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core - Apache HTTP Server Version 2.2
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type" /> <!-- XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX This file is generated from xml source: DO NOT EDIT XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --> <title>core - Apache HTTP Server Version 2.2</title> <link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> <link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> <link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" /> <script src="../style/scripts/prettify.min.js" type="text/javascript"> </script> <link href="../images/favicon.ico" rel="shortcut icon" /><link href="http://httpd.apache.org/docs/current/mod/core.html" rel="canonical" /></head> <body> <div id="page-header"> <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p> <p class="apache">Apache HTTP Server Version 2.2</p> <img alt="" src="../images/feather.gif" /></div> <div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div> <div id="path"> <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 2.2</a> > <a href="./">Modules</a></div> <div id="page-content"> <div class="retired"><h4>Please note</h4> <p>This document refers to the <strong>2.2</strong> version of Apache httpd, which is no longer maintained. The active release is documented <a href="http://httpd.apache.org/docs/current">here</a>. If you have not already upgraded, please follow <a href="http://httpd.apache.org/docs/current/upgrading.html">this link</a> for more information.</p> <p>You may follow <a href="http://httpd.apache.org/docs/current/mod/core.html">this link</a> to go to the current version of this document.</p></div><div id="preamble"><h1>Apache Core Features</h1> <div class="toplang"> <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> | <a href="../en/mod/core.html" title="English"> en </a> | <a href="../fr/mod/core.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> </div> <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Core Apache HTTP Server features that are always available</td></tr> <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Core</td></tr></table> </div> <div id="quickview"><h3 class="directives">Directives</h3> <ul id="toc"> <li><img alt="" src="../images/down.gif" /> <a href="#acceptfilter">AcceptFilter</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#acceptpathinfo">AcceptPathInfo</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#accessfilename">AccessFileName</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#adddefaultcharset">AddDefaultCharset</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#addoutputfilterbytype">AddOutputFilterByType</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#allowencodedslashes">AllowEncodedSlashes</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#allowoverride">AllowOverride</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#authname">AuthName</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#authtype">AuthType</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#cgimapextension">CGIMapExtension</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#contentdigest">ContentDigest</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#defaulttype">DefaultType</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#directory"><Directory></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#directorymatch"><DirectoryMatch></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#documentroot">DocumentRoot</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#enablemmap">EnableMMAP</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#enablesendfile">EnableSendfile</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#errordocument">ErrorDocument</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#errorlog">ErrorLog</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#fileetag">FileETag</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#files"><Files></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#filesmatch"><FilesMatch></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#forcetype">ForceType</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#gprofdir">GprofDir</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#hostnamelookups">HostnameLookups</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#httpprotocoloptions">HttpProtocolOptions</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#ifdefine"><IfDefine></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#ifmodule"><IfModule></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#include">Include</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#keepalive">KeepAlive</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#keepalivetimeout">KeepAliveTimeout</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limit"><Limit></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitexcept"><LimitExcept></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitinternalrecursion">LimitInternalRecursion</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestbody">LimitRequestBody</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfields">LimitRequestFields</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestfieldsize">LimitRequestFieldSize</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitrequestline">LimitRequestLine</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#limitxmlrequestbody">LimitXMLRequestBody</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#location"><Location></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#locationmatch"><LocationMatch></a></li> <li><img alt="" src="../images/down.gif" /> <a href="#loglevel">LogLevel</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#maxranges">MaxRanges</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#mergetrailers">MergeTrailers</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#namevirtualhost">NameVirtualHost</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#options">Options</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#protocol">Protocol</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#registerhttpmethod">RegisterHttpMethod</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#require">Require</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#rlimitcpu">RLimitCPU</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#rlimitmem">RLimitMEM</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#rlimitnproc">RLimitNPROC</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#satisfy">Satisfy</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#scriptinterpretersource">ScriptInterpreterSource</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#serveradmin">ServerAdmin</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#serveralias">ServerAlias</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#servername">ServerName</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#serverpath">ServerPath</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#serverroot">ServerRoot</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#serversignature">ServerSignature</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#servertokens">ServerTokens</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#sethandler">SetHandler</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#setinputfilter">SetInputFilter</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#setoutputfilter">SetOutputFilter</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#suexec">Suexec</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#timeout">TimeOut</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#traceenable">TraceEnable</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalname">UseCanonicalName</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></li> <li><img alt="" src="../images/down.gif" /> <a href="#virtualhost"><VirtualHost></a></li> </ul> <ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AcceptFilter" id="AcceptFilter">AcceptFilter</a> <a name="acceptfilter" id="acceptfilter">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures optimizations for a Protocol's Listener Sockets</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptFilter <var>protocol</var> <var>accept_filter</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.1.5 and later</td></tr> </table> <p>This directive enables operating system specific optimizations for a listening socket by the Protocol type. The basic premise is for the kernel to not send a socket to the server process until either data is received or an entire HTTP Request is buffered. Only <a href="http://www.freebsd.org/cgi/man.cgi?query=accept_filter&sektion=9"> FreeBSD's Accept Filters</a> and Linux's more primitive <code>TCP_DEFER_ACCEPT</code> are currently supported.</p> <p>The default values on FreeBSD are:</p> <div class="example"><p><code> AcceptFilter http httpready <br /> AcceptFilter https dataready </code></p></div> <p>The <code>httpready</code> accept filter buffers entire HTTP requests at the kernel level. Once an entire request is received, the kernel then sends it to the server. See the <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_http&sektion=9"> accf_http(9)</a> man page for more details. Since HTTPS requests are encrypted, only the <a href="http://www.freebsd.org/cgi/man.cgi?query=accf_data&sektion=9"> accf_data(9)</a> filter is used.</p> <p>The default values on Linux are:</p> <div class="example"><p><code> AcceptFilter http data <br /> AcceptFilter https data </code></p></div> <p>Linux's <code>TCP_DEFER_ACCEPT</code> does not support buffering http requests. Any value besides <code>none</code> will enable <code>TCP_DEFER_ACCEPT</code> on that listener. For more details see the Linux <a href="http://homepages.cwi.nl/~aeb/linux/man2html/man7/tcp.7.html"> tcp(7)</a> man page.</p> <p>Using <code>none</code> for an argument will disable any accept filters for that protocol. This is useful for protocols that require a server send data first, such as <code>nntp</code>:</p> <div class="example"><p><code>AcceptFilter nntp none</code></p></div> <h3>See also</h3> <ul> <li><code class="directive">Protocol</code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AcceptPathInfo" id="AcceptPathInfo">AcceptPathInfo</a> <a name="acceptpathinfo" id="acceptpathinfo">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Resources accept trailing pathname information</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AcceptPathInfo On|Off|Default</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AcceptPathInfo Default</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.30 and later</td></tr> </table> <p>This directive controls whether requests that contain trailing pathname information that follows an actual filename (or non-existent file in an existing directory) will be accepted or rejected. The trailing pathname information can be made available to scripts in the <code>PATH_INFO</code> environment variable.</p> <p>For example, assume the location <code>/test/</code> points to a directory that contains only the single file <code>here.html</code>. Then requests for <code>/test/here.html/more</code> and <code>/test/nothere.html/more</code> both collect <code>/more</code> as <code>PATH_INFO</code>.</p> <p>The three possible arguments for the <code class="directive">AcceptPathInfo</code> directive are:</p> <dl> <dt><code>Off</code></dt><dd>A request will only be accepted if it maps to a literal path that exists. Therefore a request with trailing pathname information after the true filename such as <code>/test/here.html/more</code> in the above example will return a 404 NOT FOUND error.</dd> <dt><code>On</code></dt><dd>A request will be accepted if a leading path component maps to a file that exists. The above example <code>/test/here.html/more</code> will be accepted if <code>/test/here.html</code> maps to a valid file.</dd> <dt><code>Default</code></dt><dd>The treatment of requests with trailing pathname information is determined by the <a href="../handler.html">handler</a> responsible for the request. The core handler for normal files defaults to rejecting <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 <code>PATH_INFO</code> by default.</dd> </dl> <p>The primary purpose of the <code>AcceptPathInfo</code> directive is to allow you to override the handler's choice of accepting or rejecting <code>PATH_INFO</code>. This override is required, for example, when you use a <a href="../filter.html">filter</a>, such as <a href="mod_include.html">INCLUDES</a>, to generate content based on <code>PATH_INFO</code>. The core handler would usually reject the request, so you can use the following configuration to enable such a script:</p> <div class="example"><p><code> <Files "mypaths.shtml"><br /> <span class="indent"> Options +Includes<br /> SetOutputFilter INCLUDES<br /> AcceptPathInfo On<br /> </span> </Files> </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AccessFileName" id="AccessFileName">AccessFileName</a> <a name="accessfilename" id="accessfilename">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Name of the distributed configuration file</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AccessFileName <var>filename</var> [<var>filename</var>] ...</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AccessFileName .htaccess</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>While processing a request, the server looks for the first existing configuration file from this list of names in every directory of the path to the document, if distributed configuration files are <a href="#allowoverride">enabled for that directory</a>. For example:</p> <div class="example"><p><code> AccessFileName .acl </code></p></div> <p>Before returning the document <code>/usr/local/web/index.html</code>, the server will read <code>/.acl</code>, <code>/usr/.acl</code>, <code>/usr/local/.acl</code> and <code>/usr/local/web/.acl</code> for directives unless they have been disabled with:</p> <div class="example"><p><code> <Directory /><br /> <span class="indent"> AllowOverride None<br /> </span> </Directory> </code></p></div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#allowoverride">AllowOverride</a></code></li> <li><a href="../configuring.html">Configuration Files</a></li> <li><a href="../howto/htaccess.html">.htaccess Files</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AddDefaultCharset" id="AddDefaultCharset">AddDefaultCharset</a> <a name="adddefaultcharset" id="adddefaultcharset">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default charset parameter to be added when a response content-type is <code>text/plain</code> or <code>text/html</code></td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddDefaultCharset On|Off|<var>charset</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AddDefaultCharset Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive specifies a default value for the media type charset parameter (the name of a character encoding) to be added to a response if and only if the response's content-type is either <code>text/plain</code> or <code>text/html</code>. This should override any charset specified in the body of the response via a <code>META</code> element, though the exact behavior is often dependent on the user's client configuration. A setting of <code>AddDefaultCharset Off</code> disables this functionality. <code>AddDefaultCharset On</code> enables a default charset of <code>iso-8859-1</code>. Any other value is assumed to be the <var>charset</var> to be used, which should be one of the <a href="http://www.iana.org/assignments/character-sets">IANA registered charset values</a> for use in MIME media types. For example:</p> <div class="example"><p><code> AddDefaultCharset utf-8 </code></p></div> <p><code class="directive">AddDefaultCharset</code> should only be used when all of the text resources to which it applies are known to be in that character encoding and it is too inconvenient to label their charset individually. One such example is to add the charset parameter to resources containing generated content, such as legacy CGI scripts, that might be vulnerable to cross-site scripting attacks due to user-provided data being included in the output. Note, however, that a better solution is to just fix (or delete) those scripts, since setting a default charset does not protect users that have enabled the "auto-detect character encoding" feature on their browser.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="../mod/mod_mime.html#addcharset">AddCharset</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AddOutputFilterByType" id="AddOutputFilterByType">AddOutputFilterByType</a> <a name="addoutputfilterbytype" id="addoutputfilterbytype">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>assigns an output filter to a particular MIME-type</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AddOutputFilterByType <var>filter</var>[;<var>filter</var>...] <var>MIME-type</var> [<var>MIME-type</var>] ...</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.33 and later; deprecated in Apache 2.1 and later</td></tr> </table> <p>This directive activates a particular output <a href="../filter.html">filter</a> for a request depending on the response <a class="glossarylink" href="../glossary.html#mime-type" title="see glossary">MIME-type</a>. Because of certain problems discussed below, this directive is deprecated. The same functionality is available using <code class="module"><a href="../mod/mod_filter.html">mod_filter</a></code>.</p> <p>The following example uses the <code>DEFLATE</code> filter, which is provided by <code class="module"><a href="../mod/mod_deflate.html">mod_deflate</a></code>. It will compress all output (either static or dynamic) which is labeled as <code>text/html</code> or <code>text/plain</code> before it is sent to the client.</p> <div class="example"><p><code> AddOutputFilterByType DEFLATE text/html text/plain </code></p></div> <p>If you want the content to be processed by more than one filter, their names have to be separated by semicolons. It's also possible to use one <code class="directive">AddOutputFilterByType</code> directive for each of these filters.</p> <p>The configuration below causes all script output labeled as <code>text/html</code> to be processed at first by the <code>INCLUDES</code> filter and then by the <code>DEFLATE</code> filter.</p> <div class="example"><p><code> <Location /cgi-bin/><br /> <span class="indent"> Options Includes<br /> AddOutputFilterByType INCLUDES;DEFLATE text/html<br /> </span> </Location> </code></p></div> <div class="warning"><h3>Note</h3> <p>Enabling filters with <code class="directive">AddOutputFilterByType</code> may fail partially or completely in some cases. For example, no filters are applied if the <a class="glossarylink" href="../glossary.html#mime-type" title="see glossary">MIME-type</a> could not be determined and falls back to the <code class="directive"><a href="#defaulttype">DefaultType</a></code> setting, even if the <code class="directive"><a href="#defaulttype">DefaultType</a></code> is the same.</p> <p>However, if you want to make sure, that the filters will be applied, assign the content type to a resource explicitly, for example with <code class="directive"><a href="../mod/mod_mime.html#addtype">AddType</a></code> or <code class="directive"><a href="#forcetype">ForceType</a></code>. Setting the content type within a (non-nph) CGI script is also safe.