<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE manualpage SYSTEM "/style/manualpage.dtd">

<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>

<manualpage metafile="sections.xml.meta">

<title>Configuration Sections</title>

<summary> <p>Directives in the <a

href="configuring.html">configuration files</a> may apply to the

entire server, or they may be restricted to apply only to particular

directories, files, hosts, or URLs. This document describes how to

use configuration section containers or <code>.htaccess</code> files

to change the scope of other configuration directives.</p>

</summary>

<section id="types"><title>Types of Configuration Section Containers</title>

<related>

<modulelist>

<module>core</module>

<module>mod_proxy</module>

</modulelist>

<directivelist>

<directive type="section" module="core">Directory</directive>

<directive type="section" module="core">DirectoryMatch</directive>

<directive type="section" module="core">Files</directive>

<directive type="section" module="core">FilesMatch</directive>

<directive type="section" module="core">IfDefine</directive>

<directive type="section" module="core">IfModule</directive>

<directive type="section" module="core">Location</directive>

<directive type="section" module="core">LocationMatch</directive>

<directive type="section" module="mod_proxy">Proxy</directive>

<directive type="section" module="mod_proxy">ProxyMatch</directive>

<directive type="section" module="core">VirtualHost</directive>

</directivelist>

</related>

<p>There are two basic types of containers. Most containers are

evaluated for each request. The enclosed directives are applied only

for those requests that match the containers. The <directive

type="section" module="core">IfDefine</directive> and <directive

type="section" module="core">IfModule</directive> containers, on the

other hand, are evaluated only at server startup and restart. If

their conditions are true at startup, then the enclosed directives

will apply to all requests. If the conditions are not true, the

enclosed directives will be ignored.</p>

<p>The <directive type="section" module="core">IfDefine</directive> directive

encloses directives that will only be applied if an appropriate

parameter is defined on the <code>httpd</code> command line. For example,

with the following configuration, all requests will be redirected

to another site only if the server is started using

<code>httpd -DClosedForNow</code>:</p>

<example>

&lt;IfDefine ClosedForNow&gt;<br />

Redirect / http://otherserver.example.com/<br />

&lt;/IfDefine&gt;

</example>

<p>The <directive type="section" module="core">IfModule</directive>

directive is very similar, except it encloses directives that will

only be applied if a particular module is available in the server.

The module must either be statically compiled in the server, or it

must be dynamically compiled and its <directive

module="mod_so">LoadModule</directive> line must be earlier in the

configuration file. This directive should only be used if you need

your configuration file to work whether or not certain modules are

installed. It should not be used to enclose directives that you want

to work all the time, because it can suppress useful error messages

about missing modules.</p>

<p>In the following example, the <directive

module="mod_mime_magic">MimeMagicFiles</directive> directive will be

applied only if <module>mod_mime_magic</module> is available.</p>

<example>

&lt;IfModule mod_mime_magic.c&gt;<br />

MimeMagicFile conf/magic<br />

&lt;/IfModule&gt;

</example>

<p>Both <directive type="section" module="core">IfDefine</directive>

and <directive type="section" module="core">IfModule</directive>

can apply negative conditions by preceding their test with "!".

Also, these sections can be nested to achieve more complex

restrictions.</p>

</section>

<section id="file-and-web"><title>Filesystem and Webspace</title>

<p>The most commonly used configuration section containers are the

ones that change the configuration of particular places in the

filesystem or webspace. First, it is important to understand the

difference between the two. The filesystem is the view of your disks

as seen by your operating system. For example, in a default install,

Apache resides at <code>/usr/local/apache2</code> in the Unix

filesystem or <code>"c:/Program Files/Apache Group/Apache2"</code> in

the Windows filesystem. (Note that forward slashes should always be

used as the path separator in Apache, even for Windows.) In contrast,

the webspace is the view of your site as delivered by the web server

and seen by the client. So the path <code>/dir/</code> in the

webspace corresponds to the path

<code>/usr/local/apache2/htdocs/dir/</code> in the filesystem of a

default Apache install on Unix. The webspace need not map directly to

the filesystem, since webpages may be generated dynamically

from databases or other locations.</p>

<section id="filesystem"><title>Filesystem Containers</title>

<p>The <directive type="section" module="core">Directory</directive>

and <directive type="section" module="core">Files</directive>

directives, along with their regex counterparts, apply directives to

parts of the filesystem. Directives enclosed in a <directive

type="section" module="core">Directory</directive> section apply to

the named filesystem directory and all subdirectories of that

directory. The same effect can be obtained using <a

href="howto/htaccess.html">.htaccess files</a>. For example, in the

following configuration, directory indexes will be enabled for the

<code>/var/web/dir1</code> directory and all subdirectories.</p>

<example>

&lt;Directory /var/web/dir1&gt;<br />

Options +Indexes<br />

&lt;/Directory&gt;

