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<div id="page-content">
<div id="preamble"><h1>Apache Module mod_lua</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../en/mod/mod_lua.html" title="English">&nbsp;en&nbsp;</a> |
<a href="../fr/mod/mod_lua.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Provides Lua hooks into various portions of the httpd
request processing</td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>lua_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_lua.c</td></tr>
<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>2.3 and later</td></tr></table>
<h3>Summary</h3>

<p>This module allows the server to be extended with scripts written in the
Lua programming language.  The extension points (hooks) available with
<code class="module"><a href="../mod/mod_lua.html">mod_lua</a></code> include many of the hooks available to
natively compiled Apache HTTP Server modules, such as mapping requests to
files, generating dynamic responses, access control, authentication, and
authorization</p>

<p>More information on the Lua programming language can be found at the
<a href="http://www.lua.org/">the Lua website</a>.</p>

<div class="warning"><h3>Warning</h3>
<p>This module holds a great deal of power over httpd, which is both a 
strength and a potential security risk. It is <strong>not</strong> recommended 
that you use this module on a server that is shared with users you do not 
trust, as it can be abused to change the internal workings of httpd.</p>
</div>

</div>
<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><h3>Topics</h3>
<ul id="topics">
<li><img alt="" src="../images/down.gif" /> <a href="#basicconf">Basic Configuration</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#writinghandlers">Writing Handlers</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#writingauthzproviders">Writing Authorization Providers</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#writinghooks">Writing Hooks</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#datastructures">Data Structures</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#functions">Built in functions</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#logging">Logging Functions</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#apache2">apache2 Package</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#modifying_buckets">Modifying contents with Lua filters</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#databases">Database connectivity</a></li>
</ul><h3 class="directives">Directives</h3>
<ul id="toc">
<li><img alt="" src="../images/down.gif" /> <a href="#luaauthzprovider">LuaAuthzProvider</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luacodecache">LuaCodeCache</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookaccesschecker">LuaHookAccessChecker</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookauthchecker">LuaHookAuthChecker</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookcheckuserid">LuaHookCheckUserID</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookfixups">LuaHookFixups</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookinsertfilter">LuaHookInsertFilter</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahooklog">LuaHookLog</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookmaptostorage">LuaHookMapToStorage</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahookpretranslate">LuaHookPreTranslate</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahooktranslatename">LuaHookTranslateName</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luahooktypechecker">LuaHookTypeChecker</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luainherit">LuaInherit</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luainputfilter">LuaInputFilter</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luamaphandler">LuaMapHandler</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luaoutputfilter">LuaOutputFilter</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luapackagecpath">LuaPackageCPath</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luapackagepath">LuaPackagePath</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luaquickhandler">LuaQuickHandler</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luaroot">LuaRoot</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#luascope">LuaScope</a></li>
</ul>
<h3>Bugfix checklist</h3><ul class="seealso"><li><a href="https://www.apache.org/dist/httpd/CHANGES_2.4">httpd changelog</a></li><li><a href="https://bz.apache.org/bugzilla/buglist.cgi?bug_status=__open__&amp;list_id=144532&amp;product=Apache%20httpd-2&amp;query_format=specific&amp;order=changeddate%20DESC%2Cpriority%2Cbug_severity&amp;component=mod_lua">Known issues</a></li><li><a href="https://bz.apache.org/bugzilla/enter_bug.cgi?product=Apache%20httpd-2&amp;component=mod_lua">Report a bug</a></li></ul><h3>See also</h3>
<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="basicconf" id="basicconf">Basic Configuration</a></h2>

<p>The basic module loading directive is</p>

<pre class="prettyprint lang-config">LoadModule lua_module modules/mod_lua.so</pre>


<p>
<code>mod_lua</code> provides a handler named <code>lua-script</code>,
which can be used with a <code class="directive"><a href="../mod/core.html#sethandler">SetHandler</a></code> or
<code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> directive:</p>

<pre class="prettyprint lang-config">&lt;Files "*.lua"&gt;
    SetHandler lua-script
&lt;/Files&gt;</pre>


<p>
This will cause <code>mod_lua</code> to handle requests for files
ending in <code>.lua</code> by invoking that file's
<code>handle</code> function.
</p>

<p>For more flexibility, see <code class="directive">LuaMapHandler</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="writinghandlers" id="writinghandlers">Writing Handlers</a></h2>
<p> In the Apache HTTP Server API, the handler is a specific kind of hook
responsible for generating the response.  Examples of modules that include a
handler are <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>, <code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>,
and <code class="module"><a href="../mod/mod_status.html">mod_status</a></code>.</p>

<p><code>mod_lua</code> always looks to invoke a Lua function for the handler, rather than
just evaluating a script body CGI style. A handler function looks
something like this:</p>


<pre class="prettyprint lang-lua">
<strong>example.lua</strong><br />
-- example handler

require "string"

--[[
     This is the default method name for Lua handlers, see the optional
     function-name in the LuaMapHandler directive to choose a different
     entry point.
--]]
function handle(r)
    r.content_type = "text/plain"

    if r.method == 'GET' then
        r:puts("Hello Lua World!\n")
        for k, v in pairs( r:parseargs() ) do
            r:puts( string.format("%s: %s\n", k, v) )
        end
    elseif r.method == 'POST' then
        r:puts("Hello Lua World!\n")
        for k, v in pairs( r:parsebody() ) do
            r:puts( string.format("%s: %s\n", k, v) )
        end
    elseif r.method == 'PUT' then
-- use our own Error contents
        r:puts("Unsupported HTTP method " .. r.method)
        r.status = 405
        return apache2.OK
    else
-- use the ErrorDocument
        return 501
    end
    return apache2.OK
end</pre>


<p>
This handler function just prints out the uri or form encoded
arguments to a plaintext page.
</p>

<p>
This means (and in fact encourages) that you can have multiple
handlers (or hooks, or filters) in the same script.
</p>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="writingauthzproviders" id="writingauthzproviders">Writing Authorization Providers</a></h2>


<p><code class="module"><a href="../mod/mod_authz_core.html">mod_authz_core</a></code> provides a high-level interface to
authorization that is much easier to use than using into the relevant
hooks directly. The first argument to the
<code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directive gives
the name of the responsible authorization provider. For any
<code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> line,
<code class="module"><a href="../mod/mod_authz_core.html">mod_authz_core</a></code> will call the authorization provider
of the given name, passing the rest of the line as parameters. The
provider will then check authorization and pass the result as return
value.</p>

<p>The authz provider is normally called before authentication. If it needs to
know the authenticated user name (or if the user will be authenticated at
all), the provider must return <code>apache2.AUTHZ_DENIED_NO_USER</code>.
This will cause authentication to proceed and the authz provider to be
called a second time.</p>

<p>The following authz provider function takes two arguments, one ip
address and one user name. It will allow access from the given ip address
without authentication, or if the authenticated user matches the second
argument:</p>

<pre class="prettyprint lang-lua">
<strong>authz_provider.lua</strong><br />

require 'apache2'

function authz_check_foo(r, ip, user)
    if r.useragent_ip == ip then
        return apache2.AUTHZ_GRANTED
    elseif r.user == nil then
        return apache2.AUTHZ_DENIED_NO_USER
    elseif r.user == user then
        return apache2.AUTHZ_GRANTED
    else
        return apache2.AUTHZ_DENIED
    end
end</pre>


<p>The following configuration registers this function as provider
<code>foo</code> and configures it for URL <code>/</code>:</p>
<pre class="prettyprint lang-config">LuaAuthzProvider foo authz_provider.lua authz_check_foo
&lt;Location "/"&gt;
  Require foo 10.1.2.3 john_doe
&lt;/Location&gt;</pre>


</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="writinghooks" id="writinghooks">Writing Hooks</a></h2>

<p>Hook functions are how modules (and Lua scripts) participate in the
processing of requests. Each type of hook exposed by the server exists for
a specific purpose, such as mapping requests to the file system,
performing access control, or setting mime types:</p>

