remapping.xml revision 74c8915fca028fc06596edd7796d2f66c215b109
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<?xml version="1.0" encoding="UTF-8" ?>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<!DOCTYPE manualpage SYSTEM "/style/manualpage.dtd">
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>
6896b3498e144d33f374efe93e6bab2669af535fnd<!-- $LastChangedRevision$ -->
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<!--
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen Licensed to the Apache Software Foundation (ASF) under one or more
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen contributor license agreements. See the NOTICE file distributed with
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen this work for additional information regarding copyright ownership.
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen The ASF licenses this file to You under the Apache License, Version 2.0
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen (the "License"); you may not use this file except in compliance with
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen the License. You may obtain a copy of the License at
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen http://www.apache.org/licenses/LICENSE-2.0
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen Unless required by applicable law or agreed to in writing, software
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen distributed under the License is distributed on an "AS IS" BASIS,
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen See the License for the specific language governing permissions and
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen limitations under the License.
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4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<manualpage metafile="remapping.xml.meta">
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen <parentdocument href="./">Rewrite</parentdocument>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<title>Redirecting and Remapping with mod_rewrite</title>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<summary>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim<p>This document supplements the <module>mod_rewrite</module>
2bb0656f94af82b1ff5e3e77a99b4427c52e4953rbowen<a href="/mod/mod_rewrite.html">reference documentation</a>. It describes
4a1711ab536d965e63d7be80e29f912287fe70b2rbowenhow you can use <module>mod_rewrite</module> to redirect and remap
4a1711ab536d965e63d7be80e29f912287fe70b2rbowenrequest. This includes many examples of common uses of mod_rewrite,
4a1711ab536d965e63d7be80e29f912287fe70b2rbowenincluding detailed descriptions of how each works.</p>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<note type="warning">Note that many of these examples won't work unchanged in your
4a1711ab536d965e63d7be80e29f912287fe70b2rbowenparticular server configuration, so it's important that you understand
4a1711ab536d965e63d7be80e29f912287fe70b2rbowenthem, rather than merely cutting and pasting the examples into your
1a1f0f42c4b3840641897888fec7792af8ba384frbowenconfiguration.</note>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen</summary>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<seealso><a href="/mod/mod_rewrite.html">Module documentation</a></seealso>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen<seealso><a href="intro.html">mod_rewrite introduction</a></seealso>
10705fbc225dcf590c9ba24a4f04de221358060arbowen<!--<seealso><a href="remapping.html">Redirection and remapping</a></seealso>-->
8b79a240383bcecf28b75d4803683a7d101d2713rbowen<seealso><a href="access.html">Controlling access</a></seealso>
10705fbc225dcf590c9ba24a4f04de221358060arbowen<seealso><a href="vhosts.html">Virtual hosts</a></seealso>
10705fbc225dcf590c9ba24a4f04de221358060arbowen<seealso><a href="proxy.html">Proxying</a></seealso>
3723c5ef4beec0403b4daa6c64fc0a8f53541018rbowen<seealso><a href="rewritemap.html">Using RewriteMap</a></seealso>
53abc235688d883cfa15cdfec354ba03128f357arbowen<seealso><a href="advanced.html">Advanced techniques</a></seealso>
8b79a240383bcecf28b75d4803683a7d101d2713rbowen<seealso><a href="avoid.html">When not to use mod_rewrite</a></seealso>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<section id="old-to-new">
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <title>From Old to New (internal)</title>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Description:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>Assume we have recently renamed the page
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <code>foo.html</code> to <code>bar.html</code> and now want
1a1f0f42c4b3840641897888fec7792af8ba384frbowen to provide the old URL for backward compatibility. However,
1a1f0f42c4b3840641897888fec7792af8ba384frbowen we want that users of the old URL even not recognize that
1a1f0f42c4b3840641897888fec7792af8ba384frbowen the pages was renamed - that is, we don't want the address to
1a1f0f42c4b3840641897888fec7792af8ba384frbowen change in their browser.</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Solution:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>We rewrite the old URL to the new one internally via the
1a1f0f42c4b3840641897888fec7792af8ba384frbowen following rule:</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
