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 6@setfilename info.info 7@settitle Info 8@syncodeindex fn cp 9@syncodeindex vr cp 10@syncodeindex ky cp 11@comment %**end of header 12 13@copying 14This file describes how to use Info, the on-line, menu-driven GNU 15documentation system. 16 17Copyright (C) 1989, 1992, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 18Free Software Foundation, Inc. 19 20@quotation 21Permission is granted to copy, distribute and/or modify this document 22under the terms of the GNU Free Documentation License, Version 1.1 or 23any later version published by the Free Software Foundation; with no 24Invariant Sections, with the Front-Cover texts being ``A GNU 25Manual'', and with the Back-Cover Texts as in (a) below. A copy of the 26license is included in the section entitled ``GNU Free Documentation 27License'' in the Emacs manual. 28 29(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify 30this GNU Manual, like GNU software. Copies published by the Free 31Software Foundation raise funds for GNU development.'' 32 33This document is part of a collection distributed under the GNU Free 34Documentation License. If you want to distribute this document 35separately from the collection, you can do so by adding a copy of the 36license to the document, as described in section 6 of the license. 37@end quotation 38@end copying 39 40@dircategory Texinfo documentation system 41@direntry 42* Info: (info). How to use the documentation browsing system. 43@end direntry 44 45@titlepage 46@title Info 47@subtitle The online, hyper-text GNU documentation system 48@author Brian Fox 49@author and the GNU Texinfo community 50@page 51@vskip 0pt plus 1filll 52@insertcopying 53@end titlepage 54 55@contents 56 57@ifnottex 58@node Top 59@top Info: An Introduction 60 61The GNU Project distributes most of its on-line manuals in the 62@dfn{Info format}, which you read using an @dfn{Info reader}. You are 63probably using an Info reader to read this now. 64 65There are two primary Info readers: @code{info}, a stand-alone program 66designed just to read Info files, and the @code{info} package in GNU 67Emacs, a general-purpose editor. At present, only the Emacs reader 68supports using a mouse. 69 70@ifinfo 71If you are new to the Info reader and want to learn how to use it, 72type the command @kbd{h} now. It brings you to a programmed 73instruction sequence. 74 75To read about expert-level Info commands, type @kbd{n} twice. This 76brings you to @cite{Info for Experts}, skipping over the `Getting 77Started' chapter. 78@end ifinfo 79@end ifnottex 80 81@menu 82* Getting Started:: Getting started using an Info reader. 83* Expert Info:: Info commands for experts. 84* Creating an Info File:: How to make your own Info file. 85* Index:: An index of topics, commands, and variables. 86@end menu 87 88@node Getting Started, Expert Info, Top, Top 89@comment node-name, next, previous, up 90@chapter Getting Started 91 92This first part of this Info manual describes how to get around inside 93of Info. The second part of the manual describes various advanced 94Info commands, and how to write an Info as distinct from a Texinfo 95file. The third part briefly explains how to generate Info files from 96Texinfo files. 97 98@ifnotinfo 99This manual is primarily designed for browsing with an Info reader 100program on a computer, so that you can try Info commands while reading 101about them. Reading it on paper or with an HTML browser is less 102effective, since you must take it on faith that the commands described 103really do what the manual says. By all means go through this manual 104now that you have it; but please try going through the on-line version 105as well. 106 107@cindex Info reader, how to invoke 108@cindex entering Info 109There are two ways of looking at the online version of this manual: 110 111@enumerate 112@item 113Type @code{info} at your shell's command line. This approach uses a 114stand-alone program designed just to read Info files. 115 116@item 117Type @code{emacs} at the command line; then type @kbd{C-h i} 118(@kbd{Control-h}, followed by @kbd{i}). This approach uses the Info 119mode of the Emacs editor. 120@end enumerate 121 122In either case, then type @kbd{mInfo} (just the letters), followed by 123@key{RET}---the ``Return'' or ``Enter'' key. At this point, you should 124be ready to follow the instructions in this manual as you read them on 125the screen. 126@c FIXME! (pesch@cygnus.com, 14 dec 1992) 127@c Is it worth worrying about what-if the beginner goes to somebody 128@c else's Emacs session, which already has an Info running in the middle 129@c of something---in which case these simple instructions won't work? 130@end ifnotinfo 131 132@menu 133* Help-Small-Screen:: Starting Info on a Small Screen. 134* Help:: How to use Info. 135* Help-P:: Returning to the Previous node. 136* Help-^L:: The Space, DEL, B and ^L commands. 137* Help-Inv:: Invisible text in Emacs Info. 138* Help-M:: Menus. 139* Help-Xref:: Following cross-references. 140* Help-Int:: Some intermediate Info commands. 141* Help-Q:: Quitting Info. 142@end menu 143 144@node Help-Small-Screen 145@section Starting Info on a Small Screen 146 147@ifnotinfo 148(In Info, you only see this section if your terminal has a small 149number of lines; most readers pass by it without seeing it.) 150@end ifnotinfo 151 152@cindex small screen, moving around 153Since your terminal has a relatively small number of lines on its 154screen, it is necessary to give you special advice at the beginning. 155 156If you see the text @samp{--All----} near the bottom right corner 157of the screen, it means the entire text you are looking at fits on the 158screen. If you see @samp{--Top----} instead, it means that there is 159more text below that does not fit. To move forward through the text 160and see another screen full, press @key{SPC}, the Space bar. To move 161back up, press the key labeled @samp{Backspace} or @samp{DEL} (on some 162keyboards, this key might be labeled @samp{Delete}). 163 164@ifinfo 165Here are 40 lines of junk, so you can try @key{SPC} and @key{DEL} and 166see what they do. At the end are instructions of what you should do 167next. 168 169@format 170This is line 20 171This is line 21 172This is line 22 173This is line 23 174This is line 24 175This is line 25 176This is line 26 177This is line 27 178This is line 28 179This is line 29 180This is line 30 181This is line 31 182This is line 32 183This is line 33 184This is line 34 185This is line 35 186This is line 36 187This is line 37 188This is line 38 189This is line 39 190This is line 40 191This is line 41 192This is line 42 193This is line 43 194This is line 44 195This is line 45 196This is line 46 197This is line 47 198This is line 48 199This is line 49 200This is line 50 201This is line 51 202This is line 52 203This is line 53 204This is line 54 205This is line 55 206This is line 56 207This is line 57 208This is line 58 209This is line 59 210@end format 211 212If you have managed to get here, go back to the beginning with 213@kbd{DEL} (or @key{BACKSPACE}), and come back here again, then you 214understand the about the @samp{Space} and @samp{Backspace} keys. So 215now type an @kbd{n}---just one character; don't type the quotes and 216don't type the Return key afterward---to get to the normal start of 217the course. 218@end ifinfo 219 220@node Help, Help-P, Help-Small-Screen, Getting Started 221@comment node-name, next, previous, up 222@section How to use Info 223 224You are talking to the program Info, for reading documentation. 225 226 There are two ways to use Info: from within Emacs or as a 227stand-alone reader that you can invoke from a shell using the command 228@command{info}. 229 230@cindex node, in Info documents 231 Right now you are looking at one @dfn{Node} of Information. 232A node contains text describing a specific topic at a specific 233level of detail. This node's topic is ``how to use Info''. The mode 234line says that this is node @samp{Help} in the file @file{info}. 235 236@cindex header of Info node 237 The top line of a node is its @dfn{header}. This node's header 238(look at it now) says that the @samp{Next} node after this one is the 239node called @samp{Help-P}. An advanced Info command lets you go to 240any node whose name you know. In the stand-alone Info reader program, 241the header line shows the names of this node and the info file as 242well. In Emacs, the header line is duplicated in a special typeface, 243and the duplicate remains at the top of the window all the time even 244if you scroll through the node. 245 246 Besides a @samp{Next}, a node can have a @samp{Previous} link, or an 247@samp{Up} link, or both. As you can see, this node has all of these 248links. 