+
−\input texinfo    @c -*-texinfo-*-
+
−@comment %**start of header
+
−@setfilename ../info/info.info
+
−@settitle Info
+
−@comment %**end of header
+
−@comment $Id: info.texi,v 1.9 2001/04/13 09:11:28 michaels Exp $
+
−
+
−@dircategory Texinfo documentation system
+
−@direntry
+
−* Info: (info).                 Documentation browsing system.
+
−@end direntry
+
−
+
−@ifinfo
+
−This file describes how to use Info, the on-line, menu-driven GNU
+
−documentation system.
+
−
+
−Copyright (C) 1989, 92, 96, 97, 98, 99 Free Software Foundation, Inc.
+
−
+
−Permission is granted to make and distribute verbatim copies of
+
−this manual provided the copyright notice and this permission notice
+
−are preserved on all copies.
+
−
+
−@ignore
+
−Permission is granted to process this file through TeX and print the
+
−results, provided the printed document carries copying permission
+
−notice identical to this one except for the removal of this paragraph
+
−(this paragraph not being relevant to the printed manual).
+
−
+
−@end ignore
+
−Permission is granted to copy and distribute modified versions of this
+
−manual under the conditions for verbatim copying, provided that the entire
+
−resulting derived work is distributed under the terms of a permission
+
−notice identical to this one.
+
−
+
−Permission is granted to copy and distribute translations of this manual
+
−into another language, under the above conditions for modified versions,
+
−except that this permission notice may be stated in a translation approved
+
−by the Free Software Foundation.
+
−@end ifinfo
+
−
+
−@titlepage
+
−@title Info
+
−@subtitle The online, menu-driven GNU documentation system
+
−@author Brian Fox
+
−@page
+
−@vskip 0pt plus 1filll
+
−Copyright @copyright{} 1989, 92, 93, 96, 97, 98, 99 Free Software
+
−Foundation, Inc.
+
−@sp 2
+
−Published by the Free Software Foundation @*
+
−59 Temple Place - Suite 330 @*
+
−Boston, MA 02111-1307, USA.
+
−
+
−Permission is granted to make and distribute verbatim copies of
+
−this manual provided the copyright notice and this permission notice
+
−are preserved on all copies.
+
−
+
−Permission is granted to copy and distribute modified versions of this
+
−manual under the conditions for verbatim copying, provided that the entire
+
−resulting derived work is distributed under the terms of a permission
+
−notice identical to this one.
+
−
+
−Permission is granted to copy and distribute translations of this manual
+
−into another language, under the above conditions for modified versions,
+
−except that this permission notice may be stated in a translation approved
+
−by the Free Software Foundation.
+
−@end titlepage
+
−
+
−@node Top
+
−@top Info: An Introduction
+
−
+
−Info is a program for reading documentation, which you might be using
+
−now to read this.
+
−
+
−To learn how to use Info, type the command @kbd{h} while using the Info
+
−program.  It brings you to a programmed instruction sequence.
+
−
+
−@menu
+
−* Getting Started::             Getting started using an Info reader.
+
−* Advanced Info::               Advanced commands within Info.
+
−* Creating an Info File::       How to make your own Info file.
+
−@end menu
+
−
+
−@node Getting Started, Advanced Info, Top, Top
+
−@comment  node-name,  next,  previous,  up
+
−@chapter Getting Started
+
−
+
−This first part of the Info manual describes how to get around inside
+
−of Info.  The second part of the manual describes various advanced
+
−Info commands, and how to write an Info as distinct from a Texinfo
+
−file.  The third part is about how to generate Info files from
+
−Texinfo files.
+
−
+
−@iftex
+
−This manual is primarily designed for use on a computer, so that you can
+
−try Info commands while reading about them.  Reading it on paper is less
+
−effective, since you must take it on faith that the commands described
+
−really do what the manual says.  By all means go through this manual now
+
−that you have it; but please try going through the on-line version as
+
−well.
