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Posted to cvs@httpd.apache.org by hu...@apache.org on 2012/04/23 10:30:51 UTC
svn commit: r1329124 [2/2] -
/httpd/httpd/branches/2.4.x/docs/manual/developer/modguide.xml
Modified: httpd/httpd/branches/2.4.x/docs/manual/developer/modguide.xml
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/docs/manual/developer/modguide.xml?rev=1329124&r1=1329123&r2=1329124&view=diff
==============================================================================
--- httpd/httpd/branches/2.4.x/docs/manual/developer/modguide.xml (original)
+++ httpd/httpd/branches/2.4.x/docs/manual/developer/modguide.xml Mon Apr 23 08:30:51 2012
@@ -1,7 +1,8 @@
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE manualpage SYSTEM "../style/manualpage.dtd">
<?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?>
-<!-- $LastChangedRevision: 1324862 $ -->
+
+<!-- $LastChangedRevision: 1329073 $ -->
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
@@ -46,12 +47,14 @@ MD5 digest value of the file located at
http://www.example.com/index.html</code>, we would visit <code>
http://www.example.com/index.html.sum</code>.
</p>
+
<p>
In the second part of this document, which deals with configuration
directive and context awareness, we will be looking at a module that simply
write out its own configuration to the client.
</p>
</section>
+
<section id="prerequisites"><title>Prerequisites</title>
<p>
First and foremost, you are expected to have a basic knowledge of how the C
@@ -74,45 +77,51 @@ To compile the source code we are buildi
using <a href="../programs/apxs.html">APXS</a>. Assuming your source file
is called mod_example.c, compiling, installing and activating the module is
as simple as:
+</p>
<example><pre>
apxs -i -a -c mod_example.c
</pre></example>
-</p>
+
</section>
</section>
<section id="basics"><title>Defining a module</title>
-<img src="../images/build_a_mod_3.png"/><br/>
-<p>Every module starts with the same declaration, or name tag if you will,
-that defines a module as <em>a separate entity within Apache</em>:
+<p>
+<img src="../images/build_a_mod_3.png" alt="Module name tags"/><br/>
+Every module starts with the same declaration, or name tag if you will,
+that defines a module as <em>a separate entity within Apache</em>:</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-module AP_MODULE_DECLARE_DATA example_module <code style='color:#806030; '>=</code>
-<code style='color:#806030; '>{</code>
- STANDARD20_MODULE_STUFF<code style='color:#806030; '>,</code>
- create_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-directory configuration handler */</code>
- merge_dir_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-directory configurations */</code>
- create_svr_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Per-server configuration handler */</code>
- merge_svr_conf<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Merge handler for per-server configurations */</code>
- directives<code style='color:#806030; '>,</code> <code style='color:#c34e00; '>/* Any directives we may have for httpd */</code>
- register_hooks <code style='color:#c34e00; '>/* Our hook registering function */</code>
-<code style='color:#806030; '>}</code><code style='color:#806030; '>;</code>
-</pre>
+<p class="source">
+module AP_MODULE_DECLARE_DATA example_module <code class="sh_misc">=</code>
+<code class="sh_misc">{</code>
+ STANDARD20_MODULE_STUFF<code class="sh_misc">,</code>
+ create_dir_conf<code class="sh_misc">,</code> <code class="sh_comment">/* Per-directory configuration handler */</code>
+ merge_dir_conf<code class="sh_misc">,</code> <code class="sh_comment">/* Merge handler for per-directory configurations */</code>
+ create_svr_conf<code class="sh_misc">,</code> <code class="sh_comment">/* Per-server configuration handler */</code>
+ merge_svr_conf<code class="sh_misc">,</code> <code class="sh_comment">/* Merge handler for per-server configurations */</code>
+ directives<code class="sh_misc">,</code> <code class="sh_comment">/* Any directives we may have for httpd */</code>
+ register_hooks <code class="sh_comment">/* Our hook registering function */</code>
+<code class="sh_misc">}</code><code class="sh_misc">;</code>
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
This bit of code lets the server know that we have now registered a new module
in the system, and that its name is <code>example_module</code>. The name
of the module is used primarily for two things:<br/>
+</p>
<ul>
<li>Letting the server know how to load the module using the LoadModule</li>
<li>Setting up a namespace for the module to use in configurations</li>
</ul>
+<p>
For now, we're only concerned with the first purpose of the module name,
-which comes into play when we need to load the module:<br/>
+which comes into play when we need to load the module:
+</p>
<example><pre><a href="../mod/mod_so.html#LoadModule">LoadModule</a> example_module modules/mod_example.so</pre></example>
+<p>
In essence, this tells the server to open up <code>mod_example.so</code> and look for a module
called <code>example_module</code>.