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code></li> <li><code class="directive"><a href="#setoutputfilter">SetOutputFilter</a></code></li> <li><a href="../filter.html">filters</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AllowEncodedSlashes" id="AllowEncodedSlashes">AllowEncodedSlashes</a> <a name="allowencodedslashes" id="allowencodedslashes">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines whether encoded path separators in URLs are allowed to be passed through</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowEncodedSlashes On|Off|NoDecode</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowEncodedSlashes Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.0.46 and later. NoDecode option available in 2.2.18 and later.</td></tr> </table> <p>The <code class="directive">AllowEncodedSlashes</code> directive allows URLs which contain encoded path separators (<code>%2F</code> for <code>/</code> and additionally <code>%5C</code> for <code>\</code> on accordant systems) to be used in the path info.</p> <p>With the default value, <code>Off</code>, such URLs are refused with a 404 (Not found) error.</p> <p>With the value <code>On</code>, such URLs are accepted, and encoded slashes are decoded like all other encoded characters.</p> <p>With the value <code>NoDecode</code>, such URLs are accepted, but encoded slashes are not decoded but left in their encoded state.</p> <p>Turning <code class="directive">AllowEncodedSlashes</code> <code>On</code> is mostly useful when used in conjunction with <code>PATH_INFO</code>.</p> <div class="note"><h3>Note</h3> <p>If encoded slashes are needed in path info, use of <code>NoDecode</code> is strongly recommended as a security measure. Allowing slashes to be decoded could potentially allow unsafe paths.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#acceptpathinfo">AcceptPathInfo</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AllowOverride" id="AllowOverride">AllowOverride</a> <a name="allowoverride" id="allowoverride">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Types of directives that are allowed in <code>.htaccess</code> files</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowOverride All|None|<var>directive-type</var> [<var>directive-type</var>] ...</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowOverride All</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>When the server finds an <code>.htaccess</code> file (as specified by <code class="directive"><a href="#accessfilename">AccessFileName</a></code>), it needs to know which directives declared in that file can override earlier configuration directives.</p> <div class="note"><h3>Only available in <Directory> sections</h3> <code class="directive">AllowOverride</code> is valid only in <code class="directive"><a href="#directory"><Directory></a></code> 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 <code class="directive"><a href="#files"><Files></a></code> sections. </div> <p>When this directive is set to <code>None</code>, then <a href="#accessfilename">.htaccess</a> files are completely ignored. In this case, the server will not even attempt to read <code>.htaccess</code> files in the filesystem.</p> <p>When this directive is set to <code>All</code>, then any directive which has the .htaccess <a href="directive-dict.html#Context">Context</a> is allowed in <code>.htaccess</code> files.</p> <p>The <var>directive-type</var> can be one of the following groupings of directives.</p> <dl> <dt>AuthConfig</dt> <dd> Allow use of the authorization directives (<code class="directive"><a href="../mod/mod_authz_dbm.html#authdbmgroupfile">AuthDBMGroupFile</a></code>, <code class="directive"><a href="../mod/mod_authn_dbm.html#authdbmuserfile">AuthDBMUserFile</a></code>, <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code>, <code class="directive"><a href="#authname">AuthName</a></code>, <code class="directive"><a href="#authtype">AuthType</a></code>, <code class="directive"><a href="../mod/mod_authn_file.html#authuserfile">AuthUserFile</a></code>, <code class="directive"><a href="#require">Require</a></code>, <em>etc.</em>).</dd> <dt>FileInfo</dt> <dd> 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>, <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 <code class="module"><a href="../mod/mod_mime.html">mod_mime</a></code> Add* and Remove* directives, <em>etc.</em>), document meta data (<code class="directive"><a href="../mod/mod_headers.html#header">Header</a></code>, <code class="directive"><a href="../mod/mod_headers.html#requestheader">RequestHeader</a></code>, <code class="directive"><a href="../mod/mod_setenvif.html#setenvif">SetEnvIf</a></code>, <code class="directive"><a href="../mod/mod_setenvif.html#setenvifnocase">SetEnvIfNoCase</a></code>, <code class="directive"><a href="../mod/mod_setenvif.html#browsermatch">BrowserMatch</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookieexpires">CookieExpires</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookiedomain">CookieDomain</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookiestyle">CookieStyle</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookietracking">CookieTracking</a></code>, <code class="directive"><a href="../mod/mod_usertrack.html#cookiename">CookieName</a></code>), <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> directives (<code class="directive"><a href="../mod/mod_rewrite.html#rewriteengine">RewriteEngine</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewriteoptions">RewriteOptions</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewritebase">RewriteBase</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewritecond">RewriteCond</a></code>, <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code>), <code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code> directives (<code class="directive"><a href="../mod/mod_alias.html#redirect">Redirect</a></code>, <code class="directive"><a href="../mod/mod_alias.html#redirecttemp">RedirectTemp</a></code>, <code class="directive"><a href="../mod/mod_alias.html#redirectpermanent">RedirectPermanent</a></code>, <code class="directive"><a href="../mod/mod_alias.html#redirectmatch">RedirectMatch</a></code>), and <code class="directive"><a href="../mod/mod_actions.html#action">Action</a></code> from <code class="module"><a href="../mod/mod_actions.html">mod_actions</a></code>. </dd> <dt>Indexes</dt> <dd> Allow use of the directives controlling directory indexing (<code class="directive"><a href="../mod/mod_autoindex.html#adddescription">AddDescription</a></code>, <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>, <code class="directive"><a href="../mod/mod_autoindex.html#addiconbytype">AddIconByType</a></code>, <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>, <a href="mod_autoindex.html#indexoptions.fancyindexing"><code>FancyIndexing</code> </a>, <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>, <em>etc.</em>).</dd> <dt>Limit</dt> <dd> Allow use of the directives controlling host access (<code class="directive"><a href="../mod/mod_authz_host.html#allow">Allow</a></code>, <code class="directive"><a href="../mod/mod_authz_host.html#deny">Deny</a></code> and <code class="directive"><a href="../mod/mod_authz_host.html#order">Order</a></code>).</dd> <dt>Options[=<var>Option</var>,...]</dt> <dd> Allow use of the directives controlling specific directory features (<code class="directive"><a href="#options">Options</a></code> and <code class="directive"><a href="../mod/mod_include.html#xbithack">XBitHack</a></code>). An equal sign may be given followed by a comma-separated list, without spaces, of options that may be set using the <code class="directive"><a href="#options">Options</a></code> command. <div class="note"><h3>Implicit disabling of Options</h3> <p>Even though the list of options that may be used in .htaccess files can be limited with this directive, as long as any <code class="directive"><a href="#options">Options</a></code> directive is allowed any other inherited option can be disabled by using the non-relative syntax. In other words, this mechanism cannot force a specific option to remain <em>set</em> while allowing any others to be set. </p></div> </dd> </dl> <p>Example:</p> <div class="example"><p><code> AllowOverride AuthConfig Indexes </code></p></div> <p>In the example above, all directives that are neither in the group <code>AuthConfig</code> nor <code>Indexes</code> cause an internal server error.</p> <div class="note"><p>For security and performance reasons, do not set <code>AllowOverride</code> to anything other than <code>None</code> in your <code><Directory /></code> block. Instead, find (or create) the <code><Directory></code> block that refers to the directory where you're actually planning to place a <code>.htaccess</code> file.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#accessfilename">AccessFileName</a></code></li> <li><a href="../configuring.html">Configuration Files</a></li> <li><a href="../howto/htaccess.html">.htaccess Files</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AuthName" id="AuthName">AuthName</a> <a name="authname" id="authname">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Authorization realm for use in HTTP authentication</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthName <var>auth-domain</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive sets the name of the authorization realm for a directory. This realm is given to the client so that the user knows which username and password to send. <code class="directive">AuthName</code> takes a single argument; if the realm name contains spaces, it must be enclosed in quotation 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 as <code class="directive"><a href="../mod/mod_authn_file.html#authuserfile">AuthUserFile</a></code> and <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code> to work.</p> <p>For example:</p> <div class="example"><p><code> AuthName "Top Secret" </code></p></div> <p>The string provided for the <code>AuthName</code> is what will appear in the password dialog provided by most browsers.</p> <h3>See also</h3> <ul> <li><a href="../howto/auth.html">Authentication, Authorization, and Access Control</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="AuthType" id="AuthType">AuthType</a> <a name="authtype" id="authtype">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Type of user authentication</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthType Basic|Digest</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive selects the type of user authentication for a directory. The authentication types available are <code>Basic</code> (implemented by <code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code>) and <code>Digest</code> (implemented by <code class="module"><a href="../mod/mod_auth_digest.html">mod_auth_digest</a></code>).</p> <p>To implement authentication, you must also use the <code class="directive"><a href="#authname">AuthName</a></code> and <code class="directive"><a href="#require">Require</a></code> directives. In addition, the server must have an authentication-provider module such as <code class="module"><a href="../mod/mod_authn_file.html">mod_authn_file</a></code> and an authorization module such as <code class="module"><a href="../mod/mod_authz_user.html">mod_authz_user</a></code>.</p> <h3>See also</h3> <ul> <li><a href="../howto/auth.html">Authentication and Authorization</a></li> <li><a href="../howto/access.html">Access Control</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="CGIMapExtension" id="CGIMapExtension">CGIMapExtension</a> <a name="cgimapextension" id="cgimapextension">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI scripts</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CGIMapExtension <var>cgi-path</var> <var>.extension</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>NetWare only</td></tr> </table> <p>This directive is used to control how Apache finds the interpreter used to run CGI scripts. For example, setting <code>CGIMapExtension sys:\foo.nlm .foo</code> will cause all CGI script files with a <code>.foo</code> extension to be passed to the FOO interpreter.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ContentDigest" id="ContentDigest">ContentDigest</a> <a name="contentdigest" id="contentdigest">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables the generation of <code>Content-MD5</code> HTTP Response headers</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ContentDigest On|Off</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ContentDigest Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive enables the generation of <code>Content-MD5</code> headers as defined in RFC1864 respectively RFC2616.</p> <p>MD5 is an algorithm for computing a "message digest" (sometimes called "fingerprint") of arbitrary-length data, with a high degree of confidence that any alterations in the data will be reflected in alterations in the message digest.</p> <p>The <code>Content-MD5</code> header provides an end-to-end message integrity check (MIC) of the entity-body. A proxy or client may check this header for detecting accidental modification of the entity-body in transit. Example header:</p> <div class="example"><p><code> Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA== </code></p></div> <p>Note that this can cause performance problems on your server since the message digest is computed on every request (the values are not cached).</p> <p><code>Content-MD5</code> is only sent for documents served by the <code class="module"><a href="../mod/core.html">core</a></code>, and not by any module. For example, SSI documents, output from CGI scripts, and byte range responses do not have this header.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="DefaultType" id="DefaultType">DefaultType</a> <a name="defaulttype" id="defaulttype">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>MIME content-type that will be sent if the server cannot determine a type in any other way</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DefaultType <var>MIME-type|none</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DefaultType text/plain</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The argument <code>none</code> is available in Apache 2.2.7 and later</td></tr> </table> <p>There will be times when the server is asked to provide a document whose type cannot be determined by its <a class="glossarylink" href="../glossary.html#mime-type" title="see glossary">MIME types</a> mappings.</p> <p>The server SHOULD inform the client of the content-type of the document. If the server is unable to determine this by normal means, it will set it to the configured <code>DefaultType</code>. For example:</p> <div class="example"><p><code> DefaultType image/gif </code></p></div> <p>would be appropriate for a directory which contained many GIF images with filenames missing the <code>.gif</code> extension.</p> <p>In cases where it can neither be determined by the server nor the administrator (e.g. a proxy), it is preferable to omit the MIME type altogether rather than provide information that may be false. This can be accomplished using</p> <div class="example"><p><code> DefaultType None </code></p></div> <p><code>DefaultType None</code> is only available in httpd-2.2.7 and later.</p> <p>Note that unlike <code class="directive"><a href="#forcetype">ForceType</a></code>, this directive only provides the default mime-type. All other mime-type definitions, including filename extensions, that might identify the media type will override this default.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Directory" id="Directory"><Directory></a> <a name="directory" id="directory">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose a group of directives that apply only to the named file-system directory, sub-directories, and their contents</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Directory <var>directory-path</var>> ... </Directory></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p><code class="directive"><Directory></code> and <code></Directory></code> are used to enclose a group of directives that will apply only to the named directory, sub-directories of that directory, and the files within the respective directories. Any directive that is allowed in a directory context may be used. <var>Directory-path</var> is either the full path to a directory, or a wild-card string using Unix shell-style matching. In a wild-card string, <code>?</code> matches any single character, and <code>*</code> matches any sequences of characters. You may also use <code>[]</code> character ranges. None of the wildcards match a `/' character, so <code><Directory /*/public_html></code> will not match <code>/home/user/public_html</code>, but <code><Directory /home/*/public_html></code> will match. Example:</p> <div class="example"><p><code> <Directory /usr/local/httpd/htdocs><br /> <span class="indent"> Options Indexes FollowSymLinks<br /> </span> </Directory> </code></p></div> <div class="note"> <p>Be careful with the <var>directory-path</var> arguments: They have to literally match the filesystem path which Apache uses to access the files. Directives applied to a particular <code><Directory></code> will not apply to files accessed from that same directory via a different path, such as via different symbolic links.</p> </div> <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a> can also be used, with the addition of the <code>~</code> character. For example:</p> <div class="example"><p><code> <Directory ~ "^/www/[0-9]{3}"> </code></p></div> <p>would match directories in <code>/www/</code> that consisted of three numbers.</p> <p>If multiple (non-regular expression) <code class="directive"><Directory></code> sections match the directory (or one of its parents) containing a document, then the directives are applied in the order of shortest match first, interspersed with the directives from the <a href="#accessfilename">.htaccess</a> files. For example, with</p> <div class="example"><p><code> <Directory /><br /> <span class="indent"> AllowOverride None<br /> </span> </Directory><br /> <br /> <Directory /home><br /> <span class="indent"> AllowOverride FileInfo<br /> </span> </Directory> </code></p></div> <p>for access to the document <code>/home/web/dir/doc.html</code> the steps are:</p> <ul> <li>Apply directive <code>AllowOverride None</code> (disabling <code>.htaccess</code> files).</li> <li>Apply directive <code>AllowOverride FileInfo</code> (for directory <code>/home</code>).</li> <li>Apply any <code>FileInfo</code> directives in <code>/home/.htaccess</code>, <code>/home/web/.htaccess</code> and <code>/home/web/dir/.htaccess</code> in that order.</li> </ul> <p>Regular expressions are not considered until after all of the normal sections have been applied. Then all of the regular expressions are tested in the order they appeared in the configuration file. For example, with</p> <div class="example"><p><code> <Directory ~ "public_html/.*"><br /> <span class="indent"> # ... directives here ...<br /> </span> </Directory> </code></p></div> <p>the regular expression section won't be considered until after all normal <code class="directive"><Directory></code>s and <code>.htaccess</code> files have been applied. Then the regular expression will match on <code>/home/abc/public_html/abc</code> and the corresponding <code class="directive"><Directory></code> will be applied.