1a1f0f42c4b3840641897888fec7792af8ba384frbowenRewriteRule ^<strong>/old</strong>\.html$ <strong>/new</strong>.html [PT]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen</section>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<section id="old-to-new-extern">
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <title>Rewriting From Old to New (external)</title>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Description:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>Assume again that we have recently renamed the page
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <code>foo.html</code> to <code>bar.html</code> and now want
1a1f0f42c4b3840641897888fec7792af8ba384frbowen to provide the old URL for backward compatibility. But this
1a1f0f42c4b3840641897888fec7792af8ba384frbowen time we want that the users of the old URL get hinted to
1a1f0f42c4b3840641897888fec7792af8ba384frbowen the new one, i.e. their browsers Location field should
1a1f0f42c4b3840641897888fec7792af8ba384frbowen change, too.</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Solution:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>We force a HTTP redirect to the new URL which leads to a
1a1f0f42c4b3840641897888fec7792af8ba384frbowen change of the browsers and thus the users view:</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
1a1f0f42c4b3840641897888fec7792af8ba384frbowenRewriteRule ^<strong>/foo</strong>\.html$ <strong>bar</strong>.html [<strong>R</strong>]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen</dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<dt>Discussion</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>In this example, as contrasted to the <a
1a1f0f42c4b3840641897888fec7792af8ba384frbowen href="#old-to-new-intern">internal</a> example above, we can simply
1a1f0f42c4b3840641897888fec7792af8ba384frbowen use the Redirect directive. mod_rewrite was used in that earlier
1a1f0f42c4b3840641897888fec7792af8ba384frbowen example in order to hide the redirect from the client:</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
181523b7d40e95e62d1b041846436ce1e7348e88humbedooh <highlight language="config">Redirect /foo.html /bar.html</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen</section>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen<section id="movehomedirs">
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <title>Resource Moved to Another Server</title>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <dl>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <dt>Description:</dt>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <dd>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <p>If a resource has moved to another server, you may wish to have
67398034ea8b919da6274d4e178661559e1eb1e2rbowen URLs continue to work for a time on the old server while people
67398034ea8b919da6274d4e178661559e1eb1e2rbowen update their bookmarks.</p>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen </dd>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <dt>Solution:</dt>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <dd>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen <p>You can use <module>mod_rewrite</module> to redirect these URLs
67398034ea8b919da6274d4e178661559e1eb1e2rbowen to the new server, but you might also consider using the Redirect
67398034ea8b919da6274d4e178661559e1eb1e2rbowen or RedirectMatch directive.</p>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
74c8915fca028fc06596edd7796d2f66c215b109humbedooh<highlight language="config">#With mod_rewrite
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
67398034ea8b919da6274d4e178661559e1eb1e2rbowenRewriteRule ^/docs/(.+) http://new.example.com/docs/$1 [R,L]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
74c8915fca028fc06596edd7796d2f66c215b109humbedooh<highlight language="config">#With RedirectMatch
67398034ea8b919da6274d4e178661559e1eb1e2rbowenRedirectMatch ^/docs/(.*) http://new.example.com/docs/$1
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
74c8915fca028fc06596edd7796d2f66c215b109humbedooh<highlight language="config">#With Redirect
67398034ea8b919da6274d4e178661559e1eb1e2rbowenRedirect /docs/ http://new.example.com/docs/
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen </dd>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen </dl>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
67398034ea8b919da6274d4e178661559e1eb1e2rbowen</section>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<section id="static-to-dynamic">
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <title>From Static to Dynamic</title>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Description:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>How can we transform a static page
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <code>foo.html</code> into a dynamic variant
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <code>foo.cgi</code> in a seamless way, i.e. without notice
1a1f0f42c4b3840641897888fec7792af8ba384frbowen by the browser/user.</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Solution:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>We just rewrite the URL to the CGI-script and force the
1a1f0f42c4b3840641897888fec7792af8ba384frbowen handler to be <strong>cgi-script</strong> so that it is
1a1f0f42c4b3840641897888fec7792af8ba384frbowen executed as a CGI program.