+
−
+
−There are two ways of looking at the online version of this manual:
+
−
+
−@enumerate
+
−@item
+
−Type @code{info} at your shell's command line.  This approach uses a
+
−small stand-alone program designed just to read Info files.
+
−
+
−@item
+
−Type @code{emacs} at the command line; then type @kbd{C-h i} (Control
+
−@kbd{h}, followed by @kbd{i}).  This approach uses the Info mode of the
+
−Emacs program, an editor with many other capabilities.
+
−@end enumerate
+
−
+
−In either case, then type @kbd{mInfo} (just the letters), followed by
+
−@key{RET}---the ``Return'' or ``Enter'' key.  At this point, you should
+
−be ready to follow the instructions in this manual as you read them on
+
−the screen.
+
−@c FIXME! (pesch@cygnus.com, 14 dec 1992)
+
−@c Is it worth worrying about what-if the beginner goes to somebody
+
−@c else's Emacs session, which already has an Info running in the middle
+
−@c of something---in which case these simple instructions won't work?
+
−@end iftex
+
−
+
−@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, Rubout, B and ^L commands.
+
−* Help-M::              Menus
+
−* Help-Adv::            Some advanced Info commands
+
−* Help-Q::              Quitting Info
+
−@end menu
+
−
+
−@node Help-Small-Screen, Help,  , Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section Starting Info on a Small Screen
+
−
+
−@iftex
+
−(In Info, you only see this section if your terminal has a small
+
−number of lines; most readers pass by it without seeing it.)
+
−@end iftex
+
−
+
−Since your terminal has an unusually small number of lines on its
+
−screen, it is necessary to give you special advice at the beginning.
+
−
+
−If you see the text @samp{--All----} at near the bottom right corner
+
−of the screen, it means the entire text you are looking at fits on the
+
−screen.  If you see @samp{--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 the Space bar, @key{SPC}.  To move
+
−back up, press the key labeled @samp{Backspace} or @key{Delete}.
+
−
+
−@ifinfo
+
−Here are 40 lines of junk, so you can try Spaces and Deletes and
+
−see what they do.  At the end are instructions of what you should do
+
−next.
+
−
+
−This is line 17 @*
+
−This is line 18 @*
+
−This is line 19 @*
+
−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 @*
+
−
+
−If you have managed to get here, go back to the beginning with
+
−Delete, and come back here again, then you understand Space and
+
−Delete.  So now type an @kbd{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.
+
−@end ifinfo
+
−
+
−@node Help, Help-P, Help-Small-Screen, Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section How to use Info
+
−
+
−You are talking to the program Info, for reading documentation.
+
−
+
−  Right now you are looking at one @dfn{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 top line of a node is its @dfn{header}.  This node's header (look at
+
−it now) says that it is the node named @samp{Help} in the file
+
−@file{info}.  It says that the @samp{Next} node after this one is the node
+
−called @samp{Help-P}.  An advanced Info command lets you go to any node
+
−whose name you know.
+
−
+
−  Besides a @samp{Next}, a node can have a @samp{Previous} or an @samp{Up}.
+
−This node has a @samp{Previous} but no @samp{Up}, as you can see.
+
−
+
−  Now it is time to move on to the @samp{Next} node, named @samp{Help-P}.
+
−
+
−>> Type @samp{n} to move there.  Type just one character;
+
−   do not type the quotes and do not type a @key{RET} afterward.
+
−
+
−@samp{>>} in the margin means it is really time to try a command.
+
−
+
−@node Help-P, Help-^L, Help, Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section Returning to the Previous node
+
−
+
−This node is called @samp{Help-P}.  The @samp{Previous} node, as you see,
+
−is @samp{Help}, which is the one you just came from using the @kbd{n}
+
−command.  Another @kbd{n} command now would take you to the next
+
−node, @samp{Help-^L}.
+
−
+
−>> But do not do that yet.  First, try the @kbd{p} command, which takes
+
−   you to the @samp{Previous} node.  When you get there, you can do an
+
−   @kbd{n} again to return here.