</p> <p><strong>Note that the default Apache access for <code><Directory /></code> is <code>Allow from All</code>. This means that Apache will serve any file mapped from an URL. It is recommended that you change this with a block such as</strong></p> <div class="example"><p><code> <Directory /><br /> <span class="indent"> Order Deny,Allow<br /> Deny from All<br /> </span> </Directory> </code></p></div> <p><strong>and then override this for directories you <em>want</em> accessible. See the <a href="../misc/security_tips.html">Security Tips</a> page for more details.</strong></p> <p>The directory sections occur in the <code>httpd.conf</code> file. <code class="directive"><Directory></code> directives 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> <h3>See also</h3> <ul> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="DirectoryMatch" id="DirectoryMatch"><DirectoryMatch></a> <a name="directorymatch" id="directorymatch">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enclose directives that apply to file-system directories matching a regular expression and their subdirectories</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><DirectoryMatch <var>regex</var>> ... </DirectoryMatch></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p><code class="directive"><DirectoryMatch></code> and <code></DirectoryMatch></code> are used to enclose a group of directives which will apply only to the named directory and <em>sub-directories of that directory</em> (and the files within), the same as <code class="directive"><a href="#directory"><Directory></a></code>. However, it takes as an argument a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>. For example:</p> <div class="example"><p><code> <DirectoryMatch "^/www/(.+/)?[0-9]{3}"> </code></p></div> <p>would match directories in <code>/www/</code> that consisted of three numbers.</p> <div class="note"><h3>End-of-line character</h3> <p>The end-of-line character ($) cannot be matched with this directive.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#directory"><Directory></a></code> for a description of how regular expressions are mixed in with normal <code class="directive"><Directory></code>s</li> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="DocumentRoot" id="DocumentRoot">DocumentRoot</a> <a name="documentroot" id="documentroot">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory that forms the main document tree visible from the web</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>DocumentRoot <var>directory-path</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>DocumentRoot /usr/local/apache/htdocs</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive sets the directory from which <code class="program"><a href="../programs/httpd.html">httpd</a></code> 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 path from the requested URL to the document root to make the path to the document. Example:</p> <div class="example"><p><code> DocumentRoot /usr/web </code></p></div> <p>then an access to <code>http://www.my.host.com/index.html</code> refers to <code>/usr/web/index.html</code>. If the <var>directory-path</var> is not absolute then it is assumed to be relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p> <p>The <code class="directive">DocumentRoot</code> should be specified without a trailing slash.</p> <h3>See also</h3> <ul> <li><a href="../urlmapping.html#documentroot">Mapping URLs to Filesystem Locations</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="EnableMMAP" id="EnableMMAP">EnableMMAP</a> <a name="enablemmap" id="enablemmap">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use memory-mapping to read files during delivery</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableMMAP On|Off</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableMMAP On</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive controls whether the <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use memory-mapping if it needs to read the contents of a file during delivery. By default, when the handling of a request requires access to the data within a file -- for example, when delivering a server-parsed file using <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> -- Apache memory-maps the file if the OS supports it.</p> <p>This memory-mapping sometimes yields a performance improvement. But in some environments, it is better to disable the memory-mapping to prevent operational problems:</p> <ul> <li>On some multiprocessor systems, memory-mapping can reduce the performance of the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</li> <li>Deleting or truncating a file while <code class="program"><a href="../programs/httpd.html">httpd</a></code> has it memory-mapped can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to crash with a segmentation fault. </li> </ul> <p>For server configurations that are vulnerable to these problems, you should disable memory-mapping of delivered files by specifying:</p> <div class="example"><p><code> EnableMMAP Off </code></p></div> <p>For NFS mounted files, this feature may be disabled explicitly for the offending files by specifying:</p> <div class="example"><p><code> <Directory "/path-to-nfs-files"> <span class="indent"> EnableMMAP Off </span> </Directory> </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="EnableSendfile" id="EnableSendfile">EnableSendfile</a> <a name="enablesendfile" id="enablesendfile">Directive</a></h2> <table class="directive"> <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> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>EnableSendfile On|Off</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>EnableSendfile On</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0.44 and later</td></tr> </table> <p>This directive controls whether <code class="program"><a href="../programs/httpd.html">httpd</a></code> may use the sendfile support from the kernel to transmit file contents to the client. By default, when the handling of a request requires no access to the data within a file -- for example, when delivering a static file -- Apache uses sendfile to deliver the file contents without ever reading the file if the OS supports it.</p> <p>This sendfile mechanism avoids separate read and send operations, and buffer allocations. But on some platforms or within some filesystems, it is better to disable this feature to avoid operational problems:</p> <ul> <li>Some platforms may have broken sendfile support that the build system did not detect, especially if the binaries were built on another box and moved to such a machine with broken sendfile support.</li> <li>On Linux the use of sendfile triggers TCP-checksum offloading bugs on certain networking cards when using IPv6.</li> <li>On Linux on Itanium, sendfile may be unable to handle files over 2GB in size.</li> <li>With a network-mounted <code class="directive"><a href="#documentroot">DocumentRoot</a></code> (e.g., NFS or SMB), the kernel may be unable to serve the network file through its own cache.</li> </ul> <p>For server configurations that are vulnerable to these problems, you should disable this feature by specifying:</p> <div class="example"><p><code> EnableSendfile Off </code></p></div> <p>For NFS or SMB mounted files, this feature may be disabled explicitly for the offending files by specifying:</p> <div class="example"><p><code> <Directory "/path-to-nfs-files"> <span class="indent"> EnableSendfile Off </span> </Directory> </code></p></div> <p>Please note that the per-directory and .htaccess configuration of <code class="directive">EnableSendfile</code> is not supported by <code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code>. Only global definition of <code class="directive">EnableSendfile</code> is taken into account by the module. </p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ErrorDocument" id="ErrorDocument">ErrorDocument</a> <a name="errordocument" id="errordocument">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>What the server will return to the client in case of an error</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorDocument <var>error-code</var> <var>document</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Quoting syntax for text messages is different in Apache 2.0</td></tr> </table> <p>In the event of a problem or error, Apache can be configured to do one of four things,</p> <ol> <li>output a simple hardcoded error message</li> <li>output a customized message</li> <li>internally redirect to a local <var>URL-path</var> to handle the problem/error</li> <li>redirect to an external <var>URL</var> to handle the problem/error</li> </ol> <p>The first option is the default, while options 2-4 are configured using the <code class="directive">ErrorDocument</code> directive, which is followed by the HTTP response code and a URL or a message. Apache will sometimes offer additional information regarding the problem/error.</p> <p>URLs can begin with a slash (/) for local web-paths (relative to the <code class="directive"><a href="#documentroot">DocumentRoot</a></code>), or be a full URL which the client can resolve. Alternatively, a message can be provided to be displayed by the browser. Examples:</p> <div class="example"><p><code> ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br /> ErrorDocument 404 /cgi-bin/bad_urls.pl<br /> ErrorDocument 401 /subscription_info.html<br /> ErrorDocument 403 "Sorry can't allow you access today" </code></p></div> <p>Additionally, the special value <code>default</code> can be used to specify Apache's simple hardcoded message. While not required under normal circumstances, <code>default</code> will restore Apache's simple hardcoded message for configurations that would otherwise inherit an existing <code class="directive">ErrorDocument</code>.</p> <div class="example"><p><code> ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br /> <Directory /web/docs><br /> <span class="indent"> ErrorDocument 404 default<br /> </span> </Directory> </code></p></div> <p>Note that when you specify an <code class="directive">ErrorDocument</code> that points to a remote URL (ie. anything with a method such as <code>http</code> in front of it), Apache will send a redirect to the client to tell it where to find the document, even if the document ends up being on the same server. This has several implications, the most important being that the client will not receive the original error status code, but instead will receive a redirect status code. This in turn can confuse web robots and other clients which try to determine if a URL is valid using the status code. In addition, if you use a remote URL in an <code>ErrorDocument 401</code>, the client will not know to prompt the user for a password since it will not receive the 401 status code. Therefore, <strong>if you use an <code>ErrorDocument 401</code> directive, then it must refer to a local document.</strong></p> <p>Microsoft Internet Explorer (MSIE) will by default ignore server-generated error messages when they are "too small" and substitute its own "friendly" error messages. The size threshold varies depending on the type of error, but in general, if you make your error document greater than 512 bytes, then MSIE will show the server-generated error rather than masking it. More information is available in Microsoft Knowledge Base article <a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807">Q294807</a>.</p> <p>Although most error messages can be overridden, there are certain circumstances where the internal messages are used regardless of the setting of <code class="directive"><a href="#errordocument">ErrorDocument</a></code>. In particular, if a malformed request is detected, normal request processing will be immediately halted and the internal error message returned. This is necessary to guard against security problems caused by bad requests.</p> <p>If you are using mod_proxy, you may wish to enable <code class="directive"><a href="../mod/mod_proxy.html#proxyerroroverride">ProxyErrorOverride</a></code> so that you can provide custom error messages on behalf of your Origin servers. If you don't enable ProxyErrorOverride, Apache will not generate custom error documents for proxied content.</p> <p>Prior to version 2.0, messages were indicated by prefixing them with a single unmatched double quote character.</p> <h3>See also</h3> <ul> <li><a href="../custom-error.html">documentation of customizable responses</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ErrorLog" id="ErrorLog">ErrorLog</a> <a name="errorlog" id="errorlog">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Location where the server will log errors</td></tr> <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> <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> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">ErrorLog</code> directive sets the name of the file to which the server will log any errors it encounters. If the <var>file-path</var> is not absolute then it is assumed to be relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p> <div class="example"><h3>Example</h3><p><code> ErrorLog /var/log/httpd/error_log </code></p></div> <p>If the <var>file-path</var> begins with a pipe character "<code>|</code>" then it is assumed to be a command to spawn to handle the error log.</p> <div class="example"><h3>Example</h3><p><code> ErrorLog "|/usr/local/bin/httpd_errors" </code></p></div> <p>See the notes on <a href="../logs.html#piped">piped logs</a> for more information.</p> <p>Using <code>syslog</code> instead of a filename enables logging via syslogd(8) if the system supports it. The default is to use syslog facility <code>local7</code>, but you can override this by using the <code>syslog:<var>facility</var></code> syntax where <var>facility</var> can be one of the names usually documented in syslog(1).</p> <div class="example"><h3>Example</h3><p><code> ErrorLog syslog:user </code></p></div> <p>SECURITY: See the <a href="../misc/security_tips.html#serverroot">security tips</a> document for details on why your security could be compromised if the directory where log files are stored is writable by anyone other than the user that starts the server.</p> <div class="warning"><h3>Note</h3> <p>When entering a file path on non-Unix platforms, care should be taken to make sure that only forward slashes are used even though the platform may allow the use of back slashes. In general it is a good idea to always use forward slashes throughout the configuration files.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#loglevel">LogLevel</a></code></li> <li><a href="../logs.html">Apache Log Files</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="FileETag" id="FileETag">FileETag</a> <a name="fileetag" id="fileetag">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>File attributes used to create the ETag HTTP response header for static files</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>FileETag <var>component</var> ...</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>FileETag INode MTime Size</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p> The <code class="directive">FileETag</code> directive configures the file attributes that are used to create the <code>ETag</code> (entity tag) response header field when the document is based on a static file. (The <code>ETag</code> value is used in cache management to save network bandwidth.) In Apache 1.3.22 and earlier, the <code>ETag</code> value was <em>always</em> formed from the file's inode, size, and last-modified time (mtime). The <code class="directive">FileETag</code> directive allows you to choose which of these -- if any -- should be used. The recognized keywords are: </p> <dl> <dt><strong>INode</strong></dt> <dd>The file's i-node number will be included in the calculation</dd> <dt><strong>MTime</strong></dt> <dd>The date and time the file was last modified will be included</dd> <dt><strong>Size</strong></dt> <dd>The number of bytes in the file will be included</dd> <dt><strong>All</strong></dt> <dd>All available fields will be used. This is equivalent to: <div class="example"><p><code>FileETag INode MTime Size</code></p></div></dd> <dt><strong>None</strong></dt> <dd>If a document is file-based, no <code>ETag</code> field will be included in the response</dd> </dl> <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code> keywords may be prefixed with either <code>+</code> or <code>-</code>, which allow changes to be made to the default setting inherited from a broader scope. Any keyword appearing without such a prefix immediately and completely cancels the inherited setting.</p> <p>If a directory's configuration includes <code>FileETag INode MTime Size</code>, and a subdirectory's includes <code>FileETag -INode</code>, the setting for that subdirectory (which will be inherited by any sub-subdirectories that don't override it) will be equivalent to <code>FileETag MTime Size</code>.</p> <div class="warning"><h3>Warning</h3> Do not change the default for directories or locations that have WebDAV enabled and use <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> as a storage provider. <code class="module"><a href="../mod/mod_dav_fs.html">mod_dav_fs</a></code> uses <code>INode MTime Size</code> as a fixed format for <code>ETag</code> comparisons on conditional requests. These conditional requests will break if the <code>ETag</code> format is changed via <code class="directive">FileETag</code>. </div> <div class="note"><h3>Server Side Includes</h3> An ETag is not generated for responses parsed by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> since the response entity can change without a change of the INode, MTime, or Size of the static file with embedded SSI directives. </div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Files" id="Files"><Files></a> <a name="files" id="files">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to matched filenames</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Files <var>filename</var>> ... </Files></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive"><Files></code> directive limits the scope of the enclosed directives by filename. It is comparable to the <code class="directive"><a href="#directory"><Directory></a></code> and <code class="directive"><a href="#location"><Location></a></code> directives. It should be matched with a <code></Files></code> directive. The directives given within this section will be applied to any object with a basename (last component of filename) matching the specified filename. <code class="directive"><Files></code> sections are processed in the order they appear in the configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and <code>.htaccess</code> files are read, but before <code class="directive"><a href="#location"><Location></a></code> sections. Note that <code class="directive"><Files></code> can be nested inside <code class="directive"><a href="#directory"><Directory></a></code> sections to restrict the portion of the filesystem they apply to.</p> <p>The <var>filename</var> argument should include a filename, or a wild-card string, where <code>?</code> matches any single character, and <code>*</code> matches any sequences of characters:</p> <div class="example"><pre><Files "cat.html"> # Insert stuff that applies to cat.html here </Files> <Files "?at.