\input texinfo   @c -*-texinfo-*-
@setfilename ../info/texinfo
@settitle Texinfo

@titlepage
@center @titlefont{Texinfo}
@sp 1
@center The GNU Documentation Format
@sp 2
@center Richard M. Stallman
@end titlepage

@unnumbered Distribution

Copyright @copyright{} 1985 Richard M. Stallman.

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 same conditions as for modified versions.

@node top, commands, , (DIR)
@chapter Texinfo Files

Documentation for GNU utilities and libraries should be written
in a format called @dfn{texinfo}.  This format can be translated
mechanically into either printed manuals or on-line readable
Info files.@refill

@menu
* info::       What Info files do.
* commands::   What goes into a texinfo file.
* make-info::  Making a texinfo file into an Info file.
* manual::     Making a texinfo file into a printed manual.
@end menu

@node info, commands, top, top
@section What Info Files Do

An Info file is a file formatted so that the Info documentation reading
program can operate on it.  Info files are divided into pieces called
@dfn{nodes}, each of which contains the discussion of one topic.  Each node
has a name, and contains both text for the user to read and pointers to
other nodes, which are identified by their names.  Info displays one node
at a time, and provides commands with which the user can move to the other
nodes that the current node points to.

Normally most of the nodes are arranged in a tree which branches down.
Each node may have any number of child nodes that describe subtopics of the
node's topic.  The names of these child nodes, if any, are listed in a
@dfn{menu} within the parent node; this allows certain Info commands to
be used to move to one of the child nodes.  Each child node records the
parent node name, as its `up' pointer.

All the children of any one parent are linked together in a bidirectional
chain of `next' and `previous' pointers.  Normally the order in this chain
is the same as the order of the children in the parent's menu.  The last
child has no `next' pointer, and the first child normally has the parent as
its `previous' pointer (as well as its `up' pointer, of course).

The root of the tree is the top node of the file, through which users
enter the file from the Info directory.  By convention, this node is always
called @samp{top}.  This node normally contains just a brief summary of the
file's purpose, and a large menu through which the rest of the file is
reached.

Structuring the nodes in a tree is a matter of convention, not a
requirement.  In fact, the `up', `previous' and `next' pointers of a node
can point to any other nodes, and the menu can contain any other nodes.
The structure of nodes can be any directed graph.  But it is usually more
comprehensible to the user to make it a tree.  Info provides another kind
of pointer between nodes, called a reference, that can be sprinkled through
the text of a node.  This is usually the best way to represent links that
do not fit the tree structure.

Most often the nodes fall into a strict tree structure, and most often this
structure corresponds to the structure of chapters, sections, subsections,
and so on of a printed manual.  But there are times when this is not right
for the material being discussed.  Therefore, texinfo format uses separate
commands to specify the node structure of the Info file and the section
structure of the a printed manual.  Also, texinfo requires menus to be
specified explicitly, rather than generating them automatically based on an
assumed tree structure.

@node commands, make-info, info, top
@section General Syntactic Conventions

Texinfo files contain a strictly limited set of constructs for a @TeX{}
macro package quite different from plain @TeX{}.  The strict limits make it
possible for texinfo files to be understood also by the @code{texinfo}
program, which converts them into Info files.

In order to be made into an Info file, a texinfo file must start with a
line that looks like
@example
@@setfilename @var{info-file-name}
@end example
@noindent
which specifies the name of the Info file to be generated.  In fact, there
can be other things in the file before this line, but they are ignored in
the generation of an Info file.  The @code{@@setfilename} line is ignored
when a printed manual is generated.

All ASCII printing characters except @code{@@}, @code{@{} and @code{@}} can
appear in body text in a texinfo file and stand for themselves.  @code{@@}
is the escape character which introduces commands.  @code{@{} and @code{@}}
should be used only to surround arguments to certain commands.  @code{@{}
and @code{@}} appearing anywhere else will be treated by @TeX{} as a
grouping but treated by texinfo as themselves; this inconsistency is
undesirable, so don't let it occur.  To put one of these special characters
into the document, put an @samp{@@} character in front of it.@refill

It is customary in @TeX{} to use doubled single-quote characters to begin
and end quotations.  This convention should be followed in texinfo files.

@TeX{} ignores the line-breaks in the input text, except for blank lines,
which separate paragraphs.  Texinfo generally preserves the line breaks
that are present in the input file.  Therefore, you break the lines in the
texinfo file the way you want them to appear in the output Info file, and
let @TeX{} take care of itself.

@section @@-Command Syntax

The character @@ is used to start special texinfo commands.  (It has the
same meaning that @t{\} has in plain @TeX{}.)  Syntactically, there
are three classes of @@-commands:

@enumerate
@item
Non-alphabetic commands, @@ followed by a punctuation character.
These commands are always part of the text within a paragraph, and
never take any argument.  The two characters (@@ and the other one)
are complete in themselves.
@item
Alphabetic commands used within a paragraph.  These commands have @@
followed by a word, followed by an argument within braces.  For
example, the command @code{@@i} specifies italic font (for @TeX{}
processing only); it is used as follows: @samp{I do @@i@{not@} want
to eat that.}
@item
Alphabetic commands used outside of paragraphs.  Each such command
occupies an entire line.  The line starts with @@, followed by the
name of the command (a word).  If no argument is needed, the word is
followed by the end of the line.  If there is an argument, it is
separated from the command name by a space.
@end enumerate

Thus, the alphabetic commands fall into two classes that have different
argument syntax.  You cannot tell which class a command falls in by the
appearance of its name, but you can tell by the command's meaning: if it
makes sense to use the command together with other words as part of a
paragraph, the command is in class 2 and must be followed by an argument in
braces; otherwise, it is in class 3 and uses the rest of the line as its
argument.

