summaryrefslogtreecommitdiff
path: root/Master/texmf/doc/info/info.info
blob: cd23db5383a37d04f7db44026d70b7c98c61ff0a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
This is info.info, produced by makeinfo version 4.12 from info.texi.

This file describes how to use Info, the on-line, menu-driven GNU
documentation system.

   Copyright (C) 1989, 1992, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.2 or any later version published by the Free Software
     Foundation; with no Invariant Sections, with the Front-Cover texts
     being "A GNU Manual," and with the Back-Cover Texts as in (a)
     below.  A copy of the license is included in the section entitled
     "GNU Free Documentation License" in the Emacs manual.

     (a) The FSF's Back-Cover Text is: "You have freedom to copy and
     modify this GNU Manual, like GNU software.  Buying copies from GNU
     Press supports the FSF in developing GNU and promoting software
     freedom."

     This document is part of a collection distributed under the GNU
     Free Documentation License.  If you want to distribute this
     document separately from the collection, you can do so by adding a
     copy of the license to the document, as described in section 6 of
     the license.

INFO-DIR-SECTION Texinfo documentation system
START-INFO-DIR-ENTRY
* Info: (info).         How to use the documentation browsing system.
END-INFO-DIR-ENTRY


File: info.info,  Node: Top,  Next: Getting Started,  Up: (dir)

Info: An Introduction
*********************

The GNU Project distributes most of its on-line manuals in the "Info
format", which you read using an "Info reader".  You are probably using
an Info reader to read this now.

   There are two primary Info readers: `info', a stand-alone program
designed just to read Info files, and the `info' package in GNU Emacs,
a general-purpose editor.  At present, only the Emacs reader supports
using a mouse.

   If you are new to the Info reader and want to learn how to use it,
type the command `h' now.  It brings you to a programmed instruction
sequence.

   To read about advanced Info commands, type `n' twice.  This brings
you to `Advanced Info Commands', skipping over the `Getting Started'
chapter.

* Menu:

* Getting Started::             Getting started using an Info reader.
* Advanced::                    Advanced Info commands.
* Expert Info::                 Info commands for experts.
* Index::                       An index of topics, commands, and variables.


File: info.info,  Node: Getting Started,  Next: Advanced,  Prev: Top,  Up: Top

1 Getting Started
*****************

This first part of this Info manual describes how to get around inside
of Info.  The second part of the manual describes various advanced Info
commands.  The third part briefly explains how to generate Info files
from Texinfo files, and describes how to write an Info file by hand.

* Menu:

* Help-Small-Screen::   Starting Info on a Small Screen.
* Help::                How to use Info.
* Help-P::              Returning to the Previous node.
* Help-^L::             The Space, DEL, B and ^L commands.
* Help-Inv::            Invisible text in Emacs Info.
* Help-M::              Menus.
* Help-Xref::           Following cross-references.
* Help-Int::            Some intermediate Info commands.
* Help-Q::              Quitting Info.


File: info.info,  Node: Help-Small-Screen,  Next: Help,  Up: Getting Started

1.1 Starting Info on a Small Screen
===================================

Since your terminal has a relatively small number of lines on its
screen, it is necessary to give you special advice at the beginning.

   If the entire text you are looking at fits on the screen, the text
`All' will be displayed at the bottom of the screen.  In the
stand-alone Info reader, it is displayed at the bottom right corner of
the screen; in Emacs, it is displayed on the modeline.  If you see the
text `Top' instead, it means that there is more text below that does
not fit.  To move forward through the text and see another screen full,
press <SPC>, the Space bar.  To move back up, press the key labeled
`Backspace' or `DEL' (on some keyboards, this key might be labeled
`Delete').

   Here are 40 lines of junk, so you can try <SPC> and <DEL> and see
what they do.  At the end are instructions of what you should do next.

This is line 20
This is line 21
This is line 22
This is line 23
This is line 24
This is line 25
This is line 26
This is line 27
This is line 28
This is line 29
This is line 30
This is line 31
This is line 32
This is line 33
This is line 34
This is line 35
This is line 36
This is line 37
This is line 38
This is line 39
This is line 40
This is line 41
This is line 42
This is line 43
This is line 44
This is line 45
This is line 46
This is line 47
This is line 48
This is line 49
This is line 50
This is line 51
This is line 52
This is line 53
This is line 54
This is line 55
This is line 56
This is line 57
This is line 58
This is line 59

   If you have managed to get here, go back to the beginning with `DEL'
(or <BACKSPACE>), and come back here again, then you understand the
about the `Space' and `Backspace' keys.  So now type an `n'--just one
character; don't type the quotes and don't type the Return key
afterward--to get to the normal start of the course.


File: info.info,  Node: Help,  Next: Help-P,  Prev: Help-Small-Screen,  Up: Getting Started

1.2 How to use Info
===================

You are talking to the program Info, for reading documentation.

   There are two ways to use Info: from within Emacs or as a
stand-alone reader that you can invoke from a shell using the command
`info'.

   Right now you are looking at one "Node" of Information.  A node
contains text describing a specific topic at a specific level of
detail.  This node's topic is "how to use Info".  The mode line says
that this is node `Help' in the file `info'.

   The top line of a node is its "header".  This node's header (look at
it now) says that the `Next' node after this one is the node called
`Help-P'.  An advanced Info command lets you go to any node whose name
you know.  In the stand-alone Info reader program, the header line
shows the names of this node and the Info file as well.  In Emacs, the
header line is displayed with a special typeface, and remains at the
top of the window all the time even if you scroll through the node.

   Besides a `Next', a node can have a `Previous' link, or an `Up'
link, or both.  As you can see, this node has all of these links.

   Now it is time to move on to the `Next' node, named `Help-P'.

>> Type `n' to move there.  Type just one character;
   do not type the quotes and do not type a <RET> afterward.

`>>' in the margin means it is really time to try a command.

>> If you are in Emacs and have a mouse, and if you already practiced
   typing `n' to get to the next node, click now with the left
   mouse button on the `Next' link to do the same "the mouse way".


File: info.info,  Node: Help-P,  Next: Help-^L,  Prev: Help,  Up: Getting Started

1.3 Returning to the Previous node
==================================

This node is called `Help-P'.  The `Previous' node, as you see, is
`Help', which is the one you just came from using the `n' command.
Another `n' command now would take you to the next node, `Help-^L'.