*"> # This would apply to cat.html, bat.html, hat.php and so on. </Files></pre></div> <p> <a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a> can also be used, with the addition of the <code>~</code> character. For example:</p> <div class="example"><p><code> <Files ~ "\.(gif|jpe?g|png)$"> </code></p></div> <p>would match most common Internet graphics formats. <code class="directive"><a href="#filesmatch"><FilesMatch></a></code> is preferred, however.</p> <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 <code>.htaccess</code> files. This allows users to control access to their own files, at a file-by-file level.</p> <h3>See also</h3> <ul> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="FilesMatch" id="FilesMatch"><FilesMatch></a> <a name="filesmatch" id="filesmatch">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to regular-expression matched filenames</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><FilesMatch <var>regex</var>> ... </FilesMatch></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive"><FilesMatch></code> directive limits the scope of the enclosed directives by filename, just as the <code class="directive"><a href="#files"><Files></a></code> directive does. However, it accepts a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>. For example:</p> <div class="example"><p><code> <FilesMatch "\.(gif|jpe?g|png)$"> </code></p></div> <p>would match most common Internet graphics formats.</p> <h3>See also</h3> <ul> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ForceType" id="ForceType">ForceType</a> <a name="forcetype" id="forcetype">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be served with the specified MIME content-type</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ForceType <var>MIME-type</var>|None</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved to the core in Apache 2.0</td></tr> </table> <p>When placed into an <code>.htaccess</code> file or a <code class="directive"><a href="#directory"><Directory></a></code>, or <code class="directive"><a href="#location"><Location></a></code> or <code class="directive"><a href="#files"><Files></a></code> section, this directive forces all matching files to be served with the content type identification given by <var>MIME-type</var>. For example, if you had a directory full of GIF files, but did not want to label them all with <code>.gif</code>, you might want to use:</p> <div class="example"><p><code> ForceType image/gif </code></p></div> <p>Note that unlike <code class="directive"><a href="#defaulttype">DefaultType</a></code>, this directive overrides all mime-type associations, including filename extensions, that might identify the media type.</p> <p>You can override any <code class="directive">ForceType</code> setting by using the value of <code>None</code>:</p> <div class="example"><p><code> # force all files to be image/gif:<br /> <Location /images><br /> <span class="indent"> ForceType image/gif<br /> </span> </Location><br /> <br /> # but normal mime-type associations here:<br /> <Location /images/mixed><br /> <span class="indent"> ForceType None<br /> </span> </Location> </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="GprofDir" id="GprofDir">GprofDir</a> <a name="gprofdir" id="gprofdir">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Directory to write gmon.out profiling data to. </td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>GprofDir <var>/tmp/gprof/</var>|<var>/tmp/gprof/</var>%</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>When the server has been compiled with gprof profiling support, <code class="directive">GprofDir</code> causes <code>gmon.out</code> files to be written to the specified directory when the process exits. If the argument ends with a percent symbol ('%'), subdirectories are created for each process id.</p> <p>This directive currently only works with the <code class="module"><a href="../mod/prefork.html">prefork</a></code> MPM.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="HostnameLookups" id="HostnameLookups">HostnameLookups</a> <a name="hostnamelookups" id="hostnamelookups">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables DNS lookups on client IP addresses</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HostnameLookups On|Off|Double</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>HostnameLookups Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive enables DNS lookups so that host names can be logged (and passed to CGIs/SSIs in <code>REMOTE_HOST</code>). The value <code>Double</code> refers to doing double-reverse DNS lookup. That is, after a reverse lookup is performed, a forward lookup is then performed on that result. At least one of the IP addresses in the forward lookup must match the original address. (In "tcpwrappers" terminology this is called <code>PARANOID</code>.)</p> <p>Regardless of the setting, when <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code> is used for controlling access by hostname, a double reverse lookup will be performed. This is necessary for security. Note that the result of this double-reverse isn't generally available unless you set <code>HostnameLookups Double</code>. For example, if only <code>HostnameLookups On</code> and a request is made to an object that is protected by hostname restrictions, regardless of whether the double-reverse fails or not, CGIs will still be passed the single-reverse result in <code>REMOTE_HOST</code>.</p> <p>The default is <code>Off</code> in order to save the network traffic for those sites that don't truly need the reverse lookups done. It is also better for the end users because they don't have to suffer the extra latency that a lookup entails. Heavily loaded sites should leave this directive <code>Off</code>, since DNS lookups can take considerable amounts of time. The utility <code class="program"><a href="../programs/logresolve.html">logresolve</a></code>, compiled by default to the <code>bin</code> subdirectory of your installation directory, can be used to look up host names from logged IP addresses offline.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="HttpProtocolOptions" id="HttpProtocolOptions">HttpProtocolOptions</a> <a name="httpprotocoloptions" id="httpprotocoloptions">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Modify restrictions on HTTP Request Messages</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HttpProtocolOptions [Strict|Unsafe] [RegisteredMethods|LenientMethods] [Allow0.9|Require1.0]</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>HttpProtocolOptions Strict LenientMethods Allow0.9</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.2.32 or 2.4.24 and later</td></tr> </table> <p>This directive changes the rules applied to the HTTP Request Line (<a href="https://tools.ietf.org/html/rfc7230#section-3.1.1">RFC 7230 §3.1.1</a>) and the HTTP Request Header Fields (<a href="https://tools.ietf.org/html/rfc7230#section-3.2">RFC 7230 §3.2</a>), which are now applied by default or using the <code>Strict</code> option. Due to legacy modules, applications or custom user-agents which must be deperecated the <code>Unsafe</code> option has been added to revert to the legacy behaviors. These rules are applied prior to request processing, so must be configured at the global or default (first) matching virtual host section, by IP/port interface (and not by name) to be honored.</p> <p>Prior to the introduction of this directive, the Apache HTTP Server request message parsers were tolerant of a number of forms of input which did not conform to the protocol. <a href="https://tools.ietf.org/html/rfc7230#section-9.4">RFC 7230 §9.4 Request Splitting</a> and <a href="https://tools.ietf.org/html/rfc7230#section-9.5">§9.5 Response Smuggling</a> call out only two of the potential risks of accepting non-conformant request messages, while <a href="https://tools.ietf.org/html/rfc7230#section-3.5">RFC 7230 §3.5</a> "Message Parsing Robustness" identify the risks of accepting obscure whitespace and request message formatting. As of the introduction of this directive, all grammer rules of the specification are enforced in the default <code>Strict</code> operating mode, and the strict whitespace suggested by section 3.5 is enforced and cannot be relaxed.</p> <p>Users are strongly cautioned against toggling the <code>Unsafe</code> mode of operation, particularly on outward-facing, publicly accessible server deployments. If an interface is required for faulty monitoring or other custom service consumers running on an intranet, users should toggle the Unsafe option only on a specific virtual host configured to service their internal private network.</p> <p>Reviewing the messages logged to the <code class="directive">ErrorLog</code>, configured with <code class="directive">LogLevel</code> <code>debug</code> level, can help identify such faulty requests along with their origin. Users should pay particular attention to the 400 responses in the access log for invalid requests which were unexpectedly rejected.</p> <p><a href="https://tools.ietf.org/html/rfc7231#section-4.1">RFC 7231 §4.1</a> "Request Methods" "Overview" requires that origin servers shall respond with an error when an unsupported method is encountered in the request line. This already happens when the <code>LenientMethods</code> option is used, but administrators may wish to toggle the <code>RegisteredMethods</code> option and register any non-standard methods using the <code class="directive">RegisterHttpMethod</code> directive, particularly if the <code>Unsafe</code> option has been toggled. The <code>RegisteredMethods</code> option should <strong>not</strong> be toggled for forward proxy hosts, as the methods supported by the origin servers are unknown to the proxy server.</p> <p><a href="https://tools.ietf.org/html/rfc2616#section-19.6">RFC 2616 §19.6</a> "Compatibility With Previous Versions" had encouraged HTTP servers to support legacy HTTP/0.9 requests. RFC 7230 superceeds this with "The expectation to support HTTP/0.9 requests has been removed" and offers additional comments in <a href="https://tools.ietf.org/html/rfc7230#appendix-A">RFC 7230 Appendix A</a>. The <code>Require1.0</code> option allows the user to remove support of the default <code>Allow0.9</code> option's behavior.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="IfDefine" id="IfDefine"><IfDefine></a> <a name="ifdefine" id="ifdefine">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that will be processed only if a test is true at startup</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfDefine [!]<var>parameter-name</var>> ... </IfDefine></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code><IfDefine <var>test</var>>...</IfDefine> </code> section is used to mark directives that are conditional. The directives within an <code class="directive"><IfDefine></code> section are only processed if the <var>test</var> is true. If <var> test</var> is false, everything between the start and end markers is ignored.</p> <p>The <var>test</var> in the <code class="directive"><IfDefine></code> section directive can be one of two forms:</p> <ul> <li><var>parameter-name</var></li> <li><code>!</code><var>parameter-name</var></li> </ul> <p>In the former case, the directives between the start and end markers are only processed if the parameter named <var>parameter-name</var> is defined. The second format reverses the test, and only processes the directives if <var>parameter-name</var> is <strong>not</strong> defined.</p> <p>The <var>parameter-name</var> argument is a define as given on the <code class="program"><a href="../programs/httpd.html">httpd</a></code> command line via <code>-D<var>parameter-</var> </code>, at the time the server was started.</p> <p><code class="directive"><IfDefine></code> sections are nest-able, which can be used to implement simple multiple-parameter tests. Example:</p> <div class="example"><p><code> httpd -DReverseProxy -DUseCache -DMemCache ...<br /> <br /> # httpd.conf<br /> <IfDefine ReverseProxy><br /> <span class="indent"> LoadModule proxy_module modules/mod_proxy.so<br /> LoadModule proxy_http_module modules/mod_proxy_http.so<br /> <IfDefine UseCache><br /> <span class="indent"> LoadModule cache_module modules/mod_cache.so<br /> <IfDefine MemCache><br /> <span class="indent"> LoadModule mem_cache_module modules/mod_mem_cache.so<br /> </span> </IfDefine><br /> <IfDefine !MemCache><br /> <span class="indent"> LoadModule disk_cache_module modules/mod_disk_cache.so<br /> </span> </IfDefine> </span> </IfDefine> </span> </IfDefine> </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="IfModule" id="IfModule"><IfModule></a> <a name="ifmodule" id="ifmodule">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Encloses directives that are processed conditional on the presence or absence of a specific module</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><IfModule [!]<var>module-file</var>|<var>module-identifier</var>> ... </IfModule></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Module identifiers are available in version 2.1 and later.</td></tr> </table> <p>The <code><IfModule <var>test</var>>...</IfModule></code> section is used to mark directives that are conditional on the presence of a specific module. The directives within an <code class="directive"><IfModule></code> section are only processed if the <var>test</var> is true. If <var>test</var> is false, everything between the start and end markers is ignored.</p> <p>The <var>test</var> in the <code class="directive"><IfModule></code> section directive can be one of two forms:</p> <ul> <li><var>module</var></li> <li>!<var>module</var></li> </ul> <p>In the former case, the directives between the start and end markers are only processed if the module named <var>module</var> is included in Apache -- either compiled in or dynamically loaded using <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>. The second format reverses the test, and only processes the directives if <var>module</var> is <strong>not</strong> included.</p> <p>The <var>module</var> argument can be either the module identifier or the file name of the module, at the time it was compiled. For example, <code>rewrite_module</code> is the identifier and <code>mod_rewrite.c</code> is the file name. If a module consists of several source files, use the name of the file containing the string <code>STANDARD20_MODULE_STUFF</code>.</p> <p><code class="directive"><IfModule></code> sections are nest-able, which can be used to implement simple multiple-module tests.</p> <div class="note">This section should only be used if you need to have one configuration file that works whether or not a specific module is available. In normal operation, directives need not be placed in <code class="directive"><IfModule></code> sections.</div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Include" id="Include">Include</a> <a name="include" id="include">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Includes other configuration files from within the server configuration files</td></tr> <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> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Wildcard matching available in 2.0.41 and later</td></tr> </table> <p>This directive allows inclusion of other configuration files from within the server configuration files.</p> <p>Shell-style (<code>fnmatch()</code>) wildcard characters can be used to include several files at once, in alphabetical order. In addition, if <code class="directive">Include</code> points to a directory, rather than a file, Apache will read all files in that directory and any subdirectory. But including entire directories is not recommended, because it is easy to accidentally leave temporary files in a directory that can cause <code class="program"><a href="../programs/httpd.html">httpd</a></code> to fail.</p> <p>The file path specified may be an absolute path, or may be relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory.</p> <p>Examples:</p> <div class="example"><p><code> Include /usr/local/apache2/conf/ssl.conf<br /> Include /usr/local/apache2/conf/vhosts/*.conf </code></p></div> <p>Or, providing paths relative to your <code class="directive"><a href="#serverroot">ServerRoot</a></code> directory:</p> <div class="example"><p><code> Include conf/ssl.conf<br /> Include conf/vhosts/*.conf </code></p></div> <h3>See also</h3> <ul> <li><code class="program"><a href="../programs/apachectl.html">apachectl</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="KeepAlive" id="KeepAlive">KeepAlive</a> <a name="keepalive" id="keepalive">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables HTTP persistent connections</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAlive On|Off</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAlive On</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The Keep-Alive extension to HTTP/1.0 and the persistent connection feature of HTTP/1.1 provide long-lived HTTP sessions which allow multiple requests to be sent over the same TCP connection. In some cases this has been shown to result in an almost 50% speedup in latency times for HTML documents with many images. To enable Keep-Alive connections, set <code>KeepAlive On</code>.</p> <p>For HTTP/1.0 clients, Keep-Alive connections will only be used if they are specifically requested by a client. In addition, a Keep-Alive connection with an HTTP/1.0 client can only be used when the length of the content is known in advance. This implies that dynamic content such as CGI output, SSI pages, and server-generated directory listings will generally not use Keep-Alive connections to HTTP/1.0 clients. For HTTP/1.1 clients, persistent connections are the default unless otherwise specified. If the client requests it, chunked encoding will be used in order to send content of unknown length over persistent connections.</p> <p>When a client uses a Keep-Alive connection, it will be counted as a single "request" for the MaxRequestsPerChild directive, regardless of how many requests are sent using the connection.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="#maxkeepaliverequests">MaxKeepAliveRequests</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="KeepAliveTimeout" id="KeepAliveTimeout">KeepAliveTimeout</a> <a name="keepalivetimeout" id="keepalivetimeout">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for subsequent requests on a persistent connection</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>KeepAliveTimeout <var>seconds</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>KeepAliveTimeout 5</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The number of seconds Apache will wait for a subsequent request before closing the connection. Once a request has been received, the timeout value specified by the <code class="directive"><a href="#timeout">Timeout</a></code> directive applies.</p> <p>Setting <code class="directive">KeepAliveTimeout</code> to a high value may cause performance problems in heavily loaded servers. The higher the timeout, the more server processes will be kept occupied waiting on connections with idle clients.</p> <p>In a name-based virtual host context, the value of the first defined virtual host (the default host) in a set of <code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code> will be used. The other values will be ignored.