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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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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> |
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31 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Core Apache HTTP Server features that are always
33 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Core</td></tr></table>
35 <div id="quickview"><h3 class="directives">Directives</h3>
37 <li><img alt="" src="../images/down.gif" /> <a href="#acceptfilter">AcceptFilter</a></li>
38 <li><img alt="" src="../images/down.gif" /> <a href="#acceptpathinfo">AcceptPathInfo</a></li>
39 <li><img alt="" src="../images/down.gif" /> <a href="#accessfilename">AccessFileName</a></li>
40 <li><img alt="" src="../images/down.gif" /> <a href="#adddefaultcharset">AddDefaultCharset</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="#allowoverridelist">AllowOverrideList</a></li>
44 <li><img alt="" src="../images/down.gif" /> <a href="#cgimapextension">CGIMapExtension</a></li>
45 <li><img alt="" src="../images/down.gif" /> <a href="#contentdigest">ContentDigest</a></li>
46 <li><img alt="" src="../images/down.gif" /> <a href="#defaulttype">DefaultType</a></li>
47 <li><img alt="" src="../images/down.gif" /> <a href="#define">Define</a></li>
48 <li><img alt="" src="../images/down.gif" /> <a href="#directory"><Directory></a></li>
49 <li><img alt="" src="../images/down.gif" /> <a href="#directorymatch"><DirectoryMatch></a></li>
50 <li><img alt="" src="../images/down.gif" /> <a href="#documentroot">DocumentRoot</a></li>
51 <li><img alt="" src="../images/down.gif" /> <a href="#else"><Else></a></li>
52 <li><img alt="" src="../images/down.gif" /> <a href="#elseif"><ElseIf></a></li>
53 <li><img alt="" src="../images/down.gif" /> <a href="#enablemmap">EnableMMAP</a></li>
54 <li><img alt="" src="../images/down.gif" /> <a href="#enablesendfile">EnableSendfile</a></li>
55 <li><img alt="" src="../images/down.gif" /> <a href="#error">Error</a></li>
56 <li><img alt="" src="../images/down.gif" /> <a href="#errordocument">ErrorDocument</a></li>
57 <li><img alt="" src="../images/down.gif" /> <a href="#errorlog">ErrorLog</a></li>
58 <li><img alt="" src="../images/down.gif" /> <a href="#errorlogformat">ErrorLogFormat</a></li>
59 <li><img alt="" src="../images/down.gif" /> <a href="#extendedstatus">ExtendedStatus</a></li>
60 <li><img alt="" src="../images/down.gif" /> <a href="#fileetag">FileETag</a></li>
61 <li><img alt="" src="../images/down.gif" /> <a href="#files"><Files></a></li>
62 <li><img alt="" src="../images/down.gif" /> <a href="#filesmatch"><FilesMatch></a></li>
63 <li><img alt="" src="../images/down.gif" /> <a href="#forcetype">ForceType</a></li>
64 <li><img alt="" src="../images/down.gif" /> <a href="#gprofdir">GprofDir</a></li>
65 <li><img alt="" src="../images/down.gif" /> <a href="#hostnamelookups">HostnameLookups</a></li>
66 <li><img alt="" src="../images/down.gif" /> <a href="#if"><If></a></li>
67 <li><img alt="" src="../images/down.gif" /> <a href="#ifdefine"><IfDefine></a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#ifmodule"><IfModule></a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#include">Include</a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#keepalive">KeepAlive</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#keepalivetimeout">KeepAliveTimeout</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#limit"><Limit></a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#limitexcept"><LimitExcept></a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#limitinternalrecursion">LimitInternalRecursion</a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestbody">LimitRequestBody</a></li>
76 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfields">LimitRequestFields</a></li>
77 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfieldsize">LimitRequestFieldSize</a></li>
78 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestline">LimitRequestLine</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#limitxmlrequestbody">LimitXMLRequestBody</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#location"><Location></a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#locationmatch"><LocationMatch></a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#loglevel">LogLevel</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#maxrangeoverlaps">MaxRangeOverlaps</a></li>
85 <li><img alt="" src="../images/down.gif" /> <a href="#maxrangereversals">MaxRangeReversals</a></li>
86 <li><img alt="" src="../images/down.gif" /> <a href="#maxranges">MaxRanges</a></li>
87 <li><img alt="" src="../images/down.gif" /> <a href="#mutex">Mutex</a></li>
88 <li><img alt="" src="../images/down.gif" /> <a href="#namevirtualhost">NameVirtualHost</a></li>
89 <li><img alt="" src="../images/down.gif" /> <a href="#options">Options</a></li>
90 <li><img alt="" src="../images/down.gif" /> <a href="#protocol">Protocol</a></li>
91 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitcpu">RLimitCPU</a></li>
92 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitmem">RLimitMEM</a></li>
93 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitnproc">RLimitNPROC</a></li>
94 <li><img alt="" src="../images/down.gif" /> <a href="#scriptinterpretersource">ScriptInterpreterSource</a></li>
95 <li><img alt="" src="../images/down.gif" /> <a href="#seerequesttail">SeeRequestTail</a></li>
96 <li><img alt="" src="../images/down.gif" /> <a href="#serveradmin">ServerAdmin</a></li>
97 <li><img alt="" src="../images/down.gif" /> <a href="#serveralias">ServerAlias</a></li>
98 <li><img alt="" src="../images/down.gif" /> <a href="#servername">ServerName</a></li>
99 <li><img alt="" src="../images/down.gif" /> <a href="#serverpath">ServerPath</a></li>
100 <li><img alt="" src="../images/down.gif" /> <a href="#serverroot">ServerRoot</a></li>
101 <li><img alt="" src="../images/down.gif" /> <a href="#serversignature">ServerSignature</a></li>
102 <li><img alt="" src="../images/down.gif" /> <a href="#servertokens">ServerTokens</a></li>
103 <li><img alt="" src="../images/down.gif" /> <a href="#sethandler">SetHandler</a></li>
104 <li><img alt="" src="../images/down.gif" /> <a href="#setinputfilter">SetInputFilter</a></li>
105 <li><img alt="" src="../images/down.gif" /> <a href="#setoutputfilter">SetOutputFilter</a></li>
106 <li><img alt="" src="../images/down.gif" /> <a href="#timeout">TimeOut</a></li>
107 <li><img alt="" src="../images/down.gif" /> <a href="#traceenable">TraceEnable</a></li>
108 <li><img alt="" src="../images/down.gif" /> <a href="#undefine">UnDefine</a></li>
109 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalname">UseCanonicalName</a></li>
110 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></li>
111 <li><img alt="" src="../images/down.gif" /> <a href="#virtualhost"><VirtualHost></a></li>
115 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
116 <div class="directive-section"><h2><a name="AcceptFilter" id="AcceptFilter">AcceptFilter</a> <a name="acceptfilter" id="acceptfilter">Directive</a></h2>
117 <table class="directive">
118 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures optimizations for a Protocol's Listener Sockets</td></tr>
119 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptFilter <var>protocol</var> <var>accept_filter</var></code></td></tr>
120 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
121 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
122 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
123 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.1.5 and later.
124 On Windows from Apache httpd 2.3.3 and later.</td></tr>
126 <p>This directive enables operating system specific optimizations for a
127 listening socket by the <code class="directive">Protocol</code>type.
128 The basic premise is for the kernel to not send a socket to the server
129 process until either data is received or an entire HTTP Request is buffered.
130 Only <a href="http://www.freebsd.org/cgi/man.cgi?query=accept_filter&sektion=9">
131 FreeBSD's Accept Filters</a>, Linux's more primitive
132 <code>TCP_DEFER_ACCEPT</code>, and Windows' optimized AcceptEx()
133 are currently supported.</p>
135 <p>Using <code>none</code> for an argument will disable any accept filters
136 for that protocol. This is useful for protocols that require a server
137 send data first, such as <code>ftp:</code> or <code>nntp</code>:</p>
138 <div class="example"><p><code>AcceptFilter nntp none</code></p></div>
140 <p>The default protocol names are <code>https</code> for port 443
141 and <code>http</code> for all other ports. To specify another protocol
142 is being used with a listening port, add the <var>protocol</var>
143 argument to the <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>
146 <p>The default values on FreeBSD are:</p>
147 <div class="example"><p><code>
148 AcceptFilter http httpready <br />
149 AcceptFilter https dataready
152 <p>The <code>httpready</code> accept filter buffers entire HTTP requests at
153 the kernel level. Once an entire request is received, the kernel then
154 sends it to the server. See the
155 <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_http&sektion=9">
156 accf_http(9)</a> man page for more details. Since HTTPS requests are
157 encrypted only the <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_data&sektion=9">
158 accf_data(9)</a> filter is used.</p>
160 <p>The default values on Linux are:</p>
161 <div class="example"><p><code>
162 AcceptFilter http data <br />
163 AcceptFilter https data
166 <p>Linux's <code>TCP_DEFER_ACCEPT</code> does not support buffering http
167 requests. Any value besides <code>none</code> will enable
168 <code>TCP_DEFER_ACCEPT</code> on that listener. For more details
170 <a href="http://homepages.cwi.nl/~aeb/linux/man2html/man7/tcp.7.html">
171 tcp(7)</a> man page.</p>
173 <p>The default values on Windows are:</p>
174 <div class="example"><p><code>
175 AcceptFilter http data <br />
176 AcceptFilter https data
179 <p>Window's mpm_winnt interprets the AcceptFilter to toggle the AcceptEx()
180 API, and does not support http protocol buffering. There are two values
181 which utilize the Windows AcceptEx() API and will recycle network
182 sockets between connections. <code>data</code> waits until data has
183 been transmitted as documented above, and the initial data buffer and
184 network endpoint addresses are all retrieved from the single AcceptEx()
185 invocation. <code>connect</code> will use the AcceptEx() API, also
186 retrieve the network endpoint addresses, but like <code>none</code>
187 the <code>connect</code> option does not wait for the initial data
190 <p>On Windows, <code>none</code> uses accept() rather than AcceptEx()
191 and will not recycle sockets between connections. This is useful for
192 network adapters with broken driver support, as well as some virtual
193 network providers such as vpn drivers, or spam, virus or spyware
199 <li><code class="directive">Protocol</code></li>
202 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
203 <div class="directive-section"><h2><a name="AcceptPathInfo" id="AcceptPathInfo">AcceptPathInfo</a> <a name="acceptpathinfo" id="acceptpathinfo">Directive</a></h2>
204 <table class="directive">
205 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Resources accept trailing pathname information</td></tr>
206 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptPathInfo On|Off|Default</code></td></tr>
207 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AcceptPathInfo Default</code></td></tr>
208 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
209 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
210 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
211 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
212 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.0.30 and later</td></tr>
215 <p>This directive controls whether requests that contain trailing
216 pathname information that follows an actual filename (or
217 non-existent file in an existing directory) will be accepted or
218 rejected. The trailing pathname information can be made
219 available to scripts in the <code>PATH_INFO</code> environment
222 <p>For example, assume the location <code>/test/</code> points to
223 a directory that contains only the single file
224 <code>here.html</code>. Then requests for
225 <code>/test/here.html/more</code> and
226 <code>/test/nothere.html/more</code> both collect
227 <code>/more</code> as <code>PATH_INFO</code>.</p>
229 <p>The three possible arguments for the
230 <code class="directive">AcceptPathInfo</code> directive are:</p>
232 <dt><code>Off</code></dt><dd>A request will only be accepted if it
233 maps to a literal path that exists. Therefore a request with
234 trailing pathname information after the true filename such as
235 <code>/test/here.html/more</code> in the above example will return
236 a 404 NOT FOUND error.</dd>
238 <dt><code>On</code></dt><dd>A request will be accepted if a
239 leading path component maps to a file that exists. The above
240 example <code>/test/here.html/more</code> will be accepted if
241 <code>/test/here.html</code> maps to a valid file.</dd>
243 <dt><code>Default</code></dt><dd>The treatment of requests with
244 trailing pathname information is determined by the <a href="../handler.html">handler</a> responsible for the request.
245 The core handler for normal files defaults to rejecting
246 <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
247 <code>PATH_INFO</code> by default.</dd>
250 <p>The primary purpose of the <code>AcceptPathInfo</code>
251 directive is to allow you to override the handler's choice of
252 accepting or rejecting <code>PATH_INFO</code>. This override is required,
253 for example, when you use a <a href="../filter.html">filter</a>, such
254 as <a href="mod_include.html">INCLUDES</a>, to generate content
255 based on <code>PATH_INFO</code>. The core handler would usually reject
256 the request, so you can use the following configuration to enable
259 <div class="example"><p><code>
260 <Files "mypaths.shtml"><br />
261 <span class="indent">
262 Options +Includes<br />
263 SetOutputFilter INCLUDES<br />
264 AcceptPathInfo On<br />
271 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
272 <div class="directive-section"><h2><a name="AccessFileName" id="AccessFileName">AccessFileName</a> <a name="accessfilename" id="accessfilename">Directive</a></h2>
273 <table class="directive">
274 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Name of the distributed configuration file</td></tr>
275 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AccessFileName <var>filename</var> [<var>filename</var>] ...</code></td></tr>
276 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AccessFileName .htaccess</code></td></tr>
277 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
278 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
279 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
281 <p>While processing a request the server looks for
282 the first existing configuration file from this list of names in
283 every directory of the path to the document, if distributed
284 configuration files are <a href="#allowoverride">enabled for that
285 directory</a>. For example:</p>
287 <div class="example"><p><code>
291 <p>before returning the document
292 <code>/usr/local/web/index.html</code>, the server will read
293 <code>/.acl</code>, <code>/usr/.acl</code>,
294 <code>/usr/local/.acl</code> and <code>/usr/local/web/.acl</code>
295 for directives, unless they have been disabled with</p>
297 <div class="example"><p><code>
298 <Directory /><br />
299 <span class="indent">
300 AllowOverride None<br />
307 <li><code class="directive"><a href="#allowoverride">AllowOverride</a></code></li>
308 <li><a href="../configuring.html">Configuration Files</a></li>
309 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
312 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
313 <div class="directive-section"><h2><a name="AddDefaultCharset" id="AddDefaultCharset">AddDefaultCharset</a> <a name="adddefaultcharset" id="adddefaultcharset">Directive</a></h2>
314 <table class="directive">
315 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default charset parameter to be added when a response
316 content-type is <code>text/plain</code> or <code>text/html</code></td></tr>
317 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddDefaultCharset On|Off|<var>charset</var></code></td></tr>
318 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AddDefaultCharset Off</code></td></tr>
319 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
320 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
321 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
322 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
324 <p>This directive specifies a default value for the media type
325 charset parameter (the name of a character encoding) to be added
326 to a response if and only if the response's content-type is either
327 <code>text/plain</code> or <code>text/html</code>. This should override
328 any charset specified in the body of the response via a <code>META</code>
329 element, though the exact behavior is often dependent on the user's client
330 configuration. A setting of <code>AddDefaultCharset Off</code>
331 disables this functionality. <code>AddDefaultCharset On</code> enables
332 a default charset of <code>iso-8859-1</code>. Any other value is assumed
333 to be the <var>charset</var> to be used, which should be one of the
334 <a href="http://www.iana.org/assignments/character-sets">IANA registered
335 charset values</a> for use in Internet media types (MIME types).
338 <div class="example"><p><code>
339 AddDefaultCharset utf-8
342 <p><code class="directive">AddDefaultCharset</code> should only be used when all
343 of the text resources to which it applies are known to be in that
344 character encoding and it is too inconvenient to label their charset
345 individually. One such example is to add the charset parameter
346 to resources containing generated content, such as legacy CGI
347 scripts, that might be vulnerable to cross-site scripting attacks
348 due to user-provided data being included in the output. Note, however,
349 that a better solution is to just fix (or delete) those scripts, since
350 setting a default charset does not protect users that have enabled
351 the "auto-detect character encoding" feature on their browser.</p>
355 <li><code class="directive"><a href="../mod/mod_mime.html#addcharset">AddCharset</a></code></li>
358 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
359 <div class="directive-section"><h2><a name="AllowEncodedSlashes" id="AllowEncodedSlashes">AllowEncodedSlashes</a> <a name="allowencodedslashes" id="allowencodedslashes">Directive</a></h2>
360 <table class="directive">
361 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines whether encoded path separators in URLs are allowed to
362 be passed through</td></tr>
363 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowEncodedSlashes On|Off|NoDecode</code></td></tr>
364 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowEncodedSlashes Off</code></td></tr>
365 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
366 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
367 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
368 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.0.46 and later.
369 NoDecode option available in 2.3.12 and later.</td></tr>
371 <p>The <code class="directive">AllowEncodedSlashes</code> directive allows URLs
372 which contain encoded path separators (<code>%2F</code> for <code>/</code>
373 and additionally <code>%5C</code> for <code>\</code> on according systems)
374 to be used in the path info.</p>
376 <p>With the default value, <code>Off</code>, such URLs are refused
377 with a 404 (Not found) error.</p>
379 <p>With the value <code>On</code>, such URLs are accepted, and encoded
380 slashes are decoded like all other encoded characters.</p>
382 <p>With the value <code>NoDecode</code>, such URLs are accepted, but
383 encoded slashes are not decoded but left in their encoded state.</p>
385 <p>Turning <code class="directive">AllowEncodedSlashes</code> <code>On</code> is
386 mostly useful when used in conjunction with <code>PATH_INFO</code>.</p>
388 <div class="note"><h3>Note</h3>
389 <p>If encoded slashes are needed in path info, use of <code>NoDecode</code> is
390 strongly recommended as a security measure. Allowing slashes
391 to be decoded could potentially allow unsafe paths.</p>
396 <li><code class="directive"><a href="#acceptpathinfo">AcceptPathInfo</a></code></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="AllowOverride" id="AllowOverride">AllowOverride</a> <a name="allowoverride" id="allowoverride">Directive</a></h2>
401 <table class="directive">
402 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Types of directives that are allowed in
403 <code>.htaccess</code> files</td></tr>
404 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowOverride All|None|<var>directive-type</var>
405 [<var>directive-type</var>] ...</code></td></tr>
406 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowOverride None (2.3.9 and later), AllowOverride All (2.3.8 and earlier)</code></td></tr>
407 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
408 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
409 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
411 <p>When the server finds an <code>.htaccess</code> file (as
412 specified by <code class="directive"><a href="#accessfilename">AccessFileName</a></code>)
413 it needs to know which directives declared in that file can override
414 earlier configuration directives.</p>
416 <div class="note"><h3>Only available in <Directory> sections</h3>
417 <code class="directive">AllowOverride</code> is valid only in
418 <code class="directive"><a href="#directory"><Directory></a></code>
419 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
420 <code class="directive"><a href="#files"><Files></a></code> sections.
423 <p>When this directive is set to <code>None</code> and <code class="directive"><a href="#allowoverridelist">AllowOverrideList</a></code> is set to
424 <code>None</code> <a href="#accessfilename">.htaccess</a> files are
425 completely ignored. In this case, the server will not even attempt
426 to read <code>.htaccess</code> files in the filesystem.</p>
428 <p>When this directive is set to <code>All</code>, then any
429 directive which has the .htaccess <a href="directive-dict.html#Context">Context</a> is allowed in
430 <code>.htaccess</code> files.</p>
432 <p>The <var>directive-type</var> can be one of the following
433 groupings of directives.</p>
440 Allow use of the authorization directives (<code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmgroupfile">AuthDBMGroupFile</a></code>,
441 <code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmuserfile">AuthDBMUserFile</a></code>,
442 <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code>,
443 <code class="directive"><a href="../mod/mod_authn_core.html#authname">AuthName</a></code>,
444 <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>
449 Allow use of the directives controlling document types
450 (<code class="directive"><a href="#errordocument">ErrorDocument</a></code>,
451 <code class="directive"><a href="#forcetype">ForceType</a></code>,
452 <code class="directive"><a href="../mod/mod_negotiation.html#languagepriority">LanguagePriority</a></code>,
453 <code class="directive"><a href="#sethandler">SetHandler</a></code>,
454 <code class="directive"><a href="#setinputfilter">SetInputFilter</a></code>,
455 <code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code>, and
456 <code class="module"><a href="../mod/mod_mime.html">mod_mime</a></code> Add* and Remove* directives),
457 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>),
458 <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
459 <code class="directive"><a href="../mod/mod_actions.html#action">Action</a></code> from
460 <code class="module"><a href="../mod/mod_actions.html">mod_actions</a></code>.