</example>

<p>Directives enclosed in a <directive type="section"

module="core">Files</directive> section apply to any file with

the specified name, regardless of what directory it lies in.

So for example, the following configuration directives will,

when placed in the main section of the configuration file,

deny access to any file named <code>private.html</code> regardless

of where it is found.</p>

<example>

&lt;Files private.html&gt;<br />

Order allow,deny<br />

Deny from all<br />

&lt;/Files&gt;

</example>

<p>To address files found in a particular part of the filesystem, the

<directive type="section" module="core">Files</directive> and

<directive type="section" module="core">Directory</directive> sections

can be combined. For example, the following configuration will deny

access to <code>/var/web/dir1/private.html</code>,

<code>/var/web/dir1/subdir2/private.html</code>,

<code>/var/web/dir1/subdir3/private.html</code>, and any other instance

of <code>private.html</code> found under the <code>/var/web/dir1/</code>

directory.</p>

<example>

&lt;Directory /var/web/dir1&gt;<br />

&lt;Files private.html&gt;<br />

Order allow,deny<br />

Deny from all<br />

&lt;/Files&gt;<br />

&lt;/Directory&gt;

</example>

</section>

<section id="webspace"><title>Webspace Containers</title>

<p>The <directive type="section" module="core">Location</directive>

directive and its regex counterpart, on the other hand, change the

configuration for content in the webspace. For example, the following

configuration prevents access to any URL-path that begins in /private.

In particular, it will apply to requests for

<code>http://yoursite.example.com/private</code>,

<code>http://yoursite.example.com/private123</code>, and

<code>http://yoursite.example.com/private/dir/file.html</code> as well

as any other requests starting with the <code>/private</code> string.</p>

<example>

&lt;Location /private&gt;<br />

Order Allow,Deny<br />

Deny from all<br />

&lt;/Location&gt;

</example>

<p>The <directive type="section" module="core">Location</directive>

directive need not have anything to do with the filesystem.

For example, the following example shows how to map a particular

URL to an internal Apache handler provided by <module>mod_status</module>.

No file called <code>server-status</code> needs to exist in the

filesystem.</p>

<example>

&lt;Location /server-status&gt;<br />

SetHandler server-status<br />

&lt;/Location&gt;

</example>

</section>

<section id="wildcards"><title>Wildcards and Regular Expressions</title>

<p>The <directive type="section" module="core">Directory</directive>,

<directive type="section" module="core">Files</directive>, and

<directive type="section" module="core">Location</directive>

directives can each use shell-style wildcard characters as in

<code>fnmatch</code> from the C standard library. The character "*"

matches any sequence of characters, "?" matches any single character,

and "[<em>seq</em>]" matches any character in <em>seq</em>. The "/"

character will not be matched by any wildcard; it must be specified

explicitly.</p>

<p>If even more flexible matching is required, each

container has a regular-expression (regex) counterpart <directive

type="section" module="core">DirectoryMatch</directive>, <directive

type="section" module="core">FilesMatch</directive>, and <directive

type="section" module="core">LocationMatch</directive> that allow

perl-compatible

<a href="glossary.html#regex">regular expressions</a>

to be used in choosing the matches. But see the section below on

configuration merging to find out how using regex sections will change

how directives are applied.</p>

<p>A non-regex wildcard section that changes the configuration of

all user directories could look as follows:</p>

<example>

&lt;Directory /home/*/public_html&gt;<br />

Options Indexes<br />

&lt;/Directory&gt;