249 250@kindex n @r{(Info mode)} 251 Now it is time to move on to the @samp{Next} node, named @samp{Help-P}. 252 253@format 254>> Type @kbd{n} to move there. Type just one character; 255 do not type the quotes and do not type a @key{RET} afterward. 256@end format 257 258@noindent 259@samp{>>} in the margin means it is really time to try a command. 260 261@format 262>> If you are in Emacs and have a mouse, and if you already practiced 263 typing @kbd{n} to get to the next node, click now with the middle 264 mouse button on the @samp{Next} link to do the same ``the mouse way''. 265@end format 266 267@node Help-P, Help-^L, Help, Getting Started 268@comment node-name, next, previous, up 269@section Returning to the Previous node 270 271@kindex p @r{(Info mode)} 272This node is called @samp{Help-P}. The @samp{Previous} node, as you see, 273is @samp{Help}, which is the one you just came from using the @kbd{n} 274command. Another @kbd{n} command now would take you to the next 275node, @samp{Help-^L}. 276 277@format 278>> But do not type @kbd{n} yet. First, try the @kbd{p} command, or 279 (in Emacs) click the middle mouse button on the @samp{Prev} link. 280 That takes you to the @samp{Previous} node. Then use @kbd{n} to 281 return here. 282@end format 283 284 If you read this in Emacs, you will see an @samp{Info} item in the 285menu bar, close to its right edge. Clicking the mouse on the 286@samp{Info} menu-bar item opens a menu of commands which include 287@samp{Next} and @samp{Prev} (and also some others which you didn't yet 288learn about). 289 290 This all probably seems insultingly simple so far, but @emph{please 291don't} start skimming. Things will get complicated soon enough! 292Also, please do not try a new command until you are told it is time 293to. You could make Info skip past an important warning that was 294coming up. 295 296@format 297>> Now do an @kbd{n}, or (in Emacs) click the middle mouse button on 298 the @samp{Next} link, to get to the node @samp{Help-^L} and learn more. 299@end format 300 301@node Help-^L, Help-Inv, Help-P, Getting Started 302@comment node-name, next, previous, up 303@section The Space, DEL, B and ^L commands 304 305 This node's mode line tells you that you are now at node 306@samp{Help-^L}, and the header line tells you that @kbd{p} would get 307you back to @samp{Help-P}. The node's title is highlighted and may be 308underlined as well; it says what the node is about. 309 310 This is a big node and it does not all fit on your display screen. 311You can tell that there is more that is not visible because you 312can see the string @samp{--Top-----} rather than @samp{--All----} near 313the bottom right corner of the screen. 314 315@kindex SPC @r{(Info mode)} 316@kindex DEL @r{(Info mode)} 317@kindex BACKSPACE @r{(Info mode)} 318@findex Info-scroll-up 319@findex Info-scroll-down 320 The @key{SPC}, @key{BACKSPACE} (or @key{DEL})@footnote{The key which 321we call ``Backspace or DEL'' in this manual is labeled differently on 322different keyboards. Look for a key which is a little ways above the 323@key{ENTER} or @key{RET} key and which you normally use outside Emacs 324to erase the character before the cursor, i.e.@: the character you 325typed last. It might be labeled @samp{Backspace} or @samp{<-} or 326@samp{DEL}, or sometimes @samp{Delete}.} and @kbd{b} commands exist to 327allow you to ``move around'' in a node that does not all fit on the 328screen at once. @key{SPC} moves forward, to show what was below the 329bottom of the screen. @key{DEL} or @key{BACKSPACE} moves backward, to 330show what was above the top of the screen (there is not anything above 331the top until you have typed some spaces). 332 333@format 334>> Now try typing a @key{SPC} (afterward, type a @key{BACKSPACE} to 335 return here). 336@end format 337 338 When you type the @key{SPC}, the two lines that were at the bottom of 339the screen appear at the top, followed by more lines. @key{DEL} or 340@key{BACKSPACE} takes the two lines from the top and moves them to the 341bottom, @emph{usually}, but if there are not a full screen's worth of 342lines above them they may not make it all the way to the bottom. 343 344 If you are reading this in Emacs, note that the header line is 345always visible, never scrolling off the display. That way, you can 346always see the @samp{Next}, @samp{Prev}, and @samp{Up} links, and you 347can conveniently go to one of these links at any time by 348clicking the middle mouse button on the link. 349 350@cindex reading Info documents top to bottom 351@cindex Info documents as tutorials 352 @key{SPC} and @key{DEL} not only move forward and backward through 353the current node. They also move between nodes. @key{SPC} at the end 354of a node moves to the next node; @key{DEL} (or @key{BACKSPACE}) at 355the beginning of a node moves to the previous node. In effect, these 356commands scroll through all the nodes in an Info file as a single 357logical sequence. You can read an entire manual top to bottom by just 358typing @key{SPC}, and move backward through the entire manual from 359bottom to top by typing @key{DEL} (or @key{BACKSPACE}). 360 361 In this sequence, a node's subnodes appear following their parent. 362If a node has a menu, @key{SPC} takes you into the subnodes listed in 363the menu, one by one. Once you reach the end of a node, and have seen 364all of its subnodes, @key{SPC} takes you to the next node or to the 365parent's next node. 366 367@kindex PAGEUP @r{(Info mode)} 368@kindex PAGEDOWN @r{(Info mode)} 369 Many keyboards nowadays have two scroll keys labeled @samp{PageUp} 370and @samp{PageDown} (or maybe @samp{Prior} and @samp{Next}). If your 371keyboard has these keys, you can use them to move forward and backward 372through the text of one node, like @key{SPC} and @key{BACKSPACE} (or 373@key{DEL}). However, @key{PAGEUP} and @key{PAGEDOWN} keys never 374scroll beyond the beginning or the end of the current node. 375 376@kindex C-l @r{(Info mode)} 377 If your screen is ever garbaged, you can tell Info to display it 378again by typing @kbd{C-l} (@kbd{Control-L}---that is, hold down 379@key{CTRL} and type @kbd{L} or @kbd{l}). 380 381@format 382>> Type @kbd{C-l} now. 383@end format 384 385@kindex b @r{(Info mode)} 386 To move back to the beginning of the node you are on, you can type 387the @key{BACKSPACE} key (or @key{DEL}) many times. You can also type 388@kbd{b} just once. @kbd{b} stands for ``beginning.'' 389 390@format 391>> Try that now. (We have put in enough verbiage to push this past 392 the first screenful, but screens are so big nowadays that perhaps it 393 isn't enough. You may need to shrink your Emacs or Info window.) 394 Then come back, by typing @key{SPC} one or more times. 395@end format 396 397 If your screen is very tall, all of this node might fit at once. In 398that case, @kbd{b} won't do anything. But you could observe the 399effect of the @kbd{b} key if you use a smaller window. 400 401@kindex ? @r{(Info mode)} 402@findex Info-summary 403 You have just learned a considerable number of commands. If you 404want to use one but have trouble remembering which, you should type 405a @kbd{?} (in Emacs it runs the @code{Info-summary} command) which 406displays a brief list of commands. When you are finished looking at 407the list, make it go away by typing a @key{SPC} repeatedly. 408 409@format 410>> Type a @key{?} now. Press @key{SPC} to see consecutive screenfuls of 411 the list until finished. Then type @key{SPC} several times. If 412 you are using Emacs, the help will then go away automatically. 413@end format 414 415 (If you are using the stand-alone Info reader, type @kbd{C-x 0} to 416return here, that is---press and hold @key{CTRL}, type an @kbd{x}, 417then release @key{CTRL} and @kbd{x}, and press @kbd{0}; that's a zero, 418not the letter ``o''.) 419 420 From now on, you will encounter large nodes without warning, and 421will be expected to know how to use @key{SPC} and @key{BACKSPACE} to 422move around in them without being told. Since not all terminals have 423the same size screen, it would be impossible to warn you anyway. 