466 Allow use of the directives controlling directory indexing
467 (<code class="directive"><a href="../mod/mod_autoindex.html#adddescription">AddDescription</a></code>,
468 <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>,
469 <code class="directive"><a href="../mod/mod_autoindex.html#addiconbytype">AddIconByType</a></code>,
470 <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>,
476 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>
478 <dt>Options[=<var>Option</var>,...]</dt>
481 Allow use of the directives controlling specific directory
482 features (<code class="directive"><a href="#options">Options</a></code> and
483 <code class="directive"><a href="../mod/mod_include.html#xbithack">XBitHack</a></code>).
484 An equal sign may be given followed by a comma (but no spaces)
485 separated lists of options that may be set using the <code class="directive"><a href="#options">Options</a></code> command.
487 <div class="note"><h3>Implicit disabling of Options</h3>
488 <p>Even though the list of options that may be used in .htaccess files
489 can be limited with this directive, as long as any <code class="directive"><a href="#options">Options</a></code> directive is allowed any
490 other inherited option can be disabled by using the non-relative
491 syntax. In other words, this mechanism cannot force a specific option
492 to remain <em>set</em> while allowing any others to be set.
499 <div class="example"><p><code>
500 AllowOverride AuthConfig Indexes
503 <p>In the example above all directives that are neither in the group
504 <code>AuthConfig</code> nor <code>Indexes</code> cause an internal
507 <div class="note"><p>For security and performance reasons, do not set
508 <code>AllowOverride</code> to anything other than <code>None</code>
509 in your <code><Directory /></code> block. Instead, find (or
510 create) the <code><Directory></code> block that refers to the
511 directory where you're actually planning to place a
512 <code>.htaccess</code> file.</p>
517 <li><code class="directive"><a href="#accessfilename">AccessFileName</a></code></li>
518 <li><code class="directive"><a href="#allowoverridelist">AllowOverrideList</a></code></li>
519 <li><a href="../configuring.html">Configuration Files</a></li>
520 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
523 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
524 <div class="directive-section"><h2><a name="AllowOverrideList" id="AllowOverrideList">AllowOverrideList</a> <a name="allowoverridelist" id="allowoverridelist">Directive</a></h2>
525 <table class="directive">
526 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Individual directives that are allowed in
527 <code>.htaccess</code> files</td></tr>
528 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowOverrideList None|<var>directive</var>
529 [<var>directive-type</var>] ...</code></td></tr>
530 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowOverrideList None</code></td></tr>
531 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
532 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
533 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
535 <p>When the server finds an <code>.htaccess</code> file (as
536 specified by <code class="directive"><a href="#accessfilename">AccessFileName</a></code>)
537 it needs to know which directives declared in that file can override
538 earlier configuration directives.</p>
540 <div class="note"><h3>Only available in <Directory> sections</h3>
541 <code class="directive">AllowOverrideList</code> is valid only in
542 <code class="directive"><a href="#directory"><Directory></a></code>
543 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
544 <code class="directive"><a href="#files"><Files></a></code> sections.
547 <p>When this directive is set to <code>None</code> and <code class="directive"><a href="#allowoverride">AllowOverride</a></code> is set to <code>None</code>,
548 then <a href="#accessfilename">.htaccess</a> files are completely
549 ignored. In this case, the server will not even attempt to read
550 <code>.htaccess</code> files in the filesystem.</p>
554 <div class="example"><p><code>
556 AllowOverrideList Redirect RedirectMatch
559 <p>In the example above only the <code>Redirect</code> and
560 <code>RedirectMatch</code> directives are allowed. All others will
561 cause an internal server error.</p>
565 <div class="example"><p><code>
566 AllowOverride AuthConfig
567 AllowOverrideList CookieTracking CookieName
570 <p>In the example above <code class="directive"><a href="#allowoverride ">AllowOverride
571 </a></code> grants permission to the <code>AuthConfig</code>
572 directive grouping and <code class="directive">AllowOverrideList</code> grants
573 permission to only two directves from the <code>FileInfo</code> directive
574 grouping. All others will cause an internal server error.</p>
578 <li><code class="directive"><a href="#accessfilename">AccessFileName</a></code></li>
579 <li><code class="directive"><a href="#allowoverride">AllowOverride</a></code></li>
580 <li><a href="../configuring.html">Configuration Files</a></li>
581 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
584 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
585 <div class="directive-section"><h2><a name="CGIMapExtension" id="CGIMapExtension">CGIMapExtension</a> <a name="cgimapextension" id="cgimapextension">Directive</a></h2>
586 <table class="directive">
587 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
589 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CGIMapExtension <var>cgi-path</var> <var>.extension</var></code></td></tr>
590 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
591 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
592 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
593 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
594 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>NetWare only</td></tr>
596 <p>This directive is used to control how Apache httpd finds the
597 interpreter used to run CGI scripts. For example, setting
598 <code>CGIMapExtension sys:\foo.nlm .foo</code> will
599 cause all CGI script files with a <code>.foo</code> extension to
600 be passed to the FOO interpreter.</p>
603 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
604 <div class="directive-section"><h2><a name="ContentDigest" id="ContentDigest">ContentDigest</a> <a name="contentdigest" id="contentdigest">Directive</a></h2>
605 <table class="directive">
606 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables the generation of <code>Content-MD5</code> HTTP Response
608 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ContentDigest On|Off</code></td></tr>
609 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ContentDigest Off</code></td></tr>
610 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
611 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
612 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
613 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
615 <p>This directive enables the generation of
616 <code>Content-MD5</code> headers as defined in RFC1864
617 respectively RFC2616.</p>
619 <p>MD5 is an algorithm for computing a "message digest"
620 (sometimes called "fingerprint") of arbitrary-length data, with
621 a high degree of confidence that any alterations in the data
622 will be reflected in alterations in the message digest.</p>
624 <p>The <code>Content-MD5</code> header provides an end-to-end
625 message integrity check (MIC) of the entity-body. A proxy or
626 client may check this header for detecting accidental
627 modification of the entity-body in transit. Example header:</p>
629 <div class="example"><p><code>
630 Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA==
633 <p>Note that this can cause performance problems on your server
634 since the message digest is computed on every request (the
635 values are not cached).</p>
637 <p><code>Content-MD5</code> is only sent for documents served
638 by the <code class="module"><a href="../mod/core.html">core</a></code>, and not by any module. For example,
639 SSI documents, output from CGI scripts, and byte range responses
640 do not have this header.</p>
643 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
644 <div class="directive-section"><h2><a name="DefaultType" id="DefaultType">DefaultType</a> <a name="defaulttype" id="defaulttype">Directive</a></h2>
645 <table class="directive">
646 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>This directive has no effect other than to emit warnings
647 if the value is not <code>none</code>. In prior versions, DefaultType
648 would specify a default media type to assign to response content for
649 which no other media type configuration could be found.
651 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DefaultType <var>media-type|none</var></code></td></tr>
652 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DefaultType none</code></td></tr>
653 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
654 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
655 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
656 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
657 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The argument <code>none</code> is available in Apache httpd 2.2.7 and later. All other choices are DISABLED for 2.3.x and later.</td></tr>
659 <p>This directive has been disabled. For backwards compatibility
660 of configuration files, it may be specified with the value
661 <code>none</code>, meaning no default media type. For example:</p>
663 <div class="example"><p><code>
667 <p><code>DefaultType None</code> is only available in
668 httpd-2.2.7 and later.</p>
670 <p>Use the mime.types configuration file and the
671 <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> to configure media
672 type assignments via file extensions, or the
673 <code class="directive"><a href="#forcetype">ForceType</a></code> directive to configure
674 the media type for specific resources. Otherwise, the server will
675 send the response without a Content-Type header field and the
676 recipient may attempt to guess the media type.</p>
679 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
680 <div class="directive-section"><h2><a name="Define" id="Define">Define</a> <a name="define" id="define">Directive</a></h2>
681 <table class="directive">
682 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define a variable</td></tr>
683 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Define <var>parameter-name</var> [<var>parameter-value</var>]</code></td></tr>
684 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
685 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
686 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
688 <p>In its one parameter form, <code class="directive">Define</code> is equivalent
689 to passing the <code>-D</code> argument to <code class="program"><a href="../programs/httpd.html">httpd</a></code>. It
690 can be used to toggle the use of
691 <code class="directive"><a href="#ifdefine"><IfDefine></a></code> sections
692 without needing to alter <code>-D</code> arguments in any startup
695 <p>In addition to that, if the second parameter is given, a config variable
696 is set to this value. The variable can be used in the configuration using
697 the <code>${VAR}</code> syntax. The variable is always globally defined
698 and not limited to the scope of the surrounding config section.</p>
700 <div class="example"><p><code>
701 <IfDefine TEST><br />
702 Define servername test.example.com<br />
703 </IfDefine><br />
704 <IfDefine !TEST><br />
705 Define servername www.example.com<br />
706 Define SSL<br />
707 </IfDefine><br />
710 <p>Variable names may not contain colon ":" characters, to avoid clashes
711 with <code class="directive"><a href="../mod/mod_rewrite.html#rewritemap">RewriteMap</a></code>'s syntax.</p>
714 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
715 <div class="directive-section"><h2><a name="Directory" id="Directory"><Directory></a> <a name="directory" id="directory">Directive</a></h2>
716 <table class="directive">
717 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose a group of directives that apply only to the
718 named file-system directory, sub-directories, and their contents.</td></tr>
719 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Directory <var>directory-path</var>>
720 ... </Directory></code></td></tr>
721 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
722 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
723 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
725 <p><code class="directive"><Directory></code> and
726 <code></Directory></code> are used to enclose a group of
727 directives that will apply only to the named directory,
728 sub-directories of that directory, and the files within the respective
729 directories. Any directive that is allowed
730 in a directory context may be used. <var>Directory-path</var> is
731 either the full path to a directory, or a wild-card string using
732 Unix shell-style matching. In a wild-card string, <code>?</code> matches
733 any single character, and <code>*</code> matches any sequences of
734 characters. You may also use <code>[]</code> character ranges. None
735 of the wildcards match a `/' character, so <code><Directory
736 /*/public_html></code> will not match
737 <code>/home/user/public_html</code>, but <code><Directory
738 /home/*/public_html></code> will match. Example:</p>
740 <div class="example"><p><code>
741 <Directory /usr/local/httpd/htdocs><br />
742 <span class="indent">
743 Options Indexes FollowSymLinks<br />
749 <p>Be careful with the <var>directory-path</var> arguments:
750 They have to literally match the filesystem path which Apache httpd uses
751 to access the files. Directives applied to a particular
752 <code><Directory></code> will not apply to files accessed from
753 that same directory via a different path, such as via different symbolic
757 <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular
758 expressions</a> can also be used, with the addition of the
759 <code>~</code> character. For example:</p>
761 <div class="example"><p><code>
762 <Directory ~ "^/www/.*/[0-9]{3}">
765 <p>would match directories in <code>/www/</code> that consisted of
768 <p>If multiple (non-regular expression) <code class="directive"><Directory></code> sections
769 match the directory (or one of its parents) containing a document,
770 then the directives are applied in the order of shortest match
771 first, interspersed with the directives from the <a href="#accessfilename">.htaccess</a> files. For example,
774 <div class="example"><p><code>
775 <Directory /><br />
776 <span class="indent">
777 AllowOverride None<br />
779 </Directory><br />
781 <Directory /home><br />
782 <span class="indent">
783 AllowOverride FileInfo<br />
788 <p>for access to the document <code>/home/web/dir/doc.html</code>
792 <li>Apply directive <code>AllowOverride None</code>
793 (disabling <code>.htaccess</code> files).</li>
795 <li>Apply directive <code>AllowOverride FileInfo</code> (for
796 directory <code>/home</code>).</li>
798 <li>Apply any <code>FileInfo</code> directives in
799 <code>/home/.htaccess</code>, <code>/home/web/.htaccess</code> and
800 <code>/home/web/dir/.htaccess</code> in that order.</li>
803 <p>Regular expressions are not considered until after all of the
804 normal sections have been applied. Then all of the regular
805 expressions are tested in the order they appeared in the
806 configuration file. For example, with</p>
808 <div class="example"><p><code>
809 <Directory ~ abc$><br />
810 <span class="indent">
811 # ... directives here ...<br />
816 <p>the regular expression section won't be considered until after
817 all normal <code class="directive"><Directory></code>s and
818 <code>.htaccess</code> files have been applied. Then the regular
819 expression will match on <code>/home/abc/public_html/abc</code> and
820 the corresponding <code class="directive"><Directory></code> will
823 <p><strong>Note that the default access for
824 <code><Directory /></code> is to permit all access.
825 This means that Apache httpd will serve any file mapped from an URL. It is
826 recommended that you change this with a block such
829 <div class="example"><p><code>
830 <Directory /><br />
831 <span class="indent">
832 Require all denied<br />
837 <p><strong>and then override this for directories you
838 <em>want</em> accessible. See the <a href="../misc/security_tips.html">Security Tips</a> page for more
839 details.</strong></p>
841 <p>The directory sections occur in the <code>httpd.conf</code> file.
842 <code class="directive"><Directory></code> directives
843 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>
847 <li><a href="../sections.html">How <Directory>,
848 <Location> and <Files> sections work</a> for an
849 explanation of how these different sections are combined when a
850 request is received</li>
853 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
854 <div class="directive-section"><h2><a name="DirectoryMatch" id="DirectoryMatch"><DirectoryMatch></a> <a name="directorymatch" id="directorymatch">Directive</a></h2>
855 <table class="directive">
856 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose directives that apply to
857 the contents of file-system directories matching a regular expression.</td></tr>
858 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><DirectoryMatch <var>regex</var>>
859 ... </DirectoryMatch></code></td></tr>
860 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
861 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
862 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
864 <p><code class="directive"><DirectoryMatch></code> and
865 <code></DirectoryMatch></code> are used to enclose a group
866 of directives which will apply only to the named directory (and the files within),
867 the same as <code class="directive"><a href="#directory"><Directory></a></code>.
868 However, it takes as an argument a
869 <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>. For example:</p>
871 <div class="example"><p><code>
872 <DirectoryMatch "^/www/(.+/)?[0-9]{3}">
875 <p>would match directories in <code>/www/</code> that consisted of three
878 <div class="note"><h3>Compatability</h3>
879 Prior to 2.3.9, this directive implicitly applied to sub-directories
880 (like <code class="directive"><a href="#directory"><Directory></a></code>) and
881 could not match the end of line symbol ($). In 2.3.9 and later,
882 only directories that match the expression are affected by the enclosed
886 <div class="note"><h3>Trailing Slash</h3>
887 This directive applies to requests for directories that may or may
888 not end in a trailing slash, so expressions that are anchored to the
889 end of line ($) must be written with care.
894 <li><code class="directive"><a href="#directory"><Directory></a></code> for
895 a description of how regular expressions are mixed in with normal
896 <code class="directive"><Directory></code>s</li>
897 <li><a href="../sections.html">How <Directory>, <Location> and
898 <Files> sections work</a> for an explanation of how these different
899 sections are combined when a request is received</li>
902 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
903 <div class="directive-section"><h2><a name="DocumentRoot" id="DocumentRoot">DocumentRoot</a> <a name="documentroot" id="documentroot">Directive</a></h2>
904 <table class="directive">
905 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory that forms the main document tree visible
906 from the web</td></tr>
907 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DocumentRoot <var>directory-path</var></code></td></tr>
908 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DocumentRoot /usr/local/apache/htdocs</code></td></tr>
909 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
910 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
911 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
913 <p>This directive sets the directory from which <code class="program"><a href="../programs/httpd.html">httpd</a></code>
914 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
915 path from the requested URL to the document root to make the
916 path to the document. Example:</p>
918 <div class="example"><p><code>
919 DocumentRoot /usr/web
923 <code>http://my.example.com/index.html</code> refers to
924 <code>/usr/web/index.html</code>. If the <var>directory-path</var> is
925 not absolute then it is assumed to be relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
927 <p>The <code class="directive">DocumentRoot</code> should be specified without
928 a trailing slash.</p>
932 <li><a href="../urlmapping.html#documentroot">Mapping URLs to Filesystem
936 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
937 <div class="directive-section"><h2><a name="Else" id="Else"><Else></a> <a name="else" id="else">Directive</a></h2>
938 <table class="directive">
939 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only if the condition of a
940 previous <code class="directive"><a href="#if"><If></a></code> or
941 <code class="directive"><a href="#elseif"><ElseIf></a></code> section is not
942 satisfied by a request at runtime</td></tr>
943 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Else> ... </Else></code></td></tr>
944 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
945 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
946 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
947 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
949 <p>The <code class="directive"><Else></code> applies the enclosed
950 directives if and only if the most recent
951 <code class="directive"><If></code> or
952 <code class="directive"><ElseIf></code> section
953 in the same scope has not been applied.
956 <div class="example"><p><code>
957 <If "-z req('Host')"><br />
965 <p> The <code class="directive"><If></code> would match HTTP/1.0
966 requests without a <var>Host:</var> header and the
967 <code class="directive"><Else></code> would match requests
968 with a <var>Host:</var> header.</p>
973 <li><code class="directive"><a href="#if"><If></a></code></li>
974 <li><code class="directive"><a href="#elseif"><ElseIf></a></code></li>
975 <li><a href="../sections.html">How <Directory>, <Location>,
976 <Files> sections work</a> for an explanation of how these
977 different sections are combined when a request is received.
978 <code class="directive"><If></code>,
979 <code class="directive"><ElseIf></code>, and
980 <code class="directive"><Else></code> are applied last.</li>
983 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
984 <div class="directive-section"><h2><a name="ElseIf" id="ElseIf"><ElseIf></a> <a name="elseif" id="elseif">Directive</a></h2>
985 <table class="directive">
986 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only if a condition is satisfied
987 by a request at runtime while the condition of a previous
988 <code class="directive"><a href="#if"><If></a></code> or
989 <code class="directive"><ElseIf></code> section is not
991 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><ElseIf <var>expression</var>> ... </ElseIf></code></td></tr>
992 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
993 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
994 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
995 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
997 <p>The <code class="directive"><ElseIf></code> applies the enclosed
998 directives if and only if both the given condition evaluates to true and
999 the most recent <code class="directive"><If></code> or
1000 <code class="directive"><ElseIf></code> section in the same scope has
1001 not been applied. For example: In </p>
1003 <div class="example"><p><code>
1004 <If "-R '10.1.0.0/16'"><br />
1007 <ElseIf "-R '10.0.0.0/8'"><br />
1009 </ElseIf><br />
1015 <p>The <code class="directive"><ElseIf></code> would match if
1016 the remote address of a request belongs to the subnet 10.0.0.0/8 but
1017 not to the subnet 10.1.0.0/16.</p>
1022 <li><a href="../expr.html">Expressions in Apache HTTP Server</a>,
1023 for a complete reference and more examples.</li>
1024 <li><code class="directive"><a href="#if"><If></a></code></li>
1025 <li><code class="directive"><a href="#else"><Else></a></code></li>
1026 <li><a href="../sections.html">How <Directory>, <Location>,
1027 <Files> sections work</a> for an explanation of how these
1028 different sections are combined when a request is received.
1029 <code class="directive"><If></code>,
1030 <code class="directive"><ElseIf></code>, and
1031 <code class="directive"><Else></code> are applied last.</li>
1034 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1035 <div class="directive-section"><h2><a name="EnableMMAP" id="EnableMMAP">EnableMMAP</a> <a name="enablemmap" id="enablemmap">Directive</a></h2>
1036 <table class="directive">
1037 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use memory-mapping to read files during delivery</td></tr>
1038 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableMMAP On|Off</code></td></tr>
1039 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableMMAP On</code></td></tr>
1040 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1041 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1042 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1043 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1045 <p>This directive controls whether the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use
1046 memory-mapping if it needs to read the contents of a file during
1047 delivery. By default, when the handling of a request requires
1048 access to the data within a file -- for example, when delivering a
1049 server-parsed file using <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> -- Apache httpd
1050 memory-maps the file if the OS supports it.</p>
1052 <p>This memory-mapping sometimes yields a performance improvement.
1053 But in some environments, it is better to disable the memory-mapping
1054 to prevent operational problems:</p>
1057 <li>On some multiprocessor systems, memory-mapping can reduce the
1058 performance of the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</li>
1059 <li>Deleting or truncating a file while <code class="program"><a href="../programs/httpd.html">httpd</a></code>
1060 has it memory-mapped can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to
1061 crash with a segmentation fault.
