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+<title>Developing modules for the Apache HTTP Server 2.4 - Apache HTTP Server</title>\r
+<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />\r
+<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />\r
+<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />\r
+<link href="../images/favicon.ico" rel="shortcut icon" /></head>\r
+<body id="manual-page"><div id="page-header">\r
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>\r
+<p class="apache">Apache HTTP Server Version 2.4</p>\r
+<img alt="" src="../images/feather.gif" /></div>\r
+<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>\r
+<div id="path">\r
+<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.4</a> > <a href="./">Developer</a></div><div id="page-content"><div id="preamble"><h1>Developing modules for the Apache HTTP Server 2.4</h1>\r
+<div class="toplang">\r
+<p><span>Available Languages: </span><a href="../en/developer/modguide.html" title="English"> en </a></p>\r
+</div>\r
+\r
+<p>This document explains how you can develop modules for the Apache HTTP \r
+Server 2.4</p>\r
+</div>\r
+<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#introduction">Introduction</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#basics">Defining a module</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#hooking">Getting started: Hooking into Apache</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#handling">Building a handler</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#configuration">Adding configuration options</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#context">Context aware configurations</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#summary">Summing up</a></li>\r
+<li><img alt="" src="../images/down.gif" /> <a href="#snippets">Some useful snippets of code</a></li>\r
+</ul><h3>See also</h3><ul class="seealso"><li><a href="request.html">Request Processing in Apache 2.4</a></li><li><a href="hooks.html">Apache 2.x Hook Functions</a></li></ul></div>\r
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="introduction" id="introduction">Introduction</a></h2>\r
+<h3><a name="what" id="what">What we will be discussing in this document</a></h3>\r
+<p>\r
+This document will discuss how you can easily create modules for the Apache \r
+HTTP Server 2.4 ("Apache"), by exploring an example module called \r
+<code>mod_example</code>. In the first part of this document, the purpose \r
+of this module will be to calculate and print out various digest values for \r
+existing files on your web server, whenever we access the URL <code>\r
+http://hostname/filename.sum</code>. For instance, if we want to know the \r
+MD5 digest value of the file located at <code>\r
+http://www.example.com/index.html</code>, we would visit <code>\r
+http://www.example.com/index.html.sum</code>. \r
+</p>\r
+<p>\r
+In the second part of this document, which deals with configuration \r
+directive and context awareness, we will be looking at a module that simply \r
+write out its own configuration to the client.\r
+</p>\r
+\r
+<h3><a name="prerequisites" id="prerequisites">Prerequisites</a></h3>\r
+<p>\r
+First and foremost, you are expected to have a basic knowledge of how the C \r
+programming language works. In most cases, we will try to be as pedagogical \r
+as possible and link to documents describing the functions used in the \r
+examples, but there are also many cases where it is necessary to either \r
+just assume that "it works" or do some digging youself into what the hows \r
+and whys of various function calls. \r
+</p>\r
+<p>\r
+Lastly, you will need to have a basic understanding of how modules are \r
+loaded and configured in Apache, as well as how to get the headers for \r
+Apache if you do not have them already, as these are needed for compiling \r
+new modules.\r
+</p>\r
+\r
+<h3><a name="compiling" id="compiling">Compiling your module</a></h3>\r
+<p>\r
+To compile the source code we are building in this document, we will be \r
+using <a href="../programs/apxs.html">APXS</a>. Assuming your source file \r
+is called mod_example.c, compiling, installing and activating the module is \r
+as simple as: \r
+<div class="example"><pre>\r
+apxs -i -a -c mod_example.c\r
+</pre></div>\r
+</p>\r
+\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="basics" id="basics">Defining a module</a></h2>\r
+<img src="../images/build_a_mod_3.png" /><br />\r
+<p>Every module starts with the same declaration, or name tag if you will, \r
+that defines a module as <em>a separate entity within Apache</em>:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+module AP_MODULE_DECLARE_DATA example_module <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ STANDARD20_MODULE_STUFF<code style="color:#806030; ">,</code>\r
+ create_dir_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-directory configuration handler */</code>\r
+ merge_dir_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-directory configurations */</code>\r
+ create_svr_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-server configuration handler */</code>\r
+ merge_svr_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-server configurations */</code>\r
+ directives<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Any directives we may have for httpd */</code>\r
+ register_hooks <code style="color:#c34e00; ">/* Our hook registering function */</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+</pre>\r
+\r
+\r
+\r
+This bit of code lets Apache know that we have now registered a new module \r
+in the system, and that its name is <code>example_module</code>. The name \r
+of the module is used primarilly for two things:<br />\r
+<ul>\r
+<li>Letting Apache know how to load the module using the LoadModule</li>\r
+<li>Setting up a namespace for the module to use in configurations</li>\r
+</ul>\r
+For now, we're only concerned with the first purpose of the module name, \r
+which comes into play when we need to load the module:<br />\r
+<div class="example"><pre><a href="../mod/mod_so.html#LoadModule">LoadModule</a> example_module modules/mod_example.so</pre></div>\r
+In essence, this tells Apache to open up <code>mod_example.so</code> and look for a module \r
+called <code>example_module</code>.\r
+</p>\r
+<p>\r
+Within this name tag of ours is also a bunch of references to how we would \r
+like to handle things: Which directives do we respond to in a configuration \r
+file or .htaccess, how do we operate within specific contexts, and what \r
+handlers are we interested in registering with the Apache service. We'll \r
+return to all these elements later in this document.\r
+</p>\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="hooking" id="hooking">Getting started: Hooking into Apache</a></h2>\r
+<h3><a name="hook_intro" id="hook_intro">An introduction to hooks</a></h3>\r
+<p>\r
+When handling requests in Apache, the first thing you will need to do is \r
+create a hook into the request handling process. A hook is essentially a \r
+message telling Apache that you are willing to either serve or at least \r
+take a glance at certain requests given by clients. All handlers, whether \r
+it's mod_rewrite, mod_authn_*, mod_proxy and so on, are hooked into \r
+specific parts of the request process. As you are probably aware, modules \r
+serve different purposes; Some are authentication/authorization handlers, \r
+others are file or script handlers while some third modules rewrite URIs or \r
+proxies content. Furthermore, in the end, it is up to the user of Apache \r
+how and when each module will come into place. Thus, Apache itself does not \r
+presume to know which module is responsible for handling a specific \r
+request, and will ask each module whether they have an interest in a given \r
+request or not. It is then up to each module to either gently decline \r
+serving a request, accept serving it or flat out deny the request from \r
+being served, as authentication/authorization modules do: <br />\r
+<img src="../images/build_a_mod_2.png" /><br />\r
+To make it a bit easier for handlers such as our mod_example to know \r
+whether the client is requesting content we should handle or not, Apache \r
+has directives for hinting to modules whether their assistance is needed or \r
+not. Two of these are <code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> \r
+and <code class="directive"><a href="../mod/core.html#sethandler">SetHandler</a></code>. Let's take a look at \r
+an example using <code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code>. In \r
+our example case, we want every request ending with .sum to be served by \r
+<code>mod_example</code>, so we'll add a configuration directive that tells \r
+Apache to do just that:\r
+<div class="example"><pre>\r
+AddHandler example-handler .sum\r
+</pre></div>\r
+What this tells Apache is the following: <em>Whenever we receive a request \r
+for a URI ending in .sum, we are to let all modules know that we are \r
+looking for whoever goes by the name of "example-handler" </em>. \r
+Thus, when a request is being served that ends in .sum, Apache will let all \r
+modules know, that this request should be served by "example-handler\r
+". As you will see later, when we start building mod_example, we will \r
+check for this handler tag relayed by <code>AddHandler</code> and reply to \r
+Apache based on the value of this tag.\r
+</p>\r
+\r
+<h3><a name="hook_declaration" id="hook_declaration">Hooking into httpd</a></h3>\r
+<p>\r
+To begin with, we only want to create a simple handler, that replies to the \r
+client browser when a specific URL is requested, so we won't bother setting \r
+up configuration handlers and directives just yet. Our initial module \r
+definition will look like this:<br />\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+module AP_MODULE_DECLARE_DATA example_module =\r
+{\r
+ STANDARD20_MODULE_STUFF,\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>,\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>,\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>,\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>,\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>,\r
+ <code style="color:#800040; ">register_hooks</code> <code style="color:#c34e00; "><code style="color:#c34e00; ">/* Our hook registering function */</code></code>\r
+};\r
+</pre>\r
+\r
+\r
+\r
+This lets Apache know that we are not interesting in anything fancy, we \r
+just want to hook onto the requests and possibly handle some of them. </p> \r
+<p> The reference in our example declaration, <code>register_hooks</code> \r
+is the name of a function we will create to manage how we hook onto the \r
+request process. In this example module, the function has just one purpose; \r
+To create a simple hook that gets called after all the rewrites, access \r
+control etc has been handled. Thus, we will let Apache know, that we want \r
+to hook into its process as one of the last modules: \r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">void</code> register_hooks<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Create a hook in the request handler, so we get called when a request arrives */</code>\r
+ <code style="color:#800040; ">ap_hook_handler</code><code style="color:#806030; ">(</code>example_handler<code style="color:#806030; ">,</code> <code style="color:#7f0055; font-weight:bold; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#7f0055; font-weight:bold; ">NULL</code><code style="color:#806030; ">,</code> APR_HOOK_LAST<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+The <code>example_handler</code> reference is the function that will handle \r
+the request. We will discuss how to create a handler in the next chapter.\r
+</p>\r
+\r
+<h3><a name="hook_others" id="hook_others">Other useful hooks</a></h3>\r
+<p>\r
+Hooking into the request handling phase is but one of many hooks that you \r
+can create. Some other ways of hooking are:\r
+<ul>\r
+<li><code>ap_hook_child_init</code>: Place a hook that executes when a child process is spawned (commonly used for initializing modules after Apache has forked)</li>\r
+<li><code>ap_hook_pre_config</code>: Place a hook that executes before any configuration data has been read (very early hook)</li>\r
+<li><code>ap_hook_post_config</code>: Place a hook that executes after configuration has been parsed, but before Apache has forked</li>\r
+<li><code>ap_hook_translate_name</code>: Place a hook that executes when a URI needs to be translated into a filename on the server (think <code>mod_rewrite</code>)</li>\r
+</ul>\r
+</p>\r
+\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="handling" id="handling">Building a handler</a></h2>\r
+<p>\r
+A handler is essentially a function that receives a callback when a request \r
+to Apache is made. It is passed a record of the current request (how it was \r
+made, which headers and requests were passed along, who's giving the \r
+request and so on), and is put in charge of either telling Apache that it's \r
+not interested in the request or handle the request with the tools provided.\r
+</p>\r
+<h3><a name="simple_handler" id="simple_handler">A simple "Hello, world!" \r
+handler</a></h3> Let's start off by making a very simple request handler \r
+that does the following: <br />\r