<table class="bordered"><tr class="header">
        <th>Hook phase</th>
        <th>mod_lua directive</th>
        <th>Description</th>
    </tr>
<tr>
        <td>Quick handler</td>
        <td><code class="directive"><a href="#luaquickhandler">LuaQuickHandler</a></code></td>
        <td>This is the first hook that will be called after a request has 
            been mapped to a host or virtual host</td>
    </tr>
<tr class="odd">
        <td>Pre-Translate name</td>
        <td><code class="directive"><a href="#luahookpretranslatename">LuaHookPreTranslateName</a></code></td>
        <td>This phase translates the requested URI into a filename on the
            system, before decoding occurs. Modules such as <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>
            can operate in this phase.</td>
    </tr>
<tr>
        <td>Translate name</td>
        <td><code class="directive"><a href="#luahooktranslatename">LuaHookTranslateName</a></code></td>
        <td>This phase translates the requested URI into a filename on the 
            system. Modules such as <code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code> and
            <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> operate in this phase.</td>
    </tr>
<tr class="odd">
        <td>Map to storage</td>
        <td><code class="directive"><a href="#luahookmaptostorage">LuaHookMapToStorage</a></code></td>
        <td>This phase maps files to their physical, cached or external/proxied storage. 
            It can be used by proxy or caching modules</td>
    </tr>
<tr>
        <td>Check Access</td>
        <td><code class="directive"><a href="#luahookaccesschecker">LuaHookAccessChecker</a></code></td>
        <td>This phase checks whether a client has access to a resource. This 
            phase is run before the user is authenticated, so beware.
        </td>
    </tr>
<tr class="odd">
        <td>Check User ID</td>
        <td><code class="directive"><a href="#luahookcheckuserid">LuaHookCheckUserID</a></code></td>
        <td>This phase it used to check the negotiated user ID</td>
    </tr>
<tr>
        <td>Check Authorization</td>
        <td><code class="directive"><a href="#luahookauthchecker">LuaHookAuthChecker</a></code> or 
            <code class="directive"><a href="#luaauthzprovider">LuaAuthzProvider</a></code></td>
        <td>This phase authorizes a user based on the negotiated credentials, such as 
            user ID, client certificate etc.
        </td>
    </tr>
<tr class="odd">
        <td>Check Type</td>
        <td><code class="directive"><a href="#luahooktypechecker">LuaHookTypeChecker</a></code></td>
        <td>This phase checks the requested file and assigns a content type and 
            a handler to it</td>
    </tr>
<tr>
        <td>Fixups</td>
        <td><code class="directive"><a href="#luahookfixups">LuaHookFixups</a></code></td>
        <td>This is the final "fix anything" phase before the content handlers 
            are run. Any last-minute changes to the request should be made here.</td>
    </tr>
<tr class="odd">
        <td>Content handler</td>
        <td>fx. <code>.lua</code> files or through <code class="directive"><a href="#luamaphandler">LuaMapHandler</a></code></td>
        <td>This is where the content is handled. Files are read, parsed, some are run, 
            and the result is sent to the client</td>
    </tr>
<tr>
        <td>Logging</td>
        <td><code class="directive"><a href="#luahooklog">LuaHookLog</a></code></td>
        <td>Once a request has been handled, it enters several logging phases, 
            which logs the request in either the error or access log. Mod_lua
            is able to hook into the start of this and control logging output.</td>
    </tr>
</table>

<p>Hook functions are passed the request object as their only argument 
(except for LuaAuthzProvider, which also gets passed the arguments from 
the Require directive).
They can return any value, depending on the hook, but most commonly
they'll return OK, DONE, or DECLINED, which you can write in Lua as
<code>apache2.OK</code>, <code>apache2.DONE</code>, or
<code>apache2.DECLINED</code>, or else an HTTP status code.</p>


<pre class="prettyprint lang-lua">
<strong>translate_name.lua</strong><br />
-- example hook that rewrites the URI to a filesystem path.

require 'apache2'

function translate_name(r)
    if r.uri == "/translate-name" then
        r.filename = r.document_root .. "/find_me.txt"
        return apache2.OK
    end
    -- we don't care about this URL, give another module a chance
    return apache2.DECLINED
end</pre>



<pre class="prettyprint lang-lua">
<strong>translate_name2.lua</strong><br />
--[[ example hook that rewrites one URI to another URI. It returns a
     apache2.DECLINED to give other URL mappers a chance to work on the
     substitution, including the core translate_name hook which maps based
     on the DocumentRoot.

     Note: Use the early/late flags in the directive to make it run before
           or after mod_alias.
--]]

require 'apache2'

function translate_name(r)
    if r.uri == "/translate-name" then
        r.uri = "/find_me.txt"
        return apache2.DECLINED
    end
    return apache2.DECLINED
end</pre>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="datastructures" id="datastructures">Data Structures</a></h2>

<dl>
<dt>request_rec</dt>
        <dd>
        <p>The request_rec is mapped in as a userdata. It has a metatable
        which lets you do useful things with it. For the most part it
        has the same fields as the request_rec struct, many of which are writable as
        well as readable.  (The table fields' content can be changed, but the
        fields themselves cannot be set to different tables.)</p>