1065 <p>For server configurations that are vulnerable to these problems,
1066 you should disable memory-mapping of delivered files by specifying:</p>
1068 <div class="example"><p><code>
1072 <p>For NFS mounted files, this feature may be disabled explicitly for
1073 the offending files by specifying:</p>
1075 <div class="example"><p><code>
1076 <Directory "/path-to-nfs-files">
1077 <span class="indent">
1084 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1085 <div class="directive-section"><h2><a name="EnableSendfile" id="EnableSendfile">EnableSendfile</a> <a name="enablesendfile" id="enablesendfile">Directive</a></h2>
1086 <table class="directive">
1087 <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>
1088 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableSendfile On|Off</code></td></tr>
1089 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableSendfile Off</code></td></tr>
1090 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1091 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1092 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1093 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1094 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0.44 and later. Default changed to Off in
1095 version 2.3.9.</td></tr>
1097 <p>This directive controls whether <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use the
1098 sendfile support from the kernel to transmit file contents to the client.
1099 By default, when the handling of a request requires no access
1100 to the data within a file -- for example, when delivering a
1101 static file -- Apache httpd uses sendfile to deliver the file contents
1102 without ever reading the file if the OS supports it.</p>
1104 <p>This sendfile mechanism avoids separate read and send operations,
1105 and buffer allocations. But on some platforms or within some
1106 filesystems, it is better to disable this feature to avoid
1107 operational problems:</p>
1110 <li>Some platforms may have broken sendfile support that the build
1111 system did not detect, especially if the binaries were built on
1112 another box and moved to such a machine with broken sendfile
1114 <li>On Linux the use of sendfile triggers TCP-checksum
1115 offloading bugs on certain networking cards when using IPv6.</li>
1116 <li>On Linux on Itanium, <code>sendfile</code> may be unable to handle
1117 files over 2GB in size.</li>
1118 <li>With a network-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code> (e.g., NFS, SMB, CIFS, FUSE),
1119 the kernel may be unable to serve the network file through
1123 <p>For server configurations that are not vulnerable to these problems,
1124 you may enable this feature by specifying:</p>
1126 <div class="example"><p><code>
1130 <p>For network mounted files, this feature may be disabled explicitly
1131 for the offending files by specifying:</p>
1133 <div class="example"><p><code>
1134 <Directory "/path-to-nfs-files">
1135 <span class="indent">
1140 <p>Please note that the per-directory and .htaccess configuration
1141 of <code class="directive">EnableSendfile</code> is not supported by
1142 <code class="module"><a href="../mod/mod_cache_disk.html">mod_cache_disk</a></code>.
1143 Only global definition of <code class="directive">EnableSendfile</code>
1144 is taken into account by the module.
1148 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1149 <div class="directive-section"><h2><a name="Error" id="Error">Error</a> <a name="error" id="error">Directive</a></h2>
1150 <table class="directive">
1151 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Abort configuration parsing with a custom error message</td></tr>
1152 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Error <var>message</var></code></td></tr>
1153 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1154 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1155 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1156 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.3.9 and later</td></tr>
1158 <p>If an error can be detected within the configuration, this
1159 directive can be used to generate a custom error message, and halt
1160 configuration parsing. The typical use is for reporting required
1161 modules which are missing from the configuration.</p>
1163 <div class="example"><h3>Example</h3><p><code>
1164 # ensure that mod_include is loaded<br />
1165 <IfModule !include_module><br />
1166 Error mod_include is required by mod_foo. Load it with LoadModule.<br />
1167 </IfModule><br />
1169 # ensure that exactly one of SSL,NOSSL is defined<br />
1170 <IfDefine SSL><br />
1171 <IfDefine NOSSL><br />
1172 Error Both SSL and NOSSL are defined. Define only one of them.<br />
1173 </IfDefine><br />
1174 </IfDefine><br />
1175 <IfDefine !SSL><br />
1176 <IfDefine !NOSSL><br />
1177 Error Either SSL or NOSSL must be defined.<br />
1178 </IfDefine><br />
1179 </IfDefine><br />
1184 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1185 <div class="directive-section"><h2><a name="ErrorDocument" id="ErrorDocument">ErrorDocument</a> <a name="errordocument" id="errordocument">Directive</a></h2>
1186 <table class="directive">
1187 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>What the server will return to the client
1188 in case of an error</td></tr>
1189 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorDocument <var>error-code</var> <var>document</var></code></td></tr>
1190 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1191 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1192 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1193 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1195 <p>In the event of a problem or error, Apache httpd can be configured
1196 to do one of four things,</p>
1199 <li>output a simple hardcoded error message</li>
1201 <li>output a customized message</li>
1203 <li>redirect to a local <var>URL-path</var> to handle the
1206 <li>redirect to an external <var>URL</var> to handle the
1210 <p>The first option is the default, while options 2-4 are
1211 configured using the <code class="directive">ErrorDocument</code>
1212 directive, which is followed by the HTTP response code and a URL
1213 or a message. Apache httpd will sometimes offer additional information
1214 regarding the problem/error.</p>
1216 <p>URLs can begin with a slash (/) for local web-paths (relative
1217 to the <code class="directive"><a href="#documentroot">DocumentRoot</a></code>), or be a
1218 full URL which the client can resolve. Alternatively, a message
1219 can be provided to be displayed by the browser. Examples:</p>
1221 <div class="example"><p><code>
1222 ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br />
1223 ErrorDocument 404 /cgi-bin/bad_urls.pl<br />
1224 ErrorDocument 401 /subscription_info.html<br />
1225 ErrorDocument 403 "Sorry can't allow you access today"
1228 <p>Additionally, the special value <code>default</code> can be used
1229 to specify Apache httpd's simple hardcoded message. While not required
1230 under normal circumstances, <code>default</code> will restore
1231 Apache httpd's simple hardcoded message for configurations that would
1232 otherwise inherit an existing <code class="directive">ErrorDocument</code>.</p>
1234 <div class="example"><p><code>
1235 ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br />
1236 <Directory /web/docs><br />
1237 <span class="indent">
1238 ErrorDocument 404 default<br />
1243 <p>Note that when you specify an <code class="directive">ErrorDocument</code>
1244 that points to a remote URL (ie. anything with a method such as
1245 <code>http</code> in front of it), Apache HTTP Server will send a redirect to the
1246 client to tell it where to find the document, even if the
1247 document ends up being on the same server. This has several
1248 implications, the most important being that the client will not
1249 receive the original error status code, but instead will
1250 receive a redirect status code. This in turn can confuse web
1251 robots and other clients which try to determine if a URL is
1252 valid using the status code. In addition, if you use a remote
1253 URL in an <code>ErrorDocument 401</code>, the client will not
1254 know to prompt the user for a password since it will not
1255 receive the 401 status code. Therefore, <strong>if you use an
1256 <code>ErrorDocument 401</code> directive then it must refer to a local
1257 document.</strong></p>
1259 <p>Microsoft Internet Explorer (MSIE) will by default ignore
1260 server-generated error messages when they are "too small" and substitute
1261 its own "friendly" error messages. The size threshold varies depending on
1262 the type of error, but in general, if you make your error document
1263 greater than 512 bytes, then MSIE will show the server-generated
1264 error rather than masking it. More information is available in
1265 Microsoft Knowledge Base article <a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807">Q294807</a>.</p>
1267 <p>Although most error messages can be overriden, there are certain
1268 circumstances where the internal messages are used regardless of the
1269 setting of <code class="directive"><a href="#errordocument">ErrorDocument</a></code>. In
1270 particular, if a malformed request is detected, normal request processing
1271 will be immediately halted and the internal error message returned.
1272 This is necessary to guard against security problems caused by
1275 <p>If you are using mod_proxy, you may wish to enable
1276 <code class="directive"><a href="../mod/mod_proxy.html#proxyerroroverride">ProxyErrorOverride</a></code> so that you can provide
1277 custom error messages on behalf of your Origin servers. If you don't enable ProxyErrorOverride,
1278 Apache httpd will not generate custom error documents for proxied content.</p>
1282 <li><a href="../custom-error.html">documentation of
1283 customizable responses</a></li>
1286 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1287 <div class="directive-section"><h2><a name="ErrorLog" id="ErrorLog">ErrorLog</a> <a name="errorlog" id="errorlog">Directive</a></h2>
1288 <table class="directive">
1289 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Location where the server will log errors</td></tr>
1290 <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>
1291 <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>
1292 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1293 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1294 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1296 <p>The <code class="directive">ErrorLog</code> directive sets the name of
1297 the file to which the server will log any errors it encounters. If
1298 the <var>file-path</var> is not absolute then it is assumed to be
1299 relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
1301 <div class="example"><h3>Example</h3><p><code>
1302 ErrorLog /var/log/httpd/error_log
1305 <p>If the <var>file-path</var>
1306 begins with a pipe character "<code>|</code>" then it is assumed to be a
1307 command to spawn to handle the error log.</p>
1309 <div class="example"><h3>Example</h3><p><code>
1310 ErrorLog "|/usr/local/bin/httpd_errors"
1313 <p>See the notes on <a href="../logs.html#piped">piped logs</a> for
1314 more information.</p>
1316 <p>Using <code>syslog</code> instead of a filename enables logging
1317 via syslogd(8) if the system supports it. The default is to use
1318 syslog facility <code>local7</code>, but you can override this by
1319 using the <code>syslog:<var>facility</var></code> syntax where
1320 <var>facility</var> can be one of the names usually documented in
1321 syslog(1). The facility is effectively global, and if it is changed
1322 in individual virtual hosts, the final facility specified affects the
1325 <div class="example"><h3>Example</h3><p><code>
1326 ErrorLog syslog:user
1329 <p>SECURITY: See the <a href="../misc/security_tips.html#serverroot">security tips</a>
1330 document for details on why your security could be compromised
1331 if the directory where log files are stored is writable by
1332 anyone other than the user that starts the server.</p>
1333 <div class="warning"><h3>Note</h3>
1334 <p>When entering a file path on non-Unix platforms, care should be taken
1335 to make sure that only forward slashes are used even though the platform
1336 may allow the use of back slashes. In general it is a good idea to always
1337 use forward slashes throughout the configuration files.</p>
1342 <li><code class="directive"><a href="#loglevel">LogLevel</a></code></li>
1343 <li><a href="../logs.html">Apache HTTP Server Log Files</a></li>
1346 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1347 <div class="directive-section"><h2><a name="ErrorLogFormat" id="ErrorLogFormat">ErrorLogFormat</a> <a name="errorlogformat" id="errorlogformat">Directive</a></h2>
1348 <table class="directive">
1349 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Format specification for error log entries</td></tr>
1350 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code> ErrorLog [connection|request] <var>format</var></code></td></tr>
1351 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1352 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1353 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1354 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.3.9 and later</td></tr>
1356 <p><code class="directive">ErrorLogFormat</code> allows to specify what
1357 supplementary information is logged in the error log in addition to the
1358 actual log message.</p>
1360 <div class="example"><h3>Simple example</h3><p><code>
1361 ErrorLogFormat "[%t] [%l] [pid %P] %F: %E: [client %a] %M"
1364 <p>Specifying <code>connection</code> or <code>request</code> as first
1365 parameter allows to specify additional formats, causing additional
1366 information to be logged when the first message is logged for a specific
1367 connection or request, respectivly. This additional information is only
1368 logged once per connection/request. If a connection or request is processed
1369 without causing any log message, the additional information is not logged
1372 <p>It can happen that some format string items do not produce output. For
1373 example, the Referer header is only present if the log message is
1374 associated to a request and the log message happens at a time when the
1375 Referer header has already been read from the client. If no output is
1376 produced, the default behaviour is to delete everything from the preceeding
1377 space character to the next space character. This means the log line is
1378 implicitly divided into fields on non-whitespace to whitespace transitions.
1379 If a format string item does not produce output, the whole field is
1380 ommitted. For example, if the remote address <code>%a</code> in the log
1381 format <code>[%t] [%l] [%a] %M </code> is not available, the surrounding
1382 brackets are not logged either. Space characters can be escaped with a
1383 backslash to prevent them from delimiting a field. The combination '% '
1384 (percent space) is a zero-witdh field delimiter that does not produce any
1387 <p>The above behaviour can be changed by adding modifiers to the format
1388 string item. A <code>-</code> (minus) modifier causes a minus to be logged if the
1389 respective item does not produce any output. In once-per-connection/request
1390 formats, it is also possible to use the <code>+</code> (plus) modifier. If an
1391 item with the plus modifier does not produce any output, the whole line is
1394 <p>A number as modifier can be used to assign a log severity level to a
1395 format item. The item will only be logged if the severity of the log
1396 message is not higher than the specified log severity level. The number can
1397 range from 1 (alert) over 4 (warn) and 7 (debug) to 15 (trace8).</p>
1399 <p>Some format string items accept additional parameters in braces.</p>
1401 <table class="bordered"><tr class="header"><th>Format String</th> <th>Description</th></tr>
1402 <tr><td><code>%%</code></td>
1403 <td>The percent sign</td></tr>
1404 <tr class="odd"><td><code>%...a</code></td>
1405 <td>Remote IP-address and port</td></tr>
1406 <tr><td><code>%...A</code></td>
1407 <td>Local IP-address and port</td></tr>
1408 <tr class="odd"><td><code>%...{name}e</code></td>
1409 <td>Request environment variable <code>name</code></td></tr>
1410 <tr><td><code>%...E</code></td>
1411 <td>APR/OS error status code and string</td></tr>
1412 <tr class="odd"><td><code>%...F</code></td>
1413 <td>Source file name and line number of the log call</td></tr>
1414 <tr><td><code>%...{name}i</code></td>
1415 <td>Request header <code>name</code></td></tr>
1416 <tr class="odd"><td><code>%...k</code></td>
1417 <td>Number of keep-alive requests on this connection</td></tr>
1418 <tr><td><code>%...l</code></td>
1419 <td>Loglevel of the message</td></tr>
1420 <tr class="odd"><td><code>%...L</code></td>
1421 <td>Log ID of the request</td></tr>
1422 <tr><td><code>%...{c}L</code></td>
1423 <td>Log ID of the connection</td></tr>
1424 <tr class="odd"><td><code>%...{C}L</code></td>
1425 <td>Log ID of the connection if used in connection scope, empty otherwise</td></tr>
1426 <tr><td><code>%...m</code></td>
1427 <td>Name of the module logging the message</td></tr>
1428 <tr class="odd"><td><code>%M</code></td>
1429 <td>The actual log message</td></tr>
1430 <tr><td><code>%...{name}n</code></td>
1431 <td>Request note <code>name</code></td></tr>
1432 <tr class="odd"><td><code>%...P</code></td>
1433 <td>Process ID of current process</td></tr>
1434 <tr><td><code>%...T</code></td>
1435 <td>Thread ID of current thread</td></tr>
1436 <tr class="odd"><td><code>%...{g}T</code></td>
1437 <td>System unique thread ID of current thread (the same ID as
1438 displayed by e.g. <code>top</code>; currently Linux only)</td></tr>
1439 <tr><td><code>%...t</code></td>
1440 <td>The current time</td></tr>
1441 <tr class="odd"><td><code>%...{u}t</code></td>
1442 <td>The current time including micro-seconds</td></tr>
1443 <tr><td><code>%...{cu}t</code></td>
1444 <td>The current time in compact ISO 8601 format, including
1445 micro-seconds</td></tr>
1446 <tr class="odd"><td><code>%...v</code></td>
1447 <td>The canonical <code class="directive"><a href="#servername">ServerName</a></code>
1448 of the current server.</td></tr>
1449 <tr><td><code>%...V</code></td>
1450 <td>The server name of the server serving the request according to the
1451 <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code>
1453 <tr class="odd"><td><code>\ </code> (backslash space)</td>
1454 <td>Non-field delimiting space</td></tr>
1455 <tr><td><code>% </code> (percent space)</td>
1456 <td>Field delimiter (no output)</td></tr>
1459 <p>The log ID format <code>%L</code> produces a unique id for a connection
1460 or request. This can be used to correlate which log lines belong to the
1461 same connection or request, which request happens on which connection.
1462 A <code>%L</code> format string is also available in
1463 <code class="module"><a href="../mod/mod_log_config.html">mod_log_config</a></code>, to allow to correlate access log entries
1464 with error log lines. If <code class="module"><a href="../mod/mod_unique_id.html">mod_unique_id</a></code> is loaded, its
1465 unique id will be used as log ID for requests.</p>
1467 <div class="example"><h3>Example (somewhat similar to default format)</h3><p><code>
1468 ErrorLogFormat "[%{u}t] [%-m:%l] [pid %P] %7F: %E: [client\ %a]
1469 %M% ,\ referer\ %{Referer}i"
1472 <div class="example"><h3>Example (similar to the 2.2.x format)</h3><p><code>
1473 ErrorLogFormat "[%t] [%l] %7F: %E: [client\ %a]
1474 %M% ,\ referer\ %{Referer}i"
1477 <div class="example"><h3>Advanced example with request/connection log IDs</h3><p><code>
1478 ErrorLogFormat "[%{uc}t] [%-m:%-l] [R:%L] [C:%{C}L] %7F: %E: %M"<br />
1479 ErrorLogFormat request "[%{uc}t] [R:%L] Request %k on C:%{c}L pid:%P tid:%T"<br />
1480 ErrorLogFormat request "[%{uc}t] [R:%L] UA:'%+{User-Agent}i'"<br />
1481 ErrorLogFormat request "[%{uc}t] [R:%L] Referer:'%+{Referer}i'"<br />
1482 ErrorLogFormat connection "[%{uc}t] [C:%{c}L] local\ %a remote\ %A"<br />
1488 <li><code class="directive"><a href="#errorlog">ErrorLog</a></code></li>
1489 <li><code class="directive"><a href="#loglevel">LogLevel</a></code></li>
1490 <li><a href="../logs.html">Apache HTTP Server Log Files</a></li>
1493 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1494 <div class="directive-section"><h2><a name="ExtendedStatus" id="ExtendedStatus">ExtendedStatus</a> <a name="extendedstatus" id="extendedstatus">Directive</a></h2>
1495 <table class="directive">
1496 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Keep track of extended status information for each
1498 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ExtendedStatus On|Off</code></td></tr>
1499 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ExtendedStatus Off[*]</code></td></tr>
1500 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1501 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1502 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1504 <p>This option tracks additional data per worker about the
1505 currently executing request, and a utilization summary; you
1506 can see these variables during runtime by configuring
1507 <code class="module"><a href="../mod/mod_status.html">mod_status</a></code>. Note that other modules may
1508 rely on this scoreboard.</p>
1510 <p>This setting applies to the entire server, and cannot be
1511 enabled or disabled on a virtualhost-by-virtualhost basis.
1512 The collection of extended status information can slow down
1513 the server. Also note that this setting cannot be changed
1514 during a graceful restart.</p>
1517 <p>Note that loading <code class="module"><a href="../mod/mod_status.html">mod_status</a></code> will change
1518 the default behavior to ExtendedStatus On, while other
1519 third party modules may do the same. Such modules rely on
1520 collecting detailed information about the state of all workers.
1521 The default is changed by <code class="module"><a href="../mod/mod_status.html">mod_status</a></code> beginning
1522 with version 2.3.6; the previous default was always Off.</p>
1527 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1528 <div class="directive-section"><h2><a name="FileETag" id="FileETag">FileETag</a> <a name="fileetag" id="fileetag">Directive</a></h2>
1529 <table class="directive">
1530 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>File attributes used to create the ETag
1531 HTTP response header for static files</td></tr>
1532 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>FileETag <var>component</var> ...</code></td></tr>
1533 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>FileETag INode MTime Size</code></td></tr>
1534 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1535 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1536 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1537 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1540 The <code class="directive">FileETag</code> directive configures the file
1541 attributes that are used to create the <code>ETag</code> (entity
1542 tag) response header field when the document is based on a static file.
1543 (The <code>ETag</code> value is used in cache management to save
1544 network bandwidth.) The
1545 <code class="directive">FileETag</code> directive allows you to choose
1546 which of these -- if any -- should be used. The recognized keywords are:
1550 <dt><strong>INode</strong></dt>
1551 <dd>The file's i-node number will be included in the calculation</dd>
1552 <dt><strong>MTime</strong></dt>
1553 <dd>The date and time the file was last modified will be included</dd>
1554 <dt><strong>Size</strong></dt>
1555 <dd>The number of bytes in the file will be included</dd>
1556 <dt><strong>All</strong></dt>
1557 <dd>All available fields will be used. This is equivalent to:
1558 <div class="example"><p><code>FileETag INode MTime Size</code></p></div></dd>
1559 <dt><strong>None</strong></dt>
1560 <dd>If a document is file-based, no <code>ETag</code> field will be
1561 included in the response</dd>
1564 <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code>
1565 keywords may be prefixed with either <code>+</code> or <code>-</code>,
1566 which allow changes to be made to the default setting inherited
1567 from a broader scope. Any keyword appearing without such a prefix
1568 immediately and completely cancels the inherited setting.</p>
1570 <p>If a directory's configuration includes
1571 <code>FileETag INode MTime Size</code>, and a
1572 subdirectory's includes <code>FileETag -INode</code>,
1573 the setting for that subdirectory (which will be inherited by
1574 any sub-subdirectories that don't override it) will be equivalent to
1575 <code>FileETag MTime Size</code>.</p>
1576 <div class="warning"><h3>Warning</h3>
1577 Do not change the default for directories or locations that have WebDAV
1578 enabled and use <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> as a storage provider.
