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<modulesynopsis metafile="mod_version.xml.meta">

<name>mod_version</name>

<description>Version dependent configuration</description>

<status>Extension</status>

<sourcefile>mod_version.c</sourcefile>

<identifier>version_module</identifier>

<summary>

<p>This module is designed for the use in test suites and large

networks which have to deal with different httpd versions and

different configurations. It provides a new container -- <directive

type="section" module="mod_version">IfVersion</directive>, which

allows a flexible version checking including numeric comparisons and

regular expressions.</p>

<example><title>Examples</title>

<highlight language="config">

&lt;IfVersion 2.4.2&gt;

# current httpd version is exactly 2.4.2

&lt;/IfVersion&gt;

&lt;IfVersion >= 2.5&gt;

# use really new features :-)

&lt;/IfVersion&gt;

</highlight>

</example>

<p>See below for further possibilities.</p>

</summary>

<directivesynopsis type="section">

<name>IfVersion</name>

<description>contains version dependent configuration</description>

<syntax>&lt;IfVersion [[!]<var>operator</var>] <var>version</var>&gt; ...

&lt;/IfVersion&gt;</syntax>

<contextlist><context>server config</context><context>virtual host</context>

<context>directory</context><context>.htaccess</context></contextlist>

<override>All</override>

<usage>

<p>The <directive type="section">IfVersion</directive> section encloses

configuration directives which are executed only if the

<program>httpd</program> version

matches the desired criteria. For normal (numeric) comparisons the

<var>version</var> argument has the format

<code><var>major</var>[.<var>minor</var>[.<var>patch</var>]]</code>, e.g.

<code>2.1.0</code> or <code>2.2</code>. <var>minor</var> and

<var>patch</var> are optional. If these numbers are omitted, they are

assumed to be zero. The following numerical <var>operator</var>s are

possible:</p>

<table style="zebra" border="1">

<tr><th><var>operator</var></th><th>description</th></tr>

<tr><td><code>=</code> or <code>==</code></td>

<td>httpd version is equal</td></tr>

<tr><td><code>&gt;</code></td>

<td>httpd version is greater than</td></tr>

<tr><td><code>&gt;=</code></td>

<td>httpd version is greater or equal</td></tr>

<tr><td><code>&lt;</code></td>

<td>httpd version is less than</td></tr>

<tr><td><code>&lt;=</code></td>

<td>httpd version is less or equal</td></tr>

</table>

<example><title>Example</title>

<highlight language="config">

&lt;IfVersion >= 2.3&gt;

# this happens only in versions greater or

# equal 2.3.0.

&lt;/IfVersion&gt;

</highlight>

</example>

<p>Besides the numerical comparison it is possible to match a

<glossary ref="regex">regular expression</glossary>

against the httpd version. There are two ways to write it:</p>

<table style="zebra" border="1">

<tr><th><var>operator</var></th><th>description</th></tr>

<tr><td><code>=</code> or <code>==</code></td>

<td><var>version</var> has the form

<code>/<var>regex</var>/</code></td></tr>

<tr><td><code>~</code></td>

<td><var>version</var> has the form

<code><var>regex</var></code></td></tr>

</table>

<example><title>Example</title>

<highlight language="config">

&lt;IfVersion = /^2.4.[01234]$/&gt;

# e.g. workaround for buggy versions

&lt;/IfVersion&gt;

</highlight>

</example>

<p>In order to reverse the meaning, all operators can be preceded by an

exclamation mark (<code>!</code>):</p>

<highlight language="config">

&lt;IfVersion !~ ^2.4.[01234]$&gt;

# not for those versions

&lt;/IfVersion&gt;

</highlight>

<p>If the <var>operator</var> is omitted, it is assumed to be

<code>=</code>.</p>

</usage>

</directivesynopsis>

</modulesynopsis>