</example>

<p>Using regex sections, we can deny access to many types of image files

at once:</p>

<example>

&lt;FilesMatch \.(?i:gif|jpe?g|png)$&gt;<br />

Order allow,deny<br />

Deny from all<br />

&lt;/FilesMatch&gt;

</example>

</section>

<section id="whichwhen"><title>What to use When</title>

<p>Choosing between filesystem containers and webspace containers is

actually quite easy. When applying directives to objects that reside

in the filesystem always use <directive type="section"

module="core">Directory</directive> or <directive type="section"

module="core">Files</directive>. When applying directives to objects

that do not reside in the filesystem (such as a webpage generated from

a database), use <directive type="section"

module="core">Location</directive>.</p>

<p>It is important to never use <directive type="section"

module="core">Location</directive> when trying to restrict

access to objects in the filesystem. This is because many

different webspace locations (URLs) could map to the same filesystem

location, allowing your restrictions to be circumvented.

For example, consider the following configuration:</p>

<example>

&lt;Location /dir/&gt;<br />

Order allow,deny<br />

Deny from all<br />

&lt;/Location&gt;

</example>

<p>This works fine if the request is for

<code>http://yoursite.example.com/dir/</code>. But what if you are on

a case-insensitive filesystem? Then your restriction could be easily

circumvented by requesting

<code>http://yoursite.example.com/DIR/</code>. The <directive

type="section" module="core">Directory</directive> directive, in

contrast, will apply to any content served from that location,

regardless of how it is called. (An exception is filesystem links.

The same directory can be placed in more than one part of the

filesystem using symbolic links. The <directive type="section"

module="core">Directory</directive> directive will follow the symbolic

link without resetting the pathname. Therefore, for the highest level

of security, symbolic links should be disabled with the appropriate

<directive module="core">Options</directive> directive.)</p>

<p>If you are, perhaps, thinking that none of this applies to you

because you use a case-sensitive filesystem, remember that there are

many other ways to map multiple webspace locations to the same

filesystem location. Therefore you should always use the filesystem

containers when you can. There is, however, one exception to this

rule. Putting configuration restrictions in a <code>&lt;Location

/&gt;</code> section is perfectly safe because this section will apply

to all requests regardless of the specific URL.</p>

</section>

</section>

<section id="virtualhost"><title>Virtual Hosts</title>

<p>The <directive type="section" module="core">VirtualHost</directive>

container encloses directives that apply to specific hosts.

This is useful when serving multiple hosts from the same machine

with a different configuration for each. For more information,

see the <a href="vhosts/">Virtual Host Documentation</a>.</p>

</section>

<section id="proxy"><title>Proxy</title>

<p>The <directive type="section" module="mod_proxy">Proxy</directive>

and <directive type="section" module="mod_proxy">ProxyMatch</directive>

containers apply enclosed configuration directives only

to sites accessed through <module>mod_proxy</module>'s proxy server

that match the specified URL. For example, the following configuration

will prevent the proxy server from being used to access the

<code>cnn.com</code> website.</p>

<example>

&lt;Proxy http://cnn.com/*&gt;<br />

Order allow,deny<br />

Deny from all<br />

&lt;/Proxy&gt;

</example>

</section>

<section id="whatwhere"><title>What Directives are Allowed?</title>

<p>To find out what directives are allowed in what types of

configuration sections, check the <a

href="mod/directive-dict.html#Context">Context</a> of the directive.

Everything that is allowed in

<directive type="section" module="core">Directory</directive>

sections is also syntactically allowed in

<directive type="section" module="core">DirectoryMatch</directive>,

<directive type="section" module="core">Files</directive>,

<directive type="section" module="core">FilesMatch</directive>,

<directive type="section" module="core">Location</directive>,

<directive type="section" module="core">LocationMatch</directive>,

<directive type="section" module="mod_proxy">Proxy</directive>,

and <directive type="section" module="mod_proxy">ProxyMatch</directive>

sections. There are some exceptions, however:</p>

<ul>

<li>The <directive module="core">AllowOverride</directive> directive

works only in <directive type="section" module="core">Directory</directive>

sections.</li>

<li>The <code>FollowSymLinks</code> and

<code>SymLinksIfOwnerMatch</code> <directive

module="core">Options</directive> work only in <directive

type="section" module="core">Directory</directive> sections or

<code>.htaccess</code> files.</li>

<li>The <directive module="core">Options</directive> directive cannot

be used in <directive type="section" module="core">Files</directive>

and <directive type="section" module="core">FilesMatch</directive>

sections.</li>

</ul>

</section>

<section id="mergin"><title>How the sections are merged</title>

<p>The configuration sections are applied in a very particular order.