1579 <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> uses <code>INode MTime Size</code>
1580 as a fixed format for <code>ETag</code> comparisons on conditional requests.
1581 These conditional requests will break if the <code>ETag</code> format is
1582 changed via <code class="directive">FileETag</code>.
1584 <div class="note"><h3>Server Side Includes</h3>
1585 An ETag is not generated for responses parsed by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>,
1586 since the response entity can change without a change of the INode, MTime, or Size
1587 of the static file with embedded SSI directives.
1592 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1593 <div class="directive-section"><h2><a name="Files" id="Files"><Files></a> <a name="files" id="files">Directive</a></h2>
1594 <table class="directive">
1595 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to matched
1597 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Files <var>filename</var>> ... </Files></code></td></tr>
1598 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1599 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1600 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1601 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1603 <p>The <code class="directive"><Files></code> directive
1604 limits the scope of the enclosed directives by filename. It is comparable
1605 to the <code class="directive"><a href="#directory"><Directory></a></code>
1606 and <code class="directive"><a href="#location"><Location></a></code>
1607 directives. It should be matched with a <code></Files></code>
1608 directive. The directives given within this section will be applied to
1609 any object with a basename (last component of filename) matching the
1610 specified filename. <code class="directive"><Files></code>
1611 sections are processed in the order they appear in the
1612 configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1613 <code>.htaccess</code> files are read, but before <code class="directive"><a href="#location"><Location></a></code> sections. Note
1614 that <code class="directive"><Files></code> can be nested
1615 inside <code class="directive"><a href="#directory"><Directory></a></code> sections to restrict the
1616 portion of the filesystem they apply to.</p>
1618 <p>The <var>filename</var> argument should include a filename, or
1619 a wild-card string, where <code>?</code> matches any single character,
1620 and <code>*</code> matches any sequences of characters.
1621 <a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a>
1622 can also be used, with the addition of the
1623 <code>~</code> character. For example:</p>
1625 <div class="example"><p><code>
1626 <Files ~ "\.(gif|jpe?g|png)$">
1629 <p>would match most common Internet graphics formats. <code class="directive"><a href="#filesmatch"><FilesMatch></a></code> is preferred,
1632 <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
1633 <code>.htaccess</code> files. This allows users to control access to
1634 their own files, at a file-by-file level.</p>
1639 <li><a href="../sections.html">How <Directory>, <Location>
1640 and <Files> sections work</a> for an explanation of how these
1641 different sections are combined when a request is received</li>
1644 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1645 <div class="directive-section"><h2><a name="FilesMatch" id="FilesMatch"><FilesMatch></a> <a name="filesmatch" id="filesmatch">Directive</a></h2>
1646 <table class="directive">
1647 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to regular-expression matched
1649 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><FilesMatch <var>regex</var>> ... </FilesMatch></code></td></tr>
1650 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1651 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1652 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1653 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1655 <p>The <code class="directive"><FilesMatch></code> directive
1656 limits the scope of the enclosed directives by filename, just as the
1657 <code class="directive"><a href="#files"><Files></a></code> directive
1658 does. However, it accepts a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular
1659 expression</a>. For example:</p>
1661 <div class="example"><p><code>
1662 <FilesMatch "\.(gif|jpe?g|png)$">
1665 <p>would match most common Internet graphics formats.</p>
1669 <li><a href="../sections.html">How <Directory>, <Location>
1670 and <Files> sections work</a> for an explanation of how these
1671 different sections are combined when a request is received</li>
1674 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1675 <div class="directive-section"><h2><a name="ForceType" id="ForceType">ForceType</a> <a name="forcetype" id="forcetype">Directive</a></h2>
1676 <table class="directive">
1677 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be served with the specified
1678 media type in the HTTP Content-Type header field</td></tr>
1679 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ForceType <var>media-type</var>|None</code></td></tr>
1680 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1681 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1682 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1683 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1684 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved to the core in Apache httpd 2.0</td></tr>
1686 <p>When placed into an <code>.htaccess</code> file or a
1687 <code class="directive"><a href="#directory"><Directory></a></code>, or
1688 <code class="directive"><a href="#location"><Location></a></code> or
1689 <code class="directive"><a href="#files"><Files></a></code>
1690 section, this directive forces all matching files to be served
1691 with the content type identification given by
1692 <var>media-type</var>. For example, if you had a directory full of
1693 GIF files, but did not want to label them all with <code>.gif</code>,
1694 you might want to use:</p>
1696 <div class="example"><p><code>
1700 <p>Note that this directive overrides other indirect media type
1701 associations defined in mime.types or via the
1702 <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code>.</p>
1704 <p>You can also override more general
1705 <code class="directive">ForceType</code> settings
1706 by using the value of <code>None</code>:</p>
1708 <div class="example"><p><code>
1709 # force all files to be image/gif:<br />
1710 <Location /images><br />
1711 <span class="indent">
1712 ForceType image/gif<br />
1714 </Location><br />
1716 # but normal mime-type associations here:<br />
1717 <Location /images/mixed><br />
1718 <span class="indent">
1719 ForceType None<br />
1724 <p>This directive primarily overrides the content types generated for
1725 static files served out of the filesystem. For resources other than
1726 static files, where the generator of the response typically specifies
1727 a Content-Type, this directive has no effect.</p>
1731 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1732 <div class="directive-section"><h2><a name="GprofDir" id="GprofDir">GprofDir</a> <a name="gprofdir" id="gprofdir">Directive</a></h2>
1733 <table class="directive">
1734 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory to write gmon.out profiling data to. </td></tr>
1735 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>GprofDir <var>/tmp/gprof/</var>|<var>/tmp/gprof/</var>%</code></td></tr>
1736 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1737 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1738 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1740 <p>When the server has been compiled with gprof profiling suppport,
1741 <code class="directive">GprofDir</code> causes <code>gmon.out</code> files to
1742 be written to the specified directory when the process exits. If the
1743 argument ends with a percent symbol ('%'), subdirectories are created
1744 for each process id.</p>
1746 <p>This directive currently only works with the <code class="module"><a href="../mod/prefork.html">prefork</a></code>
1750 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1751 <div class="directive-section"><h2><a name="HostnameLookups" id="HostnameLookups">HostnameLookups</a> <a name="hostnamelookups" id="hostnamelookups">Directive</a></h2>
1752 <table class="directive">
1753 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables DNS lookups on client IP addresses</td></tr>
1754 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HostnameLookups On|Off|Double</code></td></tr>
1755 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>HostnameLookups Off</code></td></tr>
1756 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1757 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1758 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1760 <p>This directive enables DNS lookups so that host names can be
1761 logged (and passed to CGIs/SSIs in <code>REMOTE_HOST</code>).
1762 The value <code>Double</code> refers to doing double-reverse
1763 DNS lookup. That is, after a reverse lookup is performed, a forward
1764 lookup is then performed on that result. At least one of the IP
1765 addresses in the forward lookup must match the original
1766 address. (In "tcpwrappers" terminology this is called
1767 <code>PARANOID</code>.)</p>
1769 <p>Regardless of the setting, when <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code> is
1770 used for controlling access by hostname, a double reverse lookup
1771 will be performed. This is necessary for security. Note that the
1772 result of this double-reverse isn't generally available unless you
1773 set <code>HostnameLookups Double</code>. For example, if only
1774 <code>HostnameLookups On</code> and a request is made to an object
1775 that is protected by hostname restrictions, regardless of whether
1776 the double-reverse fails or not, CGIs will still be passed the
1777 single-reverse result in <code>REMOTE_HOST</code>.</p>
1779 <p>The default is <code>Off</code> in order to save the network
1780 traffic for those sites that don't truly need the reverse
1781 lookups done. It is also better for the end users because they
1782 don't have to suffer the extra latency that a lookup entails.
1783 Heavily loaded sites should leave this directive
1784 <code>Off</code>, since DNS lookups can take considerable
1785 amounts of time. The utility <code class="program"><a href="../programs/logresolve.html">logresolve</a></code>, compiled by
1786 default to the <code>bin</code> subdirectory of your installation
1787 directory, can be used to look up host names from logged IP addresses
1791 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1792 <div class="directive-section"><h2><a name="If" id="If"><If></a> <a name="if" id="if">Directive</a></h2>
1793 <table class="directive">
1794 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only if a condition is
1795 satisfied by a request at runtime</td></tr>
1796 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><If <var>expression</var>> ... </If></code></td></tr>
1797 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1798 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1799 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1800 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1802 <p>The <code class="directive"><If></code> directive
1803 evaluates an expression at runtime, and applies the enclosed
1804 directives if and only if the expression evaluates to true.
1807 <div class="example"><p><code>
1808 <If "-z req('Host')">
1811 <p>would match HTTP/1.0 requests without a <var>Host:</var> header.
1812 Expressions may contain various shell-like operators for string
1813 comparison (<code>=</code>, <code>!=</code>, <code><</code>, ...),
1814 integer comparison (<code>-eq</code>, <code>-ne</code>, ...),
1815 and others (<code>-n</code>, <code>-z</code>, <code>-f</code>, ...).
1816 It is also possible to use regular expressions, </p>
1818 <div class="example"><p><code>
1819 <If "%{QUERY_STRING} =~ /(delete|commit)=.*?elem/">
1822 <p>shell-like pattern matches and many other operations. These operations
1823 can be done on request headers (<code>req</code>), environment variables
1824 (<code>env</code>), and a large number of other properties. The full
1825 documentation is available in <a href="../expr.html">Expressions in
1826 Apache HTTP Server</a>.</p>
1831 <li><a href="../expr.html">Expressions in Apache HTTP Server</a>,
1832 for a complete reference and more examples.</li>
1833 <li><code class="directive"><a href="#elseif"><ElseIf></a></code></li>
1834 <li><code class="directive"><a href="#else"><Else></a></code></li>
1835 <li><a href="../sections.html">How <Directory>, <Location>,
1836 <Files> sections work</a> for an explanation of how these
1837 different sections are combined when a request is received.
1838 <code class="directive"><If></code>,
1839 <code class="directive"><ElseIf></code>, and
1840 <code class="directive"><Else></code> are applied last.</li>
1843 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1844 <div class="directive-section"><h2><a name="IfDefine" id="IfDefine"><IfDefine></a> <a name="ifdefine" id="ifdefine">Directive</a></h2>
1845 <table class="directive">
1846 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that will be processed only
1847 if a test is true at startup</td></tr>
1848 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfDefine [!]<var>parameter-name</var>> ...
1849 </IfDefine></code></td></tr>
1850 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1851 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1852 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1853 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1855 <p>The <code><IfDefine <var>test</var>>...</IfDefine>
1856 </code> section is used to mark directives that are conditional. The
1857 directives within an <code class="directive"><IfDefine></code>
1858 section are only processed if the <var>test</var> is true. If <var>
1859 test</var> is false, everything between the start and end markers is
1862 <p>The <var>test</var> in the <code class="directive"><IfDefine></code> section directive can be one of two forms:</p>
1865 <li><var>parameter-name</var></li>
1867 <li><code>!</code><var>parameter-name</var></li>
1870 <p>In the former case, the directives between the start and end
1871 markers are only processed if the parameter named
1872 <var>parameter-name</var> is defined. The second format reverses
1873 the test, and only processes the directives if
1874 <var>parameter-name</var> is <strong>not</strong> defined.</p>
1876 <p>The <var>parameter-name</var> argument is a define as given on the
1877 <code class="program"><a href="../programs/httpd.html">httpd</a></code> command line via <code>-D<var>parameter</var>
1878 </code> at the time the server was started or by the <code class="directive"><a href="#define">Define</a></code> directive.</p>
1880 <p><code class="directive"><IfDefine></code> sections are
1881 nest-able, which can be used to implement simple
1882 multiple-parameter tests. Example:</p>
1884 <div class="example"><p><code>
1885 httpd -DReverseProxy -DUseCache -DMemCache ...<br />
1888 <IfDefine ReverseProxy><br />
1889 <span class="indent">
1890 LoadModule proxy_module modules/mod_proxy.so<br />
1891 LoadModule proxy_http_module modules/mod_proxy_http.so<br />
1892 <IfDefine UseCache><br />
1893 <span class="indent">
1894 LoadModule cache_module modules/mod_cache.so<br />
1895 <IfDefine MemCache><br />
1896 <span class="indent">
1897 LoadModule mem_cache_module modules/mod_mem_cache.so<br />
1899 </IfDefine><br />
1900 <IfDefine !MemCache><br />
1901 <span class="indent">
1902 LoadModule cache_disk_module modules/mod_cache_disk.so<br />
1912 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1913 <div class="directive-section"><h2><a name="IfModule" id="IfModule"><IfModule></a> <a name="ifmodule" id="ifmodule">Directive</a></h2>
1914 <table class="directive">
1915 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that are processed conditional on the
1916 presence or absence of a specific module</td></tr>
1917 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfModule [!]<var>module-file</var>|<var>module-identifier</var>> ...
1918 </IfModule></code></td></tr>
1919 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1920 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</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>
1923 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Module identifiers are available in version 2.1 and
1926 <p>The <code><IfModule <var>test</var>>...</IfModule></code>
1927 section is used to mark directives that are conditional on the presence of
1928 a specific module. The directives within an <code class="directive"><IfModule></code> section are only processed if the <var>test</var>
1929 is true. If <var>test</var> is false, everything between the start and
1930 end markers is ignored.</p>
1932 <p>The <var>test</var> in the <code class="directive"><IfModule></code> section directive can be one of two forms:</p>
1935 <li><var>module</var></li>
1937 <li>!<var>module</var></li>
1940 <p>In the former case, the directives between the start and end
1941 markers are only processed if the module named <var>module</var>
1942 is included in Apache httpd -- either compiled in or
1943 dynamically loaded using <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>. The second format reverses the test,
1944 and only processes the directives if <var>module</var> is
1945 <strong>not</strong> included.</p>
1947 <p>The <var>module</var> argument can be either the module identifier or
1948 the file name of the module, at the time it was compiled. For example,
1949 <code>rewrite_module</code> is the identifier and
1950 <code>mod_rewrite.c</code> is the file name. If a module consists of
1951 several source files, use the name of the file containing the string
1952 <code>STANDARD20_MODULE_STUFF</code>.</p>
1954 <p><code class="directive"><IfModule></code> sections are
1955 nest-able, which can be used to implement simple multiple-module
1958 <div class="note">This section should only be used if you need to have one
1959 configuration file that works whether or not a specific module
1960 is available. In normal operation, directives need not be
1961 placed in <code class="directive"><IfModule></code>
1965 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1966 <div class="directive-section"><h2><a name="Include" id="Include">Include</a> <a name="include" id="include">Directive</a></h2>
1967 <table class="directive">
1968 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Includes other configuration files from within
1969 the server configuration files</td></tr>
1970 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Include [<var>optional</var>|<var>strict</var>] <var>file-path</var>|<var>directory-path</var>|<var>wildcard</var></code></td></tr>
1971 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1972 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1973 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1974 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Wildcard matching available in 2.0.41 and later, directory
1975 wildcard matching available in 2.3.6 and later</td></tr>
1977 <p>This directive allows inclusion of other configuration files
1978 from within the server configuration files.</p>
1980 <p>Shell-style (<code>fnmatch()</code>) wildcard characters can be used
1981 in the filename or directory parts of the path to include several files
1982 at once, in alphabetical order. In addition, if
1983 <code class="directive">Include</code> points to a directory, rather than a file,
1984 Apache httpd will read all files in that directory and any subdirectory.
1985 However, including entire directories is not recommended, because it is
1986 easy to accidentally leave temporary files in a directory that can cause
1987 <code class="program"><a href="../programs/httpd.html">httpd</a></code> to fail. Instead, we encourage you to use the
1988 wildcard syntax shown below, to include files that match a particular
1989 pattern, such as *.conf, for example.</p>
1991 <p>When a wildcard is specified for a <strong>file</strong> component of
1992 the path, and no file matches the wildcard, the
1993 <code class="directive"><a href="#include">Include</a></code>
1994 directive will be <strong>silently ignored</strong>. When a wildcard is
1995 specified for a <strong>directory</strong> component of the path, and
1996 no directory matches the wildcard, the
1997 <code class="directive"><a href="#include">Include</a></code> directive will
1998 <strong>fail with an error</strong> saying the directory cannot be found.
2001 <p>For further control over the behaviour of the server when no files or
2002 directories match, prefix the path with the modifiers <var>optional</var>
2003 or <var>strict</var>. If <var>optional</var> is specified, any wildcard
2004 file or directory that does not match will be silently ignored. If
2005 <var>strict</var> is specified, any wildcard file or directory that does
2006 not match at least one file will cause server startup to fail.</p>
2008 <p>When a directory or file component of the path is
2009 specified exactly, and that directory or file does not exist,
2010 <code class="directive"><a href="#include">Include</a></code> directive will fail with an
2011 error saying the file or directory cannot be found.</p>
2013 <p>The file path specified may be an absolute path, or may be relative
2014 to the <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory.</p>
2018 <div class="example"><p><code>
2019 Include /usr/local/apache2/conf/ssl.conf<br />
2020 Include /usr/local/apache2/conf/vhosts/*.conf
2023 <p>Or, providing paths relative to your <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory:</p>
2025 <div class="example"><p><code>
2026 Include conf/ssl.conf<br />
2027 Include conf/vhosts/*.conf
2030 <p>Wildcards may be included in the directory or file portion of the
2031 path. In the following example, the server will fail to load if no
2032 directories match conf/vhosts/*, but will load successfully if no
2033 files match *.conf.</p>
2035 <div class="example"><p><code>
2036 Include conf/vhosts/*/vhost.conf<br />
2037 Include conf/vhosts/*/*.conf
2040 <p>In this example, the server will fail to load if either
2041 conf/vhosts/* matches no directories, or if *.conf matches no files:</p>
2043 <div class="example"><p><code>
2044 Include strict conf/vhosts/*/*.conf
2047 <p>In this example, the server load successfully if either conf/vhosts/*
2048 matches no directories, or if *.conf matches no files:</p>
2050 <div class="example"><p><code>
2051 Include optional conf/vhosts/*/*.conf
2057 <li><code class="program"><a href="../programs/apachectl.html">apachectl</a></code></li>
2060 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2061 <div class="directive-section"><h2><a name="KeepAlive" id="KeepAlive">KeepAlive</a> <a name="keepalive" id="keepalive">Directive</a></h2>
2062 <table class="directive">
2063 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables HTTP persistent connections</td></tr>
2064 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAlive On|Off</code></td></tr>
2065 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAlive On</code></td></tr>
2066 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2067 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2068 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2070 <p>The Keep-Alive extension to HTTP/1.0 and the persistent
2071 connection feature of HTTP/1.1 provide long-lived HTTP sessions
2072 which allow multiple requests to be sent over the same TCP
2073 connection. In some cases this has been shown to result in an
2074 almost 50% speedup in latency times for HTML documents with
2075 many images. To enable Keep-Alive connections, set
2076 <code>KeepAlive On</code>.</p>
2078 <p>For HTTP/1.0 clients, Keep-Alive connections will only be
2079 used if they are specifically requested by a client. In
2080 addition, a Keep-Alive connection with an HTTP/1.0 client can
2081 only be used when the length of the content is known in
2082 advance. This implies that dynamic content such as CGI output,
2083 SSI pages, and server-generated directory listings will
2084 generally not use Keep-Alive connections to HTTP/1.0 clients.
