456                 (if attrs
 457                     (save-excursion
 458                       (or buffers
 459                           (message "Composing main Info directory..."))
 460                       (set-buffer (generate-new-buffer "info dir"))
 461                       (insert-file-contents file)
 462                       (setq buffers (cons (current-buffer) buffers)
 463                             Info-dir-file-attributes
 464                             (cons (cons file attrs)
 465                                   Info-dir-file-attributes))))))
 466           (setq dirs (cdr dirs))))
 467
 468       (or buffers
 469           (error "Can't find the Info directory node"))
 470       ;; Distinguish the dir file that comes with Emacs from all the
 471       ;; others.  Yes, that is really what this is supposed to do.
 472       ;; If it doesn't work, fix it.
 473       (setq buffer (car buffers)
 474             others (cdr buffers))
 475
 476       ;; Insert the entire original dir file as a start; use its
 477       ;; default directory as the default directory for the whole
 478       ;; concatenation.
 479       (insert-buffer buffer)
 480       (setq Info-dir-contents-directory (save-excursion
 481                                           (set-buffer buffer)
 482                                           default-directory))
 483
 484       ;; Look at each of the other buffers one by one.
 485       (while others
 486         (let ((other (car others)))
 487           ;; In each, find all the menus.
 488           (save-excursion
 489             (set-buffer other)
 490             (goto-char (point-min))
 491             ;; Find each menu, and add an elt to NODES for it.
 492             (while (re-search-forward "^\\* Menu:" nil t)
 493               (let (beg nodename end)
 494                 (forward-line 1)
 495                 (setq beg (point))
 496                 (search-backward "\n\^_")
 497                 (search-forward "Node: ")
 498                 (setq nodename (Info-following-node-name))
 499                 (search-forward "\n\^_" nil 'move)
 500                 (beginning-of-line)
 501                 (setq end (point))
 502                 (setq nodes (cons (list nodename other beg end) nodes))))))
 503         (setq others (cdr others)))
 504       ;; Add to the main menu a menu item for each other node.
 505       (re-search-forward "^\\* Menu:")
 506       (forward-line 1)
 507       (let ((menu-items '("top"))
 508             (nodes nodes)
 509             (case-fold-search t)
 510             (end (save-excursion (search-forward "\^_" nil t) (point))))
 511         (while nodes
 512           (let ((nodename (car (car nodes))))
 513             (save-excursion
 514               (or (member (downcase nodename) menu-items)
 515                   (re-search-forward (concat "^\\* "
 516                                              (regexp-quote nodename)
 517                                              "::")
 518                                      end t)
 519                   (progn
 520                     (insert "* " nodename "::" "\n")
 521                     (setq menu-items (cons nodename menu-items))))))
 522           (setq nodes (cdr nodes))))
 523       ;; Now take each node of each of the other buffers
 524       ;; and merge it into the main buffer.
 525       (while nodes
 526         (let ((nodename (car (car nodes))))
 527           (goto-char (point-min))
 528           ;; Find the like-named node in the main buffer.
 529           (if (re-search-forward (concat "\n\^_.*\n.*Node: "
 530                                          (regexp-quote nodename)
 531                                          "[,\n\t]")
 532                                  nil t)
 533               (progn
 534                 (search-forward "\n\^_" nil 'move)
 535                 (beginning-of-line)
 536                 (insert "\n"))
 537             ;; If none exists, add one.
 538             (goto-char (point-max))
 539             (insert "\^_\nFile: dir\tNode: " nodename "\n\n* Menu:\n\n"))
 540           ;; Merge the text from the other buffer's menu
 541           ;; into the menu in the like-named node in the main buffer.
 542           (apply 'insert-buffer-substring (cdr (car nodes))))
 543         (setq nodes (cdr nodes)))
 544       ;; Kill all the buffers we just made.
 545       (while buffers
 546         (kill-buffer (car buffers))
 547         (setq buffers (cdr buffers)))
 548       (message "Composing main Info directory...done"))
 549     (setq Info-dir-contents (buffer-string)))
 550   (setq default-directory Info-dir-contents-directory))
 551
 552 (defun Info-read-subfile (nodepos)
 553   (set-buffer (marker-buffer Info-tag-table-marker))
 554   (goto-char (point-min))
 555   (search-forward "\n\^_")
 556   (let (lastfilepos
 557         lastfilename)
 558     (forward-line 2)
 559     (catch 'foo
 560       (while (not (looking-at "\^_"))
 561         (if (not (eolp))
 562             (let ((beg (point))
 563                   thisfilepos thisfilename)
 564               (search-forward ": ")
 565               (setq thisfilename  (buffer-substring beg (- (point) 2)))
 566               (setq thisfilepos (read (current-buffer)))
 567               ;; read in version 19 stops at the end of number.
 568               ;; Advance to the next line.
 569               (forward-line 1)
 570               (if (> thisfilepos nodepos)
 571                   (throw 'foo t))
 572               (setq lastfilename thisfilename)
 573               (setq lastfilepos thisfilepos))
 574           (forward-line 1))))
 575     (set-buffer (get-buffer "*info*"))
 576     (or (equal Info-current-subfile lastfilename)
 577         (let ((buffer-read-only nil))
 578           (setq buffer-file-name nil)
 579           (widen)
 580           (erase-buffer)
 581           (info-insert-file-contents lastfilename)
 582           (set-buffer-modified-p nil)
 583           (setq Info-current-subfile lastfilename)))
 584     (goto-char (point-min))
 585     (search-forward "\n\^_")
 586     (+ (- nodepos lastfilepos) (point))))
 587
 588 ;; Select the info node that point is in.
 589 (defun Info-select-node ()
 590   (save-excursion
 591    ;; Find beginning of node.
 592    (search-backward "\n\^_")
 593    (forward-line 2)
 594    ;; Get nodename spelled as it is in the node.
 595    (re-search-forward "Node:[ \t]*")
 596    (setq Info-current-node
 597          (buffer-substring-no-properties (point)
 598                                          (progn
 599                                           (skip-chars-forward "^,\t\n")
 600                                           (point))))
 601    (Info-set-mode-line)
 602    ;; Find the end of it, and narrow.
 603    (beginning-of-line)
 604    (let (active-expression)
 605      (narrow-to-region (point)
 606                        (if (re-search-forward "\n[\^_\f]" nil t)
 607                            (prog1
 608                             (1- (point))
 609                             (if (looking-at "[\n\^_\f]*execute: ")
 610                                 (progn
 611                                   (goto-char (match-end 0))
 612                                   (setq active-expression
 613                                         (read (current-buffer))))))
 614                          (point-max)))
 615      (if Info-enable-active-nodes (eval active-expression))
 616      (if Info-fontify (Info-fontify-node))
 617      (run-hooks 'Info-selection-hook))))
 618
 619 (defun Info-set-mode-line ()
 620   (setq mode-line-buffer-identification
 621         (concat
 622          "Info:  ("
 623          (if Info-current-file
 624              (file-name-nondirectory Info-current-file)
 625            "")
 626          ")"
 627          (or Info-current-node ""))))
 628 \f
 629 ;; Go to an info node specified with a filename-and-nodename string
 630 ;; of the sort that is found in pointers in nodes.
 631
 632 (defun Info-goto-node (nodename)
 633   "Go to info node named NAME.  Give just NODENAME or (FILENAME)NODENAME."
