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| <?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"> | |
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| <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type" /> | |
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| <title>Expressions in Apache HTTP Server - Apache HTTP Server Version 2.4</title> | |
| <link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> | |
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| <body id="manual-page"><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 2.4</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 2.4</a></div><div id="page-content"><div id="preamble"><h1>Expressions in Apache HTTP Server</h1> | |
| <div class="toplang"> | |
| <p><span>Available Languages: </span><a href="./en/expr.html" title="English"> en </a> | | |
| <a href="./fr/expr.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p> | |
| </div> | |
| <p>Historically, there are several syntax variants for expressions | |
| used to express a condition in the different modules of the Apache | |
| HTTP Server. There is some ongoing effort to only use a single | |
| variant, called <em>ap_expr</em>, for all configuration directives. | |
| This document describes the <em>ap_expr</em> expression parser. | |
| </p> | |
| <p>The <em>ap_expr</em> expression is intended to replace most other | |
| expression variants in HTTPD. For example, the deprecated <code class="directive"><a href="./mod/mod_ssl.html#sslrequire">SSLRequire</a></code> expressions can be replaced | |
| by <a href="mod/mod_authz_core.html#reqexpr">Require expr</a>. </p> | |
| </div> | |
| <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#grammar">Grammar in Backus-Naur Form notation</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#vars">Variables</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#binop">Binary operators</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#unnop">Unary operators</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#functions">Functions</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#examples">Example expressions</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#other">Other</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#sslrequire">Comparison with SSLRequire</a></li> | |
| <li><img alt="" src="./images/down.gif" /> <a href="#compatibility">Version History</a></li> | |
| </ul><h3>See also</h3><ul class="seealso"><li><code class="directive"><a href="./mod/core.html#if"><If></a></code></li><li><code class="directive"><a href="./mod/core.html#elseif"><ElseIf></a></code></li><li><code class="directive"><a href="./mod/core.html#else"><Else></a></code></li><li><code class="directive"><a href="./mod/core.html#errordocument"><ErrorDocument></a></code></li><li><code class="directive"><a href="./mod/mod_auth_basic.html#authbasicfake">AuthBasicFake</a></code></li><li><code class="directive"><a href="./mod/mod_auth_form.html#authformloginrequiredlocation">AuthFormLoginRequiredLocation</a></code></li><li><code class="directive"><a href="./mod/mod_auth_form.html#authformloginsuccesslocation">AuthFormLoginSuccessLocation</a></code></li><li><code class="directive"><a href="./mod/mod_auth_form.html#authformlogoutlocation">AuthFormLogoutLocation</a></code></li><li><code class="directive"><a href="./mod/mod_rewrite.html#rewritecond">RewriteCond</a></code></li><li><code class="directive"><a href="./mod/mod_setenvif.html#setenvifexpr">SetEnvIfExpr</a></code></li><li><code class="directive"><a href="./mod/mod_headers.html#header">Header</a></code></li><li><code class="directive"><a href="./mod/mod_headers.html#requestheader">RequestHeader</a></code></li><li><code class="directive"><a