2 <!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
3 <?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?>
4 <!-- $LastChangedRevision$ -->
7 Copyright 2002-2005 The Apache Software Foundation or its licensors, as
10 Licensed under the Apache License, Version 2.0 (the "License");
11 you may not use this file except in compliance with the License.
12 You may obtain a copy of the License at
14 http://www.apache.org/licenses/LICENSE-2.0
16 Unless required by applicable law or agreed to in writing, software
17 distributed under the License is distributed on an "AS IS" BASIS,
18 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19 See the License for the specific language governing permissions and
20 limitations under the License.
23 <modulesynopsis metafile="core.xml.meta">
26 <description>Core Apache HTTP Server features that are always
27 available</description>
31 <name>AcceptFilter</name>
32 <description>Configures optimizations for a Protocol's Listener Sockets</description>
33 <syntax>AcceptFilter <var>protocol</var> <var>accept_filter</var></syntax>
34 <contextlist><context>server config</context></contextlist>
35 <compatibility>Available in Apache 2.1.5 and later</compatibility>
38 <p>This directive enables operating system specific optimizations for a
39 listening socket by the Protocol type. The basic premise is for the
40 kernel to not send a socket to the server process until either data
41 is received or an entire HTTP Request is buffered. Only
42 <a href="http://www.freebsd.org/cgi/man.cgi?query=accept_filter&sektion=9">
43 FreeBSD's Accept Filters</a> and Linux's more primitive
44 <code>TCP_DEFER_ACCEPT</code> are currently supported.</p>
46 <p>The default values on FreeBSD are:</p>
48 AcceptFilter http httpready <br/>
49 AcceptFilter https dataready
52 <p>The <code>httpready</code> accept filter buffers entire HTTP requests at
53 the kernel level. Once an entire request is recieved, the kernel then
54 sends it to the server. See the
55 <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_http&sektion=9">
56 accf_http(9)</a> man page for more details. Since HTTPS requests are
57 encrypted only the <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_data&sektion=9">
58 accf_data(9)</a> filter is used.</p>
60 <p>The default values on Linux are:</p>
62 AcceptFilter http data <br/>
63 AcceptFilter https data
66 <p>Linux's <code>TCP_DEFER_ACCEPT</code> does not support buffering http
67 requests. Any value besides <code>none</code> will enable
68 <code>TCP_DEFER_ACCEPT</code> on that listener. For more details
70 <a href="http://homepages.cwi.nl/~aeb/linux/man2html/man7/tcp.7.html">
71 tcp(7)</a> man page.</p>
73 <p>Using <code>none</code> for an argument will disable any accept filters
74 for that protocol. This is useful for protocols that require a server
75 send data first, such as <code>nntp</code>:</p>
76 <example>AcceptFilter nttp none</example>
82 <name>AcceptPathInfo</name>
83 <description>Resources accept trailing pathname information</description>
84 <syntax>AcceptPathInfo On|Off|Default</syntax>
85 <default>AcceptPathInfo Default</default>
86 <contextlist><context>server config</context>
87 <context>virtual host</context><context>directory</context>
88 <context>.htaccess</context></contextlist>
89 <override>FileInfo</override>
90 <compatibility>Available in Apache 2.0.30 and later</compatibility>
94 <p>This directive controls whether requests that contain trailing
95 pathname information that follows an actual filename (or
96 non-existent file in an existing directory) will be accepted or
97 rejected. The trailing pathname information can be made
98 available to scripts in the <code>PATH_INFO</code> environment
101 <p>For example, assume the location <code>/test/</code> points to
102 a directory that contains only the single file
103 <code>here.html</code>. Then requests for
104 <code>/test/here.html/more</code> and
105 <code>/test/nothere.html/more</code> both collect
106 <code>/more</code> as <code>PATH_INFO</code>.</p>
108 <p>The three possible arguments for the
109 <directive>AcceptPathInfo</directive> directive are:</p>
111 <dt><code>Off</code></dt><dd>A request will only be accepted if it
112 maps to a literal path that exists. Therefore a request with
113 trailing pathname information after the true filename such as
114 <code>/test/here.html/more</code> in the above example will return
115 a 404 NOT FOUND error.</dd>
117 <dt><code>On</code></dt><dd>A request will be accepted if a
118 leading path component maps to a file that exists. The above
119 example <code>/test/here.html/more</code> will be accepted if
120 <code>/test/here.html</code> maps to a valid file.</dd>
122 <dt><code>Default</code></dt><dd>The treatment of requests with
123 trailing pathname information is determined by the <a
124 href="../handler.html">handler</a> responsible for the request.
125 The core handler for normal files defaults to rejecting
126 <code>PATH_INFO</code> requests. Handlers that serve scripts, such as <a
127 href="mod_cgi.html">cgi-script</a> and <a
128 href="mod_isapi.html">isapi-isa</a>, generally accept
129 <code>PATH_INFO</code> by default.</dd>
132 <p>The primary purpose of the <code>AcceptPathInfo</code>
133 directive is to allow you to override the handler's choice of
134 accepting or rejecting <code>PATH_INFO</code>. This override is required,
135 for example, when you use a <a href="../filter.html">filter</a>, such
136 as <a href="mod_include.html">INCLUDES</a>, to generate content
137 based on <code>PATH_INFO</code>. The core handler would usually reject
138 the request, so you can use the following configuration to enable
142 <Files "mypaths.shtml"><br />
144 Options +Includes<br />
145 SetOutputFilter INCLUDES<br />
146 AcceptPathInfo On<br />
155 <name>AccessFileName</name>
156 <description>Name of the distributed configuration file</description>
157 <syntax>AccessFileName <var>filename</var> [<var>filename</var>] ...</syntax>
158 <default>AccessFileName .htaccess</default>
159 <contextlist><context>server config</context><context>virtual host</context>
163 <p>While processing a request the server looks for
164 the first existing configuration file from this list of names in
165 every directory of the path to the document, if distributed
166 configuration files are <a href="#allowoverride">enabled for that
167 directory</a>. For example:</p>
173 <p>before returning the document
174 <code>/usr/local/web/index.html</code>, the server will read
175 <code>/.acl</code>, <code>/usr/.acl</code>,
176 <code>/usr/local/.acl</code> and <code>/usr/local/web/.acl</code>
177 for directives, unless they have been disabled with</p>
180 <Directory /><br />
182 AllowOverride None<br />
187 <seealso><directive module="core">AllowOverride</directive></seealso>
188 <seealso><a href="../configuring.html">Configuration Files</a></seealso>
189 <seealso><a href="../howto/htaccess.html">.htaccess Files</a></seealso>
193 <name>AddDefaultCharset</name>
194 <description>Default charset parameter to be added when a response
195 content-type is <code>text/plain</code> or <code>text/html</code></description>
196 <syntax>AddDefaultCharset On|Off|<var>charset</var></syntax>
197 <default>AddDefaultCharset Off</default>
198 <contextlist><context>server config</context>
199 <context>virtual host</context><context>directory</context>
200 <context>.htaccess</context></contextlist>
201 <override>FileInfo</override>
204 <p>This directive specifies a default value for the media type
205 charset parameter (the name of a character encoding) to be added
206 to a response if and only if the response's content-type is either
207 <code>text/plain</code> or <code>text/html</code>. This should override
208 any charset specified in the body of the response via a <code>META</code>
209 element, though the exact behavior is often dependent on the user's client
210 configuration. A setting of <code>AddDefaultCharset Off</code>
211 disables this functionality. <code>AddDefaultCharset On</code> enables
212 a default charset of <code>iso-8859-1</code>. Any other value is assumed
213 to be the <var>charset</var> to be used, which should be one of the
214 <a href="http://www.iana.org/assignments/character-sets">IANA registered
215 charset values</a> for use in MIME media types.
219 AddDefaultCharset utf-8
222 <p><directive>AddDefaultCharset</directive> should only be used when all
223 of the text resources to which it applies are known to be in that
224 character encoding and it is too inconvenient to label their charset
225 individually. One such example is to add the charset parameter
226 to resources containing generated content, such as legacy CGI
227 scripts, that might be vulnerable to cross-site scripting attacks
228 due to user-provided data being included in the output. Note, however,
229 that a better solution is to just fix (or delete) those scripts, since
230 setting a default charset does not protect users that have enabled
231 the "auto-detect character encoding" feature on their browser.</p>
233 <seealso><directive module="mod_mime">AddCharset</directive></seealso>
237 <name>AddOutputFilterByType</name>
238 <description>assigns an output filter to a particular MIME-type</description>
239 <syntax>AddOutputFilterByType <var>filter</var>[;<var>filter</var>...]
240 <var>MIME-type</var> [<var>MIME-type</var>] ...</syntax>
241 <contextlist><context>server config</context>
242 <context>virtual host</context><context>directory</context>
243 <context>.htaccess</context></contextlist>
244 <override>FileInfo</override>
245 <compatibility>Available in Apache 2.0.33 and later</compatibility>
248 <p>This directive activates a particular output <a
249 href="../filter.html">filter</a> for a request depending on the
250 response MIME-type.</p>
252 <p>The following example uses the <code>DEFLATE</code> filter, which
253 is provided by <module>mod_deflate</module>. It will compress all
254 output (either static or dynamic) which is labeled as
255 <code>text/html</code> or <code>text/plain</code> before it is sent
259 AddOutputFilterByType DEFLATE text/html text/plain
262 <p>If you want the content to be processed by more than one filter, their
263 names have to be separated by semicolons. It's also possible to use one
264 <directive>AddOutputFilterByType</directive> directive for each of
267 <p>The configuration below causes all script output labeled as
268 <code>text/html</code> to be processed at first by the
269 <code>INCLUDES</code> filter and then by the <code>DEFLATE</code>
273 <Location /cgi-bin/><br />
275 Options Includes<br />
276 AddOutputFilterByType INCLUDES;DEFLATE text/html<br />
281 <note type="warning"><title>Note</title>
282 <p>Enabling filters with <directive>AddOutputFilterByType</directive>
283 may fail partially or completely in some cases. For example, no
284 filters are applied if the MIME-type could not be determined and falls
285 back to the <directive module="core">DefaultType</directive> setting,
286 even if the <directive module="core">DefaultType</directive> is the
289 <p>However, if you want to make sure, that the filters will be
290 applied, assign the content type to a resource explicitly, for
291 example with <directive module="mod_mime">AddType</directive> or
292 <directive module="core">ForceType</directive>. Setting the
293 content type within a (non-nph) CGI script is also safe.</p>
295 <p>The by-type output filters are never applied on proxy requests.</p>
299 <seealso><directive module="mod_mime">AddOutputFilter</directive></seealso>
300 <seealso><directive module="core">SetOutputFilter</directive></seealso>
301 <seealso><a href="../filter.html">filters</a></seealso>
305 <name>AllowEncodedSlashes</name>
306 <description>Determines whether encoded path separators in URLs are allowed to
307 be passed through</description>
308 <syntax>AllowEncodedSlashes On|Off</syntax>
309 <default>AllowEncodedSlashes Off</default>
310 <contextlist><context>server config</context><context>virtual host</context>
312 <compatibility>Available in Apache 2.0.46 and later</compatibility>
315 <p>The <directive>AllowEncodedSlashes</directive> directive allows URLs
316 which contain encoded path separators (<code>%2F</code> for <code>/</code>
317 and additionally <code>%5C</code> for <code>\</code> on according systems)
318 to be used. Normally such URLs are refused with a 404 (Not found) error.</p>
320 <p>Turning <directive>AllowEncodedSlashes</directive> <code>On</code> is
321 mostly useful when used in conjunction with <code>PATH_INFO</code>.</p>
323 <note><title>Note</title>
324 <p>Allowing encoded slashes does <em>not</em> imply <em>decoding</em>.
325 Occurrences of <code>%2F</code> or <code>%5C</code> (<em>only</em> on
326 according systems) will be left as such in the otherwise decoded URL
330 <seealso><directive module="core">AcceptPathInfo</directive></seealso>
334 <name>AllowOverride</name>
335 <description>Types of directives that are allowed in
336 <code>.htaccess</code> files</description>
337 <syntax>AllowOverride All|None|<var>directive-type</var>
338 [<var>directive-type</var>] ...</syntax>
339 <default>AllowOverride All</default>
340 <contextlist><context>directory</context></contextlist>
343 <p>When the server finds an <code>.htaccess</code> file (as
344 specified by <directive module="core">AccessFileName</directive>)
345 it needs to know which directives declared in that file can override
346 earlier configuration directives.</p>
348 <note><title>Only available in <Directory> sections</title>
349 <directive>AllowOverride</directive> is valid only in
350 <directive type="section" module="core">Directory</directive>
351 sections specified without regular expressions, not in <directive
352 type="section" module="core">Location</directive>, <directive
353 module="core" type="section">DirectoryMatch</directive> or
354 <directive type="section" module="core">Files</directive> sections.
357 <p>When this directive is set to <code>None</code>, then
358 <a href="#accessfilename">.htaccess</a> files are completely ignored.
