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diff --git a/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en b/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en new file mode 100644 index 00000000..328bbf92 --- /dev/null +++ b/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en @@ -0,0 +1,1671 @@ +<?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>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> +<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 2.0</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 2.0</a> > <a href="./">Modules</a></div> +<div id="page-content"> +<div id="preamble"><h1>Apache Module mod_rewrite</h1> +<div class="toplang"> +<p><span>Available Languages: </span><a href="../en/mod/mod_rewrite.html" title="English"> en </a></p> +</div> +<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Provides a rule-based rewriting engine to rewrite requested +URLs on the fly</td></tr> +<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>rewrite_module</td></tr> +<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_rewrite.c</td></tr> +<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 1.3 and later</td></tr></table> +<h3>Summary</h3> + + <p>This module uses a rule-based rewriting engine (based on a + regular-expression parser) to rewrite requested URLs on the + fly. It supports an unlimited number of rules and an + unlimited number of attached rule conditions for each rule, to + provide a really flexible and powerful URL manipulation + mechanism. The URL manipulations can depend on various tests, + of server variables, environment variables, HTTP + headers, or time stamps. Even external database lookups in + various formats can be used to achieve highly granular URL + matching.</p> + + <p>This module operates on the full URLs (including the + path-info part) both in per-server context + (<code>httpd.conf</code>) and per-directory context + (<code>.htaccess</code>) and can generate query-string + parts on result. The rewritten result can lead to internal + sub-processing, external request redirection or even to an + internal proxy throughput.</p> + + <p>Further details, discussion, and examples, are provided in the + <a href="../rewrite/">detailed mod_rewrite documentation</a>.</p> +</div> +<div id="quickview"><h3 class="directives">Directives</h3> +<ul id="toc"> +<li><img alt="" src="../images/down.gif" /> <a href="#rewritebase">RewriteBase</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewritecond">RewriteCond</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewriteengine">RewriteEngine</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewritelock">RewriteLock</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewritelog">RewriteLog</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewriteloglevel">RewriteLogLevel</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewritemap">RewriteMap</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewriteoptions">RewriteOptions</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#rewriterule">RewriteRule</a></li> +</ul> +<h3>Topics</h3> +<ul id="topics"> +<li><img alt="" src="../images/down.gif" /> <a href="#InternalAPI">API Phases</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#InternalRuleset">Ruleset Processing</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#InternalBackRefs">Regex Back-Reference Availability</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#quoting">Quoting Special Characters</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#EnvVar">Environment Variables</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#Solutions">Practical Solutions</a></li> +</ul><h3>See also</h3> +<ul class="seealso"> +<li><a href="#rewriteflags">Rewrite Flags</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="InternalAPI" id="InternalAPI">API Phases</a></h2> + + <p>Apache processes a HTTP request in several phases. + A hook for each of these + phases is provided by the Apache API. <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> uses two of + these hooks: the URL-to-filename translation hook + (used after the HTTP request has been read, but before any + authorization starts) and the Fixup hook (triggered + after the authorization phases, and after the per-directory + config files (<code>.htaccess</code>) have been read, but + before the content handler is activated).</p> + + <p>Once a request comes in, and Apache has determined the + appropriate server (or virtual server), the rewrite engine + starts the URL-to-filename translation, + processing the mod_rewrite directives from the + per-server configuration. A few + steps later, when the final data directories are found, the + per-directory configuration directives of mod_rewrite are + triggered in the Fixup phase. </p> + +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="InternalRuleset" id="InternalRuleset">Ruleset Processing</a></h2> + + <p>When mod_rewrite is triggered during these two API phases, it + reads the relevant rulesets from its configuration + structure (which was either created on startup, for + per-server context, or during the directory traversal + for per-directory context). The URL rewriting + engine is started with the appropriate ruleset (one or more + rules together with their conditions), and its operation + is exactly the same for both + configuration contexts. Only the final result processing is + different. </p> + + <p>The order of rules in the ruleset is important because the + rewrite engine processes them in a particular (not always + obvious) order, as follows: The rewrite engine loops + through the rulesets (each ruleset being made up of <code class="directive"><a href="#rewriterule">RewriteRule</a></code> directives, with or without + <code class="directive"><a href="#rewritecond">RewriteCond</a></code>s), rule by rule. + When a particular rule is matched, <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> + also checks the corresponding conditions (<code>RewriteCond</code> + directives). For historical reasons the conditions are given + first, making the control flow a little bit long-winded. See + Figure 1 for more details.</p> +<p class="figure"> + <img src="../images/mod_rewrite_fig1.gif" width="428" height="385" alt="[Needs graphics capability to display]" /><br /> + <dfn>Figure 1:</dfn>The control flow of the rewrite engine through a + rewrite ruleset +</p> + <p>As above, first the URL is matched against the + <em>Pattern</em> of a rule. If it does not match, <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> immediately stops processing that rule, + and goes on to the next rule. If the <em>Pattern</em> matches, + <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> checks for rule conditions. + If none are present, the URL will be replaced with a new string, + constructed from the <em>Substitution</em> string, and <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> goes on to the next rule.</p> + <p>If <code class="directive">RewriteCond</code>s exist, an + inner loop is started, processing them in the order that they are + listed. Conditions are not matched against the current URL directly. + A <em>TestString</em> is constructed by expanding variables, + back-references, map lookups, etc., against which the + <em>CondPattern</em> is matched. If the pattern fails to match one + of the conditions, the complete set of rule and associated conditions + fails. If the pattern matches a given condition, then matching continues + to the next condition, until no more conditions are + available. If all conditions match, processing is continued + with the substitution of the <em>Substitution</em> string for the URL.</p> + +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="InternalBackRefs" id="InternalBackRefs">Regex Back-Reference Availability</a></h2> + + <p>Using parentheses in <em>Pattern</em> or in one of the + <em>CondPattern</em>s causes back-references to be internally + created. + These can later be referenced using the strings <code>$N</code> and + <code>%N</code> (see below), for creating + the <em>Substitution</em> and <em>TestString</em> strings. + Figure 2 attempts to show how the back-references are + transferred through the process for later expansion.