        <table class="bordered"><tr class="header">
          <th><strong>Name</strong></th>
          <th><strong>Lua type</strong></th>
          <th><strong>Writable</strong></th>
          <th><strong>Description</strong></th>
        </tr>
<tr>
          <td><code>allowoverrides</code></td>
          <td>string</td>
          <td>no</td>
          <td>The AllowOverride options applied to the current request.</td>
        </tr>
<tr class="odd">
          <td><code>ap_auth_type</code></td>
          <td>string</td>
          <td>no</td>
          <td>If an authentication check was made, this is set to the type 
          of authentication (f.x. <code>basic</code>)</td>
        </tr>
<tr>
          <td><code>args</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The query string arguments extracted from the request 
            (f.x. <code>foo=bar&amp;name=johnsmith</code>)</td>
        </tr>
<tr class="odd">
          <td><code>assbackwards</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Set to true if this is an HTTP/0.9 style request 
            (e.g. <code>GET /foo</code> (with no headers) )</td>
        </tr>
<tr>
          <td><code>auth_name</code></td>
          <td>string</td>
          <td>no</td>
          <td>The realm name used for authorization (if applicable).</td>
        </tr>
<tr class="odd">
          <td><code>banner</code></td>
          <td>string</td>
          <td>no</td>
          <td>The server banner, f.x. <code>Apache HTTP Server/2.4.3 openssl/0.9.8c</code></td>
        </tr>
<tr>
          <td><code>basic_auth_pw</code></td>
          <td>string</td>
          <td>no</td>
          <td>The basic auth password sent with this request, if any</td>
        </tr>
<tr class="odd">
          <td><code>canonical_filename</code></td>
          <td>string</td>
          <td>no</td>
          <td>The canonical filename of the request</td>
        </tr>
<tr>
          <td><code>content_encoding</code></td>
          <td>string</td>
          <td>no</td>
          <td>The content encoding of the current request</td>
        </tr>
<tr class="odd">
          <td><code>content_type</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The content type of the current request, as determined in the 
            type_check phase (f.x. <code>image/gif</code> or <code>text/html</code>)</td>
        </tr>
<tr>
          <td><code>context_prefix</code></td>
          <td>string</td>
          <td>no</td>
          <td />
        </tr>
<tr class="odd">
          <td><code>context_document_root</code></td>
          <td>string</td>
          <td>no</td>
          <td />
        </tr>
<tr>
          <td><code>document_root</code></td>
          <td>string</td>
          <td>no</td>
          <td>The document root of the host</td>
        </tr>
<tr class="odd">
          <td><code>err_headers_out</code></td>
          <td>table</td>
          <td>no</td>
          <td>MIME header environment for the response, printed even on errors and
            persist across internal redirects.  A read-only lua table suitable for iteration is available as r:err_headers_out_table().</td>
        </tr>
<tr>
          <td><code>filename</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The file name that the request maps to, f.x. /www/example.com/foo.txt. This can be 
            changed in the pre-translate-name, translate-name or map-to-storage phases of a request to allow the
            default handler (or script handlers) to serve a different file than what was requested.</td>
        </tr>
<tr class="odd">
          <td><code>handler</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The name of the <a href="../handler.html">handler</a> that should serve this request, f.x. 
            <code>lua-script</code> if it is to be served by mod_lua. This is typically set by the 
            <code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> or <code class="directive"><a href="../mod/core.html#sethandler">SetHandler</a></code> 
            directives, but could also be set via mod_lua to allow another handler to serve up a specific request 
            that would otherwise not be served by it.
            </td>
        </tr>
<tr>
          <td><code>headers_in</code></td>
          <td>table</td>
          <td>yes</td>
          <td>MIME header environment from the request. This contains headers such as <code>Host, 
            User-Agent, Referer</code> and so on. A read-only lua table suitable for iteration is available as r:headers_in_table().</td>
        </tr>
<tr class="odd">
          <td><code>headers_out</code></td>
          <td>table</td>
          <td>yes</td>
          <td>MIME header environment for the response. A read-only lua table suitable for iteration is available as r:headers_out_table().</td>
        </tr>
<tr>
          <td><code>hostname</code></td>
          <td>string</td>
          <td>no</td>
          <td>The host name, as set by the <code>Host:</code> header or by a full URI.</td>
        </tr>
<tr class="odd">
          <td><code>is_https</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Whether or not this request is done via HTTPS</td>
        </tr>
<tr>
          <td><code>is_initial_req</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Whether this request is the initial request or a sub-request</td>
        </tr>
<tr class="odd">
          <td><code>limit_req_body</code></td>
          <td>number</td>
          <td>no</td>
          <td>The size limit of the request body for this request, or 0 if no limit.</td>
        </tr>
<tr>
          <td><code>log_id</code></td>
          <td>string</td>
          <td>no</td>
          <td>The ID to identify request in access and error log.</td>
        </tr>
<tr class="odd">
          <td><code>method</code></td>
          <td>string</td>
          <td>no</td>
          <td>The request method, f.x. <code>GET</code> or <code>POST</code>.</td>
        </tr>
<tr>
          <td><code>notes</code></td>
          <td>table</td>
          <td>yes</td>
          <td>A list of notes that can be passed on from one module to another.  A read-only lua table suitable for iteration is available as r:notes_table().</td>
        </tr>
<tr class="odd">
          <td><code>options</code></td>
          <td>string</td>
          <td>no</td>
          <td>The Options directive applied to the current request.</td>
        </tr>
<tr>
          <td><code>path_info</code></td>
          <td>string</td>
          <td>no</td>
          <td>The PATH_INFO extracted from this request.</td>
        </tr>
<tr class="odd">
          <td><code>port</code></td>
          <td>number</td>
          <td>no</td>
          <td>The server port used by the request.</td>
        </tr>
<tr>
          <td><code>protocol</code></td>
          <td>string</td>
          <td>no</td>
          <td>The protocol used, f.x. <code>HTTP/1.1</code></td>
        </tr>
<tr class="odd">
          <td><code>proxyreq</code></td>
          <td>string</td>
          <td>yes</td>
          <td>Denotes whether this is a proxy request or not. This value is generally set in 
            the post_read_request/pre_translate_name/translate_name phase of a request.</td>
        </tr>
<tr>
          <td><code>range</code></td>
          <td>string</td>
          <td>no</td>
          <td>The contents of the <code>Range:</code> header.</td>
        </tr>
<tr class="odd">
          <td><code>remaining</code></td>
          <td>number</td>
          <td>no</td>
          <td>The number of bytes remaining to be read from the request body.</td>
        </tr>
<tr>
          <td><code>server_built</code></td>
          <td>string</td>
          <td>no</td>
          <td>The time the server executable was built.</td>
        </tr>
<tr class="odd">
          <td><code>server_name</code></td>
          <td>string</td>
          <td>no</td>
          <td>The server name for this request.</td>
        </tr>
<tr>
          <td><code>some_auth_required</code></td>
          <td>boolean</td>
          <td>no</td>
          <td>Whether some authorization is/was required for this request.</td>
        </tr>
<tr class="odd">
          <td><code>subprocess_env</code></td>
          <td>table</td>
          <td>yes</td>
          <td>The environment variables set for this request. A read-only lua table suitable for iteration is available as r:subprocess_env_table().</td>
        </tr>
<tr>
          <td><code>started</code></td>
          <td>number</td>
          <td>no</td>
          <td>The time the server was (re)started, in seconds since the epoch (Jan 1st, 1970)</td>
        </tr>
<tr class="odd">
          <td><code>status</code></td>
          <td>number</td>
          <td>yes</td>
          <td>The (current) HTTP return code for this request, f.x. <code>200</code> or <code>404</code>.</td>
        </tr>
<tr>
          <td><code>the_request</code></td>
          <td>string</td>
          <td>no</td>
          <td>The request string as sent by the client, f.x. <code>GET /foo/bar HTTP/1.1</code>.</td>
        </tr>
<tr class="odd">
          <td><code>unparsed_uri</code></td>
          <td>string</td>
          <td>no</td>
          <td>The unparsed URI of the request</td>
        </tr>
<tr>
          <td><code>uri</code></td>
          <td>string</td>
          <td>yes</td>
          <td>The URI after it has been parsed by httpd</td>
        </tr>
<tr class="odd">
          <td><code>user</code></td>
          <td>string</td>
          <td>yes</td>
          <td>If an authentication check has been made, this is set to the name of the authenticated user.</td>
        </tr>
<tr>
          <td><code>useragent_ip</code></td>
          <td>string</td>
          <td>no</td>
          <td>The IP of the user agent making the request</td>
        </tr>
</table>
           </dd>
    </dl>
</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">Built in functions</a></h2>

<p>The request_rec object has (at least) the following methods:</p>

<pre class="prettyprint lang-lua">r:flush()   -- flushes the output buffer.
            -- Returns true if the flush was successful, false otherwise.

while we_have_stuff_to_send do
    r:puts("Bla bla bla\n") -- print something to client
    r:flush() -- flush the buffer (send to client)
    r.usleep(500000) -- fake processing time for 0.5 sec. and repeat
end</pre>


<pre class="prettyprint lang-lua">r:add_output_filter(filter_name) -- add an output filter:

r:add_output_filter("fooFilter") -- add the fooFilter to the output stream</pre>


<pre class="prettyprint lang-lua">r:sendfile(filename) -- sends an entire file to the client, using sendfile if supported by the current platform:

if use_sendfile_thing then
    r:sendfile("/var/www/large_file.img")
end</pre>


<pre class="prettyprint lang-lua">r:parseargs() -- returns two tables; one standard key/value table for regular GET data, 
              -- and one for multi-value data (fx. foo=1&amp;foo=2&amp;foo=3):

local GET, GETMULTI = r:parseargs()
r:puts("Your name is: " .. GET['name'] or "Unknown")</pre>


<pre class="prettyprint lang-lua">r:parsebody([sizeLimit]) -- parse the request body as a POST and return two lua tables,
                         -- just like r:parseargs().
                         -- An optional number may be passed to specify the maximum number 
                         -- of bytes to parse. Default is 8192 bytes:
                 
local POST, POSTMULTI = r:parsebody(1024*1024)
r:puts("Your name is: " .. POST['name'] or "Unknown")</pre>


<pre class="prettyprint lang-lua">r:puts("hello", " world", "!") -- print to response body, self explanatory</pre>


<pre class="prettyprint lang-lua">r:write("a single string") -- print to response body, self explanatory</pre>


<pre class="prettyprint lang-lua">r:escape_html("&lt;html&gt;test&lt;/html&gt;") -- Escapes HTML code and returns the escaped result</pre>


<pre class="prettyprint lang-lua">r:base64_encode(string) -- Encodes a string using the Base64 encoding standard:

local encoded = r:base64_encode("This is a test") -- returns VGhpcyBpcyBhIHRlc3Q=</pre>


<pre class="prettyprint lang-lua">r:base64_decode(string) -- Decodes a Base64-encoded string:

local decoded = r:base64_decode("VGhpcyBpcyBhIHRlc3Q=") -- returns 'This is a test'</pre>


<pre class="prettyprint lang-lua">r:md5(string) -- Calculates and returns the MD5 digest of a string (binary safe):

local hash = r:md5("This is a test") -- returns ce114e4501d2f4e2dcea3e17b546f339</pre>


<pre class="prettyprint lang-lua">r:sha1(string) -- Calculates and returns the SHA1 digest of a string (binary safe):

local hash = r:sha1("This is a test") -- returns a54d88e06612d820bc3be72877c74f257b561b19</pre>


<pre class="prettyprint lang-lua">r:escape(string) -- URL-Escapes a string:

local url = "http://foo.bar/1 2 3 &amp; 4 + 5"
local escaped = r:escape(url) -- returns 'http%3a%2f%2ffoo.bar%2f1+2+3+%26+4+%2b+5'</pre>