+<ol>\r
+<li>Check that this is a request that should be served by "example-handler"</li>\r
+<li>Set the content type of our output to <code>text/html</code></li>\r
+<li>Write "Hello, world!" back to the client browser</li>\r
+<li>Let Apache know that we took care of this request and everything went fine</li>\r
+</ol>\r
+In C code, our example handler will now look like this:<br />\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* First off, we need to check if this is a call for the "example-handler" handler.</code>\r
+<code style="color:#c34e00; "> * If it is, we accept it and do our things, if not, we simply return DECLINED,</code>\r
+<code style="color:#c34e00; "> * and Apache will try somewhere else.</code>\r
+<code style="color:#c34e00; "> */</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">example-handler</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#806030; ">(</code>DECLINED<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Now that we are handling this request, we'll write out "Hello, world!" to the client.</code>\r
+<code style="color:#c34e00; "> * To do so, we must first set the appropriate content type, followed by our output.</code>\r
+<code style="color:#c34e00; "> */</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/html</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Hello, world!</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Lastly, we must tell Apache that we took care of this request and everything went fine.</code>\r
+<code style="color:#c34e00; "> * We do so by simply returning the value OK to Apache.</code>\r
+<code style="color:#c34e00; "> */</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+Now, we put all we have learned together and end up with a program that \r
+looks like \r
+<a href="http://people.apache.org/~humbedooh/mods/examples/mod_example_1.c">mod_example_1.c</a>\r
+. The functions used in this example will be explained later in the section \r
+<a href="#functions">"Some useful functions you should know"</a>\r
+. <h3><a name="request_rec" id="request_rec">The request_rec structure \r
+</a></h3> <p>The most essential part of any request is the <em>request record\r
+</em>. In a call to a handler function, this is represented by the <code>\r
+request_req* </code> structure passed along with every call that is made. \r
+This struct, typically just refered to as <code>r</code> in modules, \r
+contains all the information you need for your module to fully process any \r
+HTTP request and respond accordingly.</p> <p>Some key elements of the <code>\r
+request_req </code> structure are:\r
+<ul>\r
+<li><code><code style="color:#008833">r->handler</code> (char*)</code>: Contains the name of the handler Apache is currently asking to do the handling of this request</li>\r
+<li><code><code style="color:#008833">r->method</code> (char*)</code>: Contains the HTTP method being used, f.x. GET or POST</li>\r
+<li><code><code style="color:#008833">r->filename</code> (char*)</code>: Contains the translated filename the client is requesting</li>\r
+<li><code><code style="color:#008833">r->args</code> (char*)</code>: Contains the query string of the request, if any</li>\r
+<li><code><code style="color:#008833">r->headers_in</code> (apr_table_t*)</code>: Contains all the headers sent by the client</li>\r
+<li><code><code style="color:#008833">r->connection</code> (conn_rec*)</code>: A record containing information about the current connection</li>\r
+<li><code><code style="color:#008833">r->useragent_ip</code> (char*)</code>: The IP address of the client connecting to us</li>\r
+<li><code><code style="color:#008833">r->pool</code> (apr_pool_t*)</code>: The memory pool of this request. We'll discuss this in the "\r
+<a href="#memory">Memory management</a>" chapter.</li>\r
+</ul>\r
+A complete list of all the values contained with in the <code>request_req</code> structure can be found in \r
+the <a href="http://svn.apache.org/repos/asf/httpd/httpd/trunk/include/httpd.h"><code>httpd.h</code></a> header \r
+file or at <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/structrequest__rec.html">http://ci.apache.org/projects/httpd/trunk/doxygen/structrequest__rec.html</a>.\r
+</p>\r
+<p>\r
+Let's try out some of these variables in another example handler:<br />\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Set the appropriate content type */</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/html</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+\r
+ <code style="color:#c34e00; ">/* Print out the IP address of the client connecting to us: */</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; "><h2>Hello, </code><code style="color:#0f6900; ">%s</code><code style="color:#e60000; ">!</h2></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">useragent_ip</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* If we were reached through a GET or a POST request, be happy, else sad. */</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code> <code style="color:#806030; ">!</code><code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">method</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">POST</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#806030; ">!</code><code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">method</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">GET</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">You used a GET or a POST method, that makes us happy!<br></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> <code style="color:#806030; ">{</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">You did not use POST or GET, that makes us sad :(<br></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#c34e00; ">/* Lastly, if there was a query string, let's print that too! */</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">args</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Your query string was: </code><code style="color:#0f6900; ">%s</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">args</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+\r
+\r
+<h3><a name="return_value" id="return_value">Return values</a></h3>\r
+<p>\r
+Apache relies on return values from handlers to signify whether a request \r
+was handled or not, and if so, whether the request went well or not. If a \r
+module is not interested in handling a specific request, it should always \r
+return the value <code>DECLINED</code>. If it is handling a request, it \r
+should either return the generic value <code>OK</code>, or a specific HTTP \r
+status code, for example:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Return 404: Not found */</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> HTTP_NOT_FOUND<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+Returning <code>OK</code> or a HTTP status code does not necessarilly mean \r
+that the request will end. Apache may still have other handlers that are \r
+interested in this request, for instance the logging modules which, upon a \r
+successful request, will write down a summary of what was requested and how \r
+it went. To do a full stop and prevent any further processing after your \r
+module is done, you can return the value <code>DONE</code> to let Apache \r
+know that it should cease all activity on this request and carry on with \r
+the next, without informing other handlers.\r
+<br />\r
+<strong>General response codes:</strong>\r
+<ul>\r
+<li><code>DECLINED</code>: We are not handling this request</li>\r
+<li><code>OK</code>: We handled this request and it went well</li>\r
+<li><code>DONE</code>: We handled this request and Apache should just close this thread without further processing</li>\r
+</ul><br />\r
+<strong>HTTP specific return codes (excerpt):</strong>\r
+<ul>\r
+<li><code>HTTP_OK (200)</code>: Request was okay</li>\r
+<li><code>HTTP_MOVED_PERMANENTLY (301)</code>: The resource has moved to a new URL</li>\r
+<li><code>HTTP_UNAUTHORIZED (401)</code>: Client is not authorized to visit this page</li>\r
+<li><code>HTTP_FORBIDDEN (403)</code>: Permission denied</li>\r
+<li><code>HTTP_NOT_FOUND (404)</code>: File not found</li>\r
+<li><code>HTTP_INTERNAL_SERVER_ERROR (500)</code>: Internal server error (self explanatory)</li>\r
+</ul>\r
+</p>\r
+\r
+\r
+<h3><a name="functions" id="functions">Some useful functions you should know</a></h3>\r
+\r
+<ul>\r
+<li>\r
+ <code>ap_rputs(const char *string, request_req *r)</code>: <br />\r
+ Sends a string of text to the client. This is a shorthand version of <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gac827cd0537d2b6213a7c06d7c26cc36e">\r
+ ap_rwrite</a>.\r
+ \r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">Hello, world!</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code></pre>\r
+\r
+\r
+\r
+</li>\r
+<li>\r
+ <code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a></code>: <br />\r
+ This function works just like <code>printf</code>, except it sends the result to the client. \r
+ \r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;"><code style="color:#2e8800; "><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a></code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Hello, </code><code style="color:#0f6900; ">%s</code><code style="color:#e60000; ">!</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">useragent_ip</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code></pre>\r
+\r
+\r
+</li>\r
+<li>\r
+ <code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a>(request_req *r, const char *type)</code>: <br />\r
+ Sets the content type of the output you are sending.\r
+ \r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;"><code style="color:#2e8800; "><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a></code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/plain</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* force a raw text output */</code></pre>\r
+\r
+\r
+</li>\r
+\r
+\r
+</ul>\r
+\r
+\r
+<h3><a name="memory" id="memory">Memory management</a></h3>\r
+<p>\r
+Managing your resources in Apache is quite easy, thanks to the memory pool \r
+system. In essence, each server, connection and request have their own \r
+memory pool that gets cleaned up when its scope ends, e.g. when a request \r
+is done or when a server process shuts down. All your module needs to do is \r
+latch onto this memory pool, and you won't have to worry about having to \r
+clean up after yourself - pretty neat, huh?\r
+</p>\r
+\r
+<p>\r
+In our module, we will primarilly be allocating memory for each request, so \r
+it's appropriate to use the <code style="color:#008833">r->pool</code> \r
+reference when creating new objects. A few of the functions for allocating \r
+memory within a pool are:\r
+<ul>\r
+<li><code>void* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__pools.html#ga85f1e193c31d109affda72f9a92c6915">apr_palloc</a>(\r
+apr_pool_t *p, apr_size_t size)</code>: Allocates <code>size</code> number of bytes in the pool for you</li>\r
+<li><code>void* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__pools.html#gaf61c098ad258069d64cdf8c0a9369f9e">apr_pcalloc</a>(\r
+apr_pool_t *p, apr_size_t size)</code>: Allocates <code>size</code> number of bytes in the pool for you and sets all bytes to 0</li>\r
+<li><code>char* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__strings.html#gabc79e99ff19abbd7cfd18308c5f85d47">apr_pstrdup</a>(\r
+apr_pool_t *p, const char *s)</code>: Creates a duplicate of the string <code>s</code>. This is useful for copying constant values so you can edit them</li>\r
+<li><code>char* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__strings.html#ga3eca76b8d293c5c3f8021e45eda813d8">apr_psprintf</a>(\r
+apr_pool_t *p, const char *fmt, ...)</code>: Similar to <code>sprintf</code>, except Apache supplies you with an appropriately allocated target variable</li>\r
+\r
+</ul>\r
+Let's put these functions into an example handler:<br />\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; ">*</code> original <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">You can't edit this!</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; ">*</code> copy<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code><code style="color:#806030; ">*</code> integers<code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Allocate space for 10 integer values and set them all to zero. */</code>\r
+ integers <code style="color:#806030; ">=</code> apr_pcalloc<code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">sizeof</code><code style="color:#806030; ">(</code><code style="color:#400000; font-weight:bold; ">int</code><code style="color:#806030; ">)</code><code style="color:#806030; ">*</code><code style="color:#c00000; ">10</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code> \r
+ \r
+ <code style="color:#c34e00; ">/* Create a copy of the 'original' variable that we can edit. */</code>\r
+ copy <code style="color:#806030; ">=</code> apr_pstrdup<code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>pool<code style="color:#806030; ">,</code> original<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+This is all well and good for our module, which won't need any \r
+pre-initialized variables or structures. However, if we wanted to \r
