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15 <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
16 <p class="apache">Apache HTTP Server Version 2.0</p>
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20 <a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.0</a> > <a href="./">Modules</a></div>
21 <div id="page-content">
22 <div id="preamble"><h1>Apache Core Features</h1>
24 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
25 <a href="../en/mod/core.html" title="English"> en </a> |
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30 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Core Apache HTTP Server features that are always
32 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Core</td></tr></table>
34 <div id="quickview"><h3 class="directives">Directives</h3>
36 <li><img alt="" src="../images/down.gif" /> <a href="#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="#authname">AuthName</a></li>
43 <li><img alt="" src="../images/down.gif" /> <a href="#authtype">AuthType</a></li>
44 <li><img alt="" src="../images/down.gif" /> <a href="#cgimapextension">CGIMapExtension</a></li>
45 <li><img alt="" src="../images/down.gif" /> <a href="#contentdigest">ContentDigest</a></li>
46 <li><img alt="" src="../images/down.gif" /> <a href="#defaulttype">DefaultType</a></li>
47 <li><img alt="" src="../images/down.gif" /> <a href="#directory"><Directory></a></li>
48 <li><img alt="" src="../images/down.gif" /> <a href="#directorymatch"><DirectoryMatch></a></li>
49 <li><img alt="" src="../images/down.gif" /> <a href="#documentroot">DocumentRoot</a></li>
50 <li><img alt="" src="../images/down.gif" /> <a href="#enablemmap">EnableMMAP</a></li>
51 <li><img alt="" src="../images/down.gif" /> <a href="#enablesendfile">EnableSendfile</a></li>
52 <li><img alt="" src="../images/down.gif" /> <a href="#errordocument">ErrorDocument</a></li>
53 <li><img alt="" src="../images/down.gif" /> <a href="#errorlog">ErrorLog</a></li>
54 <li><img alt="" src="../images/down.gif" /> <a href="#fileetag">FileETag</a></li>
55 <li><img alt="" src="../images/down.gif" /> <a href="#files"><Files></a></li>
56 <li><img alt="" src="../images/down.gif" /> <a href="#filesmatch"><FilesMatch></a></li>
57 <li><img alt="" src="../images/down.gif" /> <a href="#forcetype">ForceType</a></li>
58 <li><img alt="" src="../images/down.gif" /> <a href="#hostnamelookups">HostnameLookups</a></li>
59 <li><img alt="" src="../images/down.gif" /> <a href="#identitycheck">IdentityCheck</a></li>
60 <li><img alt="" src="../images/down.gif" /> <a href="#ifdefine"><IfDefine></a></li>
61 <li><img alt="" src="../images/down.gif" /> <a href="#ifmodule"><IfModule></a></li>
62 <li><img alt="" src="../images/down.gif" /> <a href="#include">Include</a></li>
63 <li><img alt="" src="../images/down.gif" /> <a href="#keepalive">KeepAlive</a></li>
64 <li><img alt="" src="../images/down.gif" /> <a href="#keepalivetimeout">KeepAliveTimeout</a></li>
65 <li><img alt="" src="../images/down.gif" /> <a href="#limit"><Limit></a></li>
66 <li><img alt="" src="../images/down.gif" /> <a href="#limitexcept"><LimitExcept></a></li>
67 <li><img alt="" src="../images/down.gif" /> <a href="#limitinternalrecursion">LimitInternalRecursion</a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestbody">LimitRequestBody</a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfields">LimitRequestFields</a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfieldsize">LimitRequestFieldSize</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestline">LimitRequestLine</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#limitxmlrequestbody">LimitXMLRequestBody</a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#location"><Location></a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#locationmatch"><LocationMatch></a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#loglevel">LogLevel</a></li>
76 <li><img alt="" src="../images/down.gif" /> <a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></li>
77 <li><img alt="" src="../images/down.gif" /> <a href="#namevirtualhost">NameVirtualHost</a></li>
78 <li><img alt="" src="../images/down.gif" /> <a href="#options">Options</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#require">Require</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitcpu">RLimitCPU</a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitmem">RLimitMEM</a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#rlimitnproc">RLimitNPROC</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#satisfy">Satisfy</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#scriptinterpretersource">ScriptInterpreterSource</a></li>
85 <li><img alt="" src="../images/down.gif" /> <a href="#serveradmin">ServerAdmin</a></li>
86 <li><img alt="" src="../images/down.gif" /> <a href="#serveralias">ServerAlias</a></li>
87 <li><img alt="" src="../images/down.gif" /> <a href="#servername">ServerName</a></li>
88 <li><img alt="" src="../images/down.gif" /> <a href="#serverpath">ServerPath</a></li>
89 <li><img alt="" src="../images/down.gif" /> <a href="#serverroot">ServerRoot</a></li>
90 <li><img alt="" src="../images/down.gif" /> <a href="#serversignature">ServerSignature</a></li>
91 <li><img alt="" src="../images/down.gif" /> <a href="#servertokens">ServerTokens</a></li>
92 <li><img alt="" src="../images/down.gif" /> <a href="#sethandler">SetHandler</a></li>
93 <li><img alt="" src="../images/down.gif" /> <a href="#setinputfilter">SetInputFilter</a></li>
94 <li><img alt="" src="../images/down.gif" /> <a href="#setoutputfilter">SetOutputFilter</a></li>
95 <li><img alt="" src="../images/down.gif" /> <a href="#timeout">TimeOut</a></li>
96 <li><img alt="" src="../images/down.gif" /> <a href="#traceenable">TraceEnable</a></li>
97 <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalname">UseCanonicalName</a></li>
98 <li><img alt="" src="../images/down.gif" /> <a href="#virtualhost"><VirtualHost></a></li>
102 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
103 <div class="directive-section"><h2><a name="AcceptPathInfo" id="AcceptPathInfo">AcceptPathInfo</a> <a name="acceptpathinfo" id="acceptpathinfo">Directive</a></h2>
104 <table class="directive">
105 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Resources accept trailing pathname information</td></tr>
106 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptPathInfo On|Off|Default</code></td></tr>
107 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AcceptPathInfo Default</code></td></tr>
108 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
109 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
110 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
111 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
112 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.30 and later</td></tr>
115 <p>This directive controls whether requests that contain trailing
116 pathname information that follows an actual filename (or
117 non-existent file in an existing directory) will be accepted or
118 rejected. The trailing pathname information can be made
119 available to scripts in the <code>PATH_INFO</code> environment
122 <p>For example, assume the location <code>/test/</code> points to
123 a directory that contains only the single file
124 <code>here.html</code>. Then requests for
125 <code>/test/here.html/more</code> and
126 <code>/test/nothere.html/more</code> both collect
127 <code>/more</code> as <code>PATH_INFO</code>.</p>
129 <p>The three possible arguments for the
130 <code class="directive">AcceptPathInfo</code> directive are:</p>
132 <dt><code>Off</code></dt><dd>A request will only be accepted if it
133 maps to a literal path that exists. Therefore a request with
134 trailing pathname information after the true filename such as
135 <code>/test/here.html/more</code> in the above example will return
136 a 404 NOT FOUND error.</dd>
138 <dt><code>On</code></dt><dd>A request will be accepted if a
139 leading path component maps to a file that exists. The above
140 example <code>/test/here.html/more</code> will be accepted if
141 <code>/test/here.html</code> maps to a valid file.</dd>
143 <dt><code>Default</code></dt><dd>The treatment of requests with
144 trailing pathname information is determined by the <a href="../handler.html">handler</a> responsible for the request.
145 The core handler for normal files defaults to rejecting
146 <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
147 <code>PATH_INFO</code> by default.</dd>
150 <p>The primary purpose of the <code>AcceptPathInfo</code>
151 directive is to allow you to override the handler's choice of
152 accepting or rejecting <code>PATH_INFO</code>. This override is required,
153 for example, when you use a <a href="../filter.html">filter</a>, such
154 as <a href="mod_include.html">INCLUDES</a>, to generate content
155 based on <code>PATH_INFO</code>. The core handler would usually reject
156 the request, so you can use the following configuration to enable
159 <div class="example"><p><code>
160 <Files "mypaths.shtml"><br />
161 <span class="indent">
162 Options +Includes<br />
163 SetOutputFilter INCLUDES<br />
164 AcceptPathInfo On<br />
171 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
172 <div class="directive-section"><h2><a name="AccessFileName" id="AccessFileName">AccessFileName</a> <a name="accessfilename" id="accessfilename">Directive</a></h2>
173 <table class="directive">
174 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Name of the distributed configuration file</td></tr>
175 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AccessFileName <var>filename</var> [<var>filename</var>] ...</code></td></tr>
176 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AccessFileName .htaccess</code></td></tr>
177 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
178 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
179 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
181 <p>While processing a request the server looks for
182 the first existing configuration file from this list of names in
183 every directory of the path to the document, if distributed
184 configuration files are <a href="#allowoverride">enabled for that
185 directory</a>. For example:</p>
187 <div class="example"><p><code>
191 <p>before returning the document
192 <code>/usr/local/web/index.html</code>, the server will read
193 <code>/.acl</code>, <code>/usr/.acl</code>,
194 <code>/usr/local/.acl</code> and <code>/usr/local/web/.acl</code>
195 for directives, unless they have been disabled with</p>
197 <div class="example"><p><code>
198 <Directory /><br />
199 <span class="indent">
200 AllowOverride None<br />
207 <li><code class="directive"><a href="#allowoverride">AllowOverride</a></code></li>
208 <li><a href="../configuring.html">Configuration Files</a></li>
209 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
212 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
213 <div class="directive-section"><h2><a name="AddDefaultCharset" id="AddDefaultCharset">AddDefaultCharset</a> <a name="adddefaultcharset" id="adddefaultcharset">Directive</a></h2>
214 <table class="directive">
215 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default charset parameter to be added when a response
216 content-type is <code>text/plain</code> or <code>text/html</code></td></tr>
217 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddDefaultCharset On|Off|<var>charset</var></code></td></tr>
218 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AddDefaultCharset Off</code></td></tr>
219 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
220 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
221 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
222 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
224 <p>This directive specifies a default value for the media type
225 charset parameter (the name of a character encoding) to be added
226 to a response if and only if the response's content-type is either
227 <code>text/plain</code> or <code>text/html</code>. This should override
228 any charset specified in the body of the response via a <code>META</code>
229 element, though the exact behavior is often dependent on the user's client
230 configuration. A setting of <code>AddDefaultCharset Off</code>
231 disables this functionality. <code>AddDefaultCharset On</code> enables
232 a default charset of <code>iso-8859-1</code>. Any other value is assumed
233 to be the <var>charset</var> to be used, which should be one of the
234 <a href="http://www.iana.org/assignments/character-sets">IANA registered
235 charset values</a> for use in MIME media types.
238 <div class="example"><p><code>
239 AddDefaultCharset utf-8
242 <p><code class="directive">AddDefaultCharset</code> should only be used when all
243 of the text resources to which it applies are known to be in that
244 character encoding and it is too inconvenient to label their charset
245 individually. One such example is to add the charset parameter
246 to resources containing generated content, such as legacy CGI
247 scripts, that might be vulnerable to cross-site scripting attacks
248 due to user-provided data being included in the output. Note, however,
249 that a better solution is to just fix (or delete) those scripts, since
250 setting a default charset does not protect users that have enabled
251 the "auto-detect character encoding" feature on their browser.</p>
255 <li><code class="directive"><a href="../mod/mod_mime.html#addcharset">AddCharset</a></code></li>
258 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
259 <div class="directive-section"><h2><a name="AddOutputFilterByType" id="AddOutputFilterByType">AddOutputFilterByType</a> <a name="addoutputfilterbytype" id="addoutputfilterbytype">Directive</a></h2>
260 <table class="directive">
261 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>assigns an output filter to a particular MIME-type</td></tr>
262 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddOutputFilterByType <var>filter</var>[;<var>filter</var>...]
263 <var>MIME-type</var> [<var>MIME-type</var>] ...</code></td></tr>
264 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
265 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
266 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
267 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
268 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.33 and later</td></tr>
270 <p>This directive activates a particular output <a href="../filter.html">filter</a> for a request depending on the
271 response MIME-type.</p>
273 <p>The following example uses the <code>DEFLATE</code> filter, which
274 is provided by <code class="module"><a href="../mod/mod_deflate.html">mod_deflate</a></code>. It will compress all
275 output (either static or dynamic) which is labeled as
276 <code>text/html</code> or <code>text/plain</code> before it is sent
279 <div class="example"><p><code>
280 AddOutputFilterByType DEFLATE text/html text/plain
283 <p>If you want the content to be processed by more than one filter, their
284 names have to be separated by semicolons. It's also possible to use one
285 <code class="directive">AddOutputFilterByType</code> directive for each of
288 <p>The configuration below causes all script output labeled as
289 <code>text/html</code> to be processed at first by the
290 <code>INCLUDES</code> filter and then by the <code>DEFLATE</code>
293 <div class="example"><p><code>
294 <Location /cgi-bin/><br />
295 <span class="indent">
296 Options Includes<br />
297 AddOutputFilterByType INCLUDES;DEFLATE text/html<br />
302 <div class="warning"><h3>Note</h3>
303 <p>Enabling filters with <code class="directive">AddOutputFilterByType</code>
304 may fail partially or completely in some cases. For example, no
305 filters are applied if the MIME-type could not be determined and falls
306 back to the <code class="directive"><a href="#defaulttype">DefaultType</a></code> setting,
307 even if the <code class="directive"><a href="#defaulttype">DefaultType</a></code> is the
310 <p>However, if you want to make sure, that the filters will be
311 applied, assign the content type to a resource explicitly, for
312 example with <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> or
313 <code class="directive"><a href="#forcetype">ForceType</a></code>. Setting the
314 content type within a (non-nph) CGI script is also safe.</p>
316 <p>The by-type output filters are never applied on proxy requests.</p>
321 <li><code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code></li>
322 <li><code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code></li>
323 <li><a href="../filter.html">filters</a></li>
326 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
327 <div class="directive-section"><h2><a name="AllowEncodedSlashes" id="AllowEncodedSlashes">AllowEncodedSlashes</a> <a name="allowencodedslashes" id="allowencodedslashes">Directive</a></h2>
328 <table class="directive">
329 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines whether encoded path separators in URLs are allowed to
330 be passed through</td></tr>
331 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowEncodedSlashes On|Off</code></td></tr>
332 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowEncodedSlashes Off</code></td></tr>
333 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
334 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
335 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
336 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.46 and later</td></tr>
338 <p>The <code class="directive">AllowEncodedSlashes</code> directive allows URLs
339 which contain encoded path separators (<code>%2F</code> for <code>/</code>
340 and additionally <code>%5C</code> for <code>\</code> on according systems)
341 to be used. Normally such URLs are refused with a 404 (Not found) error.</p>
343 <p>Turning <code class="directive">AllowEncodedSlashes</code> <code>On</code> is
344 mostly useful when used in conjunction with <code>PATH_INFO</code>.</p>
346 <div class="note"><h3>Note</h3>
347 <p>Allowing encoded slashes does <em>not</em> imply <em>decoding</em>.