>> But do not type `n' yet.  First, try the `p' command, or
   (in Emacs) click on the `Prev' link.  That takes you to
   the `Previous' node.  Then use `n' to return here.

   If you read this in Emacs, you will see an `Info' item in the menu
bar, close to its right edge.  Clicking the mouse on the `Info'
menu-bar item opens a menu of commands which include `Next' and
`Previous' (and also some others which you didn't yet learn about).

   This all probably seems insultingly simple so far, but _please
don't_ start skimming.  Things will get complicated soon enough!  Also,
please do not try a new command until you are told it is time to.  You
could make Info skip past an important warning that was coming up.

>> Now do an `n', or (in Emacs) click the middle mouse button on
   the `Next' link, to get to the node `Help-^L' and learn more.


File: info.info,  Node: Help-^L,  Next: Help-Inv,  Prev: Help-P,  Up: Getting Started

1.4 The Space, DEL, B and ^L commands
=====================================

This node's mode line tells you that you are now at node `Help-^L', and
the header line tells you that `p' would get you back to `Help-P'.  The
node's title is highlighted and may be underlined as well; it says what
the node is about.

   This is a big node and it does not all fit on your display screen.
You can tell that there is more that is not visible because you can see
the text `Top' rather than `All' near the bottom of the screen.

   The <SPC>, <BACKSPACE> (or <DEL>)(1) and `b' commands exist to allow
you to "move around" in a node that does not all fit on the screen at
once.  <SPC> moves forward, to show what was below the bottom of the
screen.  <DEL> or <BACKSPACE> moves backward, to show what was above
the top of the screen (there is not anything above the top until you
have typed some spaces).

>> Now try typing a <SPC> (afterward, type a <BACKSPACE> to
   return here).

   When you type the <SPC>, the two lines that were at the bottom of
the screen appear at the top, followed by more lines.  <DEL> or
<BACKSPACE> takes the two lines from the top and moves them to the
bottom, _usually_, but if there are not a full screen's worth of lines
above them they may not make it all the way to the bottom.

   If you are reading this in Emacs, note that the header line is
always visible, never scrolling off the display.  That way, you can
always see the `Next', `Prev', and `Up' links, and you can conveniently
go to one of these links at any time by clicking the middle mouse
button on the link.

   <SPC> and <DEL> not only move forward and backward through the
current node.  They also move between nodes.  <SPC> at the end of a
node moves to the next node; <DEL> (or <BACKSPACE>) at the beginning of
a node moves to the previous node.  In effect, these commands scroll
through all the nodes in an Info file as a single logical sequence.
You can read an entire manual top to bottom by just typing <SPC>, and
move backward through the entire manual from bottom to top by typing
<DEL> (or <BACKSPACE>).

   In this sequence, a node's subnodes appear following their parent.
If a node has a menu, <SPC> takes you into the subnodes listed in the
menu, one by one.  Once you reach the end of a node, and have seen all
of its subnodes, <SPC> takes you to the next node or to the parent's
next node.

   Many keyboards nowadays have two scroll keys labeled `PageUp' and
`PageDown' (or maybe `Prior' and `Next').  If your keyboard has these
keys, you can use them to move forward and backward through the text of
one node, like <SPC> and <BACKSPACE> (or <DEL>).  However, <PAGEUP> and
<PAGEDOWN> keys never scroll beyond the beginning or the end of the
current node.

   If your screen is ever garbaged, you can tell Info to display it
again by typing `C-l' (`Control-L'--that is, hold down <CTRL> and type
`L' or `l').

>> Type `C-l' now.

   To move back to the beginning of the node you are on, you can type
the <BACKSPACE> key (or <DEL>) many times.  You can also type `b' just
once.  `b' stands for "beginning."

>> Try that now.  (We have put in enough verbiage to push this past
   the first screenful, but screens are so big nowadays that perhaps it
   isn't enough.  You may need to shrink your Emacs or Info window.)
   Then come back, by typing <SPC> one or more times.

   You have just learned a considerable number of commands.  If you
want to use one but have trouble remembering which, you should type
`?', which displays a brief list of commands.  When you are finished
looking at the list, make it go away by typing <SPC> repeatedly.

>> Type a <?> now.  Press <SPC> to see consecutive screenfuls of
   the list until finished.  Then type <SPC> several times.  If
   you are using Emacs, the help will then go away automatically.

   (If you are using the stand-alone Info reader, type `C-x 0' to
return here, that is--press and hold <CTRL>, type an `x', then release
<CTRL> and `x', and press `0'; that's a zero, not the letter "o".)

   From now on, you will encounter large nodes without warning, and
will be expected to know how to use <SPC> and <BACKSPACE> to move
around in them without being told.  Since not all terminals have the
same size screen, it would be impossible to warn you anyway.

>> Now type `n', or click the middle mouse button on the `Next' link,
   to visit the next node.

   ---------- Footnotes ----------

   (1) The key which we call "Backspace or DEL" in this manual is
labeled differently on different keyboards.  Look for a key which is a
little ways above the <ENTER> or <RET> key and which you normally use
outside Emacs to erase the character before the cursor, i.e. the
character you typed last.  It might be labeled `Backspace' or `<-' or
`DEL', or sometimes `Delete'.


File: info.info,  Node: Help-Inv,  Next: Help-M,  Prev: Help-^L,  Up: Getting Started

1.5 Invisible text in Emacs Info
================================

Before discussing menus, we need to make some remarks that are only
relevant to users reading Info using Emacs.  Users of the stand-alone
version can skip this node by typing `]' now.

   In Emacs, certain text that appears in the stand-alone version is
normally hidden, technically because it has the `invisibility'
property.  Invisible text is really a part of the text.  It becomes
visible (by default) after killing and yanking, it appears in printed
output, it gets saved to file just like any other text, and so on.
Thus it is useful to know it is there.

   You can make invisible text visible by using the command `M-x
visible-mode'.  Visible mode is a minor mode, so using the command a
second time will make the text invisible again.  Watch the effects of
the command on the "menu" below and the top line of this node.

