mirror of
				https://github.com/apache/httpd.git
				synced 2025-11-03 17:53:20 +03:00 
			
		
		
		
	git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1300919 13f79535-47bb-0310-9956-ffa450edef68
		
			
				
	
	
		
			646 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
			
		
		
	
	
			646 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
<?xml version="1.0" encoding="ISO-8859-1"?>
 | 
						|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 | 
						|
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
 | 
						|
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 | 
						|
              This file is generated from xml source: DO NOT EDIT
 | 
						|
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 | 
						|
      -->
 | 
						|
<title>Redirecting and Remapping with mod_rewrite - Apache HTTP Server</title>
 | 
						|
<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
 | 
						|
<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
 | 
						|
<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
 | 
						|
<link href="../images/favicon.ico" rel="shortcut icon" /></head>
 | 
						|
<body id="manual-page"><div id="page-header">
 | 
						|
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
 | 
						|
<p class="apache">Apache HTTP Server Version 2.5</p>
 | 
						|
<img alt="" src="../images/feather.gif" /></div>
 | 
						|
<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
 | 
						|
<div id="path">
 | 
						|
<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.5</a> > <a href="./">Rewrite</a></div><div id="page-content"><div id="preamble"><h1>Redirecting and Remapping with mod_rewrite</h1>
 | 
						|
<div class="toplang">
 | 
						|
<p><span>Available Languages: </span><a href="../en/rewrite/remapping.html" title="English"> en </a></p>
 | 
						|
</div>
 | 
						|
 | 
						|
 | 
						|
<p>This document supplements the <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
 | 
						|
<a href="../mod/mod_rewrite.html">reference documentation</a>. It describes
 | 
						|
how you can use <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> to redirect and remap
 | 
						|
request. This includes many examples of common uses of mod_rewrite,
 | 
						|
including detailed descriptions of how each works.</p>
 | 
						|
 | 
						|
<div class="warning">Note that many of these examples won't work unchanged in your
 | 
						|
particular server configuration, so it's important that you understand
 | 
						|
them, rather than merely cutting and pasting the examples into your
 | 
						|
configuration.</div>
 | 
						|
 | 
						|
</div>
 | 
						|
<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#old-to-new">From Old to New (internal)</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#old-to-new-extern">Rewriting From Old to New (external)</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#movehomedirs">Resource Moved to Another Server</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#static-to-dynamic">From Static to Dynamic</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#backward-compatibility">Backward Compatibility for file extension change</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#canonicalhost">Canonical Hostnames</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#multipledirs">Search for pages in more than one directory</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#archive-access-multiplexer">Redirecting to Geographically Distributed Servers</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#browser-dependent-content">Browser Dependent Content</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#canonicalurl">Canonical URLs</a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#moveddocroot">Moved <code>DocumentRoot</code></a></li>
 | 
						|
<li><img alt="" src="../images/down.gif" /> <a href="#fallback-resource">Fallback Resource</a></li>
 | 
						|
</ul><h3>See also</h3><ul class="seealso"><li><a href="../mod/mod_rewrite.html">Module documentation</a></li><li><a href="intro.html">mod_rewrite introduction</a></li><li><a href="access.html">Controlling access</a></li><li><a href="vhosts.html">Virtual hosts</a></li><li><a href="proxy.html">Proxying</a></li><li><a href="rewritemap.html">Using RewriteMap</a></li><li><a href="advanced.html">Advanced techniques</a></li><li><a href="avoid.html">When not to use mod_rewrite</a></li></ul></div>
 | 
						|
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="old-to-new" id="old-to-new">From Old to New (internal)</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>Assume we have recently renamed the page
 | 
						|
      <code>foo.html</code> to <code>bar.html</code> and now want
 | 
						|
      to provide the old URL for backward compatibility. However,
 | 
						|
      we want that users of the old URL even not recognize that
 | 
						|
      the pages was renamed - that is, we don't want the address to
 | 
						|
      change in their browser.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We rewrite the old URL to the new one internally via the
 | 
						|
      following rule:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteEngine  on<br />
 | 
						|
RewriteRule    ^<strong>/old</strong>\.html$  <strong>/new</strong>.html [PT]