href="./mod/mod_filter.html#filterprovider">FilterProvider</a></code></li><li><a href="mod/mod_authz_core.html#reqexpr">Require expr</a></li><li><a href="mod/mod_authnz_ldap.html#requser">Require ldap-user</a></li><li><a href="mod/mod_authnz_ldap.html#reqgroup">Require ldap-group</a></li><li><a href="mod/mod_authnz_ldap.html#reqdn">Require ldap-dn</a></li><li><a href="mod/mod_authnz_ldap.html#reqattribute">Require ldap-attribute</a></li><li><a href="mod/mod_authnz_ldap.html#reqfilter">Require ldap-filter</a></li><li><a href="mod/mod_authz_dbd.html#reqgroup">Require dbd-group</a></li><li><a href="mod/mod_authz_dbm.html#reqgroup">Require dbm-group</a></li><li><a href="mod/mod_authz_groupfile.html#reqgroup">Require group</a></li><li><a href="mod/mod_authz_host.html#reqhost">Require host</a></li><li><code class="directive"><a href="./mod/mod_ssl.html#sslrequire">SSLRequire</a></code></li><li><code class="directive"><a href="./mod/mod_log_debug.html#logmessage">LogMessage</a></code></li><li><code class="module"><a href="./mod/mod_include.html">mod_include</a></code></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="section"> | |
| <h2><a name="grammar" id="grammar">Grammar in Backus-Naur Form notation</a></h2> | |
| <p><a href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form">Backus-Naur | |
| Form</a> (BNF) is a notation technique for context-free grammars, | |
| often used to describe the syntax of languages used in computing. | |
| In most cases, expressions are used to express boolean values. | |
| For these, the starting point in the BNF is <code>expr</code>. | |
| However, a few directives like <code class="directive"><a href="./mod/mod_log_debug.html#logmessage">LogMessage</a></code> accept expressions | |
| that evaluate to a string value. For those, the starting point in | |
| the BNF is <code>string</code>. | |
| </p> | |
| <blockquote> | |
| <pre>expr ::= "<strong>true</strong>" | "<strong>false</strong>" | |
| | "<strong>!</strong>" expr | |
| | expr "<strong>&&</strong>" expr | |
| | expr "<strong>||</strong>" expr | |
| | "<strong>(</strong>" expr "<strong>)</strong>" | |
| | comp | |
| comp ::= stringcomp | |
| | integercomp | |
| | unaryop word | |
| | word binaryop word | |
| | word "<strong>in</strong>" "<strong>{</strong>" wordlist "<strong>}</strong>" | |
| | word "<strong>in</strong>" listfunction | |
| | word "<strong>=~</strong>" regex | |
| | word "<strong>!~</strong>" regex | |
| stringcomp ::= word "<strong>==</strong>" word | |
| | word "<strong>!=</strong>" word | |
| | word "<strong><</strong>" word | |
| | word "<strong><=</strong>" word | |
| | word "<strong>></strong>" word | |
| | word "<strong>>=</strong>" word | |
| integercomp ::= word "<strong>-eq</strong>" word | word "<strong>eq</strong>" word | |
| | word "<strong>-ne</strong>" word | word "<strong>ne</strong>" word | |
| | word "<strong>-lt</strong>" word | word "<strong>lt</strong>" word | |
| | word "<strong>-le</strong>" word | word "<strong>le</strong>" word | |
| | word "<strong>-gt</strong>" word | word "<strong>gt</strong>" word | |
| | word "<strong>-ge</strong>" word | word "<strong>ge</strong>" word | |
| wordlist ::= word | |
| | wordlist "<strong>,</strong>" word | |
| word ::= word "<strong>.</strong>" word | |
| | digit | |
| | "<strong>'</strong>" string "<strong>'</strong>" | |
| | "<strong>"</strong>" string "<strong>"</strong>" | |
| | variable | |
| | rebackref | |
| | function | |
| string ::= stringpart | |
| | string stringpart | |
| stringpart ::= cstring | |
| | variable | |
| | rebackref | |
| cstring ::= ... | |
| digit ::= [0-9]+ | |
| variable ::= "<strong>%{</strong>" varname "<strong>}</strong>" | |
| | "<strong>%{</strong>" funcname "<strong>:</strong>" funcargs "<strong>}</strong>" | |