+initialize something early on, before the requests come rolling in, we \r
+could simply add a call to a function in our <code>register_hooks</code> \r
+function to sort it out:\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">void</code> register_hooks<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Call a function that initializes some stuff */</code>\r
+ <code style="color:#800040; ">example_init_function</code><code style="color:#806030; ">(</code>pool<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/* Create a hook in the request handler, so we get called when a request arrives */</code>\r
+ <code style="color:#800040; ">ap_hook_handler</code><code style="color:#806030; ">(</code>example_handler<code style="color:#806030; ">,</code> <code style="color:#7f0055; font-weight:bold; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#7f0055; font-weight:bold; ">NULL</code><code style="color:#806030; ">,</code> APR_HOOK_LAST<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+In this pre-request initialization function we would not be using the \r
+same pool as we did when allocating resources for request-based functions. \r
+Instead, we would use the pool given to us by Apache for allocating memory \r
+on a per-process based level.\r
+\r
+</p>\r
+\r
+\r
+<h3><a name="parsing" id="parsing">Parsing request data</a></h3>\r
+<p>\r
+In our example module, we would like to add a feature, that checks which \r
+type of digest, MD5 or SHA1 the client would like to see. This could be \r
+solved by adding a query string to the request. A query string is typically \r
+comprised of several keys and values put together in a string, for instance \r
+<code>valueA=yes&valueB=no&valueC=maybe</code>. It is up to the \r
+module itself to parse these and get the data it requires. In our example, \r
+we'll be looking for a key called <code>digest</code>, and if set to <code>\r
+md5</code>, we'll produce an MD5 digest, otherwise we'll produce a SHA1 \r
+digest.\r
+</p>\r
+<p>\r
+Since the introduction of Apache 2.4, parsing request data from GET and \r
+POST requests have never been easier. All we require to parse both GET and \r
+POST data is four simple lines: \r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__apr__tables.html#gad7ea82d6608a4a633fc3775694ab71e4">apr_table_t</a> *GET;\r
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/structapr__array__header__t.html">apr_array_header_t</a> *POST;\r
+\r
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__SCRIPT.html#gaed25877b529623a4d8f99f819ba1b7bd">ap_args_to_table</a>(r, &GET);\r
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__DAEMON.html#ga9d426b6382b49754d4f87c55f65af202">ap_parse_form_data</a>(r, <code style="color:#7f0055; font-weight:bold; ">NULL</code>, &POST, -1, 8192);\r
+</pre>\r
+\r
+\r
+\r
+In our specific example module, we're looking for the <code>digest</code> \r
+value from the query string, which now resides inside a table called <code>\r
+GET</code>. To extract this value, we need only perform a simple operation:\r
+<br />\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#c34e00; ">/* Get the "digest" key from the query string, if any. */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>digestType <code style="color:#806030; ">=</code> <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__apr__tables.html#ga4db13e3915c6b9a3142b175d4c15d915">apr_table_get</a><code style="color:#806030; ">(</code>GET<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">digest</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#c34e00; ">/* If no key was returned, we will set a default value instead. */</code>\r
+<code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>digestType<code style="color:#806030; ">)</code> digestType <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">sha1</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+\r
+</pre>\r
+\r
+\r
+\r
+The structures used for the POST and GET data are not exactly the same, so \r
+if we were to fetch a value from POST data instead of the query string, we \r
+would have to resort to a few more lines, as outlined in <a href="#get_post">this example</a> in the last chapter of this document.\r
+</p>\r
+\r
+\r
+<h3><a name="advanced_handler" id="advanced_handler">Making an advanced handler</a></h3>\r
+Now that we have learned how to parse form data and manage our resources, \r
+we can move on to creating an advanced version of our module, that spits \r
+out the MD5 or SHA1 digest of files:<br />\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> rc<code style="color:#806030; ">,</code> exists<code style="color:#806030; ">;</code>\r
+ apr_finfo_t finfo<code style="color:#806030; ">;</code>\r
+ apr_file_t<code style="color:#806030; "> *</code>file<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>filename<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> buffer<code style="color:#806030; ">[</code><code style="color:#c00000; ">256</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ apr_size_t readBytes<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> n<code style="color:#806030; ">;</code>\r
+ apr_table_t<code style="color:#806030; "> *</code>GET<code style="color:#806030; ">;</code>\r
+ apr_array_header_t<code style="color:#806030; "> *</code>POST<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>digestType<code style="color:#806030; ">;</code>\r
+ \r
+ \r
+ <code style="color:#c34e00; ">/* Check that the "example-handler" handler is being called. */</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">example-handler</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#806030; ">(</code>DECLINED<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Figure out which file is being requested by removing the .sum from it */</code>\r
+ filename <code style="color:#806030; ">=</code> apr_pstrdup<code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">pool</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">filename</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ filename<code style="color:#806030; ">[</code><code style="color:#800040; ">strlen</code><code style="color:#806030; ">(</code>filename<code style="color:#806030; ">)</code><code style="color:#806030; ">-</code><code style="color:#c00000; ">4</code><code style="color:#806030; ">]</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Cut off the last 4 characters. */</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Figure out if the file we request a sum on exists and isn't a directory */</code>\r
+ rc <code style="color:#806030; ">=</code> apr_stat<code style="color:#806030; ">(</code><code style="color:#806030; ">&</code>finfo<code style="color:#806030; ">,</code> filename<code style="color:#806030; ">,</code> APR_FINFO_MIN<code style="color:#806030; ">,</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">pool</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code>rc <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> APR_SUCCESS<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ exists <code style="color:#806030; ">=</code>\r
+ <code style="color:#806030; ">(</code>\r
+ <code style="color:#806030; ">(</code>finfo<code style="color:#806030; ">.</code>filetype <code style="color:#806030; ">!</code><code style="color:#806030; ">=</code> APR_NOFILE<code style="color:#806030; ">)</code>\r
+ <code style="color:#806030; ">&</code><code style="color:#806030; ">&</code> <code style="color:#806030; ">!</code><code style="color:#806030; ">(</code>finfo<code style="color:#806030; ">.</code>filetype <code style="color:#806030; ">&</code> APR_DIR<code style="color:#806030; ">)</code>\r
+ <code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>exists<code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code> HTTP_NOT_FOUND<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Return a 404 if not found. */</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#c34e00; ">/* If apr_stat failed, we're probably not allowed to check this file. */</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> <code style="color:#400000; font-weight:bold; ">return</code> HTTP_FORBIDDEN<code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Parse the GET and, optionally, the POST data sent to us */</code>\r
+ \r
+ ap_args_to_table<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>GET<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_parse_form_data<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>POST<code style="color:#806030; ">,</code> <code style="color:#806030; ">-</code><code style="color:#c00000; ">1</code><code style="color:#806030; ">,</code> <code style="color:#c00000; ">8192</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Set the appropriate content type */</code>\r
+ ap_set_content_type<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/html</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Print a title and some general information */</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; "><h2>Information on </code><code style="color:#0f6900; ">%s</code><code style="color:#e60000; ">:</h2></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> filename<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; "><b>Size:</b> </code><code style="color:#0f6900; ">%u</code><code style="color:#e60000; "> bytes<br/></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> finfo<code style="color:#806030; ">.</code>size<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Get the digest type the client wants to see */</code>\r
+ digestType <code style="color:#806030; ">=</code> apr_table_get<code style="color:#806030; ">(</code>GET<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">digest</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>digestType<code style="color:#806030; ">)</code> digestType <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">MD5</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ \r
+ \r
+ rc <code style="color:#806030; ">=</code> apr_file_open<code style="color:#806030; ">(</code><code style="color:#806030; ">&</code>file<code style="color:#806030; ">,</code> filename<code style="color:#806030; ">,</code> APR_READ<code style="color:#806030; ">,</code> APR_OS_DEFAULT<code style="color:#806030; ">,</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">pool</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code>rc <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> APR_SUCCESS<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Are we trying to calculate the MD5 or the SHA1 digest? */</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>digestType<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">md5</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Calculate the MD5 sum of the file */</code>\r
+ <code style="color:#400000; font-weight:bold; ">union</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> chr<code style="color:#806030; ">[</code><code style="color:#c00000; ">16</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ uint32_t num<code style="color:#806030; ">[</code><code style="color:#c00000; ">4</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code> digest<code style="color:#806030; ">;</code>\r
+ apr_md5_ctx_t md5<code style="color:#806030; ">;</code>\r
+ apr_md5_init<code style="color:#806030; ">(</code><code style="color:#806030; ">&</code>md5<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ readBytes <code style="color:#806030; ">=</code> <code style="color:#c00000; ">256</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">while</code> <code style="color:#806030; ">(</code> apr_file_read<code style="color:#806030; ">(</code>file<code style="color:#806030; ">,</code> buffer<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>readBytes<code style="color:#806030; ">)</code> <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> APR_SUCCESS <code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ apr_md5_update<code style="color:#806030; ">(</code><code style="color:#806030; ">&</code>md5<code style="color:#806030; ">,</code> buffer<code style="color:#806030; ">,</code> readBytes<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ apr_md5_final<code style="color:#806030; ">(</code>digest<code style="color:#806030; ">.</code>chr<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>md5<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Print out the MD5 digest */</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; "><b>MD5: </b><code></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">for</code> <code style="color:#806030; ">(</code>n <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code> n <code style="color:#806030; "><</code> APR_MD5_DIGESTSIZE<code style="color:#806030; ">/</code><code style="color:#c00000; ">4</code><code style="color:#806030; ">;</code> n<code style="color:#806030; ">+</code><code style="color:#806030; ">+</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#0f6900; ">%08x</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> digest<code style="color:#806030; ">.</code>num<code style="color:#806030; ">[</code>n<code style="color:#806030; ">]</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; "></code></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/* Print a link to the SHA1 version */</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; "><br/><a href='?digest=sha1'>View the SHA1 hash instead</a></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Calculate the SHA1 sum of the file */</code>\r
