Texinfo

The GNU Documentation Format

Edition 2.18, for Texinfo Version Two

March 1993

Copyright © 1988, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.

This is the second edition of the Texinfo documentation,
and is consistent with version 2 of ‘texinfo.tex’.

Published by the Free Software Foundation
675 Massachusetts Avenue,
Cambridge, MA 02139 USA
Printed copies are available for $15 each.
ISBN-1882114-12-4

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.

Cover art by Etienne Suvasa.

 — The Detailed Node Listing —

Overview of Texinfo

Using Texinfo Mode

Updating Nodes and Menus

Beginning a Texinfo File

The Texinfo File Header

The Title and Copyright Pages

The ‘Top’ Node and Master Menu

Ending a Texinfo File

Chapter Structuring

Nodes

The @node Command

Menus

Cross References

@xref

Marking Words and Phrases

Indicating Definitions, Commands, etc.

Emphasizing Text

Quotations and Examples

Making Lists and Tables

Making a Two-column Table

Creating Indices

Combining Indices

Special Insertions

Inserting ‘@’, Braces, and Periods

Inserting Ellipsis, Dots, and Bullets

Inserting TeX and the Copyright Symbol

Glyphs for Examples 

Making and Preventing Breaks

Definition Commands

The Definition Commands

Conditionally Visible Text

@set, @clear, and @value

Format and Print Hardcopy

Creating an Info File

Installing an Info File

Sample Permissions

Include Files

Page Headings

Formatting Mistakes

Finding Badly Referenced Nodes

Second Edition Features

Texinfo Copying Conditions

The programs currently being distributed that relate to Texinfo include portions of GNU Emacs, plus other separate programs (including makeinfo, info, texindex, and ‘texinfo.tex’). These programs are free; this means that everyone is free to use them and free to redistribute them on a free basis. The Texinfo-related programs are not in the public domain; they are copyrighted and there are restrictions on their distribution, but these restrictions are designed to permit everything that a good cooperating citizen would want to do. What is not allowed is to try to prevent others from further sharing any version of these programs that they might get from you.

Specifically, we want to make sure that you have the right to give away copies of the programs that relate to Texinfo, that you receive source code or else can get it if you want it, that you can change these programs or use pieces of them in new free programs, and that you know you can do these things.

To make sure that everyone has such rights, we have to forbid you to deprive anyone else of these rights. For example, if you distribute copies of the Texinfo related programs, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must tell them their rights.

Also, for our own protection, we must make certain that everyone finds out that there is no warranty for the programs that relate to Texinfo. If these programs are modified by someone else and passed on, we want their recipients to know that what they have is not what we distributed, so that any problems introduced by others will not reflect on our reputation.

The precise conditions of the licenses for the programs currently being distributed that relate to Texinfo are found in the General Public Licenses that accompany them.

1 Overview of Texinfo

Texinfo(1) is a documentation system that uses a single source file to produce both on-line information and printed output. This means that instead of writing two different documents, one for the on-line help or other on-line information and the other for a typeset manual or other printed work, you need write only one document. When the work is revised, you need revise only one document. (You can read the on-line information, known as an Info file, with an Info documentation-reading program.)

Using Texinfo, you can create a printed document with the normal features of a book, including chapters, sections, cross references, and indices. From the same Texinfo source file, you can create a menu-driven, on-line Info file with nodes, menus, cross references, and indices. You can, if you wish, make the chapters and sections of the printed document correspond to the nodes of the on-line information; and you use the same cross references and indices for both the Info file and the printed work. The GNU Emacs Manual is a good example of a Texinfo file, as is this manual.

To make a printed document, you process a Texinfo source file with the TeX typesetting program. This creates a DVI file that you can typeset and print as a book or report. (Note that the Texinfo language is completely different from TeX’s usual language, PlainTeX, which Texinfo replaces.) If you do not have TeX, but do have troff or nroff, you can use the texi2roff program instead.

To make an Info file, you process a Texinfo source file with the makeinfo utility or Emacs’s texinfo-format-buffer command; this creates an Info file that you can install on-line.

TeX and texi2roff work with many types of printer; similarly, Info works with almost every type of computer terminal. This power makes Texinfo a general purpose system, but brings with it a constraint, which is that a Texinfo file may contain only the customary “typewriter” characters (letters, numbers, spaces, and punctuation marks) but no special graphics.

A Texinfo file is a plain ASCII file containing text and @-commands (words preceded by an ‘@’) that tell the typesetting and formatting programs what to do. You may edit a Texinfo file with any text editor; but it is especially convenient to use GNU Emacs since that editor has a special mode, called Texinfo mode, that provides various Texinfo-related features. (See section Using Texinfo Mode.)

Before writing a Texinfo source file, you should become familiar with the Info documentation reading program and learn about nodes, menus, cross references, and the rest. (See (info)info, for more information.)

You can use Texinfo to create both on-line help and printed manuals; moreover, Texinfo is freely redistributable. For these reasons, Texinfo is the format in which documentation for GNU utilities and libraries is written.

1.1 Info files

An Info file is a Texinfo file formatted so that the Info documentation reading program can operate on it. (makeinfo and texinfo-format-buffer are two commands that convert a Texinfo file into an Info file.)

Info files are divided into pieces called 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. The Info program displays one node at a time, and provides commands with which the user can move to other related nodes.

Each node of an Info file may have any number of child nodes that describe subtopics of the node’s topic. The names of child nodes are listed in a menu within the parent node; this allows you to use certain Info commands to move to one of the child nodes. Generally, an Info file is organized like a book. If a node is at the logical level of a chapter, its child nodes are at the level of sections; likewise, the child nodes of sections are at the level of subsections.

All the children of any one parent are linked together in a bidirectional chain of ‘Next’ and ‘Previous’ pointers. The ‘Next’ pointer provides a link to the next section, and the ‘Previous’ pointer provides a link to the previous section. This means that all the nodes that are at the level of sections within a chapter are linked together. Normally the order in this chain is the same as the order of the children in the parent’s menu. Each child node records the parent node name as its ‘Up’ pointer. The last child has no ‘Next’ pointer, and the first child has the parent both as its ‘Previous’ and as its ‘Up’ pointer.(2)

The book-like structuring of an Info file into nodes that correspond to chapters, sections, and the like is a matter of convention, not a requirement. The ‘Up’, ‘Previous’, and ‘Next’ pointers of a node can point to any other nodes, and a menu can contain any other nodes. Thus, the node structure can be any directed graph. But it is usually more comprehensible to follow a structure that corresponds to the structure of chapters and sections in a printed book or report.

In addition to menus and to ‘Next’, ‘Previous’, and ‘Up’ pointers, Info provides pointers of another kind, called references, that can be sprinkled throughout the text. This is usually the best way to represent links that do not fit a hierarchical structure.

Usually, you will design a document so that its nodes match the structure of chapters and sections in the printed output. But there are times when this is not right for the material being discussed. Therefore, Texinfo uses separate commands to specify the node structure for the Info file and the section structure for the printed output.

Generally, you enter an Info file through a node that by convention is called ‘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. From this node, you can either traverse the file systematically by going from node to node, or you can go to a specific node listed in the main menu, or you can search the index menus and then go directly to the node that has the information you want.

If you want to read through an Info file in sequence, as if it were a printed manual, you can get the whole file with the advanced Info command g* <RET>. (See (info)Advanced Info commands.)

The ‘dir’ file in the ‘info’ directory serves as the departure point for the whole Info system. From it, you can reach the ‘Top’ nodes of each of the documents in a complete Info system.

1.2 Printed Books

A Texinfo file can be formatted and typeset as a printed book or manual. To do this, you need TeX, a powerful, sophisticated typesetting program written by Donald Knuth.(3)

A Texinfo-based book is similar to any other typeset, printed work: it can have a title page, copyright page, table of contents, and preface, as well as chapters, numbered or unnumbered sections and subsections, page headers, cross references, footnotes, and indices.

You can use Texinfo to write a book without ever having the intention of converting it into on-line information. You can use Texinfo for writing a printed novel, and even to write a printed memo, although this latter application is not recommended since electronic mail is so much easier.

TeX is a general purpose typesetting program. Texinfo provides a file called ‘texinfo.tex’ that contains information (definitions or macros) that TeX uses when it typesets a Texinfo file. (‘texinfo.tex’ tells TeX how to convert the Texinfo @-commands to TeX commands, which TeX can then process to create the typeset document.) ‘texinfo.tex’ contains the specifications for printing a document.

Most often, documents are printed on 8.5 inch by 11 inch pages (216mm by 280mm; this is the default size), but you can also print for 7 inch by 9.25 inch pages (178mm by 235mm; the @smallbook size) or on European A4 size paper (@afourpaper). (See section Printing “Small” Books. Also, see Printing on A4 Paper.)

By changing the parameters in ‘texinfo.tex’, you can change the size of the printed document. In addition, you can change the style in which the printed document is formatted; for example, you can change the sizes and fonts used, the amount of indentation for each paragraph, the degree to which words are hyphenated, and the like. By changing the specifications, you can make a book look dignified, old and serious, or light-hearted, young and cheery.

TeX is freely distributable. It is written in a dialect of Pascal called WEB and can be compiled either in Pascal or (by using a conversion program that comes with the TeX distribution) in C. (See TeX Mode in The GNU Emacs Manual, for information about TeX.)

TeX is very powerful and has a great many features. Because a Texinfo file must be able to present information both on a character-only terminal in Info form and in a typeset book, the formatting commands that Texinfo supports are necessarily limited.

See section How to Obtain TeX.

1.3 @-commands

In a Texinfo file, the commands that tell TeX how to typeset the printed manual and tell makeinfo and texinfo-format-buffer how to create an Info file are preceded by ‘@’; they are called @-commands. For example, @node is the command to indicate a node and @chapter is the command to indicate the start of a chapter.

Please note: All the @-commands, with the exception of the @TeX{} command, must be written entirely in lower case.

The Texinfo @-commands are a strictly limited set of constructs. The strict limits make it possible for Texinfo files to be understood both by TeX and by the code that converts them into Info files. You can display Info files on any terminal that displays alphabetic and numeric characters. Similarly, you can print the output generated by TeX on a wide variety of printers.

Depending on what they do or what arguments(4) they take, you need to write @-commands on lines of their own or as part of sentences:

• Write a command such as @noindent at the beginning of a line as the only text on the line. (@noindent prevents the beginning of the next line from being indented as the beginning of a paragraph.)
• Write a command such as @chapter at the beginning of a line followed by the command’s arguments, in this case the chapter title, on the rest of the line. (@chapter creates chapter titles.)
• Write a command such as @dots{} wherever you wish but usually within a sentence. (@dots{} creates dots …)
• Write a command such as @code{sample-code} wherever you wish (but usually within a sentence) with its argument, sample-code in this example, between the braces. (@code marks text as being code.)
• Write a command such as @example at the beginning of a line of its own; write the body-text on following lines; and write the matching @end command, @end example in this case, at the beginning of a line of its own after the body-text. (@example … @end example indents and typesets body-text as an example.)

As a general rule, a command requires braces if it mingles among other text; but it does not need braces if it starts a line of its own. The non-alphabetic commands, such as @:, are exceptions to the rule; they do not need braces.

As you gain experience with Texinfo, you will rapidly learn how to write the different commands: the different ways to write commands make it easier to write and read Texinfo files than if all commands followed exactly the same syntax. (For details about @-command syntax, see @-Command Syntax.)

1.4 General Syntactic Conventions

All ASCII printing characters except ‘@’, ‘{’ and ‘}’ can appear in a Texinfo file and stand for themselves. ‘@’ is the escape character which introduces commands. ‘{’ and ‘}’ should be used only to surround arguments to certain commands. To put one of these special characters into the document, put an ‘@’ character in front of it, like this: ‘@@’, ‘@{’, and ‘@}’.

Use three hyphens in a row, ‘---’, for a dash—like this. In TeX, a single or even a double hyphen produces a printed dash that is shorter than the usual typeset dash. Info reduces three hyphens to two for display on the screen.

To prevent a paragraph from being indented in the printed manual, put the command @noindent on a line by itself before the paragraph.

If you mark off a region of the Texinfo file with the @iftex and @end iftex commands, that region will appear only in the printed copy; in that region, you can use certain commands borrowed from PlainTeX that you cannot use in Info. Likewise, if you mark off a region with the @ifinfo and @end ifinfo commands, that region will appear only in the Info file; in that region, you can use Info commands that you cannot use in TeX. (See section Conditionally Visible Text.)

Caution: Do not use tabs in a Texinfo file! TeX uses variable-width fonts, which means that it cannot predefine a tab to work in all circumstances. Consequently, TeX treats tabs like single spaces, and that is not what they look like.

To avoid this problem, Texinfo mode causes GNU Emacs to insert multiple spaces when you press the <TAB> key.

Also, you can run untabify in Emacs to convert tabs in a region to multiple spaces.

1.5 Comments

You can write comments in a Texinfo file that will not appear in either the Info file or the printed manual by using the @comment command (which may be abbreviated to @c). Such comments are for the person who reads the Texinfo file. All the text on a line that follows either @comment or @c is a comment; the rest of the line does not appear in either the Info file or the printed manual. (Often, you can write the @comment or @c in the middle of a line, and only the text that follows after the @comment or @c command does not appear; but some commands, such as @settitle and @setfilename, work on a whole line. You cannot use @comment or @c in a line beginning with such a command.)

You can write long stretches of text that will not appear in either the Info file or the printed manual by using the @ignore and @end ignore commands. Write each of these commands on a line of its own, starting each command at the beginning of the line. Text between these two commands does not appear in the processed output. You can use @ignore and @end ignore for writing comments. Often, @ignore and @end ignore is used to enclose a part of the copying permissions that applies to the Texinfo source file of a document, but not to the Info or printed version of the document.

1.6 What a Texinfo File Must Have

By convention, the names of Texinfo files end with one of the extensions ‘.texinfo’, ‘.texi’, or ‘.tex’. The longer extension is preferred since it describes more clearly to a human reader the nature of the file. The shorter extensions are for operating systems that cannot handle long file names.

In order to be made into a printed manual and an Info file, a Texinfo file must begin with lines like this:

\input texinfo
@setfilename info-file-name
@settitle name-of-manual

The contents of the file follow this beginning, and then you must end a Texinfo file with a line like this:

@bye

The ‘\input texinfo’ line tells TeX to use the ‘texinfo.tex’ file, which tells TeX how to translate the Texinfo @-commands into TeX typesetting commands. (Note the use of the backslash, ‘\’; this is correct for TeX.) The ‘@setfilename’ line provides a name for the Info file and the ‘@settitle’ line specifies a title for the page headers (or footers) of the printed manual.

The @bye line at the end of the file on a line of its own tells the formatters that the file is ended and to stop formatting.