The purpose of having different syntax for commands of classes 2 and 3 is
to make the texinfo file easier to read, and also to help the Emacs
paragraph and filling commands work properly.  There is only one exception
to this rule: the command @code{@@refill}, which is always used at the end
of a paragraph immediately following the final period or other punctuation
character.  @code{@@refill} takes no argument.  @code{@@refill} never
confuses the Emacs paragraph commands because it cannot start at the
beginning of a line.@refill

@section Within-Paragraph Commands

The @@-commands used within a paragraph either generate a small amount of
text or modify the treatment of some text.

@subsection @@@@

@code{@@@@} stands for a single @@ in either printed or Info output.

@subsection @@@{

@code{@@@{} stands for a single @{ in either printed or Info output.

@subsection @@@}

@code{@@@}} stands for a single @} in either printed or Info output.

@subsection @@:

@code{@@:}@: is used after a character such as period or colon which
normally causes @TeX{} to increase the width of the following whitespace,
to suppress that effect.  For example, it can be used after periods that
end abbreviations and do not end sentences.  @code{@@:}@: has no effect
on the Info file output.

@example
It displays @@code@{Foo:@}@@: at that time.
@end example

@noindent
produces

@quotation
It displays @code{Foo:}@: at that time.
@end quotation

Note that the meanings of @code{@@:}@: and @code{@@.}@: in texinfo are
not compatible with their meanings in Scribe; in fact, they are nearly the
opposite.  The meanings in texinfo were designed to work well with the
Emacs sentence motion commands.@refill

@subsection @@.

@code{@@.}@: stands for a period that really does end a sentence, useful when
@TeX{} will assume by its heuristics that that is not so.  This happens
when there is a single-capital-letter word at the end of a sentence: @TeX{}
normally guesses that it is an abbreviation.

In the Info file output, @code{@@.}@: is equivalent to a simple @samp{.}.
The texinfo program preserves the amount of space that you use, so put
two spaces after a period if you intend it to be the end of a sentence
(as well as using @code{@@.}, if necessary, for the printed manual's sake).

@example
Give it to X. Give it to X@@.  Give it to X@@.
@end example

@noindent
produces

@quotation
Give it to X. Give it to X@.  Give it to X@.
@end quotation

@subsection @@*

@code{@@*} forces a line break in the printed manual.  It has no effect on
the Info file output, where line breaks follow those in the source file.
If you want a line break at a certain spot in both forms of output, break
the line there in the source file and put @code{@@*} at the end of the
line.

@subsection @@dots

@code{@@dots@{@}} generates an ellipsis: three periods in a row, or `@dots{}'.
Do not simply write three periods in the input file; that would work ok for
the Info file output, but would produce the wrong amount of space between
the periods in the printed manual.

@subsection @@bullet

@code{@@bullet@{@}} generates a large round dot, or the closest possible
thing to one.

@subsection @@TeX

@code{@@TeX@{@}} generates `@TeX{}'.  In a printed manual, this is a special
logo that is different from three ordinary letters.

@subsection @@copyright

@code{@@copyright@{@}} generates a @samp{C} inside a circle.

@subsection @@code

@code{@@code} is used to indicate text that is a literal example of input
to a program.  The text follows, enclosed in braces.  Any time you give a
sample of an expression in C, or of a command for the shell, or any such
thing, use @code{@@code}.  In the printed manual, it puts the argument in
bold face.  In the Info file, it uses `@dots{}' quotation.  Example:

@example
To compare two files, showing text inserted or removed, use @@code@{diff@}.
@end example

@noindent
produces

@quotation
To compare two files, showing text inserted or removed, use @code{diff}.
@end quotation

@subsection @@samp

@code{@@samp} is used to indicate text that is a literal example of a
sequence of characters in a file, string, pattern, etc.  The text follows,
enclosed in braces.  The argument appears within `@dots{}' quotation in
both the Info file and the printed manual; in addition, it is printed in
a fixed-width font.

@example
To match @@samp@{foo@} at the end of the line, use the regexp @@samp@{foo$@}.
@end example

@noindent
produces

@quotation
To match @samp{foo} at the end of the line, use the regexp @samp{foo$}.
@end quotation

@subsection @@file

@code{@@file} is used to indicate text that is a file name.  Currently
it is equivalent to @code{@@samp} in its effects on the output.

@subsection @@kbd

@code{@@kbd} is used much like @code{@@code}.  The difference is that
@code{@@kbd} is for names of keys on the keyboard, or of characters you can
type.  It has the same effect as @code{@@code} in texinfo, but may produce
a different font in a printed manual.@refill

@example
To give the @@code@{logout@} command, type the characters @@kbd@{l o g o u t
@@key@{RET@}@}.
@end example

@noindent
produces

@quotation
To give the @code{logout} command, type the characters @kbd{l o g o u t
@key{RET}}.
@end quotation

@subsection @@key

@code{@@key} is used to indicate text that is the name of a key on
the keyboard, as in

@example
@@key@{RET@}
@end example

Often, @code{@@key} is used within the argument of a @code{@@kbd}
command, whenever the sequence of characters to be typed includes one or
more keys that are described by name.@refill

The recommended names to use for keys are

@table @t
@item SPC
Space.
@item RET
Return.
@item LFD
Linefeed.
@item TAB
Tab.
@item BS
Backspace.
@item ESC
Escape.
@item DEL
Delete.
@item SFT
Shift.
@item CTL
Control.
@item META
Meta.
@end table

@subsection @@ctrl

@code{@@ctrl} is used to describe an ASCII control character.  The pattern
of usage is @code{@@ctrl@{@var{ch}@}}, where @var{ch} is an ASCII character whose
control-equivalent is wanted.

