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23 <modulesynopsis metafile="mod_rewrite.xml.meta">
25 <name>mod_rewrite</name>
27 <description>Provides a rule-based rewriting engine to rewrite requested
28 URLs on the fly</description>
30 <status>Extension</status>
31 <sourcefile>mod_rewrite.c</sourcefile>
32 <identifier>rewrite_module</identifier>
35 <p>The <module>mod_rewrite</module> module uses a rule-based rewriting
36 engine, based on a regular-expression parser, to rewrite requested URLs on
37 the fly. By default, <module>mod_rewrite</module> maps a URL to a filesystem
38 path. However, it can also be used to redirect one URL to another URL, or
39 to invoke an internal proxy fetch.</p>
40 <p><module>mod_rewrite</module> provides a flexible and powerful way to
41 manipulate URLs using an unlimited number of rules. Each rule can have an
42 unlimited number of attached rule conditions, to allow you to rewrite URL
43 based on server variables, environment variables, HTTP headers, or time
45 <p><module>mod_rewrite</module> operates on the full URL path, including the
46 path-info section. A rewrite rule can be invoked in
47 <code>httpd.conf</code> or in <code>.htaccess</code>. The path generated
48 by a rewrite rule can include a query string, or can lead to internal
49 sub-processing, external request redirection, or internal proxy
52 <p>Further details, discussion, and examples, are provided in the
53 <a href="../rewrite/">detailed mod_rewrite documentation</a>.</p>
56 <section id="logging"><title>Logging</title>
58 <p><module>mod_rewrite</module> offers detailed logging of its actions
59 at the <code>trace1</code> to <code>trace8</code> log levels. The
60 log level can be set specifically for <module>mod_rewrite</module>
61 using the <directive module="core">LogLevel</directive> directive: Up to
62 level <code>debug</code>, no actions are logged, while <code>trace8</code>
63 means that practically all actions are logged.</p>
66 Using a high trace log level for <module>mod_rewrite</module>
67 will slow down your Apache HTTP Server dramatically! Use a log
68 level higher than <code>trace2</code> only for debugging!
71 <example><title>Example</title>
72 LogLevel alert rewrite:trace3
75 <note><title>RewriteLog</title>
76 <p>Those familiar with earlier versions of
77 <module>mod_rewrite</module> will no doubt be looking for the
78 <code>RewriteLog</code> and <code>RewriteLogLevel</code>
79 directives. This functionality has been completely replaced by the
80 new per-module logging configuration mentioned above.
83 <p>To get just the <module>mod_rewrite</module>-specific log
84 messages, pipe the log file through grep:</p>
86 tail -f error_log|fgrep '[rewrite:'
93 <name>RewriteEngine</name>
94 <description>Enables or disables runtime rewriting engine</description>
95 <syntax>RewriteEngine on|off</syntax>
96 <default>RewriteEngine off</default>
97 <contextlist><context>server config</context><context>virtual host</context>
98 <context>directory</context><context>.htaccess</context></contextlist>
99 <override>FileInfo</override>
103 <p>The <directive>RewriteEngine</directive> directive enables or
104 disables the runtime rewriting engine. If it is set to
105 <code>off</code> this module does no runtime processing at
106 all. It does not even update the <code>SCRIPT_URx</code>
107 environment variables.</p>
109 <p>Use this directive to disable the module instead of
110 commenting out all the <directive
111 module="mod_rewrite">RewriteRule</directive> directives!</p>
113 <p>Note that rewrite configurations are not
114 inherited by virtual hosts. This means that you need to have a
115 <code>RewriteEngine on</code> directive for each virtual host
116 in which you wish to use rewrite rules.</p>
118 <p><directive>RewriteMap</directive> directives of the type <code>prg</code>
119 are not started during server initialization if they're defined in a
120 context that does not have <directive>RewriteEngine</directive> set to
127 <name>RewriteOptions</name>
128 <description>Sets some special options for the rewrite engine</description>
129 <syntax>RewriteOptions <var>Options</var></syntax>
130 <contextlist><context>server config</context><context>virtual host</context>
131 <context>directory</context><context>.htaccess</context></contextlist>
132 <override>FileInfo</override>
133 <compatibility><code>MaxRedirects</code> is no longer available in version 2.1 and
134 later</compatibility>
137 <p>The <directive>RewriteOptions</directive> directive sets some
138 special options for the current per-server or per-directory
139 configuration. The <em>Option</em> string can currently
140 only be one of the following:</p>
143 <dt><code>Inherit</code></dt>
146 <p>This forces the current configuration to inherit the
147 configuration of the parent. In per-virtual-server context,
148 this means that the maps, conditions and rules of the main
149 server are inherited. In per-directory context this means
150 that conditions and rules of the parent directory's
151 <code>.htaccess</code> configuration or
152 <directive type="section" module="core">Directory</directive>
153 sections are inherited. The inherited rules are virtually copied
154 to the section where this directive is being used. If used in
155 combination with local rules, the inherited rules are copied behind
156 the local rules. The position of this directive - below or above
157 of local rules - has no influence on this behavior. If local
158 rules forced the rewriting to stop, the inherited rules won't
161 <note type="warning">
162 Rules inherited from the parent scope are applied
163 <strong>after</strong> rules specified in the child scope.
167 <dt><code>InheritBefore</code></dt>
169 <p> Like <code>Inherit</code> above, but the rules from the parent scope
170 are applied <strong>before</strong> rules specified in the child scope.
