| <?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 2.3</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-project/">Documentation</a> > <a href="../">Version 2.3</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 1995-2005 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> |
