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23 <manualpage metafile="modguide.xml.meta">
24 <parentdocument href="./">Developer</parentdocument>
26 <title>Developing modules for the Apache HTTP Server 2.4</title>
29 <p>This document explains how you can develop modules for the Apache HTTP
33 <seealso><a href="request.html">Request Processing in Apache 2.4</a></seealso>
34 <seealso><a href="hooks.html">Apache 2.x Hook Functions</a></seealso>
36 <section id="introduction"><title>Introduction</title>
37 <section id="what"><title>What we will be discussing in this document</title>
39 This document will discuss how you can easily create modules for the Apache
40 HTTP Server 2.4, by exploring an example module called
41 <code>mod_example</code>. In the first part of this document, the purpose
42 of this module will be to calculate and print out various digest values for
43 existing files on your web server, whenever we access the URL <code>
44 http://hostname/filename.sum</code>. For instance, if we want to know the
45 MD5 digest value of the file located at <code>
46 http://www.example.com/index.html</code>, we would visit <code>
47 http://www.example.com/index.html.sum</code>.
50 In the second part of this document, which deals with configuration
51 directive and context awareness, we will be looking at a module that simply
52 write out its own configuration to the client.
55 <section id="prerequisites"><title>Prerequisites</title>
57 First and foremost, you are expected to have a basic knowledge of how the C
58 programming language works. In most cases, we will try to be as pedagogical
59 as possible and link to documents describing the functions used in the
60 examples, but there are also many cases where it is necessary to either
61 just assume that "it works" or do some digging youself into what the hows
62 and whys of various function calls.
65 Lastly, you will need to have a basic understanding of how modules are
66 loaded and configured in the Apache HTTP Server, as well as how to get the headers for
67 Apache if you do not have them already, as these are needed for compiling
71 <section id="compiling"><title>Compiling your module</title>
73 To compile the source code we are building in this document, we will be
74 using <a href="../programs/apxs.html">APXS</a>. Assuming your source file
75 is called mod_example.c, compiling, installing and activating the module is
78 apxs -i -a -c mod_example.c
84 <section id="basics"><title>Defining a module</title>
85 <img src="../images/build_a_mod_3.png"/><br/>
86 <p>Every module starts with the same declaration, or name tag if you will,
87 that defines a module as <em>a separate entity within Apache</em>:
90 <!-- BEGIN EXAMPLE CODE -->
91 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
92 module AP_MODULE_DECLARE_DATA example_module <code style='color:#806030; '>=</code>
93 <code style='color:#806030; '>{</code>
94 STANDARD20_MODULE_STUFF<code style='color:#806030; '>,</code>
95 create_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
96 merge_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
97 create_svr_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
98 merge_svr_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
99 directives<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
100 register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
101 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
103 <!-- END EXAMPLE CODE -->
106 This bit of code lets the server know that we have now registered a new module
107 in the system, and that its name is <code>example_module</code>. The name
108 of the module is used primarilly for two things:<br/>
110 <li>Letting the server know how to load the module using the LoadModule</li>
111 <li>Setting up a namespace for the module to use in configurations</li>
113 For now, we're only concerned with the first purpose of the module name,
114 which comes into play when we need to load the module:<br/>
115 <example><pre><a href="../mod/mod_so.html#LoadModule">LoadModule</a> example_module modules/mod_example.so</pre></example>
116 In essence, this tells the server to open up <code>mod_example.so</code> and look for a module
117 called <code>example_module</code>.
120 Within this name tag of ours is also a bunch of references to how we would
121 like to handle things: Which directives do we respond to in a configuration
122 file or .htaccess, how do we operate within specific contexts, and what
123 handlers are we interested in registering with the Apache HTTP service. We'll
124 return to all these elements later in this document.
127 <section id="hooking"><title>Getting started: Hooking into the server</title>
128 <section id="hook_intro"><title>An introduction to hooks</title>
130 When handling requests in Apache HTTP Server 2.4, the first thing you will need to do is
131 create a hook into the request handling process. A hook is essentially a
132 message telling the server that you are willing to either serve or at least
133 take a glance at certain requests given by clients. All handlers, whether
134 it's mod_rewrite, mod_authn_*, mod_proxy and so on, are hooked into
135 specific parts of the request process. As you are probably aware, modules
136 serve different purposes; Some are authentication/authorization handlers,
137 others are file or script handlers while some third modules rewrite URIs or
138 proxies content. Furthermore, in the end, it is up to the user of the server
139 how and when each module will come into place. Thus, the server itself does not
140 presume to know which module is responsible for handling a specific
141 request, and will ask each module whether they have an interest in a given
142 request or not. It is then up to each module to either gently decline
143 serving a request, accept serving it or flat out deny the request from
144 being served, as authentication/authorization modules do: <br/>
145 <img src="../images/build_a_mod_2.png" /><br/>
146 To make it a bit easier for handlers such as our mod_example to know
147 whether the client is requesting content we should handle or not, the server
148 has directives for hinting to modules whether their assistance is needed or
149 not. Two of these are <directive module="mod_mime">AddHandler</directive>
150 and <directive module="core">SetHandler</directive>. Let's take a look at
151 an example using <directive module="mod_mime">AddHandler</directive>. In
152 our example case, we want every request ending with .sum to be served by
153 <code>mod_example</code>, so we'll add a configuration directive that tells
154 the server to do just that:
156 AddHandler example-handler .sum
158 What this tells the server is the following: <em>Whenever we receive a request
159 for a URI ending in .sum, we are to let all modules know that we are
160 looking for whoever goes by the name of "example-handler" </em>.
161 Thus, when a request is being served that ends in .sum, the server will let all
162 modules know, that this request should be served by "example-handler
163 ". As you will see later, when we start building mod_example, we will
164 check for this handler tag relayed by <code>AddHandler</code> and reply to
165 the server based on the value of this tag.
168 <section id="hook_declaration"><title>Hooking into httpd</title>
170 To begin with, we only want to create a simple handler, that replies to the
171 client browser when a specific URL is requested, so we won't bother setting
172 up configuration handlers and directives just yet. Our initial module
173 definition will look like this:<br/>
176 <!-- BEGIN EXAMPLE CODE -->
177 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
178 module AP_MODULE_DECLARE_DATA example_module =
180 STANDARD20_MODULE_STUFF,
181 <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
182 <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
183 <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
184 <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
185 <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
186 <code style='color:#800040; '>register_hooks</code> <code style='color:#c34e00; '><code style='color:#c34e00; '>/* Our hook registering function */</code></code>
189 <!-- END EXAMPLE CODE -->
192 This lets the server know that we are not interesting in anything fancy, we
193 just want to hook onto the requests and possibly handle some of them. </p>
194 <p> The reference in our example declaration, <code>register_hooks</code>
195 is the name of a function we will create to manage how we hook onto the
196 request process. In this example module, the function has just one purpose;
197 To create a simple hook that gets called after all the rewrites, access
198 control etc has been handled. Thus, we will let the server know, that we want
199 to hook into its process as one of the last modules:
202 <!-- BEGIN EXAMPLE CODE -->
203 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
204 <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>
205 <code style='color:#806030; '>{</code>
206 <code style='color:#c34e00; '>/* Create a hook in the request handler, so we get called when a request arrives */</code>
207 <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>
208 <code style='color:#806030; '>}</code>
210 <!-- END EXAMPLE CODE -->
213 The <code>example_handler</code> reference is the function that will handle
214 the request. We will discuss how to create a handler in the next chapter.