+
−
+
−  This all probably seems insultingly simple so far, but @emph{do not} be
+
−led into skimming.  Things will get more complicated soon.  Also,
+
−do not try a new command until you are told it is time to.  Otherwise,
+
−you may make Info skip past an important warning that was coming up.
+
−
+
−>> Now do an @kbd{n} to get to the node @samp{Help-^L} and learn more.
+
−
+
−@node Help-^L, Help-M, Help-P, Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section The Space, Delete, B and ^L commands.
+
−
+
−  This node's header tells you that you are now at node @samp{Help-^L}, and
+
−that @kbd{p} would get you back to @samp{Help-P}.  The node's title is
+
−underlined; it says what the node is about (most nodes have titles).
+
−
+
−  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 string @samp{--Top-----} rather than @samp{--All----} near
+
−the bottom right corner of the screen.
+
−
+
−  The Space, Delete and @kbd{B} commands exist to allow you to ``move
+
−around'' in a node that does not all fit on the screen at once.
+
−Space moves forward, to show what was below the bottom of the screen.
+
−Delete 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 Space (afterward, type a Delete to return here).
+
−
+
−  When you type the space, the two lines that were at the bottom of
+
−the screen appear at the top, followed by more lines.  Delete takes
+
−the two lines from the top and moves them to the bottom,
+
−@emph{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 type Space when there is no more to see, it rings the
+
−bell and otherwise does nothing.  The same goes for Delete when
+
−the header of the node is visible.
+
−
+
−  If your screen is ever garbaged, you can tell Info to print it out
+
−again by typing @kbd{C-l} (@kbd{Control-L}, that is---hold down ``Control'' and
+
−type an @key{L} or @kbd{l}).
+
−
+
−>> Type @kbd{C-l} now.
+
−
+
−  To move back to the beginning of the node you are on, you can type
+
−a lot of Deletes.  You can also type simply @kbd{b} 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, with Spaces.
+
−
+
−  If your screen is very tall, all of this node might fit at once.
+
−In that case, "b" won't do anything.  Sorry; what can we do?
+
−
+
−  You have just learned a considerable number of commands.  If you
+
−want to use one but have trouble remembering which, you should type
+
−a @key{?} which prints out a brief list of commands.  When you are
+
−finished looking at the list, make it go away by pressing @key{SPC}
+
−repeatedly.
+
−
+
−>> Type a @key{?} now.  Press @key{SPC} to see consecutive screenfuls of
+
−>> the list until finished.
+
−
+
−  From now on, you will encounter large nodes without warning, and
+
−will be expected to know how to use Space and Delete 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 @kbd{n} to see the description of the @kbd{m} command.
+
−
+
−@node Help-M, Help-Adv, Help-^L, Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section Menus
+
−
+
−Menus and the @kbd{m} command
+
−
+
−  With only the @kbd{n} and @kbd{p} 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 @samp{* 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 @samp{*}
+
−identifies one subtopic.  The line usually contains a brief name
+
−for the subtopic (followed by a @samp{:}), the name of the node that talks
+
−about that subtopic, and optionally some further description of the
+
−subtopic.  Lines in the menu that do not start with a @samp{*} have no
+
−special meaning---they are only for the human reader's benefit and do
+
−not define additional subtopics.  Here is an example:
+
−
+
−@example
+
−* Foo:  FOO's Node      This tells about FOO
+
−@end example
+
−
+
−The subtopic name is Foo, and the node describing it is @samp{FOO's Node}.
+
−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 @samp{* Menu:}.]]
+
−
+
−  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:
+
−
+
−@example
+
−* Foo::   This tells about FOO
+
−@end example
+
−
+
−@noindent
+
−This means that the subtopic name and node name are the same; they are
+
−both @samp{Foo}.
+
−
+
−>> Now use Spaces to find the menu in this node, then come back to
+
−   the front with a @kbd{b} and some Spaces.  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
+
−   @kbd{m} command is not available.