1a1f0f42c4b3840641897888fec7792af8ba384frbowen This way a request to <code>/~quux/foo.html</code>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen internally leads to the invocation of
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <code>/~quux/foo.cgi</code>.</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteBase /~quux/
1a1f0f42c4b3840641897888fec7792af8ba384frbowenRewriteRule ^foo\.<strong>html</strong>$ foo.<strong>cgi</strong> [H=<strong>cgi-script</strong>]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen</section>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen<section id="backward-compatibility">
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <title>Backward Compatibility for file extension change</title>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dl>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dt>Description:</dt>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <p>How can we make URLs backward compatible (still
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen existing virtually) after migrating <code>document.YYYY</code>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen to <code>document.XXXX</code>, e.g. after translating a
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen bunch of <code>.html</code> files to <code>.php</code>?</p>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dt>Solution:</dt>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <p>We rewrite the name to its basename and test for
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen existence of the new extension. If it exists, we take
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen that name, else we rewrite the URL to its original state.</p>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# backward compatibility ruleset for
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# rewriting document.html to document.php
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# when and only when document.php exists
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;Directory /var/www/htdocs&gt;
181523b7d40e95e62d1b041846436ce1e7348e88humbedooh RewriteEngine on
181523b7d40e95e62d1b041846436ce1e7348e88humbedooh RewriteBase /var/www/htdocs
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
181523b7d40e95e62d1b041846436ce1e7348e88humbedooh RewriteCond $1.php -f
181523b7d40e95e62d1b041846436ce1e7348e88humbedooh RewriteCond $1.html !-f
181523b7d40e95e62d1b041846436ce1e7348e88humbedooh RewriteRule ^(.*).html$ $1.php
67398034ea8b919da6274d4e178661559e1eb1e2rbowen&lt;/Directory&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dt>Discussion</dt>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <p>This example uses an often-overlooked feature of mod_rewrite,
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen by taking advantage of the order of execution of the ruleset. In
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen particular, mod_rewrite evaluates the left-hand-side of the
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen RewriteRule before it evaluates the RewriteCond directives.
0464ea692a2abb32bccd571ee98ddbd43dad4ffbrbowen Consequently, $1 is already defined by the time the RewriteCond
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen directives are evaluated. This allows us to test for the existence
48193e92704a478a74d9065fc32874505847bfd9lgentis of the original (<code>document.html</code>) and target
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen (<code>document.php</code>) files using the same base filename.</p>
67398034ea8b919da6274d4e178661559e1eb1e2rbowen
73036acae345bfcd48167c09e7ee2f0f0a19df8arbowen <p>This ruleset is designed to use in a per-directory context (In a
73036acae345bfcd48167c09e7ee2f0f0a19df8arbowen &lt;Directory&gt; block or in a .htaccess file), so that the
73036acae345bfcd48167c09e7ee2f0f0a19df8arbowen <code>-f</code> checks are looking at the correct directory path.
73036acae345bfcd48167c09e7ee2f0f0a19df8arbowen You may need to set a <directive
be882eb3b57b3e6d2995f7a9aea610eefb92d836rbowen module="mod_rewrite">RewriteBase</directive> directive to specify the
73036acae345bfcd48167c09e7ee2f0f0a19df8arbowen directory base that you're working in.</p>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dl>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen</section>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
43289eb78809cbdec92c7d90433a8852233f0b2brbowen<section id="canonicalhost">
43289eb78809cbdec92c7d90433a8852233f0b2brbowen
43289eb78809cbdec92c7d90433a8852233f0b2brbowen<title>Canonical Hostnames</title>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Description:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>The goal of this rule is to force the use of a particular
1a1f0f42c4b3840641897888fec7792af8ba384frbowen hostname, in preference to other hostnames which may be used to
1a1f0f42c4b3840641897888fec7792af8ba384frbowen reach the same site. For example, if you wish to force the use
1a1f0f42c4b3840641897888fec7792af8ba384frbowen of <strong>www.example.com</strong> instead of
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <strong>example.com</strong>, you might use a variant of the
1a1f0f42c4b3840641897888fec7792af8ba384frbowen following recipe.</dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dt>Solution:</dt>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <dd>
a58ef077d369c62da387d53516fc389cdb5c313arbowen
a58ef077d369c62da387d53516fc389cdb5c313arbowen<p>The very best way to solve this doesn't involve mod_rewrite at all,
be882eb3b57b3e6d2995f7a9aea610eefb92d836rbowenbut rather uses the <directive module="mod_alias">Redirect</directive>
59d2c89abd6eaaac4fbb9b7af6b164c3d083f11crbowendirective placed in a virtual host for the non-canonical
