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<?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>URL Rewriting Guide - 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 2.2</p> <img alt="" src="../images/feather.gif" /></div> <div class="up"><a href="./index.html"><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 2.2</a></div><div id="page-content"><div id="preamble"><h1>URL Rewriting Guide</h1> <div class="toplang"> <p><span>Available Languages: </span><a href="../en/rewrite/rewrite_guide.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 one can use Apache's <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> to solve typical URL-based problems with which webmasters are commonony confronted. We give detailed descriptions on how to solve each problem by configuring URL rewriting rulesets.</p> <div class="warning">ATTENTION: Depending on your server configuration it may be necessary to slightly change the examples for your situation, e.g. adding the <code>[PT]</code> flag when additionally using <code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code> and <code class="module"><a href="../mod/mod_userdir.html">mod_userdir</a></code>, etc. Or rewriting a ruleset to fit in <code>.htaccess</code> context instead of per-server context. Always try to understand what a particular ruleset really does before you use it. This avoids many problems.</div> </div> <div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#canonicalurl">Canonical URLs</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="#moveddocroot">Moved <code>DocumentRoot</code></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#trailingslash">Trailing Slash Problem</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#movehomedirs">Move Homedirs to Different Webserver</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#multipledirs">Search pages in more than one directory</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#setenvvars">Set Environment Variables According To URL Parts</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#uservhosts">Virtual User Hosts</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#redirecthome">Redirect Homedirs For Foreigners</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#redirectanchors">Redirecting Anchors</a></li> <li><img alt="" src="../images/down.gif" /> Time-Dependent Rewriting</li> <li><img alt="" src="../images/down.gif" /> Backward Compatibility for YYYY to XXXX migration</li> <li><img alt="" src="../images/down.gif" /> <a href="#content">Content Handling</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#access">Access Restriction</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#other">Other</a></li> </ul><h3>See also</h3><ul class="seealso"><li><a href="../mod/mod_rewrite.html">Module documentation</a></li><li><a href="rewrite_intro.html">mod_rewrite introduction</a></li><li><a href="rewrite_guide_advanced.html">Practical solutions to advanced problems</a></li><li><a href="rewrite_tech.html">Technical details</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="canonicalurl" id="canonicalurl">Canonical URLs</a></h2> <dl> <dt>Description:</dt> <dd> <p>On some webservers there are more than one URL for a resource. Usually there are canonical URLs (which should be actually used and distributed) and those which are just shortcuts, internal ones, etc. Independent of which URL the user supplied with the request he should finally see the canonical one only.</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>/~user</code> by the canonical <code>/u/user</code> and fix a missing trailing slash for <code>/u/user</code>.</p> <div class="example"><pre> RewriteRule ^/<strong>~</strong>([^/]+)/?(.*) /<strong>u</strong>/$1/$2 [<strong>R</strong>] RewriteRule ^/([uge])/(<strong>[^/]+</strong>)$ /$1/$2<strong>/</strong> [<strong>R</strong>] </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="canonicalhost" id="canonicalhost">Canonical Hostnames</a></h2> <dl> <dt>Description:</dt> <dd>The goal of this rule is to force the use of a particular hostname, in preference to other hostnames which may be used to reach the same site. For example, if you wish to force the use of <strong>www.example.com</strong> instead of <strong>example.com</strong>, you might use a variant of the following recipe.</dd> <dt>Solution:</dt> <dd> <p>For sites running on a port other than 80:</p> <div class="example"><pre> RewriteCond %{HTTP_HOST} !^fully\.qualified\.domain\.name [NC] RewriteCond %{HTTP_HOST} !^$ RewriteCond %{SERVER_PORT} !^80$ RewriteRule ^/(.*) http://fully.qualified.domain.name:%{SERVER_PORT}/$1 [L,R] </pre></div> <p>And for a site running on port 80</p> <div class="example"><pre> RewriteCond %{HTTP_HOST} !^fully\.qualified\.domain\.name [NC] RewriteCond %{HTTP_HOST} !^$ RewriteRule ^/(.