| 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 |
| 14 | This file describes how to use Info, the on-line, menu-driven GNU |
| 15 | documentation system. |
| 16 | |
| 17 | Copyright @copyright{} 1989, 1992, 1996, 1997, 1998, 1999, 2000, 2001, |
| 18 | 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| 19 | |
| 20 | @quotation |
| 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 |
| 25 | Manual,'' and with the Back-Cover Texts as in (a) below. A copy of the |
| 26 | license is included in the section entitled ``GNU Free Documentation |
| 27 | License'' in the Emacs manual. |
| 28 | |
| 29 | (a) The FSF's Back-Cover Text is: ``You have the freedom to copy and |
| 30 | modify this GNU manual. Buying copies from the FSF supports it in |
| 31 | developing GNU and promoting software freedom.'' |
| 32 | |
| 33 | This document is part of a collection distributed under the GNU Free |
| 34 | Documentation License. If you want to distribute this document |
| 35 | separately from the collection, you can do so by adding a copy of the |
| 36 | license 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 | |
| 61 | The 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 |
| 63 | probably using an Info reader to read this now. |
| 64 | |
| 65 | There are two primary Info readers: @code{info}, a stand-alone program |
| 66 | designed just to read Info files (@pxref{Top,,What is Info?, |
| 67 | info-stnd, GNU Info}), and the @code{info} package in GNU Emacs, a |
| 68 | general-purpose editor. At present, only the Emacs reader supports |
| 69 | using a mouse. |
| 70 | |
| 71 | @ifinfo |
| 72 | If you are new to the Info reader and want to learn how to use it, |
| 73 | type the command @kbd{h} now. It brings you to a programmed |
| 74 | instruction sequence. |
| 75 | |
| 76 | To read about advanced Info commands, type @kbd{n} twice. This |
| 77 | brings you to @cite{Advanced Info Commands}, skipping over the `Getting |
| 78 | Started' chapter. |
| 79 | @end ifinfo |
| 80 | @end ifnottex |
| 81 | |
| 82 | @menu |
| 83 | * Getting Started:: Getting started using an Info reader. |
| 84 | * Advanced:: Advanced Info commands. |
| 85 | * Expert Info:: Info commands for experts. |
| 86 | * Index:: An index of topics, commands, and variables. |
| 87 | @end menu |
| 88 | |
| 89 | @node Getting Started, Advanced, Top, Top |
| 90 | @comment node-name, next, previous, up |
| 91 | @chapter Getting Started |
| 92 | |
| 93 | This first part of this Info manual describes how to get around inside |
| 94 | of Info. The second part of the manual describes various advanced |
| 95 | Info commands. The third part briefly explains how to generate Info |
| 96 | files from Texinfo files, and describes how to write an Info file |
| 97 | by hand. |
| 98 | |
| 99 | @ifnotinfo |
| 100 | This manual is primarily designed for browsing with an Info reader |
| 101 | program on a computer, so that you can try Info commands while reading |
| 102 | about them. Reading it on paper or with an HTML browser is less |
| 103 | effective, since you must take it on faith that the commands described |
| 104 | really do what the manual says. By all means go through this manual |
| 105 | now that you have it; but please try going through the on-line version |
| 106 | as well. |
| 107 | |
| 108 | @cindex Info reader, how to invoke |
| 109 | @cindex entering Info |
| 110 | There are two ways of looking at the online version of this manual: |
| 111 | |
| 112 | @enumerate |
| 113 | @item |
| 114 | Type @code{info} at your shell's command line. This approach uses a |
| 115 | stand-alone program designed just to read Info files. |
| 116 | |
| 117 | @item |
| 118 | Type @code{emacs} at the command line; then type @kbd{C-h i} |
| 119 | (@kbd{Control-h}, followed by @kbd{i}). This approach uses the Info |
| 120 | mode of the Emacs editor. |
| 121 | @end enumerate |
| 122 | |
| 123 | In either case, then type @kbd{mInfo} (just the letters), followed by |
| 124 | @key{RET}---the ``Return'' or ``Enter'' key. At this point, you should |
| 125 | be ready to follow the instructions in this manual as you read them on |
| 126 | the screen. |
| 127 | @c FIXME! (pesch@cygnus.com, 14 dec 1992) |
| 128 | @c Is it worth worrying about what-if the beginner goes to somebody |
| 129 | @c else's Emacs session, which already has an Info running in the middle |
| 130 | @c of something---in which case these simple instructions won't work? |
| 131 | @end ifnotinfo |
| 132 | |
| 133 | @menu |
| 134 | * Help-Small-Screen:: Starting Info on a Small Screen. |
| 135 | * Help:: How to use Info. |
| 136 | * Help-P:: Returning to the Previous node. |
| 137 | * Help-^L:: The Space, DEL, B and ^L commands. |
| 138 | * Help-Inv:: Invisible text in Emacs Info. |
| 139 | * Help-M:: Menus. |
| 140 | * Help-Xref:: Following cross-references. |
| 141 | * Help-Int:: Some intermediate Info commands. |
| 142 | * Help-Q:: Quitting Info. |
| 143 | @end menu |
| 144 | |
| 145 | @node Help-Small-Screen |
| 146 | @section Starting Info on a Small Screen |
| 147 | |
| 148 | @ifnotinfo |
| 149 | (In Info, you only see this section if your terminal has a small |
| 150 | number of lines; most readers pass by it without seeing it.) |
| 151 | @end ifnotinfo |
| 152 | |
| 153 | @cindex small screen, moving around |
| 154 | Since your terminal has a relatively small number of lines on its |
| 155 | screen, it is necessary to give you special advice at the beginning. |
| 156 | |
| 157 | If the entire text you are looking at fits on the screen, the text |
| 158 | @samp{All} will be displayed at the bottom of the screen. In the |
| 159 | stand-alone Info reader, it is displayed at the bottom right corner of |
| 160 | the screen; in Emacs, it is displayed on the modeline. If you see the |
| 161 | text @samp{Top} instead, it means that there is more text below that |
| 162 | does not fit. To move forward through the text and see another screen |
| 163 | full, press @key{SPC}, the Space bar. To move back up, press the key |
| 164 | labeled @samp{Backspace} or @samp{DEL} (on some keyboards, this key |
| 165 | might be labeled @samp{Delete}). |
| 166 | |
| 167 | @ifinfo |
| 168 | Here are 40 lines of junk, so you can try @key{SPC} and @key{DEL} and |
| 169 | see what they do. At the end are instructions of what you should do |
| 170 | next. |
| 171 | |
| 172 | @format |
| 173 | This is line 20 |
| 174 | This is line 21 |
| 175 | This is line 22 |
| 176 | This is line 23 |
| 177 | This is line 24 |
| 178 | This is line 25 |
| 179 | This is line 26 |
| 180 | This is line 27 |
| 181 | This is line 28 |
| 182 | This is line 29 |
| 183 | This is line 30 |
| 184 | This is line 31 |
| 185 | This is line 32 |
| 186 | This is line 33 |
| 187 | This is line 34 |
| 188 | This is line 35 |
| 189 | This is line 36 |
| 190 | This is line 37 |
| 191 | This is line 38 |
| 192 | This is line 39 |
| 193 | This is line 40 |
| 194 | This is line 41 |
| 195 | This is line 42 |
| 196 | This is line 43 |
| 197 | This is line 44 |
| 198 | This is line 45 |
| 199 | This is line 46 |
| 200 | This is line 47 |
| 201 | This is line 48 |
| 202 | This is line 49 |
| 203 | This is line 50 |
| 204 | This is line 51 |
| 205 | This is line 52 |
| 206 | This is line 53 |
| 207 | This is line 54 |
| 208 | This is line 55 |
| 209 | This is line 56 |
| 210 | This is line 57 |
| 211 | This is line 58 |
| 212 | This is line 59 |
| 213 | @end format |
| 214 | |
| 215 | If you have managed to get here, go back to the beginning with |
| 216 | @kbd{DEL} (or @key{BACKSPACE}), and come back here again, then you |
| 217 | understand the about the @samp{Space} and @samp{Backspace} keys. So |
| 218 | now type an @kbd{n}---just one character; don't type the quotes and |
| 219 | don't type the Return key afterward---to get to the normal start of |
| 220 | the course. |
| 221 | @end ifinfo |
| 222 | |
| 223 | @node Help, Help-P, Help-Small-Screen, Getting Started |
| 224 | @comment node-name, next, previous, up |
| 225 | @section How to use Info |
| 226 | |
| 227 | You are talking to the program Info, for reading documentation. |
| 228 | |
| 229 | There are two ways to use Info: from within Emacs or as a |
| 230 | stand-alone reader that you can invoke from a shell using the command |
| 231 | @command{info}. |
| 232 | |
| 233 | @cindex node, in Info documents |
| 234 | Right now you are looking at one @dfn{Node} of Information. |
| 235 | A node contains text describing a specific topic at a specific |
| 236 | level of detail. This node's topic is ``how to use Info''. The mode |
| 237 | line says that this is node @samp{Help} in the file @file{info}. |
| 238 | |
| 239 | @cindex header of Info node |
| 240 | The top line of a node is its @dfn{header}. This node's header |
| 241 | (look at it now) says that the @samp{Next} node after this one is the |
| 242 | node called @samp{Help-P}. An advanced Info command lets you go to |
| 243 | any node whose name you know. In the stand-alone Info reader program, |
| 244 | the header line shows the names of this node and the Info file as |
| 245 | well. In Emacs, the header line is displayed with a special typeface, |
| 246 | and remains at the top of the window all the time even if you scroll |
| 247 | through the node. |
| 248 | |
| 249 | Besides a @samp{Next}, a node can have a @samp{Previous} link, or an |
| 250 | @samp{Up} link, or both. As you can see, this node has all of these |
| 251 | links. |
| 252 | |
| 253 | @kindex n @r{(Info mode)} |
| 254 | Now it is time to move on to the @samp{Next} node, named @samp{Help-P}. |