348 Occurrences of <code>%2F</code> or <code>%5C</code> (<em>only</em> on
349 according systems) will be left as such in the otherwise decoded URL
355 <li><code class="directive"><a href="#acceptpathinfo">AcceptPathInfo</a></code></li>
358 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
359 <div class="directive-section"><h2><a name="AllowOverride" id="AllowOverride">AllowOverride</a> <a name="allowoverride" id="allowoverride">Directive</a></h2>
360 <table class="directive">
361 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Types of directives that are allowed in
362 <code>.htaccess</code> files</td></tr>
363 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowOverride All|None|<var>directive-type</var>
364 [<var>directive-type</var>] ...</code></td></tr>
365 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowOverride All</code></td></tr>
366 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
367 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
368 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
370 <p>When the server finds an <code>.htaccess</code> file (as
371 specified by <code class="directive"><a href="#accessfilename">AccessFileName</a></code>)
372 it needs to know which directives declared in that file can override
373 earlier configuration directives.</p>
375 <div class="note"><h3>Only available in <Directory> sections</h3>
376 <code class="directive">AllowOverride</code> is valid only in
377 <code class="directive"><a href="#directory"><Directory></a></code>
378 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
379 <code class="directive"><a href="#files"><Files></a></code> sections.
382 <p>When this directive is set to <code>None</code>, then
383 <a href="#accessfilename">.htaccess</a> files are completely ignored.
384 In this case, the server will not even attempt to read
385 <code>.htaccess</code> files in the filesystem.</p>
387 <p>When this directive is set to <code>All</code>, then any
388 directive which has the .htaccess <a href="directive-dict.html#Context">Context</a> is allowed in
389 <code>.htaccess</code> files.</p>
391 <p>The <var>directive-type</var> can be one of the following
392 groupings of directives.</p>
399 Allow use of the authorization directives (<code class="directive"><a href="../mod/mod_auth_dbm.html#authdbmgroupfile">AuthDBMGroupFile</a></code>,
400 <code class="directive"><a href="../mod/mod_auth_dbm.html#authdbmuserfile">AuthDBMUserFile</a></code>,
401 <code class="directive"><a href="../mod/mod_auth.html#authgroupfile">AuthGroupFile</a></code>,
402 <code class="directive"><a href="#authname">AuthName</a></code>,
403 <code class="directive"><a href="#authtype">AuthType</a></code>, <code class="directive"><a href="../mod/mod_auth.html#authuserfile">AuthUserFile</a></code>, <code class="directive"><a href="#require">Require</a></code>, <em>etc.</em>).</dd>
408 Allow use of the directives controlling document types (<code class="directive"><a href="#defaulttype">DefaultType</a></code>, <code class="directive"><a href="#errordocument">ErrorDocument</a></code>, <code class="directive"><a href="#forcetype">ForceType</a></code>, <code class="directive"><a href="../mod/mod_negotiation.html#languagepriority">LanguagePriority</a></code>,
409 <code class="directive"><a href="#sethandler">SetHandler</a></code>, <code class="directive"><a href="#setinputfilter">SetInputFilter</a></code>, <code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code>, and
410 <code class="module"><a href="../mod/mod_mime.html">mod_mime</a></code> Add* and Remove*
411 directives, <em>etc.</em>).</dd>
416 Allow use of the directives controlling directory indexing
417 (<code class="directive"><a href="../mod/mod_autoindex.html#adddescription">AddDescription</a></code>,
418 <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>,
419 <code class="directive"><a href="../mod/mod_autoindex.html#addiconbytype">AddIconByType</a></code>,
420 <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>,
426 Allow use of the directives controlling host access (<code class="directive"><a href="../mod/mod_access.html#allow">Allow</a></code>, <code class="directive"><a href="../mod/mod_access.html#deny">Deny</a></code> and <code class="directive"><a href="../mod/mod_access.html#order">Order</a></code>).</dd>
431 Allow use of the directives controlling specific directory
432 features (<code class="directive"><a href="#options">Options</a></code> and
433 <code class="directive"><a href="../mod/mod_include.html#xbithack">XBitHack</a></code>).</dd>
438 <div class="example"><p><code>
439 AllowOverride AuthConfig Indexes
442 <p>In the example above all directives that are neither in the group
443 <code>AuthConfig</code> nor <code>Indexes</code> cause an internal
448 <li><code class="directive"><a href="#accessfilename">AccessFileName</a></code></li>
449 <li><a href="../configuring.html">Configuration Files</a></li>
450 <li><a href="../howto/htaccess.html">.htaccess Files</a></li>
453 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
454 <div class="directive-section"><h2><a name="AuthName" id="AuthName">AuthName</a> <a name="authname" id="authname">Directive</a></h2>
455 <table class="directive">
456 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Authorization realm for use in HTTP
457 authentication</td></tr>
458 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthName <var>auth-domain</var></code></td></tr>
459 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
460 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
461 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
462 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
464 <p>This directive sets the name of the authorization realm for a
465 directory. This realm is given to the client so that the user
466 knows which username and password to send.
467 <code class="directive">AuthName</code> takes a single argument; if the
468 realm name contains spaces, it must be enclosed in quotation
469 marks. It must be accompanied by <code class="directive"><a href="#authtype">AuthType</a></code> and <code class="directive"><a href="#require">Require</a></code> directives, and directives such
470 as <code class="directive"><a href="../mod/mod_auth.html#authuserfile">AuthUserFile</a></code> and
471 <code class="directive"><a href="../mod/mod_auth.html#authgroupfile">AuthGroupFile</a></code> to
476 <div class="example"><p><code>
477 AuthName "Top Secret"
480 <p>The string provided for the <code>AuthName</code> is what will
481 appear in the password dialog provided by most browsers.</p>
485 <li><a href="../howto/auth.html">Authentication, Authorization, and
486 Access Control</a></li>
489 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
490 <div class="directive-section"><h2><a name="AuthType" id="AuthType">AuthType</a> <a name="authtype" id="authtype">Directive</a></h2>
491 <table class="directive">
492 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Type of user authentication</td></tr>
493 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthType Basic|Digest</code></td></tr>
494 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
495 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
496 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
497 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
499 <p>This directive selects the type of user authentication for a
500 directory. Only <code>Basic</code> and <code>Digest</code> are
501 currently implemented.
503 It must be accompanied by <code class="directive"><a href="#authname">AuthName</a></code> and <code class="directive"><a href="#require">Require</a></code> directives, and directives such
504 as <code class="directive"><a href="../mod/mod_auth.html#authuserfile">AuthUserFile</a></code> and
505 <code class="directive"><a href="../mod/mod_auth.html#authgroupfile">AuthGroupFile</a></code> to
510 <li><a href="../howto/auth.html">Authentication, Authorization,
511 and Access Control</a></li>
514 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
515 <div class="directive-section"><h2><a name="CGIMapExtension" id="CGIMapExtension">CGIMapExtension</a> <a name="cgimapextension" id="cgimapextension">Directive</a></h2>
516 <table class="directive">
517 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
519 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CGIMapExtension <var>cgi-path</var> <var>.extension</var></code></td></tr>
520 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
521 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
522 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
523 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
524 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>NetWare only</td></tr>
526 <p>This directive is used to control how Apache finds the
527 interpreter used to run CGI scripts. For example, setting
528 <code>CGIMapExtension sys:\foo.nlm .foo</code> will
529 cause all CGI script files with a <code>.foo</code> extension to
530 be passed to the FOO interpreter.</p>
533 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
534 <div class="directive-section"><h2><a name="ContentDigest" id="ContentDigest">ContentDigest</a> <a name="contentdigest" id="contentdigest">Directive</a></h2>
535 <table class="directive">
536 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables the generation of <code>Content-MD5</code> HTTP Response
538 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ContentDigest On|Off</code></td></tr>
539 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ContentDigest Off</code></td></tr>
540 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
541 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
542 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
543 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
545 <p>This directive enables the generation of
546 <code>Content-MD5</code> headers as defined in RFC1864
547 respectively RFC2068.</p>
549 <p>MD5 is an algorithm for computing a "message digest"
550 (sometimes called "fingerprint") of arbitrary-length data, with
551 a high degree of confidence that any alterations in the data
552 will be reflected in alterations in the message digest.</p>
554 <p>The <code>Content-MD5</code> header provides an end-to-end
555 message integrity check (MIC) of the entity-body. A proxy or
556 client may check this header for detecting accidental
557 modification of the entity-body in transit. Example header:</p>
559 <div class="example"><p><code>
560 Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA==
563 <p>Note that this can cause performance problems on your server
564 since the message digest is computed on every request (the
565 values are not cached).</p>
567 <p><code>Content-MD5</code> is only sent for documents served
568 by the <code class="module"><a href="../mod/core.html">core</a></code>, and not by any module. For example,
569 SSI documents, output from CGI scripts, and byte range responses
570 do not have this header.</p>
573 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
574 <div class="directive-section"><h2><a name="DefaultType" id="DefaultType">DefaultType</a> <a name="defaulttype" id="defaulttype">Directive</a></h2>
575 <table class="directive">
576 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>MIME content-type that will be sent if the
577 server cannot determine a type in any other way</td></tr>
578 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DefaultType <var>MIME-type</var></code></td></tr>
579 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DefaultType text/plain</code></td></tr>
580 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
581 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
582 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
583 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
585 <p>There will be times when the server is asked to provide a
586 document whose type cannot be determined by its MIME types
589 <p>The server must inform the client of the content-type of the
590 document, so in the event of an unknown type it uses the
591 <code>DefaultType</code>. For example:</p>
593 <div class="example"><p><code>
594 DefaultType image/gif
597 <p>would be appropriate for a directory which contained many GIF
598 images with filenames missing the <code>.gif</code> extension.</p>
600 <p>Note that unlike <code class="directive"><a href="#forcetype">ForceType</a></code>, this directive only
601 provides the default mime-type. All other mime-type definitions,
602 including filename extensions, that might identify the media type
603 will override this default.</p>
606 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
607 <div class="directive-section"><h2><a name="Directory" id="Directory"><Directory></a> <a name="directory" id="directory">Directive</a></h2>
608 <table class="directive">
609 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose a group of directives that apply only to the
610 named file-system directory and sub-directories</td></tr>
611 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Directory <var>directory-path</var>>
612 ... </Directory></code></td></tr>
613 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
614 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
615 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
617 <p><code class="directive"><Directory></code> and
618 <code></Directory></code> are used to enclose a group of
619 directives that will apply only to the named directory and
620 sub-directories of that directory. Any directive that is allowed
621 in a directory context may be used. <var>Directory-path</var> is
622 either the full path to a directory, or a wild-card string using
623 Unix shell-style matching. In a wild-card string, <code>?</code> matches
624 any single character, and <code>*</code> matches any sequences of
625 characters. You may also use <code>[]</code> character ranges. None
626 of the wildcards match a `/' character, so <code><Directory
627 /*/public_html></code> will not match
628 <code>/home/user/public_html</code>, but <code><Directory
629 /home/*/public_html></code> will match. Example:</p>
631 <div class="example"><p><code>
632 <Directory /usr/local/httpd/htdocs><br />
633 <span class="indent">
634 Options Indexes FollowSymLinks<br />
640 <p>Be careful with the <var>directory-path</var> arguments:
641 They have to literally match the filesystem path which Apache uses
642 to access the files. Directives applied to a particular
643 <code><Directory></code> will not apply to files accessed from
644 that same directory via a different path, such as via different symbolic
649 expressions can also be used, with the addition of the
650 <code>~</code> character. For example:</p>
652 <div class="example"><p><code>
653 <Directory ~ "^/www/.*/[0-9]{3}">
656 <p>would match directories in <code>/www/</code> that consisted of
659 <p>If multiple (non-regular expression) <code class="directive"><Directory></code> sections
660 match the directory (or one of its parents) containing a document,
661 then the directives are applied in the order of shortest match
662 first, interspersed with the directives from the <a href="#accessfilename">.htaccess</a> files. For example,
665 <div class="example"><p><code>
666 <Directory /><br />
667 <span class="indent">
668 AllowOverride None<br />
670 </Directory><br />
672 <Directory /home/><br />
673 <span class="indent">
674 AllowOverride FileInfo<br />
679 <p>for access to the document <code>/home/web/dir/doc.html</code>
683 <li>Apply directive <code>AllowOverride None</code>
684 (disabling <code>.htaccess</code> files).</li>
686 <li>Apply directive <code>AllowOverride FileInfo</code> (for
687 directory <code>/home</code>).</li>
689 <li>Apply any <code>FileInfo</code> directives in
690 <code>/home/.htaccess</code>, <code>/home/web/.htaccess</code> and
691 <code>/home/web/dir/.htaccess</code> in that order.</li>
694 <p>Regular expressions are not considered until after all of the
695 normal sections have been applied. Then all of the regular
696 expressions are tested in the order they appeared in the
697 configuration file. For example, with</p>
699 <div class="example"><p><code>
700 <Directory ~ abc$><br />
701 <span class="indent">
702 # ... directives here ...<br />
707 <p>the regular expression section won't be considered until after
708 all normal <code class="directive"><Directory></code>s and
709 <code>.htaccess</code> files have been applied. Then the regular
710 expression will match on <code>/home/abc/public_html/abc</code> and
711 the corresponding <code class="directive"><Directory></code> will
714 <p><strong>Note that the default Apache access for
715 <code><Directory /></code> is <code>Allow from All</code>.
716 This means that Apache will serve any file mapped from an URL. It is
717 recommended that you change this with a block such
720 <div class="example"><p><code>
721 <Directory /><br />
722 <span class="indent">
723 Order Deny,Allow<br />
729 <p><strong>and then override this for directories you
730 <em>want</em> accessible. See the <a href="../misc/security_tips.html">Security Tips</a> page for more
731 details.</strong></p>
733 <p>The directory sections occur in the <code>httpd.conf</code> file.