 634   (interactive (list (Info-read-node-name "Goto node: ")))
 635   (let (filename)
 636     (string-match "\\s *\\((\\s *\\([^\t)]*\\)\\s *)\\s *\\|\\)\\(.*\\)"
 637                   nodename)
 638     (setq filename (if (= (match-beginning 1) (match-end 1))
 639                        ""
 640                      (substring nodename (match-beginning 2) (match-end 2)))
 641           nodename (substring nodename (match-beginning 3) (match-end 3)))
 642     (let ((trim (string-match "\\s *\\'" filename)))
 643       (if trim (setq filename (substring filename 0 trim))))
 644     (let ((trim (string-match "\\s *\\'" nodename)))
 645       (if trim (setq nodename (substring nodename 0 trim))))
 646     (if transient-mark-mode (deactivate-mark))
 647     (Info-find-node (if (equal filename "") nil filename)
 648                     (if (equal nodename "") "Top" nodename))))
 649
 650 ;; This function is used as the "completion table" while reading a node name.
 651 ;; It does completion using the alist in completion-table
 652 ;; unless STRING starts with an open-paren.
 653 (defun Info-read-node-name-1 (string predicate code)
 654   (let ((no-completion (and (> (length string) 0) (eq (aref string 0) ?\())))
 655     (cond ((eq code nil)
 656            (if no-completion
 657                string
 658              (try-completion string completion-table predicate)))
 659           ((eq code t)
 660            (if no-completion
 661                nil
 662              (all-completions string completion-table predicate)))
 663           ((eq code 'lambda)
 664            (if no-completion
 665                t
 666              (assoc string completion-table))))))
 667
 668 (defun Info-read-node-name (prompt &optional default)
 669   (let* ((completion-ignore-case t)
 670          (completion-table (Info-build-node-completions))
 671          (nodename (completing-read prompt 'Info-read-node-name-1)))
 672     (if (equal nodename "")
 673         (or default
 674             (Info-read-node-name prompt))
 675       nodename)))
 676
 677 (defun Info-build-node-completions ()
 678   (or Info-current-file-completions
 679       (let ((compl nil))
 680         (save-excursion
 681           (save-restriction
 682             (if (marker-buffer Info-tag-table-marker)
 683                 (progn
 684                   (set-buffer (marker-buffer Info-tag-table-marker))
 685                   (widen)
 686                   (goto-char Info-tag-table-marker)
 687                   (while (re-search-forward "\nNode: \\(.*\\)\177" nil t)
 688                     (setq compl
 689                           (cons (list (buffer-substring (match-beginning 1)
 690                                                         (match-end 1)))
 691                                 compl))))
 692               (widen)
 693               (goto-char (point-min))
 694               (while (search-forward "\n\^_" nil t)
 695                 (forward-line 1)
 696                 (let ((beg (point)))
 697                   (forward-line 1)
 698                   (if (re-search-backward "Node: *\\([^,\n]*\\) *[,\n\t]"
 699                                           beg t)
 700                       (setq compl
 701                             (cons (list (buffer-substring (match-beginning 1)
 702                                                           (match-end 1)))
 703                                   compl))))))))
 704         (setq Info-current-file-completions compl))))
 705 \f
 706 (defun Info-restore-point (hl)
 707   "If this node has been visited, restore the point value when we left."
 708   (while hl
 709     (if (and (equal (nth 0 (car hl)) Info-current-file)
 710              ;; Use string-equal, not equal, to ignore text props.
 711              (string-equal (nth 1 (car hl)) Info-current-node))
 712         (progn
 713           (goto-char (nth 2 (car hl)))
 714           (setq hl nil))                ;terminate the while at next iter
 715       (setq hl (cdr hl)))))
 716 \f
 717 (defvar Info-last-search nil
 718   "Default regexp for \\<Info-mode-map>\\[Info-search] command to search for.")
 719
 720 (defun Info-search (regexp)
 721   "Search for REGEXP, starting from point, and select node it's found in."
 722   (interactive "sSearch (regexp): ")
 723   (if transient-mark-mode (deactivate-mark))
 724   (if (equal regexp "")
 725       (setq regexp Info-last-search)
 726     (setq Info-last-search regexp))
 727   (let ((found ()) current
 728         (onode Info-current-node)
 729         (ofile Info-current-file)
 730         (opoint (point))
 731         (osubfile Info-current-subfile))
 732     (save-excursion
 733       (save-restriction
 734         (widen)
 735         (if (null Info-current-subfile)
 736             (progn (re-search-forward regexp) (setq found (point)))
 737           (condition-case err
 738               (progn (re-search-forward regexp) (setq found (point)))
 739             (search-failed nil)))))
 740     (if (not found) ;can only happen in subfile case -- else would have erred
 741         (unwind-protect
 742             (let ((list ()))
 743               (set-buffer (marker-buffer Info-tag-table-marker))
 744               (goto-char (point-min))
 745               (search-forward "\n\^_\nIndirect:")
 746               (save-restriction
 747                 (narrow-to-region (point)
 748                                   (progn (search-forward "\n\^_")
 749                                          (1- (point))))
 750                 (goto-char (point-min))
 751                 (search-forward (concat "\n" osubfile ": "))
 752                 (beginning-of-line)
 753                 (while (not (eobp))
 754                   (re-search-forward "\\(^.*\\): [0-9]+$")
 755                   (goto-char (+ (match-end 1) 2))
 756                   (setq list (cons (cons (read (current-buffer))
 757                                          (buffer-substring (match-beginning 1)
 758                                                            (match-end 1)))
 759                                    list))
 760                   (goto-char (1+ (match-end 0))))
 761                 (setq list (nreverse list)
 762                       current (car (car list))
 763                       list (cdr list)))
 764               (while list
 765                 (message "Searching subfile %s..." (cdr (car list)))
 766                 (Info-read-subfile (car (car list)))
 767                 (setq list (cdr list))
 768 ;;              (goto-char (point-min))
 769                 (if (re-search-forward regexp nil t)
 770                     (setq found (point) list ())))
 771               (if found
 772                   (message "")
 773                 (signal 'search-failed (list regexp))))
 774           (if (not found)
 775               (progn (Info-read-subfile opoint)
 776                      (goto-char opoint)
 777                      (Info-select-node)))))
 778     (widen)
 779     (goto-char found)
 780     (Info-select-node)
 781     ;; Use string-equal, not equal, to ignore text props.
 782     (or (and (string-equal onode Info-current-node)
 783              (equal ofile Info-current-file))
 784         (setq Info-history (cons (list ofile onode opoint)
 785                                  Info-history)))))
 786 \f
 787 ;; Extract the value of the node-pointer named NAME.
 788 ;; If there is none, use ERRORNAME in the error message;
 789 ;; if ERRORNAME is nil, just return nil.
 790 (defun Info-extract-pointer (name &optional errorname)
 791   (save-excursion
 792    (goto-char (point-min))
 793    (forward-line 1)
 794    (if (re-search-backward (concat name ":") nil t)
 795        (progn
 796          (goto-char (match-end 0))
 797          (Info-following-node-name))
 798      (if (eq errorname t)
 799          nil
 800        (error "Node has no %s" (capitalize (or errorname name)))))))
 801
 802 ;; Return the node name in the buffer following point.
 803 ;; ALLOWEDCHARS, if non-nil, goes within [...] to make a regexp
 804 ;; saying which chas may appear in the node name.
 805 (defun Info-following-node-name (&optional allowedchars)
 806   (skip-chars-forward " \t")
 807   (buffer-substring-no-properties
 808    (point)
 809    (progn
 810      (while (looking-at (concat "[" (or allowedchars "^,\t\n") "]"))
 811        (skip-chars-forward (concat (or allowedchars "^,\t\n") "("))
 812        (if (looking-at "(")
 813            (skip-chars-forward "^)")))
 814      (skip-chars-backward " ")
 815      (point))))
 816
 817 (defun Info-next ()
 818   "Go to the next node of this node."
