     [file version.texi not included]

This file, last updated UPDATED, documents the texi2html script which converts Texinfo (http://www.texinfo.org) into HTML (http://w3c.org).  This edition is for texi2html version VERSION.

Copyright © 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.

Portions of texi2html
  Copyright © 1999, 2000 Lionel Cons

  Copyright © 1999, 2000 Karl Berry

  Copyright © 1999, 2000 Olaf Bachmann

  Copyright © 2002, 2003 Patrice Dumas

  Copyright © 2001, 2002, 2003 Derek Price

  Copyright © many others.

Portions of this manual
  Copyright © 1999, 2000 Karl Heinz Marbaise (manual)

  Copyright © 2003 Patrice Dumas (manual)

  Copyright © 2003 Derek Price (manual)

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.

Texi2HTML
*********

This manual, last updated UPDATED, describes version VERSION of the texi2html Perl script which converts Texinfo (see Texinfo) into HTML.

Please send bug reports concerning this manual to the Texi2HTML user discussion list user@texi2html.cvshome.org.  Please state the exact version of the manual which contains the bug, as given above.

Copyright © 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.

Portions of texi2html
  Copyright © 1999, 2000 Lionel Cons

  Copyright © 1999, 2000 Karl Berry

  Copyright © 1999, 2000 Olaf Bachmann

  Copyright © 2002, 2003 Patrice Dumas

  Copyright © 2001, 2002, 2003 Derek Price

  Copyright © many others.

Portions of this manual
  Copyright © 1999, 2000 Karl Heinz Marbaise (manual)

  Copyright © 2003 Patrice Dumas (manual)

  Copyright © 2003 Derek Price (manual)

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.

     This manual is currently under construction and of course incomplete.  ;-)

Overview
********

Texinfo (http://www.texinfo.org) is the official documentation format of the GNU (http://www.gnu.org) project.  It uses a single source file to produce both online information and printed output.

It is often desirable to have a way to produce HTML from Texinfo sources, as GNU-Info files are produced.  It is much simpler to run a converter than it is to rewrite all the documentation in HTML, especially considering that there is so much Texinfo documentation in the world.

Some time ago makeinfo wasn't able to produce HTML output format, but people still wanted documentation in HTML.  This was the birthing hour for texi2html.  The basic purpose of texi2html is to convert Texinfo documents into HTML.

Since then, HTML support in makeinfo has improved, but texi2html is still stronger in many areas, including the degree to which it allows customization.  With texi2html, some important aspects of the resulting HTML files may be specified via command line options, and configuration files provide an even finer degree of control over the final output, allowing most every aspect of the final output not specified in the Texinfo input file to be specified.  Configuration files are written in perl, like the main program, and anything which may be specified on the command line may also be specified within a configuration file.

For an example of the kind of pages texi2html is capable of producing, have a look at the following sites: the Singular Manual (http://www.singular.uni-kl.de/Manual/html/), the Cederqvist (CVS Manual) (http://ccvs.cvshome.org/docs/manual).

Why texi2html and not makeinfo?
===============================

You would like to produce HTML files from your existing Texinfo files?  There are two programs you can use to do this.  The first is makeinfo (see Generating HTML (texinfo)). The second is texi2html.

The design goal of makeinfo's HTML output was to produce readable HTML output. It is now possible to use CSS for HTML customization. Another possibility is to use intermediate formats, like docbook or mekeinfo XML and XSL stylesheets to customize the resulting document. Still the output produced by makeinfo isn't customizable.

The current development of texi2html tries to provide for producing the more interesting and sophisticated HTML pages that today's Internet users have come to expect. The goal behind texi2html is to generate attractive HTML by default but also to allow users considerable freedom to affect the final style and design of the output HTML pages.  This is achieved via command line options and flexible configuration files.

In contrast to the HTML produced by makeinfo --html (the makeinfo program is part of the Texinfo distribution), the texi2html program, among other differences, allows for the customization of the entire page layout, including headers, footers, style sheets, etc., allows for customization of the low level HTML formatting, provides for splitting documents at various levels, and provides for using the latex2html program to convert @tex sections of the Texinfo source.

The focus on HTML is still present but with the help of the customization files it is now possible to use texi2html to produce other formats as well. texi2html may for example be turned into a texinfo to roff translator with the help of a customization file provided with the distribution.

texi2html should reasonably convert all Texinfo 4.8 constructs.  If you find it does not, please send a bug report to the users@texi2html.cvshome.org email list.

Obtaining texi2html
*******************

The latest version of the source code for texi2html should be available from texi2html.cvshome.org (http://texi2html.cvshome.org).

Installation of texi2html
*************************

To install texi2html, you must first obtain a copy of the source distribution.  See Obtaining texi2html.

texi2html also requires perl version 5.004 or above.  The current version has not been tested extensively on versions of perl below 5.6, however.

texi2html is a standard Automake-based distribution. If you have a source version, you should run ./configure to regenerate the executable texi2html file.  ./configure accepts options to select the installation directory for the texi2html file, the default directories texi2html will use to look for configuration files, and other details.  Run ./configure --help for more information.

Running ./configure combines four files into the final texi2html program file:

  * texi2html.pl contains the base program,

  * MySimple.pm handles the command line options,

  * texi2html.init is the default configuration file, and

  * T2h_i18n.pm is used for internationalization.

  * translations.pl contains the translations of the strings used in documents.

Running ./configure also builds the make configuration files (Makefiles).  To make the documentation run make.

make install performs the installation to the locations specified to the ./configure script.  This usually involves placing the actual texi2html file someplace in your path, such as /usr/local/bin or /usr/bin.

Installing texi2html in your path should be sufficient to run it.  To use default initialization files, or a configuration file for LaTeX2HTML when using latex2html to convert @tex sections (see Expanding TeX regions), install them in the package data directory specified to configure.  This is /usr/local/share/texi2html/ by default, but depends on the value of the pkgdatadir=DIR option passed to the ./configure script. Files used for strings customization and internationalization are also searched for in the i18n directory of this directory. See Using init files for more.

Invoking texi2html
******************

To produce an HTML manual, run texi2html with a Texinfo file as an argument.  For example, this manual is created with:

     $ texi2html texi2html.texi

The behaviour of texi2html may be changed with command line options.  These command line options are always associated with corresponding perl variables which may appear in init files, and these variables are presented in this chapter each time a switch is described.

Boolean command line switches always have a corresponding negated switch, obtained by prepending no or no- to the switch name. For example nomenu does the reverse of menu.

Specifying where to split the generated document
================================================

The HTML manual resulting from the processing of the Texinfo source may be split into files at different levels.  This is specified with the option split which takes an argument, namely the level of splitting (variable: $SPLIT). This level may be:

chapter
     The document is split at @chapter, @appendix, or @unnumbered.

section
     The document is split at the same places as it is using the chapter argument, and also at @section, @appendixsec or @unnumberedsec.

node
     The document is split at every sectioning command.  It is not necessarily split at each node, if the @node structure doesn't correspond with the sectioning command structure (see below).

none
     The document isn't split.  This is the default.

There are two kinds of commands which may be used to define sectioning elements in Texinfo: @node and the structuring commands (@top, @section, @appendixsubsec,  and so on).  A node just preceding a structuring command is considered to be part of the same sectioning element as that command.  If the @node Top isn't associated with a structuring command it also defines a sectioning element.

By default, nodes which aren't associated with a structuring command are not considered to be sectioning commands.  They are always considered to be part of a sectioning element defined by a structuring command.  It is possible to change this behaviour via the use-nodes option (variable $USE_NODES).  In this case, nodes not associated with structuring commands are also considered to be sectioning commands defining a sectioning element.

This default behaviour mimics texi2dvi behaviour, which ignores @node commands for the purprose of sectioning, while the second looks like makeinfo behaviour (see Two Paths (texinfo)).

As an illustration, the following table shows how a sample Texinfo document is divided into sectioning elements when use-nodes is used and not:

Texinfo code

default case

with use-nodes

     @node node1
     @chapter node 1
     node1 text

     @node node2
     node2 text

     @node node3
     node3 text
     @chapter node 3
     chapter text

first element:

     @node node1
     @chapter node 1
     node1 text

     @node node2
     node2 text

second element:

     @node node3
     node3 text
     @chapter node 3
     chapter text

first element:

     @node node1
     @chapter node 1
     node1 text

second element:

     @node node2
     node2 text

third element:

     @node node3
     node3 text
     @chapter node 3
     chapter text

Setting output file and directory names
=======================================

The manual name is constructed by stripping the .texi, .txi, .texinfo, or .txinfo extension from the Texinfo file name.

By default, texi2html generates the manual file in the current directory if the manual isn't split. A .html file extension is appended to the manual name.

If the manual is split the files are put in a directory named after the manual name. The file name is constructed using the manual name as basename. An underscore followed by a number is appended to the basename for each files corresponding with sectioning elements, with the exception of the top element. For the top element there nothing appended. The files containing special elements pages have an underscore and a 3 letter code corresponding to their content (toc for table of contents, abt for about, ovr for overview) appended.  Lastly, an .html file extension is appended.

Thus, if the texinfo file afile.texi is processed and split at chapters into 3 files, the generated files (in directory afile) will be:

     afile.html         --> @node Top or @top section
     afile_1.html       --> Chapter 1
     afile_2.html       --> Chapter 2
     afile_toc.html     --> Table of Contents
     afile_abt.html     --> About Page

This default behavior may be modified by several command line options. If the output isn't split, the prefix file name may be overrided by the output command line option (variable $OUT). If the output is split, and output is set, the files are placed in the directory specified by the argument to the option.

The basename may be overridden with prefix (variable $PREFIX).  If short-ext is given, .htm is appended instead of .html in the final step (variable $SHORTEXTN). The top-file option overrides the top element file name (variable $TOP_FILE).  This can be used to name the top element file index.html.  Similarly, toc-file changes the name of the table of contents file (variable $TOC_FILE).