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="old-to-new-extern" id="old-to-new-extern">Rewriting From Old to New (external)</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>Assume again that we have recently renamed the page
 | 
						|
      <code>foo.html</code> to <code>bar.html</code> and now want
 | 
						|
      to provide the old URL for backward compatibility. But this
 | 
						|
      time we want that the users of the old URL get hinted to
 | 
						|
      the new one, i.e. their browsers Location field should
 | 
						|
      change, too.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We force a HTTP redirect to the new URL which leads to a
 | 
						|
      change of the browsers and thus the users view:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteEngine  on<br />
 | 
						|
RewriteRule    ^<strong>/foo</strong>\.html$  <strong>bar</strong>.html  [<strong>R</strong>]
 | 
						|
</code></p></div>
 | 
						|
</dd>
 | 
						|
 | 
						|
<dt>Discussion</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
    <p>In this example, as contrasted to the <a href="#old-to-new-intern">internal</a> example above, we can simply
 | 
						|
    use the Redirect directive. mod_rewrite was used in that earlier
 | 
						|
    example in order to hide the redirect from the client:</p>
 | 
						|
 | 
						|
    <div class="example"><p><code>
 | 
						|
    Redirect /foo.html /bar.html
 | 
						|
    </code></p></div>
 | 
						|
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="movehomedirs" id="movehomedirs">Resource Moved to Another Server</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>If a resource has moved to another server, you may wish to have
 | 
						|
      URLs continue to work for a time on the old server while people
 | 
						|
      update their bookmarks.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>You can use <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> to redirect these URLs
 | 
						|
      to the new server, but you might also consider using the Redirect
 | 
						|
      or RedirectMatch directive.</p>
 | 
						|
 | 
						|
<div class="example"><h3>With mod_rewrite</h3><p><code>
 | 
						|
RewriteEngine on<br />
 | 
						|
RewriteRule   ^/docs/(.+)  http://new.example.com/docs/$1  [R,L]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<div class="example"><h3>With RedirectMatch</h3><p><code>
 | 
						|
RedirectMatch ^/docs/(.*) http://new.example.com/docs/$1
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<div class="example"><h3>With Redirect</h3><p><code>
 | 
						|
Redirect /docs/ http://new.example.com/docs/
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="static-to-dynamic" id="static-to-dynamic">From Static to Dynamic</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>How can we transform a static page
 | 
						|
      <code>foo.html</code> into a dynamic variant
 | 
						|
      <code>foo.cgi</code> in a seamless way, i.e. without notice
 | 
						|
      by the browser/user.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We just rewrite the URL to the CGI-script and force the
 | 
						|
      handler to be <strong>cgi-script</strong> so that it is
 | 
						|
      executed as a CGI program.
 | 
						|
      This way a request to <code>/~quux/foo.html</code>
 | 
						|
      internally leads to the invocation of
 | 
						|
      <code>/~quux/foo.cgi</code>.</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteEngine  on<br />
 | 
						|
RewriteBase    /~quux/<br />
 | 
						|
RewriteRule    ^foo\.<strong>html</strong>$  foo.<strong>cgi</strong>  [H=<strong>cgi-script</strong>]
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="backward-compatibility" id="backward-compatibility">Backward Compatibility for file extension change</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>How can we make URLs backward compatible (still
 | 
						|
      existing virtually) after migrating <code>document.YYYY</code>
 | 
						|
      to <code>document.XXXX</code>, e.g. after translating a
 | 
						|
      bunch of <code>.html</code> files to <code>.php</code>?</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We rewrite the name to its basename and test for
 | 
						|
      existence of the new extension. If it exists, we take
 | 
						|
      that name, else we rewrite the URL to its original state.</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
#   backward compatibility ruleset for<br />
 | 
						|
#   rewriting document.html to document.php<br />
 | 
						|
#   when and only when document.php exists<br />
 | 
						|
<Directory /var/www/htdocs><br />
 | 
						|
<span class="indent">
 | 
						|
RewriteEngine on<br />
 | 
						|
RewriteBase /var/www/htdocs<br />
 | 
						|
<br />
 | 
						|
RewriteCond $1.php -f<br />
 | 
						|
RewriteCond $1.html !-f<br />
 | 
						|
RewriteRule ^(.*).html$ $1.php<br />
 | 
						|
</span>
 | 
						|
</Directory>
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Discussion</dt>
 | 
						|
    <dd>
 | 
						|
    <p>This example uses an often-overlooked feature of mod_rewrite,
 | 
						|
    by taking advantage of the order of execution of the ruleset. In
 | 
						|
    particular, mod_rewrite evaluates the left-hand-side of the
 | 
						|
    RewriteRule before it evaluates the RewriteCond directives.
