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8 <title>core - Apache HTTP Server</title>
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14 <div id="page-header">
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>
17 <img alt="" src="../images/feather.gif" /></div>
18 <div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
20 <a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.3</a> > <a href="./">Modules</a></div>
21 <div id="page-content">
22 <div id="preamble"><h1>Apache Core Features</h1>
24 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
25 <a href="../en/mod/core.html" title="English"> en </a> |
26 <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
27 <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
29 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Core Apache HTTP Server features that are always
31 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Core</td></tr></table>
33 <div id="quickview"><h3 class="directives">Directives</h3>
35 <li><img alt="" src="../images/down.gif" /> <a href="#acceptfilter">AcceptFilter</a></li>
36 <li><img alt="" src="../images/down.gif" /> <a href="#acceptpathinfo">AcceptPathInfo</a></li>
37 <li><img alt="" src="../images/down.gif" /> <a href="#accessfilename">AccessFileName</a></li>
38 <li><img alt="" src="../images/down.gif" /> <a href="#adddefaultcharset">AddDefaultCharset</a></li>
39 <li><img alt="" src="../images/down.gif" /> <a href="#addoutputfilterbytype">AddOutputFilterByType</a></li>
40 <li><img alt="" src="../images/down.gif" /> <a href="#allowencodedslashes">AllowEncodedSlashes</a></li>
41 <li><img alt="" src="../images/down.gif" /> <a href="#allowoverride">AllowOverride</a></li>
42 <li><img alt="" src="../images/down.gif" /> <a href="#cgimapextension">CGIMapExtension</a></li>
43 <li><img alt="" src="../images/down.gif" /> <a href="#contentdigest">ContentDigest</a></li>
44 <li><img alt="" src="../images/down.gif" /> <a href="#defaulttype">DefaultType</a></li>
45 <li><img alt="" src="../images/down.gif" /> <a href="#define">Define</a></li>
46 <li><img alt="" src="../images/down.gif" /> <a href="#directory"><Directory></a></li>
47 <li><img alt="" src="../images/down.gif" /> <a href="#directorymatch"><DirectoryMatch></a></li>
48 <li><img alt="" src="../images/down.gif" /> <a href="#documentroot">DocumentRoot</a></li>
49 <li><img alt="" src="../images/down.gif" /> <a href="#enablemmap">EnableMMAP</a></li>
50 <li><img alt="" src="../images/down.gif" /> <a href="#enablesendfile">EnableSendfile</a></li>
51 <li><img alt="" src="../images/down.gif" /> <a href="#errordocument">ErrorDocument</a></li>
52 <li><img alt="" src="../images/down.gif" /> <a href="#errorlog">ErrorLog</a></li>
53 <li><img alt="" src="../images/down.gif" /> <a href="#fileetag">FileETag</a></li>
54 <li><img alt="" src="../images/down.gif" /> <a href="#files"><Files></a></li>
55 <li><img alt="" src="../images/down.gif" /> <a href="#filesmatch"><FilesMatch></a></li>
56 <li><img alt="" src="../images/down.gif" /> <a href="#forcetype">ForceType</a></li>
57 <li><img alt="" src="../images/down.gif" /> <a href="#hostnamelookups">HostnameLookups</a></li>
58 <li><img alt="" src="../images/down.gif" /> <a href="#if"><If></a></li>
59 <li><img alt="" src="../images/down.gif" /> <a href="#ifdefine"><IfDefine></a></li>
60 <li><img alt="" src="../images/down.gif" /> <a href="#ifmodule"><IfModule></a></li>
61 <li><img alt="" src="../images/down.gif" /> <a href="#include">Include</a></li>
62 <li><img alt="" src="../images/down.gif" /> <a href="#keepalive">KeepAlive</a></li>
63 <li><img alt="" src="../images/down.gif" /> <a href="#keepalivetimeout">KeepAliveTimeout</a></li>
64 <li><img alt="" src="../images/down.gif" /> <a href="#limit"><Limit></a></li>
65 <li><img alt="" src="../images/down.gif" /> <a href="#limitexcept"><LimitExcept></a></li>
66 <li><img alt="" src="../images/down.gif" /> <a href="#limitinternalrecursion">LimitInternalRecursion</a></li>
67 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestbody">LimitRequestBody</a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfields">LimitRequestFields</a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfieldsize">LimitRequestFieldSize</a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestline">LimitRequestLine</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#limitxmlrequestbody">LimitXMLRequestBody</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#location"><Location></a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#locationmatch"><LocationMatch></a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#loglevel">LogLevel</a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></li>
76 <li><img alt="" src="../images/down.gif" /> <a href="#namevirtualhost">NameVirtualHost</a></li>
77 <li><img alt="" src="../images/down.gif" /> <a href="#options">Options</a></li>
78 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitcpu">RLimitCPU</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitmem">RLimitMEM</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitnproc">RLimitNPROC</a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#scriptinterpretersource">ScriptInterpreterSource</a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#serveradmin">ServerAdmin</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#serveralias">ServerAlias</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#servername">ServerName</a></li>
85 <li><img alt="" src="../images/down.gif" /> <a href="#serverpath">ServerPath</a></li>
86 <li><img alt="" src="../images/down.gif" /> <a href="#serverroot">ServerRoot</a></li>
87 <li><img alt="" src="../images/down.gif" /> <a href="#serversignature">ServerSignature</a></li>
88 <li><img alt="" src="../images/down.gif" /> <a href="#servertokens">ServerTokens</a></li>
89 <li><img alt="" src="../images/down.gif" /> <a href="#sethandler">SetHandler</a></li>
90 <li><img alt="" src="../images/down.gif" /> <a href="#setinputfilter">SetInputFilter</a></li>
91 <li><img alt="" src="../images/down.gif" /> <a href="#setoutputfilter">SetOutputFilter</a></li>
92 <li><img alt="" src="../images/down.gif" /> <a href="#timeout">TimeOut</a></li>
93 <li><img alt="" src="../images/down.gif" /> <a href="#traceenable">TraceEnable</a></li>
94 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalname">UseCanonicalName</a></li>
95 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></li>
96 <li><img alt="" src="../images/down.gif" /> <a href="#virtualhost"><VirtualHost></a></li>
100 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
101 <div class="directive-section"><h2><a name="AcceptFilter" id="AcceptFilter">AcceptFilter</a> <a name="acceptfilter" id="acceptfilter">Directive</a></h2>
102 <table class="directive">
103 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures optimizations for a Protocol's Listener Sockets</td></tr>
104 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptFilter <var>protocol</var> <var>accept_filter</var></code></td></tr>
105 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
106 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
107 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
108 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.1.5 and later.
109 On Windows from Apache 2.3.3 and later.</td></tr>
111 <p>This directive enables operating system specific optimizations for a
112 listening socket by the Protocol type. The basic premise is for the
113 kernel to not send a socket to the server process until either data
114 is received or an entire HTTP Request is buffered. Only
115 <a href="http://www.freebsd.org/cgi/man.cgi?query=accept_filter&sektion=9">
116 FreeBSD's Accept Filters</a>, Linux's more primitive
117 <code>TCP_DEFER_ACCEPT</code>, and Windows' optimized AcceptEx()
118 are currently supported.</p>
120 <p>Using <code>none</code> for an argument will disable any accept filters
121 for that protocol. This is useful for protocols that require a server
122 send data first, such as <code>ftp:</code> or <code>nntp</code>:</p>
123 <div class="example"><p><code>AcceptFilter nntp none</code></p></div>
125 <p>The default values on FreeBSD are:</p>
126 <div class="example"><p><code>
127 AcceptFilter http httpready <br />
128 AcceptFilter https dataready
131 <p>The <code>httpready</code> accept filter buffers entire HTTP requests at
132 the kernel level. Once an entire request is received, the kernel then
133 sends it to the server. See the
134 <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_http&sektion=9">
135 accf_http(9)</a> man page for more details. Since HTTPS requests are
136 encrypted only the <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_data&sektion=9">
137 accf_data(9)</a> filter is used.</p>
139 <p>The default values on Linux are:</p>
140 <div class="example"><p><code>
141 AcceptFilter http data <br />
142 AcceptFilter https data
145 <p>Linux's <code>TCP_DEFER_ACCEPT</code> does not support buffering http
146 requests. Any value besides <code>none</code> will enable
147 <code>TCP_DEFER_ACCEPT</code> on that listener. For more details
149 <a href="http://homepages.cwi.nl/~aeb/linux/man2html/man7/tcp.7.html">
150 tcp(7)</a> man page.</p>
152 <p>The default values on Windows are:</p>
153 <div class="example"><p><code>
154 AcceptFilter http data <br />
155 AcceptFilter https data
158 <p>Window's mpm_winnt interprets the AcceptFilter to toggle the AcceptEx()
159 API, and does not support http protocol buffering. There are two values
160 which utilize the Windows AcceptEx() API and will recycle network
161 sockets between connections. <code>data</code> waits until data has
162 been transmitted as documented above, and the initial data buffer and
163 network endpoint addresses are all retrieved from the single AcceptEx()
164 invocation. <code>connect</code> will use the AcceptEx() API, also
165 retrieve the network endpoint addresses, but like <code>none</code>
166 the <code>connect</code> option does not wait for the initial data
169 <p>On Windows, <code>none</code> uses accept() rather than than AcceptEx()
170 and will not recycle sockets between connections. This is useful for
171 network adapters with broken driver support, as well as some virtual
172 network providers such as vpn drivers, or spam, virus or spyware
177 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
178 <div class="directive-section"><h2><a name="AcceptPathInfo" id="AcceptPathInfo">AcceptPathInfo</a> <a name="acceptpathinfo" id="acceptpathinfo">Directive</a></h2>
179 <table class="directive">
180 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Resources accept trailing pathname information</td></tr>
181 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptPathInfo On|Off|Default</code></td></tr>
182 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AcceptPathInfo Default</code></td></tr>
183 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
184 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
185 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
186 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
187 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.30 and later</td></tr>
190 <p>This directive controls whether requests that contain trailing
191 pathname information that follows an actual filename (or
192 non-existent file in an existing directory) will be accepted or
193 rejected. The trailing pathname information can be made
194 available to scripts in the <code>PATH_INFO</code> environment
197 <p>For example, assume the location <code>/test/</code> points to
198 a directory that contains only the single file
199 <code>here.html</code>. Then requests for
200 <code>/test/here.html/more</code> and
201 <code>/test/nothere.html/more</code> both collect
202 <code>/more</code> as <code>PATH_INFO</code>.</p>
204 <p>The three possible arguments for the
205 <code class="directive">AcceptPathInfo</code> directive are:</p>
207 <dt><code>Off</code></dt><dd>A request will only be accepted if it
208 maps to a literal path that exists. Therefore a request with
209 trailing pathname information after the true filename such as
210 <code>/test/here.html/more</code> in the above example will return
211 a 404 NOT FOUND error.</dd>
213 <dt><code>On</code></dt><dd>A request will be accepted if a
214 leading path component maps to a file that exists. The above
215 example <code>/test/here.html/more</code> will be accepted if
216 <code>/test/here.html</code> maps to a valid file.</dd>
218 <dt><code>Default</code></dt><dd>The treatment of requests with
219 trailing pathname information is determined by the <a href="../handler.html">handler</a> responsible for the request.
220 The core handler for normal files defaults to rejecting
221 <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
222 <code>PATH_INFO</code> by default.</dd>
225 <p>The primary purpose of the <code>AcceptPathInfo</code>
226 directive is to allow you to override the handler's choice of
227 accepting or rejecting <code>PATH_INFO</code>. This override is required,
228 for example, when you use a <a href="../filter.html">filter</a>, such
229 as <a href="mod_include.html">INCLUDES</a>, to generate content
230 based on <code>PATH_INFO</code>. The core handler would usually reject
231 the request, so you can use the following configuration to enable
234 <div class="example"><p><code>
235 <Files "mypaths.shtml"><br />
236 <span class="indent">
237 Options +Includes<br />
238 SetOutputFilter INCLUDES<br />
239 AcceptPathInfo On<br />
246 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
247 <div class="directive-section"><h2><a name="AccessFileName" id="AccessFileName">AccessFileName</a> <a name="accessfilename" id="accessfilename">Directive</a></h2>
248 <table class="directive">
249 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Name of the distributed configuration file</td></tr>
250 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AccessFileName <var>filename</var> [<var>filename</var>] ...</code></td></tr>
251 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AccessFileName .htaccess</code></td></tr>
252 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
253 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
254 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
256 <p>While processing a request the server looks for
257 the first existing configuration file from this list of names in
258 every directory of the path to the document, if distributed
259 configuration files are <a href="#allowoverride">enabled for that
260 directory</a>. For example:</p>
262 <div class="example"><p><code>
266 <p>before returning the document
267 <code>/usr/local/web/index.html</code>, the server will read
268 <code>/.acl</code>, <code>/usr/.acl</code>,
269 <code>/usr/local/.acl</code> and <code>/usr/local/web/.acl</code>
270 for directives, unless they have been disabled with</p>
272 <div class="example"><p><code>
273 <Directory /><br />
274 <span class="indent">
275 AllowOverride None<br />
282 <li><code class="directive"><a href="#allowoverride">AllowOverride</a></code></li>
283 <li><a href="../configuring.html">Configuration Files</a></li>
284 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
287 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
288 <div class="directive-section"><h2><a name="AddDefaultCharset" id="AddDefaultCharset">AddDefaultCharset</a> <a name="adddefaultcharset" id="adddefaultcharset">Directive</a></h2>
289 <table class="directive">
290 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default charset parameter to be added when a response
291 content-type is <code>text/plain</code> or <code>text/html</code></td></tr>
292 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddDefaultCharset On|Off|<var>charset</var></code></td></tr>
293 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AddDefaultCharset Off</code></td></tr>
294 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
295 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
296 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
297 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
299 <p>This directive specifies a default value for the media type
300 charset parameter (the name of a character encoding) to be added
301 to a response if and only if the response's content-type is either
302 <code>text/plain</code> or <code>text/html</code>. This should override
303 any charset specified in the body of the response via a <code>META</code>
304 element, though the exact behavior is often dependent on the user's client
305 configuration. A setting of <code>AddDefaultCharset Off</code>
306 disables this functionality. <code>AddDefaultCharset On</code> enables
307 a default charset of <code>iso-8859-1</code>. Any other value is assumed
308 to be the <var>charset</var> to be used, which should be one of the
309 <a href="http://www.iana.org/assignments/character-sets">IANA registered
310 charset values</a> for use in Internet media types (MIME types).
313 <div class="example"><p><code>
314 AddDefaultCharset utf-8
317 <p><code class="directive">AddDefaultCharset</code> should only be used when all
318 of the text resources to which it applies are known to be in that
319 character encoding and it is too inconvenient to label their charset
320 individually. One such example is to add the charset parameter
321 to resources containing generated content, such as legacy CGI
322 scripts, that might be vulnerable to cross-site scripting attacks
323 due to user-provided data being included in the output. Note, however,
324 that a better solution is to just fix (or delete) those scripts, since
325 setting a default charset does not protect users that have enabled
326 the "auto-detect character encoding" feature on their browser.</p>
330 <li><code class="directive"><a href="../mod/mod_mime.html#addcharset">AddCharset</a></code></li>
333 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
334 <div class="directive-section"><h2><a name="AddOutputFilterByType" id="AddOutputFilterByType">AddOutputFilterByType</a> <a name="addoutputfilterbytype" id="addoutputfilterbytype">Directive</a></h2>
335 <table class="directive">
336 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>assigns an output filter to a particular media-type</td></tr>
337 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddOutputFilterByType <var>filter</var>[;<var>filter</var>...]