Reusing the example above, but this time calling texi2html like so:

     $ texi2html -split chapter -prefix manual -short-ext -top-file index.htm -toc-file contents.htm afile.texi

we get, in manual:

     index.htm          --> @node Top or @top section
     manual_1.htm       --> Chapter 1
     manual_2.htm       --> Chapter 2
     contents.htm       --> Table of Contents
     manual_abt.htm     --> About Page

The file names generated by texi2html differ from those generated by makeinfo. makeinfo uses the node name to construct the file names while splitting at nodes.  It is possible to get the same behaviour out of texi2html by specifying the node-files option (variable $NODE_FILES).  If the output isn't split at nodes, texi2html will still output files named after the nodes, without real content but redirecting to the right file. The default is false for this option. This trick enables the generated HTML manual to be a target for the cross-references of other manuals generated by makeinfo or texi2html.

Specifying which regions get expanded
=====================================

The default for texi2html is to expand the @ifhtml, @html, and @menu regions, all the @ifnot regions except @ifnothtml, and no other @if regions.

It is possible to expand other regions by setting if<region>, where <region> is replaced by the literal name of the region (for example, --iftex).  Symetrically, if no-if<region> is specified, the <region> region is ignored.  The configuration file array, @EXPAND, holds the names of regions which should be expanded. The only region name present in @EXPAND in the default case is html.

If nomenu is set, the @menu sections are not expanded (variable $SHOW_MENU). The default is to expand @menu sections.

Command line options related to Texinfo language features
=========================================================

Miscalleneous Texinfo related things may be specified via command line options.

lang=LANG
     Sets the document language similar to the Texinfo directive, @documentlanguage LANG (variable $LANG). The default is en, that is, use the english language strings.

DVAR
     Sets VAR.  Equivalent to, @set VAR 1, in Texinfo.

UVAR
     Clears VAR.  Equivalent to, @clear VAR, in Texinfo.

PDIR
     Prepend DIR to the list of directories to search for @include files (the associated array is @PREPEND_DIRS, empty in the default case).

IDIR
     Append DIR to the list of directories to search for @include files (the associated array is @INCLUDE_DIRS, empty in the default case).

The include files are always searched for in the current directory.

Page layout related command line options
========================================

If the frames option is specified, HTML frames are used.  A file describing the frame layout is generated, and the document page is associated with a frame where the short table of content appears (variable $FRAMES). The default is not to use frames.

It is also possible to suppress the section navigation panel with nosec-nav (variable $SECTION_NAVIGATION, the default is to output all the navigation panels), and to specify whether footnotes should appear at the foot of the same page which contains the reference to the note or on a separate page with separated-footnotes (variable $SEPARATED_FOOTNOTES). The default is to have separated footnotes.

Customizing the HTML and text style
===================================

Miscalleneous style changes may be achieved with command line options.

doctype=DTD
frameset-doctype=DTD
     You can specify the document DTD by setting these options. frameset-doctype applies to the file describing the frames when frames are used (corresponding variables are $DOCTYPE and $FRAMESET_DOCTYPE).

     The default for the document doctype is:

          <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd">

     And for the frameset doctype:

          <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html401/frameset.dtd">

iso
     If this option is set, ISO8859 entities are used for some special symbols, like Copyright © (variable $USE_ISO). It is the default.

css-include=FILE
     This command line switch provides for the inclusion of an external Cascading Style Sheet (CSS) file.  More than one file may be specified, and - stands for the standard input (array @CSS_FILES).

     The option use is the same than for makeinfo and is described extensively in HTML CSS (texinfo). Briefly, the CSS @import lines from the external file CSS file are pasted  before the texi2html CSS rules, and the external file CSS rules are pasted after the texi2html CSS rules.

html-xref-prefix=PATH
     This option sets the base directory for external HTML texinfo manuals (variable $EXTERNAL_DIR).  Defaults to ../.

def-table
     If this option is set, HTML tables are used to format definition commands, rather than HTML definition tables (variable $DEF_TABLE). Default is false.

short-ref
     If this option is set, cross-references are given without section numbers (variable $SHORT_REF). Default is false.

number
     If this option is set, sections are numbered (variable $NUMBER_SECTIONS).  This is the default.

toc-links
     If this option is set, links from headings to TOC entries are created (variable $TOC_LINKS). Default is false.

Expanding @tex and @math regions using LaTeX2HTML
=================================================

It is possible to use LaTeX2HTML (http://www.latex2html.org/) to process @tex regions and @math{} commands.  This is an attractive way to display mathematical constructs in the HTML manual.  The l2h option activates this feature (variable $L2H).  It is usually desirable to expand @tex sections when this option is specified (see Expansion). The default is not to use this feature.

The l2h-l2h=PROGRAM option enables changing the name/location of the LaTeX2HTML program processing TeX regions (variable $L2H_L2H). The default is latex2html.

l2h-tmp sets the directory used for temporary files, this name shouldn't contain a dot . (variable is $L2H_TMP). Defaults to the current dir.

The file specified by l2h-file is used as LaTeX2HTML init file. It is searched at the same places than init files (see Using init files), and the default is l2h.init.

Use initialization files for fine tuning
========================================

Initialization variables are read first from /usr/local/share/texi2html/Config (the exact location being changeable with the pkgdatadir=dir option of the configure script, see Installation), /usr/local/etc/texi2html/Config (the exact location being changeable with the sysconfdir=dir option of the configure script, see Installation), from ./Config then from $HOME/.texi2html/Config. Any command-line option can override the corresponding option set in init file, and the option init-file specifies an init file to be loaded, with later settings overriding earlier ones.

The init files specified with init-file are searched first in the current directory, then in the $HOME/.texi2html/ directory, in the /usr/local/etc/texi2html/ directory and lastly in the /usr/local/share/texi2html/ directory.

A file is also included based on the language selected, by $LANG, lang or @documentlanguage. If no language was selected en is considered to be the language. All the files with name the language name in /usr/local/share/texi2html/i18n/, /usr/local/etc/texi2html/i18n/, $HOME/.texi2html/i18n/ and then ./i18n/ are included.

The default initialization options are defined in the texi2html.init file contained in the texi2html distribution (which gets included near the beginning of the texi2html script that gets installed).

To customize texi2html it is best if you copy the appropriate sections from the texi2html.init contents into an appropriate local initialization file, make the necessary changes there, and then have texi2html read this initialization file by one of the means described above.

Overview of initialization files content and loading
****************************************************

The initialization files are perl files, read as explained in Using init files. You don't need to know much of perl to do some simple changes in variable values, however, to be able to really take advantage of all the features of the initialization file, a good knowledge of perl is required.

In initialization file two kind of variables appear. These are normal variables (including arrays and hashes) and references on functions. The later permits the dynamic redefinition of functions used to produce the HTML manual. You should be able to change the value of some normal variables without a deep knowledge of perl, by looking at the existing examples. The possible mistakes in that case could be omitted ;, and bad quoting.

Initialization file are loaded from the main program by the mean of a require, while in the Texi2HTML::Config namespace. This means that the namespace of the main program and the namespace of inititalization files are distinct, which ensures that no name clash should happen. The variables are declared with the our specifier, such that it should be possible to use the use strict pragma in the initialization file code.

To avoid messing with the variables in the main namespace all the global variables which could be of use in the init files are in the Texi2HTML namespace. Notice that the functions of the main program are still in the main namespace.

Redefining functions in initialization files
============================================

To redefine a function you must replace the corresponding funtion reference with a reference on your function. Thus you should write your function, give it a name you are certain it is unique in the Texi2HTML::Config namespace, and override the value of the function reference with your own function reference. When another function from the main program (or from another functions of an initialization file) calls the reference, your function will be used.

For example the function reference corresponding with the function called when doing an anchor is called $anchor. Thus if you want to override the corresponding function you could write:

     # override the function reference
     $anchor = \&my_own_function;

     # the function reference now refers to
     sub my_own_function {
     # process arguments and return an html anchor
     }

Conventions used for function prototypes
========================================

As the functions are defined by a reference name, we will always use the reference name in function prototypes. For the function arguments we will use \@array for a reference on an array and similarly \%hash for a reference on a hash.

Thus, the prototype for the function associated with the function reference $formatting_function will be:

 -- Function Reference: $text formatting_function $arg1 \@arg2
     formatting_function takes as first argument $ARG2, as second argument a reference on an array \@ARG2 and returns the formatted text $TEXT.

To redefined the corresponding function, you should write:

     $formatting_function = \&my_formatting_function

     sub my_formatting_function($ $)
     {
         my $arg1 = shift;
         my $arg2 = shift;
         # prepare $formatted_text
         .....
         return $formatted_text
     }

Fine tuning of the page layout
******************************

Some features of the page layout might be specified with command line options, the corresponding variables are described in Page layout options. Fine tuning of the page layout may be achieved with redefinition of other variables and function references in the initialization files.

The different categories of pages and sectioning elements
=========================================================

The following sectioning elements can be associated with pages:

Normal elements
     These are normal sections or nodes. Their association with pages is determined by the splitting of the document. See Splitting output.

Top element
     The top element is the higher element in the document structure. If there is a @top section it is the element associated with that section. Otherwise it is the element associated with the @node Top. If there is no @node Top the first element is the top element.

     The top element is formatted differently than a normal element if there is a @top section or the @node Top isn't associated with a sectioning command.

Misc elements
     These elements are associated with pages if the document is split. There are four misc elements:

      1. Table of contents

      2. Short table of contents, also called Overview

      3. Footnotes page

      4. About page

     The About page shouldn't be present for documents consisting in only one sectioning element. The Footnote page should only be present if the footnotes appear on a separated page (see Page layout options), however a footnote element is present if the document isn't split. The Table of contents should only be formatted if @contents is present in the document. Similarly the Overview should only appear if @shortcontents or @summarycontents is present.

Page layout and navigation panel overview
=========================================

A page is broken up in three parts. A page header, the sections and a page footer. A common element in the page layout is a navigation panel with icons or text linking to other sections or pages. Another common element is a rule, separating sections or footer. The navigation panel and the rules may be part of the sections or part of headers or footers. You may use the variables $SMALL_RULE, $DEFAULT_RULE, $MIDDLE_RULE and $BIG_RULE for rules of different sizes. The defaults are

     $SMALL_RULE = '<hr size="1">';
     $DEFAULT_RULE = '<hr>';
     $MIDDLE_RULE = '<hr size="2">';
     $BIG_RULE = '<hr size="6">';

In the header some important meta data may be defined, like the title or style information, and textual informations may be present in comments. All this doesn't appear directly in the displayed HTML, though.

The page layout is mainly controlled by functions, the precise functions called depending on the document splitting. The navigation panel, however, can be customized with variables.

