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<title>How Directory, Location and Files sections work</title>
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<h1 ALIGN="CENTER">How Directory, Location and Files sections work</h1>
The sections <a
directives which only apply to specified directories, URLs or files
respectively. Also htaccess files can be used inside a directory to
apply directives to that directory. This document explains how these
different sections differ and how they relate to each other when
Apache decides which directives apply for a particular directory or
request URL.
<h2>Directives allowed in the sections</h2>
Everything that is syntactically allowed in
<code><Directory></code> is also allowed in
<code><Location></code> (except a sub-<code><Files></code>
section, but the code doesn't test for that, Lars has an open bug
report on that). Semantically however some things, and the most
notable is AllowOverrides, make no sense in
<code><Location></code>. The same for
<code><Files></code> -- syntactically everything is fine, but
semantically some things are different.
<h2>How the sections are merged</h2>
The order of merging is:
<ol>
<li>
<code><Directory></code> (except regular expressions) and
.htaccess done simultaneously (with .htaccess overriding
<code><Directory></code>)
</li>
<li>
<code><DirectoryMatch></code>, and
<code><Directory></code> with regular expressions
</li>
<li><code><Files></code> and <code><FilesMatch></code> done simultaneously
</li>
<li><code><Location></code> and <code><LocationMatch></code> done simultaneously
</li>
</ol>
Apart from <code><Directory></code>, each group is processed in
the order that they appear in the configuration
files. <code><Directory></code> (group 1 above) is processed in
the order shortest directory component to longest. If multiple
<code><Directory></code> sections apply to the same directory
they they are processed in the configuration file order. The
configuration files are read in the order httpd.conf, srm.conf and
directive will be treated as if they where inside the including file
at the location of the <code>Include</code> directive.
<p>
Sections inside <code><VirtualHost></code> sections are applied
<i>after</i> the corresponding sections outside the virtual host
definition. This allows virtual hosts to override the main server
configuration. (Note: this only works correctly from 1.2.2 and 1.3a2
onwards. Before those releases sections inside virtual hosts were
applied <i>before</i> the main server).
<h2>Notes about using sections</h2>
The general guidelines are:
<p>
<ul>
<li>
If you are attempting to match objects at the filesystem level
<code><Files></code>.
</li>
<li>
If you are attempting to match objects at the URL level then you
must use <code><Location></code>
</li>
</ul>
But a notable exception is:
<ul>
<li>
proxy control is done via <code><Directory></code>. This is
a legacy mistake because the proxy existed prior to
<code><Location></code>. A future version of the config
language should probably switch this to
<code><Location></code>.
</li>
</ul>
Note also that modifying .htaccess parsing during Location doesn't do
anything because .htaccess parsing has already occured.
<p>
Another note:
<p>
<ul>
<li>
There is actually a
<code><Location></code>/<code><LocationMatch></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.
</li>
</ul>
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