338 <var>media-type</var> [<var>media-type</var>] ...</code></td></tr>
339 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
340 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
341 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
342 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
343 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.33 and later; deprecated in Apache 2.1 and later</td></tr>
345 <p>This directive activates a particular output <a href="../filter.html">filter</a> for a request depending on the
346 response <a class="glossarylink" href="../glossary.html#media-type" title="see glossary">media-type</a>. Because of certain
347 problems discussed below, this directive is deprecated. The same
348 functionality is available using <code class="module"><a href="../mod/mod_filter.html">mod_filter</a></code>.</p>
350 <p>The following example uses the <code>DEFLATE</code> filter, which
351 is provided by <code class="module"><a href="../mod/mod_deflate.html">mod_deflate</a></code>. It will compress all
352 output (either static or dynamic) which is labeled as
353 <code>text/html</code> or <code>text/plain</code> before it is sent
356 <div class="example"><p><code>
357 AddOutputFilterByType DEFLATE text/html text/plain
360 <p>If you want the content to be processed by more than one filter, their
361 names have to be separated by semicolons. It's also possible to use one
362 <code class="directive">AddOutputFilterByType</code> directive for each of
365 <p>The configuration below causes all script output labeled as
366 <code>text/html</code> to be processed at first by the
367 <code>INCLUDES</code> filter and then by the <code>DEFLATE</code>
370 <div class="example"><p><code>
371 <Location /cgi-bin/><br />
372 <span class="indent">
373 Options Includes<br />
374 AddOutputFilterByType INCLUDES;DEFLATE text/html<br />
379 <div class="warning"><h3>Note</h3>
380 <p>Enabling filters with <code class="directive">AddOutputFilterByType</code>
381 may fail partially or completely in some cases. For example, no
382 filters are applied if the <a class="glossarylink" href="../glossary.html#media-type" title="see glossary">media-type</a> could not
383 be determined. If you want to make sure that the filters will be
384 applied, assign the content type to a resource explicitly; for
385 example, with <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> or
386 <code class="directive"><a href="#forcetype">ForceType</a></code>. Setting the
387 content type within a (non-nph) CGI script is also safe.</p>
393 <li><code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code></li>
394 <li><code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code></li>
395 <li><a href="../filter.html">filters</a></li>
398 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
399 <div class="directive-section"><h2><a name="AllowEncodedSlashes" id="AllowEncodedSlashes">AllowEncodedSlashes</a> <a name="allowencodedslashes" id="allowencodedslashes">Directive</a></h2>
400 <table class="directive">
401 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines whether encoded path separators in URLs are allowed to
402 be passed through</td></tr>
403 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowEncodedSlashes On|Off</code></td></tr>
404 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowEncodedSlashes Off</code></td></tr>
405 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
406 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
407 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
408 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.46 and later</td></tr>
410 <p>The <code class="directive">AllowEncodedSlashes</code> directive allows URLs
411 which contain encoded path separators (<code>%2F</code> for <code>/</code>
412 and additionally <code>%5C</code> for <code>\</code> on according systems)
413 to be used. Normally such URLs are refused with a 404 (Not found) error.</p>
415 <p>Turning <code class="directive">AllowEncodedSlashes</code> <code>On</code> is
416 mostly useful when used in conjunction with <code>PATH_INFO</code>.</p>
418 <div class="note"><h3>Note</h3>
419 <p>Allowing encoded slashes does <em>not</em> imply <em>decoding</em>.
420 Occurrences of <code>%2F</code> or <code>%5C</code> (<em>only</em> on
421 according systems) will be left as such in the otherwise decoded URL
427 <li><code class="directive"><a href="#acceptpathinfo">AcceptPathInfo</a></code></li>
430 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
431 <div class="directive-section"><h2><a name="AllowOverride" id="AllowOverride">AllowOverride</a> <a name="allowoverride" id="allowoverride">Directive</a></h2>
432 <table class="directive">
433 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Types of directives that are allowed in
434 <code>.htaccess</code> files</td></tr>
435 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowOverride All|None|<var>directive-type</var>
436 [<var>directive-type</var>] ...</code></td></tr>
437 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowOverride All</code></td></tr>
438 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
439 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
440 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
442 <p>When the server finds an <code>.htaccess</code> file (as
443 specified by <code class="directive"><a href="#accessfilename">AccessFileName</a></code>)
444 it needs to know which directives declared in that file can override
445 earlier configuration directives.</p>
447 <div class="note"><h3>Only available in <Directory> sections</h3>
448 <code class="directive">AllowOverride</code> is valid only in
449 <code class="directive"><a href="#directory"><Directory></a></code>
450 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
451 <code class="directive"><a href="#files"><Files></a></code> sections.
454 <p>When this directive is set to <code>None</code>, then
455 <a href="#accessfilename">.htaccess</a> files are completely ignored.
456 In this case, the server will not even attempt to read
457 <code>.htaccess</code> files in the filesystem.</p>
459 <p>When this directive is set to <code>All</code>, then any
460 directive which has the .htaccess <a href="directive-dict.html#Context">Context</a> is allowed in
461 <code>.htaccess</code> files.</p>
463 <p>The <var>directive-type</var> can be one of the following
464 groupings of directives.</p>
471 Allow use of the authorization directives (<code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmgroupfile">AuthDBMGroupFile</a></code>,
472 <code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmuserfile">AuthDBMUserFile</a></code>,
473 <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code>,
474 <code class="directive"><a href="../mod/mod_authn_core.html#authname">AuthName</a></code>,
475 <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>
480 Allow use of the directives controlling document types
481 (<code class="directive"><a href="#errordocument">ErrorDocument</a></code>,
482 <code class="directive"><a href="#forcetype">ForceType</a></code>,
483 <code class="directive"><a href="../mod/mod_negotiation.html#languagepriority">LanguagePriority</a></code>,
484 <code class="directive"><a href="#sethandler">SetHandler</a></code>,
485 <code class="directive"><a href="#setinputfilter">SetInputFilter</a></code>,
486 <code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code>, and
487 <code class="module"><a href="../mod/mod_mime.html">mod_mime</a></code> Add* and Remove* directives),
488 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>),
489 <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
490 <code class="directive"><a href="../mod/mod_actions.html#action">Action</a></code> from
491 <code class="module"><a href="../mod/mod_actions.html">mod_actions</a></code>.
497 Allow use of the directives controlling directory indexing
498 (<code class="directive"><a href="../mod/mod_autoindex.html#adddescription">AddDescription</a></code>,
499 <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>,
500 <code class="directive"><a href="../mod/mod_autoindex.html#addiconbytype">AddIconByType</a></code>,
501 <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>,
507 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>
509 <dt>Options[=<var>Option</var>,...]</dt>
512 Allow use of the directives controlling specific directory
513 features (<code class="directive"><a href="#options">Options</a></code> and
514 <code class="directive"><a href="../mod/mod_include.html#xbithack">XBitHack</a></code>).
515 An equal sign may be given followed by a comma (but no spaces)
516 separated lists of options that may be set using the <code class="directive"><a href="#options">Options</a></code> command.</dd>
521 <div class="example"><p><code>
522 AllowOverride AuthConfig Indexes
525 <p>In the example above all directives that are neither in the group
526 <code>AuthConfig</code> nor <code>Indexes</code> cause an internal
529 <div class="note"><p>For security and performance reasons, do not set
530 <code>AllowOverride</code> to anything other than <code>None</code>
531 in your <code><Directory /></code> block. Instead, find (or
532 create) the <code><Directory></code> block that refers to the
533 directory where you're actually planning to place a
534 <code>.htaccess</code> file.</p>
539 <li><code class="directive"><a href="#accessfilename">AccessFileName</a></code></li>
540 <li><a href="../configuring.html">Configuration Files</a></li>
541 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
544 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
545 <div class="directive-section"><h2><a name="CGIMapExtension" id="CGIMapExtension">CGIMapExtension</a> <a name="cgimapextension" id="cgimapextension">Directive</a></h2>
546 <table class="directive">
547 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
549 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CGIMapExtension <var>cgi-path</var> <var>.extension</var></code></td></tr>
550 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
551 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
552 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
553 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
554 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>NetWare only</td></tr>
556 <p>This directive is used to control how Apache finds the
557 interpreter used to run CGI scripts. For example, setting
558 <code>CGIMapExtension sys:\foo.nlm .foo</code> will
559 cause all CGI script files with a <code>.foo</code> extension to
560 be passed to the FOO interpreter.</p>
563 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
564 <div class="directive-section"><h2><a name="ContentDigest" id="ContentDigest">ContentDigest</a> <a name="contentdigest" id="contentdigest">Directive</a></h2>
565 <table class="directive">
566 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables the generation of <code>Content-MD5</code> HTTP Response
568 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ContentDigest On|Off</code></td></tr>
569 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ContentDigest Off</code></td></tr>
570 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
571 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
572 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
573 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
575 <p>This directive enables the generation of
576 <code>Content-MD5</code> headers as defined in RFC1864
577 respectively RFC2616.</p>
579 <p>MD5 is an algorithm for computing a "message digest"
580 (sometimes called "fingerprint") of arbitrary-length data, with
581 a high degree of confidence that any alterations in the data
582 will be reflected in alterations in the message digest.</p>
584 <p>The <code>Content-MD5</code> header provides an end-to-end
585 message integrity check (MIC) of the entity-body. A proxy or
586 client may check this header for detecting accidental
587 modification of the entity-body in transit. Example header:</p>
589 <div class="example"><p><code>
590 Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA==
593 <p>Note that this can cause performance problems on your server
594 since the message digest is computed on every request (the
595 values are not cached).</p>
597 <p><code>Content-MD5</code> is only sent for documents served
598 by the <code class="module"><a href="../mod/core.html">core</a></code>, and not by any module. For example,
599 SSI documents, output from CGI scripts, and byte range responses
600 do not have this header.</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="DefaultType" id="DefaultType">DefaultType</a> <a name="defaulttype" id="defaulttype">Directive</a></h2>
605 <table class="directive">
606 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>This directive has no effect other than to emit warnings
607 if the value is not <code>none</code>. In prior versions, DefaultType
608 would specify a default media type to assign to response content for
609 which no other media type configuration could be found.
611 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DefaultType <var>media-type|none</var></code></td></tr>
612 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DefaultType none</code></td></tr>
613 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
614 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
615 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
616 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
617 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The argument <code>none</code> is available in Apache 2.2.7 and later. All other choices are DISABLED for 2.3.x and later.</td></tr>
619 <p>This directive has been disabled. For backwards compatibility
620 of configuration files, it may be specified with the value
621 <code>none</code>, meaning no default media type. For example:</p>
623 <div class="example"><p><code>
627 <p><code>DefaultType None</code> is only available in
628 httpd-2.2.7 and later.</p>
630 <p>Use the mime.types configuration file and the
631 <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> to configure media
632 type assignments via file extensions, or the
633 <code class="directive"><a href="#forcetype">ForceType</a></code> directive to configure
634 the media type for specific resources. Otherwise, the server will
635 send the response without a Content-Type header field and the
636 recipient may attempt to guess the media type.</p>
639 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
640 <div class="directive-section"><h2><a name="Define" id="Define">Define</a> <a name="define" id="define">Directive</a></h2>
641 <table class="directive">
642 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define the existence of a variable</td></tr>
643 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Define <var>parameter-name</var></code></td></tr>
644 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
645 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
646 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
648 <p>Equivalent to passing the <code>-D</code> argument to <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</p>
649 <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
650 <code>-D</code> arguments in any startup scripts.</p>
653 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
654 <div class="directive-section"><h2><a name="Directory" id="Directory"><Directory></a> <a name="directory" id="directory">Directive</a></h2>
655 <table class="directive">
656 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose a group of directives that apply only to the
657 named file-system directory and sub-directories</td></tr>
658 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Directory <var>directory-path</var>>
659 ... </Directory></code></td></tr>
660 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
661 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
662 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
664 <p><code class="directive"><Directory></code> and
665 <code></Directory></code> are used to enclose a group of
666 directives that will apply only to the named directory and
667 sub-directories of that directory. Any directive that is allowed
668 in a directory context may be used. <var>Directory-path</var> is
669 either the full path to a directory, or a wild-card string using
670 Unix shell-style matching. In a wild-card string, <code>?</code> matches
671 any single character, and <code>*</code> matches any sequences of
672 characters. You may also use <code>[]</code> character ranges. None
673 of the wildcards match a `/' character, so <code><Directory
674 /*/public_html></code> will not match
675 <code>/home/user/public_html</code>, but <code><Directory
676 /home/*/public_html></code> will match. Example:</p>
678 <div class="example"><p><code>
679 <Directory /usr/local/httpd/htdocs><br />
680 <span class="indent">
681 Options Indexes FollowSymLinks<br />
687 <p>Be careful with the <var>directory-path</var> arguments:
688 They have to literally match the filesystem path which Apache uses
689 to access the files. Directives applied to a particular
690 <code><Directory></code> will not apply to files accessed from
691 that same directory via a different path, such as via different symbolic
695 <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular
696 expressions</a> can also be used, with the addition of the
697 <code>~</code> character. For example:</p>
699 <div class="example"><p><code>
700 <Directory ~ "^/www/.*/[0-9]{3}">
703 <p>would match directories in <code>/www/</code> that consisted of
706 <p>If multiple (non-regular expression) <code class="directive"><Directory></code> sections
707 match the directory (or one of its parents) containing a document,
708 then the directives are applied in the order of shortest match
709 first, interspersed with the directives from the <a href="#accessfilename">.htaccess</a> files. For example,
712 <div class="example"><p><code>
713 <Directory /><br />
714 <span class="indent">
715 AllowOverride None<br />
717 </Directory><br />
719 <Directory /home/><br />
720 <span class="indent">
721 AllowOverride FileInfo<br />
726 <p>for access to the document <code>/home/web/dir/doc.html</code>
730 <li>Apply directive <code>AllowOverride None</code>
731 (disabling <code>.htaccess</code> files).</li>
733 <li>Apply directive <code>AllowOverride FileInfo</code> (for
734 directory <code>/home</code>).</li>
736 <li>Apply any <code>FileInfo</code> directives in
737 <code>/home/.htaccess</code>, <code>/home/web/.htaccess</code> and
738 <code>/home/web/dir/.htaccess</code> in that order.</li>
741 <p>Regular expressions are not considered until after all of the
742 normal sections have been applied. Then all of the regular
743 expressions are tested in the order they appeared in the
744 configuration file. For example, with</p>
746 <div class="example"><p><code>
747 <Directory ~ abc$><br />
748 <span class="indent">
749 # ... directives here ...<br />
754 <p>the regular expression section won't be considered until after
755 all normal <code class="directive"><Directory></code>s and
756 <code>.htaccess</code> files have been applied. Then the regular
757 expression will match on <code>/home/abc/public_html/abc</code> and
758 the corresponding <code class="directive"><Directory></code> will
761 <p><strong>Note that the default Apache access for
762 <code><Directory /></code> is <code>Allow from All</code>.