</p> + +<p class="figure"> + <img src="../images/mod_rewrite_fig2.gif" width="381" height="179" alt="[Needs graphics capability to display]" /><br /> + <dfn>Figure 2:</dfn> The back-reference flow through a rule. +</p> +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="quoting" id="quoting">Quoting Special Characters</a></h2> + + <p>As of Apache 1.3.20, special characters in + <em>TestString</em> and <em>Substitution</em> strings can be + escaped (that is, treated as normal characters without their + usual special meaning) by prefixing them with a backslash ('\') + character. In other words, you can include an actual + dollar-sign character in a <em>Substitution</em> string by + using '<code>\$</code>'; this keeps mod_rewrite from trying + to treat it as a backreference.</p> +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="EnvVar" id="EnvVar">Environment Variables</a></h2> + + <p>This module keeps track of two additional (non-standard) + CGI/SSI environment variables named <code>SCRIPT_URL</code> + and <code>SCRIPT_URI</code>. These contain the + <em>logical</em> Web-view to the current resource, while the + standard CGI/SSI variables <code>SCRIPT_NAME</code> and + <code>SCRIPT_FILENAME</code> contain the <em>physical</em> + System-view. </p> + + <p>Notice: These variables hold the URI/URL <em>as they were + initially requested</em>, that is, <em>before</em> any + rewriting. This is important to note because the rewriting process is + primarily used to rewrite logical URLs to physical + pathnames.</p> + +<div class="example"><h3>Example</h3><pre> +SCRIPT_NAME=/sw/lib/w3s/tree/global/u/rse/.www/index.html +SCRIPT_FILENAME=/u/rse/.www/index.html +SCRIPT_URL=/u/rse/ +SCRIPT_URI=http://en1.engelschall.com/u/rse/ +</pre></div> + +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="Solutions" id="Solutions">Practical Solutions</a></h2> + + <p>For numerous examples of common, and not-so-common, uses for + mod_rewrite, see the <a href="../rewrite/rewrite_guide.html">Rewrite + Guide</a>, and the <a href="../rewrite/rewrite_guide_advanced.html">Advanced Rewrite + Guide</a> documents.</p> + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteBase" id="RewriteBase">RewriteBase</a> <a name="rewritebase" id="rewritebase">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the base URL for per-directory rewrites</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteBase <em>URL-path</em></code></td></tr> +<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>See usage for information.</code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> +<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +</table> + <p>The <code class="directive">RewriteBase</code> directive explicitly + sets the base URL for per-directory rewrites. As you will see + below, <code class="directive"><a href="#rewriterule">RewriteRule</a></code> + can be used in per-directory config files + (<code>.htaccess</code>). In such a case, it will act locally, + stripping the local directory prefix before processing, and applying + rewrite rules only to the remainder. When processing is complete, the + prefix is automatically added back to the + path. The default setting is; <code class="directive">RewriteBase</code> <em>physical-directory-path</em></p> + + <p>When a substitution occurs for a new URL, this module has + to re-inject the URL into the server processing. To be able + to do this it needs to know what the corresponding URL-prefix + or URL-base is. By default this prefix is the corresponding + filepath itself. <strong>However, for most websites, URLs are NOT + directly related to physical filename paths, so this + assumption will often be wrong!</strong> Therefore, you can + use the <code>RewriteBase</code> directive to specify the + correct URL-prefix.</p> + +<div class="note"> If your webserver's URLs are <strong>not</strong> directly +related to physical file paths, you will need to use +<code class="directive">RewriteBase</code> in every <code>.htaccess</code> +file where you want to use <code class="directive"><a href="#rewriterule">RewriteRule</a></code> directives. +</div> + + <p> For example, assume the following per-directory config file:</p> + +<div class="example"><pre> +# +# /abc/def/.htaccess -- per-dir config file for directory /abc/def +# Remember: /abc/def is the physical path of /xyz, <em>i.e.</em>, the server +# has a 'Alias /xyz /abc/def' directive <em>e.g.</em> +# + +RewriteEngine On + +# let the server know that we were reached via /xyz and not +# via the physical path prefix /abc/def +RewriteBase /xyz + +# now the rewriting rules +RewriteRule ^oldstuff\.html$ newstuff.html +</pre></div> + + <p>In the above example, a request to + <code>/xyz/oldstuff.html</code> gets correctly rewritten to + the physical file <code>/abc/def/newstuff.html</code>.</p> + +<div class="note"><h3>For Apache Hackers</h3> +<p>The following list gives detailed information about + the internal processing steps:</p> +<pre> +Request: + /xyz/oldstuff.html + +Internal Processing: + /xyz/oldstuff.html -> /abc/def/oldstuff.html (per-server Alias) + /abc/def/oldstuff.html -> /abc/def/newstuff.html (per-dir RewriteRule) + /abc/def/newstuff.html -> /xyz/newstuff.html (per-dir RewriteBase) + /xyz/newstuff.html -> /abc/def/newstuff.html (per-server Alias) + +Result: + /abc/def/newstuff.html +</pre> + <p>This seems very complicated, but is in fact + correct Apache internal processing. Because the + per-directory rewriting comes late in the + process, the rewritten request + has to be re-injected into the Apache kernel, as if it + were a new request. (See <a href="../rewrite/rewrite_tech.html">mod_rewrite technical + details</a>.) + This is not the serious overhead it may seem to be - + this re-injection is completely internal to the + Apache server (and the same procedure is used by + many other operations within Apache).</p> +</div> + + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteCond" id="RewriteCond">RewriteCond</a> <a name="rewritecond" id="rewritecond">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Defines a condition under which rewriting will take place +</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code> RewriteCond + <em>TestString</em> <em>CondPattern</em></code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> +<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +</table> + <p>The <code class="directive">RewriteCond</code> directive defines a + rule condition. One or more <code class="directive">RewriteCond</code> + can precede a <code class="directive"><a href="#rewriterule">RewriteRule</a></code> + directive. The following rule is then only used if both + the current state of the URI matches its pattern, <strong>and</strong> if these conditions are met.</p> + + <p><em>TestString</em> is a string which can contain the + following expanded constructs in addition to plain text:</p> + + <ul> + <li> + <strong>RewriteRule backreferences</strong>: These are + backreferences of the form <strong><code>$N</code></strong> + (0 <= N <= 9), which provide access to the grouped + parts (in parentheses) of the pattern, from the + <code>RewriteRule</code> which is subject to the current + set of <code>RewriteCond</code> conditions.. + </li> + <li> + <strong>RewriteCond backreferences</strong>: These are + backreferences of the form <strong><code>%N</code></strong> + (1 <= N <= 9), which provide access to the grouped + parts (again, in parentheses) of the pattern, from the last matched + <code>RewriteCond</code> in the current set + of conditions. + </li> + <li> + <strong>RewriteMap expansions</strong>: These are + expansions of the form <strong><code>${mapname:key|default}</code></strong>. + See <a href="#mapfunc">the documentation for + RewriteMap</a> for more details. + </li> + <li> + <strong>Server-Variables</strong>: These are variables of + the form + <strong><code>%{</code> <em>NAME_OF_VARIABLE</em> + <code>}</code></strong> + where <em>NAME_OF_VARIABLE</em> can be a string taken + from the following list: + + <table> + + <tr> + <th>HTTP headers:</th> <th>connection & request:</th> <th /> + </tr> + + <tr> + <td> + HTTP_USER_AGENT<br /> + HTTP_REFERER<br /> + HTTP_COOKIE<br /> + HTTP_FORWARDED<br /> + HTTP_HOST<br /> + HTTP_PROXY_CONNECTION<br /> + HTTP_ACCEPT<br /> + </td> + + <td> + REMOTE_ADDR<br /> + REMOTE_HOST<br /> + REMOTE_PORT<br /> + REMOTE_USER<br /> + REMOTE_IDENT<br /> + REQUEST_METHOD<br /> + SCRIPT_FILENAME<br /> + PATH_INFO<br /> + QUERY_STRING<br /> + AUTH_TYPE<br /> + </td> + + <td /> + </tr> + + <tr> + <th>server internals:</th> <th>system stuff:</th> <th>specials:</th> + </tr> + + <tr> + <td> + DOCUMENT_ROOT<br /> + SERVER_ADMIN<br /> + SERVER_NAME<br /> + SERVER_ADDR<br /> + SERVER_PORT<br /> + SERVER_PROTOCOL<br /> + SERVER_SOFTWARE<br /> + </td> + + <td> + TIME_YEAR<br /> + TIME_MON<br /> + TIME_DAY<br /> + TIME_HOUR<br /> + TIME_MIN<br /> + TIME_SEC<br /> + TIME_WDAY<br /> + TIME<br /> + </td> + + <td> + API_VERSION<br /> + THE_REQUEST<br /> + REQUEST_URI<br /> + REQUEST_FILENAME<br /> + IS_SUBREQ<br /> + HTTPS<br /> + </td> + </tr> + </table> + + <p>These variables all + correspond to the similarly named HTTP + MIME-headers, C variables of the Apache server or + <code>struct tm</code> fields of the Unix system. + Most are documented elsewhere in the Manual or in + the CGI specification. Those that are special to + mod_rewrite include those below.