217 <section id="hook_others"><title>Other useful hooks</title>
219 Hooking into the request handling phase is but one of many hooks that you
220 can create. Some other ways of hooking are:
222 <li><code>ap_hook_child_init</code>: Place a hook that executes when a child process is spawned (commonly used for initializing modules after the server has forked)</li>
223 <li><code>ap_hook_pre_config</code>: Place a hook that executes before any configuration data has been read (very early hook)</li>
224 <li><code>ap_hook_post_config</code>: Place a hook that executes after configuration has been parsed, but before the server has forked</li>
225 <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>
231 <section id="handling"><title>Building a handler</title>
233 A handler is essentially a function that receives a callback when a request
234 to the server is made. It is passed a record of the current request (how it was
235 made, which headers and requests were passed along, who's giving the
236 request and so on), and is put in charge of either telling the server that it's
237 not interested in the request or handle the request with the tools provided.
239 <section id="simple_handler"><title>A simple "Hello, world!"
240 handler</title> Let's start off by making a very simple request handler
241 that does the following: <br/>
243 <li>Check that this is a request that should be served by "example-handler"</li>
244 <li>Set the content type of our output to <code>text/html</code></li>
245 <li>Write "Hello, world!" back to the client browser</li>
246 <li>Let the server know that we took care of this request and everything went fine</li>
248 In C code, our example handler will now look like this:<br/>
251 <!-- BEGIN EXAMPLE CODE -->
252 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
253 <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>
254 <code style='color:#806030; '>{</code>
255 <code style='color:#c34e00; '>/* First off, we need to check if this is a call for the "example-handler" handler.</code>
256 <code style='color:#c34e00; '>     * If it is, we accept it and do our things, if not, we simply return DECLINED,</code>
257 <code style='color:#c34e00; '>     * and the server will try somewhere else.</code>
258 <code style='color:#c34e00; '>     */</code>
259 <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>
261 <code style='color:#c34e00; '>/* Now that we are handling this request, we'll write out "Hello, world!" to the client.</code>
262 <code style='color:#c34e00; '>     * To do so, we must first set the appropriate content type, followed by our output.</code>
263 <code style='color:#c34e00; '>     */</code>
264 <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>
265 <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>
267 <code style='color:#c34e00; '>/* Lastly, we must tell the server that we took care of this request and everything went fine.</code>
268 <code style='color:#c34e00; '>     * We do so by simply returning the value OK to the server.</code>
269 <code style='color:#c34e00; '>     */</code>
270 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
271 <code style='color:#806030; '>}</code>
273 <!-- END EXAMPLE CODE -->
276 Now, we put all we have learned together and end up with a program that
278 <a href="http://people.apache.org/~humbedooh/mods/examples/mod_example_1.c">mod_example_1.c</a>
279 . The functions used in this example will be explained later in the section
280 <a href= "#functions">"Some useful functions you should know"</a>
281 . </section> <section id="request_rec"><title>The request_rec structure
282 </title> <p>The most essential part of any request is the <em>request record
283 </em>. In a call to a handler function, this is represented by the <code>
284 request_req* </code> structure passed along with every call that is made.
285 This struct, typically just refered to as <code>r</code> in modules,
286 contains all the information you need for your module to fully process any
287 HTTP request and respond accordingly.</p> <p>Some key elements of the <code>
288 request_req </code> structure are:
290 <li><code><code style='color:#008833'>r->handler</code> (char*)</code>: Contains the name of the handler the server is currently asking to do the handling of this request</li>
291 <li><code><code style='color:#008833'>r->method</code> (char*)</code>: Contains the HTTP method being used, f.x. GET or POST</li>
292 <li><code><code style='color:#008833'>r->filename</code> (char*)</code>: Contains the translated filename the client is requesting</li>
293 <li><code><code style='color:#008833'>r->args</code> (char*)</code>: Contains the query string of the request, if any</li>
294 <li><code><code style='color:#008833'>r->headers_in</code> (apr_table_t*)</code>: Contains all the headers sent by the client</li>
295 <li><code><code style='color:#008833'>r->connection</code> (conn_rec*)</code>: A record containing information about the current connection</li>
296 <li><code><code style='color:#008833'>r->useragent_ip</code> (char*)</code>: The IP address of the client connecting to us</li>
297 <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 "
298 <a href="#memory">Memory management</a>" chapter.</li>
300 A complete list of all the values contained with in the <code>request_req</code> structure can be found in
301 the <a href="http://svn.apache.org/repos/asf/httpd/httpd/trunk/include/httpd.h"><code>httpd.h</code></a> header
302 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>.
305 Let's try out some of these variables in another example handler:<br/>
308 <!-- BEGIN EXAMPLE CODE -->
309 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
310 <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>
311 <code style='color:#806030; '>{</code>
312 <code style='color:#c34e00; '>/* Set the appropriate content type */</code>
313 <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>
315 <code style='color:#c34e00; '>/* Print out the IP address of the client connecting to us: */</code>
316 <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>
318 <code style='color:#c34e00; '>/* If we were reached through a GET or a POST request, be happy, else sad. */</code>
319 <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>
320 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>
321 <code style='color:#806030; '>}</code>
322 <code style='color:#400000; font-weight:bold; '>else</code> <code style='color:#806030; '>{</code>
323 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>
324 <code style='color:#806030; '>}</code>
326 <code style='color:#c34e00; '>/* Lastly, if there was a query string, let's print that too! */</code>
327 <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>
328 <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>
329 <code style='color:#806030; '>}</code>
330 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
331 <code style='color:#806030; '>}</code>
333 <!-- END EXAMPLE CODE -->
339 <section id="return_value"><title>Return values</title>
341 Apache relies on return values from handlers to signify whether a request
342 was handled or not, and if so, whether the request went well or not. If a
343 module is not interested in handling a specific request, it should always
344 return the value <code>DECLINED</code>. If it is handling a request, it
345 should either return the generic value <code>OK</code>, or a specific HTTP
346 status code, for example:
349 <!-- BEGIN EXAMPLE CODE -->
350 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
351 <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>
352 <code style='color:#806030; '>{</code>
353 <code style='color:#c34e00; '>/* Return 404: Not found */</code>
354 <code style='color:#400000; font-weight:bold; '>return</code> HTTP_NOT_FOUND<code style='color:#806030; '>;</code>
355 <code style='color:#806030; '>}</code>
357 <!-- END EXAMPLE CODE -->
360 Returning <code>OK</code> or a HTTP status code does not necessarilly mean
361 that the request will end. The server may still have other handlers that are
362 interested in this request, for instance the logging modules which, upon a
363 successful request, will write down a summary of what was requested and how
364 it went. To do a full stop and prevent any further processing after your
365 module is done, you can return the value <code>DONE</code> to let the server
366 know that it should cease all activity on this request and carry on with
367 the next, without informing other handlers.