 819   (interactive)
 820   (Info-goto-node (Info-extract-pointer "next")))
 821
 822 (defun Info-prev ()
 823   "Go to the previous node of this node."
 824   (interactive)
 825   (Info-goto-node (Info-extract-pointer "prev[ious]*" "previous")))
 826
 827 (defun Info-up ()
 828   "Go to the superior node of this node."
 829   (interactive)
 830   (Info-goto-node (Info-extract-pointer "up"))
 831   (Info-restore-point Info-history))
 832
 833 (defun Info-last ()
 834   "Go back to the last node visited."
 835   (interactive)
 836   (or Info-history
 837       (error "This is the first Info node you looked at"))
 838   (let (filename nodename opoint)
 839     (setq filename (car (car Info-history)))
 840     (setq nodename (car (cdr (car Info-history))))
 841     (setq opoint (car (cdr (cdr (car Info-history)))))
 842     (setq Info-history (cdr Info-history))
 843     (Info-find-node filename nodename)
 844     (setq Info-history (cdr Info-history))
 845     (goto-char opoint)))
 846
 847 (defun Info-directory ()
 848   "Go to the Info directory node."
 849   (interactive)
 850   (Info-find-node "dir" "top"))
 851 \f
 852 (defun Info-follow-reference (footnotename)
 853   "Follow cross reference named NAME to the node it refers to.
 854 NAME may be an abbreviation of the reference name."
 855   (interactive
 856    (let ((completion-ignore-case t)
 857          completions default alt-default (start-point (point)) str i bol eol)
 858      (save-excursion
 859        ;; Store end and beginning of line.
 860        (end-of-line)
 861        (setq eol (point))
 862        (beginning-of-line)
 863        (setq bol (point))
 864
 865        (goto-char (point-min))
 866        (while (re-search-forward "\\*note[ \n\t]*\\([^:]*\\):" nil t)
 867          (setq str (buffer-substring
 868                     (match-beginning 1)
 869                     (1- (point))))
 870          ;; See if this one should be the default.
 871          (and (null default)
 872               (<= (match-beginning 0) start-point)
 873               (<= start-point (point))
 874               (setq default t))
 875          ;; See if this one should be the alternate default.
 876          (and (null alt-default)
 877               (and (<= bol (match-beginning 0))
 878                    (<= (point) eol))
 879               (setq alt-default t))
 880          (setq i 0)
 881          (while (setq i (string-match "[ \n\t]+" str i))
 882            (setq str (concat (substring str 0 i) " "
 883                              (substring str (match-end 0))))
 884            (setq i (1+ i)))
 885          ;; Record as a completion and perhaps as default.
 886          (if (eq default t) (setq default str))
 887          (if (eq alt-default t) (setq alt-default str))
 888          (setq completions
 889                (cons (cons str nil)
 890                      completions))))
 891      ;; If no good default was found, try an alternate.
 892      (or default
 893          (setq default alt-default))
 894      ;; If only one cross-reference found, then make it default.
 895      (if (eq (length completions) 1)
 896          (setq default (car (car completions))))
 897      (if completions
 898          (let ((input (completing-read (if default
 899                                            (concat "Follow reference named: ("
 900                                                    default ") ")
 901                                          "Follow reference named: ")
 902                                        completions nil t)))
 903            (list (if (equal input "")
 904                      default input)))
 905        (error "No cross-references in this node"))))
 906   (let (target beg i (str (concat "\\*note " (regexp-quote footnotename))))
 907     (while (setq i (string-match " " str i))
 908       (setq str (concat (substring str 0 i) "[ \t\n]+" (substring str (1+ i))))
 909       (setq i (+ i 6)))
 910     (save-excursion
 911       (goto-char (point-min))
 912       (or (re-search-forward str nil t)
 913           (error "No cross-reference named %s" footnotename))
 914       (goto-char (+ (match-beginning 0) 5))
 915       (setq target
 916             (Info-extract-menu-node-name "Bad format cross reference" t)))
 917     (while (setq i (string-match "[ \t\n]+" target i))
 918       (setq target (concat (substring target 0 i) " "
 919                            (substring target (match-end 0))))
 920       (setq i (+ i 1)))
 921     (Info-goto-node target)))
 922
 923 (defun Info-extract-menu-node-name (&optional errmessage multi-line)
 924   (skip-chars-forward " \t\n")
 925   (let ((beg (point))
 926         str i)
 927     (skip-chars-forward "^:")
 928     (forward-char 1)
 929     (setq str
 930           (if (looking-at ":")
 931               (buffer-substring-no-properties beg (1- (point)))
 932             (skip-chars-forward " \t\n")
 933             (Info-following-node-name (if multi-line "^.,\t" "^.,\t\n"))))
 934     (while (setq i (string-match "\n" str i))
 935       (aset str i ?\ ))
 936     ;; Collapse multiple spaces.
 937     (while (string-match "  +" str)
 938       (setq str (replace-match " " t t str)))
 939     str))
 940
 941 ;; No one calls this.
 942 ;;(defun Info-menu-item-sequence (list)
 943 ;;  (while list
 944 ;;    (Info-menu (car list))
 945 ;;    (setq list (cdr list))))
 946
 947 (defun Info-complete-menu-item (string predicate action)
 948   (let ((case-fold-search t))
 949     (cond ((eq action nil)
 950            (let (completions
 951                  (pattern (concat "\n\\* \\("
 952                                   (regexp-quote string)
 953                                   "[^:\t\n]*\\):")))
 954              (save-excursion
 955                (set-buffer Info-complete-menu-buffer)
 956                (goto-char (point-min))
 957                (search-forward "\n* Menu:")
 958                (while (re-search-forward pattern nil t)
 959                  (setq completions (cons (cons (format "%s"
 960                                                        (buffer-substring
 961                                                         (match-beginning 1)
 962                                                         (match-end 1)))
 963                                                (match-beginning 1))
 964                                          completions))))
 965              (try-completion string completions predicate)))
 966           ((eq action t)
 967            (let (completions
 968                  (pattern (concat "\n\\* \\("
 969                                   (regexp-quote string)
 970                                   "[^:\t\n]*\\):")))
 971              (save-excursion
 972                (set-buffer Info-complete-menu-buffer)
 973                (goto-char (point-min))
 974                (search-forward "\n* Menu:")
 975                (while (re-search-forward pattern nil t)
 976                  (setq completions (cons (cons (format "%s"
 977                                                        (buffer-substring
 978                                                         (match-beginning 1)
 979                                                         (match-end 1)))
 980                                                (match-beginning 1))
 981                                          completions))))
 982              (all-completions string completions predicate)))
 983           (t
 984            (save-excursion
 985              (set-buffer Info-complete-menu-buffer)
 986              (goto-char (point-min))
 987              (search-forward "\n* Menu:")
 988              (re-search-forward (concat "\n\\* "
 989                                         (regexp-quote string)
 990                                         ":")
 991                                 nil t))))))
 992
 993
 994 (defun Info-menu (menu-item)
 995   "Go to node for menu item named (or abbreviated) NAME.
