expr.xml revision 2a781ea98a32c069ae57a89566ee9628e19a2ec2
db93f1f441db5c05e281f4ed3738a3660527cd8eslive<?xml version="1.0" encoding="UTF-8" ?>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<!DOCTYPE manualpage SYSTEM "/style/manualpage.dtd">
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<!-- $LastChangedRevision$ -->
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<!--
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd Licensed to the Apache Software Foundation (ASF) under one or more
3f08db06526d6901aa08c110b5bc7dde6bc39905nd contributor license agreements. See the NOTICE file distributed with
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd this work for additional information regarding copyright ownership.
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd The ASF licenses this file to You under the Apache License, Version 2.0
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen (the "License"); you may not use this file except in compliance with
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen the License. You may obtain a copy of the License at
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen http://www.apache.org/licenses/LICENSE-2.0
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd Unless required by applicable law or agreed to in writing, software
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd distributed under the License is distributed on an "AS IS" BASIS,
af33a4994ae2ff15bc67d19ff1a7feb906745bf8rbowen WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
3f08db06526d6901aa08c110b5bc7dde6bc39905nd See the License for the specific language governing permissions and
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd limitations under the License.
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd-->
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
4b5981e276e93df97c34e4da05ca5cf8bbd937dand<manualpage metafile="expr.xml.meta">
3f08db06526d6901aa08c110b5bc7dde6bc39905nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd <title>Expressions in Apache HTTP Server</title>
ed1d958582984a7c54a6ca859e15939a414fa733nd
ed1d958582984a7c54a6ca859e15939a414fa733nd <summary>
ad74a0524a06bfe11b7de9e3b4ce7233ab3bd3f7nd <p>Historically, there are several syntax variants for expressions used to express
74f9e2dc9461c0e91b182eff6a9828fe42496dbcnd a condition in the different modules of the Apache HTTP Server.
74f9e2dc9461c0e91b182eff6a9828fe42496dbcnd There is some ongoing effort to only use a single variant, called <em>ap_expr</em>,
ad74a0524a06bfe11b7de9e3b4ce7233ab3bd3f7nd for all configuration directives.
1cc20a8827ff6056399d64e3106b44d31e8e0e53nd This document describes the <em>ap_expr</em> expression parser.
74f9e2dc9461c0e91b182eff6a9828fe42496dbcnd </p>
d474d8ef01ec5c2a09341cd148851ed383c3287crbowen <p>The <em>ap_expr</em> expression is intended to replace most other
d474d8ef01ec5c2a09341cd148851ed383c3287crbowen expression variants in HTTPD. For example, the deprecated
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd <directive module="mod_ssl">SSLRequire</directive> expressions can be
4b575a6b6704b516f22d65a3ad35696d7b9ba372rpluem replaced by <a href="mod/mod_authz_core.html#reqexpr">Require expr</a>.
4b575a6b6704b516f22d65a3ad35696d7b9ba372rpluem </p>
3f08db06526d6901aa08c110b5bc7dde6bc39905nd </summary>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="core" type="section">If</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="core" type="section">ElseIf</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="core" type="section">Else</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_rewrite">RewriteCond</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_setenvif">SetEnvIfExpr</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_headers">Header</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_headers">RequestHeader</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_filter">FilterProvider</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><a href="mod/mod_authz_core.html#reqexpr">Require expr</a></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_ssl">SSLRequire</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><directive module="mod_log_debug">LogMessage</directive></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<seealso><module>mod_include</module></seealso>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd <section id="grammar">
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd <title>Grammar in Backus–Naur Form notation</title>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd <p><a href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form">Backus–Naur Form</a> (BNF) is a notation
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd technique for context-free grammars, often used to describe the syntax of languages used in computing.