*) http://fully.qualified.domain.name/$1 [L,R] </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="moveddocroot" id="moveddocroot">Moved <code>DocumentRoot</code></a></h2> <dl> <dt>Description:</dt> <dd> <p>Usually the <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code> of the webserver directly relates to the URL "<code>/</code>". But often this data is not really of top-level priority. For example, you may wish for visitors, on first entering a site, to go to a particular subdirectory <code>/about/</code>. This may be accomplished using the following ruleset:</p> </dd> <dt>Solution:</dt> <dd> <p>We redirect the URL <code>/</code> to <code>/about/</code>: </p> <div class="example"><pre> RewriteEngine on RewriteRule <strong>^/$</strong> /about/ [<strong>R</strong>] </pre></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/e/www/ </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="trailingslash" id="trailingslash">Trailing Slash Problem</a></h2> <dl> <dt>Description:</dt> <dd><p>The vast majority of "trailing slash" problems can be dealt with using the techniques discussed in the <a href="http://httpd.apache.org/docs/misc/FAQ-E.html#set-servername">FAQ entry</a>. However, occasionally, there is a need to use mod_rewrite to handle a case where a missing trailing slash causes a URL to fail. This can happen, for example, after a series of complex rewrite rules.</p> </dd> <dt>Solution:</dt> <dd> <p>The solution to this subtle problem is to let the server add the trailing slash automatically. To do this correctly we have to use an external redirect, so the browser correctly requests subsequent images etc. If we only did a internal rewrite, this would only work for the directory page, but would go wrong when any images are included into this page with relative URLs, because the browser would request an in-lined object. For instance, a request for <code>image.gif</code> in <code>/~quux/foo/index.html</code> would become <code>/~quux/image.gif</code> without the external redirect!</p> <p>So, to do this trick we write:</p> <div class="example"><pre> RewriteEngine on RewriteBase /~quux/ RewriteRule ^foo<strong>$</strong> foo<strong>/</strong> [<strong>R</strong>] </pre></div> <p>Alternately, you can put the following in a top-level <code>.htaccess</code> file in the content directory. But note that this creates some processing overhead.</p> <div class="example"><pre> RewriteEngine on RewriteBase /~quux/ RewriteCond %{REQUEST_FILENAME} <strong>-d</strong> RewriteRule ^(.+<strong>[^/]</strong>)$ $1<strong>/</strong> [R] </pre></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">Move Homedirs to Different Webserver</a></h2> <dl> <dt>Description:</dt> <dd> <p>Many webmasters have asked for a solution to the following situation: They wanted to redirect just all homedirs on a webserver to another webserver. They usually need such things when establishing a newer webserver which will replace the old one over time.</p> </dd> <dt>Solution:</dt> <dd> <p>The solution is trivial with <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>. On the old webserver we just redirect all <code>/~user/anypath</code> URLs to <code>http://newserver/~user/anypath</code>.</p> <div class="example"><pre> RewriteEngine on RewriteRule ^/~(.+) http://<strong>newserver</strong>/~$1 [R,L] </pre></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="multipledirs" id="multipledirs">Search pages in more than one directory</a></h2> <dl> <dt>Description:</dt> <dd> <p>Sometimes it is necessary to let the webserver search for pages in more than one directory. Here MultiViews or other techniques cannot help.</p> </dd> <dt>Solution:</dt> <dd> <p>We program a explicit ruleset which searches for the files in the directories.</p> <div class="example"><pre> RewriteEngine on # first try to find it in custom/... # ...and if found stop and be happy: RewriteCond /your/docroot/<strong>dir1</strong>/%{REQUEST_FILENAME} -f RewriteRule ^(.+) /your/docroot/<strong>dir1</strong>/$1 [L] # second try to find it in pub/... # ...and if found stop and be happy: RewriteCond /your/docroot/<strong>dir2</strong>/%{REQUEST_FILENAME} -f RewriteRule ^(.+) /your/docroot/<strong>dir2</strong>/$1 [L] # else go on for other Alias or ScriptAlias directives, # etc. RewriteRule ^(.+) - [PT] </pre></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="setenvvars" id="setenvvars">Set Environment Variables According To URL Parts</a></h2> <dl> <dt>Description:</dt> <dd> <p>Perhaps you want to keep status information between requests and use the URL to encode it. But you don't want to use a CGI wrapper for all pages just to strip out this information.</p> </dd> <dt>Solution:</dt> <dd> <p>We use a rewrite rule to strip out the status information and remember it via an environment variable which can be later dereferenced from within XSSI or CGI. This way a URL <code>/foo/S=java/bar/</code> gets translated to <code>/foo/bar/</code> and the environment variable named <code>STATUS</code> is set to the value "java".</p> <div class="example"><pre> RewriteEngine on RewriteRule ^(.*)/<strong>S=([^/]+)</strong>/(.