 996 Completion is allowed, and the menu item point is on is the default."
 997   (interactive
 998    (let ((completions '())
 999          ;; If point is within a menu item, use that item as the default
1000          (default nil)
1001          (p (point))
1002          beg
1003          (last nil))
1004      (save-excursion
1005        (goto-char (point-min))
1006        (if (not (search-forward "\n* menu:" nil t))
1007            (error "No menu in this node"))
1008        (setq beg (point))
1009        (and (< (point) p)
1010             (save-excursion
1011               (goto-char p)
1012               (end-of-line)
1013               (re-search-backward "\n\\* \\([^:\t\n]*\\):" beg t)
1014               (setq default (format "%s" (buffer-substring
1015                                           (match-beginning 1)
1016                                           (match-end 1)))))))
1017      (let ((item nil))
1018        (while (null item)
1019          (setq item (let ((completion-ignore-case t)
1020                           (Info-complete-menu-buffer (current-buffer)))
1021                       (completing-read (if default
1022                                            (format "Menu item (default %s): "
1023                                                    default)
1024                                            "Menu item: ")
1025                                        'Info-complete-menu-item nil t)))
1026          ;; we rely on the fact that completing-read accepts an input
1027          ;; of "" even when the require-match argument is true and ""
1028          ;; is not a valid possibility
1029          (if (string= item "")
1030              (if default
1031                  (setq item default)
1032                  ;; ask again
1033                  (setq item nil))))
1034        (list item))))
1035   ;; there is a problem here in that if several menu items have the same
1036   ;; name you can only go to the node of the first with this command.
1037   (Info-goto-node (Info-extract-menu-item menu-item)))
1038
1039 (defun Info-extract-menu-item (menu-item)
1040   (setq menu-item (regexp-quote menu-item))
1041   (save-excursion
1042     (goto-char (point-min))
1043     (or (search-forward "\n* menu:" nil t)
1044         (error "No menu in this node"))
1045     (or (re-search-forward (concat "\n\\* " menu-item ":") nil t)
1046         (re-search-forward (concat "\n\\* " menu-item) nil t)
1047         (error "No such item in menu"))
1048     (beginning-of-line)
1049     (forward-char 2)
1050     (Info-extract-menu-node-name)))
1051
1052 ;; If COUNT is nil, use the last item in the menu.
1053 (defun Info-extract-menu-counting (count)
1054   (save-excursion
1055     (goto-char (point-min))
1056     (or (search-forward "\n* menu:" nil t)
1057         (error "No menu in this node"))
1058     (if count
1059         (or (search-forward "\n* " nil t count)
1060             (error "Too few items in menu"))
1061       (while (search-forward "\n* " nil t)
1062         nil))
1063     (Info-extract-menu-node-name)))
1064
1065 (defun Info-nth-menu-item ()
1066   "Go to the node of the Nth menu item.
1067 N is the digit argument used to invoke this command."
1068   (interactive)
1069   (Info-goto-node
1070    (Info-extract-menu-counting
1071     (- (aref (this-command-keys) (1- (length (this-command-keys)))) ?0))))
1072
1073 (defun Info-top-node ()
1074   "Go to the Top node of this file."
1075   (interactive)
1076   (Info-goto-node "Top"))
1077
1078 (defun Info-final-node ()
1079   "Go to the final node in this file."
1080   (interactive)
1081   (Info-goto-node "Top")
1082   (let (Info-history)
1083     ;; Go to the last node in the menu of Top.
1084     (Info-goto-node (Info-extract-menu-counting nil))
1085     ;; If the last node in the menu is not last in pointer structure,
1086     ;; move forward until we can't go any farther.
1087     (while (Info-forward-node t t) nil)
1088     ;; Then keep moving down to last subnode, unless we reach an index.
1089     (while (and (not (string-match "\\<index\\>" Info-current-node))
1090                 (save-excursion (search-forward "\n* Menu:" nil t)))
1091       (Info-goto-node (Info-extract-menu-counting nil)))))
1092
1093 (defun Info-forward-node (&optional not-down no-error)
1094   "Go forward one node, considering all nodes as forming one sequence."
1095   (interactive)
1096   (goto-char (point-min))
1097   (forward-line 1)
1098   ;; three possibilities, in order of priority:
1099   ;;     1. next node is in a menu in this node (but not in an index)
1100   ;;     2. next node is next at same level
1101   ;;     3. next node is up and next
1102   (cond ((and (not not-down)
1103               (save-excursion (search-forward "\n* menu:" nil t))
1104               (not (string-match "\\<index\\>" Info-current-node)))
1105          (Info-goto-node (Info-extract-menu-counting 1))
1106          t)
1107         ((save-excursion (search-backward "next:" nil t))
1108          (Info-next)
1109          t)
1110         ((and (save-excursion (search-backward "up:" nil t))
1111               ;; Use string-equal, not equal, to ignore text props.
1112               (not (string-equal (downcase (Info-extract-pointer "up"))
1113                                  "top")))
1114          (let ((old-node Info-current-node))
1115            (Info-up)
1116            (let (Info-history success)
1117              (unwind-protect
1118                  (setq success (Info-forward-node t no-error))
1119                (or success (Info-goto-node old-node))))))
1120         (no-error nil)
1121         (t (error "No pointer forward from this node"))))
1122
1123 (defun Info-backward-node ()
1124   "Go backward one node, considering all nodes as forming one sequence."
1125   (interactive)
1126   (let ((prevnode (Info-extract-pointer "prev[ious]*" t))
1127         (upnode (Info-extract-pointer "up" t)))
1128     (cond ((and upnode (string-match "(" upnode))
1129            (error "First node in file"))
1130           ((and upnode (or (null prevnode)
1131                            ;; Use string-equal, not equal,
1132                            ;; to ignore text properties.
1133                            (string-equal (downcase prevnode)
1134                                          (downcase upnode))))
1135            (Info-up))
1136           (prevnode
1137            ;; If we move back at the same level,
1138            ;; go down to find the last subnode*.
1139            (Info-prev)
1140            (let (Info-history)
1141              (while (and (not (string-match "\\<index\\>" Info-current-node))
1142                          (save-excursion (search-forward "\n* Menu:" nil t)))
1143                (Info-goto-node (Info-extract-menu-counting nil)))))
1144           (t
1145            (error "No pointer backward from this node")))))
1146
1147 (defun Info-exit ()
1148   "Exit Info by selecting some other buffer."
1149   (interactive)
1150   (if Info-standalone
1151       (save-buffers-kill-emacs)
1152     (switch-to-buffer (prog1 (other-buffer (current-buffer))
1153                         (bury-buffer (current-buffer))))))
1154
1155 (defun Info-next-menu-item ()
1156   (interactive)
1157   (save-excursion
1158     (forward-line -1)
1159     (search-forward "\n* menu:" nil t)
1160     (or (search-forward "\n* " nil t)
1161         (error "No more items in menu"))
1162     (Info-goto-node (Info-extract-menu-node-name))))
1163
1164 (defun Info-last-menu-item ()
1165   (interactive)
1166   (save-excursion
1167     (forward-line 1)
1168     (let ((beg (save-excursion
1169                  (and (search-backward "\n* menu:" nil t)
1170                       (point)))))
1171       (or (and beg (search-backward "\n* " beg t))
1172           (error "No previous items in menu")))
1173     (Info-goto-node (save-excursion
1174                       (goto-char (match-end 0))
1175                       (Info-extract-menu-node-name)))))
1176
1177 (defmacro Info-no-error (&rest body)
1178   (list 'condition-case nil (cons 'progn (append body '(t))) '(error nil)))
1179
1180 (defun Info-next-preorder ()
1181   "Go to the next subnode or the next node, or go up a level."
1182   (interactive)
1183   (cond ((Info-no-error (Info-next-menu-item)))
1184         ((Info-no-error (Info-next)))
1185         ((Info-no-error (Info-up))
1186          ;; Since we have already gone thru all the items in this menu,
1187          ;; go up to the end of this node.