| rebackref ::= "<strong>$</strong>" [0-9] | |
| function ::= funcname "<strong>(</strong>" word "<strong>)</strong>" | |
| listfunction ::= listfuncname "<strong>(</strong>" word "<strong>)</strong>"</pre> | |
| </blockquote> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="vars" id="vars">Variables</a></h2> | |
| <p>The expression parser provides a number of variables of the form | |
| <code>%{HTTP_HOST}</code>. Note that the value of a variable may depend | |
| on the phase of the request processing in which it is evaluated. For | |
| example, an expression used in an <code class="directive"><If ></code> | |
| directive is evaluated before authentication is done. Therefore, | |
| <code>%{REMOTE_USER}</code> will not be set in this case.</p> | |
| <p>The following variables provide the values of the named HTTP request | |
| headers. The values of other headers can be obtained with the | |
| <code>req</code> <a href="#functions">function</a>. Using these | |
| variables may cause the header name to be added to the Vary | |
| header of the HTTP response, except where otherwise noted for the | |
| directive accepting the expression. The <code>req_novary</code> | |
| <a href="#functions">function</a> may be used to circumvent this | |
| behavior.</p> | |
| <table class="bordered"><tr class="header"><th>Name</th></tr> | |
| <tr><td><code>HTTP_ACCEPT</code></td></tr> | |
| <tr class="odd"><td><code>HTTP_COOKIE</code></td></tr> | |
| <tr><td><code>HTTP_FORWARDED</code></td></tr> | |
| <tr class="odd"><td><code>HTTP_HOST</code></td></tr> | |
| <tr><td><code>HTTP_PROXY_CONNECTION</code></td></tr> | |
| <tr class="odd"><td><code>HTTP_REFERER</code></td></tr> | |
| <tr><td><code>HTTP_USER_AGENT</code></td></tr> | |
| </table> | |
| <p>Other request related variables</p> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Description</th></tr> | |
| <tr><td><code>REQUEST_METHOD</code></td> | |
| <td>The HTTP method of the incoming request (e.g. | |
| <code>GET</code>)</td></tr> | |
| <tr class="odd"><td><code>REQUEST_SCHEME</code></td> | |
| <td>The scheme part of the request's URI</td></tr> | |
| <tr><td><code>REQUEST_URI</code></td> | |
| <td>The path part of the request's URI</td></tr> | |
| <tr class="odd"><td><code>DOCUMENT_URI</code></td> | |
| <td>Same as <code>REQUEST_URI</code></td></tr> | |
| <tr><td><code>REQUEST_FILENAME</code></td> | |
| <td>The full local filesystem path to the file or script matching the | |
| request, if this has already been determined by the server at the | |
| time <code>REQUEST_FILENAME</code> is referenced. Otherwise, such | |
| as when used in virtual host context, the same value as | |
| <code>REQUEST_URI</code> </td></tr> | |
| <tr class="odd"><td><code>SCRIPT_FILENAME</code></td> | |
| <td>Same as <code>REQUEST_FILENAME</code></td></tr> | |
| <tr><td><code>LAST_MODIFIED</code></td> | |
| <td>The date and time of last modification of the file in the format | |
| <code>20101231235959</code>, if this has already been determined by | |
| the server at the time <code>LAST_MODIFIED</code> is referenced. | |
| </td></tr> | |
| <tr class="odd"><td><code>SCRIPT_USER</code></td> | |
| <td>The user name of the owner of the script.</td></tr> | |
| <tr><td><code>SCRIPT_GROUP</code></td> | |
| <td>The group name of the group of the script.</td></tr> | |
| <tr class="odd"><td><code>PATH_INFO</code></td> | |
| <td>The trailing path name information, see | |
| <code class="directive"><a href="./mod/core.html#acceptpathinfo">AcceptPathInfo</a></code></td></tr> | |
| <tr><td><code>QUERY_STRING</code></td> | |
| <td>The query string of the current request</td></tr> | |
| <tr class="odd"><td><code>IS_SUBREQ</code></td> | |
| <td>"<code>true</code>" if the current request is a subrequest, | |