In the Info file, this generates the specified control character, output
literally into the file.

In a printed manual, this generates text to describe or identify that
control character: an uparrow followed by the character @var{ch}.

@subsection @@var

@code{@@var} is used to indicate metasyntactic variables.  Its effect in
the Info file is to upcase the argument; in the printed manual, to
italicize it.  Example:

@example
To delete file @@var@{file@}, type @@code@{rm @@var@{file@}@}.
@end example

@noindent
produces

@quotation
To delete file @var{file}, type @code{rm @var{file}}.
@end quotation

@subsection @@dfn

@code{@@dfn} is used to identify the introductory or defining use of a
technical term.  It generates italics in the printed manual, and double
quotation marks in the Info file.  Example:

@example
Getting rid of a file is called @@dfn@{deleting@} it.
@end example

@noindent
produces

@quotation
Getting rid of a file is called @dfn{deleting} it.
@end quotation

@subsection @@emph and @@strong

@code{@@emph} and @code{@@strong} two forms of emphasis.  @code{@@strong}
is stronger.

In printed output, @code{@@emph} produces italics and @code{@@strong}
produces bold.

In the Info file, both of these commands put asterisks around the
argument.

@subsection @@cite

@code{@@cite} is used for the name of a book.  It produces italics
in the printed manual, and quotation marks in the Info file.

@subsection @@i or @@b or @@t

These three commands specify font change in the printed manual and have no
effect in the Info file.  @code{@@i} requests italic font (actually,
slanted font is used by @TeX{}), @code{@@b} requests bold face, and
@code{@@t} requests the fixed-width font used by @code{@@kbd}.
All three commands apply to an argument that follows, surrounded by
braces.@refill

@subsection @@w

In a printed manual, @code{@@w@{@var{text}@}} outputs @var{text} and prohibits
line breaks within @var{text}.  @code{@@w} has no effect on the Info file
output; it is the same as would result from just @var{text}.

@subsection @@refill

If a paragraph contains sizeable @@-constructs, it may look badly filled
once texinfo is through with it.

Put @code{@@refill} at the end of the paragraph to tell texinfo to
refill the paragraph after finishing all other processing on it.
@code{@@refill} has no effect on @TeX{}, which always fills everything
that ought to be filled.  Example:@refill

@example
To use @@code@{foo@}, pass @@samp@{xx%$@} and @@var@{flag@} and type @@kbd@{x@}
after running @@code@{make-foo@}.@@refill
@end example

@noindent
produces (in the Info file)

@example
To use `foo', pass `xx%$' and FLAG and type `x' after running `make-foo'.
@end example

@noindent
whereas without the @code{@@refill} it would produce

@example
To use `foo', pass `xx%$' and FLAG and type `x'
after running `make-foo'.
@end example

@noindent
with the line broken at the same place as in the input.

@section Chapter Structuring Commands

The chapter structuring commands divide a document into a hierarchy of
chapters, sections, subsections and subsubsections.  These commands
generate large headings in the middle of the text.

In a printed manual, the table of contents is based on the information
specified by the chapter structuring commands.

@subsection @@chapter

@code{@@chapter} identifies a chapter in the document.  It is followed by a
single argument which is the rest of the line, as in

@example
@@chapter Texinfo Files
@end example

In @TeX{}, it serves to create a chapter of the document, specifying the
chapter title.

In the Info file, @code{@@chapter} causes its argument to appear on a line
by itself, with a line of asterisks inserted underneath.  Thus, the above
example produces the output@refill

@example
Texinfo Files
*************
@end example

@subsection @@unnumbered, @@appendix

These are equivalent to @code{@@chapter} for Info file output.  In a
printed manual, they generate chapters that are numbered differently in the
table of contents.  @code{@@unnumbered} chapters appear without chapter
numbers of any kind, and @code{@@appendix} chapters are given a letter
instead of a number.

@subsection @@section

@code{@@section} is like @code{@@chapter} except that in @TeX{} it makes
a section rather than a chapter.  Sections go within chapters.  In the Info
file, @code{@@chapter} and @code{@@section} differ only in that
@code{@@section} underlines with @samp{=}.@refill

@subsection @@unnumberedsec, @@appendixsec

Use these constructs for sections within chapters made by
@code{@@unnumbered} or @code{@@appendix}.

@subsection @@subsection

Subsections are to sections as sections are to chapters.  They are
underlined with @samp{-}.

@subsection @@unnumberedsubsec, @@appendixsubsec

Use these constructs for subsections within sections within chapters made
by @code{@@unnumbered} or @code{@@appendix}.

@subsection @@subsubsection

Subsubsections are to subsections as subsections are to sections.  They are
underlined with periods.

@section Nodes and Cross References

@dfn{Nodes} are the points to which cross-references can refer.  The
@code{@@node} command is used to define them.  Each node must be, also, a
chapter, section, subsection or subsubsection, and the @code{@@node}
command must always be followed by a chapter structuring command (with no
blank line between them).

In the Info file, nodes play a fundamental role.  Each node has a name,
and other nodes can refer to it by that name.  The @code{@@node} command
specifies the name of the node that it defines, and also defines certain
references to other nodes.  References to other nodes can also be defined
with @code{@@menu} and the variants of @code{@@xref}.