1188          (goto-char (point-max)))
1189         (t
1190          (error "No more nodes"))))
1191
1192 (defun Info-last-preorder ()
1193   "Go to the last node, popping up a level if there is none."
1194   (interactive)
1195   (cond ((Info-no-error
1196           (Info-last-menu-item)
1197           ;; If we go down a menu item, go to the end of the node
1198           ;; so we can scroll back through it.
1199           (goto-char (point-max)))
1200          (recenter -1))
1201         ((Info-no-error (Info-prev))
1202          (goto-char (point-max))
1203          (recenter -1))
1204         ((Info-no-error (Info-up))
1205          (goto-char (point-min))
1206          (or (search-forward "\n* Menu:" nil t)
1207              (goto-char (point-max))))
1208         (t (error "No previous nodes"))))
1209
1210 (defun Info-scroll-up ()
1211   "Scroll one screenful forward in Info, considering all nodes as one sequence.
1212 Once you scroll far enough in a node that its menu appears on the screen,
1213 the next scroll moves into its first subnode.  When you scroll past
1214 the end of a node, that goes to the next node or back up to the parent node."
1215   (interactive)
1216   (if (or (< (window-start) (point-min))
1217           (> (window-start) (point-max)))
1218       (set-window-start (selected-window) (point)))
1219   (let ((virtual-end (save-excursion
1220                        (goto-char (point-min))
1221                        (if (search-forward "\n* Menu:" nil t)
1222                            (point)
1223                          (point-max)))))
1224     (if (or (< virtual-end (window-start))
1225             (pos-visible-in-window-p virtual-end))
1226         (Info-next-preorder)
1227       (scroll-up))))
1228
1229 (defun Info-scroll-down ()
1230   "Scroll one screenful back in Info, considering all nodes as one sequence.
1231 Within the menu of a node, this goes to its last subnode.
1232 When you scroll past the beginning of a node, that goes to the
1233 previous node or back up to the parent node."
1234   (interactive)
1235   (if (or (< (window-start) (point-min))
1236           (> (window-start) (point-max)))
1237       (set-window-start (selected-window) (point)))
1238   (let ((virtual-end (save-excursion
1239                        (goto-char (point-min))
1240                        (search-forward "\n* Menu:" nil t))))
1241     (if (or virtual-end (pos-visible-in-window-p (point-min)))
1242         (Info-last-preorder)
1243       (scroll-down))))
1244
1245 (defun Info-next-reference ()
1246   "Move cursor to the next cross-reference or menu item in the node."
1247   (interactive)
1248   (let ((pat "\\*note[ \n\t]*\\([^:]*\\):\\|^\\* .*:")
1249         (old-pt (point)))
1250     (or (eobp) (forward-char 1))
1251     (or (re-search-forward pat nil t)
1252         (progn
1253           (goto-char (point-min))
1254           (or (re-search-forward pat nil t)
1255               (progn
1256                 (goto-char old-pt)
1257                 (error "No cross references in this node")))))
1258     (goto-char (match-beginning 0))
1259     (if (looking-at "\\* Menu:")
1260         (Info-next-reference))))
1261
1262 (defun Info-prev-reference ()
1263   "Move cursor to the previous cross-reference or menu item in the node."
1264   (interactive)
1265   (let ((pat "\\*note[ \n\t]*\\([^:]*\\):\\|^\\* .*:")
1266         (old-pt (point)))
1267     (or (re-search-backward pat nil t)
1268         (progn
1269           (goto-char (point-max))
1270           (or (re-search-backward pat nil t)
1271               (progn
1272                 (goto-char old-pt)
1273                 (error "No cross references in this node")))))
1274     (goto-char (match-beginning 0))
1275     (if (looking-at "\\* Menu:")
1276         (Info-prev-reference))))
1277
1278 (defun Info-index (topic)
1279   "Look up a string in the index for this file.
1280 The index is defined as the first node in the top-level menu whose
1281 name contains the word \"Index\", plus any immediately following
1282 nodes whose names also contain the word \"Index\".
1283 If there are no exact matches to the specified topic, this chooses
1284 the first match which is a case-insensitive substring of a topic.
1285 Use the `,' command to see the other matches.
1286 Give a blank topic name to go to the Index node itself."
1287   (interactive "sIndex topic: ")
1288   (let ((orignode Info-current-node)
1289         (rnode nil)
1290         (pattern (format "\n\\* \\([^\n:]*%s[^\n:]*\\):[ \t]*\\([^.\n]*\\)\\.[ \t]*\\([0-9]*\\)"
1291                          (regexp-quote topic)))
1292         node)
1293     (Info-goto-node "Top")
1294     (or (search-forward "\n* menu:" nil t)
1295         (error "No index"))
1296     (or (re-search-forward "\n\\* \\(.*\\<Index\\>\\)" nil t)
1297         (error "No index"))
1298     (goto-char (match-beginning 1))
1299     ;; Here, and subsequently in this function,
1300     ;; we bind Info-history to nil for internal node-switches
1301     ;; so that we don't put junk in the history.
1302     ;; In the first Info-goto-node call, above, we do update the history
1303     ;; because that is what the user's previous node choice into it.
1304     (let ((Info-history nil))
1305       (Info-goto-node (Info-extract-menu-node-name)))
1306     (or (equal topic "")
1307         (let ((matches nil)
1308               (exact nil)
1309               (Info-history nil)
1310               found)
1311           (while
1312               (progn
1313                 (goto-char (point-min))
1314                 (while (re-search-forward pattern nil t)
1315                   (setq matches
1316                         (cons (list (buffer-substring (match-beginning 1)
1317                                                       (match-end 1))
1318                                     (buffer-substring (match-beginning 2)
1319                                                       (match-end 2))
1320                                     Info-current-node
1321                                     (string-to-int (concat "0"
1322                                                            (buffer-substring
1323                                                             (match-beginning 3)
1324                                                             (match-end 3)))))
1325                               matches)))
1326                 (and (setq node (Info-extract-pointer "next" t))
1327                      (string-match "\\<Index\\>" node)))
1328             (Info-goto-node node))
1329           (or matches
1330               (progn
1331                 (Info-goto-node orignode)
1332                 (error "No `%s' in index" topic)))
1333           ;; Here it is a feature that assoc is case-sensitive.
1334           (while (setq found (assoc topic matches))
1335             (setq exact (cons found exact)
1336                   matches (delq found matches)))
1337           (setq Info-index-alternatives (nconc exact (nreverse matches)))
1338           (Info-index-next 0)))))
1339
1340 (defun Info-index-next (num)
1341   "Go to the next matching index item from the last `i' command."
1342   (interactive "p")
1343   (or Info-index-alternatives
1344       (error "No previous `i' command in this file"))
1345   (while (< num 0)
1346     (setq num (+ num (length Info-index-alternatives))))
1347   (while (> num 0)
1348     (setq Info-index-alternatives
1349           (nconc (cdr Info-index-alternatives)
1350                  (list (car Info-index-alternatives)))
1351           num (1- num)))
1352   (Info-goto-node (nth 1 (car Info-index-alternatives)))
1353   (if (> (nth 3 (car Info-index-alternatives)) 0)
1354       (forward-line (nth 3 (car Info-index-alternatives)))
1355     (forward-line 3)  ; don't search in headers
1356     (let ((name (car (car Info-index-alternatives))))
1357       (Info-find-index-name name)))
1358   (message "Found `%s' in %s.  %s"
1359            (car (car Info-index-alternatives))
1360            (nth 2 (car Info-index-alternatives))
1361            (if (cdr Info-index-alternatives)
1362                "(Press `,' for more)"
1363              "(Only match)")))
1364
1365 (defun Info-find-index-name (name)
1366   "Move point to the place within the current node where NAME is defined."