*) $1/$3 [E=<strong>STATUS:$2</strong>] </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="uservhosts" id="uservhosts">Virtual User Hosts</a></h2> <dl> <dt>Description:</dt> <dd> <p>Assume that you want to provide <code>www.<strong>username</strong>.host.domain.com</code> for the homepage of username via just DNS A records to the same machine and without any virtualhosts on this machine.</p> </dd> <dt>Solution:</dt> <dd> <p>For HTTP/1.0 requests there is no solution, but for HTTP/1.1 requests which contain a Host: HTTP header we can use the following ruleset to rewrite <code>http://www.username.host.com/anypath</code> internally to <code>/home/username/anypath</code>:</p> <div class="example"><pre> RewriteEngine on RewriteCond %{<strong>HTTP_HOST</strong>} ^www\.<strong>[^.]+</strong>\.host\.com$ RewriteRule ^(.+) %{HTTP_HOST}$1 [C] RewriteRule ^www\.<strong>([^.]+)</strong>\.host\.com(.*) /home/<strong>$1</strong>$2 </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="redirecthome" id="redirecthome">Redirect Homedirs For Foreigners</a></h2> <dl> <dt>Description:</dt> <dd> <p>We want to redirect homedir URLs to another webserver <code>www.somewhere.com</code> when the requesting user does not stay in the local domain <code>ourdomain.com</code>. This is sometimes used in virtual host contexts.</p> </dd> <dt>Solution:</dt> <dd> <p>Just a rewrite condition:</p> <div class="example"><pre> RewriteEngine on RewriteCond %{REMOTE_HOST} <strong>!^.+\.ourdomain\.com$</strong> RewriteRule ^(/~.+) http://www.somewhere.com/$1 [R,L] </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="redirectanchors" id="redirectanchors">Redirecting Anchors</a></h2> <dl> <dt>Description:</dt> <dd> <p>By default, redirecting to an HTML anchor doesn't work, because mod_rewrite escapes the <code>#</code> character, turning it into <code>%23</code>. This, in turn, breaks the redirection.</p> </dd> <dt>Solution:</dt> <dd> <p>Use the <code>[NE]</code> flag on the <code>RewriteRule</code>. NE stands for No Escape. </p> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2>Time-Dependent Rewriting</h2> <dl> <dt>Description:</dt> <dd> <p>When tricks like time-dependent content should happen a lot of webmasters still use CGI scripts which do for instance redirects to specialized pages. How can it be done via <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>?</p> </dd> <dt>Solution:</dt> <dd> <p>There are a lot of variables named <code>TIME_xxx</code> for rewrite conditions. In conjunction with the special lexicographic comparison patterns <code><STRING</code>, <code>>STRING</code> and <code>=STRING</code> we can do time-dependent redirects:</p> <div class="example"><pre> RewriteEngine on RewriteCond %{TIME_HOUR}%{TIME_MIN} >0700 RewriteCond %{TIME_HOUR}%{TIME_MIN} <1900 RewriteRule ^foo\.html$ foo.day.html RewriteRule ^foo\.html$ foo.night.html </pre></div> <p>This provides the content of <code>foo.day.html</code> under the URL <code>foo.html</code> from <code>07:00-19:00</code> and at the remaining time the contents of <code>foo.night.html</code>. Just a nice feature for a homepage...</p> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2>Backward Compatibility for YYYY to XXXX migration</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>.phtml</code>?</p> </dd> <dt>Solution:</dt> <dd> <p>We just 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"><pre> # backward compatibility ruleset for # rewriting document.html to document.phtml # when and only when document.phtml exists # but no longer document.html RewriteEngine on RewriteBase /~quux/ # parse out basename, but remember the fact RewriteRule ^(.*)\.html$ $1 [C,E=WasHTML:yes] # rewrite to document.phtml if exists RewriteCond %{REQUEST_FILENAME}.phtml -f RewriteRule ^(.*)$ $1.phtml [S=1] # else reverse the previous basename cutout RewriteCond %{ENV:WasHTML} ^yes$ RewriteRule ^(.*)$ $1.html </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="content" id="content">Content Handling</a></h2> <h3>From Old to New (intern)</h3> <dl> <dt>Description:</dt> <dd> <p>Assume we have recently renamed the page <code>foo.html</code> to <code>bar.html</code> and now want to provide the old URL for backward compatibility. Actually we want that users of the old URL even not recognize that the pages was renamed.</p> </dd> <dt>Solution:</dt> <dd> <p>We rewrite the old URL to the new one internally via the following rule:</p> <div class="example"><pre> RewriteEngine on RewriteBase /~quux/ RewriteRule ^<strong>foo</strong>\.html$ <strong>bar</strong>.html </pre></div> </dd> </dl> <h3>From Old to New (extern)</h3> <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"><pre> RewriteEngine on RewriteBase /~quux/ RewriteRule ^<strong>foo</strong>\.html$ <strong>bar</strong>.html [<strong>R</strong>] </pre></div> </dd> </dl> <h3>From Static to Dynamic</h3> <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 correct MIME-type so it gets really run as a CGI-script. 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"><pre> RewriteEngine on RewriteBase /~quux/ RewriteRule ^foo\.