2085 For HTTP/1.1 clients, persistent connections are the default
2086 unless otherwise specified. If the client requests it, chunked
2087 encoding will be used in order to send content of unknown
2088 length over persistent connections.</p>
2090 <p>When a client uses a Keep-Alive connection it will be counted
2091 as a single "request" for the <code class="directive"><a href="../mod/mpm_common.html#maxconnectionsperchild">MaxConnectionsPerChild</a></code> directive, regardless
2092 of how many requests are sent using the connection.</p>
2096 <li><code class="directive"><a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></code></li>
2099 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2100 <div class="directive-section"><h2><a name="KeepAliveTimeout" id="KeepAliveTimeout">KeepAliveTimeout</a> <a name="keepalivetimeout" id="keepalivetimeout">Directive</a></h2>
2101 <table class="directive">
2102 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for subsequent
2103 requests on a persistent connection</td></tr>
2104 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAliveTimeout <var>num</var>[ms]</code></td></tr>
2105 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAliveTimeout 5</code></td></tr>
2106 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2107 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2108 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2109 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Specifying a value in milliseconds is available in
2110 Apache httpd 2.3.2 and later</td></tr>
2112 <p>The number of seconds Apache httpd will wait for a subsequent
2113 request before closing the connection. By adding a postfix of ms the
2114 timeout can be also set in milliseconds. Once a request has been
2115 received, the timeout value specified by the
2116 <code class="directive"><a href="#timeout">Timeout</a></code> directive applies.</p>
2118 <p>Setting <code class="directive">KeepAliveTimeout</code> to a high value
2119 may cause performance problems in heavily loaded servers. The
2120 higher the timeout, the more server processes will be kept
2121 occupied waiting on connections with idle clients.</p>
2123 <p>In a name-based virtual host context, the value of the first
2124 defined virtual host best matching the local IP and port will be used.</p>
2127 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2128 <div class="directive-section"><h2><a name="Limit" id="Limit"><Limit></a> <a name="limit" id="limit">Directive</a></h2>
2129 <table class="directive">
2130 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict enclosed access controls to only certain HTTP
2132 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Limit <var>method</var> [<var>method</var>] ... > ...
2133 </Limit></code></td></tr>
2134 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
2135 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig, Limit</td></tr>
2136 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2137 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2139 <p>Access controls are normally effective for
2140 <strong>all</strong> access methods, and this is the usual
2141 desired behavior. <strong>In the general case, access control
2142 directives should not be placed within a
2143 <code class="directive"><Limit></code> section.</strong></p>
2145 <p>The purpose of the <code class="directive"><Limit></code>
2146 directive is to restrict the effect of the access controls to the
2147 nominated HTTP methods. For all other methods, the access
2148 restrictions that are enclosed in the <code class="directive"><Limit></code> bracket <strong>will have no
2149 effect</strong>. The following example applies the access control
2150 only to the methods <code>POST</code>, <code>PUT</code>, and
2151 <code>DELETE</code>, leaving all other methods unprotected:</p>
2153 <div class="example"><p><code>
2154 <Limit POST PUT DELETE><br />
2155 <span class="indent">
2156 Require valid-user<br />
2161 <p>The method names listed can be one or more of: <code>GET</code>,
2162 <code>POST</code>, <code>PUT</code>, <code>DELETE</code>,
2163 <code>CONNECT</code>, <code>OPTIONS</code>,
2164 <code>PATCH</code>, <code>PROPFIND</code>, <code>PROPPATCH</code>,
2165 <code>MKCOL</code>, <code>COPY</code>, <code>MOVE</code>,
2166 <code>LOCK</code>, and <code>UNLOCK</code>. <strong>The method name is
2167 case-sensitive.</strong> If <code>GET</code> is used it will also
2168 restrict <code>HEAD</code> requests. The <code>TRACE</code> method
2169 cannot be limited (see <code class="directive"><a href="#traceenable">TraceEnable</a></code>).</p>
2171 <div class="warning">A <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section should always be
2172 used in preference to a <code class="directive"><Limit></code>
2173 section when restricting access, since a <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section provides protection
2174 against arbitrary methods.</div>
2176 <p>The <code class="directive"><Limit></code> and
2177 <code class="directive"><a href="#limitexcept"><LimitExcept></a></code>
2178 directives may be nested. In this case, each successive level of
2179 <code class="directive"><Limit></code> or <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> directives must
2180 further restrict the set of methods to which access controls apply.</p>
2182 <div class="warning">When using
2183 <code class="directive"><Limit></code> or
2184 <code class="directive"><LimitExcept></code> directives with
2185 the <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directive,
2186 note that the first <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code>
2187 to succeed authorizes the request, regardless of the presence of other
2188 <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directives.</div>
2190 <p>For example, given the following configuration, all users will
2191 be authorized for <code>POST</code> requests, and the
2192 <code>Require group editors</code> directive will be ignored
2195 <div class="example"><p><code>
2196 <LimitExcept GET>
2197 <span class="indent">
2200 </LimitExcept><br />
2202 <span class="indent">
2203 Require group editors
2209 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2210 <div class="directive-section"><h2><a name="LimitExcept" id="LimitExcept"><LimitExcept></a> <a name="limitexcept" id="limitexcept">Directive</a></h2>
2211 <table class="directive">
2212 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict access controls to all HTTP methods
2213 except the named ones</td></tr>
2214 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LimitExcept <var>method</var> [<var>method</var>] ... > ...
2215 </LimitExcept></code></td></tr>
2216 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
2217 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig, Limit</td></tr>
2218 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2219 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2221 <p><code class="directive"><LimitExcept></code> and
2222 <code></LimitExcept></code> are used to enclose
2223 a group of access control directives which will then apply to any
2224 HTTP access method <strong>not</strong> listed in the arguments;
2225 i.e., it is the opposite of a <code class="directive"><a href="#limit"><Limit></a></code> section and can be used to control
2226 both standard and nonstandard/unrecognized methods. See the
2227 documentation for <code class="directive"><a href="#limit"><Limit></a></code> for more details.</p>
2231 <div class="example"><p><code>
2232 <LimitExcept POST GET><br />
2233 <span class="indent">
2234 Require valid-user<br />
2236 </LimitExcept>
2241 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2242 <div class="directive-section"><h2><a name="LimitInternalRecursion" id="LimitInternalRecursion">LimitInternalRecursion</a> <a name="limitinternalrecursion" id="limitinternalrecursion">Directive</a></h2>
2243 <table class="directive">
2244 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine maximum number of internal redirects and nested
2245 subrequests</td></tr>
2246 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitInternalRecursion <var>number</var> [<var>number</var>]</code></td></tr>
2247 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitInternalRecursion 10</code></td></tr>
2248 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2249 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2250 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2251 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.0.47 and later</td></tr>
2253 <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
2254 redirects the original request to a CGI script. A subrequest is Apache httpd's
2255 mechanism to find out what would happen for some URI if it were requested.
2256 For example, <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> uses subrequests to look for the
2257 files listed in the <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
2260 <p><code class="directive">LimitInternalRecursion</code> prevents the server
2261 from crashing when entering an infinite loop of internal redirects or
2262 subrequests. Such loops are usually caused by misconfigurations.</p>
2264 <p>The directive stores two different limits, which are evaluated on
2265 per-request basis. The first <var>number</var> is the maximum number of
2266 internal redirects, that may follow each other. The second <var>number</var>
2267 determines, how deep subrequests may be nested. If you specify only one
2268 <var>number</var>, it will be assigned to both limits.</p>
2270 <div class="example"><h3>Example</h3><p><code>
2271 LimitInternalRecursion 5
2275 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2276 <div class="directive-section"><h2><a name="LimitRequestBody" id="LimitRequestBody">LimitRequestBody</a> <a name="limitrequestbody" id="limitrequestbody">Directive</a></h2>
2277 <table class="directive">
2278 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restricts the total size of the HTTP request body sent
2279 from the client</td></tr>
2280 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestBody <var>bytes</var></code></td></tr>
2281 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestBody 0</code></td></tr>
2282 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2283 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2284 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2285 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2287 <p>This directive specifies the number of <var>bytes</var> from 0
2288 (meaning unlimited) to 2147483647 (2GB) that are allowed in a
2289 request body. See the note below for the limited applicability
2290 to proxy requests.</p>
2292 <p>The <code class="directive">LimitRequestBody</code> directive allows
2293 the user to set a limit on the allowed size of an HTTP request
2294 message body within the context in which the directive is given
2295 (server, per-directory, per-file or per-location). If the client
2296 request exceeds that limit, the server will return an error
2297 response instead of servicing the request. The size of a normal
2298 request message body will vary greatly depending on the nature of
2299 the resource and the methods allowed on that resource. CGI scripts
2300 typically use the message body for retrieving form information.
2301 Implementations of the <code>PUT</code> method will require
2302 a value at least as large as any representation that the server
2303 wishes to accept for that resource.</p>
2305 <p>This directive gives the server administrator greater
2306 control over abnormal client request behavior, which may be
2307 useful for avoiding some forms of denial-of-service
2310 <p>If, for example, you are permitting file upload to a particular
2311 location, and wish to limit the size of the uploaded file to 100K,
2312 you might use the following directive:</p>
2314 <div class="example"><p><code>
2315 LimitRequestBody 102400
2318 <div class="note"><p>For a full description of how this directive is interpreted by
2319 proxy requests, see the <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> documentation.</p>
2324 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2325 <div class="directive-section"><h2><a name="LimitRequestFields" id="LimitRequestFields">LimitRequestFields</a> <a name="limitrequestfields" id="limitrequestfields">Directive</a></h2>
2326 <table class="directive">
2327 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of HTTP request header fields that
2328 will be accepted from the client</td></tr>
2329 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFields <var>number</var></code></td></tr>
2330 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFields 100</code></td></tr>
2331 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2332 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2333 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2335 <p><var>Number</var> is an integer from 0 (meaning unlimited) to
2336 32767. The default value is defined by the compile-time
2337 constant <code>DEFAULT_LIMIT_REQUEST_FIELDS</code> (100 as
2340 <p>The <code class="directive">LimitRequestFields</code> directive allows
2341 the server administrator to modify the limit on the number of
2342 request header fields allowed in an HTTP request. A server needs
2343 this value to be larger than the number of fields that a normal
2344 client request might include. The number of request header fields
2345 used by a client rarely exceeds 20, but this may vary among
2346 different client implementations, often depending upon the extent
2347 to which a user has configured their browser to support detailed
2348 content negotiation. Optional HTTP extensions are often expressed
2349 using request header fields.</p>
2351 <p>This directive gives the server administrator greater
2352 control over abnormal client request behavior, which may be
2353 useful for avoiding some forms of denial-of-service attacks.
2354 The value should be increased if normal clients see an error
2355 response from the server that indicates too many fields were
2356 sent in the request.</p>
2360 <div class="example"><p><code>
2361 LimitRequestFields 50
2364 <div class="warning"><h3>Warning</h3>
2365 <p> When name-based virtual hosting is used, the value for this
2366 directive is taken from the default (first-listed) virtual host for the
2367 local IP and port combination</p>.
2372 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2373 <div class="directive-section"><h2><a name="LimitRequestFieldSize" id="LimitRequestFieldSize">LimitRequestFieldSize</a> <a name="limitrequestfieldsize" id="limitrequestfieldsize">Directive</a></h2>
2374 <table class="directive">
2375 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of the HTTP request header allowed from the
2377 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFieldSize <var>bytes</var></code></td></tr>
2378 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFieldSize 8190</code></td></tr>
2379 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2380 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2381 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2383 <p>This directive specifies the number of <var>bytes</var>
2384 that will be allowed in an HTTP request header.</p>
2386 <p>The <code class="directive">LimitRequestFieldSize</code> directive
2387 allows the server administrator to reduce or increase the limit
2388 on the allowed size of an HTTP request header field. A server
2389 needs this value to be large enough to hold any one header field
2390 from a normal client request. The size of a normal request header
2391 field will vary greatly among different client implementations,
2392 often depending upon the extent to which a user has configured
2393 their browser to support detailed content negotiation. SPNEGO
2394 authentication headers can be up to 12392 bytes.</p>
2396 <p>This directive gives the server administrator greater
2397 control over abnormal client request behavior, which may be
2398 useful for avoiding some forms of denial-of-service attacks.</p>
2402 <div class="example"><p><code>
2403 LimitRequestFieldSize 4094
2406 <div class="note">Under normal conditions, the value should not be changed from
2409 <div class="warning"><h3>Warning</h3>
2410 <p> When name-based virtual hosting is used, the value for this
2411 directive is taken from the default (first-listed) virtual host best
2412 matching the current IP address and port combination.</p>
2416 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2417 <div class="directive-section"><h2><a name="LimitRequestLine" id="LimitRequestLine">LimitRequestLine</a> <a name="limitrequestline" id="limitrequestline">Directive</a></h2>
2418 <table class="directive">
2419 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limit the size of the HTTP request line that will be accepted
2420 from the client</td></tr>
2421 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestLine <var>bytes</var></code></td></tr>
2422 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestLine 8190</code></td></tr>
2423 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2424 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2425 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2427 <p>This directive sets the number of <var>bytes</var> that will be
2428 allowed on the HTTP request-line.</p>
2430 <p>The <code class="directive">LimitRequestLine</code> directive allows
2431 the server administrator to reduce or increase the limit on the allowed size
2432 of a client's HTTP request-line. Since the request-line consists of the
2433 HTTP method, URI, and protocol version, the
2434 <code class="directive">LimitRequestLine</code> directive places a
2435 restriction on the length of a request-URI allowed for a request
2436 on the server. A server needs this value to be large enough to
2437 hold any of its resource names, including any information that
2438 might be passed in the query part of a <code>GET</code> request.</p>
2440 <p>This directive gives the server administrator greater
2441 control over abnormal client request behavior, which may be
2442 useful for avoiding some forms of denial-of-service attacks.</p>
2446 <div class="example"><p><code>
2447 LimitRequestLine 4094
2450 <div class="note">Under normal conditions, the value should not be changed from
2453 <div class="warning"><h3>Warning</h3>
2454 <p> When name-based virtual hosting is used, the value for this
2455 directive is taken from the default (first-listed) virtual host best
2456 matching the current IP address and port combination.</p>
2461 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2462 <div class="directive-section"><h2><a name="LimitXMLRequestBody" id="LimitXMLRequestBody">LimitXMLRequestBody</a> <a name="limitxmlrequestbody" id="limitxmlrequestbody">Directive</a></h2>
2463 <table class="directive">
2464 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of an XML-based request body</td></tr>
2465 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitXMLRequestBody <var>bytes</var></code></td></tr>
2466 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitXMLRequestBody 1000000</code></td></tr>
2467 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2468 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2469 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2470 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2472 <p>Limit (in bytes) on maximum size of an XML-based request
2473 body. A value of <code>0</code> will disable any checking.</p>
2477 <div class="example"><p><code>
2478 LimitXMLRequestBody 0
2483 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2484 <div class="directive-section"><h2><a name="Location" id="Location"><Location></a> <a name="location" id="location">Directive</a></h2>
2485 <table class="directive">
2486 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to matching
2488 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Location
2489 <var>URL-path</var>|<var>URL</var>> ... </Location></code></td></tr>
2490 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2491 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2492 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2494 <p>The <code class="directive"><Location></code> directive
2495 limits the scope of the enclosed directives by URL. It is similar to the
2496 <code class="directive"><a href="#directory"><Directory></a></code>
2497 directive, and starts a subsection which is terminated with a
2498 <code></Location></code> directive. <code class="directive"><Location></code> sections are processed in the
2499 order they appear in the configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
2500 <code>.htaccess</code> files are read, and after the <code class="directive"><a href="#files"><Files></a></code> sections.</p>
2502 <p><code class="directive"><Location></code> sections operate
2503 completely outside the filesystem. This has several consequences.
2504 Most importantly, <code class="directive"><Location></code>
2505 directives should not be used to control access to filesystem
2506 locations. Since several different URLs may map to the same
2507 filesystem location, such access controls may by circumvented.</p>
2509 <p>The enclosed directives will be applied to the request if the path component
2510 of the URL meets <em>any</em> of the following criteria:
2513 <li>The specified location matches exactly the path component of the URL.
2515 <li>The specified location, which ends in a forward slash, is a prefix
2516 of the path component of the URL (treated as a context root).
2518 <li>The specified location, with the addition of a trailing slash, is a
2519 prefix of the path component of the URL (also treated as a context root).
2523 In the example below, where no trailing slash is used, requests to
2524 /private1, /private1/ and /private1/file.txt will have the enclosed
2525 directives applied, but /private1other would not.
2527 <div class="example"><p><code>
2528 <Location /private1>
2532 In the example below, where a trailing slash is used, requests to
2533 /private2/ and /private2/file.txt will have the enclosed
2534 directives applied, but /private2 and /private2other would not.
2536 <div class="example"><p><code>
2537 <Location /private2<em>/</em>>
2541 <div class="note"><h3>When to use <code class="directive"><Location></code></h3>
2543 <p>Use <code class="directive"><Location></code> to apply
2544 directives to content that lives outside the filesystem. For
2545 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
2546 <code><Location /></code>, which is an easy way to
2547 apply a configuration to the entire server.</p>
2550 <p>For all origin (non-proxy) requests, the URL to be matched is a
2551 URL-path of the form <code>/path/</code>. <em>No scheme, hostname,
2552 port, or query string may be included.</em> For proxy requests, the
2553 URL to be matched is of the form
2554 <code>scheme://servername/path</code>, and you must include the
2557 <p>The URL may use wildcards. In a wild-card string, <code>?</code> matches
2558 any single character, and <code>*</code> matches any sequences of
2559 characters. Neither wildcard character matches a / in the URL-path.</p>
2561 <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a>
2562 can also be used, with the addition of the <code>~</code>
2563 character. For example:</p>
2565 <div class="example"><p><code>
2566 <Location ~ "/(extra|special)/data">
2569 <p>would match URLs that contained the substring <code>/extra/data</code>
2570 or <code>/special/data</code>. The directive <code class="directive"><a href="#locationmatch"><LocationMatch></a></code> behaves
2571 identical to the regex version of <code class="directive"><Location></code>, and is preferred, for the
2572 simple reason that <code>~</code> is hard to distinguish from
2573 <code>-</code> in many fonts.</p>
2575 <p>The <code class="directive"><Location></code>
2576 functionality is especially useful when combined with the
2577 <code class="directive"><a href="#sethandler">SetHandler</a></code>
2578 directive. For example, to enable status requests, but allow them
2579 only from browsers at <code>example.com</code>, you might use:</p>
2581 <div class="example"><p><code>
2582 <Location /status><br />
2583 <span class="indent">
2584 SetHandler server-status<br />
2585 Require host example.com<br />
2590 <div class="note"><h3>Note about / (slash)</h3>
2591 <p>The slash character has special meaning depending on where in a
2592 URL it appears. People may be used to its behavior in the filesystem
2593 where multiple adjacent slashes are frequently collapsed to a single
2594 slash (<em>i.e.</em>, <code>/home///foo</code> is the same as
2595 <code>/home/foo</code>). In URL-space this is not necessarily true.
2596 The <code class="directive"><a href="#locationmatch"><LocationMatch></a></code>
2597 directive and the regex version of <code class="directive"><Location></code> require you to explicitly specify multiple
2598 slashes if that is your intention.</p>
2600 <p>For example, <code><LocationMatch ^/abc></code> would match
2601 the request URL <code>/abc</code> but not the request URL <code>
2602 //abc</code>. The (non-regex) <code class="directive"><Location></code> directive behaves similarly when used for
2603 proxy requests. But when (non-regex) <code class="directive"><Location></code> is used for non-proxy requests it will
2604 implicitly match multiple slashes with a single slash. For example,
2605 if you specify <code><Location /abc/def></code> and the
2606 request is to <code>/abc//def</code> then it will match.</p>
2611 <li><a href="../sections.html">How <Directory>, <Location>
2612 and <Files> sections work</a> for an explanation of how these
2613 different sections are combined when a request is received.</li>
2614 <li><code class="directive"><a href="#locationmatch">LocationMatch</a></code></li>
2617 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2618 <div class="directive-section"><h2><a name="LocationMatch" id="LocationMatch"><LocationMatch></a> <a name="locationmatch" id="locationmatch">Directive</a></h2>
2619 <table class="directive">
2620 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to regular-expression
2621 matching URLs</td></tr>
2622 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LocationMatch
2623 <var>regex</var>> ... </LocationMatch></code></td></tr>
2624 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2625 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2626 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2628 <p>The <code class="directive"><LocationMatch></code> directive
2629 limits the scope of the enclosed directives by URL, in an identical manner
2630 to <code class="directive"><a href="#location"><Location></a></code>. However,
2631 it takes a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>
2632 as an argument instead of a simple string. For example:</p>
2634 <div class="example"><p><code>
2635 <LocationMatch "/(extra|special)/data">
2638 <p>would match URLs that contained the substring <code>/extra/data</code>
2639 or <code>/special/data</code>.</p>
2643 <li><a href="../sections.html">How <Directory>, <Location>
2644 and <Files> sections work</a> for an explanation of how these
2645 different sections are combined when a request is received</li>
2648 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2649 <div class="directive-section"><h2><a name="LogLevel" id="LogLevel">LogLevel</a> <a name="loglevel" id="loglevel">Directive</a></h2>
2650 <table class="directive">
2651 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Controls the verbosity of the ErrorLog</td></tr>
2652 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LogLevel [<var>module</var>:]<var>level</var>
2653 [<var>module</var>:<var>level</var>] ...