Element labels
--------------

There are 19 items associated with elements. Each of these is associated with a name and a reference to the element they represent, when such an element exists. The element is either a global element or an element relative to the current element. The relative elements are found with respect with the document structure defined by the section structuring commands (@chapter, @unnumbered...) or by the nodes (in that case the node directions are specified on node line or in menu organization). These items are called element labels. They may be associated with a button (see Button specifications), and used in the formatting functions (see Program variables).

Here is the list:

     An empty button

Top
     Top element. The associated name is $TOP_HEADING if that variable is defined. This variable is not set by default.

Contents
     Table of contents

About
     About (help) page

Overview
     Overview, short table of contents

First
     First element in reading order

Last
     Last element in reading order

Index
     The first chapter with @printindex. The associated name is  $INDEX_CHAPTER, if the variable is set. This variable is not set by default.

This
     The current element

Back
     Preceding element in reading order

FastBack
     Beginning of this chapter or previous chapter if the element is a chapter

Prev
     Previous section on the same level

NodePrev
     Previous node

Forward
     Next element in reading order

FastForward
     Next chapter

Next
     Next section on the same level

NodeNext
     Next node

Following
     Next node in node reading order

Up
     Up section

NodeUp
     Up node

Customization of the navigation panels buttons
==============================================

A lot of customization of the navigation panel may be achieved without redefining functions, with variables redefinition. In case it isn't enough, it is also possible to redefine the function doing the navigation panel formatting.

Controlling the navigation panel panel at a high level
------------------------------------------------------

The global formatting of the navigation panels may be changed with the following variables:

$VERTICAL_HEAD_NAVIGATION
     A vertical navigation panel will be used for the header navigation panel if this variable is true.

$ICONS
     Icons are used instead of textual buttons if this variable is true.

$SECTION_NAVIGATION
     If this variable is false there is no section navigation, no navigation panels for the elements within the pages, only at the beginning and the end of the page (see Page layout options).

Specifying the buttons formatting
---------------------------------

Several arrays and hashes enable a precise control on the buttons and their display. The following arrays determine the buttons present in navigation panels:

@SECTION_BUTTONS
     This array is used for the navigation panel buttons present at the begining of sectioning elements. If split at node or section they are also used at the page footer, and in the case of section navigation at the page header.

@SECTION_FOOTER_BUTTONS
@NODE_FOOTER_BUTTONS
     This array is used for the navigation panel buttons present at the footer of pages when split at node or at section.

     If $WORDS_IN_PAGE is set and the output is split at nodes, these buttons are only present if there are more than $WORDS_IN_PAGE words in the sectioning element text. This counting is very rough and include punctuation marks, html elements, numbers.  The default is to include the buttons after 300 words.

@CHAPTER_BUTTONS
     This array is used for the buttons appearing at the page footer if split at chapter, and at the page header if split at chapter and there is no section navigation.

@MISC_BUTTONS
     These buttons appear at the beginning of special and sections and at the end of these section pages if the output is split.

The array specify the buttons displayed in navigation panels, and how the button is displayed. Each element is associated with a button of the navigation panel from left to right. The signification of the array element value is the following:

reference on a function
     The function is called with first argument a filehandle reference on the current file and second argument a boolean true if the navigation panel should be vertical.

reference on a scalar
     The scalar value is printed. For some possibly usefull scalars, Elements hashes.

reference on an array
     In this case the first array element should be a reference on text and the second element an element label. In that case a link to the element associated with the element label with the scalar value text is generated.

     For example if the buttons array element is

          [ 'Next', \$Texi2HTML::NODE{Next} ]

     The button will be a link to the next section with text $Texi2HTML::NODE{Next}.

element label
     If icons are not used, the button is a link to the corresponding element which text is defined by the value associated with the element label in the %NAVIGATION_TEXT hash, surrounded by [ and ]. If the element label is  , there is no [ and ]. The element of the %NAVIGATION_TEXT hash are defined dynamically, in the init_out function reference (see Output initialization).

     If icons are used, the button is an image with file determined by the value associated with the element label in the %ACTIVE_ICONS hash if the the link really leads to an element, or in the %PASSIVE_ICONS hash if there is no element to link to. Of course if there is a link to the element the icon links to that element.

Changing the navigation panel formatting
----------------------------------------

If you are not satisfied with this scheme, it is possible to control exactly the formatting of navigation panels by redefining a function reference. The function controlling the display of navigation panel is associated with the following function reference:

 -- Function Reference: print_navigation $filehandle \@buttons $vertical
     $FILEHANDLE is the opened filehandle the function should write to. \@BUTTONS is an array reference which should hold the specification of the buttons for that navigation panel. $VERTICAL is true if the navigation panel should be vertical.

Main program variables and usefull functions
============================================

In the functions controlling the page layout some global variables set by the main program are available, with value corresponding with the current layout element.

Accessing elements informations
-------------------------------

Four hashes are available, with key the elements labels (as described in Element labels) and values:

%Texi2HTML::NAME
     The formatted element name

%Texi2HTML::HREF
     The element hypertext reference

%Texi2HTML::NODE
     The element node name

%Texi2HTML::NO_TEXI
     The element name after removal of texi commands

Accessing global informations
-----------------------------

Three kinds of global informations are available, miscalleneous global strings, flags set by @set and special flags and section lines.

Global strings
..............

The %Texi2HTML::THISDOC hash holds some global informations:

fulltitle
     title set by @title. If there is no @title other possibilities are tried (@settitle, @shorttitlepage...).

title
     title set by @settitle, or fulltitle.

title_no_texi
     title without texi formatting

title_texi
     title with texi commands

author
     Authors list set by @author.

authors
     A reference on an array containing each author set by @author.

copying
     Text appearing in @copying with all the texinfo commands removed, put in comments.

program
     The name and version of texi2html.

program_homepage
     Homepage for texi2html.

program_authors
     Authors of texi2html.

file_base_name
     base name of the texinfo manual file.

destination_directory
     Destination directory for the resulting files.

toc_file
     The file name of the table of contents.

today
     The date.

It also holds the arg of the following commands, associated with the command name: kbdinputstyle, paragraphindent, setchapternewpage, headings, footnotestyle, exampleindent, firstparagraphindent, everyheading, everyfooting, evenheading, evenfooting, oddheading, oddfooting.

Flags
.....

Flags defined by @set may be accessed through the %main::value hash. The key is the flag name, the value is the flag value at the end of the document.

Special flags are set by the main program. They correspond with a texinfo command, like @setfilename, or @settitle, @author... The corresponding flag is the command name with _ appended, for example, _titlefont corresponds with @titlefont. Like other flags they are available in %main::value.

Section lines
.............

The following array references or arrays holds formatted lines:

$Texi2HTML::THIS_SECTION
     Lines of the current element.

$Texi2HTML::THIS_HEADER
     Lines of the current element appearing before the element label (anchors).

$Texi2HTML::OVERVIEW
     Lines of short table of contents. See Special pages.

$Texi2HTML::TOC_LINES
     Lines of table of contents. See Special pages.

Function usefull in page formatting
-----------------------------------

The usefull function is a function used to print an array of lines, which also counts the number of words in the array, if needed.

 -- Function: $words_number main::print_lines $filehandle \@lines_array
     $FILEHANDLE is the opened filehandle the function should write to. \@LINES_ARRAY is the array line the function should write to the file. If this argument is omitted, the function uses $Texi2HTML::THIS_SECTION. $WORDS_NUMBER is the number of words in the array, only defined if split at nodes and $WORDS_IN_PAGE is defined.

Preparing the output
====================

After the texinfo file has been parsed, some information is available which can be used to modify some variables and prepare the outputting. For example the document language, the document encoding, values set with @set or @setfilename and other similar @-commands are not known before the texinfo parsing.

The following function reference may be redefined to be called after texinfo processing and before document generation:

 -- Function Reference: $encoding init_out
     This function perform the initialization of variables and any other task before document outputting. It returns the encoding used for the output files.

In the default case the $BODYTEXT (see Customizing header) and the hashes %NAVIGATION_TEXT (see Button specifications) and %BUTTONS_GOTO (see About text) are initialized.

To perform the default initializations and also add more code, you could do as in the following example (save the default function reference and call it in your own function) :

     my $default_init_out = $init_out;
     $init_out = \&makeinfo_like_init_out;
     sub makeinfo_like_init_out()
     {
        my $encoding = &$default_init_out();
        $NAVIGATION_TEXT{'Following'} = ' &gt; ';
        return $encoding;
     }

Finalizing the output
=====================

If you want to do some cleaning after the document was generated (close files, write at the end of files and so on), the following function reference may be redefined:

 -- Function Reference: finish_out
     This function is called after the document generation.

The default is to do nothing.

Customizing the texi2html css lines
===================================

It is possible to modify the texi2html css lines by modifying the entries or adding to the %css_map hash. Each key is a css selector, the corresponding value is a style string.

The whole css text is in the variable $CSS_LINES. If this variable is defined the variable value is used instead of being constructed using the %css_map entries. For example if you don't want any css entries, set

     $CSS_LINES = '';

It is also possible to change completely the way $CSS_LINES are generated by redefining the following function reference:

 -- Function Reference: css_lines \@import_lines \@rule_lines
     This function should be used to construct the $CSS_LINES. \@IMPORT_LINES are the @import lines of the files specified with include-css, and \@RULE_LINES are the css commands lines of these files. See Style options.

Customizing the page header
===========================

It is possible to add lines to the text within the <head> HTML elements, by defining the variable $EXTRA_HEAD. Similarly it is possible to add text just after the <body> element with the variable $AFTER_BODY_OPEN. These variables are empty by default.

The encoding of the texinfo file is defined by $DOCUMENT_ENCODING if no @documentencoding appears in the document. The default is a en-ascii encoding. The encoding of the resulting document is defined by $ENCODING. The default is the $DOCUMENT_ENCODING.

The description of the document may be specified in $DOCUMENT_DESCRIPTION. If this variable is undef, the text associated with @documentdescription is used, and if there isn't such test a default description is constructed using the document title and the name of the first section of the file.

The <body> element attributes may be set by defining the variable $BODYTEXT. If you want to define that variable dynamically, you should use the init_out function reference (see Output initialization).

