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| Next: <a href="_0040inlineifset-_0040inlineifclear.html" accesskey="n" rel="next"><code class="code">@inlineifset</code> and <code class="code">@inlineifclear</code></a>, Previous: <a href="_0040set-_0040value.html" accesskey="p" rel="prev"><code class="code">@set</code> and <code class="code">@value</code></a>, Up: <a href="_0040set-_0040clear-_0040value.html" accesskey="u" rel="up">Flags: <code class="code">@set</code>, <code class="code">@clear</code>, conditionals, and <code class="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> |
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| <h4 class="subsection" id="g_t_0040ifset-and-_0040ifclear">15.5.2 <code class="code">@ifset</code> and <code class="code">@ifclear</code></h4> |
| |
| <a class="anchor" id="ifset-ifclear"></a><a class="index-entry-id" id="index-ifset"></a> |
| |
| <p>When a <var class="var">flag</var> is set, the Texinfo formatting commands format text |
| between subsequent pairs of <code class="code">@ifset <var class="var">flag</var></code> and <code class="code">@end |
| ifset</code> commands. When the <var class="var">flag</var> is cleared, the Texinfo formatting |
| commands do <em class="emph">not</em> format the text. <code class="code">@ifclear</code> operates |
| analogously. |
| </p> |
| <p>Write the conditionally formatted text between <code class="code">@ifset <var class="var">flag</var></code> |
| and <code class="code">@end ifset</code> commands, like this: |
| </p> |
| <div class="example"> |
| <div class="group"><pre class="example-preformatted">@ifset <var class="var">flag</var> |
| <var class="var">conditional-text</var> |
| @end ifset |
| </pre></div></div> |
| |
| <p>For example, you can create one document that has two variants, such as |
| a manual for a ‘large’ and ‘small’ model: |
| </p> |
| <a class="index-entry-id" id="index-Shrubbery"></a> |
| <div class="example"> |
| <pre class="example-preformatted">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 class="code">@ifset large</code> and <code class="code">@end ifset</code> because the <code class="code">large</code> |
| flag is set. |
| </p> |
| <p>When <var class="var">flag</var> is cleared, the Texinfo formatting commands do |
| <em class="emph">not</em> format the text between <code class="code">@ifset <var class="var">flag</var></code> and |
| <code class="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 class="code">@clear large</code> command after the <code class="code">@set large</code> command |
| (but before the conditional text), then the Texinfo formatting commands |
| ignore the text between the <code class="code">@ifset large</code> and <code class="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> |
| <a class="index-entry-id" id="index-ifclear"></a> |
| <p>If a flag is cleared with a <code class="code">@clear <var class="var">flag</var></code> command, then |
| the formatting commands format text between subsequent pairs of |
| <code class="code">@ifclear</code> and <code class="code">@end ifclear</code> commands. But if the flag |
| is set with <code class="code">@set <var class="var">flag</var></code>, then the formatting commands do |
| <em class="emph">not</em> format text between an <code class="code">@ifclear</code> and an <code class="code">@end |
| ifclear</code> command; rather, they ignore that text. An <code class="code">@ifclear</code> |
| command looks like this: |
| </p> |
| <div class="example"> |
| <pre class="example-preformatted">@ifclear <var class="var">flag</var> |
| </pre></div> |
| |
| |
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| <p> |
| Next: <a href="_0040inlineifset-_0040inlineifclear.html"><code class="code">@inlineifset</code> and <code class="code">@inlineifclear</code></a>, Previous: <a href="_0040set-_0040value.html"><code class="code">@set</code> and <code class="code">@value</code></a>, Up: <a href="_0040set-_0040clear-_0040value.html">Flags: <code class="code">@set</code>, <code class="code">@clear</code>, conditionals, and <code class="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> |
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