+
−
+
−  The command to go to one of the subnodes is @kbd{m}---but @emph{do
+
−not do it yet!}  Before you use @kbd{m}, you must understand the
+
−difference between commands and arguments.  So far, you have learned
+
−several commands that do not need arguments.  When you type one, Info
+
−processes it and is instantly ready for another command.  The @kbd{m}
+
−command is different: it is incomplete without the @dfn{name of the
+
−subtopic}.  Once you have typed @kbd{m}, Info tries to read the
+
−subtopic name.
+
−
+
−  Now look for the line containing many dashes near the bottom of the
+
−screen.  There is one more line beneath that one, but usually it is
+
−blank.  If it is empty, Info is ready for a command, such as @kbd{n}
+
−or @kbd{b} or Space or @kbd{m}.  If that line contains text ending
+
−in a colon, it means Info is trying to read the @dfn{argument} to a
+
−command.  At such times, commands do not work, because Info tries to
+
−use them as the argument.  You must either type the argument and
+
−finish the command you started, or type @kbd{Control-g} to cancel the
+
−command.  When you have done one of those things, the line becomes
+
−blank again.
+
−
+
−  The command to go to a subnode via a menu is @kbd{m}.  After you type
+
−the @kbd{m}, the line at the bottom of the screen says @samp{Menu item: }.
+
−You must then type the name of the subtopic you want, and end it with
+
−a @key{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 @dfn{completion} feature to help enter the subtopic
+
−name.  If you type the Tab key after entering part of a name, it will
+
−magically fill in more of the name---as much as follows uniquely from
+
−what 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 Return, and it stands for
+
−the subtopic of the line you are on.
+
−
+
−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.       Strange!  two ways to get to the same place.
+
−* Help-FOO::            And yet another!
+
−@end menu
+
−
+
−>>  Now type just an @kbd{m} and see what happens:
+
−
+
−  Now you are ``inside'' an @kbd{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 @kbd{m} by typing Control-g.
+
−
+
−>> Try that now;  notice the bottom line clear.
+
−
+
−>> Then type another @kbd{m}.
+
−
+
−>> Now type @samp{BAR} item name.  Do not type Return yet.
+
−
+
−  While you are typing the item name, you can use the Delete key to
+
−cancel one character at a time if you make a mistake.
+
−
+
−>> Type one to cancel the @samp{R}.  You could type another @samp{R} to
+
−   replace it.  You do not have to, since @samp{BA} is a valid abbreviation.
+
−
+
−>> Now you are ready to go.  Type a @key{RET}.
+
−
+
−  After visiting Help-FOO, you should return here.
+
−
+
−>> Type @kbd{n} to see more commands.
+
−
+
−@c If a menu appears at the end of this node, remove it.
+
−@c It is an accident of the menu updating command.
+
−
+
−Here is another way to get to  Help-FOO, a menu.  You can ignore this
+
−if you want, or else try it (but then please come back to here).
+
−
+
−@menu
+
−* Help-FOO::
+
−@end menu
+
−
+
−@node Help-FOO,  ,  , Help-M
+
−@comment  node-name,  next,  previous,  up
+
−@subsection The @kbd{u} command
+
−
+
−  Congratulations!  This is the node @samp{Help-FOO}.  Unlike the other
+
−nodes you have seen, this one has an @samp{Up}: @samp{Help-M}, the node you
+
−just came from via the @kbd{m} command.  This is the usual
+
−convention---the nodes you reach from a menu have @samp{Up} nodes that lead
+
−back to the menu.  Menus move Down in the tree, and @samp{Up} moves Up.
+
−@samp{Previous}, on the other hand, is usually used to ``stay on the same
+
−level but go backwards''
+
−
+
−  You can go back to the node @samp{Help-M} by typing the command
+
−@kbd{u} for ``Up''.  That puts you at the @emph{front} of the
+
−node---to get back to where you were reading you have to type
+
−some @key{SPC}s.