1367   (if (or (re-search-forward (format
1368                               "[a-zA-Z]+: %s\\( \\|$\\)"
1369                               (regexp-quote name)) nil t)
1370           (search-forward (format "`%s'" name) nil t)
1371           (and (string-match "\\`.*\\( (.*)\\)\\'" name)
1372                (search-forward
1373                 (format "`%s'" (substring name 0 (match-beginning 1)))
1374                 nil t))
1375           (search-forward name nil t))
1376       (beginning-of-line)
1377     (goto-char (point-min))))
1378
1379 (defun Info-undefined ()
1380   "Make command be undefined in Info."
1381   (interactive)
1382   (ding))
1383
1384 (defun Info-help ()
1385   "Enter the Info tutorial."
1386   (interactive)
1387   (delete-other-windows)
1388   (Info-find-node "info"
1389                   (if (< (window-height) 23)
1390                       "Help-Small-Screen"
1391                     "Help")))
1392
1393 (defun Info-summary ()
1394   "Display a brief summary of all Info commands."
1395   (interactive)
1396   (save-window-excursion
1397     (switch-to-buffer "*Help*")
1398     (erase-buffer)
1399     (insert (documentation 'Info-mode))
1400     (help-mode)
1401     (goto-char (point-min))
1402     (let (ch flag)
1403       (while (progn (setq flag (not (pos-visible-in-window-p (point-max))))
1404                     (message (if flag "Type Space to see more"
1405                                "Type Space to return to Info"))
1406                     (if (not (eq ?\  (setq ch (read-event))))
1407                         (progn (setq unread-command-events (list ch)) nil)
1408                       flag))
1409         (scroll-up)))
1410     (bury-buffer "*Help*")))
1411 \f
1412 (defun Info-get-token (pos start all &optional errorstring)
1413   "Return the token around POS,
1414 POS must be somewhere inside the token
1415 START is a regular expression which will match the
1416     beginning of the tokens delimited string
1417 ALL is a regular expression with a single
1418     parenthesized subpattern which is the token to be
1419     returned. E.g. '{\(.*\)}' would return any string
1420     enclosed in braces around POS.
1421 SIG optional fourth argument, controls action on no match
1422     nil: return nil
1423     t: beep
1424     a string: signal an error, using that string."
1425   (save-excursion
1426     (goto-char pos)
1427     (re-search-backward start (max (point-min) (- pos 200)) 'yes)
1428     (let (found)
1429       (while (and (re-search-forward all (min (point-max) (+ pos 200)) 'yes)
1430                   (not (setq found (and (<= (match-beginning 0) pos)
1431                                         (> (match-end 0) pos))))))
1432       (if (and found (<= (match-beginning 0) pos)
1433                (> (match-end 0) pos))
1434           (buffer-substring (match-beginning 1) (match-end 1))
1435         (cond ((null errorstring)
1436                nil)
1437               ((eq errorstring t)
1438                (beep)
1439                nil)
1440               (t
1441                (error "No %s around position %d" errorstring pos)))))))
1442
1443 (defun Info-mouse-follow-nearest-node (click)
1444   "\\<Info-mode-map>Follow a node reference near point.
1445 Like \\[Info-menu], \\[Info-follow-reference], \\[Info-next], \\[Info-prev] or \\[Info-up] command, depending on where you click.
1446 At end of the node's text, moves to the next node, or up if none."
1447   (interactive "e")
1448   (let* ((start (event-start click))
1449          (window (car start))
1450          (pos (car (cdr start))))
1451     (select-window window)
1452     (goto-char pos))
1453   (and (not (Info-try-follow-nearest-node))
1454        (save-excursion (forward-line 1) (eobp))
1455        (Info-next-preorder)))
1456
1457 (defun Info-follow-nearest-node ()
1458   "\\<Info-mode-map>Follow a node reference near point.
1459 Like \\[Info-menu], \\[Info-follow-reference], \\[Info-next], \\[Info-prev] or \\[Info-up] command, depending on where point is.
1460 If no reference to follow, moves to the next node, or up if none."
1461   (interactive)
1462   (or (Info-try-follow-nearest-node)
1463       (Info-next-preorder)))
1464
1465 ;; Common subroutine.
1466 (defun Info-try-follow-nearest-node ()
1467   "Follow a node reference near point.  Return non-nil if successful."
1468   (let (node)
1469     (cond
1470      ((setq node (Info-get-token (point) "\\*note[ \n]"
1471                                  "\\*note[ \n]\\([^:]*\\):"))
1472       (Info-follow-reference node))
1473      ((setq node (Info-get-token (point) "\\* " "\\* \\([^:]*\\)::"))
1474       (Info-goto-node node))
1475      ((setq node (Info-get-token (point) "\\* " "\\* \\([^:]*\\):"))
1476       (Info-menu node))
1477      ((setq node (Info-get-token (point) "Up: " "Up: \\([^,\n\t]*\\)"))
1478       (Info-goto-node node))
1479      ((setq node (Info-get-token (point) "Next: " "Next: \\([^,\n\t]*\\)"))
1480       (Info-goto-node node))
1481      ((setq node (Info-get-token (point) "File: " "File: \\([^,\n\t]*\\)"))
1482       (Info-goto-node "Top"))
1483      ((setq node (Info-get-token (point) "Prev: " "Prev: \\([^,\n\t]*\\)"))
1484       (Info-goto-node node)))
1485     node))
1486 \f
1487 (defvar Info-mode-map nil
1488   "Keymap containing Info commands.")
1489 (if Info-mode-map
1490     nil
1491   (setq Info-mode-map (make-keymap))
1492   (suppress-keymap Info-mode-map)
1493   (define-key Info-mode-map "." 'beginning-of-buffer)
1494   (define-key Info-mode-map " " 'Info-scroll-up)
1495   (define-key Info-mode-map "\C-m" 'Info-follow-nearest-node)
1496   (define-key Info-mode-map "\t" 'Info-next-reference)
1497   (define-key Info-mode-map "\e\t" 'Info-prev-reference)
1498   (define-key Info-mode-map "1" 'Info-nth-menu-item)
1499   (define-key Info-mode-map "2" 'Info-nth-menu-item)
1500   (define-key Info-mode-map "3" 'Info-nth-menu-item)
1501   (define-key Info-mode-map "4" 'Info-nth-menu-item)
1502   (define-key Info-mode-map "5" 'Info-nth-menu-item)
1503   (define-key Info-mode-map "6" 'Info-nth-menu-item)
1504   (define-key Info-mode-map "7" 'Info-nth-menu-item)
1505   (define-key Info-mode-map "8" 'Info-nth-menu-item)
1506   (define-key Info-mode-map "9" 'Info-nth-menu-item)
1507   (define-key Info-mode-map "0" 'undefined)
1508   (define-key Info-mode-map "?" 'Info-summary)
1509   (define-key Info-mode-map "]" 'Info-forward-node)
1510   (define-key Info-mode-map "[" 'Info-backward-node)
1511   (define-key Info-mode-map "<" 'Info-top-node)
1512   (define-key Info-mode-map ">" 'Info-final-node)
1513   (define-key Info-mode-map "b" 'beginning-of-buffer)
1514   (define-key Info-mode-map "d" 'Info-directory)
1515   (define-key Info-mode-map "e" 'Info-edit)
1516   (define-key Info-mode-map "f" 'Info-follow-reference)
1517   (define-key Info-mode-map "g" 'Info-goto-node)
1518   (define-key Info-mode-map "h" 'Info-help)
1519   (define-key Info-mode-map "i" 'Info-index)
1520   (define-key Info-mode-map "l" 'Info-last)
1521   (define-key Info-mode-map "m" 'Info-menu)
1522   (define-key Info-mode-map "n" 'Info-next)
1523   (define-key Info-mode-map "p" 'Info-prev)
1524   (define-key Info-mode-map "q" 'Info-exit)
1525   (define-key Info-mode-map "s" 'Info-search)
1526   ;; For consistency with Rmail.
