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Edit File: Info-Format-Specification.html
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <!-- Created by GNU Texinfo 6.8, https://www.gnu.org/software/texinfo/ --> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <!-- This manual is for GNU Texinfo (version 6.8, 8 June 2021), a documentation system that can produce both online information and a printed manual from a single source using semantic markup. Copyright (C) 1988, 1990-1993, 1995-1999, 2001-2021 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". --> <title>Info Format Specification (GNU Texinfo 6.8)</title> <meta name="description" content="Info Format Specification (GNU Texinfo 6.8)"> <meta name="keywords" content="Info Format Specification (GNU Texinfo 6.8)"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="texi2any"> <meta name="viewport" content="width=device-width,initial-scale=1"> <link href="index.html" rel="start" title="Top"> <link href="Command-and-Variable-Index.html" rel="index" title="Command and Variable Index"> <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> <link href="index.html" rel="up" title="Top"> <link href="GNU-Free-Documentation-License.html" rel="next" title="GNU Free Documentation License"> <link href="Global-Document-Commands.html" rel="prev" title="Global Document Commands"> <style type="text/css"> <!-- a.copiable-anchor {visibility: hidden; text-decoration: none; line-height: 0em} a.summary-letter {text-decoration: none} blockquote.indentedblock {margin-right: 0em} div.display {margin-left: 3.2em} div.example {margin-left: 3.2em} kbd {font-style: oblique} pre.display {font-family: inherit} pre.format {font-family: inherit} pre.menu-comment {font-family: serif} pre.menu-preformatted {font-family: serif} span.nolinebreak {white-space: nowrap} span.roman {font-family: initial; font-weight: normal} span.sansserif {font-family: sans-serif; font-weight: normal} span:hover a.copiable-anchor {visibility: visible} ul.no-bullet {list-style: none} --> </style> </head> <body lang="en"> <div class="appendix" id="Info-Format-Specification"> <div class="header"> <p> Next: <a href="GNU-Free-Documentation-License.html" accesskey="n" rel="next">GNU Free Documentation License</a>, Previous: <a href="Global-Document-Commands.html" accesskey="p" rel="prev">Global Document Commands</a>, Up: <a href="index.html" accesskey="u" rel="up">Texinfo</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Command-and-Variable-Index.html" title="Index" rel="index">Index</a>]</p> </div> <hr> <span id="Info-Format-Specification-1"></span><h2 class="appendix">Appendix F Info Format Specification</h2> <span id="index-Info-format-specification"></span> <span id="index-Specification-of-Info-format"></span> <span id="index-Definition-of-Info-format"></span> <p>Here we describe the technical details of the Info format. </p> <p>In this formal description, the characters <code><>*()|=#</code> are used for the language of the description itself. Other characters are literal. The formal constructs used are typical: <code><...></code> indicates a metavariable name, ‘<samp>=</samp>’ means definition, ‘<samp>*</samp>’ repetition, ‘<samp>?</samp>’ optional, ‘<samp>()</samp>’ grouping, ‘<samp>|</samp>’ alternation, ‘<samp>#</samp>’ comment. Exception: ‘<samp>*</samp>’ at the beginning of a line is literal. </p> <p>In general, programs that read Info files should try to be case-insensitive to keywords that occur in the file (for example, ‘<samp>Tag Table</samp>’ and ‘<samp>Tag table</samp>’ should be equivalent) in order to support Info-generating programs that use different capitalization. </p> <p>The sections in an Info file (such as nodes or tag tables) are separated with a sequence: </p> <div class="example"> <pre class="example">(^L)?^_(^L)?^J </pre></div> <p>That is, a ‘<samp>CTRL-_</samp>’ character followed by a newline, with optional formfeed characters. We refer to such sequences as <tt><separator></tt>. </p> <p>We specify literal parentheses (those that are part of the Info format) with <tt><lparen></tt> and <tt><rparen></tt>, meaning the single characters ‘<samp>(</samp>’ and ‘<samp>)</samp>’ respectively. We specify the ‘<samp>CTRL-?</samp>’ character (character number 127) <tt><del></tt>. Finally, the two-character sequence ‘<samp>^<var>x</var></samp>’ means the single character ‘<samp>CTRL-<var>x</var></samp>’, for any <var>x</var>. </p> <p>This format definition was written some 25 years after the Info format was first devised. So in the event of conflicts between this definition and actual practice, practice wins. It also assumes some general knowledge of Texinfo; it is meant to be a guide for implementors rather than a rigid technical standard. We often refer back to other parts of this manual for examples and definitions, rather than redundantly spelling out every detail. </p> <ul class="section-toc"> <li><a href="Info-Format-General-Layout.html" accesskey="1">Info Format General Layout</a></li> <li><a href="Info-Format-Text-Constructs.html" accesskey="2">Info Format Text Constructs</a></li> </ul> </div> <hr> <div class="header"> <p> Next: <a href="GNU-Free-Documentation-License.html">GNU Free Documentation License</a>, Previous: <a href="Global-Document-Commands.html">Global Document Commands</a>, Up: <a href="index.html">Texinfo</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Command-and-Variable-Index.html" title="Index" rel="index">Index</a>]</p> </div> </body> </html>