734 <code class="directive"><Directory></code> directives
735 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>
739 <li><a href="../sections.html">How <Directory>,
740 <Location> and <Files> sections work</a> for an
741 explanation of how these different sections are combined when a
742 request is received</li>
745 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
746 <div class="directive-section"><h2><a name="DirectoryMatch" id="DirectoryMatch"><DirectoryMatch></a> <a name="directorymatch" id="directorymatch">Directive</a></h2>
747 <table class="directive">
748 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose directives that apply to
749 file-system directories matching a regular expression and their
750 subdirectories</td></tr>
751 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><DirectoryMatch <var>regex</var>>
752 ... </DirectoryMatch></code></td></tr>
753 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
754 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
755 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
757 <p><code class="directive"><DirectoryMatch></code> and
758 <code></DirectoryMatch></code> are used to enclose a group
759 of directives which will apply only to the named directory and
760 sub-directories of that directory, the same as <code class="directive"><a href="#directory"><Directory></a></code>. However, it
761 takes as an argument a regular expression. For example:</p>
763 <div class="example"><p><code>
764 <DirectoryMatch "^/www/(.+/)?[0-9]{3}">
767 <p>would match directories in <code>/www/</code> that consisted of three
772 <li><code class="directive"><a href="#directory"><Directory></a></code> for
773 a description of how regular expressions are mixed in with normal
774 <code class="directive"><Directory></code>s</li>
775 <li><a href="../sections.html">How <Directory>, <Location> and
776 <Files> sections work</a> for an explanation of how these different
777 sections are combined when a request is received</li>
780 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
781 <div class="directive-section"><h2><a name="DocumentRoot" id="DocumentRoot">DocumentRoot</a> <a name="documentroot" id="documentroot">Directive</a></h2>
782 <table class="directive">
783 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory that forms the main document tree visible
784 from the web</td></tr>
785 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DocumentRoot <var>directory-path</var></code></td></tr>
786 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DocumentRoot /usr/local/apache/htdocs</code></td></tr>
787 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
788 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
789 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
791 <p>This directive sets the directory from which <code class="program"><a href="../programs/httpd.html">httpd</a></code>
792 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
793 path from the requested URL to the document root to make the
794 path to the document. Example:</p>
796 <div class="example"><p><code>
797 DocumentRoot /usr/web
801 <code>http://www.my.host.com/index.html</code> refers to
802 <code>/usr/web/index.html</code>.</p>
804 <p>The <code class="directive">DocumentRoot</code> should be specified without
805 a trailing slash.</p>
809 <li><a href="../urlmapping.html">Mapping URLs to Filesystem
813 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
814 <div class="directive-section"><h2><a name="EnableMMAP" id="EnableMMAP">EnableMMAP</a> <a name="enablemmap" id="enablemmap">Directive</a></h2>
815 <table class="directive">
816 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use memory-mapping to read files during delivery</td></tr>
817 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableMMAP On|Off</code></td></tr>
818 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableMMAP On</code></td></tr>
819 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
820 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
821 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
822 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
824 <p>This directive controls whether the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use
825 memory-mapping if it needs to read the contents of a file during
826 delivery. By default, when the handling of a request requires
827 access to the data within a file -- for example, when delivering a
828 server-parsed file using <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> -- Apache
829 memory-maps the file if the OS supports it.</p>
831 <p>This memory-mapping sometimes yields a performance improvement.
832 But in some environments, it is better to disable the memory-mapping
833 to prevent operational problems:</p>
836 <li>On some multiprocessor systems, memory-mapping can reduce the
837 performance of the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</li>
838 <li>With an NFS-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code>,
839 the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may crash due to a segmentation fault if a file
840 is deleted or truncated while the <code class="program"><a href="../programs/httpd.html">httpd</a></code> has it
844 <p>For server configurations that are vulnerable to these problems,
845 you should disable memory-mapping of delivered files by specifying:</p>
847 <div class="example"><p><code>
851 <p>For NFS mounted files, this feature may be disabled explicitly for
852 the offending files by specifying:</p>
854 <div class="example"><p><code>
855 <Directory "/path-to-nfs-files">
856 <span class="indent">
863 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
864 <div class="directive-section"><h2><a name="EnableSendfile" id="EnableSendfile">EnableSendfile</a> <a name="enablesendfile" id="enablesendfile">Directive</a></h2>
865 <table class="directive">
866 <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>
867 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableSendfile On|Off</code></td></tr>
868 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableSendfile On</code></td></tr>
869 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
870 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
871 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
872 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
873 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0.44 and later</td></tr>
875 <p>This directive controls whether <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use the
876 sendfile support from the kernel to transmit file contents to the client.
877 By default, when the handling of a request requires no access
878 to the data within a file -- for example, when delivering a
879 static file -- Apache uses sendfile to deliver the file contents
880 without ever reading the file if the OS supports it.</p>
882 <p>This sendfile mechanism avoids separate read and send operations,
883 and buffer allocations. But on some platforms or within some
884 filesystems, it is better to disable this feature to avoid
885 operational problems:</p>
888 <li>Some platforms may have broken sendfile support that the build
889 system did not detect, especially if the binaries were built on
890 another box and moved to such a machine with broken sendfile
892 <li>On Linux the use of sendfile triggers TCP-checksum
893 offloading bugs on certain networking cards when using IPv6.</li>
894 <li>With a network-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code> (e.g., NFS or SMB),
895 the kernel may be unable to serve the network file through
899 <p>For server configurations that are vulnerable to these problems,
900 you should disable this feature by specifying:</p>
902 <div class="example"><p><code>
906 <p>For NFS or SMB mounted files, this feature may be disabled explicitly
907 for the offending files by specifying:</p>
909 <div class="example"><p><code>
910 <Directory "/path-to-nfs-files">
911 <span class="indent">
918 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
919 <div class="directive-section"><h2><a name="ErrorDocument" id="ErrorDocument">ErrorDocument</a> <a name="errordocument" id="errordocument">Directive</a></h2>
920 <table class="directive">
921 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>What the server will return to the client
922 in case of an error</td></tr>
923 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorDocument <var>error-code</var> <var>document</var></code></td></tr>
924 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
925 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
926 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
927 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
928 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Quoting syntax for text messages is different in Apache
931 <p>In the event of a problem or error, Apache can be configured
932 to do one of four things,</p>
935 <li>output a simple hardcoded error message</li>
937 <li>output a customized message</li>
939 <li>redirect to a local <var>URL-path</var> to handle the
942 <li>redirect to an external <var>URL</var> to handle the
946 <p>The first option is the default, while options 2-4 are
947 configured using the <code class="directive">ErrorDocument</code>
948 directive, which is followed by the HTTP response code and a URL
949 or a message. Apache will sometimes offer additional information
950 regarding the problem/error.</p>
952 <p>URLs can begin with a slash (/) for local web-paths (relative
953 to the <code class="directive"><a href="#documentroot">DocumentRoot</a></code>), or be a
954 full URL which the client can resolve. Alternatively, a message
955 can be provided to be displayed by the browser. Examples:</p>
957 <div class="example"><p><code>
958 ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br />
959 ErrorDocument 404 /cgi-bin/bad_urls.pl<br />
960 ErrorDocument 401 /subscription_info.html<br />
961 ErrorDocument 403 "Sorry can't allow you access today"
964 <p>Additionally, the special value <code>default</code> can be used
965 to specify Apache's simple hardcoded message. While not required
966 under normal circumstances, <code>default</code> will restore
967 Apache's simple hardcoded message for configurations that would
968 otherwise inherit an existing <code class="directive">ErrorDocument</code>.</p>
970 <div class="example"><p><code>
971 ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br />
972 <Directory /web/docs><br />
973 <span class="indent">
974 ErrorDocument 404 default<br />
979 <p>Note that when you specify an <code class="directive">ErrorDocument</code>
980 that points to a remote URL (ie. anything with a method such as
981 <code>http</code> in front of it), Apache will send a redirect to the
982 client to tell it where to find the document, even if the
983 document ends up being on the same server. This has several
984 implications, the most important being that the client will not
985 receive the original error status code, but instead will
986 receive a redirect status code. This in turn can confuse web
987 robots and other clients which try to determine if a URL is
988 valid using the status code. In addition, if you use a remote
989 URL in an <code>ErrorDocument 401</code>, the client will not
990 know to prompt the user for a password since it will not
991 receive the 401 status code. Therefore, <strong>if you use an
992 <code>ErrorDocument 401</code> directive then it must refer to a local
993 document.</strong></p>
995 <p>Microsoft Internet Explorer (MSIE) will by default ignore
996 server-generated error messages when they are "too small" and substitute
997 its own "friendly" error messages. The size threshold varies depending on
998 the type of error, but in general, if you make your error document
999 greater than 512 bytes, then MSIE will show the server-generated
1000 error rather than masking it. More information is available in
1001 Microsoft Knowledge Base article <a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807">Q294807</a>.</p>
1003 <p>Although most error messages can be overriden, there are certain
1004 circumstances where the internal messages are used regardless of the
1005 setting of <code class="directive"><a href="#errordocument">ErrorDocument</a></code>. In
1006 particular, if a malformed request is detected, normal request processing
1007 will be immediately halted and the internal error message returned.
1008 This is necessary to guard against security problems caused by
1011 <p>If you are using mod_proxy, you may wish to enable
1012 <code class="directive"><a href="../mod/mod_proxy.html#proxyerroroverride">ProxyErrorOverride</a></code> so that you can provide
1013 custom error messages on behalf of your Origin servers. If you don't enable ProxyErrorOverride,
1014 Apache will not generate custom error documents for proxied content.</p>
1016 <p>Prior to version 2.0, messages were indicated by prefixing
1017 them with a single unmatched double quote character.</p>
1021 <li><a href="../custom-error.html">documentation of
1022 customizable responses</a></li>
1025 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1026 <div class="directive-section"><h2><a name="ErrorLog" id="ErrorLog">ErrorLog</a> <a name="errorlog" id="errorlog">Directive</a></h2>
1027 <table class="directive">
1028 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Location where the server will log errors</td></tr>
1029 <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>
1030 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows and OS/2)</code></td></tr>
1031 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1032 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1033 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1035 <p>The <code class="directive">ErrorLog</code> directive sets the name of
1036 the file to which the server will log any errors it encounters. If
1037 the <var>file-path</var> is not absolute then it is assumed to be
1038 relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>
1040 <div class="example"><h3>Example</h3><p><code>
1041 ErrorLog /var/log/httpd/error_log
1044 <p>If the <var>file-path</var>
1045 begins with a pipe (|) then it is assumed to be a command to spawn
1046 to handle the error log.</p>
1048 <div class="example"><h3>Example</h3><p><code>
1049 ErrorLog "|/usr/local/bin/httpd_errors"
1052 <p>Using <code>syslog</code> instead of a filename enables logging
1053 via syslogd(8) if the system supports it. The default is to use
1054 syslog facility <code>local7</code>, but you can override this by
1055 using the <code>syslog:<var>facility</var></code> syntax where
1056 <var>facility</var> can be one of the names usually documented in
1059 <div class="example"><h3>Example</h3><p><code>
1060 ErrorLog syslog:user
1063 <p>SECURITY: See the <a href="../misc/security_tips.html#serverroot">security tips</a>
1064 document for details on why your security could be compromised
1065 if the directory where log files are stored is writable by
1066 anyone other than the user that starts the server.</p>
1067 <div class="warning"><h3>Note</h3>
1068 <p>When entering a file path on non-Unix platforms, care should be taken
1069 to make sure that only forward slashed are used even though the platform
1070 may allow the use of back slashes. In general it is a good idea to always
1071 use forward slashes throughout the configuration files.</p>
1076 <li><code class="directive"><a href="#loglevel">LogLevel</a></code></li>
1077 <li><a href="../logs.html">Apache Log Files</a></li>
1080 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1081 <div class="directive-section"><h2><a name="FileETag" id="FileETag">FileETag</a> <a name="fileetag" id="fileetag">Directive</a></h2>
1082 <table class="directive">
1083 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>File attributes used to create the ETag
1084 HTTP response header</td></tr>
1085 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>FileETag <var>component</var> ...</code></td></tr>
1086 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>FileETag INode MTime Size</code></td></tr>
1087 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1088 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1089 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1090 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1093 The <code class="directive">FileETag</code> directive configures the file
1094 attributes that are used to create the <code>ETag</code> (entity
1095 tag) response header field when the document is based on a file.