1527   (define-key Info-mode-map "\M-s" 'Info-search)
1528   (define-key Info-mode-map "t" 'Info-top-node)
1529   (define-key Info-mode-map "u" 'Info-up)
1530   (define-key Info-mode-map "," 'Info-index-next)
1531   (define-key Info-mode-map "\177" 'Info-scroll-down)
1532   (define-key Info-mode-map [mouse-2] 'Info-mouse-follow-nearest-node)
1533   )
1534 \f
1535 ;; Info mode is suitable only for specially formatted data.
1536 (put 'info-mode 'mode-class 'special)
1537
1538 (defun Info-mode ()
1539   "\\<Info-mode-map>
1540 Info mode provides commands for browsing through the Info documentation tree.
1541 Documentation in Info is divided into \"nodes\", each of which discusses
1542 one topic and contains references to other nodes which discuss related
1543 topics.  Info has commands to follow the references and show you other nodes.
1544
1545 \\[Info-help]   Invoke the Info tutorial.
1546
1547 Selecting other nodes:
1548 \\[Info-mouse-follow-nearest-node]
1549         Follow a node reference you click on.
1550           This works with menu items, cross references, and
1551           the \"next\", \"previous\" and \"up\", depending on where you click.
1552 \\[Info-next]   Move to the \"next\" node of this node.
1553 \\[Info-prev]   Move to the \"previous\" node of this node.
1554 \\[Info-up]     Move \"up\" from this node.
1555 \\[Info-menu]   Pick menu item specified by name (or abbreviation).
1556         Picking a menu item causes another node to be selected.
1557 \\[Info-directory]      Go to the Info directory node.
1558 \\[Info-follow-reference]       Follow a cross reference.  Reads name of reference.
1559 \\[Info-last]   Move to the last node you were at.
1560 \\[Info-index]  Look up a topic in this file's Index and move to that node.
1561 \\[Info-index-next]     (comma) Move to the next match from a previous `i' command.
1562
1563 Moving within a node:
1564 \\[Info-scroll-up]      Normally, scroll forward a full screen.  If the end of the buffer is
1565 already visible, try to go to the next menu entry, or up if there is none.
1566 \\[Info-scroll-down]  Normally, scroll backward.  If the beginning of the buffer is
1567 already visible, try to go to the previous menu entry, or up if there is none.
1568 \\[beginning-of-buffer] Go to beginning of node.
1569
1570 Advanced commands:
1571 \\[Info-exit]   Quit Info: reselect previously selected buffer.
1572 \\[Info-edit]   Edit contents of selected node.
1573 1       Pick first item in node's menu.
1574 2, 3, 4, 5   Pick second ... fifth item in node's menu.
1575 \\[Info-goto-node]      Move to node specified by name.
1576         You may include a filename as well, as (FILENAME)NODENAME.
1577 \\[universal-argument] \\[info] Move to new Info file with completion.
1578 \\[Info-search] Search through this Info file for specified regexp,
1579         and select the node in which the next occurrence is found.
1580 \\[Info-next-reference] Move cursor to next cross-reference or menu item.
1581 \\[Info-prev-reference] Move cursor to previous cross-reference or menu item."
1582   (kill-all-local-variables)
1583   (setq major-mode 'Info-mode)
1584   (setq mode-name "Info")
1585   (use-local-map Info-mode-map)
1586   (set-syntax-table text-mode-syntax-table)
1587   (setq local-abbrev-table text-mode-abbrev-table)
1588   (setq case-fold-search t)
1589   (setq buffer-read-only t)
1590   (make-local-variable 'Info-current-file)
1591   (make-local-variable 'Info-current-subfile)
1592   (make-local-variable 'Info-current-node)
1593   (make-local-variable 'Info-tag-table-marker)
1594   (make-local-variable 'Info-history)
1595   (make-local-variable 'Info-index-alternatives)
1596   (if (memq (framep (selected-frame)) '(x pc))
1597       (progn
1598         (make-face 'info-node)
1599         (make-face 'info-menu-5)
1600         (make-face 'info-xref)
1601         (or (face-differs-from-default-p 'info-node)
1602             (if (face-differs-from-default-p 'bold-italic)
1603                 (copy-face 'bold-italic 'info-node)
1604               (copy-face 'bold 'info-node)))
1605         (or (face-differs-from-default-p 'info-menu-5)
1606             (set-face-underline-p 'info-menu-5 t))
1607         (or (face-differs-from-default-p 'info-xref)
1608             (copy-face 'bold 'info-xref)))
1609     (setq Info-fontify nil))
1610   (Info-set-mode-line)
1611   (run-hooks 'Info-mode-hook))
1612
1613 (defvar Info-edit-map nil
1614   "Local keymap used within `e' command of Info.")
1615 (if Info-edit-map
1616     nil
1617   (setq Info-edit-map (nconc (make-sparse-keymap) text-mode-map))
1618   (define-key Info-edit-map "\C-c\C-c" 'Info-cease-edit))
1619
1620 ;; Info-edit mode is suitable only for specially formatted data.
1621 (put 'info-edit-mode 'mode-class 'special)
1622
1623 (defun Info-edit-mode ()
1624   "Major mode for editing the contents of an Info node.
1625 Like text mode with the addition of `Info-cease-edit'
1626 which returns to Info mode for browsing.
1627 \\{Info-edit-map}"
1628   (use-local-map Info-edit-map)
1629   (setq major-mode 'Info-edit-mode)
1630   (setq mode-name "Info Edit")
1631   (kill-local-variable 'mode-line-buffer-identification)
1632   (setq buffer-read-only nil)
1633   (force-mode-line-update)
1634   (buffer-enable-undo (current-buffer))
1635   (run-hooks 'Info-edit-mode-hook))
1636
1637 (defun Info-edit ()
1638   "Edit the contents of this Info node.
1639 Allowed only if variable `Info-enable-edit' is non-nil."
1640   (interactive)
1641   (or Info-enable-edit
1642       (error "Editing info nodes is not enabled"))
1643   (Info-edit-mode)
1644   (message "%s" (substitute-command-keys
1645             "Editing: Type \\<Info-edit-map>\\[Info-cease-edit] to return to info")))
1646
1647 (defun Info-cease-edit ()
1648   "Finish editing Info node; switch back to Info proper."
1649   (interactive)
1650   ;; Do this first, so nothing has changed if user C-g's at query.
1651   (and (buffer-modified-p)
1652        (y-or-n-p "Save the file? ")
1653        (save-buffer))
1654   (use-local-map Info-mode-map)
1655   (setq major-mode 'Info-mode)
1656   (setq mode-name "Info")
1657   (Info-set-mode-line)
1658   (setq buffer-read-only t)
1659   (force-mode-line-update)
1660   (and (marker-position Info-tag-table-marker)
1661        (buffer-modified-p)
1662        (message "Tags may have changed.  Use Info-tagify if necessary")))
1663 \f
1664 (defvar Info-file-list-for-emacs
1665   '("ediff" "forms" "gnus" "info" ("mh" . "mh-e") "sc")
1666   "List of Info files that describe Emacs commands.