| 255 | |
| 256 | @format |
| 257 | >> Type @kbd{n} to move there. Type just one character; |
| 258 | do not type the quotes and do not type a @key{RET} afterward. |
| 259 | @end format |
| 260 | |
| 261 | @noindent |
| 262 | @samp{>>} in the margin means it is really time to try a command. |
| 263 | |
| 264 | @format |
| 265 | >> If you are in Emacs and have a mouse, and if you already practiced |
| 266 | typing @kbd{n} to get to the next node, click now with the left |
| 267 | mouse button on the @samp{Next} link to do the same ``the mouse way''. |
| 268 | @end format |
| 269 | |
| 270 | @node Help-P, Help-^L, Help, Getting Started |
| 271 | @comment node-name, next, previous, up |
| 272 | @section Returning to the Previous node |
| 273 | |
| 274 | @kindex p @r{(Info mode)} |
| 275 | This node is called @samp{Help-P}. The @samp{Previous} node, as you see, |
| 276 | is @samp{Help}, which is the one you just came from using the @kbd{n} |
| 277 | command. Another @kbd{n} command now would take you to the next |
| 278 | node, @samp{Help-^L}. |
| 279 | |
| 280 | @format |
| 281 | >> But do not type @kbd{n} yet. First, try the @kbd{p} command, or |
| 282 | (in Emacs) click on the @samp{Prev} link. That takes you to |
| 283 | the @samp{Previous} node. Then use @kbd{n} to return here. |
| 284 | @end format |
| 285 | |
| 286 | If you read this in Emacs, you will see an @samp{Info} item in the |
| 287 | menu bar, close to its right edge. Clicking the mouse on the |
| 288 | @samp{Info} menu-bar item opens a menu of commands which include |
| 289 | @samp{Next} and @samp{Previous} (and also some others which you didn't yet |
| 290 | learn about). |
| 291 | |
| 292 | This all probably seems insultingly simple so far, but @emph{please |
| 293 | don't} start skimming. Things will get complicated soon enough! |
| 294 | Also, please do not try a new command until you are told it is time |
| 295 | to. You could make Info skip past an important warning that was |
| 296 | coming up. |
| 297 | |
| 298 | @format |
| 299 | >> Now do an @kbd{n}, or (in Emacs) click the middle mouse button on |
| 300 | the @samp{Next} link, to get to the node @samp{Help-^L} and learn more. |
| 301 | @end format |
| 302 | |
| 303 | @node Help-^L, Help-Inv, Help-P, Getting Started |
| 304 | @comment node-name, next, previous, up |
| 305 | @section The Space, DEL, B and ^L commands |
| 306 | |
| 307 | This node's mode line tells you that you are now at node |
| 308 | @samp{Help-^L}, and the header line tells you that @kbd{p} would get |
| 309 | you back to @samp{Help-P}. The node's title is highlighted and may be |
| 310 | underlined as well; it says what the node is about. |
| 311 | |
| 312 | This is a big node and it does not all fit on your display screen. |
| 313 | You can tell that there is more that is not visible because you |
| 314 | can see the text @samp{Top} rather than @samp{All} near the bottom of |
| 315 | the screen. |
| 316 | |
| 317 | @kindex SPC @r{(Info mode)} |
| 318 | @kindex DEL @r{(Info mode)} |
| 319 | @kindex BACKSPACE @r{(Info mode)} |
| 320 | @findex Info-scroll-up |
| 321 | @findex Info-scroll-down |
| 322 | The @key{SPC}, @key{BACKSPACE} (or @key{DEL})@footnote{The key which |
| 323 | we call ``Backspace or DEL'' in this manual is labeled differently on |
| 324 | different keyboards. Look for a key which is a little ways above the |
| 325 | @key{ENTER} or @key{RET} key and which you normally use outside Emacs |
| 326 | to erase the character before the cursor, i.e.@: the character you |
| 327 | typed last. It might be labeled @samp{Backspace} or @samp{<-} or |
| 328 | @samp{DEL}, or sometimes @samp{Delete}.} and @kbd{b} commands exist to |
| 329 | allow you to ``move around'' in a node that does not all fit on the |
| 330 | screen at once. @key{SPC} moves forward, to show what was below the |
| 331 | bottom of the screen. @key{DEL} or @key{BACKSPACE} moves backward, to |
| 332 | show what was above the top of the screen (there is not anything above |
| 333 | the top until you have typed some spaces). |
| 334 | |
| 335 | @format |
| 336 | >> Now try typing a @key{SPC} (afterward, type a @key{BACKSPACE} to |
| 337 | return here). |
| 338 | @end format |
| 339 | |
| 340 | When you type the @key{SPC}, the two lines that were at the bottom of |
| 341 | the screen appear at the top, followed by more lines. @key{DEL} or |
| 342 | @key{BACKSPACE} takes the two lines from the top and moves them to the |
| 343 | bottom, @emph{usually}, but if there are not a full screen's worth of |
| 344 | lines above them they may not make it all the way to the bottom. |
| 345 | |
| 346 | If you are reading this in Emacs, note that the header line is |
| 347 | always visible, never scrolling off the display. That way, you can |
| 348 | always see the @samp{Next}, @samp{Prev}, and @samp{Up} links, and you |
| 349 | can conveniently go to one of these links at any time by |
| 350 | clicking the middle mouse button on the link. |
| 351 | |
| 352 | @cindex reading Info documents top to bottom |
| 353 | @cindex Info documents as tutorials |
| 354 | @key{SPC} and @key{DEL} not only move forward and backward through |
| 355 | the current node. They also move between nodes. @key{SPC} at the end |
| 356 | of a node moves to the next node; @key{DEL} (or @key{BACKSPACE}) at |
| 357 | the beginning of a node moves to the previous node. In effect, these |
| 358 | commands scroll through all the nodes in an Info file as a single |
| 359 | logical sequence. You can read an entire manual top to bottom by just |
| 360 | typing @key{SPC}, and move backward through the entire manual from |
| 361 | bottom to top by typing @key{DEL} (or @key{BACKSPACE}). |
| 362 | |
| 363 | In this sequence, a node's subnodes appear following their parent. |
| 364 | If a node has a menu, @key{SPC} takes you into the subnodes listed in |
| 365 | the menu, one by one. Once you reach the end of a node, and have seen |
| 366 | all of its subnodes, @key{SPC} takes you to the next node or to the |
| 367 | parent's next node. |
| 368 | |
| 369 | @kindex PAGEUP @r{(Info mode)} |
| 370 | @kindex PAGEDOWN @r{(Info mode)} |
| 371 | Many keyboards nowadays have two scroll keys labeled @samp{PageUp} |
| 372 | and @samp{PageDown} (or maybe @samp{Prior} and @samp{Next}). If your |
| 373 | keyboard has these keys, you can use them to move forward and backward |
| 374 | through the text of one node, like @key{SPC} and @key{BACKSPACE} (or |
| 375 | @key{DEL}). However, @key{PAGEUP} and @key{PAGEDOWN} keys never |
| 376 | scroll beyond the beginning or the end of the current node. |
| 377 | |
| 378 | @kindex C-l @r{(Info mode)} |
| 379 | If your screen is ever garbaged, you can tell Info to display it |
| 380 | again by typing @kbd{C-l} (@kbd{Control-L}---that is, hold down |
| 381 | @key{CTRL} and type @kbd{L} or @kbd{l}). |
| 382 | |
| 383 | @format |
| 384 | >> Type @kbd{C-l} now. |
| 385 | @end format |
| 386 | |
| 387 | @kindex b @r{(Info mode)} |
| 388 | To move back to the beginning of the node you are on, you can type |
| 389 | the @key{BACKSPACE} key (or @key{DEL}) many times. You can also type |
| 390 | @kbd{b} just once. @kbd{b} stands for ``beginning.'' |
| 391 | |
| 392 | @format |
| 393 | >> Try that now. (We have put in enough verbiage to push this past |
| 394 | the first screenful, but screens are so big nowadays that perhaps it |
| 395 | isn't enough. You may need to shrink your Emacs or Info window.) |
| 396 | Then come back, by typing @key{SPC} one or more times. |
| 397 | @end format |
| 398 | |
| 399 | @kindex ? @r{(Info mode)} |
| 400 | @findex Info-summary |
| 401 | You have just learned a considerable number of commands. If you |
| 402 | want to use one but have trouble remembering which, you should type |
| 403 | @kbd{?}, which displays a brief list of commands. When you are |
| 404 | finished looking at the list, make it go away by typing @key{SPC} |
| 405 | repeatedly. |
| 406 | |
| 407 | @format |
| 408 | >> Type a @key{?} now. Press @key{SPC} to see consecutive screenfuls of |
| 409 | the list until finished. Then type @key{SPC} several times. If |
| 410 | you are using Emacs, the help will then go away automatically. |
| 411 | @end format |
| 412 | |
| 413 | (If you are using the stand-alone Info reader, type @kbd{C-x 0} to |
| 414 | return here, that is---press and hold @key{CTRL}, type an @kbd{x}, |
| 415 | then release @key{CTRL} and @kbd{x}, and press @kbd{0}; that's a zero, |
| 416 | not the letter ``o''.) |
| 417 | |
| 418 | From now on, you will encounter large nodes without warning, and |
| 419 | will be expected to know how to use @key{SPC} and @key{BACKSPACE} to |
| 420 | move around in them without being told. Since not all terminals have |
| 421 | the same size screen, it would be impossible to warn you anyway. |
| 422 | |
| 423 | @format |
| 424 | >> Now type @kbd{n}, or click the middle mouse button on the @samp{Next} link, |
| 425 | to visit the next node. |
| 426 | @end format |
| 427 | |
| 428 | @node Help-Inv, Help-M, Help-^L, Getting Started |
| 429 | @comment node-name, next, previous, up |
| 430 | @section Invisible text in Emacs Info |
| 431 | |
| 432 | Before discussing menus, we need to make some remarks that are only |
| 433 | relevant to users reading Info using Emacs. Users of the stand-alone |
| 434 | version can skip this node by typing @kbd{]} now. |
| 435 | |
| 436 | @cindex invisible text in Emacs |
| 437 | In Emacs, certain text that appears in the stand-alone version is |
| 438 | normally hidden, technically because it has the @samp{invisibility} |