   If you prefer to _always_ see the invisible text, you can set
`Info-hide-note-references' to `nil'.  Enabling Visible mode
permanently is not a real alternative, because Emacs Info also uses
(although less extensively) another text property that can change the
text being displayed, the `display' property.  Only the invisibility
property is affected by Visible mode.  When, in this tutorial, we refer
to the `Emacs' behavior, we mean the _default_ Emacs behavior.

   Now type `]', to learn about the `]' and `[' commands.

* Menu:

* ]:         Help-].               Node telling about ].
* stuff:     Help-].               Same node.
* Help-]::                         Yet again, same node.


File: info.info,  Node: Help-],  Up: Help-Inv

1.5.1 The `]' and `[' commands
------------------------------

If you type `n' now, you get an error message saying that this node has
no next node.  Similarly, if you type `p', the error message tells you
that there is no previous node.  (The exact message depends on the Info
reader you use.)  This is because `n' and `p' carry you to the next and
previous node _at the same level_.  The present node is contained in a
menu (see next) of the node you came from, and hence is considered to
be at a lower level.  It is the only node in the previous node's menu
(even though it was listed three times). Hence it has no next or
previous node that `n' or `p' could move to.

   If you systematically move through a manual by typing `n', you run
the risk of skipping many nodes.  You do not run this risk if you
systematically use `<SPC>', because, when you scroll to the bottom of a
node and type another `<SPC>', then this carries you to the following
node in the manual _regardless of level_.  If you immediately want to
go to that node, without having to scroll to the bottom of the screen
first, you can type `]'.

   Similarly, `<BACKSPACE>' carries you to the preceding node
regardless of level, after you scrolled to the beginning of the present
node.  If you want to go to the preceding node immediately, you can
type `['.

   For instance, typing this sequence will come back here in three
steps: `[ n ['.  To do the same backward, type `] p ]'.

   Now type `]' to go to the next node and learn about menus.


File: info.info,  Node: Help-M,  Next: Help-Xref,  Prev: Help-Inv,  Up: Getting Started

1.6 Menus and the `m' command
=============================

With only the `n' (next), `p' (previous), `<SPC>', `<BACKSPACE>', `]'
and `[' commands for moving between nodes, nodes are restricted to a
linear sequence.  Menus allow a branching structure.  A menu is a list
of other nodes you can move to.  It is actually just part of the text
of the node formatted specially so that Info can interpret it.  The
beginning of a menu is always identified by a line which starts with
`* Menu:'.  A node contains a menu if and only if it has a line in it
which starts that way.  The only menu you can use at any moment is the
one in the node you are in.  To use a menu in any other node, you must
move to that node first.

   After the start of the menu, each line that starts with a `*'
identifies one subtopic.  The line usually contains a brief name for
the subtopic (followed by a `:', normally hidden in Emacs), the name of
the node that talks about that subtopic (again, normally hidden in
Emacs), and optionally some further description of the subtopic.  Lines
in the menu that do not start with a `*' have no special meaning--they
are only for the human reader's benefit and do not define additional
subtopics.  Here is an example:

     * Foo:  Node about FOO.      This tells about FOO.

   The subtopic name is Foo, and the node describing it is `Node about
FOO'.  The rest of the line is just for the reader's Information.  [[
But this line is not a real menu item, simply because there is no line
above it which starts with `* Menu:'.  Also, in a real menu item, the
`*' would appear at the very start of the line.  This is why the
"normally hidden" text in Emacs, namely `: Node about FOO.', is
actually visible in this example, even when Visible mode is off.]]

   When you use a menu to go to another node (in a way that will be
described soon), what you specify is the subtopic name, the first thing
in the menu line.  Info uses it to find the menu line, extracts the
node name from it, and goes to that node.  The reason that there is
both a subtopic name and a node name is that the node name must be
meaningful to the computer and may therefore have to be ugly looking.
The subtopic name can be chosen just to be convenient for the user to
specify.  Often the node name is convenient for the user to specify and
so both it and the subtopic name are the same.  There is an
abbreviation for this:

     * Foo::   This tells about FOO.

This means that the subtopic name and node name are the same; they are
both `Foo'.  (The `::' is normally hidden in Emacs.)

>> Now use <SPC> to find the menu in this node, then come back to
   the front with a `b' and some <SPC>s.  As you see, a menu is
   actually visible in its node.  If you cannot find a menu in a node
   by looking at it, then the node does not have a menu and the
   `m' command is not available.

   If you keep typing <SPC> once the menu appears on the screen, it
will move to another node (the first one in the menu).  If that
happens, type <BACKSPACE> to come back.

   The command to go to one of the subnodes is `m'.  This is very
different from the commands you have used: it is a command that prompts
you for more input.

   The Info commands you know do not need additional input; when you
type one of them, Info processes it instantly and then is ready for
another command.  The `m' command is different: it needs to know the
"name of the subtopic".  Once you have typed `m', Info tries to read
the subtopic name.

   Now, in the stand-alone Info, look for the line containing many
dashes near the bottom of the screen.  (This is the stand-alone
equivalent for the mode line in Emacs.)  There is one more line beneath
that one, but usually it is blank.  (In Emacs, this is the echo area.)
When it is blank, Info is ready for a command, such as `n' or `b' or
<SPC> or `m'.  If that line contains text ending in a colon, it means
Info is reading more input for the last command.  You can't type an
Info command then, because Info is trying to read input, not commands.
You must either give the input and finish the command you started, or
type `Control-g' to cancel the command.  When you have done one of
those things, the input entry line becomes blank again.  Then you can
type Info commands again.

   The command to go to a subnode via a menu is `m'.  After you type
the `m', the line at the bottom of the screen says `Menu item: '.  You
must then type the name of the subtopic you want, and end it with a
<RET>.

   You can abbreviate the subtopic name.  If the abbreviation is not
unique, the first matching subtopic is chosen.  Some menus put the
shortest possible abbreviation for each subtopic name in capital
letters, so you can see how much you need to type.  It does not matter
whether you use upper case or lower case when you type the subtopic.
You should not put any spaces at the end, or inside of the item name,
except for one space where a space appears in the item in the menu.

   You can also use the "completion" feature to help enter the subtopic
name.  If you type the <TAB> key after entering part of a name, it will
fill in more of the name--as much as Info can deduce from the part you
have entered.