369 <strong>General response codes:</strong>
371 <li><code>DECLINED</code>: We are not handling this request</li>
372 <li><code>OK</code>: We handled this request and it went well</li>
373 <li><code>DONE</code>: We handled this request and the server should just close this thread without further processing</li>
375 <strong>HTTP specific return codes (excerpt):</strong>
377 <li><code>HTTP_OK (200)</code>: Request was okay</li>
378 <li><code>HTTP_MOVED_PERMANENTLY (301)</code>: The resource has moved to a new URL</li>
379 <li><code>HTTP_UNAUTHORIZED (401)</code>: Client is not authorized to visit this page</li>
380 <li><code>HTTP_FORBIDDEN (403)</code>: Permission denied</li>
381 <li><code>HTTP_NOT_FOUND (404)</code>: File not found</li>
382 <li><code>HTTP_INTERNAL_SERVER_ERROR (500)</code>: Internal server error (self explanatory)</li>
387 <section id="functions"><title>Some useful functions you should know</title>
391 <code>ap_rputs(const char *string, request_req *r)</code>: <br/>
392 Sends a string of text to the client. This is a shorthand version of <a
393 href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gac827cd0537d2b6213a7c06d7c26cc36e">
397 <!-- BEGIN EXAMPLE CODE -->
398 <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>
399 <!-- END EXAMPLE CODE -->
405 <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a></code>: <br/>
406 This function works just like <code>printf</code>, except it sends the result to the client.
409 <!-- BEGIN EXAMPLE CODE -->
410 <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>
411 <!-- END EXAMPLE CODE -->
416 <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/>
417 Sets the content type of the output you are sending.
420 <!-- BEGIN EXAMPLE CODE -->
421 <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>
422 <!-- END EXAMPLE CODE -->
430 <section id="memory"><title>Memory management</title>
432 Managing your resources in Apache HTTP Server 2.4 is quite easy, thanks to the memory pool
433 system. In essence, each server, connection and request have their own
434 memory pool that gets cleaned up when its scope ends, e.g. when a request
435 is done or when a server process shuts down. All your module needs to do is
436 latch onto this memory pool, and you won't have to worry about having to
437 clean up after yourself - pretty neat, huh?
441 In our module, we will primarilly be allocating memory for each request, so
442 it's appropriate to use the <code style='color:#008833'>r->pool</code>
443 reference when creating new objects. A few of the functions for allocating
444 memory within a pool are:
446 <li><code>void* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__pools.html#ga85f1e193c31d109affda72f9a92c6915">apr_palloc</a>(
447 apr_pool_t *p, apr_size_t size)</code>: Allocates <code>size</code> number of bytes in the pool for you</li>
448 <li><code>void* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__pools.html#gaf61c098ad258069d64cdf8c0a9369f9e">apr_pcalloc</a>(
449 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>
450 <li><code>char* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__strings.html#gabc79e99ff19abbd7cfd18308c5f85d47">apr_pstrdup</a>(
451 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>
452 <li><code>char* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__strings.html#ga3eca76b8d293c5c3f8021e45eda813d8">apr_psprintf</a>(
453 apr_pool_t *p, const char *fmt, ...)</code>: Similar to <code>sprintf</code>, except the server supplies you with an appropriately allocated target variable</li>
456 Let's put these functions into an example handler:<br/>
459 <!-- BEGIN EXAMPLE CODE -->
460 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
461 <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>
462 <code style='color:#806030; '>{</code>
463 <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>
464 <code style='color:#400000; font-weight:bold; '>char</code><code style='color:#806030; '>*</code> copy<code style='color:#806030; '>;</code>
465 <code style='color:#400000; font-weight:bold; '>int</code><code style='color:#806030; '>*</code> integers<code style='color:#806030; '>;</code>
467 <code style='color:#c34e00; '>/* Allocate space for 10 integer values and set them all to zero. */</code>
468 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>
470 <code style='color:#c34e00; '>/* Create a copy of the 'original' variable that we can edit. */</code>
471 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>
472 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
473 <code style='color:#806030; '>}</code>
475 <!-- END EXAMPLE CODE -->
477 This is all well and good for our module, which won't need any
478 pre-initialized variables or structures. However, if we wanted to
479 initialize something early on, before the requests come rolling in, we
480 could simply add a call to a function in our <code>register_hooks</code>
481 function to sort it out:
483 <!-- BEGIN EXAMPLE CODE -->
484 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
485 <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>
486 <code style='color:#806030; '>{</code>
487 <code style='color:#c34e00; '>/* Call a function that initializes some stuff */</code>
488 <code style='color:#800040; '>example_init_function</code><code style='color:#806030; '>(</code>pool<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
489 <code style='color:#c34e00; '>/* Create a hook in the request handler, so we get called when a request arrives */</code>
490 <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>
491 <code style='color:#806030; '>}</code>
493 <!-- END EXAMPLE CODE -->
495 In this pre-request initialization function we would not be using the
496 same pool as we did when allocating resources for request-based functions.
497 Instead, we would use the pool given to us by the server for allocating memory
498 on a per-process based level.
503 <section id="parsing"><title>Parsing request data</title>
505 In our example module, we would like to add a feature, that checks which
506 type of digest, MD5 or SHA1 the client would like to see. This could be
507 solved by adding a query string to the request. A query string is typically
508 comprised of several keys and values put together in a string, for instance
509 <code>valueA=yes&valueB=no&valueC=maybe</code>. It is up to the
510 module itself to parse these and get the data it requires. In our example,
511 we'll be looking for a key called <code>digest</code>, and if set to <code>
512 md5</code>, we'll produce an MD5 digest, otherwise we'll produce a SHA1
516 Since the introduction of Apache HTTP Server 2.4, parsing request data from GET and
517 POST requests have never been easier. All we require to parse both GET and
518 POST data is four simple lines:
521 <!-- BEGIN EXAMPLE CODE -->
522 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
523 <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__apr__tables.html#gad7ea82d6608a4a633fc3775694ab71e4">apr_table_t</a> *GET;
524 <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/structapr__array__header__t.html">apr_array_header_t</a> *POST;
526 <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__SCRIPT.html#gaed25877b529623a4d8f99f819ba1b7bd">ap_args_to_table</a>(r, &GET);
527 <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);
529 <!-- END EXAMPLE CODE -->
532 In our specific example module, we're looking for the <code>digest</code>
533 value from the query string, which now resides inside a table called <code>
534 GET</code>. To extract this value, we need only perform a simple operation:
538 <!-- BEGIN EXAMPLE CODE -->
539 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
540 <code style='color:#c34e00; '>/* Get the "digest" key from the query string, if any. */</code>
541 <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>
543 <code style='color:#c34e00; '>/* If no key was returned, we will set a default value instead. */</code>
544 <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>
547 <!-- END EXAMPLE CODE -->
550 The structures used for the POST and GET data are not exactly the same, so
551 if we were to fetch a value from POST data instead of the query string, we
552 would have to resort to a few more lines, as outlined in <a href="#get_post"
553 >this example</a> in the last chapter of this document.