424 425@format 426>> Now type @kbd{n}, or click the middle mouse button on the @samp{Next} link, 427 to visit the next node. 428@end format 429 430@node Help-Inv, Help-M, Help-^L, Getting Started 431@comment node-name, next, previous, up 432@section Invisible text in Emacs Info 433 434 Before discussing menus, we need to make some remarks that are only 435relevant to users reading Info using Emacs. Users of the stand-alone 436version can skip this node by typing @kbd{]} now. 437 438@cindex invisible text in Emacs 439 In Emacs, certain text that appears in the stand-alone version is 440normally hidden, technically because it has the @samp{invisibility} 441property. Invisible text is really a part of the text. It becomes 442visible (by default) after killing and yanking, it appears in printed 443output, it gets saved to file just like any other text, and so on. 444Thus it is useful to know it is there. 445 446@findex visible-mode 447You can make invisible text visible by using the command @kbd{M-x 448visible-mode}. Visible mode is a minor mode, so using the command a 449second time will make the text invisible again. Watch the effects of 450the command on the ``menu'' below and the top line of this node. 451 452If you prefer to @emph{always} see the invisible text, you can set 453@code{Info-hide-note-references} to @code{nil}. Enabling Visible mode 454permanently is not a real alternative, because Emacs Info also uses 455(although less extensively) another text property that can change the 456text being displayed, the @samp{display} property. Only the 457invisibility property is affected by Visible mode. When, in this 458tutorial, we refer to the @samp{Emacs} behavior, we mean the 459@emph{default} Emacs behavior. 460 461Now type @kbd{]}, to learn about the @kbd{]} and @kbd{[} commands. 462 463@menu 464* ]: Help-]. Node telling about ]. 465* stuff: Help-]. Same node. 466* Help-]:: Yet again, same node. 467@end menu 468 469@node Help-], , , Help-Inv 470@subsection The @kbd{]} and @kbd{[} commands 471 472If you type @kbd{n} now, you get an error message saying that this 473node has no next node. Similarly, if you type @kbd{p}, the error 474message tells you that there is no previous node. (The exact message 475depends on the Info reader you use.) This is because @kbd{n} and 476@kbd{p} carry you to the next and previous node @emph{at the same 477level}. The present node is contained in a menu (see next) of the 478node you came from, and hence is considered to be at a lower level. 479It is the only node in the previous node's menu (even though it was 480listed three times). Hence it has no next or previous node that 481@kbd{n} or @kbd{p} could move to. 482 483If you systematically move through a manual by typing @kbd{n}, you run 484the risk of skipping many nodes. You do not run this risk if you 485systematically use @kbd{@key{SPC}}, because, when you scroll to the 486bottom of a node and type another @kbd{@key{SPC}}, then this carries 487you to the following node in the manual @emph{regardless of level}. 488If you immediately want to go to that node, without having to scroll 489to the bottom of the screen first, you can type @kbd{]}. 490 491Similarly, @kbd{@key{BACKSPACE}} carries you to the preceding node 492regardless of level, after you scrolled to the beginning of the 493present node. If you want to go to the preceding node immediately, 494you can type @kbd{[}. 495 496For instance, typing this sequence will come back here in three steps: 497@kbd{[ n [}. To do the same backward, type @kbd{] p ]}. 498 499Now type @kbd{]} to go to the next node and learn about menus. 500 501@node Help-M, Help-Xref, Help-Inv, Getting Started 502@comment node-name, next, previous, up 503@section Menus and the @kbd{m} command 504 505@cindex menus in an Info document 506@cindex Info menus 507 With only the @kbd{n} (next), @kbd{p} (previous), @kbd{@key{SPC}}, 508@kbd{@key{BACKSPACE}}, @kbd{]} and @kbd{[} commands for moving between 509nodes, nodes are restricted to a linear sequence. Menus allow a 510branching structure. A menu is a list of other nodes you can move to. 511It is actually just part of the text of the node formatted specially 512so that Info can interpret it. The beginning of a menu is always 513identified by a line which starts with @w{@samp{* Menu:}}. A node 514contains a menu if and only if it has a line in it which starts that 515way. The only menu you can use at any moment is the one in the node 516you are in. To use a menu in any other node, you must move to that 517node first. 518 519 After the start of the menu, each line that starts with a @samp{*} 520identifies one subtopic. The line usually contains a brief name for 521the subtopic (followed by a @samp{:}, normally hidden in Emacs), the 522name of the node that talks about that subtopic (again, normally 523hidden in Emacs), and optionally some further description of the 524subtopic. Lines in the menu that do not start with a @samp{*} have no 525special meaning---they are only for the human reader's benefit and do 526not define additional subtopics. Here is an example: 527 528@example 529* Foo: Node about FOO. This tells about FOO. 530@end example 531 532The subtopic name is Foo, and the node describing it is @samp{Node 533about FOO}. The rest of the line is just for the reader's 534Information. [[ But this line is not a real menu item, simply because 535there is no line above it which starts with @w{@samp{* Menu:}}. Also, 536in a real menu item, the @samp{*} would appear at the very start of 537the line. This is why the ``normally hidden'' text in Emacs, namely 538@samp{: Node about FOO.}, is actually visible in this example, even 539when Visible mode is off.]] 540 541 When you use a menu to go to another node (in a way that will be 542described soon), what you specify is the subtopic name, the first 543thing in the menu line. Info uses it to find the menu line, extracts 544the node name from it, and goes to that node. The reason that there 545is both a subtopic name and a node name is that the node name must be 546meaningful to the computer and may therefore have to be ugly looking. 547The subtopic name can be chosen just to be convenient for the user to 548specify. Often the node name is convenient for the user to specify 549and so both it and the subtopic name are the same. There is an 550abbreviation for this: 551 552@example 553* Foo:: This tells about FOO. 554@end example 555 556@noindent 557This means that the subtopic name and node name are the same; they are 558both @samp{Foo}. (The @samp{::} is normally hidden in Emacs.) 559 560@format 561>> Now use @key{SPC} to find the menu in this node, then come back to 562 the front with a @kbd{b} and some @key{SPC}s. As you see, a menu is 563 actually visible in its node. If you cannot find a menu in a node 564 by looking at it, then the node does not have a menu and the 565 @kbd{m} command is not available. 566@end format 567 568If you keep typing @key{SPC} once the menu appears on the screen, it 569will move to another node (the first one in the menu). If that 570happens, type @key{BACKSPACE} to come back. 571 572@kindex m @r{(Info mode)} 573 The command to go to one of the subnodes is @kbd{m}. This is very 574different from the commands you have used: it is a command that 575prompts you for more input. 576 577 The Info commands you know do not need additional input; when you 578type one of them, Info processes it instantly and then is ready for 579another command. The @kbd{m} command is different: it needs to know 580the @dfn{name of the subtopic}. Once you have typed @kbd{m}, Info 581tries to read the subtopic name. 582 583 Now, in the stand-alone Info, look for the line containing many 584dashes near the bottom of the screen. (This is the stand-alone 585equivalent for the mode line in Emacs.) There is one more line 586beneath that one, but usually it is blank. (In Emacs, this is the 587echo area.) When it is blank, Info is ready for a command, such as 588@kbd{n} or @kbd{b} or @key{SPC} or @kbd{m}. If that line contains 589text ending in a colon, it means Info is reading more input for the 590last command. You can't type an Info command then, because Info is 591trying to read input, not commands. You must either give the input 592and finish the command you started, or type @kbd{Control-g} to cancel 593the command. When you have done one of those things, the input entry 594line becomes blank again. Then you can type Info commands again. 595 596@findex Info-menu 597 The command to go to a subnode via a menu is @kbd{m}. After you type 598the @kbd{m}, the line at the bottom of the screen says @samp{Menu item: }. 