Usually, you will not use quite such a spare format, but will include mode setting and start-of-header and end-of-header lines at the beginning of a Texinfo file, like this:

\input texinfo   @c -*-texinfo-*-
@c %**start of header
@setfilename info-file-name
@settitle name-of-manual
@c %**end of header

In the first line, ‘-*-texinfo-*-’ causes Emacs to switch into Texinfo mode when you edit the file.

The @c lines which surround the ‘@setfilename’ and ‘@settitle’ lines are optional, but you need them in order to run TeX or Info on just part of the file. (See section Start of Header, for more information.)

Furthermore, you will usually provide a Texinfo file with a title page, indices, and the like. But the minimum, which can be useful for short documents, is just the three lines at the beginning and the one line at the end.

1.7 Six Parts of a Texinfo File

Generally, a Texinfo file contains more than the minimal beginning and end—it usually contains six parts:

1. Header

The Header names the file, tells TeX which definitions’ file to use, and performs other “housekeeping” tasks.

2. Summary Description and Copyright

The Summary Description and Copyright segment describes the document and contains the copyright notice and copying permissions for the Info file. The segment must be enclosed between @ifinfo and @end ifinfo commands so that the formatters place it only in the Info file.

3. Title and Copyright

The Title and Copyright segment contains the title and copyright pages and copying permissions for the printed manual. The segment must be enclosed between @titlepage and @end titlepage commands. The title and copyright page appear only in the printed manual.

4. ‘Top’ Node and Master Menu

The Master Menu contains a complete menu of all the nodes in the whole Info file. It appears only in the Info file, in the ‘Top’ node.

5. Body

The Body of the document may be structured like a traditional book or encyclopedia or it may be free form.

6. End

The End contains commands for printing indices and generating the table of contents, and the @bye command on a line of its own.

1.8 A Short Sample Texinfo File

Here is a complete but very short Texinfo file, in 6 parts. The first three parts of the file, from ‘\input texinfo’ through to ‘@end titlepage’, look more intimidating than they are. Most of the material is standard boilerplate; when you write a manual, simply insert the names for your own manual in this segment. (See section Beginning a Texinfo File.)

In the following, the sample text is indented; comments on it are not. The complete file, without any comments, is shown in A Sample Texinfo File.

Part 1: Header

The header does not appear in either the Info file or the
printed output. It sets various parameters, including the
name of the Info file and the title used in the header.

\input texinfo   @c -*-texinfo-*-      
@c %**start of header
@setfilename sample.info
@settitle Sample Document
@c %**end of header

@setchapternewpage odd

Part 2: Summary Description and Copyright

The summary description and copyright segment does not
appear in the printed document.

@ifinfo
This is a short example of a complete Texinfo file.

Copyright @copyright{} 1990 Free Software Foundation, Inc.
@end ifinfo

Part 3: Titlepage and Copyright

The titlepage segment does not appear in the Info file.

@titlepage
@sp 10
@comment The title is printed in a large font.
@center @titlefont{Sample Title}

@c The following two commands start the copyright page.
@page
@vskip 0pt plus 1filll
Copyright @copyright{} 1990 Free Software Foundation, Inc.
@end titlepage

Part 4: ‘Top’ Node and Master Menu

The ‘Top’ node contains the master menu for the Info file.
Since a printed manual uses a table of contents rather than
a menu, the master menu appears only in the Info file.

@node    Top,       First Chapter, (dir),    (dir)
@comment node-name, next,          previous, up

@menu
* First Chapter::    The first chapter is the 
                     only chapter in this sample.
* Concept Index::    This index has two entries.
@end menu

Part 5: The Body of the Document

The body segment contains all the text of the document, but not the indices or table of contents. This example illustrates a node and a chapter containing an enumerated list.

@node    First Chapter, Concept Index, Top,      Top
@comment node-name,     next,          previous, up
@chapter First Chapter
@cindex Sample index entry

This is the contents of the first chapter. 
@cindex Another sample index entry

Here is a numbered list.

@enumerate
@item
This is the first item.

@item
This is the second item.
@end enumerate

The @code{makeinfo} and @code{texinfo-format-buffer}
commands transform a Texinfo file such as this into 
an Info file; and @TeX{} typesets it for a printed 
manual.

Part 6: The End of the Document

The end segment contains commands both for generating an index in a node and unnumbered chapter of its own and for generating the table of contents; and it contains the @bye command that marks the end of the document.

@node    Concept Index,    ,  First Chapter, Top
@comment node-name,    next,  previous,      up
@unnumbered Concept Index

@printindex cp

@contents
@bye

The Results

Here is what the contents of the first chapter of the sample look like:

This is the contents of the first chapter.

Here is a numbered list.

1. This is the first item.
2. This is the second item.

The makeinfo and texinfo-format-buffer commands transform a Texinfo file such as this into an Info file; and TeX typesets it for a printed manual.

1.9 Acknowledgements

Richard M. Stallman wrote Edition 1.0 of this manual. Robert J. Chassell revised and extended it, starting with Edition 1.1.

Our thanks go out to all who helped improve this work, particularly to Francois Pinard and David D. Zuhn, who tirelessly recorded and reported mistakes and obscurities; our special thanks go to Melissa Weisshaus for her frequent and often tedious reviews of nearly similar editions. Our mistakes are our own.

2 Using Texinfo Mode

You may edit a Texinfo file with any text editor you choose. A Texinfo file is no different from any other ASCII file. However, GNU Emacs comes with a special mode, called Texinfo mode, that provides Emacs commands and tools to help ease your work.

This chapter describes features of GNU Emacs’ Texinfo mode but not any features of the Texinfo formatting language. If you are reading this manual straight through from the beginning, you may want to skim through this chapter briefly and come back to it after reading succeeding chapters which describe the Texinfo formatting language in detail.

Texinfo mode provides special features for working with Texinfo files:

• Insert frequently used @commands.
• Automatically create @node lines.
• Show the structure of a Texinfo source file.
• Automatically create or update the ‘Next’,
  ‘Previous’, and ‘Up’ pointers of a node.
• Automatically create or update menus.
• Automatically create a master menu.
• Format a part or all of a file for Info.
• Typeset and print part or all of a file.

Perhaps the two most helpful features are those for inserting frequently used @-commands and for creating node pointers and menus.

2.1 The Usual GNU Emacs Editing Commands

In most cases, the usual Text mode commands work the same in Texinfo mode as they do in Text mode. Texinfo mode adds new editing commands and tools to GNU Emacs’ general purpose editing features. The major difference concerns filling. In Texinfo mode, the paragraph separation variable and syntax table are redefined so that Texinfo commands that should be on lines of their own are not inadvertently included in paragraphs. Thus, the M-q (fill-paragraph) command will refill a paragraph but not mix an indexing command on a line adjacent to it into the paragraph.

In addition, Texinfo mode sets the page-delimiter variable to the value of texinfo-chapter-level-regexp; by default, this is a regular expression matching the commands for chapters and their equivalents, such as appendices. With this value for the page delimiter, you can jump from chapter title to chapter title with the C-x ] (forward-page) and C-x [ (backward-page) commands and narrow to a chapter with the C-x p (narrow-to-page) command. (See Pages in The GNU Emacs Manual, for details about the page commands.)

You may name a Texinfo file however you wish, but the convention is to end a Texinfo file name with one of the three extensions ‘.texinfo’, ‘.texi’, or ‘.tex’. A longer extension is preferred, since it is explicit, but a shorter extension may be necessary for operating systems that limit the length of file names. GNU Emacs automatically enters Texinfo mode when you visit a file with a ‘.texinfo’ or ‘.texi’ extension. Also, Emacs switches to Texinfo mode when you visit a file that has ‘-*-texinfo-*-’ in its first line. If ever you are in another mode and wish to switch to Texinfo mode, type M-x texinfo-mode.

Like all other Emacs features, you can customize or enhance Texinfo mode as you wish. In particular, the keybindings are very easy to change. The keybindings described here are the default or standard ones.

2.2 Inserting Frequently Used Commands

Texinfo mode provides commands to insert various frequently used @-commands into the buffer. You can use these commands to save keystrokes.

The insert commands are invoked by typing C-c twice and then the first letter of the @-command:

C-c C-c c

M-x texinfo-insert-@code

Insert @code{} and put the cursor between the braces.

C-c C-c d

M-x texinfo-insert-@dfn

Insert @dfn{} and put the cursor between the braces.

C-c C-c e

M-x texinfo-insert-@end

Insert @end and attempt to insert the correct following word, such as ‘example’ or ‘table’. (This command does not handle nested lists correctly, but inserts the word appropriate to the immediately preceding list.)

C-c C-c i

M-x texinfo-insert-@item

Insert @item and put the cursor at the beginning of the next line.

C-c C-c k

M-x texinfo-insert-@kbd

Insert @kbd{} and put the cursor between the braces.

C-c C-c n

M-x texinfo-insert-@node

Insert @node and a comment line listing the sequence for the ‘Next’, ‘Previous’, and ‘Up’ nodes. Leave point after the @node.

C-c C-c o

M-x texinfo-insert-@noindent

Insert @noindent and put the cursor at the beginning of the next line.

C-c C-c s

M-x texinfo-insert-@samp

Insert @samp{} and put the cursor between the braces.

C-c C-c t

M-x texinfo-insert-@table

Insert @table followed by a <SPC> and leave the cursor after the <SPC>.

C-c C-c v

M-x texinfo-insert-@var

Insert @var{} and put the cursor between the braces.

C-c C-c x

M-x texinfo-insert-@example

Insert @example and put the cursor at the beginning of the next line.

C-c C-c {

M-x texinfo-insert-braces

Insert {} and put the cursor between the braces.

C-c C-c }

C-c C-c ]

M-x up-list

Move from between a pair of braces forward past the closing brace. Typing C-c C-c ] is easier than typing C-c C-c }, which is, however, more mnemonic; hence the two keybindings. (Also, you can move out from between braces by typing C-f.)

To put a command such as @code{…} around an existing word, position the cursor in front of the word and type C-u 1 C-c C-c c. This makes it easy to edit existing plain text. The value of the prefix argument tells Emacs how many words following point to include between braces—1 for one word, 2 for two words, and so on. Use a negative argument to enclose the previous word or words. If you do not specify a prefix argument, Emacs inserts the @-command string and positions the cursor between the braces. This feature works only for those @-commands that operate on a word or words within one line, such as @kbd and @var.

This set of insert commands was created after analyzing the frequency with which different @-commands are used in the GNU Emacs Manual and the GDB Manual. If you wish to add your own insert commands, you can bind a keyboard macro to a key, use abbreviations, or extend the code in ‘texinfo.el’.

C-c C-c C-d (texinfo-start-menu-description) is an insert command that works differently from the other insert commands. It inserts a node’s section or chapter title in the space for the description in a menu entry line. (A menu entry has three parts, the entry name, the node name, and the description. Only the node name is required, but a description helps explain what the node is about. See section The Parts of a Menu.)

To use texinfo-start-menu-description, position point in a menu entry line and type C-c C-c C-d. The command looks for and copies the title that goes with the node name, and inserts the title as a description; it positions point at beginning of the inserted text so you can edit it. The function does not insert the title if the menu entry line already contains a description.

This command is only an aid to writing descriptions; it does not do the whole job. You must edit the inserted text since a title tends to use the same words as a node name but a useful description uses different words.

2.3 Showing the Section Structure of a File

You can show the section structure of a Texinfo file by using the C-c C-s command (texinfo-show-structure). This command shows the section structure of a Texinfo file by listing the lines that begin with the @-commands for @chapter, @section, and the like. It constructs what amounts to a table of contents. These lines are displayed in another buffer called the ‘*Occur*’ buffer. In that buffer, you can position the cursor over one of the lines and use the C-c C-c command (occur-mode-goto-occurrence), to jump to the corresponding spot in the Texinfo file.

C-c C-s

M-x texinfo-show-structure

Show the @chapter, @section, and such lines of a Texinfo file.

C-c C-c

M-x occur-mode-goto-occurrence

Go to the line in the Texinfo file corresponding to the line under the cursor in the ‘*Occur*’ buffer.

If you call texinfo-show-structure with a prefix argument by typing C-u C-c C-s, it will list not only those lines with the @-commands for @chapter, @section, and the like, but also the @node lines. (This is how the texinfo-show-structure command worked without an argument in the first version of Texinfo. It was changed because @node lines clutter up the ‘*Occur*’ buffer and are usually not needed.) You can use texinfo-show-structure with a prefix argument to check whether the ‘Next’, ‘Previous’, and ‘Up’ pointers of an @node line are correct.

Often, when you are working on a manual, you will be interested only in the structure of the current chapter. In this case, you can mark off the region of the buffer that you are interested in with the C-x n (narrow-to-region) command and texinfo-show-structure will work on only that region. To see the whole buffer again, use C-x w (widen). (See Narrowing in The GNU Emacs Manual, for more information about the narrowing commands.)

In addition to providing the texinfo-show-structure command, Texinfo mode sets the value of the page delimiter variable to match the chapter-level @-commands. This enables you to use the C-x ] (forward-page) and C-x [ (backward-page) commands to move forward and backward by chapter, and to use the C-x p (narrow-to-page) command to narrow to a chapter. See Pages in The GNU Emacs Manual, for more information about the page commands.

2.4 Updating Nodes and Menus

Texinfo mode provides commands for automatically creating or updating menus and node pointers. The commands are called “update” commands because their most frequent use is for updating a Texinfo file after you have worked on it; but you can use them to insert the ‘Next’, ‘Previous’, and ‘Up’ pointers into an @node line that has none and to create menus in a file that has none.

If you do not use the updating commands, you need to write menus and node pointers by hand, which is a tedious task.

You can use the updating commands

• to insert or update the ‘Next’, ‘Previous’, and ‘Up’ pointers of a node,
• to insert or update the menu for a section, and
• to create a master menu for a Texinfo source file.

You can also use the commands to update all the nodes and menus in a region or in a whole Texinfo file.

The updating commands work only with conventional Texinfo files, which are structured hierarchically like books. In such files, a structuring command line must follow closely after each @node line, except for the ‘Top’ @node line. (A structuring command line is a line beginning with @chapter, @section, or other similar command.)

You can write the structuring command line on the line that follows immediately after an @node line or else on the line that follows after a single @comment line or a single @ifinfo line. You cannot interpose more than one line between the @node line and the structuring command line; and you may interpose only an @comment line or an @ifinfo line.

Commands which work on a whole buffer require that the ‘Top’ node be followed by a node with an @chapter or equivalent-level command. Note that the menu updating commands will not create a main or master menu for a Texinfo file that has only @chapter-level nodes! The menu updating commands only create menus within nodes for lower level nodes. To create a menu of chapters, you must provide a ‘Top’ node.

The menu updating commands remove menu entries that refer to other Info files since they do not refer to nodes within the current buffer. This is a deficiency. Rather than use menu entries, you can use cross references to refer to other Info files. None of the updating commands affect cross references.

