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8 <title>core - Apache HTTP Server</title>
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15 <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
16 <p class="apache">Apache HTTP Server Version 2.3</p>
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18 <div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
20 <a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.3</a> > <a href="./">Modules</a></div>
21 <div id="page-content">
22 <div id="preamble"><h1>Apache Core Features</h1>
24 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
25 <a href="../en/mod/core.html" title="English"> en </a> |
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27 <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
28 <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
30 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Core Apache HTTP Server features that are always
32 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Core</td></tr></table>
34 <div id="quickview"><h3 class="directives">Directives</h3>
36 <li><img alt="" src="../images/down.gif" /> <a href="#acceptfilter">AcceptFilter</a></li>
37 <li><img alt="" src="../images/down.gif" /> <a href="#acceptpathinfo">AcceptPathInfo</a></li>
38 <li><img alt="" src="../images/down.gif" /> <a href="#accessfilename">AccessFileName</a></li>
39 <li><img alt="" src="../images/down.gif" /> <a href="#adddefaultcharset">AddDefaultCharset</a></li>
40 <li><img alt="" src="../images/down.gif" /> <a href="#addoutputfilterbytype">AddOutputFilterByType</a></li>
41 <li><img alt="" src="../images/down.gif" /> <a href="#allowencodedslashes">AllowEncodedSlashes</a></li>
42 <li><img alt="" src="../images/down.gif" /> <a href="#allowoverride">AllowOverride</a></li>
43 <li><img alt="" src="../images/down.gif" /> <a href="#cgimapextension">CGIMapExtension</a></li>
44 <li><img alt="" src="../images/down.gif" /> <a href="#contentdigest">ContentDigest</a></li>
45 <li><img alt="" src="../images/down.gif" /> <a href="#defaulttype">DefaultType</a></li>
46 <li><img alt="" src="../images/down.gif" /> <a href="#define">Define</a></li>
47 <li><img alt="" src="../images/down.gif" /> <a href="#directory"><Directory></a></li>
48 <li><img alt="" src="../images/down.gif" /> <a href="#directorymatch"><DirectoryMatch></a></li>
49 <li><img alt="" src="../images/down.gif" /> <a href="#documentroot">DocumentRoot</a></li>
50 <li><img alt="" src="../images/down.gif" /> <a href="#enablemmap">EnableMMAP</a></li>
51 <li><img alt="" src="../images/down.gif" /> <a href="#enablesendfile">EnableSendfile</a></li>
52 <li><img alt="" src="../images/down.gif" /> <a href="#errordocument">ErrorDocument</a></li>
53 <li><img alt="" src="../images/down.gif" /> <a href="#errorlog">ErrorLog</a></li>
54 <li><img alt="" src="../images/down.gif" /> <a href="#fileetag">FileETag</a></li>
55 <li><img alt="" src="../images/down.gif" /> <a href="#files"><Files></a></li>
56 <li><img alt="" src="../images/down.gif" /> <a href="#filesmatch"><FilesMatch></a></li>
57 <li><img alt="" src="../images/down.gif" /> <a href="#forcetype">ForceType</a></li>
58 <li><img alt="" src="../images/down.gif" /> <a href="#hostnamelookups">HostnameLookups</a></li>
59 <li><img alt="" src="../images/down.gif" /> <a href="#if"><If></a></li>
60 <li><img alt="" src="../images/down.gif" /> <a href="#ifdefine"><IfDefine></a></li>
61 <li><img alt="" src="../images/down.gif" /> <a href="#ifmodule"><IfModule></a></li>
62 <li><img alt="" src="../images/down.gif" /> <a href="#include">Include</a></li>
63 <li><img alt="" src="../images/down.gif" /> <a href="#keepalive">KeepAlive</a></li>
64 <li><img alt="" src="../images/down.gif" /> <a href="#keepalivetimeout">KeepAliveTimeout</a></li>
65 <li><img alt="" src="../images/down.gif" /> <a href="#limit"><Limit></a></li>
66 <li><img alt="" src="../images/down.gif" /> <a href="#limitexcept"><LimitExcept></a></li>
67 <li><img alt="" src="../images/down.gif" /> <a href="#limitinternalrecursion">LimitInternalRecursion</a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestbody">LimitRequestBody</a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfields">LimitRequestFields</a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfieldsize">LimitRequestFieldSize</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestline">LimitRequestLine</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#limitxmlrequestbody">LimitXMLRequestBody</a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#location"><Location></a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#locationmatch"><LocationMatch></a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#loglevel">LogLevel</a></li>
76 <li><img alt="" src="../images/down.gif" /> <a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></li>
77 <li><img alt="" src="../images/down.gif" /> <a href="#namevirtualhost">NameVirtualHost</a></li>
78 <li><img alt="" src="../images/down.gif" /> <a href="#options">Options</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitcpu">RLimitCPU</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitmem">RLimitMEM</a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitnproc">RLimitNPROC</a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#scriptinterpretersource">ScriptInterpreterSource</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#serveradmin">ServerAdmin</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#serveralias">ServerAlias</a></li>
85 <li><img alt="" src="../images/down.gif" /> <a href="#servername">ServerName</a></li>
86 <li><img alt="" src="../images/down.gif" /> <a href="#serverpath">ServerPath</a></li>
87 <li><img alt="" src="../images/down.gif" /> <a href="#serverroot">ServerRoot</a></li>
88 <li><img alt="" src="../images/down.gif" /> <a href="#serversignature">ServerSignature</a></li>
89 <li><img alt="" src="../images/down.gif" /> <a href="#servertokens">ServerTokens</a></li>
90 <li><img alt="" src="../images/down.gif" /> <a href="#sethandler">SetHandler</a></li>
91 <li><img alt="" src="../images/down.gif" /> <a href="#setinputfilter">SetInputFilter</a></li>
92 <li><img alt="" src="../images/down.gif" /> <a href="#setoutputfilter">SetOutputFilter</a></li>
93 <li><img alt="" src="../images/down.gif" /> <a href="#timeout">TimeOut</a></li>
94 <li><img alt="" src="../images/down.gif" /> <a href="#traceenable">TraceEnable</a></li>
95 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalname">UseCanonicalName</a></li>
96 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></li>
97 <li><img alt="" src="../images/down.gif" /> <a href="#virtualhost"><VirtualHost></a></li>
101 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
102 <div class="directive-section"><h2><a name="AcceptFilter" id="AcceptFilter">AcceptFilter</a> <a name="acceptfilter" id="acceptfilter">Directive</a></h2>
103 <table class="directive">
104 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures optimizations for a Protocol's Listener Sockets</td></tr>
105 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptFilter <var>protocol</var> <var>accept_filter</var></code></td></tr>
106 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
107 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
108 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
109 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.1.5 and later.
110 On Windows from Apache 2.3.3 and later.</td></tr>
112 <p>This directive enables operating system specific optimizations for a
113 listening socket by the Protocol type. The basic premise is for the
114 kernel to not send a socket to the server process until either data
115 is received or an entire HTTP Request is buffered. Only
116 <a href="http://www.freebsd.org/cgi/man.cgi?query=accept_filter&sektion=9">
117 FreeBSD's Accept Filters</a>, Linux's more primitive
118 <code>TCP_DEFER_ACCEPT</code>, and Windows' optimized AcceptEx()
119 are currently supported.</p>
121 <p>Using <code>none</code> for an argument will disable any accept filters
122 for that protocol. This is useful for protocols that require a server
123 send data first, such as <code>ftp:</code> or <code>nntp</code>:</p>
124 <div class="example"><p><code>AcceptFilter nntp none</code></p></div>
126 <p>The default values on FreeBSD are:</p>
127 <div class="example"><p><code>
128 AcceptFilter http httpready <br />
129 AcceptFilter https dataready
132 <p>The <code>httpready</code> accept filter buffers entire HTTP requests at
133 the kernel level. Once an entire request is received, the kernel then
134 sends it to the server. See the
135 <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_http&sektion=9">
136 accf_http(9)</a> man page for more details. Since HTTPS requests are
137 encrypted only the <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_data&sektion=9">
138 accf_data(9)</a> filter is used.</p>
140 <p>The default values on Linux are:</p>
141 <div class="example"><p><code>
142 AcceptFilter http data <br />
143 AcceptFilter https data
146 <p>Linux's <code>TCP_DEFER_ACCEPT</code> does not support buffering http
147 requests. Any value besides <code>none</code> will enable
148 <code>TCP_DEFER_ACCEPT</code> on that listener. For more details
150 <a href="http://homepages.cwi.nl/~aeb/linux/man2html/man7/tcp.7.html">
151 tcp(7)</a> man page.</p>
153 <p>The default values on Windows are:</p>
154 <div class="example"><p><code>
155 AcceptFilter http data <br />
156 AcceptFilter https data
159 <p>Window's mpm_winnt interprets the AcceptFilter to toggle the AcceptEx()
160 API, and does not support http protocol buffering. There are two values
161 which utilize the Windows AcceptEx() API and will recycle network
162 sockets between connections. <code>data</code> waits until data has
163 been transmitted as documented above, and the initial data buffer and
164 network endpoint addresses are all retrieved from the single AcceptEx()
165 invocation. <code>connect</code> will use the AcceptEx() API, also
166 retrieve the network endpoint addresses, but like <code>none</code>
167 the <code>connect</code> option does not wait for the initial data
170 <p>On Windows, <code>none</code> uses accept() rather than than AcceptEx()
171 and will not recycle sockets between connections. This is useful for
172 network adapters with broken driver support, as well as some virtual
173 network providers such as vpn drivers, or spam, virus or spyware
178 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
179 <div class="directive-section"><h2><a name="AcceptPathInfo" id="AcceptPathInfo">AcceptPathInfo</a> <a name="acceptpathinfo" id="acceptpathinfo">Directive</a></h2>
180 <table class="directive">
181 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Resources accept trailing pathname information</td></tr>
182 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptPathInfo On|Off|Default</code></td></tr>
183 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AcceptPathInfo Default</code></td></tr>
184 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
185 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
186 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
187 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
188 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.30 and later</td></tr>
191 <p>This directive controls whether requests that contain trailing
192 pathname information that follows an actual filename (or
193 non-existent file in an existing directory) will be accepted or
194 rejected. The trailing pathname information can be made
195 available to scripts in the <code>PATH_INFO</code> environment
198 <p>For example, assume the location <code>/test/</code> points to
199 a directory that contains only the single file
200 <code>here.html</code>. Then requests for
201 <code>/test/here.html/more</code> and
202 <code>/test/nothere.html/more</code> both collect
203 <code>/more</code> as <code>PATH_INFO</code>.</p>
205 <p>The three possible arguments for the
206 <code class="directive">AcceptPathInfo</code> directive are:</p>
208 <dt><code>Off</code></dt><dd>A request will only be accepted if it
209 maps to a literal path that exists. Therefore a request with
210 trailing pathname information after the true filename such as
211 <code>/test/here.html/more</code> in the above example will return
212 a 404 NOT FOUND error.</dd>
214 <dt><code>On</code></dt><dd>A request will be accepted if a
215 leading path component maps to a file that exists. The above
216 example <code>/test/here.html/more</code> will be accepted if
217 <code>/test/here.html</code> maps to a valid file.</dd>
219 <dt><code>Default</code></dt><dd>The treatment of requests with
220 trailing pathname information is determined by the <a href="../handler.html">handler</a> responsible for the request.
221 The core handler for normal files defaults to rejecting
222 <code>PATH_INFO</code> requests. Handlers that serve scripts, such as <a href="mod_cgi.html">cgi-script</a> and <a href="mod_isapi.html">isapi-handler</a>, generally accept
223 <code>PATH_INFO</code> by default.</dd>
226 <p>The primary purpose of the <code>AcceptPathInfo</code>
227 directive is to allow you to override the handler's choice of
228 accepting or rejecting <code>PATH_INFO</code>. This override is required,
229 for example, when you use a <a href="../filter.html">filter</a>, such
230 as <a href="mod_include.html">INCLUDES</a>, to generate content
231 based on <code>PATH_INFO</code>. The core handler would usually reject
232 the request, so you can use the following configuration to enable
235 <div class="example"><p><code>
236 <Files "mypaths.shtml"><br />
237 <span class="indent">
238 Options +Includes<br />
239 SetOutputFilter INCLUDES<br />
240 AcceptPathInfo On<br />
247 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
248 <div class="directive-section"><h2><a name="AccessFileName" id="AccessFileName">AccessFileName</a> <a name="accessfilename" id="accessfilename">Directive</a></h2>
249 <table class="directive">
250 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Name of the distributed configuration file</td></tr>
251 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AccessFileName <var>filename</var> [<var>filename</var>] ...</code></td></tr>
252 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AccessFileName .htaccess</code></td></tr>
253 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
254 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
255 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
257 <p>While processing a request the server looks for
258 the first existing configuration file from this list of names in
259 every directory of the path to the document, if distributed
260 configuration files are <a href="#allowoverride">enabled for that
261 directory</a>. For example:</p>
263 <div class="example"><p><code>
267 <p>before returning the document
268 <code>/usr/local/web/index.html</code>, the server will read
269 <code>/.acl</code>, <code>/usr/.acl</code>,
270 <code>/usr/local/.acl</code> and <code>/usr/local/web/.acl</code>
271 for directives, unless they have been disabled with</p>
273 <div class="example"><p><code>
274 <Directory /><br />
275 <span class="indent">
276 AllowOverride None<br />
283 <li><code class="directive"><a href="#allowoverride">AllowOverride</a></code></li>
284 <li><a href="../configuring.html">Configuration Files</a></li>
285 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
288 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
289 <div class="directive-section"><h2><a name="AddDefaultCharset" id="AddDefaultCharset">AddDefaultCharset</a> <a name="adddefaultcharset" id="adddefaultcharset">Directive</a></h2>
290 <table class="directive">
291 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default charset parameter to be added when a response
292 content-type is <code>text/plain</code> or <code>text/html</code></td></tr>
293 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddDefaultCharset On|Off|<var>charset</var></code></td></tr>
294 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AddDefaultCharset Off</code></td></tr>
295 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
296 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
297 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
298 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
300 <p>This directive specifies a default value for the media type
301 charset parameter (the name of a character encoding) to be added
302 to a response if and only if the response's content-type is either
303 <code>text/plain</code> or <code>text/html</code>. This should override
304 any charset specified in the body of the response via a <code>META</code>
305 element, though the exact behavior is often dependent on the user's client
306 configuration. A setting of <code>AddDefaultCharset Off</code>
307 disables this functionality. <code>AddDefaultCharset On</code> enables
308 a default charset of <code>iso-8859-1</code>. Any other value is assumed
309 to be the <var>charset</var> to be used, which should be one of the
310 <a href="http://www.iana.org/assignments/character-sets">IANA registered
311 charset values</a> for use in Internet media types (MIME types).
314 <div class="example"><p><code>
315 AddDefaultCharset utf-8
318 <p><code class="directive">AddDefaultCharset</code> should only be used when all
319 of the text resources to which it applies are known to be in that
320 character encoding and it is too inconvenient to label their charset
321 individually. One such example is to add the charset parameter
322 to resources containing generated content, such as legacy CGI
323 scripts, that might be vulnerable to cross-site scripting attacks
324 due to user-provided data being included in the output. Note, however,
325 that a better solution is to just fix (or delete) those scripts, since
326 setting a default charset does not protect users that have enabled
327 the "auto-detect character encoding" feature on their browser.</p>
331 <li><code class="directive"><a href="../mod/mod_mime.html#addcharset">AddCharset</a></code></li>
334 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
335 <div class="directive-section"><h2><a name="AddOutputFilterByType" id="AddOutputFilterByType">AddOutputFilterByType</a> <a name="addoutputfilterbytype" id="addoutputfilterbytype">Directive</a></h2>
336 <table class="directive">
337 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>assigns an output filter to a particular media-type</td></tr>
338 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddOutputFilterByType <var>filter</var>[;<var>filter</var>...]