1096 (The <code>ETag</code> value is used in cache management to save
1097 network bandwidth.) In Apache 1.3.22 and earlier, the
1098 <code>ETag</code> value was <em>always</em> formed
1099 from the file's inode, size, and last-modified time (mtime). The
1100 <code class="directive">FileETag</code> directive allows you to choose
1101 which of these -- if any -- should be used. The recognized keywords are:
1105 <dt><strong>INode</strong></dt>
1106 <dd>The file's i-node number will be included in the calculation</dd>
1107 <dt><strong>MTime</strong></dt>
1108 <dd>The date and time the file was last modified will be included</dd>
1109 <dt><strong>Size</strong></dt>
1110 <dd>The number of bytes in the file will be included</dd>
1111 <dt><strong>All</strong></dt>
1112 <dd>All available fields will be used. This is equivalent to:
1113 <div class="example"><p><code>FileETag INode MTime Size</code></p></div></dd>
1114 <dt><strong>None</strong></dt>
1115 <dd>If a document is file-based, no <code>ETag</code> field will be
1116 included in the response</dd>
1119 <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code>
1120 keywords may be prefixed with either <code>+</code> or <code>-</code>,
1121 which allow changes to be made to the default setting inherited
1122 from a broader scope. Any keyword appearing without such a prefix
1123 immediately and completely cancels the inherited setting.</p>
1125 <p>If a directory's configuration includes
1126 <code>FileETag INode MTime Size</code>, and a
1127 subdirectory's includes <code>FileETag -INode</code>,
1128 the setting for that subdirectory (which will be inherited by
1129 any sub-subdirectories that don't override it) will be equivalent to
1130 <code>FileETag MTime Size</code>.</p>
1133 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1134 <div class="directive-section"><h2><a name="Files" id="Files"><Files></a> <a name="files" id="files">Directive</a></h2>
1135 <table class="directive">
1136 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to matched
1138 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Files <var>filename</var>> ... </Files></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>All</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>
1144 <p>The <code class="directive"><Files></code> directive
1145 limits the scope of the enclosed directives by filename. It is comparable
1146 to the <code class="directive"><a href="#directory"><Directory></a></code>
1147 and <code class="directive"><a href="#location"><Location></a></code>
1148 directives. It should be matched with a <code></Files></code>
1149 directive. The directives given within this section will be applied to
1150 any object with a basename (last component of filename) matching the
1151 specified filename. <code class="directive"><Files></code>
1152 sections are processed in the order they appear in the
1153 configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1154 <code>.htaccess</code> files are read, but before <code class="directive"><a href="#location"><Location></a></code> sections. Note
1155 that <code class="directive"><Files></code> can be nested
1156 inside <code class="directive"><a href="#directory"><Directory></a></code> sections to restrict the
1157 portion of the filesystem they apply to.</p>
1159 <p>The <var>filename</var> argument should include a filename, or
1160 a wild-card string, where <code>?</code> matches any single character,
1161 and <code>*</code> matches any sequences of characters. Extended regular
1162 expressions can also be used, with the addition of the
1163 <code>~</code> character. For example:</p>
1165 <div class="example"><p><code>
1166 <Files ~ "\.(gif|jpe?g|png)$">
1169 <p>would match most common Internet graphics formats. <code class="directive"><a href="#filesmatch"><FilesMatch></a></code> is preferred,
1172 <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
1173 <code>.htaccess</code> files. This allows users to control access to
1174 their own files, at a file-by-file level.</p>
1179 <li><a href="../sections.html">How <Directory>, <Location>
1180 and <Files> sections work</a> for an explanation of how these
1181 different sections are combined when a request is received</li>
1184 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1185 <div class="directive-section"><h2><a name="FilesMatch" id="FilesMatch"><FilesMatch></a> <a name="filesmatch" id="filesmatch">Directive</a></h2>
1186 <table class="directive">
1187 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to regular-expression matched
1189 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><FilesMatch <var>regex</var>> ... </FilesMatch></code></td></tr>
1190 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1191 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1192 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1193 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1195 <p>The <code class="directive"><FilesMatch></code> directive
1196 limits the scope of the enclosed directives by filename, just as the
1197 <code class="directive"><a href="#files"><Files></a></code> directive
1198 does. However, it accepts a regular expression. For example:</p>
1200 <div class="example"><p><code>
1201 <FilesMatch "\.(gif|jpe?g|png)$">
1204 <p>would match most common Internet graphics formats.</p>
1208 <li><a href="../sections.html">How <Directory>, <Location>
1209 and <Files> sections work</a> for an explanation of how these
1210 different sections are combined when a request is received</li>
1213 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1214 <div class="directive-section"><h2><a name="ForceType" id="ForceType">ForceType</a> <a name="forcetype" id="forcetype">Directive</a></h2>
1215 <table class="directive">
1216 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be served with the specified
1217 MIME content-type</td></tr>
1218 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ForceType <var>MIME-type</var>|None</code></td></tr>
1219 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
1220 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
1221 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1222 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1223 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved to the core in Apache 2.0</td></tr>
1225 <p>When placed into an <code>.htaccess</code> file or a
1226 <code class="directive"><a href="#directory"><Directory></a></code>, or
1227 <code class="directive"><a href="#location"><Location></a></code> or
1228 <code class="directive"><a href="#files"><Files></a></code>
1229 section, this directive forces all matching files to be served
1230 with the content type identification given by
1231 <var>MIME-type</var>. For example, if you had a directory full of
1232 GIF files, but did not want to label them all with <code>.gif</code>,
1233 you might want to use:</p>
1235 <div class="example"><p><code>
1239 <p>Note that unlike <code class="directive"><a href="#defaulttype">DefaultType</a></code>,
1240 this directive overrides all mime-type associations, including
1241 filename extensions, that might identify the media type.</p>
1243 <p>You can override any <code class="directive">ForceType</code> setting
1244 by using the value of <code>None</code>:</p>
1246 <div class="example"><p><code>
1247 # force all files to be image/gif:<br />
1248 <Location /images><br />
1249 <span class="indent">
1250 ForceType image/gif<br />
1252 </Location><br />
1254 # but normal mime-type associations here:<br />
1255 <Location /images/mixed><br />
1256 <span class="indent">
1257 ForceType None<br />
1263 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1264 <div class="directive-section"><h2><a name="HostnameLookups" id="HostnameLookups">HostnameLookups</a> <a name="hostnamelookups" id="hostnamelookups">Directive</a></h2>
1265 <table class="directive">
1266 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables DNS lookups on client IP addresses</td></tr>
1267 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HostnameLookups On|Off|Double</code></td></tr>
1268 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>HostnameLookups Off</code></td></tr>
1269 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1270 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1271 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1273 <p>This directive enables DNS lookups so that host names can be
1274 logged (and passed to CGIs/SSIs in <code>REMOTE_HOST</code>).
1275 The value <code>Double</code> refers to doing double-reverse
1276 DNS lookup. That is, after a reverse lookup is performed, a forward
1277 lookup is then performed on that result. At least one of the IP
1278 addresses in the forward lookup must match the original
1279 address. (In "tcpwrappers" terminology this is called
1280 <code>PARANOID</code>.)</p>
1282 <p>Regardless of the setting, when <code class="module"><a href="../mod/mod_access.html">mod_access</a></code> is
1283 used for controlling access by hostname, a double reverse lookup
1284 will be performed. This is necessary for security. Note that the
1285 result of this double-reverse isn't generally available unless you
1286 set <code>HostnameLookups Double</code>. For example, if only
1287 <code>HostnameLookups On</code> and a request is made to an object
1288 that is protected by hostname restrictions, regardless of whether
1289 the double-reverse fails or not, CGIs will still be passed the
1290 single-reverse result in <code>REMOTE_HOST</code>.</p>
1292 <p>The default is <code>Off</code> in order to save the network
1293 traffic for those sites that don't truly need the reverse
1294 lookups done. It is also better for the end users because they
1295 don't have to suffer the extra latency that a lookup entails.
1296 Heavily loaded sites should leave this directive
1297 <code>Off</code>, since DNS lookups can take considerable
1298 amounts of time. The utility <code class="program"><a href="../programs/logresolve.html">logresolve</a></code>, compiled by
1299 default to the <code>bin</code> subdirectory of your installation
1300 directory, can be used to look up host names from logged IP addresses
1304 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1305 <div class="directive-section"><h2><a name="IdentityCheck" id="IdentityCheck">IdentityCheck</a> <a name="identitycheck" id="identitycheck">Directive</a></h2>
1306 <table class="directive">
1307 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables logging of the RFC1413 identity of the remote
1309 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>IdentityCheck On|Off</code></td></tr>
1310 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>IdentityCheck Off</code></td></tr>
1311 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1312 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1313 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1315 <p>This directive enables RFC1413-compliant logging of the
1316 remote user name for each connection, where the client machine
1317 runs identd or something similar. This information is logged in
1320 <p>The information should not be trusted in any way except for
1321 rudimentary usage tracking.</p>
1323 <p>Note that this can cause serious latency problems accessing
1324 your server since every request requires one of these lookups
1325 to be performed. When firewalls are involved each lookup might
1326 possibly fail and add 30 seconds of latency to each hit. So in
1327 general this is not very useful on public servers accessible
1328 from the Internet.</p>
1331 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1332 <div class="directive-section"><h2><a name="IfDefine" id="IfDefine"><IfDefine></a> <a name="ifdefine" id="ifdefine">Directive</a></h2>
1333 <table class="directive">
1334 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that will be processed only
1335 if a test is true at startup</td></tr>
1336 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfDefine [!]<var>parameter-name</var>> ...
1337 </IfDefine></code></td></tr>
1338 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1339 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1340 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1341 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1343 <p>The <code><IfDefine <var>test</var>>...</IfDefine>
1344 </code> section is used to mark directives that are conditional. The
1345 directives within an <code class="directive"><IfDefine></code>
1346 section are only processed if the <var>test</var> is true. If <var>
1347 test</var> is false, everything between the start and end markers is
1350 <p>The <var>test</var> in the <code class="directive"><IfDefine></code> section directive can be one of two forms:</p>
1353 <li><var>parameter-name</var></li>
1355 <li><code>!</code><var>parameter-name</var></li>
1358 <p>In the former case, the directives between the start and end
1359 markers are only processed if the parameter named
1360 <var>parameter-name</var> is defined. The second format reverses
1361 the test, and only processes the directives if
1362 <var>parameter-name</var> is <strong>not</strong> defined.</p>
1364 <p>The <var>parameter-name</var> argument is a define as given on
1365 the <code class="program"><a href="../programs/httpd.html">httpd</a></code> command line via <code>-D<var>parameter-</var>
1366 </code>, at the time the server was started.</p>
1368 <p><code class="directive"><IfDefine></code> sections are
1369 nest-able, which can be used to implement simple
1370 multiple-parameter tests. Example:</p>
1372 <div class="example"><p><code>
1373 httpd -DReverseProxy ...<br />
1376 <IfDefine ReverseProxy><br />
1377 <span class="indent">
1378 LoadModule rewrite_module modules/mod_rewrite.so<br />
1379 LoadModule proxy_module modules/libproxy.so<br />
1385 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1386 <div class="directive-section"><h2><a name="IfModule" id="IfModule"><IfModule></a> <a name="ifmodule" id="ifmodule">Directive</a></h2>
1387 <table class="directive">
1388 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that are processed conditional on the
1389 presence or absence of a specific module</td></tr>
1390 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfModule [!]<var>module-name</var>> ...
1391 </IfModule></code></td></tr>
1392 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1393 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1394 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1395 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1397 <p>The <code><IfModule <var>test</var>>...</IfModule></code>
1398 section is used to mark directives that are conditional on the presence of
1399 a specific module. The directives within an <code class="directive"><IfModule></code> section are only processed if the <var>test</var>
1400 is true. If <var>test</var> is false, everything between the start and
1401 end markers is ignored.</p>
1403 <p>The <var>test</var> in the <code class="directive"><IfModule></code> section directive can be one of two forms:</p>
1406 <li><var>module name</var></li>
1408 <li>!<var>module name</var></li>
1411 <p>In the former case, the directives between the start and end
1412 markers are only processed if the module named <var>module
1413 name</var> is included in Apache -- either compiled in or
1414 dynamically loaded using <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>. The second format reverses the test,
1415 and only processes the directives if <var>module name</var> is
1416 <strong>not</strong> included.</p>
1418 <p>The <var>module name</var> argument is the file name of the
1419 module, at the time it was compiled. For example,
1420 <code>mod_rewrite.c</code>. If a module consists of several
1421 source files, use the name of the file containing the string
1422 <code>STANDARD20_MODULE_STUFF</code>.</p>
1424 <p><code class="directive"><IfModule></code> sections are
1425 nest-able, which can be used to implement simple multiple-module
1428 <div class="note">This section should only be used if you need to have one
1429 configuration file that works whether or not a specific module
1430 is available. In normal operation, directives need not be
1431 placed in <code class="directive"><IfModule></code>
1435 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1436 <div class="directive-section"><h2><a name="Include" id="Include">Include</a> <a name="include" id="include">Directive</a></h2>
1437 <table class="directive">
1438 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Includes other configuration files from within
1439 the server configuration files</td></tr>
1440 <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>
1441 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1442 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1443 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1444 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Wildcard matching available in 2.0.41 and later</td></tr>
1446 <p>This directive allows inclusion of other configuration files
1447 from within the server configuration files.</p>
1449 <p>Shell-style (<code>fnmatch()</code>) wildcard characters can be used to
1450 include several files at once, in alphabetical order. In
1451 addition, if <code class="directive">Include</code> points to a directory,
1452 rather than a file, Apache will read all files in that directory
1453 and any subdirectory. But including entire directories is not
1454 recommended, because it is easy to accidentally leave temporary
1455 files in a directory that can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to
1458 <p>The file path specified may be an absolute path, or may be relative
1459 to the <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory.</p>
1463 <div class="example"><p><code>
1464 Include /usr/local/apache2/conf/ssl.conf<br />
1465 Include /usr/local/apache2/conf/vhosts/*.conf
1468 <p>Or, providing paths relative to your <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory:</p>
1470 <div class="example"><p><code>
1471 Include conf/ssl.conf<br />
1472 Include conf/vhosts/*.conf
1477 <li><code class="program"><a href="../programs/apachectl.html">apachectl</a></code></li>
1480 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1481 <div class="directive-section"><h2><a name="KeepAlive" id="KeepAlive">KeepAlive</a> <a name="keepalive" id="keepalive">Directive</a></h2>
1482 <table class="directive">
1483 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables HTTP persistent connections</td></tr>
1484 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAlive On|Off</code></td></tr>
1485 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAlive On</code></td></tr>
1486 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1487 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1488 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1490 <p>The Keep-Alive extension to HTTP/1.0 and the persistent
1491 connection feature of HTTP/1.1 provide long-lived HTTP sessions
1492 which allow multiple requests to be sent over the same TCP
1493 connection. In some cases this has been shown to result in an
1494 almost 50% speedup in latency times for HTML documents with
1495 many images. To enable Keep-Alive connections, set
1496 <code>KeepAlive On</code>.</p>
1498 <p>For HTTP/1.0 clients, Keep-Alive connections will only be
1499 used if they are specifically requested by a client. In
1500 addition, a Keep-Alive connection with an HTTP/1.0 client can
1501 only be used when the length of the content is known in
1502 advance. This implies that dynamic content such as CGI output,
1503 SSI pages, and server-generated directory listings will
1504 generally not use Keep-Alive connections to HTTP/1.0 clients.
1505 For HTTP/1.1 clients, persistent connections are the default
1506 unless otherwise specified. If the client requests it, chunked
1507 encoding will be used in order to send content of unknown
1508 length over persistent connections.</p>
1512 <li><code class="directive"><a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></code></li>
1515 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1516 <div class="directive-section"><h2><a name="KeepAliveTimeout" id="KeepAliveTimeout">KeepAliveTimeout</a> <a name="keepalivetimeout" id="keepalivetimeout">Directive</a></h2>
1517 <table class="directive">
1518 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for subsequent
1519 requests on a persistent connection</td></tr>
1520 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAliveTimeout <var>seconds</var></code></td></tr>
1521 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAliveTimeout 15</code></td></tr>
1522 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1523 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1524 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1526 <p>The number of seconds Apache will wait for a subsequent
1527 request before closing the connection. Once a request has been
1528 received, the timeout value specified by the
1529 <code class="directive"><a href="#timeout">Timeout</a></code> directive applies.</p>
1531 <p>Setting <code class="directive">KeepAliveTimeout</code> to a high value
1532 may cause performance problems in heavily loaded servers. The
1533 higher the timeout, the more server processes will be kept
1534 occupied waiting on connections with idle clients.</p>
1536 <p>In a name-based virtual host context, the value of the first
1537 defined virtual host (the default host) in a set of <code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code> will be used.
1538 The other values will be ignored.</p>
1541 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1542 <div class="directive-section"><h2><a name="Limit" id="Limit"><Limit></a> <a name="limit" id="limit">Directive</a></h2>
1543 <table class="directive">
1544 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict enclosed access controls to only certain HTTP
1546 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Limit <var>method</var> [<var>method</var>] ... > ...
