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<!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>@ifset @ifclear (GNU Texinfo 6.8)</title> <meta name="description" content="@ifset @ifclear (GNU Texinfo 6.8)"> <meta name="keywords" content="@ifset @ifclear (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="_0040set-_0040clear-_0040value.html" rel="up" title="@set @clear @value"> <link href="_0040inlineifset-_0040inlineifclear.html" rel="next" title="@inlineifset @inlineifclear"> <link href="_0040set-_0040value.html" rel="prev" title="@set @value"> <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="subsection" id="g_t_0040ifset-_0040ifclear"> <div class="header"> <p> Next: <a href="_0040inlineifset-_0040inlineifclear.html" accesskey="n" rel="next"><code>@inlineifset</code> and <code>@inlineifclear</code></a>, Previous: <a href="_0040set-_0040value.html" accesskey="p" rel="prev"><code>@set</code> and <code>@value</code></a>, Up: <a href="_0040set-_0040clear-_0040value.html" accesskey="u" rel="up">Flags: <code>@set</code>, <code>@clear</code>, conditionals, and <code>@value</code></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="g_t_0040ifset-and-_0040ifclear"></span><h4 class="subsection">15.5.2 <code>@ifset</code> and <code>@ifclear</code></h4> <span id="ifset-ifclear"></span><span id="index-ifset"></span> <p>When a <var>flag</var> is set, the Texinfo formatting commands format text between subsequent pairs of <code>@ifset <var>flag</var></code> and <code>@end ifset</code> commands. When the <var>flag</var> is cleared, the Texinfo formatting commands do <em>not</em> format the text. <code>@ifclear</code> operates analogously. </p> <p>Write the conditionally formatted text between <code>@ifset <var>flag</var></code> and <code>@end ifset</code> commands, like this: </p> <div class="example"> <pre class="example">@ifset <var>flag</var> <var>conditional-text</var> @end ifset </pre></div> <p>For example, you can create one document that has two variants, such as a manual for a ‘large’ and ‘small’ model: </p> <span id="index-Shrubbery"></span> <div class="example"> <pre class="example">You can use this machine to dig up shrubs without hurting them. @set large @ifset large It can also dig up fully grown trees. @end ifset Remember to replant promptly … </pre></div> <p>In the example, the formatting commands will format the text between <code>@ifset large</code> and <code>@end ifset</code> because the <code>large</code> flag is set. </p> <p>When <var>flag</var> is cleared, the Texinfo formatting commands do <em>not</em> format the text between <code>@ifset <var>flag</var></code> and <code>@end ifset</code>; that text is ignored and does not appear in either printed or Info output. </p> <p>For example, if you clear the flag of the preceding example by writing an <code>@clear large</code> command after the <code>@set large</code> command (but before the conditional text), then the Texinfo formatting commands ignore the text between the <code>@ifset large</code> and <code>@end ifset</code> commands. In the formatted output, that text does not appear; in both printed and Info output, you see only the lines that say, “You can use this machine to dig up shrubs without hurting them. Remember to replant promptly …”. </p> <span id="index-ifclear"></span> <p>If a flag is cleared with a <code>@clear <var>flag</var></code> command, then the formatting commands format text between subsequent pairs of <code>@ifclear</code> and <code>@end ifclear</code> commands. But if the flag is set with <code>@set <var>flag</var></code>, then the formatting commands do <em>not</em> format text between an <code>@ifclear</code> and an <code>@end ifclear</code> command; rather, they ignore that text. An <code>@ifclear</code> command looks like this: </p> <div class="example"> <pre class="example">@ifclear <var>flag</var> </pre></div> </div> <hr> <div class="header"> <p> Next: <a href="_0040inlineifset-_0040inlineifclear.html"><code>@inlineifset</code> and <code>@inlineifclear</code></a>, Previous: <a href="_0040set-_0040value.html"><code>@set</code> and <code>@value</code></a>, Up: <a href="_0040set-_0040clear-_0040value.html">Flags: <code>@set</code>, <code>@clear</code>, conditionals, and <code>@value</code></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>