339 <var>media-type</var> [<var>media-type</var>] ...</code></td></tr>
340 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
341 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
342 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
343 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
344 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.33 and later; deprecated in Apache 2.1 and later</td></tr>
346 <p>This directive activates a particular output <a href="../filter.html">filter</a> for a request depending on the
347 response <a class="glossarylink" href="../glossary.html#media-type" title="see glossary">media-type</a>. Because of certain
348 problems discussed below, this directive is deprecated. The same
349 functionality is available using <code class="module"><a href="../mod/mod_filter.html">mod_filter</a></code>.</p>
351 <p>The following example uses the <code>DEFLATE</code> filter, which
352 is provided by <code class="module"><a href="../mod/mod_deflate.html">mod_deflate</a></code>. It will compress all
353 output (either static or dynamic) which is labeled as
354 <code>text/html</code> or <code>text/plain</code> before it is sent
357 <div class="example"><p><code>
358 AddOutputFilterByType DEFLATE text/html text/plain
361 <p>If you want the content to be processed by more than one filter, their
362 names have to be separated by semicolons. It's also possible to use one
363 <code class="directive">AddOutputFilterByType</code> directive for each of
366 <p>The configuration below causes all script output labeled as
367 <code>text/html</code> to be processed at first by the
368 <code>INCLUDES</code> filter and then by the <code>DEFLATE</code>
371 <div class="example"><p><code>
372 <Location /cgi-bin/><br />
373 <span class="indent">
374 Options Includes<br />
375 AddOutputFilterByType INCLUDES;DEFLATE text/html<br />
380 <div class="warning"><h3>Note</h3>
381 <p>Enabling filters with <code class="directive">AddOutputFilterByType</code>
382 may fail partially or completely in some cases. For example, no
383 filters are applied if the <a class="glossarylink" href="../glossary.html#media-type" title="see glossary">media-type</a> could not
384 be determined. If you want to make sure that the filters will be
385 applied, assign the content type to a resource explicitly; for
386 example, with <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> or
387 <code class="directive"><a href="#forcetype">ForceType</a></code>. Setting the
388 content type within a (non-nph) CGI script is also safe.</p>
394 <li><code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code></li>
395 <li><code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code></li>
396 <li><a href="../filter.html">filters</a></li>
399 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
400 <div class="directive-section"><h2><a name="AllowEncodedSlashes" id="AllowEncodedSlashes">AllowEncodedSlashes</a> <a name="allowencodedslashes" id="allowencodedslashes">Directive</a></h2>
401 <table class="directive">
402 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines whether encoded path separators in URLs are allowed to
403 be passed through</td></tr>
404 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowEncodedSlashes On|Off</code></td></tr>
405 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowEncodedSlashes Off</code></td></tr>
406 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
407 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
408 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
409 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.46 and later</td></tr>
411 <p>The <code class="directive">AllowEncodedSlashes</code> directive allows URLs
412 which contain encoded path separators (<code>%2F</code> for <code>/</code>
413 and additionally <code>%5C</code> for <code>\</code> on according systems)
414 to be used. Normally such URLs are refused with a 404 (Not found) error.</p>
416 <p>Turning <code class="directive">AllowEncodedSlashes</code> <code>On</code> is
417 mostly useful when used in conjunction with <code>PATH_INFO</code>.</p>
419 <div class="note"><h3>Note</h3>
420 <p>Allowing encoded slashes does <em>not</em> imply <em>decoding</em>.
421 Occurrences of <code>%2F</code> or <code>%5C</code> (<em>only</em> on
422 according systems) will be left as such in the otherwise decoded URL
428 <li><code class="directive"><a href="#acceptpathinfo">AcceptPathInfo</a></code></li>
431 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
432 <div class="directive-section"><h2><a name="AllowOverride" id="AllowOverride">AllowOverride</a> <a name="allowoverride" id="allowoverride">Directive</a></h2>
433 <table class="directive">
434 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Types of directives that are allowed in
435 <code>.htaccess</code> files</td></tr>
436 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowOverride All|None|<var>directive-type</var>
437 [<var>directive-type</var>] ...</code></td></tr>
438 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowOverride All</code></td></tr>
439 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
440 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
441 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
443 <p>When the server finds an <code>.htaccess</code> file (as
444 specified by <code class="directive"><a href="#accessfilename">AccessFileName</a></code>)
445 it needs to know which directives declared in that file can override
446 earlier configuration directives.</p>
448 <div class="note"><h3>Only available in <Directory> sections</h3>
449 <code class="directive">AllowOverride</code> is valid only in
450 <code class="directive"><a href="#directory"><Directory></a></code>
451 sections specified without regular expressions, not in <code class="directive"><a href="#location"><Location></a></code>, <code class="directive"><a href="#directorymatch"><DirectoryMatch></a></code> or
452 <code class="directive"><a href="#files"><Files></a></code> sections.
455 <p>When this directive is set to <code>None</code>, then
456 <a href="#accessfilename">.htaccess</a> files are completely ignored.
457 In this case, the server will not even attempt to read
458 <code>.htaccess</code> files in the filesystem.</p>
460 <p>When this directive is set to <code>All</code>, then any
461 directive which has the .htaccess <a href="directive-dict.html#Context">Context</a> is allowed in
462 <code>.htaccess</code> files.</p>
464 <p>The <var>directive-type</var> can be one of the following
465 groupings of directives.</p>
472 Allow use of the authorization directives (<code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmgroupfile">AuthDBMGroupFile</a></code>,
473 <code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmuserfile">AuthDBMUserFile</a></code>,
474 <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code>,
475 <code class="directive"><a href="../mod/mod_authn_core.html#authname">AuthName</a></code>,
476 <code class="directive"><a href="../mod/mod_authn_core.html#authtype">AuthType</a></code>, <code class="directive"><a href="../mod/mod_authn_file.html#authuserfile">AuthUserFile</a></code>, <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code>, <em>etc.</em>).</dd>
481 Allow use of the directives controlling document types
482 (<code class="directive"><a href="#errordocument">ErrorDocument</a></code>,
483 <code class="directive"><a href="#forcetype">ForceType</a></code>,
484 <code class="directive"><a href="../mod/mod_negotiation.html#languagepriority">LanguagePriority</a></code>,
485 <code class="directive"><a href="#sethandler">SetHandler</a></code>,
486 <code class="directive"><a href="#setinputfilter">SetInputFilter</a></code>,
487 <code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code>, and
488 <code class="module"><a href="../mod/mod_mime.html">mod_mime</a></code> Add* and Remove* directives),
489 document meta data (<code class="directive"><a href="../mod/mod_headers.html#header">Header</a></code>, <code class="directive"><a href="../mod/mod_headers.html#requestheader">RequestHeader</a></code>, <code class="directive"><a href="../mod/mod_setenvif.html#setenvif">SetEnvIf</a></code>, <code class="directive"><a href="../mod/mod_setenvif.html#setenvifnocase">SetEnvIfNoCase</a></code>, <code class="directive"><a href="../mod/mod_setenvif.html#browsermatch">BrowserMatch</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookieexpires">CookieExpires</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookiedomain">CookieDomain</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookiestyle">CookieStyle</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookietracking">CookieTracking</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookiename">CookieName</a></code>),
490 <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> directives <code class="directive"><a href="../mod/mod_rewrite.html#rewriteengine">RewriteEngine</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewriteoptions">RewriteOptions</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewritebase">RewriteBase</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewritecond">RewriteCond</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code>) and
491 <code class="directive"><a href="../mod/mod_actions.html#action">Action</a></code> from
492 <code class="module"><a href="../mod/mod_actions.html">mod_actions</a></code>.
498 Allow use of the directives controlling directory indexing
499 (<code class="directive"><a href="../mod/mod_autoindex.html#adddescription">AddDescription</a></code>,
500 <code class="directive"><a href="../mod/mod_autoindex.html#addicon">AddIcon</a></code>, <code class="directive"><a href="../mod/mod_autoindex.html#addiconbyencoding">AddIconByEncoding</a></code>,
501 <code class="directive"><a href="../mod/mod_autoindex.html#addiconbytype">AddIconByType</a></code>,
502 <code class="directive"><a href="../mod/mod_autoindex.html#defaulticon">DefaultIcon</a></code>, <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>, <code class="directive"><a href="../mod/mod_autoindex.html#fancyindexing">FancyIndexing</a></code>, <code class="directive"><a href="../mod/mod_autoindex.html#headername">HeaderName</a></code>, <code class="directive"><a href="../mod/mod_autoindex.html#indexignore">IndexIgnore</a></code>, <code class="directive"><a href="../mod/mod_autoindex.html#indexoptions">IndexOptions</a></code>, <code class="directive"><a href="../mod/mod_autoindex.html#readmename">ReadmeName</a></code>,
508 Allow use of the directives controlling host access (<code class="directive"><a href="../mod/mod_authz_host.html#allow">Allow</a></code>, <code class="directive"><a href="../mod/mod_authz_host.html#deny">Deny</a></code> and <code class="directive"><a href="../mod/mod_authz_host.html#order">Order</a></code>).</dd>
510 <dt>Options[=<var>Option</var>,...]</dt>
513 Allow use of the directives controlling specific directory
514 features (<code class="directive"><a href="#options">Options</a></code> and
515 <code class="directive"><a href="../mod/mod_include.html#xbithack">XBitHack</a></code>).
516 An equal sign may be given followed by a comma (but no spaces)
517 separated lists of options that may be set using the <code class="directive"><a href="#options">Options</a></code> command.</dd>
522 <div class="example"><p><code>
523 AllowOverride AuthConfig Indexes
526 <p>In the example above all directives that are neither in the group
527 <code>AuthConfig</code> nor <code>Indexes</code> cause an internal
530 <div class="note"><p>For security and performance reasons, do not set
531 <code>AllowOverride</code> to anything other than <code>None</code>
532 in your <code><Directory /></code> block. Instead, find (or
533 create) the <code><Directory></code> block that refers to the
534 directory where you're actually planning to place a
535 <code>.htaccess</code> file.</p>
540 <li><code class="directive"><a href="#accessfilename">AccessFileName</a></code></li>
541 <li><a href="../configuring.html">Configuration Files</a></li>
542 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
545 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
546 <div class="directive-section"><h2><a name="CGIMapExtension" id="CGIMapExtension">CGIMapExtension</a> <a name="cgimapextension" id="cgimapextension">Directive</a></h2>
547 <table class="directive">
548 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
550 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CGIMapExtension <var>cgi-path</var> <var>.extension</var></code></td></tr>
551 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
552 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
553 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
554 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
555 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>NetWare only</td></tr>
557 <p>This directive is used to control how Apache finds the
558 interpreter used to run CGI scripts. For example, setting
559 <code>CGIMapExtension sys:\foo.nlm .foo</code> will
560 cause all CGI script files with a <code>.foo</code> extension to
561 be passed to the FOO interpreter.</p>
564 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
565 <div class="directive-section"><h2><a name="ContentDigest" id="ContentDigest">ContentDigest</a> <a name="contentdigest" id="contentdigest">Directive</a></h2>
566 <table class="directive">
567 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables the generation of <code>Content-MD5</code> HTTP Response
569 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ContentDigest On|Off</code></td></tr>
570 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ContentDigest Off</code></td></tr>
571 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
572 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
573 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
574 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
576 <p>This directive enables the generation of
577 <code>Content-MD5</code> headers as defined in RFC1864
578 respectively RFC2616.</p>
580 <p>MD5 is an algorithm for computing a "message digest"
581 (sometimes called "fingerprint") of arbitrary-length data, with
582 a high degree of confidence that any alterations in the data
583 will be reflected in alterations in the message digest.</p>
585 <p>The <code>Content-MD5</code> header provides an end-to-end
586 message integrity check (MIC) of the entity-body. A proxy or
587 client may check this header for detecting accidental
588 modification of the entity-body in transit. Example header:</p>
590 <div class="example"><p><code>
591 Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA==
594 <p>Note that this can cause performance problems on your server
595 since the message digest is computed on every request (the
596 values are not cached).</p>
598 <p><code>Content-MD5</code> is only sent for documents served
599 by the <code class="module"><a href="../mod/core.html">core</a></code>, and not by any module. For example,
600 SSI documents, output from CGI scripts, and byte range responses
601 do not have this header.</p>
604 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
605 <div class="directive-section"><h2><a name="DefaultType" id="DefaultType">DefaultType</a> <a name="defaulttype" id="defaulttype">Directive</a></h2>
606 <table class="directive">
607 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>This directive has no effect other than to emit warnings
608 if the value is not <code>none</code>. In prior versions, DefaultType
609 would specify a default media type to assign to response content for
610 which no other media type configuration could be found.
612 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DefaultType <var>media-type|none</var></code></td></tr>
613 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DefaultType none</code></td></tr>
614 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
615 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
616 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
617 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
618 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The argument <code>none</code> is available in Apache 2.2.7 and later. All other choices are DISABLED for 2.3.x and later.</td></tr>
620 <p>This directive has been disabled. For backwards compatibility
621 of configuration files, it may be specified with the value
622 <code>none</code>, meaning no default media type. For example:</p>
624 <div class="example"><p><code>
628 <p><code>DefaultType None</code> is only available in
629 httpd-2.2.7 and later.</p>
631 <p>Use the mime.types configuration file and the
632 <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> to configure media
633 type assignments via file extensions, or the
634 <code class="directive"><a href="#forcetype">ForceType</a></code> directive to configure
635 the media type for specific resources. Otherwise, the server will
636 send the response without a Content-Type header field and the
637 recipient may attempt to guess the media type.</p>
640 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
641 <div class="directive-section"><h2><a name="Define" id="Define">Define</a> <a name="define" id="define">Directive</a></h2>
642 <table class="directive">
643 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define the existence of a variable</td></tr>
644 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Define <var>parameter-name</var></code></td></tr>
645 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
646 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
647 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
649 <p>Equivalent to passing the <code>-D</code> argument to <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</p>
650 <p>This directive can be used to toggle the use of <code class="directive"><a href="#ifdefine"><IfDefine></a></code> sections without needing to alter
651 <code>-D</code> arguments in any startup scripts.</p>
654 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
655 <div class="directive-section"><h2><a name="Directory" id="Directory"><Directory></a> <a name="directory" id="directory">Directive</a></h2>
656 <table class="directive">
657 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose a group of directives that apply only to the
658 named file-system directory and sub-directories</td></tr>
659 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Directory <var>directory-path</var>>
660 ... </Directory></code></td></tr>
661 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
662 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
663 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
665 <p><code class="directive"><Directory></code> and
666 <code></Directory></code> are used to enclose a group of
667 directives that will apply only to the named directory and
668 sub-directories of that directory. Any directive that is allowed
669 in a directory context may be used. <var>Directory-path</var> is
670 either the full path to a directory, or a wild-card string using
671 Unix shell-style matching. In a wild-card string, <code>?</code> matches
672 any single character, and <code>*</code> matches any sequences of
673 characters. You may also use <code>[]</code> character ranges. None
674 of the wildcards match a `/' character, so <code><Directory
675 /*/public_html></code> will not match
676 <code>/home/user/public_html</code>, but <code><Directory
677 /home/*/public_html></code> will match. Example:</p>
679 <div class="example"><p><code>
680 <Directory /usr/local/httpd/htdocs><br />
681 <span class="indent">
682 Options Indexes FollowSymLinks<br />
688 <p>Be careful with the <var>directory-path</var> arguments:
689 They have to literally match the filesystem path which Apache uses
690 to access the files. Directives applied to a particular
691 <code><Directory></code> will not apply to files accessed from
692 that same directory via a different path, such as via different symbolic
696 <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular
697 expressions</a> can also be used, with the addition of the
698 <code>~</code> character. For example:</p>
700 <div class="example"><p><code>
701 <Directory ~ "^/www/.*/[0-9]{3}">
704 <p>would match directories in <code>/www/</code> that consisted of
707 <p>If multiple (non-regular expression) <code class="directive"><Directory></code> sections
708 match the directory (or one of its parents) containing a document,
709 then the directives are applied in the order of shortest match
710 first, interspersed with the directives from the <a href="#accessfilename">.htaccess</a> files. For example,
713 <div class="example"><p><code>
714 <Directory /><br />
715 <span class="indent">
716 AllowOverride None<br />
718 </Directory><br />
720 <Directory /home/><br />
721 <span class="indent">
722 AllowOverride FileInfo<br />
727 <p>for access to the document <code>/home/web/dir/doc.html</code>
731 <li>Apply directive <code>AllowOverride None</code>
732 (disabling <code>.htaccess</code> files).</li>
734 <li>Apply directive <code>AllowOverride FileInfo</code> (for
735 directory <code>/home</code>).</li>
737 <li>Apply any <code>FileInfo</code> directives in
738 <code>/home/.htaccess</code>, <code>/home/web/.htaccess</code> and
739 <code>/home/web/dir/.htaccess</code> in that order.</li>
742 <p>Regular expressions are not considered until after all of the
743 normal sections have been applied. Then all of the regular
744 expressions are tested in the order they appeared in the
745 configuration file. For example, with</p>
747 <div class="example"><p><code>
748 <Directory ~ abc$><br />
749 <span class="indent">
750 # ... directives here ...<br />
755 <p>the regular expression section won't be considered until after
756 all normal <code class="directive"><Directory></code>s and
757 <code>.htaccess</code> files have been applied. Then the regular
758 expression will match on <code>/home/abc/public_html/abc</code> and
759 the corresponding <code class="directive"><Directory></code> will
762 <p><strong>Note that the default Apache access for
763 <code><Directory /></code> is <code>Allow from All</code>.