In a printed manual, nodes are not a fundamental concept, but the
@code{@@node} command still serves to define a cross-reference point
and the variants of @code{@@xref} still serve to make references.

@subsection @@node

@code{@@node} defines the beginning of a new node in the Info output file
(@inforef{top, info, info}.).  It is followed by four arguments, separated
by commas, making up the rest of the line.  For example,@refill

@example
@@node info, tex, commands, top
@end example

@noindent
defines a node named @code{info}, whose `next' pointer is to node
@code{tex}, whose `previous' pointer is to node @code{commands}, and whose
`up' pointer is to node @code{top}.  What this means is that texinfo
changes @w{@code{@@node @var{args}}} into the special text string necessary to
separate Info nodes and to identify the node that is starting and say what
nodes it points to.@refill

The pointer names should be the names of nodes defined elsewhere.  For this
example, nodes named @code{tex}, @code{commands} and @code{top} should be
defined elsewhere in the file with other @code{@@node} commands.  It does
not matter whether they are before or after the node that refers to
them.@refill

Normally, node @var{a}'s `up' should point at the node whose menu mentions
node @var{a}.  Node @var{a}'s `next' should point at the node that follows
@var{a} in that menu, and node @var{a}'s `previous' should point at the
node that precedes @var{a} in that menu.@refill

The top node of the file, named @samp{top}, should have as its parent the
name of a node in another file, where there is a menu that leads to this
file.  Specify the file name in parentheses.  If this file is to be
installed directly in the Info directory file, use @samp{(dir)} as the
parent of the top node; this is short for @samp{(dir)top}, the node @samp{top}
in the file @file{dir}, which is the main menu of Info.

In @TeX{}, @code{@@node} is nearly ignored.  It generates no text.  Its
only function is to identify the name to use for cross-references to the
following chapter or section which makes up the body of the node.  (Cross
references are made with @code{@@xref}.)@refill

@code{@@node} should be followed immediately by a chapter-structuring
command such as @code{@@chapter}, @code{@@section}, @code{@@subsection} or
@code{@@subsubsection}.

@subsection @@menu

Info file nodes can contain @dfn{menus} which point to other nodes.  You
must type the menus in by hand, and surround them with lines containing
@code{@@menu} and @code{@@end menu}.  The @code{@@menu} line changes
into @code{* Menu:}, which indicates the beginning of a menu to the Info
program.  The contents are unchanged by texinfo, except for the processing
of any other @@ commands within.  The entire menu construct has no effect
in the printed manual.@refill

@example
@@menu
* foo::         The node named foo tells you how to go fooing.
* sw: switches. Type @@code@{m sw@} to see node @@code@{switches@}.
                which describes the switches available here.
@@end menu
@end example

@noindent
produces

@example
* menu:

* foo::         The node named foo tells you how to go fooing.
* sw: switches. Type `m sw' to see node `switches'
                which describes the switches available here.
@end example

In this example, the menu has two items.  @samp{foo} is both a menu item name
and the name of the node referred to by that item.  @samp{sw} is the other
menu item name, and it refers to the node named @samp{switches}.  Since no
file name is specified with @samp{foo} or @samp{switches}, they must be the names
of other nodes in the same Info file.  Nodes in other Info files can be
referred to by putting the file name in parentheses at the beginning of the
node name.

@subsection @@xref

@code{@@xref} generates a cross-reference.  In texinfo, it turns into
an Info cross-reference which the Info @code{f} command can use
to go directly to another node.  In @TeX{}, it turns into a sentence
of the form

@example
See section @var{section} [@var{topic}], page @var{page}
@end example

@noindent
but does not generate a period to end it.

@code{@@xref} must refer to an Info node created by @code{@@node}, by the
node's name.  If I were in less of a rush, I would have made a node in this
file for each texinfo command, and put in plenty of @@xref's to
cross-reference them together.  The big node named @code{commands} would
actually contain a menu naming the nodes for individual commands.

@code{@@xref} is followed by an argument inside braces, since it is used
within a paragraph; but actually the text inside the braces is treated as
several arguments, separated by commas.  Whitespace after these commas is
ignored.  The closing brace must be followed by a period or a comma, since
one of those two is required to terminate an Info cross-reference.  This
period or comma will appear in the output, both Info file and printed
manual.

The simplest form of @code{@@xref} takes one argument, the name of another
node in the same Info file.  Here we show the input text, followed after a
blank line by the output text for Info files and the output text for
printed manuals.

@example
@@xref@{foo@}, for more info.

*note foo::, for more info.
@end example

@quotation
See section @var{nnn} [foo], page @var{ppp}, for more info.
@end quotation

With two arguments, the second one is used as the name of the Info
cross-reference, while the first argument is still the node that the
cross-reference points to:

@example
@@xref@{foo node, foo@}, for more info.

*note foo: foo node, for more info.
@end example

@quotation
See section @var{nnn} [foo node], page @var{ppp}, for more info.
@end quotation

A third argument replaces the node name when it actually appears
in the TeX output.  It should state the topic discussed by the
section being referenced.  Use a third argument when the node
name is unsuitable because of syntax, grammar or diction.

@example
@@xref@{foo node, foo, using foo@}, for more info.

*note foo: foo node, for more info.
@end example

@quotation
See section @var{nnn} [using foo], page @var{ppp}, for more info.
@end quotation

If a third argument is given and the second one is empty,
then the third argument serves both purposes:

@example
@@xref@{foo node, , using foo@}, for more info.