+ <code style="color:#400000; font-weight:bold; ">union</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> chr<code style="color:#806030; ">[</code><code style="color:#c00000; ">20</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ uint32_t num<code style="color:#806030; ">[</code><code style="color:#c00000; ">5</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code> digest<code style="color:#806030; ">;</code>\r
+ apr_sha1_ctx_t sha1<code style="color:#806030; ">;</code>\r
+ apr_sha1_init<code style="color:#806030; ">(</code><code style="color:#806030; ">&</code>sha1<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ readBytes <code style="color:#806030; ">=</code> <code style="color:#c00000; ">256</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">while</code> <code style="color:#806030; ">(</code> apr_file_read<code style="color:#806030; ">(</code>file<code style="color:#806030; ">,</code> buffer<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>readBytes<code style="color:#806030; ">)</code> <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> APR_SUCCESS <code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ apr_sha1_update<code style="color:#806030; ">(</code><code style="color:#806030; ">&</code>sha1<code style="color:#806030; ">,</code> buffer<code style="color:#806030; ">,</code> readBytes<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ apr_sha1_final<code style="color:#806030; ">(</code>digest<code style="color:#806030; ">.</code>chr<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>sha1<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Print out the SHA1 digest */</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; "><b>SHA1: </b><code></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">for</code> <code style="color:#806030; ">(</code>n <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code> n <code style="color:#806030; "><</code> APR_SHA1_DIGESTSIZE<code style="color:#806030; ">/</code><code style="color:#c00000; ">4</code><code style="color:#806030; ">;</code> n<code style="color:#806030; ">+</code><code style="color:#806030; ">+</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#0f6900; ">%08x</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> digest<code style="color:#806030; ">.</code>num<code style="color:#806030; ">[</code>n<code style="color:#806030; ">]</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; "></code></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#c34e00; ">/* Print a link to the MD5 version */</code>\r
+ ap_rputs<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; "><br/><a href='?digest=md5'>View the MD5 hash instead</a></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ apr_file_close<code style="color:#806030; ">(</code>file<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#806030; ">}</code>\r
+ \r
+ \r
+ \r
+ <code style="color:#c34e00; ">/* Let Apache know that we responded to this request. */</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+This version in its entirity can be found here: \r
+<a href="http://people.apache.org/~humbedooh/mods/examples/mod_example_2.c">mod_example_2.c</a>.\r
+\r
+\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="configuration" id="configuration">Adding configuration options</a></h2>\r
+<p>\r
+In this next segment of this document, we will turn our eyes away from the \r
+digest module and create a new example module, whose only function is to \r
+write out its own configuration. The purpose of this is to examine how \r
+Apache works with configuration, and what happens when you start writing \r
+advanced configurations \r
+for your modules.\r
+</p>\r
+<h3><a name="config_intro" id="config_intro">An introduction to configuration \r
+directives</a></h3> If you are reading this, then you probably already know \r
+what a configuration directive is. Simply put, a directive is a way of \r
+telling an individual module (or a set of modules) how to behave, such as \r
+these directives control how <code>mod_rewrite</code> works:\r
+<div class="example"><pre>\r
+RewriteEngine On\r
+RewriteCond %{REQUEST_URI} ^/foo/bar\r
+RewriteRule ^/foo/bar/(.*)$ /foobar?page=$1\r
+</pre></div>\r
+Each of these configuration directives are handled by a separate function, \r
+that parses the parameters given and sets up a configuration accordingly.\r
+\r
+<h3><a name="config_simple" id="config_simple">Making an example configuration</a></h3>\r
+To begin with, we'll create a basic configuration in C-space:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">typedef</code> <code style="color:#400000; font-weight:bold; ">struct</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> enabled<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Enable or disable our module */</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>path<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Some path to...something */</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> typeOfAction<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* 1 means action A, 2 means action B and so on */</code>\r
+<code style="color:#806030; ">}</code> example_config<code style="color:#806030; ">;</code>\r
+</pre>\r
+\r
+\r
+\r
+Now, let's put this into perspective by creating a very small module that \r
+just prints out a hard-coded configuration. You'll notice that we use the \r
+<code>register_hooks</code> function for initializing the configuration \r
+values to their defaults:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">typedef</code> <code style="color:#400000; font-weight:bold; ">struct</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> enabled<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Enable or disable our module */</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>path<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Some path to...something */</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> typeOfAction<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* 1 means action A, 2 means action B and so on */</code>\r
+<code style="color:#806030; ">}</code> example_config<code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> example_config config<code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">example-handler</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code><code style="color:#806030; ">(</code>DECLINED<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_set_content_type<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/plain</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(r, </code><code style="color:#800000; ">"</code><code style="color:#e60000; ">Enabled: </code><code style="color:#0f6900; ">%u</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">.</code>enabled<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(r, </code><code style="color:#800000; ">"</code><code style="color:#e60000; ">Path: </code><code style="color:#0f6900; ">%s</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">.</code>path<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(r, </code><code style="color:#800000; ">"</code><code style="color:#e60000; ">TypeOfAction: </code><code style="color:#0f6900; ">%x</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">.</code>typeOfAction<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">void</code> register_hooks<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">)</code> \r
+<code style="color:#806030; ">{</code>\r
+ config<code style="color:#806030; ">.</code>enabled <code style="color:#806030; ">=</code> <code style="color:#c00000; ">1</code><code style="color:#806030; ">;</code>\r
+ config<code style="color:#806030; ">.</code>path <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">/foo/bar</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x00</code><code style="color:#806030; ">;</code>\r
+ ap_hook_handler<code style="color:#806030; ">(</code>example_handler<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> APR_HOOK_LAST<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/* Define our module as an entity and assign a function for registering hooks */</code>\r
+\r
+module AP_MODULE_DECLARE_DATA example_module <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ STANDARD20_MODULE_STUFF<code style="color:#806030; ">,</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-directory configuration handler */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-directory configurations */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-server configuration handler */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-server configurations */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Any directives we may have for httpd */</code>\r
+ register_hooks <code style="color:#c34e00; ">/* Our hook registering function */</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+</pre>\r
+\r
+\r
+\r
+So far so good. To access our new handler, we could add the following to \r
+our configuration:\r
+<div class="example"><pre>\r
+<Location /example>\r
+ SetHandler example-handler\r
+</Location>\r
+</pre></div>\r
+When we visit, we'll see our current configuration being spit out by our \r
+module. \r
+\r
+\r
+<h3><a name="register_directive" id="register_directive">Registering directives with Apache</a></h3>\r
+What if we want to change our configuration, not by hard-coding new values \r
+into the module, but by using either the httpd.conf file or possibly a \r
+.htaccess file? It's time to let Apache know that we want this to be \r
+possible. To do so, we must first change our <em>name tag</em> to include a \r
+reference to the configuration directives we want to register with Apache:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+module AP_MODULE_DECLARE_DATA example_module =\r
+{\r
+ STANDARD20_MODULE_STUFF,\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>, <code style="color:#c34e00; ">/* Per-directory configuration handler */</code>\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>, <code style="color:#c34e00; ">/* Merge handler for per-directory configurations */</code>\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>, <code style="color:#c34e00; ">/* Per-server configuration handler */</code>\r
+ <code style="color:#7f0055; font-weight:bold; ">NULL</code>, <code style="color:#c34e00; ">/* Merge handler for per-server configurations */</code>\r
+ example_directives, <code style="color:#c34e00; ">/* Any directives we may have for httpd */</code>\r
+ register_hooks <code style="color:#c34e00; ">/* Our hook registering function */</code>\r
+};\r
+</pre>\r
+\r
+\r
+\r
+This will tell Apache that we are now accepting directives from the \r
+configuration files, and that the structure called <code>example_directives\r
+</code> holds information on what our directives are and how they work. \r
+Since we have three different variables in our module configuration, we \r
+will add a structure with three directives and a NULL at the end:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+static const command_rec example_directives[] =\r
+{\r
+ <code style="color:#2e8800; "><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a></code>("exampleEnabled", example_set_enabled, <code style="color:#7f0055; font-weight:bold; ">NULL</code>, RSRC_CONF, "Enable or disable mod_example"),\r
+ <code style="color:#2e8800; "><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a></code>("examplePath", example_set_path, <code style="color:#7f0055; font-weight:bold; ">NULL</code>, RSRC_CONF, "The path to whatever"),\r
+ <code style="color:#2e8800; "><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#gafaec43534fcf200f37d9fecbf9247c21">AP_INIT_TAKE2</a></code>("exampleAction", example_set_action, <code style="color:#7f0055; font-weight:bold; ">NULL</code>, RSRC_CONF, "Special action value!"),\r
+ { <code style="color:#7f0055; font-weight:bold; ">NULL</code> }\r
+};\r
+</pre>\r
+\r
+\r
+\r
+<img src="../images/build_a_mod_4.png" border="1" /><br />\r
+<p>\r
+As you can see, each directive needs at least 5 parameters set:\r
+<ol>\r
+<li><code><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a></code>: This is a macro that tells Apache that this directive takes one and only one argument. \r
+If we required two arguments, we could use the macro <code><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#gafaec43534fcf200f37d9fecbf9247c21">AP_INIT_TAKE2</a></code> and so on (refer to httpd_conf.h \r
+for more macros).</li>\r
+<li><code>exampleEnabled</code>: This is the name of our directive. More precisely, it is what the user must put in his/her \r
+configuration in order to invoke a configuration change in our module.</li>\r
+<li><code>example_set_enabled</code>: This is a reference to a C function that parses the directive and sets the configuration \r
+accordingly. We will discuss how to make this in the following paragraph.</li>\r
+<li><code>RSRC_CONF</code>: This tells Apache where the directive is permissable. We'll go into details on this value in the \r
+later chapters, but for now, <code>RSRC_CONF</code> means that Apache will only accept these directives in a server context.</li>\r