764 This means that Apache will serve any file mapped from an URL. It is
765 recommended that you change this with a block such
768 <div class="example"><p><code>
769 <Directory /><br />
770 <span class="indent">
771 Order Deny,Allow<br />
777 <p><strong>and then override this for directories you
778 <em>want</em> accessible. See the <a href="../misc/security_tips.html">Security Tips</a> page for more
779 details.</strong></p>
781 <p>The directory sections occur in the <code>httpd.conf</code> file.
782 <code class="directive"><Directory></code> directives
783 cannot nest, and cannot appear in a <code class="directive"><a href="#limit"><Limit></a></code> or <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section.</p>
787 <li><a href="../sections.html">How <Directory>,
788 <Location> and <Files> sections work</a> for an
789 explanation of how these different sections are combined when a
790 request is received</li>
793 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
794 <div class="directive-section"><h2><a name="DirectoryMatch" id="DirectoryMatch"><DirectoryMatch></a> <a name="directorymatch" id="directorymatch">Directive</a></h2>
795 <table class="directive">
796 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose directives that apply to
797 file-system directories matching a regular expression and their
798 subdirectories</td></tr>
799 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><DirectoryMatch <var>regex</var>>
800 ... </DirectoryMatch></code></td></tr>
801 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
802 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
803 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
805 <p><code class="directive"><DirectoryMatch></code> and
806 <code></DirectoryMatch></code> are used to enclose a group
807 of directives which will apply only to the named directory and
808 sub-directories of that directory, the same as <code class="directive"><a href="#directory"><Directory></a></code>. However, it
809 takes as an argument a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular
810 expression</a>. For example:</p>
812 <div class="example"><p><code>
813 <DirectoryMatch "^/www/(.+/)?[0-9]{3}">
816 <p>would match directories in <code>/www/</code> that consisted of three
821 <li><code class="directive"><a href="#directory"><Directory></a></code> for
822 a description of how regular expressions are mixed in with normal
823 <code class="directive"><Directory></code>s</li>
824 <li><a href="../sections.html">How <Directory>, <Location> and
825 <Files> sections work</a> for an explanation of how these different
826 sections are combined when a request is received</li>
829 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
830 <div class="directive-section"><h2><a name="DocumentRoot" id="DocumentRoot">DocumentRoot</a> <a name="documentroot" id="documentroot">Directive</a></h2>
831 <table class="directive">
832 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory that forms the main document tree visible
833 from the web</td></tr>
834 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DocumentRoot <var>directory-path</var></code></td></tr>
835 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DocumentRoot /usr/local/apache/htdocs</code></td></tr>
836 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
837 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
838 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
840 <p>This directive sets the directory from which <code class="program"><a href="../programs/httpd.html">httpd</a></code>
841 will serve files. Unless matched by a directive like <code class="directive"><a href="../mod/mod_alias.html#alias">Alias</a></code>, the server appends the
842 path from the requested URL to the document root to make the
843 path to the document. Example:</p>
845 <div class="example"><p><code>
846 DocumentRoot /usr/web
850 <code>http://www.my.host.com/index.html</code> refers to
851 <code>/usr/web/index.html</code>. If the <var>directory-path</var> is
852 not absolute then it is assumed to be relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
854 <p>The <code class="directive">DocumentRoot</code> should be specified without
855 a trailing slash.</p>
859 <li><a href="../urlmapping.html#documentroot">Mapping URLs to Filesystem
863 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
864 <div class="directive-section"><h2><a name="EnableMMAP" id="EnableMMAP">EnableMMAP</a> <a name="enablemmap" id="enablemmap">Directive</a></h2>
865 <table class="directive">
866 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use memory-mapping to read files during delivery</td></tr>
867 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableMMAP On|Off</code></td></tr>
868 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableMMAP On</code></td></tr>
869 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
870 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
871 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
872 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
874 <p>This directive controls whether the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use
875 memory-mapping if it needs to read the contents of a file during
876 delivery. By default, when the handling of a request requires
877 access to the data within a file -- for example, when delivering a
878 server-parsed file using <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> -- Apache
879 memory-maps the file if the OS supports it.</p>
881 <p>This memory-mapping sometimes yields a performance improvement.
882 But in some environments, it is better to disable the memory-mapping
883 to prevent operational problems:</p>
886 <li>On some multiprocessor systems, memory-mapping can reduce the
887 performance of the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</li>
888 <li>Deleting or truncating a file while <code class="program"><a href="../programs/httpd.html">httpd</a></code>
889 has it memory-mapped can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to
890 crash with a segmentation fault.
894 <p>For server configurations that are vulnerable to these problems,
895 you should disable memory-mapping of delivered files by specifying:</p>
897 <div class="example"><p><code>
901 <p>For NFS mounted files, this feature may be disabled explicitly for
902 the offending files by specifying:</p>
904 <div class="example"><p><code>
905 <Directory "/path-to-nfs-files">
906 <span class="indent">
913 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
914 <div class="directive-section"><h2><a name="EnableSendfile" id="EnableSendfile">EnableSendfile</a> <a name="enablesendfile" id="enablesendfile">Directive</a></h2>
915 <table class="directive">
916 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use the kernel sendfile support to deliver files to the client</td></tr>
917 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableSendfile On|Off</code></td></tr>
918 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableSendfile On</code></td></tr>
919 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
920 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
921 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
922 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
923 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0.44 and later</td></tr>
925 <p>This directive controls whether <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use the
926 sendfile support from the kernel to transmit file contents to the client.
927 By default, when the handling of a request requires no access
928 to the data within a file -- for example, when delivering a
929 static file -- Apache uses sendfile to deliver the file contents
930 without ever reading the file if the OS supports it.</p>
932 <p>This sendfile mechanism avoids separate read and send operations,
933 and buffer allocations. But on some platforms or within some
934 filesystems, it is better to disable this feature to avoid
935 operational problems:</p>
938 <li>Some platforms may have broken sendfile support that the build
939 system did not detect, especially if the binaries were built on
940 another box and moved to such a machine with broken sendfile
942 <li>On Linux the use of sendfile triggers TCP-checksum
943 offloading bugs on certain networking cards when using IPv6.</li>
944 <li>On Linux on Itanium, sendfile may be unable to handle files
945 over 2GB in size.</li>
946 <li>With a network-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code> (e.g., NFS or SMB),
947 the kernel may be unable to serve the network file through
951 <p>For server configurations that are vulnerable to these problems,
952 you should disable this feature by specifying:</p>
954 <div class="example"><p><code>
958 <p>For NFS or SMB mounted files, this feature may be disabled explicitly
959 for the offending files by specifying:</p>
961 <div class="example"><p><code>
962 <Directory "/path-to-nfs-files">
963 <span class="indent">
968 <p>Please note that the per-directory and .htaccess configuration
969 of <code class="directive">EnableSendfile</code> is not supported by
970 <code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code>.
971 Only global definition of <code class="directive">EnableSendfile</code>
972 is taken into account by the module.
976 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
977 <div class="directive-section"><h2><a name="ErrorDocument" id="ErrorDocument">ErrorDocument</a> <a name="errordocument" id="errordocument">Directive</a></h2>
978 <table class="directive">
979 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>What the server will return to the client
980 in case of an error</td></tr>
981 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorDocument <var>error-code</var> <var>document</var></code></td></tr>
982 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
983 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
984 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
985 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
986 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Quoting syntax for text messages is different in Apache
989 <p>In the event of a problem or error, Apache can be configured
990 to do one of four things,</p>
993 <li>output a simple hardcoded error message</li>
995 <li>output a customized message</li>
997 <li>redirect to a local <var>URL-path</var> to handle the
1000 <li>redirect to an external <var>URL</var> to handle the
1004 <p>The first option is the default, while options 2-4 are
1005 configured using the <code class="directive">ErrorDocument</code>
1006 directive, which is followed by the HTTP response code and a URL
1007 or a message. Apache will sometimes offer additional information
1008 regarding the problem/error.</p>
1010 <p>URLs can begin with a slash (/) for local web-paths (relative
1011 to the <code class="directive"><a href="#documentroot">DocumentRoot</a></code>), or be a
1012 full URL which the client can resolve. Alternatively, a message
1013 can be provided to be displayed by the browser. Examples:</p>
1015 <div class="example"><p><code>
1016 ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br />
1017 ErrorDocument 404 /cgi-bin/bad_urls.pl<br />
1018 ErrorDocument 401 /subscription_info.html<br />
1019 ErrorDocument 403 "Sorry can't allow you access today"
1022 <p>Additionally, the special value <code>default</code> can be used
1023 to specify Apache's simple hardcoded message. While not required
1024 under normal circumstances, <code>default</code> will restore
1025 Apache's simple hardcoded message for configurations that would
1026 otherwise inherit an existing <code class="directive">ErrorDocument</code>.</p>
1028 <div class="example"><p><code>
1029 ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br />
1030 <Directory /web/docs><br />
1031 <span class="indent">
1032 ErrorDocument 404 default<br />
1037 <p>Note that when you specify an <code class="directive">ErrorDocument</code>
1038 that points to a remote URL (ie. anything with a method such as
1039 <code>http</code> in front of it), Apache will send a redirect to the
1040 client to tell it where to find the document, even if the
1041 document ends up being on the same server. This has several
1042 implications, the most important being that the client will not
1043 receive the original error status code, but instead will
1044 receive a redirect status code. This in turn can confuse web
1045 robots and other clients which try to determine if a URL is
1046 valid using the status code. In addition, if you use a remote
1047 URL in an <code>ErrorDocument 401</code>, the client will not
1048 know to prompt the user for a password since it will not
1049 receive the 401 status code. Therefore, <strong>if you use an
1050 <code>ErrorDocument 401</code> directive then it must refer to a local
1051 document.</strong></p>
1053 <p>Microsoft Internet Explorer (MSIE) will by default ignore
1054 server-generated error messages when they are "too small" and substitute
1055 its own "friendly" error messages. The size threshold varies depending on
1056 the type of error, but in general, if you make your error document
1057 greater than 512 bytes, then MSIE will show the server-generated
1058 error rather than masking it. More information is available in
1059 Microsoft Knowledge Base article <a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807">Q294807</a>.</p>
1061 <p>Although most error messages can be overriden, there are certain
1062 circumstances where the internal messages are used regardless of the
1063 setting of <code class="directive"><a href="#errordocument">ErrorDocument</a></code>. In
1064 particular, if a malformed request is detected, normal request processing
1065 will be immediately halted and the internal error message returned.
1066 This is necessary to guard against security problems caused by
1069 <p>Prior to version 2.0, messages were indicated by prefixing
1070 them with a single unmatched double quote character.</p>
1074 <li><a href="../custom-error.html">documentation of
1075 customizable responses</a></li>
1078 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1079 <div class="directive-section"><h2><a name="ErrorLog" id="ErrorLog">ErrorLog</a> <a name="errorlog" id="errorlog">Directive</a></h2>
1080 <table class="directive">
1081 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Location where the server will log errors</td></tr>
1082 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code> ErrorLog <var>file-path</var>|syslog[:<var>facility</var>]</code></td></tr>
1083 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows and OS/2)</code></td></tr>
1084 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1085 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1086 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1088 <p>The <code class="directive">ErrorLog</code> directive sets the name of
1089 the file to which the server will log any errors it encounters. If
1090 the <var>file-path</var> is not absolute then it is assumed to be
1091 relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
1093 <div class="example"><h3>Example</h3><p><code>
1094 ErrorLog /var/log/httpd/error_log
1097 <p>If the <var>file-path</var>
1098 begins with a pipe (|) then it is assumed to be a command to spawn
1099 to handle the error log.</p>
1101 <div class="example"><h3>Example</h3><p><code>
1102 ErrorLog "|/usr/local/bin/httpd_errors"
1105 <p>Using <code>syslog</code> instead of a filename enables logging
1106 via syslogd(8) if the system supports it. The default is to use
1107 syslog facility <code>local7</code>, but you can override this by
1108 using the <code>syslog:<var>facility</var></code> syntax where
1109 <var>facility</var> can be one of the names usually documented in
1112 <div class="example"><h3>Example</h3><p><code>
1113 ErrorLog syslog:user
1116 <p>SECURITY: See the <a href="../misc/security_tips.html#serverroot">security tips</a>
1117 document for details on why your security could be compromised
1118 if the directory where log files are stored is writable by
1119 anyone other than the user that starts the server.</p>
1120 <div class="warning"><h3>Note</h3>
1121 <p>When entering a file path on non-Unix platforms, care should be taken
1122 to make sure that only forward slashed are used even though the platform
1123 may allow the use of back slashes. In general it is a good idea to always
1124 use forward slashes throughout the configuration files.</p>
1129 <li><code class="directive"><a href="#loglevel">LogLevel</a></code></li>
1130 <li><a href="../logs.html">Apache Log Files</a></li>
1133 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1134 <div class="directive-section"><h2><a name="FileETag" id="FileETag">FileETag</a> <a name="fileetag" id="fileetag">Directive</a></h2>
1135 <table class="directive">
1136 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>File attributes used to create the ETag
1137 HTTP response header</td></tr>
1138 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>FileETag <var>component</var> ...</code></td></tr>
1139 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>FileETag INode MTime Size</code></td></tr>
1140 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1141 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1142 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1143 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1146 The <code class="directive">FileETag</code> directive configures the file
1147 attributes that are used to create the <code>ETag</code> (entity
1148 tag) response header field when the document is based on a file.