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Limit" id="Limit"><Limit></a> <a name="limit" id="limit">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict enclosed access controls to only certain HTTP methods</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Limit <var>method</var> [<var>method</var>] ... > ... </Limit></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>Access controls are normally effective for <strong>all</strong> access methods, and this is the usual desired behavior. <strong>In the general case, access control directives should not be placed within a <code class="directive"><Limit></code> section.</strong></p> <p>The purpose of the <code class="directive"><Limit></code> directive is to restrict the effect of the access controls to the nominated HTTP methods. For all other methods, the access restrictions that are enclosed in the <code class="directive"><Limit></code> bracket <strong>will have no effect</strong>. The following example applies the access control only to the methods <code>POST</code>, <code>PUT</code>, and <code>DELETE</code>, leaving all other methods unprotected:</p> <div class="example"><p><code> <Limit POST PUT DELETE><br /> <span class="indent"> Require valid-user<br /> </span> </Limit> </code></p></div> <p>The method names listed can be one or more of: <code>GET</code>, <code>POST</code>, <code>PUT</code>, <code>DELETE</code>, <code>CONNECT</code>, <code>OPTIONS</code>, <code>PATCH</code>, <code>PROPFIND</code>, <code>PROPPATCH</code>, <code>MKCOL</code>, <code>COPY</code>, <code>MOVE</code>, <code>LOCK</code>, and <code>UNLOCK</code>. <strong>The method name is case-sensitive.</strong> If <code>GET</code> is used, it will also restrict <code>HEAD</code> requests. The <code>TRACE</code> method cannot be limited.</p> <div class="warning">A <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section should always be used in preference to a <code class="directive"><a href="#limit"><Limit></a></code> section when restricting access, since a <code class="directive"><a href="#limitexcept"><LimitExcept></a></code> section provides protection against arbitrary methods.</div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitExcept" id="LimitExcept"><LimitExcept></a> <a name="limitexcept" id="limitexcept">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restrict access controls to all HTTP methods except the named ones</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LimitExcept <var>method</var> [<var>method</var>] ... > ... </LimitExcept></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p><code class="directive"><LimitExcept></code> and <code></LimitExcept></code> are used to enclose a group of access control directives which will then apply to any HTTP access method <strong>not</strong> listed in the arguments; i.e., it is the opposite of a <code class="directive"><a href="#limit"><Limit></a></code> section and can be used to control both standard and nonstandard/unrecognized methods. See the documentation for <code class="directive"><a href="#limit"><Limit></a></code> for more details.</p> <p>For example:</p> <div class="example"><p><code> <LimitExcept POST GET><br /> <span class="indent"> Require valid-user<br /> </span> </LimitExcept> </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitInternalRecursion" id="LimitInternalRecursion">LimitInternalRecursion</a> <a name="limitinternalrecursion" id="limitinternalrecursion">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine maximum number of internal redirects and nested subrequests</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitInternalRecursion <var>number</var> [<var>number</var>]</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitInternalRecursion 10</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.47 and later</td></tr> </table> <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 redirects the original request to a CGI script. A subrequest is Apache's mechanism to find out what would happen for some URI if it were requested. For example, <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> uses subrequests to look for the files listed in the <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code> directive.</p> <p><code class="directive">LimitInternalRecursion</code> prevents the server from crashing when entering an infinite loop of internal redirects or subrequests. Such loops are usually caused by misconfigurations.</p> <p>The directive stores two different limits, which are evaluated on per-request basis. The first <var>number</var> is the maximum number of internal redirects that may follow each other. The second <var>number</var> determines how deeply subrequests may be nested. If you specify only one <var>number</var>, it will be assigned to both limits.</p> <div class="example"><h3>Example</h3><p><code> LimitInternalRecursion 5 </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitRequestBody" id="LimitRequestBody">LimitRequestBody</a> <a name="limitrequestbody" id="limitrequestbody">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Restricts the total size of the HTTP request body sent from the client</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestBody <var>bytes</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestBody 0</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive specifies the number of <var>bytes</var> from 0 (meaning unlimited) to 2147483647 (2GB) that are allowed in a request body.</p> <p>The <code class="directive">LimitRequestBody</code> directive allows the user to set a limit on the allowed size of an HTTP request message body within the context in which the directive is given (server, per-directory, per-file or per-location). If the client request exceeds that limit, the server will return an error response instead of servicing the request. The size of a normal request message body will vary greatly depending on the nature of the resource and the methods allowed on that resource. CGI scripts typically use the message body for retrieving form information. Implementations of the <code>PUT</code> method will require a value at least as large as any representation that the server wishes to accept for that resource.</p> <p>This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.</p> <p>If, for example, you are permitting file upload to a particular location and wish to limit the size of the uploaded file to 100K, you might use the following directive:</p> <div class="example"><p><code> LimitRequestBody 102400 </code></p></div> <div class="note">Note: not applicable to proxy requests.</div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitRequestFields" id="LimitRequestFields">LimitRequestFields</a> <a name="limitrequestfields" id="limitrequestfields">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of HTTP request header fields that will be accepted from the client</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFields <var>number</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFields 100</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p><var>Number</var> is an integer from 0 (meaning unlimited) to 32767. The default value is defined by the compile-time constant <code>DEFAULT_LIMIT_REQUEST_FIELDS</code> (100 as distributed).</p> <p>The <code class="directive">LimitRequestFields</code> directive allows the server administrator to modify the limit on the number of request header fields allowed in an HTTP request. A server needs this value to be larger than the number of fields that a normal client request might include. The number of request header fields used by a client rarely exceeds 20, but this may vary among different client implementations, often depending upon the extent to which a user has configured their browser to support detailed content negotiation. Optional HTTP extensions are often expressed using request header fields.</p> <p>This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks. The value should be increased if normal clients see an error response from the server that indicates too many fields were sent in the request.</p> <p>For example:</p> <div class="example"><p><code> LimitRequestFields 50 </code></p></div> <div class="warning"><h3>Warning</h3> <p> When name-based virtual hosting is used, the value for this directive is taken from the default (first-listed) virtual host for the <code class="directive">NameVirtualHost</code> the connection was mapped to.</p> </div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitRequestFieldSize" id="LimitRequestFieldSize">LimitRequestFieldSize</a> <a name="limitrequestfieldsize" id="limitrequestfieldsize">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of the HTTP request header allowed from the client</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestFieldSize <var>bytes</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestFieldSize 8190</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive specifies the number of <var>bytes</var> that will be allowed in an HTTP request header.</p> <p>The <code class="directive">LimitRequestFieldSize</code> directive allows the server administrator to set the limit on the allowed size of an HTTP request header field. A server needs this value to be large enough to hold any one header field from a normal client request. The size of a normal request header field will vary greatly among different client implementations, often depending upon the extent to which a user has configured their browser to support detailed content negotiation. SPNEGO authentication headers can be up to 12392 bytes.</p> <p>This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.</p> <p>For example:</p> <div class="example"><p><code> LimitRequestFieldSize 4094 </code></p></div> <div class="note">Under normal conditions, the value should not be changed from the default.</div> <div class="warning"><h3>Warning</h3> <p> When name-based virtual hosting is used, the value for this directive is taken from the default (first-listed) virtual host for the <code class="directive">NameVirtualHost</code> the connection was mapped to.</p> </div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitRequestLine" id="LimitRequestLine">LimitRequestLine</a> <a name="limitrequestline" id="limitrequestline">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limit the size of the HTTP request line that will be accepted from the client</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitRequestLine <var>bytes</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitRequestLine 8190</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive sets the number of <var>bytes</var> that will be allowed on the HTTP request-line.</p> <p>The <code class="directive">LimitRequestLine</code> directive allows the server administrator to set the limit on the allowed size of a client's HTTP request-line. Since the request-line consists of the HTTP method, URI, and protocol version, the <code class="directive">LimitRequestLine</code> directive places a restriction on the length of a request-URI allowed for a request on the server. A server needs this value to be large enough to hold any of its resource names, including any information that might be passed in the query part of a <code>GET</code> request.</p> <p>This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.</p> <p>For example:</p> <div class="example"><p><code> LimitRequestLine 4094 </code></p></div> <div class="note">Under normal conditions, the value should not be changed from the default.</div> <div class="warning"><h3>Warning</h3> <p> When name-based virtual hosting is used, the value for this directive is taken from the default (first-listed) virtual host for the <code class="directive">NameVirtualHost</code> the connection was mapped to.</p> </div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LimitXMLRequestBody" id="LimitXMLRequestBody">LimitXMLRequestBody</a> <a name="limitxmlrequestbody" id="limitxmlrequestbody">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the size of an XML-based request body</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LimitXMLRequestBody <var>bytes</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LimitXMLRequestBody 1000000</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>Limit (in bytes) on maximum size of an XML-based request body. A value of <code>0</code> will disable any checking.</p> <p>Example:</p> <div class="example"><p><code> LimitXMLRequestBody 0 </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Location" id="Location"><Location></a> <a name="location" id="location">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to matching URLs</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Location <var>URL-path</var>|<var>URL</var>> ... </Location></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive"><Location></code> directive limits the scope of the enclosed directives by URL. It is similar to the <code class="directive"><a href="#directory"><Directory></a></code> directive, and starts a subsection which is terminated with a <code></Location></code> directive. <code class="directive"><Location></code> sections are processed in the order they appear in the configuration file, after the <code class="directive"><a href="#directory"><Directory></a></code> sections and <code>.htaccess</code> files are read, and after the <code class="directive"><a href="#files"><Files></a></code> sections.</p> <p><code class="directive"><Location></code> sections operate completely outside the filesystem. This has several consequences. Most importantly, <code class="directive"><Location></code> directives should not be used to control access to filesystem locations. Since several different URLs may map to the same filesystem location, such access controls may by circumvented.</p> <p>The enclosed directives will be applied to the request if the path component of the URL meets <em>any</em> of the following criteria:</p> <ul> <li>The specified location matches exactly the path component of the URL. </li> <li>The specified location, which ends in a forward slash, is a prefix of the path component of the URL (treated as a context root). </li> <li>The specified location, with the addition of a trailing slash, is a prefix of the path component of the URL (also treated as a context root). </li> </ul> <p>In the example below, where no trailing slash is used, requests to /private1, /private1/ and /private1/file.txt will have the enclosed directives applied, but /private1other would not.</p> <div class="example"><p><code> <Location /private1> ... </code></p></div> <p>In the example below, where a trailing slash is used, requests to /private2/ and /private2/file.txt will have the enclosed directives applied, but /private2 and /private2other would not.</p> <div class="example"><p><code> <Location /private2<em>/</em>> ... </code></p></div> <div class="note"><h3>When to use <code class="directive"><Location></code></h3> <p>Use <code class="directive"><Location></code> to apply directives to content that lives outside the filesystem. For 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 <code><Location /></code>, which is an easy way to apply a configuration to the entire server.</p> </div> <p>For all origin (non-proxy) requests, the URL to be matched is a URL-path of the form <code>/path/</code>. <em>No scheme, hostname, port, or query string may be included.</em> For proxy requests, the URL to be matched is of the form <code>scheme://servername/path</code>, and you must include the prefix.</p> <p>The URL may use wildcards. In a wild-card string, <code>?</code> matches any single character, and <code>*</code> matches any sequences of characters. Neither wildcard character matches a / in the URL-path.</p> <p><a class="glossarylink" href="../glossary.html#regex" title="see glossary">Regular expressions</a> can also be used, with the addition of the <code>~</code> character. For example:</p> <div class="example"><p><code> <Location ~ "/(extra|special)/data"> </code></p></div> <p>would match URLs that contained the substring <code>/extra/data</code> or <code>/special/data</code>. The directive <code class="directive"><a href="#locationmatch"><LocationMatch></a></code> behaves identical to the regex version of <code class="directive"><Location></code>.</p> <p>The <code class="directive"><Location></code> functionality is especially useful when combined with the <code class="directive"><a href="#sethandler">SetHandler</a></code> directive. For example, to enable status requests but allow them only from browsers at <code>example.com</code>, you might use:</p> <div class="example"><p><code> <Location /status><br /> <span class="indent"> SetHandler server-status<br /> Order Deny,Allow<br /> Deny from all<br /> Allow from .example.com<br /> </span> </Location> </code></p></div> <div class="note"><h3>Note about / (slash)</h3> <p>The slash character has special meaning depending on where in a URL it appears. People may be used to its behavior in the filesystem where multiple adjacent slashes are frequently collapsed to a single slash (<em>i.e.</em>, <code>/home///foo</code> is the same as <code>/home/foo</code>). In URL-space this is not necessarily true. The <code class="directive"><a href="#locationmatch"><LocationMatch></a></code> directive and the regex version of <code class="directive"><Location></code> require you to explicitly specify multiple slashes if that is your intention.</p> <p>For example, <code><LocationMatch ^/abc></code> would match the request URL <code>/abc</code> but not the request URL <code> //abc</code>. The (non-regex) <code class="directive"><Location></code> directive behaves similarly when used for proxy requests. But when (non-regex) <code class="directive"><Location></code> is used for non-proxy requests it will implicitly match multiple slashes with a single slash. For example, if you specify <code><Location /abc/def></code> and the request is to <code>/abc//def</code> then it will match.</p> </div> <h3>See also</h3> <ul> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LocationMatch" id="LocationMatch"><LocationMatch></a> <a name="locationmatch" id="locationmatch">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Applies the enclosed directives only to regular-expression matching URLs</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><LocationMatch <var>regex</var>> ... </LocationMatch></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive"><LocationMatch></code> directive limits the scope of the enclosed directives by URL, in an identical manner to <code class="directive"><a href="#location"><Location></a></code>. However, it takes a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a> as an argument instead of a simple string. For example:</p> <div class="example"><p><code> <LocationMatch "/(extra|special)/data"> </code></p></div> <p>would match URLs that contained the substring <code>/extra/data</code> or <code>/special/data</code>.</p> <h3>See also</h3> <ul> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="LogLevel" id="LogLevel">LogLevel</a> <a name="loglevel" id="loglevel">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Controls the verbosity of the ErrorLog</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LogLevel <var>level</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LogLevel warn</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p><code class="directive">LogLevel</code> adjusts the verbosity of the messages recorded in the error logs (see <code class="directive"><a href="#errorlog">ErrorLog</a></code> directive). The following <var>level</var>s are available, in order of decreasing significance:</p> <table class="bordered"> <tr> <th><strong>Level</strong> </th> <th><strong>Description</strong> </th> <th><strong>Example</strong> </th> </tr> <tr> <td><code>emerg</code> </td> <td>Emergencies - system is unusable.