359 In this case, the server will not even attempt to read
360 <code>.htaccess</code> files in the filesystem.</p>
362 <p>When this directive is set to <code>All</code>, then any
363 directive which has the .htaccess <a
364 href="directive-dict.html#Context">Context</a> is allowed in
365 <code>.htaccess</code> files.</p>
367 <p>The <var>directive-type</var> can be one of the following
368 groupings of directives.</p>
375 Allow use of the authorization directives (<directive
376 module="mod_authn_dbm">AuthDBMGroupFile</directive>,
377 <directive module="mod_authn_dbm">AuthDBMUserFile</directive>,
378 <directive module="mod_authz_groupfile">AuthGroupFile</directive>,
379 <directive module="core">AuthName</directive>,
380 <directive module="core">AuthType</directive>, <directive
381 module="mod_authn_file">AuthUserFile</directive>, <directive
382 module="core">Require</directive>, <em>etc.</em>).</dd>
387 Allow use of the directives controlling document types (<directive
388 module="core">DefaultType</directive>, <directive
389 module="core">ErrorDocument</directive>, <directive
390 module="core">ForceType</directive>, <directive
391 module="mod_negotiation">LanguagePriority</directive>,
392 <directive module="core">SetHandler</directive>, <directive
393 module="core">SetInputFilter</directive>, <directive
394 module="core">SetOutputFilter</directive>, and
395 <module>mod_mime</module> Add* and Remove*
396 directives, <em>etc.</em>).</dd>
401 Allow use of the directives controlling directory indexing
403 module="mod_autoindex">AddDescription</directive>,
404 <directive module="mod_autoindex">AddIcon</directive>, <directive
405 module="mod_autoindex">AddIconByEncoding</directive>,
406 <directive module="mod_autoindex">AddIconByType</directive>,
407 <directive module="mod_autoindex">DefaultIcon</directive>, <directive
408 module="mod_dir">DirectoryIndex</directive>, <directive
409 module="mod_autoindex">FancyIndexing</directive>, <directive
410 module="mod_autoindex">HeaderName</directive>, <directive
411 module="mod_autoindex">IndexIgnore</directive>, <directive
412 module="mod_autoindex">IndexOptions</directive>, <directive
413 module="mod_autoindex">ReadmeName</directive>,
419 Allow use of the directives controlling host access (<directive
420 module="mod_authz_host">Allow</directive>, <directive
421 module="mod_authz_host">Deny</directive> and <directive
422 module="mod_authz_host">Order</directive>).</dd>
424 <dt>Options[=<var>Option</var>,...]</dt>
427 Allow use of the directives controlling specific directory
428 features (<directive module="core">Options</directive> and
429 <directive module="mod_include">XBitHack</directive>).
430 An equal sign may be given followed by a comma (but no spaces)
431 separated lists of options that may be set using the <directive
432 module="core">Options</directive> command.</dd>
438 AllowOverride AuthConfig Indexes
441 <p>In the example above all directives that are neither in the group
442 <code>AuthConfig</code> nor <code>Indexes</code> cause an internal
446 <seealso><directive module="core">AccessFileName</directive></seealso>
447 <seealso><a href="../configuring.html">Configuration Files</a></seealso>
448 <seealso><a href="../howto/htaccess.html">.htaccess Files</a></seealso>
452 <name>AuthName</name>
453 <description>Authorization realm for use in HTTP
454 authentication</description>
455 <syntax>AuthName <var>auth-domain</var></syntax>
456 <contextlist><context>directory</context><context>.htaccess</context>
458 <override>AuthConfig</override>
461 <p>This directive sets the name of the authorization realm for a
462 directory. This realm is given to the client so that the user
463 knows which username and password to send.
464 <directive>AuthName</directive> takes a single argument; if the
465 realm name contains spaces, it must be enclosed in quotation
466 marks. It must be accompanied by <directive
467 module="core">AuthType</directive> and <directive
468 module="core">Require</directive> directives, and directives such
469 as <directive module="mod_authn_file">AuthUserFile</directive> and
470 <directive module="mod_authz_groupfile">AuthGroupFile</directive> to
476 AuthName "Top Secret"
479 <p>The string provided for the <code>AuthName</code> is what will
480 appear in the password dialog provided by most browsers.</p>
483 href="../howto/auth.html">Authentication, Authorization, and
484 Access Control</a></seealso>
488 <name>AuthType</name>
489 <description>Type of user authentication</description>
490 <syntax>AuthType Basic|Digest</syntax>
491 <contextlist><context>directory</context><context>.htaccess</context>
493 <override>AuthConfig</override>
496 <p>This directive selects the type of user authentication for a
497 directory. Only <code>Basic</code> and <code>Digest</code> are
498 currently implemented.
500 It must be accompanied by <directive
501 module="core">AuthName</directive> and <directive
502 module="core">Require</directive> directives, and directives such
503 as <directive module="mod_authn_file">AuthUserFile</directive> and
504 <directive module="mod_authz_groupfile">AuthGroupFile</directive> to
507 <seealso><a href="../howto/auth.html">Authentication, Authorization,
508 and Access Control</a></seealso>
512 <name>CGIMapExtension</name>
513 <description>Technique for locating the interpreter for CGI
514 scripts</description>
515 <syntax>CGIMapExtension <var>cgi-path</var> <var>.extension</var></syntax>
516 <contextlist><context>directory</context><context>.htaccess</context>
518 <override>FileInfo</override>
519 <compatibility>NetWare only</compatibility>
522 <p>This directive is used to control how Apache finds the
523 interpreter used to run CGI scripts. For example, setting
524 <code>CGIMapExtension sys:\foo.nlm .foo</code> will
525 cause all CGI script files with a <code>.foo</code> extension to
526 be passed to the FOO interpreter.</p>
531 <name>ContentDigest</name>
532 <description>Enables the generation of <code>Content-MD5</code> HTTP Response
533 headers</description>
534 <syntax>ContentDigest On|Off</syntax>
535 <default>ContentDigest Off</default>
536 <contextlist><context>server config</context><context>virtual host</context>
537 <context>directory</context><context>.htaccess</context>
539 <override>Options</override>
540 <status>Experimental</status>
543 <p>This directive enables the generation of
544 <code>Content-MD5</code> headers as defined in RFC1864
545 respectively RFC2068.</p>
547 <p>MD5 is an algorithm for computing a "message digest"
548 (sometimes called "fingerprint") of arbitrary-length data, with
549 a high degree of confidence that any alterations in the data
550 will be reflected in alterations in the message digest.</p>
552 <p>The <code>Content-MD5</code> header provides an end-to-end
553 message integrity check (MIC) of the entity-body. A proxy or
554 client may check this header for detecting accidental
555 modification of the entity-body in transit. Example header:</p>
558 Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA==
561 <p>Note that this can cause performance problems on your server
562 since the message digest is computed on every request (the
563 values are not cached).</p>
565 <p><code>Content-MD5</code> is only sent for documents served
566 by the <module>core</module>, and not by any module. For example,
567 SSI documents, output from CGI scripts, and byte range responses
568 do not have this header.</p>
573 <name>DefaultType</name>
574 <description>MIME content-type that will be sent if the
575 server cannot determine a type in any other way</description>
576 <syntax>DefaultType <var>MIME-type</var></syntax>
577 <default>DefaultType text/plain</default>
578 <contextlist><context>server config</context><context>virtual host</context>
579 <context>directory</context><context>.htaccess</context>
581 <override>FileInfo</override>
584 <p>There will be times when the server is asked to provide a
585 document whose type cannot be determined by its MIME types
588 <p>The server must inform the client of the content-type of the
589 document, so in the event of an unknown type it uses the
590 <code>DefaultType</code>. For example:</p>
593 DefaultType image/gif
596 <p>would be appropriate for a directory which contained many GIF
597 images with filenames missing the <code>.gif</code> extension.</p>
599 <p>Note that unlike <directive
600 module="core">ForceType</directive>, this directive only
601 provides the default mime-type. All other mime-type definitions,
602 including filename extensions, that might identify the media type
603 will override this default.</p>
607 <directivesynopsis type="section">
608 <name>Directory</name>
609 <description>Enclose a group of directives that apply only to the
610 named file-system directory and sub-directories</description>
611 <syntax><Directory <var>directory-path</var>>
612 ... </Directory></syntax>
613 <contextlist><context>server config</context><context>virtual host</context>
617 <p><directive type="section">Directory</directive> and
618 <code></Directory></code> are used to enclose a group of
619 directives that will apply only to the named directory and
620 sub-directories of that directory. Any directive that is allowed
621 in a directory context may be used. <var>Directory-path</var> is
622 either the full path to a directory, or a wild-card string using
623 Unix shell-style matching. In a wild-card string, <code>?</code> matches
624 any single character, and <code>*</code> matches any sequences of
625 characters. You may also use <code>[]</code> character ranges. None
626 of the wildcards match a `/' character, so <code><Directory
627 /*/public_html></code> will not match
628 <code>/home/user/public_html</code>, but <code><Directory
629 /home/*/public_html></code> will match. Example:</p>
632 <Directory /usr/local/httpd/htdocs><br />
634 Options Indexes FollowSymLinks<br />
640 <p>Be careful with the <var>directory-path</var> arguments:
641 They have to literally match the filesystem path which Apache uses
642 to access the files. Directives applied to a particular
643 <code><Directory></code> will not apply to files accessed from
644 that same directory via a different path, such as via different symbolic
649 expressions can also be used, with the addition of the
650 <code>~</code> character. For example:</p>
653 <Directory ~ "^/www/.*/[0-9]{3}">
656 <p>would match directories in <code>/www/</code> that consisted of
659 <p>If multiple (non-regular expression) <directive
660 type="section">Directory</directive> sections
661 match the directory (or one of its parents) containing a document,
662 then the directives are applied in the order of shortest match
663 first, interspersed with the directives from the <a
664 href="#accessfilename">.htaccess</a> files. For example,
668 <Directory /><br />
670 AllowOverride None<br />
672 </Directory><br />
674 <Directory /home/><br />
676 AllowOverride FileInfo<br />
681 <p>for access to the document <code>/home/web/dir/doc.html</code>
685 <li>Apply directive <code>AllowOverride None</code>
686 (disabling <code>.htaccess</code> files).</li>
688 <li>Apply directive <code>AllowOverride FileInfo</code> (for
689 directory <code>/home</code>).</li>
691 <li>Apply any <code>FileInfo</code> directives in
692 <code>/home/.htaccess</code>, <code>/home/web/.htaccess</code> and
693 <code>/home/web/dir/.htaccess</code> in that order.</li>
696 <p>Regular expressions are not considered until after all of the
697 normal sections have been applied. Then all of the regular
698 expressions are tested in the order they appeared in the
699 configuration file. For example, with</p>
702 <Directory ~ abc$><br />
704 # ... directives here ...<br />
709 <p>the regular expression section won't be considered until after
710 all normal <directive type="section">Directory</directive>s and
711 <code>.htaccess</code> files have been applied. Then the regular
712 expression will match on <code>/home/abc/public_html/abc</code> and
713 the corresponding <directive type="section">Directory</directive> will
716 <p><strong>Note that the default Apache access for
717 <code><Directory /></code> is <code>Allow from All</code>.
718 This means that Apache will serve any file mapped from an URL. It is
719 recommended that you change this with a block such
723 <Directory /><br />
725 Order Deny,Allow<br />
731 <p><strong>and then override this for directories you
732 <em>want</em> accessible. See the <a
733 href="../misc/security_tips.html">Security Tips</a> page for more
734 details.</strong></p>
736 <p>The directory sections occur in the <code>httpd.conf</code> file.
737 <directive type="section">Directory</directive> directives
738 cannot nest, and cannot appear in a <directive module="core"
739 type="section">Limit</directive> or <directive module="core"
740 type="section">LimitExcept</directive> section.</p>
742 <seealso><a href="../sections.html">How <Directory>,
743 <Location> and <Files> sections work</a> for an
744 explanation of how these different sections are combined when a
745 request is received</seealso>
748 <directivesynopsis type="section">
749 <name>DirectoryMatch</name>
750 <description>Enclose directives that apply to
751 file-system directories matching a regular expression and their
752 subdirectories</description>
753 <syntax><DirectoryMatch <var>regex</var>>
754 ... </DirectoryMatch></syntax>
755 <contextlist><context>server config</context><context>virtual host</context>
759 <p><directive type="section">DirectoryMatch</directive> and
760 <code></DirectoryMatch></code> are used to enclose a group
761 of directives which will apply only to the named directory and
762 sub-directories of that directory, the same as <directive
763 module="core" type="section">Directory</directive>. However, it
764 takes as an argument a regular expression. For example:</p>
767 <DirectoryMatch "^/www/(.+/)?[0-9]{3}">
770 <p>would match directories in <code>/www/</code> that consisted of three
773 <seealso><directive type="section" module="core">Directory</directive> for
774 a description of how regular expressions are mixed in with normal
775 <directive type="section">Directory</directive>s</seealso>
777 href="../sections.html">How <Directory>, <Location> and
778 <Files> sections work</a> for an explanation of how these different
779 sections are combined when a request is received</seealso>
783 <name>DocumentRoot</name>
784 <description>Directory that forms the main document tree visible
785 from the web</description>
786 <syntax>DocumentRoot <var>directory-path</var></syntax>
787 <default>DocumentRoot /usr/local/apache/htdocs</default>
788 <contextlist><context>server config</context><context>virtual host</context>
792 <p>This directive sets the directory from which <program>httpd</program>
793 will serve files. Unless matched by a directive like <directive
794 module="mod_alias">Alias</directive>, the server appends the
795 path from the requested URL to the document root to make the
796 path to the document. Example:</p>
799 DocumentRoot /usr/web
803 <code>http://www.my.host.com/index.html</code> refers to
804 <code>/usr/web/index.html</code>. If the <var>directory-path</var> is
805 not absolute then it is assumed to be relative to the <directive
806 module="core">ServerRoot</directive>.</p>
808 <p>The <directive>DocumentRoot</directive> should be specified without
809 a trailing slash.</p>
811 <seealso><a href="../urlmapping.html">Mapping URLs to Filesystem
812 Location</a></seealso>
816 <name>EnableMMAP</name>
817 <description>Use memory-mapping to read files during delivery</description>
818 <syntax>EnableMMAP On|Off</syntax>
819 <default>EnableMMAP On</default>
820 <contextlist><context>server config</context><context>virtual host</context>
821 <context>directory</context><context>.htaccess</context>
823 <override>FileInfo</override>
826 <p>This directive controls whether the <program>httpd</program> may use
827 memory-mapping if it needs to read the contents of a file during
828 delivery. By default, when the handling of a request requires
829 access to the data within a file -- for example, when delivering a
830 server-parsed file using <module>mod_include</module> -- Apache
831 memory-maps the file if the OS supports it.</p>
833 <p>This memory-mapping sometimes yields a performance improvement.