Texinfo mode has five updating commands that are used most often: two are for updating the node pointers or menu of a single node (or a region); two are for updating every node pointer and menu in a file; and one, the texinfo-master-menu command, is for creating a master menu for a complete file, and optionally, for updating every node and menu in the whole Texinfo file.

The texinfo-master-menu command is the primary command:

C-c C-u m

M-x texinfo-master-menu

Create or update a master menu that includes all the other menus (incorporating the descriptions from pre-existing menus, if any).

With an argument (prefix argument, C-u, if interactive), first create or update all the nodes and all the regular menus in the buffer before constructing the master menu. (See section The Top Node and Master Menu, for more about a master menu.)

For texinfo-master-menu to work, the Texinfo file must have a ‘Top’ node and at least one subsequent node.

After extensively editing a Texinfo file, you can type the following:

C-u M-x texinfo-master-menu
or
C-u C-c C-u m

This updates all the nodes and menus completely and all at once.

The other major updating commands do smaller jobs and are designed for the person who updates nodes and menus as he or she writes a Texinfo file.

The commands are:

C-c C-u C-n

M-x texinfo-update-node

Insert the ‘Next’, ‘Previous’, and ‘Up’ pointers for the node that point is within (i.e., for the @node line preceding point). If the @node line has pre-existing ‘Next’, ‘Previous’, or ‘Up’ pointers in it, the old pointers are removed and new ones inserted. With an argument (prefix argument, C-u, if interactive), this command updates all @node lines in the region (which is the text between point and mark).

C-c C-u C-m

M-x texinfo-make-menu

Create or update the menu in the node that point is within. With an argument (C-u as prefix argument, if interactive), the command makes or updates menus for the nodes which are either within or a part of the region.

Whenever texinfo-make-menu updates an existing menu, the descriptions from that menu are incorporated into the new menu. This is done by copying descriptions from the existing menu to the entries in the new menu that have the same node names. If the node names are different, the descriptions are not copied to the new menu.

C-c C-u C-e

M-x texinfo-every-node-update

Insert or update the ‘Next’, ‘Previous’, and ‘Up’ pointers for every node in the buffer.

C-c C-u C-a

M-x texinfo-all-menus-update

Create or update all the menus in the buffer. With an argument (C-u as prefix argument, if interactive), first insert or update all the node pointers before working on the menus.

If a master menu exists, the texinfo-all-menus-update command updates it; but the command does not create a new master menu if none already exists. (Use the texinfo-master-menu command for that.)

When working on a document that does not merit a master menu, you can type the following:

C-u C-c C-u C-a
or 
C-u M-x texinfo-all-menus-update

This updates all the nodes and menus.

The texinfo-column-for-description variable specifies the column to which menu descriptions are indented. By default, the value is 32 although it is often useful to reduce it to as low as 24. You can set the variable with the M-x edit-options command (see Editing Variable Values in The GNU Emacs Manual) or with the M-x set-variable command (see Examining and Setting Variables in The GNU Emacs Manual).

Also, the texinfo-indent-menu-description command may be used to indent existing menu descriptions to a specified column. Finally, if you wish, you can use the texinfo-insert-node-lines command to insert missing @node lines into a file. (See section Other Updating Commands, for more information.)

2.4.1 Updating Requirements

To use the updating commands, you must organize the Texinfo file hierarchically with chapters, sections, subsections, and the like. When you construct the hierarchy of the manual, do not ‘jump down’ more than one level at a time: you can follow the ‘Top’ node with a chapter, but not with a section; you can follow a chapter with a section, but not with a subsection. However, you may ‘jump up’ any number of levels at one time—for example, from a subsection to a chapter.

Each @node line, with the exception of the line for the ‘Top’ node, must be followed by a line with a structuring command such as @chapter, @section, or @unnumberedsubsec.

Each @node line/structuring-command line combination must look either like this:

@node     Comments,  Minimum, Conventions, Overview
@comment  node-name, next,    previous,    up
@section Comments

or like this (without the @comment line):

@node Comments, Minimum, Conventions, Overview
@section Comments

In this example, ‘Comments’ is the name of both the node and the section. The next node is called ‘Minimum’ and the previous node is called ‘Conventions’. The ‘Comments’ section is within the ‘Overview’ node, which is specified by the ‘Up’ pointer. (Instead of an @comment line, you can write an @ifinfo line.)

If a file has a ‘Top’ node, it must be called ‘top’ or ‘Top’ and be the first node in the file.

The menu updating commands create a menu of sections within a chapter, a menu of subsections within a section, and so on. This means that you must have a ‘Top’ node if you want a menu of chapters.

Incidentally, the makeinfo command will create an Info file for a hierarchically organized Texinfo file that lacks ‘Next’, ‘Previous’ and ‘Up’ pointers. Thus, if you can be sure that your Texinfo file will be formatted with makeinfo, you have no need for the ‘update node’ commands. (See section Creating an Info File, for more information about makeinfo.) However, both makeinfo and the texinfo-format-… commands require that you insert menus in the file.

2.4.2 Other Updating Commands

In addition to the five major updating commands, Texinfo mode possesses several less frequently used updating commands:

M-x texinfo-insert-node-lines

Insert @node lines before the @chapter, @section, and other sectioning commands wherever they are missing throughout a region in a Texinfo file.

With an argument (C-u as prefix argument, if interactive), the texinfo-insert-node-lines command not only inserts @node lines but also inserts the chapter or section titles as the names of the corresponding nodes. In addition, it inserts the titles as node names in pre-existing @node lines that lack names. Since node names should be more concise than section or chapter titles, you must manually edit node names so inserted.

For example, the following marks a whole buffer as a region and inserts @node lines and titles throughout:

C-x h C-u M-x texinfo-insert-node-lines

(Note that this command inserts titles as node names in @node lines; the texinfo-start-menu-description command (see section Inserting Frequently Used Commands) inserts titles as descriptions in menu entries, a different action. However, in both cases, you need to edit the inserted text.)

M-x texinfo-multiple-files-update

Update nodes and menus in a document built from several separate files. With C-u as a prefix argument, create and insert a master menu in the outer file. With a numeric prefix argument, such as C-u 2, first update all the menus and all the ‘Next’, ‘Previous’, and ‘Up’ pointers of all the included files before creating and inserting a master menu in the outer file. The texinfo-multiple-files-update command is described in the appendix on @include files.

M-x texinfo-indent-menu-description

Indent every description in the menu following point to the specified column. You can use this command to give yourself more space for descriptions. With an argument (C-u as prefix argument, if interactive), the texinfo-indent-menu-description command indents every description in every menu in the region. However, this command does not indent the second and subsequent lines of a multi-line description.

M-x texinfo-sequential-node-update

Insert the names of the nodes immediately following and preceding the current node as the ‘Next’ or ‘Previous’ pointers regardless of those nodes’ hierarchical level. This means that the ‘Next’ node of a subsection may well be the next chapter. Sequentially ordered nodes are useful for novels and other documents that you read through sequentially. (However, in Info, the g* <RET> command lets you look through the file sequentially, so sequentially ordered nodes are not strictly necessary.) With an argument (prefix argument, if interactive), the texinfo-sequential-node-update command sequentially updates all the nodes in the region.

2.5 Formatting for Info

Texinfo mode provides several commands for formatting part or all of a Texinfo file for Info. Often, when you are writing a document, you want to format only part of a file—that is, a region.

You can use either the texinfo-format-region or the makeinfo-region command to format a region:

C-c C-e C-r

M-x texinfo-format-region

C-c C-m C-r

M-x makeinfo-region

Format the current region for Info.

You can use either the texinfo-format-buffer or the makeinfo-buffer command to format a whole buffer:

C-c C-e C-b

M-x texinfo-format-buffer

C-c C-m C-b

M-x makeinfo-buffer

Format the current buffer for Info.

For example, after writing a Texinfo file, you can type the following:

C-u C-c C-u m
or
C-u M-x texinfo-master-menu

This updates all the nodes and menus. Then type the following to create an Info file:

C-c C-m C-b
or
M-x makeinfo-buffer

For the Info formatting commands to work, the file must include a line that has @setfilename in its header.

Not all systems support the makeinfo-based formatting commands.

See section Creating an Info File, for details about Info formatting.

2.6 Formatting and Printing

Typesetting and printing a Texinfo file is a multi-step process in which you first create a file for printing (called a DVI file), and then print the file. Optionally, you may also create indices. To do this, you must run the texindex command after first running the tex typesetting command; and then you must run the tex command again.

Often, when you are writing a document, you want to typeset and print only part of a file to see what it will look like. You can use the texinfo-tex-region and related commands for this purpose. Use the texinfo-tex-buffer command to format all of a buffer.

C-c C-t C-r

M-x texinfo-tex-region

Run TeX on the region.

C-c C-t C-b

M-x texinfo-tex-buffer

Run TeX on the buffer.

C-c C-t C-i

M-x texinfo-texindex

Run texindex to sort the indices of a Texinfo file formatted with texinfo-tex-region or texinfo-tex-buffer. You must run the tex command a second time after sorting the raw index files.

C-c C-t C-p

M-x texinfo-tex-print

Print the file (or the part of the file) previously formatted with texinfo-tex-buffer or texinfo-tex-region.

For texinfo-tex-region or texinfo-tex-buffer to work, the file must start with a ‘\input texinfo’ line and must include an @settitle line. The file must end with @bye on a line by itself. (When you use texinfo-tex-region, you must surround the @settitle line with start-of-header and end-of-header lines.)

See section Format and Print Hardcopy, for a description of the other TeX related commands, such as tex-show-print-queue.

2.7 Texinfo Mode Summary

In Texinfo mode, each set of commands has default keybindings that begin with the same keys. All the commands that are custom-created for Texinfo mode begin with C-c. The keys are somewhat mnemonic.

Insert Commands

The insert commands are invoked by typing C-c twice and then the first letter of the @-command to be inserted. (It might make more sense mnemonically to use C-c C-i, for ‘custom insert’, but C-c C-c is quick to type.)

C-c C-c c       Insert ‘@code’.
C-c C-c d       Insert ‘@dfn’.
C-c C-c e       Insert ‘@end’.
C-c C-c i       Insert ‘@item’.
C-c C-c n       Insert ‘@node’.
C-c C-c s       Insert ‘@samp’.
C-c C-c v       Insert ‘@var’.
C-c C-c {       Insert braces.
C-c C-c ]
C-c C-c }       Move out of enclosing braces.

C-c C-c C-d     Insert a node's section title
                in the space for the description
                in a menu entry line.

Show Structure

The texinfo-show-structure command is often used within a narrowed region.

C-c C-s         List all the headings.

The Master Update Command

The texinfo-master-menu command creates a master menu; and can be used to update every node and menu in a file as well.

C-c C-u m
M-x texinfo-master-menu
                Create or update a master menu.

C-u C-c C-u m   With C-u as a prefix argument, first
                create or update all nodes and regular
                menus, and then create a master menu.

Update Pointers

The update pointer commands are invoked by typing C-c C-u and then either typing C-n for texinfo-update-node or typing C-e for texinfo-every-node-update.

C-c C-u C-n     Update a node.
C-c C-u C-e     Update every node in the buffer.

Update Menus

Invoke the update menu commands by typing C-c C-u and then either C-m for texinfo-make-menu or C-a for texinfo-all-menus-update. To update both nodes and menus at the same time, precede C-c C-u C-a with C-u.

C-c C-u C-m     Make or update a menu.

C-c C-u C-a     Make or update all
                menus in a buffer. 

C-u C-c C-u C-a With C-u as a prefix argument,
                first create or update all nodes and
                then create or update all menus.

Format for Info

The Info formatting commands that are written in Emacs Lisp are invoked by typing C-c C-e and then either C-r for a region or C-b for the whole buffer.

The Info formatting commands that are written in C and based on the makeinfo program are invoked by typing C-c C-m and then either C-r for a region or C-b for the whole buffer.

Use the texinfo-format… commands:

C-c C-e C-r     Format the region.
C-c C-e C-b     Format the buffer.

Use makeinfo:

C-c C-m C-r     Format the region.
C-c C-m C-b     Format the buffer.
C-c C-m C-l     Recenter the makeinfo output buffer.
C-c C-m C-k     Kill the makeinfo formatting job.

Typeset and Print

The TeX typesetting and printing commands are invoked by typing C-c C-t and then another control command: C-r for texinfo-tex-region, C-b for texinfo-tex-buffer, and so on.

C-c C-t C-r     Run TeX on the region.
C-c C-t C-b     Run TeX on the buffer.
C-c C-t C-i     Run texindex.
C-c C-t C-p     Print the DVI file.
C-c C-t C-q     Show the print queue.
C-c C-t C-d     Delete a job from the print queue.
C-c C-t C-k     Kill the current TeX formatting job.
C-c C-t C-x     Quit a currently stopped TeX formatting job.
C-c C-t C-l     Recenter the output buffer.

Other Updating Commands

The ‘other updating commands’ do not have standard keybindings because they are rarely used.

M-x texinfo-insert-node-lines
                Insert missing @node lines in region.
                With C-u as a prefix argument,
                use section titles as node names.

M-x texinfo-multiple-files-update
                Update a multi-file document.
                With C-u 2 as a prefix argument,
                create or update all nodes and menus
                in all included files first.

M-x texinfo-indent-menu-description
                Indent descriptions.

M-x texinfo-sequential-node-update
                Insert node pointers in strict sequence.

3 Beginning a Texinfo File

Certain pieces of information must be provided at the beginning of a Texinfo file, such as the name of the file and the title of the document.

Generally, the beginning of a Texinfo file has four parts:

1. The header, delimited by special comment lines, that includes the commands for naming the Texinfo file and telling TeX what definitions’ file to use when processing the Texinfo file.
2. A short statement of what the file is about, with a copyright notice and copying permissions. This is enclosed in @ifinfo and @end ifinfo commands so that the formatters place it only in the Info file.
3. A title page and copyright page, with a copyright notice and copying permissions. This is enclosed between @titlepage and @end titlepage commands. The title and copyright page appear only in the printed manual.
4. The ‘Top’ node that contains a menu for the whole Info file. The contents of this node appear only in the Info file.

Also, optionally, you may include the copying conditions for a program and a warranty disclaimer. The copying section will be followed by an introduction or else by the first chapter of the manual.

Since the copyright notice and copying permissions for the Texinfo document (in contrast to the copying permissions for a program) are in parts that appear only in the Info file or only in the printed manual, this information must be given twice.

3.1 Sample Texinfo File Beginning

The following sample shows what is needed.

\input texinfo   @c -*-texinfo-*-
@c %**start of header
@setfilename name-of-info-file
@settitle name-of-manual
@setchapternewpage odd
@c %**end of header

@ifinfo
This file documents …

Copyright year copyright-owner

Permission is granted to …
@end ifinfo

@c  This title page illustrates only one of the
@c  two methods of forming a title page.