2655 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LogLevel warn</code></td></tr>
2656 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
2657 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2658 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2659 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Per-module and per-directory configuration is available in
2660 Apache HTTP Server 2.3.6 and later</td></tr>
2662 <p><code class="directive">LogLevel</code> adjusts the verbosity of the
2663 messages recorded in the error logs (see <code class="directive"><a href="#errorlog">ErrorLog</a></code> directive). The following
2664 <var>level</var>s are available, in order of decreasing
2667 <table class="bordered">
2670 <th><strong>Level</strong> </th>
2672 <th><strong>Description</strong> </th>
2674 <th><strong>Example</strong> </th>
2678 <td><code>emerg</code> </td>
2680 <td>Emergencies - system is unusable.</td>
2682 <td>"Child cannot open lock file. Exiting"</td>
2686 <td><code>alert</code> </td>
2688 <td>Action must be taken immediately.</td>
2690 <td>"getpwuid: couldn't determine user name from uid"</td>
2694 <td><code>crit</code> </td>
2696 <td>Critical Conditions.</td>
2698 <td>"socket: Failed to get a socket, exiting child"</td>
2702 <td><code>error</code> </td>
2704 <td>Error conditions.</td>
2706 <td>"Premature end of script headers"</td>
2710 <td><code>warn</code> </td>
2712 <td>Warning conditions.</td>
2714 <td>"child process 1234 did not exit, sending another
2719 <td><code>notice</code> </td>
2721 <td>Normal but significant condition.</td>
2723 <td>"httpd: caught SIGBUS, attempting to dump core in
2728 <td><code>info</code> </td>
2730 <td>Informational.</td>
2732 <td>"Server seems busy, (you may need to increase
2733 StartServers, or Min/MaxSpareServers)..."</td>
2737 <td><code>debug</code> </td>
2739 <td>Debug-level messages</td>
2741 <td>"Opening config file ..."</td>
2744 <td><code>trace1</code> </td>
2746 <td>Trace messages</td>
2748 <td>"proxy: FTP: control connection complete"</td>
2751 <td><code>trace2</code> </td>
2753 <td>Trace messages</td>
2755 <td>"proxy: CONNECT: sending the CONNECT request to the remote proxy"</td>
2758 <td><code>trace3</code> </td>
2760 <td>Trace messages</td>
2762 <td>"openssl: Handshake: start"</td>
2765 <td><code>trace4</code> </td>
2767 <td>Trace messages</td>
2769 <td>"read from buffered SSL brigade, mode 0, 17 bytes"</td>
2772 <td><code>trace5</code> </td>
2774 <td>Trace messages</td>
2776 <td>"map lookup FAILED: map=rewritemap key=keyname"</td>
2779 <td><code>trace6</code> </td>
2781 <td>Trace messages</td>
2783 <td>"cache lookup FAILED, forcing new map lookup"</td>
2786 <td><code>trace7</code> </td>
2788 <td>Trace messages, dumping large amounts of data</td>
2790 <td>"| 0000: 02 23 44 30 13 40 ac 34 df 3d bf 9a 19 49 39 15 |"</td>
2793 <td><code>trace8</code> </td>
2795 <td>Trace messages, dumping large amounts of data</td>
2797 <td>"| 0000: 02 23 44 30 13 40 ac 34 df 3d bf 9a 19 49 39 15 |"</td>
2801 <p>When a particular level is specified, messages from all
2802 other levels of higher significance will be reported as well.
2803 <em>E.g.</em>, when <code>LogLevel info</code> is specified,
2804 then messages with log levels of <code>notice</code> and
2805 <code>warn</code> will also be posted.</p>
2807 <p>Using a level of at least <code>crit</code> is
2812 <div class="example"><p><code>
2816 <div class="note"><h3>Note</h3>
2817 <p>When logging to a regular file messages of the level
2818 <code>notice</code> cannot be suppressed and thus are always
2819 logged. However, this doesn't apply when logging is done
2820 using <code>syslog</code>.</p>
2823 <p>Specifying a level without a module name will reset the level
2824 for all modules to that level. Specifying a level with a module
2825 name will set the level for that module only. It is possible to
2826 use the module source file name, the module identifier, or the
2827 module identifier with the trailing <code>_module</code> omitted
2828 as module specification. This means the following three specifications
2831 <div class="example"><p><code>
2832 LogLevel info ssl:warn<br />
2833 LogLevel info mod_ssl.c:warn<br />
2834 LogLevel info ssl_module:warn<br />
2837 <p>It is also possible to change the level per directory:</p>
2839 <div class="example"><p><code>
2841 <Directory /usr/local/apache/htdocs/app><br />
2842 LogLevel debug<br />
2847 Per directory loglevel configuration only affects messages that are
2848 logged after the request has been parsed and that are associated with
2849 the request. Log messages which are associated with the connection or
2850 the server are not affected.
2854 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2855 <div class="directive-section"><h2><a name="MaxKeepAliveRequests" id="MaxKeepAliveRequests">MaxKeepAliveRequests</a> <a name="maxkeepaliverequests" id="maxkeepaliverequests">Directive</a></h2>
2856 <table class="directive">
2857 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of requests allowed on a persistent
2858 connection</td></tr>
2859 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxKeepAliveRequests <var>number</var></code></td></tr>
2860 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxKeepAliveRequests 100</code></td></tr>
2861 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2862 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2863 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2865 <p>The <code class="directive">MaxKeepAliveRequests</code> directive
2866 limits the number of requests allowed per connection when
2867 <code class="directive"><a href="#keepalive">KeepAlive</a></code> is on. If it is
2868 set to <code>0</code>, unlimited requests will be allowed. We
2869 recommend that this setting be kept to a high value for maximum
2870 server performance.</p>
2874 <div class="example"><p><code>
2875 MaxKeepAliveRequests 500
2879 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2880 <div class="directive-section"><h2><a name="MaxRangeOverlaps" id="MaxRangeOverlaps">MaxRangeOverlaps</a> <a name="maxrangeoverlaps" id="maxrangeoverlaps">Directive</a></h2>
2881 <table class="directive">
2882 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of overlapping ranges (eg: <code>100-200,150-300</code>) allowed before returning the complete
2884 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxRangeOverlaps default | unlimited | none | <var>number-of-ranges</var></code></td></tr>
2885 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxRangeOverlaps 20</code></td></tr>
2886 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
2887 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2888 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2889 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache HTTP Server 2.3.15 and later</td></tr>
2891 <p>The <code class="directive">MaxRangeOverlaps</code> directive
2892 limits the number of overlapping HTTP ranges the server is willing to
2893 return to the client. If more overlapping ranges then permitted are requested,
2894 the complete resource is returned instead.</p>
2897 <dt><strong>default</strong></dt>
2898 <dd>Limits the number of overlapping ranges to a compile-time default of 20.</dd>
2900 <dt><strong>none</strong></dt>
2901 <dd>No overlapping Range headers are allowed.</dd>
2903 <dt><strong>unlimited</strong></dt>
2904 <dd>The server does not limit the number of overlapping ranges it is
2905 willing to satisfy.</dd>
2907 <dt><var>number-of-ranges</var></dt>
2908 <dd>A positive number representing the maximum number of overlapping ranges the
2909 server is willing to satisfy.</dd>
2913 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2914 <div class="directive-section"><h2><a name="MaxRangeReversals" id="MaxRangeReversals">MaxRangeReversals</a> <a name="maxrangereversals" id="maxrangereversals">Directive</a></h2>
2915 <table class="directive">
2916 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of range reversals (eg: <code>100-200,50-70</code>) allowed before returning the complete
2918 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxRangeReversals default | unlimited | none | <var>number-of-ranges</var></code></td></tr>
2919 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxRangeReversals 20</code></td></tr>
2920 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
2921 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2922 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2923 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache HTTP Server 2.3.15 and later</td></tr>
2925 <p>The <code class="directive">MaxRangeReversals</code> directive
2926 limits the number of HTTP Range reversals the server is willing to
2927 return to the client. If more ranges reversals then permitted are requested,
2928 the complete resource is returned instead.</p>
2931 <dt><strong>default</strong></dt>
2932 <dd>Limits the number of range reversals to a compile-time default of 20.</dd>
2934 <dt><strong>none</strong></dt>
2935 <dd>No Range reversals headers are allowed.</dd>
2937 <dt><strong>unlimited</strong></dt>
2938 <dd>The server does not limit the number of range reversals it is
2939 willing to satisfy.</dd>
2941 <dt><var>number-of-ranges</var></dt>
2942 <dd>A positive number representing the maximum number of range reversals the
2943 server is willing to satisfy.</dd>
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="MaxRanges" id="MaxRanges">MaxRanges</a> <a name="maxranges" id="maxranges">Directive</a></h2>
2949 <table class="directive">
2950 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of ranges allowed before returning the complete
2952 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxRanges default | unlimited | none | <var>number-of-ranges</var></code></td></tr>
2953 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxRanges 200</code></td></tr>
2954 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</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>Available in Apache HTTP Server 2.3.15 and later</td></tr>
2959 <p>The <code class="directive">MaxRanges</code> directive
2960 limits the number of HTTP ranges the server is willing to
2961 return to the client. If more ranges then permitted are requested,
2962 the complete resource is returned instead.</p>
2965 <dt><strong>default</strong></dt>
2966 <dd>Limits the number of ranges to a compile-time default of 200.</dd>
2968 <dt><strong>none</strong></dt>
2969 <dd>Range headers are ignored.</dd>
2971 <dt><strong>unlimited</strong></dt>
2972 <dd>The server does not limit the number of ranges it is
2973 willing to satisfy.</dd>
2975 <dt><var>number-of-ranges</var></dt>
2976 <dd>A positive number representing the maximum number of ranges the
2977 server is willing to satisfy.</dd>
2981 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2982 <div class="directive-section"><h2><a name="Mutex" id="Mutex">Mutex</a> <a name="mutex" id="mutex">Directive</a></h2>
2983 <table class="directive">
2984 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures mutex mechanism and lock file directory for all
2985 or specified mutexes</td></tr>
2986 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Mutex <var>mechanism</var> [default|<var>mutex-name</var>] ... [OmitPID]</code></td></tr>
2987 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Mutex default</code></td></tr>
2988 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2989 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2990 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2991 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache HTTP Server 2.3.4 and later</td></tr>
2993 <p>The <code class="directive">Mutex</code> directive sets the mechanism,
2994 and optionally the lock file location, that httpd and modules use
2995 to serialize access to resources. Specify <code>default</code> as
2996 the first argument to change the settings for all mutexes; specify
2997 a mutex name (see table below) as the first argument to override
2998 defaults only for that mutex.</p>
3000 <p>The <code class="directive">Mutex</code> directive is typically used in
3001 the following exceptional situations:</p>
3004 <li>change the mutex mechanism when the default mechanism selected
3005 by <a class="glossarylink" href="../glossary.html#apr" title="see glossary">APR</a> has a functional or performance
3008 <li>change the directory used by file-based mutexes when the
3009 default directory does not support locking</li>
3012 <div class="note"><h3>Supported modules</h3>
3013 <p>This directive only configures mutexes which have been registered
3014 with the core server using the <code>ap_mutex_register()</code> API.
3015 All modules bundled with httpd support the <code class="directive">Mutex</code>
3016 directive, but third-party modules may not. Consult the documentation
3017 of the third-party module, which must indicate the mutex name(s) which
3018 can be configured if this directive is supported.</p>
3021 <p>The following mutex <em>mechanisms</em> are available:</p>
3023 <li><code>default | yes</code>
3024 <p>This selects the default locking implementation, as determined by
3025 <a class="glossarylink" href="../glossary.html#apr" title="see glossary">APR</a>. The default locking implementation can
3026 be displayed by running <code class="program"><a href="../programs/httpd.html">httpd</a></code> with the
3027 <code>-V</code> option.</p></li>
3029 <li><code>none | no</code>
3030 <p>This effectively disables the mutex, and is only allowed for a
3031 mutex if the module indicates that it is a valid choice. Consult the
3032 module documentation for more information.</p></li>
3034 <li><code>posixsem</code>
3035 <p>This is a mutex variant based on a Posix semaphore.</p>
3037 <div class="warning"><h3>Warning</h3>
3038 <p>The semaphore ownership is not recovered if a thread in the process
3039 holding the mutex segfaults, resulting in a hang of the web server.</p>
3043 <li><code>sysvsem</code>
3044 <p>This is a mutex variant based on a SystemV IPC semaphore.</p>
3046 <div class="warning"><h3>Warning</h3>
3047 <p>It is possible to "leak" SysV semaphores if processes crash
3048 before the semaphore is removed.</p>
3051 <div class="warning"><h3>Security</h3>
3052 <p>The semaphore API allows for a denial of service attack by any
3053 CGIs running under the same uid as the webserver (<em>i.e.</em>,
3054 all CGIs, unless you use something like <code class="program"><a href="../programs/suexec.html">suexec</a></code>
3055 or <code>cgiwrapper</code>).</p>
3059 <li><code>sem</code>
3060 <p>This selects the "best" available semaphore implementation, choosing
3061 between Posix and SystemV IPC semaphores, in that order.</p></li>
3063 <li><code>pthread</code>
3064 <p>This is a mutex variant based on cross-process Posix thread
3067 <div class="warning"><h3>Warning</h3>
3068 <p>On most systems, if a child process terminates abnormally while
3069 holding a mutex that uses this implementation, the server will deadlock
3070 and stop responding to requests. When this occurs, the server will
3071 require a manual restart to recover.</p>
3072 <p>Solaris is a notable exception as it provides a mechanism which
3073 usually allows the mutex to be recovered after a child process
3074 terminates abnormally while holding a mutex.</p>
3075 <p>If your system implements the
3076 <code>pthread_mutexattr_setrobust_np()</code> function, you may be able
3077 to use the <code>pthread</code> option safely.</p>
3081 <li><code>fcntl:/path/to/mutex</code>
3082 <p>This is a mutex variant where a physical (lock-)file and the
3083 <code>fcntl()</code> function are used as the mutex.</p>
3085 <div class="warning"><h3>Warning</h3>
3086 <p>When multiple mutexes based on this mechanism are used within
3087 multi-threaded, multi-process environments, deadlock errors (EDEADLK)
3088 can be reported for valid mutex operations if <code>fcntl()</code>
3089 is not thread-aware, such as on Solaris.</p>
3093 <li><code>flock:/path/to/mutex</code>
3094 <p>This is similar to the <code>fcntl:/path/to/mutex</code> method
3095 with the exception that the <code>flock()</code> function is used to
3096 provide file locking.</p></li>
3098 <li><code>file:/path/to/mutex</code>
3099 <p>This selects the "best" available file locking implementation,
3100 choosing between <code>fcntl</code> and <code>flock</code>, in that
3104 <p>Most mechanisms are only available on selected platforms, where the
3105 underlying platform and <a class="glossarylink" href="../glossary.html#apr" title="see glossary">APR</a> support it. Mechanisms
3106 which aren't available on all platforms are <em>posixsem</em>,
3107 <em>sysvsem</em>, <em>sem</em>, <em>pthread</em>, <em>fcntl</em>,
3108 <em>flock</em>, and <em>file</em>.</p>
3110 <p>With the file-based mechanisms <em>fcntl</em> and <em>flock</em>,
3111 the path, if provided, is a directory where the lock file will be created.
3112 The default directory is httpd's run-time file directory relative to
3113 <code class="directive"><a href="#serverroot">ServerRoot</a></code>. Always use a local disk
3114 filesystem for <code>/path/to/mutex</code> and never a directory residing
3115 on a NFS- or AFS-filesystem. The basename of the file will be the mutex
3116 type, an optional instance string provided by the module, and unless the
3117 <code>OmitPID</code> keyword is specified, the process id of the httpd
3118 parent process will be appended to to make the file name unique, avoiding
3119 conflicts when multiple httpd instances share a lock file directory. For
3120 example, if the mutex name is <code>mpm-accept</code> and the lock file
3121 directory is <code>/var/httpd/locks</code>, the lock file name for the
3122 httpd instance with parent process id 12345 would be
3123 <code>/var/httpd/locks/mpm-accept.12345</code>.</p>
3125 <div class="warning"><h3>Security</h3>
3126 <p>It is best to <em>avoid</em> putting mutex files in a world-writable
3127 directory such as <code>/var/tmp</code> because someone could create
3128 a denial of service attack and prevent the server from starting by
3129 creating a lockfile with the same name as the one the server will try
3133 <p>The following table documents the names of mutexes used by httpd
3134 and bundled modules.</p>
3136 <table class="bordered"><tr class="header">
3139 <th>Protected resource</th>
3142 <td><code>mpm-accept</code></td>
3143 <td><code class="module"><a href="../mod/prefork.html">prefork</a></code> and <code class="module"><a href="../mod/worker.html">worker</a></code> MPMs</td>
3144 <td>incoming connections, to avoid the thundering herd problem;
3145 for more information, refer to the
3146 <a href="../misc/perf-tuning.html">performance tuning</a>
3150 <td><code>authdigest-client</code></td>
3151 <td><code class="module"><a href="../mod/mod_auth_digest.html">mod_auth_digest</a></code></td>
3152 <td>client list in shared memory</td>
3155 <td><code>authdigest-opaque</code></td>
3156 <td><code class="module"><a href="../mod/mod_auth_digest.html">mod_auth_digest</a></code></td>
3157 <td>counter in shared memory</td>
3160 <td><code>ldap-cache</code></td>
3161 <td><code class="module"><a href="../mod/mod_ldap.html">mod_ldap</a></code></td>
3162 <td>LDAP result cache</td>
3165 <td><code>rewrite-map</code></td>
3166 <td><code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code></td>
3167 <td>communication with external mapping programs, to avoid
3168 intermixed I/O from multiple requests</td>
3171 <td><code>ssl-cache</code></td>
3172 <td><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code></td>
3173 <td>SSL session cache</td>
3176 <td><code>ssl-stapling</code></td>
3177 <td><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code></td>
3178 <td>OCSP stapling response cache</td>
3181 <td><code>watchdog-callback</code></td>
3182 <td><code class="module"><a href="../mod/mod_watchdog.html">mod_watchdog</a></code></td>
3183 <td>callback function of a particular client module</td>
3187 <p>The <code>OmitPID</code> keyword suppresses the addition of the httpd
3188 parent process id from the lock file name.</p>
3190 <p>In the following example, the mutex mechanism for the MPM accept
3191 mutex will be changed from the compiled-in default to <code>fcntl</code>,
3192 with the associated lock file created in directory
3193 <code>/var/httpd/locks</code>. The mutex mechanism for all other mutexes
3194 will be changed from the compiled-in default to <code>sysvsem</code>.</p>
3196 <div class="example"><p><code>
3197 Mutex default sysvsem<br />
3198 Mutex mpm-accept fcntl:/var/httpd/locks
3202 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3203 <div class="directive-section"><h2><a name="NameVirtualHost" id="NameVirtualHost">NameVirtualHost</a> <a name="namevirtualhost" id="namevirtualhost">Directive</a></h2>
3204 <table class="directive">
3205 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Designates an IP address for name-virtual
3207 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NameVirtualHost <var>addr</var>[:<var>port</var>]</code></td></tr>
3208 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3209 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3210 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3213 <p>Prior to 2.3.11, <code class="directive">NameVirtualHost</code> was required
3214 to instruct the server that a particular IP address and port combination
3215 was usable as a name-based virtual host. In 2.3.11 and later,
3216 any time an IP address and port combination is used in multiple virtual
3217 hosts, name-based virtual hosting is automatically enabled for that address.</p>
3219 <p>This directive currently has no effect.</p>
3223 <li><a href="../vhosts/">Virtual Hosts
3224 documentation</a></li>
3227 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3228 <div class="directive-section"><h2><a name="Options" id="Options">Options</a> <a name="options" id="options">Directive</a></h2>
3229 <table class="directive">
3230 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures what features are available in a particular
3232 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Options
3233 [+|-]<var>option</var> [[+|-]<var>option</var>] ...</code></td></tr>
3234 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Options FollowSymlinks</code></td></tr>
3235 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3236 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
3237 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3238 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3239 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The default was changed from All to FollowSymlinks in 2.3.11</td></tr>
3241 <p>The <code class="directive">Options</code> directive controls which
3242 server features are available in a particular directory.</p>
3244 <p><var>option</var> can be set to <code>None</code>, in which
3245 case none of the extra features are enabled, or one or more of
3249 <dt><code>All</code></dt>
3251 <dd>All options except for <code>MultiViews</code>.</dd>
3253 <dt><code>ExecCGI</code></dt>
3256 Execution of CGI scripts using <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>
3259 <dt><code>FollowSymLinks</code></dt>
3262 The server will follow symbolic links in this directory. This is
3263 the default setting.