 | 
						|
    Consequently, $1 is already defined by the time the RewriteCond
 | 
						|
    directives are evaluated. This allows us to test for the existence
 | 
						|
    of the original (<code>document.html</code>) and target
 | 
						|
    (<code>document.php</code>) files using the same base filename.</p>
 | 
						|
 | 
						|
    <p>This ruleset is designed to use in a per-directory context (In a
 | 
						|
    <Directory> block or in a .htaccess file), so that the
 | 
						|
    <code>-f</code> checks are looking at the correct directory path.
 | 
						|
    You may need to set a <code class="directive"><a href="../mod/mod_rewrite.html#rewritebase">RewriteBase</a></code> directive to specify the
 | 
						|
    directory base that you're working in.</p>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="canonicalhost" id="canonicalhost">Canonical Hostnames</a></h2>
 | 
						|
 | 
						|
 | 
						|
 | 
						|
      <dl>
 | 
						|
        <dt>Description:</dt>
 | 
						|
 | 
						|
        <dd>The goal of this rule is to force the use of a particular
 | 
						|
        hostname, in preference to other hostnames which may be used to
 | 
						|
        reach the same site. For example, if you wish to force the use
 | 
						|
        of <strong>www.example.com</strong> instead of
 | 
						|
        <strong>example.com</strong>, you might use a variant of the
 | 
						|
        following recipe.</dd>
 | 
						|
 | 
						|
        <dt>Solution:</dt>
 | 
						|
 | 
						|
        <dd>
 | 
						|
 | 
						|
<p>The very best way to solve this doesn't involve mod_rewrite at all,
 | 
						|
but rather uses the <code class="directive"><a href="../mod/mod_alias.html#redirect">Redirect</a></code>
 | 
						|
directive placed in a virtual host for the non-canonical
 | 
						|
hostname(s).</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
<VirtualHost *:80><br />
 | 
						|
<span class="indent">
 | 
						|
  ServerName undesired.example.com<br />
 | 
						|
  ServerAlias example.com notthis.example.com<br />
 | 
						|
<br />
 | 
						|
  Redirect / http://www.example.com/<br />
 | 
						|
</span>
 | 
						|
</VirtualHost><br />
 | 
						|
<br />
 | 
						|
<VirtualHost *:80><br />
 | 
						|
<span class="indent">
 | 
						|
  ServerName www.example.com<br />
 | 
						|
</span>
 | 
						|
</VirtualHost>
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>You can alternatively accomplish this using the
 | 
						|
<code class="directive"><a href="../mod/core.html#if"><If></a></code>
 | 
						|
directive:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
<If "%{HTTP_HOST} != 'www.example.com'"><br />
 | 
						|
<span class="indent">
 | 
						|
Redirect / http://www.example.com/
 | 
						|
</span>
 | 
						|
</If>
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>Or, for example, to redirect a portion of your site to HTTPS, you
 | 
						|
might do the following:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
<If "%{SERVER_PROTOCOL} != 'HTTPS'"><br />
 | 
						|
<span class="indent">
 | 
						|
Redirect /admin/ https://www.example.com/admin/
 | 
						|
</span>
 | 
						|
</If>
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>If, for whatever reason, you still want to use <code>mod_rewrite</code>
 | 
						|
- if, for example, you need this to work with a larger set of RewriteRules -
 | 
						|
you might use one of the recipes below.</p>
 | 
						|
 | 
						|
<p>For sites running on a port other than 80:</p>
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteCond %{HTTP_HOST}   !^www\.example\.com [NC]<br />
 | 
						|
RewriteCond %{HTTP_HOST}   !^$<br />
 | 
						|
RewriteCond %{SERVER_PORT} !^80$<br />
 | 
						|
RewriteRule ^/?(.*)         http://www.example.com:%{SERVER_PORT}/$1 [L,R,NE]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>And for a site running on port 80</p>
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteCond %{HTTP_HOST}   !^www\.example\.com [NC]<br />
 | 
						|
RewriteCond %{HTTP_HOST}   !^$<br />
 | 
						|
RewriteRule ^/?(.*)         http://www.example.com/$1 [L,R,NE]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
        <p>
 | 
						|
        If you wanted to do this generically for all domain names - that
 | 
						|
        is, if you want to redirect <strong>example.com</strong> to
 | 
						|
        <strong>www.example.com</strong> for all possible values of
 | 
						|
        <strong>example.com</strong>, you could use the following
 | 
						|
        recipe:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteCond %{HTTP_HOST} !^www\. [NC]<br />
 | 
						|
RewriteCond %{HTTP_HOST} !^$<br />
 | 
						|
RewriteRule ^/?(.*) http://www.%{HTTP_HOST}/$1 [L,R,NE]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
    <p>These rulesets will work either in your main server configuration
 | 
						|