@titlepage
@title name-of-manual-when-printed
@subtitle subtitle-if-any
@subtitle second-subtitle
@author author

@c  The following two commands 
@c  start the copyright page.
@page
@vskip 0pt plus 1filll
Copyright @copyright{} year copyright-owner

Published by …

Permission is granted to …
@end titlepage

@node Top, Overview, (dir), (dir)

@ifinfo
This document describes … 

This document applies to version … 
of the program named …
@end ifinfo

@menu
* Copying::          Your rights and freedoms.
* First Chapter::    Getting started …
* Second Chapter::              …
  …
  …
@end menu

@node    First Chapter, Second Chapter, top,      top
@comment node-name,     next,           previous, up
@chapter First Chapter
@cindex Index entry for First Chapter

3.2 The Texinfo File Header

Texinfo files start with at least three lines that provide Info and TeX with necessary information. These are the \input texinfo line, the @settitle line, and the @setfilename line. If you want to run TeX on just a part of the Texinfo File, you must write the @settitle and @setfilename lines between start-of-header and end-of-header lines.

Thus, the beginning of a Texinfo file looks like this:

\input texinfo   @c -*-texinfo-*-      
@setfilename sample.info
@settitle Sample Document

or else like this:

\input texinfo   @c -*-texinfo-*-      
@c %**start of header
@setfilename sample.info
@settitle Sample Document
@c %**end of header

3.2.1 The First Line of a Texinfo File

Every Texinfo file that is to be the top-level input to TeX must begin with a line that looks like this:

\input texinfo   @c -*-texinfo-*-

This line serves two functions:

1. When the file is processed by TeX, the \input texinfo command tells TeX to load the macros needed for processing a Texinfo file. These are in a file called ‘texinfo.tex’, which is usually located in the ‘/usr/lib/tex/macros’ directory. TeX uses the backslash, ‘\’, to mark the beginning of a command, just as Texinfo uses @. The ‘texinfo.tex’ file causes the switch from ‘\’ to ‘@’; before the switch occurs, TeX requires ‘\’, which is why it appears at the beginning of the file.
2. When the file is edited in GNU Emacs, the ‘-*-texinfo-*-’ mode specification tells Emacs to use Texinfo mode.

3.2.2 Start of Header

Write a start-of-header line on the second line of a Texinfo file. Follow the start-of-header line with @setfilename and @settitle lines and, optionally, with other command lines, such as @smallbook or @footnotestyle; and then by an end-of-header line (see section End of Header).

With these lines, you can format part of a Texinfo file for Info or typeset part for printing.

A start-of-header line looks like this:

@c %**start of header

The odd string of characters, ‘%**’, is to ensure that no other comment is accidentally taken for a start-of-header line.

3.2.3 @setfilename

In order to be made into an Info file, a Texinfo file must contain a line that looks like this:

@setfilename info-file-name

Write the @setfilename command at the beginning of a line and follow it on the same line by the Info file name. Do not write anything else on the line; anything on the line after the command is considered part of the file name, including a comment.

The @setfilename line specifies the name of the Info file to be generated. This name should be different from the name of the Texinfo file. The convention is to write a name with a ‘.info’ extension, to produce an Info file name such as ‘texinfo.info’.

Some operating systems cannot handle long file names. You can run into a problem even when the file name you specify is itself short enough. This occurs because the Info formatters split a long Info file into short indirect subfiles, and name them by appending ‘-1’, ‘-2’, …, ‘-10’, ‘-11’, and so on, to the original file name. (See section Tag Files and Split Files.) The subfile name ‘texinfo.info-10’, for example, is too long for some systems; so the Info file name for this document is actually ‘texinfo’ rather than ‘texinfo.info’.

The Info formatting commands ignore everything written before the @setfilename line, which is why the very first line of the file (the \input line) does not need to be commented out. The @setfilename line is ignored when you typeset a printed manual.

3.2.4 @settitle

In order to be made into a printed manual, a Texinfo file must contain a line that looks like this:

@settitle title

Write the @settitle command at the beginning of a line and follow it on the same line by the title. This tells TeX the title to use in a header or footer. Do not write anything else on the line; anything on the line after the command is considered part of the title, including a comment.

Conventionally, TeX formats a Texinfo file for double-sided output so as to print the title in the left-hand (even-numbered) page headings and the current chapter titles in the right-hand (odd-numbered) page headings. (TeX learns the title of each chapter from each @chapter command.) Page footers are not printed.

Even if you are printing in a single-sided style, TeX looks for an @settitle command line, in case you include the manual title in the heading.

The @settitle command should precede everything that generates actual output in TeX.

Although the title in the @settitle command is usually the same as the title on the title page, it does not affect the title as it appears on the title page. Thus, the two do not need not match exactly; and the title in the @settitle command can be a shortened or expanded version of the title as it appears on the title page. (See section @titlepage.)

TeX prints page headings only for that text that comes after the @end titlepage command in the Texinfo file, or that comes after an @headings command that turns on headings. (See section The @headings Command, for more information.)

You may, if you wish, create your own, customized headings and footings. See section Page Headings, for a detailed discussion of this process.

3.2.5 @setchapternewpage

In a book or a manual, text is usually printed on both sides of the paper, chapters start on right-hand pages, and right-hand pages have odd numbers. But in short reports, text often is printed only on one side of the paper. Also in short reports, chapters sometimes do not start on new pages, but are printed on the same page as the end of the preceding chapter, after a small amount of vertical whitespace.

You can use the @setchapternewpage command with various arguments to specify how TeX should start chapters and whether it should typeset pages for printing on one or both sides of the paper (single-sided or double-sided printing).

Write the @setchapternewpage command at the beginning of a line followed by its argument.

For example, you would write the following to cause each chapter to start on a fresh odd-numbered page:

@setchapternewpage odd

You can specify one of three alternatives with the @setchapternewpage command:

@setchapternewpage off

Cause TeX to typeset a new chapter on the same page as the last chapter, after skipping some vertical whitespace. Also, cause TeX to format page headers for single-sided printing. (You can override the headers format with the @headings double command; see The @headings Command.)

@setchapternewpage on

Cause TeX to start new chapters on new pages and to typeset page headers for single-sided printing. This is the form most often used for short reports.

This alternative is the default.

@setchapternewpage odd

Cause TeX to start new chapters on new, odd-numbered pages (right-handed pages) and to typeset for double-sided printing. This is the form most often used for books and manuals.

Texinfo does not have an @setchapternewpage even command.

(You can countermand or modify an @setchapternewpage command with an @headings command. See section The @headings Command.)

At the beginning of a manual or book, pages are not numbered—for example, the title and copyright pages of a book are not numbered. By convention, table of contents pages are numbered with roman numerals and not in sequence with the rest of the document.

Since an Info file does not have pages, the @setchapternewpage command has no effect on it.

Usually, you do not write an @setchapternewpage command for single-sided printing, but accept the default which is to typeset for single-sided printing and to start new chapters on new pages. Usually, you write an @setchapternewpage odd command for double-sided printing.

3.2.6 Paragraph Indenting

The Info formatting commands may insert spaces at the beginning of the first line of each paragraph, thereby indenting that paragraph. You can use the @paragraphindent command to specify the indentation. Write an @paragraphindent command at the beginning of a line followed by either ‘asis’ or a number. The template is:

@paragraphindent indent

The Info formatting commands indent according to the value of indent:

• If the value of indent is ‘asis’, the Info formatting commands do not change the existing indentation.
• If the value of indent is 0, the Info formatting commands delete existing indentation.
• If the value of indent is greater than 0, the Info formatting commands indent the paragraph by that number of spaces.

The default value of indent is ‘asis’.

Write the @paragraphindent command before or shortly after the end-of-header line at the beginning of a Texinfo file. (If you write the command between the start-of-header and end-of-header lines, the region formatting commands indent paragraphs as specified.)

A peculiarity of texinfo-format-buffer and texinfo-format-region is that they do not indent (nor fill) paragraphs that contain @w or @* commands. See section Refilling Paragraphs, for a detailed description of what goes on.

3.2.7 End of Header

Follow the header lines with an end-of-header line. An end-of-header line looks like this:

@c %**end of header

If you include the @setchapternewpage command between the start-of-header and end-of-header lines, TeX will typeset a region as that command specifies. Similarly, if you include an @smallbook command between the start-of-header and end-of-header lines, TeX will typeset a region in the “small” book format.

3.3 Summary and Copying Permissions for Info

The title page and the copyright page appear only in the printed copy of the manual; therefore, the same information must be inserted in a section that appears only in the Info file. This section usually contains a brief description of the contents of the Info file, a copyright notice, and copying permissions.

The copyright notice should read:

Copyright year copyright-owner

and be put on a line by itself.

Standard text for the copyright permissions is contained in an appendix to this manual; see ‘ifinfo’ Copying Permissions, for the complete text.

The permissions text appears in an Info file before the first node. This mean that a reader does not see this text when reading the file using Info, except when using the advanced Info command g *.

3.4 The Title and Copyright Pages

A manual’s name and author are usually printed on a title page. Sometimes copyright information is printed on the title page as well; more often, copyright information is printed on the back of the title page.

The title and copyright pages appear in the printed manual, but not in the Info file. Because of this, it is possible to use several slightly obscure TeX typesetting commands that cannot be used in an Info file. In addition, this part of the beginning of a Texinfo file contains the text of the copying permissions that will appear in the printed manual.

See section Titlepage Copying Permissions, for the standard text for the copyright permissions.

3.4.1 @titlepage

Start the material for the title page and following copyright page with @titlepage on a line by itself and end it with @end titlepage on a line by itself.

The @end titlepage command starts a new page and turns on page numbering. (See section Page Headings, for details about how to generate of page headings.) All the material that you want to appear on unnumbered pages should be put between the @titlepage and @end titlepage commands. By using the @page command you can force a page break within the region delineated by the @titlepage and @end titlepage commands and thereby create more than one unnumbered page. This is how the copyright page is produced. (The @titlepage command might perhaps have been better named the @titleandadditionalpages command, but that would have been rather long!)

When you write a manual about a computer program, you should write the version of the program to which the manual applies on the title page. If the manual changes more frequently than the program or is independent of it, you should also include an edition number(5) for the manual. This helps readers keep track of which manual is for which version of the program. (The ‘Top’ node should also contain this information; see @top.)

Texinfo provides two methods for creating a title page. One method uses the @titlefont, @sp, and @center commands to generate a title page in which the words on the page are centered.

The second method uses the @title, @subtitle, and @author commands to create a title page with black rules under the title and author lines and the subtitle text set flush to the right hand side of the page. With this method, you do not specify any of the actual formatting of the title page. You specify the text you want, and Texinfo does the formatting. You may use either method.

3.4.2 @titlefont, @center, and @sp

You can use the @titlefont, @sp, and @center commands to create a title page for a printed document. (This is the first of the two methods for creating a title page in Texinfo.)

Use the @titlefont command to select a large font suitable for the title itself.

For example:

@titlefont{Texinfo}

Use the @center command at the beginning of a line to center the remaining text on that line. Thus,

@center @titlefont{Texinfo}

centers the title, which in this example is “Texinfo” printed in the title font.

Use the @sp command to insert vertical space. For example:

@sp 2

This inserts two blank lines on the printed page. (See section @sp, for more information about the @sp command.)

A template for this method looks like this:

@titlepage
@sp 10
@center @titlefont{name-of-manual-when-printed}
@sp 2
@center subtitle-if-any
@sp 2
@center author
…
@end titlepage

The spacing of the example fits an 8 1/2 by 11 inch manual.

3.4.3 @title, @subtitle, and @author

You can use the @title, @subtitle, and @author commands to create a title page in which the vertical and horizontal spacing is done for you automatically. This contrasts with the method described in the previous section, in which the @sp command is needed to adjust vertical spacing.

Write the @title, @subtitle, or @author commands at the beginning of a line followed by the title, subtitle, or author.

The @title command produces a line in which the title is set flush to the left-hand side of the page in a larger than normal font. The title is underlined with a black rule.

The @subtitle command sets subtitles in a normal-sized font flush to the right-hand side of the page.

The @author command sets the names of the author or authors in a middle-sized font flush to the left-hand side of the page on a line near the bottom of the title page. The names are underlined with a black rule that is thinner than the rule that underlines the title. (The black rule only occurs if the @author command line is followed by an @page command line.)

There are two ways to use the @author command: you can write the name or names on the remaining part of the line that starts with an @author command:

@author by Jane Smith and John Doe

or you can write the names one above each other by using two (or more) @author commands:

@author Jane Smith
@author John Doe

(Only the bottom name is underlined with a black rule.)

A template for this method looks like this:

@titlepage
@title name-of-manual-when-printed
@subtitle subtitle-if-any
@subtitle second-subtitle
@author author
@page
…
@end titlepage

3.4.4 Copyright Page and Permissions

By international treaty, the copyright notice for a book should be either on the title page or on the back of the title page. The copyright notice should include the year followed by the name of the organization or person who owns the copyright.

When the copyright notice is on the back of the title page, that page is customarily not numbered. Therefore, in Texinfo, the information on the copyright page should be within @titlepage and @end titlepage commands.

Use the @page command to cause a page break. To push the copyright notice and the other text on the copyright page towards the bottom of the page, you can write a somewhat mysterious line after the @page command that reads like this:

@vskip 0pt plus 1filll

This is a TeX command that is not supported by the Info formatting commands. The @vskip command inserts whitespace. The ‘0pt plus 1filll’ means to put in zero points of mandatory whitespace, and as much optional whitespace as needed to push the following text to the bottom of the page. Note the use of three ‘l’s in the word ‘filll’; this is the correct usage in TeX.

In a printed manual, the @copyright{} command generates a ‘c’ inside a circle. (In Info, it generates ‘(C)’.) The copyright notice itself has the following legally defined sequence:

Copyright © year copyright-owner

It is customary to put information on how to get a manual after the copyright notice, followed by the copying permissions for the manual.

Note that permissions must be given here as well as in the summary segment within @ifinfo and @end ifinfo that immediately follows the header since this text appears only in the printed manual and the ‘ifinfo’ text appears only in the Info file.

See section Sample Permissions, for the standard text.

3.4.5 Heading Generation

An @end titlepage command on a line by itself not only marks the end of the title and copyright pages, but also causes TeX to start generating page headings and page numbers.

To repeat what is said elsewhere, Texinfo has two standard page heading formats, one for documents which are printed on one side of each sheet of paper (single-sided printing), and the other for documents which are printed on both sides of each sheet (double-sided printing). (See section @setchapternewpage.) You can specify these formats in different ways:

• The conventional way is to write an @setchapternewpage command before the title page commands, and then have the @end titlepage command start generating page headings in the manner desired. (See section @setchapternewpage.)
• Alternatively, you can use the @headings command to prevent page headings from being generated or to start them for either single or double-sided printing. (Write an @headings command immediately after the @end titlepage command. See section The @headings Command, for more information.)
• Or, you may specify your own page heading and footing format. See section Page Headings, for detailed information about page headings and footings.