</p> + <div class="note"> + <dl> + <dt><code>IS_SUBREQ</code></dt> + + <dd>Will contain the text "true" if the request + currently being processed is a sub-request, + "false" otherwise. Sub-requests may be generated + by modules that need to resolve additional files + or URIs in order to complete their tasks.</dd> + + <dt><code>API_VERSION</code></dt> + + <dd>This is the version of the Apache module API + (the internal interface between server and + module) in the current httpd build, as defined in + include/ap_mmn.h. The module API version + corresponds to the version of Apache in use (in + the release version of Apache 1.3.14, for + instance, it is 19990320:10), but is mainly of + interest to module authors.</dd> + + <dt><code>THE_REQUEST</code></dt> + + <dd>The full HTTP request line sent by the + browser to the server (e.g., "<code>GET + /index.html HTTP/1.1</code>"). This does not + include any additional headers sent by the + browser.</dd> + + <dt><code>REQUEST_URI</code></dt> + + <dd>The resource requested in the HTTP request + line. (In the example above, this would be + "/index.html".)</dd> + + <dt><code>REQUEST_FILENAME</code></dt> + + <dd>The full local filesystem path to the file or + script matching the request.</dd> + + <dt><code>HTTPS</code></dt> + + <dd>Will contain the text "on" if the connection is + using SSL/TLS, or "off" otherwise. (This variable + can be safely used regardless of whether or not + <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> is loaded).</dd> + + </dl> +</div> + </li> + </ul> + + <p>Other things you should be aware of:</p> + + <ol> + <li>The variables SCRIPT_FILENAME and REQUEST_FILENAME + contain the same value - the value of the + <code>filename</code> field of the internal + <code>request_rec</code> structure of the Apache server. + The first name is the commonly known CGI variable name + while the second is the appropriate counterpart of + REQUEST_URI (which contains the value of the + <code>uri</code> field of <code>request_rec</code>).</li> + + <li> + <code>%{ENV:variable}</code>, where <em>variable</em> can be + any environment variable, is also available. + This is looked-up via internal + Apache structures and (if not found there) via + <code>getenv()</code> from the Apache server process.</li> + + <li> + <code>%{SSL:variable}</code>, where <em>variable</em> is the + name of an <a href="mod_ssl.html#envvars">SSL environment + variable</a>, can be used whether or not + <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> is loaded, but will always expand to + the empty string if it is not. Example: + <code>%{SSL:SSL_CIPHER_USEKEYSIZE}</code> may expand to + <code>128</code>.</li> + + <li> + <code>%{HTTP:header}</code>, where <em>header</em> can be + any HTTP MIME-header name, can always be used to obtain the + value of a header sent in the HTTP request. + Example: <code>%{HTTP:Proxy-Connection}</code> is + the value of the HTTP header + ``<code>Proxy-Connection:</code>''.</li> + + <li> + <code>%{LA-U:variable}</code> can be used for look-aheads which perform + an internal (URL-based) sub-request to determine the final + value of <em>variable</em>. This can be used to access + variable for rewriting which is not available at the current + stage, but will be set in a later phase. + <p>For instance, to rewrite according to the + <code>REMOTE_USER</code> variable from within the + per-server context (<code>httpd.conf</code> file) you must + use <code>%{LA-U:REMOTE_USER}</code> - this + variable is set by the authorization phases, which come + <em>after</em> the URL translation phase (during which mod_rewrite + operates).</p> + <p>On the other hand, because mod_rewrite implements + its per-directory context (<code>.htaccess</code> file) via + the Fixup phase of the API and because the authorization + phases come <em>before</em> this phase, you just can use + <code>%{REMOTE_USER}</code> in that context.</p></li> + + <li> + <code>%{LA-F:variable}</code> can be used to perform an internal + (filename-based) sub-request, to determine the final value + of <em>variable</em>. Most of the time, this is the same as + LA-U above.</li> + </ol> + + <p><em>CondPattern</em> is the condition pattern, + a regular expression which is applied to the + current instance of the <em>TestString</em>. + <em>TestString</em> is first evaluated, before being matched against + <em>CondPattern</em>.</p> + + <p><strong>Remember:</strong> <em>CondPattern</em> is a + <em>perl compatible regular expression</em> with some + additions:</p> + + <ol> + <li>You can prefix the pattern string with a + '<code>!</code>' character (exclamation mark) to specify a + <strong>non</strong>-matching pattern.</li> + + <li> + There are some special variants of <em>CondPatterns</em>. + Instead of real regular expression strings you can also + use one of the following: + + <ul> + + <li>'<strong><CondPattern</strong>' (lexicographically + precedes)<br /> + Treats the <em>CondPattern</em> as a plain string and + compares it lexicographically to <em>TestString</em>. True if + <em>TestString</em> lexicographically precedes + <em>CondPattern</em>.</li> + + <li>'<strong>>CondPattern</strong>' (lexicographically + follows)<br /> + Treats the <em>CondPattern</em> as a plain string and + compares it lexicographically to <em>TestString</em>. True if + <em>TestString</em> lexicographically follows + <em>CondPattern</em>.</li> + + <li>'<strong>=CondPattern</strong>' (lexicographically + equal)<br /> + Treats the <em>CondPattern</em> as a plain string and + compares it lexicographically to <em>TestString</em>. True if + <em>TestString</em> is lexicographically equal to + <em>CondPattern</em> (the two strings are exactly + equal, character for character). If <em>CondPattern</em> + is <code>""</code> (two quotation marks) this + compares <em>TestString</em> to the empty string.</li> + + <li>'<strong>-d</strong>' (is + <strong>d</strong>irectory)<br /> + Treats the <em>TestString</em> as a pathname and tests + whether or not it exists, and is a directory.</li> + + <li>'<strong>-f</strong>' (is regular + <strong>f</strong>ile)<br /> + Treats the <em>TestString</em> as a pathname and tests + whether or not it exists, and is a regular file.</li> + + <li>'<strong>-s</strong>' (is regular file, with + <strong>s</strong>ize)<br /> + Treats the <em>TestString</em> as a pathname and tests + whether or not it exists, and is a regular file with size greater + than zero.</li> + + <li>'<strong>-l</strong>' (is symbolic + <strong>l</strong>ink)<br /> + Treats the <em>TestString</em> as a pathname and tests + whether or not it exists, and is a symbolic link.</li> + + <li>'<strong>-F</strong>' (is existing file, via + subrequest)<br /> + Checks whether or not <em>TestString</em> is a valid file, + accessible via all the server's currently-configured + access controls for that path. This uses an internal + subrequest to do the check, so use it with care - + it can impact your server's performance!</li> + + <li>'<strong>-U</strong>' (is existing URL, via + subrequest)<br /> + Checks whether or not <em>TestString</em> is a valid URL, + accessible via all the server's currently-configured + access controls for that path. This uses an internal + subrequest to do the check, so use it with care - + it can impact your server's performance!