</td> <td>"Child cannot open lock file. Exiting"</td> </tr> <tr> <td><code>alert</code> </td> <td>Action must be taken immediately.</td> <td>"getpwuid: couldn't determine user name from uid"</td> </tr> <tr> <td><code>crit</code> </td> <td>Critical Conditions.</td> <td>"socket: Failed to get a socket, exiting child"</td> </tr> <tr> <td><code>error</code> </td> <td>Error conditions.</td> <td>"Premature end of script headers"</td> </tr> <tr> <td><code>warn</code> </td> <td>Warning conditions.</td> <td>"child process 1234 did not exit, sending another SIGHUP"</td> </tr> <tr> <td><code>notice</code> </td> <td>Normal but significant condition.</td> <td>"httpd: caught SIGBUS, attempting to dump core in ..."</td> </tr> <tr> <td><code>info</code> </td> <td>Informational.</td> <td>"Server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers)..."</td> </tr> <tr> <td><code>debug</code> </td> <td>Debug-level messages</td> <td>"Opening config file ..."</td> </tr> </table> <p>When a particular level is specified, messages from all other levels of higher significance will be reported as well. <em>E.g.</em>, when <code>LogLevel info</code> is specified, then messages with log levels of <code>notice</code> and <code>warn</code> will also be posted.</p> <p>Using a level of at least <code>crit</code> is recommended.</p> <p>For example:</p> <div class="example"><p><code> LogLevel notice </code></p></div> <div class="note"><h3>Note</h3> <p>When logging to a regular file, messages of the level <code>notice</code> cannot be suppressed and thus are always logged. However, this doesn't apply when logging is done using <code>syslog</code>.</p> </div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="MaxKeepAliveRequests" id="MaxKeepAliveRequests">MaxKeepAliveRequests</a> <a name="maxkeepaliverequests" id="maxkeepaliverequests">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of requests allowed on a persistent connection</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxKeepAliveRequests <var>number</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxKeepAliveRequests 100</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">MaxKeepAliveRequests</code> directive limits the number of requests allowed per connection when <code class="directive"><a href="#keepalive">KeepAlive</a></code> is on. If it is set to <code>0</code>, unlimited requests will be allowed. We recommend that this setting be kept to a high value for maximum server performance.</p> <p>For example:</p> <div class="example"><p><code> MaxKeepAliveRequests 500 </code></p></div> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="MaxRanges" id="MaxRanges">MaxRanges</a> <a name="maxranges" id="maxranges">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Number of ranges allowed before returning the complete resource </td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxRanges default | unlimited | none | <var>number-of-ranges</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxRanges 200</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache HTTP Server 2.2.21 and later</td></tr> </table> <p>The <code class="directive">MaxRanges</code> directive limits the number of HTTP ranges the server is willing to return to the client. If more ranges than permitted are requested, the complete resource is returned instead.</p> <dl> <dt><strong>default</strong></dt> <dd>Limits the number of ranges to a compile-time default of 200.</dd> <dt><strong>none</strong></dt> <dd>Range headers are ignored.</dd> <dt><strong>unlimited</strong></dt> <dd>The server does not limit the number of ranges it is willing to satisfy.</dd> <dt><var>number-of-ranges</var></dt> <dd>A positive number representing the maximum number of ranges the server is willing to satisfy.</dd> </dl> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="MergeTrailers" id="MergeTrailers">MergeTrailers</a> <a name="mergetrailers" id="mergetrailers">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines whether trailers are merged into headers</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MergeTrailers [on|off]</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MergeTrailers off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.2.28 and later</td></tr> </table> <p>This directive controls whether HTTP trailers are copied into the internal representation of HTTP headers. This merging occurs when the request body has been completely consumed, long after most header processing would have a chance to examine or modify request headers.</p> <p>This option is provided for compatibility with releases prior to 2.2.28, where trailers were always merged.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="NameVirtualHost" id="NameVirtualHost">NameVirtualHost</a> <a name="namevirtualhost" id="namevirtualhost">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Designates an IP address for name-virtual hosting</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NameVirtualHost <var>addr</var>[:<var>port</var>]</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">NameVirtualHost</code> directive is a required directive if you want to configure <a href="../vhosts/">name-based virtual hosts</a>.</p> <p>Although <var>addr</var> can be hostname it is recommended that you always use an IP address and a port, e.g.</p> <div class="example"><p><code> NameVirtualHost 111.22.33.44:80 </code></p></div> <p>With the <code class="directive">NameVirtualHost</code> directive you specify the IP address on which the server will receive requests for the name-based virtual hosts. This will usually be the address to which your name-based virtual host names resolve. In cases where a firewall or other proxy receives the requests and forwards them on a different IP address to the server, you must specify the IP address of the physical interface on the machine which will be servicing the requests. If you have multiple name-based hosts on multiple addresses, repeat the directive for each address.</p> <div class="note"><h3>Note</h3> <p>Note, that the "main server" and any <code>_default_</code> servers will <strong>never</strong> be served for a request to a <code class="directive">NameVirtualHost</code> IP address (unless for some reason you specify <code class="directive">NameVirtualHost</code> but then don't define any <code class="directive">VirtualHost</code>s for that address).</p> </div> <p>Optionally you can specify a port number on which the name-based virtual hosts should be used, e.g.</p> <div class="example"><p><code> NameVirtualHost 111.22.33.44:8080 </code></p></div> <p>IPv6 addresses must be enclosed in square brackets, as shown in the following example:</p> <div class="example"><p><code> NameVirtualHost [2001:db8::a00:20ff:fea7:ccea]:8080 </code></p></div> <p>To receive requests on all interfaces, you can use an argument of <code>*:80</code>, or, if you are listening on multiple ports and really want the server to respond on all of them with a particular set of virtual hosts, <code>*</code></p> <div class="example"><p><code> NameVirtualHost *:80 </code></p></div> <div class="note"><h3>Argument to <code class="directive"><VirtualHost></code> directive</h3> <p>Note that the argument to the <code class="directive"><VirtualHost></code> directive must exactly match the argument to the <code class="directive">NameVirtualHost</code> directive.</p> <div class="example"><p><code> NameVirtualHost 1.2.3.4:80<br /> <VirtualHost 1.2.3.4:80><br /> # ...<br /> </VirtualHost><br /> </code></p></div> </div> <h3>See also</h3> <ul> <li><a href="../vhosts/">Virtual Hosts documentation</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Options" id="Options">Options</a> <a name="options" id="options">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures what features are available in a particular directory</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Options [+|-]<var>option</var> [[+|-]<var>option</var>] ...</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Options All</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>Options</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">Options</code> directive controls which server features are available in a particular directory.</p> <p><var>option</var> can be set to <code>None</code>, in which case none of the extra features are enabled, or one or more of the following:</p> <dl> <dt><code>All</code></dt> <dd>All options except for <code>MultiViews</code>. This is the default setting.</dd> <dt><code>ExecCGI</code></dt> <dd> Execution of CGI scripts using <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code> is permitted.</dd> <dt><code>FollowSymLinks</code></dt> <dd> The server will follow symbolic links in this directory. <div class="note"> <p>Even though the server follows the symlink it does <em>not</em> change the pathname used to match against <code class="directive"><a href="#directory"><Directory></a></code> sections.</p> <p>The <code>FollowSymLinks</code> and <code>SymLinksIfOwnerMatch</code> <code class="directive"><a href="#options">Options</a></code> work only in <code class="directive"><a href="#directory"><Directory></a></code> sections or <code>.htaccess</code> files.</p> <p>Omitting this option should not be considered a security restriction, since symlink testing is subject to race conditions that make it circumventable.</p> </div></dd> <dt><code>Includes</code></dt> <dd> Server-side includes provided by <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> are permitted.</dd> <dt><code>IncludesNOEXEC</code></dt> <dd> Server-side includes are permitted, but the <code>#exec cmd</code> and <code>#exec cgi</code> are disabled. It is still possible to <code>#include virtual</code> CGI scripts from <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>ed directories.</dd> <dt><code>Indexes</code></dt> <dd> If a URL which maps to a directory is requested and there is no <code class="directive"><a href="../mod/mod_dir.html#directoryindex">DirectoryIndex</a></code> (<em>e.g.</em>, <code>index.html</code>) in that directory, then <code class="module"><a href="../mod/mod_autoindex.html">mod_autoindex</a></code> will return a formatted listing of the directory.</dd> <dt><code>MultiViews</code></dt> <dd> <a href="../content-negotiation.html">Content negotiated</a> "MultiViews" are allowed using <code class="module"><a href="../mod/mod_negotiation.html">mod_negotiation</a></code>.</dd> <dt><code>SymLinksIfOwnerMatch</code></dt> <dd>The server will only follow symbolic links for which the target file or directory is owned by the same user id as the link. <div class="note"><h3>Note</h3> <p>The <code>FollowSymLinks</code> and <code>SymLinksIfOwnerMatch</code> <code class="directive"><a href="#options">Options</a></code> work only in <code class="directive"><a href="#directory"><Directory></a></code> sections or <code>.htaccess</code> files.</p> <p>This option should not be considered a security restriction, since symlink testing is subject to race conditions that make it circumventable.</p> </div> </dd> </dl> <p>Normally, if multiple <code class="directive">Options</code> could apply to a directory, then the most specific one is used and others are ignored; the options are not merged. (See <a href="../sections.html#mergin">how sections are merged</a>.) However if <em>all</em> the options on the <code class="directive">Options</code> directive are preceded by a <code>+</code> or <code>-</code> symbol, the options are merged. Any options preceded by a <code>+</code> are added to the options currently in force, and any options preceded by a <code>-</code> are removed from the options currently in force. </p> <div class="warning"><h3>Warning</h3> <p>Mixing <code class="directive">Options</code> with a <code>+</code> or <code>-</code> with those without is not valid syntax and is likely to cause unexpected results.</p> </div> <p>For example, without any <code>+</code> and <code>-</code> symbols:</p> <div class="example"><p><code> <Directory /web/docs><br /> <span class="indent"> Options Indexes FollowSymLinks<br /> </span> </Directory><br /> <br /> <Directory /web/docs/spec><br /> <span class="indent"> Options Includes<br /> </span> </Directory> </code></p></div> <p>then only <code>Includes</code> will be set for the <code>/web/docs/spec</code> directory. However if the second <code class="directive">Options</code> directive uses the <code>+</code> and <code>-</code> symbols:</p> <div class="example"><p><code> <Directory /web/docs><br /> <span class="indent"> Options Indexes FollowSymLinks<br /> </span> </Directory><br /> <br /> <Directory /web/docs/spec><br /> <span class="indent"> Options +Includes -Indexes<br /> </span> </Directory> </code></p></div> <p>then the options <code>FollowSymLinks</code> and <code>Includes</code> are set for the <code>/web/docs/spec</code> directory.</p> <div class="note"><h3>Note</h3> <p>Using <code>-IncludesNOEXEC</code> or <code>-Includes</code> disables server-side includes completely regardless of the previous setting.</p> </div> <p>The default in the absence of any other settings is <code>All</code>.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Protocol" id="Protocol">Protocol</a> <a name="protocol" id="protocol">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Protocol for a listening socket</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Protocol <var>protocol</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.1.5 and later. On Windows, from Apache 2.3.3 and later.</td></tr> </table> <p>This directive specifies the protocol used for a specific listening socket. The protocol is used to determine which module should handle a request and to apply protocol specific optimizations with the <code class="directive">AcceptFilter</code> directive.</p> <p>You only need to set the protocol if you are running on non-standard ports; otherwise, <code>http</code> is assumed for port 80 and <code>https</code> for port 443.</p> <p>For example, if you are running <code>https</code> on a non-standard port, specify the protocol explicitly:</p> <div class="example"><p><code> Protocol https </code></p></div> <p>You can also specify the protocol using the <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code> directive.</p> <h3>See also</h3> <ul> <li><code class="directive">AcceptFilter</code></li> <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="RegisterHttpMethod" id="RegisterHttpMethod">RegisterHttpMethod</a> <a name="registerhttpmethod" id="registerhttpmethod">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Register non-standard HTTP methods</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RegisterHttpMethod <var>method</var> [<var>method</var> [...]]</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>HTTP Methods that are not conforming to the relvant RFCs are normally rejected by request processing in Apache HTTPD. To avoid this, modules can register non-standard HTTP methods they support. The <code class="directive">RegisterHttpMethod</code> allows to register such methods manually. This can be useful for if such methods are forwared for external processing, e.g. to a CGI script.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Require" id="Require">Require</a> <a name="require" id="require">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Selects which authenticated users can access a resource</td></tr> <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> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive selects which authenticated users can access a resource. Multiple instances of this directive are combined with a logical "OR", such that a user matching any <code class="directive">Require </code>line is granted access. The restrictions are processed by authorization modules. Some of the allowed syntaxes provided by <code class="module"><a href="../mod/mod_authz_user.html">mod_authz_user</a></code> and <code class="module"><a href="../mod/mod_authz_groupfile.html">mod_authz_groupfile</a></code> are:</p> <dl> <dt><code>Require user <var>userid</var> [<var>userid</var>] ...</code></dt> <dd>Only the named users can access the resource.</dd> <dt><code>Require group <var>group-name</var> [<var>group-name</var>] ...</code></dt> <dd>Only users in the named groups can access the resource.</dd> <dt><code>Require valid-user</code></dt> <dd>All valid users can access the resource.</dd> </dl> <p>Other authorization modules that implement require options include <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code>, <code class="module"><a href="../mod/mod_authz_dbm.html">mod_authz_dbm</a></code>, and <code class="module"><a href="../mod/mod_authz_owner.html">mod_authz_owner</a></code>.</p> <p><code class="directive">Require</code> must be accompanied by <code class="directive"><a href="#authname">AuthName</a></code> and <code class="directive"><a href="#authtype">AuthType</a></code> directives, and directives such as <code class="directive"><a href="../mod/mod_authn_file.html#authuserfile">AuthUserFile</a></code> and <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code> (to define users and groups) in order to work correctly. Example:</p> <div class="example"><p><code> AuthType Basic<br /> AuthName "Restricted Resource"<br /> AuthUserFile /web/users<br /> AuthGroupFile /web/groups<br /> Require group admin </code></p></div> <p>Access controls which are applied in this way are effective for <strong>all</strong> methods. <strong>This is what is normally desired.</strong> If you wish to apply access controls only to specific methods, while leaving other methods unprotected, then place the <code class="directive">Require</code> statement into a <code class="directive"><a href="#limit"><Limit></a></code> section.</p> <p>If <code class="directive">Require</code> is used together with the <code class="directive"><a href="../mod/mod_authz_host.html#allow">Allow</a></code> or <code class="directive"><a href="../mod/mod_authz_host.html#deny">Deny</a></code> directives, then the interaction of these restrictions is controlled by the <code class="directive"><a href="#satisfy">Satisfy</a></code> directive.</p> <p>Multiple <code class="directive">Require</code> directives do operate as logical "OR", but some underlying authentication modules may require an explicit configuration to let authentication be chained to others. This is typically the case with <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code>, which exports the <code class="directive">AuthzLDAPAuthoritative</code> in that intent.</p> <div class="note"><h3>Removing controls in subdirectories</h3> <p>The following example shows how to use the <code class="directive"><a href="#satisfy">Satisfy</a></code> directive to disable access controls in a subdirectory of a protected directory. This technique should be used with caution, because it will also disable any access controls imposed by <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code>.