a58ef077d369c62da387d53516fc389cdb5c313arbowenhostname(s).</p>
a58ef077d369c62da387d53516fc389cdb5c313arbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;VirtualHost *:80&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh ServerName undesired.example.com
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh ServerAlias example.com notthis.example.com
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh Redirect / http://www.example.com/
a58ef077d369c62da387d53516fc389cdb5c313arbowen&lt;/VirtualHost&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;VirtualHost *:80&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh ServerName www.example.com
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;/VirtualHost&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
a58ef077d369c62da387d53516fc389cdb5c313arbowen
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim<p>You can alternatively accomplish this using the
97aaaf4db69986e48302566b12ceef65380647carbowen<directive module="core" type="section">If</directive>
97aaaf4db69986e48302566b12ceef65380647carbowendirective:</p>
97aaaf4db69986e48302566b12ceef65380647carbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;If "%{HTTP_HOST} != 'www.example.com'"&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh Redirect / http://www.example.com/
97aaaf4db69986e48302566b12ceef65380647carbowen&lt;/If&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
97aaaf4db69986e48302566b12ceef65380647carbowen
97aaaf4db69986e48302566b12ceef65380647carbowen<p>Or, for example, to redirect a portion of your site to HTTPS, you
97aaaf4db69986e48302566b12ceef65380647carbowenmight do the following:</p>
97aaaf4db69986e48302566b12ceef65380647carbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;If "%{SERVER_PROTOCOL} != 'HTTPS'"&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh Redirect /admin/ https://www.example.com/admin/
97aaaf4db69986e48302566b12ceef65380647carbowen&lt;/If&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
97aaaf4db69986e48302566b12ceef65380647carbowen
97aaaf4db69986e48302566b12ceef65380647carbowen<p>If, for whatever reason, you still want to use <code>mod_rewrite</code>
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim- if, for example, you need this to work with a larger set of RewriteRules -
97aaaf4db69986e48302566b12ceef65380647carbowenyou might use one of the recipes below.</p>
a58ef077d369c62da387d53516fc389cdb5c313arbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<p>For sites running on a port other than 80:</p>
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_HOST} !^www\.example\.com [NC]
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_HOST} !^$
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{SERVER_PORT} !^80$
1a1f0f42c4b3840641897888fec7792af8ba384frbowenRewriteRule ^/?(.*) http://www.example.com:%{SERVER_PORT}/$1 [L,R,NE]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen<p>And for a site running on port 80</p>
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_HOST} !^www\.example\.com [NC]
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_HOST} !^$
1a1f0f42c4b3840641897888fec7792af8ba384frbowenRewriteRule ^/?(.*) http://www.example.com/$1 [L,R,NE]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen If you wanted to do this generically for all domain names - that
1a1f0f42c4b3840641897888fec7792af8ba384frbowen is, if you want to redirect <strong>example.com</strong> to
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <strong>www.example.com</strong> for all possible values of
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <strong>example.com</strong>, you could use the following
1a1f0f42c4b3840641897888fec7792af8ba384frbowen recipe:</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_HOST} !^www\. [NC]
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_HOST} !^$
1a1f0f42c4b3840641897888fec7792af8ba384frbowenRewriteRule ^/?(.*) http://www.%{HTTP_HOST}/$1 [L,R,NE]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
1a1f0f42c4b3840641897888fec7792af8ba384frbowen <p>These rulesets will work either in your main server configuration
1a1f0f42c4b3840641897888fec7792af8ba384frbowen file, or in a <code>.htaccess</code> file placed in the <directive
1a1f0f42c4b3840641897888fec7792af8ba384frbowen module="core">DocumentRoot</directive> of the server.</p>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dd>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen </dl>
1a1f0f42c4b3840641897888fec7792af8ba384frbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen</section>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen<section id="multipledirs">
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <title>Search for pages in more than one directory</title>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dl>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dt>Description:</dt>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <p>A particular resource might exist in one of several places, and
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen we want to look in those places for the resource when it is
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen requested. Perhaps we've recently rearranged our directory
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen structure, dividing content into several locations.</p>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dt>Solution:</dt>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen <p>The following ruleset searches in two directories to find the
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen resource, and, if not finding it in either place, will attempt to
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen just serve it out of the location requested.</p>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# first try to find it in dir1/...