1149 (The <code>ETag</code> value is used in cache management to save
1150 network bandwidth.) In Apache 1.3.22 and earlier, the
1151 <code>ETag</code> value was <em>always</em> formed
1152 from the file's inode, size, and last-modified time (mtime). The
1153 <code class="directive">FileETag</code> directive allows you to choose
1154 which of these -- if any -- should be used. The recognized keywords are:
1158 <dt><strong>INode</strong></dt>
1159 <dd>The file's i-node number will be included in the calculation</dd>
1160 <dt><strong>MTime</strong></dt>
1161 <dd>The date and time the file was last modified will be included</dd>
1162 <dt><strong>Size</strong></dt>
1163 <dd>The number of bytes in the file will be included</dd>
1164 <dt><strong>All</strong></dt>
1165 <dd>All available fields will be used. This is equivalent to:
1166 <div class="example"><p><code>FileETag INode MTime Size</code></p></div></dd>
1167 <dt><strong>None</strong></dt>
1168 <dd>If a document is file-based, no <code>ETag</code> field will be
1169 included in the response</dd>
1172 <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code>
1173 keywords may be prefixed with either <code>+</code> or <code>-</code>,
1174 which allow changes to be made to the default setting inherited
1175 from a broader scope. Any keyword appearing without such a prefix
1176 immediately and completely cancels the inherited setting.</p>
1178 <p>If a directory's configuration includes
1179 <code>FileETag INode MTime Size</code>, and a
1180 subdirectory's includes <code>FileETag -INode</code>,
1181 the setting for that subdirectory (which will be inherited by
1182 any sub-subdirectories that don't override it) will be equivalent to
1183 <code>FileETag MTime Size</code>.</p>
1184 <div class="warning"><h3>Warning</h3>
1185 Do not change the default for directories or locations that have WebDAV
1186 enabled and use <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> as a storage provider.
1187 <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> uses <code>INode MTime Size</code>
1188 as a fixed format for <code>ETag</code> comparisons on conditional requests.
1189 These conditional requests will break if the <code>ETag</code> format is
1190 changed via <code class="directive">FileETag</code>.
1194 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1195 <div class="directive-section"><h2><a name="Files" id="Files"><Files></a> <a name="files" id="files">Directive</a></h2>
1196 <table class="directive">
1197 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to matched
1199 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Files <var>filename</var>> ... </Files></code></td></tr>
1200 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1201 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1202 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1203 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1205 <p>The <code class="directive"><Files></code> directive
1206 limits the scope of the enclosed directives by filename. It is comparable
1207 to the <code class="directive"><a href="#directory"><Directory></a></code>
1208 and <code class="directive"><a href="#location"><Location></a></code>
1209 directives. It should be matched with a <code></Files></code>
1210 directive. The directives given within this section will be applied to
1211 any object with a basename (last component of filename) matching the
1212 specified filename. <code class="directive"><Files></code>
1213 sections are processed in the order they appear in the
1214 configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1215 <code>.htaccess</code> files are read, but before <code class="directive"><a href="#location"><Location></a></code> sections. Note
1216 that <code class="directive"><Files></code> can be nested
1217 inside <code class="directive"><a href="#directory"><Directory></a></code> sections to restrict the
1218 portion of the filesystem they apply to.</p>
1220 <p>The <var>filename</var> argument should include a filename, or
1221 a wild-card string, where <code>?</code> matches any single character,
1222 and <code>*</code> matches any sequences of characters.
1223 <a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a>
1224 can also be used, with the addition of the
1225 <code>~</code> character. For example:</p>
1227 <div class="example"><p><code>
1228 <Files ~ "\.(gif|jpe?g|png)$">
1231 <p>would match most common Internet graphics formats. <code class="directive"><a href="#filesmatch"><FilesMatch></a></code> is preferred,
1234 <p>Note that unlike <code class="directive"><a href="#directory"><Directory></a></code> and <code class="directive"><a href="#location"><Location></a></code> sections, <code class="directive"><Files></code> sections can be used inside
1235 <code>.htaccess</code> files. This allows users to control access to
1236 their own files, at a file-by-file level.</p>
1241 <li><a href="../sections.html">How <Directory>, <Location>
1242 and <Files> sections work</a> for an explanation of how these
1243 different sections are combined when a request is received</li>
1246 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1247 <div class="directive-section"><h2><a name="FilesMatch" id="FilesMatch"><FilesMatch></a> <a name="filesmatch" id="filesmatch">Directive</a></h2>
1248 <table class="directive">
1249 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to regular-expression matched
1251 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><FilesMatch <var>regex</var>> ... </FilesMatch></code></td></tr>
1252 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1253 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1254 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1255 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1257 <p>The <code class="directive"><FilesMatch></code> directive
1258 limits the scope of the enclosed directives by filename, just as the
1259 <code class="directive"><a href="#files"><Files></a></code> directive
1260 does. However, it accepts a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular
1261 expression</a>. For example:</p>
1263 <div class="example"><p><code>
1264 <FilesMatch "\.(gif|jpe?g|png)$">
1267 <p>would match most common Internet graphics formats.</p>
1271 <li><a href="../sections.html">How <Directory>, <Location>
1272 and <Files> sections work</a> for an explanation of how these
1273 different sections are combined when a request is received</li>
1276 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1277 <div class="directive-section"><h2><a name="ForceType" id="ForceType">ForceType</a> <a name="forcetype" id="forcetype">Directive</a></h2>
1278 <table class="directive">
1279 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be served with the specified
1280 media type in the HTTP Content-Type header field</td></tr>
1281 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ForceType <var>media-type</var>|None</code></td></tr>
1282 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1283 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1284 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1285 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1286 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved to the core in Apache 2.0</td></tr>
1288 <p>When placed into an <code>.htaccess</code> file or a
1289 <code class="directive"><a href="#directory"><Directory></a></code>, or
1290 <code class="directive"><a href="#location"><Location></a></code> or
1291 <code class="directive"><a href="#files"><Files></a></code>
1292 section, this directive forces all matching files to be served
1293 with the content type identification given by
1294 <var>media-type</var>. For example, if you had a directory full of
1295 GIF files, but did not want to label them all with <code>.gif</code>,
1296 you might want to use:</p>
1298 <div class="example"><p><code>
1302 <p>Note that this directive overrides other indirect media type
1303 associations defined in mime.types or via the
1304 <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code>.</p>
1306 <p>You can also override more general
1307 <code class="directive">ForceType</code> settings
1308 by using the value of <code>None</code>:</p>
1310 <div class="example"><p><code>
1311 # force all files to be image/gif:<br />
1312 <Location /images><br />
1313 <span class="indent">
1314 ForceType image/gif<br />
1316 </Location><br />
1318 # but normal mime-type associations here:<br />
1319 <Location /images/mixed><br />
1320 <span class="indent">
1321 ForceType None<br />
1327 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1328 <div class="directive-section"><h2><a name="HostnameLookups" id="HostnameLookups">HostnameLookups</a> <a name="hostnamelookups" id="hostnamelookups">Directive</a></h2>
1329 <table class="directive">
1330 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables DNS lookups on client IP addresses</td></tr>
1331 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HostnameLookups On|Off|Double</code></td></tr>
1332 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>HostnameLookups Off</code></td></tr>
1333 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1334 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1335 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1337 <p>This directive enables DNS lookups so that host names can be
1338 logged (and passed to CGIs/SSIs in <code>REMOTE_HOST</code>).
1339 The value <code>Double</code> refers to doing double-reverse
1340 DNS lookup. That is, after a reverse lookup is performed, a forward
1341 lookup is then performed on that result. At least one of the IP
1342 addresses in the forward lookup must match the original
1343 address. (In "tcpwrappers" terminology this is called
1344 <code>PARANOID</code>.)</p>
1346 <p>Regardless of the setting, when <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code> is
1347 used for controlling access by hostname, a double reverse lookup
1348 will be performed. This is necessary for security. Note that the
1349 result of this double-reverse isn't generally available unless you
1350 set <code>HostnameLookups Double</code>. For example, if only
1351 <code>HostnameLookups On</code> and a request is made to an object
1352 that is protected by hostname restrictions, regardless of whether
1353 the double-reverse fails or not, CGIs will still be passed the
1354 single-reverse result in <code>REMOTE_HOST</code>.</p>
1356 <p>The default is <code>Off</code> in order to save the network
1357 traffic for those sites that don't truly need the reverse
1358 lookups done. It is also better for the end users because they
1359 don't have to suffer the extra latency that a lookup entails.
1360 Heavily loaded sites should leave this directive
1361 <code>Off</code>, since DNS lookups can take considerable
1362 amounts of time. The utility <code class="program"><a href="../programs/logresolve.html">logresolve</a></code>, compiled by
1363 default to the <code>bin</code> subdirectory of your installation
1364 directory, can be used to look up host names from logged IP addresses
1368 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1369 <div class="directive-section"><h2><a name="If" id="If"><If></a> <a name="if" id="if">Directive</a></h2>
1370 <table class="directive">
1371 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only if a condition is
1372 satisfied by a request at runtime</td></tr>
1373 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><If <var>expression</var>> ... </If></code></td></tr>
1374 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1375 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1376 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1377 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1379 <p>The <code class="directive"><If></code> directive
1380 evaluates an expression at runtime, and applies the enclosed
1381 directives if and only if the expression evaluates to true.
1384 <div class="example"><p><code>
1385 <If "$req{Host} = ''">
1388 <p>would match HTTP/1.0 requests without a <var>Host:</var> header.</p>
1390 <p>You may compare the value of any variable in the request headers
1391 ($req), response headers ($resp) or environment ($env) in your
1396 <li><a href="../sections.html">How <Directory>, <Location>,
1397 <Files> sections work</a> for an explanation of how these
1398 different sections are combined when a request is received.
1399 <code class="directive"><If></code> has the same precedence
1400 and usage as <code class="directive"><Files></code></li>
1403 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1404 <div class="directive-section"><h2><a name="IfDefine" id="IfDefine"><IfDefine></a> <a name="ifdefine" id="ifdefine">Directive</a></h2>
1405 <table class="directive">
1406 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that will be processed only
1407 if a test is true at startup</td></tr>
1408 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfDefine [!]<var>parameter-name</var>> ...
1409 </IfDefine></code></td></tr>
1410 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1411 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1412 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1413 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1415 <p>The <code><IfDefine <var>test</var>>...</IfDefine>
1416 </code> section is used to mark directives that are conditional. The
1417 directives within an <code class="directive"><IfDefine></code>
1418 section are only processed if the <var>test</var> is true. If <var>
1419 test</var> is false, everything between the start and end markers is
1422 <p>The <var>test</var> in the <code class="directive"><IfDefine></code> section directive can be one of two forms:</p>
1425 <li><var>parameter-name</var></li>
1427 <li><code>!</code><var>parameter-name</var></li>
1430 <p>In the former case, the directives between the start and end
1431 markers are only processed if the parameter named
1432 <var>parameter-name</var> is defined. The second format reverses
1433 the test, and only processes the directives if
1434 <var>parameter-name</var> is <strong>not</strong> defined.</p>
1436 <p>The <var>parameter-name</var> argument is a define as given on the
1437 <code class="program"><a href="../programs/httpd.html">httpd</a></code> command line via <code>-D<var>parameter</var>
1438 </code> at the time the server was started or by the <code class="directive"><a href="#define">Define</a></code> directive.</p>
1440 <p><code class="directive"><IfDefine></code> sections are
1441 nest-able, which can be used to implement simple
1442 multiple-parameter tests. Example:</p>
1444 <div class="example"><p><code>
1445 httpd -DReverseProxy -DUseCache -DMemCache ...<br />
1448 <IfDefine ReverseProxy><br />
1449 <span class="indent">
1450 LoadModule proxy_module modules/mod_proxy.so<br />
1451 LoadModule proxy_http_module modules/mod_proxy_http.so<br />
1452 <IfDefine UseCache><br />
1453 <span class="indent">
1454 LoadModule cache_module modules/mod_cache.so<br />
1455 <IfDefine MemCache><br />
1456 <span class="indent">
1457 LoadModule mem_cache_module modules/mod_mem_cache.so<br />
1459 </IfDefine><br />
1460 <IfDefine !MemCache><br />
1461 <span class="indent">
1462 LoadModule disk_cache_module modules/mod_disk_cache.so<br />
1472 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1473 <div class="directive-section"><h2><a name="IfModule" id="IfModule"><IfModule></a> <a name="ifmodule" id="ifmodule">Directive</a></h2>
1474 <table class="directive">
1475 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that are processed conditional on the
1476 presence or absence of a specific module</td></tr>
1477 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfModule [!]<var>module-file</var>|<var>module-identifier</var>> ...
1478 </IfModule></code></td></tr>
1479 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1480 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1481 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1482 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1483 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Module identifiers are available in version 2.1 and
1486 <p>The <code><IfModule <var>test</var>>...</IfModule></code>
1487 section is used to mark directives that are conditional on the presence of
1488 a specific module. The directives within an <code class="directive"><IfModule></code> section are only processed if the <var>test</var>
1489 is true. If <var>test</var> is false, everything between the start and
1490 end markers is ignored.</p>
1492 <p>The <var>test</var> in the <code class="directive"><IfModule></code> section directive can be one of two forms:</p>
1495 <li><var>module</var></li>
1497 <li>!<var>module</var></li>
1500 <p>In the former case, the directives between the start and end
1501 markers are only processed if the module named <var>module</var>
1502 is included in Apache -- either compiled in or
1503 dynamically loaded using <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>. The second format reverses the test,
1504 and only processes the directives if <var>module</var> is
1505 <strong>not</strong> included.</p>
1507 <p>The <var>module</var> argument can be either the module identifier or
1508 the file name of the module, at the time it was compiled. For example,
1509 <code>rewrite_module</code> is the identifier and
1510 <code>mod_rewrite.c</code> is the file name. If a module consists of
1511 several source files, use the name of the file containing the string
1512 <code>STANDARD20_MODULE_STUFF</code>.</p>
1514 <p><code class="directive"><IfModule></code> sections are
1515 nest-able, which can be used to implement simple multiple-module
1518 <div class="note">This section should only be used if you need to have one
1519 configuration file that works whether or not a specific module
1520 is available. In normal operation, directives need not be
1521 placed in <code class="directive"><IfModule></code>
1525 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1526 <div class="directive-section"><h2><a name="Include" id="Include">Include</a> <a name="include" id="include">Directive</a></h2>
1527 <table class="directive">
1528 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Includes other configuration files from within
1529 the server configuration files</td></tr>
1530 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Include <var>file-path</var>|<var>directory-path</var></code></td></tr>
1531 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1532 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1533 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1534 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Wildcard matching available in 2.0.41 and later</td></tr>
1536 <p>This directive allows inclusion of other configuration files
1537 from within the server configuration files.</p>
1539 <p>Shell-style (<code>fnmatch()</code>) wildcard characters can be used to
1540 include several files at once, in alphabetical order. In
1541 addition, if <code class="directive">Include</code> points to a directory,
1542 rather than a file, Apache will read all files in that directory
1543 and any subdirectory. However, including entire directories is not
1544 recommended, because it is easy to accidentally leave temporary
1545 files in a directory that can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to
1546 fail. Instead, we encourage you to use the wildcard syntax shown
1547 below, to include files that match a particular pattern, such as
1548 *.conf, for example.</p>
1550 <p>The file path specified may be an absolute path, or may be relative
1551 to the <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory.</p>
1555 <div class="example"><p><code>
1556 Include /usr/local/apache2/conf/ssl.conf<br />
1557 Include /usr/local/apache2/conf/vhosts/*.conf
1560 <p>Or, providing paths relative to your <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory:</p>
1562 <div class="example"><p><code>
1563 Include conf/ssl.conf<br />
1564 Include conf/vhosts/*.conf
1569 <li><code class="program"><a href="../programs/apachectl.html">apachectl</a></code></li>
1572 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1573 <div class="directive-section"><h2><a name="KeepAlive" id="KeepAlive">KeepAlive</a> <a name="keepalive" id="keepalive">Directive</a></h2>
1574 <table class="directive">
1575 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables HTTP persistent connections</td></tr>
1576 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAlive On|Off</code></td></tr>
1577 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAlive On</code></td></tr>
1578 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1579 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1580 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1582 <p>The Keep-Alive extension to HTTP/1.0 and the persistent
1583 connection feature of HTTP/1.1 provide long-lived HTTP sessions
1584 which allow multiple requests to be sent over the same TCP
1585 connection. In some cases this has been shown to result in an
1586 almost 50% speedup in latency times for HTML documents with
1587 many images. To enable Keep-Alive connections, set
1588 <code>KeepAlive On</code>.</p>
1590 <p>For HTTP/1.0 clients, Keep-Alive connections will only be
1591 used if they are specifically requested by a client. In
1592 addition, a Keep-Alive connection with an HTTP/1.0 client can
1593 only be used when the length of the content is known in
1594 advance. This implies that dynamic content such as CGI output,
1595 SSI pages, and server-generated directory listings will
1596 generally not use Keep-Alive connections to HTTP/1.0 clients.