763 This means that Apache will serve any file mapped from an URL. It is
764 recommended that you change this with a block such
767 <div class="example"><p><code>
768 <Directory /><br />
769 <span class="indent">
770 Order Deny,Allow<br />
776 <p><strong>and then override this for directories you
777 <em>want</em> accessible. See the <a href="../misc/security_tips.html">Security Tips</a> page for more
778 details.</strong></p>
780 <p>The directory sections occur in the <code>httpd.conf</code> file.
781 <code class="directive"><Directory></code> directives
782 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>
786 <li><a href="../sections.html">How <Directory>,
787 <Location> and <Files> sections work</a> for an
788 explanation of how these different sections are combined when a
789 request is received</li>
792 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
793 <div class="directive-section"><h2><a name="DirectoryMatch" id="DirectoryMatch"><DirectoryMatch></a> <a name="directorymatch" id="directorymatch">Directive</a></h2>
794 <table class="directive">
795 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose directives that apply to
796 file-system directories matching a regular expression and their
797 subdirectories</td></tr>
798 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><DirectoryMatch <var>regex</var>>
799 ... </DirectoryMatch></code></td></tr>
800 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
801 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
802 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
804 <p><code class="directive"><DirectoryMatch></code> and
805 <code></DirectoryMatch></code> are used to enclose a group
806 of directives which will apply only to the named directory and
807 sub-directories of that directory, the same as <code class="directive"><a href="#directory"><Directory></a></code>. However, it
808 takes as an argument a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular
809 expression</a>. For example:</p>
811 <div class="example"><p><code>
812 <DirectoryMatch "^/www/(.+/)?[0-9]{3}">
815 <p>would match directories in <code>/www/</code> that consisted of three
820 <li><code class="directive"><a href="#directory"><Directory></a></code> for
821 a description of how regular expressions are mixed in with normal
822 <code class="directive"><Directory></code>s</li>
823 <li><a href="../sections.html">How <Directory>, <Location> and
824 <Files> sections work</a> for an explanation of how these different
825 sections are combined when a request is received</li>
828 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
829 <div class="directive-section"><h2><a name="DocumentRoot" id="DocumentRoot">DocumentRoot</a> <a name="documentroot" id="documentroot">Directive</a></h2>
830 <table class="directive">
831 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory that forms the main document tree visible
832 from the web</td></tr>
833 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DocumentRoot <var>directory-path</var></code></td></tr>
834 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DocumentRoot /usr/local/apache/htdocs</code></td></tr>
835 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
836 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
837 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
839 <p>This directive sets the directory from which <code class="program"><a href="../programs/httpd.html">httpd</a></code>
840 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
841 path from the requested URL to the document root to make the
842 path to the document. Example:</p>
844 <div class="example"><p><code>
845 DocumentRoot /usr/web
849 <code>http://www.my.host.com/index.html</code> refers to
850 <code>/usr/web/index.html</code>. If the <var>directory-path</var> is
851 not absolute then it is assumed to be relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
853 <p>The <code class="directive">DocumentRoot</code> should be specified without
854 a trailing slash.</p>
858 <li><a href="../urlmapping.html#documentroot">Mapping URLs to Filesystem
862 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
863 <div class="directive-section"><h2><a name="EnableMMAP" id="EnableMMAP">EnableMMAP</a> <a name="enablemmap" id="enablemmap">Directive</a></h2>
864 <table class="directive">
865 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use memory-mapping to read files during delivery</td></tr>
866 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableMMAP On|Off</code></td></tr>
867 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableMMAP On</code></td></tr>
868 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
869 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
870 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
871 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
873 <p>This directive controls whether the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use
874 memory-mapping if it needs to read the contents of a file during
875 delivery. By default, when the handling of a request requires
876 access to the data within a file -- for example, when delivering a
877 server-parsed file using <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> -- Apache
878 memory-maps the file if the OS supports it.</p>
880 <p>This memory-mapping sometimes yields a performance improvement.
881 But in some environments, it is better to disable the memory-mapping
882 to prevent operational problems:</p>
885 <li>On some multiprocessor systems, memory-mapping can reduce the
886 performance of the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</li>
887 <li>With an NFS-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code>,
888 the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may crash due to a segmentation fault if a file
889 is deleted or truncated while the <code class="program"><a href="../programs/httpd.html">httpd</a></code> has it
893 <p>For server configurations that are vulnerable to these problems,
894 you should disable memory-mapping of delivered files by specifying:</p>
896 <div class="example"><p><code>
900 <p>For NFS mounted files, this feature may be disabled explicitly for
901 the offending files by specifying:</p>
903 <div class="example"><p><code>
904 <Directory "/path-to-nfs-files">
905 <span class="indent">
912 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
913 <div class="directive-section"><h2><a name="EnableSendfile" id="EnableSendfile">EnableSendfile</a> <a name="enablesendfile" id="enablesendfile">Directive</a></h2>
914 <table class="directive">
915 <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>
916 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableSendfile On|Off</code></td></tr>
917 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableSendfile On</code></td></tr>
918 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
919 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
920 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
921 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
922 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0.44 and later</td></tr>
924 <p>This directive controls whether <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use the
925 sendfile support from the kernel to transmit file contents to the client.
926 By default, when the handling of a request requires no access
927 to the data within a file -- for example, when delivering a
928 static file -- Apache uses sendfile to deliver the file contents
929 without ever reading the file if the OS supports it.</p>
931 <p>This sendfile mechanism avoids separate read and send operations,
932 and buffer allocations. But on some platforms or within some
933 filesystems, it is better to disable this feature to avoid
934 operational problems:</p>
937 <li>Some platforms may have broken sendfile support that the build
938 system did not detect, especially if the binaries were built on
939 another box and moved to such a machine with broken sendfile
941 <li>On Linux the use of sendfile triggers TCP-checksum
942 offloading bugs on certain networking cards when using IPv6.</li>
943 <li>On Linux on Itanium, sendfile may be unable to handle files
944 over 2GB in size.</li>
945 <li>With a network-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code> (e.g., NFS or SMB),
946 the kernel may be unable to serve the network file through
950 <p>For server configurations that are vulnerable to these problems,
951 you should disable this feature by specifying:</p>
953 <div class="example"><p><code>
957 <p>For NFS or SMB mounted files, this feature may be disabled explicitly
958 for the offending files by specifying:</p>
960 <div class="example"><p><code>
961 <Directory "/path-to-nfs-files">
962 <span class="indent">
967 <p>Please note that the per-directory and .htaccess configuration
968 of <code class="directive">EnableSendfile</code> is not supported by
969 <code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code>.
970 Only global definition of <code class="directive">EnableSendfile</code>
971 is taken into account by the module.
975 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
976 <div class="directive-section"><h2><a name="ErrorDocument" id="ErrorDocument">ErrorDocument</a> <a name="errordocument" id="errordocument">Directive</a></h2>
977 <table class="directive">
978 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>What the server will return to the client
979 in case of an error</td></tr>
980 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorDocument <var>error-code</var> <var>document</var></code></td></tr>
981 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
982 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
983 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
984 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
985 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Quoting syntax for text messages is different in Apache
988 <p>In the event of a problem or error, Apache can be configured
989 to do one of four things,</p>
992 <li>output a simple hardcoded error message</li>
994 <li>output a customized message</li>
996 <li>redirect to a local <var>URL-path</var> to handle the
999 <li>redirect to an external <var>URL</var> to handle the
1003 <p>The first option is the default, while options 2-4 are
1004 configured using the <code class="directive">ErrorDocument</code>
1005 directive, which is followed by the HTTP response code and a URL
1006 or a message. Apache will sometimes offer additional information
1007 regarding the problem/error.</p>
1009 <p>URLs can begin with a slash (/) for local web-paths (relative
1010 to the <code class="directive"><a href="#documentroot">DocumentRoot</a></code>), or be a
1011 full URL which the client can resolve. Alternatively, a message
1012 can be provided to be displayed by the browser. Examples:</p>
1014 <div class="example"><p><code>
1015 ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br />
1016 ErrorDocument 404 /cgi-bin/bad_urls.pl<br />
1017 ErrorDocument 401 /subscription_info.html<br />
1018 ErrorDocument 403 "Sorry can't allow you access today"
1021 <p>Additionally, the special value <code>default</code> can be used
1022 to specify Apache's simple hardcoded message. While not required
1023 under normal circumstances, <code>default</code> will restore
1024 Apache's simple hardcoded message for configurations that would
1025 otherwise inherit an existing <code class="directive">ErrorDocument</code>.</p>
1027 <div class="example"><p><code>
1028 ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br />
1029 <Directory /web/docs><br />
1030 <span class="indent">
1031 ErrorDocument 404 default<br />
1036 <p>Note that when you specify an <code class="directive">ErrorDocument</code>
1037 that points to a remote URL (ie. anything with a method such as
1038 <code>http</code> in front of it), Apache will send a redirect to the
1039 client to tell it where to find the document, even if the
1040 document ends up being on the same server. This has several
1041 implications, the most important being that the client will not
1042 receive the original error status code, but instead will
1043 receive a redirect status code. This in turn can confuse web
1044 robots and other clients which try to determine if a URL is
1045 valid using the status code. In addition, if you use a remote
1046 URL in an <code>ErrorDocument 401</code>, the client will not
1047 know to prompt the user for a password since it will not
1048 receive the 401 status code. Therefore, <strong>if you use an
1049 <code>ErrorDocument 401</code> directive then it must refer to a local
1050 document.</strong></p>
1052 <p>Microsoft Internet Explorer (MSIE) will by default ignore
1053 server-generated error messages when they are "too small" and substitute
1054 its own "friendly" error messages. The size threshold varies depending on
1055 the type of error, but in general, if you make your error document
1056 greater than 512 bytes, then MSIE will show the server-generated
1057 error rather than masking it. More information is available in
1058 Microsoft Knowledge Base article <a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807">Q294807</a>.</p>
1060 <p>Although most error messages can be overriden, there are certain
1061 circumstances where the internal messages are used regardless of the
1062 setting of <code class="directive"><a href="#errordocument">ErrorDocument</a></code>. In
1063 particular, if a malformed request is detected, normal request processing
1064 will be immediately halted and the internal error message returned.
1065 This is necessary to guard against security problems caused by
1068 <p>Prior to version 2.0, messages were indicated by prefixing
1069 them with a single unmatched double quote character.</p>
1073 <li><a href="../custom-error.html">documentation of
1074 customizable responses</a></li>
1077 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1078 <div class="directive-section"><h2><a name="ErrorLog" id="ErrorLog">ErrorLog</a> <a name="errorlog" id="errorlog">Directive</a></h2>
1079 <table class="directive">
1080 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Location where the server will log errors</td></tr>
1081 <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>
1082 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows)</code></td></tr>
1083 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1084 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1085 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1087 <p>The <code class="directive">ErrorLog</code> directive sets the name of
1088 the file to which the server will log any errors it encounters. If
1089 the <var>file-path</var> is not absolute then it is assumed to be
1090 relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
1092 <div class="example"><h3>Example</h3><p><code>
1093 ErrorLog /var/log/httpd/error_log
1096 <p>If the <var>file-path</var>
1097 begins with a pipe (|) then it is assumed to be a command to spawn
1098 to handle the error log.</p>
1100 <div class="example"><h3>Example</h3><p><code>
1101 ErrorLog "|/usr/local/bin/httpd_errors"
1104 <p>Using <code>syslog</code> instead of a filename enables logging
1105 via syslogd(8) if the system supports it. The default is to use
1106 syslog facility <code>local7</code>, but you can override this by
1107 using the <code>syslog:<var>facility</var></code> syntax where
1108 <var>facility</var> can be one of the names usually documented in
1111 <div class="example"><h3>Example</h3><p><code>
1112 ErrorLog syslog:user
1115 <p>SECURITY: See the <a href="../misc/security_tips.html#serverroot">security tips</a>
1116 document for details on why your security could be compromised
1117 if the directory where log files are stored is writable by
1118 anyone other than the user that starts the server.</p>
1119 <div class="warning"><h3>Note</h3>
1120 <p>When entering a file path on non-Unix platforms, care should be taken
1121 to make sure that only forward slashed are used even though the platform
1122 may allow the use of back slashes. In general it is a good idea to always
1123 use forward slashes throughout the configuration files.</p>
1128 <li><code class="directive"><a href="#loglevel">LogLevel</a></code></li>
1129 <li><a href="../logs.html">Apache Log Files</a></li>
1132 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1133 <div class="directive-section"><h2><a name="FileETag" id="FileETag">FileETag</a> <a name="fileetag" id="fileetag">Directive</a></h2>
1134 <table class="directive">
1135 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>File attributes used to create the ETag
1136 HTTP response header</td></tr>
1137 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>FileETag <var>component</var> ...</code></td></tr>
1138 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>FileETag INode MTime Size</code></td></tr>
1139 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1140 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1141 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1142 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1145 The <code class="directive">FileETag</code> directive configures the file
1146 attributes that are used to create the <code>ETag</code> (entity
1147 tag) response header field when the document is based on a file.
1148 (The <code>ETag</code> value is used in cache management to save
1149 network bandwidth.) In Apache 1.3.22 and earlier, the
1150 <code>ETag</code> value was <em>always</em> formed
1151 from the file's inode, size, and last-modified time (mtime). The
1152 <code class="directive">FileETag</code> directive allows you to choose
1153 which of these -- if any -- should be used. The recognized keywords are:
1157 <dt><strong>INode</strong></dt>
1158 <dd>The file's i-node number will be included in the calculation</dd>
1159 <dt><strong>MTime</strong></dt>
1160 <dd>The date and time the file was last modified will be included</dd>
1161 <dt><strong>Size</strong></dt>
1162 <dd>The number of bytes in the file will be included</dd>
1163 <dt><strong>All</strong></dt>
1164 <dd>All available fields will be used. This is equivalent to:
1165 <div class="example"><p><code>FileETag INode MTime Size</code></p></div></dd>
1166 <dt><strong>None</strong></dt>
1167 <dd>If a document is file-based, no <code>ETag</code> field will be
1168 included in the response</dd>
1171 <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code>
1172 keywords may be prefixed with either <code>+</code> or <code>-</code>,
1173 which allow changes to be made to the default setting inherited
1174 from a broader scope. Any keyword appearing without such a prefix
1175 immediately and completely cancels the inherited setting.</p>
1177 <p>If a directory's configuration includes
1178 <code>FileETag INode MTime Size</code>, and a
1179 subdirectory's includes <code>FileETag -INode</code>,
1180 the setting for that subdirectory (which will be inherited by
1181 any sub-subdirectories that don't override it) will be equivalent to
1182 <code>FileETag MTime Size</code>.</p>
1183 <div class="warning"><h3>Warning</h3>
1184 Do not change the default for directories or locations that have WebDAV
1185 enabled and use <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> as a storage provider.
1186 <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> uses <code>INode MTime Size</code>
1187 as a fixed format for <code>ETag</code> comparisons on conditional requests.
1188 These conditional requests will break if the <code>ETag</code> format is
1189 changed via <code class="directive">FileETag</code>.