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# ...and if found stop and be happy:
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{DOCUMENT_ROOT}/<strong>dir1</strong>/%{REQUEST_URI} -f
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteRule ^(.+) %{DOCUMENT_ROOT}/<strong>dir1</strong>/$1 [L]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# second try to find it in dir2/...
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# ...and if found stop and be happy:
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{DOCUMENT_ROOT}/<strong>dir2</strong>/%{REQUEST_URI} -f
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteRule ^(.+) %{DOCUMENT_ROOT}/<strong>dir2</strong>/$1 [L]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# else go on for other Alias or ScriptAlias directives,
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh# etc.
3fba18303c1f1e90cd0f9348045283250ce448f1rbowenRewriteRule ^ - [PT]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dd>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen </dl>
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen
13e125c14cbafff43783b7f3aed11de6d4cb5b14rbowen</section>
4a1711ab536d965e63d7be80e29f912287fe70b2rbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen<section id="archive-access-multiplexer">
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <title>Redirecting to Geographically Distributed Servers</title>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dl>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dt>Description:</dt>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dd>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <p>We have numerous mirrors of our website, and want to redirect
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen people to the one that is located in the country where they are
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen located.</p>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen </dd>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dt>Solution:</dt>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dd>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <p>Looking at the hostname of the requesting client, we determine
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen which country they are coming from. If we can't do a lookup on their
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen IP address, we fall back to a default server.</p>
48193e92704a478a74d9065fc32874505847bfd9lgentis <p>We'll use a <directive module="mod_rewrite">RewriteMap</directive>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen directive to build a list of servers that we wish to use.</p>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohHostnameLookups on
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteMap multiplex txt:/path/to/map.mirrors
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{REMOTE_HOST} ([a-z]+)$ [NC]
4634fe331f9689ad14057c5ca77d285b50ce08c4rbowenRewriteRule ^/(.*)$ ${multiplex:<strong>%1</strong>|http://www.example.com/}$1 [R,L]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
bdf760e4562a3fb875452418faf0fcd3680184d8rbowen<example>
bdf760e4562a3fb875452418faf0fcd3680184d8rbowen## map.mirrors -- Multiplexing Map<br />
bdf760e4562a3fb875452418faf0fcd3680184d8rbowen<br />
bdf760e4562a3fb875452418faf0fcd3680184d8rbowende http://www.example.de/<br />
bdf760e4562a3fb875452418faf0fcd3680184d8rbowenuk http://www.example.uk/<br />
bdf760e4562a3fb875452418faf0fcd3680184d8rbowencom http://www.example.com/<br />
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen##EOF##
bdf760e4562a3fb875452418faf0fcd3680184d8rbowen</example>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen </dd>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dt>Discussion</dt>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <dd>
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim <note type="warning">This ruleset relies on
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim <directive module="core">HostNameLookups</directive>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen being set <code>on</code>, which can be
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen a significant performance hit.</note>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen <p>The <directive module="mod_rewrite">RewriteCond</directive>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen directive captures the last portion of the hostname of the
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen requesting client - the country code - and the following RewriteRule
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen uses that value to look up the appropriate mirror host in the map
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen file.</p>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen </dd>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen </dl>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen</section>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen<section id="browser-dependent-content">
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <title>Browser Dependent Content</title>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <dl>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <dt>Description:</dt>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <dd>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <p>We wish to provide different content based on the browser, or
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen user-agent, which is requesting the content.</p>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen </dd>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <dt>Solution:</dt>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <dd>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen <p>We have to decide, based on the HTTP header "User-Agent",
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen which content to serve. The following config
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen does the following: If the HTTP header "User-Agent"
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen contains "Mozilla/3", the page <code>foo.html</code>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen is rewritten to <code>foo.NS.html</code> and the
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen rewriting stops. If the browser is "Lynx" or "Mozilla" of
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen version 1 or 2, the URL becomes <code>foo.20.html</code>.
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen All other browsers receive page <code>foo.32.html</code>.