+
−
+
−>> Now type @kbd{u} to move back up to @samp{Help-M}.
+
−
+
−@node Help-Adv, Help-Q, Help-M, Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section Some advanced Info commands
+
−
+
−  The course is almost over, so please stick with it to the end.
+
−
+
−  If you have been moving around to different nodes and wish to
+
−retrace your steps, the @kbd{l} command (@kbd{l} for @dfn{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
+
−@kbd{l} command revisits nodes in the history list; each successive
+
−@kbd{l} command moves one step back through the history.
+
−
+
−  If you have been following directions, ad @kbd{l} command now will get
+
−you back to @samp{Help-M}.  Another @kbd{l} command would undo the
+
−@kbd{u} and get you back to @samp{Help-FOO}.  Another @kbd{l} would undo
+
−the @kbd{m} and get you back to @samp{Help-M}.
+
−
+
−>> Try typing three @kbd{l}'s, pausing in between to see what each
+
−    @kbd{l} does.
+
−
+
−Then follow directions again and you will end up back here.
+
−
+
−  Note the difference between @kbd{l} and @kbd{p}: @kbd{l} moves to
+
−where @emph{you} last were, whereas @kbd{p} always moves to the node
+
−which the header says is the @samp{Previous} node (from this node, to
+
−@samp{Help-M}).
+
−
+
−  The @samp{d} command 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.
+
−
+
−>> Try doing a @samp{d}, then do an @kbd{l} to return here (yes,
+
−   @emph{do} return).
+
−
+
−  Sometimes, in Info documentation, you will see a cross reference.
+
−Cross references look like this: @xref{Help-Cross, Cross}.  That is a
+
−real, live cross reference which is named @samp{Cross} and points at
+
−the node named @samp{Help-Cross}.
+
−
+
−  If you wish to follow a cross reference, you must use the @samp{f}
+
−command.  The @samp{f} must be followed by the cross reference name
+
−(in this case, @samp{Cross}).  While you enter the name, you can use the
+
−Delete key to edit your input.  If you change your mind about following
+
−any reference, you can use @kbd{Control-g} to cancel the command.
+
−
+
−  Completion is available in the @samp{f} command; you can complete among
+
−all the cross reference names in the current node by typing a Tab.
+
−
+
−>> Type @samp{f}, followed by @samp{Cross}, and a @key{RET}.
+
−
+
−  To get a list of all the cross references in the current node, you can
+
−type @kbd{?} after an @samp{f}.  The @samp{f} continues to await a
+
−cross reference name even after printing the list, so if you don't
+
−actually want to follow a reference, you should type a @kbd{Control-g}
+
−to cancel the @samp{f}.
+
−
+
−>> Type "f?" to get a list of the cross references in this node.  Then
+
−   type a @kbd{Control-g} and see how the @samp{f} gives up.
+
−
+
−>> Now type @kbd{n} to see the last node of the course.
+
−
+
−@c If a menu appears at the end of this node, remove it.
+
−@c It is an accident of the menu updating command.
+
−
+
−@node Help-Cross,  ,  , Help-Adv
+
−@subsection The node reached by the cross reference in Info
+
−
+
−  This is the node reached by the cross reference named @samp{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 Info.  So you cannot expect the
+
−footnote to have a @samp{Next}, @samp{Previous} or @samp{Up} pointing
+
−back to where you came from.  In general, the @kbd{l} (el) command is
+
−the only way to get back there.
+
−
+
−>> Type @kbd{l} to return to the node where the cross reference was.
+
−
+
−@node Help-Q,  , Help-Adv, Getting Started
+
−@comment  node-name,  next,  previous,  up
+
−@section Quitting Info
+
−
+
−  To get out of Info, back to what you were doing before, type @kbd{q}
+
−for @dfn{Quit}.
+
−
+
−  This is the end of the course on using Info.  There are some other
+
−commands that are meant for experienced users; they are useful, and 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 @samp{d} to go to the Info directory node; then type
+
−   @samp{mInfo} and Return, to get to the node about Info and
+
−   see what other help is available.