Most documents are formatted with the standard single-sided or double-sided format, using @setchapternewpage odd for double-sided printing and no @setchapternewpage command for single-sided printing.

3.4.6 The @headings Command

The @headings command is rarely used. It specifies what kind of page headings and footings to print on each page. Usually, this is controlled by the @setchapternewpage command. You need the @headings command only if the @setchapternewpage command does not do what you want, or if you want to turn off pre-defined page headings prior to defining your own. Write an @headings command immediately after the @end titlepage command.

There are four ways to use the @headings command:

@headings off

Turn off printing of page headings.

@headings single

Turn on page headings appropriate for single-sided printing.

@headings double

@headings on

Turn on page headings appropriate for double-sided printing. The two commands, @headings on and @headings double, are synonymous.

For example, suppose you write @setchapternewpage off before the @titlepage command to tell TeX to start a new chapter on the same page as the end of the last chapter. This command also causes TeX to typeset page headers for single-sided printing. To cause TeX to typeset for double sided printing, write @headings double after the @end titlepage command.

You can stop TeX from generating any page headings at all by writing @headings off on a line of its own immediately after the line containing the @end titlepage command, like this:

@end titlepage
@headings off

The @headings off command overrides the @end titlepage command, which would otherwise cause TeX to print page headings.

You can also specify your own style of page heading and footing. See section Page Headings, for more information.

3.5 The ‘Top’ Node and Master Menu

The ‘Top’ node is the node from which you enter an Info file.

A ‘Top’ node should contain a brief description of the Info file and an extensive, master menu for the whole Info file. This helps the reader understand what the Info file is about. Also, you should write the version number of the program to which the Info file applies; or, at least, the edition number.

The contents of the ‘Top’ node should appear only in the Info file; none of it should appear in printed output, so enclose it between @ifinfo and @end ifinfo commands. (TeX does not print either an @node line or a menu; they appear only in Info; strictly speaking, you are not required to enclose these parts between @ifinfo and @end ifinfo, but it is simplest to do so. See section Conditionally Visible Text.)

Sometimes, you will want to place an @top sectioning command line containing the title of the document immediately after the @node Top line (see section The @top Sectioning Command, for more information).

For example, the beginning of the Top node of this manual contains an @top sectioning command, a short description, and edition and version information. It looks like this:

…
@end titlepage

@ifinfo
@node Top, Copying, (dir), (dir)
@top Texinfo

Texinfo is a documentation system…

This is edition…
…
@end ifinfo

@menu
* Copying::                 Texinfo is freely 
                              redistributable.
* Overview::                What is Texinfo?
…

@end menu

In a ‘Top’ node, the ‘Previous’, and ‘Up’ nodes usually refer to the top level directory of the whole Info system, which is called ‘(dir)’. The ‘Next’ node refers to the first node that follows the main or master menu, which is usually the copying permissions, introduction, or first chapter.

3.5.1 Parts of a Master Menu

A master menu is a detailed main menu listing all the nodes in a file.

A master menu is enclosed in @menu and @end menu commands and does not appear in the printed document.

Generally, a master menu is divided into parts.

• The first part contains the major nodes in the Texinfo file: the nodes for the chapters, chapter-like sections, and the appendices.
• The second part contains nodes for the indices.
• The third and subsequent parts contain a listing of the other, lower level nodes, often ordered by chapter. This way, rather than go through an intermediary menu, an inquirer can go directly to a particular node when searching for specific information. These menu items are not required; add them if you think they are a convenience.

Each section in the menu can be introduced by a descriptive line. So long as the line does not begin with an asterisk, it will not be treated as a menu entry. (See section Writing a Menu, for more information.)

For example, the master menu for this manual looks like the following (but has many more entries):

@menu
* Copying::             Texinfo is freely 
                          redistributable.
* Overview::            What is Texinfo?
* Texinfo Mode::        Special features in GNU Emacs.
…
…

* Command and Variable Index::    
                        An entry for each @-command.
* Concept Index::       An entry for each concept.

 --- The Detailed Node Listing ---

Overview of Texinfo

* Info Files::          What is an Info file?
* Printed Manuals::     Characteristics of 
                          a printed manual.
…
…

Using Texinfo Mode

* Info on a Region::    Formatting part of a file 
                          for Info.
…
…
@end menu

3.6 Software Copying Permissions

If the Texinfo file has a section containing the “General Public License” and the distribution information and a warranty disclaimer for the software that is documented, this section usually follows the ‘Top’ node. The General Public License is very important to Project GNU software. It ensures that you and others will continue to have a right to use and share the software.

The copying and distribution information and the disclaimer are followed by an introduction or else by the first chapter of the manual.

Although an introduction is not a required part of a Texinfo file, it is very helpful. Ideally, it should state clearly and concisely what the file is about and who would be interested in reading it. In general, an introduction would follow the licensing and distribution information, although sometimes people put it earlier in the document. Usually, an introduction is put in an @unnumbered section. (See section The @unnumbered and @appendix Commands.)

4 Ending a Texinfo File

The end of a Texinfo file should include the commands that create indices and generate detailed and summary tables of contents. And it must include the @bye command that marks the last line processed by TeX.

For example:

@node    Concept Index,     , Variables Index, Top
@c        node-name,    next, previous,        up
@unnumbered Concept Index

@printindex cp

@contents
@bye

4.1 Index Menus and 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 @cindex or other index-entry generating commands in the Texinfo file; those just cause the raw data for the index to be accumulated. To generate an index, you must include the @printindex command at the place in the document where you want the index to appear. Also, as part of the process of creating a printed manual, you must run a program called texindex (see section Format and Print Hardcopy) to sort the raw data to produce a sorted index file. The sorted index file is what is actually used to print the index.

Texinfo offers six different types of predefined index: the concept index, the function index, the variables index, the keystroke index, the program index, and the data type index (see section Predefined Indices). Each index type has a two-letter name: ‘cp’, ‘fn’, ‘vr’, ‘ky’, ‘pg’, and ‘tp’. You may merge indices, or put them into separate sections (see section Combining Indices); or you may define your own indices (see section Defining New Indices).

The @printindex command takes a two-letter index name, reads the corresponding sorted index file and formats it appropriately into an index.

The @printindex command does not generate a chapter heading for the index. Consequently, you should precede the @printindex command with a suitable section or chapter command (usually @unnumbered) to supply the chapter heading and put the index into the table of contents. Precede the @unnumbered command with an @node line.

For example:

@node Variable Index, Concept Index, Function Index, Top
@comment    node-name,         next,       previous, up
@unnumbered Variable Index

@printindex vr

@node     Concept Index,     , Variable Index, Top
@comment      node-name, next,       previous, up
@unnumbered Concept Index

@printindex cp

@summarycontents
@contents
@bye

(Readers often prefer that the concept index come last in a book, since that makes it easiest to find.)

4.2 Generating a Table of Contents

The @chapter, @section, and other structuring commands supply the information to make up a table of contents, but they do not cause an actual table to appear in the manual. To do this, you must use the @contents and @summarycontents commands:

@contents

Generate a table of contents in a printed manual, including all chapters, sections, subsections, etc., as well as appendices and unnumbered chapters. (Headings generated by the @heading series of commands do not appear in the table of contents.) The @contents command should be written on a line by itself.

@shortcontents

@summarycontents

(@summarycontents is a synonym for @shortcontents; the two commands are exactly the same.)

Generate a short or summary table of contents that lists only the chapters (and appendices and unnumbered chapters). Omit sections, subsections and subsubsections. Only a long manual needs a short table of contents in addition to the full table of contents.

Write the @shortcontents command on a line by itself right before the @contents command.

The table of contents commands automatically generate a chapter-like heading at the top of the first table of contents page. Write the table of contents commands at the very end of a Texinfo file, just before the @bye command, following any index sections—anything in the Texinfo file after the table of contents commands will be omitted from the table of contents.

When you print a manual with a table of contents, the table of contents are printed last and numbered with roman numerals. You need to place those pages in their proper place, after the title page, yourself. (This is the only collating you need to do for a printed manual. The table of contents is printed last because it is generated after the rest of the manual is typeset.)

Here is an example of where to write table of contents commands:

indices…
@shortcontents
@contents
@bye

Since an Info file uses menus instead of tables of contents, the Info formatting commands ignore the @contents and @shortcontents commands.

4.3 @bye File Ending

An @bye command terminates TeX or Info formatting. None of the formatting commands see any of the file following @bye. The @bye command should be on a line by itself.

If you wish, you may follow the @bye line with notes. These notes will not be formatted and will not appear in either Info or a printed manual; it is as if text after @bye were within @ignore … @end ignore. Also, you may follow the @bye line with a local variables list. See section Using Local Variables and the Compile Command, for more information.

5 Chapter Structuring

The chapter structuring commands divide a document into a hierarchy of chapters, sections, subsections, and subsubsections. These commands generate large headings; they also provide information for the table of contents of a printed manual (see section Generating a Table of Contents).

The chapter structuring commands do not create an Info node structure, so normally you should put an @node command immediately before each chapter structuring command (see section Nodes). The only time you are likely to use the chapter structuring commands without using the node structuring commands is if you are writing a document that contains no cross references and will never be transformed into Info format.

It is unlikely that you will ever write a Texinfo file that is intended only as an Info file and not as a printable document. If you do, you might still use chapter structuring commands to create a heading at the top of each node—but you don’t need to.

5.1 Tree Structure of Sections

A Texinfo file is usually structured like a book with chapters, sections, subsections, and the like. This structure can be visualized as a tree (or rather as an upside-down tree) with the root at the top and the levels corresponding to chapters, sections, subsection, and subsubsections.

Here is a diagram that shows a Texinfo file with three chapters, each of which has two sections.

                          Top
                           |
         -------------------------------------
        |                  |                  |
     Chapter 1          Chapter 2          Chapter 3
        |                  |                  |
     --------           --------           --------
    |        |         |        |         |        |         
 Section  Section   Section  Section   Section  Section
   1.1      1.2       2.1      2.2       3.1      3.2

In a Texinfo file that has this structure, the beginning of Chapter 2 looks like this:

@node    Chapter 2,  Chapter 3, Chapter 1, top
@chapter Chapter 2

The chapter structuring commands are described in the sections that follow; the @node and @menu commands are described in following chapters. (See section Nodes, and see Menus.)

5.2 Types of Structuring Command

The chapter structuring commands fall into four groups or series, each of which contains structuring commands corresponding to the hierarchical levels of chapters, sections, subsections, and subsubsections.

The four groups are the @chapter series, the @unnumbered series, the @appendix series, and the @heading series.

Each command produces titles that have a different appearance on the printed page or Info file; only some of the commands produce titles that are listed in the table of contents of a printed book or manual.

• The @chapter and @appendix series of commands produce numbered or lettered entries both in the body of a printed work and in its table of contents.
• The @unnumbered series of commands produce unnumbered entries both in the body of a printed work and in its table of contents. The @top command, which has a special use, is a member of this series (see section @top).
• The @heading series of commands produce unnumbered headings that do not appear in a table of contents. The heading commands never start a new page.
• The @majorheading command produces results similar to using the @chapheading command but generates a larger vertical whitespace before the heading.
• When an @setchapternewpage command says to do so, the @chapter, @unnumbered, and @appendix commands start new pages in the printed manual; the @heading commands do not.

Here are the four groups of chapter structuring commands:

5.3 @top

The @top command is a special sectioning command that you use only after an @node Top line at the beginning of a Texinfo file. The @top command tells the makeinfo formatter which node is the ‘Top’ node. It has the same typesetting effect as @unnumbered (see (@appendix)@unnumbered). For detailed information, see The @top Command.

5.4 @chapter

@chapter identifies a chapter in the document. Write the command at the beginning of a line and follow it on the same line by the title of the chapter.

For example, this chapter in this manual is entitled “Chapter Structuring”; the @chapter line looks like this:

@chapter Chapter Structuring

In TeX, the @chapter command creates a chapter in the document, specifying the chapter title. The chapter is numbered automatically.

In Info, the @chapter command causes the title to appear on a line by itself, with a line of asterisks inserted underneath. Thus, in Info, the above example produces the following output:

Chapter Structuring
*******************

5.5 @unnumbered, @appendix

Use the @unnumbered command to create a chapter that appears in a printed manual without chapter numbers of any kind. Use the @appendix command to create an appendix in a printed manual that is labelled by letter instead of by number.

For Info file output, the @unnumbered and @appendix commands are equivalent to @chapter: the title is printed on a line by itself with a line of asterisks underneath. (See section @chapter.)

To create an appendix or an unnumbered chapter, write an @appendix or @unnumbered command at the beginning of a line and follow it on the same line by the title, as you would if you were creating a chapter.

5.6 @majorheading, @chapheading

The @majorheading and @chapheading commands put chapter-like headings in the body of a document.

However, neither command causes TeX to produce a numbered heading or an entry in the table of contents; and neither command causes TeX to start a new page in a printed manual.

In TeX, an @majorheading command generates a larger vertical whitespace before the heading than an @chapheading command but is otherwise the same.

In Info, the @majorheading and @chapheading commands are equivalent to @chapter: the title is printed on a line by itself with a line of asterisks underneath. (See section @chapter.)

5.7 @section

In a printed manual, an @section command identifies a numbered section within a chapter. The section title appears in the table of contents. In Info, an @section command provides a title for a segment of text, underlined with ‘=’.

This section is headed with an @section command and looks like this in the Texinfo file:

@section @code{@@section}

To create a section, write the @section command at the beginning of a line and follow it on the same line by the section title.

Thus,

@section This is a section

produces

This is a section
=================

in Info.

5.8 @unnumberedsec, @appendixsec, @heading

The @unnumberedsec, @appendixsec, and @heading commands are, respectively, the unnumbered, appendix-like, and heading-like equivalents of the @section command. (See section @section.)

@unnumberedsec

The @unnumberedsec command may be used within an unnumbered chapter or within a regular chapter or appendix to provide an unnumbered section.

@appendixsec

@appendixsection

@appendixsection is a longer spelling of the @appendixsec command; the two are synonymous.

Conventionally, the @appendixsec or @appendixsection command is used only within appendices.

@heading

You may use the @heading command anywhere you wish for a section-style heading that will not appear in the table of contents.

5.9 The @subsection Command

Subsections are to sections as sections are to chapters. (See section @section.) In Info, subsection titles are underlined with ‘-’. For example,

@subsection This is a subsection

produces

This is a subsection
--------------------

In a printed manual, subsections are listed in the table of contents and are numbered three levels deep.