599You must then type the name of the subtopic you want, and end it with 600a @key{RET}. In Emacs, @kbd{m} runs the command @code{Info-menu}. 601 602@cindex abbreviating Info subnodes 603 You can abbreviate the subtopic name. If the abbreviation is not 604unique, the first matching subtopic is chosen. Some menus put 605the shortest possible abbreviation for each subtopic name in capital 606letters, so you can see how much you need to type. It does not 607matter whether you use upper case or lower case when you type the 608subtopic. You should not put any spaces at the end, or inside of the 609item name, except for one space where a space appears in the item in 610the menu. 611 612@cindex completion of Info node names 613 You can also use the @dfn{completion} feature to help enter the 614subtopic name. If you type the @key{TAB} key after entering part of a 615name, it will fill in more of the name---as much as Info can deduce 616from the part you have entered. 617 618 If you move the cursor to one of the menu subtopic lines, then you do 619not need to type the argument: you just type a @key{RET}, and it 620stands for the subtopic of the line you are on. You can also click 621the middle mouse button directly on the subtopic line to go there. 622 623Here is a menu to give you a chance to practice. This menu gives you 624three ways of going to one place, Help-FOO: 625 626@menu 627* Foo: Help-FOO. A node you can visit for fun. 628* Bar: Help-FOO. We have made two ways to get to the same place. 629* Help-FOO:: And yet another! 630@end menu 631 632(Turn Visible mode on if you are using Emacs.) 633 634@format 635>> Now type just an @kbd{m} and see what happens: 636@end format 637 638 Now you are ``inside'' an @kbd{m} command. Commands cannot be used 639now; the next thing you will type must be the name of a subtopic. 640 641 You can change your mind about doing the @kbd{m} by typing 642@kbd{Control-g}. 643 644@format 645>> Try that now; notice the bottom line clear. 646@end format 647 648@format 649>> Then type another @kbd{m}. 650@end format 651 652@format 653>> Now type @kbd{BAR}, the item name. Do not type @key{RET} yet. 654@end format 655 656 While you are typing the item name, you can use the @key{DEL} (or 657@key{BACKSPACE}) key to cancel one character at a time if you make a 658mistake. 659 660@format 661>> Press @key{DEL} to cancel the @samp{R}. You could type another @kbd{R} 662 to replace it. But you do not have to, since @samp{BA} is a valid 663 abbreviation. 664@end format 665 666@format 667>> Now you are ready to go. Type a @key{RET}. 668@end format 669 670 After visiting @samp{Help-FOO}, you should return here. 671 672 Another way to move to the menu subtopic lines and between them is 673to type @key{TAB}. Each time you type a @key{TAB}, you move to the 674next subtopic line. To move to a previous subtopic line, type 675@kbd{M-@key{TAB}}---that is, press and hold the @key{META} key and then 676press @key{TAB}. (On some keyboards, the @key{META} key might be labeled 677@samp{Alt}.) 678 679 Once you move cursor to a subtopic line, press @key{RET} to go to 680that subtopic's node. 681 682@cindex mouse support in Info mode 683@kindex Mouse-2 @r{(Info mode)} 684 If your terminal supports a mouse, you have yet another way of going 685to a subtopic. Move your mouse pointer to the subtopic line, 686somewhere between the beginning @samp{*} and the colon @samp{:} which 687ends the subtopic's brief name. You will see the subtopic's name 688change its appearance (usually, its background color will change), and 689the shape of the mouse pointer will change if your platform supports 690that. After a while, if you leave the mouse on that spot, a small 691window will pop up, saying ``Mouse-2: go to that node'', or the same 692message may appear at the bottom of the screen. 693 694 @kbd{Mouse-2} is the second button of your mouse counting from the 695left---the middle button on a 3-button mouse. (On a 2-button mouse, 696you may have to press both buttons together to ``press the middle 697button''.) The message tells you pressing @kbd{Mouse-2} with the 698current position of the mouse pointer (on subtopic in the menu) will 699go to that subtopic. 700 701@findex Info-mouse-follow-nearest-node 702 More generally, @kbd{Mouse-2} in an Info buffer finds the nearest 703link to another node and goes there. For example, near a cross 704reference it acts like @kbd{f}, in a menu it acts like @kbd{m}, on the 705node's header line it acts like @kbd{n}, @kbd{p}, or @kbd{u}, etc. At 706end of the node's text @kbd{Mouse-2} moves to the next node, or up if 707there's no next node. 708 709@format 710>> Type @kbd{n} to see more commands. 711@end format 712 713@node Help-FOO, , , Help-M 714@subsection The @kbd{u} command 715 716 Congratulations! This is the node @samp{Help-FOO}. It has an @samp{Up} 717pointer @samp{Help-M}, the node you just came from via the @kbd{m} 718command. This is the usual convention---the nodes you reach from a menu 719have @samp{Up} nodes that lead back to the menu. Menus move Down in the 720tree, and @samp{Up} moves Up. @samp{Previous}, on the other hand, is 721usually used to ``stay on the same level but go backwards''. 722 723@kindex u @r{(Info mode)} 724@findex Info-up 725 You can go back to the node @samp{Help-M} by typing the command 726@kbd{u} for ``Up'' (the Emacs command run by @kbd{u} is 727@code{Info-up}). That puts you at the @emph{front} of the node---to 728get back to where you were reading you have to type some @key{SPC}s. 729(Some Info readers, such as the one built into Emacs, put you at the 730same place where you were reading in @samp{Help-M}.) 731 732 Another way to go Up is to click @kbd{Mouse-2} on the @samp{Up} 733pointer shown in the header line (provided that you have a mouse). 734 735@format 736>> Now type @kbd{u} to move back up to @samp{Help-M}. 737@end format 738 739@node Help-Xref, Help-Int, Help-M, Getting Started 740@comment node-name, next, previous, up 741@section Following Cross-References 742 743@cindex cross references in Info documents 744 In Info documentation, you will see many @dfn{cross references}. 745Cross references look like this: @xref{Help-Cross, Cross}. That text 746is a real, live cross reference, whose name is @samp{Cross} and which 747points to the node named @samp{Help-Cross}. (The node name is hidden 748in Emacs. Do @kbd{M-x visible-mode} to show or hide it.) 749 750@kindex f @r{(Info mode)} 751@findex Info-follow-reference 752 There are two ways to follow a cross reference. You can move the 753cursor to it and press @key{RET}, just as in a menu. @key{RET} 754follows the cross reference that the cursor is on. Or you can type 755@kbd{f} and then specify the name of the cross reference (in this 756case, @samp{Cross}) as an argument. In Emacs Info, @kbd{f} runs 757@code{Info-follow-reference}, 758 759 In the @kbd{f} command, you select the cross reference with its 760name, so it does not matter where the cursor was. If the cursor is on 761or near a cross reference, @kbd{f} suggests that reference name in 762parentheses as the default; typing @key{RET} will follow that 763reference. However, if you type a different reference name, @kbd{f} 764will follow the other reference which has that name. 765 766@format 767>> Type @kbd{f}, followed by @kbd{Cross}, and then @key{RET}. 768@end format 769 770 As you enter the reference name, you can use the @key{DEL} (or 771@key{BACKSPACE}) key to edit your input. If you change your mind 772about following any reference, you can use @kbd{Control-g} to cancel 773the command. Completion is available in the @kbd{f} command; you can 774complete among all the cross reference names in the current node by 775typing a @key{TAB}. 776 777 To get a list of all the cross references in the current node, you 778can type @kbd{?} after an @kbd{f}. The @kbd{f} continues to await a 779cross reference name even after displaying the list, so if you don't 780actually want to follow a reference, you should type a @kbd{Control-g} 781to cancel the @kbd{f}. 782 783@format 784>> Type @kbd{f?} to get a list of the cross references in this node. Then 785 type a @kbd{Control-g} and see how the @samp{f} gives up. 786@end format 787 788 The @key{TAB} and @kbd{M-@key{TAB}} key, which move between menu 789items in a menu, also move between cross references outside of menus. 