    file, or in a <code>.htaccess</code> file placed in the <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code> of the server.</p>
 | 
						|
        </dd>
 | 
						|
      </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="multipledirs" id="multipledirs">Search for pages in more than one directory</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>A particular resource might exist in one of several places, and
 | 
						|
      we want to look in those places for the resource when it is
 | 
						|
      requested. Perhaps we've recently rearranged our directory
 | 
						|
      structure, dividing content into several locations.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>The following ruleset searches in two directories to find the
 | 
						|
      resource, and, if not finding it in either place, will attempt to
 | 
						|
      just serve it out of the location requested.</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteEngine on<br />
 | 
						|
<br />
 | 
						|
#   first try to find it in dir1/...<br />
 | 
						|
#   ...and if found stop and be happy:<br />
 | 
						|
RewriteCond         %{DOCUMENT_ROOT}/<strong>dir1</strong>/%{REQUEST_URI}  -f<br />
 | 
						|
RewriteRule  ^(.+)  %{DOCUMENT_ROOT}/<strong>dir1</strong>/$1  [L]<br />
 | 
						|
<br />
 | 
						|
#   second try to find it in dir2/...<br />
 | 
						|
#   ...and if found stop and be happy:<br />
 | 
						|
RewriteCond         %{DOCUMENT_ROOT}/<strong>dir2</strong>/%{REQUEST_URI}  -f<br />
 | 
						|
RewriteRule  ^(.+)  %{DOCUMENT_ROOT}/<strong>dir2</strong>/$1  [L]<br />
 | 
						|
<br />
 | 
						|
#   else go on for other Alias or ScriptAlias directives,<br />
 | 
						|
#   etc.<br />
 | 
						|
RewriteRule   ^  -  [PT]
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="archive-access-multiplexer" id="archive-access-multiplexer">Redirecting to Geographically Distributed Servers</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
    <p>We have numerous mirrors of our website, and want to redirect
 | 
						|
    people to the one that is located in the country where they are
 | 
						|
    located.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
    <p>Looking at the hostname of the requesting client, we determine
 | 
						|
    which country they are coming from. If we can't do a lookup on their
 | 
						|
    IP address, we fall back to a default server.</p>
 | 
						|
    <p>We'll use a <code class="directive"><a href="../mod/mod_rewrite.html#rewritemap">RewriteMap</a></code>
 | 
						|
    directive to build a list of servers that we wish to use.</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
HostnameLookups on<br />
 | 
						|
RewriteEngine on<br />
 | 
						|
RewriteMap    multiplex         txt:/path/to/map.mirrors<br />
 | 
						|
RewriteCond  %{REMOTE_HOST}     ([a-z]+)$ [NC]<br />
 | 
						|
RewriteRule   ^/(.*)$  ${multiplex:<strong>%1</strong>|http://www.example.com/}$1  [R,L]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
##  map.mirrors -- Multiplexing Map<br />
 | 
						|
<br />
 | 
						|
de        http://www.example.de/<br />
 | 
						|
uk        http://www.example.uk/<br />
 | 
						|
com       http://www.example.com/<br />
 | 
						|
##EOF##
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Discussion</dt>
 | 
						|
    <dd>
 | 
						|
    <div class="warning">This ruleset relies on
 | 
						|
    <code class="directive"><a href="../mod/core.html#hostnamelookups">HostNameLookups</a></code>
 | 
						|
    being set <code>on</code>, which can be
 | 
						|
    a significant performance hit.</div>
 | 
						|
 | 
						|
    <p>The <code class="directive"><a href="../mod/mod_rewrite.html#rewritecond">RewriteCond</a></code>
 | 
						|
    directive captures the last portion of the hostname of the
 | 
						|
    requesting client - the country code - and the following RewriteRule
 | 
						|
    uses that value to look up the appropriate mirror host in the map
 | 
						|
    file.</p>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="browser-dependent-content" id="browser-dependent-content">Browser Dependent Content</a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We wish to provide different content based on the browser, or
 | 
						|
      user-agent, which is requesting the content.</p>
 | 
						|
    </dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We have to decide, based on the HTTP header "User-Agent",
 | 
						|
      which content to serve. The following config
 | 
						|
      does the following: If the HTTP header "User-Agent"
 | 
						|
      contains "Mozilla/3", the page <code>foo.html</code>
 | 
						|
      is rewritten to <code>foo.NS.html</code> and the
 | 
						|
      rewriting stops. If the browser is "Lynx" or "Mozilla" of
 | 
						|
      version 1 or 2, the URL becomes <code>foo.20.html</code>.