   If you move the cursor to one of the menu subtopic lines, then you do
not need to type the argument: you just type a <RET>, and it stands for
the subtopic of the line you are on.  You can also click the middle
mouse button directly on the subtopic line to go there.

   Here is a menu to give you a chance to practice.  This menu gives you
three ways of going to one place, Help-FOO:

* Menu:

* Foo:  Help-FOO.       A node you can visit for fun.
* Bar:  Help-FOO.       We have made two ways to get to the same place.
* Help-FOO::            And yet another!

   (Turn Visible mode on if you are using Emacs.)

>>  Now type just an `m' and see what happens:

   Now you are "inside" an `m' command.  Commands cannot be used now;
the next thing you will type must be the name of a subtopic.

   You can change your mind about doing the `m' by typing `Control-g'.

>> Try that now;  notice the bottom line clear.

>> Then type another `m'.

>> Now type `BAR', the item name.  Do not type <RET> yet.

   While you are typing the item name, you can use the <DEL> (or
<BACKSPACE>) key to cancel one character at a time if you make a
mistake.

>> Press <DEL> to cancel the `R'.  You could type another `R'
   to replace it.  But you do not have to, since `BA' is a valid
   abbreviation.

>> Now you are ready to go.  Type a <RET>.

   After visiting `Help-FOO', you should return here.

   Another way to move to the menu subtopic lines and between them is
to type <TAB>.  Each time you type a <TAB>, you move to the next
subtopic line.  To move to a previous subtopic line in the stand-alone
reader, type `M-<TAB>'--that is, press and hold the <META> key and then
press <TAB>.  (On some keyboards, the <META> key might be labeled
`Alt'.)  In Emacs Info, type `S-<TAB>' to move to a previous subtopic
line (press and hold the <Shift> key and then press <TAB>).

   Once you move cursor to a subtopic line, press <RET> to go to that
subtopic's node.

   If your terminal supports a mouse, you have yet another way of going
to a subtopic.  Move your mouse pointer to the subtopic line, somewhere
between the beginning `*' and the colon `:' which ends the subtopic's
brief name.  You will see the subtopic's name change its appearance
(usually, its background color will change), and the shape of the mouse
pointer will change if your platform supports that.  After a while, if
you leave the mouse on that spot, a small window will pop up, saying
"Mouse-2: go to that node," or the same message may appear at the
bottom of the screen.

   `Mouse-2' is the second button of your mouse counting from the
left--the middle button on a 3-button mouse.  (On a 2-button mouse, you
may have to press both buttons together to "press the middle button".)
The message tells you pressing `Mouse-2' with the current position of
the mouse pointer (on subtopic in the menu) will go to that subtopic.

   More generally, `Mouse-2' in an Info buffer finds the nearest link
to another node and goes there.  For example, near a cross reference it
acts like `f', in a menu it acts like `m', on the node's header line it
acts like `n', `p', or `u', etc.  At end of the node's text `Mouse-2'
moves to the next node, or up if there's no next node.

>> Type `n' to see more commands.


File: info.info,  Node: Help-FOO,  Up: Help-M

1.6.1 The `u' command
---------------------

Congratulations!  This is the node `Help-FOO'.  It has an `Up' pointer
`Help-M', the node you just came from via the `m' command.  This is the
usual convention--the nodes you reach from a menu have `Up' nodes that
lead back to the menu.  Menus move Down in the tree, and `Up' moves Up.
`Previous', on the other hand, is usually used to "stay on the same
level but go backwards".

   You can go back to the node `Help-M' by typing the command `u' for
"Up".  This puts you at the menu subtopic line pointing to the subnode
that the `u' command brought you from.  (Some Info readers may put you
at the _front_ of the node instead--to get back to where you were
reading, you have to type some <SPC>s.)

   Another way to go Up is to click `Mouse-2' on the `Up' pointer shown
in the header line (provided that you have a mouse).

>> Now type `u' to move back up to `Help-M'.


File: info.info,  Node: Help-Xref,  Next: Help-Int,  Prev: Help-M,  Up: Getting Started

1.7 Following Cross-References
==============================

In Info documentation, you will see many "cross references".  Cross
references look like this: *Note Cross: Help-Cross.  That text is a
real, live cross reference, whose name is `Cross' and which points to
the node named `Help-Cross'.  (The node name is hidden in Emacs.  Do
`M-x visible-mode' to show or hide it.)

   You can follow a cross reference by moving the cursor to it and
press <RET>, just as in a menu.  In Emacs, you can also click `Mouse-1'
on a cross reference to follow it; you can see that the cross reference
is mouse-sensitive by moving the mouse pointer to the reference and
watching how the underlying text and the mouse pointer change in
response.

   Another way to follow a cross reference is to type `f' and then
specify the name of the cross reference (in this case, `Cross') as an
argument.  For this command, it does not matter where the cursor was.
If the cursor is on or near a cross reference, `f' suggests that
reference name in parentheses as the default; typing <RET> will follow
that reference.  However, if you type a different reference name, `f'
will follow the other reference which has that name.

>> Type `f', followed by `Cross', and then <RET>.

   As you enter the reference name, you can use the <DEL> (or
<BACKSPACE>) key to edit your input.  If you change your mind about
following any reference, you can use `Control-g' to cancel the command.
Completion is available in the `f' command; you can complete among all
the cross reference names in the current node by typing a <TAB>.

   To get a list of all the cross references in the current node, you
can type `?' after an `f'.  The `f' continues to await a cross
reference name even after displaying the list, so if you don't actually
want to follow a reference, you should type a `Control-g' to cancel the
`f'.

>> Type `f?' to get a list of the cross references in this node.  Then
   type a `Control-g' and see how the `f' gives up.

   The <TAB>, `M-<TAB>' and `S-<TAB>' keys, which move between menu
items in a menu, also move between cross references outside of menus.

   Sometimes a cross reference (or a node) can lead to another file (in
other words another "manual"), or, on occasion, even a file on a remote
machine (although Info files distributed with Emacs or the stand-alone
Info avoid using remote links).  Such a cross reference looks like
this: *Note Overview of Texinfo: (texinfo)Top.  (After following this
link, type `l' to get back to this node.)  Here the name `texinfo'
between parentheses refers to the file name.  This file name appears in
cross references and node names if it differs from the current file, so
you can always know that you are going to be switching to another
manual and which one.