| 439 | property. Invisible text is really a part of the text. It becomes |
| 440 | visible (by default) after killing and yanking, it appears in printed |
| 441 | output, it gets saved to file just like any other text, and so on. |
| 442 | Thus it is useful to know it is there. |
| 443 | |
| 444 | @findex visible-mode |
| 445 | You can make invisible text visible by using the command @kbd{M-x |
| 446 | visible-mode}. Visible mode is a minor mode, so using the command a |
| 447 | second time will make the text invisible again. Watch the effects of |
| 448 | the command on the ``menu'' below and the top line of this node. |
| 449 | |
| 450 | If you prefer to @emph{always} see the invisible text, you can set |
| 451 | @code{Info-hide-note-references} to @code{nil}. Enabling Visible mode |
| 452 | permanently is not a real alternative, because Emacs Info also uses |
| 453 | (although less extensively) another text property that can change the |
| 454 | text being displayed, the @samp{display} property. Only the |
| 455 | invisibility property is affected by Visible mode. When, in this |
| 456 | tutorial, we refer to the @samp{Emacs} behavior, we mean the |
| 457 | @emph{default} Emacs behavior. |
| 458 | |
| 459 | Now type @kbd{]}, to learn about the @kbd{]} and @kbd{[} commands. |
| 460 | |
| 461 | @menu |
| 462 | * ]: Help-]. Node telling about ]. |
| 463 | * stuff: Help-]. Same node. |
| 464 | * Help-]:: Yet again, same node. |
| 465 | @end menu |
| 466 | |
| 467 | @node Help-], , , Help-Inv |
| 468 | @subsection The @kbd{]} and @kbd{[} commands |
| 469 | |
| 470 | If you type @kbd{n} now, you get an error message saying that this |
| 471 | node has no next node. Similarly, if you type @kbd{p}, the error |
| 472 | message tells you that there is no previous node. (The exact message |
| 473 | depends on the Info reader you use.) This is because @kbd{n} and |
| 474 | @kbd{p} carry you to the next and previous node @emph{at the same |
| 475 | level}. The present node is contained in a menu (see next) of the |
| 476 | node you came from, and hence is considered to be at a lower level. |
| 477 | It is the only node in the previous node's menu (even though it was |
| 478 | listed three times). Hence it has no next or previous node that |
| 479 | @kbd{n} or @kbd{p} could move to. |
| 480 | |
| 481 | If you systematically move through a manual by typing @kbd{n}, you run |
| 482 | the risk of skipping many nodes. You do not run this risk if you |
| 483 | systematically use @kbd{@key{SPC}}, because, when you scroll to the |
| 484 | bottom of a node and type another @kbd{@key{SPC}}, then this carries |
| 485 | you to the following node in the manual @emph{regardless of level}. |
| 486 | If you immediately want to go to that node, without having to scroll |
| 487 | to the bottom of the screen first, you can type @kbd{]}. |
| 488 | |
| 489 | Similarly, @kbd{@key{BACKSPACE}} carries you to the preceding node |
| 490 | regardless of level, after you scrolled to the beginning of the |
| 491 | present node. If you want to go to the preceding node immediately, |
| 492 | you can type @kbd{[}. |
| 493 | |
| 494 | For instance, typing this sequence will come back here in three steps: |
| 495 | @kbd{[ n [}. To do the same backward, type @kbd{] p ]}. |
| 496 | |
| 497 | Now type @kbd{]} to go to the next node and learn about menus. |
| 498 | |
| 499 | @node Help-M, Help-Xref, Help-Inv, Getting Started |
| 500 | @comment node-name, next, previous, up |
| 501 | @section Menus and the @kbd{m} command |
| 502 | |
| 503 | @cindex menus in an Info document |
| 504 | @cindex Info menus |
| 505 | With only the @kbd{n} (next), @kbd{p} (previous), @kbd{@key{SPC}}, |
| 506 | @kbd{@key{BACKSPACE}}, @kbd{]} and @kbd{[} commands for moving between |
| 507 | nodes, nodes are restricted to a linear sequence. Menus allow a |
| 508 | branching structure. A menu is a list of other nodes you can move to. |
| 509 | It is actually just part of the text of the node formatted specially |
| 510 | so that Info can interpret it. The beginning of a menu is always |
| 511 | identified by a line which starts with @w{@samp{* Menu:}}. A node |
| 512 | contains a menu if and only if it has a line in it which starts that |
| 513 | way. The only menu you can use at any moment is the one in the node |
| 514 | you are in. To use a menu in any other node, you must move to that |
| 515 | node first. |
| 516 | |
| 517 | After the start of the menu, each line that starts with a @samp{*} |
| 518 | identifies one subtopic. The line usually contains a brief name for |
| 519 | the subtopic (followed by a @samp{:}, normally hidden in Emacs), the |
| 520 | name of the node that talks about that subtopic (again, normally |
| 521 | hidden in Emacs), and optionally some further description of the |
| 522 | subtopic. Lines in the menu that do not start with a @samp{*} have no |
| 523 | special meaning---they are only for the human reader's benefit and do |
| 524 | not define additional subtopics. Here is an example: |
| 525 | |
| 526 | @example |
| 527 | * Foo: Node about FOO. This tells about FOO. |
| 528 | @end example |
| 529 | |
| 530 | The subtopic name is Foo, and the node describing it is @samp{Node |
| 531 | about FOO}. The rest of the line is just for the reader's |
| 532 | Information. [[ But this line is not a real menu item, simply because |
| 533 | there is no line above it which starts with @w{@samp{* Menu:}}. Also, |
| 534 | in a real menu item, the @samp{*} would appear at the very start of |
| 535 | the line. This is why the ``normally hidden'' text in Emacs, namely |
| 536 | @samp{: Node about FOO.}, is actually visible in this example, even |
| 537 | when Visible mode is off.]] |
| 538 | |
| 539 | When you use a menu to go to another node (in a way that will be |
| 540 | described soon), what you specify is the subtopic name, the first |
| 541 | thing in the menu line. Info uses it to find the menu line, extracts |
| 542 | the node name from it, and goes to that node. The reason that there |
| 543 | is both a subtopic name and a node name is that the node name must be |
| 544 | meaningful to the computer and may therefore have to be ugly looking. |
| 545 | The subtopic name can be chosen just to be convenient for the user to |
| 546 | specify. Often the node name is convenient for the user to specify |
| 547 | and so both it and the subtopic name are the same. There is an |
| 548 | abbreviation for this: |
| 549 | |
| 550 | @example |
| 551 | * Foo:: This tells about FOO. |
| 552 | @end example |
| 553 | |
| 554 | @noindent |
| 555 | This means that the subtopic name and node name are the same; they are |
| 556 | both @samp{Foo}. (The @samp{::} is normally hidden in Emacs.) |
| 557 | |
| 558 | @format |
| 559 | >> Now use @key{SPC} to find the menu in this node, then come back to |
| 560 | the front with a @kbd{b} and some @key{SPC}s. As you see, a menu is |
| 561 | actually visible in its node. If you cannot find a menu in a node |
| 562 | by looking at it, then the node does not have a menu and the |
| 563 | @kbd{m} command is not available. |
| 564 | @end format |
| 565 | |
| 566 | If you keep typing @key{SPC} once the menu appears on the screen, it |
| 567 | will move to another node (the first one in the menu). If that |
| 568 | happens, type @key{BACKSPACE} to come back. |
| 569 | |
| 570 | @kindex m @r{(Info mode)} |
| 571 | The command to go to one of the subnodes is @kbd{m}. This is very |
| 572 | different from the commands you have used: it is a command that |
| 573 | prompts you for more input. |
| 574 | |
| 575 | The Info commands you know do not need additional input; when you |
| 576 | type one of them, Info processes it instantly and then is ready for |
| 577 | another command. The @kbd{m} command is different: it needs to know |
| 578 | the @dfn{name of the subtopic}. Once you have typed @kbd{m}, Info |
| 579 | tries to read the subtopic name. |
| 580 | |
| 581 | Now, in the stand-alone Info, look for the line containing many |
| 582 | dashes near the bottom of the screen. (This is the stand-alone |
| 583 | equivalent for the mode line in Emacs.) There is one more line |
| 584 | beneath that one, but usually it is blank. (In Emacs, this is the |
| 585 | echo area.) When it is blank, Info is ready for a command, such as |
| 586 | @kbd{n} or @kbd{b} or @key{SPC} or @kbd{m}. If that line contains |
| 587 | text ending in a colon, it means Info is reading more input for the |
| 588 | last command. You can't type an Info command then, because Info is |
| 589 | trying to read input, not commands. You must either give the input |
| 590 | and finish the command you started, or type @kbd{Control-g} to cancel |
| 591 | the command. When you have done one of those things, the input entry |
| 592 | line becomes blank again. Then you can type Info commands again. |
| 593 | |
| 594 | @findex Info-menu |
| 595 | The command to go to a subnode via a menu is @kbd{m}. After you type |
| 596 | the @kbd{m}, the line at the bottom of the screen says @samp{Menu item: }. |
| 597 | You must then type the name of the subtopic you want, and end it with |
| 598 | a @key{RET}. |
| 599 | |
| 600 | @cindex abbreviating Info subnodes |
| 601 | You can abbreviate the subtopic name. If the abbreviation is not |
| 602 | unique, the first matching subtopic is chosen. Some menus put |
| 603 | the shortest possible abbreviation for each subtopic name in capital |
| 604 | letters, so you can see how much you need to type. It does not |