1193 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1194 <div class="directive-section"><h2><a name="Files" id="Files"><Files></a> <a name="files" id="files">Directive</a></h2>
1195 <table class="directive">
1196 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to matched
1198 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Files <var>filename</var>> ... </Files></code></td></tr>
1199 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1200 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1201 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1202 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1204 <p>The <code class="directive"><Files></code> directive
1205 limits the scope of the enclosed directives by filename. It is comparable
1206 to the <code class="directive"><a href="#directory"><Directory></a></code>
1207 and <code class="directive"><a href="#location"><Location></a></code>
1208 directives. It should be matched with a <code></Files></code>
1209 directive. The directives given within this section will be applied to
1210 any object with a basename (last component of filename) matching the
1211 specified filename. <code class="directive"><Files></code>
1212 sections are processed in the order they appear in the
1213 configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1214 <code>.htaccess</code> files are read, but before <code class="directive"><a href="#location"><Location></a></code> sections. Note
1215 that <code class="directive"><Files></code> can be nested
1216 inside <code class="directive"><a href="#directory"><Directory></a></code> sections to restrict the
1217 portion of the filesystem they apply to.</p>
1219 <p>The <var>filename</var> argument should include a filename, or
1220 a wild-card string, where <code>?</code> matches any single character,
1221 and <code>*</code> matches any sequences of characters.
1222 <a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a>
1223 can also be used, with the addition of the
1224 <code>~</code> character. For example:</p>
1226 <div class="example"><p><code>
1227 <Files ~ "\.(gif|jpe?g|png)$">
1230 <p>would match most common Internet graphics formats. <code class="directive"><a href="#filesmatch"><FilesMatch></a></code> is preferred,
1233 <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
1234 <code>.htaccess</code> files. This allows users to control access to
1235 their own files, at a file-by-file level.</p>
1240 <li><a href="../sections.html">How <Directory>, <Location>
1241 and <Files> sections work</a> for an explanation of how these
1242 different sections are combined when a request is received</li>
1245 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1246 <div class="directive-section"><h2><a name="FilesMatch" id="FilesMatch"><FilesMatch></a> <a name="filesmatch" id="filesmatch">Directive</a></h2>
1247 <table class="directive">
1248 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to regular-expression matched
1250 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><FilesMatch <var>regex</var>> ... </FilesMatch></code></td></tr>
1251 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1252 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1253 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1254 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1256 <p>The <code class="directive"><FilesMatch></code> directive
1257 limits the scope of the enclosed directives by filename, just as the
1258 <code class="directive"><a href="#files"><Files></a></code> directive
1259 does. However, it accepts a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular
1260 expression</a>. For example:</p>
1262 <div class="example"><p><code>
1263 <FilesMatch "\.(gif|jpe?g|png)$">
1266 <p>would match most common Internet graphics formats.</p>
1270 <li><a href="../sections.html">How <Directory>, <Location>
1271 and <Files> sections work</a> for an explanation of how these
1272 different sections are combined when a request is received</li>
1275 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1276 <div class="directive-section"><h2><a name="ForceType" id="ForceType">ForceType</a> <a name="forcetype" id="forcetype">Directive</a></h2>
1277 <table class="directive">
1278 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be served with the specified
1279 media type in the HTTP Content-Type header field</td></tr>
1280 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ForceType <var>media-type</var>|None</code></td></tr>
1281 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1282 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1283 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1284 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1285 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved to the core in Apache 2.0</td></tr>
1287 <p>When placed into an <code>.htaccess</code> file or a
1288 <code class="directive"><a href="#directory"><Directory></a></code>, or
1289 <code class="directive"><a href="#location"><Location></a></code> or
1290 <code class="directive"><a href="#files"><Files></a></code>
1291 section, this directive forces all matching files to be served
1292 with the content type identification given by
1293 <var>media-type</var>. For example, if you had a directory full of
1294 GIF files, but did not want to label them all with <code>.gif</code>,
1295 you might want to use:</p>
1297 <div class="example"><p><code>
1301 <p>Note that this directive overrides other indirect media type
1302 associations defined in mime.types or via the
1303 <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code>.</p>
1305 <p>You can also override more general
1306 <code class="directive">ForceType</code> settings
1307 by using the value of <code>None</code>:</p>
1309 <div class="example"><p><code>
1310 # force all files to be image/gif:<br />
1311 <Location /images><br />
1312 <span class="indent">
1313 ForceType image/gif<br />
1315 </Location><br />
1317 # but normal mime-type associations here:<br />
1318 <Location /images/mixed><br />
1319 <span class="indent">
1320 ForceType None<br />
1326 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1327 <div class="directive-section"><h2><a name="HostnameLookups" id="HostnameLookups">HostnameLookups</a> <a name="hostnamelookups" id="hostnamelookups">Directive</a></h2>
1328 <table class="directive">
1329 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables DNS lookups on client IP addresses</td></tr>
1330 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HostnameLookups On|Off|Double</code></td></tr>
1331 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>HostnameLookups Off</code></td></tr>
1332 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1333 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1334 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1336 <p>This directive enables DNS lookups so that host names can be
1337 logged (and passed to CGIs/SSIs in <code>REMOTE_HOST</code>).
1338 The value <code>Double</code> refers to doing double-reverse
1339 DNS lookup. That is, after a reverse lookup is performed, a forward
1340 lookup is then performed on that result. At least one of the IP
1341 addresses in the forward lookup must match the original
1342 address. (In "tcpwrappers" terminology this is called
1343 <code>PARANOID</code>.)</p>
1345 <p>Regardless of the setting, when <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code> is
1346 used for controlling access by hostname, a double reverse lookup
1347 will be performed. This is necessary for security. Note that the
1348 result of this double-reverse isn't generally available unless you
1349 set <code>HostnameLookups Double</code>. For example, if only
1350 <code>HostnameLookups On</code> and a request is made to an object
1351 that is protected by hostname restrictions, regardless of whether
1352 the double-reverse fails or not, CGIs will still be passed the
1353 single-reverse result in <code>REMOTE_HOST</code>.</p>
1355 <p>The default is <code>Off</code> in order to save the network
1356 traffic for those sites that don't truly need the reverse
1357 lookups done. It is also better for the end users because they
1358 don't have to suffer the extra latency that a lookup entails.
1359 Heavily loaded sites should leave this directive
1360 <code>Off</code>, since DNS lookups can take considerable
1361 amounts of time. The utility <code class="program"><a href="../programs/logresolve.html">logresolve</a></code>, compiled by
1362 default to the <code>bin</code> subdirectory of your installation
1363 directory, can be used to look up host names from logged IP addresses
1367 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1368 <div class="directive-section"><h2><a name="If" id="If"><If></a> <a name="if" id="if">Directive</a></h2>
1369 <table class="directive">
1370 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only if a condition is
1371 satisfied by a request at runtime</td></tr>
1372 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><If <var>expression</var>> ... </If></code></td></tr>
1373 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1374 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1375 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1376 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1378 <p>The <code class="directive"><If></code> directive
1379 evaluates an expression at runtime, and applies the enclosed
1380 directives if and only if the expression evaluates to true.
1383 <div class="example"><p><code>
1384 <If "$req{Host} = ''">
1387 <p>would match HTTP/1.0 requests without a <var>Host:</var> header.</p>
1391 <li><a href="../sections.html">How <Directory>, <Location>,
1392 <Files> sections work</a> for an explanation of how these
1393 different sections are combined when a request is received.
1394 <code class="directive"><If></code> has the same precedence
1395 and usage as <code class="directive"><Files></code></li>
1398 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1399 <div class="directive-section"><h2><a name="IfDefine" id="IfDefine"><IfDefine></a> <a name="ifdefine" id="ifdefine">Directive</a></h2>
1400 <table class="directive">
1401 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that will be processed only
1402 if a test is true at startup</td></tr>
1403 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfDefine [!]<var>parameter-name</var>> ...
1404 </IfDefine></code></td></tr>
1405 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1406 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1407 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1408 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1410 <p>The <code><IfDefine <var>test</var>>...</IfDefine>
1411 </code> section is used to mark directives that are conditional. The
1412 directives within an <code class="directive"><IfDefine></code>
1413 section are only processed if the <var>test</var> is true. If <var>
1414 test</var> is false, everything between the start and end markers is
1417 <p>The <var>test</var> in the <code class="directive"><IfDefine></code> section directive can be one of two forms:</p>
1420 <li><var>parameter-name</var></li>
1422 <li><code>!</code><var>parameter-name</var></li>
1425 <p>In the former case, the directives between the start and end
1426 markers are only processed if the parameter named
1427 <var>parameter-name</var> is defined. The second format reverses
1428 the test, and only processes the directives if
1429 <var>parameter-name</var> is <strong>not</strong> defined.</p>
1431 <p>The <var>parameter-name</var> argument is a define as given on the
1432 <code class="program"><a href="../programs/httpd.html">httpd</a></code> command line via <code>-D<var>parameter</var>
1433 </code> at the time the server was started or by the <code class="directive"><a href="#define">Define</a></code> directive.</p>
1435 <p><code class="directive"><IfDefine></code> sections are
1436 nest-able, which can be used to implement simple
1437 multiple-parameter tests. Example:</p>
1439 <div class="example"><p><code>
1440 httpd -DReverseProxy -DUseCache -DMemCache ...<br />
1443 <IfDefine ReverseProxy><br />
1444 <span class="indent">
1445 LoadModule proxy_module modules/mod_proxy.so<br />
1446 LoadModule proxy_http_module modules/mod_proxy_http.so<br />
1447 <IfDefine UseCache><br />
1448 <span class="indent">
1449 LoadModule cache_module modules/mod_cache.so<br />
1450 <IfDefine MemCache><br />
1451 <span class="indent">
1452 LoadModule mem_cache_module modules/mod_mem_cache.so<br />
1454 </IfDefine><br />
1455 <IfDefine !MemCache><br />
1456 <span class="indent">
1457 LoadModule disk_cache_module modules/mod_disk_cache.so<br />
1467 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1468 <div class="directive-section"><h2><a name="IfModule" id="IfModule"><IfModule></a> <a name="ifmodule" id="ifmodule">Directive</a></h2>
1469 <table class="directive">
1470 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that are processed conditional on the
1471 presence or absence of a specific module</td></tr>
1472 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfModule [!]<var>module-file</var>|<var>module-identifier</var>> ...
1473 </IfModule></code></td></tr>
1474 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1475 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1476 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1477 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1478 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Module identifiers are available in version 2.1 and
1481 <p>The <code><IfModule <var>test</var>>...</IfModule></code>
1482 section is used to mark directives that are conditional on the presence of
1483 a specific module. The directives within an <code class="directive"><IfModule></code> section are only processed if the <var>test</var>
1484 is true. If <var>test</var> is false, everything between the start and
1485 end markers is ignored.</p>
1487 <p>The <var>test</var> in the <code class="directive"><IfModule></code> section directive can be one of two forms:</p>
1490 <li><var>module</var></li>
1492 <li>!<var>module</var></li>
1495 <p>In the former case, the directives between the start and end
1496 markers are only processed if the module named <var>module</var>
1497 is included in Apache -- either compiled in or
1498 dynamically loaded using <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>. The second format reverses the test,
1499 and only processes the directives if <var>module</var> is
1500 <strong>not</strong> included.</p>
1502 <p>The <var>module</var> argument can be either the module identifier or
1503 the file name of the module, at the time it was compiled. For example,
1504 <code>rewrite_module</code> is the identifier and
1505 <code>mod_rewrite.c</code> is the file name. If a module consists of
1506 several source files, use the name of the file containing the string
1507 <code>STANDARD20_MODULE_STUFF</code>.</p>
1509 <p><code class="directive"><IfModule></code> sections are
1510 nest-able, which can be used to implement simple multiple-module
1513 <div class="note">This section should only be used if you need to have one
1514 configuration file that works whether or not a specific module
1515 is available. In normal operation, directives need not be
1516 placed in <code class="directive"><IfModule></code>
1520 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1521 <div class="directive-section"><h2><a name="Include" id="Include">Include</a> <a name="include" id="include">Directive</a></h2>
1522 <table class="directive">
1523 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Includes other configuration files from within
1524 the server configuration files</td></tr>
1525 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Include <var>file-path</var>|<var>directory-path</var></code></td></tr>
1526 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1527 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1528 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1529 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Wildcard matching available in 2.0.41 and later</td></tr>
1531 <p>This directive allows inclusion of other configuration files
1532 from within the server configuration files.</p>
1534 <p>Shell-style (<code>fnmatch()</code>) wildcard characters can be used to
1535 include several files at once, in alphabetical order. In
1536 addition, if <code class="directive">Include</code> points to a directory,
1537 rather than a file, Apache will read all files in that directory
1538 and any subdirectory. However, including entire directories is not
1539 recommended, because it is easy to accidentally leave temporary
1540 files in a directory that can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to
1541 fail. Instead, we encourage you to use the wildcard syntax shown
1542 below, to include files that match a particular pattern, such as
1543 *.conf, for example.</p>
1545 <p>The file path specified may be an absolute path, or may be relative
1546 to the <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory.</p>
1550 <div class="example"><p><code>
1551 Include /usr/local/apache2/conf/ssl.conf<br />
1552 Include /usr/local/apache2/conf/vhosts/*.conf
1555 <p>Or, providing paths relative to your <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory:</p>
1557 <div class="example"><p><code>
1558 Include conf/ssl.conf<br />
1559 Include conf/vhosts/*.conf
1564 <li><code class="program"><a href="../programs/apachectl.html">apachectl</a></code></li>
1567 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1568 <div class="directive-section"><h2><a name="KeepAlive" id="KeepAlive">KeepAlive</a> <a name="keepalive" id="keepalive">Directive</a></h2>
1569 <table class="directive">
1570 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables HTTP persistent connections</td></tr>
1571 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAlive On|Off</code></td></tr>
1572 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAlive On</code></td></tr>
1573 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1574 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1575 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1577 <p>The Keep-Alive extension to HTTP/1.0 and the persistent
1578 connection feature of HTTP/1.1 provide long-lived HTTP sessions
1579 which allow multiple requests to be sent over the same TCP
1580 connection. In some cases this has been shown to result in an
1581 almost 50% speedup in latency times for HTML documents with
1582 many images. To enable Keep-Alive connections, set
1583 <code>KeepAlive On</code>.</p>
1585 <p>For HTTP/1.0 clients, Keep-Alive connections will only be
1586 used if they are specifically requested by a client. In
1587 addition, a Keep-Alive connection with an HTTP/1.0 client can
1588 only be used when the length of the content is known in
1589 advance. This implies that dynamic content such as CGI output,
1590 SSI pages, and server-generated directory listings will
1591 generally not use Keep-Alive connections to HTTP/1.0 clients.