+<li><code>"Enable or disable...."</code>: This is simply a brief description of what the directive does.</li>\r
+</ol>\r
+(<em>The "missing" parameter in our definition, which is usually set to \r
+<code>NULL</code>, is an optional function that can be run after the \r
+initial function to parse the arguments have been run. This is usually \r
+omitted, as the function for verifying arguments might as well be used to \r
+set them.</em>)\r
+</p>\r
+\r
+<h3><a name="directive_handler" id="directive_handler">The directive handler function</a></h3>\r
+<p>\r
+Now that we've told Apache to expect some directives for our module, it's \r
+time to make a few functions for handling these. What Apache reads in the \r
+configuration file(s) is text, and so naturally, what it passes along to \r
+our directive handler is one or more strings, that we ourselves need to \r
+recognize and act upon. You'll notice, that since we set our <code>\r
+exampleAction</code> directive to accept two arguments, its C function also \r
+has an additional parameter defined:<br /> \r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#c34e00; ">/* Handler for the "exambleEnabled" directive */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>example_set_enabled<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">on</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> config<code style="color:#806030; ">.</code>enabled <code style="color:#806030; ">=</code> <code style="color:#c00000; ">1</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> config<code style="color:#806030; ">.</code>enabled <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/* Handler for the "examplePath" directive */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>example_set_path<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ config<code style="color:#806030; ">.</code>path <code style="color:#806030; ">=</code> arg<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/* Handler for the "exampleAction" directive */</code>\r
+<code style="color:#c34e00; ">/* Let's pretend this one takes one argument (file or db), and a second (deny or allow), */</code>\r
+<code style="color:#c34e00; ">/* and we store it in a bit-wise manner. */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>example_set_action<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg1<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; ">*</code> arg2<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg1<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">file</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x01</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x02</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg2<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">deny</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x10</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x20</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+\r
+<h3><a name="directive_complete" id="directive_complete">Putting it all together</a></h3>\r
+<p>\r
+Now that we have our directives set up, and handlers configured for them, \r
+we can assemble our module into one big file:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#c34e00; ">/* mod_example_config_simple.c: */</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; "><</code><code style="color:#40015a; ">stdio.h</code><code style="color:#800000; ">></code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">apr_hash.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">ap_config.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">ap_provider.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">httpd.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_core.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_config.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_log.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_protocol.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_request.h</code><code style="color:#800000; ">"</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> Our configuration prototype and declaration:</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">typedef</code> <code style="color:#400000; font-weight:bold; ">struct</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> enabled<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Enable or disable our module */</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>path<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* Some path to...something */</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> typeOfAction<code style="color:#806030; ">;</code> <code style="color:#c34e00; ">/* 1 means action A, 2 means action B and so on */</code>\r
+<code style="color:#806030; ">}</code> example_config<code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> example_config config<code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> Our directive handlers:</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#c34e00; ">/* Handler for the "exambleEnabled" directive */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>example_set_enabled<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">on</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> config<code style="color:#806030; ">.</code>enabled <code style="color:#806030; ">=</code> <code style="color:#c00000; ">1</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> config<code style="color:#806030; ">.</code>enabled <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/* Handler for the "examplePath" directive */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>example_set_path<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ config<code style="color:#806030; ">.</code>path <code style="color:#806030; ">=</code> arg<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/* Handler for the "exampleAction" directive */</code>\r
+<code style="color:#c34e00; ">/* Let's pretend this one takes one argument (file or db), and a second (deny or allow), */</code>\r
+<code style="color:#c34e00; ">/* and we store it in a bit-wise manner. */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; "> *</code>example_set_action<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg1<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; ">*</code> arg2<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg1<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">file</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x01</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x02</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg2<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">deny</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x10</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x20</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> The directive structure for our name tag:</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">const</code> command_rec example_directives<code style="color:#806030; ">[</code><code style="color:#806030; ">]</code> <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a><code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">exampleEnabled</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> example_set_enabled<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> RSRC_CONF<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Enable or disable mod_example</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">,</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a><code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">examplePath</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> example_set_path<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> RSRC_CONF<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">The path to whatever</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">,</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#gafaec43534fcf200f37d9fecbf9247c21">AP_INIT_TAKE2</a><code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">exampleAction</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> example_set_action<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> RSRC_CONF<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Special action value!</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">,</code>\r
+ <code style="color:#806030; ">{</code> <code style="color:#007d45; ">NULL</code> <code style="color:#806030; ">}</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> Our module handler:</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">example-handler</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code><code style="color:#806030; ">(</code>DECLINED<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_set_content_type<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/plain</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Enabled: </code><code style="color:#0f6900; ">%u</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">.</code>enabled<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Path: </code><code style="color:#0f6900; ">%s</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">.</code>path<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">TypeOfAction: </code><code style="color:#0f6900; ">%x</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">.</code>typeOfAction<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> The hook registration function (also initializes the default config values):</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">void</code> register_hooks<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">)</code> \r
+<code style="color:#806030; ">{</code>\r
+ config<code style="color:#806030; ">.</code>enabled <code style="color:#806030; ">=</code> <code style="color:#c00000; ">1</code><code style="color:#806030; ">;</code>\r
+ config<code style="color:#806030; ">.</code>path <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">/foo/bar</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ config<code style="color:#806030; ">.</code>typeOfAction <code style="color:#806030; ">=</code> <code style="color:#c00000; ">3</code><code style="color:#806030; ">;</code>\r
+ ap_hook_handler<code style="color:#806030; ">(</code>example_handler<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> APR_HOOK_LAST<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> Our module name tag:</code>\r
+<code style="color:#c34e00; "> ==============================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+module AP_MODULE_DECLARE_DATA example_module <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ STANDARD20_MODULE_STUFF<code style="color:#806030; ">,</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-directory configuration handler */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-directory configurations */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-server configuration handler */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-server configurations */</code>\r
+ example_directives<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Any directives we may have for httpd */</code>\r
+ register_hooks <code style="color:#c34e00; ">/* Our hook registering function */</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+<p>\r
+In our httpd.conf file, we can now change the hard-coded configuration by \r
+adding a few lines:\r
+<div class="example"><pre>\r
+ExampleEnabled On\r
+ExamplePath "/usr/bin/foo"\r
+ExampleAction file allow\r
+</pre></div>\r
+And thus we apply the configuration, visit <code>/example</code> on our \r
+web site, and we see the configuration has adapted to what we wrote in our \r
+configuration file.\r
+</p>\r
+\r
+\r
+\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="context" id="context">Context aware configurations</a></h2>\r
+<h3><a name="context_intro" id="context_intro">Introduction to context aware configurations</a></h3>\r
+<p>\r
+In Apache, different URLs, virtual hosts, directories etc can have very \r
+different meanings to the user of Apache, and thus different contexts \r
+within which modules must operate. For example, let's assume you have this \r
+configuration set up for mod_rewrite:\r
+<div class="example"><pre>\r
+<Directory "/var/www">\r
+ RewriteCond %{HTTP_HOST} ^example.com$\r
+ RewriteRule (.*) http://www.example.com/$1\r
+</Directory>\r
+<Directory "/var/www/sub">\r
+ RewriteRule ^foobar$ index.php?foobar=true\r
+</Directory>\r
+</pre></div>\r
+In this example, you will have set up two different contexts for \r
+mod_rewrite:\r
+<ol>\r
+<li>Inside <code>/var/www</code>, all requests for <code>http://example.com</code> must go to <code>http://www.example.com</code></li>\r
+<li>Inside <code>/var/www/sub</code>, all requests for <code>foobar</code> must go to <code>index.php?foobar=true</code></li>\r
+</ol>\r
+If mod_rewrite (or Apache for that matter) wasn't context aware, then \r
+these rewrite rules would just apply to every and any request made, \r
+regardless of where and how they were made, but since the module can pull \r
+the context specific configuration straight from Apache, it does not need \r
+to know itself, which of the directives are valid in this context, since \r
+Apache takes care of this.</p>\r
+\r
+<p>\r