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd </p>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<blockquote>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd<pre>
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndexpr ::= "<strong>true</strong>" | "<strong>false</strong>"
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | "<strong>!</strong>" expr
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | expr "<strong>&amp;&amp;</strong>" expr
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | expr "<strong>||</strong>" expr
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | "<strong>(</strong>" expr "<strong>)</strong>"
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | comp
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndcomp ::= stringcomp
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | integercomp
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | unaryop word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word binaryop word
5ae30adbe59946de742ab0cd6be3b7457471a698takashi | word "<strong>in</strong>" "<strong>{</strong>" wordlist "<strong>}</strong>"
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>in</strong>" listfunction
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>=~</strong>" regex
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>!~</strong>" regex
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
5652dbe450e4fcfdf36d4cfb42d7f2345ded29a4maczniakstringcomp ::= word "<strong>==</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>!=</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>&lt;</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>&lt;=</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>&gt;</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>&gt;=</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndintegercomp ::= word "<strong>-eq</strong>" word | word "<strong>eq</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>-ne</strong>" word | word "<strong>ne</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>-lt</strong>" word | word "<strong>lt</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>-le</strong>" word | word "<strong>le</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>-gt</strong>" word | word "<strong>gt</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | word "<strong>-ge</strong>" word | word "<strong>ge</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndwordlist ::= word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd | wordlist "<strong>,</strong>" word
6116c12fdd3ed06d388fe6572e50a22e9320dfa5nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndword ::= word "<strong>.</strong>" word
ed1d958582984a7c54a6ca859e15939a414fa733nd | digit
ed1d958582984a7c54a6ca859e15939a414fa733nd | "<strong>'</strong>" string "<strong>'</strong>"
ad74a0524a06bfe11b7de9e3b4ce7233ab3bd3f7nd | "<strong>"</strong>" string "<strong>"</strong>"
74f9e2dc9461c0e91b182eff6a9828fe42496dbcnd | variable
74f9e2dc9461c0e91b182eff6a9828fe42496dbcnd | rebackref
ad74a0524a06bfe11b7de9e3b4ce7233ab3bd3f7nd | function
1cc20a8827ff6056399d64e3106b44d31e8e0e53nd
74f9e2dc9461c0e91b182eff6a9828fe42496dbcndstring ::= stringpart
d474d8ef01ec5c2a09341cd148851ed383c3287crbowen | string stringpart
d474d8ef01ec5c2a09341cd148851ed383c3287crbowen
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndstringpart ::= cstring
1a1356f375e36db7bee379ea0684ab389579f798rbowen | variable
af33a4994ae2ff15bc67d19ff1a7feb906745bf8rbowen | rebackref
0d0ba3a410038e179b695446bb149cce6264e0abnd
7fec19672a491661b2fe4b29f685bc7f4efa64d4ndcstring ::= ...
7fec19672a491661b2fe4b29f685bc7f4efa64d4nddigit ::= [0-9]+
7fec19672a491661b2fe4b29f685bc7f4efa64d4nd
6116c12fdd3ed06d388fe6572e50a22e9320dfa5ndvariable ::= "<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>
</section>
<section id="vars">
<title>Variables</title>
<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 <directive>&lt;If &gt;</directive>
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 witht the
<code>req</code> <a href="#functions">function</a>.</p>
<table border="1" style="zebra">
<columnspec><column width="1"/></columnspec>
<tr><th>Name</th></tr>
<tr><td><code>HTTP_ACCEPT</code></td></tr>
<tr><td><code>HTTP_FORWARDED</code></td></tr>
<tr><td><code>HTTP_HOST</code></td></tr>
<tr><td><code>HTTP_PROXY_CONNECTION</code></td></tr>
<tr><td><code>HTTP_REFERER</code></td></tr>
<tr><td><code>HTTP_USER_AGENT</code></td></tr>
</table>
<p>Other request related variables</p>
<table border="1" style="zebra">
<columnspec><column width=".4"/><column width=".6"/></columnspec>
<tr><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><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><td><code>DOCUMENT_URI</code></td>
<td>Same as REQUEST_URI</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><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><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><td><code>PATH_INFO</code></td>
<td>The trailing path name information, see
<directive module="core">AcceptPathInfo</directive></td></tr>
<tr><td><code>QUERY_STRING</code></td>
<td>The query string of the current request</td></tr>
<tr><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><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><td><code>REMOTE_USER</code></td>
<td>The name of the authenticated user (if any)</td></tr>
<tr><td><code>REMOTE_IDENT</code></td>
<td>The user name set by <module>mod_ident</module></td></tr>
<tr><td><code>SERVER_NAME</code></td>
<td>The <directive module="core">ServerName</directive> of
the current vhost</td></tr>
<tr><td><code>SERVER_PORT</code></td>
<td>The server port of the current vhost, see
<directive module="core">ServerName</directive></td></tr>
<tr><td><code>SERVER_ADMIN</code></td>
<td>The <directive module="core">ServerAdmin</directive> of
the current vhost</td></tr>
<tr><td><code>SERVER_PROTOCOL</code></td>
<td>The protocol used by the request</td></tr>
<tr><td><code>DOCUMENT_ROOT</code></td>
<td>The <directive module="core">DocumentRoot</directive> of
the current vhost</td></tr>
<tr><td><code>AUTH_TYPE</code></td>
<td>The configured <directive module="mod_authn_core">AuthType</directive>