1597 For HTTP/1.1 clients, persistent connections are the default
1598 unless otherwise specified. If the client requests it, chunked
1599 encoding will be used in order to send content of unknown
1600 length over persistent connections.</p>
1602 <p>When a client uses a Keep-Alive connection it will be counted
1603 as a single "request" for the <code class="directive"><a href="../mod/mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></code> directive, regardless
1604 of how many requests are sent using the connection.</p>
1608 <li><code class="directive"><a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></code></li>
1611 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1612 <div class="directive-section"><h2><a name="KeepAliveTimeout" id="KeepAliveTimeout">KeepAliveTimeout</a> <a name="keepalivetimeout" id="keepalivetimeout">Directive</a></h2>
1613 <table class="directive">
1614 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for subsequent
1615 requests on a persistent connection</td></tr>
1616 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAliveTimeout <var>num</var>[ms]</code></td></tr>
1617 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAliveTimeout 5</code></td></tr>
1618 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1619 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1620 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1621 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Specifying a value in milliseconds is available in
1622 Apache 2.3.2 and later</td></tr>
1624 <p>The number of seconds Apache will wait for a subsequent
1625 request before closing the connection. By adding a postfix of ms the
1626 timeout can be also set in milliseconds. Once a request has been
1627 received, the timeout value specified by the
1628 <code class="directive"><a href="#timeout">Timeout</a></code> directive applies.</p>
1630 <p>Setting <code class="directive">KeepAliveTimeout</code> to a high value
1631 may cause performance problems in heavily loaded servers. The
1632 higher the timeout, the more server processes will be kept
1633 occupied waiting on connections with idle clients.</p>
1635 <p>In a name-based virtual host context, the value of the first
1636 defined virtual host (the default host) in a set of <code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code> will be used.
1637 The other values will be ignored.</p>
1640 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1641 <div class="directive-section"><h2><a name="Limit" id="Limit"><Limit></a> <a name="limit" id="limit">Directive</a></h2>
1642 <table class="directive">
1643 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict enclosed access controls to only certain HTTP
1645 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Limit <var>method</var> [<var>method</var>] ... > ...
1646 </Limit></code></td></tr>
1647 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1648 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig, Limit</td></tr>
1649 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1650 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1652 <p>Access controls are normally effective for
1653 <strong>all</strong> access methods, and this is the usual
1654 desired behavior. <strong>In the general case, access control
1655 directives should not be placed within a
1656 <code class="directive"><Limit></code> section.</strong></p>
1658 <p>The purpose of the <code class="directive"><Limit></code>
1659 directive is to restrict the effect of the access controls to the
1660 nominated HTTP methods. For all other methods, the access
1661 restrictions that are enclosed in the <code class="directive"><Limit></code> bracket <strong>will have no
1662 effect</strong>. The following example applies the access control
1663 only to the methods <code>POST</code>, <code>PUT</code>, and
1664 <code>DELETE</code>, leaving all other methods unprotected:</p>
1666 <div class="example"><p><code>
1667 <Limit POST PUT DELETE><br />
1668 <span class="indent">
1669 Require valid-user<br />
1674 <p>The method names listed can be one or more of: <code>GET</code>,
1675 <code>POST</code>, <code>PUT</code>, <code>DELETE</code>,
1676 <code>CONNECT</code>, <code>OPTIONS</code>,
1677 <code>PATCH</code>, <code>PROPFIND</code>, <code>PROPPATCH</code>,
1678 <code>MKCOL</code>, <code>COPY</code>, <code>MOVE</code>,
1679 <code>LOCK</code>, and <code>UNLOCK</code>. <strong>The method name is
1680 case-sensitive.</strong> If <code>GET</code> is used it will also
1681 restrict <code>HEAD</code> requests. The <code>TRACE</code> method
1682 cannot be limited (see <code class="directive"><a href="#traceenable">TraceEnable</a></code>).</p>
1684 <div class="warning">A <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section should always be
1685 used in preference to a <code class="directive"><Limit></code>
1686 section when restricting access, since a <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section provides protection
1687 against arbitrary methods.</div>
1689 <p>The <code class="directive"><Limit></code> and
1690 <code class="directive"><a href="#limitexcept"><LimitExcept></a></code>
1691 directives may be nested. In this case, each successive level of
1692 <code class="directive"><Limit></code> or <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> directives must
1693 further restrict the set of methods to which access controls apply.</p>
1695 <div class="warning">When using
1696 <code class="directive"><Limit></code> or
1697 <code class="directive"><LimitExcept></code> directives with
1698 the <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directive,
1699 note that the first <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code>
1700 to succeed authorizes the request, regardless of the presence of other
1701 <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directives.</div>
1703 <p>For example, given the following configuration, all users will
1704 be authorized for <code>POST</code> requests, and the
1705 <code>Require group editors</code> directive will be ignored
1708 <div class="example"><p><code>
1709 <LimitExcept GET>
1710 <span class="indent">
1713 </LimitExcept><br />
1715 <span class="indent">
1716 Require group editors
1722 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1723 <div class="directive-section"><h2><a name="LimitExcept" id="LimitExcept"><LimitExcept></a> <a name="limitexcept" id="limitexcept">Directive</a></h2>
1724 <table class="directive">
1725 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict access controls to all HTTP methods
1726 except the named ones</td></tr>
1727 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LimitExcept <var>method</var> [<var>method</var>] ... > ...
1728 </LimitExcept></code></td></tr>
1729 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1730 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig, Limit</td></tr>
1731 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1732 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1734 <p><code class="directive"><LimitExcept></code> and
1735 <code></LimitExcept></code> are used to enclose
1736 a group of access control directives which will then apply to any
1737 HTTP access method <strong>not</strong> listed in the arguments;
1738 i.e., it is the opposite of a <code class="directive"><a href="#limit"><Limit></a></code> section and can be used to control
1739 both standard and nonstandard/unrecognized methods. See the
1740 documentation for <code class="directive"><a href="#limit"><Limit></a></code> for more details.</p>
1744 <div class="example"><p><code>
1745 <LimitExcept POST GET><br />
1746 <span class="indent">
1747 Require valid-user<br />
1749 </LimitExcept>
1754 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1755 <div class="directive-section"><h2><a name="LimitInternalRecursion" id="LimitInternalRecursion">LimitInternalRecursion</a> <a name="limitinternalrecursion" id="limitinternalrecursion">Directive</a></h2>
1756 <table class="directive">
1757 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine maximum number of internal redirects and nested
1758 subrequests</td></tr>
1759 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitInternalRecursion <var>number</var> [<var>number</var>]</code></td></tr>
1760 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitInternalRecursion 10</code></td></tr>
1761 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1762 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1763 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1764 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.47 and later</td></tr>
1766 <p>An internal redirect happens, for example, when using the <code class="directive"><a href="../mod/mod_actions.html#action">Action</a></code> directive, which internally
1767 redirects the original request to a CGI script. A subrequest is Apache's
1768 mechanism to find out what would happen for some URI if it were requested.
1769 For example, <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> uses subrequests to look for the
1770 files listed in the <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
1773 <p><code class="directive">LimitInternalRecursion</code> prevents the server
1774 from crashing when entering an infinite loop of internal redirects or
1775 subrequests. Such loops are usually caused by misconfigurations.</p>
1777 <p>The directive stores two different limits, which are evaluated on
1778 per-request basis. The first <var>number</var> is the maximum number of
1779 internal redirects, that may follow each other. The second <var>number</var>
1780 determines, how deep subrequests may be nested. If you specify only one
1781 <var>number</var>, it will be assigned to both limits.</p>
1783 <div class="example"><h3>Example</h3><p><code>
1784 LimitInternalRecursion 5
1788 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1789 <div class="directive-section"><h2><a name="LimitRequestBody" id="LimitRequestBody">LimitRequestBody</a> <a name="limitrequestbody" id="limitrequestbody">Directive</a></h2>
1790 <table class="directive">
1791 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restricts the total size of the HTTP request body sent
1792 from the client</td></tr>
1793 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestBody <var>bytes</var></code></td></tr>
1794 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestBody 0</code></td></tr>
1795 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1796 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1797 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1798 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1800 <p>This directive specifies the number of <var>bytes</var> from 0
1801 (meaning unlimited) to 2147483647 (2GB) that are allowed in a
1804 <p>The <code class="directive">LimitRequestBody</code> directive allows
1805 the user to set a limit on the allowed size of an HTTP request
1806 message body within the context in which the directive is given
1807 (server, per-directory, per-file or per-location). If the client
1808 request exceeds that limit, the server will return an error
1809 response instead of servicing the request. The size of a normal
1810 request message body will vary greatly depending on the nature of
1811 the resource and the methods allowed on that resource. CGI scripts
1812 typically use the message body for retrieving form information.
1813 Implementations of the <code>PUT</code> method will require
1814 a value at least as large as any representation that the server
1815 wishes to accept for that resource.</p>
1817 <p>This directive gives the server administrator greater
1818 control over abnormal client request behavior, which may be
1819 useful for avoiding some forms of denial-of-service
1822 <p>If, for example, you are permitting file upload to a particular
1823 location, and wish to limit the size of the uploaded file to 100K,
1824 you might use the following directive:</p>
1826 <div class="example"><p><code>
1827 LimitRequestBody 102400
1832 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1833 <div class="directive-section"><h2><a name="LimitRequestFields" id="LimitRequestFields">LimitRequestFields</a> <a name="limitrequestfields" id="limitrequestfields">Directive</a></h2>
1834 <table class="directive">
1835 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of HTTP request header fields that
1836 will be accepted from the client</td></tr>
1837 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFields <var>number</var></code></td></tr>
1838 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFields 100</code></td></tr>
1839 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1840 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1841 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1843 <p><var>Number</var> is an integer from 0 (meaning unlimited) to
1844 32767. The default value is defined by the compile-time
1845 constant <code>DEFAULT_LIMIT_REQUEST_FIELDS</code> (100 as
1848 <p>The <code class="directive">LimitRequestFields</code> directive allows
1849 the server administrator to modify the limit on the number of
1850 request header fields allowed in an HTTP request. A server needs
1851 this value to be larger than the number of fields that a normal
1852 client request might include. The number of request header fields
1853 used by a client rarely exceeds 20, but this may vary among
1854 different client implementations, often depending upon the extent
1855 to which a user has configured their browser to support detailed
1856 content negotiation. Optional HTTP extensions are often expressed
1857 using request header fields.</p>
1859 <p>This directive gives the server administrator greater
1860 control over abnormal client request behavior, which may be
1861 useful for avoiding some forms of denial-of-service attacks.
1862 The value should be increased if normal clients see an error
1863 response from the server that indicates too many fields were
1864 sent in the request.</p>
1868 <div class="example"><p><code>
1869 LimitRequestFields 50
1874 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1875 <div class="directive-section"><h2><a name="LimitRequestFieldSize" id="LimitRequestFieldSize">LimitRequestFieldSize</a> <a name="limitrequestfieldsize" id="limitrequestfieldsize">Directive</a></h2>
1876 <table class="directive">
1877 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of the HTTP request header allowed from the
1879 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFieldSize <var>bytes</var></code></td></tr>
1880 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFieldSize 8190</code></td></tr>
1881 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1882 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1883 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1885 <p>This directive specifies the number of <var>bytes</var>
1886 that will be allowed in an HTTP request header.</p>
1888 <p>The <code class="directive">LimitRequestFieldSize</code> directive
1889 allows the server administrator to reduce or increase the limit
1890 on the allowed size of an HTTP request header field. A server
1891 needs this value to be large enough to hold any one header field
1892 from a normal client request. The size of a normal request header
1893 field will vary greatly among different client implementations,
1894 often depending upon the extent to which a user has configured
1895 their browser to support detailed content negotiation. SPNEGO
1896 authentication headers can be up to 12392 bytes.</p>
1898 <p>This directive gives the server administrator greater
1899 control over abnormal client request behavior, which may be
1900 useful for avoiding some forms of denial-of-service attacks.</p>
1904 <div class="example"><p><code>
1905 LimitRequestFieldSize 4094
1908 <div class="note">Under normal conditions, the value should not be changed from
1913 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1914 <div class="directive-section"><h2><a name="LimitRequestLine" id="LimitRequestLine">LimitRequestLine</a> <a name="limitrequestline" id="limitrequestline">Directive</a></h2>
1915 <table class="directive">
1916 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limit the size of the HTTP request line that will be accepted
1917 from the client</td></tr>
1918 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestLine <var>bytes</var></code></td></tr>
1919 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestLine 8190</code></td></tr>
1920 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1921 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1922 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1924 <p>This directive sets the number of <var>bytes</var> that will be
1925 allowed on the HTTP request-line.</p>
1927 <p>The <code class="directive">LimitRequestLine</code> directive allows
1928 the server administrator to reduce or increase the limit on the allowed size
1929 of a client's HTTP request-line. Since the request-line consists of the
1930 HTTP method, URI, and protocol version, the
1931 <code class="directive">LimitRequestLine</code> directive places a
1932 restriction on the length of a request-URI allowed for a request
1933 on the server. A server needs this value to be large enough to
1934 hold any of its resource names, including any information that
1935 might be passed in the query part of a <code>GET</code> request.</p>
1937 <p>This directive gives the server administrator greater
1938 control over abnormal client request behavior, which may be
1939 useful for avoiding some forms of denial-of-service attacks.</p>
1943 <div class="example"><p><code>
1944 LimitRequestLine 4094
1947 <div class="note">Under normal conditions, the value should not be changed from
1951 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1952 <div class="directive-section"><h2><a name="LimitXMLRequestBody" id="LimitXMLRequestBody">LimitXMLRequestBody</a> <a name="limitxmlrequestbody" id="limitxmlrequestbody">Directive</a></h2>
1953 <table class="directive">
1954 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of an XML-based request body</td></tr>
1955 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitXMLRequestBody <var>bytes</var></code></td></tr>
1956 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitXMLRequestBody 1000000</code></td></tr>
1957 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1958 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1959 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1960 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1962 <p>Limit (in bytes) on maximum size of an XML-based request
1963 body. A value of <code>0</code> will disable any checking.</p>
1967 <div class="example"><p><code>
1968 LimitXMLRequestBody 0
1973 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1974 <div class="directive-section"><h2><a name="Location" id="Location"><Location></a> <a name="location" id="location">Directive</a></h2>
1975 <table class="directive">
1976 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to matching
1978 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Location
1979 <var>URL-path</var>|<var>URL</var>> ... </Location></code></td></tr>
1980 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1981 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1982 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1984 <p>The <code class="directive"><Location></code> directive
1985 limits the scope of the enclosed directives by URL. It is similar to the
1986 <code class="directive"><a href="#directory"><Directory></a></code>
1987 directive, and starts a subsection which is terminated with a
1988 <code></Location></code> directive. <code class="directive"><Location></code> sections are processed in the
1989 order they appear in the configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1990 <code>.htaccess</code> files are read, and after the <code class="directive"><a href="#files"><Files></a></code> sections.</p>
1992 <p><code class="directive"><Location></code> sections operate
1993 completely outside the filesystem. This has several consequences.