1547 </Limit></code></td></tr>
1548 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1549 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1550 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1551 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1553 <p>Access controls are normally effective for
1554 <strong>all</strong> access methods, and this is the usual
1555 desired behavior. <strong>In the general case, access control
1556 directives should not be placed within a
1557 <code class="directive"><Limit></code> section.</strong></p>
1559 <p>The purpose of the <code class="directive"><Limit></code>
1560 directive is to restrict the effect of the access controls to the
1561 nominated HTTP methods. For all other methods, the access
1562 restrictions that are enclosed in the <code class="directive"><Limit></code> bracket <strong>will have no
1563 effect</strong>. The following example applies the access control
1564 only to the methods <code>POST</code>, <code>PUT</code>, and
1565 <code>DELETE</code>, leaving all other methods unprotected:</p>
1567 <div class="example"><p><code>
1568 <Limit POST PUT DELETE><br />
1569 <span class="indent">
1570 Require valid-user<br />
1575 <p>The method names listed can be one or more of: <code>GET</code>,
1576 <code>POST</code>, <code>PUT</code>, <code>DELETE</code>,
1577 <code>CONNECT</code>, <code>OPTIONS</code>,
1578 <code>PATCH</code>, <code>PROPFIND</code>, <code>PROPPATCH</code>,
1579 <code>MKCOL</code>, <code>COPY</code>, <code>MOVE</code>,
1580 <code>LOCK</code>, and <code>UNLOCK</code>. <strong>The method name is
1581 case-sensitive.</strong> If <code>GET</code> is used it will also
1582 restrict <code>HEAD</code> requests. The <code>TRACE</code> method
1583 cannot be limited.</p>
1585 <div class="warning">A <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section should always be
1586 used in preference to a <code class="directive"><a href="#limit"><Limit></a></code> section when restricting access,
1587 since a <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section provides protection
1588 against arbitrary methods.</div>
1592 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1593 <div class="directive-section"><h2><a name="LimitExcept" id="LimitExcept"><LimitExcept></a> <a name="limitexcept" id="limitexcept">Directive</a></h2>
1594 <table class="directive">
1595 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict access controls to all HTTP methods
1596 except the named ones</td></tr>
1597 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LimitExcept <var>method</var> [<var>method</var>] ... > ...
1598 </LimitExcept></code></td></tr>
1599 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1600 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1601 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1602 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1604 <p><code class="directive"><LimitExcept></code> and
1605 <code></LimitExcept></code> are used to enclose
1606 a group of access control directives which will then apply to any
1607 HTTP access method <strong>not</strong> listed in the arguments;
1608 i.e., it is the opposite of a <code class="directive"><a href="#limit"><Limit></a></code> section and can be used to control
1609 both standard and nonstandard/unrecognized methods. See the
1610 documentation for <code class="directive"><a href="#limit"><Limit></a></code> for more details.</p>
1614 <div class="example"><p><code>
1615 <LimitExcept POST GET><br />
1616 <span class="indent">
1617 Require valid-user<br />
1619 </LimitExcept>
1624 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1625 <div class="directive-section"><h2><a name="LimitInternalRecursion" id="LimitInternalRecursion">LimitInternalRecursion</a> <a name="limitinternalrecursion" id="limitinternalrecursion">Directive</a></h2>
1626 <table class="directive">
1627 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine maximum number of internal redirects and nested
1628 subrequests</td></tr>
1629 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitInternalRecursion <var>number</var> [<var>number</var>]</code></td></tr>
1630 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitInternalRecursion 10</code></td></tr>
1631 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1632 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1633 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1634 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.47 and later</td></tr>
1636 <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
1637 redirects the original request to a CGI script. A subrequest is Apache's
1638 mechanism to find out what would happen for some URI if it were requested.
1639 For example, <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> uses subrequests to look for the
1640 files listed in the <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
1643 <p><code class="directive">LimitInternalRecursion</code> prevents the server
1644 from crashing when entering an infinite loop of internal redirects or
1645 subrequests. Such loops are usually caused by misconfigurations.</p>
1647 <p>The directive stores two different limits, which are evaluated on
1648 per-request basis. The first <var>number</var> is the maximum number of
1649 internal redirects, that may follow each other. The second <var>number</var>
1650 determines, how deep subrequests may be nested. If you specify only one
1651 <var>number</var>, it will be assigned to both limits.</p>
1653 <div class="example"><h3>Example</h3><p><code>
1654 LimitInternalRecursion 5
1658 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1659 <div class="directive-section"><h2><a name="LimitRequestBody" id="LimitRequestBody">LimitRequestBody</a> <a name="limitrequestbody" id="limitrequestbody">Directive</a></h2>
1660 <table class="directive">
1661 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restricts the total size of the HTTP request body sent
1662 from the client</td></tr>
1663 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestBody <var>bytes</var></code></td></tr>
1664 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestBody 0</code></td></tr>
1665 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1666 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1667 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1668 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1670 <p>This directive specifies the number of <var>bytes</var> from 0
1671 (meaning unlimited) to 2147483647 (2GB) that are allowed in a
1674 <p>The <code class="directive">LimitRequestBody</code> directive allows
1675 the user to set a limit on the allowed size of an HTTP request
1676 message body within the context in which the directive is given
1677 (server, per-directory, per-file or per-location). If the client
1678 request exceeds that limit, the server will return an error
1679 response instead of servicing the request. The size of a normal
1680 request message body will vary greatly depending on the nature of
1681 the resource and the methods allowed on that resource. CGI scripts
1682 typically use the message body for retrieving form information.
1683 Implementations of the <code>PUT</code> method will require
1684 a value at least as large as any representation that the server
1685 wishes to accept for that resource.</p>
1687 <p>This directive gives the server administrator greater
1688 control over abnormal client request behavior, which may be
1689 useful for avoiding some forms of denial-of-service
1692 <p>If, for example, you are permitting file upload to a particular
1693 location, and wish to limit the size of the uploaded file to 100K,
1694 you might use the following directive:</p>
1696 <div class="example"><p><code>
1697 LimitRequestBody 102400
1702 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1703 <div class="directive-section"><h2><a name="LimitRequestFields" id="LimitRequestFields">LimitRequestFields</a> <a name="limitrequestfields" id="limitrequestfields">Directive</a></h2>
1704 <table class="directive">
1705 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of HTTP request header fields that
1706 will be accepted from the client</td></tr>
1707 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFields <var>number</var></code></td></tr>
1708 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFields 100</code></td></tr>
1709 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1710 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1711 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1713 <p><var>Number</var> is an integer from 0 (meaning unlimited) to
1714 32767. The default value is defined by the compile-time
1715 constant <code>DEFAULT_LIMIT_REQUEST_FIELDS</code> (100 as
1718 <p>The <code class="directive">LimitRequestFields</code> directive allows
1719 the server administrator to modify the limit on the number of
1720 request header fields allowed in an HTTP request. A server needs
1721 this value to be larger than the number of fields that a normal
1722 client request might include. The number of request header fields
1723 used by a client rarely exceeds 20, but this may vary among
1724 different client implementations, often depending upon the extent
1725 to which a user has configured their browser to support detailed
1726 content negotiation. Optional HTTP extensions are often expressed
1727 using request header fields.</p>
1729 <p>This directive gives the server administrator greater
1730 control over abnormal client request behavior, which may be
1731 useful for avoiding some forms of denial-of-service attacks.
1732 The value should be increased if normal clients see an error
1733 response from the server that indicates too many fields were
1734 sent in the request.</p>
1738 <div class="example"><p><code>
1739 LimitRequestFields 50
1744 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1745 <div class="directive-section"><h2><a name="LimitRequestFieldSize" id="LimitRequestFieldSize">LimitRequestFieldSize</a> <a name="limitrequestfieldsize" id="limitrequestfieldsize">Directive</a></h2>
1746 <table class="directive">
1747 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of the HTTP request header allowed from the
1749 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFieldsize <var>bytes</var></code></td></tr>
1750 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFieldsize 8190</code></td></tr>
1751 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1752 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1753 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1755 <p>This directive specifies the number of <var>bytes</var>
1756 that will be allowed in an HTTP request header.</p>
1758 <p>The <code class="directive">LimitRequestFieldSize</code> directive
1759 allows the server administrator to reduce or increase the limit
1760 on the allowed size of an HTTP request header field. A server
1761 needs this value to be large enough to hold any one header field
1762 from a normal client request. The size of a normal request header
1763 field will vary greatly among different client implementations,
1764 often depending upon the extent to which a user has configured
1765 their browser to support detailed content negotiation. SPNEGO
1766 authentication headers can be up to 12392 bytes.</p>
1768 <p>This directive gives the server administrator greater
1769 control over abnormal client request behavior, which may be
1770 useful for avoiding some forms of denial-of-service attacks.</p>
1774 <div class="example"><p><code>
1775 LimitRequestFieldSize 4094
1778 <div class="note">Under normal conditions, the value should not be changed from
1781 <div class="note">Apache 2.0.53 or higher is required for increasing the
1782 limit above the compiled-in value of DEFAULT_LIMIT_REQUEST_FIELDSIZE
1783 (8190 as distributed).
1788 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1789 <div class="directive-section"><h2><a name="LimitRequestLine" id="LimitRequestLine">LimitRequestLine</a> <a name="limitrequestline" id="limitrequestline">Directive</a></h2>
1790 <table class="directive">
1791 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limit the size of the HTTP request line that will be accepted
1792 from the client</td></tr>
1793 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestLine <var>bytes</var></code></td></tr>
1794 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestLine 8190</code></td></tr>
1795 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
1796 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1797 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1799 <p>This directive sets the number of <var>bytes</var> from 0 to
1800 the value of the compile-time constant
1801 <code>DEFAULT_LIMIT_REQUEST_LINE</code> (8190 as distributed)
1802 that will be allowed on the HTTP request-line.</p>
1804 <p>The <code class="directive">LimitRequestLine</code> directive allows
1805 the server administrator to reduce the limit on the allowed size
1806 of a client's HTTP request-line below the normal input buffer size
1807 compiled with the server. Since the request-line consists of the
1808 HTTP method, URI, and protocol version, the
1809 <code class="directive">LimitRequestLine</code> directive places a
1810 restriction on the length of a request-URI allowed for a request
1811 on the server. A server needs this value to be large enough to
1812 hold any of its resource names, including any information that
1813 might be passed in the query part of a <code>GET</code> request.</p>
1815 <p>This directive gives the server administrator greater
1816 control over abnormal client request behavior, which may be
1817 useful for avoiding some forms of denial-of-service attacks.</p>
1821 <div class="example"><p><code>
1822 LimitRequestLine 4094
1825 <div class="note">Under normal conditions, the value should not be changed from
1829 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1830 <div class="directive-section"><h2><a name="LimitXMLRequestBody" id="LimitXMLRequestBody">LimitXMLRequestBody</a> <a name="limitxmlrequestbody" id="limitxmlrequestbody">Directive</a></h2>
1831 <table class="directive">
1832 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of an XML-based request body</td></tr>
1833 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitXMLRequestBody <var>bytes</var></code></td></tr>
1834 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitXMLRequestBody 1000000</code></td></tr>
1835 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
1836 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
1837 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1838 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1840 <p>Limit (in bytes) on maximum size of an XML-based request
1841 body. A value of <code>0</code> will disable any checking.</p>
1845 <div class="example"><p><code>
1846 LimitXMLRequestBody 0
1851 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1852 <div class="directive-section"><h2><a name="Location" id="Location"><Location></a> <a name="location" id="location">Directive</a></h2>
1853 <table class="directive">
1854 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to matching
1856 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Location
1857 <var>URL-path</var>|<var>URL</var>> ... </Location></code></td></tr>
1858 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1859 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1860 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1862 <p>The <code class="directive"><Location></code> directive
1863 limits the scope of the enclosed directives by URL. It is similar to the
1864 <code class="directive"><a href="#directory"><Directory></a></code>
1865 directive, and starts a subsection which is terminated with a
1866 <code></Location></code> directive. <code class="directive"><Location></code> sections are processed in the
1867 order they appear in the configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and
1868 <code>.htaccess</code> files are read, and after the <code class="directive"><a href="#files"><Files></a></code> sections.</p>
1870 <p><code class="directive"><Location></code> sections operate
1871 completely outside the filesystem. This has several consequences.
1872 Most importantly, <code class="directive"><Location></code>
1873 directives should not be used to control access to filesystem
1874 locations. Since several different URLs may map to the same
1875 filesystem location, such access controls may by circumvented.</p>
1877 <div class="note"><h3>When to use <code class="directive"><Location></code></h3>
1879 <p>Use <code class="directive"><Location></code> to apply
1880 directives to content that lives outside the filesystem. For
1881 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
1882 <code><Location /></code>, which is an easy way to
1883 apply a configuration to the entire server.</p>
1886 <p>For all origin (non-proxy) requests, the URL to be matched is a
1887 URL-path of the form <code>/path/</code>. No scheme, hostname,
1888 port, or query string may be included. For proxy requests, the
1889 URL to be matched is of the form
1890 <code>scheme://servername/path</code>, and you must include the
1893 <p>The URL may use wildcards. In a wild-card string, <code>?</code> matches
1894 any single character, and <code>*</code> matches any sequences of
1898 expressions can also be used, with the addition of the
1899 <code>~</code> character. For example:</p>
1901 <div class="example"><p><code>
1902 <Location ~ "/(extra|special)/data">
1905 <p>would match URLs that contained the substring <code>/extra/data</code>
1906 or <code>/special/data</code>. The directive <code class="directive"><a href="#locationmatch"><LocationMatch></a></code> behaves
1907 identical to the regex version of <code class="directive"><Location></code>.</p>
1909 <p>The <code class="directive"><Location></code>
1910 functionality is especially useful when combined with the
1911 <code class="directive"><a href="#sethandler">SetHandler</a></code>
1912 directive. For example, to enable status requests, but allow them
1913 only from browsers at <code>foo.com</code>, you might use:</p>
1915 <div class="example"><p><code>
1916 <Location /status><br />
1917 <span class="indent">
1918 SetHandler server-status<br />
1919 Order Deny,Allow<br />
1921 Allow from .foo.com<br />
1926 <div class="note"><h3>Note about / (slash)</h3>
1927 <p>The slash character has special meaning depending on where in a
1928 URL it appears. People may be used to its behavior in the filesystem
1929 where multiple adjacent slashes are frequently collapsed to a single
1930 slash (<em>i.e.</em>, <code>/home///foo</code> is the same as
1931 <code>/home/foo</code>). In URL-space this is not necessarily true.