| 605 | matter whether you use upper case or lower case when you type the |
| 606 | subtopic. You should not put any spaces at the end, or inside of the |
| 607 | item name, except for one space where a space appears in the item in |
| 608 | the menu. |
| 609 | |
| 610 | @cindex completion of Info node names |
| 611 | You can also use the @dfn{completion} feature to help enter the |
| 612 | subtopic name. If you type the @key{TAB} key after entering part of a |
| 613 | name, it will fill in more of the name---as much as Info can deduce |
| 614 | from the part you have entered. |
| 615 | |
| 616 | If you move the cursor to one of the menu subtopic lines, then you do |
| 617 | not need to type the argument: you just type a @key{RET}, and it |
| 618 | stands for the subtopic of the line you are on. You can also click |
| 619 | the middle mouse button directly on the subtopic line to go there. |
| 620 | |
| 621 | Here is a menu to give you a chance to practice. This menu gives you |
| 622 | three ways of going to one place, Help-FOO: |
| 623 | |
| 624 | @menu |
| 625 | * Foo: Help-FOO. A node you can visit for fun. |
| 626 | * Bar: Help-FOO. We have made two ways to get to the same place. |
| 627 | * Help-FOO:: And yet another! |
| 628 | @end menu |
| 629 | |
| 630 | (Turn Visible mode on if you are using Emacs.) |
| 631 | |
| 632 | @format |
| 633 | >> Now type just an @kbd{m} and see what happens: |
| 634 | @end format |
| 635 | |
| 636 | Now you are ``inside'' an @kbd{m} command. Commands cannot be used |
| 637 | now; the next thing you will type must be the name of a subtopic. |
| 638 | |
| 639 | You can change your mind about doing the @kbd{m} by typing |
| 640 | @kbd{Control-g}. |
| 641 | |
| 642 | @format |
| 643 | >> Try that now; notice the bottom line clear. |
| 644 | @end format |
| 645 | |
| 646 | @format |
| 647 | >> Then type another @kbd{m}. |
| 648 | @end format |
| 649 | |
| 650 | @format |
| 651 | >> Now type @kbd{BAR}, the item name. Do not type @key{RET} yet. |
| 652 | @end format |
| 653 | |
| 654 | While you are typing the item name, you can use the @key{DEL} (or |
| 655 | @key{BACKSPACE}) key to cancel one character at a time if you make a |
| 656 | mistake. |
| 657 | |
| 658 | @format |
| 659 | >> Press @key{DEL} to cancel the @samp{R}. You could type another @kbd{R} |
| 660 | to replace it. But you do not have to, since @samp{BA} is a valid |
| 661 | abbreviation. |
| 662 | @end format |
| 663 | |
| 664 | @format |
| 665 | >> Now you are ready to go. Type a @key{RET}. |
| 666 | @end format |
| 667 | |
| 668 | After visiting @samp{Help-FOO}, you should return here. |
| 669 | |
| 670 | Another way to move to the menu subtopic lines and between them is |
| 671 | to type @key{TAB}. Each time you type a @key{TAB}, you move to the |
| 672 | next subtopic line. To move to a previous subtopic line in the |
| 673 | stand-alone reader, type @kbd{M-@key{TAB}}---that is, press and hold |
| 674 | the @key{META} key and then press @key{TAB}. (On some keyboards, the |
| 675 | @key{META} key might be labeled @samp{Alt}.) In Emacs Info, type |
| 676 | @kbd{S-@key{TAB}} to move to a previous subtopic line (press and hold |
| 677 | the @key{Shift} key and then press @key{TAB}). |
| 678 | |
| 679 | Once you move cursor to a subtopic line, press @key{RET} to go to |
| 680 | that 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 |
| 685 | to a subtopic. Move your mouse pointer to the subtopic line, |
| 686 | somewhere between the beginning @samp{*} and the colon @samp{:} which |
| 687 | ends the subtopic's brief name. You will see the subtopic's name |
| 688 | change its appearance (usually, its background color will change), and |
| 689 | the shape of the mouse pointer will change if your platform supports |
| 690 | that. After a while, if you leave the mouse on that spot, a small |
| 691 | window will pop up, saying ``Mouse-2: go to that node,'' or the same |
| 692 | message may appear at the bottom of the screen. |
| 693 | |
| 694 | @kbd{Mouse-2} is the second button of your mouse counting from the |
| 695 | left---the middle button on a 3-button mouse. (On a 2-button mouse, |
| 696 | you may have to press both buttons together to ``press the middle |
| 697 | button''.) The message tells you pressing @kbd{Mouse-2} with the |
| 698 | current position of the mouse pointer (on subtopic in the menu) will |
| 699 | go to that subtopic. |
| 700 | |
| 701 | @findex Info-mouse-follow-nearest-node |
| 702 | More generally, @kbd{Mouse-2} in an Info buffer finds the nearest |
| 703 | link to another node and goes there. For example, near a cross |
| 704 | reference it acts like @kbd{f}, in a menu it acts like @kbd{m}, on the |
| 705 | node's header line it acts like @kbd{n}, @kbd{p}, or @kbd{u}, etc. At |
| 706 | end of the node's text @kbd{Mouse-2} moves to the next node, or up if |
| 707 | there'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} |
| 717 | pointer @samp{Help-M}, the node you just came from via the @kbd{m} |
| 718 | command. This is the usual convention---the nodes you reach from a menu |
| 719 | have @samp{Up} nodes that lead back to the menu. Menus move Down in the |
| 720 | tree, and @samp{Up} moves Up. @samp{Previous}, on the other hand, is |
| 721 | usually 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''. This puts you at the menu subtopic line pointing |
| 727 | to the subnode that the @kbd{u} command brought you from. (Some Info |
| 728 | readers may put you at the @emph{front} of the node instead---to get |
| 729 | back to where you were reading, you have to type some @key{SPC}s.) |
| 730 | |
| 731 | Another way to go Up is to click @kbd{Mouse-2} on the @samp{Up} |
| 732 | pointer shown in the header line (provided that you have a mouse). |
| 733 | |
| 734 | @format |
| 735 | >> Now type @kbd{u} to move back up to @samp{Help-M}. |
| 736 | @end format |
| 737 | |
| 738 | @node Help-Xref, Help-Int, Help-M, Getting Started |
| 739 | @comment node-name, next, previous, up |
| 740 | @section Following Cross-References |
| 741 | |
| 742 | @cindex cross references in Info documents |
| 743 | In Info documentation, you will see many @dfn{cross references}. |
| 744 | Cross references look like this: @xref{Help-Cross, Cross}. That text |
| 745 | is a real, live cross reference, whose name is @samp{Cross} and which |
| 746 | points to the node named @samp{Help-Cross}. (The node name is hidden |
| 747 | in Emacs. Do @kbd{M-x visible-mode} to show or hide it.) |
| 748 | |
| 749 | @kindex f @r{(Info mode)} |
| 750 | @findex Info-follow-reference |
| 751 | You can follow a cross reference by moving the cursor to it and |
| 752 | press @key{RET}, just as in a menu. In Emacs, you can also click |
| 753 | @kbd{Mouse-1} on a cross reference to follow it; you can see that the |
| 754 | cross reference is mouse-sensitive by moving the mouse pointer to the |
| 755 | reference and watching how the underlying text and the mouse pointer |
| 756 | change in response. |
| 757 | |
| 758 | Another way to follow a cross reference is to type @kbd{f} and then |
| 759 | specify the name of the cross reference (in this case, @samp{Cross}) |
| 760 | as an argument. For this command, it does not matter where the cursor |
| 761 | was. If the cursor is on or near a cross reference, @kbd{f} suggests |
| 762 | that reference name in parentheses as the default; typing @key{RET} |
| 763 | will follow that reference. However, if you type a different |
| 764 | reference name, @kbd{f} will follow the other reference which has that |
| 765 | name. |
| 766 | |
| 767 | @format |
| 768 | >> Type @kbd{f}, followed by @kbd{Cross}, and then @key{RET}. |
| 769 | @end format |
| 770 | |
| 771 | As you enter the reference name, you can use the @key{DEL} (or |
| 772 | @key{BACKSPACE}) key to edit your input. If you change your mind |
| 773 | about following any reference, you can use @kbd{Control-g} to cancel |
| 774 | the command. Completion is available in the @kbd{f} command; you can |
| 775 | complete among all the cross reference names in the current node by |
| 776 | typing a @key{TAB}. |
| 777 | |
| 778 | To get a list of all the cross references in the current node, you |
| 779 | can type @kbd{?} after an @kbd{f}. The @kbd{f} continues to await a |
| 780 | cross reference name even after displaying the list, so if you don't |
| 781 | actually want to follow a reference, you should type a @kbd{Control-g} |
| 782 | to cancel the @kbd{f}. |
| 783 | |
| 784 | @format |
| 785 | >> Type @kbd{f?} to get a list of the cross references in this node. Then |
| 786 | type a @kbd{Control-g} and see how the @samp{f} gives up. |
| 787 | @end format |
| 788 | |
| 789 | The @key{TAB}, @kbd{M-@key{TAB}} and @kbd{S-@key{TAB}} keys, |
| 790 | which move between menu items in a menu, also move between cross |
| 791 | references outside of menus. |
| 792 | |
| 793 | Sometimes a cross reference (or a node) can lead to another file (in |
| 794 | other words another ``manual''), or, on occasion, even a file on a |
| 795 | remote machine (although Info files distributed with Emacs or the |
| 796 | stand-alone Info avoid using remote links). Such a cross reference |
| 797 | looks like this: @xref{Top,, Overview of Texinfo, texinfo, Texinfo: |
| 798 | The GNU Documentation Format}. (After following this link, type |
| 799 | @kbd{l} to get back to this node.) Here the name @samp{texinfo} |
| 800 | between parentheses refers to the file name. This file name appears |
| 801 | in cross references and node names if it differs from the current |