</p> <div class="example"><p><code> <Directory /path/to/protected/><br /> <span class="indent"> Require user david<br /> </span> </Directory><br /> <Directory /path/to/protected/unprotected><br /> <span class="indent"> # All access controls and authentication are disabled<br /> # in this directory<br /> Satisfy Any<br /> Allow from all<br /> </span> </Directory><br /> </code></p></div> </div> <h3>See also</h3> <ul> <li><a href="../howto/auth.html">Authentication and Authorization</a></li> <li><a href="../howto/access.html">Access Control</a></li> <li><code class="directive"><a href="#satisfy">Satisfy</a></code></li> <li><code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="RLimitCPU" id="RLimitCPU">RLimitCPU</a> <a name="rlimitcpu" id="rlimitcpu">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the CPU consumption of processes launched by Apache children</td></tr> <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> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all processes and the second parameter sets the maximum resource limit. Either parameter can be a number, or <code>max</code> to indicate to the server that the limit should be set to the maximum allowed by the operating system configuration. Raising the maximum resource limit requires that the server is running as <code>root</code> or in the initial startup phase.</p> <p>This applies to processes forked from Apache children servicing requests, not the Apache children themselves. This includes CGI scripts and SSI exec commands, but not any processes forked from the Apache parent, such as piped logs.</p> <p>CPU resource limits are expressed in seconds per process.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li> <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="RLimitMEM" id="RLimitMEM">RLimitMEM</a> <a name="rlimitmem" id="rlimitmem">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the memory consumption of processes launched by Apache children</td></tr> <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> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all processes and the second parameter sets the maximum resource limit. Either parameter can be a number, or <code>max</code> to indicate to the server that the limit should be set to the maximum allowed by the operating system configuration. Raising the maximum resource limit requires that the server is running as <code>root</code> or in the initial startup phase.</p> <p>This applies to processes forked from Apache children servicing requests, not the Apache children themselves. This includes CGI scripts and SSI exec commands, but not any processes forked from the Apache parent, such as piped logs.</p> <p>Memory resource limits are expressed in bytes per process.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li> <li><code class="directive"><a href="#rlimitnproc">RLimitNPROC</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="RLimitNPROC" id="RLimitNPROC">RLimitNPROC</a> <a name="rlimitnproc" id="rlimitnproc">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Limits the number of processes that can be launched by processes launched by Apache children</td></tr> <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> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Unset; uses operating system defaults</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all processes, and the second parameter sets the maximum resource limit. Either parameter can be a number, or <code>max</code> to indicate to the server that the limit should be set to the maximum allowed by the operating system configuration. Raising the maximum resource limit requires that the server is running as <code>root</code> or in the initial startup phase.</p> <p>This applies to processes forked from Apache children servicing requests, not the Apache children themselves. This includes CGI scripts and SSI exec commands, but not any processes forked from the Apache parent, such as piped logs.</p> <p>Process limits control the number of processes per user.</p> <div class="note"><h3>Note</h3> <p>If CGI processes are <strong>not</strong> running under user ids other than the web server user id, this directive will limit the number of processes that the server itself can create. Evidence of this situation will be indicated by <strong><code>cannot fork</code></strong> messages in the <code>error_log</code>.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#rlimitmem">RLimitMEM</a></code></li> <li><code class="directive"><a href="#rlimitcpu">RLimitCPU</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Satisfy" id="Satisfy">Satisfy</a> <a name="satisfy" id="satisfy">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Interaction between host-level access control and user authentication</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Satisfy Any|All</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Satisfy All</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <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 later</td></tr> </table> <p>Access policy if both <code class="directive"><a href="../mod/mod_authz_host.html#allow">Allow</a></code> and <code class="directive"><a href="#require">Require</a></code> used. The parameter can be either <code>All</code> or <code>Any</code>. This directive is only useful if access to a particular area is being restricted by both username/password <em>and</em> client host address. In this case the default behavior (<code>All</code>) is to require that the client passes the address access restriction <em>and</em> enters a valid username and password. With the <code>Any</code> option the client will be granted access if they either pass the host restriction or enter a valid username and password. This can be used to password restrict an area, but to let clients from particular addresses in without prompting for a password.</p> <p>For example, if you wanted to let people on your network have unrestricted access to a portion of your website, but require that people outside of your network provide a password, you could use a configuration similar to the following:</p> <div class="example"><p><code> Require valid-user<br /> Order allow,deny<br /> Allow from 192.168.1<br /> Satisfy Any </code></p></div> <p>Since version 2.0.51 <code class="directive">Satisfy</code> directives can 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> <h3>See also</h3> <ul> <li><code class="directive"><a href="../mod/mod_authz_host.html#allow">Allow</a></code></li> <li><code class="directive"><a href="#require">Require</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ScriptInterpreterSource" id="ScriptInterpreterSource">ScriptInterpreterSource</a> <a name="scriptinterpretersource" id="scriptinterpretersource">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Technique for locating the interpreter for CGI scripts</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ScriptInterpreterSource Registry|Registry-Strict|Script</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ScriptInterpreterSource Script</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Win32 only; option <code>Registry-Strict</code> is available in Apache 2.0 and later</td></tr> </table> <p>This directive is used to control how Apache finds the interpreter used to run CGI scripts. The default setting is <code>Script</code>. This causes Apache to use the interpreter pointed to by the shebang line (first line, starting with <code>#!</code>) in the script. On Win32 systems this line usually looks like:</p> <div class="example"><p><code> #!C:/Perl/bin/perl.exe </code></p></div> <p>or, if <code>perl</code> is in the <code>PATH</code>, simply:</p> <div class="example"><p><code> #!perl </code></p></div> <p>Setting <code>ScriptInterpreterSource Registry</code> will cause the Windows Registry tree <code>HKEY_CLASSES_ROOT</code> to be searched using the script file extension (e.g., <code>.pl</code>) as a search key. The command defined by the registry subkey <code>Shell\ExecCGI\Command</code> or, if it does not exist, by the subkey <code>Shell\Open\Command</code> is used to open the script file. If the registry keys cannot be found, Apache falls back to the behavior of the <code>Script</code> option.</p> <p>For example, the registry setting to have a script with the .pl extension processed via perl would be:</p> <div class="example"><p><code><code>HKEY_CLASSES_ROOT\.pl\Shell\ExecCGI\Command\(Default) => C:\Perl\bin\perl.exe -wT</code></code></p></div> <div class="warning"><h3>Security</h3> <p>Be careful when using <code>ScriptInterpreterSource Registry</code> with <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>'ed directories, because Apache will try to execute <strong>every</strong> file within this directory. The <code>Registry</code> setting may cause undesired program calls on files which are typically not executed. For example, the default open command on <code>.htm</code> files on most Windows systems will execute Microsoft Internet Explorer, so any HTTP request for an <code>.htm</code> file existing within the script directory would start the browser in the background on the server. This is a good way to crash your system within a minute or so.</p> </div> <p>The option <code>Registry-Strict</code> which is new in Apache 2.0 does the same thing as <code>Registry</code> but uses only the subkey <code>Shell\ExecCGI\Command</code>. The <code>ExecCGI</code> key is not a common one. It must be configured manually in the windows registry and hence prevents accidental program calls on your system.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerAdmin" id="ServerAdmin">ServerAdmin</a> <a name="serveradmin" id="serveradmin">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Email address that the server includes in error messages sent to the client</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAdmin <var>email-address</var>|<var>URL</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">ServerAdmin</code> sets the contact address that the server includes in any error messages it returns to the client. If the <code>httpd</code> doesn't recognize the supplied argument as an URL, it assumes, that it's an <var>email-address</var> and prepends it with <code>mailto:</code> in hyperlink targets. However, it's recommended to actually use an email address, since there are a lot of CGI scripts that make that assumption. If you want to use an URL, it should point to another server under your control. Otherwise users may not be able to contact you in case of errors.</p> <p>It may be worth setting up a dedicated address for this, e.g.</p> <div class="example"><p><code> ServerAdmin www-admin@foo.example.com </code></p></div> <p>as users do not always mention that they are talking about the server!</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerAlias" id="ServerAlias">ServerAlias</a> <a name="serveralias" id="serveralias">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Alternate names for a host used when matching requests to name-virtual hosts</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerAlias <var>hostname</var> [<var>hostname</var>] ...</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">ServerAlias</code> directive sets the alternate names for a host, for use with <a href="../vhosts/name-based.html">name-based virtual hosts</a>. The <code class="directive">ServerAlias</code> may include wildcards, if appropriate.</p> <div class="example"><p><code> <VirtualHost *:80><br /> ServerName server.domain.com<br /> ServerAlias server server2.domain.com server2<br /> ServerAlias *.example.com<br /> UseCanonicalName Off<br /> # ...<br /> </VirtualHost> </code></p></div> <p>Name-based virtual hosts for the best-matching set of <code class="directive"><a href="#virtualhost"><virtualhost></a></code>s are processed in the order they appear in the configuration. The first matching <code class="directive"><a href="#servername">ServerName</a></code> or <code class="directive"><a href="#serveralias">ServerAlias</a></code> is used, with no different precedence for wildcards (nor for ServerName vs. ServerAlias). </p> <p>The complete list of names in the <code class="directive">VirtualHost</code> directive are treated just like a (non wildcard) <code class="directive">ServerAlias</code>.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li> <li><a href="../vhosts/">Apache Virtual Host documentation</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerName" id="ServerName">ServerName</a> <a name="servername" id="servername">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hostname and port that the server uses to identify itself</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerName [<var>scheme</var>://]<var>fully-qualified-domain-name</var>[:<var>port</var>]</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>In version 2.0, this directive supersedes the functionality of the <code class="directive">Port</code> directive from version 1.3.</td></tr> </table> <p>The <code class="directive">ServerName</code> directive sets the request scheme, hostname and port that the server uses to identify itself. This is used when creating redirection URLs.</p> <p>Additionally, <code class="directive">ServerName</code> is used (possibly in conjunction with <code class="directive">ServerAlias</code>) to uniquely identify a virtual host, when using <a href="../vhosts/name-based.html">name-based virtual hosts</a>.</p> <p>For example, if the name of the machine hosting the web server is <code>simple.example.com</code>, but the machine also has the DNS alias <code>www.example.com</code> and you wish the web server to be so identified, the following directive should be used:</p> <div class="example"><p><code> ServerName www.example.com </code></p></div> <p>If no <code class="directive">ServerName</code> is specified, then the server attempts to deduce the hostname by performing a reverse lookup on the IP address. If no port is specified in the <code class="directive">ServerName</code>, then the server will use the port from the incoming request. For optimal reliability and predictability, you should specify an explicit hostname and port using the <code class="directive">ServerName</code> directive.</p> <p>If you are using <a href="../vhosts/name-based.html">name-based virtual hosts</a>, the <code class="directive">ServerName</code> inside a <code class="directive"><a href="#virtualhost"><VirtualHost></a></code> section specifies what hostname must appear in the request's <code>Host:</code> header to match this virtual host.</p> <p>Sometimes, the server runs behind a device that processes SSL, such as a reverse proxy, load balancer or SSL offload appliance. When this is the case, specify the <code>https://</code> scheme and the port number to which the clients connect in the <code class="directive">ServerName</code> directive to make sure that the server generates the correct self-referential URLs. </p> <p>See the description of the <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> and <code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code> directives for settings which determine whether self-referential URLs (e.g., by the <code class="module"><a href="../mod/mod_dir.html">mod_dir</a></code> module) will refer to the specified port, or to the port number given in the client's request. </p> <h3>See also</h3> <ul> <li><a href="../dns-caveats.html">Issues Regarding DNS and Apache</a></li> <li><a href="../vhosts/">Apache virtual host documentation</a></li> <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li> <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li> <li><code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code></li> <li><code class="directive"><a href="#serveralias">ServerAlias</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerPath" id="ServerPath">ServerPath</a> <a name="serverpath" id="serverpath">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Legacy URL pathname for a name-based virtual host that is accessed by an incompatible browser</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerPath <var>URL-path</var></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">ServerPath</code> directive sets the legacy URL pathname for a host, for use with <a href="../vhosts/">name-based virtual hosts</a>.</p> <h3>See also</h3> <ul> <li><a href="../vhosts/">Apache Virtual Host documentation</a></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerRoot" id="ServerRoot">ServerRoot</a> <a name="serverroot" id="serverroot">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Base directory for the server installation</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerRoot <var>directory-path</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerRoot /usr/local/apache</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">ServerRoot</code> directive sets the directory in which the server lives. Typically it will contain the subdirectories <code>conf/</code> and <code>logs/</code>. Relative 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 relative to this directory.</p> <div class="example"><h3>Example</h3><p><code> ServerRoot /home/httpd </code></p></div> <h3>See also</h3> <ul> <li><a href="../invoking.html">the <code>-d</code> option to <code>httpd</code></a></li> <li><a href="../misc/security_tips.html#serverroot">the security tips</a> for information on how to properly set permissions on the <code class="directive">ServerRoot</code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerSignature" id="ServerSignature">ServerSignature</a> <a name="serversignature" id="serversignature">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the footer on server-generated documents</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ServerSignature On|Off|EMail</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerSignature Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>All</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">ServerSignature</code> directive allows the configuration of a trailing footer line under server-generated documents (error messages, <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> ftp directory listings, <code class="module"><a href="../mod/mod_info.html">mod_info</a></code> output, ...). The reason why you would want to enable such a footer line is that in a chain of proxies, the user often has no possibility to tell which of the chained servers actually produced a returned error message.</p> <p>The <code>Off</code> setting, which is the default, suppresses the footer line (and is therefore compatible with the behavior of Apache-1.2 and below). The <code>On</code> setting simply adds a line with the server version number and <code class="directive"><a href="#servername">ServerName</a></code> of the serving virtual host, and the <code>EMail</code> setting additionally creates a "mailto:" reference to the <code class="directive"><a href="#serveradmin">ServerAdmin</a></code> of the referenced document.</p> <p>After version 2.0.44, the details of the server version number presented are controlled by the <code class="directive"><a href="#servertokens">ServerTokens</a></code> directive.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="#servertokens">ServerTokens</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="ServerTokens" id="ServerTokens">ServerTokens</a> <a name="servertokens" id="servertokens">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures the <code>Server</code> HTTP response header</td></tr> <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> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ServerTokens Full</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>This directive controls whether <code>Server</code> response header field which is sent back to clients includes a description of the generic OS-type of the server as well as information about compiled-in modules.