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen This is done with the following ruleset:</p>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_USER_AGENT} ^<strong>Mozilla/3</strong>.*
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteRule ^foo\.html$ foo.<strong>NS</strong>.html [<strong>L</strong>]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_USER_AGENT} ^<strong>Lynx/</strong> [OR]
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteCond %{HTTP_USER_AGENT} ^<strong>Mozilla/[12]</strong>
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteRule ^foo\.html$ foo.<strong>20</strong>.html [<strong>L</strong>]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowenRewriteRule ^foo\.html$ foo.<strong>32</strong>.html [<strong>L</strong>]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen </dd>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen </dl>
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen
32e1018ca3ab0e0bd089fd38ce8d97bb7a607639rbowen</section>
aa3ddf73a3cb180f88a18742f363f2cb9a0c5cderbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen<section id="canonicalurl">
856d8f134df3b2d23a76717121e042877f85ae3brbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen<title>Canonical URLs</title>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen<dl>
856d8f134df3b2d23a76717121e042877f85ae3brbowen <dt>Description:</dt>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen <dd>
856d8f134df3b2d23a76717121e042877f85ae3brbowen <p>On some webservers there is more than one URL for a
856d8f134df3b2d23a76717121e042877f85ae3brbowen resource. Usually there are canonical URLs (which are be
856d8f134df3b2d23a76717121e042877f85ae3brbowen actually used and distributed) and those which are just
856d8f134df3b2d23a76717121e042877f85ae3brbowen shortcuts, internal ones, and so on. Independent of which URL the
856d8f134df3b2d23a76717121e042877f85ae3brbowen user supplied with the request, they should finally see the
856d8f134df3b2d23a76717121e042877f85ae3brbowen canonical one in their browser address bar.</p>
856d8f134df3b2d23a76717121e042877f85ae3brbowen </dd>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen <dt>Solution:</dt>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen <dd>
856d8f134df3b2d23a76717121e042877f85ae3brbowen <p>We do an external HTTP redirect for all non-canonical
856d8f134df3b2d23a76717121e042877f85ae3brbowen URLs to fix them in the location view of the Browser and
856d8f134df3b2d23a76717121e042877f85ae3brbowen for all subsequent requests. In the example ruleset below
856d8f134df3b2d23a76717121e042877f85ae3brbowen we replace <code>/puppies</code> and <code>/canines</code>
856d8f134df3b2d23a76717121e042877f85ae3brbowen by the canonical <code>/dogs</code>.</p>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">RewriteRule ^/(puppies|canines)/(.*) /dogs/$2 [R]</highlight>
856d8f134df3b2d23a76717121e042877f85ae3brbowen </dd>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
856d8f134df3b2d23a76717121e042877f85ae3brbowen <dt>Discussion:</dt>
856d8f134df3b2d23a76717121e042877f85ae3brbowen <dd>
856d8f134df3b2d23a76717121e042877f85ae3brbowen This should really be accomplished with Redirect or RedirectMatch
856d8f134df3b2d23a76717121e042877f85ae3brbowen directives:
856d8f134df3b2d23a76717121e042877f85ae3brbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh <highlight language="config"> RedirectMatch ^/(puppies|canines)/(.*) /dogs/$2 </highlight>
856d8f134df3b2d23a76717121e042877f85ae3brbowen </dd>
856d8f134df3b2d23a76717121e042877f85ae3brbowen </dl>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
331e7d505cac0db96920e7177d6f476bc4986341rbowen</section>
331e7d505cac0db96920e7177d6f476bc4986341rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen<section id="moveddocroot">
331e7d505cac0db96920e7177d6f476bc4986341rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen <title>Moved <code>DocumentRoot</code></title>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen <dl>
9e4b928f0fa926f7d86413e5043993547df97753rbowen <dt>Description:</dt>
9e4b928f0fa926f7d86413e5043993547df97753rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen <dd>
9e4b928f0fa926f7d86413e5043993547df97753rbowen<p>Usually the <directive module="core">DocumentRoot</directive>
9e4b928f0fa926f7d86413e5043993547df97753rbowenof the webserver directly relates to the URL "<code>/</code>".