| "<code>false</code>" otherwise</td></tr> | |
| <tr><td><code>THE_REQUEST</code></td> | |
| <td>The complete request line (e.g., | |
| "<code>GET /index.html HTTP/1.1</code>")</td></tr> | |
| <tr class="odd"><td><code>REMOTE_ADDR</code></td> | |
| <td>The IP address of the remote host</td></tr> | |
| <tr><td><code>REMOTE_HOST</code></td> | |
| <td>The host name of the remote host</td></tr> | |
| <tr class="odd"><td><code>REMOTE_USER</code></td> | |
| <td>The name of the authenticated user, if any (not available during <code class="directive"><If ></code>)</td></tr> | |
| <tr><td><code>REMOTE_IDENT</code></td> | |
| <td>The user name set by <code class="module"><a href="./mod/mod_ident.html">mod_ident</a></code></td></tr> | |
| <tr class="odd"><td><code>SERVER_NAME</code></td> | |
| <td>The <code class="directive"><a href="./mod/core.html#servername">ServerName</a></code> of | |
| the current vhost</td></tr> | |
| <tr><td><code>SERVER_PORT</code></td> | |
| <td>The server port of the current vhost, see | |
| <code class="directive"><a href="./mod/core.html#servername">ServerName</a></code></td></tr> | |
| <tr class="odd"><td><code>SERVER_ADMIN</code></td> | |
| <td>The <code class="directive"><a href="./mod/core.html#serveradmin">ServerAdmin</a></code> of | |
| the current vhost</td></tr> | |
| <tr><td><code>SERVER_PROTOCOL</code></td> | |
| <td>The protocol used by the request</td></tr> | |
| <tr class="odd"><td><code>DOCUMENT_ROOT</code></td> | |
| <td>The <code class="directive"><a href="./mod/core.html#documentroot">DocumentRoot</a></code> of | |
| the current vhost</td></tr> | |
| <tr><td><code>AUTH_TYPE</code></td> | |
| <td>The configured <code class="directive"><a href="./mod/mod_authn_core.html#authtype">AuthType</a></code> (e.g. | |
| "<code>basic</code>")</td></tr> | |
| <tr class="odd"><td><code>CONTENT_TYPE</code></td> | |
| <td>The content type of the response (not available during <code class="directive"><If ></code>)</td></tr> | |
| <tr><td><code>HANDLER</code></td> | |
| <td>The name of the <a href="handler.html">handler</a> creating | |
| the response</td></tr> | |
| <tr class="odd"><td><code>HTTPS</code></td> | |
| <td>"<code>on</code>" if the request uses https, | |
| "<code>off</code>" otherwise</td></tr> | |
| <tr><td><code>IPV6</code></td> | |
| <td>"<code>on</code>" if the connection uses IPv6, | |
| "<code>off</code>" otherwise</td></tr> | |
| <tr class="odd"><td><code>REQUEST_STATUS</code></td> | |
| <td>The HTTP error status of the request (not available during <code class="directive"><If ></code>)</td></tr> | |
| <tr><td><code>REQUEST_LOG_ID</code></td> | |
| <td>The error log id of the request (see | |
| <code class="directive"><a href="./mod/core.html#errorlogformat">ErrorLogFormat</a></code>)</td></tr> | |
| <tr class="odd"><td><code>CONN_LOG_ID</code></td> | |
| <td>The error log id of the connection (see | |
| <code class="directive"><a href="./mod/core.html#errorlogformat">ErrorLogFormat</a></code>)</td></tr> | |
| <tr><td><code>CONN_REMOTE_ADDR</code></td> | |
| <td>The peer IP address of the connection (see the | |
| <code class="module"><a href="./mod/mod_remoteip.html">mod_remoteip</a></code> module)</td></tr> | |
| <tr class="odd"><td><code>CONTEXT_PREFIX</code></td> | |
| <td /></tr> | |
| <tr><td><code>CONTEXT_DOCUMENT_ROOT</code></td> | |
| <td /></tr> | |
| </table> | |
| <p>Misc variables</p> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Description</th></tr> | |
| <tr><td><code>TIME_YEAR</code></td> | |
| <td>The current year (e.g. <code>2010</code>)</td></tr> | |
| <tr class="odd"><td><code>TIME_MON</code></td> | |
| <td>The current month (<code>1</code>, ..., <code>12</code>)</td></tr> | |
| <tr><td><code>TIME_DAY</code></td> | |
| <td>The current day of the month</td></tr> | |