<pre class="prettyprint lang-lua">r:unescape(string) -- Unescapes an URL-escaped string:

local url = "http%3a%2f%2ffoo.bar%2f1+2+3+%26+4+%2b+5"
local unescaped = r:unescape(url) -- returns 'http://foo.bar/1 2 3 &amp; 4 + 5'</pre>


<pre class="prettyprint lang-lua">r:construct_url(string) -- Constructs an URL from an URI

local url = r:construct_url(r.uri)</pre>


<pre class="prettyprint lang-lua">r.mpm_query(number) -- Queries the server for MPM information using ap_mpm_query:

local mpm = r.mpm_query(14)
if mpm == 1 then
    r:puts("This server uses the Event MPM")
end</pre>


<pre class="prettyprint lang-lua">r:expr(string) -- Evaluates an <a href="../expr.html">expr</a> string.

if r:expr("%{HTTP_HOST} =~ /^www/") then
    r:puts("This host name starts with www")
end</pre>


<pre class="prettyprint lang-lua">r:scoreboard_process(a) -- Queries the server for information about the process at position <code>a</code>:

local process = r:scoreboard_process(1)
r:puts("Server 1 has PID " .. process.pid)</pre>


<pre class="prettyprint lang-lua">r:scoreboard_worker(a, b) -- Queries for information about the worker thread, <code>b</code>, in process <code>a</code>:

local thread = r:scoreboard_worker(1, 1)
r:puts("Server 1's thread 1 has thread ID " .. thread.tid .. " and is in " .. thread.status .. " status")</pre>



<pre class="prettyprint lang-lua">r:clock() -- Returns the current time with microsecond precision</pre>


<pre class="prettyprint lang-lua">r:requestbody(filename) -- Reads and returns the request body of a request.
                -- If 'filename' is specified, it instead saves the
                -- contents to that file:
                
local input = r:requestbody()
r:puts("You sent the following request body to me:\n")
r:puts(input)</pre>


<pre class="prettyprint lang-lua">r:add_input_filter(filter_name) -- Adds 'filter_name' as an input filter</pre>


<pre class="prettyprint lang-lua">r.module_info(module_name) -- Queries the server for information about a module

local mod = r.module_info("mod_lua.c")
if mod then
    for k, v in pairs(mod.commands) do
       r:puts( ("%s: %s\n"):format(k,v)) -- print out all directives accepted by this module
    end
end</pre>


<pre class="prettyprint lang-lua">r:loaded_modules() -- Returns a list of modules loaded by httpd:

for k, module in pairs(r:loaded_modules()) do
    r:puts("I have loaded module " .. module .. "\n")
end</pre>


<pre class="prettyprint lang-lua">r:runtime_dir_relative(filename) -- Compute the name of a run-time file (e.g., shared memory "file") 
                         -- relative to the appropriate run-time directory.</pre>


<pre class="prettyprint lang-lua">r:server_info() -- Returns a table containing server information, such as 
                -- the name of the httpd executable file, mpm used etc.</pre>


<pre class="prettyprint lang-lua">r:set_document_root(file_path) -- Sets the document root for the request to file_path</pre>




<pre class="prettyprint lang-lua">r:set_context_info(prefix, docroot) -- Sets the context prefix and context document root for a request</pre>


<pre class="prettyprint lang-lua">r:os_escape_path(file_path) -- Converts an OS path to a URL in an OS dependent way</pre>


<pre class="prettyprint lang-lua">r:escape_logitem(string) -- Escapes a string for logging</pre>


<pre class="prettyprint lang-lua">r.strcmp_match(string, pattern) -- Checks if 'string' matches 'pattern' using strcmp_match (globs).
                        -- fx. whether 'www.example.com' matches '*.example.com':
                        
local match = r.strcmp_match("foobar.com", "foo*.com")
if match then 
    r:puts("foobar.com matches foo*.com")
end</pre>


<pre class="prettyprint lang-lua">r:set_keepalive() -- Sets the keepalive status for a request. Returns true if possible, false otherwise.</pre>


<pre class="prettyprint lang-lua">r:make_etag() -- Constructs and returns the etag for the current request.</pre>


<pre class="prettyprint lang-lua">r:send_interim_response(clear) -- Sends an interim (1xx) response to the client.
                       -- if 'clear' is true, available headers will be sent and cleared.</pre>


<pre class="prettyprint lang-lua">r:custom_response(status_code, string) -- Construct and set a custom response for a given status code.
                               -- This works much like the ErrorDocument directive:
                               
r:custom_response(404, "Baleted!")</pre>


<pre class="prettyprint lang-lua">r.exists_config_define(string) -- Checks whether a configuration definition exists or not:

if r.exists_config_define("FOO") then
    r:puts("httpd was probably run with -DFOO, or it was defined in the configuration")
end</pre>


<pre class="prettyprint lang-lua">r:state_query(string) -- Queries the server for state information</pre>


<pre class="prettyprint lang-lua">r:stat(filename [,wanted]) -- Runs stat() on a file, and returns a table with file information:

local info = r:stat("/var/www/foo.txt")
if info then
    r:puts("This file exists and was last modified at: " .. info.modified)
end</pre>


<pre class="prettyprint lang-lua">r:regex(string, pattern [,flags]) -- Runs a regular expression match on a string, returning captures if matched:

local matches = r:regex("foo bar baz", [[foo (\w+) (\S*)]])
if matches then
    r:puts("The regex matched, and the last word captured ($2) was: " .. matches[2])
end

-- Example ignoring case sensitivity:
local matches = r:regex("FOO bar BAz", [[(foo) bar]], 1)

-- Flags can be a bitwise combination of:
-- 0x01: Ignore case
-- 0x02: Multiline search</pre>


<pre class="prettyprint lang-lua">r.usleep(number_of_microseconds) -- Puts the script to sleep for a given number of microseconds.</pre>


<pre class="prettyprint lang-lua">r:dbacquire(dbType[, dbParams]) -- Acquires a connection to a database and returns a database class.
                        -- See '<a href="#databases">Database connectivity</a>' for details.</pre>


<pre class="prettyprint lang-lua">r:ivm_set("key", value) -- Set an Inter-VM variable to hold a specific value.
                        -- These values persist even though the VM is gone or not being used,
                        -- and so should only be used if MaxConnectionsPerChild is &gt; 0
                        -- Values can be numbers, strings and booleans, and are stored on a 
                        -- per process basis (so they won't do much good with a prefork mpm)
                        
r:ivm_get("key")        -- Fetches a variable set by ivm_set. Returns the contents of the variable
                        -- if it exists or nil if no such variable exists.
                        
-- An example getter/setter that saves a global variable outside the VM:
function handle(r)
    -- First VM to call this will get no value, and will have to create it
    local foo = r:ivm_get("cached_data")
    if not foo then
        foo = do_some_calcs() -- fake some return value
        r:ivm_set("cached_data", foo) -- set it globally
    end
    r:puts("Cached data is: ", foo)
end</pre>


<pre class="prettyprint lang-lua">r:htpassword(string [,algorithm [,cost]]) -- Creates a password hash from a string.
                                          -- algorithm: 0 = APMD5 (default), 1 = SHA, 2 = BCRYPT, 3 = CRYPT.
                                          -- cost: only valid with BCRYPT algorithm (default = 5).</pre>


<pre class="prettyprint lang-lua">r:mkdir(dir [,mode]) -- Creates a directory and sets mode to optional mode parameter.</pre>


<pre class="prettyprint lang-lua">r:mkrdir(dir [,mode]) -- Creates directories recursive and sets mode to optional mode parameter.</pre>


<pre class="prettyprint lang-lua">r:rmdir(dir) -- Removes a directory.</pre>


<pre class="prettyprint lang-lua">r:touch(file [,mtime]) -- Sets the file modification time to current time or to optional mtime msec value.</pre>


<pre class="prettyprint lang-lua">r:get_direntries(dir) -- Returns a table with all directory entries.

function handle(r)
  local dir = r.context_document_root
  for _, f in ipairs(r:get_direntries(dir)) do
    local info = r:stat(dir .. "/" .. f)
    if info then
      local mtime = os.date(fmt, info.mtime / 1000000)
      local ftype = (info.filetype == 2) and "[dir] " or "[file]"
      r:puts( ("%s %s %10i %s\n"):format(ftype, mtime, info.size, f) )
    end
  end
end</pre>