1932 The <code class="directive"><a href="#locationmatch"><LocationMatch></a></code>
1933 directive and the regex version of <code class="directive"><Location></code> require you to explicitly specify multiple
1934 slashes if that is your intention.</p>
1936 <p>For example, <code><LocationMatch ^/abc></code> would match
1937 the request URL <code>/abc</code> but not the request URL <code>
1938 //abc</code>. The (non-regex) <code class="directive"><Location></code> directive behaves similarly when used for
1939 proxy requests. But when (non-regex) <code class="directive"><Location></code> is used for non-proxy requests it will
1940 implicitly match multiple slashes with a single slash. For example,
1941 if you specify <code><Location /abc/def></code> and the
1942 request is to <code>/abc//def</code> then it will match.</p>
1947 <li><a href="../sections.html">How <Directory>, <Location>
1948 and <Files> sections work</a> for an explanation of how these
1949 different sections are combined when a request is received</li>
1952 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1953 <div class="directive-section"><h2><a name="LocationMatch" id="LocationMatch"><LocationMatch></a> <a name="locationmatch" id="locationmatch">Directive</a></h2>
1954 <table class="directive">
1955 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to regular-expression
1956 matching URLs</td></tr>
1957 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LocationMatch
1958 <var>regex</var>> ... </LocationMatch></code></td></tr>
1959 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1960 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1961 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1963 <p>The <code class="directive"><LocationMatch></code> directive
1964 limits the scope of the enclosed directives by URL, in an identical manner
1965 to <code class="directive"><a href="#location"><Location></a></code>. However,
1966 it takes a regular expression as an argument instead of a simple
1967 string. For example:</p>
1969 <div class="example"><p><code>
1970 <LocationMatch "/(extra|special)/data">
1973 <p>would match URLs that contained the substring <code>/extra/data</code>
1974 or <code>/special/data</code>.</p>
1978 <li><a href="../sections.html">How <Directory>, <Location>
1979 and <Files> sections work</a> for an explanation of how these
1980 different sections are combined when a request is received</li>
1983 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1984 <div class="directive-section"><h2><a name="LogLevel" id="LogLevel">LogLevel</a> <a name="loglevel" id="loglevel">Directive</a></h2>
1985 <table class="directive">
1986 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Controls the verbosity of the ErrorLog</td></tr>
1987 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LogLevel <var>level</var></code></td></tr>
1988 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LogLevel warn</code></td></tr>
1989 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1990 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
1991 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
1993 <p><code class="directive">LogLevel</code> adjusts the verbosity of the
1994 messages recorded in the error logs (see <code class="directive"><a href="#errorlog">ErrorLog</a></code> directive). The following
1995 <var>level</var>s are available, in order of decreasing
1998 <table class="bordered">
2001 <th><strong>Level</strong> </th>
2003 <th><strong>Description</strong> </th>
2005 <th><strong>Example</strong> </th>
2009 <td><code>emerg</code> </td>
2011 <td>Emergencies - system is unusable.</td>
2013 <td>"Child cannot open lock file. Exiting"</td>
2017 <td><code>alert</code> </td>
2019 <td>Action must be taken immediately.</td>
2021 <td>"getpwuid: couldn't determine user name from uid"</td>
2025 <td><code>crit</code> </td>
2027 <td>Critical Conditions.</td>
2029 <td>"socket: Failed to get a socket, exiting child"</td>
2033 <td><code>error</code> </td>
2035 <td>Error conditions.</td>
2037 <td>"Premature end of script headers"</td>
2041 <td><code>warn</code> </td>
2043 <td>Warning conditions.</td>
2045 <td>"child process 1234 did not exit, sending another
2050 <td><code>notice</code> </td>
2052 <td>Normal but significant condition.</td>
2054 <td>"httpd: caught SIGBUS, attempting to dump core in
2059 <td><code>info</code> </td>
2061 <td>Informational.</td>
2063 <td>"Server seems busy, (you may need to increase
2064 StartServers, or Min/MaxSpareServers)..."</td>
2068 <td><code>debug</code> </td>
2070 <td>Debug-level messages</td>
2072 <td>"Opening config file ..."</td>
2076 <p>When a particular level is specified, messages from all
2077 other levels of higher significance will be reported as well.
2078 <em>E.g.</em>, when <code>LogLevel info</code> is specified,
2079 then messages with log levels of <code>notice</code> and
2080 <code>warn</code> will also be posted.</p>
2082 <p>Using a level of at least <code>crit</code> is
2087 <div class="example"><p><code>
2091 <div class="note"><h3>Note</h3>
2092 <p>When logging to a regular file messages of the level
2093 <code>notice</code> cannot be suppressed and thus are always
2094 logged. However, this doesn't apply when logging is done
2095 using <code>syslog</code>.</p>
2099 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2100 <div class="directive-section"><h2><a name="MaxKeepAliveRequests" id="MaxKeepAliveRequests">MaxKeepAliveRequests</a> <a name="maxkeepaliverequests" id="maxkeepaliverequests">Directive</a></h2>
2101 <table class="directive">
2102 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of requests allowed on a persistent
2103 connection</td></tr>
2104 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxKeepAliveRequests <var>number</var></code></td></tr>
2105 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxKeepAliveRequests 100</code></td></tr>
2106 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2107 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2108 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2110 <p>The <code class="directive">MaxKeepAliveRequests</code> directive
2111 limits the number of requests allowed per connection when
2112 <code class="directive"><a href="#keepalive">KeepAlive</a></code> is on. If it is
2113 set to <code>0</code>, unlimited requests will be allowed. We
2114 recommend that this setting be kept to a high value for maximum
2115 server performance.</p>
2119 <div class="example"><p><code>
2120 MaxKeepAliveRequests 500
2124 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2125 <div class="directive-section"><h2><a name="NameVirtualHost" id="NameVirtualHost">NameVirtualHost</a> <a name="namevirtualhost" id="namevirtualhost">Directive</a></h2>
2126 <table class="directive">
2127 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Designates an IP address for name-virtual
2129 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NameVirtualHost <var>addr</var>[:<var>port</var>]</code></td></tr>
2130 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2131 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2132 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2134 <p>The <code class="directive">NameVirtualHost</code> directive is a
2135 required directive if you want to configure <a href="../vhosts/">name-based virtual hosts</a>.</p>
2137 <p>Although <var>addr</var> can be hostname it is recommended
2138 that you always use an IP address, e.g.</p>
2140 <div class="example"><p><code>
2141 NameVirtualHost 111.22.33.44
2144 <p>With the <code class="directive">NameVirtualHost</code> directive you
2145 specify the IP address on which the server will receive requests
2146 for the name-based virtual hosts. This will usually be the address
2147 to which your name-based virtual host names resolve. In cases
2148 where a firewall or other proxy receives the requests and forwards
2149 them on a different IP address to the server, you must specify the
2150 IP address of the physical interface on the machine which will be
2151 servicing the requests. If you have multiple name-based hosts on
2152 multiple addresses, repeat the directive for each address.</p>
2154 <div class="note"><h3>Note</h3>
2155 <p>Note, that the "main server" and any <code>_default_</code> servers
2156 will <strong>never</strong> be served for a request to a
2157 <code class="directive">NameVirtualHost</code> IP address (unless for some
2158 reason you specify <code class="directive">NameVirtualHost</code> but then
2159 don't define any <code class="directive">VirtualHost</code>s for that
2163 <p>Optionally you can specify a port number on which the
2164 name-based virtual hosts should be used, e.g.</p>
2166 <div class="example"><p><code>
2167 NameVirtualHost 111.22.33.44:8080
2170 <p>IPv6 addresses must be enclosed in square brackets, as shown
2171 in the following example:</p>
2173 <div class="example"><p><code>
2174 NameVirtualHost [2001:db8::a00:20ff:fea7:ccea]:8080
2177 <p>To receive requests on all interfaces, you can use an argument of
2180 <div class="example"><p><code>
2184 <div class="note"><h3>Argument to <code class="directive"><VirtualHost></code>
2186 <p>Note that the argument to the <code class="directive"><VirtualHost></code> directive must
2187 exactly match the argument to the <code class="directive">NameVirtualHost</code> directive.</p>
2189 <div class="example"><p><code>
2190 NameVirtualHost 1.2.3.4<br />
2191 <VirtualHost 1.2.3.4><br />
2193 </VirtualHost><br />
2199 <li><a href="../vhosts/">Virtual Hosts
2200 documentation</a></li>
2203 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2204 <div class="directive-section"><h2><a name="Options" id="Options">Options</a> <a name="options" id="options">Directive</a></h2>
2205 <table class="directive">
2206 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures what features are available in a particular
2208 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Options
2209 [+|-]<var>option</var> [[+|-]<var>option</var>] ...</code></td></tr>
2210 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Options All</code></td></tr>
2211 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2212 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr>
2213 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2214 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2216 <p>The <code class="directive">Options</code> directive controls which
2217 server features are available in a particular directory.</p>
2219 <p><var>option</var> can be set to <code>None</code>, in which
2220 case none of the extra features are enabled, or one or more of
2224 <dt><code>All</code></dt>
2226 <dd>All options except for <code>MultiViews</code>. This is the default
2229 <dt><code>ExecCGI</code></dt>
2232 Execution of CGI scripts using <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>
2235 <dt><code>FollowSymLinks</code></dt>
2239 The server will follow symbolic links in this directory.
2241 <p>Even though the server follows the symlink it does <em>not</em>
2242 change the pathname used to match against <code class="directive"><a href="#directory"><Directory></a></code> sections.</p>
2243 <p>Note also, that this option <strong>gets ignored</strong> if set
2244 inside a <code class="directive"><a href="#location"><Location></a></code>
2248 <dt><code>Includes</code></dt>
2251 Server-side includes provided by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>
2254 <dt><code>IncludesNOEXEC</code></dt>
2258 Server-side includes are permitted, but the <code>#exec
2259 cmd</code> and <code>#exec cgi</code> are disabled. It is still
2260 possible to <code>#include virtual</code> CGI scripts from
2261 <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>ed
2264 <dt><code>Indexes</code></dt>
2267 If a URL which maps to a directory is requested, and there
2268 is no <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code>
2269 (<em>e.g.</em>, <code>index.html</code>) in that directory, then
2270 <code class="module"><a href="../mod/mod_autoindex.html">mod_autoindex</a></code> will return a formatted listing
2271 of the directory.</dd>
2273 <dt><code>MultiViews</code></dt>
2276 <a href="../content-negotiation.html">Content negotiated</a>
2277 "MultiViews" are allowed using
2278 <code class="module"><a href="../mod/mod_negotiation.html">mod_negotiation</a></code>.</dd>
2280 <dt><code>SymLinksIfOwnerMatch</code></dt>
2282 <dd>The server will only follow symbolic links for which the
2283 target file or directory is owned by the same user id as the
2286 <div class="note"><h3>Note</h3> This option gets ignored if
2287 set inside a <code class="directive"><a href="#location"><Location></a></code> section.</div>
2291 <p>Normally, if multiple <code class="directive">Options</code> could
2292 apply to a directory, then the most specific one is used and
2293 others are ignored; the options are not merged. (See <a href="../sections.html#mergin">how sections are merged</a>.)
2294 However if <em>all</em> the options on the
2295 <code class="directive">Options</code> directive are preceded by a
2296 <code>+</code> or <code>-</code> symbol, the options are
2297 merged. Any options preceded by a <code>+</code> are added to the
2298 options currently in force, and any options preceded by a
2299 <code>-</code> are removed from the options currently in
2302 <div class="warning"><h3>Warning</h3>
2303 <p>Mixing <code class="directive">Options</code> with a <code>+</code> or
2304 <code>-</code> with those without is not valid syntax, and is likely
2305 to cause unexpected results.</p>
2308 <p>For example, without any <code>+</code> and <code>-</code> symbols:</p>
2310 <div class="example"><p><code>
2311 <Directory /web/docs><br />
2312 <span class="indent">
2313 Options Indexes FollowSymLinks<br />
2315 </Directory><br />
2317 <Directory /web/docs/spec><br />
2318 <span class="indent">
2319 Options Includes<br />
2324 <p>then only <code>Includes</code> will be set for the
2325 <code>/web/docs/spec</code> directory. However if the second
2326 <code class="directive">Options</code> directive uses the <code>+</code> and
2327 <code>-</code> symbols:</p>
2329 <div class="example"><p><code>
2330 <Directory /web/docs><br />
2331 <span class="indent">
2332 Options Indexes FollowSymLinks<br />
2334 </Directory><br />
2336 <Directory /web/docs/spec><br />
2337 <span class="indent">
2338 Options +Includes -Indexes<br />
2343 <p>then the options <code>FollowSymLinks</code> and
2344 <code>Includes</code> are set for the <code>/web/docs/spec</code>
2347 <div class="note"><h3>Note</h3>
2348 <p>Using <code>-IncludesNOEXEC</code> or
2349 <code>-Includes</code> disables server-side includes completely
2350 regardless of the previous setting.</p>
2353 <p>The default in the absence of any other settings is
2354 <code>All</code>.</p>
2357 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2358 <div class="directive-section"><h2><a name="Require" id="Require">Require</a> <a name="require" id="require">Directive</a></h2>
2359 <table class="directive">
2360 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Selects which authenticated users can access
2361 a resource</td></tr>
2362 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Require <var>entity-name</var> [<var>entity-name</var>] ...</code></td></tr>
2363 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
2364 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
2365 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2366 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2368 <p>This directive selects which authenticated users can access
2369 a resource. The allowed syntaxes are:</p>
2372 <dt><code>Require user <var>userid</var> [<var>userid</var>]
2374 <dd>Only the named users can access the resource.</dd>
2376 <dt><code>Require group <var>group-name</var> [<var>group-name</var>]
2378 <dd>Only users in the named groups can access the resource.</dd>
2380 <dt><code>Require valid-user</code></dt>
2381 <dd>All valid users can access the resource.</dd>
2384 <p><code class="directive">Require</code> must be accompanied by
2385 <code class="directive"><a href="#authname">AuthName</a></code> and <code class="directive"><a href="#authtype">AuthType</a></code> directives, and directives such
2386 as <code class="directive"><a href="../mod/mod_auth.html#authuserfile">AuthUserFile</a></code>
2387 and <code class="directive"><a href="../mod/mod_auth.html#authgroupfile">AuthGroupFile</a></code> (to
2388 define users and groups) in order to work correctly. Example:</p>
