1 \input texinfo.tex @c -*-texinfo-*-
2 @c We must \input texinfo.tex instead of texinfo, otherwise make
3 @c distcheck in the Texinfo distribution fails, because the texinfo Info
4 @c file is made first, and texi2dvi must include . first in the path.
5 @comment %**start of header
11 @documentencoding UTF-8
12 @comment %**end of header
15 This file describes how to use Info, the on-line, menu-driven GNU
18 Copyright @copyright{} 1989, 1992, 1996--2014 Free Software Foundation, Inc.
21 Permission is granted to copy, distribute and/or modify this document
22 under the terms of the GNU Free Documentation License, Version 1.3 or
23 any later version published by the Free Software Foundation; with no
24 Invariant Sections, with the Front-Cover texts being ``A GNU Manual,''
25 and with the Back-Cover Texts as in (a) below. A copy of the license
26 is included in the section entitled ``GNU Free Documentation License''.
28 (a) The FSF's Back-Cover Text is: ``You have the freedom to copy and
29 modify this GNU manual.''
33 @dircategory Texinfo documentation system
35 * Info: (info). How to use the documentation browsing system.
40 @subtitle The online, hyper-text GNU documentation system
42 @author and the GNU Texinfo community
44 @vskip 0pt plus 1filll
52 @top Info: An Introduction
54 The GNU Project distributes most of its on-line manuals in the
55 @dfn{Info format}, which you read using an @dfn{Info reader}. You are
56 probably using an Info reader to read this now.
58 There are two primary Info readers: @code{info}, a stand-alone program
59 designed just to read Info files (@pxref{Top,,What is Info?,
60 info-stnd, GNU Info}), and the @code{info} package in GNU Emacs, a
61 general-purpose editor. At present, only the Emacs reader supports
65 If you are new to the Info reader and want to learn how to use it,
66 type the command @kbd{h} now. It brings you to a programmed
69 To read about advanced Info commands, type @kbd{n} twice. This
70 brings you to @cite{Advanced Info Commands}, skipping over the `Getting
73 Type @kbd{H} to see a summary of all available commands.
80 * Getting Started:: Getting started using an Info reader.
81 * Advanced:: Advanced Info commands.
82 * Expert Info:: Info commands for experts.
83 * GNU Free Documentation License:: The license for this documentation.
84 * Index:: An index of topics, commands, and variables.
88 @chapter Getting Started
90 This first part of this Info manual describes how to get around inside
91 of Info. The second part of the manual describes various advanced
92 Info commands. The third part briefly explains how to generate Info
93 files from Texinfo files, and describes how to write an Info file
97 This manual is primarily designed for browsing with an Info reader
98 program on a computer, so that you can try Info commands while reading
99 about them. Reading it on paper or with an HTML browser is less
100 effective, since you must take it on faith that the commands described
101 really do what the manual says. By all means go through this manual
102 now that you have it; but please try going through the on-line version
105 @cindex Info reader, how to invoke
106 @cindex entering Info
107 There are two ways of looking at the online version of this manual:
111 Type @code{info} at your shell's command line. This approach uses a
112 stand-alone program designed just to read Info files.
115 Type @code{emacs} at the command line; then type @kbd{C-h i}
116 (@kbd{Control-h}, followed by @kbd{i}). This approach uses the Info
117 mode of the Emacs editor.
120 In either case, then type @kbd{mInfo} (just the letters), followed by
121 @key{RET}---the ``Return'' or ``Enter'' key. At this point, you should
122 be ready to follow the instructions in this manual as you read them on
124 @c FIXME! (pesch@cygnus.com, 14 dec 1992)
125 @c Is it worth worrying about what-if the beginner goes to somebody
126 @c else's Emacs session, which already has an Info running in the middle
127 @c of something---in which case these simple instructions won't work?
131 * Help-Small-Screen:: Starting Info on a Small Screen.
132 * Help:: How to use Info.
133 * Help-P:: Returning to the Previous node.
134 * Help-^L:: The Space, DEL, B and ^L commands.
135 * Help-Inv:: Invisible text in Emacs Info.
137 * Help-Xref:: Following cross-references.
138 * Help-Int:: Some intermediate Info commands.
139 * Help-Q:: Quitting Info.
142 @node Help-Small-Screen
143 @section Starting Info on a Small Screen
146 (In Info, you only see this section if your terminal has a small
147 number of lines; most readers pass by it without seeing it.)
150 @cindex small screen, moving around
151 Since your terminal has a relatively small number of lines on its
152 screen, it is necessary to give you special advice at the beginning.
154 If the entire text you are looking at fits on the screen, the text
155 @samp{All} will be displayed at the bottom of the screen. In the
156 stand-alone Info reader, it is displayed at the bottom right corner of
157 the screen; in Emacs, it is displayed on the modeline. If you see the
158 text @samp{Top} instead, it means that there is more text below that
159 does not fit. To move forward through the text and see another screen
160 full, press @key{SPC}, the Space bar. To move back up, press the key
161 labeled @samp{Backspace} or @samp{DEL} (on some keyboards, this key
162 might be labeled @samp{Delete}), or @key{S-SPC}.
165 Here are 40 lines of junk, so you can try @key{SPC} and @key{DEL} (or
166 @key{S-SPC}) and see what they do. At the end are instructions of
167 what you should do next.
212 If you have managed to get here, go back to the beginning with
213 @kbd{DEL} (or @key{S-SPC}), and come back here again, then you
214 understand the about the @samp{Space} and @samp{Backspace} keys. So
215 now type an @kbd{n}---just one character; don't type the quotes and
216 don't type the Return key afterward---to get to the normal start of
221 @section How to use Info
223 You are talking to the program Info, for reading documentation.
225 There are two ways to use Info: from within Emacs or as a
226 stand-alone reader that you can invoke from a shell using the command
229 @cindex node, in Info documents
230 Right now you are looking at one @dfn{Node} of Information.
231 A node contains text describing a specific topic at a specific
232 level of detail. This node's topic is ``how to use Info''. The mode
233 line says that this is node @samp{Help} in the file @file{info}.
235 @cindex header of Info node
236 The top line of a node is its @dfn{header}. This node's header
237 (look at it now) says that the @samp{Next} node after this one is the
238 node called @samp{Help-P}. An advanced Info command lets you go to
239 any node whose name you know. In the stand-alone Info reader program,
240 the header line shows the names of this node and the Info file as
241 well. In Emacs, the header line is displayed with a special typeface,
242 and remains at the top of the window all the time even if you scroll
245 Besides a @samp{Next}, a node can have a @samp{Previous} link, or an
246 @samp{Up} link, or both. As you can see, this node has all of these
249 @kindex n @r{(Info mode)}
250 Now it is time to move on to the @samp{Next} node, named @samp{Help-P}.
253 >> Type @kbd{n} to move there. Type just one character;
254 do not type the quotes and do not type a @key{RET} afterward.
258 @samp{>>} in the margin means it is really time to try a command.
261 >> If you are in Emacs and have a mouse, and if you already practiced
262 typing @kbd{n} to get to the next node, click now with the left
263 mouse button on the @samp{Next} link to do the same ``the mouse way''.
267 @section Returning to the Previous node
269 @kindex p @r{(Info mode)}
270 This node is called @samp{Help-P}. The @samp{Previous} node, as you see,
271 is @samp{Help}, which is the one you just came from using the @kbd{n}
272 command. Another @kbd{n} command now would take you to the next
273 node, @samp{Help-^L}.