*note using foo: foo node, for more info.
@end example

@quotation
See section @var{nnn} [using foo], page @var{ppp}, for more info.
@end quotation

A fourth argument specifies the name of the Info file in which
the referenced node is located, assuming it is not the one which
the reference appears in.  @code{@@xref} with only four arguments
is used when the reference is not within one Info file, but is
within a single printed manual---when multiple texinfo files are
incorporated into the same TeX run but make separate Info files.

@example
@@xref@{foo node, foo, using foo, myinfofile@}, for more info.

*note foo: (myinfofile) foo node, for more info.
@end example

@quotation
See section @var{nnn} [using foo], page @var{ppp}, for more info.
@end quotation

A fifth argument is used when referencing another Info file
which is also part of another printed manual.  It gives the
title of that manual.

@example
@@xref@{foo node, foo, using foo, myinfofile, Mymanual@},
for more info.

*note foo: (myinfofile) foo node, for more info.
@end example

@quotation
See section @var{nnn} [using foo], page @var{ppp}
of Mymanual, for more info.
@end quotation

@subsection @@pxref

@code{@@pxref} is nearly the same as @code{@@xref}; it differs in only
two ways:

@enumerate
@item
The output starts with lower case `see' rather than `See'.
@item
A period is generated automatically in the Info file output to end the
Info cross-reference.
@end enumerate

The purpose of @code{@@pxref} is to be used inside parentheses as part of
another sentence.  In the printed manual, no period is needed after the
cross reference text itself (within the parentheses), but a period is
needed there in the Info file because only thus can Info recognize the end
of the cross-reference.  @code{@@pxref} spares you the need to use complicated
methods to put a period into one form of the output and not the other.

@subsection @@inforef

@code{@@inforef} is used for cross-references to Info files for which
there are no printed manuals.  Even in a printed manual, @code{@@inforef}
generates a reference directing the user to look in an Info file.  The
syntax is @code{@@inforef@{@var{node}, @var{name}, @var{file}@}}.

@example
@@inforef@{foo node, fooing, FOO@}, to lose.

*note fooing: (FOO) foo node, to lose.
@end example

@quotation
See Info file @file{FOO}, node `foo node', to lose.
@end quotation

@section Insertions

Insertions are blocks of text, consisting of one or more whole paragraphs
that are set off from the bulk of the text and treated differently.  They
are usually indented, and often not filled.

In texinfo, an insertion is always begun by an @@-command on a line by
itself, and ended with an @code{@@end} command.  For example, an @dfn{example}
is a kind of insertion that is begun with @code{@@example} and ended with
@code{@@end example}.

@subsection @@quotation

@code{@@quotation} is used to indicate text that is excerpted from another
(real or hypothetical) printed work.  The inside of a quotation is
processed normally except that

@enumerate
@item
The margins are narrower.
@item
Paragraphs are not indented.
@item
Interline spacing and interparagraph spacing are reduced.
@end enumerate

Thus, the input

@example
@@quotation
This is
a foo.
@@end quotation
@end example

@noindent
produces in the printed manual

@quotation
@quotation
This is a foo.
@end quotation
@end quotation

@noindent
and in the Info file

@quotation
@example
This is
a foo.
@end example
@end quotation

@subsection @@example

@code{@@example} is used to indicate an example that is not part of the
running text.  In the printed manual, this is done by switching to
a fixed width font, turning off filling, and making extra spaces
and blank lines significant.  In the Info file, an analogous result
is obtained by indenting each line with five extra spaces.

@code{@@example} should appear on a line by itself; this line will
disappear from the output.  Mark the end of the example with a line
containing @code{@@end example}, which will likewise disappear.
Example:

@example
@@example
mv foo bar
@@end example
@end example

@noindent
produces

@quotation
@example
mv foo bar
@end example
@end quotation

Don't use tabs in lines of an example!

@subsection @@display

@code{@@display} is just like @code{@@example} except that, in the
printed manual, @code{@@display} does not select the fixed-width font.
In fact, it does not specify the font at all, so that the text appears
in the same font it would have appeared in without the @code{@@display}.@refill

@subsection @@itemize

@code{@@itemize} is used to produce sequences of indented paragraphs, with
a mark inside the left margin at the beginning of each.  The rest of the
line that starts with @code{@@itemize} should contain the character or
texinfo commands to generate such a mark.  It should ultimately result in a
single character, or the indentation will come out wrong.  You may use
the texinfo commands that are normally followed by @samp{@{@}}; in fact, you 
may omit the @samp{@{@}} after the command if you use just one command
and nothing else.

The text of the indented paragraphs themselves come after the @code{@@itemize},
up to another line that says @code{@@end @@itemize}.

Before each paragraph for which a mark in the margin is desired, place a
line that says just @code{@@item}.

Here is an example of the use of @code{@@itemize}, followed by the output
it produces.  Note that @code{@@bullet} produces a @code{*} in texinfo and
a round dot in @TeX{}.

@example
@@itemize @@bullet
@@item
Some text for foo.
@@item
Some text
for bar.
@@end itemize
@end example

@noindent
produces

@quotation
@itemize @bullet
@item
Some text for foo.
@item
Some text
for bar.
@end itemize
@end quotation

Texinfo indents the lines of the itemization by five additional columns,
but it does not fill them.  If @code{@@refill} is used, the paragraph is
filled to the narrowed width.