<pre class="prettyprint lang-lua">r.date_parse_rfc(string) -- Parses a date/time string and returns seconds since epoche.</pre>


<pre class="prettyprint lang-lua">r:getcookie(key) -- Gets a HTTP cookie</pre>


<pre class="prettyprint lang-lua">r:setcookie{
  key = [key],
  value = [value],
  expires = [expiry],
  secure = [boolean],
  httponly = [boolean],
  path = [path],
  domain = [domain]
} -- Sets a HTTP cookie, for instance:

r:setcookie{
  key = "cookie1",
  value = "HDHfa9eyffh396rt",
  expires = os.time() + 86400,
  secure = true
}</pre>


<pre class="prettyprint lang-lua">r:wsupgrade() -- Upgrades a connection to WebSockets if possible (and requested):
if r:wsupgrade() then -- if we can upgrade:
    r:wswrite("Welcome to websockets!") -- write something to the client
    r:wsclose()  -- goodbye!
end</pre>


<pre class="prettyprint lang-lua">r:wsread() -- Reads a WebSocket frame from a WebSocket upgraded connection (see above):

local line, isFinal = r:wsread() -- isFinal denotes whether this is the final frame.
                                 -- If it isn't, then more frames can be read
r:wswrite("You wrote: " .. line)</pre>


<pre class="prettyprint lang-lua">r:wswrite(line) -- Writes a frame to a WebSocket client:
r:wswrite("Hello, world!")</pre>


<pre class="prettyprint lang-lua">r:wsclose() -- Closes a WebSocket request and terminates it for httpd:

if r:wsupgrade() then
    r:wswrite("Write something: ")
    local line = r:wsread() or "nothing"
    r:wswrite("You wrote: " .. line);
    r:wswrite("Goodbye!")
    r:wsclose()
end</pre>


</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="logging" id="logging">Logging Functions</a></h2>

<pre class="prettyprint lang-lua">-- examples of logging messages
r:trace1("This is a trace log message") -- trace1 through trace8 can be used
r:debug("This is a debug log message")
r:info("This is an info log message")
r:notice("This is a notice log message")
r:warn("This is a warn log message")
r:err("This is an err log message")
r:alert("This is an alert log message")
r:crit("This is a crit log message")
r:emerg("This is an emerg log message")</pre>


</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="apache2" id="apache2">apache2 Package</a></h2>
<p>A package named <code>apache2</code> is available with (at least) the following contents.</p>
<dl>
  <dt>apache2.OK</dt>
  <dd>internal constant OK.  Handlers should return this if they've
  handled the request.</dd>
  <dt>apache2.DECLINED</dt>
  <dd>internal constant DECLINED.  Handlers should return this if
  they are not going to handle the request.</dd>
  <dt>apache2.DONE</dt>
  <dd>internal constant DONE.</dd>
  <dt>apache2.version</dt>
  <dd>Apache HTTP server version string</dd>
  <dt>apache2.HTTP_MOVED_TEMPORARILY</dt>
  <dd>HTTP status code</dd>
  <dt>apache2.PROXYREQ_NONE, apache2.PROXYREQ_PROXY, apache2.PROXYREQ_REVERSE, apache2.PROXYREQ_RESPONSE</dt>
  <dd>internal constants used by <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code></dd>
  <dt>apache2.AUTHZ_DENIED, apache2.AUTHZ_GRANTED, apache2.AUTHZ_NEUTRAL, apache2.AUTHZ_GENERAL_ERROR, apache2.AUTHZ_DENIED_NO_USER</dt>
  <dd>internal constants used by <code class="module"><a href="../mod/mod_authz_core.html">mod_authz_core</a></code></dd>

</dl>
<p>(Other HTTP status codes are not yet implemented.)</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="modifying_buckets" id="modifying_buckets">Modifying contents with Lua filters</a></h2>
    
    <p>
    Filter functions implemented via <code class="directive"><a href="#luainputfilter">LuaInputFilter</a></code> 
    or <code class="directive"><a href="#luaoutputfilter">LuaOutputFilter</a></code> are designed as 
    three-stage non-blocking functions using coroutines to suspend and resume a 
    function as buckets are sent down the filter chain. The core structure of 
    such a function is:
    </p>
    <pre class="prettyprint lang-lua">function filter(r)
    -- Our first yield is to signal that we are ready to receive buckets.
    -- Before this yield, we can set up our environment, check for conditions,
    -- and, if we deem it necessary, decline filtering a request altogether:
    if something_bad then
        return -- This would skip this filter.
    end
    -- Regardless of whether we have data to prepend, a yield MUST be called here.
    -- Note that only output filters can prepend data. Input filters must use the 
    -- final stage to append data to the content.
    coroutine.yield([optional header to be prepended to the content])
    
    -- After we have yielded, buckets will be sent to us, one by one, and we can 
    -- do whatever we want with them and then pass on the result.
    -- Buckets are stored in the global variable 'bucket', so we create a loop
    -- that checks if 'bucket' is not nil:
    while bucket ~= nil do
        local output = mangle(bucket) -- Do some stuff to the content
        coroutine.yield(output) -- Return our new content to the filter chain
    end

    -- Once the buckets are gone, 'bucket' is set to nil, which will exit the 
    -- loop and land us here. Anything extra we want to append to the content
    -- can be done by doing a final yield here. Both input and output filters 
    -- can append data to the content in this phase.
    coroutine.yield([optional footer to be appended to the content])
end</pre>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="databases" id="databases">Database connectivity</a></h2>
    
    <p>
    Mod_lua implements a simple database feature for querying and running commands
    on the most popular database engines (mySQL, PostgreSQL, FreeTDS, ODBC, SQLite, Oracle)
    as well as mod_dbd.</p>
    <p>
    The <code>dbType</code> to use as the first parameter of <code>dbacquire</code>
    is case sensitive.</p>
    <p>
    It should be one of <code>mysql</code>, <code>pgsql</code>, <code>freetds</code>,
    <code>odbc</code>, <code>sqlite2</code>, <code>sqlite3</code>, <code>oracle</code>
    or <code>mod_dbd</code>.
    </p>
    <p>The example below shows how to acquire a database handle and return information from a table:</p>
    <pre class="prettyprint lang-lua">function handle(r)
    -- Acquire a database handle
    local database, err = r:dbacquire("mysql", "server=localhost,user=someuser,pass=somepass,dbname=mydb")
    if not err then
        -- Select some information from it
        local results, err = database:select(r, "SELECT `name`, `age` FROM `people` WHERE 1")
        if not err then
            local rows = results(0) -- fetch all rows synchronously
            for k, row in pairs(rows) do
                r:puts( string.format("Name: %s, Age: %s&lt;br/&gt;", row[1], row[2]) )
            end
        else
            r:puts("Database query error: " .. err)
        end
        database:close()
    else
        r:puts("Could not connect to the database: " .. err)
    end
end</pre>

    <p>
    To utilize <code class="module"><a href="../mod/mod_dbd.html">mod_dbd</a></code>, specify <code>mod_dbd</code>
    as the database type, or leave the field blank:
    </p>
    <pre class="prettyprint lang-lua">local database = r:dbacquire("mod_dbd")</pre>

    <h3><a name="database_object" id="database_object">Database object and contained functions</a></h3>
        
        <p>The database object returned by <code>dbacquire</code> has the following methods:</p>
        <p><strong>Normal select and query from a database:</strong></p>
    <pre class="prettyprint lang-lua">-- Run a statement and return the number of rows affected:
local affected, errmsg = database:query(r, "DELETE FROM `tbl` WHERE 1")

-- Run a statement and return a result set that can be used synchronously or async:
local result, errmsg = database:select(r, "SELECT * FROM `people` WHERE 1")</pre>

        <p><strong>Using prepared statements (recommended):</strong></p>
    <pre class="prettyprint lang-lua">-- Create and run a prepared statement:
local statement, errmsg = database:prepare(r, "DELETE FROM `tbl` WHERE `age` &gt; %u")
if not errmsg then
    local result, errmsg = statement:query(20) -- run the statement with age &gt; 20
end

-- Fetch a prepared statement from a DBDPrepareSQL directive:
local statement, errmsg = database:prepared(r, "someTag")
if not errmsg then
    local result, errmsg = statement:select("John Doe", 123) -- inject the values "John Doe" and 123 into the statement
end</pre>