1994 Most importantly, <code class="directive"><Location></code>
1995 directives should not be used to control access to filesystem
1996 locations. Since several different URLs may map to the same
1997 filesystem location, such access controls may by circumvented.</p>
1999 <div class="note"><h3>When to use <code class="directive"><Location></code></h3>
2001 <p>Use <code class="directive"><Location></code> to apply
2002 directives to content that lives outside the filesystem. For
2003 content that lives in the filesystem, use <code class="directive"><a href="#directory"><Directory></a></code> and <code class="directive"><a href="#files"><Files></a></code>. An exception is
2004 <code><Location /></code>, which is an easy way to
2005 apply a configuration to the entire server.</p>
2008 <p>For all origin (non-proxy) requests, the URL to be matched is a
2009 URL-path of the form <code>/path/</code>. <em>No scheme, hostname,
2010 port, or query string may be included.</em> For proxy requests, the
2011 URL to be matched is of the form
2012 <code>scheme://servername/path</code>, and you must include the
2015 <p>The URL may use wildcards. In a wild-card string, <code>?</code> matches
2016 any single character, and <code>*</code> matches any sequences of
2017 characters. Neither wildcard character matches a / in the URL-path.</p>
2019 <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a>
2020 can also be used, with the addition of the <code>~</code>
2021 character. For example:</p>
2023 <div class="example"><p><code>
2024 <Location ~ "/(extra|special)/data">
2027 <p>would match URLs that contained the substring <code>/extra/data</code>
2028 or <code>/special/data</code>. The directive <code class="directive"><a href="#locationmatch"><LocationMatch></a></code> behaves
2029 identical to the regex version of <code class="directive"><Location></code>, and is preferred, for the
2030 simple reason that <code>~</code> is hard to distinguish from
2031 <code>-</code> in many fonts.</p>
2033 <p>The <code class="directive"><Location></code>
2034 functionality is especially useful when combined with the
2035 <code class="directive"><a href="#sethandler">SetHandler</a></code>
2036 directive. For example, to enable status requests, but allow them
2037 only from browsers at <code>example.com</code>, you might use:</p>
2039 <div class="example"><p><code>
2040 <Location /status><br />
2041 <span class="indent">
2042 SetHandler server-status<br />
2043 Order Deny,Allow<br />
2045 Allow from .example.com<br />
2050 <div class="note"><h3>Note about / (slash)</h3>
2051 <p>The slash character has special meaning depending on where in a
2052 URL it appears. People may be used to its behavior in the filesystem
2053 where multiple adjacent slashes are frequently collapsed to a single
2054 slash (<em>i.e.</em>, <code>/home///foo</code> is the same as
2055 <code>/home/foo</code>). In URL-space this is not necessarily true.
2056 The <code class="directive"><a href="#locationmatch"><LocationMatch></a></code>
2057 directive and the regex version of <code class="directive"><Location></code> require you to explicitly specify multiple
2058 slashes if that is your intention.</p>
2060 <p>For example, <code><LocationMatch ^/abc></code> would match
2061 the request URL <code>/abc</code> but not the request URL <code>
2062 //abc</code>. The (non-regex) <code class="directive"><Location></code> directive behaves similarly when used for
2063 proxy requests. But when (non-regex) <code class="directive"><Location></code> is used for non-proxy requests it will
2064 implicitly match multiple slashes with a single slash. For example,
2065 if you specify <code><Location /abc/def></code> and the
2066 request is to <code>/abc//def</code> then it will match.</p>
2071 <li><a href="../sections.html">How <Directory>, <Location>
2072 and <Files> sections work</a> for an explanation of how these
2073 different sections are combined when a request is received.</li>
2074 <li><code class="directive"><a href="#locationmatch">LocationMatch</a></code></li>
2077 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2078 <div class="directive-section"><h2><a name="LocationMatch" id="LocationMatch"><LocationMatch></a> <a name="locationmatch" id="locationmatch">Directive</a></h2>
2079 <table class="directive">
2080 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to regular-expression
2081 matching URLs</td></tr>
2082 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LocationMatch
2083 <var>regex</var>> ... </LocationMatch></code></td></tr>
2084 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2085 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2086 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2088 <p>The <code class="directive"><LocationMatch></code> directive
2089 limits the scope of the enclosed directives by URL, in an identical manner
2090 to <code class="directive"><a href="#location"><Location></a></code>. However,
2091 it takes a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>
2092 as an argument instead of a simple string. For example:</p>
2094 <div class="example"><p><code>
2095 <LocationMatch "/(extra|special)/data">
2098 <p>would match URLs that contained the substring <code>/extra/data</code>
2099 or <code>/special/data</code>.</p>
2103 <li><a href="../sections.html">How <Directory>, <Location>
2104 and <Files> sections work</a> for an explanation of how these
2105 different sections are combined when a request is received</li>
2108 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2109 <div class="directive-section"><h2><a name="LogLevel" id="LogLevel">LogLevel</a> <a name="loglevel" id="loglevel">Directive</a></h2>
2110 <table class="directive">
2111 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Controls the verbosity of the ErrorLog</td></tr>
2112 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LogLevel <var>level</var></code></td></tr>
2113 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LogLevel warn</code></td></tr>
2114 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2115 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2116 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2118 <p><code class="directive">LogLevel</code> adjusts the verbosity of the
2119 messages recorded in the error logs (see <code class="directive"><a href="#errorlog">ErrorLog</a></code> directive). The following
2120 <var>level</var>s are available, in order of decreasing
2123 <table class="bordered">
2126 <th><strong>Level</strong> </th>
2128 <th><strong>Description</strong> </th>
2130 <th><strong>Example</strong> </th>
2134 <td><code>emerg</code> </td>
2136 <td>Emergencies - system is unusable.</td>
2138 <td>"Child cannot open lock file. Exiting"</td>
2142 <td><code>alert</code> </td>
2144 <td>Action must be taken immediately.</td>
2146 <td>"getpwuid: couldn't determine user name from uid"</td>
2150 <td><code>crit</code> </td>
2152 <td>Critical Conditions.</td>
2154 <td>"socket: Failed to get a socket, exiting child"</td>
2158 <td><code>error</code> </td>
2160 <td>Error conditions.</td>
2162 <td>"Premature end of script headers"</td>
2166 <td><code>warn</code> </td>
2168 <td>Warning conditions.</td>
2170 <td>"child process 1234 did not exit, sending another
2175 <td><code>notice</code> </td>
2177 <td>Normal but significant condition.</td>
2179 <td>"httpd: caught SIGBUS, attempting to dump core in
2184 <td><code>info</code> </td>
2186 <td>Informational.</td>
2188 <td>"Server seems busy, (you may need to increase
2189 StartServers, or Min/MaxSpareServers)..."</td>
2193 <td><code>debug</code> </td>
2195 <td>Debug-level messages</td>
2197 <td>"Opening config file ..."</td>
2201 <p>When a particular level is specified, messages from all
2202 other levels of higher significance will be reported as well.
2203 <em>E.g.</em>, when <code>LogLevel info</code> is specified,
2204 then messages with log levels of <code>notice</code> and
2205 <code>warn</code> will also be posted.</p>
2207 <p>Using a level of at least <code>crit</code> is
2212 <div class="example"><p><code>
2216 <div class="note"><h3>Note</h3>
2217 <p>When logging to a regular file messages of the level
2218 <code>notice</code> cannot be suppressed and thus are always
2219 logged. However, this doesn't apply when logging is done
2220 using <code>syslog</code>.</p>
2224 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2225 <div class="directive-section"><h2><a name="MaxKeepAliveRequests" id="MaxKeepAliveRequests">MaxKeepAliveRequests</a> <a name="maxkeepaliverequests" id="maxkeepaliverequests">Directive</a></h2>
2226 <table class="directive">
2227 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of requests allowed on a persistent
2228 connection</td></tr>
2229 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxKeepAliveRequests <var>number</var></code></td></tr>
2230 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxKeepAliveRequests 100</code></td></tr>
2231 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2232 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2233 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2235 <p>The <code class="directive">MaxKeepAliveRequests</code> directive
2236 limits the number of requests allowed per connection when
2237 <code class="directive"><a href="#keepalive">KeepAlive</a></code> is on. If it is
2238 set to <code>0</code>, unlimited requests will be allowed. We
2239 recommend that this setting be kept to a high value for maximum
2240 server performance.</p>
2244 <div class="example"><p><code>
2245 MaxKeepAliveRequests 500
2249 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2250 <div class="directive-section"><h2><a name="NameVirtualHost" id="NameVirtualHost">NameVirtualHost</a> <a name="namevirtualhost" id="namevirtualhost">Directive</a></h2>
2251 <table class="directive">
2252 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Designates an IP address for name-virtual
2254 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NameVirtualHost <var>addr</var>[:<var>port</var>]</code></td></tr>
2255 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2256 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2257 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2260 <p>A single <code class="directive">NameVirtualHost</code> directive
2261 identifies a set of identical virtual hosts on which the server will
2262 further select from on the basis of the <em>hostname</em>
2263 requested by the client. The <code class="directive">NameVirtualHost</code>
2264 directive is a required directive if you want to configure
2265 <a href="../vhosts/">name-based virtual hosts</a>.</p>
2267 <p>This directive, and the corresponding <code class="directive">VirtualHost</code>,
2268 <em>must</em> be qualified with a port number if the server supports both HTTP
2269 and HTTPS connections.</p>
2271 <p>Although <var>addr</var> can be a hostname, it is recommended
2272 that you always use an IP address or a wildcard. A wildcard
2273 NameVirtualHost matches only virtualhosts that also have a literal wildcard
2274 as their argument.</p>
2276 <p>In cases where a firewall or other proxy receives the requests and
2277 forwards them on a different IP address to the server, you must specify the
2278 IP address of the physical interface on the machine which will be
2279 servicing the requests. </p>
2281 <p> In the example below, requests received on interface 192.0.2.1 and port 80
2282 will only select among the first two virtual hosts. Requests received on
2283 port 80 on any other interface will only select among the third and fourth
2284 virtual hosts. In the common case where the interface isn't important
2285 to the mapping, only the "*:80" NameVirtualHost and VirtualHost directives
2288 <div class="example"><p><code>
2289 NameVirtualHost 192.0.2.1:80<br />
2290 NameVirtualHost *:80<br /><br />
2292 <VirtualHost 192.0.2.1:80><br />
2293 ServerName namebased-a.example.com<br />
2294 </VirtualHost><br />
2296 <VirtualHost 192.0.2.1:80><br />
2297 Servername namebased-b.example.com<br />
2298 </VirtualHost><br />
2300 <VirtualHost *:80><br />
2301 ServerName namebased-c.example.com <br />
2302 </VirtualHost><br />
2304 <VirtualHost *:80><br />
2305 ServerName namebased-d.example.com <br />
2306 </VirtualHost><br />
2311 <p>IPv6 addresses must be enclosed in square brackets, as shown
2312 in the following example:</p>
2314 <div class="example"><p><code>
2315 NameVirtualHost [2001:db8::a00:20ff:fea7:ccea]:8080
2318 <div class="note"><h3>Argument to <code class="directive"><VirtualHost></code>
2320 <p>Note that the argument to the <code class="directive"><VirtualHost></code> directive must
2321 exactly match the argument to the <code class="directive">NameVirtualHost</code> directive.</p>
2323 <div class="example"><p><code>
2324 NameVirtualHost 192.0.2.2:80<br />
2325 <VirtualHost 192.0.2.2:80><br />
2327 </VirtualHost><br />
2333 <li><a href="../vhosts/">Virtual Hosts
2334 documentation</a></li>
2337 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2338 <div class="directive-section"><h2><a name="Options" id="Options">Options</a> <a name="options" id="options">Directive</a></h2>
2339 <table class="directive">
2340 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures what features are available in a particular
2342 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Options
2343 [+|-]<var>option</var> [[+|-]<var>option</var>] ...</code></td></tr>
2344 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Options All</code></td></tr>
2345 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2346 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
2347 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2348 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2350 <p>The <code class="directive">Options</code> directive controls which
2351 server features are available in a particular directory.</p>
2353 <p><var>option</var> can be set to <code>None</code>, in which
2354 case none of the extra features are enabled, or one or more of
2358 <dt><code>All</code></dt>
2360 <dd>All options except for <code>MultiViews</code>. This is the default
2363 <dt><code>ExecCGI</code></dt>
2366 Execution of CGI scripts using <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>
2369 <dt><code>FollowSymLinks</code></dt>
2373 The server will follow symbolic links in this directory.
2375 <p>Even though the server follows the symlink it does <em>not</em>
2376 change the pathname used to match against <code class="directive"><a href="#directory"><Directory></a></code> sections.</p>
2377 <p>Note also, that this option <strong>gets ignored</strong> if set
2378 inside a <code class="directive"><a href="#location"><Location></a></code>
2380 <p>Omitting this option should not be considered a security restriction,
2381 since symlink testing is subject to race conditions that make it
2385 <dt><code>Includes</code></dt>
2388 Server-side includes provided by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>
2391 <dt><code>IncludesNOEXEC</code></dt>
2395 Server-side includes are permitted, but the <code>#exec
2396 cmd</code> and <code>#exec cgi</code> are disabled. It is still
2397 possible to <code>#include virtual</code> CGI scripts from
2398 <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>ed
2401 <dt><code>Indexes</code></dt>
2404 If a URL which maps to a directory is requested, and there
2405 is no <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
2406 (<em>e.g.</em>, <code>index.html</code>) in that directory, then
2407 <code class="module"><a href="../mod/mod_autoindex.html">mod_autoindex</a></code> will return a formatted listing
2408 of the directory.</dd>
2410 <dt><code>MultiViews</code></dt>
2413 <a href="../content-negotiation.html">Content negotiated</a>
2414 "MultiViews" are allowed using
2415 <code class="module"><a href="../mod/mod_negotiation.html">mod_negotiation</a></code>.</dd>
2417 <dt><code>SymLinksIfOwnerMatch</code></dt>
2419 <dd>The server will only follow symbolic links for which the
2420 target file or directory is owned by the same user id as the
2423 <div class="note"><h3>Note</h3> <p>This option gets ignored if
2424 set inside a <code class="directive"><a href="#location"><Location></a></code> section.</p>
2425 <p>This option should not be considered a security restriction,
2426 since symlink testing is subject to race conditions that make it
2427 circumventable.</p></div>
2431 <p>Normally, if multiple <code class="directive">Options</code> could
2432 apply to a directory, then the most specific one is used and
2433 others are ignored; the options are not merged. (See <a href="../sections.html#mergin">how sections are merged</a>.)