| <tr class="odd"><td><code>TIME_HOUR</code></td> | |
| <td>The hour part of the current time | |
| (<code>0</code>, ..., <code>23</code>)</td></tr> | |
| <tr><td><code>TIME_MIN</code></td> | |
| <td>The minute part of the current time </td></tr> | |
| <tr class="odd"><td><code>TIME_SEC</code></td> | |
| <td>The second part of the current time </td></tr> | |
| <tr><td><code>TIME_WDAY</code></td> | |
| <td>The day of the week (starting with <code>0</code> | |
| for Sunday)</td></tr> | |
| <tr class="odd"><td><code>TIME</code></td> | |
| <td>The date and time in the format | |
| <code>20101231235959</code></td></tr> | |
| <tr><td><code>SERVER_SOFTWARE</code></td> | |
| <td>The server version string</td></tr> | |
| <tr class="odd"><td><code>API_VERSION</code></td> | |
| <td>The date of the API version (module magic number)</td></tr> | |
| </table> | |
| <p>Some modules register additional variables, see e.g. | |
| <code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code>.</p> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="binop" id="binop">Binary operators</a></h2> | |
| <p>With the exception of some built-in comparison operators, binary | |
| operators have the form "<code>-[a-zA-Z][a-zA-Z0-9_]+</code>", i.e. a | |
| minus and at least two characters. The name is not case sensitive. | |
| Modules may register additional binary operators.</p> | |
| <h3><a name="comp" id="comp">Comparison operators</a></h3> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Alternative</th> <th>Description</th></tr> | |
| <tr><td><code>==</code></td> | |
| <td><code>=</code></td> | |
| <td>String equality</td></tr> | |
| <tr class="odd"><td><code>!=</code></td> | |
| <td /> | |
| <td>String inequality</td></tr> | |
| <tr><td><code><</code></td> | |
| <td /> | |
| <td>String less than</td></tr> | |
| <tr class="odd"><td><code><=</code></td> | |
| <td /> | |
| <td>String less than or equal</td></tr> | |
| <tr><td><code>></code></td> | |
| <td /> | |
| <td>String greater than</td></tr> | |
| <tr class="odd"><td><code>>=</code></td> | |
| <td /> | |
| <td>String greater than or equal</td></tr> | |
| <tr><td><code>-eq</code></td> | |
| <td><code>eq</code></td> | |
| <td>Integer equality</td></tr> | |
| <tr class="odd"><td><code>-ne</code></td> | |
| <td><code>ne</code></td> | |
| <td>Integer inequality</td></tr> | |
| <tr><td><code>-lt</code></td> | |
| <td><code>lt</code></td> | |
| <td>Integer less than</td></tr> | |
| <tr class="odd"><td><code>-le</code></td> | |
| <td><code>le</code></td> | |
| <td>Integer less than or equal</td></tr> | |
| <tr><td><code>-gt</code></td> | |
| <td><code>gt</code></td> | |
| <td>Integer greater than</td></tr> | |
| <tr class="odd"><td><code>-ge</code></td> | |
| <td><code>ge</code></td> | |
| <td>Integer greater than or equal</td></tr> | |
| </table> | |
| <h3><a name="binaryother" id="binaryother">Other binary operators</a></h3> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Description</th></tr> | |
| <tr><td><code>-ipmatch</code></td> | |
| <td>IP address matches address/netmask</td></tr> | |
| <tr class="odd"><td><code>-strmatch</code></td> | |
| <td>left string matches pattern given by right string (containing | |
| wildcards *, ?, [])</td></tr> | |
| <tr><td><code>-strcmatch</code></td> | |
| <td>same as <code>-strmatch</code>, but case insensitive</td></tr> | |
| <tr class="odd"><td><code>-fnmatch</code></td> | |
| <td>same as <code>-strmatch</code>, but slashes are not matched by | |
| wildcards</td></tr> | |
| </table> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="unnop" id="unnop">Unary operators</a></h2> | |
| <p>Unary operators take one argument and have the form | |
| "<code>-[a-zA-Z]</code>", i.e. a minus and one character. | |