276 >> But do not type @kbd{n} yet. First, try the @kbd{p} command, or
277 (in Emacs) click on the @samp{Prev} link. That takes you to
278 the @samp{Previous} node. Then use @kbd{n} to return here.
281 If you read this in Emacs, you will see an @samp{Info} item in the
282 menu bar, close to its right edge. Clicking the mouse on the
283 @samp{Info} menu-bar item opens a menu of commands which include
284 @samp{Next} and @samp{Previous} (and also some others which you didn't yet
287 This all probably seems insultingly simple so far, but @emph{please
288 don't} start skimming. Things will get complicated soon enough!
289 Also, please do not try a new command until you are told it is time
290 to. You could make Info skip past an important warning that was
294 >> Now do an @kbd{n}, or (in Emacs) click the middle mouse button on
295 the @samp{Next} link, to get to the node @samp{Help-^L} and learn more.
299 @section The Space, DEL, B and ^L commands
301 This node's mode line tells you that you are now at node
302 @samp{Help-^L}, and the header line tells you that @kbd{p} would get
303 you back to @samp{Help-P}. The node's title is highlighted and may be
304 underlined as well; it says what the node is about.
306 This is a big node and it does not all fit on your display screen.
307 You can tell that there is more that is not visible because you
308 can see the text @samp{Top} rather than @samp{All} near the bottom of
311 @kindex SPC @r{(Info mode)}
312 @kindex DEL @r{(Info mode)}
313 @kindex BACKSPACE @r{(Info mode)}
314 @findex Info-scroll-up
315 @findex Info-scroll-down
316 The @key{SPC}, @key{BACKSPACE} (or @key{DEL})@footnote{The key which
317 we call ``Backspace or DEL'' in this manual is labeled differently on
318 different keyboards. Look for a key which is a little ways above the
319 @key{ENTER} or @key{RET} key and which you normally use outside Emacs
320 to erase the character before the cursor, i.e., the character you
321 typed last. It might be labeled @samp{Backspace} or @samp{<-} or
322 @samp{DEL}, or sometimes @samp{Delete}.} and @kbd{b} commands exist to
323 allow you to ``move around'' in a node that does not all fit on the
324 screen at once. @key{SPC} moves forward, to show what was below the
325 bottom of the screen. @key{DEL} or @key{BACKSPACE} moves backward, to
326 show what was above the top of the screen (there is not anything above
327 the top until you have typed some spaces).
330 >> Now try typing a @key{SPC} (afterward, type a @key{BACKSPACE} to
334 When you type the @key{SPC}, the two lines that were at the bottom of
335 the screen appear at the top, followed by more lines. @key{DEL} or
336 @key{BACKSPACE} takes the two lines from the top and moves them to the
337 bottom, @emph{usually}, but if there are not a full screen's worth of
338 lines above them they may not make it all the way to the bottom.
340 If you are reading this in Emacs, note that the header line is
341 always visible, never scrolling off the display. That way, you can
342 always see the @samp{Next}, @samp{Prev}, and @samp{Up} links, and you
343 can conveniently go to one of these links at any time by
344 clicking the middle mouse button on the link.
346 @cindex reading Info documents top to bottom
347 @cindex Info documents as tutorials
348 @key{SPC} and @key{DEL} not only move forward and backward through
349 the current node. They also move between nodes. @key{SPC} at the end
350 of a node moves to the next node; @key{DEL} (or @key{BACKSPACE}) at
351 the beginning of a node moves to the previous node. In effect, these
352 commands scroll through all the nodes in an Info file as a single
353 logical sequence. You can read an entire manual top to bottom by just
354 typing @key{SPC}, and move backward through the entire manual from
355 bottom to top by typing @key{DEL} (or @key{BACKSPACE}).
357 In this sequence, a node's subnodes appear following their parent.
358 If a node has a menu, @key{SPC} takes you into the subnodes listed in
359 the menu, one by one. Once you reach the end of a node, and have seen
360 all of its subnodes, @key{SPC} takes you to the next node or to the
363 @kindex PAGEUP @r{(Info mode)}
364 @kindex PAGEDOWN @r{(Info mode)}
365 Many keyboards nowadays have two scroll keys labeled @samp{PageUp}
366 and @samp{PageDown} (or maybe @samp{Prior} and @samp{Next}). If your
367 keyboard has these keys, you can use them to move forward and backward
368 through the text of one node, like @key{SPC} and @key{BACKSPACE} (or
369 @key{DEL}). However, @key{PAGEUP} and @key{PAGEDOWN} keys never
370 scroll beyond the beginning or the end of the current node.
372 @kindex C-l @r{(Info mode)}
373 If your screen is ever garbaged, you can tell Info to display it
374 again by typing @kbd{C-l} (@kbd{Control-L}---that is, hold down
375 @key{CTRL} and type @kbd{L} or @kbd{l}).
378 >> Type @kbd{C-l} now.
381 @kindex b @r{(Info mode)}
382 To move back to the beginning of the node you are on, you can type
383 the @key{BACKSPACE} key (or @key{DEL}) many times. You can also type
384 @kbd{b} just once. @kbd{b} stands for ``beginning.''
387 >> Try that now. (We have put in enough verbiage to push this past
388 the first screenful, but screens are so big nowadays that perhaps it
389 isn't enough. You may need to shrink your Emacs or Info window.)
390 Then come back, by typing @key{SPC} one or more times.
393 @kindex ? @r{(Info mode)}
395 You have just learned a considerable number of commands. If you
396 want to use one but have trouble remembering which, you should type
397 @kbd{?}, which displays a brief list of commands. When you are
398 finished looking at the list, make it go away by typing @key{SPC}
402 >> Type a @key{?} now. Press @key{SPC} to see consecutive screenfuls of
403 the list until finished. Then type @key{SPC} several times. If
404 you are using Emacs, the help will then go away automatically.
407 (If you are using the stand-alone Info reader, type @kbd{C-x 0} to
408 return here, that is---press and hold @key{CTRL}, type an @kbd{x},
409 then release @key{CTRL} and @kbd{x}, and press @kbd{0}; that's a zero,
410 not the letter ``o''.)
412 From now on, you will encounter large nodes without warning, and
413 will be expected to know how to use @key{SPC} and @key{BACKSPACE} to
414 move around in them without being told. Since not all terminals have
415 the same size screen, it would be impossible to warn you anyway.
418 >> Now type @kbd{n}, or click the middle mouse button on the @samp{Next} link,
419 to visit the next node.
423 @section Invisible text in Emacs Info
425 Before discussing menus, we need to make some remarks that are only
426 relevant to users reading Info using Emacs. Users of the stand-alone
427 version can skip this node by typing @kbd{]} now.
429 @cindex invisible text in Emacs
430 In Emacs, certain text that appears in the stand-alone version is
431 normally hidden, technically because it has the @samp{invisibility}
432 property. Invisible text is really a part of the text. It becomes
433 visible (by default) after killing and yanking, it appears in printed
434 output, it gets saved to file just like any other text, and so on.
435 Thus it is useful to know it is there.
438 You can make invisible text visible by using the command @kbd{M-x
439 visible-mode}. Visible mode is a minor mode, so using the command a
440 second time will make the text invisible again. Watch the effects of
441 the command on the ``menu'' below and the top line of this node.