| 802 | file, so you can always know that you are going to be switching to |
| 803 | another manual and which one. |
| 804 | |
| 805 | However, Emacs normally hides some other text in cross-references. |
| 806 | If you put your mouse over the cross reference, then the information |
| 807 | appearing in a separate box (tool tip) or in the echo area will show |
| 808 | the full cross-reference including the file name and the node name of |
| 809 | the cross reference. If you have a mouse, just leave it over the |
| 810 | cross reference @xref{Top,, Overview of Texinfo, texinfo, Texinfo: |
| 811 | The GNU Documentation Format}, and watch what happens. If you |
| 812 | always like to have that information visible without having to move |
| 813 | your mouse over the cross reference, use @kbd{M-x visible-mode}, or |
| 814 | set @code{Info-hide-note-references} to a value other than @code{t} |
| 815 | (@pxref{Emacs Info Variables}). |
| 816 | |
| 817 | @format |
| 818 | >> Now type @kbd{n} to learn more commands. |
| 819 | @end format |
| 820 | |
| 821 | @node Help-Int, Help-Q, Help-Xref, Getting Started |
| 822 | @comment node-name, next, previous, up |
| 823 | @section Some intermediate Info commands |
| 824 | |
| 825 | The introductory course is almost over; please continue |
| 826 | a little longer to learn some intermediate-level commands. |
| 827 | |
| 828 | Most Info files have an index, which is actually a large node |
| 829 | containing little but a menu. The menu has one menu item for each |
| 830 | topic listed in the index. (As a special feature, menus for indices |
| 831 | may also include the line number within the node of the index entry. |
| 832 | This allows Info readers to go to the exact line of an entry, not just |
| 833 | the start of the containing node.) |
| 834 | |
| 835 | You can get to the index from the main menu of the file with the |
| 836 | @kbd{m} command and the name of the index node; then you can use the |
| 837 | @kbd{m} command again in the index node to go to the node that |
| 838 | describes the topic you want. |
| 839 | |
| 840 | There is also a short-cut Info command, @kbd{i}, which does all of |
| 841 | that for you. It searches the index for a given topic (a string) and |
| 842 | goes to the node which is listed in the index for that topic. |
| 843 | @xref{Search Index}, for a full explanation. |
| 844 | |
| 845 | @kindex l @r{(Info mode)} |
| 846 | @findex Info-history-back |
| 847 | @cindex going back in Info history |
| 848 | If you have been moving around to different nodes and wish to |
| 849 | retrace your steps, the @kbd{l} command (@kbd{l} for @dfn{last}) will |
| 850 | do that, one node-step at a time. As you move from node to node, Info |
| 851 | records the nodes where you have been in a special history list. The |
| 852 | @kbd{l} command revisits nodes in the history list; each successive |
| 853 | @kbd{l} command moves one step back through the history. |
| 854 | |
| 855 | @format |
| 856 | >> Try typing @kbd{p p n} and then three @kbd{l}'s, pausing in between |
| 857 | to see what each @kbd{l} does. You should wind up right back here. |
| 858 | @end format |
| 859 | |
| 860 | Note the difference between @kbd{l} and @kbd{p}: @kbd{l} moves to |
| 861 | where @emph{you} last were, whereas @kbd{p} always moves to the node |
| 862 | which the header says is the @samp{Previous} node (from this node, the |
| 863 | @samp{Prev} link leads to @samp{Help-Xref}). |
| 864 | |
| 865 | @kindex r @r{(Info mode)} |
| 866 | @findex Info-history-forward |
| 867 | @cindex going forward in Info history |
| 868 | You can use the @kbd{r} command (@code{Info-history-forward} in Emacs) |
| 869 | to revisit nodes in the history list in the forward direction, so that |
| 870 | @kbd{r} will return you to the node you came from by typing @kbd{l}. |
| 871 | |
| 872 | @kindex L @r{(Info mode)} |
| 873 | @findex Info-history |
| 874 | @cindex history list of visited nodes |
| 875 | The @kbd{L} command (@code{Info-history} in Emacs) creates a virtual |
| 876 | node that contains a list of all nodes you visited. You can select |
| 877 | a previously visited node from this menu to revisit it. |
| 878 | |
| 879 | @kindex d @r{(Info mode)} |
| 880 | @findex Info-directory |
| 881 | @cindex go to Directory node |
| 882 | The @kbd{d} command (@code{Info-directory} in Emacs) gets you |
| 883 | instantly to the Directory node. This node, which is the first one |
| 884 | you saw when you entered Info, has a menu which leads (directly or |
| 885 | indirectly, through other menus), to all the nodes that exist. The |
| 886 | Directory node lists all the manuals and other Info documents that |
| 887 | are, or could be, installed on your system. |
| 888 | |
| 889 | @format |
| 890 | >> Try doing a @kbd{d}, then do an @kbd{l} to return here (yes, |
| 891 | @emph{do} return). |
| 892 | @end format |
| 893 | |
| 894 | @kindex t @r{(Info mode)} |
| 895 | @findex Info-top-node |
| 896 | @cindex go to Top node |
| 897 | The @kbd{t} command moves to the @samp{Top} node of the manual. |
| 898 | This is useful if you want to browse the manual's main menu, or select |
| 899 | some specific top-level menu item. The Emacs command run by @kbd{t} |
| 900 | is @code{Info-top-node}. |
| 901 | |
| 902 | @format |
| 903 | >> Now type @kbd{n} to see the last node of the course. |
| 904 | @end format |
| 905 | |
| 906 | @xref{Advanced}, for more advanced Info features. |
| 907 | |
| 908 | @c If a menu appears at the end of this node, remove it. |
| 909 | @c It is an accident of the menu updating command. |
| 910 | |
| 911 | @node Help-Q, , Help-Int, Getting Started |
| 912 | @comment node-name, next, previous, up |
| 913 | @section Quitting Info |
| 914 | |
| 915 | @kindex q @r{(Info mode)} |
| 916 | @findex Info-exit |
| 917 | @cindex quitting Info mode |
| 918 | To get out of Info, back to what you were doing before, type @kbd{q} |
| 919 | for @dfn{Quit}. This runs @code{Info-exit} in Emacs. |
| 920 | |
| 921 | This is the end of the basic course on using Info. You have learned |
| 922 | how to move in an Info document, and how to follow menus and cross |
| 923 | references. This makes you ready for reading manuals top to bottom, |
| 924 | as new users should do when they learn a new package. |
| 925 | |
| 926 | Another set of Info commands is useful when you need to find |
| 927 | something quickly in a manual---that is, when you need to use a manual |
| 928 | as a reference rather than as a tutorial. We urge you to learn |
| 929 | these search commands as well. If you want to do that now, follow this |
| 930 | cross reference to @ref{Advanced}. |
| 931 | |
| 932 | Yet another set of commands are meant for experienced users; you can |
| 933 | find them by looking in the Directory node for documentation on Info. |
| 934 | Finding them will be a good exercise in using Info in the usual |
| 935 | manner. |
| 936 | |
| 937 | @format |
| 938 | >> Type @kbd{d} to go to the Info directory node; then type |
| 939 | @kbd{mInfo} and Return, to get to the node about Info and |
| 940 | see what other help is available. |
| 941 | @end format |
| 942 | |
| 943 | |
| 944 | @node Advanced |
| 945 | @chapter Advanced Info Commands |
| 946 | |
| 947 | This chapter describes various advanced Info commands. (If you |
| 948 | are using a stand-alone Info reader, there are additional commands |
| 949 | specific to it, which are documented in several chapters of @ref{Top,, |
| 950 | GNU Info, info-stnd, GNU Info}.) |
| 951 | |
| 952 | @kindex C-q @r{(Info mode)} |
| 953 | One advanced command useful with most of the others described here |
| 954 | is @kbd{C-q}, which ``quotes'' the next character so that it is |
| 955 | entered literally (@pxref{Inserting Text,,,emacs,The GNU Emacs |
| 956 | Manual}). For example, pressing @kbd{?} ordinarily brings up a list |
| 957 | of completion possibilities. If you want to (for example) search for |
| 958 | an actual @samp{?} character, the simplest way is to insert it using |
| 959 | @kbd{C-q ?}. This works the same in Emacs and stand-alone Info. |
| 960 | |
| 961 | @menu |
| 962 | * Search Text:: How to search Info documents. |
| 963 | * Search Index:: How to search the indices for specific subjects. |
| 964 | * Go to node:: How to go to a node by name. |
| 965 | * Choose menu subtopic:: How to choose a menu subtopic by its number. |
| 966 | * Create Info buffer:: How to create a new Info buffer in Emacs. |
| 967 | * Emacs Info Variables:: Variables modifying the behavior of Emacs Info. |
| 968 | @end menu |
| 969 | |
| 970 | |
| 971 | @node Search Text, Search Index, , Advanced |
| 972 | @comment node-name, next, previous, up |
| 973 | @section @kbd{s} searches Info documents |
| 974 | |
| 975 | @cindex searching Info documents |
| 976 | @cindex Info document as a reference |
| 977 | The commands which move between and inside nodes allow you to read |
| 978 | the entire manual or its large portions. But what if you need to find |
| 979 | some information in the manual as fast as you can, and you don't know |
| 980 | or don't remember in what node to look for it? This need arises when |
| 981 | you use a manual as a @dfn{reference}, or when it is impractical to |
| 982 | read the entire manual before you start using the programs it |
| 983 | describes. |
| 984 | |
| 985 | Info has powerful searching facilities that let you find things |
| 986 | quickly. You can search either the manual text or its indices. |
| 987 | |
| 988 | @kindex s @r{(Info mode)} |
| 989 | @findex Info-search |