171 Available in Apache HTTP Server 2.3.10 and later.</p>
181 <name>RewriteMap</name>
182 <description>Defines a mapping function for key-lookup</description>
183 <syntax>RewriteMap <em>MapName</em> <em>MapType</em>:<em>MapSource</em>
185 <contextlist><context>server config</context><context>virtual host</context>
187 <compatibility>The choice of different dbm types is available in
188 Apache HTTP Server 2.0.41 and later</compatibility>
191 <p>The <directive>RewriteMap</directive> directive defines a
192 <em>Rewriting Map</em> which can be used inside rule
193 substitution strings by the mapping-functions to
194 insert/substitute fields through a key lookup. The source of
195 this lookup can be of various types.</p>
197 <p>The <a id="mapfunc" name="mapfunc"><em>MapName</em></a> is
198 the name of the map and will be used to specify a
199 mapping-function for the substitution strings of a rewriting
200 rule via one of the following constructs:</p>
203 <strong><code>${</code> <em>MapName</em> <code>:</code>
204 <em>LookupKey</em> <code>}</code><br />
205 <code>${</code> <em>MapName</em> <code>:</code>
206 <em>LookupKey</em> <code>|</code> <em>DefaultValue</em>
207 <code>}</code></strong>
210 <p>When such a construct occurs, the map <em>MapName</em> is
211 consulted and the key <em>LookupKey</em> is looked-up. If the
212 key is found, the map-function construct is substituted by
213 <em>SubstValue</em>. If the key is not found then it is
214 substituted by <em>DefaultValue</em> or by the empty string
215 if no <em>DefaultValue</em> was specified. Empty values
216 behave as if the key was absent, therefore it is not possible
217 to distinguish between empty-valued keys and absent keys.</p>
219 <p>For example, you might define a
220 <directive>RewriteMap</directive> as:</p>
223 RewriteMap examplemap txt:/path/to/file/map.txt
226 <p>You would then be able to use this map in a
227 <directive>RewriteRule</directive> as follows:</p>
230 RewriteRule ^/ex/(.*) ${examplemap:$1}
233 <p>The following combinations for <em>MapType</em> and
234 <em>MapSource</em> can be used:</p>
239 <dd>A plain text file containing space-separated key-value
240 pairs, one per line. (<a href="../rewrite/rewritemap.html#txt">Details ...</a>)</dd>
243 <dd>Randomly selects an entry from a plain text file (<a href="../rewrite/rewritemap.html#rnd">Details ...</a>)</dd>
246 <dd>Looks up an entry in a dbm file containing name, value
247 pairs. Hash is constructed from a plain text file format using
248 the <code><a href="../programs/httxt2dbm.html">httxt2dbm</a></code>
249 utility. (<a href="../rewrite/rewritemap.html#dbm">Details ...</a>)</dd>
252 <dd>One of the four available internal functions provided by
253 <code>RewriteMap</code>: toupper, tolower, escape or
254 unescape. (<a href="../rewrite/rewritemap.html#int">Details ...</a>)</dd>
257 <dd>Calls an external program or script to process the
258 rewriting. (<a href="../rewrite/rewritemap.html#prg">Details ...</a>)</dd>
260 <dt>dbd or fastdbd</dt>
261 <dd>A SQL SELECT statement to be performed to look up the
262 rewrite target. (<a href="../rewrite/rewritemap.html#dbd">Details ...</a>)</dd>
265 <p>Further details, and numerous examples, may be found in the <a
266 href="../rewrite/rewritemap.html">RewriteMap HowTo</a></p>
272 <name>RewriteBase</name>
273 <description>Sets the base URL for per-directory rewrites</description>
274 <syntax>RewriteBase <em>URL-path</em></syntax>
275 <default>None</default>
276 <contextlist><context>directory</context><context>.htaccess</context>
278 <override>FileInfo</override>
281 <p>The <directive>RewriteBase</directive> directive explicitly
282 sets the base URL-path (not filesystem directory path!) for per-directory rewrites
283 that result in the substitution of a relative path.
284 When you use a <directive module="mod_rewrite">RewriteRule</directive>
285 in a <code>.htaccess</code> file, <module>mod_rewrite</module> strips off
286 the local directory prefix before processing, then rewrites the rest of
287 the URL. When the rewrite is completed, <module>mod_rewrite</module>
288 automatically adds the local directory prefix (or the
289 <directive>RewriteBase</directive> when set) back on to the substitution
290 before handing it back to the core of the server as if it were the original
293 <p>This directive is <em>required</em> for per-directory rewrites whose context
294 is a directory made available via the <directive module="mod_alias">Alias</directive>
295 directive, when the substitution uses a relative path.</p>
297 <p>If your URL path does not exist verbatim on the filesystem,
298 or isn't directly under your <directive module="core">DocumentRoot</directive>,
299 you must use <directive>RewriteBase</directive> in every
300 <code>.htaccess</code> file where you want to use <directive
301 module="mod_rewrite">RewriteRule</directive> directives.</p>
303 <p>The example below demonstrates how to map
304 http://example.com/myapp/index.html to
305 /home/www/example/newsite.html, in a <code>.htaccess</code> file. This
306 assumes that the content available at
307 http://example.com/ is on disk at /home/www/example/</p>
311 # The URL-path used to get to this context, not the filesystem path
313 RewriteRule ^index\.html$ newsite.html
322 <name>RewriteCond</name>
323 <description>Defines a condition under which rewriting will take place
326 <em>TestString</em> <em>CondPattern</em></syntax>
327 <contextlist><context>server config</context><context>virtual host</context>
328 <context>directory</context><context>.htaccess</context></contextlist>
329 <override>FileInfo</override>
332 <p>The <directive>RewriteCond</directive> directive defines a
333 rule condition. One or more <directive>RewriteCond</directive>
334 can precede a <directive module="mod_rewrite">RewriteRule</directive>
335 directive. The following rule is then only used if both
336 the current state of the URI matches its pattern, <strong
337 >and</strong> if these conditions are met.</p>
339 <p><em>TestString</em> is a string which can contain the
340 following expanded constructs in addition to plain text:</p>
344 <strong>RewriteRule backreferences</strong>: These are
345 backreferences of the form <strong><code>$N</code></strong>
346 (0 <= N <= 9). $1 to $9 provide access to the grouped
347 parts (in parentheses) of the pattern, from the
348 <code>RewriteRule</code> which is subject to the current
349 set of <code>RewriteCond</code> conditions. $0 provides
350 access to the whole string matched by that pattern.