+
−
+
−
+
−@node Advanced Info
+
−@chapter Info for Experts
+
−
+
−This chapter describes various advanced Info commands, and how to write
+
−an Info as distinct from a Texinfo file.  (However, in most cases, writing a
+
−Texinfo file is better, since you can use it @emph{both} to generate an
+
−Info file and to make a printed manual.  @xref{Top,, Overview of
+
−Texinfo, texinfo, Texinfo}.)
+
−
+
−@menu
+
−* Expert::               Advanced Info commands: g, s, e, and 1 - 5.
+
−* 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 tag tables for Info files.
+
−* Checking::             Checking an Info File
+
−* Emacs Info Variables:: Variables modifying the behavior of Emacs Info.
+
−@end menu
+
−
+
−@node Expert, Add,  , Advanced Info
+
−@comment  node-name,  next,  previous,  up
+
−@section Advanced Info Commands
+
−
+
−@kbd{g}, @kbd{s}, @kbd{1}, -- @kbd{9}, and @kbd{e}
+
−
+
−If you know a node's name, you can go there by typing @kbd{g}, the
+
−name, and @key{RET}.  Thus, @kbd{gTop@key{RET}} would go to the node
+
−called @samp{Top} in this file (its directory node).
+
−@kbd{gExpert@key{RET}} would come back here.
+
−
+
−Unlike @kbd{m}, @kbd{g} does not allow the use of abbreviations.
+
−
+
−To go to a node in another file, you can include the filename in the
+
−node name by putting it at the front, in parentheses.  Thus,
+
−@kbd{g(dir)Top@key{RET}} would go to the Info Directory node, which is
+
−node @samp{Top} in the file @file{dir}.
+
−
+
−The node name @samp{*} specifies the whole file.  So you can look at
+
−all of the current file by typing @kbd{g*@key{RET}} or all of any
+
−other file with @kbd{g(FILENAME)@key{RET}}.
+
−
+
−The @kbd{s} command allows you to search a whole file for a string.
+
−It switches to the next node if and when that is necessary.  You
+
−type @kbd{s} followed by the string to search for, terminated by
+
−@key{RET}.  To search for the same string again, just @kbd{s} followed
+
−by @key{RET} will do.  The file's nodes are scanned in the order
+
−they are in in the file, which has no necessary relationship to the
+
−order that they may be in in the tree structure of menus and @samp{next}
+
−pointers.  But normally the two orders are not very different.  In any
+
−case, you can always do a @kbd{b} to find out what node you have
+
−reached, if the header is not visible (this can happen, because @kbd{s}
+
−puts your cursor at the occurrence of the string, not at the beginning
+
−of the node).
+
−
+
−If you grudge the system each character of type-in it requires, you
+
−might like to use the commands @kbd{1}, @kbd{2}, @kbd{3}, @kbd{4}, ...
+
−@kbd{9}.  They are short for the @kbd{m} command together with an
+
−argument.  @kbd{1} goes through the first item in the current node's
+
−menu; @kbd{2} goes through the second item, etc.
+
−
+
−If your display supports multiple fonts, and you are using Emacs' Info
+
−mode to read Info files, the @samp{*} for the fifth menu item is
+
−underlined, and so is the @samp{*} for the ninth item; these underlines
+
−make it easy to see at a glance which number to use for an item.
+
−
+
−On ordinary terminals, you won't have underlining.  If you need to
+
−actually count items, it is better to use @kbd{m} instead, and specify
+
−the name.
+
−
+
−The Info command @kbd{e} changes from Info mode to an ordinary
+
−Emacs editing mode, so that you can edit the text of the current node.
+
−Type @kbd{C-c C-c} to switch back to Info.  The @kbd{e} command is allowed
+
−only if the variable @code{Info-enable-edit} is non-@code{nil}.