| 990 | The @kbd{s} command allows you to search a whole Info file for a string. |
| 991 | It switches to the next node if and when that is necessary. You |
| 992 | type @kbd{s} followed by the string to search for, terminated by |
| 993 | @key{RET}. To search for the same string again, just @kbd{s} followed |
| 994 | by @key{RET} will do. The file's nodes are scanned in the order |
| 995 | they are in the file, which has no necessary relationship to the |
| 996 | order that they may be in the tree structure of menus and @samp{next} |
| 997 | pointers. But normally the two orders are not very different. In any |
| 998 | case, you can always look at the mode line to find out what node you have |
| 999 | reached, if the header is not visible (this can happen, because @kbd{s} |
| 1000 | puts your cursor at the occurrence of the string, not at the beginning |
| 1001 | of the node). |
| 1002 | |
| 1003 | @kindex C-s @r{(Info mode)} |
| 1004 | @kindex C-r @r{(Info mode)} |
| 1005 | @findex isearch |
| 1006 | Instead of using @kbd{s} in Emacs Info and in the stand-alone Info, |
| 1007 | you can use an incremental search started with @kbd{C-s} or @kbd{C-r}. |
| 1008 | It can search through multiple Info nodes. @xref{Incremental Search,,, |
| 1009 | emacs, The GNU Emacs Manual}. In Emacs, you can disable this behavior |
| 1010 | by setting the variable @code{Info-isearch-search} to @code{nil} |
| 1011 | (@pxref{Emacs Info Variables}). |
| 1012 | |
| 1013 | @node Search Index, Go to node, Search Text, Advanced |
| 1014 | @comment node-name, next, previous, up |
| 1015 | @section @kbd{i} searches the indices for specific subjects |
| 1016 | |
| 1017 | @cindex searching Info indices |
| 1018 | @kindex i @r{(Info mode)} |
| 1019 | @findex Info-index |
| 1020 | Since most topics in the manual should be indexed, you should try |
| 1021 | the index search first before the text search. The @kbd{i} command |
| 1022 | prompts you for a subject and then looks up that subject in the |
| 1023 | indices. If it finds an index entry with the subject you typed, it |
| 1024 | goes to the node to which that index entry points. You should browse |
| 1025 | through that node to see whether the issue you are looking for is |
| 1026 | described there. If it isn't, type @kbd{,} one or more times to go |
| 1027 | through additional index entries which match your subject. |
| 1028 | |
| 1029 | The @kbd{i} command and subsequent @kbd{,} commands find all index |
| 1030 | entries which include the string you typed @emph{as a substring}. |
| 1031 | For each match, Info shows in the echo area the full index entry it |
| 1032 | found. Often, the text of the full index entry already gives you |
| 1033 | enough information to decide whether it is relevant to what you are |
| 1034 | looking for, so we recommend that you read what Info shows in the echo |
| 1035 | area before looking at the node it displays. |
| 1036 | |
| 1037 | Since @kbd{i} looks for a substring, you can search for subjects even |
| 1038 | if you are not sure how they are spelled in the index. For example, |
| 1039 | suppose you want to find something that is pertinent to commands which |
| 1040 | complete partial input (e.g., when you type @key{TAB}). If you want |
| 1041 | to catch index entries that refer to ``complete,'' ``completion,'' and |
| 1042 | ``completing,'' you could type @kbd{icomplet@key{RET}}. |
| 1043 | |
| 1044 | Info documents which describe programs should index the commands, |
| 1045 | options, and key sequences that the program provides. If you are |
| 1046 | looking for a description of a command, an option, or a key, just type |
| 1047 | their names when @kbd{i} prompts you for a topic. For example, if you |
| 1048 | want to read the description of what the @kbd{C-l} key does, type |
| 1049 | @kbd{iC-l@key{RET}} literally. |
| 1050 | |
| 1051 | @findex info-apropos |
| 1052 | @findex index-apropos |
| 1053 | If you aren't sure which manual documents the topic you are looking |
| 1054 | for, try the @kbd{M-x info-apropos} command in Emacs, or the @kbd{M-x |
| 1055 | index-apropos} command in the stand-alone reader. It prompts for |
| 1056 | a string and then looks up that string in all the indices of all the |
| 1057 | Info documents installed on your system. |
| 1058 | |
| 1059 | @node Go to node, Choose menu subtopic, Search Index, Advanced |
| 1060 | @comment node-name, next, previous, up |
| 1061 | @section @kbd{g} goes to a node by name |
| 1062 | |
| 1063 | @kindex g @r{(Info mode)} |
| 1064 | @findex Info-goto-node |
| 1065 | @cindex go to a node by name |
| 1066 | If you know a node's name, you can go there by typing @kbd{g}, the |
| 1067 | name, and @key{RET}. Thus, @kbd{gTop@key{RET}} would go to the node |
| 1068 | called @samp{Top} in this file. (This is equivalent to @kbd{t}, see |
| 1069 | @ref{Help-Int}.) @kbd{gGo to node@key{RET}} would come back here. |
| 1070 | |
| 1071 | Unlike @kbd{m}, @kbd{g} does not allow the use of abbreviations. |
| 1072 | But it does allow completion, so you can type @key{TAB} to complete a |
| 1073 | partial node name. |
| 1074 | |
| 1075 | @cindex go to another Info file |
| 1076 | To go to a node in another file, you can include the file name in the |
| 1077 | node name by putting it at the front, in parentheses. Thus, |
| 1078 | @kbd{g(dir)Top@key{RET}} would go to the Info Directory node, which is |
| 1079 | the node @samp{Top} in the Info file @file{dir}. Likewise, |
| 1080 | @kbd{g(emacs)Top@key{RET}} goes to the top node of the Emacs manual. |
| 1081 | |
| 1082 | The node name @samp{*} specifies the whole file. So you can look at |
| 1083 | all of the current file by typing @kbd{g*@key{RET}} or all of any |
| 1084 | other file with @kbd{g(@var{filename})*@key{RET}}. |
| 1085 | |
| 1086 | @node Choose menu subtopic, Create Info buffer, Go to node, Advanced |
| 1087 | @comment node-name, next, previous, up |
| 1088 | @section @kbd{1}--@kbd{9} choose a menu subtopic by its number |
| 1089 | |
| 1090 | @kindex 1 @r{through} 9 @r{(Info mode)} |
| 1091 | @findex Info-nth-menu-item |
| 1092 | @cindex select @var{n}'th menu item |
| 1093 | If you begrudge each character of type-in which your system requires, |
| 1094 | you might like to use the commands @kbd{1}, @kbd{2}, @kbd{3}, @kbd{4}, |
| 1095 | @dots{}, @kbd{9}. They are short for the @kbd{m} command together |
| 1096 | with a name of a menu subtopic. @kbd{1} goes through the first item |
| 1097 | in the current node's menu; @kbd{2} goes through the second item, etc. |
| 1098 | In the stand-alone reader, @kbd{0} goes through the last menu item; |
| 1099 | this is so you need not count how many entries are there. |
| 1100 | |
| 1101 | If your display supports multiple fonts, colors or underlining, and |
| 1102 | you are using Emacs' Info mode to read Info files, the third, sixth |
| 1103 | and ninth menu items have a @samp{*} that stands out, either in color |
| 1104 | or in some other attribute, such as underline; this makes it easy to |
| 1105 | see at a glance which number to use for an item. |
| 1106 | |
| 1107 | Some terminals don't support either multiple fonts, colors or |
| 1108 | underlining. If you need to actually count items, it is better to use |
| 1109 | @kbd{m} instead, and specify the name, or use @key{TAB} to quickly |
| 1110 | move between menu items. |
| 1111 | |
| 1112 | @node Create Info buffer, Emacs Info Variables, Choose menu subtopic, Advanced |
| 1113 | @comment node-name, next, previous, up |
| 1114 | @section @kbd{M-n} creates a new independent Info buffer in Emacs |
| 1115 | |
| 1116 | @kindex M-n @r{(Info mode)} |
| 1117 | @findex clone-buffer |
| 1118 | @cindex multiple Info buffers |
| 1119 | If you are reading Info in Emacs, you can select a new independent |
| 1120 | Info buffer in a new Emacs window by typing @kbd{M-n}. The new buffer |
| 1121 | starts out as an exact copy of the old one, but you will be able to |
| 1122 | move independently between nodes in the two buffers. (In Info mode, |
| 1123 | @kbd{M-n} runs the Emacs command @code{clone-buffer}.) |
| 1124 | |
| 1125 | In Emacs Info, you can also produce new Info buffers by giving a |
| 1126 | numeric prefix argument to the @kbd{m} and @kbd{g} commands. @kbd{C-u |
| 1127 | m} and @kbd{C-u g} go to a new node in exactly the same way that |
| 1128 | @kbd{m} and @kbd{g} do, but they do so in a new Info buffer which they |
| 1129 | select in another window. |
| 1130 | |
| 1131 | Another way to produce new Info buffers in Emacs is to use a numeric |
| 1132 | prefix argument for the @kbd{C-h i} command (@code{info}) which |
| 1133 | switches to the Info buffer with that number. Thus, @kbd{C-u 2 C-h i} |
| 1134 | switches to the buffer @samp{*info*<2>}, creating it if necessary. |
| 1135 | |
| 1136 | @node Emacs Info Variables, , Create Info buffer, Advanced |
| 1137 | @comment node-name, next, previous, up |
| 1138 | @section Emacs Info-mode Variables |
| 1139 | |
| 1140 | The following variables may modify the behavior of Info-mode in Emacs; |
| 1141 | you may wish to set one or several of these variables interactively, |
| 1142 | or in your init file. @xref{Examining, Examining and Setting |
| 1143 | Variables, Examining and Setting Variables, emacs, The GNU Emacs |
| 1144 | Manual}. The stand-alone Info reader program has its own set of |
| 1145 | variables, described in @ref{Variables,, Manipulating Variables, |
| 1146 | info-stnd, GNU Info}. |
| 1147 | |
| 1148 | @vtable @code |
| 1149 | @item Info-directory-list |
| 1150 | The list of directories to search for Info files. Each element is a |