353 <strong>RewriteCond backreferences</strong>: These are
354 backreferences of the form <strong><code>%N</code></strong>
355 (0 <= N <= 9). %1 to %9 provide access to the grouped
356 parts (again, in parentheses) of the pattern, from the last matched
357 <code>RewriteCond</code> in the current set
358 of conditions. %0 provides access to the whole string matched by
362 <strong>RewriteMap expansions</strong>: These are
363 expansions of the form <strong><code
364 >${mapname:key|default}</code></strong>.
365 See <a href="#mapfunc">the documentation for
366 RewriteMap</a> for more details.
369 <strong>Server-Variables</strong>: These are variables of
371 <strong><code>%{</code> <em>NAME_OF_VARIABLE</em>
372 <code>}</code></strong>
373 where <em>NAME_OF_VARIABLE</em> can be a string taken
374 from the following list:
377 <columnspec><column width=".3"/><column width=".3"/>
378 <column width=".3"/></columnspec>
380 <th>HTTP headers:</th> <th>connection & request:</th> <th></th>
385 HTTP_USER_AGENT<br />
390 HTTP_PROXY_CONNECTION<br />
401 SCRIPT_FILENAME<br />
411 <th>server internals:</th> <th>date and time:</th> <th>specials:</th>
421 SERVER_PROTOCOL<br />
422 SERVER_SOFTWARE<br />
440 REQUEST_FILENAME<br />
448 <p>These variables all
449 correspond to the similarly named HTTP
450 MIME-headers, C variables of the Apache HTTP Server or
451 <code>struct tm</code> fields of the Unix system.
452 Most are documented elsewhere in the Manual or in
453 the CGI specification.</p>
455 <p>SERVER_NAME and SERVER_PORT depend on the values of
456 <directive module="core">UseCanonicalName</directive> and
457 <directive module="core">UseCanonicalPhysicalPort</directive>
460 <p>Those that are special to mod_rewrite include those below.</p>
463 <dt><code>IS_SUBREQ</code></dt>
465 <dd>Will contain the text "true" if the request
466 currently being processed is a sub-request,
467 "false" otherwise. Sub-requests may be generated
468 by modules that need to resolve additional files
469 or URIs in order to complete their tasks.</dd>
471 <dt><code>API_VERSION</code></dt>
473 <dd>This is the version of the Apache httpd module API
474 (the internal interface between server and
475 module) in the current httpd build, as defined in
476 include/ap_mmn.h. The module API version
477 corresponds to the version of Apache httpd in use (in
478 the release version of Apache httpd 1.3.14, for
479 instance, it is 19990320:10), but is mainly of
480 interest to module authors.</dd>
482 <dt><code>THE_REQUEST</code></dt>
484 <dd>The full HTTP request line sent by the
485 browser to the server (e.g., "<code>GET
486 /index.html HTTP/1.1</code>"). This does not
487 include any additional headers sent by the
490 <dt><code>REQUEST_URI</code></dt>
492 <dd>The resource requested in the HTTP request
493 line. (In the example above, this would be
496 <dt><code>REQUEST_FILENAME</code></dt>
498 <dd>The full local filesystem path to the file or
499 script matching the request, if this has already
500 been determined by the server at the time
501 <code>REQUEST_FILENAME</code> is referenced. Otherwise,
502 such as when used in virtual host context, the same
503 value as <code>REQUEST_URI</code>.</dd>
505 <dt><code>HTTPS</code></dt>
507 <dd>Will contain the text "on" if the connection is
508 using SSL/TLS, or "off" otherwise. (This variable
509 can be safely used regardless of whether or not
510 <module>mod_ssl</module> is loaded).</dd>
512 <dt><code>REQUEST_SCHEME</code></dt>
514 <dd>Will contain the scheme of the request (ususally
515 "http" or "https"). This value can be influenced with
516 <directive module="core">ServerName</directive>.</dd>
523 <p>If the <em>TestString</em> has the special value <code>expr</code>, the
524 <em>CondPattern</em> will be treated as a
525 <a href="../expr.html">ap_expr</a>.</p>
527 <p>Other things you should be aware of:</p>
531 <p>The variables SCRIPT_FILENAME and REQUEST_FILENAME
532 contain the same value - the value of the
533 <code>filename</code> field of the internal
534 <code>request_rec</code> structure of the Apache HTTP Server.
535 The first name is the commonly known CGI variable name
536 while the second is the appropriate counterpart of
537 REQUEST_URI (which contains the value of the
538 <code>uri</code> field of <code>request_rec</code>).</p>
539 <p>If a substitution occurred and the rewriting continues,
540 the value of both variables will be updated accordingly.</p>
541 <p>If used in per-server context (<em>i.e.</em>, before the
542 request is mapped to the filesystem) SCRIPT_FILENAME and
543 REQUEST_FILENAME cannot contain the full local filesystem
544 path since the path is unknown at this stage of processing.
545 Both variables will initially contain the value of REQUEST_URI
546 in that case. In order to obtain the full local filesystem
547 path of the request in per-server context, use an URL-based
548 look-ahead <code>%{LA-U:REQUEST_FILENAME}</code> to determine
549 the final value of REQUEST_FILENAME.</p></li>
552 <code>%{ENV:variable}</code>, where <em>variable</em> can be
553 any environment variable, is also available.
554 This is looked-up via internal
555 Apache httpd structures and (if not found there) via
556 <code>getenv()</code> from the Apache httpd server process.</li>
559 <code>%{SSL:variable}</code>, where <em>variable</em> is the
560 name of an <a href="mod_ssl.html#envvars">SSL environment
561 variable</a>, can be used whether or not
562 <module>mod_ssl</module> is loaded, but will always expand to
563 the empty string if it is not. Example:
564 <code>%{SSL:SSL_CIPHER_USEKEYSIZE}</code> may expand to
565 <code>128</code>.</li>
568 <code>%{HTTP:header}</code>, where <em>header</em> can be
569 any HTTP MIME-header name, can always be used to obtain the
570 value of a header sent in the HTTP request.