1667 An element can be a file name, or a list of the form (PREFIX . FILE)
1668 where PREFIX is a name prefix and FILE is the file to look in.
1669 If the element is just a file name, the file name also serves as the prefix.")
1670
1671 (defun Info-find-emacs-command-nodes (command)
1672   "Return a list of locations documenting COMMAND.
1673 The `info-file' property of COMMAND says which Info manual to search.
1674 If COMMAND has no property, the variable `Info-file-list-for-emacs'
1675 defines heuristics for which Info manual to try.
1676 The locations are of the format used in Info-history, i.e.
1677 \(FILENAME NODENAME BUFFERPOS\)."
1678   (let ((where '())
1679         (cmd-desc (concat "^\\* " (regexp-quote (symbol-name command))
1680                           ":\\s *\\(.*\\)\\.$"))
1681         (info-file "emacs"))            ;default
1682     ;; Determine which info file this command is documented in.
1683     (if (get command 'info-file)
1684         (setq info-file (get command 'info-file))
1685       ;; If it doesn't say explicitly, test its name against
1686       ;; various prefixes that we know.
1687       (let ((file-list Info-file-list-for-emacs))
1688         (while file-list
1689           (let* ((elt (car file-list))
1690                  (name (if (consp elt)
1691                            (car elt)
1692                          elt))
1693                  (file (if (consp elt) (cdr elt) elt))
1694                  (regexp (concat "\\`" (regexp-quote name)
1695                                  "\\(\\'\\|-\\)")))
1696             (if (string-match regexp (symbol-name command))
1697                 (setq info-file file file-list nil))
1698             (setq file-list (cdr file-list))))))
1699     (save-excursion
1700       (condition-case nil
1701           (Info-find-node info-file "Command Index")
1702         ;; Some manuals may not have a separate Command Index node,
1703         ;; so try just Index instead.
1704         (error
1705          (Info-find-node info-file "Index")))
1706       ;; Take the index node off the Info history.
1707       (setq Info-history (cdr Info-history))
1708       (goto-char (point-max))
1709       (while (re-search-backward cmd-desc nil t)
1710           (setq where (cons (list Info-current-file
1711                                   (buffer-substring
1712                                    (match-beginning 1)
1713                                    (match-end 1))
1714                                   0)
1715                             where)))
1716       where)))
1717
1718 ;;;###autoload
1719 (defun Info-goto-emacs-command-node (command)
1720   "Go to the Info node in the Emacs manual for command COMMAND.
1721 The command is found by looking up in Emacs manual's Command Index
1722 or in another manual found via COMMAND's `info-file' property or
1723 the variable `Info-file-list-for-emacs'."
1724   (interactive "CFind documentation for command: ")
1725   (or (commandp command)
1726       (signal 'wrong-type-argument (list 'commandp command)))
1727   (let ((where (Info-find-emacs-command-nodes command)))
1728     (if where
1729         (let ((num-matches (length where)))
1730           ;; Get Info running, and pop to it in another window.
1731           (save-window-excursion
1732             (info))
1733           (pop-to-buffer "*info*")
1734           (Info-find-node (car (car where))
1735                           (car (cdr (car where))))
1736           (if (> num-matches 1)
1737               (progn
1738                 ;; Info-find-node already pushed (car where) onto
1739                 ;; Info-history.  Put the other nodes that were found on
1740                 ;; the history.
1741                 (setq Info-history (nconc (cdr where) Info-history))
1742                 (message "Found %d other entr%s.  Use %s to see %s."
1743                          (1- num-matches)
1744                          (if (> num-matches 2) "ies" "y")
1745                          (substitute-command-keys "\\[Info-last]")
1746                          (if (> num-matches 2) "them" "it")))))
1747       (error "Couldn't find documentation for %s" command))))
1748
1749 ;;;###autoload
1750 (defun Info-goto-emacs-key-command-node (key)
1751   "Go to the Info node in the Emacs manual the command bound to KEY, a string.
1752 Interactively, if the binding is execute-extended-command, a command is read.
1753 The command is found by looking up in Emacs manual's Command Index
1754 or in another manual found via COMMAND's `info-file' property or
1755 the variable `Info-file-list-for-emacs'."
1756   (interactive "kFind documentation for key:")
1757   (let ((command (key-binding key)))
1758     (cond ((null command)
1759            (message "%s is undefined" (key-description key)))
1760           ((and (interactive-p)
1761                 (eq command 'execute-extended-command))
1762            (Info-goto-emacs-command-node
1763             (read-command "Find documentation for command: ")))
1764           (t
1765            (Info-goto-emacs-command-node command)))))
1766 \f
1767 (defvar Info-title-face-alist
1768   '((?* bold underline)
1769     (?= bold-italic underline)
1770     (?- italic underline))
1771   "*Alist of face or list of faces to use for pseudo-underlined titles.
1772 The alist key is the character the title is underlined with (?*, ?= or ?-).")
1773
1774 (defun Info-fontify-node ()
1775   (save-excursion
1776     (let ((buffer-read-only nil))
1777       (goto-char (point-min))
1778       (if (looking-at "^File: [^,: \t]+,?[ \t]+")
1779           (progn
1780             (goto-char (match-end 0))
1781             (while
1782                 (looking-at "[ \t]*[^:, \t\n]+:[ \t]+\\([^:,\t\n]+\\),?")
1783               (goto-char (match-end 0))
1784               (put-text-property (match-beginning 1) (match-end 1)
1785                                  'face 'info-xref)
1786               (put-text-property (match-beginning 1) (match-end 1)
1787                                  'mouse-face 'highlight))))
1788       (goto-char (point-min))
1789       (while (re-search-forward "\n\\([^ \t\n].+\\)\n\\(\\*+\\|=+\\|-+\\)$"
1790                                  nil t)
1791         (put-text-property (match-beginning 1) (match-end 1)
1792                            'face
1793                            (cdr (assq (preceding-char) Info-title-face-alist)))
1794         (put-text-property (match-end 1) (match-end 2)
1795                            'invisible t))
1796       (goto-char (point-min))
1797       (while (re-search-forward "\\*Note[ \n\t]+\\([^:]*\\):" nil t)
1798         (if (= (char-after (1- (match-beginning 0))) ?\") ; hack
1799             nil
1800           (put-text-property (match-beginning 1) (match-end 1)
1801                              'face 'info-xref)
1802           (put-text-property (match-beginning 1) (match-end 1)
1803                              'mouse-face 'highlight)))
1804       (goto-char (point-min))
1805       (if (and (search-forward "\n* Menu:" nil t)
1806                (not (string-match "\\<Index\\>" Info-current-node))
1807                ;; Don't take time to annotate huge menus
1808                (< (- (point-max) (point)) Info-fontify-maximum-menu-size))
1809           (let ((n 0))
1810             (while (re-search-forward "^\\* \\([^:\t\n]*\\):" nil t)
1811               (setq n (1+ n))
1812               (if (memq n '(5 9))   ; visual aids to help with 1-9 keys
1813                   (put-text-property (match-beginning 0)
1814                                      (1+ (match-beginning 0))
1815                                      'face 'info-menu-5))
1816               (put-text-property (match-beginning 1) (match-end 1)
1817                                  'face 'info-node)
1818               (put-text-property (match-beginning 1) (match-end 1)
1819                                  'mouse-face 'highlight))))
1820       (set-buffer-modified-p nil))))
1821
1822 (provide 'info)
1823
1824 ;;; info.el ends here