</li> + </ul> + +<div class="note"><h3>Note</h3> + All of these tests can + also be prefixed by an exclamation mark ('!') to + negate their meaning. +</div> + </li> + + <li>You can also set special flags for + <em>CondPattern</em> by appending + <strong><code>[</code><em>flags</em><code>]</code></strong> + as the third argument to the <code>RewriteCond</code> + directive, where <em>flags</em> is a comma-separated list of any of the + following flags: + + <ul> + <li>'<strong><code>nocase|NC</code></strong>' + (<strong>n</strong>o <strong>c</strong>ase)<br /> + This makes the test case-insensitive - differences + between 'A-Z' and 'a-z' are ignored, both in the + expanded <em>TestString</em> and the <em>CondPattern</em>. + This flag is effective only for comparisons between + <em>TestString</em> and <em>CondPattern</em>. It has no + effect on filesystem and subrequest checks.</li> + + <li> + '<strong><code>ornext|OR</code></strong>' + (<strong>or</strong> next condition)<br /> + Use this to combine rule conditions with a local OR + instead of the implicit AND. Typical example: + +<div class="example"><pre> +RewriteCond %{REMOTE_HOST} ^host1.* [OR] +RewriteCond %{REMOTE_HOST} ^host2.* [OR] +RewriteCond %{REMOTE_HOST} ^host3.* +RewriteRule ...some special stuff for any of these hosts... +</pre></div> + + Without this flag you would have to write the condition/rule + pair three times. + </li> + </ul> + </li> + </ol> + + <p><strong>Example:</strong></p> + + <p>To rewrite the Homepage of a site according to the + ``<code>User-Agent:</code>'' header of the request, you can + use the following: </p> + +<div class="example"><pre> +RewriteCond %{HTTP_USER_AGENT} ^Mozilla.* +RewriteRule ^/$ /homepage.max.html [L] + +RewriteCond %{HTTP_USER_AGENT} ^Lynx.* +RewriteRule ^/$ /homepage.min.html [L] + +RewriteRule ^/$ /homepage.std.html [L] +</pre></div> + + <p>Explanation: If you use a browser which identifies itself + as 'Mozilla' (including Netscape Navigator, Mozilla etc), then you + get the max homepage (which could include frames, or other special + features). + If you use the Lynx browser (which is terminal-based), then + you get the min homepage (which could be a version designed for + easy, text-only browsing). + If neither of these conditions apply (you use any other browser, + or your browser identifies itself as something non-standard), you get + the std (standard) homepage.</p> + + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteEngine" id="RewriteEngine">RewriteEngine</a> <a name="rewriteengine" id="rewriteengine">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables or disables runtime rewriting engine</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteEngine on|off</code></td></tr> +<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>RewriteEngine off</code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> +<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +</table> + + <p>The <code class="directive">RewriteEngine</code> directive enables or + disables the runtime rewriting engine. If it is set to + <code>off</code> this module does no runtime processing at + all. It does not even update the <code>SCRIPT_URx</code> + environment variables.</p> + + <p>Use this directive to disable the module instead of + commenting out all the <code class="directive"><a href="#rewriterule">RewriteRule</a></code> directives!</p> + + <p>Note that, by default, rewrite configurations are not + inherited. This means that you need to have a + <code>RewriteEngine on</code> directive for each virtual host + in which you wish to use it.</p> + + <p><code class="directive">RewriteMap</code> directives of the type <code>prg</code> + are not started during server initialization if they're defined in a + context that does not have <code class="directive">RewriteEngine</code> set to + <code>on</code></p> + + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteLock" id="RewriteLock">RewriteLock</a> <a name="rewritelock" id="rewritelock">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the name of the lock file used for <code class="directive"><a href="#rewritemap">RewriteMap</a></code> +synchronization</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteLock <em>file-path</em></code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +</table> + <p>This directive sets the filename for a synchronization + lockfile which mod_rewrite needs to communicate with <code class="directive"><a href="#rewritemap">RewriteMap</a></code> + <em>programs</em>. Set this lockfile to a local path (not on a + NFS-mounted device) when you want to use a rewriting + map-program. It is not required for other types of rewriting + maps.</p> + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteLog" id="RewriteLog">RewriteLog</a> <a name="rewritelog" id="rewritelog">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the name of the file used for logging rewrite engine +processing</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteLog <em>file-path</em></code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +</table> + <p>The <code class="directive">RewriteLog</code> directive sets the name + of the file to which the server logs any rewriting actions it + performs. If the name does not begin with a slash + ('<code>/</code>') then it is assumed to be relative to the + <em>Server Root</em>. The directive should occur only once per + server config.</p> + +<div class="note"> To disable the logging of + rewriting actions it is not recommended to set + <em>Filename</em> to <code>/dev/null</code>, because + although the rewriting engine does not then output to a + logfile it still creates the logfile output internally. + <strong>This will slow down the server with no advantage + to the administrator!</strong> To disable logging either + remove or comment out the <code class="directive">RewriteLog</code> + directive or use <code>RewriteLogLevel 0</code>! +</div> + +<div class="note"><h3>Security</h3> + +See the <a href="../misc/security_tips.html">Apache Security Tips</a> +document for details on how your security could be compromised if the +directory where logfiles are stored is writable by anyone other than +the user that starts the server. +</div> + +<div class="example"><h3>Example</h3><p><code> +RewriteLog "/usr/local/var/apache/logs/rewrite.log" +</code></p></div> + + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteLogLevel" id="RewriteLogLevel">RewriteLogLevel</a> <a name="rewriteloglevel" id="rewriteloglevel">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the verbosity of the log file used by the rewrite +engine</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteLogLevel <em>Level</em></code></td></tr> +<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>RewriteLogLevel 0</code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +</table> + <p>The <code class="directive">RewriteLogLevel</code> directive sets the + verbosity level of the rewriting logfile. The default level 0 + means no logging, while 9 or more means that practically all + actions are logged.</p> + + <p>To disable the logging of rewriting actions simply set + <em>Level</em> to 0. This disables all rewrite action + logs.</p> + +<div class="note"> Using a high value for + <em>Level</em> will slow down your Apache server + dramatically! Use the rewriting logfile at a + <em>Level</em> greater than 2 only for debugging! +</div> + +<div class="example"><h3>Example</h3><p><code> +RewriteLogLevel 3 +</code></p></div> + + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteMap" id="RewriteMap">RewriteMap</a> <a name="rewritemap" id="rewritemap">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Defines a mapping function for key-lookup</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteMap <em>MapName</em> <em>MapType</em>:<em>MapSource</em> +</code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The choice of different dbm types is available in +Apache 2.0.41 and later</td></tr> +</table> + <p>The <code class="directive">RewriteMap</code> directive defines a + <em>Rewriting Map</em> which can be used inside rule + substitution strings by the mapping-functions to + insert/substitute fields through a key lookup. The source of + this lookup can be of various types.