| The name <em>is</em> case sensitive. | |
| Modules may register additional unary operators.</p> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Description</th><th>Restricted</th></tr> | |
| <tr><td><code>-d</code></td> | |
| <td>The argument is treated as a filename. | |
| True if the file exists and is a directory</td><td>yes</td></tr> | |
| <tr class="odd"><td><code>-e</code></td> | |
| <td>The argument is treated as a filename. | |
| True if the file (or dir or special) exists</td><td>yes</td></tr> | |
| <tr><td><code>-f</code></td> | |
| <td>The argument is treated as a filename. | |
| True if the file exists and is regular file</td><td>yes</td></tr> | |
| <tr class="odd"><td><code>-s</code></td> | |
| <td>The argument is treated as a filename. | |
| True if the file exists and is not empty</td><td>yes</td></tr> | |
| <tr><td><code>-L</code></td> | |
| <td>The argument is treated as a filename. | |
| True if the file exists and is symlink</td><td>yes</td></tr> | |
| <tr class="odd"><td><code>-h</code></td> | |
| <td>The argument is treated as a filename. | |
| True if the file exists and is symlink | |
| (same as <code>-L</code>)</td><td>yes</td></tr> | |
| <tr><td><code>-F</code></td> | |
| <td>True if string is a valid file, accessible via all the server's | |
| currently-configured access controls for that path. This uses an | |
| internal subrequest to do the check, so use it with care - it can | |
| impact your server's performance!</td><td /></tr> | |
| <tr class="odd"><td><code>-U</code></td> | |
| <td>True if string is a valid URL, accessible via all the server's | |
| currently-configured access controls for that path. This uses an | |
| internal subrequest to do the check, so use it with care - it can | |
| impact your server's performance!</td><td /></tr> | |
| <tr><td><code>-A</code></td> | |
| <td>Alias for <code>-U</code></td><td /></tr> | |
| <tr class="odd"><td><code>-n</code></td> | |
| <td>True if string is not empty</td><td /></tr> | |
| <tr><td><code>-z</code></td> | |
| <td>True if string is empty</td><td /></tr> | |
| <tr class="odd"><td><code>-T</code></td> | |
| <td>False if string is empty, "<code>0</code>", "<code>off</code>", | |
| "<code>false</code>", or "<code>no</code>" (case insensitive). | |
| True otherwise.</td><td /></tr> | |
| <tr><td><code>-R</code></td> | |
| <td>Same as "<code>%{REMOTE_ADDR} -ipmatch ...</code>", but more | |
| efficient | |
| </td><td /></tr> | |
| </table> | |
| <p>The operators marked as "restricted" are not available in some modules | |
| like <code class="module"><a href="./mod/mod_include.html">mod_include</a></code>.</p> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="functions" id="functions">Functions</a></h2> | |
| <p>Normal string-valued functions take one string as argument and return | |
| a string. Functions names are not case sensitive. | |
| Modules may register additional functions.</p> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Description</th><th>Restricted</th></tr> | |
| <tr><td><code>req</code>, <code>http</code></td> | |
| <td>Get HTTP request header; header names may be added to the Vary | |
| header, see below</td><td /></tr> | |
| <tr class="odd"><td><code>req_novary</code></td> | |
| <td>Same as <code>req</code>, but header names will not be added to the | |
| Vary header</td><td /></tr> | |
| <tr><td><code>resp</code></td> | |
| <td>Get HTTP response header</td><td /></tr> | |
| <tr class="odd"><td><code>reqenv</code></td> | |
| <td>Lookup request environment variable (as a shortcut, | |
| <code>v</code> can be used too to access | |
| variables).</td><td /></tr> | |
| <tr><td><code>osenv</code></td> | |
| <td>Lookup operating system environment variable</td><td /></tr> | |
| <tr class="odd"><td><code>note</code></td> | |