834 But in some environments, it is better to disable the memory-mapping
835 to prevent operational problems:</p>
838 <li>On some multiprocessor systems, memory-mapping can reduce the
839 performance of the <program>httpd</program>.</li>
840 <li>With an NFS-mounted <directive module="core">DocumentRoot</directive>,
841 the <program>httpd</program> may crash due to a segmentation fault if a file
842 is deleted or truncated while the <program>httpd</program> has it
846 <p>For server configurations that are vulnerable to these problems,
847 you should disable memory-mapping of delivered files by specifying:</p>
853 <p>For NFS mounted files, this feature may be disabled explicitly for
854 the offending files by specifying:</p>
857 <Directory "/path-to-nfs-files">
867 <name>EnableSendfile</name>
868 <description>Use the kernel sendfile support to deliver files to the client</description>
869 <syntax>EnableSendfile On|Off</syntax>
870 <default>EnableSendfile On</default>
871 <contextlist><context>server config</context><context>virtual host</context>
872 <context>directory</context><context>.htaccess</context>
874 <override>FileInfo</override>
875 <compatibility>Available in version 2.0.44 and later</compatibility>
878 <p>This directive controls whether <program>httpd</program> may use the
879 sendfile support from the kernel to transmit file contents to the client.
880 By default, when the handling of a request requires no access
881 to the data within a file -- for example, when delivering a
882 static file -- Apache uses sendfile to deliver the file contents
883 without ever reading the file if the OS supports it.</p>
885 <p>This sendfile mechanism avoids separate read and send operations,
886 and buffer allocations. But on some platforms or within some
887 filesystems, it is better to disable this feature to avoid
888 operational problems:</p>
891 <li>Some platforms may have broken sendfile support that the build
892 system did not detect, especially if the binaries were built on
893 another box and moved to such a machine with broken sendfile
895 <li>On Linux the use of sendfile triggers TCP-checksum
896 offloading bugs on certain networking cards when using IPv6.</li>
897 <li>With a network-mounted <directive
898 module="core">DocumentRoot</directive> (e.g., NFS or SMB),
899 the kernel may be unable to serve the network file through
903 <p>For server configurations that are vulnerable to these problems,
904 you should disable this feature by specifying:</p>
910 <p>For NFS or SMB mounted files, this feature may be disabled explicitly
911 for the offending files by specifying:</p>
914 <Directory "/path-to-nfs-files">
924 <name>ErrorDocument</name>
925 <description>What the server will return to the client
926 in case of an error</description>
927 <syntax>ErrorDocument <var>error-code</var> <var>document</var></syntax>
928 <contextlist><context>server config</context><context>virtual host</context>
929 <context>directory</context><context>.htaccess</context>
931 <override>FileInfo</override>
932 <compatibility>Quoting syntax for text messages is different in Apache
936 <p>In the event of a problem or error, Apache can be configured
937 to do one of four things,</p>
940 <li>output a simple hardcoded error message</li>
942 <li>output a customized message</li>
944 <li>redirect to a local <var>URL-path</var> to handle the
947 <li>redirect to an external <var>URL</var> to handle the
951 <p>The first option is the default, while options 2-4 are
952 configured using the <directive>ErrorDocument</directive>
953 directive, which is followed by the HTTP response code and a URL
954 or a message. Apache will sometimes offer additional information
955 regarding the problem/error.</p>
957 <p>URLs can begin with a slash (/) for local web-paths (relative
958 to the <directive module="core">DocumentRoot</directive>), or be a
959 full URL which the client can resolve. Alternatively, a message
960 can be provided to be displayed by the browser. Examples:</p>
963 ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br />
964 ErrorDocument 404 /cgi-bin/bad_urls.pl<br />
965 ErrorDocument 401 /subscription_info.html<br />
966 ErrorDocument 403 "Sorry can't allow you access today"
969 <p>Additionally, the special value <code>default</code> can be used
970 to specify Apache's simple hardcoded message. While not required
971 under normal circumstances, <code>default</code> will restore
972 Apache's simple hardcoded message for configurations that would
973 otherwise inherit an existing <directive>ErrorDocument</directive>.</p>
976 ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br />
977 <Directory /web/docs><br />
979 ErrorDocument 404 default<br />
984 <p>Note that when you specify an <directive>ErrorDocument</directive>
985 that points to a remote URL (ie. anything with a method such as
986 <code>http</code> in front of it), Apache will send a redirect to the
987 client to tell it where to find the document, even if the
988 document ends up being on the same server. This has several
989 implications, the most important being that the client will not
990 receive the original error status code, but instead will
991 receive a redirect status code. This in turn can confuse web
992 robots and other clients which try to determine if a URL is
993 valid using the status code. In addition, if you use a remote
994 URL in an <code>ErrorDocument 401</code>, the client will not
995 know to prompt the user for a password since it will not
996 receive the 401 status code. Therefore, <strong>if you use an
997 <code>ErrorDocument 401</code> directive then it must refer to a local
998 document.</strong></p>
1000 <p>Microsoft Internet Explorer (MSIE) will by default ignore
1001 server-generated error messages when they are "too small" and substitute
1002 its own "friendly" error messages. The size threshold varies depending on
1003 the type of error, but in general, if you make your error document
1004 greater than 512 bytes, then MSIE will show the server-generated
1005 error rather than masking it. More information is available in
1006 Microsoft Knowledge Base article <a
1007 href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807"
1010 <p>Although most error messages can be overriden, there are certain
1011 circumstances where the internal messages are used regardless of the
1012 setting of <directive module="core">ErrorDocument</directive>. In
1013 particular, if a malformed request is detected, normal request processing
1014 will be immediately halted and the internal error message returned.
1015 This is necessary to guard against security problems caused by
1018 <p>Prior to version 2.0, messages were indicated by prefixing
1019 them with a single unmatched double quote character.</p>
1022 <seealso><a href="../custom-error.html">documentation of
1023 customizable responses</a></seealso>
1024 </directivesynopsis>
1027 <name>ErrorLog</name>
1028 <description>Location where the server will log errors</description>
1029 <syntax> ErrorLog <var>file-path</var>|syslog[:<var>facility</var>]</syntax>
1030 <default>ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows and OS/2)</default>
1031 <contextlist><context>server config</context><context>virtual host</context>
1035 <p>The <directive>ErrorLog</directive> directive sets the name of
1036 the file to which the server will log any errors it encounters. If
1037 the <var>file-path</var> is not absolute then it is assumed to be
1038 relative to the <directive module="core">ServerRoot</directive>.</p>
1040 <example><title>Example</title>
1041 ErrorLog /var/log/httpd/error_log
1044 <p>If the <var>file-path</var>
1045 begins with a pipe (|) then it is assumed to be a command to spawn
1046 to handle the error log.</p>
1048 <example><title>Example</title>
1049 ErrorLog "|/usr/local/bin/httpd_errors"
1052 <p>Using <code>syslog</code> instead of a filename enables logging
1053 via syslogd(8) if the system supports it. The default is to use
1054 syslog facility <code>local7</code>, but you can override this by
1055 using the <code>syslog:<var>facility</var></code> syntax where
1056 <var>facility</var> can be one of the names usually documented in
1059 <example><title>Example</title>
1060 ErrorLog syslog:user
1063 <p>SECURITY: See the <a
1064 href="../misc/security_tips.html#serverroot">security tips</a>
1065 document for details on why your security could be compromised
1066 if the directory where log files are stored is writable by
1067 anyone other than the user that starts the server.</p>
1068 <note type="warning"><title>Note</title>
1069 <p>When entering a file path on non-Unix platforms, care should be taken
1070 to make sure that only forward slashed are used even though the platform
1071 may allow the use of back slashes. In general it is a good idea to always
1072 use forward slashes throughout the configuration files.</p>
1075 <seealso><directive module="core">LogLevel</directive></seealso>
1076 <seealso><a href="../logs.html">Apache Log Files</a></seealso>
1077 </directivesynopsis>
1080 <name>FileETag</name>
1081 <description>File attributes used to create the ETag
1082 HTTP response header</description>
1083 <syntax>FileETag <var>component</var> ...</syntax>
1084 <default>FileETag INode MTime Size</default>
1085 <contextlist><context>server config</context><context>virtual host</context>
1086 <context>directory</context><context>.htaccess</context>
1088 <override>FileInfo</override>
1092 The <directive>FileETag</directive> directive configures the file
1093 attributes that are used to create the <code>ETag</code> (entity
1094 tag) response header field when the document is based on a file.
1095 (The <code>ETag</code> value is used in cache management to save
1096 network bandwidth.) In Apache 1.3.22 and earlier, the
1097 <code>ETag</code> value was <em>always</em> formed
1098 from the file's inode, size, and last-modified time (mtime). The
1099 <directive>FileETag</directive> directive allows you to choose
1100 which of these -- if any -- should be used. The recognized keywords are:
1104 <dt><strong>INode</strong></dt>
1105 <dd>The file's i-node number will be included in the calculation</dd>
1106 <dt><strong>MTime</strong></dt>
1107 <dd>The date and time the file was last modified will be included</dd>
1108 <dt><strong>Size</strong></dt>
1109 <dd>The number of bytes in the file will be included</dd>
1110 <dt><strong>All</strong></dt>
1111 <dd>All available fields will be used. This is equivalent to:
1112 <example>FileETag INode MTime Size</example></dd>
1113 <dt><strong>None</strong></dt>
1114 <dd>If a document is file-based, no <code>ETag</code> field will be
1115 included in the response</dd>
1118 <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code>
1119 keywords may be prefixed with either <code>+</code> or <code>-</code>,
1120 which allow changes to be made to the default setting inherited
1121 from a broader scope. Any keyword appearing without such a prefix
1122 immediately and completely cancels the inherited setting.</p>
1124 <p>If a directory's configuration includes
1125 <code>FileETag INode MTime Size</code>, and a
1126 subdirectory's includes <code>FileETag -INode</code>,
1127 the setting for that subdirectory (which will be inherited by
1128 any sub-subdirectories that don't override it) will be equivalent to
1129 <code>FileETag MTime Size</code>.</p>
1131 </directivesynopsis>
1133 <directivesynopsis type="section">
1135 <description>Contains directives that apply to matched
1136 filenames</description>
1137 <syntax><Files <var>filename</var>> ... </Files></syntax>
1138 <contextlist><context>server config</context><context>virtual host</context>
1139 <context>directory</context><context>.htaccess</context>
1141 <override>All</override>
1144 <p>The <directive type="section">Files</directive> directive
1145 limits the scope of the enclosed directives by filename. It is comparable
1146 to the <directive module="core" type="section">Directory</directive>
1147 and <directive module="core" type="section">Location</directive>
1148 directives. It should be matched with a <code></Files></code>
1149 directive. The directives given within this section will be applied to
1150 any object with a basename (last component of filename) matching the
1151 specified filename. <directive type="section">Files</directive>
1152 sections are processed in the order they appear in the
1153 configuration file, after the <directive module="core"
1154 type="section">Directory</directive> sections and
1155 <code>.htaccess</code> files are read, but before <directive
1156 type="section" module="core">Location</directive> sections. Note
1157 that <directive type="section">Files</directive> can be nested
1158 inside <directive type="section"
1159 module="core">Directory</directive> sections to restrict the
1160 portion of the filesystem they apply to.</p>
1162 <p>The <var>filename</var> argument should include a filename, or
1163 a wild-card string, where <code>?</code> matches any single character,
1164 and <code>*</code> matches any sequences of characters. Extended regular
1165 expressions can also be used, with the addition of the
1166 <code>~</code> character. For example:</p>
1169 <Files ~ "\.(gif|jpe?g|png)$">
1172 <p>would match most common Internet graphics formats. <directive
1173 module="core" type="section">FilesMatch</directive> is preferred,
1176 <p>Note that unlike <directive type="section"
1177 module="core">Directory</directive> and <directive type="section"
1178 module="core">Location</directive> sections, <directive
1179 type="section">Files</directive> sections can be used inside
1180 <code>.htaccess</code> files. This allows users to control access to
1181 their own files, at a file-by-file level.</p>
1184 <seealso><a href="../sections.html">How <Directory>, <Location>
1185 and <Files> sections work</a> for an explanation of how these
1186 different sections are combined when a request is received</seealso>
1187 </directivesynopsis>
1189 <directivesynopsis type="section">
1190 <name>FilesMatch</name>
1191 <description>Contains directives that apply to regular-expression matched
1192 filenames</description>
1193 <syntax><FilesMatch <var>regex</var>> ... </FilesMatch></syntax>
1194 <contextlist><context>server config</context><context>virtual host</context>
1195 <context>directory</context><context>.htaccess</context>
1197 <override>All</override>
1200 <p>The <directive type="section">FilesMatch</directive> directive
1201 limits the scope of the enclosed directives by filename, just as the
1202 <directive module="core" type="section">Files</directive> directive
1203 does. However, it accepts a regular expression. For example:</p>
1206 <FilesMatch "\.(gif|jpe?g|png)$">
1209 <p>would match most common Internet graphics formats.</p>
1212 <seealso><a href="../sections.html">How <Directory>, <Location>
1213 and <Files> sections work</a> for an explanation of how these
1214 different sections are combined when a request is received</seealso>
1215 </directivesynopsis>
1218 <name>ForceType</name>
1219 <description>Forces all matching files to be served with the specified
1220 MIME content-type</description>
1221 <syntax>ForceType <var>MIME-type</var>|None</syntax>
1222 <contextlist><context>directory</context><context>.htaccess</context>
1224 <override>FileInfo</override>
1225 <compatibility>Moved to the core in Apache 2.0</compatibility>
1228 <p>When placed into an <code>.htaccess</code> file or a
1229 <directive type="section" module="core">Directory</directive>, or
1230 <directive type="section" module="core">Location</directive> or
1231 <directive type="section" module="core">Files</directive>
1232 section, this directive forces all matching files to be served
1233 with the content type identification given by
1234 <var>MIME-type</var>. For example, if you had a directory full of
1235 GIF files, but did not want to label them all with <code>.gif</code>,
1236 you might want to use:</p>
1242 <p>Note that unlike <directive module="core">DefaultType</directive>,
1243 this directive overrides all mime-type associations, including
1244 filename extensions, that might identify the media type.</p>
1246 <p>You can override any <directive>ForceType</directive> setting
1247 by using the value of <code>None</code>:</p>
1250 # force all files to be image/gif:<br />
1251 <Location /images><br />
1253 ForceType image/gif<br />
1255 </Location><br />
1257 # but normal mime-type associations here:<br />
1258 <Location /images/mixed><br />
1260 ForceType None<br />
1265 </directivesynopsis>
1268 <name>HostnameLookups</name>
1269 <description>Enables DNS lookups on client IP addresses</description>
1270 <syntax>HostnameLookups On|Off|Double</syntax>
1271 <default>HostnameLookups Off</default>
1272 <contextlist><context>server config</context><context>virtual host</context>
1273 <context>directory</context></contextlist>
1276 <p>This directive enables DNS lookups so that host names can be
1277 logged (and passed to CGIs/SSIs in <code>REMOTE_HOST</code>).