+So how does a module get the specific configuration for the server, \r
+directory or location in question? It does so by making one simple call:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+\r
+\r
+\r
+example_config *config = (example_config*) <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga1093a5908a384eacc929b028c79f2a02">ap_get_module_config</a>(<code style="color:#008833">r->per_dir_config</code>, &example_module);\r
+</pre>\r
+That's it! Of course, a whole lot goes on behind the scenes, which we will \r
+discuss in this chapter, starting with how Apache came to know what our \r
+configuration looks like, and how it came to be set up as it is in the \r
+specific context.\r
+</p>\r
+\r
+\r
+<h3><a name="context_base" id="context_base">Our basic configuration setup</a></h3>\r
+<p>In this chapter, we will be working with a slightly modified version of \r
+our previous context structure. We will set a <code>context</code> \r
+variable that we can use to track which context configuration is being \r
+used by Apache in various places:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">typedef</code> <code style="color:#400000; font-weight:bold; ">struct</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> context<code style="color:#806030; ">[</code><code style="color:#c00000; ">256</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> path<code style="color:#806030; ">[</code><code style="color:#c00000; ">256</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> typeOfAction<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> enabled<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code> example_config<code style="color:#806030; ">;</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+\r
+<p>Our handler for requests will also be modified, yet still very simple:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">example-handler</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code><code style="color:#806030; ">(</code>DECLINED<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ example_config<code style="color:#806030; "> *</code>config <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config<code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> ap_get_module_config<code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">per_dir_config</code><code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>example_module<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_set_content_type<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/plain</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">Enabled: </code><code style="color:#0f6900; ">%u</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">Path: </code><code style="color:#0f6900; ">%s</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">TypeOfAction: </code><code style="color:#0f6900; ">%x</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">Context: </code><code style="color:#0f6900; ">%s</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">context</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+\r
+\r
+\r
+<h3><a name="context_which" id="context_which">Choosing a context</a></h3>\r
+<p>\r
+Before we can start making our module context aware, we must first define, \r
+which contexts we will accept. As we saw in the previous chapter, defining \r
+a directive required five elements be set:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#2e8800; "><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a></code>("exampleEnabled", example_set_enabled, <code style="color:#7f0055; font-weight:bold; ">NULL</code>, RSRC_CONF, "Enable or disable mod_example"),\r
+</pre>\r
+\r
+\r
+\r
+The <code>RSRC_CONF</code> definition told Apache that we would only allow \r
+this directive in a global server context, but since we are now trying out \r
+a context aware version of our module, we should set this to something \r
+more lenient, namely the value <code>ACCESS_CONF</code>, which lets us use \r
+the directive inside <Directory> and <Location> blocks.\r
+</p>\r
+\r
+\r
+<h3><a name="context_pool" id="context_pool">Using Apache to allocate configuration slots</a></h3>\r
+<p> A much smarter way to manage your configurations is by letting Apache \r
+help you create them. To do so, we must first start off by changing our \r
+<em>name tag</em> to let Apache know, that it should assist us in creating \r
+and managing our configurations. Since we have chosen the per-directory \r
+(or per-location) context for our module configurations, we'll add a \r
+per-directory creator and merger function reference in our tag:\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+module AP_MODULE_DECLARE_DATA example_module <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ STANDARD20_MODULE_STUFF<code style="color:#806030; ">,</code>\r
+ create_dir_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-directory configuration handler */</code>\r
+ merge_dir_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-directory configurations */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-server configuration handler */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-server configurations */</code>\r
+ directives<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Any directives we may have for httpd */</code>\r
+ register_hooks <code style="color:#c34e00; ">/* Our hook registering function */</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+\r
+\r
+\r
+\r
+\r
+<h3><a name="context_which" id="context_which">Creating new context configurations</a></h3>\r
+<p>\r
+Now that we have told Apache to help us create and manage configurations, \r
+our first step is to make a function for creating new, blank \r
+configurations. We do so by creating the function we just referenced in \r
+our name tag as the Per-directory configuration handler:\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">void</code><code style="color:#806030; ">*</code> example_create_dir_conf<code style="color:#806030; ">(</code>apr_pool_t<code style="color:#806030; ">*</code> pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">char</code><code style="color:#806030; ">*</code> context<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ context <code style="color:#806030; ">=</code> context <code style="color:#806030; ">?</code> context <code style="color:#806030; ">:</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">(undefined context)</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ example_config<code style="color:#806030; "> *</code>cfg <code style="color:#806030; ">=</code> apr_pcalloc<code style="color:#806030; ">(</code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">sizeof</code><code style="color:#806030; ">(</code>example_config<code style="color:#806030; ">)</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>cfg<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Set some default values */</code>\r
+ <code style="color:#800040; ">strcpy</code><code style="color:#806030; ">(</code>cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">context</code><code style="color:#806030; ">,</code> x<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code> <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">/foo/bar</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x11</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> cfg<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+</p>\r
+\r
+\r
+<h3><a name="context_which" id="context_which">Merging configurations</a></h3>\r
+<p>\r
+Our next step in creating a context aware configuration is merging \r
+configurations. This part of the process particularly apply to scenarios \r
+where you have a parent configuration and a child, such as the following: \r
+<div class="example"><pre>\r
+<Directory "/var/www">\r
+ ExampleEnable On\r
+ ExamplePath /foo/bar\r
+ ExampleAction file allow\r
+</Directory>\r
+<Directory "/var/www/subdir">\r
+ ExampleAction file deny\r
+</Directory>\r
+</pre></div>\r
+In this example, it is natural to assume that the directory <code>\r
+/var/www/subdir</code> should inherit the value set for the <code>/var/www\r
+</code> directory, as we did not specify a <code>ExampleEnable</code> nor \r
+an <code>ExamplePath</code> for this directory. Apache does not presume to \r
+know if this is true, but cleverly does the following:\r
+<ol>\r
+<li>Creates a new configuration for <code>/var/www</code></li>\r
+<li>Sets the configuration values according to the directives given for <code>/var/www</code></li>\r
+<li>Creates a new configuration for <code>/var/www/subdir</code></li>\r
+<li>Sets the configuration values according to the directives given for <code>/var/www/subdir</code></li>\r
+<li><strong>Proposes a merge</strong> of the two configurations into a new configuration for <code>/var/www/subdir</code></li>\r
+</ol>\r
+This proposal is handled by the <code>merge_dir_conf</code> function we \r
+referenced in our name tag. The purpose of this function is to assess the \r
+two configurations and decide how they are to be merged:\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">void</code><code style="color:#806030; ">*</code> merge_dir_conf<code style="color:#806030; ">(</code>apr_pool_t<code style="color:#806030; ">*</code> pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code><code style="color:#806030; ">*</code> BASE<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code><code style="color:#806030; ">*</code> ADD<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ example_config<code style="color:#806030; ">*</code> base <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> BASE <code style="color:#806030; ">;</code>\r
+ example_config<code style="color:#806030; ">*</code> add <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> ADD <code style="color:#806030; ">;</code>\r
+ example_config<code style="color:#806030; ">*</code> conf <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> create_dir_conf<code style="color:#806030; ">(</code>pool<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Merged configuration</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code> <code style="color:#806030; ">)</code> <code style="color:#806030; ">?</code> base<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">:</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">;</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">=</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">?</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">:</code> base<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#800040; ">strcpy</code><code style="color:#806030; ">(</code>conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">,</code> <code style="color:#800040; ">strlen</code><code style="color:#806030; ">(</code>add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">?</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code> <code style="color:#806030; ">:</code> base<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ <code style="color:#400000; font-weight:bold; ">return</code> conf <code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+</p>\r
+\r
+\r
+<h3><a name="context_which" id="context_which">Trying out our new context aware configurations</a></h3>\r
+<p>\r
+Now, let's try putting it all together to create a new module that is \r
+context aware. First off, we'll create a configuration that lets us test \r
+how the module works:\r
+<div class="example"><pre>\r
+<Location "/a">\r
+ SetHandler example-handler\r
+ ExampleEnabled on\r
+ ExamplePath "/foo/bar"\r
+ ExampleAction file allow\r
+</Location>\r
+\r
+<Location "/a/b">\r
+ ExampleAction file deny\r
+ ExampleEnabled off\r
+</Location>\r
+\r
+<Location "/a/b/c">\r
+ ExampleAction db deny\r
+ ExamplePath "/foo/bar/baz"\r
+ ExampleEnabled on\r
+</Location>\r
+</pre></div>\r
+Then we'll assemble our module code. Note, that since we are now using our \r
+name tag as reference when fetching configurations in our handler, I have \r
+added some prototypes to keep the compiler happy:\r
+</p>\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#c34e00; ">/*$6</code>\r
+<code style="color:#c34e00; "> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</code>\r
+<code style="color:#c34e00; "> * mod_example_config.c</code>\r
+<code style="color:#c34e00; "> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</code>\r
+<code style="color:#c34e00; "> */</code>\r
+\r
+\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; "><</code><code style="color:#40015a; ">stdio.h</code><code style="color:#800000; ">></code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">apr_hash.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">ap_config.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">ap_provider.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">httpd.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_core.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_config.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_log.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_protocol.h</code><code style="color:#800000; ">"</code>\r
+<code style="color:#004a43; ">#</code><code style="color:#004a43; ">include </code><code style="color:#800000; ">"</code><code style="color:#40015a; ">http_request.h</code><code style="color:#800000; ">"</code>\r
+\r