@subsection @@enumerate

@code{@@enumerate} is like @code{@@itemize} except that the marks in the
left margin contain successive integers starting with 1.  Do not put any
argument on the same line as @code{@@enumerate}.@refill

@example
@@enumerate
@@item
Some text for foo.
@@item
Some text
for bar.
@@end enumerate
@end example

@noindent
produces

@quotation
@enumerate
@item
Some text for foo.
@item
Some text
for bar.
@end enumerate
@end quotation

@subsection @@table

@code{@@table} is similar to @code{@@itemize}, but allows you to specify a
name or heading line for each item.

You must follow each use of @code{@@item} inside of @code{@@table} with
text to serve as the heading line for that item.

Also, @code{@@table} itself must be followed by an argument that is a
texinfo command such as @code{@@code}, @code{@@var}, @code{@@kbd} or
@code{@@asis}.  This command will be applied to the text of each item.
@code{@@asis} is a command that does nothing; in that case, each item will
come out exactly as it specifies.  (Various other command names might work
in this context.  Only commands that normally take arguments in braces may
be used, but here you use the command name without an argument.
@code{@@item} supplies the arguments.)@refill

@example
@@table @@samp
@@item foo
This is the text for
@@samp@{foo@}.
@@item bar
Text for @@samp@{bar@}.
@@end table
@end example

@noindent
produces

@quotation
@table @samp
@item foo
This is the text for
@samp{foo}.
@item bar
Text for @samp{bar}.
@end table
@end quotation

@subsection @@itemx

@code{@@itemx} is used inside a @code{@@table} when you have
two or more named items for the same block of text.  Use @code{@@itemx}
for all but the first of the items.  It works exactly like @code{@@item}
except that it does not generate extra vertical space above the item text.
Example:@refill

@example
@@table @@code
@@item upcase
@@itemx downcase
These two functions accept a character or a string as argument,
and return the corresponding upper case (lower case) character
or string.
@@end table
@end example

@noindent
produces

@quotation
@table @code
@item upcase
@itemx downcase
These two functions accept a character or a string as argument,
and return the corresponding upper case (lower case) character
or string.
@end table
@end quotation

@subsection @@noindent

@code{@@noindent} is not a kind of insertion, but it is normally used
following an insertion.

If you have text following an @code{@@example} or other similar ``special
paragraph'' that reads as a continuation of the text before the
@code{@@example}, it is good to prevent this text from being indented as a
new paragraph.  To accomplish this, put @code{@@noindent} on a line by
itself before the start of the text that should not be indented.

To adjust the number of blank lines properly in the Info file output,
remember that the line containing @code{@@noindent} does not generate a
blank line, and neither does the @code{@@end example} line.

In the texinfo source file for this documentation, each of the lines that
says `produces' is preceded by a line containing @code{@@noindent}.

@section Other Paragraph-Separating Commands

@subsection @@setfilename

@code{@@setfilename @var{file}} informs texinfo that the Info file being
produced is named @var{file}.  This information is entered in every node
header.  It also tells texinfo the name for the output file.

@subsection @@comment

A line starting with @code{@@comment} or @code{@@c} is ignored in both
printed and Info output.

@subsection @@ignore

A line saying @code{@@ignore} causes everything up to the following
@code{@@end ignore} to be ignored in both printed and Info output.

@subsection @@br

In a printed manual, a line containing @code{@@br} forces a paragraph
break; in the Info file output, it does nothing (not even a blank line
results from it).

@subsection @@sp

A line containing @code{@@sp @var{n}} generates @var{n} blank lines of space in either the
printed manual or the Info file.

@subsection @@page

A line containing @code{@@page} starts a new page in a printed manual.  The
line has no effect on Info files since they are not paginated.

@subsection @@group

A line containing @code{@@group} begins an unsplittable vertical group,
which must appear entirely on one page.  The group is terminated by a line
containing @code{@@end group}.  These two lines produce no output of their
own, and in the Info file output they have no effect at all.

@subsection @@need

A line containing @code{@@need @var{n}} starts a new page in a printed
manual if fewer than @var{n} mils (thousandths of an inch) remain on the
current page.  The line has no effect on Info files since they are not
paginated.@refill

@subsection @@center

A line containing @code{@@center @var{text}} produces a line of output containing @var{text},
centered between the margins.

@subsection Conditionals

You may not always be able to use the same text for @TeX{} and texinfo.
Use the conditional commands to specify which text is for @TeX{} and which
is for texinfo.

@code{@@ifinfo} begins text that should be ignored by @TeX{}.  It should
appear on a line by itself.  End the texinfo-only text with a line
containing @code{@@end ifinfo}.@refill

Likewise, @code{@@iftex} and @code{@@end iftex} lines delimit code
that should be ignored by texinfo.@refill

@section Generating Indices

Texinfo files can generate indices automatically.  Each index covers
a certain kind of entry (functions, or variables, or concepts, etc.)@:
and lists all of those entries in alphabetical order, together with
information on how to find the discussion of each entry.  In a printed
manual, this information consists of page numbers.  In an Info file,
it consists of a menu item leading to the node in which the entry
is discussed.


Normally, six indices are provided for:

@itemize @bullet
@item
A @dfn{program index} listing names of programs and leading to the places
where those programs are documented.

@item
A @dfn{function index} listing functions (such as, entry points of
libraries).

@item
A @dfn{variables index} listing variables (such as, external variables of
libraries).

@item
A @dfn{data type index} listing data types (such as, structures defined in
header files).

@item
A @dfn{keystroke index} listing keyboard commands.

@item
A @dfn{concept index} listing concepts that are discussed.
@end itemize

@noindent
Not every manual needs all of these.  Two or more indices can be combined
into one using the @code{@@synindex} command as described below.