The default functions call the function associated with $print_head_navigation to format the navigation panel for the page header. Thus you can control parts of the formatting by redefining the function reference.

 -- Function Reference: print_head_navigation $filehandle \@buttons
     $FILEHANDLE is the opened filehandle the function should write to. \@BUTTONS is an array reference which should hold the specification of the buttons for the navigation panel.

If you want even more control, you can have full control over the page header formatting by redefining three function references. The function associated with $print_page_head is called for all the pages, and after that, the function associated with $print_chapter_header is called if the document is split at chapters, or the function associated with $print_section_header is called if the document is split at sections.

 -- Function Reference: print_page_head $filehandle
     $FILEHANDLE is the opened filehandle the function should write to. This function should print the page head, including the <body> element.

 -- Function Reference: print_chapter_header $filehandle
     $FILEHANDLE is the opened filehandle the function should write to. This function is called if the document is split at chapters, after print_page_head.

 -- Function Reference: print_section_header $filehandle
     $FILEHANDLE is the opened filehandle the function should write to. This function is called if the document is split at sections, after print_page_head.

Customizing the sections
========================

The functions associated with the following function references are used for the formatting of sections:

 -- Function Reference: print_section $filehandle $first_in_page $previous_is_top
     $FILEHANDLE is the opened filehandle the function should write to. $FIRST_IN_PAGE is true if this section is the first section in the page. $PREVIOUS_IS_TOP is true if this section is the section following the Top section. This function should print the current section.

 -- Function Reference: end_section $filehandle $last_element_or_before_top
     $FILEHANDLE is the opened filehandle the function should write to. $LAST_ELEMENT_OR_BEFORE_TOP is true if this section precedes the top element or is the last one in page, or before the special elements.

Customizing the page footer
===========================

It is possible to add text just before the </body> element with the variable $PRE_BODY_CLOSE. Nothing is added by default.

The default functions call the function associated with $print_foot_navigation to format the navigation panel for the page footer. Thus you can control parts of the formatting by redefining the function reference.

 -- Function Reference: print_foot_navigation $filehandle \@buttons
     $FILEHANDLE is the opened filehandle the function should write to. \@BUTTONS is an array reference which should hold the specification of the buttons for the navigation panel.

If you want even more control, you can have full control the page footer formatting by redefining three function references. The function associated with $print_chapter_footer is called if the document is split at chapters, or the function associated with $print_section_footer is called if the document is split at sections. After that the function associated with $print_page_foot is called.

 -- Function Reference: print_page_foot $filehandle
     $FILEHANDLE is the opened filehandle the function should write to. This function should print the page foot, including the </body> element.

 -- Function Reference: print_chapter_footer $filehandle
     $FILEHANDLE is the opened filehandle the function should write to. This function is called if the document is split at chapters, before print_page_foot.

 -- Function Reference: print_section_footer $filehandle
     $FILEHANDLE is the opened filehandle the function should write to. This function is called if the document is split at sections, before print_page_foot.

Special pages formatting
========================

For the special elements, two things must be formatted: the content and the page layout

Customizing the content of the special pages
--------------------------------------------

Top element text formatting
...........................

The top element formatting is controlled by three function which also controls the layout of the top element page or section. The associated function references are:

 -- Function Reference: print_Top_header $filehandle $begin_page
     $FILEHANDLE is the opened filehandle the function should write to. $BEGIN_PAGE is true if the element is the first in a page. This function should begin the Top element. At the time this function is called the top element text hasn't been parsed.

 -- Function Reference: print_Top $filehandle $has_top_heading
     $FILEHANDLE is the opened filehandle the function should write to. $HAS_TOP_HEADING is true if there is a @heading command or @titlefont command appearing in the Top element text. This function should be used to format the Top element text and navigation panel.

 -- Function Reference: print_Top_footer $filehandle $end_page
     $FILEHANDLE is the opened filehandle the function should write to. $END_PAGE is true if the element is the last in a page. This function should end the Top element.

Table of contents and Short table of contents
.............................................

Several variables may be used to control the formatting of table of contents and short table of contents:

$DO_CONTENTS
     If the variable is true a table of contents is done even if there is no @contents command.

$DO_SCONTENTS
     If the variable is true a short table of contents is done even if there is no @summarycontents command.

$BEFORE_OVERVIEW
     The variable value is inserted before the short table of contents text.

$AFTER_OVERVIEW
     The variable value is inserted after the short table of contents text.

$BEFORE_TOC_LINES
     The variable value is inserted before the table of contents text.

$AFTER_TOC_LINES
     The variable value is inserted after the table of contents text.

$TOC_LIST_STYLE
     This should contain a css style used for the list style if the tables of content are formatted with a list.

$TOC_LIST_ATTRIBUTE
     This should contain an attribute text used for the list element if the tables of content are formatted with a list.

More control on the table of contents and short table of contents formatting may be achieved by redefining a function with the following associated function reference:

 -- Function Reference: toc_body \@elements
     \@ELEMENTS is an array reference contining informations about all the elements of the document. Each of the entry of this array is an hash reference which entries correspond with different informations about the element. Interesting keys have the following meaning:

     top
          true if the element is the top element,

     index_page
          true if the element is an index page added because of index splitting,

     toc_level
          level of the element in the table of content. Highest level is 1 for the top element and for chapters, appendix and so on, 2 for section, unnumberedsec and so on...

     tocid
          label used for reference linking to the element in table of contents,

     file
          the file containing the element, usefull to do href to that file in case the document is split,

     text
          text of the element, with section number,

     name
          text of the element, without section number.

     This function doesn't return anything but should fill the array corresponding with the $Texi2HTML::TOC_LINES and $Texi2HTML::OVERVIEW references with the table of contents and short table of contents.

Formatting of footnotes text
............................

The footnotes text is allready formatting when @footnote commands are expanded. See Footnotes.

Formatting of about text
........................

The default about element contains an explaination of the buttons used in the document (@SECTION_BUTTONS, Button specifications) and an example locating the buttons targets in an example. The formatting of this text may be influenced by the following hashes and variables:

$PRE_ABOUT
$AFTER_ABOUT
     This variable may be a scalar or a function reference. If it is a scalar, the value is used. If this is a function reference it is expanded and the returned text is used. The text is added before or after the main about text.

%BUTTONS_GOTO

     The keys of this hash are element labels (see Element labels). The value is the text associated with the element label in the about text. The element of the hash are defined dynamically, you should in the init_out function reference (see Output initialization).

%BUTTONS_EXAMPLE

     The keys of this hash are  element labels (see Element labels). The value is the text associated with the element label in the about example, typically a section number.

If this is not enough and you want to control exactly the formatting of the about text, you can redefine the function associated with the following function reference:

 -- Function Reference: $about_text print_about
     This function should return the about text.

Customizing the layout of the special pages
-------------------------------------------

The formatting of each of the special pages, or section in case the document is not split, is controlled by a function. The associated function reference is called accordingly:

print_Top

print_Top_header

print_Top_footer
     Formatting of top element page or section. It is also used for the formatting of the top element text (see Top element text).

print_Toc
     Formatting of table of contents page or section

print_Overview
     Formatting of short table of contents page or section

print_About
     Formatting of about (help) page or section

print_Footnotes
     Formatting of footnotes section or page in case footnotes are on a separated page or the document isn't split.

In the default case, $print_Top calls $print_Top_header for the header and $print_Top_footer for the footer of top element. All the other function call $print_misc which in turn calls $print_misc_header for the headers and  $print_misc_footer for the footers.

Customizing the file names
==========================

It is possible to specify the file names with more control than with the command line options (see Output files). First the extension may be overrided by the variable $EXTENSION value. Two function references enable further customization. One is usefull in case $NODE_FILES is true and it is used to customize the node file name itself and is also used to produce a file name with a redirection leading to the node file.

 -- Function Reference: ($node_file $redirection_node_file) node_file_name $node
     $NODE is a hash reference with the following interesting keys (there are much more keys):

     texi
          The texinfo node name.

     with_section
          True if associated with a section.

     The result is the node file name $NODE_FILE, and the file containing a redirection to the node $REDIRECTION_NODE_FILE.

The other is usefull if $NODE_FILES isn't true. It is used to customize the file associated with each element.
 -- Function Reference: $file element_file_name $element $is_top $docu_name
     $ELEMENT is a hash reference with the following interesting keys (there are much more keys):

     texi
          The texinfo element name.

     number
          The number associated with a section.

     doc_nr
          A number incremented whenever a new file should begin, based on how the document is split (see Splitting output).

     text
          The element text.

     name
          The element text without section number.

     $IS_TOP is true if the element is considered as the top element. $DOCU_NAME is the basename of the texinfo manual. The result is the element file name.

Generation of external files for index entries
==============================================

Within the document, @printindex commands are expanded as explained in Index list. In case you want to do something special with index entries, outside of the document, you should first set the variable $IDX_SUMMARY true. After that some function reference will be called for each non empty index. For each index there are 3 function references, one called for initialization, one called for each index entry and the last one called for finalazation.

 -- Function Reference: index_summary_file_begin $index_name $is_printed
     $INDEX_NAME is the two letters name for the index. This function is called for each index appearing in the document, before index_summary_file_entry. $IS_PRINTED is true if there is a @printindex for that index.

 -- Function Reference: index_summary_file_entry $index_name $entry_text $entry_reference $formatted_entry $texi_entry $entry_element_reference $entry_element_header $is_printed
     This function is called for each entry of an index. INDEX_NAME is the name of the index. $ENTRY_TEXT is the entry in plain text, $FORMATTED_ENTRY is the index entry formatted, $TEXI_ENTRY is the entry with texinfo commands. $ENTRY_REFERENCE is the reference placed at the index entry place, in the form file#id. $ENTRY_ELEMENT_HEADER is the formatted header of the element containing the index entry. ENTRY_ELEMENT_HEADER is the reference to the beginning of the element containing the index entry, in the form file#id. $IS_PRINTED is true if there is a @printindex for that index.

 -- Function Reference: index_summary_file_end $index_name $is_printed
     $INDEX_NAME is the two letters name for the index. This function is called for each index appearing in the document, after index_summary_file_entry. $IS_PRINTED is true if there is a @printindex for that index.

Customizing HTML and text style in init files
*********************************************

Some simple customization may be achieved with the redefinition of the variables associated with the command line options. For the description and an explanation of the meaning of these variables, Style options.