1592 For HTTP/1.1 clients, persistent connections are the default
1593 unless otherwise specified. If the client requests it, chunked
1594 encoding will be used in order to send content of unknown
1595 length over persistent connections.</p>
1597 <p>When a client uses a Keep-Alive connection it will be counted
1598 as a single "request" for the <code class="directive"><a href="../mod/mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></code> directive, regardless
1599 of how many requests are sent using the connection.</p>
1603 <li><code class="directive"><a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></code></li>
1606 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1607 <div class="directive-section"><h2><a name="KeepAliveTimeout" id="KeepAliveTimeout">KeepAliveTimeout</a> <a name="keepalivetimeout" id="keepalivetimeout">Directive</a></h2>
1608 <table class="directive">
1609 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for subsequent
1610 requests on a persistent connection</td></tr>
1611 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAliveTimeout <var>num</var>[ms]</code></td></tr>
1612 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAliveTimeout 5</code></td></tr>
1613 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1614 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1615 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1616 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Specifying a value in milliseconds is available in
1617 Apache 2.3.2 and later</td></tr>
1619 <p>The number of seconds Apache will wait for a subsequent
1620 request before closing the connection. By adding a postfix of ms the
1621 timeout can be also set in milliseconds. Once a request has been
1622 received, the timeout value specified by the
1623 <code class="directive"><a href="#timeout">Timeout</a></code> directive applies.</p>
1625 <p>Setting <code class="directive">KeepAliveTimeout</code> to a high value
1626 may cause performance problems in heavily loaded servers. The
1627 higher the timeout, the more server processes will be kept
1628 occupied waiting on connections with idle clients.</p>
1630 <p>In a name-based virtual host context, the value of the first
1631 defined virtual host (the default host) in a set of <code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code> will be used.
1632 The other values will be ignored.</p>
1635 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1636 <div class="directive-section"><h2><a name="Limit" id="Limit"><Limit></a> <a name="limit" id="limit">Directive</a></h2>
1637 <table class="directive">
1638 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict enclosed access controls to only certain HTTP
1640 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Limit <var>method</var> [<var>method</var>] ... > ...
1641 </Limit></code></td></tr>
1642 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1643 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig, Limit</td></tr>
1644 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1645 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1647 <p>Access controls are normally effective for
1648 <strong>all</strong> access methods, and this is the usual
1649 desired behavior. <strong>In the general case, access control
1650 directives should not be placed within a
1651 <code class="directive"><Limit></code> section.</strong></p>
1653 <p>The purpose of the <code class="directive"><Limit></code>
1654 directive is to restrict the effect of the access controls to the
1655 nominated HTTP methods. For all other methods, the access
1656 restrictions that are enclosed in the <code class="directive"><Limit></code> bracket <strong>will have no
1657 effect</strong>. The following example applies the access control
1658 only to the methods <code>POST</code>, <code>PUT</code>, and
1659 <code>DELETE</code>, leaving all other methods unprotected:</p>
1661 <div class="example"><p><code>
1662 <Limit POST PUT DELETE><br />
1663 <span class="indent">
1664 Require valid-user<br />
1669 <p>The method names listed can be one or more of: <code>GET</code>,
1670 <code>POST</code>, <code>PUT</code>, <code>DELETE</code>,
1671 <code>CONNECT</code>, <code>OPTIONS</code>,
1672 <code>PATCH</code>, <code>PROPFIND</code>, <code>PROPPATCH</code>,
1673 <code>MKCOL</code>, <code>COPY</code>, <code>MOVE</code>,
1674 <code>LOCK</code>, and <code>UNLOCK</code>. <strong>The method name is
1675 case-sensitive.</strong> If <code>GET</code> is used it will also
1676 restrict <code>HEAD</code> requests. The <code>TRACE</code> method
1677 cannot be limited (see <code class="directive"><a href="#traceenable">TraceEnable</a></code>).</p>
1679 <div class="warning">A <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section should always be
1680 used in preference to a <code class="directive"><Limit></code>
1681 section when restricting access, since a <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section provides protection
1682 against arbitrary methods.</div>
1684 <p>The <code class="directive"><Limit></code> and
1685 <code class="directive"><a href="#limitexcept"><LimitExcept></a></code>
1686 directives may be nested. In this case, each successive level of
1687 <code class="directive"><Limit></code> or <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> directives must
1688 further restrict the set of methods to which access controls apply.</p>
1690 <div class="warning">When using
1691 <code class="directive"><Limit></code> or
1692 <code class="directive"><LimitExcept></code> directives with
1693 the <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directive,
1694 note that the first <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code>
1695 to succeed authorizes the request, regardless of the presence of other
1696 <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directives.</div>
1698 <p>For example, given the following configuration, all users will
1699 be authorized for <code>POST</code> requests, and the
1700 <code>Require group editors</code> directive will be ignored
1703 <div class="example"><p><code>
1704 <LimitExcept GET>
1705 <span class="indent">
1708 </LimitExcept><br />
1710 <span class="indent">
1711 Require group editors
1717 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1718 <div class="directive-section"><h2><a name="LimitExcept" id="LimitExcept"><LimitExcept></a> <a name="limitexcept" id="limitexcept">Directive</a></h2>
1719 <table class="directive">
1720 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict access controls to all HTTP methods
1721 except the named ones</td></tr>
1722 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LimitExcept <var>method</var> [<var>method</var>] ... > ...
1723 </LimitExcept></code></td></tr>
1724 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1725 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig, Limit</td></tr>
1726 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1727 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1729 <p><code class="directive"><LimitExcept></code> and
1730 <code></LimitExcept></code> are used to enclose
1731 a group of access control directives which will then apply to any
1732 HTTP access method <strong>not</strong> listed in the arguments;
1733 i.e., it is the opposite of a <code class="directive"><a href="#limit"><Limit></a></code> section and can be used to control
1734 both standard and nonstandard/unrecognized methods. See the
1735 documentation for <code class="directive"><a href="#limit"><Limit></a></code> for more details.</p>
1739 <div class="example"><p><code>
1740 <LimitExcept POST GET><br />
1741 <span class="indent">
1742 Require valid-user<br />
1744 </LimitExcept>
1749 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1750 <div class="directive-section"><h2><a name="LimitInternalRecursion" id="LimitInternalRecursion">LimitInternalRecursion</a> <a name="limitinternalrecursion" id="limitinternalrecursion">Directive</a></h2>
1751 <table class="directive">
1752 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine maximum number of internal redirects and nested
1753 subrequests</td></tr>
1754 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitInternalRecursion <var>number</var> [<var>number</var>]</code></td></tr>
1755 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitInternalRecursion 10</code></td></tr>
1756 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</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>
1759 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.47 and later</td></tr>
1761 <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
1762 redirects the original request to a CGI script. A subrequest is Apache's
1763 mechanism to find out what would happen for some URI if it were requested.
1764 For example, <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> uses subrequests to look for the
1765 files listed in the <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
1768 <p><code class="directive">LimitInternalRecursion</code> prevents the server
1769 from crashing when entering an infinite loop of internal redirects or
1770 subrequests. Such loops are usually caused by misconfigurations.</p>
1772 <p>The directive stores two different limits, which are evaluated on
1773 per-request basis. The first <var>number</var> is the maximum number of
1774 internal redirects, that may follow each other. The second <var>number</var>
1775 determines, how deep subrequests may be nested. If you specify only one
1776 <var>number</var>, it will be assigned to both limits.</p>
1778 <div class="example"><h3>Example</h3><p><code>
1779 LimitInternalRecursion 5
1783 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1784 <div class="directive-section"><h2><a name="LimitRequestBody" id="LimitRequestBody">LimitRequestBody</a> <a name="limitrequestbody" id="limitrequestbody">Directive</a></h2>
1785 <table class="directive">
1786 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restricts the total size of the HTTP request body sent
1787 from the client</td></tr>
1788 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestBody <var>bytes</var></code></td></tr>
1789 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestBody 0</code></td></tr>
1790 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1791 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1792 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1793 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1795 <p>This directive specifies the number of <var>bytes</var> from 0
1796 (meaning unlimited) to 2147483647 (2GB) that are allowed in a
1799 <p>The <code class="directive">LimitRequestBody</code> directive allows
1800 the user to set a limit on the allowed size of an HTTP request
1801 message body within the context in which the directive is given
1802 (server, per-directory, per-file or per-location). If the client
1803 request exceeds that limit, the server will return an error
1804 response instead of servicing the request. The size of a normal
1805 request message body will vary greatly depending on the nature of
1806 the resource and the methods allowed on that resource. CGI scripts
1807 typically use the message body for retrieving form information.
1808 Implementations of the <code>PUT</code> method will require
1809 a value at least as large as any representation that the server
1810 wishes to accept for that resource.</p>
1812 <p>This directive gives the server administrator greater
1813 control over abnormal client request behavior, which may be
1814 useful for avoiding some forms of denial-of-service
1817 <p>If, for example, you are permitting file upload to a particular
1818 location, and wish to limit the size of the uploaded file to 100K,
1819 you might use the following directive:</p>
1821 <div class="example"><p><code>
1822 LimitRequestBody 102400
1827 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1828 <div class="directive-section"><h2><a name="LimitRequestFields" id="LimitRequestFields">LimitRequestFields</a> <a name="limitrequestfields" id="limitrequestfields">Directive</a></h2>
1829 <table class="directive">
1830 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of HTTP request header fields that
1831 will be accepted from the client</td></tr>
1832 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFields <var>number</var></code></td></tr>
1833 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFields 100</code></td></tr>
1834 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1835 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1836 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1838 <p><var>Number</var> is an integer from 0 (meaning unlimited) to
1839 32767. The default value is defined by the compile-time
1840 constant <code>DEFAULT_LIMIT_REQUEST_FIELDS</code> (100 as
1843 <p>The <code class="directive">LimitRequestFields</code> directive allows
1844 the server administrator to modify the limit on the number of
1845 request header fields allowed in an HTTP request. A server needs
1846 this value to be larger than the number of fields that a normal
1847 client request might include. The number of request header fields
1848 used by a client rarely exceeds 20, but this may vary among
1849 different client implementations, often depending upon the extent
1850 to which a user has configured their browser to support detailed
1851 content negotiation. Optional HTTP extensions are often expressed
1852 using request header fields.</p>
1854 <p>This directive gives the server administrator greater
1855 control over abnormal client request behavior, which may be
1856 useful for avoiding some forms of denial-of-service attacks.
1857 The value should be increased if normal clients see an error
1858 response from the server that indicates too many fields were
1859 sent in the request.</p>
1863 <div class="example"><p><code>
1864 LimitRequestFields 50
1869 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1870 <div class="directive-section"><h2><a name="LimitRequestFieldSize" id="LimitRequestFieldSize">LimitRequestFieldSize</a> <a name="limitrequestfieldsize" id="limitrequestfieldsize">Directive</a></h2>
1871 <table class="directive">
1872 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of the HTTP request header allowed from the
1874 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFieldSize <var>bytes</var></code></td></tr>
1875 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFieldSize 8190</code></td></tr>
1876 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1877 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1878 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1880 <p>This directive specifies the number of <var>bytes</var>
1881 that will be allowed in an HTTP request header.</p>
1883 <p>The <code class="directive">LimitRequestFieldSize</code> directive
1884 allows the server administrator to reduce or increase the limit
1885 on the allowed size of an HTTP request header field. A server
1886 needs this value to be large enough to hold any one header field
1887 from a normal client request. The size of a normal request header
1888 field will vary greatly among different client implementations,
1889 often depending upon the extent to which a user has configured
1890 their browser to support detailed content negotiation. SPNEGO
1891 authentication headers can be up to 12392 bytes.</p>
1893 <p>This directive gives the server administrator greater
1894 control over abnormal client request behavior, which may be
1895 useful for avoiding some forms of denial-of-service attacks.</p>
1899 <div class="example"><p><code>
1900 LimitRequestFieldSize 4094
1903 <div class="note">Under normal conditions, the value should not be changed from
1908 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1909 <div class="directive-section"><h2><a name="LimitRequestLine" id="LimitRequestLine">LimitRequestLine</a> <a name="limitrequestline" id="limitrequestline">Directive</a></h2>
1910 <table class="directive">
1911 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limit the size of the HTTP request line that will be accepted
1912 from the client</td></tr>
1913 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestLine <var>bytes</var></code></td></tr>
1914 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestLine 8190</code></td></tr>
1915 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1916 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1917 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1919 <p>This directive sets the number of <var>bytes</var> that will be
1920 allowed on the HTTP request-line.</p>
1922 <p>The <code class="directive">LimitRequestLine</code> directive allows
1923 the server administrator to reduce or increase the limit on the allowed size
1924 of a client's HTTP request-line. Since the request-line consists of the
1925 HTTP method, URI, and protocol version, the
1926 <code class="directive">LimitRequestLine</code> directive places a
1927 restriction on the length of a request-URI allowed for a request
1928 on the server. A server needs this value to be large enough to
1929 hold any of its resource names, including any information that
1930 might be passed in the query part of a <code>GET</code> request.</p>
1932 <p>This directive gives the server administrator greater
1933 control over abnormal client request behavior, which may be
1934 useful for avoiding some forms of denial-of-service attacks.</p>
1938 <div class="example"><p><code>
1939 LimitRequestLine 4094
1942 <div class="note">Under normal conditions, the value should not be changed from
1946 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1947 <div class="directive-section"><h2><a name="LimitXMLRequestBody" id="LimitXMLRequestBody">LimitXMLRequestBody</a> <a name="limitxmlrequestbody" id="limitxmlrequestbody">Directive</a></h2>
1948 <table class="directive">
1949 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of an XML-based request body</td></tr>
1950 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitXMLRequestBody <var>bytes</var></code></td></tr>
1951 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitXMLRequestBody 1000000</code></td></tr>
1952 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1953 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1954 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1955 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1957 <p>Limit (in bytes) on maximum size of an XML-based request
1958 body. A value of <code>0</code> will disable any checking.</p>
1962 <div class="example"><p><code>
1963 LimitXMLRequestBody 0
1968 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1969 <div class="directive-section"><h2><a name="Location" id="Location"><Location></a> <a name="location" id="location">Directive</a></h2>
1970 <table class="directive">
1971 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to matching
1973 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Location
1974 <var>URL-path</var>|<var>URL</var>> ... </Location></code></td></tr>
1975 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1976 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1977 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1979 <p>The <code class="directive"><Location></code> directive
1980 limits the scope of the enclosed directives by URL. It is similar to the
1981 <code class="directive"><a href="#directory"><Directory></a></code>
1982 directive, and starts a subsection which is terminated with a
1983 <code></Location></code> directive. <code class="directive"><Location></code> sections are processed in the
1984 order they appear in the configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1985 <code>.htaccess</code> files are read, and after the <code class="directive"><a href="#files"><Files></a></code> sections.</p>
1987 <p><code class="directive"><Location></code> sections operate
1988 completely outside the filesystem. This has several consequences.