@subsection Defining the Entries of an Index

The data to make an index comes from many individual commands scattered
throughout the source file.  Each command says to add one entry to a
particular index, giving the current page number or node name as the
reference.

@table @code
@item @@cindex @var{concept}
Make an entry in the concept index for @var{concept}, referring to the
current page or node.
@item @@findex @var{function}
Make an entry in the function index for @var{function}, referring to the
current page or node.
@item @@vindex @var{variable}
Make an entry in the variable index for @var{variable}, referring to the
current page or node.
@item @@pindex @var{program}
Make an entry in the program index for @var{program}, referring to the
current page or node.
@item @@kindex @var{key}
Make an entry in the key index for @var{key}, referring to the
current page or node.
@item @@tindex @var{data type}
Make an entry in the data type index for @var{data type}, referring to the
current page or node.
@end table

If the same name is indexed on several pages, all the pages are listed
in the printed manual's index.  However, only the first node referenced
will appear in the index of an Info file.

You are not actually required to use these indices for their canonical
purposes.  For example, you might wish to index some C preprocessor macros.
You could put them in the function index along with actual functions, just
by writing @code{@@findex} commands for them; then, when you print the
``function index'', you could give it the title `Function and Macro Index'
and all will be consistent for the reader.  Or you could put the macros in
with the data types by writing @code{@@tindex} commands for them, and give
that index a suitable title so the reader will understand.

@subsection Combining Indices

Sometimes you will want to combine two disparate indices such as functions
and variables, perhaps because you have few enough of one of them that
a separate index for them would look silly.

You could put variables into the function index by writing @code{@@findex}
commands for them instead of @code{@@vindex} commands, and produce a
consistent manual by printing the function index with the title `Function
and Variable Index' and not printing the ``variable index'' at all; but this
is not a robust procedure.  It works only as long as your document is never
included in part of or together with another document that is designed to
have a separate variable index; if you did that, the variables from your
document and those from the other would not end up together.

What you should do instead when you want functions and variables in one
index is to index the variables with @code{@@vindex} as they should be,
but in the overall file for the document use @code{@@synindex} to redirect
these @code{@@vindex} commands to the function index.  @code{@@synindex} takes two
arguments: the name of an index to redirect, and the name of an index to
redirect it to.  For this purpose, the indices are given two-letter names:

@table @samp
@item cp
the concept index.
@item vr
the variable index.
@item fn
the function index.
@item ky
the key index.
@item pg
the program index.
@item tp
the data type index.
@end table

Thus, @code{@@synindex vr fn} at the front of an overall manual file
will cause all entries designated for the variable index to go to
the function index as well.  But the included files of this manual
could be used in some other manual, that does not do @code{@@synindex},
and generate a separate variable index.

If the texinfo file containing @code{@@synindex} is also to be made into
an Info file itself, you should use @code{@@iftex} around the @code{@@synindex}
commands.

@subsection Printing an Index

To print an index means to include it as part of a manual or Info file.
This does not happen automatically just because you use @code{@@cindex} or
other index-entry generating commands in the input; those just cause the
raw data for the index to be accumulated.  To print an index, you must
include special texinfo commands at the place in the document where you
want the index to appear.  Also, for the case of the printed manual, you
must run a special program to sort the raw data to produce a sorted index
file, which is what will actually be used to print the index.@refill

The texinfo command you need is @code{@@printindex}.  It takes the
two-letter index name (see table above) as an argument without braces, and
reads the corresponding sorted index file and formats it appropriately into
an index.@refill

@code{@@printindex} does not generate a chapter heading for the index.
You should precede it with a suitable section or chapter command (usually
@code{@@unnumbered}) to supply the chapter heading and put the index into
the table of contents.  And before that, you probably need a @code{@@node}
command.  For example,@refill

@example
@@node Variables Index, Concept Index, Function Index, Top
@@unnumbered Variable Index

@@printindex vr

@@node Concept index,, Variables Index, Top
@@unnumbered Concept Index

@@printindex cp
@end example

@subsection Sorting Indices

In @TeX{}, @code{@@printindex} needs a sorted index file to work from.
@TeX{} does not know how to do sorting; this is one of the main
deficiencies of @TeX{}.  You must invoke the program @code{texindex} to do
so, giving it the names of the raw index files to be sorted as arguments.
You do not have to run @code{texindex} on all of them; only the ones you
are going to print.

@TeX{} outputs raw index files under names that obey a standard convention.
These names are the name of your main input file to @TeX{}, with everything
after the first period thrown away, and the two letter names of indices
added at the end.  For example, the raw index output files for the input
file @file{foo.texinfo} would be @file{foo.cp}, @file{foo.vr},
@file{foo.fn}, @file{foo.tp}, @file{foo.pg} and @file{foo.ky}.  Those are
exactly the arguments to give to @code{texindex}.@refill

For each file specified, @code{texindex} generates a sorted index file whose
name is made by appending @samp{s} to the input file name.  The
@code{@@printindex} command knows to look for a file of that name.
@code{texindex} does not alter the raw index output file.@refill

You need not run @code{texindex} after each @TeX{} run.  If you don't, the
next @TeX{} run will use whatever sorted index files happen to exist from
the previous use of @code{texindex}.  This is usually ok while you are
debugging.

