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