+<code style="color:#c34e00; ">/*$1</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> Configuration structure</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> */</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">typedef</code> <code style="color:#400000; font-weight:bold; ">struct</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> context<code style="color:#806030; ">[</code><code style="color:#c00000; ">256</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> path<code style="color:#806030; ">[</code><code style="color:#c00000; ">256</code><code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> typeOfAction<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> enabled<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code> example_config<code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#c34e00; ">/*$1</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> Prototypes</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> */</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>example_set_enabled<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>example_set_path<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>example_set_action<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg1<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg2<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>create_dir_conf<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>context<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>merge_dir_conf<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>BASE<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>ADD<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">void</code> register_hooks<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#c34e00; ">/*$1</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> Configuration directives</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> */</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">const</code> command_rec directives<code style="color:#806030; ">[</code><code style="color:#806030; ">]</code> <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a><code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">exampleEnabled</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> example_set_enabled<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> ACCESS_CONF<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Enable or disable mod_example</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">,</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#ga07c7d22ae17805e61204463326cf9c34">AP_INIT_TAKE1</a><code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">examplePath</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> example_set_path<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> ACCESS_CONF<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">The path to whatever</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">,</code>\r
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__CONFIG.html#gafaec43534fcf200f37d9fecbf9247c21">AP_INIT_TAKE2</a><code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">exampleAction</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> example_set_action<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> ACCESS_CONF<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Special action value!</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">,</code>\r
+ <code style="color:#806030; ">{</code> <code style="color:#007d45; ">NULL</code> <code style="color:#806030; ">}</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#c34e00; ">/*$1</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> Our name tag</code>\r
+<code style="color:#c34e00; "> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>\r
+<code style="color:#c34e00; "> */</code>\r
+\r
+module AP_MODULE_DECLARE_DATA example_module <code style="color:#806030; ">=</code>\r
+<code style="color:#806030; ">{</code>\r
+ STANDARD20_MODULE_STUFF<code style="color:#806030; ">,</code>\r
+ create_dir_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-directory configuration handler */</code>\r
+ merge_dir_conf<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-directory configurations */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Per-server configuration handler */</code>\r
+ <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Merge handler for per-server configurations */</code>\r
+ directives<code style="color:#806030; ">,</code> <code style="color:#c34e00; ">/* Any directives we may have for httpd */</code>\r
+ register_hooks <code style="color:#c34e00; ">/* Our hook registering function */</code>\r
+<code style="color:#806030; ">}</code><code style="color:#806030; ">;</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Hook registration function</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">void</code> register_hooks<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ ap_hook_handler<code style="color:#806030; ">(</code>example_handler<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> APR_HOOK_LAST<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Our example web service handler</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code> <code style="color:#806030; ">|</code><code style="color:#806030; ">|</code> <code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">handler</code><code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">example-handler</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code><code style="color:#806030; ">(</code>DECLINED<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ example_config <code style="color:#806030; ">*</code>config <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> ap_get_module_config<code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">per_dir_config</code><code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>example_module<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ ap_set_content_type<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">text/plain</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Enabled: </code><code style="color:#0f6900; ">%u</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Path: </code><code style="color:#0f6900; ">%s</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">TypeOfAction: </code><code style="color:#0f6900; ">%x</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Context: </code><code style="color:#0f6900; ">%s</code><code style="color:#0f6900; ">\n</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> config<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">context</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Handler for the "exambleEnabled" directive</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>example_set_enabled<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ example_config <code style="color:#806030; ">*</code>conf <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> cfg<code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>conf<code style="color:#806030; ">)</code>\r
+ <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">on</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">1</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Handler for the "examplePath" directive</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>example_set_path<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ example_config <code style="color:#806030; ">*</code>conf <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> cfg<code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>conf<code style="color:#806030; ">)</code>\r
+ <code style="color:#806030; ">{</code>\r
+ <code style="color:#800040; ">strcpy</code><code style="color:#806030; ">(</code>conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">,</code> arg<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Handler for the "exampleAction" directive ;</code>\r
+<code style="color:#c34e00; "> Let's pretend this one takes one argument (file or db), and a second (deny or allow), ;</code>\r
+<code style="color:#c34e00; "> and we store it in a bit-wise manner.</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>example_set_action<code style="color:#806030; ">(</code>cmd_parms <code style="color:#806030; ">*</code>cmd<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>cfg<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg1<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>arg2<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ example_config <code style="color:#806030; ">*</code>conf <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> cfg<code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>conf<code style="color:#806030; ">)</code>\r
+ <code style="color:#806030; ">{</code>\r
+ <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg1<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">file</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x01</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x02</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>strcasecmp<code style="color:#806030; ">(</code>arg2<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">deny</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x10</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x20</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Function for creating new configurations for per-directory contexts</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>create_dir_conf<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>context<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ context <code style="color:#806030; ">=</code> context <code style="color:#806030; ">?</code> context <code style="color:#806030; ">:</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Newly created configuration</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ example_config <code style="color:#806030; ">*</code>cfg <code style="color:#806030; ">=</code> apr_pcalloc<code style="color:#806030; ">(</code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">sizeof</code><code style="color:#806030; ">(</code>example_config<code style="color:#806030; ">)</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>cfg<code style="color:#806030; ">)</code>\r
+ <code style="color:#806030; ">{</code>\r
+ <code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/* Set some default values */</code>\r
+ <code style="color:#800040; ">strcpy</code><code style="color:#806030; ">(</code>cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">context</code><code style="color:#806030; ">,</code> context<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#800040; ">memset</code><code style="color:#806030; ">(</code>cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">,</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">,</code> <code style="color:#c00000; ">256</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ cfg<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0x00</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">return</code> cfg<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#c34e00; ">/*</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> Merging function for configurations</code>\r
+<code style="color:#c34e00; "> =======================================================================================================================</code>\r
+<code style="color:#c34e00; "> */</code>\r
+<code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>merge_dir_conf<code style="color:#806030; ">(</code>apr_pool_t <code style="color:#806030; ">*</code>pool<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>BASE<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">void</code> <code style="color:#806030; ">*</code>ADD<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ example_config <code style="color:#806030; ">*</code>base <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> BASE<code style="color:#806030; ">;</code>\r
+ example_config <code style="color:#806030; ">*</code>add <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> ADD<code style="color:#806030; ">;</code>\r
+ example_config <code style="color:#806030; ">*</code>conf <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>example_config <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> create_dir_conf<code style="color:#806030; ">(</code>pool<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">Merged configuration</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">?</code> base<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code> <code style="color:#806030; ">:</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">enabled</code><code style="color:#806030; ">;</code>\r
+ conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">=</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">?</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code> <code style="color:#806030; ">:</code> base<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">typeOfAction</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#800040; ">strcpy</code><code style="color:#806030; ">(</code>conf<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">,</code> <code style="color:#800040; ">strlen</code><code style="color:#806030; ">(</code>add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">?</code> add<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code> <code style="color:#806030; ">:</code> base<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">path</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> conf<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+</pre>\r