443 If you prefer to @emph{always} see the invisible text, you can set
444 @code{Info-hide-note-references} to @code{nil}. Enabling Visible mode
445 permanently is not a real alternative, because Emacs Info also uses
446 (although less extensively) another text property that can change the
447 text being displayed, the @samp{display} property. Only the
448 invisibility property is affected by Visible mode. When, in this
449 tutorial, we refer to the @samp{Emacs} behavior, we mean the
450 @emph{default} Emacs behavior.
452 Now type @kbd{]}, to learn about the @kbd{]} and @kbd{[} commands.
455 * ]: Help-]. Node telling about ].
456 * stuff: Help-]. Same node.
457 * Help-]:: Yet again, same node.
460 @node Help-], , , Help-Inv
461 @subsection The @kbd{]} and @kbd{[} commands
463 If you type @kbd{n} now, you get an error message saying that this
464 node has no next node. Similarly, if you type @kbd{p}, the error
465 message tells you that there is no previous node. (The exact message
466 depends on the Info reader you use.) This is because @kbd{n} and
467 @kbd{p} carry you to the next and previous node @emph{at the same
468 level}. The present node is contained in a menu (see next) of the
469 node you came from, and hence is considered to be at a lower level.
470 It is the only node in the previous node's menu (even though it was
471 listed three times). Hence it has no next or previous node that
472 @kbd{n} or @kbd{p} could move to.
474 If you systematically move through a manual by typing @kbd{n}, you run
475 the risk of skipping many nodes. You do not run this risk if you
476 systematically use @kbd{@key{SPC}}, because, when you scroll to the
477 bottom of a node and type another @kbd{@key{SPC}}, then this carries
478 you to the following node in the manual @emph{regardless of level}.
479 If you immediately want to go to that node, without having to scroll
480 to the bottom of the screen first, you can type @kbd{]}.
482 Similarly, @kbd{@key{BACKSPACE}} (or @kbd{@key{S-SPC}}) carries you to
483 the preceding node regardless of level, after you scrolled to the
484 beginning of the present node. If you want to go to the preceding
485 node immediately, you can type @kbd{[}.
487 For instance, typing this sequence will come back here in three steps:
488 @kbd{[ n [}. To do the same backward, type @kbd{] p ]}.
490 Now type @kbd{]} to go to the next node and learn about menus.
493 @section Menus and the @kbd{m} command
495 @cindex menus in an Info document
497 With only the @kbd{n} (next), @kbd{p} (previous), @kbd{@key{SPC}},
498 @kbd{@key{BACKSPACE}}, @kbd{]} and @kbd{[} commands for moving between
499 nodes, nodes are restricted to a linear sequence. Menus allow a
500 branching structure. A menu is a list of other nodes you can move to.
501 It is actually just part of the text of the node formatted specially
502 so that Info can interpret it. The beginning of a menu is always
503 identified by a line which starts with @w{@samp{* Menu:}}. A node
504 contains a menu if and only if it has a line in it which starts that
505 way. The only menu you can use at any moment is the one in the node
506 you are in. To use a menu in any other node, you must move to that
509 After the start of the menu, each line that starts with a @samp{*}
510 identifies one subtopic. The line usually contains a brief name for
511 the subtopic (followed by a @samp{:}, normally hidden in Emacs), the
512 name of the node that talks about that subtopic (again, normally
513 hidden in Emacs), and optionally some further description of the
514 subtopic. Lines in the menu that do not start with a @samp{*} have no
515 special meaning---they are only for the human reader's benefit and do
516 not define additional subtopics. Here is an example:
519 * Foo: Node about FOO. This tells about FOO.
522 The subtopic name is Foo, and the node describing it is @samp{Node
523 about FOO}. The rest of the line is just for the reader's
524 Information. [[ But this line is not a real menu item, simply because
525 there is no line above it which starts with @w{@samp{* Menu:}}. Also,
526 in a real menu item, the @samp{*} would appear at the very start of
527 the line. This is why the ``normally hidden'' text in Emacs, namely
528 @samp{: Node about FOO.}, is actually visible in this example, even
529 when Visible mode is off.]]
531 When you use a menu to go to another node (in a way that will be
532 described soon), what you specify is the subtopic name, the first
533 thing in the menu line. Info uses it to find the menu line, extracts
534 the node name from it, and goes to that node. The reason that there
535 is both a subtopic name and a node name is that the node name must be
536 meaningful to the computer and may therefore have to be ugly looking.
537 The subtopic name can be chosen just to be convenient for the user to
538 specify. Often the node name is convenient for the user to specify
539 and so both it and the subtopic name are the same. There is an
540 abbreviation for this:
543 * Foo:: This tells about FOO.
547 This means that the subtopic name and node name are the same; they are
548 both @samp{Foo}. (The @samp{::} is normally hidden in Emacs.)
551 >> Now use @key{SPC} to find the menu in this node, then come back to
552 the front with a @kbd{b} and some @key{SPC}s. As you see, a menu is
553 actually visible in its node. If you cannot find a menu in a node
554 by looking at it, then the node does not have a menu and the
555 @kbd{m} command is not available.
558 If you keep typing @key{SPC} once the menu appears on the screen, it
559 will move to another node (the first one in the menu). If that
560 happens, type @key{BACKSPACE} to come back.
562 @kindex m @r{(Info mode)}
563 The command to go to one of the subnodes is @kbd{m}. This is very
564 different from the commands you have used: it is a command that
565 prompts you for more input.
567 The Info commands you know do not need additional input; when you
568 type one of them, Info processes it instantly and then is ready for
569 another command. The @kbd{m} command is different: it needs to know
570 the @dfn{name of the subtopic}. Once you have typed @kbd{m}, Info
571 tries to read the subtopic name.
573 Now, in the stand-alone Info, look for the line containing many
574 dashes near the bottom of the screen. (This is the stand-alone
575 equivalent for the mode line in Emacs.) There is one more line
576 beneath that one, but usually it is blank. (In Emacs, this is the
577 echo area.) When it is blank, Info is ready for a command, such as
578 @kbd{n} or @kbd{b} or @key{SPC} or @kbd{m}. If that line contains
579 text ending in a colon, it means Info is reading more input for the
580 last command. You can't type an Info command then, because Info is
581 trying to read input, not commands. You must either give the input
582 and finish the command you started, or type @kbd{Control-g} to cancel
583 the command. When you have done one of those things, the input entry
584 line becomes blank again. Then you can type Info commands again.
587 The command to go to a subnode via a menu is @kbd{m}. After you type
588 the @kbd{m}, the line at the bottom of the screen says @samp{Menu item: }.
589 You must then type the name of the subtopic you want, and end it with
592 @cindex abbreviating Info subnodes
593 You can abbreviate the subtopic name. If the abbreviation is not
594 unique, the first matching subtopic is chosen. Some menus put
595 the shortest possible abbreviation for each subtopic name in capital
596 letters, so you can see how much you need to type. It does not
597 matter whether you use upper case or lower case when you type the
598 subtopic. You should not put any spaces at the end, or inside of the
599 item name, except for one space where a space appears in the item in
602 @cindex completion of Info node names
603 You can also use the @dfn{completion} feature to help enter the
604 subtopic name. If you type the @key{TAB} key after entering part of a
605 name, it will fill in more of the name---as much as Info can deduce
606 from the part you have entered.
608 If you move the cursor to one of the menu subtopic lines, then you do
609 not need to type the argument: you just type a @key{RET}, and it
610 stands for the subtopic of the line you are on. You can also click
611 the middle mouse button directly on the subtopic line to go there.
