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| <ul><li><a href="http://httpd.apache.org/docs/current/">Current release version of Apache HTTP Server documentation</a></li></ul><p>You may follow <a href="http://httpd.apache.org/docs/current/mod/mod_rewrite.html">this link</a> to go to the current version of this document.</p></div><div id="preamble"><h1>Apache Module mod_rewrite</h1> |
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| </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> |
| |
| <dt><code>AllowAnyURI</code></dt> |
| <dd> |
| |
| <p>When <code class="directive"><a href="#rewriterule">RewriteRule</a></code> |
| is used in <code>VirtualHost</code> or server context with |
| version 2.0.65 or later of httpd, <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> |
| will only process the rewrite rules if the request URI is a <a href="./directive-dict.html#Syntax">URL-path</a>. This avoids |
| some security issues where particular rules could allow |
| "surprising" pattern expansions (see <a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3368">CVE-2011-3368</a> |
| and <a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-4317">CVE-2011-4317</a>). |
| To lift the restriction on matching a URL-path, the |
| <code>AllowAnyURI</code> option can be enabled, and |
| <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> will apply the rule set to any |
| request URI string, regardless of whether that string matches |
| the URL-path grammar required by the HTTP specification.</p> |
| |
| <div class="warning"> |
| <h3>Security Warning</h3> |
| |
| <p>Enabling this option will make the server vulnerable to |
| security issues if used with rewrite rules which are not |
| carefully authored. It is <strong>strongly recommended</strong> |
| that this option is not used. In particular, beware of input |
| strings containing the '<code>@</code>' character which could |
| change the interpretation of the transformed URI, as per the |
| above CVE names.</p> |
| </div> |
| </dd> |
| |
| <dt><code>MergeBase</code></dt> |
| <dd> |
| |
| <p>With this option, the value of <code class="directive"><a href="#rewritebase">RewriteBase</a></code> is copied from where it's explicitly defined |
| into any sub-directory or sub-location that doesn't define its own |
| <code class="directive"><a href="#rewritebase">RewriteBase</a></code>. |
| This flag is available for Apache HTTP Server 2.0.65 and later.</p> |
| </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> |
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