557 <section id="advanced_handler"><title>Making an advanced handler</title>
558 Now that we have learned how to parse form data and manage our resources,
559 we can move on to creating an advanced version of our module, that spits
560 out the MD5 or SHA1 digest of files:<br/>
563 <!-- BEGIN EXAMPLE CODE -->
564 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
565 <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>
566 <code style='color:#806030; '>{</code>
567 <code style='color:#400000; font-weight:bold; '>int</code> rc<code style='color:#806030; '>,</code> exists<code style='color:#806030; '>;</code>
568 apr_finfo_t finfo<code style='color:#806030; '>;</code>
569 apr_file_t<code style='color:#806030; '> *</code>file<code style='color:#806030; '>;</code>
570 <code style='color:#400000; font-weight:bold; '>char</code> <code style='color:#806030; '>*</code>filename<code style='color:#806030; '>;</code>
571 <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>
572 apr_size_t readBytes<code style='color:#806030; '>;</code>
573 <code style='color:#400000; font-weight:bold; '>int</code> n<code style='color:#806030; '>;</code>
574 apr_table_t<code style='color:#806030; '> *</code>GET<code style='color:#806030; '>;</code>
575 apr_array_header_t<code style='color:#806030; '> *</code>POST<code style='color:#806030; '>;</code>
576 <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>
579 <code style='color:#c34e00; '>/* Check that the "example-handler" handler is being called. */</code>
580 <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>
582 <code style='color:#c34e00; '>/* Figure out which file is being requested by removing the .sum from it */</code>
583 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>
584 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>
586 <code style='color:#c34e00; '>/* Figure out if the file we request a sum on exists and isn't a directory */</code>
587 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>
588 <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>
589 exists <code style='color:#806030; '>=</code>
590 <code style='color:#806030; '>(</code>
591 <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>
592 <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>
593 <code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
594 <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>
595 <code style='color:#806030; '>}</code>
596 <code style='color:#c34e00; '>/* If apr_stat failed, we're probably not allowed to check this file. */</code>
597 <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>
599 <code style='color:#c34e00; '>/* Parse the GET and, optionally, the POST data sent to us */</code>
601 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>
602 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>
604 <code style='color:#c34e00; '>/* Set the appropriate content type */</code>
605 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>
607 <code style='color:#c34e00; '>/* Print a title and some general information */</code>
608 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>
609 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>
611 <code style='color:#c34e00; '>/* Get the digest type the client wants to see */</code>
612 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>
613 <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>
616 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>
617 <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>
619 <code style='color:#c34e00; '>/* Are we trying to calculate the MD5 or the SHA1 digest? */</code>
620 <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>
621 <code style='color:#c34e00; '>/* Calculate the MD5 sum of the file */</code>
622 <code style='color:#400000; font-weight:bold; '>union</code> <code style='color:#806030; '>{</code>
623 <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>
624 uint32_t num<code style='color:#806030; '>[</code><code style='color:#c00000; '>4</code><code style='color:#806030; '>]</code><code style='color:#806030; '>;</code>
625 <code style='color:#806030; '>}</code> digest<code style='color:#806030; '>;</code>
626 apr_md5_ctx_t md5<code style='color:#806030; '>;</code>
627 apr_md5_init<code style='color:#806030; '>(</code><code style='color:#806030; '>&</code>md5<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
628 readBytes <code style='color:#806030; '>=</code> <code style='color:#c00000; '>256</code><code style='color:#806030; '>;</code>
629 <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>
630 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>
631 <code style='color:#806030; '>}</code>
632 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>
634 <code style='color:#c34e00; '>/* Print out the MD5 digest */</code>
635 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>
636 <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>
637 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>
638 <code style='color:#806030; '>}</code>
639 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>
640 <code style='color:#c34e00; '>/* Print a link to the SHA1 version */</code>
641 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>
642 <code style='color:#806030; '>}</code>
643 <code style='color:#400000; font-weight:bold; '>else</code> <code style='color:#806030; '>{</code>
644 <code style='color:#c34e00; '>/* Calculate the SHA1 sum of the file */</code>
645 <code style='color:#400000; font-weight:bold; '>union</code> <code style='color:#806030; '>{</code>
646 <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>
647 uint32_t num<code style='color:#806030; '>[</code><code style='color:#c00000; '>5</code><code style='color:#806030; '>]</code><code style='color:#806030; '>;</code>
648 <code style='color:#806030; '>}</code> digest<code style='color:#806030; '>;</code>
649 apr_sha1_ctx_t sha1<code style='color:#806030; '>;</code>
650 apr_sha1_init<code style='color:#806030; '>(</code><code style='color:#806030; '>&</code>sha1<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
651 readBytes <code style='color:#806030; '>=</code> <code style='color:#c00000; '>256</code><code style='color:#806030; '>;</code>
652 <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>
653 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>
654 <code style='color:#806030; '>}</code>
655 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>
657 <code style='color:#c34e00; '>/* Print out the SHA1 digest */</code>
658 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>
659 <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>
660 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>
661 <code style='color:#806030; '>}</code>
662 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>
664 <code style='color:#c34e00; '>/* Print a link to the MD5 version */</code>
665 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>
666 <code style='color:#806030; '>}</code>
667 apr_file_close<code style='color:#806030; '>(</code>file<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
669 <code style='color:#806030; '>}</code>
673 <code style='color:#c34e00; '>/* Let the server know that we responded to this request. */</code>
674 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
675 <code style='color:#806030; '>}</code>
677 <!-- END EXAMPLE CODE -->
680 This version in its entirity can be found here:
681 <a href="http://people.apache.org/~humbedooh/mods/examples/mod_example_2.c">mod_example_2.c</a>.
686 <section id="configuration"><title>Adding configuration options</title>
688 In this next segment of this document, we will turn our eyes away from the
689 digest module and create a new example module, whose only function is to
690 write out its own configuration. The purpose of this is to examine how
691 the server works with configuration, and what happens when you start writing
692 advanced configurations
695 <section id="config_intro"><title>An introduction to configuration
696 directives</title> If you are reading this, then you probably already know
697 what a configuration directive is. Simply put, a directive is a way of
698 telling an individual module (or a set of modules) how to behave, such as
699 these directives control how <code>mod_rewrite</code> works:
702 RewriteCond %{REQUEST_URI} ^/foo/bar
703 RewriteRule ^/foo/bar/(.*)$ /foobar?page=$1
705 Each of these configuration directives are handled by a separate function,
706 that parses the parameters given and sets up a configuration accordingly.
708 <section id="config_simple"><title>Making an example configuration</title>
709 To begin with, we'll create a basic configuration in C-space:
712 <!-- BEGIN EXAMPLE CODE -->
713 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
714 <code style='color:#400000; font-weight:bold; '>typedef</code> <code style='color:#400000; font-weight:bold; '>struct</code> <code style='color:#806030; '>{</code>
715 <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>
716 <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>
717 <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>
718 <code style='color:#806030; '>}</code> example_config<code style='color:#806030; '>;</code>
720 <!-- END EXAMPLE CODE -->
723 Now, let's put this into perspective by creating a very small module that
724 just prints out a hard-coded configuration. You'll notice that we use the
725 <code>register_hooks</code> function for initializing the configuration
726 values to their defaults:
729 <!-- BEGIN EXAMPLE CODE -->
730 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
731 <code style='color:#400000; font-weight:bold; '>typedef</code> <code style='color:#400000; font-weight:bold; '>struct</code> <code style='color:#806030; '>{</code>
732 <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>
733 <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>
734 <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>
735 <code style='color:#806030; '>}</code> example_config<code style='color:#806030; '>;</code>
737 <code style='color:#400000; font-weight:bold; '>static</code> example_config config<code style='color:#806030; '>;</code>
739 <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>
740 <code style='color:#806030; '>{</code>
741 <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>
742 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>
743 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>
744 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>
745 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>
746 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
747 <code style='color:#806030; '>}</code>
749 <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>
750 <code style='color:#806030; '>{</code>
751 config<code style='color:#806030; '>.</code>enabled <code style='color:#806030; '>=</code> <code style='color:#c00000; '>1</code><code style='color:#806030; '>;</code>
752 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>
753 config<code style='color:#806030; '>.</code>typeOfAction <code style='color:#806030; '>=</code> <code style='color:#c00000; '>0x00</code><code style='color:#806030; '>;</code>
754 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>
755 <code style='color:#806030; '>}</code>
757 <code style='color:#c34e00; '>/* Define our module as an entity and assign a function for registering hooks */</code>
759 module AP_MODULE_DECLARE_DATA example_module <code style='color:#806030; '>=</code>
760 <code style='color:#806030; '>{</code>
761 STANDARD20_MODULE_STUFF<code style='color:#806030; '>,</code>
762 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
763 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
764 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
765 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
766 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
767 register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
768 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
770 <!-- END EXAMPLE CODE -->
773 So far so good. To access our new handler, we could add the following to
776 <Location /example>
777 SetHandler example-handler
780 When we visit, we'll see our current configuration being spit out by our
784 <section id="register_directive"><title>Registering directives with the server</title>
785 What if we want to change our configuration, not by hard-coding new values
786 into the module, but by using either the httpd.conf file or possibly a
787 .htaccess file? It's time to let the server know that we want this to be
788 possible. To do so, we must first change our <em>name tag</em> to include a
789 reference to the configuration directives we want to register with the server:
792 <!-- BEGIN EXAMPLE CODE -->
793 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
794 module AP_MODULE_DECLARE_DATA example_module =
796 STANDARD20_MODULE_STUFF,
797 <code style='color:#7f0055; font-weight:bold; '>NULL</code>, <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
798 <code style='color:#7f0055; font-weight:bold; '>NULL</code>, <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
799 <code style='color:#7f0055; font-weight:bold; '>NULL</code>, <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
800 <code style='color:#7f0055; font-weight:bold; '>NULL</code>, <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
801 example_directives, <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
802 register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
805 <!-- END EXAMPLE CODE -->
808 This will tell the server that we are now accepting directives from the
809 configuration files, and that the structure called <code>example_directives
810 </code> holds information on what our directives are and how they work.