2390 <div class="example"><p><code>
2391 AuthType Basic<br />
2392 AuthName "Restricted Resource"<br />
2393 AuthUserFile /web/users<br />
2394 AuthGroupFile /web/groups<br />
2398 <p>Access controls which are applied in this way are effective for
2399 <strong>all</strong> methods. <strong>This is what is normally
2400 desired.</strong> If you wish to apply access controls only to
2401 specific methods, while leaving other methods unprotected, then
2402 place the <code class="directive">Require</code> statement into a
2403 <code class="directive"><a href="#limit"><Limit></a></code>
2408 <li><code class="directive"><a href="#satisfy">Satisfy</a></code></li>
2409 <li><code class="module"><a href="../mod/mod_access.html">mod_access</a></code></li>
2412 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2413 <div class="directive-section"><h2><a name="RLimitCPU" id="RLimitCPU">RLimitCPU</a> <a name="rlimitcpu" id="rlimitcpu">Directive</a></h2>
2414 <table class="directive">
2415 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the CPU consumption of processes launched
2416 by Apache children</td></tr>
2417 <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>
2418 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2419 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2420 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2421 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2422 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2424 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2425 resource limit for all processes and the second parameter sets
2426 the maximum resource limit. Either parameter can be a number,
2427 or <code>max</code> to indicate to the server that the limit should
2428 be set to the maximum allowed by the operating system
2429 configuration. Raising the maximum resource limit requires that
2430 the server is running as <code>root</code>, or in the initial startup
2433 <p>This applies to processes forked off from Apache children
2434 servicing requests, not the Apache children themselves. This
2435 includes CGI scripts and SSI exec commands, but not any
2436 processes forked off from the Apache parent such as piped
2439 <p>CPU resource limits are expressed in seconds per
2444 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
2445 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
2448 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2449 <div class="directive-section"><h2><a name="RLimitMEM" id="RLimitMEM">RLimitMEM</a> <a name="rlimitmem" id="rlimitmem">Directive</a></h2>
2450 <table class="directive">
2451 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the memory consumption of processes launched
2452 by Apache children</td></tr>
2453 <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>
2454 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2455 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2456 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2457 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2458 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2460 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2461 resource limit for all processes and the second parameter sets
2462 the maximum resource limit. Either parameter can be a number,
2463 or <code>max</code> to indicate to the server that the limit should
2464 be set to the maximum allowed by the operating system
2465 configuration. Raising the maximum resource limit requires that
2466 the server is running as <code>root</code>, or in the initial startup
2469 <p>This applies to processes forked off from Apache children
2470 servicing requests, not the Apache children themselves. This
2471 includes CGI scripts and SSI exec commands, but not any
2472 processes forked off from the Apache parent such as piped
2475 <p>Memory resource limits are expressed in bytes per
2480 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li>
2481 <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li>
2484 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2485 <div class="directive-section"><h2><a name="RLimitNPROC" id="RLimitNPROC">RLimitNPROC</a> <a name="rlimitnproc" id="rlimitnproc">Directive</a></h2>
2486 <table class="directive">
2487 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of processes that can be launched by
2488 processes launched by Apache children</td></tr>
2489 <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>
2490 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr>
2491 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2492 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2493 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2494 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2496 <p>Takes 1 or 2 parameters. The first parameter sets the soft
2497 resource limit for all processes and the second parameter sets
2498 the maximum resource limit. Either parameter can be a number,
2499 or <code>max</code> to indicate to the server that the limit
2500 should be set to the maximum allowed by the operating system
2501 configuration. Raising the maximum resource limit requires that
2502 the server is running as <code>root</code>, or in the initial startup
2505 <p>This applies to processes forked off from Apache children
2506 servicing requests, not the Apache children themselves. This
2507 includes CGI scripts and SSI exec commands, but not any
2508 processes forked off from the Apache parent such as piped
2511 <p>Process limits control the number of processes per user.</p>
2513 <div class="note"><h3>Note</h3>
2514 <p>If CGI processes are <strong>not</strong> running
2515 under user ids other than the web server user id, this directive
2516 will limit the number of processes that the server itself can
2517 create. Evidence of this situation will be indicated by
2518 <strong><code>cannot fork</code></strong> messages in the
2519 <code>error_log</code>.</p>
2524 <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li>
2525 <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</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="Satisfy" id="Satisfy">Satisfy</a> <a name="satisfy" id="satisfy">Directive</a></h2>
2530 <table class="directive">
2531 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Interaction between host-level access control and
2532 user authentication</td></tr>
2533 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Satisfy Any|All</code></td></tr>
2534 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Satisfy All</code></td></tr>
2535 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
2536 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</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>
2539 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Influenced by <code class="directive"><a href="#limit"><Limit></a></code> and <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> in version 2.0.51 and
2542 <p>Access policy if both <code class="directive"><a href="../mod/mod_access.html#allow">Allow</a></code> and <code class="directive"><a href="#require">Require</a></code> used. The parameter can be
2543 either <code>All</code> or <code>Any</code>. This directive is only
2544 useful if access to a particular area is being restricted by both
2545 username/password <em>and</em> client host address. In this case
2546 the default behavior (<code>All</code>) is to require that the client
2547 passes the address access restriction <em>and</em> enters a valid
2548 username and password. With the <code>Any</code> option the client will be
2549 granted access if they either pass the host restriction or enter a
2550 valid username and password. This can be used to password restrict
2551 an area, but to let clients from particular addresses in without
2552 prompting for a password.</p>
2554 <p>For example, if you wanted to let people on your network have
2555 unrestricted access to a portion of your website, but require that
2556 people outside of your network provide a password, you could use a
2557 configuration similar to the following:</p>
2559 <div class="example"><p><code>
2560 Require valid-user<br />
2561 Allow from 192.168.1<br />
2565 <p>Since version 2.0.51 <code class="directive">Satisfy</code> directives can
2566 be restricted to particular methods by <code class="directive"><a href="#limit"><Limit></a></code> and <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> sections.</p>
2570 <li><code class="directive"><a href="../mod/mod_access.html#allow">Allow</a></code></li>
2571 <li><code class="directive"><a href="#require">Require</a></code></li>
2574 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2575 <div class="directive-section"><h2><a name="ScriptInterpreterSource" id="ScriptInterpreterSource">ScriptInterpreterSource</a> <a name="scriptinterpretersource" id="scriptinterpretersource">Directive</a></h2>
2576 <table class="directive">
2577 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI
2579 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ScriptInterpreterSource Registry|Registry-Strict|Script</code></td></tr>
2580 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ScriptInterpreterSource Script</code></td></tr>
2581 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2582 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2583 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2584 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2585 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Win32 only;
2586 option <code>Registry-Strict</code> is available in Apache 2.0 and
2589 <p>This directive is used to control how Apache finds the
2590 interpreter used to run CGI scripts. The default setting is
2591 <code>Script</code>. This causes Apache to use the interpreter pointed to
2592 by the shebang line (first line, starting with <code>#!</code>) in the
2593 script. On Win32 systems this line usually looks like:</p>
2595 <div class="example"><p><code>
2596 #!C:/Perl/bin/perl.exe
2599 <p>or, if <code>perl</code> is in the <code>PATH</code>, simply:</p>
2601 <div class="example"><p><code>
2605 <p>Setting <code>ScriptInterpreterSource Registry</code> will
2606 cause the Windows Registry tree <code>HKEY_CLASSES_ROOT</code> to be
2607 searched using the script file extension (e.g., <code>.pl</code>) as a
2608 search key. The command defined by the registry subkey
2609 <code>Shell\ExecCGI\Command</code> or, if it does not exist, by the subkey
2610 <code>Shell\Open\Command</code> is used to open the script file. If the
2611 registry keys cannot be found, Apache falls back to the behavior of the
2612 <code>Script</code> option.</p>
2614 <div class="warning"><h3>Security</h3>
2615 <p>Be careful when using <code>ScriptInterpreterSource
2616 Registry</code> with <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>'ed directories, because
2617 Apache will try to execute <strong>every</strong> file within this
2618 directory. The <code>Registry</code> setting may cause undesired
2619 program calls on files which are typically not executed. For
2620 example, the default open command on <code>.htm</code> files on
2621 most Windows systems will execute Microsoft Internet Explorer, so
2622 any HTTP request for an <code>.htm</code> file existing within the
2623 script directory would start the browser in the background on the
2624 server. This is a good way to crash your system within a minute or
2628 <p>The option <code>Registry-Strict</code> which is new in Apache
2629 2.0 does the same thing as <code>Registry</code> but uses only the
2630 subkey <code>Shell\ExecCGI\Command</code>. The
2631 <code>ExecCGI</code> key is not a common one. It must be
2632 configured manually in the windows registry and hence prevents
2633 accidental program calls on your system.</p>
2636 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2637 <div class="directive-section"><h2><a name="ServerAdmin" id="ServerAdmin">ServerAdmin</a> <a name="serveradmin" id="serveradmin">Directive</a></h2>
2638 <table class="directive">
2639 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Email address that the server includes in error
2640 messages sent to the client</td></tr>
2641 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAdmin <var>email-address</var></code></td></tr>
2642 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2643 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2644 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2646 <p>The <code class="directive">ServerAdmin</code> sets the e-mail address
2647 that the server includes in any error messages it returns to the
2650 <p>It may be worth setting up a dedicated address for this, e.g.</p>
2652 <div class="example"><p><code>
2653 ServerAdmin www-admin@foo.example.com
2655 <p>as users do not always mention that they are talking about the
2659 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2660 <div class="directive-section"><h2><a name="ServerAlias" id="ServerAlias">ServerAlias</a> <a name="serveralias" id="serveralias">Directive</a></h2>
2661 <table class="directive">
2662 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Alternate names for a host used when matching requests
2663 to name-virtual hosts</td></tr>
2664 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAlias <var>hostname</var> [<var>hostname</var>] ...</code></td></tr>
2665 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
2666 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2667 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2669 <p>The <code class="directive">ServerAlias</code> directive sets the
2670 alternate names for a host, for use with <a href="../vhosts/name-based.html">name-based virtual hosts</a>.</p>
2672 <div class="example"><p><code>
2673 <VirtualHost *><br />
2674 ServerName server.domain.com<br />
2675 ServerAlias server server2.domain.com server2<br />
2677 </VirtualHost>
2682 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
2685 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2686 <div class="directive-section"><h2><a name="ServerName" id="ServerName">ServerName</a> <a name="servername" id="servername">Directive</a></h2>
2687 <table class="directive">
2688 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hostname and port that the server uses to identify
2690 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerName <var>fully-qualified-domain-name</var>[:<var>port</var>]</code></td></tr>
2691 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
2692 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2693 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2694 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>In version 2.0, this
2695 directive supersedes the functionality of the <code class="directive">Port</code>
2696 directive from version 1.3.</td></tr>
2698 <p>The <code class="directive">ServerName</code> directive sets the hostname and
2699 port that the server uses to identify itself. This is used when
2700 creating redirection URLs. For example, if the name of the
2701 machine hosting the web server is <code>simple.example.com</code>,
2702 but the machine also has the DNS alias <code>www.example.com</code>
2703 and you wish the web server to be so identified, the following
2704 directive should be used:</p>
2706 <div class="example"><p><code>
2707 ServerName www.example.com:80
2710 <p>If no <code class="directive">ServerName</code> is specified, then the
2711 server attempts to deduce the hostname by performing a reverse
2712 lookup on the IP address. If no port is specified in the
2713 <code class="directive">ServerName</code>, then the server will use the port
2715 request. For optimal reliability and predictability, you should
2716 specify an explicit hostname and port using the
2717 <code class="directive">ServerName</code> directive.</p>
2719 <p>If you are using <a href="../vhosts/name-based.html">name-based virtual hosts</a>,
2720 the <code class="directive">ServerName</code> inside a
2721 <code class="directive"><a href="#virtualhost"><VirtualHost></a></code>
2722 section specifies what hostname must appear in the request's
2723 <code>Host:</code> header to match this virtual host.</p>
2725 <p>See the description of the
2726 <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> directive for
2727 settings which determine whether self-referential URL's (e.g., by the
2728 <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> module) will refer to the
2729 specified port, or to the port number given in the client's request.