</p> + + <p>The <a id="mapfunc" name="mapfunc"><em>MapName</em></a> is + the name of the map and will be used to specify a + mapping-function for the substitution strings of a rewriting + rule via one of the following constructs:</p> + + <p class="indent"> + <strong><code>${</code> <em>MapName</em> <code>:</code> + <em>LookupKey</em> <code>}</code><br /> + <code>${</code> <em>MapName</em> <code>:</code> + <em>LookupKey</em> <code>|</code> <em>DefaultValue</em> + <code>}</code></strong> + </p> + + <p>When such a construct occurs, the map <em>MapName</em> is + consulted and the key <em>LookupKey</em> is looked-up. If the + key is found, the map-function construct is substituted by + <em>SubstValue</em>. If the key is not found then it is + substituted by <em>DefaultValue</em> or by the empty string + if no <em>DefaultValue</em> was specified.</p> + + <p>For example, you might define a + <code class="directive">RewriteMap</code> as:</p> + + <div class="example"><p><code> + RewriteMap examplemap txt:/path/to/file/map.txt + </code></p></div> + + <p>You would then be able to use this map in a + <code class="directive">RewriteRule</code> as follows:</p> + + <div class="example"><p><code> + RewriteRule ^/ex/(.*) ${examplemap:$1} + </code></p></div> + + <p>The following combinations for <em>MapType</em> and + <em>MapSource</em> can be used:</p> + + <ul> + <li> + <strong>Standard Plain Text</strong><br /> + MapType: <code>txt</code>, MapSource: Unix filesystem + path to valid regular file + + <p>This is the standard rewriting map feature where the + <em>MapSource</em> is a plain ASCII file containing + either blank lines, comment lines (starting with a '#' + character) or pairs like the following - one per + line.</p> + + <p class="indent"> + <strong><em>MatchingKey</em> + <em>SubstValue</em></strong> + </p> + +<div class="example"><h3>Example</h3><pre> +## +## map.txt -- rewriting map +## + +Ralf.S.Engelschall rse # Bastard Operator From Hell +Mr.Joe.Average joe # Mr. Average +</pre></div> + +<div class="example"><p><code> +RewriteMap real-to-user txt:/path/to/file/map.txt +</code></p></div> + </li> + + <li> + <strong>Randomized Plain Text</strong><br /> + MapType: <code>rnd</code>, MapSource: Unix filesystem + path to valid regular file + + <p>This is identical to the Standard Plain Text variant + above but with a special post-processing feature: After + looking up a value it is parsed according to contained + ``<code>|</code>'' characters which have the meaning of + ``or''. In other words they indicate a set of + alternatives from which the actual returned value is + chosen randomly. For example, you might use the following map + file and directives to provide a random load balancing between + several back-end server, via a reverse-proxy. Images are sent + to one of the servers in the 'static' pool, while everything + else is sent to one of the 'dynamic' pool.</p> + <p>Example:</p> + +<div class="example"><h3>Rewrite map file</h3><pre> +## +## map.txt -- rewriting map +## + +static www1|www2|www3|www4 +dynamic www5|www6 +</pre></div> + +<div class="example"><h3>Configuration directives</h3><p><code> +RewriteMap servers rnd:/path/to/file/map.txt<br /> +<br /> +RewriteRule ^/(.*\.(png|gif|jpg)) http://${servers:static}/$1 +[NC,P,L]<br /> +RewriteRule ^/(.*) http://${servers:dynamic}/$1 [P,L] +</code></p></div> + </li> + + <li> + <strong>Hash File</strong><br /> MapType: + <code>dbm[=<em>type</em>]</code>, MapSource: Unix filesystem + path to valid regular file + + <p>Here the source is a binary format DBM file containing + the same contents as a <em>Plain Text</em> format file, but + in a special representation which is optimized for really + fast lookups. The <em>type</em> can be sdbm, gdbm, ndbm, or + db depending on <a href="../install.html#dbm">compile-time + settings</a>. If the <em>type</em> is ommitted, the + compile-time default will be chosen. You can create such a + file with any DBM tool or with the following Perl + script. Be sure to adjust it to create the appropriate + type of DBM. The example creates an NDBM file.</p> + +<div class="example"><pre> +#!/path/to/bin/perl +## +## txt2dbm -- convert txt map to dbm format +## + +use NDBM_File; +use Fcntl; + +($txtmap, $dbmmap) = @ARGV; + +open(TXT, "<$txtmap") or die "Couldn't open $txtmap!\n"; +tie (%DB, 'NDBM_File', $dbmmap,O_RDWR|O_TRUNC|O_CREAT, 0644) + or die "Couldn't create $dbmmap!\n"; + +while (<TXT>) { + next if (/^\s*#/ or /^\s*$/); + $DB{$1} = $2 if (/^\s*(\S+)\s+(\S+)/); +} + +untie %DB; +close(TXT); +</pre></div> + +<div class="example"><p><code> +$ txt2dbm map.txt map.db +</code></p></div> + </li> + + <li> + <strong>Internal Function</strong><br /> + MapType: <code>int</code>, MapSource: Internal Apache + function + + <p>Here, the source is an internal Apache function. + Currently you cannot create your own, but the following + functions already exist:</p> + + <ul> + <li><strong>toupper</strong>:<br /> + Converts the key to all upper case.</li> + + <li><strong>tolower</strong>:<br /> + Converts the key to all lower case.</li> + + <li><strong>escape</strong>:<br /> + Translates special characters in the key to + hex-encodings.</li> + + <li><strong>unescape</strong>:<br /> + Translates hex-encodings in the key back to + special characters.</li> + </ul> + </li> + + <li> + <strong>External Rewriting Program</strong><br /> + MapType: <code>prg</code>, MapSource: Unix filesystem + path to valid regular file + + <p>Here the source is a program, not a map file. To + create it you can use a language of your choice, but + the result has to be an executable program (either + object-code or a script with the magic cookie trick + '<code>#!/path/to/interpreter</code>' as the first + line).</p> + + <p>This program is started once, when the Apache server + is started, and then communicates with the rewriting engine + via its <code>stdin</code> and <code>stdout</code> + file-handles. For each map-function lookup it will + receive the key to lookup as a newline-terminated string + on <code>stdin</code>. It then has to give back the + looked-up value as a newline-terminated string on + <code>stdout</code> or the four-character string + ``<code>NULL</code>'' if it fails (<em>i.e.</em>, there + is no corresponding value for the given key). A trivial + program which will implement a 1:1 map (<em>i.e.</em>, + key == value) could be:</p> + + <p>External rewriting programs are not started if they're defined in a + context that does not have <code class="directive">RewriteEngine</code> set to + <code>on</code></p>. + +<div class="example"><pre> +#!/usr/bin/perl +$| = 1; +while (<STDIN>) { + # ...put here any transformations or lookups... + print $_; +} +</pre></div> + + <p>But be very careful:</p> + + <ol> + <li>``<em>Keep it simple, stupid</em>'' (KISS). + If this program hangs, it will cause Apache to hang + when trying to use the relevant rewrite rule.</li> + + <li>A common mistake is to use buffered I/O on + <code>stdout</code>. Avoid this, as it will cause a deadloop! + ``<code>$|=1</code>'' is used above, to prevent this.</li> + + <li>The <code class="directive"><a href="#rewritelock">RewriteLock</a></code> directive can + be used to define a lockfile which mod_rewrite can use to synchronize + communication with the mapping program. By default no such + synchronization takes place.</li> + </ol> + </li> + </ul> + <p>The <code class="directive">RewriteMap</code> directive can occur more than + once. For each mapping-function use one + <code class="directive">RewriteMap</code> directive to declare its rewriting + mapfile. While you cannot <strong>declare</strong> a map in + per-directory context it is of course possible to + <strong>use</strong> this map in per-directory context. </p> + +<div class="note"><h3>Note</h3> For plain text and DBM format files the +looked-up keys are cached in-core until the <code>mtime</code> of the +mapfile changes or the server does a restart. This way you can have +map-functions in rules which are used for <strong>every</strong> +request. This is no problem, because the external lookup only happens +once! +</div> + + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteOptions" id="RewriteOptions">RewriteOptions</a> <a name="rewriteoptions" id="rewriteoptions">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets some special options for the rewrite engine</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteOptions <var>Options</var></code></td></tr> +<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>RewriteOptions MaxRedirects=10</code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> +<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td><code>MaxRedirects</code> is available in Apache 2.0.45 and +later</td></tr> +</table> + + <p>The <code class="directive">RewriteOptions</code> directive sets some + special options for the current per-server or per-directory + configuration. The <em>Option</em> strings can be one of the + following:</p> + + <dl> + <dt><code>inherit</code></dt> + <dd>This forces the current configuration to inherit the + configuration of the parent. In per-virtual-server context + this means that the maps, conditions and rules of the main + server are inherited. In per-directory context this means + that conditions and rules of the parent directory's + <code>.htaccess</code> configuration are inherited.