613 Here is a menu to give you a chance to practice. This menu gives you
614 three ways of going to one place, Help-FOO:
617 * Foo: Help-FOO. A node you can visit for fun.
618 * Bar: Help-FOO. We have made two ways to get to the same place.
619 * Help-FOO:: And yet another!
622 (Turn Visible mode on if you are using Emacs.)
625 >> Now type just an @kbd{m} and see what happens:
628 Now you are ``inside'' an @kbd{m} command. Commands cannot be used
629 now; the next thing you will type must be the name of a subtopic.
631 You can change your mind about doing the @kbd{m} by typing
635 >> Try that now; notice the bottom line clear.
639 >> Then type another @kbd{m}.
643 >> Now type @kbd{BAR}, the item name. Do not type @key{RET} yet.
646 While you are typing the item name, you can use the @key{DEL} (or
647 @key{BACKSPACE}) key to cancel one character at a time if you make a
651 >> Press @key{DEL} to cancel the @samp{R}. You could type another @kbd{R}
652 to replace it. But you do not have to, since @samp{BA} is a valid
657 >> Now you are ready to go. Type a @key{RET}.
660 After visiting @samp{Help-FOO}, you should return here.
662 Another way to move to the menu subtopic lines and between them is
663 to type @key{TAB}. Each time you type a @key{TAB}, you move to the
664 next subtopic line. To move to a previous subtopic line in the
665 stand-alone reader, type @kbd{M-@key{TAB}}---that is, press and hold
666 the @key{META} key and then press @key{TAB}. (On some keyboards, the
667 @key{META} key might be labeled @samp{Alt}.) In Emacs Info, type
668 @kbd{S-@key{TAB}} to move to a previous subtopic line (press and hold
669 the @key{Shift} key and then press @key{TAB}).
671 Once you move cursor to a subtopic line, press @key{RET} to go to
672 that subtopic's node.
674 @cindex mouse support in Info mode
675 @kindex Mouse-2 @r{(Info mode)}
676 If your terminal supports a mouse, you have yet another way of going
677 to a subtopic. Move your mouse pointer to the subtopic line,
678 somewhere between the beginning @samp{*} and the colon @samp{:} which
679 ends the subtopic's brief name. You will see the subtopic's name
680 change its appearance (usually, its background color will change), and
681 the shape of the mouse pointer will change if your platform supports
682 that. After a while, if you leave the mouse on that spot, a small
683 window will pop up, saying ``Mouse-2: go to that node,'' or the same
684 message may appear at the bottom of the screen.
686 @kbd{Mouse-2} is the second button of your mouse counting from the
687 left---the middle button on a 3-button mouse. (On a 2-button mouse,
688 you may have to press both buttons together to ``press the middle
689 button''.) The message tells you pressing @kbd{Mouse-2} with the
690 current position of the mouse pointer (on subtopic in the menu) will
693 @findex Info-mouse-follow-nearest-node
694 More generally, @kbd{Mouse-2} in an Info buffer finds the nearest
695 link to another node and goes there. For example, near a cross
696 reference it acts like @kbd{f}, in a menu it acts like @kbd{m}, on the
697 node's header line it acts like @kbd{n}, @kbd{p}, or @kbd{u}, etc. At
698 end of the node's text @kbd{Mouse-2} moves to the next node, or up if
699 there's no next node.
702 >> Type @kbd{n} to see more commands.
705 @node Help-FOO, , , Help-M
706 @subsection The @kbd{u} command
708 Congratulations! This is the node @samp{Help-FOO}. It has an @samp{Up}
709 pointer @samp{Help-M}, the node you just came from via the @kbd{m}
710 command. This is the usual convention---the nodes you reach from a menu
711 have @samp{Up} nodes that lead back to the menu. Menus move Down in the
712 tree, and @samp{Up} moves Up. @samp{Previous}, on the other hand, is
713 usually used to ``stay on the same level but go backwards''.
715 @kindex u @r{(Info mode)}
717 You can go back to the node @samp{Help-M} by typing the command
718 @kbd{u} for ``Up''. This puts you at the menu subtopic line pointing
719 to the subnode that the @kbd{u} command brought you from. (Some Info
720 readers may put you at the @emph{front} of the node instead---to get
721 back to where you were reading, you have to type some @key{SPC}s.)
723 Another way to go Up is to click @kbd{Mouse-2} on the @samp{Up}
724 pointer shown in the header line (provided that you have a mouse).
727 >> Now type @kbd{u} to move back up to @samp{Help-M}.
731 @section Following Cross-References
733 @cindex cross references in Info documents
734 In Info documentation, you will see many @dfn{cross references}.
735 Cross references look like this: @xref{Help-Cross, Cross}. That text
736 is a real, live cross reference, whose name is @samp{Cross} and which
737 points to the node named @samp{Help-Cross}. (The node name is hidden
738 in Emacs. Do @kbd{M-x visible-mode} to show or hide it.)
740 @kindex f @r{(Info mode)}
741 @findex Info-follow-reference
742 You can follow a cross reference by moving the cursor to it and
743 press @key{RET}, just as in a menu. In Emacs, you can also click
744 @kbd{Mouse-1} on a cross reference to follow it; you can see that the
745 cross reference is mouse-sensitive by moving the mouse pointer to the
746 reference and watching how the underlying text and the mouse pointer
749 Another way to follow a cross reference is to type @kbd{f} and then
750 specify the name of the cross reference (in this case, @samp{Cross})
751 as an argument. For this command, it does not matter where the cursor
752 was. If the cursor is on or near a cross reference, @kbd{f} suggests
753 that reference name in parentheses as the default; typing @key{RET}
754 will follow that reference. However, if you type a different
755 reference name, @kbd{f} will follow the other reference which has that
759 >> Type @kbd{f}, followed by @kbd{Cross}, and then @key{RET}.
762 As you enter the reference name, you can use the @key{DEL} (or
763 @key{BACKSPACE}) key to edit your input. If you change your mind
764 about following any reference, you can use @kbd{Control-g} to cancel
765 the command. Completion is available in the @kbd{f} command; you can
766 complete among all the cross reference names in the current node by
769 To get a list of all the cross references in the current node, you
770 can type @kbd{?} after an @kbd{f}. The @kbd{f} continues to await a
771 cross reference name even after displaying the list, so if you don't
772 actually want to follow a reference, you should type a @kbd{Control-g}
773 to cancel the @kbd{f}.
776 >> Type @kbd{f?} to get a list of the cross references in this node. Then
777 type a @kbd{Control-g} and see how the @samp{f} gives up.
780 The @key{TAB}, @kbd{M-@key{TAB}} and @kbd{S-@key{TAB}} keys,
781 which move between menu items in a menu, also move between cross
782 references outside of menus.
784 Sometimes a cross reference (or a node) can lead to another file (in
785 other words another ``manual''), or, on occasion, even a file on a
786 remote machine (although Info files distributed with Emacs or the
787 stand-alone Info avoid using remote links). Such a cross reference
788 looks like this: @xref{Top,, Overview of Texinfo, texinfo, Texinfo:
789 The GNU Documentation Format}. (After following this link, type
790 @kbd{l} to get back to this node.) Here the name @samp{texinfo}
791 between parentheses refers to the file name. This file name appears
792 in cross references and node names if it differs from the current
793 file, so you can always know that you are going to be switching to
794 another manual and which one.