        <p><strong>Escaping values, closing databases etc:</strong></p>
    <pre class="prettyprint lang-lua">-- Escape a value for use in a statement:
local escaped = database:escape(r, [["'|blabla]])

-- Close a database connection and free up handles:
database:close()

-- Check whether a database connection is up and running:
local connected = database:active()</pre>

    
    <h3><a name="result_sets" id="result_sets">Working with result sets</a></h3>
    
    <p>The result set returned by <code>db:select</code> or by the prepared statement functions 
    created through <code>db:prepare</code> can be used to
    fetch rows synchronously or asynchronously, depending on the row number specified:<br />
    <code>result(0)</code> fetches all rows in a synchronous manner, returning a table of rows.<br />
    <code>result(-1)</code> fetches the next available row in the set, asynchronously.<br />
    <code>result(N)</code> fetches row number <code>N</code>, asynchronously:
    </p>
    <pre class="prettyprint lang-lua">-- fetch a result set using a regular query:
local result, err = db:select(r, "SELECT * FROM `tbl` WHERE 1")

local rows = result(0) -- Fetch ALL rows synchronously
local row = result(-1) -- Fetch the next available row, asynchronously
local row = result(1234) -- Fetch row number 1234, asynchronously
local row = result(-1, true) -- Fetch the next available row, using row names as key indexes.</pre>

    <p>One can construct a function that returns an iterative function to iterate over all rows 
    in a synchronous or asynchronous way, depending on the async argument:
    </p>
    <pre class="prettyprint lang-lua">function rows(resultset, async)
    local a = 0
    local function getnext()
        a = a + 1
        local row = resultset(-1)
        return row and a or nil, row
    end
    if not async then
        return pairs(resultset(0))
    else
        return getnext, self
    end
end

local statement, err = db:prepare(r, "SELECT * FROM `tbl` WHERE `age` &gt; %u")
if not err then
     -- fetch rows asynchronously:
    local result, err = statement:select(20)
    if not err then
        for index, row in rows(result, true) do
            ....
        end
    end

     -- fetch rows synchronously:
    local result, err = statement:select(20)
    if not err then
        for index, row in rows(result, false) do
            ....
        end
    end
end</pre>

    
    <h3><a name="closing_databases" id="closing_databases">Closing a database connection</a></h3>
        

    <p>Database handles should be closed using <code>database:close()</code> when they are no longer
    needed. If you do not close them manually, they will eventually be garbage collected and 
    closed by mod_lua, but you may end up having too many unused connections to the database 
    if you leave the closing up to mod_lua. Essentially, the following two measures are
    the same:
    </p>
    <pre class="prettyprint lang-lua">-- Method 1: Manually close a handle
local database = r:dbacquire("mod_dbd")
database:close() -- All done

-- Method 2: Letting the garbage collector close it
local database = r:dbacquire("mod_dbd")
database = nil -- throw away the reference
collectgarbage() -- close the handle via GC</pre>

    
    <h3><a name="database_caveat" id="database_caveat">Precautions when working with databases</a></h3>
    
    <p>Although the standard <code>query</code> and <code>run</code> functions are freely 
    available, it is recommended that you use prepared statements whenever possible, to 
    both optimize performance (if your db handle lives on for a long time) and to minimize 
    the risk of SQL injection attacks. <code>run</code> and <code>query</code> should only
    be used when there are no variables inserted into a statement (a static statement). 
    When using dynamic statements, use <code>db:prepare</code> or <code>db:prepared</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="LuaAuthzProvider" id="LuaAuthzProvider">LuaAuthzProvider</a> <a name="luaauthzprovider" id="luaauthzprovider">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Plug an authorization provider function into <code class="module"><a href="../mod/mod_authz_core.html">mod_authz_core</a></code>
</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaAuthzProvider provider_name /path/to/lua/script.lua function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.4.3 and later</td></tr>
</table>
<p>After a lua function has been registered as authorization provider, it can be used
with the <code class="directive"><a href="../mod/mod_authz_core.html#require">Require</a></code> directive:</p>

<pre class="prettyprint lang-config">LuaRoot "/usr/local/apache2/lua"
LuaAuthzProvider foo authz.lua authz_check_foo
&lt;Location "/"&gt;
  Require foo johndoe
&lt;/Location&gt;</pre>

<pre class="prettyprint lang-lua">require "apache2"
function authz_check_foo(r, who)
    if r.user ~= who then return apache2.AUTHZ_DENIED
    return apache2.AUTHZ_GRANTED
end</pre>




</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="LuaCodeCache" id="LuaCodeCache">LuaCodeCache</a> <a name="luacodecache" id="luacodecache">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure the compiled code cache.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaCodeCache stat|forever|never</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LuaCodeCache stat</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table><p>
    Specify the behavior of the in-memory code cache. The default
    is stat, which stats the top level script (not any included
    ones) each time that file is needed, and reloads it if the
    modified time indicates it is newer than the one it has
    already loaded. The other values cause it to keep the file
    cached forever (don't stat and replace) or to never cache the
    file.</p>

    <p>In general stat or forever is good for production, and stat or never
    for development.</p>

    <div class="example"><h3>Examples:</h3><pre class="prettyprint lang-config">LuaCodeCache stat
LuaCodeCache forever
LuaCodeCache never</pre>
</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="LuaHookAccessChecker" id="LuaHookAccessChecker">LuaHookAccessChecker</a> <a name="luahookaccesschecker" id="luahookaccesschecker">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the access_checker phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookAccessChecker  /path/to/lua/script.lua  hook_function_name [early|late]</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The optional third argument is supported in 2.3.15 and later</td></tr>
</table>
<p>Add your hook to the access_checker phase.  An access checker
hook function usually returns OK, DECLINED, or HTTP_FORBIDDEN.</p>
   <div class="note"><h3>Ordering</h3><p>The optional arguments "early" or "late" 
   control when this script runs relative to other modules.</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="LuaHookAuthChecker" id="LuaHookAuthChecker">LuaHookAuthChecker</a> <a name="luahookauthchecker" id="luahookauthchecker">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the auth_checker phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookAuthChecker  /path/to/lua/script.lua hook_function_name [early|late]</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The optional third argument is supported in 2.3.15 and later</td></tr>
</table>
<p>Invoke a lua function in the auth_checker phase of processing
a request.  This can be used to implement arbitrary authentication
and authorization checking.  A very simple example:
</p>
<pre class="prettyprint lang-lua">require 'apache2'

-- fake authcheck hook
-- If request has no auth info, set the response header and
-- return a 401 to ask the browser for basic auth info.
-- If request has auth info, don't actually look at it, just
-- pretend we got userid 'foo' and validated it.
-- Then check if the userid is 'foo' and accept the request.
function authcheck_hook(r)

   -- look for auth info
   auth = r.headers_in['Authorization']
   if auth ~= nil then
     -- fake the user
     r.user = 'foo'
   end

   if r.user == nil then
      r:debug("authcheck: user is nil, returning 401")
      r.err_headers_out['WWW-Authenticate'] = 'Basic realm="WallyWorld"'
      return 401
   elseif r.user == "foo" then
      r:debug('user foo: OK')
   else
      r:debug("authcheck: user='" .. r.user .. "'")
      r.err_headers_out['WWW-Authenticate'] = 'Basic realm="WallyWorld"'
      return 401
   end
   return apache2.OK
end</pre>