571 Example: <code>%{HTTP:Proxy-Connection}</code> is
572 the value of the HTTP header
573 ``<code>Proxy-Connection:</code>''.
574 <p>If a HTTP header is used in a condition this header is added to
575 the Vary header of the response in case the condition evaluates to
576 to true for the request. It is <strong>not</strong> added if the
577 condition evaluates to false for the request. Adding the HTTP header
578 to the Vary header of the response is needed for proper caching.</p>
579 <p>It has to be kept in mind that conditions follow a short circuit
580 logic in the case of the '<strong><code>ornext|OR</code></strong>' flag
581 so that certain conditions might not be evaluated at all.</p></li>
584 <code>%{LA-U:variable}</code> can be used for look-aheads which perform
585 an internal (URL-based) sub-request to determine the final
586 value of <em>variable</em>. This can be used to access
587 variable for rewriting which is not available at the current
588 stage, but will be set in a later phase.
589 <p>For instance, to rewrite according to the
590 <code>REMOTE_USER</code> variable from within the
591 per-server context (<code>httpd.conf</code> file) you must
592 use <code>%{LA-U:REMOTE_USER}</code> - this
593 variable is set by the authorization phases, which come
594 <em>after</em> the URL translation phase (during which mod_rewrite
596 <p>On the other hand, because mod_rewrite implements
597 its per-directory context (<code>.htaccess</code> file) via
598 the Fixup phase of the API and because the authorization
599 phases come <em>before</em> this phase, you just can use
600 <code>%{REMOTE_USER}</code> in that context.</p></li>
603 <code>%{LA-F:variable}</code> can be used to perform an internal
604 (filename-based) sub-request, to determine the final value
605 of <em>variable</em>. Most of the time, this is the same as
609 <p><em>CondPattern</em> is the condition pattern,
610 a regular expression which is applied to the
611 current instance of the <em>TestString</em>.
612 <em>TestString</em> is first evaluated, before being matched against
613 <em>CondPattern</em>.</p>
615 <p><em>CondPattern</em> is usually a
616 <em>perl compatible regular expression</em>, but there is
617 additional syntax available to perform other useful tests against
618 the <em>Teststring</em>:</p>
621 <li>You can prefix the pattern string with a
622 '<code>!</code>' character (exclamation mark) to specify a
623 <strong>non</strong>-matching pattern.</li>
626 You can perform lexicographical string comparisons:
629 <li>'<strong><CondPattern</strong>' (lexicographically
631 Treats the <em>CondPattern</em> as a plain string and
632 compares it lexicographically to <em>TestString</em>. True if
633 <em>TestString</em> lexicographically precedes
634 <em>CondPattern</em>.</li>
636 <li>'<strong>>CondPattern</strong>' (lexicographically
638 Treats the <em>CondPattern</em> as a plain string and
639 compares it lexicographically to <em>TestString</em>. True if
640 <em>TestString</em> lexicographically follows
641 <em>CondPattern</em>.</li>
643 <li>'<strong>=CondPattern</strong>' (lexicographically
645 Treats the <em>CondPattern</em> as a plain string and
646 compares it lexicographically to <em>TestString</em>. True if
647 <em>TestString</em> is lexicographically equal to
648 <em>CondPattern</em> (the two strings are exactly
649 equal, character for character). If <em>CondPattern</em>
650 is <code>""</code> (two quotation marks) this
651 compares <em>TestString</em> to the empty string.</li>
653 <li>'<strong><=CondPattern</strong>' (lexicographically
654 less than or equal to)<br />
655 Treats the <em>CondPattern</em> as a plain string and
656 compares it lexicographically to <em>TestString</em>. True
657 if <em>TestString</em> lexicographically precedes
658 <em>CondPattern</em>, or is equal to <em>CondPattern</em>
659 (the two strings are equal, character for character).</li>
661 <li>'<strong>>=CondPattern</strong>' (lexicographically
662 greater than or equal to)<br />
663 Treats the <em>CondPattern</em> as a plain string and
664 compares it lexicographically to <em>TestString</em>. True
665 if <em>TestString</em> lexicographically follows
666 <em>CondPattern</em>, or is equal to <em>CondPattern</em>
667 (the two strings are equal, character for character).</li>
671 You can perform integer comparisons:
674 <li>'<strong>-eq</strong>' (is numerically
675 <strong>eq</strong>ual to)<br />
676 The <em>TestString</em> is treated as an integer, and is
677 numerically compared to the <em>CondPattern</em>. True if
678 the two are numerically equal.</li>
680 <li>'<strong>-ge</strong>' (is numerically
681 <strong>g</strong>reater than or <strong>e</strong>qual to)<br />
682 The <em>TestString</em> is treated as an integer, and is
683 numerically compared to the <em>CondPattern</em>. True if
684 the <em>TestString</em> is numerically greater than or equal
685 to the <em>CondPattern</em>.</li>
687 <li>'<strong>-gt</strong>' (is numerically
688 <strong>g</strong>reater <strong>t</strong>han)<br />
689 The <em>TestString</em> is treated as an integer, and is
690 numerically compared to the <em>CondPattern</em>. True if
691 the <em>TestString</em> is numerically greater than
692 the <em>CondPattern</em>.</li>
694 <li>'<strong>-le</strong>' (is numerically
695 <strong>l</strong>ess than or <strong>e</strong>qual to)<br />
696 The <em>TestString</em> is treated as an integer, and is
697 numerically compared to the <em>CondPattern</em>. True if
698 the <em>TestString</em> is numerically less than or equal
699 to the <em>CondPattern</em>. Avoid confusion with the
700 <strong>-l</strong> by using the <strong>-L</strong> or