   However, Emacs normally hides some other text in cross-references.
If you put your mouse over the cross reference, then the information
appearing in a separate box (tool tip) or in the echo area will show
the full cross-reference including the file name and the node name of
the cross reference.  If you have a mouse, just leave it over the cross
reference *Note Overview of Texinfo: (texinfo)Top, and watch what
happens.  If you always like to have that information visible without
having to move your mouse over the cross reference, use `M-x
visible-mode', or set `Info-hide-note-references' to a value other than
`t' (*note Emacs Info Variables::).

>> Now type `n' to learn more commands.


File: info.info,  Node: Help-Int,  Next: Help-Q,  Prev: Help-Xref,  Up: Getting Started

1.8 Some intermediate Info commands
===================================

The introductory course is almost over; please continue a little longer
to learn some intermediate-level commands.

   Most Info files have an index, which is actually a large node
containing little but a menu.  The menu has one menu item for each
topic listed in the index.  (As a special feature, menus for indices
may also include the line number within the node of the index entry.
This allows Info readers to go to the exact line of an entry, not just
the start of the containing node.)

   You can get to the index from the main menu of the file with the `m'
command and the name of the index node; then you can use the `m'
command again in the index node to go to the node that describes the
topic you want.

   There is also a short-cut Info command, `i', which does all of that
for you.  It searches the index for a given topic (a string) and goes
to the node which is listed in the index for that topic.  *Note Search
Index::, for a full explanation.

   If you have been moving around to different nodes and wish to
retrace your steps, the `l' command (`l' for "last") will do that, one
node-step at a time.  As you move from node to node, Info records the
nodes where you have been in a special history list.  The `l' command
revisits nodes in the history list; each successive `l' command moves
one step back through the history.

>> Try typing `p p n' and then three `l''s, pausing in between
to see what each `l' does.  You should wind up right back here.

   Note the difference between `l' and `p': `l' moves to where _you_
last were, whereas `p' always moves to the node which the header says
is the `Previous' node (from this node, the `Prev' link leads to
`Help-Xref').

   You can use the `r' command (`Info-history-forward' in Emacs) to
revisit nodes in the history list in the forward direction, so that `r'
will return you to the node you came from by typing `l'.

   The `L' command (`Info-history' in Emacs) creates a virtual node
that contains a list of all nodes you visited.  You can select a
previously visited node from this menu to revisit it.

   The `d' command (`Info-directory' in Emacs) gets you instantly to
the Directory node.  This node, which is the first one you saw when you
entered Info, has a menu which leads (directly or indirectly, through
other menus), to all the nodes that exist.  The Directory node lists
all the manuals and other Info documents that are, or could be,
installed on your system.

>> Try doing a `d', then do an `l' to return here (yes,
   _do_ return).

   The `t' command moves to the `Top' node of the manual.  This is
useful if you want to browse the manual's main menu, or select some
specific top-level menu item.  The Emacs command run by `t' is
`Info-top-node'.

>> Now type `n' to see the last node of the course.

   *Note Advanced::, for more advanced Info features.


File: info.info,  Node: Help-Q,  Prev: Help-Int,  Up: Getting Started

1.9 Quitting Info
=================

To get out of Info, back to what you were doing before, type `q' for
"Quit".  This runs `Info-exit' in Emacs.

   This is the end of the basic course on using Info.  You have learned
how to move in an Info document, and how to follow menus and cross
references.  This makes you ready for reading manuals top to bottom, as
new users should do when they learn a new package.

   Another set of Info commands is useful when you need to find
something quickly in a manual--that is, when you need to use a manual
as a reference rather than as a tutorial.  We urge you to learn these
search commands as well.  If you want to do that now, follow this cross
reference to *note Advanced::.

   Yet another set of commands are meant for experienced users; you can
find them by looking in the Directory node for documentation on Info.
Finding them will be a good exercise in using Info in the usual manner.

>> Type `d' to go to the Info directory node; then type
   `mInfo' and Return, to get to the node about Info and
   see what other help is available.


File: info.info,  Node: Advanced,  Next: Expert Info,  Prev: Getting Started,  Up: Top

2 Advanced Info Commands
************************

This chapter describes various advanced Info commands.  (If you are
using a stand-alone Info reader, there are additional commands specific
to it, which are documented in several chapters of *note GNU Info:
(info-stnd)Top.)

   One advanced command useful with most of the others described here
is `C-q', which "quotes" the next character so that it is entered
literally (*note Inserting Text: (emacs)Inserting Text.).  For example,
pressing `?' ordinarily brings up a list of completion possibilities.
If you want to (for example) search for an actual `?' character, the
simplest way is to insert it using `C-q ?'.  This works the same in
Emacs and stand-alone Info.

* Menu:

* Search Text::          How to search Info documents.
* Search Index::         How to search the indices for specific subjects.
* Go to node::           How to go to a node by name.
* Choose menu subtopic:: How to choose a menu subtopic by its number.
* Create Info buffer::   How to create a new Info buffer in Emacs.
* Emacs Info Variables:: Variables modifying the behavior of Emacs Info.


File: info.info,  Node: Search Text,  Next: Search Index,  Up: Advanced

2.1 `s' searches Info documents
===============================

The commands which move between and inside nodes allow you to read the
entire manual or its large portions.  But what if you need to find some
information in the manual as fast as you can, and you don't know or
don't remember in what node to look for it?  This need arises when you
use a manual as a "reference", or when it is impractical to read the
entire manual before you start using the programs it describes.

   Info has powerful searching facilities that let you find things
quickly.  You can search either the manual text or its indices.

   The `s' command allows you to search a whole Info file for a string.
It switches to the next node if and when that is necessary.  You type
`s' followed by the string to search for, terminated by <RET>.  To
search for the same string again, just `s' followed by <RET> will do.
The file's nodes are scanned in the order they are in the file, which
has no necessary relationship to the order that they may be in the tree
structure of menus and `next' pointers.  But normally the two orders
are not very different.  In any case, you can always look at the mode
line to find out what node you have reached, if the header is not
visible (this can happen, because `s' puts your cursor at the
occurrence of the string, not at the beginning of the node).