<strong>html</strong>$ foo.<strong>cgi</strong> [T=<strong>application/x-httpd-cgi</strong>] </pre></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="access" id="access">Access Restriction</a></h2> <h3>Blocking of Robots</h3> <dl> <dt>Description:</dt> <dd> <p>How can we block a really annoying robot from retrieving pages of a specific webarea? A <code>/robots.txt</code> file containing entries of the "Robot Exclusion Protocol" is typically not enough to get rid of such a robot.</p> </dd> <dt>Solution:</dt> <dd> <p>We use a ruleset which forbids the URLs of the webarea <code>/~quux/foo/arc/</code> (perhaps a very deep directory indexed area where the robot traversal would create big server load). We have to make sure that we forbid access only to the particular robot, i.e. just forbidding the host where the robot runs is not enough. This would block users from this host, too. We accomplish this by also matching the User-Agent HTTP header information.</p> <div class="example"><pre> RewriteCond %{HTTP_USER_AGENT} ^<strong>NameOfBadRobot</strong>.* RewriteCond %{REMOTE_ADDR} ^<strong>123\.45\.67\.[8-9]</strong>$ RewriteRule ^<strong>/~quux/foo/arc/</strong>.+ - [<strong>F</strong>] </pre></div> </dd> </dl> <h3>Blocked Inline-Images</h3> <dl> <dt>Description:</dt> <dd> <p>Assume we have under <code>http://www.quux-corp.de/~quux/</code> some pages with inlined GIF graphics. These graphics are nice, so others directly incorporate them via hyperlinks to their pages. We don't like this practice because it adds useless traffic to our server.</p> </dd> <dt>Solution:</dt> <dd> <p>While we cannot 100% protect the images from inclusion, we can at least restrict the cases where the browser sends a HTTP Referer header.</p> <div class="example"><pre> RewriteCond %{HTTP_REFERER} <strong>!^$</strong> RewriteCond %{HTTP_REFERER} !^http://www.quux-corp.de/~quux/.*$ [NC] RewriteRule <strong>.*\.gif$</strong> - [F] </pre></div> <div class="example"><pre> RewriteCond %{HTTP_REFERER} !^$ RewriteCond %{HTTP_REFERER} !.*/foo-with-gif\.html$ RewriteRule <strong>^inlined-in-foo\.gif$</strong> - [F] </pre></div> </dd> </dl> <h3>Proxy Deny</h3> <dl> <dt>Description:</dt> <dd> <p>How can we forbid a certain host or even a user of a special host from using the Apache proxy?</p> </dd> <dt>Solution:</dt> <dd> <p>We first have to make sure <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> is below(!) <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> in the Configuration file when compiling the Apache webserver. This way it gets called <em>before</em> <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>. Then we configure the following for a host-dependent deny...</p> <div class="example"><pre> RewriteCond %{REMOTE_HOST} <strong>^badhost\.mydomain\.com$</strong> RewriteRule !^http://[^/.]\.mydomain.com.* - [F] </pre></div> <p>...and this one for a user@host-dependent deny:</p> <div class="example"><pre> RewriteCond %{REMOTE_IDENT}@%{REMOTE_HOST} <strong>^badguy@badhost\.mydomain\.com$</strong> RewriteRule !^http://[^/.]\.mydomain.com.* - [F] </pre></div> </dd> </dl> </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="section"> <h2><a name="other" id="other">Other</a></h2> <h3>External Rewriting Engine</h3> <dl> <dt>Description:</dt> <dd> <p>A FAQ: How can we solve the FOO/BAR/QUUX/etc. problem? There seems no solution by the use of <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>...</p> </dd> <dt>Solution:</dt> <dd> <p>Use an external <code class="directive"><a href="../mod/mod_rewrite.html#rewritemap">RewriteMap</a></code>, i.e. a program which acts like a <code class="directive"><a href="../mod/mod_rewrite.html#rewritemap">RewriteMap</a></code>. It is run once on startup of Apache receives the requested URLs on <code>STDIN</code> and has to put the resulting (usually rewritten) URL on <code>STDOUT</code> (same order!).</p> <div class="example"><pre> RewriteEngine on RewriteMap quux-map <strong>prg:</strong>/path/to/map.quux.pl RewriteRule ^/~quux/(.*)$ /~quux/<strong>${quux-map:$1}</strong> </pre></div> <div class="example"><pre> #!/path/to/perl # disable buffered I/O which would lead # to deadloops for the Apache server $| = 1; # read URLs one per line from stdin and # generate substitution URL on stdout while (<>) { s|^foo/|bar/|; print $_; } </pre></div> <p>This is a demonstration-only example and just rewrites all URLs <code>/~quux/foo/...</code> to <code>/~quux/bar/...</code>. Actually you can program whatever you like. But notice that while such maps can be <strong>used</strong> also by an average user, only the system administrator can <strong>define</strong> it.</p> </dd> </dl> </div></div> <div class="bottomlang"> <p><span>Available Languages: </span><a href="../en/rewrite/rewrite_guide.html" title="English"> en </a></p> </div><div id="footer"> <p class="apache">Copyright 1995-2006 The Apache Software Foundation or its licensors, as applicable.<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> 