Other variables and hash entries can be modified in initialization file to achieve more customization. Lastly, functions references corresponding with functions called from the main program and initialization files may be redefined.

Three contexts for expansions: preformatted, normal and string
==============================================================

There are three contexts of interest, one is the normal context, the other is a special context, called the preformatted context and the last is the string context. The preformatted context occurs when the spacing between words is kept. This is the case, for example, in @display or @example regions, and in menu comments (see Menus). The preformatted regions are usually rendered in <pre> elements in HTML. The string context occurs when rendering strings without formatting elements, in comments or titles for example.

Customizing the formatting of commands without argument
=======================================================

This includes the commands whose name is a nonletter character like @@, the commands with lettered characters and braces but whose braces should be empty, like @TeX{}, or some commands associated with accentted letters like @AA{}. If there happens to be something within the braces, it is put after the command, thus

     @TeX{something}

leads to the same than

     @TeX{} something

Each of these categories of commands have three associated hashes, one for normal context, the other for preformatted context and the last in strings. The keys of the hashes are the command names, the associated value is the text replacing the command.

The hashes are:

command type   normal text   preformatted text   string
one nonlettered character   %simple_map   %simple_map_pre   %simple_map_texi
nothing in braces   %things_map   %pre_map   %texi_map

To change the HTML resulting from these constructs, just change the value. For example, if you want &shy; to be outputted for @- in normal and preformatted context, write in your init file:

     $simple_map{'-'} = '&shy;';
     $simple_map_pre{'-'} = '&shy;';

Customizing accent, style and other simple commands
===================================================

The formatting of the HTML produced by style and indicatric commands (@tt, @code, @email, @titlefont), the accentuation related commands taking argument (@', @udotaccent, @dotless) and miscalleneous commands (@email, @verb, @w, @uref, @math, @asis) is controlled by two hash in the default case, %style_map for normal context, %style_map_pre for preformatted context and %style_map_texi in string context.

The key of the hashes are the command names. There are two possibilities for the values corresponding with two interfaces. The values may be strings or hash references, and you can chose the interface depending on the one you prefer. The interface with hash reference is a bit more flexible but might also be regarded as more complex. If you don't like either of these interfaces you can define your own.

Some remarks are in order:

  * The nonlettered accent commands which following character is considered to be the argument (like in @`a) should be keys of the hash %accent_map hash, even if no value is associated.

  * @math is handled differently if LaTeX2HTML is used.

An interface for commands formatting with a hash reference
----------------------------------------------------------

The key of the hashes are the command names. The value determine how the command argument is formatted. This value is a reference on a hash. In this hash each key corresponds with a type of information for the formatting, and the value is the corresponding information. For example, in

     $style_map{'command'} = { 'args' => ['code'], 'attribute' => 'code'};

the arguments for @command are interpreted as specified by the values associated with the args key while the attribute associated with that command is code.

The following keys in the hashes associated with each command have the following meaning:

args
     The value associated is a reference on an array. Each element of the array defines how the arguments (separated by , in the texinfo code) for the @-command should be formatted. The possibilities are

     normal
          for normal text,

     code
          for text with ---, --, '' and  `` kept as is,

     keep
          if the texinfo should be kept as is, without interpretation of the @-commands.

     For example, we have

          $style_map{'email'}->{'args'} = ['code', 'normal'];

     because ---, --, '' and  `` should be kept as is in the first argument of @email.

     The default is ['normal'].

attribute

     If the associated value is a word, it is considered to be an HTML element name, and the argument is enclosed between the element opening and the element closing. For example, if the value is elem, the resulting HTML is <elem>ARG</elem>.

     If the text is a word followed by some text, the word and is interpreted as above, and the text is considered to be the attributes text of the element. Thus elem class="elem" leads to <elem class="elem">ARG</elem>.

     This works only if there is only one argument.

begin

     The associated value is added in front of the text.

begin

     The associated value is added after the text.

quotes

     If the corresponding value is true, the result is enclosed in quotes $OPEN_QUOTE_SYMBOL and $CLOSE_QUOTE_SYMBOL, with defaults ` and '.

function

     The corresponding value should be a function reference. The corresponding function is called with the following arguments:

     $command
          The @-command name

     $args
          A reference on an array containing the arguments of the @-command.

     $style_stack
          A reference on an array containing the name of the @-commands containing the @-command being formatted.

     $state
          A reference on a hash containing a lot of informations about the context of the @-command.

     $line_nr
          An opaque structure containing the information about the line number of the @-command. It can be used to call main::echo_error or main::echo_warning with first argument a message, and second argument $line_nr.

An interface for commands formatting with a string
--------------------------------------------------

The keys of the hashes are the command names. The value determine how the command argument is formatted. If the value begins with ", the result is enclosed in quotes $OPEN_QUOTE_SYMBOL and $CLOSE_QUOTE_SYMBOL, with defaults ` and '.

The command argument is allready formatted as HTML. The remaining of the value text (or the value text if there were no ") is interpreted as follow:

  * If the text is empty the argument of the command is left as is.

  * If the text is a & followed by a name, like &function, the name is considered to be a function name, and this function is called to format the argument of the command. The first argument of the function is the command name, the second is the command argument. For example, if the value associated with the (fictituous) command @foo is &my_func and we have:

          sub my_func
          {
              my @args = split /,\s*/ $_[1];
              return "$_[0]: $args[0]" if ($args[1] = 1);
              return "$args[0]";
          }

     The result of

          @foo{truc, 1}
          @foo{truc, bidule}

     will be

          foo: truc
          truc

  * If the text is a word, it is considered to be an HTML element name, and the argument is enclosed between the element opening and the element closing. For example, if the value is elem, the resulting HTML is <elem>ARG</elem>. Similarly "quoted leads to `<quoted>ARG</quoted>'.

  * If the text is a word followed by some text, the word and is interpreted as above, and the text is considered to be the attributes text of the element. Thus elem class="elem" leads to <elem class="elem">ARG</elem>.

Defining the style and indicatric commands interface
----------------------------------------------------

If you don't like this scheme, it is possible to change how those commands are processed by redefining the following function reference:

 -- Function Reference: $resulting_text style $style $command $text $args $no_close $no_open $line_nr $state $style_stack
     $COMMAND is the @-command, $STYLE is the value associated with the $COMMAND in the %style_map, %style_map_pre or %style_map_texi hashes. The $TEXT is the text appearing within the @-command braces. ARGS is a reference on an array contening the command arguments formatted according to the same conventions than with the reference hash style (provided the value associated with the @-command is a hash reference with a $ARG key as described in Reference hash args). If $TEXT is split in paragraphs each paragraph is passed through the function, and $NO_CLOSE is true if it is not the last paragraph, while $NO_OPEN is true if it is not the first paragraph. $LINE_NR is an opaque structure containing the information about the line number of the @-command. It can be used to call main::echo_error or main::echo_warning with first argument a message, and second argument $line_nr. $STATE is a reference on a hash containing a lot of informations about the context of the @-command. $STYLE_STACK is a reference on an array containing the name of the @-commands containing the @-command being formatted.

Formatting of special simple commands
=====================================

The formatting of special simple commands is controlled by functions. To customize the output, the corresponding function references should be redefined. All these functions return a formatted text.

The formatting of anchors is controlled by $anchor, but the function associated with the function reference does more, it is usefull to produce a reference target or link.
 -- Function Reference: $anchor anchor $identifier $href $text $attributes
     If $IDENTIFIER is not empty, this value should be used to create a target for links (typically associated with a name or id attribute in HTML). The $HREF argument specifies a hpertextual reference which should be used to link to a target. In case both $IDENTIFIER and  $HREF are given the text produced should be both a target for $IDENTIFIER and a link to $HREF. $TEXT is the text to be displayed. $ATTRIBUTES are additional attributes. It should be reasonable to assume that the attributes are for a <a> HTML element.

The formatting of @image is controlled by:
 -- Function Reference: $image image $file_path $basename $preformatted $file_name
     $FILE_PATH is the image file name with the path, $BASENAME is the alternate text or the file name without extension if no alternate text is given. $PREFORMATTED is true if the image appears in preformatted text. $FILE_NAME is the file name without path but with extension.

The formatting of @sp is controlled by:
 -- Function Reference: $sp sp $number $preformatted
     $NUMBER is the numeric argument of @sp. $PREFORMATTED is true if the @sp appears in preformatted text.

The formatting of @acronym and @abbr is controlled by:
 -- Function Reference: $acronym acronym_like $acronym_texi $acronym_text $with_explanation \@explanation_lines $explanation_text $explanation_simply_formatted
     $ACRONYM_TEXI is the acronym argument with texinfo @-commands, $ACRONYM_TEXT is formatted.

     The other arguments are related with the explanation, the second arg of the acronym. $WITH_EXPLANATION is true if the second argument of the acronym command is present. If an explanation exists, coming from previous @acronym or as an arg of this command, the other args are defined: \@EXPLANATION_LINES is a reference on an array containing the unformatted explanation lines, $EXPLANATION_TEXT is the explanation text formatted, $EXPLANATION_SIMPLY_FORMATTED is the explanation with a light formatting, unabling in HTML (or XML) the explanation to be in an attribute.

Processing special characters in text
=====================================

Some characters are processed especially in text: ---, --, `` and ''. This is done only if in normal text and not in some commands (@code, @env...). A function reference is called to process those characters in text

 -- Function Reference: $processed_text normal_text $text
     The function processes ---, --, `` and '' in $TEXT and returns $PROCESSED_TEXT. The default is to change --- to --, -- to -, and `` and '' to ".

Some characters are special in HTML (&, ", < and >) and should be protected. This is done by the function associated with the function reference

 -- Function Reference: $protected_text protect_text $text
     The function processes the unprotected text $TEXT and returns the resulting protected text $PROTECTED_TEXT.

Empty lines are processed by the following function reference, which could be usefull if empty lines are to be removed for example

 -- Function Reference: $resulting_text empty_line $empty_line
     This function processes an $EMPTY_LINE and returns the resulting text $RESULTING_TEXT. Empty lines are left as is by default.

Customizing strings written by texi2html
========================================

texi2html writes some strings in the generated document at various places, at the page footers, on the help page, for special section headings, buttons alt text and so on. These strings are customizable. The string chosen depends on the language of the document (set by lang, $LANG or @documentlanguage). This is the basis for internationalization as it allows for strings translations.