790 791 Sometimes a cross reference (or a node) can lead to another file (in 792other words another ``manual''), or, on occasion, even a file on a 793remote machine (although Info files distributed with Emacs or the 794stand-alone Info avoid using remote links). Such a cross reference 795looks like this: @xref{Top,, Overview of Texinfo, texinfo, Texinfo: 796The GNU Documentation Format}. (After following this link, type 797@kbd{l} to get back to this node.) Here the name @samp{texinfo} 798between parentheses (shown in the stand-alone version) refers to the 799file name. This file name appears in cross references and node names 800if it differs from the current file. In Emacs, the file name is 801hidden (along with other text). (Use @kbd{M-x visible-mode} to show 802or hide it.) 803 804 The remainder of this node applies only to the Emacs version. If 805you use the stand-alone version, you can type @kbd{n} immediately. 806 807 To some users, switching manuals is a much bigger switch than 808switching sections. These users like to know that they are going to 809be switching to another manual (and which one) before actually doing 810so, especially given that, if one does not notice, Info commands like 811@kbd{t} (see the next node) can have confusing results. 812 813 If you put your mouse over the cross reference and if the cross 814reference leads to a different manual, then the information appearing 815in a separate box (tool tip) or in the echo area, will mention the 816file the cross reference will carry you to (between parentheses). 817This is also true for menu subtopic names. If you have a mouse, just 818leave it over the @samp{Overview} cross reference above and watch what 819happens. 820 821 If you always like to have that information available without having 822to move your mouse over the cross reference, set 823@code{Info-hide-note-references} to a value other than t (@pxref{Emacs 824Info Variables}). You might also want to do that if you have a lot of 825cross references to files on remote machines and have non-permanent or 826slow access, since otherwise you might not be able to distinguish 827between local and remote links. 828 829@format 830>> Now type @kbd{n} to learn more commands. 831@end format 832 833@node Help-Int, Help-Q, Help-Xref, Getting Started 834@comment node-name, next, previous, up 835@section Some intermediate Info commands 836 837 The introductory course is almost over; please continue 838a little longer to learn some intermediate-level commands. 839 840 Most Info files have an index, which is actually a large node 841containing little but a menu. The menu has one menu item for each 842topic listed in the index. (As a special feature, menus for indices 843may also include the line number within the node of the index entry. 844This allows Info readers to go to the exact line of an entry, not just 845the start of the containing node.) 846 847 You can get to the index from the main menu of the file with the 848@kbd{m} command; then you can use the @kbd{m} command again in the 849index node to go to the node that describes the topic you want. 850 851 There is also a short-cut Info command, @kbd{i}, which does all of 852that for you. It searches the index for a given topic (a string) and 853goes to the node which is listed in the index for that topic. 854@xref{Info Search}, for a full explanation. 855 856@kindex l @r{(Info mode)} 857@findex Info-last 858@cindex going back in Info mode 859 If you have been moving around to different nodes and wish to 860retrace your steps, the @kbd{l} command (@kbd{l} for @dfn{last}) will 861do that, one node-step at a time. As you move from node to node, Info 862records the nodes where you have been in a special history list. The 863@kbd{l} command revisits nodes in the history list; each successive 864@kbd{l} command moves one step back through the history. 865 866 In Emacs, @kbd{l} runs the command @code{Info-last}. 867 868@format 869>> Try typing @kbd{p p n} and then three @kbd{l}'s, pausing in between 870to see what each @kbd{l} does. You should wind up right back here. 871@end format 872 873 Note the difference between @kbd{l} and @kbd{p}: @kbd{l} moves to 874where @emph{you} last were, whereas @kbd{p} always moves to the node 875which the header says is the @samp{Previous} node (from this node, the 876@samp{Prev} link leads to @samp{Help-Xref}). 877 878@kindex d @r{(Info mode)} 879@findex Info-directory 880@cindex go to Directory node 881 The @kbd{d} command (@code{Info-directory} in Emacs) gets you 882instantly to the Directory node. This node, which is the first one 883you saw when you entered Info, has a menu which leads (directly or 884indirectly, through other menus), to all the nodes that exist. The 885Directory node lists all the manuals and other Info documents that 886are, or could be, installed on your system. 887 888@format 889>> Try doing a @kbd{d}, then do an @kbd{l} to return here (yes, 890 @emph{do} return). 891@end format 892 893@kindex t @r{(Info mode)} 894@findex Info-top-node 895@cindex go to Top node 896 The @kbd{t} command moves to the @samp{Top} node of the manual. 897This is useful if you want to browse the manual's main menu, or select 898some specific top-level menu item. The Emacs command run by @kbd{t} 899is @code{Info-top-node}. 900 901 Clicking @kbd{Mouse-2} on or near a cross reference also follows the 902reference. You can see that the cross reference is mouse-sensitive by 903moving the mouse pointer to the reference and watching how the 904underlying text and the mouse pointer change in response. 905 906@format 907>> Now type @kbd{n} to see the last node of the course. 908@end format 909 910 @xref{Expert Info}, for more advanced Info features. 911 912@c If a menu appears at the end of this node, remove it. 913@c It is an accident of the menu updating command. 914 915@node Expert Info 916@chapter Info for Experts 917 918 This chapter describes various Info commands for experts. (If you 919are using a stand-alone Info reader, there are additional commands 920specific to it, which are documented in several chapters of @ref{Top,, 921GNU Info, info-stnd, GNU Info}.) 922 923 This chapter also explains how to write an Info as distinct from a 924Texinfo file. (However, in most cases, writing a Texinfo file is 925better, since you can use it to make a printed manual or produce other 926formats, such as HTML and DocBook, as well as for generating Info 927files.) @xref{Top,, Overview of Texinfo, texinfo, Texinfo: The GNU 928Documentation Format}. 929 930@menu 931* Advanced:: Advanced Info commands: g, e, and 1 - 9. 932* Info Search:: How to search Info documents for specific subjects. 933* Add:: Describes how to add new nodes to the hierarchy. 934 Also tells what nodes look like. 935* Menus:: How to add to or create menus in Info nodes. 936* Cross-refs:: How to add cross-references to Info nodes. 937* Tags:: How to make tags tables for Info files. 938* Checking:: Checking an Info File 939* Emacs Info Variables:: Variables modifying the behavior of Emacs Info. 940@end menu 941 942@node Advanced, Info Search, , Expert Info 943@comment node-name, next, previous, up 944@section Advanced Info Commands 945 946Here are some more Info commands that make it easier to move around. 947 948@subheading @kbd{g} goes to a node by name 949 950@kindex g @r{(Info mode)} 951@findex Info-goto-node 952@cindex go to a node by name 953 If you know a node's name, you can go there by typing @kbd{g}, the 954name, and @key{RET}. Thus, @kbd{gTop@key{RET}} would go to the node 955called @samp{Top} in this file. (This is equivalent to @kbd{t}, see 956@ref{Help-Int}.) @kbd{gAdvanced@key{RET}} would come back here. 957@kbd{g} in Emacs runs the command @code{Info-goto-node}. 958 959 Unlike @kbd{m}, @kbd{g} does not allow the use of abbreviations. 960But it does allow completion, so you can type @key{TAB} to complete a 961partial node name. 962 963@cindex go to another Info file 964 To go to a node in another file, you can include the file name in the 965node name by putting it at the front, in parentheses. Thus, 966@kbd{g(dir)Top@key{RET}} would go to the Info Directory node, which is 967the node @samp{Top} in the Info file @file{dir}. Likewise, 968@kbd{g(emacs)Top@key{RET}} goes to the top node of the Emacs manual. 969 970 The node name @samp{*} specifies the whole file. So you can look at 971all of the current file by typing @kbd{g*@key{RET}} or all of any 972other file with @kbd{g(@var{filename})@key{RET}}. 