2434 However if <em>all</em> the options on the
2435 <code class="directive">Options</code> directive are preceded by a
2436 <code>+</code> or <code>-</code> symbol, the options are
2437 merged. Any options preceded by a <code>+</code> are added to the
2438 options currently in force, and any options preceded by a
2439 <code>-</code> are removed from the options currently in
2442 <div class="warning"><h3>Warning</h3>
2443 <p>Mixing <code class="directive">Options</code> with a <code>+</code> or
2444 <code>-</code> with those without is not valid syntax, and is likely
2445 to cause unexpected results.</p>
2448 <p>For example, without any <code>+</code> and <code>-</code> symbols:</p>
2450 <div class="example"><p><code>
2451 <Directory /web/docs><br />
2452 <span class="indent">
2453 Options Indexes FollowSymLinks<br />
2455 </Directory><br />
2457 <Directory /web/docs/spec><br />
2458 <span class="indent">
2459 Options Includes<br />
2464 <p>then only <code>Includes</code> will be set for the
2465 <code>/web/docs/spec</code> directory. However if the second
2466 <code class="directive">Options</code> directive uses the <code>+</code> and
2467 <code>-</code> symbols:</p>
2469 <div class="example"><p><code>
2470 <Directory /web/docs><br />
2471 <span class="indent">
2472 Options Indexes FollowSymLinks<br />
2474 </Directory><br />
2476 <Directory /web/docs/spec><br />
2477 <span class="indent">
2478 Options +Includes -Indexes<br />
2483 <p>then the options <code>FollowSymLinks</code> and
2484 <code>Includes</code> are set for the <code>/web/docs/spec</code>
2487 <div class="note"><h3>Note</h3>
2488 <p>Using <code>-IncludesNOEXEC</code> or
2489 <code>-Includes</code> disables server-side includes completely
2490 regardless of the previous setting.</p>
2493 <p>The default in the absence of any other settings is
2494 <code>All</code>.</p>
2497 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2498 <div class="directive-section"><h2><a name="RLimitCPU" id="RLimitCPU">RLimitCPU</a> <a name="rlimitcpu" id="rlimitcpu">Directive</a></h2>
2499 <table class="directive">
2500 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the CPU consumption of processes launched
2501 by Apache children</td></tr>
2502 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RLimitCPU <var>seconds</var>|max [<var>seconds</var>|max]</code></td></tr>
2503 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2504 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2505 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2506 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2507 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2509 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2510 resource limit for all processes and the second parameter sets
2511 the maximum resource limit. Either parameter can be a number,
2512 or <code>max</code> to indicate to the server that the limit should
2513 be set to the maximum allowed by the operating system
2514 configuration. Raising the maximum resource limit requires that
2515 the server is running as <code>root</code>, or in the initial startup
2518 <p>This applies to processes forked off from Apache children
2519 servicing requests, not the Apache children themselves. This
2520 includes CGI scripts and SSI exec commands, but not any
2521 processes forked off from the Apache parent such as piped
2524 <p>CPU resource limits are expressed in seconds per
2529 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
2530 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
2533 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2534 <div class="directive-section"><h2><a name="RLimitMEM" id="RLimitMEM">RLimitMEM</a> <a name="rlimitmem" id="rlimitmem">Directive</a></h2>
2535 <table class="directive">
2536 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the memory consumption of processes launched
2537 by Apache children</td></tr>
2538 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RLimitMEM <var>bytes</var>|max [<var>bytes</var>|max]</code></td></tr>
2539 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2540 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2541 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2542 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2543 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2545 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2546 resource limit for all processes and the second parameter sets
2547 the maximum resource limit. Either parameter can be a number,
2548 or <code>max</code> to indicate to the server that the limit should
2549 be set to the maximum allowed by the operating system
2550 configuration. Raising the maximum resource limit requires that
2551 the server is running as <code>root</code>, or in the initial startup
2554 <p>This applies to processes forked off from Apache children
2555 servicing requests, not the Apache children themselves. This
2556 includes CGI scripts and SSI exec commands, but not any
2557 processes forked off from the Apache parent such as piped
2560 <p>Memory resource limits are expressed in bytes per
2565 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
2566 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
2569 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2570 <div class="directive-section"><h2><a name="RLimitNPROC" id="RLimitNPROC">RLimitNPROC</a> <a name="rlimitnproc" id="rlimitnproc">Directive</a></h2>
2571 <table class="directive">
2572 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of processes that can be launched by
2573 processes launched by Apache children</td></tr>
2574 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RLimitNPROC <var>number</var>|max [<var>number</var>|max]</code></td></tr>
2575 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2576 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2577 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2578 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2579 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2581 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2582 resource limit for all processes and the second parameter sets
2583 the maximum resource limit. Either parameter can be a number,
2584 or <code>max</code> to indicate to the server that the limit
2585 should be set to the maximum allowed by the operating system
2586 configuration. Raising the maximum resource limit requires that
2587 the server is running as <code>root</code>, or in the initial startup
2590 <p>This applies to processes forked off from Apache children
2591 servicing requests, not the Apache children themselves. This
2592 includes CGI scripts and SSI exec commands, but not any
2593 processes forked off from the Apache parent such as piped
2596 <p>Process limits control the number of processes per user.</p>
2598 <div class="note"><h3>Note</h3>
2599 <p>If CGI processes are <strong>not</strong> running
2600 under user ids other than the web server user id, this directive
2601 will limit the number of processes that the server itself can
2602 create. Evidence of this situation will be indicated by
2603 <strong><code>cannot fork</code></strong> messages in the
2604 <code>error_log</code>.</p>
2609 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
2610 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
2613 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2614 <div class="directive-section"><h2><a name="ScriptInterpreterSource" id="ScriptInterpreterSource">ScriptInterpreterSource</a> <a name="scriptinterpretersource" id="scriptinterpretersource">Directive</a></h2>
2615 <table class="directive">
2616 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
2618 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ScriptInterpreterSource Registry|Registry-Strict|Script</code></td></tr>
2619 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ScriptInterpreterSource Script</code></td></tr>
2620 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2621 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2622 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2623 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2624 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Win32 only;
2625 option <code>Registry-Strict</code> is available in Apache 2.0 and
2628 <p>This directive is used to control how Apache finds the
2629 interpreter used to run CGI scripts. The default setting is
2630 <code>Script</code>. This causes Apache to use the interpreter pointed to
2631 by the shebang line (first line, starting with <code>#!</code>) in the
2632 script. On Win32 systems this line usually looks like:</p>
2634 <div class="example"><p><code>
2635 #!C:/Perl/bin/perl.exe
2638 <p>or, if <code>perl</code> is in the <code>PATH</code>, simply:</p>
2640 <div class="example"><p><code>
2644 <p>Setting <code>ScriptInterpreterSource Registry</code> will
2645 cause the Windows Registry tree <code>HKEY_CLASSES_ROOT</code> to be
2646 searched using the script file extension (e.g., <code>.pl</code>) as a
2647 search key. The command defined by the registry subkey
2648 <code>Shell\ExecCGI\Command</code> or, if it does not exist, by the subkey
2649 <code>Shell\Open\Command</code> is used to open the script file. If the
2650 registry keys cannot be found, Apache falls back to the behavior of the
2651 <code>Script</code> option.</p>
2653 <div class="warning"><h3>Security</h3>
2654 <p>Be careful when using <code>ScriptInterpreterSource
2655 Registry</code> with <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>'ed directories, because
2656 Apache will try to execute <strong>every</strong> file within this
2657 directory. The <code>Registry</code> setting may cause undesired
2658 program calls on files which are typically not executed. For
2659 example, the default open command on <code>.htm</code> files on
2660 most Windows systems will execute Microsoft Internet Explorer, so
2661 any HTTP request for an <code>.htm</code> file existing within the
2662 script directory would start the browser in the background on the
2663 server. This is a good way to crash your system within a minute or
2667 <p>The option <code>Registry-Strict</code> which is new in Apache
2668 2.0 does the same thing as <code>Registry</code> but uses only the
2669 subkey <code>Shell\ExecCGI\Command</code>. The
2670 <code>ExecCGI</code> key is not a common one. It must be
2671 configured manually in the windows registry and hence prevents
2672 accidental program calls on your system.</p>
2675 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2676 <div class="directive-section"><h2><a name="ServerAdmin" id="ServerAdmin">ServerAdmin</a> <a name="serveradmin" id="serveradmin">Directive</a></h2>
2677 <table class="directive">
2678 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Email address that the server includes in error
2679 messages sent to the client</td></tr>
2680 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAdmin <var>email-address</var>|<var>URL</var></code></td></tr>
2681 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2682 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2683 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2685 <p>The <code class="directive">ServerAdmin</code> sets the contact address
2686 that the server includes in any error messages it returns to the
2687 client. If the <code>httpd</code> doesn't recognize the supplied argument
2689 assumes, that it's an <var>email-address</var> and prepends it with
2690 <code>mailto:</code> in hyperlink targets. However, it's recommended to
2691 actually use an email address, since there are a lot of CGI scripts that
2692 make that assumption. If you want to use an URL, it should point to another
2693 server under your control. Otherwise users may not be able to contact you in
2696 <p>It may be worth setting up a dedicated address for this, e.g.</p>
2698 <div class="example"><p><code>
2699 ServerAdmin www-admin@foo.example.com
2701 <p>as users do not always mention that they are talking about the
2705 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2706 <div class="directive-section"><h2><a name="ServerAlias" id="ServerAlias">ServerAlias</a> <a name="serveralias" id="serveralias">Directive</a></h2>
2707 <table class="directive">
2708 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Alternate names for a host used when matching requests
2709 to name-virtual hosts</td></tr>
2710 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAlias <var>hostname</var> [<var>hostname</var>] ...</code></td></tr>
2711 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
2712 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2713 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2715 <p>The <code class="directive">ServerAlias</code> directive sets the
2716 alternate names for a host, for use with <a href="../vhosts/name-based.html">name-based virtual hosts</a>. The
2717 <code class="directive">ServerAlias</code> may include wildcards, if appropriate.</p>
2719 <div class="example"><p><code>
2720 <VirtualHost *:80><br />
2721 ServerName server.domain.com<br />
2722 ServerAlias server server2.domain.com server2<br />
2723 ServerAlias *.example.com<br />
2725 </VirtualHost>
2730 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
2733 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2734 <div class="directive-section"><h2><a name="ServerName" id="ServerName">ServerName</a> <a name="servername" id="servername">Directive</a></h2>
2735 <table class="directive">
2736 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hostname and port that the server uses to identify
2738 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerName [<var>scheme</var>://]<var>fully-qualified-domain-name</var>[:<var>port</var>]</code></td></tr>
2739 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2740 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2741 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2742 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>In version 2.0, this
2743 directive supersedes the functionality of the <code class="directive">Port</code>
2744 directive from version 1.3.</td></tr>
2746 <p>The <code class="directive">ServerName</code> directive sets the
2747 request scheme, hostname and
2748 port that the server uses to identify itself. This is used when
2749 creating redirection URLs. For example, if the name of the
2750 machine hosting the web server is <code>simple.example.com</code>,
2751 but the machine also has the DNS alias <code>www.example.com</code>
2752 and you wish the web server to be so identified, the following
2753 directive should be used:</p>
2755 <div class="example"><p><code>
2756 ServerName www.example.com:80
2759 <p>If no <code class="directive">ServerName</code> is specified, then the
2760 server attempts to deduce the hostname by performing a reverse
2761 lookup on the IP address. If no port is specified in the
2762 <code class="directive">ServerName</code>, then the server will use the
2763 port from the incoming request. For optimal reliability and
2764 predictability, you should specify an explicit hostname and port
2765 using the <code class="directive">ServerName</code> directive.</p>
2767 <p>If you are using <a href="../vhosts/name-based.html">name-based virtual hosts</a>,
2768 the <code class="directive">ServerName</code> inside a
2769 <code class="directive"><a href="#virtualhost"><VirtualHost></a></code>
2770 section specifies what hostname must appear in the request's
2771 <code>Host:</code> header to match this virtual host.</p>
2774 <p>Sometimes, the server runs behind a device that processes SSL,
2775 such as a reverse proxy, load balancer or SSL offload
2776 appliance. When this is the case, specify the
2777 <code>https://</code> scheme and the port number to which the
2778 clients connect in the <code class="directive">ServerName</code> directive
2779 to make sure that the server generates the correct
2780 self-referential URLs.
2783 <p>See the description of the
2784 <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> and
2785 <code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code> directives for
2786 settings which determine whether self-referential URLs (e.g., by the
2787 <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> module) will refer to the
2788 specified port, or to the port number given in the client's request.
2794 <li><a href="../dns-caveats.html">Issues Regarding DNS and
2796 <li><a href="../vhosts/">Apache virtual host
2797 documentation</a></li>
2798 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
2799 <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li>
2800 <li><code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code></li>
2801 <li><code class="directive"><a href="#serveralias">ServerAlias</a></code></li>
2804 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2805 <div class="directive-section"><h2><a name="ServerPath" id="ServerPath">ServerPath</a> <a name="serverpath" id="serverpath">Directive</a></h2>
2806 <table class="directive">
2807 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Legacy URL pathname for a name-based virtual host that
2808 is accessed by an incompatible browser</td></tr>
2809 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerPath <var>URL-path</var></code></td></tr>
2810 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
2811 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2812 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2814 <p>The <code class="directive">ServerPath</code> directive sets the legacy
2815 URL pathname for a host, for use with <a href="../vhosts/">name-based virtual hosts</a>.</p>
2819 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
2822 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2823 <div class="directive-section"><h2><a name="ServerRoot" id="ServerRoot">ServerRoot</a> <a name="serverroot" id="serverroot">Directive</a></h2>
2824 <table class="directive">
2825 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Base directory for the server installation</td></tr>
2826 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerRoot <var>directory-path</var></code></td></tr>
2827 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerRoot /usr/local/apache</code></td></tr>
2828 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2829 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2830 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2832 <p>The <code class="directive">ServerRoot</code> directive sets the
2833 directory in which the server lives. Typically it will contain the
2834 subdirectories <code>conf/</code> and <code>logs/</code>. Relative
2835 paths in other configuration directives (such as <code class="directive"><a href="#include">Include</a></code> or <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>, for example) are taken as
2836 relative to this directory.</p>
2838 <div class="example"><h3>Example</h3><p><code>
2839 ServerRoot /home/httpd
2845 <li><a href="../invoking.html">the <code>-d</code>
2846 option to <code>httpd</code></a></li>
2847 <li><a href="../misc/security_tips.html#serverroot">the
2848 security tips</a> for information on how to properly set
2849 permissions on the <code class="directive">ServerRoot</code></li>
2852 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2853 <div class="directive-section"><h2><a name="ServerSignature" id="ServerSignature">ServerSignature</a> <a name="serversignature" id="serversignature">Directive</a></h2>
2854 <table class="directive">
2855 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the footer on server-generated documents</td></tr>
2856 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerSignature On|Off|EMail</code></td></tr>
2857 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerSignature Off</code></td></tr>
2858 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2859 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2860 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2861 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2863 <p>The <code class="directive">ServerSignature</code> directive allows the
2864 configuration of a trailing footer line under server-generated
2865 documents (error messages, <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> ftp directory
2866 listings, <code class="module"><a href="../mod/mod_info.html">mod_info</a></code> output, ...). The reason why you
2867 would want to enable such a footer line is that in a chain of proxies,
2868 the user often has no possibility to tell which of the chained servers
2869 actually produced a returned error message.</p>
2871 <p>The <code>Off</code>
2872 setting, which is the default, suppresses the footer line (and is
2873 therefore compatible with the behavior of Apache-1.2 and
2874 below). The <code>On</code> setting simply adds a line with the
2875 server version number and <code class="directive"><a href="#servername">ServerName</a></code> of the serving virtual host,
2876 and the <code>EMail</code> setting additionally creates a
2877 "mailto:" reference to the <code class="directive"><a href="#serveradmin">ServerAdmin</a></code> of the referenced
2880 <p>After version 2.0.44, the details of the server version number
2881 presented are controlled by the <code class="directive"><a href="#servertokens">ServerTokens</a></code> directive.</p>
2885 <li><code class="directive"><a href="#servertokens">ServerTokens</a></code></li>