811 Since we have three different variables in our module configuration, we
812 will add a structure with three directives and a NULL at the end:
815 <!-- BEGIN EXAMPLE CODE -->
816 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
817 static const command_rec example_directives[] =
819 <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"),
820 <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"),
821 <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!"),
822 { <code style='color:#7f0055; font-weight:bold; '>NULL</code> }
825 <!-- END EXAMPLE CODE -->
828 <img src="../images/build_a_mod_4.png" border="1"/><br/>
830 As you can see, each directive needs at least 5 parameters set:
832 <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 the server that this directive takes one and only one argument.
833 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
834 for more macros).</li>
835 <li><code>exampleEnabled</code>: This is the name of our directive. More precisely, it is what the user must put in his/her
836 configuration in order to invoke a configuration change in our module.</li>
837 <li><code>example_set_enabled</code>: This is a reference to a C function that parses the directive and sets the configuration
838 accordingly. We will discuss how to make this in the following paragraph.</li>
839 <li><code>RSRC_CONF</code>: This tells the server where the directive is permissable. We'll go into details on this value in the
840 later chapters, but for now, <code>RSRC_CONF</code> means that the server will only accept these directives in a server context.</li>
841 <li><code>"Enable or disable...."</code>: This is simply a brief description of what the directive does.</li>
843 (<em>The "missing" parameter in our definition, which is usually set to
844 <code>NULL</code>, is an optional function that can be run after the
845 initial function to parse the arguments have been run. This is usually
846 omitted, as the function for verifying arguments might as well be used to
850 <section id="directive_handler"><title>The directive handler function</title>
852 Now that we've told the server to expect some directives for our module, it's
853 time to make a few functions for handling these. What the server reads in the
854 configuration file(s) is text, and so naturally, what it passes along to
855 our directive handler is one or more strings, that we ourselves need to
856 recognize and act upon. You'll notice, that since we set our <code>
857 exampleAction</code> directive to accept two arguments, its C function also
858 has an additional parameter defined:<br/>
860 <!-- BEGIN EXAMPLE CODE -->
861 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
862 <code style='color:#c34e00; '>/* Handler for the "exambleEnabled" directive */</code>
863 <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>
864 <code style='color:#806030; '>{</code>
865 <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>
866 <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>
867 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
868 <code style='color:#806030; '>}</code>
870 <code style='color:#c34e00; '>/* Handler for the "examplePath" directive */</code>
871 <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>
872 <code style='color:#806030; '>{</code>
873 config<code style='color:#806030; '>.</code>path <code style='color:#806030; '>=</code> arg<code style='color:#806030; '>;</code>
874 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
875 <code style='color:#806030; '>}</code>
877 <code style='color:#c34e00; '>/* Handler for the "exampleAction" directive */</code>
878 <code style='color:#c34e00; '>/* Let's pretend this one takes one argument (file or db), and a second (deny or allow), */</code>
879 <code style='color:#c34e00; '>/* and we store it in a bit-wise manner. */</code>
880 <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>
881 <code style='color:#806030; '>{</code>
882 <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>
883 <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>
885 <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>
886 <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>
887 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
888 <code style='color:#806030; '>}</code>
890 <!-- END EXAMPLE CODE -->
895 <section id="directive_complete"><title>Putting it all together</title>
897 Now that we have our directives set up, and handlers configured for them,
898 we can assemble our module into one big file:
901 <!-- BEGIN EXAMPLE CODE -->
902 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
903 <code style='color:#c34e00; '>/* mod_example_config_simple.c: */</code>
904 <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>
905 <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>
906 <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>
907 <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>
908 <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>
909 <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>
910 <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>
911 <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>
912 <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>
913 <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>
915 <code style='color:#c34e00; '>/*</code>
916 <code style='color:#c34e00; '> ==============================================================================</code>
917 <code style='color:#c34e00; '> Our configuration prototype and declaration:</code>
918 <code style='color:#c34e00; '> ==============================================================================</code>
919 <code style='color:#c34e00; '> */</code>
920 <code style='color:#400000; font-weight:bold; '>typedef</code> <code style='color:#400000; font-weight:bold; '>struct</code> <code style='color:#806030; '>{</code>
921 <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>
922 <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>
923 <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>
924 <code style='color:#806030; '>}</code> example_config<code style='color:#806030; '>;</code>
926 <code style='color:#400000; font-weight:bold; '>static</code> example_config config<code style='color:#806030; '>;</code>
928 <code style='color:#c34e00; '>/*</code>
929 <code style='color:#c34e00; '> ==============================================================================</code>
930 <code style='color:#c34e00; '> Our directive handlers:</code>
931 <code style='color:#c34e00; '> ==============================================================================</code>
932 <code style='color:#c34e00; '> */</code>
933 <code style='color:#c34e00; '>/* Handler for the "exambleEnabled" directive */</code>
934 <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>
935 <code style='color:#806030; '>{</code>
936 <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>
937 <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>
938 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
939 <code style='color:#806030; '>}</code>
941 <code style='color:#c34e00; '>/* Handler for the "examplePath" directive */</code>
942 <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>
943 <code style='color:#806030; '>{</code>
944 config<code style='color:#806030; '>.</code>path <code style='color:#806030; '>=</code> arg<code style='color:#806030; '>;</code>
945 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
946 <code style='color:#806030; '>}</code>
948 <code style='color:#c34e00; '>/* Handler for the "exampleAction" directive */</code>
949 <code style='color:#c34e00; '>/* Let's pretend this one takes one argument (file or db), and a second (deny or allow), */</code>
950 <code style='color:#c34e00; '>/* and we store it in a bit-wise manner. */</code>
951 <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>
952 <code style='color:#806030; '>{</code>
953 <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>
954 <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>
956 <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>
957 <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>
958 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
959 <code style='color:#806030; '>}</code>
961 <code style='color:#c34e00; '>/*</code>
962 <code style='color:#c34e00; '> ==============================================================================</code>
963 <code style='color:#c34e00; '> The directive structure for our name tag:</code>
964 <code style='color:#c34e00; '> ==============================================================================</code>