973 974@subheading @kbd{1}--@kbd{9} choose a menu subtopic by its number 975 976@kindex 1 @r{through} 9 @r{(Info mode)} 977@findex Info-nth-menu-item 978@cindex select @var{n}'th menu item 979 If you begrudge each character of type-in which your system requires, 980you might like to use the commands @kbd{1}, @kbd{2}, @kbd{3}, @kbd{4}, 981@dots{}, @kbd{9}. They are short for the @kbd{m} command together 982with a name of a menu subtopic. @kbd{1} goes through the first item 983in the current node's menu; @kbd{2} goes through the second item, etc. 984In the stand-alone reader, @kbd{0} goes through the last menu item; 985this is so you need not count how many entries are there. In Emacs, 986the digit keys run the command @code{Info-nth-menu-item}. 987 988 If your display supports multiple fonts, colors or underlining, and 989you are using Emacs' Info mode to read Info files, the third, sixth 990and ninth menu items have a @samp{*} that stands out, either in color 991or in some other attribute, such as underline; this makes it easy to 992see at a glance which number to use for an item. 993 994 Some terminals don't support either multiple fonts, colors or 995underlining. If you need to actually count items, it is better to use 996@kbd{m} instead, and specify the name, or use @key{TAB} to quickly 997move between menu items. 998 999@subheading @kbd{e} makes Info document editable 1000 1001@kindex e @r{(Info mode)} 1002@findex Info-edit 1003@cindex edit Info document 1004 The Info command @kbd{e} changes from Info mode to an ordinary 1005Emacs editing mode, so that you can edit the text of the current node. 1006Type @kbd{C-c C-c} to switch back to Info. The @kbd{e} command is allowed 1007only if the variable @code{Info-enable-edit} is non-@code{nil}. 1008 1009 The @kbd{e} command only works in Emacs, where it runs the command 1010@code{Info-edit}. The stand-alone Info reader doesn't allow you to 1011edit the Info file, so typing @kbd{e} there goes to the end of the 1012current node. 1013 1014@subheading @kbd{M-n} creates a new independent Info buffer in Emacs 1015 1016@kindex M-n @r{(Info mode)} 1017@findex clone-buffer 1018@cindex multiple Info buffers 1019 If you are reading Info in Emacs, you can select a new independent 1020Info buffer in another window by typing @kbd{M-n}. The new buffer 1021starts out as an exact copy of the old one, but you will be able to 1022move independently between nodes in the two buffers. (In Info mode, 1023@kbd{M-n} runs the Emacs command @code{clone-buffer}.) 1024 1025 In Emacs Info, you can also produce new Info buffers by giving a 1026numeric prefix argument to the @kbd{m} and @kbd{g} commands. @kbd{C-u 1027m} and @kbd{C-u g} go to a new node in exactly the same way that 1028@kbd{m} and @kbd{g} do, but they do so in a new Info buffer which they 1029select in another window. 1030 1031@node Info Search, Add, Advanced, Expert Info 1032@comment node-name, next, previous, up 1033@section How to search Info documents for specific subjects 1034 1035@cindex searching Info documents 1036@cindex Info document as a reference 1037 The commands which move between and inside nodes allow you to read 1038the entire manual or its large portions. But what if you need to find 1039some information in the manual as fast as you can, and you don't know 1040or don't remember in what node to look for it? This need arises when 1041you use a manual as a @dfn{reference}, or when it is impractical to 1042read the entire manual before you start using the programs it 1043describes. 1044 1045 Info has powerful searching facilities that let you find things 1046quickly. You can search either the manual indices or its text. 1047 1048@kindex i @r{(Info mode)} 1049@findex Info-index 1050 Since most subjects related to what the manual describes should be 1051indexed, you should try the index search first. The @kbd{i} command 1052prompts you for a subject and then looks up that subject in the 1053indices. If it finds an index entry with the subject you typed, it 1054goes to the node to which that index entry points. You should browse 1055through that node to see whether the issue you are looking for is 1056described there. If it isn't, type @kbd{,} one or more times to go 1057through additional index entries which match your subject. 1058 1059 The @kbd{i} command finds all index entries which include the string 1060you typed @emph{as a substring}. For each match, Info shows in the 1061echo area the full index entry it found. Often, the text of the full 1062index entry already gives you enough information to decide whether it 1063is relevant to what you are looking for, so we recommend that you read 1064what Info shows in the echo area before looking at the node it 1065displays. 1066 1067 Since @kbd{i} looks for a substring, you can search for subjects even 1068if you are not sure how they are spelled in the index. For example, 1069suppose you want to find something that is pertinent to commands which 1070complete partial input (e.g., when you type @key{TAB}). If you want 1071to catch index entries that refer to ``complete'', ``completion'', and 1072``completing'', you could type @kbd{icomplet@key{RET}}. 1073 1074 Info documents which describe programs should index the commands, 1075options, and key sequences that the program provides. If you are 1076looking for a description of a command, an option, or a key, just type 1077their names when @kbd{i} prompts you for a topic. For example, if you 1078want to read the description of what the @kbd{C-f} key does, type 1079@kbd{i C - f @key{RET}}. Here @kbd{C-f} are 3 literal characters 1080@samp{C}, @samp{-}, and @samp{f}, not the ``Control-f'' command key 1081you type inside Emacs to run the command bound to @kbd{C-f}. 1082 1083 In Emacs, @kbd{i} runs the command @code{Info-index}. 1084 1085@findex info-apropos 1086If you don't know what manual documents something, try the @kbd{M-x 1087info-apropos} command. It prompts for a string and then looks up that 1088string in all the indices of all the Info documents installed on your 1089system. 1090 1091@kindex s @r{(Info mode)} 1092@findex Info-search 1093 The @kbd{s} command allows you to search a whole file for a string. 1094It switches to the next node if and when that is necessary. You 1095type @kbd{s} followed by the string to search for, terminated by 1096@key{RET}. To search for the same string again, just @kbd{s} followed 1097by @key{RET} will do. The file's nodes are scanned in the order 1098they are in in the file, which has no necessary relationship to the 1099order that they may be in the tree structure of menus and @samp{next} 1100pointers. But normally the two orders are not very different. In any 1101case, you can always do a @kbd{b} to find out what node you have 1102reached, if the header is not visible (this can happen, because @kbd{s} 1103puts your cursor at the occurrence of the string, not at the beginning 1104of the node). 1105 1106@kindex M-s @r{(Info mode)} 1107 In Emacs, @kbd{Meta-s} is equivalent to @kbd{s}. That is for 1108compatibility with other GNU packages that use @kbd{M-s} for a similar 1109kind of search command. Both @kbd{s} and @kbd{M-s} run in Emacs the 1110command @code{Info-search}. 1111 1112 1113@node Add, Menus, Info Search, Expert Info 1114@comment node-name, next, previous, up 1115@section Adding a new node to Info 1116 1117To add a new topic to the list in the Info directory, you must: 1118 1119@enumerate 1120@item 1121Create some nodes, in some file, to document that topic. 1122@item 1123Put that topic in the menu in the directory. @xref{Menus, Menu}. 1124@end enumerate 1125 1126 Usually, the way to create the nodes is with Texinfo (@pxref{Top,, 1127Overview of Texinfo, texinfo, Texinfo: The GNU Documentation Format}); 1128this has the advantage that you can also make a printed manual or HTML 1129from them. You would use the @samp{@@dircategory} and 1130@samp{@@direntry} commands to put the manual into the Info directory. 1131However, if you want to edit an Info file manually and install it 1132manually, here is how. 1133 1134@cindex node delimiters 1135 The new node can live in an existing documentation file, or in a new 1136one. It must have a @samp{^_} character before it (invisible to the 1137user; this node has one but you cannot see it), and it ends with either 1138a @samp{^_}, a @samp{^L} (``formfeed''), or the end of file.