1278 The value <code>Double</code> refers to doing double-reverse
1279 DNS lookup. That is, after a reverse lookup is performed, a forward
1280 lookup is then performed on that result. At least one of the IP
1281 addresses in the forward lookup must match the original
1282 address. (In "tcpwrappers" terminology this is called
1283 <code>PARANOID</code>.)</p>
1285 <p>Regardless of the setting, when <module>mod_authz_host</module> is
1286 used for controlling access by hostname, a double reverse lookup
1287 will be performed. This is necessary for security. Note that the
1288 result of this double-reverse isn't generally available unless you
1289 set <code>HostnameLookups Double</code>. For example, if only
1290 <code>HostnameLookups On</code> and a request is made to an object
1291 that is protected by hostname restrictions, regardless of whether
1292 the double-reverse fails or not, CGIs will still be passed the
1293 single-reverse result in <code>REMOTE_HOST</code>.</p>
1295 <p>The default is <code>Off</code> in order to save the network
1296 traffic for those sites that don't truly need the reverse
1297 lookups done. It is also better for the end users because they
1298 don't have to suffer the extra latency that a lookup entails.
1299 Heavily loaded sites should leave this directive
1300 <code>Off</code>, since DNS lookups can take considerable
1301 amounts of time. The utility <program>logresolve</program>, compiled by
1302 default to the <code>bin</code> subdirectory of your installation
1303 directory, can be used to look up host names from logged IP addresses
1306 </directivesynopsis>
1308 <directivesynopsis type="section">
1309 <name>IfDefine</name>
1310 <description>Encloses directives that will be processed only
1311 if a test is true at startup</description>
1312 <syntax><IfDefine [!]<var>parameter-name</var>> ...
1313 </IfDefine></syntax>
1314 <contextlist><context>server config</context><context>virtual host</context>
1315 <context>directory</context><context>.htaccess</context>
1317 <override>All</override>
1320 <p>The <code><IfDefine <var>test</var>>...</IfDefine>
1321 </code> section is used to mark directives that are conditional. The
1322 directives within an <directive type="section">IfDefine</directive>
1323 section are only processed if the <var>test</var> is true. If <var>
1324 test</var> is false, everything between the start and end markers is
1327 <p>The <var>test</var> in the <directive type="section"
1328 >IfDefine</directive> section directive can be one of two forms:</p>
1331 <li><var>parameter-name</var></li>
1333 <li><code>!</code><var>parameter-name</var></li>
1336 <p>In the former case, the directives between the start and end
1337 markers are only processed if the parameter named
1338 <var>parameter-name</var> is defined. The second format reverses
1339 the test, and only processes the directives if
1340 <var>parameter-name</var> is <strong>not</strong> defined.</p>
1342 <p>The <var>parameter-name</var> argument is a define as given on
1343 the <program>httpd</program> command line via <code>-D<var>parameter-</var>
1344 </code>, at the time the server was started.</p>
1346 <p><directive type="section">IfDefine</directive> sections are
1347 nest-able, which can be used to implement simple
1348 multiple-parameter tests. Example:</p>
1351 httpd -DReverseProxy ...<br />
1354 <IfDefine ReverseProxy><br />
1356 LoadModule rewrite_module modules/mod_rewrite.so<br />
1357 LoadModule proxy_module modules/libproxy.so<br />
1362 </directivesynopsis>
1364 <directivesynopsis type="section">
1365 <name>IfModule</name>
1366 <description>Encloses directives that are processed conditional on the
1367 presence or absence of a specific module</description>
1368 <syntax><IfModule [!]<var>module-file</var>|<var>module-identifier</var>> ...
1369 </IfModule></syntax>
1370 <contextlist><context>server config</context><context>virtual host</context>
1371 <context>directory</context><context>.htaccess</context>
1373 <override>All</override>
1374 <compatibility>Module identifiers are available in version 2.1 and
1375 later.</compatibility>
1378 <p>The <code><IfModule <var>test</var>>...</IfModule></code>
1379 section is used to mark directives that are conditional on the presence of
1380 a specific module. The directives within an <directive type="section"
1381 >IfModule</directive> section are only processed if the <var>test</var>
1382 is true. If <var>test</var> is false, everything between the start and
1383 end markers is ignored.</p>
1385 <p>The <var>test</var> in the <directive type="section"
1386 >IfModule</directive> section directive can be one of two forms:</p>
1389 <li><var>module</var></li>
1391 <li>!<var>module</var></li>
1394 <p>In the former case, the directives between the start and end
1395 markers are only processed if the module named <var>module</var>
1396 is included in Apache -- either compiled in or
1397 dynamically loaded using <directive module="mod_so"
1398 >LoadModule</directive>. The second format reverses the test,
1399 and only processes the directives if <var>module</var> is
1400 <strong>not</strong> included.</p>
1402 <p>The <var>module</var> argument can be either the module identifier or
1403 the file name of the module, at the time it was compiled. For example,
1404 <code>rewrite_module</code> is the identifier and
1405 <code>mod_rewrite.c</code> is the file name. If a module consists of
1406 several source files, use the name of the file containing the string
1407 <code>STANDARD20_MODULE_STUFF</code>.</p>
1409 <p><directive type="section">IfModule</directive> sections are
1410 nest-able, which can be used to implement simple multiple-module
1413 <note>This section should only be used if you need to have one
1414 configuration file that works whether or not a specific module
1415 is available. In normal operation, directives need not be
1416 placed in <directive type="section">IfModule</directive>
1419 </directivesynopsis>
1422 <name>Include</name>
1423 <description>Includes other configuration files from within
1424 the server configuration files</description>
1425 <syntax>Include <var>file-path</var>|<var>directory-path</var></syntax>
1426 <contextlist><context>server config</context><context>virtual host</context>
1427 <context>directory</context>
1429 <compatibility>Wildcard matching available in 2.0.41 and later</compatibility>
1432 <p>This directive allows inclusion of other configuration files
1433 from within the server configuration files.</p>
1435 <p>Shell-style (<code>fnmatch()</code>) wildcard characters can be used to
1436 include several files at once, in alphabetical order. In
1437 addition, if <directive>Include</directive> points to a directory,
1438 rather than a file, Apache will read all files in that directory
1439 and any subdirectory. But including entire directories is not
1440 recommended, because it is easy to accidentally leave temporary
1441 files in a directory that can cause <program>httpd</program> to
1444 <p>The file path specified may be an absolute path, or may be relative
1445 to the <directive module="core">ServerRoot</directive> directory.</p>
1450 Include /usr/local/apache2/conf/ssl.conf<br />
1451 Include /usr/local/apache2/conf/vhosts/*.conf
1454 <p>Or, providing paths relative to your <directive
1455 module="core">ServerRoot</directive> directory:</p>
1458 Include conf/ssl.conf<br />
1459 Include conf/vhosts/*.conf
1462 <p>Running <code>apachectl configtest</code> will give you a list
1463 of the files that are being processed during the configuration
1467 root@host# apachectl configtest<br />
1468 Processing config file: /usr/local/apache2/conf/ssl.conf<br />
1469 Processing config file: /usr/local/apache2/conf/vhosts/vhost1.conf<br />
1470 Processing config file: /usr/local/apache2/conf/vhosts/vhost2.conf<br />
1475 <seealso><program>apachectl</program></seealso>
1476 </directivesynopsis>
1479 <name>KeepAlive</name>
1480 <description>Enables HTTP persistent connections</description>
1481 <syntax>KeepAlive On|Off</syntax>
1482 <default>KeepAlive On</default>
1483 <contextlist><context>server config</context><context>virtual host</context>
1487 <p>The Keep-Alive extension to HTTP/1.0 and the persistent
1488 connection feature of HTTP/1.1 provide long-lived HTTP sessions
1489 which allow multiple requests to be sent over the same TCP
1490 connection. In some cases this has been shown to result in an
1491 almost 50% speedup in latency times for HTML documents with
1492 many images. To enable Keep-Alive connections, set
1493 <code>KeepAlive On</code>.</p>
1495 <p>For HTTP/1.0 clients, Keep-Alive connections will only be
1496 used if they are specifically requested by a client. In
1497 addition, a Keep-Alive connection with an HTTP/1.0 client can
1498 only be used when the length of the content is known in
1499 advance. This implies that dynamic content such as CGI output,
1500 SSI pages, and server-generated directory listings will
1501 generally not use Keep-Alive connections to HTTP/1.0 clients.
1502 For HTTP/1.1 clients, persistent connections are the default
1503 unless otherwise specified. If the client requests it, chunked
1504 encoding will be used in order to send content of unknown
1505 length over persistent connections.</p>
1508 <seealso><directive module="core">MaxKeepAliveRequests</directive></seealso>
1509 </directivesynopsis>
1512 <name>KeepAliveTimeout</name>
1513 <description>Amount of time the server will wait for subsequent
1514 requests on a persistent connection</description>
1515 <syntax>KeepAliveTimeout <var>seconds</var></syntax>
1516 <default>KeepAliveTimeout 5</default>
1517 <contextlist><context>server config</context><context>virtual host</context>
1521 <p>The number of seconds Apache will wait for a subsequent
1522 request before closing the connection. Once a request has been
1523 received, the timeout value specified by the
1524 <directive module="core">Timeout</directive> directive applies.</p>
1526 <p>Setting <directive>KeepAliveTimeout</directive> to a high value
1527 may cause performance problems in heavily loaded servers. The
1528 higher the timeout, the more server processes will be kept
1529 occupied waiting on connections with idle clients.</p>
1531 </directivesynopsis>
1533 <directivesynopsis type="section">
1535 <description>Restrict enclosed access controls to only certain HTTP
1536 methods</description>
1537 <syntax><Limit <var>method</var> [<var>method</var>] ... > ...
1538 </Limit></syntax>
1539 <contextlist><context>server config</context><context>virtual host</context>
1540 <context>directory</context><context>.htaccess</context>
1542 <override>All</override>
1545 <p>Access controls are normally effective for
1546 <strong>all</strong> access methods, and this is the usual
1547 desired behavior. <strong>In the general case, access control
1548 directives should not be placed within a
1549 <directive type="section">Limit</directive> section.</strong></p>
1551 <p>The purpose of the <directive type="section">Limit</directive>
1552 directive is to restrict the effect of the access controls to the
1553 nominated HTTP methods. For all other methods, the access
1554 restrictions that are enclosed in the <directive
1555 type="section">Limit</directive> bracket <strong>will have no
1556 effect</strong>. The following example applies the access control
1557 only to the methods <code>POST</code>, <code>PUT</code>, and
1558 <code>DELETE</code>, leaving all other methods unprotected:</p>
1561 <Limit POST PUT DELETE><br />
1563 Require valid-user<br />
1568 <p>The method names listed can be one or more of: <code>GET</code>,
1569 <code>POST</code>, <code>PUT</code>, <code>DELETE</code>,
1570 <code>CONNECT</code>, <code>OPTIONS</code>,
1571 <code>PATCH</code>, <code>PROPFIND</code>, <code>PROPPATCH</code>,
1572 <code>MKCOL</code>, <code>COPY</code>, <code>MOVE</code>,
1573 <code>LOCK</code>, and <code>UNLOCK</code>. <strong>The method name is
1574 case-sensitive.</strong> If <code>GET</code> is used it will also
1575 restrict <code>HEAD</code> requests. The <code>TRACE</code> method
1576 cannot be limited.</p>
1578 <note type="warning">A <directive type="section"
1579 module="core">LimitExcept</directive> section should always be
1580 used in preference to a <directive type="section"
1581 module="core">Limit</directive> section when restricting access,
1582 since a <directive type="section"
1583 module="core">LimitExcept</directive> section provides protection
1584 against arbitrary methods.</note>
1587 </directivesynopsis>
1589 <directivesynopsis type="section">
1590 <name>LimitExcept</name>
1591 <description>Restrict access controls to all HTTP methods
1592 except the named ones</description>
1593 <syntax><LimitExcept <var>method</var> [<var>method</var>] ... > ...