965 <code style='color:#c34e00; '> */</code>
966 <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>
967 <code style='color:#806030; '>{</code>
968 <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>
969 <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>
970 <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>
971 <code style='color:#806030; '>{</code> <code style='color:#007d45; '>NULL</code> <code style='color:#806030; '>}</code>
972 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
973 <code style='color:#c34e00; '>/*</code>
974 <code style='color:#c34e00; '> ==============================================================================</code>
975 <code style='color:#c34e00; '> Our module handler:</code>
976 <code style='color:#c34e00; '> ==============================================================================</code>
977 <code style='color:#c34e00; '> */</code>
978 <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>
979 <code style='color:#806030; '>{</code>
980 <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>
981 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>
982 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>
983 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>
984 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>
985 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
986 <code style='color:#806030; '>}</code>
988 <code style='color:#c34e00; '>/*</code>
989 <code style='color:#c34e00; '> ==============================================================================</code>
990 <code style='color:#c34e00; '> The hook registration function (also initializes the default config values):</code>
991 <code style='color:#c34e00; '> ==============================================================================</code>
992 <code style='color:#c34e00; '> */</code>
993 <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>
994 <code style='color:#806030; '>{</code>
995 config<code style='color:#806030; '>.</code>enabled <code style='color:#806030; '>=</code> <code style='color:#c00000; '>1</code><code style='color:#806030; '>;</code>
996 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>
997 config<code style='color:#806030; '>.</code>typeOfAction <code style='color:#806030; '>=</code> <code style='color:#c00000; '>3</code><code style='color:#806030; '>;</code>
998 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>
999 <code style='color:#806030; '>}</code>
1000 <code style='color:#c34e00; '>/*</code>
1001 <code style='color:#c34e00; '> ==============================================================================</code>
1002 <code style='color:#c34e00; '> Our module name tag:</code>
1003 <code style='color:#c34e00; '> ==============================================================================</code>
1004 <code style='color:#c34e00; '> */</code>
1005 module AP_MODULE_DECLARE_DATA example_module <code style='color:#806030; '>=</code>
1006 <code style='color:#806030; '>{</code>
1007 STANDARD20_MODULE_STUFF<code style='color:#806030; '>,</code>
1008 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
1009 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
1010 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
1011 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
1012 example_directives<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
1013 register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
1014 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
1016 <!-- END EXAMPLE CODE -->
1021 In our httpd.conf file, we can now change the hard-coded configuration by
1025 ExamplePath "/usr/bin/foo"
1026 ExampleAction file allow
1028 And thus we apply the configuration, visit <code>/example</code> on our
1029 web site, and we see the configuration has adapted to what we wrote in our
1037 <section id="context"><title>Context aware configurations</title>
1038 <section id="context_intro"><title>Introduction to context aware configurations</title>
1040 In Apache HTTP Server 2.4, different URLs, virtual hosts, directories etc can have very
1041 different meanings to the user of the server, and thus different contexts
1042 within which modules must operate. For example, let's assume you have this
1043 configuration set up for mod_rewrite:
1045 <Directory "/var/www">
1046 RewriteCond %{HTTP_HOST} ^example.com$
1047 RewriteRule (.*) http://www.example.com/$1
1049 <Directory "/var/www/sub">
1050 RewriteRule ^foobar$ index.php?foobar=true
1053 In this example, you will have set up two different contexts for
1056 <li>Inside <code>/var/www</code>, all requests for <code>http://example.com</code> must go to <code>http://www.example.com</code></li>
1057 <li>Inside <code>/var/www/sub</code>, all requests for <code>foobar</code> must go to <code>index.php?foobar=true</code></li>
1059 If mod_rewrite (or the entire server for that matter) wasn't context aware, then
1060 these rewrite rules would just apply to every and any request made,
1061 regardless of where and how they were made, but since the module can pull
1062 the context specific configuration straight from the server, it does not need
1063 to know itself, which of the directives are valid in this context, since
1064 the server takes care of this.</p>
1067 So how does a module get the specific configuration for the server,
1068 directory or location in question? It does so by making one simple call:
1071 <!-- BEGIN EXAMPLE CODE -->
1072 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1073 <!-- END EXAMPLE CODE -->
1076 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);
1078 That's it! Of course, a whole lot goes on behind the scenes, which we will
1079 discuss in this chapter, starting with how the server came to know what our
1080 configuration looks like, and how it came to be set up as it is in the
1085 <section id="context_base"><title>Our basic configuration setup</title>
1086 <p>In this chapter, we will be working with a slightly modified version of
1087 our previous context structure. We will set a <code>context</code>
1088 variable that we can use to track which context configuration is being
1089 used by the server in various places:
1092 <!-- BEGIN EXAMPLE CODE -->
1093 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1094 <code style='color:#400000; font-weight:bold; '>typedef</code> <code style='color:#400000; font-weight:bold; '>struct</code> <code style='color:#806030; '>{</code>
1095 <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>
1096 <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>
1097 <code style='color:#400000; font-weight:bold; '>int</code> typeOfAction<code style='color:#806030; '>;</code>
1098 <code style='color:#400000; font-weight:bold; '>int</code> enabled<code style='color:#806030; '>;</code>
1099 <code style='color:#806030; '>}</code> example_config<code style='color:#806030; '>;</code>
1101 <!-- END EXAMPLE CODE -->
1106 <p>Our handler for requests will also be modified, yet still very simple:
1109 <!-- BEGIN EXAMPLE CODE -->
1110 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1111 <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>
1112 <code style='color:#806030; '>{</code>
1113 <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>
1114 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>
1115 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>
1116 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>
1117 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>
1118 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>
1119 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>
1120 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
1121 <code style='color:#806030; '>}</code>
1123 <!-- END EXAMPLE CODE -->
1130 <section id="context_which"><title>Choosing a context</title>
1132 Before we can start making our module context aware, we must first define,
1133 which contexts we will accept. As we saw in the previous chapter, defining
1134 a directive required five elements be set:
1137 <!-- BEGIN EXAMPLE CODE -->
1138 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1139 <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"),
1141 <!-- END EXAMPLE CODE -->
1144 The <code>RSRC_CONF</code> definition told the server that we would only allow
1145 this directive in a global server context, but since we are now trying out
1146 a context aware version of our module, we should set this to something
1147 more lenient, namely the value <code>ACCESS_CONF</code>, which lets us use
1148 the directive inside <Directory> and <Location> blocks.