(e.g. "<code>basic</code>")</td></tr>
<tr><td><code>CONTENT_TYPE</code></td>
<td>The content type of the response</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><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><td><code>REQUEST_STATUS</code></td>
<td>The HTTP error status of the request</td></tr>
<tr><td><code>REQUEST_LOG_ID</code></td>
<td>The error log id of the request (see
<directive module="core">ErrorLogFormat</directive>)</td></tr>
<tr><td><code>CONN_LOG_ID</code></td>
<td>The error log id of the connection (see
<directive module="core">ErrorLogFormat</directive>)</td></tr>
<tr><td><code>CONN_REMOTE_ADDR</code></td>
<td>The raw IP address of the remote host (see the
<module>mod_remoteip</module> module)</td></tr>
</table>
<p>Misc variables</p>
<table border="1" style="zebra">
<columnspec><column width=".4"/><column width=".6"/></columnspec>
<tr><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><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><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><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><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><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. <module>mod_ssl</module>.</p>
</section>
<section id="binop">
<title>Binary operators</title>
<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>
<section id="comp">
<title>Comparison operators</title>
<table border="1" style="zebra">
<columnspec><column width=".2"/><column width=".2"/><column width=".6"/></columnspec>
<tr><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><td><code>!=</code></td>
<td></td>
<td>String inequality</td></tr>
<tr><td><code>&lt;</code></td>
<td></td>
<td>String less than</td></tr>
<tr><td><code>&lt;=</code></td>
<td></td>
<td>String less than or equal</td></tr>
<tr><td><code>&gt;</code></td>
<td></td>
<td>String greater than</td></tr>
<tr><td><code>&gt;=</code></td>
<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><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><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><td><code>-ge</code></td>
<td><code>ge</code></td>
<td>Integer greater than or equal</td></tr>
</table>
</section>
<section id="binaryother">
<title>Other binary operators</title>
<table border="1" style="zebra">
<columnspec><column width=".2"/><column width=".8"/></columnspec>
<tr><th>Name</th><th>Description</th></tr>
<tr><td><code>-ipmatch</code></td>
<td>IP address matches address/netmask</td></tr>
<tr><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><td><code>-fnmatch</code></td>
<td>same as <code>-strmatch</code>, but slashes are not matched by
wildcards</td></tr>
</table>
</section>
</section>
<section id="unnop">
<title>Unary operators</title>
<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 border="1" style="zebra">
<columnspec><column width=".2"/><column width=".2"/><column width=".6"/></columnspec>
<tr><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><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><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><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></td></tr>
<tr><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></td></tr>
<tr><td><code>-A</code></td>
<td>Alias for <code>-U</code></td><td></td></tr>
<tr><td><code>-n</code></td>
<td>True if string is not empty</td><td></td></tr>
<tr><td><code>-z</code></td>
<td>True if string is empty</td><td></td></tr>
<tr><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></td></tr>
<tr><td><code>-R</code></td>
<td>Same as "<code>%{REMOTE_ADDR} -ipmatch ...</code>", but more efficient
</td><td></td></tr>
</table>
<p>The operators marked as "restricted" are not available in some modules
like <module>mod_include</module>.</p>
</section>
<section id="functions">
<title>Functions</title>
<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 border="1" style="zebra">
<columnspec><column width=".2"/><column width=".8"/></columnspec>
<tr><th>Name</th><th>Description</th><th>Restricted</th></tr>
<tr><td><code>req</code>, <code>http</code></td>
<td>Get HTTP request header</td><td></td></tr>
<tr><td><code>resp</code></td>
<td>Get HTTP response header</td><td></td></tr>
<tr><td><code>reqenv</code></td>
<td>Lookup request environment variable</td><td></td></tr>
<tr><td><code>osenv</code></td>
<td>Lookup operating system environment variable</td><td></td></tr>
<tr><td><code>note</code></td>
<td>Lookup request note</td><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></td></tr>
<tr><td><code>tolower</code></td>
<td>Convert string to lower case</td><td></td></tr>
<tr><td><code>toupper</code></td>
<td>Convert string to uppser case</td><td></td></tr>
<tr><td><code>escape</code></td>
<td>Escape special characters in %hex encoding</td><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></td></tr>
<tr><td><code>file</code></td>
<td>Read contents from a file</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 <module>mod_include</module>.</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. <module>mod_ssl</module>
provides <code>PeerExtList</code>. See the description of
<directive module="mod_ssl">SSLRequire</directive> for details
(but <code>PeerExtList</code> is also usable outside
of <directive module="mod_ssl">SSLRequire</directive>).</p>
</section>
<section id="other">
<title>Other</title>
<table border="1" style="zebra">
<columnspec><column width=".2"/><column width=".2"/><column width=".6"/></columnspec>
<tr><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 string list</td></tr>
<tr><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><td><code>$0 ... $9</code></td>
<td></td>
<td>Regular expression backreferences</td></tr>
</table>
<section id="rebackref">
<title>Regular expression backreferences</title>
<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>
</section>
</section>
<section id="sslrequire">
<title>Comparison with SSLRequire</title>
<p>The <em>ap_expr</em> syntax is mostly a superset of the syntax of the
deprecated <directive module="mod_ssl">SSLRequire</directive> directive.
The differences are described in <directive
module="mod_ssl">SSLRequire</directive>'s documentation.</p>
</section>
</manualpage>