1989 Most importantly, <code class="directive"><Location></code>
1990 directives should not be used to control access to filesystem
1991 locations. Since several different URLs may map to the same
1992 filesystem location, such access controls may by circumvented.</p>
1994 <div class="note"><h3>When to use <code class="directive"><Location></code></h3>
1996 <p>Use <code class="directive"><Location></code> to apply
1997 directives to content that lives outside the filesystem. For
1998 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
1999 <code><Location /></code>, which is an easy way to
2000 apply a configuration to the entire server.</p>
2003 <p>For all origin (non-proxy) requests, the URL to be matched is a
2004 URL-path of the form <code>/path/</code>. <em>No scheme, hostname,
2005 port, or query string may be included.</em> For proxy requests, the
2006 URL to be matched is of the form
2007 <code>scheme://servername/path</code>, and you must include the
2010 <p>The URL may use wildcards. In a wild-card string, <code>?</code> matches
2011 any single character, and <code>*</code> matches any sequences of
2012 characters. Neither wildcard character matches a / in the URL-path.</p>
2014 <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a>
2015 can also be used, with the addition of the <code>~</code>
2016 character. For example:</p>
2018 <div class="example"><p><code>
2019 <Location ~ "/(extra|special)/data">
2022 <p>would match URLs that contained the substring <code>/extra/data</code>
2023 or <code>/special/data</code>. The directive <code class="directive"><a href="#locationmatch"><LocationMatch></a></code> behaves
2024 identical to the regex version of <code class="directive"><Location></code>, and is preferred, for the
2025 simple reason that <code>~</code> is hard to distinguish from
2026 <code>-</code> in many fonts.</p>
2028 <p>The <code class="directive"><Location></code>
2029 functionality is especially useful when combined with the
2030 <code class="directive"><a href="#sethandler">SetHandler</a></code>
2031 directive. For example, to enable status requests, but allow them
2032 only from browsers at <code>example.com</code>, you might use:</p>
2034 <div class="example"><p><code>
2035 <Location /status><br />
2036 <span class="indent">
2037 SetHandler server-status<br />
2038 Order Deny,Allow<br />
2040 Allow from .example.com<br />
2045 <div class="note"><h3>Note about / (slash)</h3>
2046 <p>The slash character has special meaning depending on where in a
2047 URL it appears. People may be used to its behavior in the filesystem
2048 where multiple adjacent slashes are frequently collapsed to a single
2049 slash (<em>i.e.</em>, <code>/home///foo</code> is the same as
2050 <code>/home/foo</code>). In URL-space this is not necessarily true.
2051 The <code class="directive"><a href="#locationmatch"><LocationMatch></a></code>
2052 directive and the regex version of <code class="directive"><Location></code> require you to explicitly specify multiple
2053 slashes if that is your intention.</p>
2055 <p>For example, <code><LocationMatch ^/abc></code> would match
2056 the request URL <code>/abc</code> but not the request URL <code>
2057 //abc</code>. The (non-regex) <code class="directive"><Location></code> directive behaves similarly when used for
2058 proxy requests. But when (non-regex) <code class="directive"><Location></code> is used for non-proxy requests it will
2059 implicitly match multiple slashes with a single slash. For example,
2060 if you specify <code><Location /abc/def></code> and the
2061 request is to <code>/abc//def</code> then it will match.</p>
2066 <li><a href="../sections.html">How <Directory>, <Location>
2067 and <Files> sections work</a> for an explanation of how these
2068 different sections are combined when a request is received.</li>
2069 <li><code class="directive"><a href="#locationmatch">LocationMatch</a></code></li>
2072 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2073 <div class="directive-section"><h2><a name="LocationMatch" id="LocationMatch"><LocationMatch></a> <a name="locationmatch" id="locationmatch">Directive</a></h2>
2074 <table class="directive">
2075 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to regular-expression
2076 matching URLs</td></tr>
2077 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LocationMatch
2078 <var>regex</var>> ... </LocationMatch></code></td></tr>
2079 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2080 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2081 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2083 <p>The <code class="directive"><LocationMatch></code> directive
2084 limits the scope of the enclosed directives by URL, in an identical manner
2085 to <code class="directive"><a href="#location"><Location></a></code>. However,
2086 it takes a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>
2087 as an argument instead of a simple string. For example:</p>
2089 <div class="example"><p><code>
2090 <LocationMatch "/(extra|special)/data">
2093 <p>would match URLs that contained the substring <code>/extra/data</code>
2094 or <code>/special/data</code>.</p>
2098 <li><a href="../sections.html">How <Directory>, <Location>
2099 and <Files> sections work</a> for an explanation of how these
2100 different sections are combined when a request is received</li>
2103 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2104 <div class="directive-section"><h2><a name="LogLevel" id="LogLevel">LogLevel</a> <a name="loglevel" id="loglevel">Directive</a></h2>
2105 <table class="directive">
2106 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Controls the verbosity of the ErrorLog</td></tr>
2107 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LogLevel <var>level</var></code></td></tr>
2108 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LogLevel warn</code></td></tr>
2109 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2110 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2111 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2113 <p><code class="directive">LogLevel</code> adjusts the verbosity of the
2114 messages recorded in the error logs (see <code class="directive"><a href="#errorlog">ErrorLog</a></code> directive). The following
2115 <var>level</var>s are available, in order of decreasing
2118 <table class="bordered">
2121 <th><strong>Level</strong> </th>
2123 <th><strong>Description</strong> </th>
2125 <th><strong>Example</strong> </th>
2129 <td><code>emerg</code> </td>
2131 <td>Emergencies - system is unusable.</td>
2133 <td>"Child cannot open lock file. Exiting"</td>
2137 <td><code>alert</code> </td>
2139 <td>Action must be taken immediately.</td>
2141 <td>"getpwuid: couldn't determine user name from uid"</td>
2145 <td><code>crit</code> </td>
2147 <td>Critical Conditions.</td>
2149 <td>"socket: Failed to get a socket, exiting child"</td>
2153 <td><code>error</code> </td>
2155 <td>Error conditions.</td>
2157 <td>"Premature end of script headers"</td>
2161 <td><code>warn</code> </td>
2163 <td>Warning conditions.</td>
2165 <td>"child process 1234 did not exit, sending another
2170 <td><code>notice</code> </td>
2172 <td>Normal but significant condition.</td>
2174 <td>"httpd: caught SIGBUS, attempting to dump core in
2179 <td><code>info</code> </td>
2181 <td>Informational.</td>
2183 <td>"Server seems busy, (you may need to increase
2184 StartServers, or Min/MaxSpareServers)..."</td>
2188 <td><code>debug</code> </td>
2190 <td>Debug-level messages</td>
2192 <td>"Opening config file ..."</td>
2196 <p>When a particular level is specified, messages from all
2197 other levels of higher significance will be reported as well.
2198 <em>E.g.</em>, when <code>LogLevel info</code> is specified,
2199 then messages with log levels of <code>notice</code> and
2200 <code>warn</code> will also be posted.</p>
2202 <p>Using a level of at least <code>crit</code> is
2207 <div class="example"><p><code>
2211 <div class="note"><h3>Note</h3>
2212 <p>When logging to a regular file messages of the level
2213 <code>notice</code> cannot be suppressed and thus are always
2214 logged. However, this doesn't apply when logging is done
2215 using <code>syslog</code>.</p>
2219 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2220 <div class="directive-section"><h2><a name="MaxKeepAliveRequests" id="MaxKeepAliveRequests">MaxKeepAliveRequests</a> <a name="maxkeepaliverequests" id="maxkeepaliverequests">Directive</a></h2>
2221 <table class="directive">
2222 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of requests allowed on a persistent
2223 connection</td></tr>
2224 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxKeepAliveRequests <var>number</var></code></td></tr>
2225 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxKeepAliveRequests 100</code></td></tr>
2226 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2227 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2228 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2230 <p>The <code class="directive">MaxKeepAliveRequests</code> directive
2231 limits the number of requests allowed per connection when
2232 <code class="directive"><a href="#keepalive">KeepAlive</a></code> is on. If it is
2233 set to <code>0</code>, unlimited requests will be allowed. We
2234 recommend that this setting be kept to a high value for maximum
2235 server performance.</p>
2239 <div class="example"><p><code>
2240 MaxKeepAliveRequests 500
2244 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2245 <div class="directive-section"><h2><a name="NameVirtualHost" id="NameVirtualHost">NameVirtualHost</a> <a name="namevirtualhost" id="namevirtualhost">Directive</a></h2>
2246 <table class="directive">
2247 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Designates an IP address for name-virtual
2249 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NameVirtualHost <var>addr</var>[:<var>port</var>]</code></td></tr>
2250 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2251 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2252 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2255 <p>A single <code class="directive">NameVirtualHost</code> directive
2256 identifies a set of identical virtual hosts on which the server will
2257 further select from on the basis of the <em>hostname</em>
2258 requested by the client. The <code class="directive">NameVirtualHost</code>
2259 directive is a required directive if you want to configure
2260 <a href="../vhosts/">name-based virtual hosts</a>.</p>
2262 <p>This directive, and the corresponding <code class="directive">VirtualHost</code>,
2263 <em>must</em> be qualified with a port number if the server supports both HTTP
2264 and HTTPS connections.</p>
2266 <p>Although <var>addr</var> can be a hostname, it is recommended
2267 that you always use an IP address or a wildcard. A wildcard
2268 NameVirtualHost matches only virtualhosts that also have a literal wildcard
2269 as their argument.</p>
2271 <p>In cases where a firewall or other proxy receives the requests and
2272 forwards them on a different IP address to the server, you must specify the
2273 IP address of the physical interface on the machine which will be
2274 servicing the requests. </p>
2276 <p> In the example below, requests received on interface 192.0.2.1 and port 80
2277 will only select among the first two virtual hosts. Requests received on
2278 port 80 on any other interface will only select among the third and fourth
2279 virtual hosts. In the common case where the interface isn't important
2280 to the mapping, only the "*:80" NameVirtualHost and VirtualHost directives
2283 <div class="example"><p><code>
2284 NameVirtualHost 192.0.2.1:80<br />
2285 NameVirtualHost *:80<br /><br />
2287 <VirtualHost 192.0.2.1:80><br />
2288 ServerName namebased-a.example.com<br />
2289 </VirtualHost><br />
2291 <VirtualHost 192.0.2.1:80><br />
2292 Servername namebased-b.example.com<br />
2293 </VirtualHost><br />
2295 <VirtualHost *:80><br />
2296 ServerName namebased-c.example.com <br />
2297 </VirtualHost><br />
2299 <VirtualHost *:80><br />
2300 ServerName namebased-d.example.com <br />
2301 </VirtualHost><br />
2306 <p>IPv6 addresses must be enclosed in square brackets, as shown
2307 in the following example:</p>
2309 <div class="example"><p><code>
2310 NameVirtualHost [2001:db8::a00:20ff:fea7:ccea]:8080
2313 <div class="note"><h3>Argument to <code class="directive"><VirtualHost></code>
2315 <p>Note that the argument to the <code class="directive"><VirtualHost></code> directive must
2316 exactly match the argument to the <code class="directive">NameVirtualHost</code> directive.</p>
2318 <div class="example"><p><code>
2319 NameVirtualHost 192.0.2.2:80<br />
2320 <VirtualHost 192.0.2.2:80><br />
2322 </VirtualHost><br />
2328 <li><a href="../vhosts/">Virtual Hosts
2329 documentation</a></li>
2332 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2333 <div class="directive-section"><h2><a name="Options" id="Options">Options</a> <a name="options" id="options">Directive</a></h2>
2334 <table class="directive">
2335 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures what features are available in a particular
2337 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Options
2338 [+|-]<var>option</var> [[+|-]<var>option</var>] ...</code></td></tr>
2339 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Options All</code></td></tr>
2340 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2341 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
2342 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2343 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2345 <p>The <code class="directive">Options</code> directive controls which
2346 server features are available in a particular directory.</p>
2348 <p><var>option</var> can be set to <code>None</code>, in which
2349 case none of the extra features are enabled, or one or more of
2353 <dt><code>All</code></dt>
2355 <dd>All options except for <code>MultiViews</code>. This is the default
2358 <dt><code>ExecCGI</code></dt>
2361 Execution of CGI scripts using <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>
2364 <dt><code>FollowSymLinks</code></dt>
2368 The server will follow symbolic links in this directory.
2370 <p>Even though the server follows the symlink it does <em>not</em>
2371 change the pathname used to match against <code class="directive"><a href="#directory"><Directory></a></code> sections.</p>
2372 <p>Note also, that this option <strong>gets ignored</strong> if set
2373 inside a <code class="directive"><a href="#location"><Location></a></code>
2375 <p>Omitting this option should not be considered a security restriction,
2376 since symlink testing is subject to race conditions that make it
2380 <dt><code>Includes</code></dt>
2383 Server-side includes provided by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>
2386 <dt><code>IncludesNOEXEC</code></dt>
2390 Server-side includes are permitted, but the <code>#exec
2391 cmd</code> and <code>#exec cgi</code> are disabled. It is still
2392 possible to <code>#include virtual</code> CGI scripts from
2393 <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>ed
2396 <dt><code>Indexes</code></dt>
2399 If a URL which maps to a directory is requested, and there
2400 is no <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
2401 (<em>e.g.</em>, <code>index.html</code>) in that directory, then
2402 <code class="module"><a href="../mod/mod_autoindex.html">mod_autoindex</a></code> will return a formatted listing
2403 of the directory.</dd>
2405 <dt><code>MultiViews</code></dt>
2408 <a href="../content-negotiation.html">Content negotiated</a>
2409 "MultiViews" are allowed using
2410 <code class="module"><a href="../mod/mod_negotiation.html">mod_negotiation</a></code>.</dd>
2412 <dt><code>SymLinksIfOwnerMatch</code></dt>
2414 <dd>The server will only follow symbolic links for which the
2415 target file or directory is owned by the same user id as the
2418 <div class="note"><h3>Note</h3> <p>This option gets ignored if
2419 set inside a <code class="directive"><a href="#location"><Location></a></code> section.</p>
2420 <p>This option should not be considered a security restriction,
2421 since symlink testing is subject to race conditions that make it
2422 circumventable.</p></div>
2426 <p>Normally, if multiple <code class="directive">Options</code> could
2427 apply to a directory, then the most specific one is used and
2428 others are ignored; the options are not merged. (See <a href="../sections.html#mergin">how sections are merged</a>.)