   <div class="note"><h3>Ordering</h3><p>The optional arguments "early" or "late" 
   control when this script runs relative to other modules.</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="LuaHookCheckUserID" id="LuaHookCheckUserID">LuaHookCheckUserID</a> <a name="luahookcheckuserid" id="luahookcheckuserid">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the check_user_id phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookCheckUserID  /path/to/lua/script.lua hook_function_name [early|late]</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The optional third argument is supported in 2.3.15 and later</td></tr>
</table><p>...</p>
   <div class="note"><h3>Ordering</h3><p>The optional arguments "early" or "late" 
   control when this script runs relative to other modules.</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="LuaHookFixups" id="LuaHookFixups">LuaHookFixups</a> <a name="luahookfixups" id="luahookfixups">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the fixups phase of a request
processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookFixups  /path/to/lua/script.lua hook_function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
<p>
    Just like LuaHookTranslateName, but executed at the fixups phase
</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="LuaHookInsertFilter" id="LuaHookInsertFilter">LuaHookInsertFilter</a> <a name="luahookinsertfilter" id="luahookinsertfilter">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the insert_filter phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookInsertFilter  /path/to/lua/script.lua hook_function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table><p>Not Yet Implemented</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="LuaHookLog" id="LuaHookLog">LuaHookLog</a> <a name="luahooklog" id="luahooklog">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the access log phase of a request
processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookLog  /path/to/lua/script.lua log_function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
<p>
    This simple logging hook allows you to run a function when httpd enters the 
    logging phase of a request. With it, you can append data to your own logs, 
    manipulate data before the regular log is written, or prevent a log entry 
    from being created. To prevent the usual logging from happening, simply return
    <code>apache2.DONE</code> in your logging handler, otherwise return 
    <code>apache2.OK</code> to tell httpd to log as normal.
</p>
<p>Example:</p>
<pre class="prettyprint lang-config">LuaHookLog "/path/to/script.lua" logger</pre>

<pre class="prettyprint lang-lua">-- /path/to/script.lua --
function logger(r)
    -- flip a coin:
    -- If 1, then we write to our own Lua log and tell httpd not to log
    -- in the main log.
    -- If 2, then we just sanitize the output a bit and tell httpd to 
    -- log the sanitized bits.

    if math.random(1,2) == 1 then
        -- Log stuff ourselves and don't log in the regular log
        local f = io.open("/foo/secret.log", "a")
        if f then
            f:write("Something secret happened at " .. r.uri .. "\n")
            f:close()
        end
        return apache2.DONE -- Tell httpd not to use the regular logging functions
    else
        r.uri = r.uri:gsub("somesecretstuff", "") -- sanitize the URI
        return apache2.OK -- tell httpd to log it.
    end
end</pre>


</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="LuaHookMapToStorage" id="LuaHookMapToStorage">LuaHookMapToStorage</a> <a name="luahookmaptostorage" id="luahookmaptostorage">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the map_to_storage phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookMapToStorage  /path/to/lua/script.lua hook_function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
    <p>Like <code class="directive">LuaHookTranslateName</code> but executed at the 
    map-to-storage phase of a request. Modules like <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> run at this phase,
    which makes for an interesting example on what to do here:</p>
    <pre class="prettyprint lang-config">LuaHookMapToStorage "/path/to/lua/script.lua" check_cache</pre>

    <pre class="prettyprint lang-lua">require"apache2"
cached_files = {}

function read_file(filename) 
    local input = io.open(filename, "r")
    if input then
        local data = input:read("*a")
        cached_files[filename] = data
        file = cached_files[filename]
        input:close()
    end
    return cached_files[filename]
end

function check_cache(r)
    if r.filename:match("%.png$") then -- Only match PNG files
        local file = cached_files[r.filename] -- Check cache entries
        if not file then
            file = read_file(r.filename)  -- Read file into cache
        end
        if file then -- If file exists, write it out
            r.status = 200
            r:write(file)
            r:info(("Sent %s to client from cache"):format(r.filename))
            return apache2.DONE -- skip default handler for PNG files
        end
    end
    return apache2.DECLINED -- If we had nothing to do, let others serve this.
end</pre>


    
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="LuaHookPreTranslate" id="LuaHookPreTranslate">LuaHookPreTranslate</a> <a name="luahookpretranslate" id="luahookpretranslate">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the pre_translate phase of a request
processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookPreTranslate  /path/to/lua/script.lua hook_function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
<p>
    Just like LuaHookTranslateName, but executed at the pre_translate phase,
    where the URI-path is not percent decoded.
</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="LuaHookTranslateName" id="LuaHookTranslateName">LuaHookTranslateName</a> <a name="luahooktranslatename" id="luahooktranslatename">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the translate name phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookTranslateName  /path/to/lua/script.lua  hook_function_name [early|late]</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#Override">Override:</a></th><td>All</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>The optional third argument is supported in 2.3.15 and later</td></tr>
</table><p>
    Add a hook (at APR_HOOK_MIDDLE) to the translate name phase of
    request processing. The hook function receives a single
    argument, the request_rec, and should return a status code,
    which is either an HTTP error code, or the constants defined
    in the apache2 module: apache2.OK, apache2.DECLINED, or
    apache2.DONE. </p>

    <p>For those new to hooks, basically each hook will be invoked
    until one of them returns apache2.OK. If your hook doesn't
    want to do the translation it should just return
    apache2.DECLINED. If the request should stop processing, then
    return apache2.DONE.</p>

    <p>Example:</p>

<pre class="prettyprint lang-config"># httpd.conf
LuaHookTranslateName "/scripts/conf/hooks.lua" silly_mapper</pre>


<pre class="prettyprint lang-lua">-- /scripts/conf/hooks.lua --
require "apache2"
function silly_mapper(r)
    if r.uri == "/" then
        r.filename = "/var/www/home.lua"
        return apache2.OK
    else
        return apache2.DECLINED
    end
end</pre>


   <div class="note"><h3>Context</h3><p>This directive is not valid in <code class="directive"><a href="../mod/core.html#directory">&lt;Directory&gt;</a></code>, <code class="directive"><a href="../mod/core.html#files">&lt;Files&gt;</a></code>, or htaccess
   context.</p></div>

   <div class="note"><h3>Ordering</h3><p>The optional arguments "early" or "late" 
   control when this script runs relative to other modules.</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="LuaHookTypeChecker" id="LuaHookTypeChecker">LuaHookTypeChecker</a> <a name="luahooktypechecker" id="luahooktypechecker">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the type_checker phase of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaHookTypeChecker  /path/to/lua/script.lua hook_function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table><p>
    This directive provides a hook for the type_checker phase of the request processing. 
    This phase is where requests are assigned a content type and a handler, and thus can 
    be used to modify the type and handler based on input:
    </p>
    <pre class="prettyprint lang-config">LuaHookTypeChecker "/path/to/lua/script.lua" type_checker</pre>

    <pre class="prettyprint lang-lua">    function type_checker(r)
        if r.uri:match("%.to_gif$") then -- match foo.png.to_gif
            r.content_type = "image/gif" -- assign it the image/gif type
            r.handler = "gifWizard"      -- tell the gifWizard module to handle this
            r.filename = r.uri:gsub("%.to_gif$", "") -- fix the filename requested
            return apache2.OK
        end

        return apache2.DECLINED
    end</pre>


</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="LuaInherit" id="LuaInherit">LuaInherit</a> <a name="luainherit" id="luainherit">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Controls how parent configuration sections are merged into children</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaInherit none|parent-first|parent-last</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LuaInherit parent-first</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.4.0 and later</td></tr>
</table><p>By default, if LuaHook* directives are used in overlapping
    Directory or Location configuration sections, the scripts defined in the
    more specific section are run <em>after</em> those defined in the more
    generic section (LuaInherit parent-first).  You can reverse this order, or
    make the parent context not apply at all.</p>
    
    <p> In previous 2.3.x releases, the default was effectively to ignore LuaHook*
    directives from parent configuration sections.</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="LuaInputFilter" id="LuaInputFilter">LuaInputFilter</a> <a name="luainputfilter" id="luainputfilter">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a Lua function for content input filtering</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaInputFilter filter_name /path/to/lua/script.lua function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.4.5 and later</td></tr>
</table>
<p>Provides a means of adding a Lua function as an input filter. 
As with output filters, input filters work as coroutines, 
first yielding before buffers are sent, then yielding whenever 
a bucket needs to be passed down the chain, and finally (optionally) 
yielding anything that needs to be appended to the input data. The 
global variable <code>bucket</code> holds the buckets as they are passed 
onto the Lua script:
</p>

<pre class="prettyprint lang-config">LuaInputFilter myInputFilter "/www/filter.lua" input_filter
&lt;Files "*.lua"&gt;
  SetInputFilter myInputFilter
&lt;/Files&gt;</pre>

<pre class="prettyprint lang-lua">--[[
    Example input filter that converts all POST data to uppercase.
]]--
function input_filter(r)
    print("luaInputFilter called") -- debug print
    coroutine.yield() -- Yield and wait for buckets
    while bucket do -- For each bucket, do...
        local output = string.upper(bucket) -- Convert all POST data to uppercase
        coroutine.yield(output) -- Send converted data down the chain
    end
    -- No more buckets available.
    coroutine.yield("&amp;filterSignature=1234") -- Append signature at the end
end</pre>