| <td>Lookup request note</td><td /></tr> | |
| <tr><td><code>env</code></td> | |
| <td>Return first match of <code>note</code>, <code>reqenv</code>, | |
| <code>osenv</code></td><td /></tr> | |
| <tr class="odd"><td><code>tolower</code></td> | |
| <td>Convert string to lower case</td><td /></tr> | |
| <tr><td><code>toupper</code></td> | |
| <td>Convert string to upper case</td><td /></tr> | |
| <tr class="odd"><td><code>escape</code></td> | |
| <td>Escape special characters in %hex encoding</td><td /></tr> | |
| <tr><td><code>unescape</code></td> | |
| <td>Unescape %hex encoded string, leaving encoded slashes alone; | |
| return empty string if %00 is found</td><td /></tr> | |
| <tr class="odd"><td><code>base64</code></td> | |
| <td>Encode the string using base64 encoding</td><td /></tr> | |
| <tr><td><code>unbase64</code></td> | |
| <td>Decode base64 encoded string, return truncated string if 0x00 is | |
| found</td><td /></tr> | |
| <tr class="odd"><td><code>md5</code></td> | |
| <td>Hash the string using MD5, then encode the hash with hexadecimal | |
| encoding</td><td /></tr> | |
| <tr><td><code>sha1</code></td> | |
| <td>Hash the string using SHA1, then encode the hash with hexadecimal | |
| encoding</td><td /></tr> | |
| <tr class="odd"><td><code>file</code></td> | |
| <td>Read contents from a file (including line endings, when present) | |
| </td><td>yes</td></tr> | |
| <tr><td><code>filesize</code></td> | |
| <td>Return size of a file (or 0 if file does not exist or is not | |
| regular file)</td><td>yes</td></tr> | |
| </table> | |
| <p>The functions marked as "restricted" are not available in some modules | |
| like <code class="module"><a href="./mod/mod_include.html">mod_include</a></code>.</p> | |
| <p>When the functions <code>req</code> or <code>http</code> are used, | |
| the header name will automatically be added to the Vary header of the | |
| HTTP response, except where otherwise noted for the directive accepting | |
| the expression. The <code>req_novary</code> function can be used to | |
| prevent names from being added to the Vary header.</p> | |
| <p>In addition to string-valued functions, there are also | |
| list-valued functions which take one string as argument and return a | |
| wordlist, i.e. a list of strings. The wordlist can be used with the | |
| special <code>-in</code> operator. Functions names are not case | |
| sensitive. Modules may register additional functions.</p> | |
| <p>There are no built-in list-valued functions. <code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> | |
| provides <code>PeerExtList</code>. See the description of | |
| <code class="directive"><a href="./mod/mod_ssl.html#sslrequire">SSLRequire</a></code> for details | |
| (but <code>PeerExtList</code> is also usable outside | |
| of <code class="directive"><a href="./mod/mod_ssl.html#sslrequire">SSLRequire</a></code>).</p> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="examples" id="examples">Example expressions</a></h2> | |
| <p>The following examples show how expressions might be used to | |
| evaluate requests:</p> | |
| <pre class="prettyprint lang-config"># Compare the host name to example.com and redirect to www.example.com if it matches | |
| <If "%{HTTP_HOST} == 'example.com'"> | |
| Redirect permanent "/" "http://www.example.com/" | |
| </If> | |
| # Force text/plain if requesting a file with the query string contains 'forcetext' | |
| <If "%{QUERY_STRING} =~ /forcetext/"> | |
| ForceType text/plain | |
| </If> | |
| # Only allow access to this content during business hours | |
| <Directory "/foo/bar/business"> | |
| Require expr %{TIME_HOUR} -gt 9 && %{TIME_HOUR} -lt 17 | |
| </Directory> | |
| # Check a HTTP header for a list of values | |