796 However, Emacs normally hides some other text in cross-references.
797 If you put your mouse over the cross reference, then the information
798 appearing in a separate box (tool tip) or in the echo area will show
799 the full cross-reference including the file name and the node name of
800 the cross reference. If you have a mouse, just leave it over the
801 cross reference @xref{Top,, Overview of Texinfo, texinfo, Texinfo:
802 The GNU Documentation Format}, and watch what happens. If you
803 always like to have that information visible without having to move
804 your mouse over the cross reference, use @kbd{M-x visible-mode}, or
805 set @code{Info-hide-note-references} to a value other than @code{t}
806 (@pxref{Emacs Info Variables}).
809 >> Now type @kbd{n} to learn more commands.
813 @section Some intermediate Info commands
815 The introductory course is almost over; please continue
816 a little longer to learn some intermediate-level commands.
818 Most Info files have an index, which is actually a large node
819 containing little but a menu. The menu has one menu item for each
820 topic listed in the index. (As a special feature, menus for indices
821 may also include the line number within the node of the index entry.
822 This allows Info readers to go to the exact line of an entry, not just
823 the start of the containing node.)
825 You can get to the index from the main menu of the file with the
826 @kbd{m} command and the name of the index node; then you can use the
827 @kbd{m} command again in the index node to go to the node that
828 describes the topic you want.
830 There is also a short-cut Info command, @kbd{i}, which does all of
831 that for you. It searches the index for a given topic (a string) and
832 goes to the node which is listed in the index for that topic.
833 @xref{Search Index}, for a full explanation.
835 @kindex l @r{(Info mode)}
836 @findex Info-history-back
837 @cindex going back in Info history
838 If you have been moving around to different nodes and wish to
839 retrace your steps, the @kbd{l} command (@kbd{l} for @dfn{last}) will
840 do that, one node-step at a time. As you move from node to node, Info
841 records the nodes where you have been in a special history list. The
842 @kbd{l} command revisits nodes in the history list; each successive
843 @kbd{l} command moves one step back through the history.
846 >> Try typing @kbd{p p n} and then three @kbd{l}'s, pausing in between
847 to see what each @kbd{l} does. You should wind up right back here.
850 Note the difference between @kbd{l} and @kbd{p}: @kbd{l} moves to
851 where @emph{you} last were, whereas @kbd{p} always moves to the node
852 which the header says is the @samp{Previous} node (from this node, the
853 @samp{Prev} link leads to @samp{Help-Xref}).
855 @kindex r @r{(Info mode)}
856 @findex Info-history-forward
857 @cindex going forward in Info history
858 You can use the @kbd{r} command (@code{Info-history-forward} in Emacs)
859 to revisit nodes in the history list in the forward direction, so that
860 @kbd{r} will return you to the node you came from by typing @kbd{l}.
862 @kindex L @r{(Info mode)}
864 @cindex history list of visited nodes
865 The @kbd{L} command (@code{Info-history} in Emacs) creates a virtual
866 node that contains a list of all nodes you visited. You can select
867 a previously visited node from this menu to revisit it.
869 @kindex d @r{(Info mode)}
870 @findex Info-directory
871 @cindex go to Directory node
872 The @kbd{d} command (@code{Info-directory} in Emacs) gets you
873 instantly to the Directory node. This node, which is the first one
874 you saw when you entered Info, has a menu which leads (directly or
875 indirectly, through other menus), to all the nodes that exist. The
876 Directory node lists all the manuals and other Info documents that
877 are, or could be, installed on your system.
880 >> Try doing a @kbd{d}, then do an @kbd{l} to return here (yes,
884 @kindex t @r{(Info mode)}
885 @findex Info-top-node
886 @cindex go to Top node
887 The @kbd{t} command moves to the @samp{Top} node of the manual.
888 This is useful if you want to browse the manual's main menu, or select
889 some specific top-level menu item. The Emacs command run by @kbd{t}
890 is @code{Info-top-node}.
893 >> Now type @kbd{n} to see the last node of the course.
896 @xref{Advanced}, for more advanced Info features.
898 @c If a menu appears at the end of this node, remove it.
899 @c It is an accident of the menu updating command.
902 @section Quitting Info
904 @kindex q @r{(Info mode)}
906 @cindex quitting Info mode
907 To get out of Info, back to what you were doing before, type @kbd{q}
908 for @dfn{Quit}. This runs @code{Info-exit} in Emacs.
910 This is the end of the basic course on using Info. You have learned
911 how to move in an Info document, and how to follow menus and cross
912 references. This makes you ready for reading manuals top to bottom,
913 as new users should do when they learn a new package.
915 Another set of Info commands is useful when you need to find
916 something quickly in a manual---that is, when you need to use a manual
917 as a reference rather than as a tutorial. We urge you to learn
918 these search commands as well. If you want to do that now, follow this
919 cross reference to @ref{Advanced}.
921 Yet another set of commands are meant for experienced users; you can
922 find them by looking in the Directory node for documentation on Info.
923 Finding them will be a good exercise in using Info in the usual
927 >> Type @kbd{d} to go to the Info directory node; then type
928 @kbd{mInfo} and Return, to get to the node about Info and
929 see what other help is available.
934 @chapter Advanced Info Commands
936 This chapter describes various advanced Info commands. (If you
937 are using a stand-alone Info reader, there are additional commands
938 specific to it, which are documented in several chapters of @ref{Top,,
939 GNU Info, info-stnd, GNU Info}.)
941 @kindex C-q @r{(Info mode)}
942 One advanced command useful with most of the others described here
943 is @kbd{C-q}, which ``quotes'' the next character so that it is
944 entered literally (@pxref{Inserting Text,,,emacs,The GNU Emacs
945 Manual}). For example, pressing @kbd{?} ordinarily brings up a list
946 of completion possibilities. If you want to (for example) search for
947 an actual @samp{?} character, the simplest way is to insert it using
948 @kbd{C-q ?}. This works the same in Emacs and stand-alone Info.
951 * Search Text:: How to search Info documents.
952 * Search Index:: How to search the indices for specific subjects.
953 * Go to node:: How to go to a node by name.
954 * Choose menu subtopic:: How to choose a menu subtopic by its number.
955 * Create Info buffer:: How to create a new Info buffer in Emacs.
956 * Emacs Info Variables:: Variables modifying the behavior of Emacs Info.
961 @section @kbd{s} searches Info documents
963 @cindex searching Info documents
964 @cindex Info document as a reference
965 The commands which move between and inside nodes allow you to read
966 the entire manual or its large portions. But what if you need to find
967 some information in the manual as fast as you can, and you don't know
968 or don't remember in what node to look for it? This need arises when
969 you use a manual as a @dfn{reference}, or when it is impractical to
970 read the entire manual before you start using the programs it
973 Info has powerful searching facilities that let you find things
974 quickly. You can search either the manual text or its indices.
976 @kindex s @r{(Info mode)}
978 The @kbd{s} command allows you to search a whole Info file for a string.
979 It switches to the next node if and when that is necessary. You
980 type @kbd{s} followed by the string to search for, terminated by
981 @key{RET}. To search for the same string again, just @kbd{s} followed
982 by @key{RET} will do. The file's nodes are scanned in the order
983 they are in the file, which has no necessary relationship to the
984 order that they may be in the tree structure of menus and @samp{next}
985 pointers. But normally the two orders are not very different. In any
986 case, you can always look at the mode line to find out what node you have
987 reached, if the header is not visible (this can happen, because @kbd{s}
988 puts your cursor at the occurrence of the string, not at the beginning
991 @kindex C-s @r{(Info mode)}
992 @kindex C-r @r{(Info mode)}
994 Instead of using @kbd{s} in Emacs Info and in the stand-alone Info,
995 you can use an incremental search started with @kbd{C-s} or @kbd{C-r}.