| 1151 | string (directory name) or @code{nil} (try default directory). If not |
| 1152 | initialized Info uses the environment variable @env{INFOPATH} to |
| 1153 | initialize it, or @code{Info-default-directory-list} if there is no |
| 1154 | @env{INFOPATH} variable in the environment. |
| 1155 | |
| 1156 | If you wish to customize the Info directory search list for both Emacs |
| 1157 | Info and stand-alone Info, it is best to set the @env{INFOPATH} |
| 1158 | environment variable, since that applies to both programs. |
| 1159 | |
| 1160 | @item Info-additional-directory-list |
| 1161 | A list of additional directories to search for Info documentation files. |
| 1162 | These directories are not searched for merging the @file{dir} file. |
| 1163 | |
| 1164 | @item Info-mode-hook |
| 1165 | Hooks run when @code{Info-mode} is called. By default, it contains |
| 1166 | the hook @code{turn-on-font-lock} which enables highlighting of Info |
| 1167 | files. You can change how the highlighting looks by customizing the |
| 1168 | faces @code{info-node}, @code{info-xref}, @code{info-xref-visited}, |
| 1169 | @code{info-header-xref}, @code{info-header-node}, @code{info-menu-header}, |
| 1170 | @code{info-menu-star}, and @code{info-title-@var{n}} (where @var{n} |
| 1171 | is the level of the section, a number between 1 and 4). To customize |
| 1172 | a face, type @kbd{M-x customize-face @key{RET} @var{face} @key{RET}}, |
| 1173 | where @var{face} is one of the face names listed here. |
| 1174 | |
| 1175 | @item Info-fontify-maximum-menu-size |
| 1176 | Maximum size of menu to fontify if @code{font-lock-mode} is non-@code{nil}. |
| 1177 | |
| 1178 | @item Info-fontify-visited-nodes |
| 1179 | If non-@code{nil}, menu items and cross-references pointing to visited |
| 1180 | nodes are displayed in the @code{info-xref-visited} face. |
| 1181 | |
| 1182 | @item Info-use-header-line |
| 1183 | If non-@code{nil}, Emacs puts in the Info buffer a header line showing |
| 1184 | the @samp{Next}, @samp{Prev}, and @samp{Up} links. A header line does |
| 1185 | not scroll with the rest of the buffer, making these links always |
| 1186 | visible. |
| 1187 | |
| 1188 | @item Info-hide-note-references |
| 1189 | As explained in earlier nodes, the Emacs version of Info normally |
| 1190 | hides some text in menus and cross-references. You can completely |
| 1191 | disable this feature, by setting this option to @code{nil}. Setting |
| 1192 | it to a value that is neither @code{nil} nor @code{t} produces an |
| 1193 | intermediate behavior, hiding a limited amount of text, but showing |
| 1194 | all text that could potentially be useful. |
| 1195 | |
| 1196 | @item Info-scroll-prefer-subnodes |
| 1197 | If set to a non-@code{nil} value, @key{SPC} and @key{BACKSPACE} (or |
| 1198 | @key{DEL}) keys in a menu visit subnodes of the current node before |
| 1199 | scrolling to its end or beginning, respectively. For example, if the |
| 1200 | node's menu appears on the screen, the next @key{SPC} moves to a |
| 1201 | subnode indicated by the following menu item. Setting this option to |
| 1202 | @code{nil} results in behavior similar to the stand-alone Info reader |
| 1203 | program, which visits the first subnode from the menu only when you |
| 1204 | hit the end of the current node. The default is @code{nil}. |
| 1205 | |
| 1206 | @item Info-isearch-search |
| 1207 | If non-@code{nil}, isearch in Info searches through multiple nodes. |
| 1208 | |
| 1209 | @item Info-enable-active-nodes |
| 1210 | When set to a non-@code{nil} value, allows Info to execute Lisp code |
| 1211 | associated with nodes. The Lisp code is executed when the node is |
| 1212 | selected. The Lisp code to be executed should follow the node |
| 1213 | delimiter (the @samp{DEL} character) and an @samp{execute: } tag, like |
| 1214 | this: |
| 1215 | |
| 1216 | @example |
| 1217 | ^_execute: (message "This is an active node!") |
| 1218 | @end example |
| 1219 | @end vtable |
| 1220 | |
| 1221 | |
| 1222 | @node Expert Info |
| 1223 | @chapter Info for Experts |
| 1224 | |
| 1225 | This chapter explains how to write an Info file by hand. However, |
| 1226 | in most cases, writing a Texinfo file is better, since you can use it |
| 1227 | to make a printed manual or produce other formats, such as HTML and |
| 1228 | DocBook, as well as for generating Info files. |
| 1229 | |
| 1230 | The @code{makeinfo} command converts a Texinfo file into an Info file; |
| 1231 | @code{texinfo-format-region} and @code{texinfo-format-buffer} are GNU |
| 1232 | Emacs functions that do the same. |
| 1233 | |
| 1234 | @xref{Top,, Overview of Texinfo, texinfo, Texinfo: The GNU |
| 1235 | Documentation Format}, for how to write a Texinfo file. |
| 1236 | |
| 1237 | @xref{Creating an Info File,,, texinfo, Texinfo: The GNU Documentation |
| 1238 | Format}, for how to create an Info file from a Texinfo file. |
| 1239 | |
| 1240 | @xref{Installing an Info File,,, texinfo, Texinfo: The GNU |
| 1241 | Documentation Format}, for how to install an Info file after you |
| 1242 | have created one. |
| 1243 | |
| 1244 | However, if you want to edit an Info file manually and install it manually, |
| 1245 | here is how. |
| 1246 | |
| 1247 | @menu |
| 1248 | * Add:: Describes how to add new nodes to the hierarchy. |
| 1249 | Also tells what nodes look like. |
| 1250 | * Menus:: How to add to or create menus in Info nodes. |
| 1251 | * Cross-refs:: How to add cross-references to Info nodes. |
| 1252 | * Tags:: How to make tags tables for Info files. |
| 1253 | * Checking:: Checking an Info File. |
| 1254 | @end menu |
| 1255 | |
| 1256 | @node Add, Menus, , Expert Info |
| 1257 | @comment node-name, next, previous, up |
| 1258 | @section Adding a new node to Info |
| 1259 | |
| 1260 | To add a new topic to the list in the Info directory, you must: |
| 1261 | |
| 1262 | @enumerate |
| 1263 | @item |
| 1264 | Create some nodes, in some file, to document that topic. |
| 1265 | @item |
| 1266 | Put that topic in the menu in the directory. @xref{Menus, Menu}. |
| 1267 | @end enumerate |
| 1268 | |
| 1269 | @cindex node delimiters |
| 1270 | The new node can live in an existing documentation file, or in a new |
| 1271 | one. It must have a @samp{^_} character before it (invisible to the |
| 1272 | user; this node has one but you cannot see it), and it ends with either |
| 1273 | a @samp{^_}, a @samp{^L} (``formfeed''), or the end of file.@footnote{If |
| 1274 | you put in a @samp{^L} to end a new node, be sure that there is a |
| 1275 | @samp{^_} after it to start the next one, since @samp{^L} cannot |
| 1276 | @emph{start} a node. Also, a nicer way to make a node boundary be a |
| 1277 | page boundary as well is to put a @samp{^L} @emph{right after} the |
| 1278 | @samp{^_}.} |
| 1279 | |
| 1280 | The @samp{^_} starting a node must be followed by a newline or a |
| 1281 | @samp{^L} newline, after which comes the node's header line. The |
| 1282 | header line must give the node's name (by which Info finds it), and |
| 1283 | state the names of the @samp{Next}, @samp{Previous}, and @samp{Up} |
| 1284 | nodes (if there are any). As you can see, this node's @samp{Up} node |
| 1285 | is the node @samp{Expert Info}. The @samp{Next} node is @samp{Menus}. |
| 1286 | |
| 1287 | @cindex node header line format |
| 1288 | @cindex format of node headers |
| 1289 | The keywords @dfn{Node}, @dfn{Next}, @dfn{Previous}, and @dfn{Up} |
| 1290 | may appear in any order, anywhere in the header line, but the |
| 1291 | recommended order is the one in this sentence. Each keyword must be |
| 1292 | followed by a colon, spaces and tabs, and then the appropriate name. |
| 1293 | The name may be terminated with a tab, a comma, or a newline. A space |
| 1294 | does not end it; node names may contain spaces. The case of letters |
| 1295 | in the names is insignificant. |
| 1296 | |
| 1297 | @cindex node name format |
| 1298 | @cindex Directory node |
| 1299 | A node name has two forms. A node in the current file is named by |
| 1300 | what appears after the @samp{Node: } in that node's first line. For |
| 1301 | example, this node's name is @samp{Add}. A node in another file is |
| 1302 | named by @samp{(@var{filename})@var{node-within-file}}, as in |
| 1303 | @samp{(info)Add} for this node. If the file name starts with @samp{./}, |
| 1304 | then it is relative to the current directory; otherwise, it is |
| 1305 | relative starting from the standard directory for Info files of your |
| 1306 | site. The name @samp{(@var{filename})Top} can be abbreviated to just |
| 1307 | @samp{(@var{filename})}. By convention, the name @samp{Top} is used |
| 1308 | for the ``highest'' node in any single file---the node whose @samp{Up} |
| 1309 | points out of the file. The @samp{Directory} node is @file{(dir)}, it |
| 1310 | points to a file @file{dir} which holds a large menu listing all the |
| 1311 | Info documents installed on your site. The @samp{Top} node of a |
| 1312 | document file listed in the @samp{Directory} should have an @samp{Up: |
| 1313 | (dir)} in it. |
| 1314 | |
| 1315 | @cindex unstructured documents |
| 1316 | The node name @kbd{*} is special: it refers to the entire file. |
| 1317 | Thus, @kbd{g*} shows you the whole current file. The use of the |
| 1318 | node @kbd{*} is to make it possible to make old-fashioned, |
| 1319 | unstructured files into nodes of the tree. |
| 1320 | |
| 1321 | The @samp{Node:} name, in which a node states its own name, must not |
| 1322 | contain a file name, since when Info searches for a node, it does not |