+\r
+\r
+\r
+\r
+\r
+\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="summary" id="summary">Summing up</a></h2>\r
+<p>\r
+We have now looked at how to create simple modules for Apache and \r
+configuring them. What you do next is entirely up to you, but it is my \r
+hope that something valuable has come out of reading this documentation. \r
+If you have questions on how to further develop modules, you are welcome \r
+to join our <a href="http://httpd.apache.org/lists.html">mailing lists</a> \r
+or check out the rest of our documentation for further tips.\r
+</p>\r
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>\r
+<div class="section">\r
+<h2><a name="snippets" id="snippets">Some useful snippets of code</a></h2>\r
+\r
+<h3><a name="get_post" id="get_post">Retrieve a variable from POST form data</a></h3>\r
+\r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>read_post_value<code style="color:#806030; ">(</code><code style="color:#400000; font-weight:bold; ">const</code> apr_array_header_t <code style="color:#806030; ">*</code>fields<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>key<code style="color:#806030; ">)</code> \r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> i<code style="color:#806030; ">;</code>\r
+ apr_table_entry_t <code style="color:#806030; ">*</code>e <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ e <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>apr_table_entry_t <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> fields<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>elts<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">for</code><code style="color:#806030; ">(</code>i <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code> i <code style="color:#806030; "><</code> fields<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>nelts<code style="color:#806030; ">;</code> i<code style="color:#806030; ">+</code><code style="color:#806030; ">+</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">!</code><code style="color:#800040; ">strcmp</code><code style="color:#806030; ">(</code>e<code style="color:#806030; ">[</code>i<code style="color:#806030; ">]</code><code style="color:#806030; ">.</code>key<code style="color:#806030; ">,</code> key<code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#400000; font-weight:bold; ">return</code> e<code style="color:#806030; ">[</code>i<code style="color:#806030; ">]</code><code style="color:#806030; ">.</code>val<code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_req <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code> \r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ apr_array_header_t <code style="color:#806030; ">*</code>POST<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>value<code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ ap_parse_form_data<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#007d45; ">NULL</code><code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>POST<code style="color:#806030; ">,</code> <code style="color:#806030; ">-</code><code style="color:#c00000; ">1</code><code style="color:#806030; ">,</code> <code style="color:#c00000; ">8192</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ \r
+ value <code style="color:#806030; ">=</code> read_post_value<code style="color:#806030; ">(</code>POST<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">valueA</code><code style="color:#800000; ">"</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code> <code style="color:#806030; ">(</code><code style="color:#806030; ">!</code>value<code style="color:#806030; ">)</code> value <code style="color:#806030; ">=</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">(undefined)</code><code style="color:#800000; ">"</code><code style="color:#806030; ">;</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; ">The value of valueA is: </code><code style="color:#0f6900; ">%s</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> value<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+ </pre>\r
+\r
+\r
+\r
+ \r
+ \r
+ <h3><a name="headers_out" id="headers_out">Printing out every HTTP header received</a></h3>\r
+ \r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_req <code style="color:#806030; ">*</code>r<code style="color:#806030; ">)</code> \r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> apr_array_header_t <code style="color:#806030; ">*</code>fields<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> i<code style="color:#806030; ">;</code>\r
+ apr_table_entry_t <code style="color:#806030; ">*</code>e <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ fields <code style="color:#806030; ">=</code> <a href="http://apr.apache.org/docs/apr/1.4/group__apr__tables.html#gaea3005541cce67481f48ab201b5c0cf3">apr_table_elts</a><code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>headers_in<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ e <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code>apr_table_entry_t <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> fields<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>elts<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">for</code><code style="color:#806030; ">(</code>i <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code> i <code style="color:#806030; "><</code> fields<code style="color:#806030; ">-</code><code style="color:#806030; ">></code>nelts<code style="color:#806030; ">;</code> i<code style="color:#806030; ">+</code><code style="color:#806030; ">+</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#800000; ">"</code><code style="color:#e60000; "><b></code><code style="color:#0f6900; ">%s</code><code style="color:#e60000; "></b>: </code><code style="color:#0f6900; ">%s</code><code style="color:#e60000; "><br/></code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> e<code style="color:#806030; ">[</code>i<code style="color:#806030; ">]</code><code style="color:#806030; ">.</code>key<code style="color:#806030; ">,</code> e<code style="color:#806030; ">[</code>i<code style="color:#806030; ">]</code><code style="color:#806030; ">.</code>val<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+ </pre>\r
+\r
+\r
+\r
+ \r
+ \r
+ <h3><a name="request_body" id="request_body">Reading the request body into memory</a></h3>\r
+ \r
+\r
+\r
+<pre style="color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;">\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> util_read<code style="color:#806030; ">(</code>request_rec <code style="color:#806030; ">*</code>r<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code><code style="color:#806030; ">*</code>rbuf<code style="color:#806030; ">,</code> apr_off_t <code style="color:#806030; ">*</code>size<code style="color:#806030; ">)</code>\r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~*/</code>\r
+ <code style="color:#400000; font-weight:bold; ">int</code> rc <code style="color:#806030; ">=</code> OK<code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~*/</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">(</code>rc <code style="color:#806030; ">=</code> ap_setup_client_block<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> REQUEST_CHUNKED_ERROR<code style="color:#806030; ">)</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code><code style="color:#806030; ">(</code>rc<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>ap_should_client_block<code style="color:#806030; ">(</code>r<code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+ <code style="color:#400000; font-weight:bold; ">char</code> argsbuffer<code style="color:#806030; ">[</code>HUGE_STRING_LEN<code style="color:#806030; ">]</code><code style="color:#806030; ">;</code>\r
+ apr_off_t rsize<code style="color:#806030; ">,</code> len_read<code style="color:#806030; ">,</code> rpos <code style="color:#806030; ">=</code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">;</code>\r
+ apr_off_t length <code style="color:#806030; ">=</code> r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">remaining</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ <code style="color:#806030; ">*</code>rbuf <code style="color:#806030; ">=</code> <code style="color:#806030; ">(</code><code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> apr_pcalloc<code style="color:#806030; ">(</code>r<code style="color:#806030; ">-</code><code style="color:#806030; ">></code><code style="color:#008833">pool</code><code style="color:#806030; ">,</code> <code style="color:#806030; ">(</code>apr_size_t<code style="color:#806030; ">)</code> <code style="color:#806030; ">(</code>length <code style="color:#806030; ">+</code> <code style="color:#c00000; ">1</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">*</code>size <code style="color:#806030; ">=</code> length<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">while</code><code style="color:#806030; ">(</code><code style="color:#806030; ">(</code>len_read <code style="color:#806030; ">=</code> ap_get_client_block<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> argsbuffer<code style="color:#806030; ">,</code> <code style="color:#400000; font-weight:bold; ">sizeof</code><code style="color:#806030; ">(</code>argsbuffer<code style="color:#806030; ">)</code><code style="color:#806030; ">)</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">></code> <code style="color:#c00000; ">0</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code><code style="color:#806030; ">(</code>rpos <code style="color:#806030; ">+</code> len_read<code style="color:#806030; ">)</code> <code style="color:#806030; ">></code> length<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ rsize <code style="color:#806030; ">=</code> length <code style="color:#806030; ">-</code> rpos<code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">else</code> <code style="color:#806030; ">{</code>\r
+ rsize <code style="color:#806030; ">=</code> len_read<code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+\r
+ <code style="color:#800040; ">memcpy</code><code style="color:#806030; ">(</code><code style="color:#806030; ">(</code><code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code><code style="color:#806030; ">)</code> <code style="color:#806030; ">*</code>rbuf <code style="color:#806030; ">+</code> rpos<code style="color:#806030; ">,</code> argsbuffer<code style="color:#806030; ">,</code> <code style="color:#806030; ">(</code><code style="color:#800040; ">size_t</code><code style="color:#806030; ">)</code> rsize<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ rpos <code style="color:#806030; ">+</code><code style="color:#806030; ">=</code> rsize<code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code><code style="color:#806030; ">(</code>rc<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+\r
+<code style="color:#400000; font-weight:bold; ">static</code> <code style="color:#400000; font-weight:bold; ">int</code> example_handler<code style="color:#806030; ">(</code>request_req<code style="color:#806030; ">*</code> r<code style="color:#806030; ">)</code> \r
+<code style="color:#806030; ">{</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~*/</code>\r
+ apr_off_t size<code style="color:#806030; ">;</code>\r
+ <code style="color:#400000; font-weight:bold; ">const</code> <code style="color:#400000; font-weight:bold; ">char</code> <code style="color:#806030; ">*</code>buffer<code style="color:#806030; ">;</code>\r
+ <code style="color:#c34e00; ">/*~~~~~~~~~~~~~~~~*/</code>\r
+\r
+ <code style="color:#400000; font-weight:bold; ">if</code><code style="color:#806030; ">(</code>util_read<code style="color:#806030; ">(</code>r<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>data<code style="color:#806030; ">,</code> <code style="color:#806030; ">&</code>size<code style="color:#806030; ">)</code> <code style="color:#806030; ">=</code><code style="color:#806030; ">=</code> OK<code style="color:#806030; ">)</code> <code style="color:#806030; ">{</code>\r
+ ap_rprintf<code style="color:#806030; ">(</code><code style="color:#800000; ">"</code><code style="color:#e60000; ">We read a request body that was </code><code style="color:#0f6900; ">%u</code><code style="color:#e60000; "> bytes long</code><code style="color:#800000; ">"</code><code style="color:#806030; ">,</code> size<code style="color:#806030; ">)</code><code style="color:#806030; ">;</code>\r
+ <code style="color:#806030; ">}</code>\r
+ <code style="color:#400000; font-weight:bold; ">return</code> OK<code style="color:#806030; ">;</code>\r
+<code style="color:#806030; ">}</code>\r
+ </pre>\r
+\r
+\r
+\r
+ \r
+\r
+</div></div>\r
+<div class="bottomlang">\r
+<p><span>Available Languages: </span><a href="../en/developer/modguide.html" title="English"> en </a></p>\r
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+<p class="apache">Copyright 2012 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>\r
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