   In Emacs, `Meta-s' is equivalent to `s'.  That is for compatibility
with other GNU packages that use `M-s' for a similar kind of search
command.  Both `s' and `M-s' run in Emacs the command `Info-search'.

   Instead of using `s' in Emacs Info and in the stand-alone Info, you
can use an incremental search started with `C-s' or `C-r'.  It can
search through multiple Info nodes.  *Note Incremental Search:
(emacs)Incremental Search.  In Emacs, you can disable this behavior by
setting the variable `Info-isearch-search' to `nil' (*note Emacs Info
Variables::).


File: info.info,  Node: Search Index,  Next: Go to node,  Prev: Search Text,  Up: Advanced

2.2 `i' searches the indices for specific subjects
==================================================

Since most topics in the manual should be indexed, you should try the
index search first before the text search.  The `i' command prompts you
for a subject and then looks up that subject in the indices.  If it
finds an index entry with the subject you typed, it goes to the node to
which that index entry points.  You should browse through that node to
see whether the issue you are looking for is described there.  If it
isn't, type `,' one or more times to go through additional index
entries which match your subject.

   The `i' command and subsequent `,' commands find all index entries
which include the string you typed _as a substring_.  For each match,
Info shows in the echo area the full index entry it found.  Often, the
text of the full index entry already gives you enough information to
decide whether it is relevant to what you are looking for, so we
recommend that you read what Info shows in the echo area before looking
at the node it displays.

   Since `i' looks for a substring, you can search for subjects even if
you are not sure how they are spelled in the index.  For example,
suppose you want to find something that is pertinent to commands which
complete partial input (e.g., when you type <TAB>).  If you want to
catch index entries that refer to "complete," "completion," and
"completing," you could type `icomplet<RET>'.

   Info documents which describe programs should index the commands,
options, and key sequences that the program provides.  If you are
looking for a description of a command, an option, or a key, just type
their names when `i' prompts you for a topic.  For example, if you want
to read the description of what the `C-l' key does, type `iC-l<RET>'
literally.

   If you aren't sure which manual documents the topic you are looking
for, try the `M-x info-apropos' command in Emacs, or the `M-x
index-apropos' command in the stand-alone reader.  It prompts for a
string and then looks up that string in all the indices of all the Info
documents installed on your system.


File: info.info,  Node: Go to node,  Next: Choose menu subtopic,  Prev: Search Index,  Up: Advanced

2.3 `g' goes to a node by name
==============================

If you know a node's name, you can go there by typing `g', the name,
and <RET>.  Thus, `gTop<RET>' would go to the node called `Top' in this
file.  (This is equivalent to `t', see *note Help-Int::.)  `gGo to
node<RET>' would come back here.

   Unlike `m', `g' does not allow the use of abbreviations.  But it
does allow completion, so you can type <TAB> to complete a partial node
name.

   To go to a node in another file, you can include the file name in the
node name by putting it at the front, in parentheses.  Thus,
`g(dir)Top<RET>' would go to the Info Directory node, which is the node
`Top' in the Info file `dir'.  Likewise, `g(emacs)Top<RET>' goes to the
top node of the Emacs manual.

   The node name `*' specifies the whole file.  So you can look at all
of the current file by typing `g*<RET>' or all of any other file with
`g(FILENAME)*<RET>'.


File: info.info,  Node: Choose menu subtopic,  Next: Create Info buffer,  Prev: Go to node,  Up: Advanced

2.4 `1'-`9' choose a menu subtopic by its number
================================================

If you begrudge each character of type-in which your system requires,
you might like to use the commands `1', `2', `3', `4', ..., `9'.  They
are short for the `m' command together with a name of a menu subtopic.
`1' goes through the first item in the current node's menu; `2' goes
through the second item, etc.  In the stand-alone reader, `0' goes
through the last menu item; this is so you need not count how many
entries are there.

   If your display supports multiple fonts, colors or underlining, and
you are using Emacs' Info mode to read Info files, the third, sixth and
ninth menu items have a `*' that stands out, either in color or in some
other attribute, such as underline; this makes it easy to see at a
glance which number to use for an item.

   Some terminals don't support either multiple fonts, colors or
underlining.  If you need to actually count items, it is better to use
`m' instead, and specify the name, or use <TAB> to quickly move between
menu items.


File: info.info,  Node: Create Info buffer,  Next: Emacs Info Variables,  Prev: Choose menu subtopic,  Up: Advanced

2.5 `M-n' creates a new independent Info buffer in Emacs
========================================================

If you are reading Info in Emacs, you can select a new independent Info
buffer in a new Emacs window by typing `M-n'.  The new buffer starts
out as an exact copy of the old one, but you will be able to move
independently between nodes in the two buffers.  (In Info mode, `M-n'
runs the Emacs command `clone-buffer'.)

   In Emacs Info, you can also produce new Info buffers by giving a
numeric prefix argument to the `m' and `g' commands.  `C-u m' and `C-u
g' go to a new node in exactly the same way that `m' and `g' do, but
they do so in a new Info buffer which they select in another window.

   Another way to produce new Info buffers in Emacs is to use a numeric
prefix argument for the `C-h i' command (`info') which switches to the
Info buffer with that number.  Thus, `C-u 2 C-h i' switches to the
buffer `*info*<2>', creating it if necessary.


File: info.info,  Node: Emacs Info Variables,  Prev: Create Info buffer,  Up: Advanced

2.6 Emacs Info-mode Variables
=============================

The following variables may modify the behavior of Info-mode in Emacs;
you may wish to set one or several of these variables interactively, or
in your init file.  *Note Examining and Setting Variables:
(emacs)Examining.  The stand-alone Info reader program has its own set
of variables, described in *note Manipulating Variables:
(info-stnd)Variables.

`Info-directory-list'
     The list of directories to search for Info files.  Each element is
     a string (directory name) or `nil' (try default directory).  If not
     initialized Info uses the environment variable `INFOPATH' to
     initialize it, or `Info-default-directory-list' if there is no
     `INFOPATH' variable in the environment.

     If you wish to customize the Info directory search list for both
     Emacs Info and stand-alone Info, it is best to set the `INFOPATH'
     environment variable, since that applies to both programs.