The strings are found in a hash reference, $LANGUAGES. Each key is a language code. The associated value is also a hash reference. The key is an english string and the associated value is the string replacing the english string, if present. For example, we have

     $LANGUAGES->{'fr'} = {
                   ' Up ' => 'Plus haut',
     };

It means that whenever the string  Up  is to be written and the language is fr, Plus haut is written. It is possible to customize the english strings by redefining the en language hash.

When a string contains a % followed by { NAME } it means that the string will be expanded by texi2html. For example, if we have

     $LANGUAGES->{'fr'} = {
                   'See %{node_file_href}' => 'Voir %{node_file_href}',
     };

%{node_file_href} will be expanded to an href for a node in a file by texi2html in the string. A %% will be expanded as %.

For more on internationalization, see Internationalization.

References
==========

Reference to external manual
----------------------------

The references are produced with two function references, one for the hypertextual reference construction, the other for the full reference to external manual.

 -- Function Reference: $href external_href $node $node_identifier $xml_node_identifier $manual_file_name
     $NODE is the node name, with @-commands. $NODE_IDENTIFER is the node name mapped to an identifier acceptable as a file name. $XML_NODE_IDENTIFIER is the node name mapped to an identifier acceptable as an XML identifier. Those identifiers are built as explained in HTML Xref (texinfo), thus allowing for cross references to external manuals. $FILE is the manual or file name of the external reference. This function should return an href leading to the external manual.

     The default for this function is to make a reference compatible with makeinfo  (see HTML Xref (texinfo)).

 -- Function Reference: $text external_ref $command $section $book $node_and_file $href $cross_ref_name
     This function formats a reference to an external texinfo manual. The $COMMAND is the ref command (ref, xref or pxref, in text, at sentence beginning or in parenthesis). The optionnal $SECTION argument is the section in the book and BOOK is the book title. $NODE_AND_FILE is the node and file name formatted according to the convention used in info: (file)node. $HREF it an hypertextual reference to the distant manual constructed using the above function. $CROSS_REF_NAME is an optionnal cross reference name appearing in the reference command. This function returns the text corresponding with the external html manual reference. This function returns the full formatted text of the external reference.

Reference to an internal node
-----------------------------

A function reference is available for internal references.

 -- Function Reference: $text internal_ref $command $href $short_name $name $is_section
     This function formats a reference to a node in the current manual. The $COMMAND is the ref command (ref, xref or pxref, in text, at sentence beginning or in parenthesis). $HREF it an hypertextual reference linking to the corresponding node or section. $SHORT_NAME and $NAME hold the text for the reference but $SHORT_NAME can be the node name which is assumed to be shorter than the section name. $IS_SECTION is a boolean true if the reference is a reference to a section. This function returns the full formatted text of the internal reference.

Commands used for centering and flushing of text
================================================

When a command controlling the alignement of text is used (@center, @flushleft and @flushright), the main program takes care of opening and closing paragraphs. The alignement commands are the key of the %paragraph_style hash. The value is used in the function doing the formatting of the paragraphs. See Paragraph and preformatted region.

A function references allows for a customization of the formatting of the text appearing in the command block.

 -- Function Reference: $result paragraph_style_command $command $text
     $COMMAND is the command name, $TEXT is the text appearing within the command. This function returns a formatted text. The default is to return the text unmodified.

Formatting or not a paragraph or a preformatted region
======================================================

Paragraph and preformatted region formatting
--------------------------------------------

The formatting of a paragraph region or a preformatted region, is controlled by function references:

 -- Function Reference: $paragraph_text paragraph $text $alignement $formatting_command $formatting_command_formatted \$paragraph_number $format $item_number $enumerate_style $number
     This function formats a paragraph. $TEXT is the text of the paragraph, $ALIGNEMENT is the empty string when no alignement command has been seen, otherwise it is the current alignement command name. See Alignement commands.

     The remaining arguments are usefull when the paragraph appears within a list or table. It is usefull whenever the paragraph has to be formatted differently when appearing in such environments. Moreover in that case the format command (@itemize...) may have an associated formatting command. $FORMATTING_COMMAND is this  formatting command (like @minus). $FORMATTING_COMMAND_FORMATTED is the command formatted in html in case the formatting command is a leading command (like @minus) which should be leading the first paragraph. \$PARAGRAPH_NUMBER is a reference on the number of paragraphs in that format command. The corresponding variable should be increased when a paragraph is added. $FORMAT is the format command. See Table and list items.

     If the $FORMAT is an enumerate, $ITEM_NUMBER is the number of the item in the list, $ENUMERATE_STYLE is the argument of the enumerate, $NUMBER is the number or letter corresponding with this item.

 -- Function Reference: $preformatted_text preformatted $text $style $region_name $formatting_command $formatting_command_formatted \$preformatted_number $format $item_number $enumerate_style $number
     This function formats a preformatted region. $TEXT is the text of the preformatted region, $STYLE is the css style associated with that preformatted region (see css). $REGION_NAME is the name of the command opening the preformatted region (example..., see Complex formats) or a identifier for the preformatted context (for example menu-comment, see Menus). The alignment commands are not taken into account, as the spaces are preserved in preformatted regions, you should flush and center by hand.

     The remaining arguments are usefull when the preformatted region appears within a list or table. It is usefull whenever the preformatted region has to be formatted differently when appearing in such environments. Moreover in that case the format command (@itemize...) may have an associated formatting command. $FORMATTING_COMMAND is this  formatting command (like @minus). $FORMATTING_COMMAND_FORMATTED is the command formatted in html in case the formatting command is a leading command (like @minus) which should be leading the first preformatted region. \$PREFORMATTED_NUMBER is a reference on the number of preformatted regions in that format command. The corresponding variable should be increased when a preformatted region is added. $FORMAT is the format command. See Table and list items.

     If the $FORMAT is an enumerate, $ITEM_NUMBER is the number of the item in the list, $ENUMERATE_STYLE is the argument of the enumerate, $NUMBER is the number or letter corresponding with this item.

Avoiding paragraphs in formats
------------------------------

It is possible to avoid that a format closes the previous paragraph or preformatted region and reopens one, by putting the format command in a hash, %format_in_paragraph with a true value.

Formatting of complex formats (@example, @display...)
=====================================================

Here we see how a whole complex format is formatted. For the formatting of the text, see Paragraph and preformatted region.

The formatting of the complex formats is ultimately controlled by a function, however the default for this function uses a hash reference and changing the hash reference values should be enough in most cases. This hash reference is called $complex_format_map. It has a key for each of the complex format commands (example, smallexample, lisp, smalllisp, display, smalldisplay, format, smallformat).

The associated value is also a reference on a hash. The keys are begin and end. An eval of begin should lead to the beginning of the formatted HTML, an eval of end should lead to the end of the formatted HTML. The enclosed text will be formatted as described in Paragraph and preformatted region, and the name of the complex format will be available to the function formatting the text.

If you aren't satisfied with this scheme, you can redefine the following function reference for a better control over the complex format formatting:

 -- Function Reference: $complex_format_text complex_format $format_name $preformatted_text

     $FORMAT_NAME is the complex format name, $PREFORMATTED_TEXT is the text allready formatted as described in Paragraph and preformatted region. This function returns the whole complex format.

Customizing the formatting of lists and tables
==============================================

The formatting of lists and tables is done at two levels:

  * At the level of the whole region (table or list),

  * At the level of the individual items, rows or cells of the list or table.

Formatting individual table and list items
------------------------------------------

In texinfo it is possible to give @itemize or table command (hereafter called a format command) a formatting command. For example @minus is the formatting command here:

     @table @minus

The default is to apply the command to the text item, however it is possible to avoid it. The hash %special_list_commands has an entry for each of the format command. Each of these entries is a hash reference. If a formatting command is a key of the hash reference, then the formatting command is not applied to the text item for that format command. For example, if we have:

     $special_list_commands{'itemize'} = { 'bullet' => '' };

and we have the following @itemize:

     @itemize @bullet
     @item an item
     @end itemize

then @bullet will not be applied to an item.

lists
     The items of lists are formatted using the following function reference:
      -- Function Reference: $list_item list_item $text $format $command $formatted_command $item_number $enumerate_style $number
          This function formats the text between @item commands. $TEXT is the text corresponding with the item. $FORMAT is the type of format, itemize or enumerate. $COMMAND is the formatting command given in argument to @itemize, $FORMATTED_COMMAND is this command formatted if it is a leading command, like @minus.

          If the $FORMAT is an enumerate, $ITEM_NUMBER is the number of the item in the list, $ENUMERATE_STYLE is the argument of the enumerate, $NUMBER is the number or letter corresponding with this item.

two column tables
     The two columns tables (@table, @ftable and @vtable), items are formatted using two function references, one for the first line located on the @item line corresponding with the first column, the other for the text appearing on the following lines, corresponding with the second column text.

      -- Function Reference: $table_item table_item $item_text $index_label_text $format $command $formatted_command
          This function is used to format the text on the @item line. $TEXT_ITEM is the text line. In case there is an index entry associated with the @item (as with @ftable and @vtable), $INDEX_LABEL_TEXT is the text inserted at the place where an index entry appears. See Index entry place. $FORMAT is the type of format, table, ftable or vtable. $COMMAND is the formatting command given in argument to the table format command, $FORMATTED_COMMAND is this command formatted if it is a leading command, like @minus.

      -- Function Reference: $table_line table_line $text
          This function is used to format the text on the lines following the @item line. $TEXT is the corresponding text.

multitable
     The multitable elements formatting is controlled by the functions associated with two function references. One for a cell, and the other for a row.

      -- Function Reference: $multitable_cell cell $text
          This function is used to format the text of a multitable cell, the text following a @item or a @tab. $TEXT is the corresponding text.

      -- Function Reference: $multitable_row row $text $item_command
          This function is used to format a multitable row. $TEXT is the row text, with cells allready formatted with the $cell function reference. $ITEM_COMMAND is the command used to introduce the row, such that it is possible to distinguish between @item and @headitem.