701 <strong>-h</strong> variant.</li>
703 <li>'<strong>-lt</strong>' (is numerically
704 <strong>l</strong>ess <strong>t</strong>han)<br />
705 The <em>TestString</em> is treated as an integer, and is
706 numerically compared to the <em>CondPattern</em>. True if
707 the <em>TestString</em> is numerically less than
708 the <em>CondPattern</em>. Avoid confusion with the
709 <strong>-l</strong> by using the <strong>-L</strong> or
710 <strong>-h</strong> variant.</li>
715 <li>You can perform various file attribute tests:
717 <li>'<strong>-d</strong>' (is
718 <strong>d</strong>irectory)<br />
719 Treats the <em>TestString</em> as a pathname and tests
720 whether or not it exists, and is a directory.</li>
722 <li>'<strong>-f</strong>' (is regular
723 <strong>f</strong>ile)<br />
724 Treats the <em>TestString</em> as a pathname and tests
725 whether or not it exists, and is a regular file.</li>
727 <li>'<strong>-F</strong>' (is existing file, via
729 Checks whether or not <em>TestString</em> is a valid file,
730 accessible via all the server's currently-configured
731 access controls for that path. This uses an internal
732 subrequest to do the check, so use it with care -
733 it can impact your server's performance!</li>
735 <li>'<strong>-H</strong>' (is symbolic link, bash convention)<br />
736 See <strong>-l</strong>.</li>
738 <li>'<strong>-l</strong>' (is symbolic
739 <strong>l</strong>ink)<br />
740 Treats the <em>TestString</em> as a pathname and tests
741 whether or not it exists, and is a symbolic link. May also
742 use the bash convention of <strong>-L</strong> or
743 <strong>-h</strong> if there's a possibility of confusion
744 such as when using the <strong>-lt</strong> or
745 <strong>-le</strong> tests.</li>
747 <li>'<strong>-L</strong>' (is symbolic link, bash convention)<br />
748 See <strong>-l</strong>.</li>
750 <li>'<strong>-s</strong>' (is regular file, with
751 <strong>s</strong>ize)<br />
752 Treats the <em>TestString</em> as a pathname and tests
753 whether or not it exists, and is a regular file with size greater
756 <li>'<strong>-U</strong>' (is existing URL, via
758 Checks whether or not <em>TestString</em> is a valid URL,
759 accessible via all the server's currently-configured
760 access controls for that path. This uses an internal
761 subrequest to do the check, so use it with care -
762 it can impact your server's performance!</li>
764 <li>'<strong>-x</strong>' (has e<strong>x</strong>ecutable
766 Treats the <em>TestString</em> as a pathname and tests
767 whether or not it exists, and has executable permissions.
768 These permissions are determined according to
769 the underlying OS.</li>
773 <note><title>Note:</title>
774 All of these tests can
775 also be prefixed by an exclamation mark ('!') to
776 negate their meaning.
781 <p>If the <em>TestString</em> has the special value <code>expr</code>, the
782 <em>CondPattern</em> will be treated as a
783 <a href="../expr.html">ap_expr</a>.</p>
786 In the below example, <code>-strmatch</code> is used to
787 compare the <code>REFERER</code> against the site hostname,
788 to block unwanted hotlinking.
792 RewriteCond expr "! %{HTTP_REFERER} -strmatch '*://%{HTTP_HOST}/*'"<br />
793 RewriteRule ^/images - [F]
797 <li>You can also set special flags for
798 <em>CondPattern</em> by appending
799 <strong><code>[</code><em>flags</em><code>]</code></strong>
800 as the third argument to the <code>RewriteCond</code>
801 directive, where <em>flags</em> is a comma-separated list of any of the
805 <li>'<strong><code>nocase|NC</code></strong>'
806 (<strong>n</strong>o <strong>c</strong>ase)<br />
807 This makes the test case-insensitive - differences
808 between 'A-Z' and 'a-z' are ignored, both in the
809 expanded <em>TestString</em> and the <em>CondPattern</em>.
810 This flag is effective only for comparisons between
811 <em>TestString</em> and <em>CondPattern</em>. It has no
812 effect on filesystem and subrequest checks.</li>
815 '<strong><code>ornext|OR</code></strong>'
816 (<strong>or</strong> next condition)<br />
817 Use this to combine rule conditions with a local OR
818 instead of the implicit AND. Typical example:
822 RewriteCond %{REMOTE_HOST} ^host1 [OR]
823 RewriteCond %{REMOTE_HOST} ^host2 [OR]
824 RewriteCond %{REMOTE_HOST} ^host3
825 RewriteRule ...some special stuff for any of these hosts...
829 Without this flag you would have to write the condition/rule
833 <li>'<strong><code>novary|NV</code></strong>'
834 (<strong>n</strong>o <strong>v</strong>ary)<br />
835 If a HTTP header is used in the condition, this flag prevents
836 this header from being added to the Vary header of the response. <br />
837 Using this flag might break proper caching of the response if
838 the representation of this response varies on the value of this header.
839 So this flag should be only used if the meaning of the Vary header
846 <p><strong>Example:</strong></p>
848 <p>To rewrite the Homepage of a site according to the
849 ``<code>User-Agent:</code>'' header of the request, you can
850 use the following: </p>
854 RewriteCond %{HTTP_USER_AGENT} ^Mozilla
855 RewriteRule ^/$ /homepage.max.html [L]
857 RewriteCond %{HTTP_USER_AGENT} ^Lynx
858 RewriteRule ^/$ /homepage.min.html [L]
860 RewriteRule ^/$ /homepage.std.html [L]
864 <p>Explanation: If you use a browser which identifies itself
865 as 'Mozilla' (including Netscape Navigator, Mozilla etc), then you
866 get the max homepage (which could include frames, or other special
868 If you use the Lynx browser (which is terminal-based), then
869 you get the min homepage (which could be a version designed for
870 easy, text-only browsing).