`Info-additional-directory-list'
     A list of additional directories to search for Info documentation
     files.  These directories are not searched for merging the `dir'
     file.

`Info-mode-hook'
     Hooks run when `Info-mode' is called.  By default, it contains the
     hook `turn-on-font-lock' which enables highlighting of Info files.
     You can change how the highlighting looks by customizing the faces
     `info-node', `info-xref', `info-xref-visited', `info-header-xref',
     `info-header-node', `info-menu-header', `info-menu-star', and
     `info-title-N' (where N is the level of the section, a number
     between 1 and 4).  To customize a face, type `M-x customize-face
     <RET> FACE <RET>', where FACE is one of the face names listed here.

`Info-fontify-maximum-menu-size'
     Maximum size of menu to fontify if `font-lock-mode' is non-`nil'.

`Info-fontify-visited-nodes'
     If non-`nil', menu items and cross-references pointing to visited
     nodes are displayed in the `info-xref-visited' face.

`Info-use-header-line'
     If non-`nil', Emacs puts in the Info buffer a header line showing
     the `Next', `Prev', and `Up' links.  A header line does not scroll
     with the rest of the buffer, making these links always visible.

`Info-hide-note-references'
     As explained in earlier nodes, the Emacs version of Info normally
     hides some text in menus and cross-references.  You can completely
     disable this feature, by setting this option to `nil'.  Setting it
     to a value that is neither `nil' nor `t' produces an intermediate
     behavior, hiding a limited amount of text, but showing all text
     that could potentially be useful.

`Info-scroll-prefer-subnodes'
     If set to a non-`nil' value, <SPC> and <BACKSPACE> (or <DEL>) keys
     in a menu visit subnodes of the current node before scrolling to
     its end or beginning, respectively.  For example, if the node's
     menu appears on the screen, the next <SPC> moves to a subnode
     indicated by the following menu item.  Setting this option to
     `nil' results in behavior similar to the stand-alone Info reader
     program, which visits the first subnode from the menu only when you
     hit the end of the current node.  The default is `nil'.

`Info-isearch-search'
     If non-`nil', isearch in Info searches through multiple nodes.

`Info-enable-active-nodes'
     When set to a non-`nil' value, allows Info to execute Lisp code
     associated with nodes.  The Lisp code is executed when the node is
     selected.  The Lisp code to be executed should follow the node
     delimiter (the `DEL' character) and an `execute: ' tag, like this:

          ^_execute: (message "This is an active node!")


File: info.info,  Node: Expert Info,  Next: Index,  Prev: Advanced,  Up: Top

3 Info for Experts
******************

This chapter explains how to write an Info file by hand.  However, in
most cases, writing a Texinfo file is better, since you can use it to
make a printed manual or produce other formats, such as HTML and
DocBook, as well as for generating Info files.

   The `makeinfo' command converts a Texinfo file into an Info file;
`texinfo-format-region' and `texinfo-format-buffer' are GNU Emacs
functions that do the same.

   *Note Overview of Texinfo: (texinfo)Top, for how to write a Texinfo
file.

   *Note Creating an Info File: (texinfo)Creating an Info File, for how
to create an Info file from a Texinfo file.

   *Note Installing an Info File: (texinfo)Installing an Info File, for
how to install an Info file after you have created one.

   However, if you want to edit an Info file manually and install it
manually, here is how.

* Menu:

* Add::                   Describes how to add new nodes to the hierarchy.
                            Also tells what nodes look like.
* Menus::                 How to add to or create menus in Info nodes.
* Cross-refs::            How to add cross-references to Info nodes.
* Tags::                  How to make tags tables for Info files.
* Checking::              Checking an Info File.


File: info.info,  Node: Add,  Next: Menus,  Up: Expert Info

3.1 Adding a new node to Info
=============================

To add a new topic to the list in the Info directory, you must:

  1. Create some nodes, in some file, to document that topic.

  2. Put that topic in the menu in the directory.  *Note Menu: Menus.

   The new node can live in an existing documentation file, or in a new
one.  It must have a `^_' character before it (invisible to the user;
this node has one but you cannot see it), and it ends with either a
`^_', a `^L' ("formfeed"), or the end of file.(1)

   The `^_' starting a node must be followed by a newline or a `^L'
newline, after which comes the node's header line.  The header line
must give the node's name (by which Info finds it), and state the names
of the `Next', `Previous', and `Up' nodes (if there are any).  As you
can see, this node's `Up' node is the node `Expert Info'.  The `Next'
node is `Menus'.

   The keywords "Node", "Next", "Previous", and "Up" may appear in any
order, anywhere in the header line, but the recommended order is the
one in this sentence.  Each keyword must be followed by a colon, spaces
and tabs, and then the appropriate name.  The name may be terminated
with a tab, a comma, or a newline.  A space does not end it; node names
may contain spaces.  The case of letters in the names is insignificant.

   A node name has two forms.  A node in the current file is named by
what appears after the `Node: ' in that node's first line.  For
example, this node's name is `Add'.  A node in another file is named by
`(FILENAME)NODE-WITHIN-FILE', as in `(info)Add' for this node.  If the
file name starts with `./', then it is relative to the current
directory; otherwise, it is relative starting from the standard
directory for Info files of your site.  The name `(FILENAME)Top' can be
abbreviated to just `(FILENAME)'.  By convention, the name `Top' is used
for the "highest" node in any single file--the node whose `Up' points
out of the file.  The `Directory' node is `(dir)', it points to a file
`dir' which holds a large menu listing all the Info documents installed
on your site.  The `Top' node of a document file listed in the
`Directory' should have an `Up: (dir)' in it.

   The node name `*' is special: it refers to the entire file.  Thus,
`g*' shows you the whole current file.  The use of the node `*' is to
make it possible to make old-fashioned, unstructured files into nodes
of the tree.

   The `Node:' name, in which a node states its own name, must not
contain a file name, since when Info searches for a node, it does not
expect a file name to be there.  The `Next', `Previous' and `Up' names
may contain them.  In this node, since the `Up' node is in the same
file, it was not necessary to use one.

   Note that the nodes in this file have a file name in the header
line.  The file names are ignored by Info, but they serve as comments
to help identify the node for the user.