@footnote{If 1139you put in a @samp{^L} to end a new node, be sure that there is a 1140@samp{^_} after it to start the next one, since @samp{^L} cannot 1141@emph{start} a node. Also, a nicer way to make a node boundary be a 1142page boundary as well is to put a @samp{^L} @emph{right after} the 1143@samp{^_}.} 1144 1145 The @samp{^_} starting a node must be followed by a newline or a 1146@samp{^L} newline, after which comes the node's header line. The 1147header line must give the node's name (by which Info finds it), and 1148state the names of the @samp{Next}, @samp{Previous}, and @samp{Up} 1149nodes (if there are any). As you can see, this node's @samp{Up} node 1150is the node @samp{Expert Info}. The @samp{Next} node is @samp{Menus}. 1151 1152@cindex node header line format 1153@cindex format of node headers 1154 The keywords @dfn{Node}, @dfn{Next}, @dfn{Previous}, and @dfn{Up} 1155may appear in any order, anywhere in the header line, but the 1156recommended order is the one in this sentence. Each keyword must be 1157followed by a colon, spaces and tabs, and then the appropriate name. 1158The name may be terminated with a tab, a comma, or a newline. A space 1159does not end it; node names may contain spaces. The case of letters 1160in the names is insignificant. 1161 1162@cindex node name format 1163@cindex Directory node 1164 A node name has two forms. A node in the current file is named by 1165what appears after the @samp{Node: } in that node's first line. For 1166example, this node's name is @samp{Add}. A node in another file is 1167named by @samp{(@var{filename})@var{node-within-file}}, as in 1168@samp{(info)Add} for this node. If the file name starts with ``./'', 1169then it is relative to the current directory; otherwise, it is 1170relative starting from the standard directory for Info files of your 1171site. The name @samp{(@var{filename})Top} can be abbreviated to just 1172@samp{(@var{filename})}. By convention, the name @samp{Top} is used 1173for the ``highest'' node in any single file---the node whose @samp{Up} 1174points out of the file. The @samp{Directory} node is @file{(dir)}, it 1175points to a file @file{dir} which holds a large menu listing all the 1176Info documents installed on your site. The @samp{Top} node of a 1177document file listed in the @samp{Directory} should have an @samp{Up: 1178(dir)} in it. 1179 1180@cindex unstructured documents 1181 The node name @kbd{*} is special: it refers to the entire file. 1182Thus, @kbd{g*} shows you the whole current file. The use of the 1183node @kbd{*} is to make it possible to make old-fashioned, 1184unstructured files into nodes of the tree. 1185 1186 The @samp{Node:} name, in which a node states its own name, must not 1187contain a file name, since when Info searches for a node, it does not 1188expect a file name to be there. The @samp{Next}, @samp{Previous} and 1189@samp{Up} names may contain them. In this node, since the @samp{Up} 1190node is in the same file, it was not necessary to use one. 1191 1192 Note that the nodes in this file have a file name in the header 1193line. The file names are ignored by Info, but they serve as comments 1194to help identify the node for the user. 1195 1196@node Menus, Cross-refs, Add, Expert Info 1197@comment node-name, next, previous, up 1198@section How to Create Menus 1199 1200 Any node in the Info hierarchy may have a @dfn{menu}---a list of subnodes. 1201The @kbd{m} command searches the current node's menu for the topic which it 1202reads from the terminal. 1203 1204@cindex menu and menu entry format 1205 A menu begins with a line starting with @w{@samp{* Menu:}}. The 1206rest of the line is a comment. After the starting line, every line 1207that begins with a @samp{* } lists a single topic. The name of the 1208topic---what the user must type at the @kbd{m}'s command prompt to 1209select this topic---comes right after the star and space, and is 1210followed by a colon, spaces and tabs, and the name of the node which 1211discusses that topic. The node name, like node names following 1212@samp{Next}, @samp{Previous} and @samp{Up}, may be terminated with a 1213tab, comma, or newline; it may also be terminated with a period. 1214 1215 If the node name and topic name are the same, then rather than 1216giving the name twice, the abbreviation @samp{* @var{name}::} may be 1217used (and should be used, whenever possible, as it reduces the visual 1218clutter in the menu). 1219 1220 It is considerate to choose the topic names so that they differ 1221from each other very near the beginning---this allows the user to type 1222short abbreviations. In a long menu, it is a good idea to capitalize 1223the beginning of each item name which is the minimum acceptable 1224abbreviation for it (a long menu is more than 5 or so entries). 1225 1226 The nodes listed in a node's menu are called its ``subnodes'', and it 1227is their ``superior''. They should each have an @samp{Up:} pointing at 1228the superior. It is often useful to arrange all or most of the subnodes 1229in a sequence of @samp{Next} and @samp{Previous} pointers so that 1230someone who wants to see them all need not keep revisiting the Menu. 1231 1232 The Info Directory is simply the menu of the node @samp{(dir)Top}---that 1233is, node @samp{Top} in file @file{.../info/dir}. You can put new entries 1234in that menu just like any other menu. The Info Directory is @emph{not} the 1235same as the file directory called @file{info}. It happens that many of 1236Info's files live in that file directory, but they do not have to; and 1237files in that directory are not automatically listed in the Info 1238Directory node. 1239 1240 Also, although the Info node graph is claimed to be a ``hierarchy'', 1241in fact it can be @emph{any} directed graph. Shared structures and 1242pointer cycles are perfectly possible, and can be used if they are 1243appropriate to the meaning to be expressed. There is no need for all 1244the nodes in a file to form a connected structure. In fact, this file 1245has two connected components. You are in one of them, which is under 1246the node @samp{Top}; the other contains the node @samp{Help} which the 1247@kbd{h} command goes to. In fact, since there is no garbage 1248collector, nothing terrible happens if a substructure is not pointed 1249to, but such a substructure is rather useless since nobody can 1250ever find out that it exists. 1251 1252@node Cross-refs, Tags, Menus, Expert Info 1253@comment node-name, next, previous, up 1254@section Creating Cross References 1255 1256@cindex cross reference format 1257 A cross reference can be placed anywhere in the text, unlike a menu 1258item which must go at the front of a line. A cross reference looks 1259like a menu item except that it has @samp{*note} instead of @samp{*}. 1260It @emph{cannot} be terminated by a @samp{)}, because @samp{)}'s are 1261so often part of node names. If you wish to enclose a cross reference 1262in parentheses, terminate it with a period first. Here are two 1263examples of cross references pointers: 1264 1265@example 1266*Note details: commands. (See *note 3: Full Proof.) 1267@end example 1268 1269@noindent 1270@emph{These are just examples.} The places they ``lead to'' do not 1271really exist! 1272 1273@menu 1274* Help-Cross:: Target of a cross-reference. 1275@end menu 1276 1277 1278@node Help-Cross, , , Cross-refs 1279@subsection The node reached by the cross reference in Info 1280 1281 This is the node reached by the cross reference named @samp{Cross}. 1282 1283 While this node is specifically intended to be reached by a cross 1284reference, most cross references lead to nodes that ``belong'' 1285someplace else far away in the structure of an Info document. So you 1286cannot expect this node to have a @samp{Next}, @samp{Previous} or 1287@samp{Up} links pointing back to where you came from. In general, the 1288@kbd{l} (el) command is the only way to get back there. 1289 1290@format 1291>> Type @kbd{l} to return to the node where the cross reference was. 1292@end format 1293 1294@node Help-Q, , Help-Int, Getting Started 1295@comment node-name, next, previous, up 1296@section Quitting Info 1297 1298@kindex q @r{(Info mode)} 1299@findex Info-exit 1300@cindex quitting Info mode 1301 To get out of Info, back to what you were doing before, type @kbd{q} 1302for @dfn{Quit}. This runs @code{Info-exit} in Emacs. 1303 1304 This is the end of the basic course on using Info. You have learned 1305how to move in an Info document, and how to follow menus and cross 1306references. This makes you ready for reading manuals top to bottom, 1307as new users should do when they learn a new package. 