+
−
+
−@node Add, Menus, Expert, Advanced Info
+
−@comment  node-name,  next,  previous,  up
+
−@section Adding a new node to Info
+
−
+
−To add a new topic to the list in the Info directory, you must:
+
−@enumerate
+
−@item
+
−Create some nodes, in some file, to document that topic.
+
−@item
+
−Put that topic in the menu in the directory.  @xref{Menus, Menu}.
+
−@end enumerate
+
−
+
−Usually, the way to create the nodes is with Texinfo (@pxref{Top,,
+
−Overview of Texinfo, texinfo, Texinfo}); this has the advantage that you
+
−can also make a printed manual from them.  However, if you want to edit
+
−an Info file, here is how.
+
−
+
−The new node can live in an existing documentation file, or in a new
+
−one.  It must have a @key{^_} character before it (invisible to the
+
−user; this node has one but you cannot see it), and it ends with either
+
−a @key{^_}, a @key{^L}, or the end of file.  Note: If you put in a
+
−@key{^L} to end a new node, be sure that there is a @key{^_} after it
+
−to start the next one, since @key{^L} cannot @emph{start} a node.
+
−Also, a nicer way to make a node boundary be a page boundary as well
+
−is to put a @key{^L} @emph{right after} the @key{^_}.
+
−
+
−  The @key{^_} starting a node must be followed by a newline or a
+
−@key{^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 @samp{Next}, @samp{Previous}, and @samp{Up} nodes (if there
+
−are any).  As you can see, this node's @samp{Up} node is the node
+
−@samp{Top}, which points at all the documentation for Info.  The
+
−@samp{Next} node is @samp{Menus}.
+
−
+
−  The keywords @dfn{Node}, @dfn{Previous}, @dfn{Up}, and @dfn{Next},
+
−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 @samp{Node: } in that node's first line.  For
+
−example, this node's name is @samp{Add}.  A node in another file is
+
−named by @samp{(@var{filename})@var{node-within-file}}, as in
+
−@samp{(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 Info file directory of your site.
+
−The name @samp{(@var{filename})Top} can be abbreviated to just
+
−@samp{(@var{filename})}.  By convention, the name @samp{Top} is used for
+
−the ``highest'' node in any single file---the node whose @samp{Up} points
+
−out of the file.  The Directory node is @file{(dir)}.  The @samp{Top} node
+
−of a document file listed in the Directory should have an @samp{Up:
+
−(dir)} in it.
+
−
+
−  The node name @kbd{*} is special: it refers to the entire file.
+
−Thus, @kbd{g*} shows you the whole current file.  The use of the
+
−node @kbd{*} is to make it possible to make old-fashioned,
+
−unstructured files into nodes of the tree.
+
−
+
−  The @samp{Node:} name, in which a node states its own name, must not
+
−contain a filename, since Info when searching for a node does not expect
+
−one to be there.  The @samp{Next}, @samp{Previous} and @samp{Up} names
+
−may contain them.  In this node, since the @samp{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.
+
−
+
−@node Menus, Cross-refs, Add, Advanced Info
+
−@comment  node-name,  next,  previous,  up
+
−@section How to Create Menus
+
−
+
−  Any node in the Info hierarchy may have a @dfn{menu}---a list of subnodes.
+
−The @kbd{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 @samp{* Menu:}.  The rest of the
+
−line is a comment.  After the starting line, every line that begins
+
−with a @samp{* } lists a single topic.  The name of the topic--the
+
−argument that the user must give to the @kbd{m} command 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 @samp{Next}, @samp{Previous}
+
−and @samp{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 @samp{* 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 @samp{Up:} pointing at
+
−the superior.  It is often useful to arrange all or most of the subnodes
+
−in a sequence of @samp{Next} and @samp{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 @samp{(dir)Top}---that
+
−is, node @samp{Top} in file @file{.../info/dir}.  You can put new entries
+
−in that menu just like any other menu.  The Info Directory is @emph{not} the
+
−same as the file directory called @file{info}.  It happens that many of
+
−Info's files live on that file directory, but they do not have to; and
+
−files on 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 @emph{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 @samp{Top}; the other contains the node @samp{Help} which the
+
−@kbd{h} command goes to.  In fact, since there is no garbage
+
−collector, 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.