5.10 The @subsection-like Commands

The @unnumberedsubsec, @appendixsubsec, and @subheading commands are, respectively, the unnumbered, appendix-like, and heading-like equivalents of the @subsection command. (See section @subsection.)

In Info, the @subsection-like commands generate a title underlined with hyphens. In a printed manual, an @subheading command produces a heading like that of a subsection except that it is not numbered and does not appear in the table of contents. Similarly, an @unnumberedsubsec command produces an unnumbered heading like that of a subsection and an @appendixsubsec command produces a subsection-like heading labelled with a letter and numbers; both of these commands produce headings that appear in the table of contents.

5.11 The ‘subsub’ Commands

The fourth and lowest level sectioning commands in Texinfo are the ‘subsub’ commands. They are:

@subsubsection

Subsubsections are to subsections as subsections are to sections. (See section @subsection.) In a printed manual, subsubsection titles appear in the table of contents and are numbered four levels deep.

@unnumberedsubsubsec

Unnumbered subsubsection titles appear in the table of contents of a printed manual, but lack numbers. Otherwise, unnumbered subsubsections are the same as subsubsections. In Info, unnumbered subsubsections look exactly like ordinary subsubsections.

@appendixsubsubsec

Conventionally, appendix commands are used only for appendices and are lettered and numbered appropriately in a printed manual. They also appear in the table of contents. In Info, appendix subsubsections look exactly like ordinary subsubsections.

@subsubheading

The @subsubheading command may be used anywhere that you need a small heading that will not appear in the table of contents. In Info, subsubheadings look exactly like ordinary subsubsection headings.

In Info, ‘subsub’ titles are underlined with periods. For example,

@subsubsection This is a subsubsection

produces

This is a subsubsection
.......................

6 Nodes

Nodes are the primary segments of a Texinfo file. They do not themselves impose a hierarchic or any other kind of structure on a file. Nodes contain node pointers that name other nodes, and can contain menus which are lists of nodes. In Info, the movement commands can carry you to a pointed-to node or to a node listed in a menu. Node pointers and menus provide structure for Info files just as chapters, sections, subsections, and the like, provide structure for printed books.

The node and menu commands and the chapter structuring commands are independent of each other:

• In Info, node and menu commands provide structure. The chapter structuring commands generate headings with different kinds of underlining—asterisks for chapters, hyphens for sections, and so on; they do nothing else.
• In TeX, the chapter structuring commands generate chapter and section numbers and tables of contents. The node and menu commands provide information for cross references; they do nothing else.

You can use node pointers and menus to structure an Info file any way you want; and you can write a Texinfo file so that its Info output has a different structure than its printed output. However, most Texinfo files are written such that the structure for the Info output corresponds to the structure for the printed output. It is not convenient to do otherwise.

Generally, printed output is structured in a tree-like hierarchy in which the chapters are the major limbs from which the sections branch out. Similarly, node pointers and menus are organized to create a matching structure in the Info output.

6.1 Node and Menu Illustration

Here is a copy of the diagram shown earlier that illustrates a Texinfo file with three chapters, each of which contains two sections.

Note that the “root” is at the top of the diagram and the “leaves” are at the bottom. This is how such a diagram is drawn conventionally; it illustrates an upside-down tree. For this reason, the root node is called the ‘Top’ node, and ‘Up’ node pointers carry you closer to the root.

                          Top
                           |
         -------------------------------------
        |                  |                  |
     Chapter 1          Chapter 2          Chapter 3
        |                  |                  |
     --------           --------           --------
    |        |         |        |         |        |         
 Section  Section   Section  Section   Section  Section
   1.1      1.2       2.1      2.2       3.1      3.2

Write the beginning of the node for Chapter 2 like this:

@node     Chapter 2,  Chapter 3, Chapter 1, top
@comment  node-name,  next,      previous,  up

This @node line says that the name of this node is “Chapter 2”, the name of the ‘Next’ node is “Chapter 3”, the name of the ‘Previous’ node is “Chapter 1”, and the name of the ‘Up’ node is “Top”.

Please Note: ‘Next’ refers to the next node at the same hierarchical level in the manual, not necessarily to the next node within the Texinfo file. In the Texinfo file, the subsequent node may be at a lower level—a section-level node may follow a chapter-level node, and a subsection-level node may follow a section-level node. ‘Next’ and ‘Previous’ refer to nodes at the same hierarchical level. (The ‘Top’ node contains the exception to this rule. Since the ‘Top’ node is the only node at that level, ‘Next’ refers to the first following node, which is almost always a chapter or chapter-level node.)

To go to Sections 2.1 and 2.2 using Info, you need a menu inside Chapter 2. (See section Menus.) You would write the menu just before the beginning of Section 2.1, like this:

    @menu
    * Sect. 2.1::    Description of this section.
    * Sect. 2.2::  
    @end menu

Write the node for Sect. 2.1 like this:

    @node     Sect. 2.1, Sect. 2.2, Chapter 2, Chapter 2
    @comment  node-name, next,      previous,  up

In Info format, the ‘Next’ and ‘Previous’ pointers of a node usually lead to other nodes at the same level—from chapter to chapter or from section to section (sometimes, as shown, the ‘Previous’ pointer points up); an ‘Up’ pointer usually leads to a node at the level above (closer to the ‘Top’ node); and a ‘Menu’ leads to nodes at a level below (closer to ‘leaves’). (A cross reference can point to a node at any level; see Cross References.)

Usually, an @node command and a chapter structuring command are used in sequence, along with indexing commands. (You may follow the @node line with a comment line that reminds you which pointer is which.)

Here is the beginning of the chapter in this manual called “Ending a Texinfo File”. This shows an @node line followed by a comment line, an @chapter line, and then by indexing lines.

@node    Ending a File, Structuring, Beginning a File, Top
@comment node-name,     next,        previous,         up
@chapter Ending a Texinfo File
@cindex Ending a Texinfo file
@cindex Texinfo file ending
@cindex File ending

6.2 The @node Command

A node is a segment of text that begins at an @node command and continues until the next @node command. The definition of node is different from that for chapter or section. A chapter may contain sections and a section may contain subsections; but a node cannot contain subnodes; the text of a node continues only until the next @node command in the file. A node usually contains only one chapter structuring command, the one that follows the @node line. On the other hand, in printed output nodes are used only for cross references, so a chapter or section may contain any number of nodes. Indeed, a chapter usually contains several nodes, one for each section, subsection, and subsubsection.

To create a node, write an @node command at the beginning of a line, and follow it with four arguments, separated by commas, on the rest of the same line. These arguments are the name of the node, and the names of the ‘Next’, ‘Previous’, and ‘Up’ pointers, in that order. You may insert spaces before each pointer if you wish; the spaces are ignored. You must write the name of the node, and the names of the ‘Next’, ‘Previous’, and ‘Up’ pointers, all on the same line. Otherwise, the formatters fail. (See (info)info, for more information about nodes in Info.)

Usually, you write one of the chapter-structuring command lines immediately after an @node line—for example, an @section or @subsection line. (See section Types of Structuring Command.)

Please note: The GNU Emacs Texinfo mode updating commands work only with Texinfo files in which @node lines are followed by chapter structuring lines. See section Updating Requirements.

TeX uses @node lines to identify the names to use for cross references. For this reason, you must write @node lines in a Texinfo file that you intend to format for printing, even if you do not intend to format it for Info. (Cross references, such as the one at the end of this sentence, are made with @xref and its related commands; see Cross References.)

The name of a node identifies the node. The pointers enable you to reach other nodes and consist of the names of those nodes.

Normally, a node’s ‘Up’ pointer contains the name of the node whose menu mentions that node. The node’s ‘Next’ pointer contains the name of the node that follows that node in that menu and its ‘Previous’ pointer contains the name of the node that precedes it in that menu. When a node’s ‘Previous’ node is the same as its ‘Up’ node, both node pointers name the same node.

Usually, the first node of a Texinfo file is the ‘Top’ node, and its ‘Up’ and ‘Previous’ pointers point to the ‘dir’ file, which contains the main menu for all of Info.

The ‘Top’ node itself contains the main or master menu for the manual. Also, it is helpful to include a brief description of the manual in the ‘Top’ node. See section The First Node, for information on how to write the first node of a Texinfo file.

6.2.1 How to Write an @node Line

The easiest way to write an @node line is to write @node at the beginning of a line and then the name of the node, like this:

@node node-name

If you are using GNU Emacs, you can use the update node commands provided by Texinfo mode to insert the names of the pointers; or you can leave the pointers out of the Texinfo file and let makeinfo insert node pointers into the Info file it creates. (See section Using Texinfo Mode, and Creating Pointers with makeinfo.)

Alternatively, you can insert the ‘Next’, ‘Previous’, and ‘Up’ pointers yourself. If you do this, you may find it helpful to use the Texinfo mode keyboard command C-c C-c n. This command inserts ‘@node’ and a comment line listing the names of the pointers in their proper order. The comment line helps you keep track of which arguments are for which pointers. This comment line is especially useful if you are not familiar with Texinfo.

The template for a node line with ‘Next’, ‘Previous’, and ‘Up’ pointers looks like this:

@node node-name, next, previous, up

If you wish, you can ignore @node lines altogether in your first draft and then use the texinfo-insert-node-lines command to create @node lines for you. However, we do not recommend this practice. It is better to name the node itself at the same time that you write a segment so you can easily make cross references. A large number of cross references are an especially important feature of a good Info file.

After you have inserted an @node line, you should immediately write an @-command for the chapter or section and insert its name. Next (and this is important!), put in several index entries. Usually, you will find at least two and often as many as four or five ways of referring to the node in the index. Use them all. This will make it much easier for people to find the node.

6.2.2 @node Line Tips

Here are three suggestions:

• Try to pick node names that are informative but short.

  In the Info file, the file name, node name, and pointer names are all inserted on one line, which may run into the right edge of the window. (This does not cause a problem with Info, but is ugly.)

• Try to pick node names that differ from each other near the beginnings of their names. This way, it is easy to use automatic name completion in Info.
• By convention, node names are capitalized just as they would be for section or chapter titles—initial and significant words are capitalized; others are not.

6.2.3 @node Line Requirements

Here are several requirements for @node lines:

• All the node names for a single Info file must be unique.

  Duplicates confuse the Info movement commands. This means, for example, that if you end every chapter with a summary, you must name each summary node differently. You cannot just call each one “Summary”. You may, however, duplicate the titles of chapters, sections, and the like. Thus you can end each chapter in a book with a section called “Summary”, so long as the node names for those sections are all different.

• A pointer name must be the name of a node.

  The node to which a pointer points may come before or after the node containing the pointer.

• You cannot use any of the Texinfo @-commands in a node name; @-commands confuse Info.

  Thus, the beginning of the section called @chapter looks like this:

  @node  chapter, unnumbered & appendix, makeinfo top, Structuring
  @comment  node-name,  next,  previous,  up
  @section @code{@@chapter}
  @findex chapter
  

• You cannot use commas, colons, or apostrophes within a node name; these confuse TeX or the Info formatters.

  For example, the following is a section title:

  @code{@@unnumberedsec}, @code{@@appendixsec}, @code{@@heading} 
  

  The corresponding node name is:

  unnumberedsec appendixsec heading
  

• Case is significant.

6.2.4 The First Node

The first node of a Texinfo file is the ‘Top’ node, except in an included file (see section Include Files).

The ‘Top’ node (which must be named ‘top’ or ‘Top’) should have as its ‘Up’ and ‘Previous’ nodes 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 the file is to be installed directly in the Info directory file, use ‘(dir)’ as the parent of the ‘Top’ node; this is short for ‘(dir)top’, and specifies the ‘Top’ node in the ‘dir’ file, which contains the main menu for Info. For example, the @node Top line of this manual looks like this:

@node Top, Overview, (dir), (dir)

(You may use the Texinfo updating commands or the makeinfo utility to insert these ‘Next’ and ‘(dir)’ pointers automatically.)

See section Installing an Info File, for more information about installing an Info file in the ‘info’ directory.

The ‘Top’ node contains the main or master menu for the document.

6.2.5 The @top Sectioning Command

A special sectioning command, @top, has been created for use with the @node Top line. The @top sectioning command tells makeinfo that it marks the ‘Top’ node in the file. It provides the information that makeinfo needs to insert node pointers automatically. Write the @top command at the beginning of the line immediately following the @node Top line. Write the title on the remaining part of the same line as the @top command.

In Info, the @top sectioning command causes the title to appear on a line by itself, with a line of asterisks inserted underneath.

In TeX and texinfo-format-buffer, the @top sectioning command is merely a synonym for @unnumbered. Neither of these formatters require an @top command, and do nothing special with it. You can use @chapter or @unnumbered after the @node Top line when you use these formatters. Also, you can use @chapter or @unnumbered when you use the Texinfo updating commands to create or update pointers and menus.

Whatever sectioning command follows an @node Top line, whether it be @top or @chapter, the @node Top line and the immediately following line and any additional text must be enclosed between @ifinfo and @end ifinfo commands. (See section Conditionally Visible Text.) This prevents the title and the accompanying text from appearing in printed output. Write the @ifinfo command before the @node line and write the @end ifinfo command after the @top or other sectioning command and after any additional text. (You can write the @end ifinfo command after the @end menu command if you like.)

6.2.6 The ‘Top’ Node Summary

You can help readers by writing a summary in the ‘Top’ node, after the @top line, before the main or master menu. The summary should briefly describe the Info file. You should also write the version number of the program to which the manual applies in this section. This helps the reader keep track of which manual is for which version of the program. If the manual changes more frequently than the program or is independent of it, you should also include an edition number for the manual. (The title page should also contain this information: see @titlepage.)

Put the whole of the ‘Top’ node, including the @top sectioning command line if you have one, between @ifinfo and @end ifinfo so none of the text appears in the printed output (see section Conditionally Visible Text). (You may want to repeat the brief description from the ‘Top’ node within @iftex … @end iftex at the beginning of the first chapter, for those who read the printed manual.)

6.3 Creating Pointers with makeinfo

The makeinfo program has a feature for automatically creating node pointers for a hierarchically organized file that lacks them.

When you take advantage of this feature, you do not need to write the ‘Next’, ‘Previous’, and ‘Up’ pointers after the name of a node. However, you must write a sectioning command, such as @chapter or @section, on the line immediately following each truncated @node line. You cannot write a comment line after a node line; the section line must follow it immediately.

In addition, you must follow the ‘Top’ @node line with a line beginning with @top to mark the ‘Top’ node in the file. See section @top.

Finally, you must write the name of each node (except for the ‘Top’ node) in a menu that is one or more hierarchical levels above the node’s hierarchical level.

This node pointer insertion feature in makeinfo is an alternative to the menu and pointer creation and update commands in Texinfo mode. (See section Updating Nodes and Menus.) It is especially helpful to people who do not use GNU Emacs for writing Texinfo documents.