1594 </LimitExcept></syntax>
1595 <contextlist><context>server config</context><context>virtual host</context>
1596 <context>directory</context><context>.htaccess</context>
1598 <override>All</override>
1601 <p><directive type="section">LimitExcept</directive> and
1602 <code></LimitExcept></code> are used to enclose
1603 a group of access control directives which will then apply to any
1604 HTTP access method <strong>not</strong> listed in the arguments;
1605 i.e., it is the opposite of a <directive type="section"
1606 module="core">Limit</directive> section and can be used to control
1607 both standard and nonstandard/unrecognized methods. See the
1608 documentation for <directive module="core"
1609 type="section">Limit</directive> for more details.</p>
1614 <LimitExcept POST GET><br />
1616 Require valid-user<br />
1618 </LimitExcept>
1622 </directivesynopsis>
1625 <name>LimitInternalRecursion</name>
1626 <description>Determine maximum number of internal redirects and nested
1627 subrequests</description>
1628 <syntax>LimitInternalRecursion <var>number</var> [<var>number</var>]</syntax>
1629 <default>LimitInternalRecursion 10</default>
1630 <contextlist><context>server config</context><context>virtual host</context>
1632 <compatibility>Available in Apache 2.0.47 and later</compatibility>
1635 <p>An internal redirect happens, for example, when using the <directive
1636 module="mod_actions">Action</directive> directive, which internally
1637 redirects the original request to a CGI script. A subrequest is Apache's
1638 mechanism to find out what would happen for some URI if it were requested.
1639 For example, <module>mod_dir</module> uses subrequests to look for the
1640 files listed in the <directive module="mod_dir">DirectoryIndex</directive>
1643 <p><directive>LimitInternalRecursion</directive> prevents the server
1644 from crashing when entering an infinite loop of internal redirects or
1645 subrequests. Such loops are usually caused by misconfigurations.</p>
1647 <p>The directive stores two different limits, which are evaluated on
1648 per-request basis. The first <var>number</var> is the maximum number of
1649 internal redirects, that may follow each other. The second <var>number</var>
1650 determines, how deep subrequests may be nested. If you specify only one
1651 <var>number</var>, it will be assigned to both limits.</p>
1653 <example><title>Example</title>
1654 LimitInternalRecursion 5
1657 </directivesynopsis>
1660 <name>LimitRequestBody</name>
1661 <description>Restricts the total size of the HTTP request body sent
1662 from the client</description>
1663 <syntax>LimitRequestBody <var>bytes</var></syntax>
1664 <default>LimitRequestBody 0</default>
1665 <contextlist><context>server config</context><context>virtual host</context>
1666 <context>directory</context><context>.htaccess</context>
1668 <override>All</override>
1671 <p>This directive specifies the number of <var>bytes</var> from 0
1672 (meaning unlimited) to 2147483647 (2GB) that are allowed in a
1675 <p>The <directive>LimitRequestBody</directive> directive allows
1676 the user to set a limit on the allowed size of an HTTP request
1677 message body within the context in which the directive is given
1678 (server, per-directory, per-file or per-location). If the client
1679 request exceeds that limit, the server will return an error
1680 response instead of servicing the request. The size of a normal
1681 request message body will vary greatly depending on the nature of
1682 the resource and the methods allowed on that resource. CGI scripts
1683 typically use the message body for retrieving form information.
1684 Implementations of the <code>PUT</code> method will require
1685 a value at least as large as any representation that the server
1686 wishes to accept for that resource.</p>
1688 <p>This directive gives the server administrator greater
1689 control over abnormal client request behavior, which may be
1690 useful for avoiding some forms of denial-of-service
1693 <p>If, for example, you are permitting file upload to a particular
1694 location, and wish to limit the size of the uploaded file to 100K,
1695 you might use the following directive:</p>
1698 LimitRequestBody 102400
1702 </directivesynopsis>
1705 <name>LimitRequestFields</name>
1706 <description>Limits the number of HTTP request header fields that
1707 will be accepted from the client</description>
1708 <syntax>LimitRequestFields <var>number</var></syntax>
1709 <default>LimitRequestFields 100</default>
1710 <contextlist><context>server config</context></contextlist>
1713 <p><var>Number</var> is an integer from 0 (meaning unlimited) to
1714 32767. The default value is defined by the compile-time
1715 constant <code>DEFAULT_LIMIT_REQUEST_FIELDS</code> (100 as
1718 <p>The <directive>LimitRequestFields</directive> directive allows
1719 the server administrator to modify the limit on the number of
1720 request header fields allowed in an HTTP request. A server needs
1721 this value to be larger than the number of fields that a normal
1722 client request might include. The number of request header fields
1723 used by a client rarely exceeds 20, but this may vary among
1724 different client implementations, often depending upon the extent
1725 to which a user has configured their browser to support detailed
1726 content negotiation. Optional HTTP extensions are often expressed
1727 using request header fields.</p>
1729 <p>This directive gives the server administrator greater
1730 control over abnormal client request behavior, which may be
1731 useful for avoiding some forms of denial-of-service attacks.
1732 The value should be increased if normal clients see an error
1733 response from the server that indicates too many fields were
1734 sent in the request.</p>
1739 LimitRequestFields 50
1743 </directivesynopsis>
1746 <name>LimitRequestFieldSize</name>
1747 <description>Limits the size of the HTTP request header allowed from the
1748 client</description>
1749 <syntax>LimitRequestFieldsize <var>bytes</var></syntax>
1750 <default>LimitRequestFieldsize 8190</default>
1751 <contextlist><context>server config</context></contextlist>
1754 <p>This directive specifies the number of <var>bytes</var>
1755 that will be allowed in an HTTP request header.</p>
1757 <p>The <directive>LimitRequestFieldSize</directive> directive
1758 allows the server administrator to reduce or increase the limit
1759 on the allowed size of an HTTP request header field. A server
1760 needs this value to be large enough to hold any one header field
1761 from a normal client request. The size of a normal request header
1762 field will vary greatly among different client implementations,
1763 often depending upon the extent to which a user has configured
1764 their browser to support detailed content negotiation. SPNEGO
1765 authentication headers can be up to 12392 bytes.</p>
1767 <p>This directive gives the server administrator greater
1768 control over abnormal client request behavior, which may be
1769 useful for avoiding some forms of denial-of-service attacks.</p>
1774 LimitRequestFieldSize 4094
1777 <note>Under normal conditions, the value should not be changed from
1781 </directivesynopsis>
1784 <name>LimitRequestLine</name>
1785 <description>Limit the size of the HTTP request line that will be accepted
1786 from the client</description>
1787 <syntax>LimitRequestLine <var>bytes</var></syntax>
1788 <default>LimitRequestLine 8190</default>
1789 <contextlist><context>server config</context></contextlist>
1792 <p>This directive sets the number of <var>bytes</var> that will be
1793 allowed on the HTTP request-line.</p>
1795 <p>The <directive>LimitRequestLine</directive> directive allows
1796 the server administrator to reduce or increase the limit on the allowed size
1797 of a client's HTTP request-line. Since the request-line consists of the
1798 HTTP method, URI, and protocol version, the
1799 <directive>LimitRequestLine</directive> directive places a
1800 restriction on the length of a request-URI allowed for a request
1801 on the server. A server needs this value to be large enough to
1802 hold any of its resource names, including any information that
1803 might be passed in the query part of a <code>GET</code> request.</p>
1805 <p>This directive gives the server administrator greater
1806 control over abnormal client request behavior, which may be
1807 useful for avoiding some forms of denial-of-service attacks.</p>
1812 LimitRequestLine 4094
1815 <note>Under normal conditions, the value should not be changed from
1818 </directivesynopsis>
1821 <name>LimitXMLRequestBody</name>
1822 <description>Limits the size of an XML-based request body</description>
1823 <syntax>LimitXMLRequestBody <var>bytes</var></syntax>
1824 <default>LimitXMLRequestBody 1000000</default>
1825 <contextlist><context>server config</context><context>virtual host</context>
1826 <context>directory</context><context>.htaccess</context></contextlist>
1827 <override>All</override>
1830 <p>Limit (in bytes) on maximum size of an XML-based request
1831 body. A value of <code>0</code> will disable any checking.</p>
1836 LimitXMLRequestBody 0
1840 </directivesynopsis>
1842 <directivesynopsis type="section">
1843 <name>Location</name>
1844 <description>Applies the enclosed directives only to matching
1846 <syntax><Location
1847 <var>URL-path</var>|<var>URL</var>> ... </Location></syntax>
1848 <contextlist><context>server config</context><context>virtual host</context>
1852 <p>The <directive type="section">Location</directive> directive
1853 limits the scope of the enclosed directives by URL. It is similar to the
1854 <directive type="section" module="core">Directory</directive>
1855 directive, and starts a subsection which is terminated with a
1856 <code></Location></code> directive. <directive
1857 type="section">Location</directive> sections are processed in the
1858 order they appear in the configuration file, after the <directive
1859 type="section" module="core">Directory</directive> sections and
1860 <code>.htaccess</code> files are read, and after the <directive
1861 type="section" module="core">Files</directive> sections.</p>
1863 <p><directive type="section">Location</directive> sections operate
1864 completely outside the filesystem. This has several consequences.
1865 Most importantly, <directive type="section">Location</directive>
1866 directives should not be used to control access to filesystem
1867 locations. Since several different URLs may map to the same
1868 filesystem location, such access controls may by circumvented.</p>
1870 <note><title>When to use <directive
1871 type="section">Location</directive></title>
1873 <p>Use <directive type="section">Location</directive> to apply
1874 directives to content that lives outside the filesystem. For
1875 content that lives in the filesystem, use <directive
1876 type="section" module="core">Directory</directive> and <directive
1877 type="section" module="core">Files</directive>. An exception is
1878 <code><Location /></code>, which is an easy way to
1879 apply a configuration to the entire server.</p>
1882 <p>For all origin (non-proxy) requests, the URL to be matched is a
1883 URL-path of the form <code>/path/</code>. No scheme, hostname,
1884 port, or query string may be included. For proxy requests, the
1885 URL to be matched is of the form
1886 <code>scheme://servername/path</code>, and you must include the
1889 <p>The URL may use wildcards. In a wild-card string, <code>?</code> matches
1890 any single character, and <code>*</code> matches any sequences of
1894 expressions can also be used, with the addition of the
1895 <code>~</code> character. For example:</p>
1898 <Location ~ "/(extra|special)/data">
1901 <p>would match URLs that contained the substring <code>/extra/data</code>
1902 or <code>/special/data</code>. The directive <directive
1903 type="section" module="core">LocationMatch</directive> behaves
1904 identical to the regex version of <directive
1905 type="section">Location</directive>.</p>
1907 <p>The <directive type="section">Location</directive>
1908 functionality is especially useful when combined with the
1909 <directive module="core">SetHandler</directive>
1910 directive. For example, to enable status requests, but allow them
1911 only from browsers at <code>foo.com</code>, you might use:</p>
1914 <Location /status><br />
1916 SetHandler server-status<br />
1917 Order Deny,Allow<br />
1919 Allow from .foo.com<br />
1924 <note><title>Note about / (slash)</title>
1925 <p>The slash character has special meaning depending on where in a
1926 URL it appears. People may be used to its behavior in the filesystem
1927 where multiple adjacent slashes are frequently collapsed to a single
1928 slash (<em>i.e.</em>, <code>/home///foo</code> is the same as
1929 <code>/home/foo</code>). In URL-space this is not necessarily true.
1930 The <directive type="section" module="core">LocationMatch</directive>
1931 directive and the regex version of <directive type="section"
1932 >Location</directive> require you to explicitly specify multiple
1933 slashes if that is your intention.</p>
1935 <p>For example, <code><LocationMatch ^/abc></code> would match
1936 the request URL <code>/abc</code> but not the request URL <code>
1937 //abc</code>. The (non-regex) <directive type="section"
1938 >Location</directive> directive behaves similarly when used for
1939 proxy requests. But when (non-regex) <directive type="section"
1940 >Location</directive> is used for non-proxy requests it will
1941 implicitly match multiple slashes with a single slash. For example,
1942 if you specify <code><Location /abc/def></code> and the
1943 request is to <code>/abc//def</code> then it will match.</p>
1946 <seealso><a href="../sections.html">How <Directory>, <Location>
1947 and <Files> sections work</a> for an explanation of how these
1948 different sections are combined when a request is received</seealso>
1949 </directivesynopsis>
1951 <directivesynopsis type="section">
1952 <name>LocationMatch</name>
1953 <description>Applies the enclosed directives only to regular-expression
1954 matching URLs</description>
1955 <syntax><LocationMatch
1956 <var>regex</var>> ... </LocationMatch></syntax>
1957 <contextlist><context>server config</context><context>virtual host</context>
1961 <p>The <directive type="section">LocationMatch</directive> directive
1962 limits the scope of the enclosed directives by URL, in an identical manner
1963 to <directive module="core" type="section">Location</directive>. However,
1964 it takes a regular expression as an argument instead of a simple
1965 string. For example:</p>
1968 <LocationMatch "/(extra|special)/data">
1971 <p>would match URLs that contained the substring <code>/extra/data</code>
1972 or <code>/special/data</code>.</p>
1975 <seealso><a href="../sections.html">How <Directory>, <Location>
1976 and <Files> sections work</a> for an explanation of how these
1977 different sections are combined when a request is received</seealso>
1978 </directivesynopsis>
1981 <name>LogLevel</name>
1982 <description>Controls the verbosity of the ErrorLog</description>
1983 <syntax>LogLevel <var>level</var></syntax>
1984 <default>LogLevel warn</default>
1985 <contextlist><context>server config</context><context>virtual host</context>
1989 <p><directive>LogLevel</directive> adjusts the verbosity of the
1990 messages recorded in the error logs (see <directive
1991 module="core">ErrorLog</directive> directive). The following
1992 <var>level</var>s are available, in order of decreasing
1996 <columnspec><column width=".2"/><column width=".3"/><column width=".5"/>
1999 <th><strong>Level</strong> </th>
2001 <th><strong>Description</strong> </th>
2003 <th><strong>Example</strong> </th>
2007 <td><code>emerg</code> </td>
2009 <td>Emergencies - system is unusable.</td>
2011 <td>"Child cannot open lock file. Exiting"</td>
2015 <td><code>alert</code> </td>
2017 <td>Action must be taken immediately.</td>
2019 <td>"getpwuid: couldn't determine user name from uid"</td>
2023 <td><code>crit</code> </td>
2025 <td>Critical Conditions.</td>
2027 <td>"socket: Failed to get a socket, exiting child"</td>
2031 <td><code>error</code> </td>
2033 <td>Error conditions.</td>
2035 <td>"Premature end of script headers"</td>
2039 <td><code>warn</code> </td>
2041 <td>Warning conditions.</td>
2043 <td>"child process 1234 did not exit, sending another
2048 <td><code>notice</code> </td>
2050 <td>Normal but significant condition.</td>
2052 <td>"httpd: caught SIGBUS, attempting to dump core in
2057 <td><code>info</code> </td>
2059 <td>Informational.</td>
2061 <td>"Server seems busy, (you may need to increase
2062 StartServers, or Min/MaxSpareServers)..."</td>
2066 <td><code>debug</code> </td>
2068 <td>Debug-level messages</td>
2070 <td>"Opening config file ..."</td>
2074 <p>When a particular level is specified, messages from all
2075 other levels of higher significance will be reported as well.