2734 <li><a href="../dns-caveats.html">Issues Regarding DNS and
2736 <li><a href="../vhosts/">Apache virtual host
2737 documentation</a></li>
2738 <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li>
2739 <li><code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code></li>
2740 <li><code class="directive"><a href="#serveralias">ServerAlias</a></code></li>
2743 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2744 <div class="directive-section"><h2><a name="ServerPath" id="ServerPath">ServerPath</a> <a name="serverpath" id="serverpath">Directive</a></h2>
2745 <table class="directive">
2746 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Legacy URL pathname for a name-based virtual host that
2747 is accessed by an incompatible browser</td></tr>
2748 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerPath <var>URL-path</var></code></td></tr>
2749 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
2750 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2751 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2753 <p>The <code class="directive">ServerPath</code> directive sets the legacy
2754 URL pathname for a host, for use with <a href="../vhosts/">name-based virtual hosts</a>.</p>
2758 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
2761 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2762 <div class="directive-section"><h2><a name="ServerRoot" id="ServerRoot">ServerRoot</a> <a name="serverroot" id="serverroot">Directive</a></h2>
2763 <table class="directive">
2764 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Base directory for the server installation</td></tr>
2765 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerRoot <var>directory-path</var></code></td></tr>
2766 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerRoot /usr/local/apache</code></td></tr>
2767 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2768 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2769 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2771 <p>The <code class="directive">ServerRoot</code> directive sets the
2772 directory in which the server lives. Typically it will contain the
2773 subdirectories <code>conf/</code> and <code>logs/</code>. Relative
2774 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
2775 relative to this directory.</p>
2777 <div class="example"><h3>Example</h3><p><code>
2778 ServerRoot /home/httpd
2784 <li><a href="../invoking.html">the <code>-d</code>
2785 option to <code>httpd</code></a></li>
2786 <li><a href="../misc/security_tips.html#serverroot">the
2787 security tips</a> for information on how to properly set
2788 permissions on the <code class="directive">ServerRoot</code></li>
2791 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2792 <div class="directive-section"><h2><a name="ServerSignature" id="ServerSignature">ServerSignature</a> <a name="serversignature" id="serversignature">Directive</a></h2>
2793 <table class="directive">
2794 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the footer on server-generated documents</td></tr>
2795 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerSignature On|Off|EMail</code></td></tr>
2796 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerSignature Off</code></td></tr>
2797 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2798 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr>
2799 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2800 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2802 <p>The <code class="directive">ServerSignature</code> directive allows the
2803 configuration of a trailing footer line under server-generated
2804 documents (error messages, <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> ftp directory
2805 listings, <code class="module"><a href="../mod/mod_info.html">mod_info</a></code> output, ...). The reason why you
2806 would want to enable such a footer line is that in a chain of proxies,
2807 the user often has no possibility to tell which of the chained servers
2808 actually produced a returned error message.</p>
2810 <p>The <code>Off</code>
2811 setting, which is the default, suppresses the footer line (and is
2812 therefore compatible with the behavior of Apache-1.2 and
2813 below). The <code>On</code> setting simply adds a line with the
2814 server version number and <code class="directive"><a href="#servername">ServerName</a></code> of the serving virtual host,
2815 and the <code>EMail</code> setting additionally creates a
2816 "mailto:" reference to the <code class="directive"><a href="#serveradmin">ServerAdmin</a></code> of the referenced
2819 <p>After version 2.0.44, the details of the server version number
2820 presented are controlled by the <code class="directive"><a href="#servertokens">ServerTokens</a></code> directive.</p>
2824 <li><code class="directive"><a href="#servertokens">ServerTokens</a></code></li>
2827 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2828 <div class="directive-section"><h2><a name="ServerTokens" id="ServerTokens">ServerTokens</a> <a name="servertokens" id="servertokens">Directive</a></h2>
2829 <table class="directive">
2830 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the <code>Server</code> HTTP response
2832 <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>
2833 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerTokens Full</code></td></tr>
2834 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
2835 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2836 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2838 <p>This directive controls whether <code>Server</code> response
2839 header field which is sent back to clients includes a
2840 description of the generic OS-type of the server as well as
2841 information about compiled-in modules.</p>
2844 <dt><code>ServerTokens Prod[uctOnly]</code></dt>
2846 <dd>Server sends (<em>e.g.</em>): <code>Server:
2849 <dt><code>ServerTokens Major</code></dt>
2851 <dd>Server sends (<em>e.g.</em>): <code>Server:
2852 Apache/2</code></dd>
2854 <dt><code>ServerTokens Minor</code></dt>
2856 <dd>Server sends (<em>e.g.</em>): <code>Server:
2857 Apache/2.0</code></dd>
2859 <dt><code>ServerTokens Min[imal]</code></dt>
2861 <dd>Server sends (<em>e.g.</em>): <code>Server:
2862 Apache/2.0.41</code></dd>
2864 <dt><code>ServerTokens OS</code></dt>
2866 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2869 <dt><code>ServerTokens Full</code> (or not specified)</dt>
2871 <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41
2872 (Unix) PHP/4.2.2 MyMod/1.2</code></dd>
2875 <p>This setting applies to the entire server, and cannot be
2876 enabled or disabled on a virtualhost-by-virtualhost basis.</p>
2878 <p>After version 2.0.44, this directive also controls the
2879 information presented by the <code class="directive"><a href="#serversignature">ServerSignature</a></code> directive.</p>
2883 <li><code class="directive"><a href="#serversignature">ServerSignature</a></code></li>
2886 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2887 <div class="directive-section"><h2><a name="SetHandler" id="SetHandler">SetHandler</a> <a name="sethandler" id="sethandler">Directive</a></h2>
2888 <table class="directive">
2889 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be processed by a
2891 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetHandler <var>handler-name</var>|None</code></td></tr>
2892 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2893 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2894 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2895 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2896 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved into the core in Apache 2.0</td></tr>
2898 <p>When placed into an <code>.htaccess</code> file or a
2899 <code class="directive"><a href="#directory"><Directory></a></code> or
2900 <code class="directive"><a href="#location"><Location></a></code>
2901 section, this directive forces all matching files to be parsed
2902 through the <a href="../handler.html">handler</a> given by
2903 <var>handler-name</var>. For example, if you had a directory you
2904 wanted to be parsed entirely as imagemap rule files, regardless
2905 of extension, you might put the following into an
2906 <code>.htaccess</code> file in that directory:</p>
2908 <div class="example"><p><code>
2909 SetHandler imap-file
2912 <p>Another example: if you wanted to have the server display a
2913 status report whenever a URL of
2914 <code>http://servername/status</code> was called, you might put
2915 the following into <code>httpd.conf</code>:</p>
2917 <div class="example"><p><code>
2918 <Location /status><br />
2919 <span class="indent">
2920 SetHandler server-status<br />
2925 <p>You can override an earlier defined <code class="directive">SetHandler</code>
2926 directive by using the value <code>None</code>.</p>
2930 <li><code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code></li>
2933 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2934 <div class="directive-section"><h2><a name="SetInputFilter" id="SetInputFilter">SetInputFilter</a> <a name="setinputfilter" id="setinputfilter">Directive</a></h2>
2935 <table class="directive">
2936 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process client requests and POST
2938 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetInputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
2939 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2940 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2941 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2942 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2944 <p>The <code class="directive">SetInputFilter</code> directive sets the
2945 filter or filters which will process client requests and POST
2946 input when they are received by the server. This is in addition to
2947 any filters defined elsewhere, including the
2948 <code class="directive"><a href="../mod/mod_mime.html#addinputfilter">AddInputFilter</a></code>
2951 <p>If more than one filter is specified, they must be separated
2952 by semicolons in the order in which they should process the
2957 <li><a href="../filter.html">Filters</a> documentation</li>
2960 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
2961 <div class="directive-section"><h2><a name="SetOutputFilter" id="SetOutputFilter">SetOutputFilter</a> <a name="setoutputfilter" id="setoutputfilter">Directive</a></h2>
2962 <table class="directive">
2963 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process responses from the
2965 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetOutputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr>
2966 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
2967 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
2968 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
2969 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
2971 <p>The <code class="directive">SetOutputFilter</code> directive sets the filters
2972 which will process responses from the server before they are
2973 sent to the client. This is in addition to any filters defined
2974 elsewhere, including the
2975 <code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code>
2978 <p>For example, the following configuration will process all files
2979 in the <code>/www/data/</code> directory for server-side
2982 <div class="example"><p><code>
2983 <Directory /www/data/><br />
2984 <span class="indent">
2985 SetOutputFilter INCLUDES<br />
2990 <p>If more than one filter is specified, they must be separated
2991 by semicolons in the order in which they should process the
2996 <li><a href="../filter.html">Filters</a> documentation</li>
2999 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3000 <div class="directive-section"><h2><a name="TimeOut" id="TimeOut">TimeOut</a> <a name="timeout" id="timeout">Directive</a></h2>
3001 <table class="directive">
3002 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for
3003 certain events before failing a request</td></tr>
3004 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TimeOut <var>seconds</var></code></td></tr>
3005 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TimeOut 300</code></td></tr>
3006 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
3007 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3008 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3010 <p>The <code class="directive">TimeOut</code> directive currently defines
3011 the amount of time Apache will wait for three things:</p>
3014 <li>The total amount of time it takes to receive a GET
3017 <li>The amount of time between receipt of TCP packets on a
3018 POST or PUT request.</li>
3020 <li>The amount of time between ACKs on transmissions of TCP
3021 packets in responses.</li>
3024 <p>We plan on making these separately configurable at some point
3025 down the road. The timer used to default to 1200 before 1.2,
3026 but has been lowered to 300 which is still far more than
3027 necessary in most situations. It is not set any lower by
3028 default because there may still be odd places in the code where
3029 the timer is not reset when a packet is sent. </p>
3032 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3033 <div class="directive-section"><h2><a name="TraceEnable" id="TraceEnable">TraceEnable</a> <a name="traceenable" id="traceenable">Directive</a></h2>
3034 <table class="directive">
3035 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines the behaviour on <code>TRACE</code>
3037 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TraceEnable <var>[on|off|extended]</var></code></td></tr>
3038 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TraceEnable on</code></td></tr>
3039 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3040 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3041 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3042 <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>
3044 <p>This directive overrides the behavior of <code>TRACE</code> for both
3045 the core server and <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>. The default
3046 <code>TraceEnable on</code> permits <code>TRACE</code> requests per
3047 RFC 2616, which disallows any request body to accompany the request.
3048 <code>TraceEnable off</code> causes the core server and
3049 <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> to return a <code>405</code> (Method not
3050 allowed) error to the client.</p>
3052 <p>Finally, for testing and diagnostic purposes only, request
3053 bodies may be allowed using the non-compliant <code>TraceEnable
3054 extended</code> directive. The core (as an origin server) will
3055 restrict the request body to 64k (plus 8k for chunk headers if
3056 <code>Transfer-Encoding: chunked</code> is used). The core will
3057 reflect the full headers and all chunk headers with the response
3058 body. As a proxy server, the request body is not restricted to 64k.</p>
3061 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3062 <div class="directive-section"><h2><a name="UseCanonicalName" id="UseCanonicalName">UseCanonicalName</a> <a name="usecanonicalname" id="usecanonicalname">Directive</a></h2>
3063 <table class="directive">
3064 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and
3066 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalName On|Off|DNS</code></td></tr>
3067 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalName On</code></td></tr>
3068 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
3069 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3070 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3072 <p>In many situations Apache must construct a <em>self-referential</em>
3073 URL -- that is, a URL that refers back to the same server. With
3074 <code>UseCanonicalName On</code> Apache will use the hostname and port
3075 specified in the <code class="directive"><a href="#servername">ServerName</a></code>
3076 directive to construct the canonical name for the server. This name
3077 is used in all self-referential URLs, and for the values of
3078 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> in CGIs.</p>
3080 <p>With <code>UseCanonicalName Off</code> Apache will form
3081 self-referential URLs using the hostname and port supplied by
3082 the client if any are supplied (otherwise it will use the
3083 canonical name, as defined above). These values are the same
3084 that are used to implement <a href="../vhosts/name-based.html">name based virtual hosts</a>,
3085 and are available with the same clients. The CGI variables
3086 <code>SERVER_NAME</code> and <code>SERVER_PORT</code> will be
3087 constructed from the client supplied values as well.</p>
3089 <p>An example where this may be useful is on an intranet server
3090 where you have users connecting to the machine using short
3091 names such as <code>www</code>. You'll notice that if the users
3092 type a shortname, and a URL which is a directory, such as
3093 <code>http://www/splat</code>, <em>without the trailing
3094 slash</em> then Apache will redirect them to
3095 <code>http://www.domain.com/splat/</code>. If you have
3096 authentication enabled, this will cause the user to have to
3097 authenticate twice (once for <code>www</code> and once again
3098 for <code>www.domain.com</code> -- see <a href="http://httpd.apache.org/docs/misc/FAQ.html#prompted-twice">the
3099 FAQ on this subject for more information</a>). But if
3100 <code class="directive">UseCanonicalName</code> is set <code>Off</code>, then
3101 Apache will redirect to <code>http://www/splat/</code>.</p>
3103 <p>There is a third option, <code>UseCanonicalName DNS</code>,
3104 which is intended for use with mass IP-based virtual hosting to
3105 support ancient clients that do not provide a
3106 <code>Host:</code> header. With this option Apache does a
3107 reverse DNS lookup on the server IP address that the client
3108 connected to in order to work out self-referential URLs.</p>
3110 <div class="warning"><h3>Warning</h3>
3111 <p>If CGIs make assumptions about the values of <code>SERVER_NAME</code>
3112 they may be broken by this option. The client is essentially free
3113 to give whatever value they want as a hostname. But if the CGI is
3114 only using <code>SERVER_NAME</code> to construct self-referential URLs
3115 then it should be just fine.</p>
3120 <li><code class="directive"><a href="#servername">ServerName</a></code></li>
3121 <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li>
3124 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
3125 <div class="directive-section"><h2><a name="VirtualHost" id="VirtualHost"><VirtualHost></a> <a name="virtualhost" id="virtualhost">Directive</a></h2>
3126 <table class="directive">
3127 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only to a specific
3128 hostname or IP address</td></tr>
3129 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><VirtualHost
3130 <var>addr</var>[:<var>port</var>] [<var>addr</var>[:<var>port</var>]]
3131 ...> ... </VirtualHost></code></td></tr>
3132 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
3133 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
3134 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
3136 <p><code class="directive"><VirtualHost></code> and
3137 <code></VirtualHost></code> are used to enclose a group of
3138 directives that will apply only to a particular virtual host. Any
3139 directive that is allowed in a virtual host context may be
3140 used. When the server receives a request for a document on a
3141 particular virtual host, it uses the configuration directives
3142 enclosed in the <code class="directive"><VirtualHost></code>
3143 section. <var>Addr</var> can be:</p>
3146 <li>The IP address of the virtual host;</li>
3148 <li>A fully qualified domain name for the IP address of the
3151 <li>The character <code>*</code>, which is used only in combination with
3152 <code>NameVirtualHost *</code> to match all IP addresses; or</li>
3154 <li>The string <code>_default_</code>, which is used only
3155 with IP virtual hosting to catch unmatched IP addresses.</li>
3158 <div class="example"><h3>Example</h3><p><code>
3159 <VirtualHost 10.1.2.3><br />
3160 <span class="indent">
3161 ServerAdmin webmaster@host.foo.com<br />
3162 DocumentRoot /www/docs/host.foo.com<br />
3163 ServerName host.foo.com<br />
3164 ErrorLog logs/host.foo.com-error_log<br />
3165 TransferLog logs/host.foo.com-access_log<br />
3167 </VirtualHost>
3171 <p>IPv6 addresses must be specified in square brackets because
3172 the optional port number could not be determined otherwise. An
3173 IPv6 example is shown below:</p>
3175 <div class="example"><p><code>
3176 <VirtualHost [2001:db8::a00:20ff:fea7:ccea]><br />
3177 <span class="indent">
3178 ServerAdmin webmaster@host.example.com<br />
3179 DocumentRoot /www/docs/host.example.com<br />
3180 ServerName host.example.com<br />
3181 ErrorLog logs/host.example.com-error_log<br />
3182 TransferLog logs/host.example.com-access_log<br />
3184 </VirtualHost>
3187 <p>Each Virtual Host must correspond to a different IP address,
3188 different port number or a different host name for the server,
3189 in the former case the server machine must be configured to
3190 accept IP packets for multiple addresses. (If the machine does
3191 not have multiple network interfaces, then this can be
3192 accomplished with the <code>ifconfig alias</code> command -- if
3193 your OS supports it).</p>
3195 <div class="note"><h3>Note</h3>
3196 <p>The use of <code class="directive"><VirtualHost></code> does
3197 <strong>not</strong> affect what addresses Apache listens on. You
3198 may need to ensure that Apache is listening on the correct addresses
3199 using <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>.</p>
3202 <p>When using IP-based virtual hosting, the special name
3203 <code>_default_</code> can be specified in
3204 which case this virtual host will match any IP address that is
3205 not explicitly listed in another virtual host. In the absence
3206 of any <code>_default_</code> virtual host the "main" server config,
3207 consisting of all those definitions outside any VirtualHost
3208 section, is used when no IP-match occurs. (But note that any IP
3209 address that matches a <code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code> directive will use neither
3210 the "main" server config nor the <code>_default_</code> virtual host.
3211 See the <a href="../vhosts/name-based.html">name-based virtual hosting</a>
3212 documentation for further details.)</p>
3214 <p>You can specify a <code>:port</code> to change the port that is
3215 matched. If unspecified then it defaults to the same port as the
3216 most recent <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>
3217 statement of the main server. You may also specify <code>:*</code>
3218 to match all ports on that address. (This is recommended when used
3219 with <code>_default_</code>.)</p>
3221 <div class="warning"><h3>Security</h3>
3222 <p>See the <a href="../misc/security_tips.html">security tips</a>
3223 document for details on why your security could be compromised if the
3224 directory where log files are stored is writable by anyone other
3225 than the user that starts the server.</p>
3230 <li><a href="../vhosts/">Apache Virtual Host documentation</a></li>
3231 <li><a href="../dns-caveats.html">Issues Regarding DNS and
3233 <li><a href="../bind.html">Setting
3234 which addresses and ports Apache uses</a></li>
3235 <li><a href="../sections.html">How <Directory>, <Location>
3236 and <Files> sections work</a> for an explanation of how these
3237 different sections are combined when a request is received</li>
3241 <div class="bottomlang">
3242 <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
3243 <a href="../en/mod/core.html" title="English"> en </a> |
3244 <a href="../es/mod/core.html" hreflang="es" rel="alternate" title="Español"> es </a> |
3245 <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
3246 <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
3247 </div><div id="footer">
3248 <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>
3249 <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>