diff options
| author |   hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 03:10:21 -0500 |
|---|---|---|
| committer | hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 03:10:21 -0500 |
| commit | c0b7206652b2852bc574694e7ba07ba1c2acdc00 (patch) | |
| tree | 5cb95cb0e19e03610525903df46279df2c3b7eb1 /rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en | |
| parent | b6d3d6e668b793220f2d3af1bc3e828553dc3fe6 (diff) | |
delete app
Change-Id: Id4c572809969ebe89e946e88063eaed262cff3f2
Signed-off-by: hongbotian <hongbo.tianhongbo@huawei.com>
Diffstat (limited to 'rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en')
| -rw-r--r-- | rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en | 1671 |
1 files changed, 0 insertions, 1671 deletions
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 deleted file mode 100644 index 328bbf92..00000000 --- a/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_rewrite.html.en +++ /dev/null @@ -1,1671 +0,0 @@ -<?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>
\ No newline at end of file |