</dd> + + <dt><code>MaxRedirects=<var>number</var></code></dt> + <dd>In order to prevent endless loops of internal redirects + issued by per-directory <code class="directive"><a href="#rewriterule">RewriteRule</a></code>s, <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> aborts + the request after reaching a maximum number of such redirects and + responds with an 500 Internal Server Error. If you really need + more internal redirects than 10 per request, you may increase + the default to the desired value.</dd> + </dl> + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="RewriteRule" id="RewriteRule">RewriteRule</a> <a name="rewriterule" id="rewriterule">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Defines rules for the rewriting engine</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RewriteRule + <em>Pattern</em> <em>Substitution</em></code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> +<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_rewrite</td></tr> +<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The cookie-flag is available in Apache 2.0.40 and later.</td></tr> +</table> + <p>The <code class="directive">RewriteRule</code> directive is the real + rewriting workhorse. The directive can occur more than once, with + each instance defining a single rewrite rule. The + order in which these rules are defined is important - this is the order + in which they will be applied at run-time.</p> + + <p><a id="patterns" name="patterns"><em>Pattern</em></a> is + a perl compatible <a id="regexp" name="regexp">regular + expression</a>, which is applied to the current URL. + ``Current'' means the value of the URL when this rule is + applied. This may not be the originally requested URL, + which may already have matched a previous rule, and have + been altered.</p> + + <p>Some hints on the syntax of regular expressions:</p> + +<div class="note"><pre> +<strong>Text:</strong> + <strong><code>.</code></strong> Any single character + <strong><code>[</code></strong>chars<strong><code>]</code></strong> Character class: Any character of the class ``chars'' + <strong><code>[^</code></strong>chars<strong><code>]</code></strong> Character class: Not a character of the class ``chars'' + text1<strong><code>|</code></strong>text2 Alternative: text1 or text2 + +<strong>Quantifiers:</strong> + <strong><code>?</code></strong> 0 or 1 occurrences of the preceding text + <strong><code>*</code></strong> 0 or N occurrences of the preceding text (N > 0) + <strong><code>+</code></strong> 1 or N occurrences of the preceding text (N > 1) + +<strong>Grouping:</strong> + <strong><code>(</code></strong>text<strong><code>)</code></strong> Grouping of text + (used either to set the borders of an alternative as above, or + to make backreferences, where the <strong>N</strong>th group can + be referred to on the RHS of a RewriteRule as <code>$</code><strong>N</strong>) + +<strong>Anchors:</strong> + <strong><code>^</code></strong> Start-of-line anchor + <strong><code>$</code></strong> End-of-line anchor + +<strong>Escaping:</strong> + <strong><code>\</code></strong>char escape the given char + (for instance, to specify the chars "<code>.[]()</code>" <em>etc.</em>) +</pre></div> + + <p>For more information about regular expressions, have a look at the + perl regular expression manpage ("<a href="http://perldoc.perl.org/perlre.html">perldoc + perlre</a>"). If you are interested in more detailed + information about regular expressions and their variants + (POSIX regex etc.) the following book is dedicated to this topic:</p> + + <p class="indent"> + <em>Mastering Regular Expressions, 2nd Edition</em><br /> + Jeffrey E.F. Friedl<br /> + O'Reilly & Associates, Inc. 2002<br /> + ISBN 0-596-00289-0<br /> + </p> + + <p>In mod_rewrite, the NOT character + ('<code>!</code>') is also available as a possible pattern + prefix. This enables you to negate a pattern; to say, for instance: + ``<em>if the current URL does <strong>NOT</strong> match this + pattern</em>''. This can be used for exceptional cases, where + it is easier to match the negative pattern, or as a last + default rule.</p> + +<div class="note"><h3>Note</h3> +When using the NOT character to negate a pattern, you cannot include +grouped wildcard parts in that pattern. This is because, when the +pattern does NOT match (ie, the negation matches), there are no +contents for the groups. Thus, if negated patterns are used, you +cannot use <code>$N</code> in the substitution string! +</div> + + <p>The <a id="rhs" name="rhs"><em>substitution</em></a> of a + rewrite rule is the string which is substituted for (or + replaces) the original URL which <em>Pattern</em> + matched. In addition to plain text, it can include</p> + + <ol> + <li>back-references (<code>$N</code>) to the RewriteRule + pattern</li> + + <li>back-references (<code>%N</code>) to the last matched + RewriteCond pattern</li> + + <li>server-variables as in rule condition test-strings + (<code>%{VARNAME}</code>)</li> + + <li><a href="#mapfunc">mapping-function</a> calls + (<code>${mapname:key|default}</code>)</li> + </ol> + + <p>Back-references are identifiers of the form + <code>$</code><strong>N</strong> + (<strong>N</strong>=0..9), which will be replaced + by the contents of the <strong>N</strong>th group of the + matched <em>Pattern</em>. The server-variables are the same + as for the <em>TestString</em> of a <code>RewriteCond</code> + directive. The mapping-functions come from the + <code>RewriteMap</code> directive and are explained there. + These three types of variables are expanded in the order above.</p> + + <p>As already mentioned, all rewrite rules are + applied to the <em>Substitution</em> (in the order in which + they are defined + in the config file). The URL is <strong>completely + replaced</strong> by the <em>Substitution</em> and the + rewriting process continues until all rules have been applied, + or it is explicitly terminated by a + <code><strong>L</strong></code> flag - see below.</p> + + <p>There is a special substitution string named + '<code>-</code>' which means: <strong>NO + substitution</strong>! This is useful in providing + rewriting rules which <strong>only</strong> match + URLs but do not substitute anything for them. It is commonly used + in conjunction with the <strong>C</strong> (chain) flag, in order + to apply more than one pattern before substitution occurs.</p> + + <p>Additionally you can set special <a name="rewriteflags" id="rewriteflags">flags</a> for <em>Substitution</em> by + appending <strong><code>[</code><em>flags</em><code>]</code></strong> + as the third argument to the <code>RewriteRule</code> + directive. <em>Flags</em> is a comma-separated list of any of the + following flags: </p> + + <ul> + <li>'<strong><code>chain|C</code></strong>' + (<strong>c</strong>hained with next rule)<br /> + This flag chains the current rule with the next rule + (which itself can be chained with the following rule, + and so on). This has the following effect: if a rule + matches, then processing continues as usual - + the flag has no effect. If the rule does + <strong>not</strong> match, then all following chained + rules are skipped. For instance, it can be used to remove the + ``<code>.www</code>'' part, inside a per-directory rule set, + when you let an external redirect happen (where the + ``<code>.www</code>'' part should not occur!).