2076 <em>E.g.</em>, when <code>LogLevel info</code> is specified,
2077 then messages with log levels of <code>notice</code> and
2078 <code>warn</code> will also be posted.</p>
2080 <p>Using a level of at least <code>crit</code> is
2089 <note><title>Note</title>
2090 <p>When logging to a regular file messages of the level
2091 <code>notice</code> cannot be suppressed and thus are always
2092 logged. However, this doesn't apply when logging is done
2093 using <code>syslog</code>.</p>
2096 </directivesynopsis>
2099 <name>MaxKeepAliveRequests</name>
2100 <description>Number of requests allowed on a persistent
2101 connection</description>
2102 <syntax>MaxKeepAliveRequests <var>number</var></syntax>
2103 <default>MaxKeepAliveRequests 100</default>
2104 <contextlist><context>server config</context><context>virtual host</context>
2108 <p>The <directive>MaxKeepAliveRequests</directive> directive
2109 limits the number of requests allowed per connection when
2110 <directive module="core" >KeepAlive</directive> is on. If it is
2111 set to <code>0</code>, unlimited requests will be allowed. We
2112 recommend that this setting be kept to a high value for maximum
2113 server performance.</p>
2118 MaxKeepAliveRequests 500
2121 </directivesynopsis>
2124 <name>NameVirtualHost</name>
2125 <description>Designates an IP address for name-virtual
2126 hosting</description>
2127 <syntax>NameVirtualHost <var>addr</var>[:<var>port</var>]</syntax>
2128 <contextlist><context>server config</context></contextlist>
2131 <p>The <directive>NameVirtualHost</directive> directive is a
2132 required directive if you want to configure <a
2133 href="../vhosts/">name-based virtual hosts</a>.</p>
2135 <p>Although <var>addr</var> can be hostname it is recommended
2136 that you always use an IP address, e.g.</p>
2139 NameVirtualHost 111.22.33.44
2142 <p>With the <directive>NameVirtualHost</directive> directive you
2143 specify the IP address on which the server will receive requests
2144 for the name-based virtual hosts. This will usually be the address
2145 to which your name-based virtual host names resolve. In cases
2146 where a firewall or other proxy receives the requests and forwards
2147 them on a different IP address to the server, you must specify the
2148 IP address of the physical interface on the machine which will be
2149 servicing the requests. If you have multiple name-based hosts on
2150 multiple addresses, repeat the directive for each address.</p>
2152 <note><title>Note</title>
2153 <p>Note, that the "main server" and any <code>_default_</code> servers
2154 will <strong>never</strong> be served for a request to a
2155 <directive>NameVirtualHost</directive> IP address (unless for some
2156 reason you specify <directive>NameVirtualHost</directive> but then
2157 don't define any <directive>VirtualHost</directive>s for that
2161 <p>Optionally you can specify a port number on which the
2162 name-based virtual hosts should be used, e.g.</p>
2165 NameVirtualHost 111.22.33.44:8080
2168 <p>IPv6 addresses must be enclosed in square brackets, as shown
2169 in the following example:</p>
2172 NameVirtualHost [fe80::a00:20ff:fea7:ccea]:8080
2175 <p>To receive requests on all interfaces, you can use an argument of
2182 <note><title>Argument to <directive type="section">VirtualHost</directive>
2184 <p>Note that the argument to the <directive
2185 type="section">VirtualHost</directive> directive must
2186 exactly match the argument to the <directive
2187 >NameVirtualHost</directive> directive.</p>
2190 NameVirtualHost 1.2.3.4<br />
2191 <VirtualHost 1.2.3.4><br />
2193 </VirtualHost><br />
2198 <seealso><a href="../vhosts/">Virtual Hosts
2199 documentation</a></seealso>
2201 </directivesynopsis>
2204 <name>Options</name>
2205 <description>Configures what features are available in a particular
2206 directory</description>
2208 [+|-]<var>option</var> [[+|-]<var>option</var>] ...</syntax>
2209 <default>Options All</default>
2210 <contextlist><context>server config</context><context>virtual host</context>
2211 <context>directory</context><context>.htaccess</context>
2213 <override>Options</override>
2216 <p>The <directive>Options</directive> directive controls which
2217 server features are available in a particular directory.</p>
2219 <p><var>option</var> can be set to <code>None</code>, in which
2220 case none of the extra features are enabled, or one or more of
2224 <dt><code>All</code></dt>
2226 <dd>All options except for <code>MultiViews</code>. This is the default
2229 <dt><code>ExecCGI</code></dt>
2232 Execution of CGI scripts using <module>mod_cgi</module>
2235 <dt><code>FollowSymLinks</code></dt>
2239 The server will follow symbolic links in this directory.
2241 <p>Even though the server follows the symlink it does <em>not</em>
2242 change the pathname used to match against <directive type="section"
2243 module="core">Directory</directive> sections.</p>
2244 <p>Note also, that this option <strong>gets ignored</strong> if set
2245 inside a <directive type="section" module="core">Location</directive>
2249 <dt><code>Includes</code></dt>
2252 Server-side includes provided by <module>mod_include</module>
2255 <dt><code>IncludesNOEXEC</code></dt>
2259 Server-side includes are permitted, but the <code>#exec
2260 cmd</code> and <code>#exec cgi</code> are disabled. It is still
2261 possible to <code>#include virtual</code> CGI scripts from
2262 <directive module="mod_alias">ScriptAlias</directive>ed
2265 <dt><code>Indexes</code></dt>
2268 If a URL which maps to a directory is requested, and there
2269 is no <directive module="mod_dir">DirectoryIndex</directive>
2270 (<em>e.g.</em>, <code>index.html</code>) in that directory, then
2271 <module>mod_autoindex</module> will return a formatted listing
2272 of the directory.</dd>
2274 <dt><code>MultiViews</code></dt>
2277 <a href="../content-negotiation.html">Content negotiated</a>
2278 "MultiViews" are allowed using
2279 <module>mod_negotiation</module>.</dd>
2281 <dt><code>SymLinksIfOwnerMatch</code></dt>
2283 <dd>The server will only follow symbolic links for which the
2284 target file or directory is owned by the same user id as the
2287 <note><title>Note</title> This option gets ignored if
2288 set inside a <directive module="core"
2289 type="section">Location</directive> section.</note>
2293 <p>Normally, if multiple <directive>Options</directive> could
2294 apply to a directory, then the most specific one is used and
2295 others are ignored; the options are not merged. (See <a
2296 href="../sections.html#mergin">how sections are merged</a>.)
2297 However if <em>all</em> the options on the
2298 <directive>Options</directive> directive are preceded by a
2299 <code>+</code> or <code>-</code> symbol, the options are
2300 merged. Any options preceded by a <code>+</code> are added to the
2301 options currently in force, and any options preceded by a
2302 <code>-</code> are removed from the options currently in
2305 <p>For example, without any <code>+</code> and <code>-</code> symbols:</p>
2308 <Directory /web/docs><br />
2310 Options Indexes FollowSymLinks<br />
2312 </Directory><br />
2314 <Directory /web/docs/spec><br />
2316 Options Includes<br />
2321 <p>then only <code>Includes</code> will be set for the
2322 <code>/web/docs/spec</code> directory. However if the second
2323 <directive>Options</directive> directive uses the <code>+</code> and
2324 <code>-</code> symbols:</p>
2327 <Directory /web/docs><br />
2329 Options Indexes FollowSymLinks<br />
2331 </Directory><br />
2333 <Directory /web/docs/spec><br />
2335 Options +Includes -Indexes<br />
2340 <p>then the options <code>FollowSymLinks</code> and
2341 <code>Includes</code> are set for the <code>/web/docs/spec</code>
2344 <note><title>Note</title>
2345 <p>Using <code>-IncludesNOEXEC</code> or
2346 <code>-Includes</code> disables server-side includes completely
2347 regardless of the previous setting.</p>
2350 <p>The default in the absence of any other settings is
2351 <code>All</code>.</p>
2353 </directivesynopsis>
2356 <name>Require</name>
2357 <description>Selects which authenticated users can access
2358 a resource</description>
2359 <syntax>Require <var>entity-name</var> [<var>entity-name</var>] ...</syntax>
2360 <contextlist><context>directory</context><context>.htaccess</context>
2362 <override>AuthConfig</override>
2365 <p>This directive selects which authenticated users can access
2366 a resource. The allowed syntaxes are:</p>
2369 <dt><code>Require user <var>userid</var> [<var>userid</var>]
2371 <dd>Only the named users can access the resource.</dd>
2373 <dt><code>Require group <var>group-name</var> [<var>group-name</var>]
2375 <dd>Only users in the named groups can access the resource.</dd>
2377 <dt><code>Require valid-user</code></dt>
2378 <dd>All valid users can access the resource.</dd>
2381 <p><directive>Require</directive> must be accompanied by
2382 <directive module="core">AuthName</directive> and <directive
2383 module="core">AuthType</directive> directives, and directives such
2384 as <directive module="mod_authn_file">AuthUserFile</directive>
2385 and <directive module="mod_authz_groupfile">AuthGroupFile</directive> (to
2386 define users and groups) in order to work correctly. Example:</p>
2389 AuthType Basic<br />
2390 AuthName "Restricted Resource"<br />
2391 AuthUserFile /web/users<br />
2392 AuthGroupFile /web/groups<br />
2396 <p>Access controls which are applied in this way are effective for
2397 <strong>all</strong> methods. <strong>This is what is normally
2398 desired.</strong> If you wish to apply access controls only to
2399 specific methods, while leaving other methods unprotected, then
2400 place the <directive>Require</directive> statement into a
2401 <directive module="core" type="section">Limit</directive>
2404 <seealso><directive module="core">Satisfy</directive></seealso>
2405 <seealso><module>mod_authz_host</module></seealso>
2406 </directivesynopsis>
2409 <name>RLimitCPU</name>
2410 <description>Limits the CPU consumption of processes launched
2411 by Apache children</description>
2412 <syntax>RLimitCPU <var>seconds</var>|max [<var>seconds</var>|max]</syntax>
2413 <default>Unset; uses operating system defaults</default>
2414 <contextlist><context>server config</context><context>virtual host</context>
2415 <context>directory</context><context>.htaccess</context></contextlist>
2416 <override>All</override>
2419 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2420 resource limit for all processes and the second parameter sets
2421 the maximum resource limit. Either parameter can be a number,
2422 or <code>max</code> to indicate to the server that the limit should
2423 be set to the maximum allowed by the operating system
2424 configuration. Raising the maximum resource limit requires that
2425 the server is running as <code>root</code>, or in the initial startup
2428 <p>This applies to processes forked off from Apache children
2429 servicing requests, not the Apache children themselves. This
2430 includes CGI scripts and SSI exec commands, but not any
2431 processes forked off from the Apache parent such as piped
2434 <p>CPU resource limits are expressed in seconds per
2437 <seealso><directive module="core">RLimitMEM</directive></seealso>
2438 <seealso><directive module="core">RLimitNPROC</directive></seealso>
2439 </directivesynopsis>
2442 <name>RLimitMEM</name>
2443 <description>Limits the memory consumption of processes launched
2444 by Apache children</description>
2445 <syntax>RLimitMEM <var>bytes</var>|max [<var>bytes</var>|max]</syntax>
2446 <default>Unset; uses operating system defaults</default>
2447 <contextlist><context>server config</context><context>virtual host</context>
2448 <context>directory</context><context>.htaccess</context></contextlist>
2449 <override>All</override>
2452 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2453 resource limit for all processes and the second parameter sets
2454 the maximum resource limit. Either parameter can be a number,
2455 or <code>max</code> to indicate to the server that the limit should
2456 be set to the maximum allowed by the operating system
2457 configuration. Raising the maximum resource limit requires that
2458 the server is running as <code>root</code>, or in the initial startup
2461 <p>This applies to processes forked off from Apache children
2462 servicing requests, not the Apache children themselves. This
2463 includes CGI scripts and SSI exec commands, but not any
2464 processes forked off from the Apache parent such as piped
2467 <p>Memory resource limits are expressed in bytes per
2470 <seealso><directive module="core">RLimitCPU</directive></seealso>
2471 <seealso><directive module="core">RLimitNPROC</directive></seealso>
2472 </directivesynopsis>
2475 <name>RLimitNPROC</name>
2476 <description>Limits the number of processes that can be launched by
2477 processes launched by Apache children</description>
2478 <syntax>RLimitNPROC <var>number</var>|max [<var>number</var>|max]</syntax>
2479 <default>Unset; uses operating system defaults</default>
2480 <contextlist><context>server config</context><context>virtual host</context>
2481 <context>directory</context><context>.htaccess</context></contextlist>
2482 <override>All</override>
2485 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2486 resource limit for all processes and the second parameter sets
2487 the maximum resource limit. Either parameter can be a number,
2488 or <code>max</code> to indicate to the server that the limit
2489 should be set to the maximum allowed by the operating system
2490 configuration. Raising the maximum resource limit requires that
2491 the server is running as <code>root</code>, or in the initial startup
2494 <p>This applies to processes forked off from Apache children
2495 servicing requests, not the Apache children themselves. This
2496 includes CGI scripts and SSI exec commands, but not any
2497 processes forked off from the Apache parent such as piped
2500 <p>Process limits control the number of processes per user.</p>
2502 <note><title>Note</title>
2503 <p>If CGI processes are <strong>not</strong> running
2504 under user ids other than the web server user id, this directive
2505 will limit the number of processes that the server itself can