@node make-info, manual ,commands, top
@section Converting Texinfo Files into Info Files

Just visit a texinfo file and invoke

@example
@kbd{Meta-x texinfo-format-buffer}
@end example

@noindent
to convert it to an Info file.  A new buffer is created and the Info file
text is generated there.  @kbd{C-x C-s} will save it under the name specified
in the @code{@@setfilename} command.

If the file is large (more than 30 nodes) it is desirable to make a
@dfn{tag table} for it.  To do this, load the @code{info} library
into Emacs with @kbd{M-x load @key{RET} info @key{RET}} and then
do @kbd{M-x Info-tagify}.@refill

To check your node structure for errors, load Info and then do
@kbd{M-x Info-validate}.

@node manual,, make-info, top
@section Generating a Real Manual

Most of the time a single printed manual will be made from several texinfo
source files, each of which is made into a single Info file.  Also, the
real manual should have a table of contents.  Several special commands are
used for these purposes.

Every texinfo file that is to be the top-level input to @TeX{} must begin
with a line that looks like

@example
\input texinfo   @@c -*-texinfo-*-
@end example

@noindent
This serves two functions.

@enumerate
@item
When the file is processed by @TeX{}, it loads the macros needed for
processing a texinfo file.
@item
When the file is edited in Emacs, it causes Texinfo Mode to be used.
@end enumerate

Every such texinfo file must end with a line saying

@example
@@bye
@end example

which terminates @TeX{} processing and forces out unfinished pages.

You might also want to include a line saying

@example
@@setchapternewpage odd
@end example

@noindent
to cause each chapter to start on a fresh odd-numbered page.

Here is an example of a texinfo file used to generate a manual from two
other texinfo files, @samp{foo.texinfo} and @samp{bar.texinfo}, each of
which makes a separate Info file.  The commands used in it are explained
in the rest of this section.@refill

@example
\input texinfo @@c -*-texinfo-*-
@@settitle This Manual

@@c put entries intended for the data type index
@@c into the variable index instead.
@@synindex tp vr
@@setchapternewpage odd

@@titlepage
@@sp 10
@@center @@titlefont@{This Manual@}
@@sp 3
@@center by
@@sp 3
@@center @@titlefont@{Me@}
@@end titlepage

@@c Include the files with the actual text
@@include foo.texinfo
@@include bar.texinfo

@@c Print the indices
@@unnumbered Function Index
@@printindex fn
@@unnumbered Variable and Data Type Index
@@printindex vr
@@unnumbered Program Index
@@printindex pg
@@unnumbered Concept Index
@@printindex cp

@@c Print the tables of contents
@@summarycontents
@@contents

@@c That's all
@@bye
@end example

@subsection Title Page

Start the material for the title page with @samp{@@titlepage} and follow it
with @samp{@@end titlepage}.  Both of these commands should stand alone on
a line.  They cause the title material to appear only in the printed
manual, not in an info file.  Also, the @samp{@@end titlepage} command
starts a new page and turns on page numbering (generation of headings).

The within-paragraph command @samp{@@titlefont} can be used to select a
large font suitable for the title itself.

@subsection Headings

Texinfo prints the manual title on every other page as a heading, and the
current chapter title on the remaining pages.  It knows the chapter title
automatically, but you must tell it the manual title with @code{@@settitle}:

@example
@@settitle @var{title}
@end example

@noindent
on a line by itself causes @var{title} to be used for the headings.

The @code{@@settitle} command should precede everything that generates
actual output.

Normally, headings appear on all pages following the @samp{@@end titlepage}
command.  (Headings are not wanted on the title page.)  However, you can
turn headings on and off explicitly with the @samp{@@headings} command:

@example
@@headings on
@end example

@noindent
to start output of headings (starting with the page containing the command)
or

@example
@@headings off
@end example

@noindent
to stop output of headings (starting also with the current page).

@subsection @@include

A line of the form @code{@@include @var{filename}} is ignored when generating an
Info file, but in a printed manual it causes the contents of the file
@var{filename} to be processed at that point.

Normally, the file named @var{filename} is made into a separate Info file.
The file containing the @code{@@include} may refer to the other Info file
with Info cross-references or menus, since those fill the function of
inclusion for the Info data base.

Another technique is to have a special file, used only for making a
comprehensive manual, containing nothing but the beginning, the end, and a
bunch of @code{@@include} commands.

A file that is intended to be processed with @code{@@include} should not
start with @samp{\input texinfo}, as that has already been done by the
outer file, and the character @samp{\} has already been redefined to
generate a backslash in the output.

A file that is intended to be processed with @code{@@include} should not
end with @code{@@bye}, since that would terminate @TeX{} processing immediately.

@subsection Table of Contents

The commands @code{@@chapter}, @code{@@section}, etc., supply the
information to make up a table of contents, but they do not cause an actual
table to be output.  To do this, you must use the commands
@code{@@contents} and @code{@@summarycontents}.@refill

@code{@@contents}, which should be used on a line by itself, outputs (into
a printed manual) a complete table of contents, based on the
@code{@@chapter} and other sectioning commands already seen.@refill

@code{@@summarycontents} generates a summary table of contents that lists
only the chapters (and appendixes and unnumbered chapters); sections,
subsections and subsubsections are omitted.

You can use either one of these commands, or both.  Each one automatically
generates a chapter-like heading at the top of the page.  Tables of
contents should be generated at the very end of the manual, just before the
@code{@@bye} command; they should follow any indices that are output, so
that the indices will appear in the contents.

@example
@var{indices}@dots{}
@@summarycontents
@@contents
@@bye
@end example

The commands @code{@@contents} and @code{@@summarycontents} are ignored when an
Info file is being generated.

@contents
@bye