7 Menus

Menus contain pointers to subordinate nodes.(6) In Info, you use menus to go to such nodes. Menus have no effect in printed manuals and do not appear in them.

By convention, a menu is put at the end of a node since a reader who uses the menu may not see text that follows it.

The short text before a menu may look awkward in a printed manual. To avoid this, you can write a menu near the beginning of its node and follow the menu by an @node line, and then an @heading line located within @ifinfo and @end ifinfo. This way, the menu, @node line, and title appear only in the Info file, not the printed document.

For example, the preceding two paragraphs follow an Info-only menu, @node line, and heading, and look like this:

@menu
* Menu Location::             Put a menu in a short node.
* Writing a Menu::            What is a menu?
* Menu Parts::                A menu entry has three parts.
* Less Cluttered Menu Entry:: Two part menu entry.
* Menu Example::              Two and three part entries.
* Other Info Files::          How to refer to a different 
                                Info file.
@end menu

@node Menu Location, Writing a Menu,  , Menus
@ifinfo
@heading Menus Need Short Nodes
@end ifinfo

The Texinfo file for this document contains more than a dozen examples of this procedure. One is at the beginning of this chapter; another is at the beginning of the “Cross References” chapter.

7.1 Writing a Menu

A menu consists of an @menu command on a line by itself followed by menu entry lines or menu comment lines and then by an @end menu command on a line by itself.

A menu looks like this:

@menu
Larger Units of Text

* Files::                       All about handling files.
* Multiples: Buffers.           Multiple buffers; editing 
                                  several files at once.
@end menu

In a menu, every line that begins with an ‘* ’ is a menu entry. (Note the space after the asterisk.) A line that does not start with an ‘* ’ may also appear in a menu. Such a line is not a menu entry but is a menu comment line that appears in the Info file. In the example above, the line ‘Larger Units of Text’ is a menu comment line; the two lines starting with ‘* ’ are menu entries.

7.2 The Parts of a Menu

A menu entry has three parts, only the second of which is required:

1. The menu entry name.
2. The name of the node (required).
3. A description of the item.

The template for a menu entry looks like this:

* menu-entry-name: node-name.   description

Follow the menu entry name with a single colon and follow the node name with tab, comma, period, or newline.

In Info, a user selects a node with the m (Info-menu) command. The menu entry name is what the user types after the m command.

The third part of a menu entry is a descriptive phrase or sentence. Menu entry names and node names are often short; the description explains to the reader what the node is about. The description, which is optional, can spread over two or more lines. A useful description complements the node name rather than repeats it.

7.3 Less Cluttered Menu Entry

When the menu entry name and node name are the same, you can write the name immediately after the asterisk and space at the beginning of the line and follow the name with two colons.

For example, write

* Name::                                    description

instead of

* Name: Name.                               description

You should use the node name for the menu entry name whenever possible, since it reduces visual clutter in the menu.

7.4 A Menu Example

A menu looks like this in Texinfo:

@menu
* menu entry name: Node name.   A short description.
* Node name::                   This form is preferred.
@end menu

This produces:

* menu:

* menu entry name: Node name.   A short description.
* Node name::                   This form is preferred.

Here is an example as you might see it in a Texinfo file:

@menu
Larger Units of Text

* Files::                       All about handling files.
* Multiples: Buffers.           Multiple buffers; editing 
                                  several files at once.
@end menu

This produces:

* menu:
Larger Units of Text

* Files::                       All about handling files.
* Multiples: Buffers.           Multiple buffers; editing 
                                  several files at once.

In this example, the menu has two entries. ‘Files’ is both a menu entry name and the name of the node referred to by that name. ‘Multiples’ is the menu entry name; it refers to the node named ‘Buffers’. The line ‘Larger Units of Text’ is a comment; it appears in the menu, but is not an entry.

Since no file name is specified with either ‘Files’ or ‘Buffers’, they must be the names of nodes in the same Info file (see section Referring to Other Info Files).

7.5 Referring to Other Info Files

You can create a menu entry that enables a reader in Info to go to a node in another Info file by writing the file name in parentheses just before the node name. In this case, you should use the three-part menu entry format, which saves the reader from having to type the file name.

The format looks like this:

@menu
* first-entry-name:(filename)nodename.     description
* second-entry-name:(filename)second-node. description
@end menu

For example, to refer directly to the ‘Outlining’ and ‘Rebinding’ nodes in the Emacs Manual, you would write a menu like this:

@menu
* Outlining: (emacs)Outline Mode. The major mode for 
                                  editing outlines.
* Rebinding: (emacs)Rebinding.    How to redefine the 
                                  meaning of a key.
@end menu

If you do not list the node name, but only name the file, then Info presumes that you are referring to the ‘Top’ node.

The ‘dir’ file that contains the main menu for Info has menu entries that list only file names. These take you directly to the ‘Top’ nodes of each Info document. (See section Installing an Info File.)

For example:

* Info: (info).         Documentation browsing system.
* Emacs: (emacs).       The extensible, self-documenting 
                        text editor.

(The ‘dir’ top level directory for the Info system is an Info file, not a Texinfo file, but a menu entry looks the same in both types of file.)

Note that the GNU Emacs Texinfo mode menu updating commands only work with nodes within the current buffer, so you cannot use them to create menus that refer to other files. You must write such menus by hand.

8 Cross References

Cross references are used to refer the reader to other parts of the same or different Texinfo files. In Texinfo, nodes are the places to which cross references can refer.

Often, but not always, a printed document should be designed so that it can be read sequentially. People tire of flipping back and forth to find information that should be presented to them as they need it.

However, in any document, some information will be too detailed for the current context, or incidental to it; use cross references to provide access to such information. Also, an on-line help system or a reference manual is not like a novel; few read such documents in sequence from beginning to end. Instead, people look up what they need. For this reason, such creations should contain many cross references to help readers find other information that they may not have read.

In a printed manual, a cross reference results in a page reference, unless it is to another manual altogether, in which case the cross reference names that manual.

In Info, a cross reference results in an entry that you can follow using the Info ‘f’ command. (See (info)Some advanced Info commands.)

The various cross reference commands use nodes to define cross reference locations. This is evident in Info, in which a cross reference takes you to the specified node. TeX also uses nodes to define cross reference locations, but the action is less obvious. When TeX generates a DVI file, it records nodes’ page numbers and uses the page numbers in making references. Thus, if you are writing a manual that will only be printed, and will not be used on-line, you must nonetheless write @node lines to name the places to which you make cross references.

8.1 Different Cross Reference Commands

There are four different cross reference commands:

@xref

Used to start a sentence in the printed manual saying ‘See …’ or an entry in the Info file saying ‘*Note …’.

@ref

Used within or, more often, at the end of a sentence; same as @xref for Info; produces just the reference in the printed manual without a preceding ‘See’.

@pxref

Used within parentheses to make a reference that suits both an Info file and a printed book. Starts with a lower case ‘see’ within the printed manual. (‘p’ is for ‘parenthesis’.)

@inforef

Used to make a reference to an Info file for which there is no printed manual.

(The @cite command is used to make references to books and manuals for which there is no corresponding Info file and, therefore, no node to which to point. See section @cite.)

8.2 Parts of a Cross Reference

A cross reference command requires only one argument, which is the name of the node to which it refers. But a cross reference command may contain up to four additional arguments. By using these arguments, you can provide a cross reference name for Info, a topic description or section title for the printed output, the name of a different Info file, and the name of a different printed manual.

Here is a simple cross reference example:

@xref{Node name}.

which produces

*Note Node name::.

and

See Section nnn [Node name], page ppp.

Here is an example of a full five-part cross reference:

@xref{Node name, Cross Reference Name, Particular Topic, 
info-file-name, A Printed Manual}, for details.

which produces

*Note Cross Reference Name: (info-file-name)Node name,
for details.

in Info and

See section “Particular Topic” in A Printed Manual, for details.

in a printed book.

The five possible arguments for a cross reference are:

1. The node name (required). This is the node to which the cross reference takes you. In a printed document, the location of the node provides the page reference only for references within the same document.
2. The cross reference name for the Info reference, if it is to be different from the node name. If you include this argument, it argument becomes the first part of the cross reference. It is usually omitted.
3. A topic description or section name. Often, this is the title of the section. This is used as the name of the reference in the printed manual. If omitted, the node name is used.
4. The name of the Info file in which the reference is located, if it is different from the current file.
5. The name of a printed manual from a different Texinfo file.

The template for a full five argument cross reference looks like this:

@xref{node-name, cross-reference-name, title-or-topic,
info-file-name, printed-manual-title}.

Cross references with one, two, three, four, and five arguments are described separately following the description of @xref.

Write a node name in a cross reference in exactly the same way as in the @node line, including the same capitalization; otherwise, the formatters may not find the reference.

You can write cross reference commands within a paragraph, but note how Info and TeX format the output of each of the various commands: write @xref at the beginning of a sentence; write @pxref only within parentheses, and so on.

8.3 @xref

The @xref command generates a cross reference for the beginning of a sentence. The Info formatting commands convert it into an Info cross reference, which the Info ‘f’ command can use to bring you directly to another node. The TeX typesetting commands convert it into a page reference, or a reference to another book or manual.

Most often, an Info cross reference looks like this:

*Note node-name::.

or like this

*Note cross-reference-name: node-name.

In TeX, a cross reference looks like this:

See Section section-number [node-name], page page.

or like this

See Section section-number [title-or-topic], page page.

The @xref command does not generate a period or comma to end the cross reference in either the Info file or the printed output. You must write that period or comma yourself; otherwise, Info will not recognize the end of the reference. (The @pxref command works differently. See section @pxref.)

Please note: A period or comma must follow the closing brace of an @xref. It is required to terminate the cross reference. This period or comma will appear in the output, both in the Info file and in the printed manual.

@xref must refer to an Info node by name. Use @node to define the node (see section How to Write an @node Line).

@xref is followed by several arguments inside braces, separated by commas. Whitespace before and after these commas is ignored.

A cross reference requires only the name of a node; but it may contain up to four additional arguments. Each of these variations produces a cross reference that looks somewhat different.

Please note: Commas separate arguments in a cross reference; avoid including them in the title or other part lest the formatters mistake them for separators.

8.3.1 @xref with One Argument

The simplest form of @xref takes one argument, the name of another node in the same Info file. The Info formatters produce output that the Info readers can use to jump to the reference; TeX produces output that specifies the page and section number for you.

For example,

@xref{Tropical Storms}.

produces

*Note Tropical Storms::.

and

See Section 3.1 [Tropical Storms], page 24.

(Note that in the preceding example the closing brace is followed by a period.)

You can write a clause after the cross reference, like this:

@xref{Tropical Storms}, for more info.

which produces

*Note Tropical Storms::, for more info.

See Section 3.1 [Tropical Storms], page 24, for more info.

(Note that in the preceding example the closing brace is followed by a comma, and then by the clause, which is followed by a period.)

8.3.2 @xref with Two Arguments

With two arguments, the second is used as the name of the Info cross reference, while the first is still the name of the node to which the cross reference points.

The template is like this:

@xref{node-name, cross-reference-name}.

For example,

@xref{Electrical Effects, Lightning}.

produces:

*Note Lightning: Electrical Effects.

and

See Section 5.2 [Electrical Effects], page 57.

(Note that in the preceding example the closing brace is followed by a period; and that the node name is printed, not the cross reference name.)

You can write a clause after the cross reference, like this:

@xref{Electrical Effects, Lightning}, for more info.

which produces

*Note Lightning: Electrical Effects, for more info.

and

See Section 5.2 [Electrical Effects], page 57, for more info.

(Note that in the preceding example the closing brace is followed by a comma, and then by the clause, which is followed by a period.)

8.3.3 @xref with Three Arguments

A third argument replaces the node name in the TeX output. The third argument should be the name of the section in the printed output, or else state the topic discussed by that section. Often, you will want to use initial upper case letters so it will be easier to read when the reference is printed. Use a third argument when the node name is unsuitable because of syntax or meaning.

Remember to avoid placing a comma within the title or topic section of a cross reference, or within any other section. The formatters divide cross references into arguments according to the commas; a comma within a title or other section will divide it into two arguments. In a reference, you need to write a title such as “Clouds, Mist, and Fog” without the commas.

Also, remember to write a comma or period after the closing brace of a @xref to terminate the cross reference. In the following examples, a clause follows a terminating comma.

The template is like this:

@xref{node-name, cross-reference-name, title-or-topic}.

For example,

@xref{Electrical Effects, Lightning, Thunder and Lightning},
for details.

produces

*Note Lightning: Electrical Effects, for details.

and

See Section 5.2 [Thunder and Lightning], page 57, for details.

If a third argument is given and the second one is empty, then the third argument serves both. (Note how two commas, side by side, mark the empty second argument.)

@xref{Electrical Effects, , Thunder and Lightning},
for details.

produces

*Note Thunder and Lightning: Electrical Effects, for details.

and

See Section 5.2 [Thunder and Lightning], page 57, for details.

As a practical matter, it is often best to write cross references with just the first argument if the node name and the section title are the same, and with the first and third arguments if the node name and title are different.

Here are several examples from The GAWK Manual:

@xref{Sample Program}.
@xref{Glossary}.
@xref{Case-sensitivity, ,Case-sensitivity in Matching}.
@xref{Close Output, , Closing Output Files and Pipes}, 
   for more information.
@xref{Regexp, , Regular Expressions as Patterns}.

8.3.4 @xref with Four and Five Arguments

In a cross reference, a fourth argument specifies the name of another Info file, different from the file in which the reference appears, and a fifth argument specifies its title as a printed manual.

Remember that a comma or period must follow the closing brace of an @xref command to terminate the cross reference. In the following examples, a clause follows a terminating comma.

The template is:

@xref{node-name, cross-reference-name, title-or-topic,
info-file-name, printed-manual-title}.

For example,

@xref{Electrical Effects, Lightning, Thunder and Lightning, 
weather, An Introduction to Meteorology}, for details.

produces

*Note Lightning: (weather)Electrical Effects, for details.

The name of the Info file is enclosed in parentheses and precedes the name of the node.

In a printed manual, the reference looks like this:

See section “Thunder and Lightning” in An Introduction to Meteorology, for details.

The title of the printed manual is typeset in italics; and the reference lacks a page number since TeX cannot know to which page a reference refers when that reference is to another manual.

Often, you will leave out the second argument when you use the long version of @xref. In this case, the third argument, the topic description, will be used as the cross reference name in Info.

The template looks like this:

@xref{node-name, , title-or-topic, info-file-name,
printed-manual-title}, for details.

which produces

*Note title-or-topic: (info-file-name)node-name, for details.

and

See section title-or-topic in printed-manual-title, for details.

For example,

@xref{Electrical Effects, , Thunder and Lightning, 
weather, An Introduction to Meteorology}, for details.

produces

*Note Thunder and Lightning: (weather)Electrical Effects,
for details.

and

See section “Thunder and Lightning” in An Introduction to Meteorology, for details.