 | 
						|
      All other browsers receive page <code>foo.32.html</code>.
 | 
						|
      This is done with the following ruleset:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteCond %{HTTP_USER_AGENT}  ^<strong>Mozilla/3</strong>.*<br />
 | 
						|
RewriteRule ^foo\.html$         foo.<strong>NS</strong>.html          [<strong>L</strong>]<br />
 | 
						|
<br />
 | 
						|
RewriteCond %{HTTP_USER_AGENT}  ^<strong>Lynx/</strong>         [OR]<br />
 | 
						|
RewriteCond %{HTTP_USER_AGENT}  ^<strong>Mozilla/[12]</strong><br />
 | 
						|
RewriteRule ^foo\.html$         foo.<strong>20</strong>.html          [<strong>L</strong>]<br />
 | 
						|
<br />
 | 
						|
RewriteRule ^foo\.html$         foo.<strong>32</strong>.html          [<strong>L</strong>]
 | 
						|
</code></p></div>
 | 
						|
    </dd>
 | 
						|
  </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="canonicalurl" id="canonicalurl">Canonical URLs</a></h2>
 | 
						|
 | 
						|
 | 
						|
 | 
						|
<dl>
 | 
						|
 <dt>Description:</dt>
 | 
						|
 | 
						|
   <dd>
 | 
						|
     <p>On some webservers there is more than one URL for a
 | 
						|
     resource. Usually there are canonical URLs (which are be
 | 
						|
     actually used and distributed) and those which are just
 | 
						|
     shortcuts, internal ones, and so on. Independent of which URL the
 | 
						|
     user supplied with the request, they should finally see the
 | 
						|
     canonical one in their browser address bar.</p>
 | 
						|
   </dd>
 | 
						|
 | 
						|
   <dt>Solution:</dt>
 | 
						|
 | 
						|
     <dd>
 | 
						|
       <p>We do an external HTTP redirect for all non-canonical
 | 
						|
       URLs to fix them in the location view of the Browser and
 | 
						|
       for all subsequent requests. In the example ruleset below
 | 
						|
       we replace <code>/puppies</code> and <code>/canines</code>
 | 
						|
       by the canonical <code>/dogs</code>.</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteRule   ^/(puppies|canines)/(.*)    /dogs/$2  [R]
 | 
						|
</code></p></div>
 | 
						|
        </dd>
 | 
						|
 | 
						|
     <dt>Discussion:</dt>
 | 
						|
     <dd>
 | 
						|
     This should really be accomplished with Redirect or RedirectMatch
 | 
						|
     directives:
 | 
						|
 | 
						|
     <div class="example"><p><code>
 | 
						|
     RedirectMatch ^/(puppies|canines)/(.*) /dogs/$2
 | 
						|
     </code></p></div>
 | 
						|
     </dd>
 | 
						|
      </dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="moveddocroot" id="moveddocroot">Moved <code>DocumentRoot</code></a></h2>
 | 
						|
 | 
						|
  
 | 
						|
 | 
						|
  <dl>
 | 
						|
    <dt>Description:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
<p>Usually the <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code>
 | 
						|
of the webserver directly relates to the URL "<code>/</code>".