996 It can search through multiple Info nodes. @xref{Incremental Search,,,
997 emacs, The GNU Emacs Manual}. In Emacs, you can disable this behavior
998 by setting the variable @code{Info-isearch-search} to @code{nil}
999 (@pxref{Emacs Info Variables}).
1002 @section @kbd{i} searches the indices for specific subjects
1004 @cindex searching Info indices
1005 @kindex i @r{(Info mode)}
1007 Since most topics in the manual should be indexed, you should try
1008 the index search first before the text search. The @kbd{i} command
1009 prompts you for a subject and then looks up that subject in the
1010 indices. If it finds an index entry with the subject you typed, it
1011 goes to the node to which that index entry points. You should browse
1012 through that node to see whether the issue you are looking for is
1013 described there. If it isn't, type @kbd{,} one or more times to go
1014 through additional index entries which match your subject.
1016 The @kbd{i} command and subsequent @kbd{,} commands find all index
1017 entries which include the string you typed @emph{as a substring}.
1018 For each match, Info shows in the echo area the full index entry it
1019 found. Often, the text of the full index entry already gives you
1020 enough information to decide whether it is relevant to what you are
1021 looking for, so we recommend that you read what Info shows in the echo
1022 area before looking at the node it displays.
1024 Since @kbd{i} looks for a substring, you can search for subjects even
1025 if you are not sure how they are spelled in the index. For example,
1026 suppose you want to find something that is pertinent to commands which
1027 complete partial input (e.g., when you type @key{TAB}). If you want
1028 to catch index entries that refer to ``complete,'' ``completion,'' and
1029 ``completing,'' you could type @kbd{icomplet@key{RET}}.
1031 Info documents which describe programs should index the commands,
1032 options, and key sequences that the program provides. If you are
1033 looking for a description of a command, an option, or a key, just type
1034 their names when @kbd{i} prompts you for a topic. For example, if you
1035 want to read the description of what the @kbd{C-l} key does, type
1036 @kbd{iC-l@key{RET}} literally.
1038 @findex Info-virtual-index
1039 @kindex I @r{(Info mode)}
1040 Emacs provides the command @code{Info-virtual-index}, bound to the
1041 @kbd{I} key. This behaves like @kbd{i}, but constructs a virtual
1042 info node displaying the results of an index search, making it easier
1043 to select the one you want.
1045 @findex info-apropos
1046 @findex index-apropos
1047 If you aren't sure which manual documents the topic you are looking
1048 for, try the @kbd{M-x info-apropos} command in Emacs, or the @kbd{M-x
1049 index-apropos} command in the stand-alone reader. It prompts for
1050 a string and then looks up that string in all the indices of all the
1051 Info documents installed on your system.
1054 @section @kbd{g} goes to a node by name
1056 @kindex g @r{(Info mode)}
1057 @findex Info-goto-node
1058 @cindex go to a node by name
1059 If you know a node's name, you can go there by typing @kbd{g}, the
1060 name, and @key{RET}. Thus, @kbd{gTop@key{RET}} would go to the node
1061 called @samp{Top} in this file. (This is equivalent to @kbd{t}, see
1062 @ref{Help-Int}.) @kbd{gGo to node@key{RET}} would come back here.
1064 Unlike @kbd{m}, @kbd{g} does not allow the use of abbreviations.
1065 But it does allow completion, so you can type @key{TAB} to complete a
1068 @cindex go to another Info file
1069 To go to a node in another file, you can include the file name in the
1070 node name by putting it at the front, in parentheses. Thus,
1071 @kbd{g(dir)Top@key{RET}} would go to the Info Directory node, which is
1072 the node @samp{Top} in the Info file @file{dir}. Likewise,
1073 @kbd{g(emacs)Top@key{RET}} (or just @kbd{g(emacs)@key{RET}}) goes to the
1074 top node of the Emacs manual.
1076 The node name @samp{*} specifies the whole file. So you can look at
1077 all of the current file by typing @kbd{g*@key{RET}} or all of any
1078 other file with @kbd{g(@var{filename})*@key{RET}}.
1080 @node Choose menu subtopic
1081 @section @kbd{1}--@kbd{9} choose a menu subtopic by its number
1083 @kindex 1 @r{through} 9 @r{(Info mode)}
1084 @findex Info-nth-menu-item
1085 @cindex select @var{n}'th menu item
1086 If you begrudge each character of type-in which your system requires,
1087 you might like to use the commands @kbd{1}, @kbd{2}, @kbd{3}, @kbd{4},
1088 @dots{}, @kbd{9}. They are short for the @kbd{m} command together
1089 with a name of a menu subtopic. @kbd{1} goes through the first item
1090 in the current node's menu; @kbd{2} goes through the second item, etc.
1091 In the stand-alone reader, @kbd{0} goes through the last menu item;
1092 this is so you need not count how many entries are there.
1094 If your display supports multiple fonts, colors or underlining, and
1095 you are using Emacs's Info mode to read Info files, the third, sixth
1096 and ninth menu items have a @samp{*} that stands out, either in color
1097 or in some other attribute, such as underline; this makes it easy to
1098 see at a glance which number to use for an item.
1100 Some terminals don't support either multiple fonts, colors or
1101 underlining. If you need to actually count items, it is better to use
1102 @kbd{m} instead, and specify the name, or use @key{TAB} to quickly
1103 move between menu items.
1105 @node Create Info buffer
1106 @section @kbd{M-n} creates a new independent Info buffer in Emacs
1108 @kindex M-n @r{(Info mode)}
1109 @findex clone-buffer
1110 @cindex multiple Info buffers
1111 If you are reading Info in Emacs, you can select a new independent
1112 Info buffer in a new Emacs window by typing @kbd{M-n}. The new buffer
1113 starts out as an exact copy of the old one, but you will be able to
1114 move independently between nodes in the two buffers. (In Info mode,
1115 @kbd{M-n} runs the Emacs command @code{clone-buffer}.)
1117 In Emacs Info, you can also produce new Info buffers by giving a
1118 numeric prefix argument to the @kbd{m} and @kbd{g} commands. @kbd{C-u
1119 m} and @kbd{C-u g} go to a new node in exactly the same way that
1120 @kbd{m} and @kbd{g} do, but they do so in a new Info buffer which they
1121 select in another window.
1123 Another way to produce new Info buffers in Emacs is to use a numeric
1124 prefix argument for the @kbd{C-h i} command (@code{info}) which
1125 switches to the Info buffer with that number. Thus, @kbd{C-u 2 C-h i}
1126 switches to the buffer @samp{*info*<2>}, creating it if necessary.
1128 @findex info-display-manual
1129 If you have created many Info buffers in Emacs, you might find it
1130 difficult to remember which buffer is showing which manual. You can
1131 use the command @kbd{M-x info-display-manual} to show an Info manual
1132 by name, reusing an existing buffer if there is one.
1134 @node Emacs Info Variables
1135 @section Emacs Info-mode Variables
1137 The following variables may modify the behavior of Info-mode in Emacs;
1138 you may wish to set one or several of these variables interactively,
1139 or in your init file. @xref{Examining, Examining and Setting
1140 Variables, Examining and Setting Variables, emacs, The GNU Emacs
1141 Manual}. The stand-alone Info reader program has its own set of
1142 variables, described in @ref{Variables,, Manipulating Variables,
1143 info-stnd, GNU Info}.