| <If "%{HTTP:X-example-header} in { 'foo', 'bar', 'baz' }"> | |
| Header set matched true | |
| </If> | |
| # Check an environment variable for a regular expression, negated. | |
| <If "! reqenv('REDIRECT_FOO') =~ /bar/"> | |
| Header set matched true | |
| </If> | |
| # Check result of URI mapping by running in Directory context with -f | |
| <Directory "/var/www"> | |
| AddEncoding x-gzip gz | |
| <If "-f '%{REQUEST_FILENAME}.unzipme' && ! %{HTTP:Accept-Encoding} =~ /gzip/"> | |
| SetOutputFilter INFLATE | |
| </If> | |
| </Directory> | |
| # Function examples in boolean context | |
| <If "md5('foo') == 'acbd18db4cc2f85cedef654fccc4a4d8'"> | |
| Header set checksum-matched true | |
| </If> | |
| <If "md5('foo') == replace('md5:XXXd18db4cc2f85cedef654fccc4a4d8', 'md5:XXX', 'acb')> | |
| Header set checksum-matched-2 true | |
| </If> | |
| # Function example in string context | |
| Header set foo-checksum "expr=%{md5:foo}" | |
| # This delays the evaluation of the condition clause compared to <If> | |
| Header always set CustomHeader my-value "expr=%{REQUEST_URI} =~ m#^/special_path.php$#"</pre> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="other" id="other">Other</a></h2> | |
| <table class="bordered"><tr class="header"><th>Name</th><th>Alternative</th> <th>Description</th></tr> | |
| <tr><td><code>-in</code></td> | |
| <td><code>in</code></td> | |
| <td>string contained in wordlist</td></tr> | |
| <tr class="odd"><td><code>/regexp/</code></td> | |
| <td><code>m#regexp#</code></td> | |
| <td>Regular expression (the second form allows different | |
| delimiters than /)</td></tr> | |
| <tr><td><code>/regexp/i</code></td> | |
| <td><code>m#regexp#i</code></td> | |
| <td>Case insensitive regular expression</td></tr> | |
| <tr class="odd"><td><code>$0 ... $9</code></td> | |
| <td /> | |
| <td>Regular expression backreferences</td></tr> | |
| </table> | |
| <h3><a name="rebackref" id="rebackref">Regular expression backreferences</a></h3> | |
| <p>The strings <code>$0</code> ... <code>$9</code> allow to reference | |
| the capture groups from a previously executed, successfully | |
| matching regular expressions. They can normally only be used in the | |
| same expression as the matching regex, but some modules allow special | |
| uses.</p> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="sslrequire" id="sslrequire">Comparison with SSLRequire</a></h2> | |
| <p>The <em>ap_expr</em> syntax is mostly a superset of the syntax of the | |
| deprecated <code class="directive"><a href="./mod/mod_ssl.html#sslrequire">SSLRequire</a></code> directive. | |
| The differences are described in <code class="directive"><a href="./mod/mod_ssl.html#sslrequire">SSLRequire</a></code>'s documentation.</p> | |
| </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> | |
| <div class="section"> | |
| <h2><a name="compatibility" id="compatibility">Version History</a></h2> | |
| <p>The <code>req_novary</code> <a href="#functions">function</a> | |
| is available for versions 2.4.4 and later.</p> | |
| </div></div> | |
| <div class="bottomlang"> | |
| <p><span>Available Languages: </span><a href="./en/expr.html" title="English"> en </a> | | |
| <a href="./fr/expr.html" hreflang="fr" rel="alternate" title="Français"> fr </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. Comments placed here should be pointed towards suggestions on improving the documentation or server, and may be removed again by our moderators if they are either implemented or considered invalid/off-topic. Questions on how to manage the Apache HTTP Server should be directed at either our IRC channel, #httpd, on Freenode, or sent to our <a href="http://httpd.apache.org/lists.html">mailing lists</a>.</div> | |
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