2429 However if <em>all</em> the options on the
2430 <code class="directive">Options</code> directive are preceded by a
2431 <code>+</code> or <code>-</code> symbol, the options are
2432 merged. Any options preceded by a <code>+</code> are added to the
2433 options currently in force, and any options preceded by a
2434 <code>-</code> are removed from the options currently in
2437 <div class="warning"><h3>Warning</h3>
2438 <p>Mixing <code class="directive">Options</code> with a <code>+</code> or
2439 <code>-</code> with those without is not valid syntax, and is likely
2440 to cause unexpected results.</p>
2443 <p>For example, without any <code>+</code> and <code>-</code> symbols:</p>
2445 <div class="example"><p><code>
2446 <Directory /web/docs><br />
2447 <span class="indent">
2448 Options Indexes FollowSymLinks<br />
2450 </Directory><br />
2452 <Directory /web/docs/spec><br />
2453 <span class="indent">
2454 Options Includes<br />
2459 <p>then only <code>Includes</code> will be set for the
2460 <code>/web/docs/spec</code> directory. However if the second
2461 <code class="directive">Options</code> directive uses the <code>+</code> and
2462 <code>-</code> symbols:</p>
2464 <div class="example"><p><code>
2465 <Directory /web/docs><br />
2466 <span class="indent">
2467 Options Indexes FollowSymLinks<br />
2469 </Directory><br />
2471 <Directory /web/docs/spec><br />
2472 <span class="indent">
2473 Options +Includes -Indexes<br />
2478 <p>then the options <code>FollowSymLinks</code> and
2479 <code>Includes</code> are set for the <code>/web/docs/spec</code>
2482 <div class="note"><h3>Note</h3>
2483 <p>Using <code>-IncludesNOEXEC</code> or
2484 <code>-Includes</code> disables server-side includes completely
2485 regardless of the previous setting.</p>
2488 <p>The default in the absence of any other settings is
2489 <code>All</code>.</p>
2492 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2493 <div class="directive-section"><h2><a name="RLimitCPU" id="RLimitCPU">RLimitCPU</a> <a name="rlimitcpu" id="rlimitcpu">Directive</a></h2>
2494 <table class="directive">
2495 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the CPU consumption of processes launched
2496 by Apache children</td></tr>
2497 <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>
2498 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2499 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2500 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2501 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2502 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2504 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2505 resource limit for all processes and the second parameter sets
2506 the maximum resource limit. Either parameter can be a number,
2507 or <code>max</code> to indicate to the server that the limit should
2508 be set to the maximum allowed by the operating system
2509 configuration. Raising the maximum resource limit requires that
2510 the server is running as <code>root</code>, or in the initial startup
2513 <p>This applies to processes forked off from Apache children
2514 servicing requests, not the Apache children themselves. This
2515 includes CGI scripts and SSI exec commands, but not any
2516 processes forked off from the Apache parent such as piped
2519 <p>CPU resource limits are expressed in seconds per
2524 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
2525 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
2528 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2529 <div class="directive-section"><h2><a name="RLimitMEM" id="RLimitMEM">RLimitMEM</a> <a name="rlimitmem" id="rlimitmem">Directive</a></h2>
2530 <table class="directive">
2531 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the memory consumption of processes launched
2532 by Apache children</td></tr>
2533 <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>
2534 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2535 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2536 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2537 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2538 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2540 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2541 resource limit for all processes and the second parameter sets
2542 the maximum resource limit. Either parameter can be a number,
2543 or <code>max</code> to indicate to the server that the limit should
2544 be set to the maximum allowed by the operating system
2545 configuration. Raising the maximum resource limit requires that
2546 the server is running as <code>root</code>, or in the initial startup
2549 <p>This applies to processes forked off from Apache children
2550 servicing requests, not the Apache children themselves. This
2551 includes CGI scripts and SSI exec commands, but not any
2552 processes forked off from the Apache parent such as piped
2555 <p>Memory resource limits are expressed in bytes per
2560 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
2561 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
2564 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2565 <div class="directive-section"><h2><a name="RLimitNPROC" id="RLimitNPROC">RLimitNPROC</a> <a name="rlimitnproc" id="rlimitnproc">Directive</a></h2>
2566 <table class="directive">
2567 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of processes that can be launched by
2568 processes launched by Apache children</td></tr>
2569 <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>
2570 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2571 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2572 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2573 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2574 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2576 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2577 resource limit for all processes and the second parameter sets
2578 the maximum resource limit. Either parameter can be a number,
2579 or <code>max</code> to indicate to the server that the limit
2580 should be set to the maximum allowed by the operating system
2581 configuration. Raising the maximum resource limit requires that
2582 the server is running as <code>root</code>, or in the initial startup
2585 <p>This applies to processes forked off from Apache children
2586 servicing requests, not the Apache children themselves. This
2587 includes CGI scripts and SSI exec commands, but not any
2588 processes forked off from the Apache parent such as piped
2591 <p>Process limits control the number of processes per user.</p>
2593 <div class="note"><h3>Note</h3>
2594 <p>If CGI processes are <strong>not</strong> running
2595 under user ids other than the web server user id, this directive
2596 will limit the number of processes that the server itself can
2597 create. Evidence of this situation will be indicated by
2598 <strong><code>cannot fork</code></strong> messages in the
2599 <code>error_log</code>.</p>
2604 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
2605 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
2608 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2609 <div class="directive-section"><h2><a name="ScriptInterpreterSource" id="ScriptInterpreterSource">ScriptInterpreterSource</a> <a name="scriptinterpretersource" id="scriptinterpretersource">Directive</a></h2>
2610 <table class="directive">
2611 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
2613 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ScriptInterpreterSource Registry|Registry-Strict|Script</code></td></tr>
2614 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ScriptInterpreterSource Script</code></td></tr>
2615 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2616 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2617 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2618 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2619 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Win32 only;
2620 option <code>Registry-Strict</code> is available in Apache 2.0 and
2623 <p>This directive is used to control how Apache finds the
2624 interpreter used to run CGI scripts. The default setting is
2625 <code>Script</code>. This causes Apache to use the interpreter pointed to
2626 by the shebang line (first line, starting with <code>#!</code>) in the
2627 script. On Win32 systems this line usually looks like:</p>
2629 <div class="example"><p><code>
2630 #!C:/Perl/bin/perl.exe
2633 <p>or, if <code>perl</code> is in the <code>PATH</code>, simply:</p>
2635 <div class="example"><p><code>
2639 <p>Setting <code>ScriptInterpreterSource Registry</code> will
2640 cause the Windows Registry tree <code>HKEY_CLASSES_ROOT</code> to be
2641 searched using the script file extension (e.g., <code>.pl</code>) as a
2642 search key. The command defined by the registry subkey
2643 <code>Shell\ExecCGI\Command</code> or, if it does not exist, by the subkey
2644 <code>Shell\Open\Command</code> is used to open the script file. If the
2645 registry keys cannot be found, Apache falls back to the behavior of the
2646 <code>Script</code> option.</p>
2648 <div class="warning"><h3>Security</h3>
2649 <p>Be careful when using <code>ScriptInterpreterSource
2650 Registry</code> with <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>'ed directories, because
2651 Apache will try to execute <strong>every</strong> file within this
2652 directory. The <code>Registry</code> setting may cause undesired
2653 program calls on files which are typically not executed. For
2654 example, the default open command on <code>.htm</code> files on
2655 most Windows systems will execute Microsoft Internet Explorer, so
2656 any HTTP request for an <code>.htm</code> file existing within the
2657 script directory would start the browser in the background on the
2658 server. This is a good way to crash your system within a minute or
2662 <p>The option <code>Registry-Strict</code> which is new in Apache
2663 2.0 does the same thing as <code>Registry</code> but uses only the
2664 subkey <code>Shell\ExecCGI\Command</code>. The
2665 <code>ExecCGI</code> key is not a common one. It must be
2666 configured manually in the windows registry and hence prevents
2667 accidental program calls on your system.</p>
2670 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2671 <div class="directive-section"><h2><a name="ServerAdmin" id="ServerAdmin">ServerAdmin</a> <a name="serveradmin" id="serveradmin">Directive</a></h2>
2672 <table class="directive">
2673 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Email address that the server includes in error
2674 messages sent to the client</td></tr>
2675 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAdmin <var>email-address</var>|<var>URL</var></code></td></tr>
2676 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2677 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2678 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2680 <p>The <code class="directive">ServerAdmin</code> sets the contact address
2681 that the server includes in any error messages it returns to the
2682 client. If the <code>httpd</code> doesn't recognize the supplied argument
2684 assumes, that it's an <var>email-address</var> and prepends it with
2685 <code>mailto:</code> in hyperlink targets. However, it's recommended to
2686 actually use an email address, since there are a lot of CGI scripts that
2687 make that assumption. If you want to use an URL, it should point to another
2688 server under your control. Otherwise users may not be able to contact you in
2691 <p>It may be worth setting up a dedicated address for this, e.g.</p>
2693 <div class="example"><p><code>
2694 ServerAdmin www-admin@foo.example.com
2696 <p>as users do not always mention that they are talking about the
2700 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2701 <div class="directive-section"><h2><a name="ServerAlias" id="ServerAlias">ServerAlias</a> <a name="serveralias" id="serveralias">Directive</a></h2>
2702 <table class="directive">
2703 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Alternate names for a host used when matching requests
2704 to name-virtual hosts</td></tr>
2705 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAlias <var>hostname</var> [<var>hostname</var>] ...</code></td></tr>
2706 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
2707 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2708 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2710 <p>The <code class="directive">ServerAlias</code> directive sets the
2711 alternate names for a host, for use with <a href="../vhosts/name-based.html">name-based virtual hosts</a>. The
2712 <code class="directive">ServerAlias</code> may include wildcards, if appropriate.</p>
2714 <div class="example"><p><code>
2715 <VirtualHost *:80><br />
2716 ServerName server.domain.com<br />
2717 ServerAlias server server2.domain.com server2<br />
2718 ServerAlias *.example.com<br />
2720 </VirtualHost>
2725 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
2728 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2729 <div class="directive-section"><h2><a name="ServerName" id="ServerName">ServerName</a> <a name="servername" id="servername">Directive</a></h2>
2730 <table class="directive">
2731 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hostname and port that the server uses to identify
2733 <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>
2734 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2735 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2736 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2737 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>In version 2.0, this
2738 directive supersedes the functionality of the <code class="directive">Port</code>
2739 directive from version 1.3.</td></tr>
2741 <p>The <code class="directive">ServerName</code> directive sets the
2742 request scheme, hostname and
2743 port that the server uses to identify itself. This is used when
2744 creating redirection URLs. For example, if the name of the
2745 machine hosting the web server is <code>simple.example.com</code>,
2746 but the machine also has the DNS alias <code>www.example.com</code>
2747 and you wish the web server to be so identified, the following
2748 directive should be used:</p>
2750 <div class="example"><p><code>
2751 ServerName www.example.com:80
2754 <p>If no <code class="directive">ServerName</code> is specified, then the
2755 server attempts to deduce the hostname by performing a reverse
2756 lookup on the IP address. If no port is specified in the
2757 <code class="directive">ServerName</code>, then the server will use the
2758 port from the incoming request. For optimal reliability and
2759 predictability, you should specify an explicit hostname and port
2760 using the <code class="directive">ServerName</code> directive.</p>
2762 <p>If you are using <a href="../vhosts/name-based.html">name-based virtual hosts</a>,
2763 the <code class="directive">ServerName</code> inside a
2764 <code class="directive"><a href="#virtualhost"><VirtualHost></a></code>
2765 section specifies what hostname must appear in the request's
2766 <code>Host:</code> header to match this virtual host.</p>
2769 <p>Sometimes, the server runs behind a device that processes SSL,
2770 such as a reverse proxy, load balancer or SSL offload
2771 appliance. When this is the case, specify the
2772 <code>https://</code> scheme and the port number to which the
2773 clients connect in the <code class="directive">ServerName</code> directive
2774 to make sure that the server generates the correct
2775 self-referential URLs.
2778 <p>See the description of the
2779 <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> and
2780 <code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code> directives for
2781 settings which determine whether self-referential URLs (e.g., by the
2782 <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> module) will refer to the
2783 specified port, or to the port number given in the client's request.
2789 <li><a href="../dns-caveats.html">Issues Regarding DNS and
2791 <li><a href="../vhosts/">Apache virtual host
2792 documentation</a></li>
2793 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
2794 <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li>
2795 <li><code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code></li>
2796 <li><code class="directive"><a href="#serveralias">ServerAlias</a></code></li>
2799 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2800 <div class="directive-section"><h2><a name="ServerPath" id="ServerPath">ServerPath</a> <a name="serverpath" id="serverpath">Directive</a></h2>
2801 <table class="directive">
2802 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Legacy URL pathname for a name-based virtual host that
2803 is accessed by an incompatible browser</td></tr>
2804 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerPath <var>URL-path</var></code></td></tr>
2805 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
2806 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2807 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2809 <p>The <code class="directive">ServerPath</code> directive sets the legacy
2810 URL pathname for a host, for use with <a href="../vhosts/">name-based virtual hosts</a>.</p>
2814 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
2817 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2818 <div class="directive-section"><h2><a name="ServerRoot" id="ServerRoot">ServerRoot</a> <a name="serverroot" id="serverroot">Directive</a></h2>
2819 <table class="directive">
2820 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Base directory for the server installation</td></tr>
2821 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerRoot <var>directory-path</var></code></td></tr>
2822 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerRoot /usr/local/apache</code></td></tr>
2823 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2824 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2825 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2827 <p>The <code class="directive">ServerRoot</code> directive sets the
2828 directory in which the server lives. Typically it will contain the
2829 subdirectories <code>conf/</code> and <code>logs/</code>. Relative
2830 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
2831 relative to this directory.</p>
2833 <div class="example"><h3>Example</h3><p><code>
2834 ServerRoot /home/httpd
2840 <li><a href="../invoking.html">the <code>-d</code>
2841 option to <code>httpd</code></a></li>
2842 <li><a href="../misc/security_tips.html#serverroot">the
2843 security tips</a> for information on how to properly set
2844 permissions on the <code class="directive">ServerRoot</code></li>
2847 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2848 <div class="directive-section"><h2><a name="ServerSignature" id="ServerSignature">ServerSignature</a> <a name="serversignature" id="serversignature">Directive</a></h2>
2849 <table class="directive">
2850 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the footer on server-generated documents</td></tr>
2851 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerSignature On|Off|EMail</code></td></tr>
2852 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerSignature Off</code></td></tr>
2853 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2854 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2855 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2856 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2858 <p>The <code class="directive">ServerSignature</code> directive allows the
2859 configuration of a trailing footer line under server-generated
2860 documents (error messages, <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> ftp directory
2861 listings, <code class="module"><a href="../mod/mod_info.html">mod_info</a></code> output, ...). The reason why you
2862 would want to enable such a footer line is that in a chain of proxies,
2863 the user often has no possibility to tell which of the chained servers
2864 actually produced a returned error message.</p>
2866 <p>The <code>Off</code>
2867 setting, which is the default, suppresses the footer line (and is
2868 therefore compatible with the behavior of Apache-1.2 and
2869 below). The <code>On</code> setting simply adds a line with the
2870 server version number and <code class="directive"><a href="#servername">ServerName</a></code> of the serving virtual host,
2871 and the <code>EMail</code> setting additionally creates a
2872 "mailto:" reference to the <code class="directive"><a href="#serveradmin">ServerAdmin</a></code> of the referenced
2875 <p>After version 2.0.44, the details of the server version number
2876 presented are controlled by the <code class="directive"><a href="#servertokens">ServerTokens</a></code> directive.</p>
2880 <li><code class="directive"><a href="#servertokens">ServerTokens</a></code></li>
2883 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2884 <div class="directive-section"><h2><a name="ServerTokens" id="ServerTokens">ServerTokens</a> <a name="servertokens" id="servertokens">Directive</a></h2>
2885 <table class="directive">
2886 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the <code>Server</code> HTTP response