+
−
+
−@node Cross-refs, Tags, Menus, Advanced Info
+
−@comment  node-name,  next,  previous,  up
+
−@section 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 @samp{*note} instead of @kbd{*}.
+
−It @emph{cannot} be terminated by a @samp{)}, because @samp{)}'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:
+
−
+
−@example
+
−*Note details: commands.  (See *note 3: Full Proof.)
+
−@end example
+
−
+
−They are just examples.  The places they ``lead to'' do not really exist!
+
−
+
−@node Tags, Checking, Cross-refs, Advanced Info
+
−@comment  node-name,  next,  previous,  up
+
−@section Tag Tables for Info Files
+
−
+
−  You can speed up the access to nodes of a large Info file by giving
+
−it a tag table.  Unlike the tag table for a program, the tag table for
+
−an Info file lives inside the file itself and is used
+
−automatically whenever Info reads in the file.
+
−
+
−  To make a tag table, go to a node in the file using Emacs Info mode and type
+
−@kbd{M-x Info-tagify}.  Then you must use @kbd{C-x C-s} to save the
+
−file.
+
−
+
−  Once the Info file has a tag table, you must make certain it is up
+
−to date.  If, 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 tag table, Info will no longer be able to find that
+
−node.  To update the tag table, use the @code{Info-tagify} command again.
+
−
+
−  An Info file tag table appears at the end of the file and looks like
+
−this:
+
−
+
−@example
+
−^_
+
−Tag Table:
+
−File: info, Node: Cross-refs^?21419
+
−File: info,  Node: Tags^?22145
+
−^_
+
−End Tag Table
+
−@end example
+
−
+
−@noindent
+
−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 Delete character, and the character position in the file of the
+
−beginning of the node.
+
−
+
−
+
−@node Checking, Emacs Info Variables, Tags, Advanced Info
+
−@section 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 @samp{Next}, @samp{Previous}, and
+
−@samp{Up} is checked, as is every menu item and every cross reference.  In
+
−addition, any @samp{Next} which does not have a @samp{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 @kbd{M-x Info-validate} while looking at any
+
−node of the file with Emacs Info mode.
+
−
+
−@node Emacs Info Variables, , Checking, Advanced Info
+
−@section 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 @file{~/.emacs} init file.  @xref{Examining, Examining and
+
−Setting Variables, Examining and Setting Variables, xemacs, XEmacs
+
−User's Manual}.
+
−
+
−
+
−@vtable @code
+
−@item Info-enable-edit
+
−Set to @code{nil}, disables the @samp{e} (@code{Info-edit}) command.  A
+
−non-@code{nil} value enables it.  @xref{Add, Edit}.
+
−
+
−@item Info-enable-active-nodes
+
−When set to a non-@code{nil} value, allows Info to execute Lisp code
+
−associated with nodes.  The Lisp code is executed when the node is
+
−selected.
+
−
+
−@item Info-directory-list
+
−The list of directories to search for Info files.  Each element is a
+
−string (directory name) or @code{nil} (try default directory).
+
−
+
−@item Info-directory
+
−The standard directory for Info documentation files.  Only used when the
+
−function @code{Info-directory} is called.
+
−@end vtable
+
−
+
−
+
−@node Creating an Info File
+
−@chapter Creating an Info File
+
−
+
−@xref{Top,, Overview of Texinfo, texinfo, Texinfo}, to learn how to
+
−write a Texinfo file.
+
−
+
−@xref{Create an Info File, , Creating an Info File, texinfo, Texinfo},
+
−to learn how to create an Info file from a Texinfo file.
+
−
+
−@xref{Install an Info File, , Installing an Info File, texinfo, Texinfo},
+
−to learn how to install an Info file after you have created one.
+
−
+
−@bye