2506 create. Evidence of this situation will be indicated by
2507 <strong><code>cannot fork</code></strong> messages in the
2508 <code>error_log</code>.</p>
2511 <seealso><directive module="core">RLimitMEM</directive></seealso>
2512 <seealso><directive module="core">RLimitCPU</directive></seealso>
2513 </directivesynopsis>
2516 <name>Satisfy</name>
2517 <description>Interaction between host-level access control and
2518 user authentication</description>
2519 <syntax>Satisfy Any|All</syntax>
2520 <default>Satisfy All</default>
2521 <contextlist><context>directory</context><context>.htaccess</context>
2523 <override>AuthConfig</override>
2524 <compatibility>Influenced by <directive module="core" type="section"
2525 >Limit</directive> and <directive module="core"
2526 type="section">LimitExcept</directive> in version 2.0.51 and
2527 later</compatibility>
2530 <p>Access policy if both <directive
2531 module="mod_authz_host">Allow</directive> and <directive
2532 module="core">Require</directive> used. The parameter can be
2533 either <code>All</code> or <code>Any</code>. This directive is only
2534 useful if access to a particular area is being restricted by both
2535 username/password <em>and</em> client host address. In this case
2536 the default behavior (<code>All</code>) is to require that the client
2537 passes the address access restriction <em>and</em> enters a valid
2538 username and password. With the <code>Any</code> option the client will be
2539 granted access if they either pass the host restriction or enter a
2540 valid username and password. This can be used to password restrict
2541 an area, but to let clients from particular addresses in without
2542 prompting for a password.</p>
2544 <p>For example, if you wanted to let people on your network have
2545 unrestricted access to a portion of your website, but require that
2546 people outside of your network provide a password, you could use a
2547 configuration similar to the following:</p>
2550 Require valid-user<br />
2551 Allow from 192.168.1<br />
2555 <p>Since version 2.0.51 <directive>Satisfy</directive> directives can
2556 be restricted to particular methods by <directive module="core"
2557 type="section">Limit</directive> and <directive module="core" type="section"
2558 >LimitExcept</directive> sections.</p>
2560 <seealso><directive module="mod_authz_host">Allow</directive></seealso>
2561 <seealso><directive module="core">Require</directive></seealso>
2562 </directivesynopsis>
2565 <name>ScriptInterpreterSource</name>
2566 <description>Technique for locating the interpreter for CGI
2567 scripts</description>
2568 <syntax>ScriptInterpreterSource Registry|Registry-Strict|Script</syntax>
2569 <default>ScriptInterpreterSource Script</default>
2570 <contextlist><context>server config</context><context>virtual host</context>
2571 <context>directory</context><context>.htaccess</context></contextlist>
2572 <override>FileInfo</override>
2573 <compatibility>Win32 only;
2574 option <code>Registry-Strict</code> is available in Apache 2.0 and
2575 later</compatibility>
2578 <p>This directive is used to control how Apache finds the
2579 interpreter used to run CGI scripts. The default setting is
2580 <code>Script</code>. This causes Apache to use the interpreter pointed to
2581 by the shebang line (first line, starting with <code>#!</code>) in the
2582 script. On Win32 systems this line usually looks like:</p>
2585 #!C:/Perl/bin/perl.exe
2588 <p>or, if <code>perl</code> is in the <code>PATH</code>, simply:</p>
2594 <p>Setting <code>ScriptInterpreterSource Registry</code> will
2595 cause the Windows Registry tree <code>HKEY_CLASSES_ROOT</code> to be
2596 searched using the script file extension (e.g., <code>.pl</code>) as a
2597 search key. The command defined by the registry subkey
2598 <code>Shell\ExecCGI\Command</code> or, if it does not exist, by the subkey
2599 <code>Shell\Open\Command</code> is used to open the script file. If the
2600 registry keys cannot be found, Apache falls back to the behavior of the
2601 <code>Script</code> option.</p>
2603 <note type="warning"><title>Security</title>
2604 <p>Be careful when using <code>ScriptInterpreterSource
2605 Registry</code> with <directive
2606 module="mod_alias">ScriptAlias</directive>'ed directories, because
2607 Apache will try to execute <strong>every</strong> file within this
2608 directory. The <code>Registry</code> setting may cause undesired
2609 program calls on files which are typically not executed. For
2610 example, the default open command on <code>.htm</code> files on
2611 most Windows systems will execute Microsoft Internet Explorer, so
2612 any HTTP request for an <code>.htm</code> file existing within the
2613 script directory would start the browser in the background on the
2614 server. This is a good way to crash your system within a minute or
2618 <p>The option <code>Registry-Strict</code> which is new in Apache
2619 2.0 does the same thing as <code>Registry</code> but uses only the
2620 subkey <code>Shell\ExecCGI\Command</code>. The
2621 <code>ExecCGI</code> key is not a common one. It must be
2622 configured manually in the windows registry and hence prevents
2623 accidental program calls on your system.</p>
2625 </directivesynopsis>
2628 <name>ServerAdmin</name>
2629 <description>Email address that the server includes in error
2630 messages sent to the client</description>
2631 <syntax>ServerAdmin <var>email-address</var>|<var>URL</var></syntax>
2632 <contextlist><context>server config</context><context>virtual host</context>
2636 <p>The <directive>ServerAdmin</directive> sets the contact address
2637 that the server includes in any error messages it returns to the
2638 client. If the <code>httpd</code> doesn't recognize the supplied argument
2640 assumes, that it's an <var>email-address</var> and prepends it with
2641 <code>mailto:</code> in hyperlink targets. However, it's recommended to
2642 actually use an email address, since there are a lot of CGI scripts that
2643 make that assumption. If you want to use an URL, it should point to another
2644 server under your control. Otherwise users may not be able to contact you in
2647 <p>It may be worth setting up a dedicated address for this, e.g.</p>
2650 ServerAdmin www-admin@foo.example.com
2652 <p>as users do not always mention that they are talking about the
2655 </directivesynopsis>
2658 <name>ServerAlias</name>
2659 <description>Alternate names for a host used when matching requests
2660 to name-virtual hosts</description>
2661 <syntax>ServerAlias <var>hostname</var> [<var>hostname</var>] ...</syntax>
2662 <contextlist><context>virtual host</context></contextlist>
2665 <p>The <directive>ServerAlias</directive> directive sets the
2666 alternate names for a host, for use with <a
2667 href="../vhosts/name-based.html">name-based virtual hosts</a>.</p>
2670 <VirtualHost *><br />
2671 ServerName server.domain.com<br />
2672 ServerAlias server server2.domain.com server2<br />
2674 </VirtualHost>
2677 <seealso><a href="../vhosts/">Apache Virtual Host documentation</a></seealso>
2678 </directivesynopsis>
2681 <name>ServerName</name>
2682 <description>Hostname and port that the server uses to identify
2683 itself</description>
2684 <syntax>ServerName <var>fully-qualified-domain-name</var>[:<var>port</var>]</syntax>
2685 <contextlist><context>server config</context><context>virtual host</context>
2687 <compatibility>In version 2.0, this
2688 directive supersedes the functionality of the <directive>Port</directive>
2689 directive from version 1.3.</compatibility>
2692 <p>The <directive>ServerName</directive> directive sets the hostname and
2693 port that the server uses to identify itself. This is used when
2694 creating redirection URLs. For example, if the name of the
2695 machine hosting the web server is <code>simple.example.com</code>,
2696 but the machine also has the DNS alias <code>www.example.com</code>
2697 and you wish the web server to be so identified, the following
2698 directive should be used:</p>
2701 ServerName www.example.com:80
2704 <p>If no <directive>ServerName</directive> is specified, then the
2705 server attempts to deduce the hostname by performing a reverse
2706 lookup on the IP address. If no port is specified in the
2707 <directive>ServerName</directive>, then the server will use the port
2709 request. For optimal reliability and predictability, you should
2710 specify an explicit hostname and port using the
2711 <directive>ServerName</directive> directive.</p>
2713 <p>If you are using <a
2714 href="../vhosts/name-based.html">name-based virtual hosts</a>,
2715 the <directive>ServerName</directive> inside a
2716 <directive type="section" module="core">VirtualHost</directive>
2717 section specifies what hostname must appear in the request's
2718 <code>Host:</code> header to match this virtual host.</p>
2720 <p>See the description of the
2721 <directive module="core">UseCanonicalName</directive> directive for
2722 settings which determine whether self-referential URL's (e.g., by the
2723 <module>mod_dir</module> module) will refer to the
2724 specified port, or to the port number given in the client's request.
2728 <seealso><a href="../dns-caveats.html">Issues Regarding DNS and
2729 Apache</a></seealso>
2730 <seealso><a href="../vhosts/">Apache virtual host
2731 documentation</a></seealso>
2732 <seealso><directive module="core">UseCanonicalName</directive></seealso>
2733 <seealso><directive module="core">NameVirtualHost</directive></seealso>
2734 <seealso><directive module="core">ServerAlias</directive></seealso>
2735 </directivesynopsis>
2738 <name>ServerPath</name>
2739 <description>Legacy URL pathname for a name-based virtual host that
2740 is accessed by an incompatible browser</description>
2741 <syntax>ServerPath <var>URL-path</var></syntax>
2742 <contextlist><context>virtual host</context></contextlist>
2745 <p>The <directive>ServerPath</directive> directive sets the legacy
2746 URL pathname for a host, for use with <a
2747 href="../vhosts/">name-based virtual hosts</a>.</p>
2749 <seealso><a href="../vhosts/">Apache Virtual Host documentation</a></seealso>
2750 </directivesynopsis>
2753 <name>ServerRoot</name>
2754 <description>Base directory for the server installation</description>
2755 <syntax>ServerRoot <var>directory-path</var></syntax>
2756 <default>ServerRoot /usr/local/apache</default>
2757 <contextlist><context>server config</context></contextlist>
2760 <p>The <directive>ServerRoot</directive> directive sets the
2761 directory in which the server lives. Typically it will contain the
2762 subdirectories <code>conf/</code> and <code>logs/</code>. Relative
2763 paths in other configuration directives (such as <directive
2764 module="core">Include</directive> or <directive
2765 module="mod_so">LoadModule</directive>, for example) are taken as
2766 relative to this directory.</p>
2768 <example><title>Example</title>
2769 ServerRoot /home/httpd
2773 <seealso><a href="../invoking.html">the <code>-d</code>
2774 option to <code>httpd</code></a></seealso>
2775 <seealso><a href="../misc/security_tips.html#serverroot">the
2776 security tips</a> for information on how to properly set
2777 permissions on the <directive>ServerRoot</directive></seealso>
2778 </directivesynopsis>
2781 <name>ServerSignature</name>
2782 <description>Configures the footer on server-generated documents</description>
2783 <syntax>ServerSignature On|Off|EMail</syntax>
2784 <default>ServerSignature Off</default>
2785 <contextlist><context>server config</context><context>virtual host</context>
2786 <context>directory</context><context>.htaccess</context>
2788 <override>All</override>
2791 <p>The <directive>ServerSignature</directive> directive allows the
2792 configuration of a trailing footer line under server-generated
2793 documents (error messages, <module>mod_proxy</module> ftp directory
2794 listings, <module>mod_info</module> output, ...). The reason why you
2795 would want to enable such a footer line is that in a chain of proxies,
2796 the user often has no possibility to tell which of the chained servers
2797 actually produced a returned error message.</p>
2799 <p>The <code>Off</code>
2800 setting, which is the default, suppresses the footer line (and is
2801 therefore compatible with the behavior of Apache-1.2 and
2802 below). The <code>On</code> setting simply adds a line with the
2803 server version number and <directive
2804 module="core">ServerName</directive> of the serving virtual host,
2805 and the <code>EMail</code> setting additionally creates a
2806 "mailto:" reference to the <directive
2807 module="core">ServerAdmin</directive> of the referenced
2810 <p>After version 2.0.44, the details of the server version number
2811 presented are controlled by the <directive
2812 module="core">ServerTokens</directive> directive.</p>
2814 <seealso><directive module="core">ServerTokens</directive></seealso>
2815 </directivesynopsis>
2818 <name>ServerTokens</name>
2819 <description>Configures the <code>Server</code> HTTP response
2820 header</description>
2821 <syntax>ServerTokens Major|Minor|Min[imal]|Prod[uctOnly]|OS|Full</syntax>
2822 <default>ServerTokens Full</default>
2823 <contextlist><context>server config</context></contextlist>
2826 <p>This directive controls whether <code>Server</code> response
2827 header field which is sent back to clients includes a
2828 description of the generic OS-type of the server as well as
2829 information about compiled-in modules.</p>
2832 <dt><code>ServerTokens Prod[uctOnly]</code></dt>
2834 <dd>Server sends (<em>e.g.</em>): <code>Server:
2837 <dt><code>ServerTokens Major</code></dt>
2839 <dd>Server sends (<em>e.g.</em>): <code>Server:
2840 Apache/2</code></dd>
2842 <dt><code>ServerTokens Minor</code></dt>
2844 <dd>Server sends (<em>e.g.</em>): <code>Server:
2845 Apache/2.0</code></dd>
2847 <dt><code>ServerTokens Min[imal]</code></dt>
2849 <dd>Server sends (<em>e.g.</em>): <code>Server:
2850 Apache/2.0.41</code></dd>
2852 <dt><code>ServerTokens OS</code></dt>
2854 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2857 <dt><code>ServerTokens Full</code> (or not specified)</dt>
2859 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2860 (Unix) PHP/4.2.2 MyMod/1.2</code></dd>
