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The Apache HTTP Server Reference Manual
by Apache Software Foundation
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ISBN 9781906966034
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3.77  Apache Module mod_version



Description:

Version dependent configuration

Status:

Extension

Module Identifier:

version_module

Source File:

mod_version.c

Compatibility:

Available in version 2.0.56 and later



Summary

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 – <IfVersion>, which allows a flexible version checking including numeric comparisons and regular expressions.

Examples

<IfVersion 2.1.0>

# current httpd version is exactly 2.1.0

</IfVersion>

<IfVersion >= 2.2>

# use really new features :-)

</IfVersion>

See below for further possibilities.

Directives:

<IfVersion>

IfVersion Directive

Description:

contains version dependent configuration

Syntax:

<IfVersion [[!]operator] version> </IfVersion>

Context:

server config, virtual host, directory, .htaccess

Override:

All

Status:

Extension

Module:

mod_version

The <IfVersion> section encloses configuration directives which are executed only if the httpd version matches the desired criteria. For normal (numeric) comparisons the version argument has the format major[.minor[.patch]], e.g. 2.1.0 or 2.2. minor and patch are optional. If these numbers are omitted, they are assumed to be zero. The following numerical operators are possible:



operator description


= or == httpd version is equal
> httpd version is greater than
>= httpd version is greater or equal
< httpd version is less than
<= httpd version is less or equal


Example

<IfVersion >= 2.1>

# this happens only in versions greater or
# equal 2.1.0.

</IfVersion>

Besides the numerical comparison it is possible to match a regular expression against the httpd version. There are two ways to write it:



operator description


= or == version has the form /regex/
~ version has the form regex


Example

<IfVersion = /^2.1.[01234]$/>

# e.g. workaround for buggy versions

</IfVersion>

In order to reverse the meaning, all operators can be preceded by an exclamation mark (!):

<IfVersion !~ ^2.1.[01234]$>

# not for those versions

</IfVersion>

If the operator is omitted, it is assumed to be =.

ISBN 9781906966034The Apache HTTP Server Reference ManualSee the print edition