Formatting of a whole table or list
-----------------------------------

If the Texinfo command is a key of the %format_map, the associated value is used to specify the formatting of the construct, otherwise a function is called. The value in %format_map associated with a command is interpreted similarly with values associated with more simpler commands:

  * If the text is a word, it is considered to be an HTML element name, and the whole table or list is enclosed between the element opening and the element closing.

  * If the text is a word followed by some text, the word and is interpreted as above, and the text is considered to be the attributes text of the element.

  * If the text is empty nothing is added to the text.

In case the %format_map isn't used, a function reference called $table_list should be redefined, the associated function will be called each time a command isn't found in %format_map.

 -- Function Reference: $whole_table_list table_list $command $text
     $COMMAND is the Texinfo command name, $TEXT is the formatted items.

If you still want to use %format_map but differently from the default, it is possible to redefine the following function reference:

 -- Function Reference: $whole_table_list format $command $format $text
     $COMMAND is the @-command, $FORMAT is the entry associated with $COMMAND in %format_map. $TEXT is the formatted items.

Definition commands formatting
==============================

The formatting of definition commands is controlled by a hash and four functions. The hash describes how the text on the definition line is interpreted, the functions control the formatting of the definition line and the definition function text.

Customizing the interpretation of a definition line
---------------------------------------------------

The keys of the hash %def_map are definition command names. There are two types of entries:

  * If the command is a shortcut for another definition command the value is a text and the definition command is replaced by the text.

     For example if we have:

          $def_map{'deftruc'} = '@defvr {A truc}';

     and a line like

          @deftruc var

     the line will be transformed in

          @defvr {A truc} var

  * If the command isn't a shortcut, it is associated with an array reference. The first element is f, v or t corresponding with the index type (f for function, v for variable, t for type).

     The remaining of the array describes how to interpret the text following the definition command on the definition command line. The entry item specify what corresponds with the next bracketed item or word. Currently the possibilities are category, name, type, class and arg.

     For example if we have

          def_map{'defvr'} = [ 'v', 'category', 'name' ];

     The first bracketed item following @defvr is considered to be the category and the next one is the name. The index associated with the definition line is the variables index.

Customization of the definition formatting
------------------------------------------

Four functions are used when formatting a definition command:

category name
      -- Function Reference: $category definition_category $category_or_name $class $style
          This function precise a category or an index entry name associating a class $CLASS (if given) with $CATEGORY_OR_NAME. The $STYLE of the definition may be f, for function, v, for variable or t, for type.

formatting of the definition line
      -- Function Reference: $line def_line $category $name $type $arguments $index_label
          This function formats the definition line. $CATEGORY is the category formatted with $definition_category, $NAME, $TYPE and ARGUMENTS are the element of the definition line. $INDEX_LABEL is the text inserted at the place where an index entry appears. See Index entry place.

definition text
      -- Function Reference: $definition_text def_item $text
          This function formats the definition text, $TEXT.

the whole definition
      -- Function Reference: $definition def $text
          This function formats the whole definition. The definition line and text formatted by the above functions are in $TEXT.

Customizing headings formatting
===============================

A function controls the formatting of sectioning element headings, with the corresponding function reference:
 -- Function Reference: $heading_text heading \%element_reference
     The \%ELEMENT_REFERENCE is a reference on a hash corresponding with the sectioning element. The following keys are of interest:

     text
          The heading text

     name
          The heading text without section number

     node
          true if the sectioning element is a node without associated structuring command

     level
          The level of the element in the document tree. 0 is for @top, 1 for @chapter and so on

     tag_level
          the sectioning element name, with @raisesections and @lowersections taken into account

Formatting of special regions (@verbatim, @cartouche, @quotation)
=================================================================

Regions corresponding with raw text, like @verbatim, @html or @tex are formatted according to the following function reference:

 -- Function Reference: $raw_region raw $command $text
     $COMMAND is the command name, $TEXT is the raw text.

If LaTeX2HTML is used, @tex regions are handled differently, from within the main program.

The @cartouche command formatting is controlled by the function reference:

 -- Function Reference: $cartouche cartouche $text
     $TEXT is the text appearing within the cartouche.

The formatting of @quotation is controlled by two function references. The first one is usefull in case the @quotation has an argument, as it allows to prepend a string to the quotation text:

 -- Function Reference: $prepended_string quotation_prepend_text $style $text
     $STYLE is the first argument of the @quotation if there are two arguments. $TEXT is the second argument or the first if there is one argument. There are still @-commands in these strings. This function can return a string which will be prepended to the quotation text.

The whole quotation is formatted by:

 -- Function Reference: $quotation quotation $quotation_text $argument_text $argument_style_texi $argument_style_id
     $QUOTATION_TEXT is the quotation text, formatted, with the text prepended by the function above. $ARGUMENT_TEXT is the second argument of the @quotation or the first if there is one argument, formatted. The other arguments are defiend if there are two arguments for the @quotation, $ARGUMENT_STYLE_TEXI is this argument, with @-commands, and  $ARGUMENT_STYLE_ID is this argument transformed in an identifier which can be used as an XML identifier.

Menu formatting
===============

To understand how the formatting of menus is controlled, the different parts of a menu are first described, then how to control the formatting of each of these parts.

The structure of a menu
-----------------------

In texi2html, a menu is considered to be composed of 2 parts, the menu entries and the menu comments. Menu entries are further divided in an entry link and optionnaly an entry description. The entry link consists in a node name and an optionnal  menu entry name.

A menu entry begins with * at the beginning of the line. It begins with the entry link, followed by the description. The description spans until the next menu entry, or some text begining at the first character of a line or an empty line, not contained within a command block which begun in the description. An empty line or a line with text at the first character starts a menu comment, which spans until the next menu entry.

Here is an illustration of these rules:

     @menu
     * node name: entry name.        description begins
        description continues
     * another menu entry::
        description begins
                         description continues

        A menu comment, after an empty line

     * node::                        description begins
     A menu comment. The line starts at the first character

     * last entry::         description begins text
     of the description, even if the line begins at the first character,
     because we are in @emph.
     @end menu

The formatting of the different menu components
-----------------------------------------------

In the default case, the name of the section corresponding with the node is used instead of the node name. If $NODE_NAME_IN_MENU is true, however, node names are used. If $AVOID_MENU_REDUNDANCY is true and menu entry equal menu description the description isn't printed. This is the default. Likewise, if node or section name equal entry name, do not print entry name.

A symbol, $MENU_SYMBOL is put at the beginning of menu entries when the node name is used. The default is &bull;. If $UNNUMBERED_SYMBOL_IN_MENU is true it is also put at the beginning of unnumbered section names. This is not done by default.

The menu comments are considered to be preformatted text. The style associated with this preformatted text is determined by $MENU_PRE_STYLE. Default is font-family: serif. The css class associated with menu comments is menu-comments.

Three function references are associated with the formatting of the different parts of a menu:
 -- Function Reference: $link menu_link $section \%state $href $node $name $ending
     $SECTION is the section name corresponding with the link, $HREF is the link hypertextual reference. $HREF may be absent. \%STATE holds informations about the current context. The only key which could be of interest is preformatted, true if the context is a preformatted context. See Three contexts. $NODE is the node name, $NAME is the name of the node, and $ENDING is the text ending the link entry.

 -- Function Reference: $description menu_description $description_text \%state
     $DESCRIPTION_TEXT is the text of the menu description. \%STATE should be used similarly than for the menu link.

 -- Function Reference: $menu_comment menu_comment $text
     $TEXT is the text of the menu comment. It is in a preformatted environment.

The following function reference controls the formatting of a wole menu:

 -- Function Reference: $menu menu $menu_components_text
     $MENU_COMPONENTS_TEXT is the formatted menu components text, obtained as explained above.

The last function reference corresponds with a special case. It is used when a menu entry appears within another block command, to avoid the possibilities of invalid HTML production. In that case the menu description and menu comments are not formatted specially, but treated like normal text.
 -- Function Reference: $link simple_menu_link $link_text $href $node $name $ending
     $LINK_TEXT is the text corresponding with the link name, $HREF is the link hypertextual reference. $NODE is the node name, $NAME is the name of the node, and $ENDING is the text ending the link entry.

Indices formatting
==================

Two different things needs to be handled for indices formatting, the place where the index term appears, the index entry, and the index list itself. The indexing commands like @cindex determines where index entries appear, and the index list is printed with a @printindex command.

Formatting of index entries
---------------------------

Index entry places in the main text may be the target for hypertext references. Their formatting is controlled by the function associated with the following function reference:

 -- Function Reference: $target index_entry_label $identifier $preformatted
     $IDENTIFIER should be used to create a target for links (typically associated with a name or id attribute in HTML). $PREFORMATTED is true if the index entry appeared in preformatted text.

Customizing the formatting of index lists
-----------------------------------------

The index entries are sorted alphabetically. A whole index list is considered to be composed of letter entries. A letter entry is composed by all the index entries beginning with that letter. A letter may be a non alphabetical character, but we call it letter here.

An index summary appears at the beginning and at the end of an index list, and should be used to jump directly to a letter entry. Indices lists may be split across pages, thus the different letters may appear on different files. The number of index entries appearing on each page is determined by a variable $SPLIT_INDEX if set. The default is to split indices after 100 entries.

The formatting of all these elements is controlled by the following function references:

formatting of a letter in a summary
      -- Function Reference: $letter summary_letter $letter $file $identifier
          This function is used to format a letter appearing in a summary, refering to a letter entry in the index list. $LETTER is the letter. $FILE is the file name where the letter entry appears. More precisely, it is empty when the letter entry is on the same page than the summary, it contains the file name when the index page is split accross page. $IDENTIFIER is an identifier for the target letter entry.

formatting of a summary
      -- Function Reference: $summary index_summary \@alphabetical_letters \@nonalphabetical_letters
          \@ALPHABETICAL_LETTERS and \@NONALPHABETICAL_LETTERS contain the formatted summary letters, formatted with the above function.

formatting of an index entry
      -- Function Reference: $entry index_entry $entry_href $entry_text $section_href $section_heading
          $ENTRY_HREF is a reference to the place where the index entry appeared, $ENTRY_TEXT is the corresponding text. $SECTION_HREF is a reference to the beginning of the sectioning element containing the index entry, $SECTION_HEADING is the heading of the element.

formatting of letter entry
      -- Function Reference: $letter_entry index_letter $letter $identifier $index_entries_text
          This function formats a letter entry, consisting in all the index entries beginning with this letter. $LETTER is the letter, $IDENTIFIER should be used to create a target for links (typically links from summaries), and $INDEX_ENTRIES_TEXT is the text of the index entries formatted as described above.

formatting of whole index
      -- Function Reference: $index print_index $index_text $index_name
          $INDEX_TEXT is the text of all the index entries grouped by letter appearing in that page formatted as above. INDEX_NAME is the name of the index, the argument of @printindex.

