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<parentdocument href="./">Rewrite</parentdocument>

<title>Redirecting and Remapping with mod_rewrite</title>

<summary>

<p>This document supplements the <module>mod_rewrite</module>

<a href="/mod/mod_rewrite.html">reference documentation</a>. It describes

how you can use <module>mod_rewrite</module> to redirect and remap

request. This includes many examples of common uses of mod_rewrite,

including detailed descriptions of how each works.</p>

<note type="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.</note>

</summary>

<seealso><a href="/mod/mod_rewrite.html">Module documentation</a></seealso>

<seealso><a href="intro.html">mod_rewrite introduction</a></seealso>

<seealso><a href="access.html">Controlling access</a></seealso>

<seealso><a href="vhosts.html">Virtual hosts</a></seealso>

<seealso><a href="proxy.html">Proxying</a></seealso>

<seealso><a href="rewritemap.html">Using RewriteMap</a></seealso>

<seealso><a href="advanced.html">Advanced techniques</a></seealso>

<seealso><a href="avoid.html">When not to use mod_rewrite</a></seealso>

<section id="old-to-new">

<title>From Old to New (internal)</title>

<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>

<highlight language="config">

RewriteEngine on

RewriteRule ^<strong>/foo</strong>\.html$ <strong>/bar</strong>.html [PT]

</highlight>

</dd>

</dl>

</section>

<section id="old-to-new-extern">

<title>Rewriting From Old to New (external)</title>

<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>

<highlight language="config">

RewriteEngine on

RewriteRule ^<strong>/foo</strong>\.html$ <strong>bar</strong>.html [<strong>R</strong>]

</highlight>

</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>

<highlight language="config">

Redirect "/foo.html" "/bar.html"

</highlight>

</dd>

</dl>

</section>

<section id="movehomedirs">

<title>Resource Moved to Another Server</title>

<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 <module>mod_rewrite</module> to redirect these URLs

to the new server, but you might also consider using the Redirect

or RedirectMatch directive.</p>

<highlight language="config">

#With mod_rewrite

RewriteEngine on

RewriteRule ^/docs/(.+) http://new.example.com/docs/$1 [R,L]

</highlight>

<highlight language="config">

#With RedirectMatch

RedirectMatch "^/docs/(.*)" "http://new.example.com/docs/$1"

</highlight>

<highlight language="config">

#With Redirect

Redirect "/docs/" "http://new.example.com/docs/"

</highlight>

</dd>

</dl>

</section>

<section id="static-to-dynamic">

<title>From Static to Dynamic</title>

<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>

<highlight language="config">

RewriteEngine on

RewriteBase /~quux/

RewriteRule ^foo\.html$ foo.cgi &nbsp; [H=<strong>cgi-script</strong>]

</highlight>

</dd>

</dl>

</section>

<section id="backward-compatibility">

<title>Backward Compatibility for file extension change</title>

<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>

<highlight language="config">

# backward compatibility ruleset for

# rewriting document.html to document.php

# when and only when document.php exists

&lt;Directory "/var/www/htdocs"&gt;

RewriteEngine on

RewriteBase /var/www/htdocs

RewriteCond $1.php -f

RewriteCond $1.html !-f

RewriteRule ^(.*).html$ $1.php

&lt;/Directory&gt;

</highlight>

</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

&lt;Directory&gt; 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 <directive

module="mod_rewrite">RewriteBase</directive> directive to specify the

directory base that you're working in.</p>

</dd>

</dl>

</section>

<section id="canonicalhost">

<title>Canonical Hostnames</title>

<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 <directive module="mod_alias">Redirect</directive>

directive placed in a virtual host for the non-canonical

hostname(s).</p>

<highlight language="config">

&lt;VirtualHost *:80&gt;

ServerName undesired.example.com

ServerAlias example.com notthis.example.com

Redirect "/" "http://www.example.com/"

&lt;/VirtualHost&gt;