2863 <p>This setting applies to the entire server, and cannot be
2864 enabled or disabled on a virtualhost-by-virtualhost basis.</p>
2866 <p>After version 2.0.44, this directive also controls the
2867 information presented by the <directive
2868 module="core">ServerSignature</directive> directive.</p>
2870 <seealso><directive module="core">ServerSignature</directive></seealso>
2871 </directivesynopsis>
2874 <name>SetHandler</name>
2875 <description>Forces all matching files to be processed by a
2876 handler</description>
2877 <syntax>SetHandler <var>handler-name</var>|None</syntax>
2878 <contextlist><context>server config</context><context>virtual host</context>
2879 <context>directory</context><context>.htaccess</context>
2881 <override>FileInfo</override>
2882 <compatibility>Moved into the core in Apache 2.0</compatibility>
2885 <p>When placed into an <code>.htaccess</code> file or a
2886 <directive type="section" module="core">Directory</directive> or
2887 <directive type="section" module="core">Location</directive>
2888 section, this directive forces all matching files to be parsed
2889 through the <a href="../handler.html">handler</a> given by
2890 <var>handler-name</var>. For example, if you had a directory you
2891 wanted to be parsed entirely as imagemap rule files, regardless
2892 of extension, you might put the following into an
2893 <code>.htaccess</code> file in that directory:</p>
2896 SetHandler imap-file
2899 <p>Another example: if you wanted to have the server display a
2900 status report whenever a URL of
2901 <code>http://servername/status</code> was called, you might put
2902 the following into <code>httpd.conf</code>:</p>
2905 <Location /status><br />
2907 SetHandler server-status<br />
2912 <p>You can override an earlier defined <directive>SetHandler</directive>
2913 directive by using the value <code>None</code>.</p>
2916 <seealso><directive module="mod_mime">AddHandler</directive></seealso>
2918 </directivesynopsis>
2921 <name>SetInputFilter</name>
2922 <description>Sets the filters that will process client requests and POST
2924 <syntax>SetInputFilter <var>filter</var>[;<var>filter</var>...]</syntax>
2925 <contextlist><context>server config</context><context>virtual host</context>
2926 <context>directory</context><context>.htaccess</context>
2928 <override>FileInfo</override>
2931 <p>The <directive>SetInputFilter</directive> directive sets the
2932 filter or filters which will process client requests and POST
2933 input when they are received by the server. This is in addition to
2934 any filters defined elsewhere, including the
2935 <directive module="mod_mime">AddInputFilter</directive>
2938 <p>If more than one filter is specified, they must be separated
2939 by semicolons in the order in which they should process the
2942 <seealso><a href="../filter.html">Filters</a> documentation</seealso>
2943 </directivesynopsis>
2946 <name>SetOutputFilter</name>
2947 <description>Sets the filters that will process responses from the
2948 server</description>
2949 <syntax>SetOutputFilter <var>filter</var>[;<var>filter</var>...]</syntax>
2950 <contextlist><context>server config</context><context>virtual host</context>
2951 <context>directory</context><context>.htaccess</context>
2953 <override>FileInfo</override>
2956 <p>The <directive>SetOutputFilter</directive> directive sets the filters
2957 which will process responses from the server before they are
2958 sent to the client. This is in addition to any filters defined
2959 elsewhere, including the
2960 <directive module="mod_mime">AddOutputFilter</directive>
2963 <p>For example, the following configuration will process all files
2964 in the <code>/www/data/</code> directory for server-side
2968 <Directory /www/data/><br />
2970 SetOutputFilter INCLUDES<br />
2975 <p>If more than one filter is specified, they must be separated
2976 by semicolons in the order in which they should process the
2979 <seealso><a href="../filter.html">Filters</a> documentation</seealso>
2980 </directivesynopsis>
2983 <name>TimeOut</name>
2984 <description>Amount of time the server will wait for
2985 certain events before failing a request</description>
2986 <syntax>TimeOut <var>seconds</var></syntax>
2987 <default>TimeOut 300</default>
2988 <contextlist><context>server config</context></contextlist>
2991 <p>The <directive>TimeOut</directive> directive currently defines
2992 the amount of time Apache will wait for three things:</p>
2995 <li>The total amount of time it takes to receive a GET
2998 <li>The amount of time between receipt of TCP packets on a
2999 POST or PUT request.</li>
3001 <li>The amount of time between ACKs on transmissions of TCP
3002 packets in responses.</li>
3005 <p>We plan on making these separately configurable at some point
3006 down the road. The timer used to default to 1200 before 1.2,
3007 but has been lowered to 300 which is still far more than
3008 necessary in most situations. It is not set any lower by
3009 default because there may still be odd places in the code where
3010 the timer is not reset when a packet is sent. </p>
3012 </directivesynopsis>
3015 <name>TraceEnable</name>
3016 <description>Name of the distributed configuration file</description>
3017 <syntax>TraceEnable <var>[on|off|extended]</var></syntax>
3018 <default>TraceEnable on</default>
3019 <contextlist><context>server config</context>
3023 <p>This directive overrides the behavior of TRACE for both
3024 the core server and mod_proxy. The default <code>TraceEnable
3025 on</code> permits TRACE requests per RFC 2616, which disallows
3026 any request body to accompany the request. <code>TraceEnable
3027 off</code> causes the core server and mod_proxy to return
3028 a 405 FORBIDDEN error to the client.</p>
3030 <p>Finally, for testing and diagnostic purposes only, request
3031 bodies may be allowed using the non-compliant <code>TraceEnable
3032 extended</code> directive. The core (as an origin server) will
3033 restrict the request body to 64k (plus 8k for chunk headers if
3034 Transfer-Encoding: chunked is used). The core will reflect the
3035 full headers and all chunk headers with the request body. As a
3036 proxy server, the request body is not restricted to 64k.</p>
3038 </directivesynopsis>
3041 <name>UseCanonicalName</name>
3042 <description>Configures how the server determines its own name and
3044 <syntax>UseCanonicalName On|Off|DNS</syntax>
3045 <default>UseCanonicalName Off</default>
3046 <contextlist><context>server config</context><context>virtual host</context>
3047 <context>directory</context></contextlist>
3050 <p>In many situations Apache must construct a <em>self-referential</em>
3051 URL -- that is, a URL that refers back to the same server. With
3052 <code>UseCanonicalName On</code> Apache will use the hostname and port
3053 specified in the <directive module="core">ServerName</directive>
3054 directive to construct the canonical name for the server. This name
3055 is used in all self-referential URLs, and for the values of
3056 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> in CGIs.</p>
3058 <p>With <code>UseCanonicalName Off</code> Apache will form
3059 self-referential URLs using the hostname and port supplied by
3060 the client if any are supplied (otherwise it will use the
3061 canonical name, as defined above). These values are the same
3062 that are used to implement <a
3063 href="../vhosts/name-based.html">name based virtual hosts</a>,
3064 and are available with the same clients. The CGI variables
3065 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> will be
3066 constructed from the client supplied values as well.</p>
3068 <p>An example where this may be useful is on an intranet server
3069 where you have users connecting to the machine using short
3070 names such as <code>www</code>. You'll notice that if the users
3071 type a shortname, and a URL which is a directory, such as
3072 <code>http://www/splat</code>, <em>without the trailing
3073 slash</em> then Apache will redirect them to
3074 <code>http://www.domain.com/splat/</code>. If you have
3075 authentication enabled, this will cause the user to have to
3076 authenticate twice (once for <code>www</code> and once again
3077 for <code>www.domain.com</code> -- see <a
3078 href="http://httpd.apache.org/docs/misc/FAQ.html#prompted-twice">the
3079 FAQ on this subject for more information</a>). But if
3080 <directive>UseCanonicalName</directive> is set <code>Off</code>, then
3081 Apache will redirect to <code>http://www/splat/</code>.</p>
3083 <p>There is a third option, <code>UseCanonicalName DNS</code>,
3084 which is intended for use with mass IP-based virtual hosting to
3085 support ancient clients that do not provide a
3086 <code>Host:</code> header. With this option Apache does a
3087 reverse DNS lookup on the server IP address that the client
3088 connected to in order to work out self-referential URLs.</p>
3090 <note type="warning"><title>Warning</title>
3091 <p>If CGIs make assumptions about the values of <code>SERVER_NAME</code>
3092 they may be broken by this option. The client is essentially free
3093 to give whatever value they want as a hostname. But if the CGI is
3094 only using <code>SERVER_NAME</code> to construct self-referential URLs
3095 then it should be just fine.</p>
3098 <seealso><directive module="core">ServerName</directive></seealso>
3099 <seealso><directive module="mpm_common">Listen</directive></seealso>
3100 </directivesynopsis>
3102 <directivesynopsis type="section">
3103 <name>VirtualHost</name>
3104 <description>Contains directives that apply only to a specific
3105 hostname or IP address</description>
3106 <syntax><VirtualHost
3107 <var>addr</var>[:<var>port</var>] [<var>addr</var>[:<var>port</var>]]
3108 ...> ... </VirtualHost></syntax>
3109 <contextlist><context>server config</context></contextlist>
3112 <p><directive type="section">VirtualHost</directive> and
3113 <code></VirtualHost></code> are used to enclose a group of
3114 directives that will apply only to a particular virtual host. Any
3115 directive that is allowed in a virtual host context may be
3116 used. When the server receives a request for a document on a
3117 particular virtual host, it uses the configuration directives
3118 enclosed in the <directive type="section">VirtualHost</directive>
3119 section. <var>Addr</var> can be:</p>
3122 <li>The IP address of the virtual host;</li>
3124 <li>A fully qualified domain name for the IP address of the
3127 <li>The character <code>*</code>, which is used only in combination with
3128 <code>NameVirtualHost *</code> to match all IP addresses; or</li>
3130 <li>The string <code>_default_</code>, which is used only
3131 with IP virtual hosting to catch unmatched IP addresses.</li>
3134 <example><title>Example</title>
3135 <VirtualHost 10.1.2.3><br />
3137 ServerAdmin webmaster@host.foo.com<br />
3138 DocumentRoot /www/docs/host.foo.com<br />
3139 ServerName host.foo.com<br />
3140 ErrorLog logs/host.foo.com-error_log<br />
3141 TransferLog logs/host.foo.com-access_log<br />
3143 </VirtualHost>
3147 <p>IPv6 addresses must be specified in square brackets because
3148 the optional port number could not be determined otherwise. An
3149 IPv6 example is shown below:</p>
3152 <VirtualHost [fe80::a00:20ff:fea7:ccea]><br />
3154 ServerAdmin webmaster@host.example.com<br />
3155 DocumentRoot /www/docs/host.example.com<br />
3156 ServerName host.example.com<br />
3157 ErrorLog logs/host.example.com-error_log<br />
3158 TransferLog logs/host.example.com-access_log<br />
3160 </VirtualHost>
3163 <p>Each Virtual Host must correspond to a different IP address,
3164 different port number or a different host name for the server,
3165 in the former case the server machine must be configured to
3166 accept IP packets for multiple addresses. (If the machine does
3167 not have multiple network interfaces, then this can be
3168 accomplished with the <code>ifconfig alias</code> command -- if
3169 your OS supports it).</p>
3171 <note><title>Note</title>
3172 <p>The use of <directive type="section">VirtualHost</directive> does
3173 <strong>not</strong> affect what addresses Apache listens on. You
3174 may need to ensure that Apache is listening on the correct addresses
3175 using <directive module="mpm_common">Listen</directive>.</p>
3178 <p>When using IP-based virtual hosting, the special name
3179 <code>_default_</code> can be specified in
3180 which case this virtual host will match any IP address that is
3181 not explicitly listed in another virtual host. In the absence
3182 of any <code>_default_</code> virtual host the "main" server config,
3183 consisting of all those definitions outside any VirtualHost
3184 section, is used when no IP-match occurs. (But note that any IP
3185 address that matches a <directive
3186 module="core">NameVirtualHost</directive> directive will use neither
3187 the "main" server config nor the <code>_default_</code> virtual host.
3188 See the <a href="../vhosts/name-based.html">name-based virtual hosting</a>
3189 documentation for further details.)</p>
3191 <p>You can specify a <code>:port</code> to change the port that is
3192 matched. If unspecified then it defaults to the same port as the
3193 most recent <directive module="mpm_common">Listen</directive>
3194 statement of the main server. You may also specify <code>:*</code>
3195 to match all ports on that address. (This is recommended when used
3196 with <code>_default_</code>.)</p>
3198 <note type="warning"><title>Security</title>
3199 <p>See the <a href="../misc/security_tips.html">security tips</a>
3200 document for details on why your security could be compromised if the
3201 directory where log files are stored is writable by anyone other
3202 than the user that starts the server.</p>
3205 <seealso><a href="../vhosts/">Apache Virtual Host documentation</a></seealso>
3206 <seealso><a href="../dns-caveats.html">Issues Regarding DNS and
3207 Apache</a></seealso>
3208 <seealso><a href="../bind.html">Setting
3209 which addresses and ports Apache uses</a></seealso>
3210 <seealso><a href="../sections.html">How <Directory>, <Location>
3211 and <Files> sections work</a> for an explanation of how these
3212 different sections are combined when a request is received</seealso>
3213 </directivesynopsis>