871 If neither of these conditions apply (you use any other browser,
872 or your browser identifies itself as something non-standard), you get
873 the std (standard) homepage.</p>
880 <name>RewriteRule</name>
881 <description>Defines rules for the rewriting engine</description>
883 <em>Pattern</em> <em>Substitution</em> [<em>flags</em>]</syntax>
884 <contextlist><context>server config</context><context>virtual host</context>
885 <context>directory</context><context>.htaccess</context></contextlist>
886 <override>FileInfo</override>
889 <p>The <directive>RewriteRule</directive> directive is the real
890 rewriting workhorse. The directive can occur more than once,
891 with each instance defining a single rewrite rule. The
892 order in which these rules are defined is important - this is the order
893 in which they will be applied at run-time.</p>
895 <p><a id="patterns" name="patterns"><em>Pattern</em></a> is
896 a perl compatible <a id="regexp" name="regexp">regular
897 expression</a>. On the first RewriteRule it is applied to the (%-encoded)
898 <a href="./directive-dict.html#Syntax">URL-path</a> of the request;
899 subsequent patterns are applied to the output of the last matched
902 <note><title>What is matched?</title>
903 <p>In <directive module="core">VirtualHost</directive> context,
904 The <em>Pattern</em> will initially be matched against the part of the
905 URL after the hostname and port, and before the query string (e.g. "/app1/index.html").</p>
907 <p>In <directive module="core">Directory</directive> and htaccess context,
908 the <em>Pattern</em> will initially be matched against the
909 <em>filesystem</em> path, after removing the prefix that lead the server
910 to the current <directive>RewriteRule</directive> (e.g. "app1/index.html"
911 or "index.html" depending on where the directives are defined).</p>
913 <p>If you wish to match against the hostname, port, or query string, use a
914 <directive module="mod_rewrite">RewriteCond</directive> with the
915 <code>%{HTTP_HOST}</code>, <code>%{SERVER_PORT}</code>, or
916 <code>%{QUERY_STRING}</code> variables respectively.</p>
920 <note><title>Per-directory Rewrites</title>
922 <li>The rewrite engine may be used in <a
923 href="../howto/htaccess.html">.htaccess</a> files and in <directive type="section"
924 module="core">Directory</directive> sections, with some additional
927 <li>To enable the rewrite engine in this context, you need to set
928 "<code>RewriteEngine On</code>" <strong>and</strong>
929 "<code>Options FollowSymLinks</code>" must be enabled. If your
930 administrator has disabled override of <code>FollowSymLinks</code> for
931 a user's directory, then you cannot use the rewrite engine. This
932 restriction is required for security reasons.</li>
934 <li>When using the rewrite engine in <code>.htaccess</code> files the
935 per-directory prefix (which always is the same for a specific
936 directory) is automatically <em>removed</em> for the RewriteRule pattern matching
937 and automatically <em>added</em> after any relative (not starting with a
938 slash or protocol name) substitution encounters the end of a rule set.
939 See the <directive module="mod_rewrite">RewriteBase</directive>
940 directive for more information regarding what prefix will be added back to
941 relative substutions.</li>
943 <li> If you wish to match against the full URL-path in a per-directory
944 (htaccess) RewriteRule, use the <code>%{REQUEST_URI}</code> variable in
945 a <directive>RewriteCond</directive>.</li>
947 <li>The removed prefix always ends with a slash, meaning the matching occurs against a string which
948 <em>never</em> has a leading slash. Therefore, a <em>Pattern</em> with <code>^/</code> never
949 matches in per-directory context.</li>
951 <li>Although rewrite rules are syntactically permitted in <directive
952 type="section" module="core">Location</directive> and <directive
953 type="section" module="core">Files</directive> sections, this
954 should never be necessary and is unsupported.</li>
958 <p>For some hints on <glossary ref="regex">regular
959 expressions</glossary>, see
960 the <a href="../rewrite/intro.html#regex">mod_rewrite
961 Introduction</a>.</p>
963 <p>In mod_rewrite, the NOT character
964 ('<code>!</code>') is also available as a possible pattern
965 prefix. This enables you to negate a pattern; to say, for instance:
966 ``<em>if the current URL does <strong>NOT</strong> match this
967 pattern</em>''. This can be used for exceptional cases, where
968 it is easier to match the negative pattern, or as a last
971 <note><title>Note</title>
972 When using the NOT character to negate a pattern, you cannot include
973 grouped wildcard parts in that pattern. This is because, when the
974 pattern does NOT match (ie, the negation matches), there are no
975 contents for the groups. Thus, if negated patterns are used, you
976 cannot use <code>$N</code> in the substitution string!
979 <p>The <a id="rhs" name="rhs"><em>Substitution</em></a> of a
980 rewrite rule is the string that replaces the original URL-path that
981 was matched by <em>Pattern</em>. The <em>Substitution</em> may
986 <dt>file-system path</dt>
988 <dd>Designates the location on the file-system of the resource
989 to be delivered to the client.</dd>
994 module="core">DocumentRoot</directive>-relative path to the
995 resource to be served. Note that <module>mod_rewrite</module>
996 tries to guess whether you have specified a file-system path
997 or a URL-path by checking to see if the first segment of the
998 path exists at the root of the file-system. For example, if
999 you specify a <em>Substitution</em> string of
1000 <code>/www/file.html</code>, then this will be treated as a
1001 URL-path <em>unless</em> a directory named <code>www</code>
1002 exists at the root or your file-system, in which case it will
1003 be treated as a file-system path. If you wish other
1004 URL-mapping directives (such as <directive
1005 module="mod_alias">Alias</directive>) to be applied to the
1006 resulting URL-path, use the <code>[PT]</code> flag as
1007 described below.</dd>
1009 <dt>Absolute URL</dt>
1011 <dd>If an absolute URL is specified,
1012 <module>mod_rewrite</module> checks to see whether the
1013 hostname matches the current host. If it does, the scheme and
1014 hostname are stripped out and the resulting path is treated as
1015 a URL-path. Otherwise, an external redirect is performed for
1016 the given URL. To force an external redirect back to the
1017 current host, see the <code>[R]</code> flag below.</dd>
1019 <dt><code>-</code> (dash)</dt>
1021 <dd>A dash indicates that no substitution should be performed
1022 (the existing path is passed through untouched). This is used
1023 when a flag (see below) needs to be applied without changing
1028 <p>In addition to plain text, the <em>Substition</em> string can include</p>
1031 <li>back-references (<code>$N</code>) to the RewriteRule
1034 <li>back-references (<code>%N</code>) to the last matched
1035 RewriteCond pattern</li>
1037 <li>server-variables as in rule condition test-strings
1038 (<code>%{VARNAME}</code>)</li>
1040 <li><a href="#mapfunc">mapping-function</a> calls
1041 (<code>${mapname:key|default}</code>)</li>
1044 <p>Back-references are identifiers of the form
1045 <code>$</code><strong>N</strong>
1046 (<strong>N</strong>=0..9), which will be replaced
1047 by the contents of the <strong>N</strong>th group of the
1048 matched <em>Pattern</em>. The server-variables are the same
1049 as for the <em>TestString</em> of a <code>RewriteCond</code>
1050 directive. The mapping-functions come from the
1051 <code>RewriteMap</code> directive and are explained there.