1152 <section id="context_pool"><title>Using the server to allocate configuration slots</title>
1153 <p> A much smarter way to manage your configurations is by letting the server
1154 help you create them. To do so, we must first start off by changing our
1155 <em>name tag</em> to let the server know, that it should assist us in creating
1156 and managing our configurations. Since we have chosen the per-directory
1157 (or per-location) context for our module configurations, we'll add a
1158 per-directory creator and merger function reference in our tag:
1160 <!-- BEGIN EXAMPLE CODE -->
1161 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1162 module AP_MODULE_DECLARE_DATA example_module <code style='color:#806030; '>=</code>
1163 <code style='color:#806030; '>{</code>
1164 STANDARD20_MODULE_STUFF<code style='color:#806030; '>,</code>
1165 create_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
1166 merge_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
1167 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
1168 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
1169 directives<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
1170 register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
1171 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
1173 <!-- END EXAMPLE CODE -->
1182 <section id="context_which"><title>Creating new context configurations</title>
1184 Now that we have told the server to help us create and manage configurations,
1185 our first step is to make a function for creating new, blank
1186 configurations. We do so by creating the function we just referenced in
1187 our name tag as the Per-directory configuration handler:
1188 <!-- BEGIN EXAMPLE CODE -->
1189 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1190 <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>
1191 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>
1192 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>
1193 <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>
1194 <code style='color:#c34e00; '>/* Set some default values */</code>
1195 <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>
1196 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>
1197 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>
1198 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>
1199 <code style='color:#806030; '>}</code>
1200 <code style='color:#400000; font-weight:bold; '>return</code> cfg<code style='color:#806030; '>;</code>
1201 <code style='color:#806030; '>}</code>
1203 <!-- END EXAMPLE CODE -->
1209 <section id="context_which"><title>Merging configurations</title>
1211 Our next step in creating a context aware configuration is merging
1212 configurations. This part of the process particularly apply to scenarios
1213 where you have a parent configuration and a child, such as the following:
1215 <Directory "/var/www">
1217 ExamplePath /foo/bar
1218 ExampleAction file allow
1220 <Directory "/var/www/subdir">
1221 ExampleAction file deny
1224 In this example, it is natural to assume that the directory <code>
1225 /var/www/subdir</code> should inherit the value set for the <code>/var/www
1226 </code> directory, as we did not specify a <code>ExampleEnable</code> nor
1227 an <code>ExamplePath</code> for this directory. The server does not presume to
1228 know if this is true, but cleverly does the following:
1230 <li>Creates a new configuration for <code>/var/www</code></li>
1231 <li>Sets the configuration values according to the directives given for <code>/var/www</code></li>
1232 <li>Creates a new configuration for <code>/var/www/subdir</code></li>
1233 <li>Sets the configuration values according to the directives given for <code>/var/www/subdir</code></li>
1234 <li><strong>Proposes a merge</strong> of the two configurations into a new configuration for <code>/var/www/subdir</code></li>
1236 This proposal is handled by the <code>merge_dir_conf</code> function we
1237 referenced in our name tag. The purpose of this function is to assess the
1238 two configurations and decide how they are to be merged:
1241 <!-- BEGIN EXAMPLE CODE -->
1242 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1243 <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>
1244 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>
1245 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>
1246 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>
1248 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>
1249 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>
1250 <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>
1252 <code style='color:#400000; font-weight:bold; '>return</code> conf <code style='color:#806030; '>;</code>
1253 <code style='color:#806030; '>}</code>
1255 <!-- END EXAMPLE CODE -->
1260 <section id="context_which"><title>Trying out our new context aware configurations</title>
1262 Now, let's try putting it all together to create a new module that is
1263 context aware. First off, we'll create a configuration that lets us test
1264 how the module works:
1266 <Location "/a">
1267 SetHandler example-handler
1269 ExamplePath "/foo/bar"
1270 ExampleAction file allow
1273 <Location "/a/b">
1274 ExampleAction file deny
1278 <Location "/a/b/c">
1279 ExampleAction db deny
1280 ExamplePath "/foo/bar/baz"
1284 Then we'll assemble our module code. Note, that since we are now using our
1285 name tag as reference when fetching configurations in our handler, I have
1286 added some prototypes to keep the compiler happy:
1289 <!-- BEGIN EXAMPLE CODE -->
1290 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1291 <code style='color:#c34e00; '>/*$6</code>
1292 <code style='color:#c34e00; '> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</code>
1293 <code style='color:#c34e00; '> * mod_example_config.c</code>
1294 <code style='color:#c34e00; '> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</code>
1295 <code style='color:#c34e00; '> */</code>
1298 <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>
1299 <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>
1300 <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>
1301 <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>
1302 <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>
1303 <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>
1304 <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>
1305 <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>
1306 <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>
1307 <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>
1309 <code style='color:#c34e00; '>/*$1</code>
1310 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1311 <code style='color:#c34e00; '>    Configuration structure</code>
1312 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1313 <code style='color:#c34e00; '> */</code>
1315 <code style='color:#400000; font-weight:bold; '>typedef</code> <code style='color:#400000; font-weight:bold; '>struct</code>
1316 <code style='color:#806030; '>{</code>
1317 <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>
1318 <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>
1319 <code style='color:#400000; font-weight:bold; '>int</code> typeOfAction<code style='color:#806030; '>;</code>
1320 <code style='color:#400000; font-weight:bold; '>int</code> enabled<code style='color:#806030; '>;</code>
1321 <code style='color:#806030; '>}</code> example_config<code style='color:#806030; '>;</code>
1323 <code style='color:#c34e00; '>/*$1</code>
1324 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1325 <code style='color:#c34e00; '>    Prototypes</code>
1326 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1327 <code style='color:#c34e00; '> */</code>
1329 <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>
1330 <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>
1331 <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>
1332 <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>
1333 <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>
1334 <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>
1335 <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>
1337 <code style='color:#c34e00; '>/*$1</code>
1338 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1339 <code style='color:#c34e00; '>    Configuration directives</code>
1340 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1341 <code style='color:#c34e00; '> */</code>
1343 <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>
1344 <code style='color:#806030; '>{</code>
1345 <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>
1346 <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>
1347 <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>
1348 <code style='color:#806030; '>{</code> <code style='color:#007d45; '>NULL</code> <code style='color:#806030; '>}</code>
1349 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
1351 <code style='color:#c34e00; '>/*$1</code>
1352 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1353 <code style='color:#c34e00; '>    Our name tag</code>
1354 <code style='color:#c34e00; '> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</code>
1355 <code style='color:#c34e00; '> */</code>
1357 module AP_MODULE_DECLARE_DATA example_module <code style='color:#806030; '>=</code>
1358 <code style='color:#806030; '>{</code>
1359 STANDARD20_MODULE_STUFF<code style='color:#806030; '>,</code>
1360 create_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
1361 merge_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
1362 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
1363 <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
1364 directives<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
1365 register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
1366 <code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
1368 <code style='color:#c34e00; '>/*</code>
1369 <code style='color:#c34e00; '> =======================================================================================================================</code>
1370 <code style='color:#c34e00; '>    Hook registration function</code>
1371 <code style='color:#c34e00; '> =======================================================================================================================</code>
1372 <code style='color:#c34e00; '> */</code>
1373 <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>
1374 <code style='color:#806030; '>{</code>
1375 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>
1376 <code style='color:#806030; '>}</code>
1378 <code style='color:#c34e00; '>/*</code>
1379 <code style='color:#c34e00; '> =======================================================================================================================</code>
1380 <code style='color:#c34e00; '>    Our example web service handler</code>
1381 <code style='color:#c34e00; '> =======================================================================================================================</code>
1382 <code style='color:#c34e00; '> */</code>
1383 <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>
1384 <code style='color:#806030; '>{</code>
1385 <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>
1387 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1388 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>
1389 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1391 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>
1392 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>
1393 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>
1394 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>
1395 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>
1396 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
1397 <code style='color:#806030; '>}</code>
1399 <code style='color:#c34e00; '>/*</code>
1400 <code style='color:#c34e00; '> =======================================================================================================================</code>
1401 <code style='color:#c34e00; '>    Handler for the "exambleEnabled" directive</code>
1402 <code style='color:#c34e00; '> =======================================================================================================================</code>
1403 <code style='color:#c34e00; '> */</code>
1404 <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>
1405 <code style='color:#806030; '>{</code>
1406 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1407 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>
1408 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1410 <code style='color:#400000; font-weight:bold; '>if</code><code style='color:#806030; '>(</code>conf<code style='color:#806030; '>)</code>
1411 <code style='color:#806030; '>{</code>