</p> <dl> <dt><code>ServerTokens Prod[uctOnly]</code></dt> <dd>Server sends (<em>e.g.</em>): <code>Server: Apache</code></dd> <dt><code>ServerTokens Major</code></dt> <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2</code></dd> <dt><code>ServerTokens Minor</code></dt> <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0</code></dd> <dt><code>ServerTokens Min[imal]</code></dt> <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41</code></dd> <dt><code>ServerTokens OS</code></dt> <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41 (Unix)</code></dd> <dt><code>ServerTokens Full</code> (or not specified)</dt> <dd>Server sends (<em>e.g.</em>): <code>Server: Apache/2.0.41 (Unix) PHP/4.2.2 MyMod/1.2</code></dd> </dl> <p>This setting applies to the entire server and cannot be enabled or disabled on a virtualhost-by-virtualhost basis.</p> <p>After version 2.0.44, this directive also controls the information presented by the <code class="directive"><a href="#serversignature">ServerSignature</a></code> directive.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="#serversignature">ServerSignature</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="SetHandler" id="SetHandler">SetHandler</a> <a name="sethandler" id="sethandler">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Forces all matching files to be processed by a handler</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetHandler <var>handler-name</var>|None</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Moved into the core in Apache 2.0</td></tr> </table> <p>When placed into an <code>.htaccess</code> file or a <code class="directive"><a href="#directory"><Directory></a></code> or <code class="directive"><a href="#location"><Location></a></code> section, this directive forces all matching files to be parsed through the <a href="../handler.html">handler</a> given by <var>handler-name</var>. For example, if you had a directory you wanted to be parsed entirely as imagemap rule files, regardless of extension, you might put the following into an <code>.htaccess</code> file in that directory:</p> <div class="example"><p><code> SetHandler imap-file </code></p></div> <p>Another example: if you wanted to have the server display a status report whenever a URL of <code>http://servername/status</code> was called, you might put the following into <code>httpd.conf</code>:</p> <div class="example"><p><code> <Location /status><br /> <span class="indent"> SetHandler server-status<br /> </span> </Location> </code></p></div> <p>You can override an earlier defined <code class="directive">SetHandler</code> directive by using the value <code>None</code>.</p> <h3>See also</h3> <ul> <li><code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="SetInputFilter" id="SetInputFilter">SetInputFilter</a> <a name="setinputfilter" id="setinputfilter">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process client requests and POST input</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetInputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">SetInputFilter</code> directive sets the filter or filters which will process client requests and POST input when they are received by the server. This is in addition to any filters defined elsewhere, including the <code class="directive"><a href="../mod/mod_mime.html#addinputfilter">AddInputFilter</a></code> directive.</p> <p>If more than one filter is specified, they must be separated by semicolons in the order in which they should process the content.</p> <h3>See also</h3> <ul> <li><a href="../filter.html">Filters</a> documentation</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="SetOutputFilter" id="SetOutputFilter">SetOutputFilter</a> <a name="setoutputfilter" id="setoutputfilter">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets the filters that will process responses from the server</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SetOutputFilter <var>filter</var>[;<var>filter</var>...]</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">SetOutputFilter</code> directive sets the filters which will process responses from the server before they are sent to the client. This is in addition to any filters defined elsewhere, including the <code class="directive"><a href="../mod/mod_mime.html#addoutputfilter">AddOutputFilter</a></code> directive.</p> <p>For example, the following configuration will process all files in the <code>/www/data/</code> directory for server-side includes.</p> <div class="example"><p><code> <Directory /www/data/><br /> <span class="indent"> SetOutputFilter INCLUDES<br /> </span> </Directory> </code></p></div> <p>If more than one filter is specified, they must be separated by semicolons in the order in which they should process the content.</p> <h3>See also</h3> <ul> <li><a href="../filter.html">Filters</a> documentation</li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Suexec" id="Suexec">Suexec</a> <a name="suexec" id="suexec">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enable or disable the suEXEC feature</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Suexec On|Off</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>On if suexec binary exists with proper owner and mode, Off otherwise</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache httpd 2.2.18 and later</td></tr> </table> <p>When On, startup will fail if the suexec binary doesn't exist or has an invalid owner or file mode.</p> <p>When Off, suEXEC will be disabled even if the suexec binary exists and has a valid owner and file mode.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="TimeOut" id="TimeOut">TimeOut</a> <a name="timeout" id="timeout">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Amount of time the server will wait for certain events before failing a request</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TimeOut <var>seconds</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TimeOut 300</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>The <code class="directive">TimeOut</code> directive defines the length of time Apache will wait for I/O in various circumstances:</p> <ol> <li>When reading data from the client, the length of time to wait for a TCP packet to arrive if the read buffer is empty.</li> <li>When writing data to the client, the length of time to wait for an acknowledgement of a packet if the send buffer is full.</li> <li>In <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>, the length of time to wait for output from a CGI script.</li> <li>In <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code>, the length of time to wait for output from a filtering process.</li> <li>In <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>, the default timeout value if <code class="directive"><a href="../mod/mod_proxy.html#proxytimeout">ProxyTimeout</a></code> is not configured.</li> </ol> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="TraceEnable" id="TraceEnable">TraceEnable</a> <a name="traceenable" id="traceenable">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines the behaviour on <code>TRACE</code> requests</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TraceEnable <var>[on|off|extended]</var></code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>TraceEnable on</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> <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> </table> <p>This directive overrides the behavior of <code>TRACE</code> for both the core server and <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>. The default <code>TraceEnable on</code> permits <code>TRACE</code> requests per RFC 2616, which disallows any request body to accompany the request. <code>TraceEnable off</code> causes the core server and <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> to return a <code>405</code> (Method not allowed) error to the client.</p> <p>Finally, for testing and diagnostic purposes only, request bodies may be allowed using the non-compliant <code>TraceEnable extended</code> directive. The core (as an origin server) will restrict the request body to 64k (plus 8k for chunk headers if <code>Transfer-Encoding: chunked</code> is used). The core will reflect the full headers and all chunk headers with the response body. As a proxy server, the request body is not restricted to 64k.</p> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="UseCanonicalName" id="UseCanonicalName">UseCanonicalName</a> <a name="usecanonicalname" id="usecanonicalname">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and port</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalName On|Off|DNS</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalName Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>In many situations Apache must construct a <em>self-referential</em> URL -- that is, a URL that refers back to the same server. With <code>UseCanonicalName On</code> Apache will use the hostname and port specified in the <code class="directive"><a href="#servername">ServerName</a></code> directive to construct the canonical name for the server. This name is used in all self-referential URLs, and for the values of <code>SERVER_NAME</code> and <code>SERVER_PORT</code> in CGIs.</p> <p>With <code>UseCanonicalName Off</code> Apache will form self-referential URLs using the hostname and port supplied by the client if any are supplied (otherwise it will use the canonical name, as defined above). These values are the same that are used to implement <a href="../vhosts/name-based.html">name based virtual hosts</a>, and are available with the same clients. The CGI variables <code>SERVER_NAME</code> and <code>SERVER_PORT</code> will be constructed from the client supplied values as well.</p> <p>An example where this may be useful is on an intranet server where you have users connecting to the machine using short names such as <code>www</code>. You'll notice that if the users type a shortname and a URL which is a directory, such as <code>http://www/splat</code>, <em>without the trailing slash</em>, then Apache will redirect them to <code>http://www.domain.com/splat/</code>. If you have authentication enabled, this will cause the user to have to authenticate twice (once for <code>www</code> and once again for <code>www.domain.com</code> -- see <a href="http://wiki.apache.org/httpd/FAQ#Why_does_Apache_ask_for_my_password_twice_before_serving_a_file.3F">the FAQ on this subject for more information</a>). But if <code class="directive">UseCanonicalName</code> is set <code>Off</code>, then Apache will redirect to <code>http://www/splat/</code>.</p> <p>There is a third option, <code>UseCanonicalName DNS</code>, which is intended for use with mass IP-based virtual hosting to support ancient clients that do not provide a <code>Host:</code> header. With this option, Apache does a reverse DNS lookup on the server IP address that the client connected to in order to work out self-referential URLs.</p> <div class="warning"><h3>Warning</h3> <p>If CGIs make assumptions about the values of <code>SERVER_NAME</code>, they may be broken by this option. The client is essentially free to give whatever value they want as a hostname. But if the CGI is only using <code>SERVER_NAME</code> to construct self-referential URLs, then it should be just fine.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#usecanonicalphysicalport">UseCanonicalPhysicalPort</a></code></li> <li><code class="directive"><a href="#servername">ServerName</a></code></li> <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="UseCanonicalPhysicalPort" id="UseCanonicalPhysicalPort">UseCanonicalPhysicalPort</a> <a name="usecanonicalphysicalport" id="usecanonicalphysicalport">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configures how the server determines its own name and port</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>UseCanonicalPhysicalPort On|Off</code></td></tr> <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>UseCanonicalPhysicalPort Off</code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p>In many situations Apache must construct a <em>self-referential</em> URL -- that is, a URL that refers back to the same server. With <code>UseCanonicalPhysicalPort On</code>, Apache will, when constructing the canonical port for the server to honor the <code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code> directive, provide the actual physical port number being used by this request as a potential port. With <code>UseCanonicalPhysicalPort Off</code>, Apache will not ever use the actual physical port number, instead relying on all configured information to construct a valid port number.</p> <div class="note"><h3>Note</h3> <p>The ordering of when the physical port is used is as follows:<br /><br /> <code>UseCanonicalName On</code></p> <ul> <li>Port provided in <code>Servername</code></li> <li>Physical port</li> <li>Default port</li> </ul> <code>UseCanonicalName Off | DNS</code> <ul> <li>Parsed port from <code>Host:</code> header</li> <li>Physical port</li> <li>Port provided in <code>Servername</code></li> <li>Default port</li> </ul> <p>With <code>UseCanonicalPhysicalPort Off</code>, the physical ports are removed from the ordering.</p> </div> <h3>See also</h3> <ul> <li><code class="directive"><a href="#usecanonicalname">UseCanonicalName</a></code></li> <li><code class="directive"><a href="#servername">ServerName</a></code></li> <li><code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code></li> </ul> </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="VirtualHost" id="VirtualHost"><VirtualHost></a> <a name="virtualhost" id="virtualhost">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply only to a specific hostname or IP address</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><VirtualHost <var>addr</var>[:<var>port</var>] [<var>addr</var>[:<var>port</var>]] ...> ... </VirtualHost></code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr> </table> <p><code class="directive"><VirtualHost></code> and <code></VirtualHost></code> are used to enclose a group of directives that will apply only to a particular virtual host. Any directive that is allowed in a virtual host context may be used. When the server receives a request for a document on a particular virtual host, it uses the configuration directives enclosed in the <code class="directive"><VirtualHost></code> section. <var>Addr</var> can be:</p> <ul> <li>The IP address of the virtual host;</li> <li>A fully qualified domain name for the IP address of the virtual host (not recommended);</li> <li>The character <code>*</code>, which is used only in combination with <code>NameVirtualHost *</code> to match all IP addresses; or</li> <li>The string <code>_default_</code>, which is used only with IP virtual hosting to catch unmatched IP addresses.</li> </ul> <div class="example"><h3>Example</h3><p><code> <VirtualHost 10.1.2.3:80><br /> <span class="indent"> ServerAdmin webmaster@host.example.com<br /> DocumentRoot /www/docs/host.example.com<br /> ServerName host.example.com<br /> ErrorLog logs/host.example.com-error_log<br /> TransferLog logs/host.example.com-access_log<br /> </span> </VirtualHost> </code></p></div> <p>IPv6 addresses must be specified in square brackets because the optional port number could not be determined otherwise. An IPv6 example is shown below:</p> <div class="example"><p><code> <VirtualHost [2001:db8::a00:20ff:fea7:ccea]:80><br /> <span class="indent"> ServerAdmin webmaster@host.example.com<br /> DocumentRoot /www/docs/host.example.com<br /> ServerName host.example.com<br /> ErrorLog logs/host.example.com-error_log<br /> TransferLog logs/host.example.com-access_log<br /> </span> </VirtualHost> </code></p></div> <p>Each Virtual Host must correspond to a different IP address, different port number, or a different host name for the server, in the former case the server machine must be configured to accept IP packets for multiple addresses. (If the machine does not have multiple network interfaces, then this can be accomplished with the <code>ifconfig alias</code> command -- if your OS supports it).</p> <div class="note"><h3>Note</h3> <p>The use of <code class="directive"><VirtualHost></code> does <strong>not</strong> affect what addresses Apache listens on. You may need to ensure that Apache is listening on the correct addresses using <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code>.</p> </div> <p>When using IP-based virtual hosting, the special name <code>_default_</code> can be specified in which case this virtual host will match any IP address that is not explicitly listed in another virtual host. In the absence of any <code>_default_</code> virtual host the "main" server config, consisting of all those definitions outside any VirtualHost section, is used when no IP-match occurs. (But note that any IP address that matches a <code class="directive"><a href="#namevirtualhost">NameVirtualHost</a></code> directive will use neither the "main" server config nor the <code>_default_</code> virtual host. See the <a href="../vhosts/name-based.html">name-based virtual hosting</a> documentation for further details.)</p> <p>You can specify a <code>:port</code> to change the port that is matched. If unspecified then it defaults to the same port as the most recent <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code> statement of the main server. You may also specify <code>:*</code> to match all ports on that address. (This is recommended when used with <code>_default_</code>.)</p> <p>A <code class="directive"><a href="#servername">ServerName</a></code> should be specified inside each <code class="directive"><VirtualHost></code> block. If it is absent, the <code class="directive"><a href="#servername">ServerName</a></code> from the "main" server configuration will be inherited.</p> <div class="warning"><h3>Security</h3> <p>See the <a href="../misc/security_tips.html">security tips</a> document for details on why your security could be compromised if the directory where log files are stored is writable by anyone other than the user that starts the server.</p> </div> <h3>See also</h3> <ul> <li><a href="../vhosts/">Apache Virtual Host documentation</a></li> <li><a href="../dns-caveats.html">Issues Regarding DNS and Apache</a></li> <li><a href="../bind.html">Setting which addresses and ports Apache uses</a></li> <li><a href="../sections.html">How <Directory>, <Location> and <Files> sections work</a> for an explanation of how these different sections are combined when a request is received</li> </ul> </div> </div> <div class="bottomlang"> <p><span>Available Languages: </span><a href="../de/mod/core.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> | <a href="../en/mod/core.html" title="English"> en </a> | <a href="../fr/mod/core.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | <a href="../ja/mod/core.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | <a href="../tr/mod/core.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> </div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. 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