2888 <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>
2889 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerTokens Full</code></td></tr>
2890 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2891 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2892 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2894 <p>This directive controls whether <code>Server</code> response
2895 header field which is sent back to clients includes a
2896 description of the generic OS-type of the server as well as
2897 information about compiled-in modules.</p>
2900 <dt><code>ServerTokens Prod[uctOnly]</code></dt>
2902 <dd>Server sends (<em>e.g.</em>): <code>Server:
2905 <dt><code>ServerTokens Major</code></dt>
2907 <dd>Server sends (<em>e.g.</em>): <code>Server:
2908 Apache/2</code></dd>
2910 <dt><code>ServerTokens Minor</code></dt>
2912 <dd>Server sends (<em>e.g.</em>): <code>Server:
2913 Apache/2.0</code></dd>
2915 <dt><code>ServerTokens Min[imal]</code></dt>
2917 <dd>Server sends (<em>e.g.</em>): <code>Server:
2918 Apache/2.0.41</code></dd>
2920 <dt><code>ServerTokens OS</code></dt>
2922 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2925 <dt><code>ServerTokens Full</code> (or not specified)</dt>
2927 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2928 (Unix) PHP/4.2.2 MyMod/1.2</code></dd>
2931 <p>This setting applies to the entire server, and cannot be
2932 enabled or disabled on a virtualhost-by-virtualhost basis.</p>
2934 <p>After version 2.0.44, this directive also controls the
2935 information presented by the <code class="directive"><a href="#serversignature">ServerSignature</a></code> directive.</p>
2939 <li><code class="directive"><a href="#serversignature">ServerSignature</a></code></li>
2942 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2943 <div class="directive-section"><h2><a name="SetHandler" id="SetHandler">SetHandler</a> <a name="sethandler" id="sethandler">Directive</a></h2>
2944 <table class="directive">
2945 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be processed by a
2947 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetHandler <var>handler-name</var>|None</code></td></tr>
2948 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2949 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2950 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2951 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2952 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved into the core in Apache 2.0</td></tr>
2954 <p>When placed into an <code>.htaccess</code> file or a
2955 <code class="directive"><a href="#directory"><Directory></a></code> or
2956 <code class="directive"><a href="#location"><Location></a></code>
2957 section, this directive forces all matching files to be parsed
2958 through the <a href="../handler.html">handler</a> given by
2959 <var>handler-name</var>. For example, if you had a directory you
2960 wanted to be parsed entirely as imagemap rule files, regardless
2961 of extension, you might put the following into an
2962 <code>.htaccess</code> file in that directory:</p>
2964 <div class="example"><p><code>
2965 SetHandler imap-file
2968 <p>Another example: if you wanted to have the server display a
2969 status report whenever a URL of
2970 <code>http://servername/status</code> was called, you might put
2971 the following into <code>httpd.conf</code>:</p>
2973 <div class="example"><p><code>
2974 <Location /status><br />
2975 <span class="indent">
2976 SetHandler server-status<br />
2981 <p>You can override an earlier defined <code class="directive">SetHandler</code>
2982 directive by using the value <code>None</code>.</p>
2983 <p><strong>Note:</strong> because SetHandler overrides default handlers,
2984 normal behaviour such as handling of URLs ending in a slash (/) as
2985 directories or index files is suppressed.</p>
2989 <li><code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code></li>
2992 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2993 <div class="directive-section"><h2><a name="SetInputFilter" id="SetInputFilter">SetInputFilter</a> <a name="setinputfilter" id="setinputfilter">Directive</a></h2>
2994 <table class="directive">
2995 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process client requests and POST
2997 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetInputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
2998 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2999 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
3000 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3001 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3003 <p>The <code class="directive">SetInputFilter</code> directive sets the
3004 filter or filters which will process client requests and POST
3005 input when they are received by the server. This is in addition to
3006 any filters defined elsewhere, including the
3007 <code class="directive"><a href="../mod/mod_mime.html#addinputfilter">AddInputFilter</a></code>
3010 <p>If more than one filter is specified, they must be separated
3011 by semicolons in the order in which they should process the
3016 <li><a href="../filter.html">Filters</a> documentation</li>
3019 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3020 <div class="directive-section"><h2><a name="SetOutputFilter" id="SetOutputFilter">SetOutputFilter</a> <a name="setoutputfilter" id="setoutputfilter">Directive</a></h2>
3021 <table class="directive">
3022 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process responses from the
3024 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetOutputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
3025 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
3026 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
3027 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3028 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3030 <p>The <code class="directive">SetOutputFilter</code> directive sets the filters
3031 which will process responses from the server before they are
3032 sent to the client. This is in addition to any filters defined
3033 elsewhere, including the
3034 <code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code>
3037 <p>For example, the following configuration will process all files
3038 in the <code>/www/data/</code> directory for server-side
3041 <div class="example"><p><code>
3042 <Directory /www/data/><br />
3043 <span class="indent">
3044 SetOutputFilter INCLUDES<br />
3049 <p>If more than one filter is specified, they must be separated
3050 by semicolons in the order in which they should process the
3055 <li><a href="../filter.html">Filters</a> documentation</li>
3058 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3059 <div class="directive-section"><h2><a name="TimeOut" id="TimeOut">TimeOut</a> <a name="timeout" id="timeout">Directive</a></h2>
3060 <table class="directive">
3061 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for
3062 certain events before failing a request</td></tr>
3063 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TimeOut <var>seconds</var></code></td></tr>
3064 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TimeOut 300</code></td></tr>
3065 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
3066 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3067 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3069 <p>The <code class="directive">TimeOut</code> directive defines the length
3070 of time Apache will wait for I/O in various circumstances:</p>
3073 <li>When reading data from the client, the length of time to
3074 wait for a TCP packet to arrive if the read buffer is
3077 <li>When writing data to the client, the length of time to wait
3078 for an acknowledgement of a packet if the send buffer is
3081 <li>In <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>, the length of time to wait for
3082 output from a CGI script.</li>
3084 <li>In <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code>, the length of time to
3085 wait for output from a filtering process.</li>
3087 <li>In <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>, the default timeout value if
3088 <code class="directive"><a href="../mod/mod_proxy.html#proxytimeout">ProxyTimeout</a></code> is not
3094 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3095 <div class="directive-section"><h2><a name="TraceEnable" id="TraceEnable">TraceEnable</a> <a name="traceenable" id="traceenable">Directive</a></h2>
3096 <table class="directive">
3097 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines the behaviour on <code>TRACE</code>
3099 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TraceEnable <var>[on|off|extended]</var></code></td></tr>
3100 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TraceEnable on</code></td></tr>
3101 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3102 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3103 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3104 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 1.3.34, 2.0.55 and later</td></tr>
3106 <p>This directive overrides the behavior of <code>TRACE</code> for both
3107 the core server and <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>. The default
3108 <code>TraceEnable on</code> permits <code>TRACE</code> requests per
3109 RFC 2616, which disallows any request body to accompany the request.
3110 <code>TraceEnable off</code> causes the core server and
3111 <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> to return a <code>405</code> (Method not
3112 allowed) error to the client.</p>
3114 <p>Finally, for testing and diagnostic purposes only, request
3115 bodies may be allowed using the non-compliant <code>TraceEnable
3116 extended</code> directive. The core (as an origin server) will
3117 restrict the request body to 64k (plus 8k for chunk headers if
3118 <code>Transfer-Encoding: chunked</code> is used). The core will
3119 reflect the full headers and all chunk headers with the response
3120 body. As a proxy server, the request body is not restricted to 64k.</p>
3123 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3124 <div class="directive-section"><h2><a name="UseCanonicalName" id="UseCanonicalName">UseCanonicalName</a> <a name="usecanonicalname" id="usecanonicalname">Directive</a></h2>
3125 <table class="directive">
3126 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and
3128 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalName On|Off|DNS</code></td></tr>
3129 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalName Off</code></td></tr>
3130 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
3131 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3132 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3134 <p>In many situations Apache must construct a <em>self-referential</em>
3135 URL -- that is, a URL that refers back to the same server. With
3136 <code>UseCanonicalName On</code> Apache will use the hostname and port
3137 specified in the <code class="directive"><a href="#servername">ServerName</a></code>
3138 directive to construct the canonical name for the server. This name
3139 is used in all self-referential URLs, and for the values of
3140 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> in CGIs.</p>
3142 <p>With <code>UseCanonicalName Off</code> Apache will form
3143 self-referential URLs using the hostname and port supplied by
3144 the client if any are supplied (otherwise it will use the
3145 canonical name, as defined above). These values are the same
3146 that are used to implement <a href="../vhosts/name-based.html">name based virtual hosts</a>,
3147 and are available with the same clients. The CGI variables
3148 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> will be
3149 constructed from the client supplied values as well.</p>
3151 <p>An example where this may be useful is on an intranet server
3152 where you have users connecting to the machine using short
3153 names such as <code>www</code>. You'll notice that if the users
3154 type a shortname, and a URL which is a directory, such as
3155 <code>http://www/splat</code>, <em>without the trailing
3156 slash</em> then Apache will redirect them to
3157 <code>http://www.domain.com/splat/</code>. If you have
3158 authentication enabled, this will cause the user to have to
3159 authenticate twice (once for <code>www</code> and once again
3160 for <code>www.domain.com</code> -- see <a href="http://httpd.apache.org/docs/misc/FAQ.html#prompted-twice">the
3161 FAQ on this subject for more information</a>). But if
3162 <code class="directive">UseCanonicalName</code> is set <code>Off</code>, then
3163 Apache will redirect to <code>http://www/splat/</code>.</p>
3165 <p>There is a third option, <code>UseCanonicalName DNS</code>,
3166 which is intended for use with mass IP-based virtual hosting to
3167 support ancient clients that do not provide a
3168 <code>Host:</code> header. With this option Apache does a
3169 reverse DNS lookup on the server IP address that the client
3170 connected to in order to work out self-referential URLs.</p>
3172 <div class="warning"><h3>Warning</h3>
3173 <p>If CGIs make assumptions about the values of <code>SERVER_NAME</code>
3174 they may be broken by this option. The client is essentially free
3175 to give whatever value they want as a hostname. But if the CGI is
3176 only using <code>SERVER_NAME</code> to construct self-referential URLs
3177 then it should be just fine.</p>
3182 <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li>
3183 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
3184 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
3187 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3188 <div class="directive-section"><h2><a name="UseCanonicalPhysicalPort" id="UseCanonicalPhysicalPort">UseCanonicalPhysicalPort</a> <a name="usecanonicalphysicalport" id="usecanonicalphysicalport">Directive</a></h2>
3189 <table class="directive">
3190 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and
3192 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalPhysicalPort On|Off</code></td></tr>
3193 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalPhysicalPort Off</code></td></tr>
3194 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
3195 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3196 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3198 <p>In many situations Apache must construct a <em>self-referential</em>
3199 URL -- that is, a URL that refers back to the same server. With
3200 <code>UseCanonicalPhysicalPort On</code> Apache will, when
3201 constructing the canonical port for the server to honor
3202 the <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> directive,
3203 provide the actual physical port number being used by this request
3204 as a potential port. With <code>UseCanonicalPhysicalPort Off</code>
3205 Apache will not ever use the actual physical port number, instead
3206 relying on all configured information to construct a valid port number.</p>
3208 <div class="note"><h3>Note</h3>
3209 <p>The ordering of when the physical port is used is as follows:<br /><br />
3210 <code>UseCanonicalName On</code></p>
3212 <li>Port provided in <code>Servername</code></li>
3213 <li>Physical port</li>
3214 <li>Default port</li>
3216 <code>UseCanonicalName Off | DNS</code>
3218 <li>Parsed port from <code>Host:</code> header</li>
3219 <li>Physical port</li>
3220 <li>Port provided in <code>Servername</code></li>
3221 <li>Default port</li>
3224 <p>With <code>UseCanonicalPhysicalPort Off</code>, the
3225 physical ports are removed from the ordering.</p>
3231 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
3232 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
3233 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
3236 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3237 <div class="directive-section"><h2><a name="VirtualHost" id="VirtualHost"><VirtualHost></a> <a name="virtualhost" id="virtualhost">Directive</a></h2>
3238 <table class="directive">
3239 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only to a specific
3240 hostname or IP address</td></tr>
3241 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><VirtualHost
3242 <var>addr</var>[:<var>port</var>] [<var>addr</var>[:<var>port</var>]]
3243 ...> ... </VirtualHost></code></td></tr>
3244 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3245 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3246 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3248 <p><code class="directive"><VirtualHost></code> and
3249 <code></VirtualHost></code> are used to enclose a group of
3250 directives that will apply only to a particular virtual host. Any
3251 directive that is allowed in a virtual host context may be
3252 used. When the server receives a request for a document on a
3253 particular virtual host, it uses the configuration directives
3254 enclosed in the <code class="directive"><VirtualHost></code>
3255 section. <var>Addr</var> can be:</p>
3258 <li>The IP address of the virtual host;</li>
3260 <li>A fully qualified domain name for the IP address of the
3261 virtual host (not recommended);</li>
3263 <li>The character <code>*</code>, which is used only in combination with
3264 <code>NameVirtualHost *</code> to match all IP addresses; or</li>
3266 <li>The string <code>_default_</code>, which is used only
3267 with IP virtual hosting to catch unmatched IP addresses.</li>
3270 <div class="example"><h3>Example</h3><p><code>
3271 <VirtualHost 10.1.2.3><br />
3272 <span class="indent">
3273 ServerAdmin webmaster@host.example.com<br />
3274 DocumentRoot /www/docs/host.example.com<br />
3275 ServerName host.example.com<br />
3276 ErrorLog logs/host.example.com-error_log<br />
3277 TransferLog logs/host.example.com-access_log<br />
3279 </VirtualHost>
3283 <p>IPv6 addresses must be specified in square brackets because
3284 the optional port number could not be determined otherwise. An
3285 IPv6 example is shown below:</p>
3287 <div class="example"><p><code>
3288 <VirtualHost [2001:db8::a00:20ff:fea7:ccea]><br />
3289 <span class="indent">
3290 ServerAdmin webmaster@host.example.com<br />
3291 DocumentRoot /www/docs/host.example.com<br />
3292 ServerName host.example.com<br />
3293 ErrorLog logs/host.example.com-error_log<br />
3294 TransferLog logs/host.example.com-access_log<br />
3296 </VirtualHost>
3299 <p>Each Virtual Host must correspond to a different IP address,
3300 different port number or a different host name for the server,
3301 in the former case the server machine must be configured to
3302 accept IP packets for multiple addresses. (If the machine does
3303 not have multiple network interfaces, then this can be
3304 accomplished with the <code>ifconfig alias</code> command -- if
3305 your OS supports it).</p>
3307 <div class="note"><h3>Note</h3>
3308 <p>The use of <code class="directive"><VirtualHost></code> does
3309 <strong>not</strong> affect what addresses Apache listens on. You
3310 may need to ensure that Apache is listening on the correct addresses
3311 using <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>.</p>
3314 <p>When using IP-based virtual hosting, the special name
3315 <code>_default_</code> can be specified in
3316 which case this virtual host will match any IP address that is
3317 not explicitly listed in another virtual host. In the absence
3318 of any <code>_default_</code> virtual host the "main" server config,
3319 consisting of all those definitions outside any VirtualHost
3320 section, is used when no IP-match occurs.</p>
3322 <p>You can specify a <code>:port</code> to change the port that is
3323 matched. If unspecified then it defaults to the same port as the
3324 most recent <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>
3325 statement of the main server. You may also specify <code>:*</code>
3326 to match all ports on that address. (This is recommended when used
3327 with <code>_default_</code>.)</p>
3329 <p>A <code class="directive"><a href="#servername">ServerName</a></code> should be
3330 specified inside each <code class="directive"><VirtualHost></code> block. If it is absent, the
3331 <code class="directive"><a href="#servername">ServerName</a></code> from the "main"
3332 server configuration will be inherited.</p>
3334 <div class="warning"><h3>Security</h3>
3335 <p>See the <a href="../misc/security_tips.html">security tips</a>
3336 document for details on why your security could be compromised if the
3337 directory where log files are stored is writable by anyone other
3338 than the user that starts the server.</p>
3343 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
3344 <li><a href="../dns-caveats.html">Issues Regarding DNS and
3346 <li><a href="../bind.html">Setting
3347 which addresses and ports Apache uses</a></li>
3348 <li><a href="../sections.html">How <Directory>, <Location>
3349 and <Files> sections work</a> for an explanation of how these
3350 different sections are combined when a request is received</li>
3354 <div class="bottomlang">
3355 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
3356 <a href="../en/mod/core.html" title="English"> en </a> |
3357 <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
3358 <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
3359 </div><div id="footer">
3360 <p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
3361 <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>