1052 These three types of variables are expanded in the order above.</p>
1054 <p>As already mentioned, all rewrite rules are
1055 applied to the <em>Substitution</em> (in the order in which
1057 in the config file). The URL is <strong>completely
1058 replaced</strong> by the <em>Substitution</em> and the
1059 rewriting process continues until all rules have been applied,
1060 or it is explicitly terminated by a
1061 <code><strong>L</strong></code> flag.</p>
1063 <note><title>Modifying the Query String</title>
1064 <p>By default, the query string is passed through unchanged. You
1065 can, however, create URLs in the substitution string containing
1066 a query string part. Simply use a question mark inside the
1067 substitution string to indicate that the following text should
1068 be re-injected into the query string. When you want to erase an
1069 existing query string, end the substitution string with just a
1070 question mark. To combine new and old query strings, use the
1071 <code>[QSA]</code> flag.</p>
1074 <p>Additionally you can set special <a name="rewriteflags"
1075 id="rewriteflags">actions</a> to be performed by
1076 appending <strong><code>[</code><em>flags</em><code>]</code></strong>
1077 as the third argument to the <code>RewriteRule</code>
1078 directive. <em>Flags</em> is a comma-separated list, surround by square
1079 brackets, of any of the flags in the following table. More
1080 details, and examples, for each flag, are available in the <a
1081 href="../rewrite/flags.html">Rewrite Flags document</a>.</p>
1084 <tr><th>Flag and syntax</th>
1089 <td>Escape non-alphanumeric characters <em>before</em> applying
1090 the transformation. <em><a
1091 href="../rewrite/flags.html#flag_b">details ...</a></em></td>
1095 <td>Rule is chained to the following rule. If the rule fails,
1096 the rule(s) chained to it will be skipped. <em><a
1097 href="../rewrite/flags.html#flag_c">details ...</a></em></td>
1100 <td>cookie|CO=<em>NAME</em>:<em>VAL</em></td>
1101 <td>Sets a cookie in the client browser. Full syntax is:
1102 CO=<em>NAME</em>:<em>VAL</em>[:<em>domain</em>[:<em>lifetime</em>[:<em>path</em>[:<em>secure</em>[:<em>httponly</em>]]]]] <em><a href="../rewrite/flags.html#flag_co">details ...</a></em>
1106 <td>discardpath|DPI</td>
1107 <td>Causes the PATH_INFO portion of the rewritten URI to be
1108 discarded. <em><a href="../rewrite/flags.html#flag_dpi">details
1112 <td>env|E=[!]<em>VAR</em>[:<em>VAL</em>]</td>
1113 <td>Causes an environment variable <em>VAR</em> to be set (to the
1114 value <em>VAL</em> if provided). The form !<em>VAR</em> causes
1115 the environment variable <em>VAR</em> to be unset.<em><a
1116 href="../rewrite/flags.html#flag_e">details ...</a></em></td>
1119 <td>forbidden|F</td>
1120 <td>Returns a 403 FORBIDDEN response to the client browser.
1121 <em><a href="../rewrite/flags.html#flag_f">details ...</a></em></td>
1125 <td>Returns a 410 GONE response to the client browser. <em><a
1126 href="../rewrite/flags.html#flag_g">details ...</a></em></td>
1129 <td>Handler|H=<em>Content-handler</em></td>
1130 <td>Causes the resulting URI to be sent to the specified
1131 <em>Content-handler</em> for processing. <em><a
1132 href="../rewrite/flags.html#flag_h">details ...</a></em></td>
1136 <td>Stop the rewriting process immediately and don't apply any
1137 more rules. Especially note caveats for per-directory and
1138 .htaccess context (see also the END flag). <em><a
1139 href="../rewrite/flags.html#flag_l">details ...</a></em></td>
1143 <td>Re-run the rewriting process, starting again with the first
1144 rule, using the result of the ruleset so far as a starting
1145 point. <em><a href="../rewrite/flags.html#flag_n">details
1150 <td>Makes the pattern pattern comparison case-insensitive.
1151 <em><a href="../rewrite/flags.html#flag_nc">details ...</a></em></td>
1154 <td>noescape|NE</td>
1155 <td>Prevent mod_rewrite from applying hexcode escaping of
1156 special characters in the result of the rewrite. <em><a
1157 href="../rewrite/flags.html#flag_ne">details ...</a></em></td>
1160 <td>nosubreq|NS</td>
1161 <td>Causes a rule to be skipped if the current request is an
1162 internal sub-request. <em><a
1163 href="../rewrite/flags.html#flag_ns">details ...</a></em></td>
1167 <td>Force the substitution URL to be internally sent as a proxy
1168 request. <em><a href="../rewrite/flags.html#flag_p">details
1172 <td>passthrough|PT</td>
1173 <td>Forces the resulting URI to be passed back to the URL
1174 mapping engine for processing of other URI-to-filename
1175 translators, such as <code>Alias</code> or
1176 <code>Redirect</code>. <em><a
1177 href="../rewrite/flags.html#flag_pt">details ...</a></em></td>
1180 <td>qsappend|QSA</td>
1181 <td>Appends any query string created in the rewrite target to
1182 any query string that was in the original request URL. <em><a
1183 href="../rewrite/flags.html#flag_qsa">details ...</a></em></td>
1186 <td>qsdiscard|QSD</td>
1187 <td>Discard any query string attached to the incoming URI.