<p>
The input filter supports denying/skipping a filter if it is deemed unwanted:
</p>
<pre class="prettyprint lang-lua">function input_filter(r)
    if not good then
        return -- Simply deny filtering, passing on the original content instead
    end
    coroutine.yield() -- wait for buckets
    ... -- insert filter stuff here
end</pre>

<p>
See "<a href="#modifying_buckets">Modifying contents with Lua 
filters</a>" for more information.
</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="LuaMapHandler" id="LuaMapHandler">LuaMapHandler</a> <a name="luamaphandler" id="luamaphandler">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Map a path to a lua handler</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaMapHandler uri-pattern /path/to/lua/script.lua [function-name]</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
    <p>This directive matches a uri pattern to invoke a specific
    handler function in a specific file. It uses PCRE regular
    expressions to match the uri, and supports interpolating
    match groups into both the file path and the function name. 
    Be careful writing your regular expressions to avoid security
    issues.</p>
   <div class="example"><h3>Examples:</h3><pre class="prettyprint lang-config">LuaMapHandler "/(\w+)/(\w+)" "/scripts/$1.lua" "handle_$2"</pre>
</div>
        <p>This would match uri's such as /photos/show?id=9
        to the file /scripts/photos.lua and invoke the
        handler function handle_show on the lua vm after
        loading that file.</p>

<pre class="prettyprint lang-config">LuaMapHandler "/bingo" "/scripts/wombat.lua"</pre>

        <p>This would invoke the "handle" function, which
        is the default if no specific function name is
        provided.</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="LuaOutputFilter" id="LuaOutputFilter">LuaOutputFilter</a> <a name="luaoutputfilter" id="luaoutputfilter">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a Lua function for content output filtering</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaOutputFilter filter_name /path/to/lua/script.lua function_name</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>2.4.5 and later</td></tr>
</table>
<p>Provides a means of adding a Lua function as an output filter. 
As with input filters, output filters work as coroutines, 
first yielding before buffers are sent, then yielding whenever 
a bucket needs to be passed down the chain, and finally (optionally) 
yielding anything that needs to be appended to the input data. The 
global variable <code>bucket</code> holds the buckets as they are passed 
onto the Lua script:
</p>

<pre class="prettyprint lang-config">LuaOutputFilter myOutputFilter "/www/filter.lua" output_filter
&lt;Files "*.lua"&gt;
  SetOutputFilter myOutputFilter
&lt;/Files&gt;</pre>

<pre class="prettyprint lang-lua">--[[
    Example output filter that escapes all HTML entities in the output
]]--
function output_filter(r)
    coroutine.yield("(Handled by myOutputFilter)&lt;br/&gt;\n") -- Prepend some data to the output,
                                                          -- yield and wait for buckets.
    while bucket do -- For each bucket, do...
        local output = r:escape_html(bucket) -- Escape all output
        coroutine.yield(output) -- Send converted data down the chain
    end
    -- No more buckets available.
end</pre>

<p>
As with the input filter, the output filter supports denying/skipping a filter 
if it is deemed unwanted:
</p>
<pre class="prettyprint lang-lua">function output_filter(r)
    if not r.content_type:match("text/html") then
        return -- Simply deny filtering, passing on the original content instead
    end
    coroutine.yield() -- wait for buckets
    ... -- insert filter stuff here
end</pre>

<div class="note"><h3>Lua filters with <code class="module"><a href="../mod/mod_filter.html">mod_filter</a></code></h3>
<p> When a Lua filter is used as the underlying provider via the 
<code class="directive"><a href="../mod/mod_filter.html#filterprovider">FilterProvider</a></code> directive, filtering 
will only work when the <var>filter-name</var> is identical to the <var>provider-name</var>.
</p> </div>

<p>
See "<a href="#modifying_buckets">Modifying contents with Lua filters</a>" for more 
information.
</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="LuaPackageCPath" id="LuaPackageCPath">LuaPackageCPath</a> <a name="luapackagecpath" id="luapackagecpath">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Add a directory to lua's package.cpath</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaPackageCPath /path/to/include/?.soa</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
    <p>Add a path to lua's shared library search path. Follows the same
    conventions as lua. This just munges the package.cpath in the
    lua vms.</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="LuaPackagePath" id="LuaPackagePath">LuaPackagePath</a> <a name="luapackagepath" id="luapackagepath">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Add a directory to lua's package.path</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaPackagePath /path/to/include/?.lua</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table><p>Add a path to lua's module search path. Follows the same
    conventions as lua. This just munges the package.path in the
    lua vms.</p>

    <div class="example"><h3>Examples:</h3><pre class="prettyprint lang-config">LuaPackagePath "/scripts/lib/?.lua"
LuaPackagePath "/scripts/lib/?/init.lua"</pre>
</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="LuaQuickHandler" id="LuaQuickHandler">LuaQuickHandler</a> <a name="luaquickhandler" id="luaquickhandler">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Provide a hook for the quick handler of request processing</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaQuickHandler /path/to/script.lua hook_function_name</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#Override">Override:</a></th><td>All</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
    <p>
    This phase is run immediately after the request has been mapped to a virtual host, 
    and can be used to either do some request processing before the other phases kick 
    in, or to serve a request without the need to translate, map to storage et cetera. 
    As this phase is run before anything else, directives such as <code class="directive"><a href="../mod/core.html#location">&lt;Location&gt;</a></code> or <code class="directive"><a href="../mod/core.html#directory">&lt;Directory&gt;</a></code> are void in this phase, just as 
    URIs have not been properly parsed yet.
    </p>
   <div class="note"><h3>Context</h3><p>This directive is not valid in <code class="directive"><a href="../mod/core.html#directory">&lt;Directory&gt;</a></code>, <code class="directive"><a href="../mod/core.html#files">&lt;Files&gt;</a></code>, or htaccess
   context.</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="LuaRoot" id="LuaRoot">LuaRoot</a> <a name="luaroot" id="luaroot">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Specify the base path for resolving relative paths for mod_lua directives</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaRoot /path/to/a/directory</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
    <p>Specify the base path which will be used to evaluate all
    relative paths within mod_lua. If not specified they
    will be resolved relative to the current working directory,
    which may not always work well for a 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="LuaScope" id="LuaScope">LuaScope</a> <a name="luascope" id="luascope">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>One of once, request, conn, thread -- default is once</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LuaScope once|request|conn|thread|server [min] [max]</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LuaScope once</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>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_lua</td></tr>
</table>
    <p>Specify the life cycle scope of the Lua interpreter which will
    be used by handlers in this "Directory." The default is "once"</p>

   <dl>
    <dt>once:</dt> <dd>use the interpreter once and throw it away.</dd>

    <dt>request:</dt> <dd>use the interpreter to handle anything based on
             the same file within this request, which is also
             request scoped.</dd>

    <dt>conn:</dt> <dd>Same as request but attached to the connection_rec</dd>

    <dt>thread:</dt> <dd>Use the interpreter for the lifetime of the thread 
            handling the request (only available with threaded MPMs).</dd>

    <dt>server:</dt>  <dd>This one is different than others because the
            server scope is quite long lived, and multiple threads
            will have the same server_rec. To accommodate this,
            server scoped Lua states are stored in an apr
            resource list. The <code>min</code> and <code>max</code> arguments 
            specify the minimum and maximum number of Lua states to keep in the 
            pool.</dd>
   </dl>
    <p>
    Generally speaking, the <code>thread</code> and <code>server</code> scopes 
    execute roughly 2-3 times faster than the rest, because they don't have to 
    spawn new Lua states on every request (especially with the event MPM, as 
    even keepalive requests will use a new thread for each request). If you are 
    satisfied that your scripts will not have problems reusing a state, then 
    the <code>thread</code> or <code>server</code> scopes should be used for 
    maximum performance. While the <code>thread</code> scope will provide the 
    fastest responses, the <code>server</code> scope will use less memory, as 
    states are pooled, allowing f.x. 1000 threads to share only 100 Lua states, 
    thus using only 10% of the memory required by the <code>thread</code> scope.
    </p>

</div>
</div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="../en/mod/mod_lua.html" title="English">&nbsp;en&nbsp;</a> |
<a href="../fr/mod/mod_lua.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
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