1412 <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>
1413 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>
1414 <code style='color:#400000; font-weight:bold; '>else</code>
1415 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>
1416 <code style='color:#806030; '>}</code>
1418 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
1419 <code style='color:#806030; '>}</code>
1421 <code style='color:#c34e00; '>/*</code>
1422 <code style='color:#c34e00; '> =======================================================================================================================</code>
1423 <code style='color:#c34e00; '>    Handler for the "examplePath" directive</code>
1424 <code style='color:#c34e00; '> =======================================================================================================================</code>
1425 <code style='color:#c34e00; '> */</code>
1426 <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>
1427 <code style='color:#806030; '>{</code>
1428 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1429 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>
1430 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1432 <code style='color:#400000; font-weight:bold; '>if</code><code style='color:#806030; '>(</code>conf<code style='color:#806030; '>)</code>
1433 <code style='color:#806030; '>{</code>
1434 <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>
1435 <code style='color:#806030; '>}</code>
1437 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
1438 <code style='color:#806030; '>}</code>
1440 <code style='color:#c34e00; '>/*</code>
1441 <code style='color:#c34e00; '> =======================================================================================================================</code>
1442 <code style='color:#c34e00; '>    Handler for the "exampleAction" directive ;</code>
1443 <code style='color:#c34e00; '>    Let's pretend this one takes one argument (file or db), and a second (deny or allow), ;</code>
1444 <code style='color:#c34e00; '>    and we store it in a bit-wise manner.</code>
1445 <code style='color:#c34e00; '> =======================================================================================================================</code>
1446 <code style='color:#c34e00; '> */</code>
1447 <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>
1448 <code style='color:#806030; '>{</code>
1449 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1450 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>
1451 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1453 <code style='color:#400000; font-weight:bold; '>if</code><code style='color:#806030; '>(</code>conf<code style='color:#806030; '>)</code>
1454 <code style='color:#806030; '>{</code>
1455 <code style='color:#806030; '>{</code>
1456 <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>
1457 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>
1458 <code style='color:#400000; font-weight:bold; '>else</code>
1459 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>
1460 <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>
1461 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>
1462 <code style='color:#400000; font-weight:bold; '>else</code>
1463 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>
1464 <code style='color:#806030; '>}</code>
1465 <code style='color:#806030; '>}</code>
1467 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#007d45; '>NULL</code><code style='color:#806030; '>;</code>
1468 <code style='color:#806030; '>}</code>
1470 <code style='color:#c34e00; '>/*</code>
1471 <code style='color:#c34e00; '> =======================================================================================================================</code>
1472 <code style='color:#c34e00; '>    Function for creating new configurations for per-directory contexts</code>
1473 <code style='color:#c34e00; '> =======================================================================================================================</code>
1474 <code style='color:#c34e00; '> */</code>
1475 <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>
1476 <code style='color:#806030; '>{</code>
1477 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>
1479 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1480 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>
1481 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1483 <code style='color:#400000; font-weight:bold; '>if</code><code style='color:#806030; '>(</code>cfg<code style='color:#806030; '>)</code>
1484 <code style='color:#806030; '>{</code>
1485 <code style='color:#806030; '>{</code>
1486 <code style='color:#c34e00; '>/* Set some default values */</code>
1487 <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>
1488 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>
1489 <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>
1490 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>
1491 <code style='color:#806030; '>}</code>
1492 <code style='color:#806030; '>}</code>
1494 <code style='color:#400000; font-weight:bold; '>return</code> cfg<code style='color:#806030; '>;</code>
1495 <code style='color:#806030; '>}</code>
1497 <code style='color:#c34e00; '>/*</code>
1498 <code style='color:#c34e00; '> =======================================================================================================================</code>
1499 <code style='color:#c34e00; '>    Merging function for configurations</code>
1500 <code style='color:#c34e00; '> =======================================================================================================================</code>
1501 <code style='color:#c34e00; '> */</code>
1502 <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>
1503 <code style='color:#806030; '>{</code>
1504 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1505 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>
1506 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>
1507 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>
1508 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1510 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>
1511 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>
1512 <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>
1513 <code style='color:#400000; font-weight:bold; '>return</code> conf<code style='color:#806030; '>;</code>
1514 <code style='color:#806030; '>}</code>
1516 <!-- END EXAMPLE CODE -->
1524 <section id="summary"><title>Summing up</title>
1526 We have now looked at how to create simple modules for Apache HTTP Server 2.4 and
1527 configuring them. What you do next is entirely up to you, but it is my
1528 hope that something valuable has come out of reading this documentation.
1529 If you have questions on how to further develop modules, you are welcome
1530 to join our <a href="http://httpd.apache.org/lists.html">mailing lists</a>
1531 or check out the rest of our documentation for further tips.
1535 <section id="snippets"><title>Some useful snippets of code</title>
1537 <section id="get_post"><title>Retrieve a variable from POST form data</title>
1540 <!-- BEGIN EXAMPLE CODE -->
1541 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1542 <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>
1543 <code style='color:#806030; '>{</code>
1544 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1545 <code style='color:#400000; font-weight:bold; '>int</code> i<code style='color:#806030; '>;</code>
1546 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>
1547 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1548 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>
1549 <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>
1550 <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>
1551 <code style='color:#806030; '>}</code>
1552 <code style='color:#400000; font-weight:bold; '>return</code> <code style='color:#c00000; '>0</code><code style='color:#806030; '>;</code>
1553 <code style='color:#806030; '>}</code>
1554 <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>
1555 <code style='color:#806030; '>{</code>
1556 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~*/</code>
1557 apr_array_header_t <code style='color:#806030; '>*</code>POST<code style='color:#806030; '>;</code>
1558 <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>
1559 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~*/</code>
1560 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>
1562 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>
1563 <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>
1564 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>
1565 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
1566 <code style='color:#806030; '>}</code>
1568 <!-- END EXAMPLE CODE -->
1573 <section id="headers_out"><title>Printing out every HTTP header received</title>
1576 <!-- BEGIN EXAMPLE CODE -->
1577 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1578 <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>
1579 <code style='color:#806030; '>{</code>
1580 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1581 <code style='color:#400000; font-weight:bold; '>const</code> apr_array_header_t <code style='color:#806030; '>*</code>fields<code style='color:#806030; '>;</code>
1582 <code style='color:#400000; font-weight:bold; '>int</code> i<code style='color:#806030; '>;</code>
1583 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>
1584 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1586 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>
1587 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>
1588 <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>
1589 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>
1590 <code style='color:#806030; '>}</code>
1591 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
1592 <code style='color:#806030; '>}</code>
1594 <!-- END EXAMPLE CODE -->
1599 <section id="request_body"><title>Reading the request body into memory</title>
1602 <!-- BEGIN EXAMPLE CODE -->
1603 <pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
1604 <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>
1605 <code style='color:#806030; '>{</code>
1606 <code style='color:#c34e00; '>/*~~~~~~~~*/</code>
1607 <code style='color:#400000; font-weight:bold; '>int</code> rc <code style='color:#806030; '>=</code> OK<code style='color:#806030; '>;</code>
1608 <code style='color:#c34e00; '>/*~~~~~~~~*/</code>
1610 <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>
1611 <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>
1612 <code style='color:#806030; '>}</code>
1614 <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>
1616 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1617 <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>
1618 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>
1619 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>
1620 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/</code>
1622 <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>
1623 <code style='color:#806030; '>*</code>size <code style='color:#806030; '>=</code> length<code style='color:#806030; '>;</code>
1624 <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>
1625 <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>
1626 rsize <code style='color:#806030; '>=</code> length <code style='color:#806030; '>-</code> rpos<code style='color:#806030; '>;</code>
1627 <code style='color:#806030; '>}</code>
1628 <code style='color:#400000; font-weight:bold; '>else</code> <code style='color:#806030; '>{</code>
1629 rsize <code style='color:#806030; '>=</code> len_read<code style='color:#806030; '>;</code>
1630 <code style='color:#806030; '>}</code>
1632 <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>
1633 rpos <code style='color:#806030; '>+</code><code style='color:#806030; '>=</code> rsize<code style='color:#806030; '>;</code>
1634 <code style='color:#806030; '>}</code>
1635 <code style='color:#806030; '>}</code>
1636 <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>
1637 <code style='color:#806030; '>}</code>
1639 <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>
1640 <code style='color:#806030; '>{</code>
1641 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~*/</code>
1642 apr_off_t size<code style='color:#806030; '>;</code>
1643 <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>
1644 <code style='color:#c34e00; '>/*~~~~~~~~~~~~~~~~*/</code>
1646 <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>
1647 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>
1648 <code style='color:#806030; '>}</code>
1649 <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
1650 <code style='color:#806030; '>}</code>
1652 <!-- END EXAMPLE CODE -->