9e4b928f0fa926f7d86413e5043993547df97753rbowenBut often this data is not really of top-level priority. For example,
9e4b928f0fa926f7d86413e5043993547df97753rbowenyou may wish for visitors, on first entering a site, to go to a
9e4b928f0fa926f7d86413e5043993547df97753rbowenparticular subdirectory <code>/about/</code>. This may be accomplished
9e4b928f0fa926f7d86413e5043993547df97753rbowenusing the following ruleset:</p>
9e4b928f0fa926f7d86413e5043993547df97753rbowen</dd>
9e4b928f0fa926f7d86413e5043993547df97753rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen <dt>Solution:</dt>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen <dd>
9e4b928f0fa926f7d86413e5043993547df97753rbowen <p>We redirect the URL <code>/</code> to
9e4b928f0fa926f7d86413e5043993547df97753rbowen <code>/about/</code>:
9e4b928f0fa926f7d86413e5043993547df97753rbowen </p>
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedoohRewriteEngine on
9e4b928f0fa926f7d86413e5043993547df97753rbowenRewriteRule <strong>^/$</strong> /about/ [<strong>R</strong>]
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
9e4b928f0fa926f7d86413e5043993547df97753rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen<p>Note that this can also be handled using the <directive
9e4b928f0fa926f7d86413e5043993547df97753rbowenmodule="mod_alias">RedirectMatch</directive> directive:</p>
9e4b928f0fa926f7d86413e5043993547df97753rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">RedirectMatch ^/$ http://example.com/about/</highlight>
9e4b928f0fa926f7d86413e5043993547df97753rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen<p>Note also that the example rewrites only the root URL. That is, it
9e4b928f0fa926f7d86413e5043993547df97753rbowenrewrites a request for <code>http://example.com/</code>, but not a
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jimrequest for <code>http://example.com/page.html</code>. If you have in
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jimfact changed your document root - that is, if <strong>all</strong> of
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jimyour content is in fact in that subdirectory, it is greatly preferable
9e4b928f0fa926f7d86413e5043993547df97753rbowento simply change your <directive module="core">DocumentRoot</directive>
9e4b928f0fa926f7d86413e5043993547df97753rbowendirective, or move all of the content up one directory,
9e4b928f0fa926f7d86413e5043993547df97753rbowenrather than rewriting URLs.</p>
9e4b928f0fa926f7d86413e5043993547df97753rbowen</dd>
9e4b928f0fa926f7d86413e5043993547df97753rbowen</dl>
9e4b928f0fa926f7d86413e5043993547df97753rbowen
9e4b928f0fa926f7d86413e5043993547df97753rbowen</section>
856d8f134df3b2d23a76717121e042877f85ae3brbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<section id="fallback-resource">
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<title>Fallback Resource</title>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<dl>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<dt>Description:</dt>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<dd>You want a single resource (say, a certain file, like index.php) to
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowenhandle all requests that come to a particular directory, except those
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowenthat should go to an existing resource such as an image, or a css file.</dd>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<dt>Solution:</dt>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<dd>
0f2508167dcce6e6221f1fd27698a4f11cdfd9f5igalic<p>As of version 2.2.16, you should use the <directive
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowenmodule="mod_dir">FallbackResource</directive> directive for this:</p>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;Directory /var/www/my_blog&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh FallbackResource index.php
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen&lt;/Directory&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<p>However, in earlier versions of Apache, or if your needs are more
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowencomplicated than this, you can use a variation of the following rewrite
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowenset to accomplish the same thing:</p>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh&lt;Directory /var/www/my_blog&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh RewriteBase /my_blog
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh RewriteCond /var/www/my_blog/%{REQUEST_FILENAME} !-f
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh RewriteCond /var/www/my_blog/%{REQUEST_FILENAME} !-d
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh RewriteRule ^ index.php [PT]
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen&lt;/Directory&gt;
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh</highlight>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen<p>If, on the other hand, you wish to pass the requested URI as a query
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowenstring argument to index.php, you can replace that RewriteRule with:</p>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
0a0fd048f54df3e9053942466292da579524c1fdhumbedooh<highlight language="config">RewriteRule (.*) index.php?$1 [PT,QSA]</highlight>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
9d7ecbe91ba405b87f677ec1e322b8e92533172cigalic<p>Note that these rulesets can be used in a <code>.htaccess</code>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowenfile, as well as in a &lt;Directory&gt; block.</p>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen</dd>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen</dl>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen</section>
8ecfbb3fce5da653749fdc9d97dc6561d4c32ef4rbowen
860b4efe27e7c1c9a2bf5c872b29c90f76849b51jim</manualpage>