1146 @item Info-directory-list
1147 The list of directories to search for Info files. Each element is a
1148 string (directory name) or @code{nil} (try default directory). If not
1149 initialized Info uses the environment variable @env{INFOPATH} to
1150 initialize it, or @code{Info-default-directory-list} if there is no
1151 @env{INFOPATH} variable in the environment.
1153 If you wish to customize the Info directory search list for both Emacs
1154 Info and stand-alone Info, it is best to set the @env{INFOPATH}
1155 environment variable, since that applies to both programs.
1157 @item Info-additional-directory-list
1158 A list of additional directories to search for Info documentation files.
1159 These directories are not searched for merging the @file{dir} file.
1161 @item Info-mode-hook
1162 Hooks run when @code{Info-mode} is called. By default, it contains
1163 the hook @code{turn-on-font-lock} which enables highlighting of Info
1164 files. You can change how the highlighting looks by customizing the
1165 faces @code{info-node}, @code{info-xref}, @code{info-xref-visited},
1166 @code{info-header-xref}, @code{info-header-node}, @code{info-menu-header},
1167 @code{info-menu-star}, and @code{info-title-@var{n}} (where @var{n}
1168 is the level of the section, a number between 1 and 4). To customize
1169 a face, type @kbd{M-x customize-face @key{RET} @var{face} @key{RET}},
1170 where @var{face} is one of the face names listed here.
1172 @item Info-fontify-maximum-menu-size
1173 Maximum size of menu to fontify if @code{font-lock-mode} is non-@code{nil}.
1175 @item Info-fontify-visited-nodes
1176 If non-@code{nil}, menu items and cross-references pointing to visited
1177 nodes are displayed in the @code{info-xref-visited} face.
1179 @item Info-use-header-line
1180 If non-@code{nil}, Emacs puts in the Info buffer a header line showing
1181 the @samp{Next}, @samp{Prev}, and @samp{Up} links. A header line does
1182 not scroll with the rest of the buffer, making these links always
1185 @item Info-hide-note-references
1186 As explained in earlier nodes, the Emacs version of Info normally
1187 hides some text in menus and cross-references. You can completely
1188 disable this feature, by setting this option to @code{nil}. Setting
1189 it to a value that is neither @code{nil} nor @code{t} produces an
1190 intermediate behavior, hiding a limited amount of text, but showing
1191 all text that could potentially be useful.
1193 @item Info-scroll-prefer-subnodes
1194 If set to a non-@code{nil} value, @key{SPC} and @key{BACKSPACE} (or
1195 @key{DEL}, or @key{S-SPC}) keys in a menu visit subnodes of the
1196 current node before scrolling to its end or beginning, respectively.
1197 For example, if the node's menu appears on the screen, the next
1198 @key{SPC} moves to a subnode indicated by the following menu item.
1199 Setting this option to @code{nil} results in behavior similar to the
1200 stand-alone Info reader program, which visits the first subnode from
1201 the menu only when you hit the end of the current node. The default
1204 @item Info-isearch-search
1205 If non-@code{nil}, isearch in Info searches through multiple nodes.
1207 @item Info-enable-active-nodes
1208 When set to a non-@code{nil} value, allows Info to execute Lisp code
1209 associated with nodes. The Lisp code is executed when the node is
1210 selected. The Lisp code to be executed should follow the node
1211 delimiter (the @samp{DEL} character) and an @samp{execute: } tag, like
1215 ^_execute: (message "This is an active node!")
1221 @chapter Info for Experts
1224 This chapter explains how to write an Info file by hand. However,
1225 in most cases, writing a Texinfo file is better, since you can use it
1226 to make a printed manual or produce other formats, such as HTML and
1227 DocBook, as well as for generating Info files.
1229 The @code{makeinfo} command converts a Texinfo file into an Info file;
1230 @code{texinfo-format-region} and @code{texinfo-format-buffer} are GNU
1231 Emacs functions that do the same.
1233 @xref{Top,, Overview of Texinfo, texinfo, Texinfo: The GNU
1234 Documentation Format}, for how to write a Texinfo file.
1236 @xref{Creating an Info File,,, texinfo, Texinfo: The GNU Documentation
1237 Format}, for how to create an Info file from a Texinfo file.
1239 @xref{Installing an Info File,,, texinfo, Texinfo: The GNU
1240 Documentation Format}, for how to install an Info file after you
1243 However, if you want to edit an Info file manually and install it manually,
1247 * Add:: Describes how to add new nodes to the hierarchy.
1248 Also tells what nodes look like.
1249 * Menus:: How to add to or create menus in Info nodes.
1250 * Cross-refs:: How to add cross-references to Info nodes.
1251 * Tags:: How to make tags tables for Info files.
1252 * Checking:: Checking an Info File.
1256 @section Adding a new node to Info
1258 To add a new topic to the list in the Info directory, you must:
1262 Create some nodes, in some file, to document that topic.
1264 Put that topic in the menu in the directory. @xref{Menus, Menu}.
1267 @cindex node delimiters
1268 The new node can live in an existing documentation file, or in a new
1269 one. It must have a @samp{^_} character before it (invisible to the
1270 user; this node has one but you cannot see it), and it ends with either
1271 a @samp{^_}, a @samp{^L} (``formfeed''), or the end of file.@footnote{If
1272 you put in a @samp{^L} to end a new node, be sure that there is a
1273 @samp{^_} after it to start the next one, since @samp{^L} cannot
1274 @emph{start} a node. Also, a nicer way to make a node boundary be a
1275 page boundary as well is to put a @samp{^L} @emph{right after} the
1278 The @samp{^_} starting a node must be followed by a newline or a
1279 @samp{^L} newline, after which comes the node's header line. The
1280 header line must give the node's name (by which Info finds it), and
1281 state the names of the @samp{Next}, @samp{Previous}, and @samp{Up}
1282 nodes (if there are any). As you can see, this node's @samp{Up} node
1283 is the node @samp{Expert Info}. The @samp{Next} node is @samp{Menus}.
1285 @cindex node header line format
1286 @cindex format of node headers
1287 The keywords @dfn{Node}, @dfn{Next}, @dfn{Previous}, and @dfn{Up}
1288 may appear in any order, anywhere in the header line, but the
1289 recommended order is the one in this sentence. Each keyword must be
1290 followed by a colon, spaces and tabs, and then the appropriate name.
1291 The name may be terminated with a tab, a comma, or a newline. A space
1292 does not end it; node names may contain spaces. The case of letters
1293 in the names is insignificant.
1295 @cindex node name format
1296 @cindex Directory node
1297 A node name has two forms. A node in the current file is named by
1298 what appears after the @samp{Node: } in that node's first line. For
1299 example, this node's name is @samp{Add}. A node in another file is
1300 named by @samp{(@var{filename})@var{node-within-file}}, as in
1301 @samp{(info)Add} for this node. If the file name starts with @samp{./},
1302 then it is relative to the current directory; otherwise, it is
1303 relative starting from the standard directory for Info files of your
1304 site. The name @samp{(@var{filename})Top} can be abbreviated to just
1305 @samp{(@var{filename})}. By convention, the name @samp{Top} is used
1306 for the ``highest'' node in any single file---the node whose @samp{Up}
1307 points out of the file. The @samp{Directory} node is @file{(dir)}, it
1308 points to a file @file{dir} which holds a large menu listing all the
1309 Info documents installed on your site. The @samp{Top} node of a
1310 document file listed in the @samp{Directory} should have an @samp{Up:
1313 @cindex unstructured documents
1314 The node name @kbd{*} is special: it refers to the entire file.
1315 Thus, @kbd{g*} shows you the whole current file. The use of the
1316 node @kbd{*} is to make it possible to make old-fashioned,
1317 unstructured files into nodes of the tree.