| 1323 | expect a file name to be there. The @samp{Next}, @samp{Previous} and |
| 1324 | @samp{Up} names may contain them. In this node, since the @samp{Up} |
| 1325 | node is in the same file, it was not necessary to use one. |
| 1326 | |
| 1327 | Note that the nodes in this file have a file name in the header |
| 1328 | line. The file names are ignored by Info, but they serve as comments |
| 1329 | to help identify the node for the user. |
| 1330 | |
| 1331 | @node Menus, Cross-refs, Add, Expert Info |
| 1332 | @comment node-name, next, previous, up |
| 1333 | @section How to Create Menus |
| 1334 | |
| 1335 | Any node in the Info hierarchy may have a @dfn{menu}---a list of subnodes. |
| 1336 | The @kbd{m} command searches the current node's menu for the topic which it |
| 1337 | reads from the terminal. |
| 1338 | |
| 1339 | @cindex menu and menu entry format |
| 1340 | A menu begins with a line starting with @w{@samp{* Menu:}}. The |
| 1341 | rest of the line is a comment. After the starting line, every line |
| 1342 | that begins with a @samp{* } lists a single topic. The name of the |
| 1343 | topic---what the user must type at the @kbd{m}'s command prompt to |
| 1344 | select this topic---comes right after the star and space, and is |
| 1345 | followed by a colon, spaces and tabs, and the name of the node which |
| 1346 | discusses that topic. The node name, like node names following |
| 1347 | @samp{Next}, @samp{Previous} and @samp{Up}, may be terminated with a |
| 1348 | tab, comma, or newline; it may also be terminated with a period. |
| 1349 | |
| 1350 | If the node name and topic name are the same, then rather than |
| 1351 | giving the name twice, the abbreviation @samp{* @var{name}::} may be |
| 1352 | used (and should be used, whenever possible, as it reduces the visual |
| 1353 | clutter in the menu). |
| 1354 | |
| 1355 | It is considerate to choose the topic names so that they differ |
| 1356 | from each other very near the beginning---this allows the user to type |
| 1357 | short abbreviations. In a long menu, it is a good idea to capitalize |
| 1358 | the beginning of each item name which is the minimum acceptable |
| 1359 | abbreviation for it (a long menu is more than 5 or so entries). |
| 1360 | |
| 1361 | The nodes listed in a node's menu are called its ``subnodes,'' and it |
| 1362 | is their ``superior''. They should each have an @samp{Up:} pointing at |
| 1363 | the superior. It is often useful to arrange all or most of the subnodes |
| 1364 | in a sequence of @samp{Next} and @samp{Previous} pointers so that |
| 1365 | someone who wants to see them all need not keep revisiting the Menu. |
| 1366 | |
| 1367 | The Info Directory is simply the menu of the node @samp{(dir)Top}---that |
| 1368 | is, node @samp{Top} in file @file{.../info/dir}. You can put new entries |
| 1369 | in that menu just like any other menu. The Info Directory is @emph{not} the |
| 1370 | same as the file directory called @file{info}. It happens that many of |
| 1371 | Info's files live in that file directory, but they do not have to; and |
| 1372 | files in that directory are not automatically listed in the Info |
| 1373 | Directory node. |
| 1374 | |
| 1375 | Also, although the Info node graph is claimed to be a ``hierarchy,'' |
| 1376 | in fact it can be @emph{any} directed graph. Shared structures and |
| 1377 | pointer cycles are perfectly possible, and can be used if they are |
| 1378 | appropriate to the meaning to be expressed. There is no need for all |
| 1379 | the nodes in a file to form a connected structure. In fact, this file |
| 1380 | has two connected components. You are in one of them, which is under |
| 1381 | the node @samp{Top}; the other contains the node @samp{Help} which the |
| 1382 | @kbd{h} command goes to. In fact, since there is no garbage |
| 1383 | collector on the node graph, nothing terrible happens if a substructure |
| 1384 | is not pointed to, but such a substructure is rather useless since nobody |
| 1385 | can ever find out that it exists. |
| 1386 | |
| 1387 | @node Cross-refs, Tags, Menus, Expert Info |
| 1388 | @comment node-name, next, previous, up |
| 1389 | @section Creating Cross References |
| 1390 | |
| 1391 | @cindex cross reference format |
| 1392 | A cross reference can be placed anywhere in the text, unlike a menu |
| 1393 | item which must go at the front of a line. A cross reference looks |
| 1394 | like a menu item except that it has @samp{*note} instead of @samp{*}. |
| 1395 | It @emph{cannot} be terminated by a @samp{)}, because @samp{)}'s are |
| 1396 | so often part of node names. If you wish to enclose a cross reference |
| 1397 | in parentheses, terminate it with a period first. Here are two |
| 1398 | examples of cross references pointers: |
| 1399 | |
| 1400 | @example |
| 1401 | *Note details: commands. (See *note 3: Full Proof.) |
| 1402 | @end example |
| 1403 | |
| 1404 | @noindent |
| 1405 | @emph{These are just examples.} The places they ``lead to'' do not |
| 1406 | really exist! |
| 1407 | |
| 1408 | @menu |
| 1409 | * Help-Cross:: Target of a cross-reference. |
| 1410 | @end menu |
| 1411 | |
| 1412 | |
| 1413 | @node Help-Cross, , , Cross-refs |
| 1414 | @subsection The node reached by the cross reference in Info |
| 1415 | |
| 1416 | This is the node reached by the cross reference named @samp{Cross}. |
| 1417 | |
| 1418 | While this node is specifically intended to be reached by a cross |
| 1419 | reference, most cross references lead to nodes that ``belong'' |
| 1420 | someplace else far away in the structure of an Info document. So you |
| 1421 | cannot expect this node to have a @samp{Next}, @samp{Previous} or |
| 1422 | @samp{Up} links pointing back to where you came from. In general, the |
| 1423 | @kbd{l} (el) command is the only way to get back there. |
| 1424 | |
| 1425 | @format |
| 1426 | >> Type @kbd{l} to return to the node where the cross reference was. |
| 1427 | @end format |
| 1428 | |
| 1429 | @node Tags, Checking, Cross-refs, Expert Info |
| 1430 | @comment node-name, next, previous, up |
| 1431 | @section Tags Tables for Info Files |
| 1432 | |
| 1433 | @cindex tags tables in Info files |
| 1434 | You can speed up the access to nodes of a large Info file by giving |
| 1435 | it a tags table. Unlike the tags table for a program, the tags table for |
| 1436 | an Info file lives inside the file itself and is used |
| 1437 | automatically whenever Info reads in the file. |
| 1438 | |
| 1439 | @findex Info-tagify |
| 1440 | To make a tags table, go to a node in the file using Emacs Info mode and type |
| 1441 | @kbd{M-x Info-tagify}. Then you must use @kbd{C-x C-s} to save the |
| 1442 | file. Info files produced by the @code{makeinfo} command that is part |
| 1443 | of the Texinfo package always have tags tables to begin with. |
| 1444 | |
| 1445 | @cindex stale tags tables |
| 1446 | @cindex update Info tags table |
| 1447 | Once the Info file has a tags table, you must make certain it is up |
| 1448 | to date. If you edit an Info file directly (as opposed to editing its |
| 1449 | Texinfo source), and, as a result of deletion of text, any node moves back |
| 1450 | more than a thousand characters in the file from the position |
| 1451 | recorded in the tags table, Info will no longer be able to find that |
| 1452 | node. To update the tags table, use the @code{Info-tagify} command |
| 1453 | again. |
| 1454 | |
| 1455 | An Info file tags table appears at the end of the file and looks like |
| 1456 | this: |
| 1457 | |
| 1458 | @example |
| 1459 | ^_^L |
| 1460 | Tag Table: |
| 1461 | File: info, Node: Cross-refs^?21419 |
| 1462 | File: info, Node: Tags^?22145 |
| 1463 | ^_ |
| 1464 | End Tag Table |
| 1465 | @end example |
| 1466 | |
| 1467 | @noindent |
| 1468 | Note that it contains one line per node, and this line contains |
| 1469 | the beginning of the node's header (ending just after the node name), |
| 1470 | a @samp{DEL} character, and the character position in the file of the |
| 1471 | beginning of the node. |
| 1472 | |
| 1473 | @node Checking, , Tags, Expert Info |
| 1474 | @section Checking an Info File |
| 1475 | |
| 1476 | When creating an Info file, it is easy to forget the name of a node when |
| 1477 | you are making a pointer to it from another node. If you put in the |
| 1478 | wrong name for a node, this is not detected until someone tries to go |
| 1479 | through the pointer using Info. Verification of the Info file is an |
| 1480 | automatic process which checks all pointers to nodes and reports any |
| 1481 | pointers which are invalid. Every @samp{Next}, @samp{Previous}, and |
| 1482 | @samp{Up} is checked, as is every menu item and every cross reference. In |
| 1483 | addition, any @samp{Next} which does not have a @samp{Previous} pointing |
| 1484 | back is reported. Only pointers within the file are checked, because |
| 1485 | checking pointers to other files would be terribly slow. But those are |
| 1486 | usually few. |
| 1487 | |
| 1488 | @findex Info-validate |
| 1489 | To check an Info file, do @kbd{M-x Info-validate} while looking at any |
| 1490 | node of the file with Emacs Info mode. |
| 1491 | |
| 1492 | @node Index |
| 1493 | @unnumbered Index |
| 1494 | |
| 1495 | This is an alphabetical listing of all the commands, variables, and |
| 1496 | topics discussed in this document. |
| 1497 | |
| 1498 | @printindex cp |
| 1499 | |
| 1500 | @bye |
| 1501 | |
| 1502 | @ignore |
| 1503 | arch-tag: 965c1638-01d6-4156-9227-b10418b9d8e8 |
| 1504 | @end ignore |