   ---------- Footnotes ----------

   (1) If you put in a `^L' to end a new node, be sure that there is a
`^_' after it to start the next one, since `^L' cannot _start_ a node.
Also, a nicer way to make a node boundary be a page boundary as well is
to put a `^L' _right after_ the `^_'.


File: info.info,  Node: Menus,  Next: Cross-refs,  Prev: Add,  Up: Expert Info

3.2 How to Create Menus
=======================

Any node in the Info hierarchy may have a "menu"--a list of subnodes.
The `m' command searches the current node's menu for the topic which it
reads from the terminal.

   A menu begins with a line starting with `* Menu:'.  The rest of the
line is a comment.  After the starting line, every line that begins
with a `* ' lists a single topic.  The name of the topic--what the user
must type at the `m''s command prompt to select this topic--comes right
after the star and space, and is followed by a colon, spaces and tabs,
and the name of the node which discusses that topic.  The node name,
like node names following `Next', `Previous' and `Up', may be
terminated with a tab, comma, or newline; it may also be terminated
with a period.

   If the node name and topic name are the same, then rather than
giving the name twice, the abbreviation `* NAME::' may be used (and
should be used, whenever possible, as it reduces the visual clutter in
the menu).

   It is considerate to choose the topic names so that they differ from
each other very near the beginning--this allows the user to type short
abbreviations.  In a long menu, it is a good idea to capitalize the
beginning of each item name which is the minimum acceptable
abbreviation for it (a long menu is more than 5 or so entries).

   The nodes listed in a node's menu are called its "subnodes," and it
is their "superior".  They should each have an `Up:' pointing at the
superior.  It is often useful to arrange all or most of the subnodes in
a sequence of `Next' and `Previous' pointers so that someone who wants
to see them all need not keep revisiting the Menu.

   The Info Directory is simply the menu of the node `(dir)Top'--that
is, node `Top' in file `.../info/dir'.  You can put new entries in that
menu just like any other menu.  The Info Directory is _not_ the same as
the file directory called `info'.  It happens that many of Info's files
live in that file directory, but they do not have to; and files in that
directory are not automatically listed in the Info Directory node.

   Also, although the Info node graph is claimed to be a "hierarchy,"
in fact it can be _any_ directed graph.  Shared structures and pointer
cycles are perfectly possible, and can be used if they are appropriate
to the meaning to be expressed.  There is no need for all the nodes in
a file to form a connected structure.  In fact, this file has two
connected components.  You are in one of them, which is under the node
`Top'; the other contains the node `Help' which the `h' command goes
to.  In fact, since there is no garbage collector on the node graph,
nothing terrible happens if a substructure is not pointed to, but such
a substructure is rather useless since nobody can ever find out that it
exists.


File: info.info,  Node: Cross-refs,  Next: Tags,  Prev: Menus,  Up: Expert Info

3.3 Creating Cross References
=============================

A cross reference can be placed anywhere in the text, unlike a menu
item which must go at the front of a line.  A cross reference looks
like a menu item except that it has `*note' instead of `*'.  It
_cannot_ be terminated by a `)', because `)''s are so often part of
node names.  If you wish to enclose a cross reference in parentheses,
terminate it with a period first.  Here are two examples of cross
references pointers:

     *Note details: commands.  (See *note 3: Full Proof.)

_These are just examples._  The places they "lead to" do not really
exist!

* Menu:

* Help-Cross::                  Target of a cross-reference.


File: info.info,  Node: Help-Cross,  Up: Cross-refs

3.3.1 The node reached by the cross reference in Info
-----------------------------------------------------

This is the node reached by the cross reference named `Cross'.

   While this node is specifically intended to be reached by a cross
reference, most cross references lead to nodes that "belong" someplace
else far away in the structure of an Info document.  So you cannot
expect this node to have a `Next', `Previous' or `Up' links pointing
back to where you came from.  In general, the `l' (el) command is the
only way to get back there.

>> Type `l' to return to the node where the cross reference was.


File: info.info,  Node: Tags,  Next: Checking,  Prev: Cross-refs,  Up: Expert Info

3.4 Tags Tables for Info Files
==============================

You can speed up the access to nodes of a large Info file by giving it
a tags table.  Unlike the tags table for a program, the tags table for
an Info file lives inside the file itself and is used automatically
whenever Info reads in the file.

   To make a tags table, go to a node in the file using Emacs Info mode
and type `M-x Info-tagify'.  Then you must use `C-x C-s' to save the
file.  Info files produced by the `makeinfo' command that is part of
the Texinfo package always have tags tables to begin with.

   Once the Info file has a tags table, you must make certain it is up
to date.  If you edit an Info file directly (as opposed to editing its
Texinfo source), and, as a result of deletion of text, any node moves
back more than a thousand characters in the file from the position
recorded in the tags table, Info will no longer be able to find that
node.  To update the tags table, use the `Info-tagify' command again.

   An Info file tags table appears at the end of the file and looks like
this:

     ^_^L
     Tag Table:
     File: info, Node: Cross-refs^?21419
     File: info,  Node: Tags^?22145
     ^_
     End Tag Table

Note that it contains one line per node, and this line contains the
beginning of the node's header (ending just after the node name), a
`DEL' character, and the character position in the file of the
beginning of the node.


File: info.info,  Node: Checking,  Prev: Tags,  Up: Expert Info

3.5 Checking an Info File
=========================

When creating an Info file, it is easy to forget the name of a node when
you are making a pointer to it from another node.  If you put in the
wrong name for a node, this is not detected until someone tries to go
through the pointer using Info.  Verification of the Info file is an
automatic process which checks all pointers to nodes and reports any
pointers which are invalid.  Every `Next', `Previous', and `Up' is
checked, as is every menu item and every cross reference.  In addition,
any `Next' which does not have a `Previous' pointing back is reported.
Only pointers within the file are checked, because checking pointers to
other files would be terribly slow.  But those are usually few.

   To check an Info file, do `M-x Info-validate' while looking at any
node of the file with Emacs Info mode.


File: info.info,  Node: Index,  Prev: Expert Info,  Up: Top

Index
*****

This is an alphabetical listing of all the commands, variables, and
topics discussed in this document.