1319 The @samp{Node:} name, in which a node states its own name, must not
1320 contain a file name, since when Info searches for a node, it does not
1321 expect a file name to be there. The @samp{Next}, @samp{Previous} and
1322 @samp{Up} names may contain them. In this node, since the @samp{Up}
1323 node is in the same file, it was not necessary to use one.
1325 Note that the nodes in this file have a file name in the header
1326 line. The file names are ignored by Info, but they serve as comments
1327 to help identify the node for the user.
1330 @section How to Create Menus
1332 Any node in the Info hierarchy may have a @dfn{menu}---a list of subnodes.
1333 The @kbd{m} command searches the current node's menu for the topic which it
1334 reads from the terminal.
1336 @cindex menu and menu entry format
1337 A menu begins with a line starting with @w{@samp{* Menu:}}. The
1338 rest of the line is a comment. After the starting line, every line
1339 that begins with a @samp{* } lists a single topic. The name of the
1340 topic---what the user must type at the @kbd{m}'s command prompt to
1341 select this topic---comes right after the star and space, and is
1342 followed by a colon, spaces and tabs, and the name of the node which
1343 discusses that topic. The node name, like node names following
1344 @samp{Next}, @samp{Previous} and @samp{Up}, may be terminated with a
1345 tab, comma, or newline; it may also be terminated with a period.
1347 If the node name and topic name are the same, then rather than
1348 giving the name twice, the abbreviation @samp{* @var{name}::} may be
1349 used (and should be used, whenever possible, as it reduces the visual
1350 clutter in the menu).
1352 It is considerate to choose the topic names so that they differ
1353 from each other very near the beginning---this allows the user to type
1354 short abbreviations. In a long menu, it is a good idea to capitalize
1355 the beginning of each item name which is the minimum acceptable
1356 abbreviation for it (a long menu is more than 5 or so entries).
1358 The nodes listed in a node's menu are called its ``subnodes,'' and it
1359 is their ``superior''. They should each have an @samp{Up:} pointing at
1360 the superior. It is often useful to arrange all or most of the subnodes
1361 in a sequence of @samp{Next} and @samp{Previous} pointers so that
1362 someone who wants to see them all need not keep revisiting the Menu.
1364 The Info Directory is simply the menu of the node @samp{(dir)Top}---that
1365 is, node @samp{Top} in file @file{.../info/dir}. You can put new entries
1366 in that menu just like any other menu. The Info Directory is @emph{not} the
1367 same as the file directory called @file{info}. It happens that many of
1368 Info's files live in that file directory, but they do not have to; and
1369 files in that directory are not automatically listed in the Info
1372 Also, although the Info node graph is claimed to be a ``hierarchy,''
1373 in fact it can be @emph{any} directed graph. Shared structures and
1374 pointer cycles are perfectly possible, and can be used if they are
1375 appropriate to the meaning to be expressed. There is no need for all
1376 the nodes in a file to form a connected structure. In fact, this file
1377 has two connected components. You are in one of them, which is under
1378 the node @samp{Top}; the other contains the node @samp{Help} which the
1379 @kbd{h} command goes to. In fact, since there is no garbage
1380 collector on the node graph, nothing terrible happens if a substructure
1381 is not pointed to, but such a substructure is rather useless since nobody
1382 can ever find out that it exists.
1385 @section Creating Cross References
1387 @cindex cross reference format
1388 A cross reference can be placed anywhere in the text, unlike a menu
1389 item which must go at the front of a line. A cross reference looks
1390 like a menu item except that it has @samp{*note} instead of @samp{*}.
1391 It @emph{cannot} be terminated by a @samp{)}, because @samp{)}'s are
1392 so often part of node names. If you wish to enclose a cross reference
1393 in parentheses, terminate it with a period first. Here are two
1394 examples of cross references pointers:
1397 *Note details: commands. (See *note 3: Full Proof.)
1401 @emph{These are just examples.} The places they ``lead to'' do not
1405 * Help-Cross:: Target of a cross-reference.
1410 @subsection The node reached by the cross reference in Info
1412 This is the node reached by the cross reference named @samp{Cross}.
1414 While this node is specifically intended to be reached by a cross
1415 reference, most cross references lead to nodes that ``belong''
1416 someplace else far away in the structure of an Info document. So you
1417 cannot expect this node to have a @samp{Next}, @samp{Previous} or
1418 @samp{Up} links pointing back to where you came from. In general, the
1419 @kbd{l} (el) command is the only way to get back there.
1422 >> Type @kbd{l} to return to the node where the cross reference was.
1426 @section Tags Tables for Info Files
1428 @cindex tags tables in Info files
1429 You can speed up the access to nodes of a large Info file by giving
1430 it a tags table. Unlike the tags table for a program, the tags table for
1431 an Info file lives inside the file itself and is used
1432 automatically whenever Info reads in the file.
1435 To make a tags table, go to a node in the file using Emacs Info mode and type
1436 @kbd{M-x Info-tagify}. Then you must use @kbd{C-x C-s} to save the
1437 file. Info files produced by the @code{makeinfo} command that is part
1438 of the Texinfo package always have tags tables to begin with.
1440 @cindex stale tags tables
1441 @cindex update Info tags table
1442 Once the Info file has a tags table, you must make certain it is up
1443 to date. If you edit an Info file directly (as opposed to editing its
1444 Texinfo source), and, as a result of deletion of text, any node moves back
1445 more than a thousand characters in the file from the position
1446 recorded in the tags table, Info will no longer be able to find that
1447 node. To update the tags table, use the @code{Info-tagify} command
1450 An Info file tags table appears at the end of the file and looks like
1456 File: info, Node: Cross-refs^?21419
1457 File: info, Node: Tags^?22145
1463 Note that it contains one line per node, and this line contains
1464 the beginning of the node's header (ending just after the node name),
1465 a @samp{DEL} character, and the character position in the file of the
1466 beginning of the node.
1469 @section Checking an Info File
1471 When creating an Info file, it is easy to forget the name of a node when
1472 you are making a pointer to it from another node. If you put in the
1473 wrong name for a node, this is not detected until someone tries to go
1474 through the pointer using Info. Verification of the Info file is an
1475 automatic process which checks all pointers to nodes and reports any
1476 pointers which are invalid. Every @samp{Next}, @samp{Previous}, and
1477 @samp{Up} is checked, as is every menu item and every cross reference. In
1478 addition, any @samp{Next} which does not have a @samp{Previous} pointing
1479 back is reported. Only pointers within the file are checked, because
1480 checking pointers to other files would be terribly slow. But those are
1483 @findex Info-validate
1484 To check an Info file, do @kbd{M-x Info-validate} while looking at any
1485 node of the file with Emacs Info mode.
1487 @node GNU Free Documentation License
1488 @appendix GNU Free Documentation License
1489 @include doclicense.texi
1494 This is an alphabetical listing of all the commands, variables, and
1495 topics discussed in this document.