Since this can have important effects on how configuration directives

are interpreted, it is important to understand how this works.</p>

<p>The order of merging is:</p>

<ol>

<li> <directive type="section"

module="core">Directory</directive> (except regular expressions)

and <code>.htaccess</code> done simultaneously (with

<code>.htaccess</code>, if allowed, overriding

<directive type="section" module="core">Directory</directive>)</li>

<li><directive type="section" module="core">DirectoryMatch</directive>

(and <code>&lt;Directory ~&gt;</code>)</li>

<li><directive type="section"

module="core">Files</directive> and <directive

type="section" module="core">FilesMatch</directive> done

simultaneously</li>

<li><directive type="section" module="core">Location</directive>

and <directive type="section"

module="core">LocationMatch</directive> done simultaneously</li>

</ol>

<p>Apart from <directive type="section"

module="core">Directory</directive>, each group is processed in

the order that they appear in the configuration files. <directive

type="section" module="core">Directory</directive> (group 1 above)

is processed in the order shortest directory component to longest.

So for example, <code>&lt;Directory /var/web/dir&gt;</code> will

be processed before <code>&lt;Directory

/var/web/dir/subdir&gt;</code>. If multiple <directive

type="section" module="core">Directory</directive> sections apply

to the same directory they are processed in the configuration file

order. Configurations included via the <directive

module="core">Include</directive> directive will be treated as if

they were inside the including file at the location of the

<directive module="core">Include</directive> directive.</p>

<p>Sections inside <directive type="section"

module="core">VirtualHost</directive> sections

are applied <em>after</em> the corresponding sections outside

the virtual host definition. This allows virtual hosts to

override the main server configuration.</p>

<p>When the request is served by <module>mod_proxy</module>, the

<directive module="mod_proxy" type="section">Proxy</directive>

container takes the place of the <directive module="core"

type="section">Directory</directive> container in the processing

order.</p>

<p>Later sections override earlier ones.</p>

<note><title>Technical Note</title>

There is actually a

<code>&lt;Location&gt;</code>/<code>&lt;LocationMatch&gt;</code>

sequence performed just before the name translation phase

(where <code>Aliases</code> and <code>DocumentRoots</code>

are used to map URLs to filenames). The results of this

sequence are completely thrown away after the translation has

completed.

</note>

<section id="merge-examples"><title>Some Examples</title>

<p>Below is an artificial example to show the order of

merging. Assuming they all apply to the request, the directives in

this example will be applied in the order A &gt; B &gt; C &gt; D &gt;

E.</p>

<example>

&lt;Location /&gt;<br />

E<br />

&lt;/Location&gt;<br />

<br />

&lt;Files f.html&gt;<br />

D<br />

&lt;/Files&gt;<br />

<br />

&lt;VirtualHost *&gt;<br />

&lt;Directory /a/b&gt;<br />

B<br />

&lt;/Directory&gt;<br />

&lt;/VirtualHost&gt;<br />

<br />

&lt;DirectoryMatch "^.*b$"&gt;<br />

C<br />

&lt;/DirectoryMatch&gt;<br />

<br />

&lt;Directory /a/b&gt;<br />

A<br />

&lt;/Directory&gt;<br />

<br />

</example>

<p>For a more concrete example, consider the following. Regardless of

any access restrictions placed in <directive module="core"

type="section">Directory</directive> sections, the <directive

module="core" type="section">Location</directive> section will be

evaluated last and will allow unrestricted access to the server. In

other words, order of merging is important, so be careful!</p>

<example>

&lt;Location /&gt;<br />

Order deny,allow<br />

Allow from all<br />

&lt;/Location&gt;<br />

<br />

# Woops! This &lt;Directory&gt; section will have no effect<br />

&lt;Directory /&gt;<br />

Order allow,deny<br />

Allow from all<br />

Deny from badguy.example.com<br />

&lt;/Directory&gt;

</example>

</section>

</section>

</manualpage>