On rare occasions, you may want to refer to another Info file that is within a single printed manual—when multiple Texinfo files are incorporated into the same TeX run but make separate Info files. In this case, you need to specify only the fourth argument, and not the fifth.

8.4 Naming a ‘Top’ Node

In a cross reference, you must always name a node. This means that in order to refer to a whole manual, you must identify the ‘Top’ node by writing it as the first argument to the @xref command. (This is different from the way you write a menu entry; see Referring to Other Info Files.) At the same time, to provide a meaningful section topic or title in the printed cross reference (instead of the word ‘Top’), you must write an appropriate entry for the third argument to the @xref command.

Thus, to make a cross reference to The GNU Make Manual, write:

@xref{Top, , Overview, make, The GNU Make Manual}.

which produces

*Note Overview: (make)Top.

and

See section “Overview” in The GNU Make Manual.

In this example, ‘Top’ is the name of the first node, and ‘Overview’ is the name of the first section of the manual.

8.5 @ref

@ref is nearly the same as @xref except that it does not generate a ‘See’ in the printed output, just the reference itself. This makes it useful as the last part of a sentence.

For example,

For more information, see @ref{Hurricanes}.

produces

For more information, see *Note Hurricanes.

and

For more information, see Section 8.2 [Hurricanes], page 123.

The @ref command sometimes leads writers to express themselves in a manner that is suitable for a printed manual but looks awkward in the Info format. Bear in mind that your audience will be using both the printed and the Info format.

For example,

Sea surges are described in @ref{Hurricanes}.

produces

Sea surges are described in Section 6.7 [Hurricanes], page 72.

in a printed document, and the following in Info:

Sea surges are described in *Note Hurricanes::.

Caution: You must write a period or comma immediately after an @ref command with two or more arguments. Otherwise, Info will not find the end of the cross reference entry and its attempt to follow the cross reference will fail. As a general rule, you should write a period or comma after every @ref command. This looks best in both the printed and the Info output.

8.6 @pxref

The parenthetical reference command, @pxref, is nearly the same as @xref, but you use it only inside parentheses and you do not type a comma or period after the command’s closing brace. The command differs from @xref in two ways:

1. TeX typesets the reference for the printed manual with a lower case ‘see’ rather than an upper case ‘See’.
2. The Info formatting commands automatically end the reference with a closing colon or period.

Because one type of formatting automatically inserts closing punctuation and the other does not, you should use @pxref only inside parentheses as part of another sentence. Also, you yourself should not insert punctuation after the reference, as you do with @xref.

@pxref is designed so that the output looks right and works right between parentheses both in printed output and in an Info file. In a printed manual, a closing comma or period should not follow a cross reference within parentheses; such punctuation is wrong. But in an Info file, suitable closing punctuation must follow the cross reference so Info can recognize its end. @pxref spares you the need to use complicated methods to put a terminator into one form of the output and not the other.

With one argument, a parenthetical cross reference looks like this:

… storms cause flooding (@pxref{Hurricanes}) …

which produces

… storms cause flooding (*Note Hurricanes::) …

and

… storms cause flooding (see Section 6.7 [Hurricanes], page 72) …

With two arguments, a parenthetical cross reference has this template:

… (@pxref{node-name, cross-reference-name}) …

which produces

… (*Note cross-reference-name: node-name.) …

and

… (see Section nnn [node-name], page ppp) …

@pxref can be used with up to five arguments just like @xref (see section @xref).

Please note: Use @pxref only as a parenthetical reference. Do not try to use @pxref as a clause in a sentence. It will look bad in either the Info file, the printed output, or both.

Also, parenthetical cross references look best at the ends of sentences. Although you may write them in the middle of a sentence, that location breaks up the flow of text.

8.7 @inforef

@inforef is used for cross references to Info files for which there are no printed manuals. Even in a printed manual, @inforef generates a reference directing the user to look in an Info file.

The command takes either two or three arguments, in the following order:

1. The node name.
2. The cross reference name (optional).
3. The Info file name.

Separate the arguments with commas, as with @xref. Also, you must terminate the reference with a comma or period after the ‘}’, as you do with @xref.

The template is:

@inforef{node-name, cross-reference-name, info-file-name},

Thus,

@inforef{Expert, Advanced Info commands, info},
for more information.

produces

*Note Advanced Info commands: (info)Expert,
for more information.

and

See Info file ‘info’, node ‘Expert’, for more information.

Similarly,

@inforef{Expert, , info}, for more information.

produces

*Note (info)Expert::, for more information.

and

See Info file ‘info’, node ‘Expert’, for more information.

The converse of @inforef is @cite, which is used to refer to printed works for which no Info form exists. See section @cite.

9 Marking Words and Phrases

In Texinfo, you can mark words and phrases in a variety of ways. The Texinfo formatters use this information to determine how to highlight the text. You can specify, for example, whether a word or phrase is a defining occurrence, a metasyntactic variable, or a symbol used in a program. Also, you can emphasize text.

9.1 Indicating Definitions, Commands, etc.

Texinfo has commands for indicating just what kind of object a piece of text refers to. For example, metasyntactic variables are marked by @var, and code by @code. Since the pieces of text are labelled by commands that tell what kind of object they are, it is easy to change the way the Texinfo formatters prepare such text. (Texinfo is an intentional formatting language rather than a typesetting formatting language.)

For example, in a printed manual, code is usually illustrated in a typewriter font; @code tells TeX to typeset this text in this font. But it would be easy to change the way TeX highlights code to use another font, and this change would not effect how keystroke examples are highlighted. If straight typesetting commands were used in the body of the file and you wanted to make a change, you would need to check every single occurrence to make sure that you were changing code and not something else that should not be changed.

The highlighting commands can be used to generate useful information from the file, such as lists of functions or file names. It is possible, for example, to write a program in Emacs Lisp (or a keyboard macro) to insert an index entry after every paragraph that contains words or phrases marked by a specified command. You could do this to construct an index of functions if you had not already made the entries.

The commands serve a variety of purposes:

@code{sample-code}

Indicate text that is a literal example of a piece of a program.

@kbd{keyboard-characters}

Indicate keyboard input.

@key{key-name}

Indicate the conventional name for a key on a keyboard.

@samp{text}

Indicate text that is a literal example of a sequence of characters.

@var{metasyntactic-variable}

Indicate a metasyntactic variable.

@file{file-name}

Indicate the name of a file.

@dfn{term}

Indicate the introductory or defining use of a term.

@cite{reference}

Indicate the name of a book.

9.1.1 @code{sample-code}

Use the @code command to indicate text that is a piece of a program and which consists of entire syntactic tokens. Enclose the text in braces.

Thus, you should use @code for an expression in a program, for the name of a variable or function used in a program, or for a keyword. Also, you should use @code for the name of a program, such as diff, that is a name used in the machine. (You should write the name of a program in the ordinary text font if you regard it as a new English word, such as ‘Emacs’ or ‘Bison’.)

Use @code for environment variables such as TEXINPUTS, and other variables.

Use @code for command names in command languages that resemble programming languages, such as Texinfo or the shell. For example, @code and @samp are produced by writing ‘@code{@@code}’ and ‘@code{@@samp}’ in the Texinfo source, respectively.

Note, however, that you should not use @code for shell options such as ‘-c’ when such options stand alone. (Use @samp.) Also, an entire shell command often looks better if written using @samp rather than @code. In this case, the rule is to choose the more pleasing format.

It is incorrect to alter the case of a word inside an @code command when it appears at the beginning of a sentence. Most computer languages are case sensitive. In C, for example, Printf is different from the identifier printf, and most likely is a misspelling of it. Even in languages which are not case sensitive, it is confusing to a human reader to see identifiers spelled in different ways. Pick one spelling and always use that. If you do not want to start a sentence with a command written all in lower case, you should rearrange the sentence.

Do not use the @code command for a string of characters shorter than a syntactic token. If you are writing about ‘TEXINPU’, which is just a part of the name for the TEXINPUTS environment variable, you should use @samp.

In particular, you should not use the @code command when writing about the characters used in a token; do not, for example, use @code when you are explaining what letters or printable symbols can be used in the names of functions. (Use @samp.) Also, you should not use @code to mark text that is considered input to programs unless the input is written in a language that is like a programming language. For example, you should not use @code for the keystroke commands of GNU Emacs (use @kbd instead) although you may use @code for the names of the Emacs Lisp functions that the keystroke commands invoke.

In the printed manual, @code causes TeX to typeset the argument in a typewriter face. In the Info file, it causes the Info formatting commands to use single quotation marks around the text.

For example,

Use @code{diff} to compare two files.

produces this in the printed manual:

Use diff to compare two files.

9.1.2 @kbd{keyboard-characters}

Use the @kbd command for characters of input to be typed by users. For example, to refer to the characters M-a, write

@kbd{M-a}

and to refer to the characters M-x shell, write

@kbd{M-x shell}

The @kbd command has the same effect as @code in Info, but may produce a different font in a printed manual.

You can embed another @-command inside the braces of an @kbd command. Here, for example, is the way to describe a command that would be described more verbosely as “press an ‘r’ and then press the <RET> key”:

@kbd{r @key{RET}}  

This produces: r <RET>

You also use the @kbd command if you are spelling out the letters you type; for example:

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

This produces:

To give the logout command, type the characters l o g o u t <RET>.

(Also, this example shows that you can add spaces for clarity. If you really want to mention a space character as one of the characters of input, write @key{SPC} for it.)

9.1.3 @key{key-name}

Use the @key command for the conventional name for a key on a keyboard, as in:

@key{RET}

You can use the @key command within the argument of an @kbd command when the sequence of characters to be typed includes one or more keys that are described by name.

For example, to produce C-x <ESC> you would type:

@kbd{C-x @key{ESC}}

Here is a list of the recommended names for keys; they are all in upper case:

SPC

Space

RET

Return

LFD

Linefeed

TAB

Tab

BS

Backspace

ESC

Escape

DEL

Delete

SFT

Shift

CTL

Control

META

Meta

There are subtleties to handling words like ‘meta’ or ‘ctl’ that are names of shift keys. When mentioning a character in which the shift key is used, such as Meta-a, use the @kbd command alone; do not use the @key command; but when you are referring to the shift key in isolation, use the @key command. For example, write ‘@kbd{Meta-a}’ to produce Meta-a and ‘@key{META}’ to produce <META>. This is because Meta-a refers to keys that you press on a keyboard, but <META> refers to a key without implying that you press it. In short, use @kbd for what you do, and use @key for what you talk about: “Press @kbd{M-a} to move point to the beginning of the sentence. The @key{META} key is often in the lower left of the keyboard.”

9.1.4 @samp{text}

Use the @samp command to indicate text that is a literal example or ‘sample’ of a sequence of characters in a file, string, pattern, etc. Enclose the text in braces. The argument appears within single quotation marks in both the Info file and the printed manual; in addition, it is printed in a fixed-width font.

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

produces

To match ‘foo’ at the end of the line, use the regexp ‘foo$’.

Any time you are referring to single characters, you should use @samp unless @kbd is more appropriate. Use @samp for the names of command-line options. Also, you may use @samp for entire statements in C and for entire shell commands—in this case, @samp often looks better than @code. Basically, @samp is a catchall for whatever is not covered by @code, @kbd, or @key.

Only include punctuation marks within braces if they are part of the string you are specifying. Write punctuation marks outside the braces if those punctuation marks are part of the English text that surrounds the string. In the following sentence, for example, the commas and period are outside of the braces:

In English, the vowels are @samp{a}, @samp{e}, 
@samp{i}, @samp{o}, @samp{u}, and sometimes 
@samp{y}.

This produces:

In English, the vowels are ‘a’, ‘e’, ‘i’, ‘o’, ‘u’, and sometimes ‘y’.

9.1.5 @var{metasyntactic-variable}

Use the @var command to indicate metasyntactic variables. A metasyntactic variable is something that stands for another piece of text. For example, you should use a metasyntactic variable in the documentation of a function to describe the arguments that are passed to that function.

Do not use @var for the names of particular variables in programming languages. These are specific names from a program, so @code is correct for them. For example, the Lisp variable texinfo-tex-command is not a metasyntactic variable; it is properly formatted using @code.

The effect of @var in the Info file is to change the case of the argument to all upper case; in the printed manual, to italicize it.

For example,

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

produces

To delete file filename, type rm filename.

(Note that @var may appear inside @code, @samp, @file, etc.)

Write a metasyntactic variable all in lower case without spaces, and use hyphens to make it more readable. Thus, the Texinfo source for the illustration of how to begin a Texinfo manual looks like this:

\input texinfo
@@setfilename @var{info-file-name}
@@settitle @var{name-of-manual}

This produces:

\input texinfo
@setfilename info-file-name
@settitle name-of-manual

In some documentation styles, metasyntactic variables are shown with angle brackets, for example:

…, type rm <filename>

However, that is not the style that Texinfo uses. (You can, of course, modify the sources to TeX and the Info formatting commands to output the <…> format if you wish.)

9.1.6 @file{file-name}

Use the @file command to indicate text that is the name of a file, buffer, or directory, or is the name of a node in Info. You can also use the command for file name suffixes. Do not use @file for symbols in a programming language; use @code.

Currently, @file is equivalent to @samp in its effects. For example,

The @file{.el} files are in 
the @file{/usr/local/emacs/lisp} directory.

produces

The ‘.el’ files are in the ‘/usr/local/emacs/lisp’ directory.

9.1.7 @dfn{term}

Use the @dfn command to identify the introductory or defining use of a technical term. Use the command only in passages whose purpose is to introduce a term which will be used again or which the reader ought to know. Mere passing mention of a term for the first time does not deserve @dfn. The command generates italics in the printed manual, and double quotation marks in the Info file. For example:

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

produces

Getting rid of a file is called deleting it.

As a general rule, a sentence containing the defining occurrence of a term should be a definition of the term. The sentence does not need to say explicitly that it is a definition, but it should contain the information of a definition—it should make the meaning clear.

9.1.8 @cite{reference}

Use the @cite command for the name of a book that lacks a companion Info file. The command produces italics in the printed manual, and quotation marks in the Info file.

(If a book is written in Texinfo, it is better to use a cross reference command since a reader can easily follow such a reference in Info. See section @xref.)

9.2 Emphasizing Text

Usually, Texinfo changes the font to mark words in the text according to what category the words belong to; an example is the @code command. Most often, this is the best way to mark words. However, sometimes you will want to emphasize text without indicating a category. Texinfo has two commands to do this. Also, Texinfo has several commands that specify the font in which TeX will typeset text. These commands have no affect on Info and only one of them, the @r command, has any regular use.

9.2.1 @emph{text} and @strong{text}

The @emph and @strong commands are for emphasis; @strong is stronger. In printed output, @emph produces italics and @strong produces bold.