 | 
						|
But often this data is not really of top-level priority. For example,
 | 
						|
you may wish for visitors, on first entering a site, to go to a
 | 
						|
particular subdirectory <code>/about/</code>. This may be accomplished
 | 
						|
using the following ruleset:</p>
 | 
						|
</dd>
 | 
						|
 | 
						|
    <dt>Solution:</dt>
 | 
						|
 | 
						|
    <dd>
 | 
						|
      <p>We redirect the URL <code>/</code> to
 | 
						|
      <code>/about/</code>:
 | 
						|
      </p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RewriteEngine on<br />
 | 
						|
RewriteRule   <strong>^/$</strong>  /about/  [<strong>R</strong>]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>Note that this can also be handled using the <code class="directive"><a href="../mod/mod_alias.html#redirectmatch">RedirectMatch</a></code> directive:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
RedirectMatch ^/$ http://example.com/about/
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>Note also that the example rewrites only the root URL. That is, it
 | 
						|
rewrites a request for <code>http://example.com/</code>, but not a
 | 
						|
request for <code>http://example.com/page.html</code>. If you have in
 | 
						|
fact changed your document root - that is, if <strong>all</strong> of
 | 
						|
your content is in fact in that subdirectory, it is greatly preferable
 | 
						|
to simply change your <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code>
 | 
						|
directive, or move all of the content up one directory,
 | 
						|
rather than rewriting URLs.</p>
 | 
						|
</dd>
 | 
						|
</dl>
 | 
						|
 | 
						|
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						|
<div class="section">
 | 
						|
<h2><a name="fallback-resource" id="fallback-resource">Fallback Resource</a></h2>
 | 
						|
 | 
						|
 | 
						|
<dl>
 | 
						|
<dt>Description:</dt>
 | 
						|
<dd>You want a single resource (say, a certain file, like index.php) to
 | 
						|
handle all requests that come to a particular directory, except those
 | 
						|
that should go to an existing resource such as an image, or a css file.</dd>
 | 
						|
 | 
						|
<dt>Solution:</dt>
 | 
						|
<dd>
 | 
						|
<p>As of version 2.2.16, you should use the <code class="directive"><a href="../mod/mod_dir.html#fallbackresource">FallbackResource</a></code> directive for this:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
<Directory /var/www/my_blog><br />
 | 
						|
<span class="indent">
 | 
						|
  FallbackResource index.php<br />
 | 
						|
</span>
 | 
						|
</Directory>
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>However, in earlier versions of Apache, or if your needs are more
 | 
						|
complicated than this, you can use a variation of the following rewrite
 | 
						|
set to accomplish the same thing:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
<Directory /var/www/my_blog><br />
 | 
						|
<span class="indent">
 | 
						|
  RewriteBase /my_blog<br />
 | 
						|
<br />
 | 
						|
  RewriteCond /var/www/my_blog/%{REQUEST_FILENAME} !-f<br />
 | 
						|
  RewriteCond /var/www/my_blog/%{REQUEST_FILENAME} !-d<br />
 | 
						|
  RewriteRule ^ index.php [PT]<br />
 | 
						|
</span>
 | 
						|
</Directory>
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>If, on the other hand, you wish to pass the requested URI as a query
 | 
						|
string argument to index.php, you can replace that RewriteRule with:</p>
 | 
						|
 | 
						|
<div class="example"><p><code>
 | 
						|
  RewriteRule (.*) index.php?$1 [PT,QSA]
 | 
						|
</code></p></div>
 | 
						|
 | 
						|
<p>Note that these rulesets can be used in a <code>.htaccess</code>
 | 
						|
file, as well as in a <Directory> block.</p>
 | 
						|
 | 
						|
</dd>
 | 
						|
 | 
						|
</dl>
 | 
						|
 | 
						|
</div></div>
 | 
						|
<div class="bottomlang">
 | 
						|
<p><span>Available Languages: </span><a href="../en/rewrite/remapping.html" title="English"> en </a></p>
 | 
						|
</div><div id="footer">
 | 
						|
<p class="apache">Copyright 2012 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
 | 
						|
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
 | 
						|
</body></html> |