2888 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2889 <div class="directive-section"><h2><a name="ServerTokens" id="ServerTokens">ServerTokens</a> <a name="servertokens" id="servertokens">Directive</a></h2>
2890 <table class="directive">
2891 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the <code>Server</code> HTTP response
2893 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerTokens Major|Minor|Min[imal]|Prod[uctOnly]|OS|Full</code></td></tr>
2894 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerTokens Full</code></td></tr>
2895 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2896 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2897 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2899 <p>This directive controls whether <code>Server</code> response
2900 header field which is sent back to clients includes a
2901 description of the generic OS-type of the server as well as
2902 information about compiled-in modules.</p>
2905 <dt><code>ServerTokens Prod[uctOnly]</code></dt>
2907 <dd>Server sends (<em>e.g.</em>): <code>Server:
2910 <dt><code>ServerTokens Major</code></dt>
2912 <dd>Server sends (<em>e.g.</em>): <code>Server:
2913 Apache/2</code></dd>
2915 <dt><code>ServerTokens Minor</code></dt>
2917 <dd>Server sends (<em>e.g.</em>): <code>Server:
2918 Apache/2.0</code></dd>
2920 <dt><code>ServerTokens Min[imal]</code></dt>
2922 <dd>Server sends (<em>e.g.</em>): <code>Server:
2923 Apache/2.0.41</code></dd>
2925 <dt><code>ServerTokens OS</code></dt>
2927 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2930 <dt><code>ServerTokens Full</code> (or not specified)</dt>
2932 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2933 (Unix) PHP/4.2.2 MyMod/1.2</code></dd>
2936 <p>This setting applies to the entire server, and cannot be
2937 enabled or disabled on a virtualhost-by-virtualhost basis.</p>
2939 <p>After version 2.0.44, this directive also controls the
2940 information presented by the <code class="directive"><a href="#serversignature">ServerSignature</a></code> directive.</p>
2944 <li><code class="directive"><a href="#serversignature">ServerSignature</a></code></li>
2947 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2948 <div class="directive-section"><h2><a name="SetHandler" id="SetHandler">SetHandler</a> <a name="sethandler" id="sethandler">Directive</a></h2>
2949 <table class="directive">
2950 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be processed by a
2952 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetHandler <var>handler-name</var>|None</code></td></tr>
2953 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2954 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2955 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2956 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2957 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved into the core in Apache 2.0</td></tr>
2959 <p>When placed into an <code>.htaccess</code> file or a
2960 <code class="directive"><a href="#directory"><Directory></a></code> or
2961 <code class="directive"><a href="#location"><Location></a></code>
2962 section, this directive forces all matching files to be parsed
2963 through the <a href="../handler.html">handler</a> given by
2964 <var>handler-name</var>. For example, if you had a directory you
2965 wanted to be parsed entirely as imagemap rule files, regardless
2966 of extension, you might put the following into an
2967 <code>.htaccess</code> file in that directory:</p>
2969 <div class="example"><p><code>
2970 SetHandler imap-file
2973 <p>Another example: if you wanted to have the server display a
2974 status report whenever a URL of
2975 <code>http://servername/status</code> was called, you might put
2976 the following into <code>httpd.conf</code>:</p>
2978 <div class="example"><p><code>
2979 <Location /status><br />
2980 <span class="indent">
2981 SetHandler server-status<br />
2986 <p>You can override an earlier defined <code class="directive">SetHandler</code>
2987 directive by using the value <code>None</code>.</p>
2988 <p><strong>Note:</strong> because SetHandler overrides default handlers,
2989 normal behaviour such as handling of URLs ending in a slash (/) as
2990 directories or index files is suppressed.</p>
2994 <li><code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code></li>
2997 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2998 <div class="directive-section"><h2><a name="SetInputFilter" id="SetInputFilter">SetInputFilter</a> <a name="setinputfilter" id="setinputfilter">Directive</a></h2>
2999 <table class="directive">
3000 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process client requests and POST
3002 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetInputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
3003 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3004 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
3005 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3006 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3008 <p>The <code class="directive">SetInputFilter</code> directive sets the
3009 filter or filters which will process client requests and POST
3010 input when they are received by the server. This is in addition to
3011 any filters defined elsewhere, including the
3012 <code class="directive"><a href="../mod/mod_mime.html#addinputfilter">AddInputFilter</a></code>
3015 <p>If more than one filter is specified, they must be separated
3016 by semicolons in the order in which they should process the
3021 <li><a href="../filter.html">Filters</a> documentation</li>
3024 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3025 <div class="directive-section"><h2><a name="SetOutputFilter" id="SetOutputFilter">SetOutputFilter</a> <a name="setoutputfilter" id="setoutputfilter">Directive</a></h2>
3026 <table class="directive">
3027 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process responses from the
3029 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetOutputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
3030 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3031 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
3032 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3033 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3035 <p>The <code class="directive">SetOutputFilter</code> directive sets the filters
3036 which will process responses from the server before they are
3037 sent to the client. This is in addition to any filters defined
3038 elsewhere, including the
3039 <code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code>
3042 <p>For example, the following configuration will process all files
3043 in the <code>/www/data/</code> directory for server-side
3046 <div class="example"><p><code>
3047 <Directory /www/data/><br />
3048 <span class="indent">
3049 SetOutputFilter INCLUDES<br />
3054 <p>If more than one filter is specified, they must be separated
3055 by semicolons in the order in which they should process the
3060 <li><a href="../filter.html">Filters</a> documentation</li>
3063 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3064 <div class="directive-section"><h2><a name="TimeOut" id="TimeOut">TimeOut</a> <a name="timeout" id="timeout">Directive</a></h2>
3065 <table class="directive">
3066 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for
3067 certain events before failing a request</td></tr>
3068 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TimeOut <var>seconds</var></code></td></tr>
3069 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TimeOut 300</code></td></tr>
3070 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
3071 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3072 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3074 <p>The <code class="directive">TimeOut</code> directive defines the length
3075 of time Apache will wait for I/O in various circumstances:</p>
3078 <li>When reading data from the client, the length of time to
3079 wait for a TCP packet to arrive if the read buffer is
3082 <li>When writing data to the client, the length of time to wait
3083 for an acknowledgement of a packet if the send buffer is
3086 <li>In <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>, the length of time to wait for
3087 output from a CGI script.</li>
3089 <li>In <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code>, the length of time to
3090 wait for output from a filtering process.</li>
3092 <li>In <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>, the default timeout value if
3093 <code class="directive"><a href="../mod/mod_proxy.html#proxytimeout">ProxyTimeout</a></code> is not
3099 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3100 <div class="directive-section"><h2><a name="TraceEnable" id="TraceEnable">TraceEnable</a> <a name="traceenable" id="traceenable">Directive</a></h2>
3101 <table class="directive">
3102 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines the behaviour on <code>TRACE</code>
3104 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TraceEnable <var>[on|off|extended]</var></code></td></tr>
3105 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TraceEnable on</code></td></tr>
3106 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3107 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3108 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3109 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 1.3.34, 2.0.55 and later</td></tr>
3111 <p>This directive overrides the behavior of <code>TRACE</code> for both
3112 the core server and <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>. The default
3113 <code>TraceEnable on</code> permits <code>TRACE</code> requests per
3114 RFC 2616, which disallows any request body to accompany the request.
3115 <code>TraceEnable off</code> causes the core server and
3116 <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> to return a <code>405</code> (Method not
3117 allowed) error to the client.</p>
3119 <p>Finally, for testing and diagnostic purposes only, request
3120 bodies may be allowed using the non-compliant <code>TraceEnable
3121 extended</code> directive. The core (as an origin server) will
3122 restrict the request body to 64k (plus 8k for chunk headers if
3123 <code>Transfer-Encoding: chunked</code> is used). The core will
3124 reflect the full headers and all chunk headers with the response
3125 body. As a proxy server, the request body is not restricted to 64k.</p>
3128 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3129 <div class="directive-section"><h2><a name="UseCanonicalName" id="UseCanonicalName">UseCanonicalName</a> <a name="usecanonicalname" id="usecanonicalname">Directive</a></h2>
3130 <table class="directive">
3131 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and
3133 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalName On|Off|DNS</code></td></tr>
3134 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalName Off</code></td></tr>
3135 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
3136 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3137 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3139 <p>In many situations Apache must construct a <em>self-referential</em>
3140 URL -- that is, a URL that refers back to the same server. With
3141 <code>UseCanonicalName On</code> Apache will use the hostname and port
3142 specified in the <code class="directive"><a href="#servername">ServerName</a></code>
3143 directive to construct the canonical name for the server. This name
3144 is used in all self-referential URLs, and for the values of
3145 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> in CGIs.</p>
3147 <p>With <code>UseCanonicalName Off</code> Apache will form
3148 self-referential URLs using the hostname and port supplied by
3149 the client if any are supplied (otherwise it will use the
3150 canonical name, as defined above). These values are the same
3151 that are used to implement <a href="../vhosts/name-based.html">name based virtual hosts</a>,
3152 and are available with the same clients. The CGI variables
3153 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> will be
3154 constructed from the client supplied values as well.</p>
3156 <p>An example where this may be useful is on an intranet server
3157 where you have users connecting to the machine using short
3158 names such as <code>www</code>. You'll notice that if the users
3159 type a shortname, and a URL which is a directory, such as
3160 <code>http://www/splat</code>, <em>without the trailing
3161 slash</em> then Apache will redirect them to
3162 <code>http://www.domain.com/splat/</code>. If you have
3163 authentication enabled, this will cause the user to have to
3164 authenticate twice (once for <code>www</code> and once again
3165 for <code>www.domain.com</code> -- see <a href="http://httpd.apache.org/docs/misc/FAQ.html#prompted-twice">the
3166 FAQ on this subject for more information</a>). But if
3167 <code class="directive">UseCanonicalName</code> is set <code>Off</code>, then
3168 Apache will redirect to <code>http://www/splat/</code>.</p>
3170 <p>There is a third option, <code>UseCanonicalName DNS</code>,
3171 which is intended for use with mass IP-based virtual hosting to
3172 support ancient clients that do not provide a
3173 <code>Host:</code> header. With this option Apache does a
3174 reverse DNS lookup on the server IP address that the client
3175 connected to in order to work out self-referential URLs.</p>
3177 <div class="warning"><h3>Warning</h3>
3178 <p>If CGIs make assumptions about the values of <code>SERVER_NAME</code>
3179 they may be broken by this option. The client is essentially free
3180 to give whatever value they want as a hostname. But if the CGI is
3181 only using <code>SERVER_NAME</code> to construct self-referential URLs
3182 then it should be just fine.</p>
3187 <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li>
3188 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
3189 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
3192 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3193 <div class="directive-section"><h2><a name="UseCanonicalPhysicalPort" id="UseCanonicalPhysicalPort">UseCanonicalPhysicalPort</a> <a name="usecanonicalphysicalport" id="usecanonicalphysicalport">Directive</a></h2>
3194 <table class="directive">
3195 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and
3197 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalPhysicalPort On|Off</code></td></tr>
3198 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalPhysicalPort Off</code></td></tr>
3199 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
3200 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3201 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3203 <p>In many situations Apache must construct a <em>self-referential</em>
3204 URL -- that is, a URL that refers back to the same server. With
3205 <code>UseCanonicalPhysicalPort On</code> Apache will, when
3206 constructing the canonical port for the server to honor
3207 the <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> directive,
3208 provide the actual physical port number being used by this request
3209 as a potential port. With <code>UseCanonicalPhysicalPort Off</code>
3210 Apache will not ever use the actual physical port number, instead
3211 relying on all configured information to construct a valid port number.</p>
3213 <div class="note"><h3>Note</h3>
3214 <p>The ordering of when the physical port is used is as follows:<br /><br />
3215 <code>UseCanonicalName On</code></p>
3217 <li>Port provided in <code>Servername</code></li>
3218 <li>Physical port</li>
3219 <li>Default port</li>
3221 <code>UseCanonicalName Off | DNS</code>
3223 <li>Parsed port from <code>Host:</code> header</li>
3224 <li>Physical port</li>
3225 <li>Port provided in <code>Servername</code></li>
3226 <li>Default port</li>
3229 <p>With <code>UseCanonicalPhysicalPort Off</code>, the
3230 physical ports are removed from the ordering.</p>
3236 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
3237 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
3238 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
3241 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3242 <div class="directive-section"><h2><a name="VirtualHost" id="VirtualHost"><VirtualHost></a> <a name="virtualhost" id="virtualhost">Directive</a></h2>
3243 <table class="directive">
3244 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only to a specific
3245 hostname or IP address</td></tr>
3246 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><VirtualHost
3247 <var>addr</var>[:<var>port</var>] [<var>addr</var>[:<var>port</var>]]
3248 ...> ... </VirtualHost></code></td></tr>
3249 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3250 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3251 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3253 <p><code class="directive"><VirtualHost></code> and
3254 <code></VirtualHost></code> are used to enclose a group of
3255 directives that will apply only to a particular virtual host. Any
3256 directive that is allowed in a virtual host context may be
3257 used. When the server receives a request for a document on a
3258 particular virtual host, it uses the configuration directives
3259 enclosed in the <code class="directive"><VirtualHost></code>
3260 section. <var>Addr</var> can be:</p>
3263 <li>The IP address of the virtual host;</li>
3265 <li>A fully qualified domain name for the IP address of the
3266 virtual host (not recommended);</li>
3268 <li>The character <code>*</code>, which is used only in combination with
3269 <code>NameVirtualHost *</code> to match all IP addresses; or</li>
3271 <li>The string <code>_default_</code>, which is used only
3272 with IP virtual hosting to catch unmatched IP addresses.</li>
3275 <div class="example"><h3>Example</h3><p><code>
3276 <VirtualHost 10.1.2.3><br />
3277 <span class="indent">
3278 ServerAdmin webmaster@host.example.com<br />
3279 DocumentRoot /www/docs/host.example.com<br />
3280 ServerName host.example.com<br />
3281 ErrorLog logs/host.example.com-error_log<br />
3282 TransferLog logs/host.example.com-access_log<br />
3284 </VirtualHost>
3288 <p>IPv6 addresses must be specified in square brackets because
3289 the optional port number could not be determined otherwise. An
3290 IPv6 example is shown below:</p>
3292 <div class="example"><p><code>
3293 <VirtualHost [2001:db8::a00:20ff:fea7:ccea]><br />
3294 <span class="indent">
3295 ServerAdmin webmaster@host.example.com<br />
3296 DocumentRoot /www/docs/host.example.com<br />
3297 ServerName host.example.com<br />
3298 ErrorLog logs/host.example.com-error_log<br />
3299 TransferLog logs/host.example.com-access_log<br />
3301 </VirtualHost>
3304 <p>Each Virtual Host must correspond to a different IP address,
3305 different port number or a different host name for the server,
3306 in the former case the server machine must be configured to
3307 accept IP packets for multiple addresses. (If the machine does
3308 not have multiple network interfaces, then this can be
3309 accomplished with the <code>ifconfig alias</code> command -- if
3310 your OS supports it).</p>
3312 <div class="note"><h3>Note</h3>
3313 <p>The use of <code class="directive"><VirtualHost></code> does
3314 <strong>not</strong> affect what addresses Apache listens on. You
3315 may need to ensure that Apache is listening on the correct addresses
3316 using <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>.</p>
3319 <p>When using IP-based virtual hosting, the special name
3320 <code>_default_</code> can be specified in
3321 which case this virtual host will match any IP address that is
3322 not explicitly listed in another virtual host. In the absence
3323 of any <code>_default_</code> virtual host the "main" server config,
3324 consisting of all those definitions outside any VirtualHost
3325 section, is used when no IP-match occurs.</p>
3327 <p>You can specify a <code>:port</code> to change the port that is
3328 matched. If unspecified then it defaults to the same port as the
3329 most recent <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>
3330 statement of the main server. You may also specify <code>:*</code>
3331 to match all ports on that address. (This is recommended when used
3332 with <code>_default_</code>.)</p>
3334 <p>A <code class="directive"><a href="#servername">ServerName</a></code> should be
3335 specified inside each <code class="directive"><VirtualHost></code> block. If it is absent, the
3336 <code class="directive"><a href="#servername">ServerName</a></code> from the "main"
3337 server configuration will be inherited.</p>
3339 <div class="warning"><h3>Security</h3>
3340 <p>See the <a href="../misc/security_tips.html">security tips</a>
3341 document for details on why your security could be compromised if the
3342 directory where log files are stored is writable by anyone other
3343 than the user that starts the server.</p>
3348 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
3349 <li><a href="../dns-caveats.html">Issues Regarding DNS and
3351 <li><a href="../bind.html">Setting
3352 which addresses and ports Apache uses</a></li>
3353 <li><a href="../sections.html">How <Directory>, <Location>
3354 and <Files> sections work</a> for an explanation of how these
3355 different sections are combined when a request is received</li>
3359 <div class="bottomlang">
3360 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
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3365 </div><div id="footer">
3366 <p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
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