1308 1309 Another set of Info commands is useful when you need to find 1310something quickly in a manual---that is, when you need to use a manual 1311as a reference rather than as a tutorial. We urge you to learn 1312these search commands as well. If you want to do that now, follow this 1313cross reference to @ref{Info Search}. 1314 1315Yet another set of commands are meant for experienced users; you can 1316find them by looking in the Directory node for documentation on Info. 1317Finding them will be a good exercise in using Info in the usual 1318manner. 1319 1320@format 1321>> Type @kbd{d} to go to the Info directory node; then type 1322 @kbd{mInfo} and Return, to get to the node about Info and 1323 see what other help is available. 1324@end format 1325 1326 1327@node Tags, Checking, Cross-refs, Expert Info 1328@comment node-name, next, previous, up 1329@section Tags Tables for Info Files 1330 1331@cindex tags tables in info files 1332 You can speed up the access to nodes of a large Info file by giving 1333it a tags table. Unlike the tags table for a program, the tags table for 1334an Info file lives inside the file itself and is used 1335automatically whenever Info reads in the file. 1336 1337@findex Info-tagify 1338 To make a tags table, go to a node in the file using Emacs Info mode and type 1339@kbd{M-x Info-tagify}. Then you must use @kbd{C-x C-s} to save the 1340file. Info files produced by the @code{makeinfo} command that is part 1341of the Texinfo package always have tags tables to begin with. 1342 1343@cindex stale tags tables 1344@cindex update Info tags table 1345 Once the Info file has a tags table, you must make certain it is up 1346to date. If you edit an Info file directly (as opposed to editing its 1347Texinfo source), and, as a result of deletion of text, any node moves back 1348more than a thousand characters in the file from the position 1349recorded in the tags table, Info will no longer be able to find that 1350node. To update the tags table, use the @code{Info-tagify} command 1351again. 1352 1353 An Info file tags table appears at the end of the file and looks like 1354this: 1355 1356@example 1357^_^L 1358Tag Table: 1359File: info, Node: Cross-refs^?21419 1360File: info, Node: Tags^?22145 1361^_ 1362End Tag Table 1363@end example 1364 1365@noindent 1366Note that it contains one line per node, and this line contains 1367the beginning of the node's header (ending just after the node name), 1368a @samp{DEL} character, and the character position in the file of the 1369beginning of the node. 1370 1371 1372@node Checking, Emacs Info Variables, Tags, Expert Info 1373@section Checking an Info File 1374 1375When creating an Info file, it is easy to forget the name of a node when 1376you are making a pointer to it from another node. If you put in the 1377wrong name for a node, this is not detected until someone tries to go 1378through the pointer using Info. Verification of the Info file is an 1379automatic process which checks all pointers to nodes and reports any 1380pointers which are invalid. Every @samp{Next}, @samp{Previous}, and 1381@samp{Up} is checked, as is every menu item and every cross reference. In 1382addition, any @samp{Next} which does not have a @samp{Previous} pointing 1383back is reported. Only pointers within the file are checked, because 1384checking pointers to other files would be terribly slow. But those are 1385usually few. 1386 1387@findex Info-validate 1388To check an Info file, do @kbd{M-x Info-validate} while looking at any 1389node of the file with Emacs Info mode. 1390 1391@node Emacs Info Variables, , Checking, Expert Info 1392@section Emacs Info-mode Variables 1393 1394The following variables may modify the behavior of Info-mode in Emacs; 1395you may wish to set one or several of these variables interactively, or 1396in your @file{~/.emacs} init file. @xref{Examining, Examining and Setting 1397Variables, Examining and Setting Variables, emacs, The GNU Emacs 1398Manual}. The stand-alone Info reader program has its own set of 1399variables, described in @ref{Variables,, Manipulating Variables, 1400info-stnd, GNU Info}. 1401 1402@vtable @code 1403@item Info-directory-list 1404The list of directories to search for Info files. Each element is a 1405string (directory name) or @code{nil} (try default directory). If not 1406initialized Info uses the environment variable @env{INFOPATH} to 1407initialize it, or @code{Info-default-directory-list} if there is no 1408@env{INFOPATH} variable in the environment. 1409 1410If you wish to customize the Info directory search list for both Emacs 1411info and stand-alone Info, it is best to set the @env{INFOPATH} 1412environment variable, since that applies to both programs. 1413 1414@item Info-additional-directory-list 1415A list of additional directories to search for Info documentation files. 1416These directories are not searched for merging the @file{dir} file. 1417 1418@item Info-fontify 1419When set to a non-@code{nil} value, enables highlighting of Info 1420files. The default is @code{t}. You can change how the highlighting 1421looks by customizing the faces @code{info-node}, @code{info-xref}, 1422@code{info-header-xref}, @code{info-header-node}, @code{info-menu-5}, 1423@code{info-menu-header}, and @code{info-title-@var{n}-face} (where 1424@var{n} is the level of the section, a number between 1 and 4). To 1425customize a face, type @kbd{M-x customize-face @key{RET} @var{face} 1426@key{RET}}, where @var{face} is one of the face names listed here. 1427 1428@item Info-use-header-line 1429If non-@code{nil}, Emacs puts in the Info buffer a header line showing 1430the @samp{Next}, @samp{Prev}, and @samp{Up} links. A header line does 1431not scroll with the rest of the buffer, making these links always 1432visible. 1433 1434@item Info-hide-note-references 1435As explained in earlier nodes, the Emacs version of Info normally 1436hides some text in menus and cross-references. You can completely 1437disable this feature, by setting this option to @code{nil}. Setting 1438it to a value that is neither @code{nil} nor @code{t} produces an 1439intermediate behavior, hiding a limited amount of text, but showing 1440all text that could potentially be useful. 1441 1442@item Info-scroll-prefer-subnodes 1443If set to a non-@code{nil} value, @key{SPC} and @key{BACKSPACE} (or 1444@key{DEL}) keys in a menu visit subnodes of the current node before 1445scrolling to its end or beginning, respectively. For example, if the 1446node's menu appears on the screen, the next @key{SPC} moves to a 1447subnode indicated by the following menu item. Setting this option to 1448@code{nil} results in behavior similar to the stand-alone Info reader 1449program, which visits the first subnode from the menu only when you 1450hit the end of the current node. The default is @code{nil}. 1451 1452@item Info-enable-active-nodes 1453When set to a non-@code{nil} value, allows Info to execute Lisp code 1454associated with nodes. The Lisp code is executed when the node is 1455selected. The Lisp code to be executed should follow the node 1456delimiter (the @samp{DEL} character) and an @samp{execute: } tag, like 1457this: 1458 1459@example 1460^_execute: (message "This is an active node!") 1461@end example 1462 1463@item Info-enable-edit 1464Set to @code{nil}, disables the @samp{e} (@code{Info-edit}) command. A 1465non-@code{nil} value enables it. @xref{Add, Edit}. 1466@end vtable 1467 1468 1469@node Creating an Info File 1470@chapter Creating an Info File from a Texinfo File 1471 1472@code{makeinfo} is a utility that converts a Texinfo file into an Info 1473file; @code{texinfo-format-region} and @code{texinfo-format-buffer} are 1474GNU Emacs functions that do the same. 1475 1476@xref{Top,, Overview of Texinfo, texinfo, Texinfo: The GNU 1477Documentation Format}, to learn how to write a Texinfo file. 1478 1479@xref{Creating an Info File,,, texinfo, Texinfo: The GNU Documentation 1480Format}, to learn how to create an Info file from a Texinfo file. 1481 1482@xref{Installing an Info File,,, texinfo, Texinfo: The GNU 1483Documentation Format}, to learn how to install an Info file after you 1484have created one. 1485 1486@node Index 1487@unnumbered Index 1488 1489This is an alphabetical listing of all the commands, variables, and 1490topics discussed in this document. 1491 1492@printindex cp 1493 1494@bye 1495 1496@ignore 1497 arch-tag: 965c1638-01d6-4156-9227-b10418b9d8e8 1498@end ignore 1499