</li> + + <li> + '<strong><code>cookie|CO=</code></strong><em>NAME</em>:<em>VAL</em>:<em>domain</em>[:<em>lifetime</em>[:<em>path</em>]]' + (set <strong>co</strong>okie)<br /> + This sets a cookie in the client's browser. The cookie's name + is specified by <em>NAME</em> and the value is + <em>VAL</em>. The <em>domain</em> field is the domain of the + cookie, such as '.apache.org', the optional <em>lifetime</em> + is the lifetime of the cookie in minutes, and the optional + <em>path</em> is the path of the cookie</li> + + <li> + '<strong><code>env|E=</code></strong><em>VAR</em>:<em>VAL</em>' + (set <strong>e</strong>nvironment variable)<br /> + This forces an environment variable named <em>VAR</em> to + be set to the value <em>VAL</em>, where <em>VAL</em> can + contain regexp backreferences (<code>$N</code> and + <code>%N</code>) which will be expanded. You can use this + flag more than once, to set more than one variable. The + variables can later be dereferenced in many situations, most commonly + from within XSSI (via <code><!--#echo + var="VAR"--></code>) or CGI (<code>$ENV{'VAR'}</code>). + You can also dereference the variable in a later RewriteCond pattern, using + <code>%{ENV:VAR}</code>. Use this to strip + information from URLs, while maintaining a record of that information.</li> + + <li>'<strong><code>forbidden|F</code></strong>' (force URL + to be <strong>f</strong>orbidden)<br /> + This forces the current URL to be forbidden - it immediately + sends back a HTTP response of 403 (FORBIDDEN). + Use this flag in conjunction with + appropriate RewriteConds to conditionally block some + URLs.</li> + + <li>'<strong><code>gone|G</code></strong>' (force URL to be + <strong>g</strong>one)<br /> + This forces the current URL to be gone - it + immediately sends back a HTTP response of 410 (GONE). Use + this flag to mark pages which no longer exist as gone.</li> + + <li>'<strong><code>last|L</code></strong>' + (<strong>l</strong>ast rule)<br /> + Stop the rewriting process here and don't apply any more + rewrite rules. This corresponds to the Perl + <code>last</code> command or the <code>break</code> command + in C. Use this flag to prevent the currently + rewritten URL from being rewritten further by following + rules. For example, use it to rewrite the root-path URL + ('<code>/</code>') to a real one, <em>e.g.</em>, + '<code>/e/www/</code>'.</li> + + <li>'<strong><code>next|N</code></strong>' + (<strong>n</strong>ext round)<br /> + Re-run the rewriting process (starting again with the + first rewriting rule). This time, the URL to match is no longer + the original URL, but rather the URL returned by the last rewriting rule. + This corresponds to the Perl <code>next</code> command or + the <code>continue</code> command in C. Use + this flag to restart the rewriting process - + to immediately go to the top of the loop.<br /> + <strong>Be careful not to create an infinite + loop!</strong></li> + + <li>'<strong><code>nocase|NC</code></strong>' + (<strong>n</strong>o <strong>c</strong>ase)<br /> + This makes the <em>Pattern</em> case-insensitive, + ignoring difference between 'A-Z' and + 'a-z' when <em>Pattern</em> is matched against the current + URL.</li> + + <li> + '<strong><code>noescape|NE</code></strong>' + (<strong>n</strong>o URI <strong>e</strong>scaping of + output)<br /> + This flag prevents mod_rewrite from applying the usual URI + escaping rules to the result of a rewrite. Ordinarily, + special characters (such as '%', '$', ';', and so on) + will be escaped into their hexcode equivalents ('%25', + '%24', and '%3B', respectively); this flag prevents this + from happening. This allows percent symbols to appear in + the output, as in +<div class="example"><p><code> + RewriteRule /foo/(.*) /bar?arg=P1\%3d$1 [R,NE] +</code></p></div> + + which would turn '<code>/foo/zed</code>' into a safe + request for '<code>/bar?arg=P1=zed</code>'. + </li> + + <li> + '<strong><code>nosubreq|NS</code></strong>' ( + <strong>n</strong>ot for internal + <strong>s</strong>ub-requests)<br /> + This flag forces the rewrite engine to skip a + rewrite rule if the current request is an internal + sub-request. For instance, sub-requests occur internally + in Apache when <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> tries to find out + information about possible directory default files + (<code>index.xxx</code>). On sub-requests it is not + always useful, and can even cause errors, if + the complete set of rules are applied. Use this flag to + exclude some rules.<br /> + To decide whether or not to use this rule: if you + prefix URLs with CGI-scripts, to force them to be + processed by the CGI-script, it's likely that you + will run into problems (or significant overhead) on + sub-requests. In these cases, use this flag. + </li> + + <li> + '<strong><code>proxy|P</code></strong>' (force + <strong>p</strong>roxy)<br /> + This flag forces the substitution part to be internally + sent as a proxy request and immediately (rewrite + processing stops here) put through the <a href="mod_proxy.html">proxy module</a>. You must make + sure that the substitution string is a valid URI + (typically starting with + <code>http://</code><em>hostname</em>) which can be + handled by the Apache proxy module. If not, you will get an + error from the proxy module. Use this flag to achieve a + more powerful implementation of the <a href="mod_proxy.html#proxypass">ProxyPass</a> directive, + to map remote content into the namespace of the local + server. + + <p>Note: <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> must be enabled in order + to use this flag.</p> + </li> + + <li> + '<strong><code>passthrough|PT</code></strong>' + (<strong>p</strong>ass <strong>t</strong>hrough to next + handler)<br /> + This flag forces the rewrite engine to set the + <code>uri</code> field of the internal + <code>request_rec</code> structure to the value of the + <code>filename</code> field. This flag is just a hack to + enable post-processing of the output of + <code>RewriteRule</code> directives, using + <code>Alias</code>, <code>ScriptAlias</code>, + <code>Redirect</code>, and other directives from + various URI-to-filename translators. For example, to rewrite + <code>/abc</code> to <code>/def</code> using + <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>, and then + <code>/def</code> to <code>/ghi</code> using + <code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code>: +<div class="example"><p><code> + RewriteRule ^/abc(.*) /def$1 [PT]<br /> + Alias /def /ghi +</code></p></div> + If you omit the <code>PT</code> flag, + <code>mod_rewrite</code> will rewrite + <code>uri=/abc/...</code> to + <code>filename=/def/...</code> as a full API-compliant + URI-to-filename translator should do. Then + <code>mod_alias</code> will try to do a + URI-to-filename transition, which will fail. + + <p>Note: <strong>You must use this flag if you want to + mix directives from different modules which allow + URL-to-filename translators</strong>. The typical example + is the use of <code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code> and + <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>.</p> + </li> + + <li>'<strong><code>qsappend|QSA</code></strong>' + (<strong>q</strong>uery <strong>s</strong>tring + <strong>a</strong>ppend)<br /> + This flag forces the rewrite engine to append a query + string part of the substitution string to the existing string, + instead of replacing it. Use this when you want to add more + data to the query string via a rewrite rule.</li> + + <li>'<strong><code>redirect|R</code> + [=<em>code</em>]</strong>' (force <a id="redirect" name="redirect"><strong>r</strong>edirect</a>)<br /> + Prefix <em>Substitution</em> with + <code>http://thishost[:thisport]/</code> (which makes the + new URL a URI) to force a external redirection. If no + <em>code</em> is given, a HTTP response of 302 (MOVED + TEMPORARILY) will be returned. If you want to use other response + codes in the range 300-400, simply specify the appropriate number + or use one of the following symbolic names: + <code>temp</code> (default), <code>permanent</code>, + <code>seeother</code>. Use this for rules to + canonicalize the URL and return it to the client - to + translate ``<code>/~</code>'' into + ``<code>/u/</code>'', or to always append a slash to + <code>/u/</code><em>user</em>, etc.