3265 <p>Even though the server follows the symlink it does <em>not</em>
3266 change the pathname used to match against <code class="directive"><a href="#directory"><Directory></a></code> sections.</p>
3267 <p>Note also, that this option <strong>gets ignored</strong> if set
3268 inside a <code class="directive"><a href="#location"><Location></a></code>
3270 <p>Omitting this option should not be considered a security restriction,
3271 since symlink testing is subject to race conditions that make it
3275 <dt><code>Includes</code></dt>
3278 Server-side includes provided by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>
3281 <dt><code>IncludesNOEXEC</code></dt>
3285 Server-side includes are permitted, but the <code>#exec
3286 cmd</code> and <code>#exec cgi</code> are disabled. It is still
3287 possible to <code>#include virtual</code> CGI scripts from
3288 <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>ed
3291 <dt><code>Indexes</code></dt>
3294 If a URL which maps to a directory is requested, and there
3295 is no <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
3296 (<em>e.g.</em>, <code>index.html</code>) in that directory, then
3297 <code class="module"><a href="../mod/mod_autoindex.html">mod_autoindex</a></code> will return a formatted listing
3298 of the directory.</dd>
3300 <dt><code>MultiViews</code></dt>
3303 <a href="../content-negotiation.html">Content negotiated</a>
3304 "MultiViews" are allowed using
3305 <code class="module"><a href="../mod/mod_negotiation.html">mod_negotiation</a></code>.
3306 <div class="note"><h3>Note</h3> <p>This option gets ignored if set
3307 anywhere other than <code class="directive"><a href="#directory"><Directory></a></code>, as <code class="module"><a href="../mod/mod_negotiation.html">mod_negotiation</a></code>
3308 needs real resources to compare against and evaluate from.</p></div>
3311 <dt><code>SymLinksIfOwnerMatch</code></dt>
3313 <dd>The server will only follow symbolic links for which the
3314 target file or directory is owned by the same user id as the
3317 <div class="note"><h3>Note</h3> <p>This option gets ignored if
3318 set inside a <code class="directive"><a href="#location"><Location></a></code> section.</p>
3319 <p>This option should not be considered a security restriction,
3320 since symlink testing is subject to race conditions that make it
3321 circumventable.</p></div>
3325 <p>Normally, if multiple <code class="directive">Options</code> could
3326 apply to a directory, then the most specific one is used and
3327 others are ignored; the options are not merged. (See <a href="../sections.html#mergin">how sections are merged</a>.)
3328 However if <em>all</em> the options on the
3329 <code class="directive">Options</code> directive are preceded by a
3330 <code>+</code> or <code>-</code> symbol, the options are
3331 merged. Any options preceded by a <code>+</code> are added to the
3332 options currently in force, and any options preceded by a
3333 <code>-</code> are removed from the options currently in
3336 <div class="note"><h3>Note</h3>
3337 <p>Mixing <code class="directive">Options</code> with a <code>+</code> or
3338 <code>-</code> with those without is not valid syntax, and will be
3339 rejected during server startup by the syntax check with an abort.</p>
3342 <p>For example, without any <code>+</code> and <code>-</code> symbols:</p>
3344 <div class="example"><p><code>
3345 <Directory /web/docs><br />
3346 <span class="indent">
3347 Options Indexes FollowSymLinks<br />
3349 </Directory><br />
3351 <Directory /web/docs/spec><br />
3352 <span class="indent">
3353 Options Includes<br />
3358 <p>then only <code>Includes</code> will be set for the
3359 <code>/web/docs/spec</code> directory. However if the second
3360 <code class="directive">Options</code> directive uses the <code>+</code> and
3361 <code>-</code> symbols:</p>
3363 <div class="example"><p><code>
3364 <Directory /web/docs><br />
3365 <span class="indent">
3366 Options Indexes FollowSymLinks<br />
3368 </Directory><br />
3370 <Directory /web/docs/spec><br />
3371 <span class="indent">
3372 Options +Includes -Indexes<br />
3377 <p>then the options <code>FollowSymLinks</code> and
3378 <code>Includes</code> are set for the <code>/web/docs/spec</code>
3381 <div class="note"><h3>Note</h3>
3382 <p>Using <code>-IncludesNOEXEC</code> or
3383 <code>-Includes</code> disables server-side includes completely
3384 regardless of the previous setting.</p>
3387 <p>The default in the absence of any other settings is
3388 <code>FollowSymlinks</code>.</p>
3391 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3392 <div class="directive-section"><h2><a name="Protocol" id="Protocol">Protocol</a> <a name="protocol" id="protocol">Directive</a></h2>
3393 <table class="directive">
3394 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Protocol for a listening socket</td></tr>
3395 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Protocol <var>protocol</var></code></td></tr>
3396 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
3397 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3398 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3399 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.1.5 and later.
3400 On Windows from Apache 2.3.3 and later.</td></tr>
3402 <p>This directive specifies the protocol used for a specific listening socket.
3403 The protocol is used to determine which module should handle a request, and
3404 to apply protocol specific optimizations with the <code class="directive">AcceptFilter</code>
3407 <p>You only need to set the protocol if you are running on non-standard ports, otherwise <code>http</code> is assumed for port 80 and <code>https</code> for port 443.</p>
3409 <p>For example, if you are running <code>https</code> on a non-standard port, specify the protocol explicitly:</p>
3411 <div class="example"><p><code>
3415 <p>You can also specify the protocol using the <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code> directive.</p>
3419 <li><code class="directive">AcceptFilter</code></li>
3420 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
3423 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3424 <div class="directive-section"><h2><a name="RLimitCPU" id="RLimitCPU">RLimitCPU</a> <a name="rlimitcpu" id="rlimitcpu">Directive</a></h2>
3425 <table class="directive">
3426 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the CPU consumption of processes launched
3427 by Apache httpd children</td></tr>
3428 <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>
3429 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
3430 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3431 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
3432 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3433 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3435 <p>Takes 1 or 2 parameters. The first parameter sets the soft
3436 resource limit for all processes and the second parameter sets
3437 the maximum resource limit. Either parameter can be a number,
3438 or <code>max</code> to indicate to the server that the limit should
3439 be set to the maximum allowed by the operating system
3440 configuration. Raising the maximum resource limit requires that
3441 the server is running as <code>root</code>, or in the initial startup
3444 <p>This applies to processes forked off from Apache httpd children
3445 servicing requests, not the Apache httpd children themselves. This
3446 includes CGI scripts and SSI exec commands, but not any
3447 processes forked off from the Apache httpd parent such as piped
3450 <p>CPU resource limits are expressed in seconds per
3455 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
3456 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
3459 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3460 <div class="directive-section"><h2><a name="RLimitMEM" id="RLimitMEM">RLimitMEM</a> <a name="rlimitmem" id="rlimitmem">Directive</a></h2>
3461 <table class="directive">
3462 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the memory consumption of processes launched
3463 by Apache httpd children</td></tr>
3464 <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>
3465 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
3466 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3467 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
3468 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3469 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3471 <p>Takes 1 or 2 parameters. The first parameter sets the soft
3472 resource limit for all processes and the second parameter sets
3473 the maximum resource limit. Either parameter can be a number,
3474 or <code>max</code> to indicate to the server that the limit should
3475 be set to the maximum allowed by the operating system
3476 configuration. Raising the maximum resource limit requires that
3477 the server is running as <code>root</code>, or in the initial startup
3480 <p>This applies to processes forked off from Apache httpd children
3481 servicing requests, not the Apache httpd children themselves. This
3482 includes CGI scripts and SSI exec commands, but not any
3483 processes forked off from the Apache httpd parent such as piped
3486 <p>Memory resource limits are expressed in bytes per
3491 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
3492 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
3495 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3496 <div class="directive-section"><h2><a name="RLimitNPROC" id="RLimitNPROC">RLimitNPROC</a> <a name="rlimitnproc" id="rlimitnproc">Directive</a></h2>
3497 <table class="directive">
3498 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of processes that can be launched by
3499 processes launched by Apache httpd children</td></tr>
3500 <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>
3501 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
3502 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3503 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
3504 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3505 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3507 <p>Takes 1 or 2 parameters. The first parameter sets the soft
3508 resource limit for all processes and the second parameter sets
3509 the maximum resource limit. Either parameter can be a number,
3510 or <code>max</code> to indicate to the server that the limit
3511 should be set to the maximum allowed by the operating system
3512 configuration. Raising the maximum resource limit requires that
3513 the server is running as <code>root</code>, or in the initial startup
3516 <p>This applies to processes forked off from Apache httpd children
3517 servicing requests, not the Apache httpd children themselves. This
3518 includes CGI scripts and SSI exec commands, but not any
3519 processes forked off from the Apache httpd parent such as piped
3522 <p>Process limits control the number of processes per user.</p>
3524 <div class="note"><h3>Note</h3>
3525 <p>If CGI processes are <strong>not</strong> running
3526 under user ids other than the web server user id, this directive
3527 will limit the number of processes that the server itself can
3528 create. Evidence of this situation will be indicated by
3529 <strong><code>cannot fork</code></strong> messages in the
3530 <code>error_log</code>.</p>
3535 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
3536 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
3539 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3540 <div class="directive-section"><h2><a name="ScriptInterpreterSource" id="ScriptInterpreterSource">ScriptInterpreterSource</a> <a name="scriptinterpretersource" id="scriptinterpretersource">Directive</a></h2>
3541 <table class="directive">
3542 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
3544 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ScriptInterpreterSource Registry|Registry-Strict|Script</code></td></tr>
3545 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ScriptInterpreterSource Script</code></td></tr>
3546 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3547 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
3548 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3549 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3550 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Win32 only;
3551 option <code>Registry-Strict</code> is available in Apache HTTP Server 2.0 and
3554 <p>This directive is used to control how Apache httpd finds the
3555 interpreter used to run CGI scripts. The default setting is
3556 <code>Script</code>. This causes Apache httpd to use the interpreter pointed to
3557 by the shebang line (first line, starting with <code>#!</code>) in the
3558 script. On Win32 systems this line usually looks like:</p>
3560 <div class="example"><p><code>
3561 #!C:/Perl/bin/perl.exe
3564 <p>or, if <code>perl</code> is in the <code>PATH</code>, simply:</p>
3566 <div class="example"><p><code>
3570 <p>Setting <code>ScriptInterpreterSource Registry</code> will
3571 cause the Windows Registry tree <code>HKEY_CLASSES_ROOT</code> to be
3572 searched using the script file extension (e.g., <code>.pl</code>) as a
3573 search key. The command defined by the registry subkey
3574 <code>Shell\ExecCGI\Command</code> or, if it does not exist, by the subkey
3575 <code>Shell\Open\Command</code> is used to open the script file. If the
3576 registry keys cannot be found, Apache httpd falls back to the behavior of the
3577 <code>Script</code> option.</p>
3579 <div class="warning"><h3>Security</h3>
3580 <p>Be careful when using <code>ScriptInterpreterSource
3581 Registry</code> with <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>'ed directories, because
3582 Apache httpd will try to execute <strong>every</strong> file within this
3583 directory. The <code>Registry</code> setting may cause undesired
3584 program calls on files which are typically not executed. For
3585 example, the default open command on <code>.htm</code> files on
3586 most Windows systems will execute Microsoft Internet Explorer, so
3587 any HTTP request for an <code>.htm</code> file existing within the
3588 script directory would start the browser in the background on the
3589 server. This is a good way to crash your system within a minute or
3593 <p>The option <code>Registry-Strict</code> which is new in Apache HTTP Server
3594 2.0 does the same thing as <code>Registry</code> but uses only the
3595 subkey <code>Shell\ExecCGI\Command</code>. The
3596 <code>ExecCGI</code> key is not a common one. It must be
3597 configured manually in the windows registry and hence prevents
3598 accidental program calls on your system.</p>
3601 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3602 <div class="directive-section"><h2><a name="SeeRequestTail" id="SeeRequestTail">SeeRequestTail</a> <a name="seerequesttail" id="seerequesttail">Directive</a></h2>
3603 <table class="directive">
3604 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine if mod_status displays the first 63 characters
3605 of a request or the last 63, assuming the request itself is greater than
3607 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SeeRequestTail On|Off</code></td></tr>
3608 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>SeeRequestTail Off</code></td></tr>
3609 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3610 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3611 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3612 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.2.7 and later.</td></tr>
3614 <p>mod_status with <code>ExtendedStatus On</code>
3615 displays the actual request being handled.
3616 For historical purposes, only 63 characters of the request
3617 are actually stored for display purposes. This directive
3618 controls whether the 1st 63 characters are stored (the previous
3619 behavior and the default) or if the last 63 characters are. This
3620 is only applicable, of course, if the length of the request is
3621 64 characters or greater.</p>
3623 <p>If Apache httpd is handling <code>GET /disk1/storage/apache/htdocs/images/imagestore1/food/apples.jpg HTTP/1.1</code> mod_status displays as follows:
3626 <table class="bordered">
3628 <th>Off (default)</th>
3629 <td>GET /disk1/storage/apache/htdocs/images/imagestore1/food/apples</td>
3633 <td>orage/apache/htdocs/images/imagestore1/food/apples.jpg HTTP/1.1</td>
3639 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3640 <div class="directive-section"><h2><a name="ServerAdmin" id="ServerAdmin">ServerAdmin</a> <a name="serveradmin" id="serveradmin">Directive</a></h2>
3641 <table class="directive">
3642 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Email address that the server includes in error
3643 messages sent to the client</td></tr>
3644 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAdmin <var>email-address</var>|<var>URL</var></code></td></tr>
3645 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
3646 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3647 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3649 <p>The <code class="directive">ServerAdmin</code> sets the contact address
3650 that the server includes in any error messages it returns to the
3651 client. If the <code>httpd</code> doesn't recognize the supplied argument
3653 assumes, that it's an <var>email-address</var> and prepends it with
3654 <code>mailto:</code> in hyperlink targets. However, it's recommended to
3655 actually use an email address, since there are a lot of CGI scripts that
3656 make that assumption. If you want to use an URL, it should point to another
3657 server under your control. Otherwise users may not be able to contact you in
3660 <p>It may be worth setting up a dedicated address for this, e.g.</p>
3662 <div class="example"><p><code>
3663 ServerAdmin www-admin@foo.example.com
3665 <p>as users do not always mention that they are talking about the
3669 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3670 <div class="directive-section"><h2><a name="ServerAlias" id="ServerAlias">ServerAlias</a> <a name="serveralias" id="serveralias">Directive</a></h2>
3671 <table class="directive">
3672 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Alternate names for a host used when matching requests
3673 to name-virtual hosts</td></tr>
3674 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAlias <var>hostname</var> [<var>hostname</var>] ...</code></td></tr>
3675 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
3676 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3677 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3679 <p>The <code class="directive">ServerAlias</code> directive sets the
3680 alternate names for a host, for use with <a href="../vhosts/name-based.html">name-based virtual hosts</a>. The
3681 <code class="directive">ServerAlias</code> may include wildcards, if appropriate.</p>
3683 <div class="example"><p><code>
3684 <VirtualHost *:80><br />
3685 ServerName server.example.com<br />
3686 ServerAlias server server2.example.com server2<br />
3687 ServerAlias *.example.com<br />
3688 UseCanonicalName Off<br />
3690 </VirtualHost>
3695 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
3696 <li><a href="../vhosts/">Apache HTTP Server Virtual Host documentation</a></li>
3699 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3700 <div class="directive-section"><h2><a name="ServerName" id="ServerName">ServerName</a> <a name="servername" id="servername">Directive</a></h2>
3701 <table class="directive">
3702 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hostname and port that the server uses to identify
3704 <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>
3705 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
3706 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3707 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3709 <p>The <code class="directive">ServerName</code> directive sets the
3710 request scheme, hostname and
3711 port that the server uses to identify itself. This is used when
3712 creating redirection URLs.</p>
3714 <p>Additionally, <code class="directive">ServerName</code> is used (possibly
3715 in conjunction with <code class="directive">ServerAlias</code>) to uniquely
3716 identify a virtual host, when using <a href="../vhosts/name-based.html">name-based virtual hosts</a>.</p>
3718 <p>For example, if the name of the
3719 machine hosting the web server is <code>simple.example.com</code>,
3720 but the machine also has the DNS alias <code>www.example.com</code>
3721 and you wish the web server to be so identified, the following
3722 directive should be used:</p>
3724 <div class="example"><p><code>
3725 ServerName www.example.com
3728 <p>The <code class="directive">ServerName</code> directive
3729 may appear anywhere within the definition of a server. However,
3730 each appearance overrides the previous appearance (within that
3733 <p>If no <code class="directive">ServerName</code> is specified, then the
3734 server attempts to deduce the hostname by performing a reverse
3735 lookup on the IP address. If no port is specified in the
3736 <code class="directive">ServerName</code>, then the server will use the
3737 port from the incoming request. For optimal reliability and
3738 predictability, you should specify an explicit hostname and port
3739 using the <code class="directive">ServerName</code> directive.</p>
3741 <p>If you are using <a href="../vhosts/name-based.html">name-based virtual hosts</a>,
3742 the <code class="directive">ServerName</code> inside a
3743 <code class="directive"><a href="#virtualhost"><VirtualHost></a></code>
3744 section specifies what hostname must appear in the request's
3745 <code>Host:</code> header to match this virtual host.</p>
3747 <p>Sometimes, the server runs behind a device that processes SSL,
3748 such as a reverse proxy, load balancer or SSL offload
3749 appliance. When this is the case, specify the
3750 <code>https://</code> scheme and the port number to which the
3751 clients connect in the <code class="directive">ServerName</code> directive
3752 to make sure that the server generates the correct
3753 self-referential URLs.
3756 <p>See the description of the
3757 <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> and
3758 <code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code> directives for
3759 settings which determine whether self-referential URLs (e.g., by the
3760 <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> module) will refer to the
3761 specified port, or to the port number given in the client's request.