1188 <em><a href="../rewrite/flags.html#flag_qsd">details
1192 <td>redirect|R[=<em>code</em>]</td>
1193 <td>Forces an external redirect, optionally with the specified
1194 HTTP status code. <em><a
1195 href="../rewrite/flags.html#flag_r">details ...</a></em>
1200 <td>Stop the rewriting process immediately and don't apply any
1201 more rules. Also prevents further execution of rewrite rules
1202 in per-directory and .htaccess context. (Available in 2.3.9 and later)
1203 <em><a href="../rewrite/flags.html#flag_l">details ...</a></em></td>
1206 <td>skip|S=<em>num</em></td>
1207 <td>Tells the rewriting engine to skip the next <em>num</em>
1208 rules if the current rule matches. <em><a
1209 href="../rewrite/flags.html#flag_s">details ...</a></em></td>
1212 <td>tyle|T=<em>MIME-type</em></td>
1213 <td>Force the <glossary>MIME-type</glossary> of the target file
1214 to be the specified type. <em><a
1215 href="../rewrite/flags.html#flag_t">details ...</a></em></td>
1219 <note><title>Home directory expansion</title>
1220 <p> When the substitution string begins with a string
1221 resembling "/~user" (via explicit text or backreferences), mod_rewrite performs
1222 home directory expansion independent of the presence or configuration
1223 of <module>mod_userdir</module>.</p>
1225 <p> This expansion does not occur when the <em>PT</em>
1226 flag is used on the <directive module="mod_rewrite">RewriteRule</directive>
1231 <p>Here are all possible substitution combinations and their
1234 <p><strong>Inside per-server configuration
1235 (<code>httpd.conf</code>)<br />
1236 for request ``<code>GET
1237 /somepath/pathinfo</code>'':</strong><br />
1243 <th>Resulting Substitution</th>
1247 <td>^/somepath(.*) otherpath$1</td>
1248 <td>invalid, not supported</td>
1252 <td>^/somepath(.*) otherpath$1 [R]</td>
1253 <td>invalid, not supported</td>
1257 <td>^/somepath(.*) otherpath$1 [P]</td>
1258 <td>invalid, not supported</td>
1262 <td>^/somepath(.*) /otherpath$1</td>
1263 <td>/otherpath/pathinfo</td>
1267 <td>^/somepath(.*) /otherpath$1 [R]</td>
1268 <td>http://thishost/otherpath/pathinfo via external redirection</td>
1272 <td>^/somepath(.*) /otherpath$1 [P]</td>
1273 <td>doesn't make sense, not supported</td>
1277 <td>^/somepath(.*) http://thishost/otherpath$1</td>
1278 <td>/otherpath/pathinfo</td>
1282 <td>^/somepath(.*) http://thishost/otherpath$1 [R]</td>
1283 <td>http://thishost/otherpath/pathinfo via external redirection</td>
1287 <td>^/somepath(.*) http://thishost/otherpath$1 [P]</td>
1288 <td>doesn't make sense, not supported</td>
1292 <td>^/somepath(.*) http://otherhost/otherpath$1</td>
1293 <td>http://otherhost/otherpath/pathinfo via external redirection</td>
1297 <td>^/somepath(.*) http://otherhost/otherpath$1 [R]</td>
1298 <td>http://otherhost/otherpath/pathinfo via external redirection (the [R] flag is redundant)</td>
1302 <td>^/somepath(.*) http://otherhost/otherpath$1 [P]</td>
1303 <td>http://otherhost/otherpath/pathinfo via internal proxy</td>
1307 <p><strong>Inside per-directory configuration for
1308 <code>/somepath</code><br />
1309 (<code>/physical/path/to/somepath/.htacccess</code>, with
1310 <code>RewriteBase /somepath</code>)<br />
1311 for request ``<code>GET
1312 /somepath/localpath/pathinfo</code>'':</strong><br />
1319 <th>Resulting Substitution</th>
1323 <td>^localpath(.*) otherpath$1</td>
1324 <td>/somepath/otherpath/pathinfo</td>
1328 <td>^localpath(.*) otherpath$1 [R]</td>
1329 <td>http://thishost/somepath/otherpath/pathinfo via external
1334 <td>^localpath(.*) otherpath$1 [P]</td>
1335 <td>doesn't make sense, not supported</td>
1339 <td>^localpath(.*) /otherpath$1</td>
1340 <td>/otherpath/pathinfo</td>
1344 <td>^localpath(.*) /otherpath$1 [R]</td>
1345 <td>http://thishost/otherpath/pathinfo via external redirection</td>
1349 <td>^localpath(.*) /otherpath$1 [P]</td>
1350 <td>doesn't make sense, not supported</td>
1354 <td>^localpath(.*) http://thishost/otherpath$1</td>
1355 <td>/otherpath/pathinfo</td>
1359 <td>^localpath(.*) http://thishost/otherpath$1 [R]</td>
1360 <td>http://thishost/otherpath/pathinfo via external redirection</td>
1364 <td>^localpath(.*) http://thishost/otherpath$1 [P]</td>
1365 <td>doesn't make sense, not supported</td>
1369 <td>^localpath(.*) http://otherhost/otherpath$1</td>
1370 <td>http://otherhost/otherpath/pathinfo via external redirection</td>
1374 <td>^localpath(.*) http://otherhost/otherpath$1 [R]</td>
1375 <td>http://otherhost/otherpath/pathinfo via external redirection (the [R] flag is redundant)</td>
1379 <td>^localpath(.*) http://otherhost/otherpath$1 [P]</td>
1380 <td>http://otherhost/otherpath/pathinfo via internal proxy</td>
1386 </directivesynopsis>