<br /> + <strong>Note:</strong> When you use this flag, make + sure that the substitution field is a valid URL! Otherwise, + you will be redirecting to an invalid location. Remember + that this flag on its own will only prepend + <code>http://thishost[:thisport]/</code> to the URL, and rewriting + will continue. Usually, you will want to stop rewriting at this point, + and redirect immediately. To stop rewriting, you should add + the 'L' flag. + </li> + + <li>'<strong><code>skip|S</code></strong>=<em>num</em>' + (<strong>s</strong>kip next rule(s))<br /> + This flag forces the rewriting engine to skip the next + <em>num</em> rules in sequence, if the current rule + matches. Use this to make pseudo if-then-else constructs: + The last rule of the then-clause becomes + <code>skip=N</code>, where N is the number of rules in the + else-clause. (This is <strong>not</strong> the same as the + 'chain|C' flag!)</li> + + <li> + '<strong><code>type|T</code></strong>=<em>MIME-type</em>' + (force MIME <strong>t</strong>ype)<br /> + Force the MIME-type of the target file to be + <em>MIME-type</em>. This can be used to + set up the content-type based on some conditions. + For example, the following snippet allows <code>.php</code> files to + be <em>displayed</em> by <code>mod_php</code> if they are called with + the <code>.phps</code> extension: + <div class="example"><p><code> + RewriteRule ^(.+\.php)s$ $1 [T=application/x-httpd-php-source] + </code></p></div> + </li> + + </ul> + +<div class="note"><h3>Home directory expansion</h3> +<p> When the substitution string begins with a string +resembling "/~user" (via explicit text or backreferences), mod_rewrite performs +home directory expansion independent of the presence or configuration +of <code class="module"><a href="../mod/mod_userdir.html">mod_userdir</a></code>.</p> + +<p> This expansion does not occur when the <em>PT</em> +flag is used on the <code class="directive"><a href="#rewriterule">RewriteRule</a></code> +directive.</p> +</div> + +<div class="note"><h3>Note: Enabling rewrites in per-directory context</h3> + To enable the rewriting engine + for per-directory configuration files, you need to set + ``<code>RewriteEngine On</code>'' in these files + <strong>and</strong> ``<code>Options + FollowSymLinks</code>'' must be enabled. If your + administrator has disabled override of + <code>FollowSymLinks</code> for a user's directory, then + you cannot use the rewriting engine. This restriction is + needed for security reasons. + </div> + + <div class="note"><h3>Note: Pattern matching in per-directory context</h3> + Never forget that <em>Pattern</em> is +applied to a complete URL in per-server configuration +files. <strong>However, in per-directory configuration files, the +per-directory prefix (which always is the same for a specific +directory) is automatically <em>removed</em> for the pattern matching +and automatically <em>added</em> after the substitution has been +done.</strong> This feature is essential for many sorts of rewriting - +without this, you would always have to match the parent +directory which is not always possible. + + <p>There is one exception: If a substitution string + starts with ``<code>http://</code>'', then the directory + prefix will <strong>not</strong> be added, and an + external redirect or proxy throughput (if flag + <strong>P</strong> is used) is forced!</p> +</div> + + +<div class="note"><h3>Note: Substitution of Absolute URLs</h3> + <p>When you prefix a substitution field with + <code>http://thishost[:thisport]</code>, + <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> will automatically strip that + out. This auto-reduction on URLs with an implicit external redirect + is most useful in combination with + a mapping-function which generates the + hostname part.</p> + + <p><strong>Remember:</strong> An unconditional external + redirect to your own server will not work with the prefix + <code>http://thishost</code> because of this feature. To + achieve such a self-redirect, you have to use the + <strong>R</strong>-flag.</p> +</div> + +<div class="note"><h3>Note: Query String</h3> + <p>The <em>Pattern</em> will not be matched against the query string. + Instead, you must use a <code class="directive"><a href="#rewritecond">RewriteCond</a></code> with the + <code>%{QUERY_STRING}</code> variable. You can, however, create + URLs in the substitution string, containing a query string + part. Simply use a question mark inside the substitution string, to + indicate that the following text should be re-injected into the + query string. When you want to erase an existing query string, + end the substitution string with just a question mark. To + combine a new query string with an old one, use the + <code>[QSA]</code> flag.</p> +</div> + + <p>Here are all possible substitution combinations and their + meanings:</p> + + <p><strong>Inside per-server configuration + (<code>httpd.conf</code>)<br /> + for request ``<code>GET + /somepath/pathinfo</code>'':</strong><br /> + </p> + +<div class="note"><pre> +<strong>Given Rule</strong> <strong>Resulting Substitution</strong> +---------------------------------------------- ---------------------------------- +^/somepath(.*) otherpath$1 invalid, not supported + +^/somepath(.*) otherpath$1 [R] invalid, not supported + +^/somepath(.*) otherpath$1 [P] invalid, not supported +---------------------------------------------- ---------------------------------- +^/somepath(.*) /otherpath$1 /otherpath/pathinfo + +^/somepath(.*) /otherpath$1 [R] http://thishost/otherpath/pathinfo + via external redirection + +^/somepath(.*) /otherpath$1 [P] doesn't make sense, not supported +---------------------------------------------- ---------------------------------- +^/somepath(.*) http://thishost/otherpath$1 /otherpath/pathinfo + +^/somepath(.*) http://thishost/otherpath$1 [R] http://thishost/otherpath/pathinfo + via external redirection + +^/somepath(.*) http://thishost/otherpath$1 [P] doesn't make sense, not supported +---------------------------------------------- ---------------------------------- +^/somepath(.*) http://otherhost/otherpath$1 http://otherhost/otherpath/pathinfo + via external redirection + +^/somepath(.*) http://otherhost/otherpath$1 [R] http://otherhost/otherpath/pathinfo + via external redirection + (the [R] flag is redundant) + +^/somepath(.*) http://otherhost/otherpath$1 [P] http://otherhost/otherpath/pathinfo + via internal proxy +</pre></div> + + <p><strong>Inside per-directory configuration for + <code>/somepath</code><br /> + (<code>/physical/path/to/somepath/.htacccess</code>, with + <code>RewriteBase /somepath</code>)<br /> + for request ``<code>GET + /somepath/localpath/pathinfo</code>'':</strong><br /> + </p> + +<div class="note"><pre> +<strong>Given Rule</strong> <strong>Resulting Substitution</strong> +---------------------------------------------- ---------------------------------- +^localpath(.*) otherpath$1 /somepath/otherpath/pathinfo + +^localpath(.*) otherpath$1 [R] http://thishost/somepath/otherpath/pathinfo + via external redirection + +^localpath(.*) otherpath$1 [P] doesn't make sense, not supported +---------------------------------------------- ---------------------------------- +^localpath(.*) /otherpath$1 /otherpath/pathinfo + +^localpath(.*) /otherpath$1 [R] http://thishost/otherpath/pathinfo + via external redirection + +^localpath(.*) /otherpath$1 [P] doesn't make sense, not supported +---------------------------------------------- ---------------------------------- +^localpath(.*) http://thishost/otherpath$1 /otherpath/pathinfo + +^localpath(.*) http://thishost/otherpath$1 [R] http://thishost/otherpath/pathinfo + via external redirection + +^localpath(.*) http://thishost/otherpath$1 [P] doesn't make sense, not supported +---------------------------------------------- ---------------------------------- +^localpath(.*) http://otherhost/otherpath$1 http://otherhost/otherpath/pathinfo + via external redirection + +^localpath(.*) http://otherhost/otherpath$1 [R] http://otherhost/otherpath/pathinfo + via external redirection + (the [R] flag is redundant) + +^localpath(.*) http://otherhost/otherpath$1 [P] http://otherhost/otherpath/pathinfo + via internal proxy +</pre></div> + +</div> +</div> +<div class="bottomlang"> +<p><span>Available Languages: </span><a href="../en/mod/mod_rewrite.html" title="English"> en </a></p> +</div><div id="footer"> +<p class="apache">Copyright 2009 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>
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