3764 <div class="warning">
3765 <p>Failure to set <code class="directive">ServerName</code> to a name that
3766 your server can resolve to an IP address will result in a startup
3767 warning. <code>httpd</code> will then use whatever hostname it can
3768 determine, using the system's <code>hostname</code> command. This
3769 will almost never be the hostname you actually want.</p>
3770 <div class="example"><p><code>
3771 httpd: Could not reliably determine the server's fully qualified domain name, using rocinante.local for ServerName
3778 <li><a href="../dns-caveats.html">Issues Regarding DNS and
3779 Apache HTTP Server</a></li>
3780 <li><a href="../vhosts/">Apache HTTP Server virtual host
3781 documentation</a></li>
3782 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
3783 <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li>
3784 <li><code class="directive"><a href="#serveralias">ServerAlias</a></code></li>
3787 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3788 <div class="directive-section"><h2><a name="ServerPath" id="ServerPath">ServerPath</a> <a name="serverpath" id="serverpath">Directive</a></h2>
3789 <table class="directive">
3790 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Legacy URL pathname for a name-based virtual host that
3791 is accessed by an incompatible browser</td></tr>
3792 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerPath <var>URL-path</var></code></td></tr>
3793 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
3794 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3795 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3797 <p>The <code class="directive">ServerPath</code> directive sets the legacy
3798 URL pathname for a host, for use with <a href="../vhosts/">name-based virtual hosts</a>.</p>
3802 <li><a href="../vhosts/">Apache HTTP Server Virtual Host documentation</a></li>
3805 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3806 <div class="directive-section"><h2><a name="ServerRoot" id="ServerRoot">ServerRoot</a> <a name="serverroot" id="serverroot">Directive</a></h2>
3807 <table class="directive">
3808 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Base directory for the server installation</td></tr>
3809 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerRoot <var>directory-path</var></code></td></tr>
3810 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerRoot /usr/local/apache</code></td></tr>
3811 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3812 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3813 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3815 <p>The <code class="directive">ServerRoot</code> directive sets the
3816 directory in which the server lives. Typically it will contain the
3817 subdirectories <code>conf/</code> and <code>logs/</code>. Relative
3818 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
3819 relative to this directory.</p>
3821 <div class="example"><h3>Example</h3><p><code>
3822 ServerRoot /home/httpd
3825 <p>The default location of <code class="directive">ServerRoot</code> may be
3826 modified by using the <code>--prefix</code> argument to
3827 <a href="../programs/configure.html"><code>configure</code></a>, and
3828 most third-party distributions of the server have a different
3829 default location from the one listed above.</p>
3834 <li><a href="../invoking.html">the <code>-d</code>
3835 option to <code>httpd</code></a></li>
3836 <li><a href="../misc/security_tips.html#serverroot">the
3837 security tips</a> for information on how to properly set
3838 permissions on the <code class="directive">ServerRoot</code></li>
3841 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3842 <div class="directive-section"><h2><a name="ServerSignature" id="ServerSignature">ServerSignature</a> <a name="serversignature" id="serversignature">Directive</a></h2>
3843 <table class="directive">
3844 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the footer on server-generated documents</td></tr>
3845 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerSignature On|Off|EMail</code></td></tr>
3846 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerSignature Off</code></td></tr>
3847 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3848 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
3849 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3850 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3852 <p>The <code class="directive">ServerSignature</code> directive allows the
3853 configuration of a trailing footer line under server-generated
3854 documents (error messages, <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> ftp directory
3855 listings, <code class="module"><a href="../mod/mod_info.html">mod_info</a></code> output, ...). The reason why you
3856 would want to enable such a footer line is that in a chain of proxies,
3857 the user often has no possibility to tell which of the chained servers
3858 actually produced a returned error message.</p>
3860 <p>The <code>Off</code>
3861 setting, which is the default, suppresses the footer line (and is
3862 therefore compatible with the behavior of Apache-1.2 and
3863 below). The <code>On</code> setting simply adds a line with the
3864 server version number and <code class="directive"><a href="#servername">ServerName</a></code> of the serving virtual host,
3865 and the <code>EMail</code> setting additionally creates a
3866 "mailto:" reference to the <code class="directive"><a href="#serveradmin">ServerAdmin</a></code> of the referenced
3869 <p>After version 2.0.44, the details of the server version number
3870 presented are controlled by the <code class="directive"><a href="#servertokens">ServerTokens</a></code> directive.</p>
3874 <li><code class="directive"><a href="#servertokens">ServerTokens</a></code></li>
3877 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3878 <div class="directive-section"><h2><a name="ServerTokens" id="ServerTokens">ServerTokens</a> <a name="servertokens" id="servertokens">Directive</a></h2>
3879 <table class="directive">
3880 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the <code>Server</code> HTTP response
3882 <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>
3883 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerTokens Full</code></td></tr>
3884 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3885 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3886 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3888 <p>This directive controls whether <code>Server</code> response
3889 header field which is sent back to clients includes a
3890 description of the generic OS-type of the server as well as
3891 information about compiled-in modules.</p>
3894 <dt><code>ServerTokens Full</code> (or not specified)</dt>
3896 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.4.1
3897 (Unix) PHP/4.2.2 MyMod/1.2</code></dd>
3899 <dt><code>ServerTokens Prod[uctOnly]</code></dt>
3901 <dd>Server sends (<em>e.g.</em>): <code>Server:
3904 <dt><code>ServerTokens Major</code></dt>
3906 <dd>Server sends (<em>e.g.</em>): <code>Server:
3907 Apache/2</code></dd>
3909 <dt><code>ServerTokens Minor</code></dt>
3911 <dd>Server sends (<em>e.g.</em>): <code>Server:
3912 Apache/2.4</code></dd>
3914 <dt><code>ServerTokens Min[imal]</code></dt>
3916 <dd>Server sends (<em>e.g.</em>): <code>Server:
3917 Apache/2.4.1</code></dd>
3919 <dt><code>ServerTokens OS</code></dt>
3921 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.4.1
3926 <p>This setting applies to the entire server, and cannot be
3927 enabled or disabled on a virtualhost-by-virtualhost basis.</p>
3929 <p>After version 2.0.44, this directive also controls the
3930 information presented by the <code class="directive"><a href="#serversignature">ServerSignature</a></code> directive.</p>
3932 <div class="note">Setting <code class="directive">ServerTokens</code> to less than
3933 <code>minimal</code> is not recommended because it makes it more
3934 difficult to debug interoperational problems. Also note that
3935 disabling the Server: header does nothing at all to make your
3936 server more secure; the idea of "security through obscurity"
3937 is a myth and leads to a false sense of safety.</div>
3942 <li><code class="directive"><a href="#serversignature">ServerSignature</a></code></li>
3945 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3946 <div class="directive-section"><h2><a name="SetHandler" id="SetHandler">SetHandler</a> <a name="sethandler" id="sethandler">Directive</a></h2>
3947 <table class="directive">
3948 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be processed by a
3950 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetHandler <var>handler-name</var>|None</code></td></tr>
3951 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3952 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
3953 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3954 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3955 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved into the core in Apache httpd 2.0</td></tr>
3957 <p>When placed into an <code>.htaccess</code> file or a
3958 <code class="directive"><a href="#directory"><Directory></a></code> or
3959 <code class="directive"><a href="#location"><Location></a></code>
3960 section, this directive forces all matching files to be parsed
3961 through the <a href="../handler.html">handler</a> given by
3962 <var>handler-name</var>. For example, if you had a directory you
3963 wanted to be parsed entirely as imagemap rule files, regardless
3964 of extension, you might put the following into an
3965 <code>.htaccess</code> file in that directory:</p>
3967 <div class="example"><p><code>
3968 SetHandler imap-file
3971 <p>Another example: if you wanted to have the server display a
3972 status report whenever a URL of
3973 <code>http://servername/status</code> was called, you might put
3974 the following into <code>httpd.conf</code>:</p>
3976 <div class="example"><p><code>
3977 <Location /status><br />
3978 <span class="indent">
3979 SetHandler server-status<br />
3984 <p>You can override an earlier defined <code class="directive">SetHandler</code>
3985 directive by using the value <code>None</code>.</p>
3987 <div class="note"><h3>Note</h3>
3988 <p>Because <code class="directive">SetHandler</code> overrides default handlers,
3989 normal behaviour such as handling of URLs ending in a slash (/) as
3990 directories or index files is suppressed.</p></div>
3994 <li><code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code></li>
3997 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3998 <div class="directive-section"><h2><a name="SetInputFilter" id="SetInputFilter">SetInputFilter</a> <a name="setinputfilter" id="setinputfilter">Directive</a></h2>
3999 <table class="directive">
4000 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process client requests and POST
4002 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetInputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
4003 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
4004 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
4005 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4006 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4008 <p>The <code class="directive">SetInputFilter</code> directive sets the
4009 filter or filters which will process client requests and POST
4010 input when they are received by the server. This is in addition to
4011 any filters defined elsewhere, including the
4012 <code class="directive"><a href="../mod/mod_mime.html#addinputfilter">AddInputFilter</a></code>
4015 <p>If more than one filter is specified, they must be separated
4016 by semicolons in the order in which they should process the
4021 <li><a href="../filter.html">Filters</a> documentation</li>
4024 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4025 <div class="directive-section"><h2><a name="SetOutputFilter" id="SetOutputFilter">SetOutputFilter</a> <a name="setoutputfilter" id="setoutputfilter">Directive</a></h2>
4026 <table class="directive">
4027 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process responses from the
4029 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetOutputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
4030 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
4031 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
4032 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4033 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4035 <p>The <code class="directive">SetOutputFilter</code> directive sets the filters
4036 which will process responses from the server before they are
4037 sent to the client. This is in addition to any filters defined
4038 elsewhere, including the
4039 <code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code>
4042 <p>For example, the following configuration will process all files
4043 in the <code>/www/data/</code> directory for server-side
4046 <div class="example"><p><code>
4047 <Directory /www/data/><br />
4048 <span class="indent">
4049 SetOutputFilter INCLUDES<br />
4054 <p>If more than one filter is specified, they must be separated
4055 by semicolons in the order in which they should process the
4060 <li><a href="../filter.html">Filters</a> documentation</li>
4063 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4064 <div class="directive-section"><h2><a name="TimeOut" id="TimeOut">TimeOut</a> <a name="timeout" id="timeout">Directive</a></h2>
4065 <table class="directive">
4066 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for
4067 certain events before failing a request</td></tr>
4068 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TimeOut <var>seconds</var></code></td></tr>
4069 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TimeOut 300</code></td></tr>
4070 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
4071 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4072 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4074 <p>The <code class="directive">TimeOut</code> directive defines the length
4075 of time Apache httpd will wait for I/O in various circumstances:</p>
4078 <li>When reading data from the client, the length of time to
4079 wait for a TCP packet to arrive if the read buffer is
4082 <li>When writing data to the client, the length of time to wait
4083 for an acknowledgement of a packet if the send buffer is
4086 <li>In <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>, the length of time to wait for
4087 output from a CGI script.</li>
4089 <li>In <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code>, the length of time to
4090 wait for output from a filtering process.</li>
4092 <li>In <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>, the default timeout value if
4093 <code class="directive"><a href="../mod/mod_proxy.html#proxytimeout">ProxyTimeout</a></code> is not
4099 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4100 <div class="directive-section"><h2><a name="TraceEnable" id="TraceEnable">TraceEnable</a> <a name="traceenable" id="traceenable">Directive</a></h2>
4101 <table class="directive">
4102 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines the behaviour on <code>TRACE</code> requests</td></tr>
4103 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TraceEnable <var>[on|off|extended]</var></code></td></tr>
4104 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TraceEnable on</code></td></tr>
4105 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
4106 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4107 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4108 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache HTTP Server 1.3.34, 2.0.55 and later</td></tr>
4110 <p>This directive overrides the behavior of <code>TRACE</code> for both
4111 the core server and <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>. The default
4112 <code>TraceEnable on</code> permits <code>TRACE</code> requests per
4113 RFC 2616, which disallows any request body to accompany the request.
4114 <code>TraceEnable off</code> causes the core server and
4115 <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> to return a <code>405</code> (Method not
4116 allowed) error to the client.</p>
4118 <p>Finally, for testing and diagnostic purposes only, request
4119 bodies may be allowed using the non-compliant <code>TraceEnable
4120 extended</code> directive. The core (as an origin server) will
4121 restrict the request body to 64k (plus 8k for chunk headers if
4122 <code>Transfer-Encoding: chunked</code> is used). The core will
4123 reflect the full headers and all chunk headers with the response
4124 body. As a proxy server, the request body is not restricted to 64k.</p>
4127 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4128 <div class="directive-section"><h2><a name="UnDefine" id="UnDefine">UnDefine</a> <a name="undefine" id="undefine">Directive</a></h2>
4129 <table class="directive">
4130 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Undefine the existence of a variable</td></tr>
4131 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UnDefine <var>parameter-name</var></code></td></tr>
4132 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
4133 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4134 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4136 <p>Undoes the effect of a <code class="directive"><a href="#define">Define</a></code> or
4137 of passing a <code>-D</code> argument to <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</p>
4138 <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
4139 <code>-D</code> arguments in any startup scripts.</p>
4142 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4143 <div class="directive-section"><h2><a name="UseCanonicalName" id="UseCanonicalName">UseCanonicalName</a> <a name="usecanonicalname" id="usecanonicalname">Directive</a></h2>
4144 <table class="directive">
4145 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and
4147 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalName On|Off|DNS</code></td></tr>
4148 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalName Off</code></td></tr>
4149 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
4150 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4151 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4153 <p>In many situations Apache httpd must construct a <em>self-referential</em>
4154 URL -- that is, a URL that refers back to the same server. With
4155 <code>UseCanonicalName On</code> Apache httpd will use the hostname and port
4156 specified in the <code class="directive"><a href="#servername">ServerName</a></code>
4157 directive to construct the canonical name for the server. This name
4158 is used in all self-referential URLs, and for the values of
4159 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> in CGIs.</p>
4161 <p>With <code>UseCanonicalName Off</code> Apache httpd will form
4162 self-referential URLs using the hostname and port supplied by
4163 the client if any are supplied (otherwise it will use the
4164 canonical name, as defined above). These values are the same
4165 that are used to implement <a href="../vhosts/name-based.html">name-based virtual hosts</a>,
4166 and are available with the same clients. The CGI variables
4167 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> will be
4168 constructed from the client supplied values as well.</p>
4170 <p>An example where this may be useful is on an intranet server
4171 where you have users connecting to the machine using short
4172 names such as <code>www</code>. You'll notice that if the users
4173 type a shortname, and a URL which is a directory, such as
4174 <code>http://www/splat</code>, <em>without the trailing
4175 slash</em> then Apache httpd will redirect them to
4176 <code>http://www.example.com/splat/</code>. If you have
4177 authentication enabled, this will cause the user to have to
4178 authenticate twice (once for <code>www</code> and once again
4179 for <code>www.example.com</code> -- see <a href="http://httpd.apache.org/docs/misc/FAQ.html#prompted-twice">the
4180 FAQ on this subject for more information</a>). But if
4181 <code class="directive">UseCanonicalName</code> is set <code>Off</code>, then
4182 Apache httpd will redirect to <code>http://www/splat/</code>.</p>
4184 <p>There is a third option, <code>UseCanonicalName DNS</code>,
4185 which is intended for use with mass IP-based virtual hosting to
4186 support ancient clients that do not provide a
4187 <code>Host:</code> header. With this option Apache httpd does a
4188 reverse DNS lookup on the server IP address that the client
4189 connected to in order to work out self-referential URLs.</p>
4191 <div class="warning"><h3>Warning</h3>
4192 <p>If CGIs make assumptions about the values of <code>SERVER_NAME</code>
4193 they may be broken by this option. The client is essentially free
4194 to give whatever value they want as a hostname. But if the CGI is
4195 only using <code>SERVER_NAME</code> to construct self-referential URLs
4196 then it should be just fine.</p>
4201 <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li>
4202 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
4203 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
4206 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4207 <div class="directive-section"><h2><a name="UseCanonicalPhysicalPort" id="UseCanonicalPhysicalPort">UseCanonicalPhysicalPort</a> <a name="usecanonicalphysicalport" id="usecanonicalphysicalport">Directive</a></h2>
4208 <table class="directive">
4209 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own port</td></tr>
4210 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalPhysicalPort On|Off</code></td></tr>
4211 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalPhysicalPort Off</code></td></tr>
4212 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
4213 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4214 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4216 <p>In many situations Apache httpd must construct a <em>self-referential</em>
4217 URL -- that is, a URL that refers back to the same server. With
4218 <code>UseCanonicalPhysicalPort On</code> Apache httpd will, when
4219 constructing the canonical port for the server to honor
4220 the <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> directive,
4221 provide the actual physical port number being used by this request
4222 as a potential port. With <code>UseCanonicalPhysicalPort Off</code>
4223 Apache httpd will not ever use the actual physical port number, instead
4224 relying on all configured information to construct a valid port number.</p>
4226 <div class="note"><h3>Note</h3>
4227 <p>The ordering of the lookup when the physical port is used is as
4230 <dt><code>UseCanonicalName On</code></dt>
4233 <li>Port provided in <code class="directive"><a href="#servername">Servername</a></code></li>
4234 <li>Physical port</li>
4235 <li>Default port</li>
4238 <dt><code>UseCanonicalName Off | DNS</code></dt>
4241 <li>Parsed port from <code>Host:</code> header</li>
4242 <li>Physical port</li>
4243 <li>Port provided in <code class="directive"><a href="#servername">Servername</a></code></li>
4244 <li>Default port</li>
4249 <p>With <code>UseCanonicalPhysicalPort Off</code>, the
4250 physical ports are removed from the ordering.</p>
4256 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
4257 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
4258 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
4261 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
4262 <div class="directive-section"><h2><a name="VirtualHost" id="VirtualHost"><VirtualHost></a> <a name="virtualhost" id="virtualhost">Directive</a></h2>
4263 <table class="directive">
4264 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only to a specific
4265 hostname or IP address</td></tr>
4266 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><VirtualHost
4267 <var>addr</var>[:<var>port</var>] [<var>addr</var>[:<var>port</var>]]
4268 ...> ... </VirtualHost></code></td></tr>
4269 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
4270 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
4271 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
4273 <p><code class="directive"><VirtualHost></code> and
4274 <code></VirtualHost></code> are used to enclose a group of
4275 directives that will apply only to a particular virtual host. Any
4276 directive that is allowed in a virtual host context may be
4277 used. When the server receives a request for a document on a
4278 particular virtual host, it uses the configuration directives
4279 enclosed in the <code class="directive"><VirtualHost></code>
4280 section. <var>Addr</var> can be any of the following, optionally followed by
4281 a colon and a port number (or *):</p>
4284 <li>The IP address of the virtual host;</li>
4286 <li>A fully qualified domain name for the IP address of the
4287 virtual host (not recommended);</li>
4289 <li>The character <code>*</code>, which acts as a wildcard and matches
4290 any IP address.</li>
4292 <li>The string <code>_default_</code>, which is an alias for <code>*</code></li>
4296 <div class="example"><h3>Example</h3><p><code>
4297 <VirtualHost 10.1.2.3:80><br />
4298 <span class="indent">
4299 ServerAdmin webmaster@host.example.com<br />
4300 DocumentRoot /www/docs/host.example.com<br />
4301 ServerName host.example.com<br />
4302 ErrorLog logs/host.example.com-error_log<br />
4303 TransferLog logs/host.example.com-access_log<br />
4305 </VirtualHost>
4309 <p>IPv6 addresses must be specified in square brackets because
4310 the optional port number could not be determined otherwise. An
4311 IPv6 example is shown below:</p>
4313 <div class="example"><p><code>
4314 <VirtualHost [2001:db8::a00:20ff:fea7:ccea]:80><br />
4315 <span class="indent">
4316 ServerAdmin webmaster@host.example.com<br />
4317 DocumentRoot /www/docs/host.example.com<br />
4318 ServerName host.example.com<br />
4319 ErrorLog logs/host.example.com-error_log<br />
4320 TransferLog logs/host.example.com-access_log<br />
4322 </VirtualHost>
4325 <p>Each Virtual Host must correspond to a different IP address,
4326 different port number or a different host name for the server,
4327 in the former case the server machine must be configured to
4328 accept IP packets for multiple addresses. (If the machine does
4329 not have multiple network interfaces, then this can be
4330 accomplished with the <code>ifconfig alias</code> command -- if
4331 your OS supports it).</p>
4333 <div class="note"><h3>Note</h3>
4334 <p>The use of <code class="directive"><VirtualHost></code> does
4335 <strong>not</strong> affect what addresses Apache httpd listens on. You
4336 may need to ensure that Apache httpd is listening on the correct addresses
4337 using <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>.</p>
4340 <p>A <code class="directive"><a href="#servername">ServerName</a></code> should be
4341 specified inside each <code class="directive"><VirtualHost></code> block. If it is absent, the
4342 <code class="directive"><a href="#servername">ServerName</a></code> from the "main"
4343 server configuration will be inherited.</p>
4345 <p>When a request is received, the server first maps it to the best matching
4346 <code class="directive"><VirtualHost></code> based on the local
4347 IP address and port combination only. Non-wildcards have a higher
4348 precedence. If no match based on IP and port occurs at all, the
4349 "main" server configuration is used.</p>
4351 <p>If multiple virtual hosts contain the best matching IP address and port,
4352 the server selects from these virtual hosts the best match based on the
4353 requested hostname. If no matching name-based virtual host is found,
4354 then the first listed virtual host that matched the IP address will be
4355 used. As a consequence, the first listed virtual host for a given IP address
4356 and port combination is default virtual host for that IP and port
4359 <div class="warning"><h3>Security</h3>
4360 <p>See the <a href="../misc/security_tips.html">security tips</a>
4361 document for details on why your security could be compromised if the
4362 directory where log files are stored is writable by anyone other
4363 than the user that starts the server.</p>
4368 <li><a href="../vhosts/">Apache HTTP Server Virtual Host documentation</a></li>
4369 <li><a href="../dns-caveats.html">Issues Regarding DNS and
4370 Apache HTTP Server</a></li>
4371 <li><a href="../bind.html">Setting
4372 which addresses and ports Apache HTTP Server uses</a></li>
4373 <li><a href="../sections.html">How <Directory>, <Location>
4374 and <Files> sections work</a> for an explanation of how these
4375 different sections are combined when a request is received</li>
4379 <div class="bottomlang">
4380 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
4381 <a href="../en/mod/core.html" title="English"> en </a> |
4382 <a href="../es/mod/core.html" hreflang="es" rel="alternate" title="Español"> es </a> |
4383 <a href="../fr/mod/core.html" hreflang="fr" rel="alternate" title="Français"> fr </a> |
4384 <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
4385 <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
4386 </div><div id="footer">
4387 <p class="apache">Copyright 2011 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>
4388 <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
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