&lt;VirtualHost *:80&gt;

ServerName www.example.com

&lt;/VirtualHost&gt;

</highlight>

<p>You can alternatively accomplish this using the

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

directive:</p>

<highlight language="config">

&lt;If "%{HTTP_HOST} != 'www.example.com'"&gt;

Redirect "/" "http://www.example.com/"

&lt;/If&gt;

</highlight>

<p>Or, for example, to redirect a portion of your site to HTTPS, you

might do the following:</p>

<highlight language="config">

&lt;If "%{SERVER_PROTOCOL} != 'HTTPS'"&gt;

Redirect "/admin/" "https://www.example.com/admin/"

&lt;/If&gt;

</highlight>

<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>

<highlight language="config">

RewriteCond %{HTTP_HOST} !^www\.example\.com [NC]

RewriteCond %{HTTP_HOST} !^$

RewriteCond %{SERVER_PORT} !^80$

RewriteRule ^/?(.*) http://www.example.com:%{SERVER_PORT}/$1 [L,R,NE]

</highlight>

<p>And for a site running on port 80</p>

<highlight language="config">

RewriteCond %{HTTP_HOST} !^www\.example\.com [NC]

RewriteCond %{HTTP_HOST} !^$

RewriteRule ^/?(.*) http://www.example.com/$1 [L,R,NE]

</highlight>

<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>

<highlight language="config">

RewriteCond %{HTTP_HOST} !^www\. [NC]

RewriteCond %{HTTP_HOST} !^$

RewriteRule ^/?(.*) http://www.%{HTTP_HOST}/$1 [L,R,NE]

</highlight>

<p>These rulesets will work either in your main server configuration

file, or in a <code>.htaccess</code> file placed in the <directive

module="core">DocumentRoot</directive> of the server.</p>

</dd>

</dl>

</section>

<section id="multipledirs">

<title>Search for pages in more than one directory</title>

<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>

<highlight language="config">

RewriteEngine on

# first try to find it in dir1/...

# ...and if found stop and be happy:

RewriteCond %{DOCUMENT_ROOT}/<strong>dir1</strong>/%{REQUEST_URI} -f

RewriteRule ^(.+) %{DOCUMENT_ROOT}/<strong>dir1</strong>/$1 [L]

# second try to find it in dir2/...

# ...and if found stop and be happy:

RewriteCond %{DOCUMENT_ROOT}/<strong>dir2</strong>/%{REQUEST_URI} -f

RewriteRule ^(.+) %{DOCUMENT_ROOT}/<strong>dir2</strong>/$1 [L]

# else go on for other Alias or ScriptAlias directives,

# etc.

RewriteRule ^ - [PT]

</highlight>

</dd>

</dl>

</section>

<section id="archive-access-multiplexer">

<title>Redirecting to Geographically Distributed Servers</title>

<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 <directive module="mod_rewrite">RewriteMap</directive>

directive to build a list of servers that we wish to use.</p>

<highlight language="config">

HostnameLookups on

RewriteEngine on

RewriteMap multiplex txt:/path/to/map.mirrors

RewriteCond %{REMOTE_HOST} ([a-z]+)$ [NC]

RewriteRule ^/(.*)$ ${multiplex:<strong>%1</strong>|http://www.example.com/}$1 [R,L]

</highlight>

<example>

## 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##

</example>

</dd>

<dt>Discussion</dt>

<dd>

<note type="warning">This ruleset relies on

<directive module="core">HostNameLookups</directive>

being set <code>on</code>, which can be

a significant performance hit.</note>

<p>The <directive module="mod_rewrite">RewriteCond</directive>

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>

</section>

<section id="canonicalurl">

<title>Canonical URLs</title>

<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>

<highlight language="config">

RewriteRule ^/(puppies|canines)/(.*) /dogs/$2 [R]

</highlight>

</dd>

<dt>Discussion:</dt>

<dd>

This should really be accomplished with Redirect or RedirectMatch

directives:

<highlight language="config">

RedirectMatch "^/(puppies|canines)/(.*)" "/dogs/$2"

</highlight>

</dd>

</dl>

</section>

<section id="moveddocroot">

<title>Moved <code>DocumentRoot</code></title>

<dl>

<dt>Description:</dt>

<dd>

<p>Usually the <directive module="core">DocumentRoot</directive>

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>

<highlight language="config">

RewriteEngine on

RewriteRule ^/$ /about/ [<strong>R</strong>]

</highlight>

<p>Note that this can also be handled using the <directive

module="mod_alias">RedirectMatch</directive> directive:</p>

<highlight language="config">

RedirectMatch "^/$" "http://example.com/about/"

</highlight>

<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 <directive module="core">DocumentRoot</directive>

directive, or move all of the content up one directory,

rather than rewriting URLs.</p>

</dd>

</dl>

</section>

<section id="fallback-resource">

<title>Fallback Resource</title>

<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 <directive

module="mod_dir">FallbackResource</directive> directive for this:</p>

<highlight language="config">

&lt;Directory "/var/www/my_blog"&gt;

FallbackResource index.php

&lt;/Directory&gt;

</highlight>

<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>

<highlight language="config">

&lt;Directory "/var/www/my_blog"&gt;

RewriteBase /my_blog

RewriteCond /var/www/my_blog/%{REQUEST_FILENAME} !-f

RewriteCond /var/www/my_blog/%{REQUEST_FILENAME} !-d

RewriteRule ^ index.php [PT]

&lt;/Directory&gt;

</highlight>

<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>

<highlight language="config">

RewriteRule (.*) index.php?$1 [PT,QSA]

</highlight>

<p>Note that these rulesets can be used in a <code>.htaccess</code>

file, as well as in a &lt;Directory&gt; block.</p>

</dd>

</dl>

</section>

<section id="rewrite-query">

<title>Rewrite query string</title>

<dl>

<dt>Description:</dt>

<dd>You want to capture a particular value from a query string

and either replace it or incorporate it into another component

of the URL.</dd>

<dt>Solutions:</dt>

<dd>

<p> Many of the solutions in this section will all use the same condition,

which leaves the matched value in the %2 backreference. %1 is the beginining

of the query string (up to the key of intererest), and %3 is the remainder. This

condition is a bit complex for flexibility and to avoid double '&amp;&amp;' in the

substitutions.</p>

<ul>

<li>This solution removes the matching key and value:

<highlight language="config">

# Remove mykey=???

RewriteCond %{QUERY_STRING} (.*(?:^|&amp;))mykey=([^&amp;]*)&amp;?(.*)&amp;?$

RewriteRule (.*) $1?%1%3

</highlight>

</li>

<li>This solution uses the captured value in the URL subsitution,

discarding the rest of the original query by appending a '?':

<highlight language="config">

# Copy from query string to PATH_INFO

RewriteCond %{QUERY_STRING} (.*(?:^|&amp;))mykey=([^&amp;]*)&amp;?(.*)&amp;?$

RewriteRule (.*) $1/products/%2/? [PT]

</highlight>

</li>

<li>This solution checks the captured value in a subsequent condition:

<highlight language="config">

# Capture the value of mykey in the query string

RewriteCond %{QUERY_STRING} (.*(?:^|&amp;))mykey=([^&amp;]*)&amp;?(.*)&amp;?$

RewriteCond %2 !=not-so-secret-value

RewriteRule (.*) - [F]

</highlight>

</li>

<li>This solution shows the reverse of the previous ones, copying

path components (perhaps PATH_INFO) from the URL into the query string.

<highlight language="config">

# The desired URL might be /products/kitchen-sink, and the script expects

# /path?products=kitchen-sink.

RewriteRule ^/?path/([^/]+)/([^/]+) /path?$1=$2 [PT]

</highlight>

</li>

</ul>

</dd>

</dl>

</section>

</manualpage>