Floats and lists of floats
==========================

Floats appear in the @float environment, optionaly with a style and a label, and with optionnal @caption and @shortcaption. Their list appear after a @listoffloats.

A hash reference is associated with each float, it is available in some formatting functions. The keys are:

caption_texi
shortcaption_texi
     A reference on an array containing the caption or shortcaption lines, unformatted.

style_texi
     The style with texi @-commands.

style_id
     The unique identifier associated with the style.

nr
     The number with the same conventions than makeinfo (use the chapter number a dot and then the number of the float of that style in the chapter, or an absolute number if in unnumbered).

chapter_nr
     The number of the chapter containing the float.

nr_in_chapter
     The number of the float in the chapter.

absolut_nr
     The number of the float in the document.

texi
     The label with @-commands.

id
     The unique identifier associated with the label. Usefull to make an anchor or a reference.

element
     A reference on a structure representing the element the float appear in.

Formatting a float
------------------

First there is an occasion to construct a texinfo text for the caption, using the caption texinfo lines and the informations in the float structure. The returned lines will be formatted in the main program. A function reference is used here:

 -- Function Reference: (\@caption_lines_returned, \@shortcaption_lines_returned) caption_shortcaption \%float \@caption_lines \@shortcaption_lines
     \%FLOAT is the structure defined above. \@CAPTION_LINES and \@SHORTCAPTION_LINES are references on arrays containing the texinfo lines for caption and short caption. \@CAPTION_LINES_RETURNED and \@SHORTCAPTION_LINES_RETURNED are references on an array containing the texinfo lines for the caption and shortcaption.

Then the float is formatted with the following function reference:

 -- Function Reference: $text float $float_text \%float $caption_text $shortcaption_text
     $FLOAT_TEXT is the text appearing within the @float, formatted. \%FLOAT is still the structure defined above. $CAPTION_TEXT and $SHORTCAPTION_TEXT are the caption and short caption build with the above function and formatted.

Formatting lists of floats
--------------------------

A list of floats is introduced by @listoffloats. The argument of @listoffloats is the style. First the style texinfo can be modified with the following function reference:

 -- Function Reference: $style_texi_returned listoffloats_style $style_texi
     $STYLE_TEXI is the @listoffloats argument with texinfo @-commands kept. It is possible to make changes to the $STYLE_TEXI and return a modified string, still with @-commands. The modified string is formatted in the main program.

After that, for each of the floats with that style, first there is a possibility to modify the float style and the float caption before they are formatted in the main program, with the following function references:

 -- Function Reference: $float_style_texi_returned listoffloats_float_style $style_texi \%float
     $STYLE_TEXI is the style, and \%FLOAT is the structure described above. This function reference returns a style to be formatted in the main program.

 -- Function Reference: $caption_texi_returned listoffloats_caption \%float
     \%FLOAT is the structure described above. This function reference returns a caption to be formatted in the main program.

Each entry is formatted by:

 -- Function Reference: $listoffloats_entry listoffloats_entry $style_texi \%float $float_style $caption $href
     $STYLE_TEXI is the style with @-commands, $FLOAT_STYLE is the style returned by the above function and formatted. $CAPTION is the caption returned by the above function formatted. \%FLOAT is the structure corresponding with the float, and $HREF is an href pointing to the float location.

Lastly, the whole @listoffloats is formatted by:

 -- Function Reference: $listoffloats listoffloats $style_texi $style \@listoffloats_entries
     $STYLE_TEXI is the style with @-commands, $STYLE is the style returned by the above function and formatted. The array reference \@LISTOFFLOATS_ENTRIES holds the entries formatted by the above function.

Customizing the footnotes formatting
====================================

Each footnote is associated with a footnote entry. Several footnote entries are grouped in a footnote section. When a footnote appears, two things must be formatted: in the main text the place where the footnote appear and the footnote text.

Two functions, with corresponding function references control the formatting of the footnotes:

 -- Function Reference: (\@lines $text_for_document) foot_line_and_ref $number_in_doc $number_in_page $footnote_id $place_id $document_file $footnote_file \@lines \%state
     $NUMBER_IN_DOC is the footnote number in the whole document, $NUMBER_IN_PAGE is the footnote number in the current page. $FOOTNOTE_ID is an identifier for the footnote in the footnote text which should be used to make target for references to that footnote, while $PLACE_ID is an identifier for the location of the footnote in the main document. Similarly, $DOCUMENT_FILE is the file name of the file containing the text where the footnote appears in the main document, while $FOOTNOTE_FILE is the file name of the file where the footnote text appears.

     \@LINES is a reference on an array containing the footnote text lines, allready formatted. And \%STATE holds informations about the context at the footnote place in the main document. As usual the most usefull entry is preformatted which is true if the footnote appears in a preformatted context.

     This function returns a reference on an array, \@LINES containing the updated footnote text for the footnote entry, and $TEXT_FOR_DOCUMENT, the text appearing at the footnote place in the main document, linking to the footnote entry.

The following function is only used when footnotes are at the bottom of a page and the document is split. For customization of the footnotes page in case they are on a separated page or section, Special pages layout. For the determination of the footnote locations, Page layout options.

 -- Function Reference: foot_section \@footnotes_lines
     This function formats a group of footnotes. \@FOOTNOTES_LINES is a reference on an array holding the lines of all the footnote entries formatted as explained above. This function modifies the reference.

Customizing other commands, and unknown commands
================================================

Many commands without braces are available in texinfo, sometimes with a specific syntax. For example we have @sp, @noindent, @documentlanguage, @oddheading, @headings, @shortcontents, @shorttitlepage or @comment. texi2html interprets some of these commands and some functions or variables are used for their formatting or to access their information. In the default case, however, most of these constructs are ignored.

It is possible to change how the things following these commands on the line are handled, what is considered to be an arg for those commands and it is also possible to keep them instead of discarding them such that it is possible to handle them specially, with the same function than the one used for unknown commands.

Those special commands without braces are the key of a hash: %misc_command. The associated value is a reference on a hash enabling to set the properties of these commands. The keys of this hash reference is the name of a property, the value is the value of the property. For example here we have line for the arg property for the command @-command.

     $misc_command{'command'} = {'arg' => 'line', 'skip' => 'space'};

The properties and possible values are:

skip
     This property enables to set what is skipped after the command arguments. Here are the possible values:

     line
          The remaining of the line is skipped.

     space
          Spaces are skipped but not newline.

     whitespace
          Spaces are skipped

     linewhitespace
          Spaces are skipped if there are only spaces remaining on the line.

     linespace
          Spaces are skipped, but not newline if there are only spaces remaining on the line

arg
     If the associated value is line the line is considered to be the argument. If it is a number it is the number of args (separated by spaces).

texi
     If true the arguments are considered to real texinfo, therefore @value and @macro are expanded.

keep
     If true the args and the macro are kept, otherwise they are discarded. The defaut is to have keep undef for all the commands. If keep is true for @verbatiminclude the default action for this macro isn't done.

Commands which don't appear in the hashes %simple_map, %simple_map_pre, %simple_map_texi and %misc_command, or that appear in %misc_command but with keep true are processed by the following function reference:

 -- Function Reference: ($result_line, $result, $result_text, $message) unknown $command $line
     $COMMAND is the @-command, $LINE is the line following the $COMMAND. $RESULT is a boolean. If it is true then the other return values are taken into account otherwise the default actions are used. In case $RESULT is true, $RESULT_LINE is the new line to be processed further, $RESULT_TEXT is the resulting formatted text and $MESSAGE, if defined is a message outputted to the output with line number added by texi2html.

Commands with braces not specified above nor in %style_map, %style_map_pre and %style_map_texi are processed by the following function reference

 -- Function Reference: ($result, $result_text, $message) unknown_style $command $text
     $COMMAND is the @-command, $TEXT is the text appearing within the braces (allready formatted). $RESULT is a boolean. If it is true then the other return values are taken into account otherwise the default actions are used. In case $RESULT is true, $RESULT_TEXT is the resulting formatted text and $MESSAGE, if defined is a message outputted to the output with line number added by texi2html.

Internationalization
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The strings written in the document are selected based on the document language. This can be used to customize the strings, as described in Strings. This also enables translation of the strings.

Translating strings
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If the language is allready supported, then there will be a file in the i18n directory with name the two-letter ISO-639 language code. In that case you can enhance the translations by editing this file. There is a $LANGUAGES->{'LANGUAGE'} hash in that file. The keys are the english strings, in '', the values (in '' after =>) are the translations. When a string contains a % followed by { NAME } it means that the string will be expanded by texi2html. For an example, see Strings.

After that you should run the command ./manage_i18n.pl all in the top directory, it should merge your file with the existing files in translations.pl, which is incorporated to the texi2html script by ./configure.

If the language isn't currently supported, copy the en file in i18n to a file with name the two-letter ISO-639 language code of your language and then add your translations to the strings. You could also add your two-letter language code in the manage_i18n.pl file in the @known_languages array.

After that you should similarly run the command ./manage_i18n.pl all in the top directory.

Obsoleted strings are not removed from the files, they are still present in the $T2H_OBSOLETE_STRINGS->{'LANGUAGE'} hash in case the string is reused later.

If you made change to strings specified in installed files (see Installation) you will have to reinstall them otherwise the installated files will take precedence (see Using init files).

Adding new strings written to document
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If you need to write strings, for example the new string A STRING to the resulting document, call &$I('a string'). Use simple quotes. If you want to substitute a value in the string put %{STRING_VALUE}, in the string, and give a second argument to &$I, a hash reference with key STRING_VALUE and value the what you want to substitute. Here is an example:

     return &$I('%{name} of %{class}', { 'name' => $name, 'class' => $class });

In that case %{name} is substituted by $name in the translated string.

After that you should run the command ./manage_i18n.pl all in the top directory, it should add your new strings to all the files in the i18n directory.