</p>
@@ -142,7 +151,7 @@ request, and will ask each module whethe
request or not. It is then up to each module to either gently decline
serving a request, accept serving it or flat out deny the request from
being served, as authentication/authorization modules do: <br/>
-<img src="../images/build_a_mod_2.png" /><br/>
+<img src="../images/build_a_mod_2.png" alt="Hook handling in httpd"/><br/>
To make it a bit easier for handlers such as our mod_example to know
whether the client is requesting content we should handle or not, the server
has directives for hinting to modules whether their assistance is needed or
@@ -152,9 +161,11 @@ an example using <directive module="mod_
our example case, we want every request ending with .sum to be served by
<code>mod_example</code>, so we'll add a configuration directive that tells
the server to do just that:
+</p>
<example><pre>
AddHandler example-handler .sum
</pre></example>
+<p>
What this tells the server is the following: <em>Whenever we receive a request
for a URI ending in .sum, we are to let all modules know that we are
looking for whoever goes by the name of "example-handler" </em>.
@@ -170,46 +181,47 @@ the server based on the value of this ta
To begin with, we only want to create a simple handler, that replies to the
client browser when a specific URL is requested, so we won't bother setting
up configuration handlers and directives just yet. Our initial module
-definition will look like this:<br/>
+definition will look like this:</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
+<p class="source">
module AP_MODULE_DECLARE_DATA example_module =
{
STANDARD20_MODULE_STUFF,
- <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
- <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
- <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
- <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
- <code style='color:#7f0055; font-weight:bold; '>NULL</code>,
- <code style='color:#800040; '>register_hooks</code> <code style='color:#c34e00; '><code style='color:#c34e00; '>/* Our hook registering function */</code></code>
+ <code class="sh_constant">NULL</code>,
+ <code class="sh_constant">NULL</code>,
+ <code class="sh_constant">NULL</code>,
+ <code class="sh_constant">NULL</code>,
+ <code class="sh_constant">NULL</code>,
+ <code class="sh_function">register_hooks</code> <code class="sh_comment"><code class="sh_comment">/* Our hook registering function */</code></code>
};
-</pre>
+</p>
<!-- END EXAMPLE CODE -->
-This lets the server know that we are not interesting in anything fancy, we
+<p>This lets the server know that we are not interesting in anything fancy, we
just want to hook onto the requests and possibly handle some of them. </p>
+
<p> The reference in our example declaration, <code>register_hooks</code>
is the name of a function we will create to manage how we hook onto the
request process. In this example module, the function has just one purpose;
To create a simple hook that gets called after all the rewrites, access
control etc has been handled. Thus, we will let the server know, that we want
to hook into its process as one of the last modules:
-
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <code style='color:#c34e00; '>/* Create a hook in the request handler, so we get called when a request arrives */</code>
- <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>
-<code style='color:#806030; '>}</code>
-</pre>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">void</code> register_hooks<code class="sh_misc">(</code>apr_pool_t <code class="sh_misc">*</code>pool<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_comment">/* Create a hook in the request handler, so we get called when a request arrives */</code>
+ <code class="sh_function">ap_hook_handler</code><code class="sh_misc">(</code>example_handler<code class="sh_misc">,</code> <code class="sh_constant">NULL</code><code class="sh_misc">,</code> <code class="sh_constant">NULL</code><code class="sh_misc">,</code> APR_HOOK_LAST<code class="sh_misc">)</code><code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
The <code>example_handler</code> reference is the function that will handle
the request. We will discuss how to create a handler in the next chapter.
</p>
@@ -218,13 +230,14 @@ the request. We will discuss how to crea
<p>
Hooking into the request handling phase is but one of many hooks that you
can create. Some other ways of hooking are:
+</p>
<ul>
<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>
<li><code>ap_hook_pre_config</code>: Place a hook that executes before any configuration data has been read (very early hook)</li>
<li><code>ap_hook_post_config</code>: Place a hook that executes after configuration has been parsed, but before the server has forked</li>
<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>
</ul>
-</p>
+
</section>
</section>
@@ -237,103 +250,110 @@ request and so on), and is put in charge
not interested in the request or handle the request with the tools provided.
</p>
<section id="simple_handler"><title>A simple "Hello, world!"
-handler</title> Let's start off by making a very simple request handler
-that does the following: <br/>
+handler</title>
+<p>Let's start off by making a very simple request handler
+that does the following:
+</p>
<ol>
<li>Check that this is a request that should be served by "example-handler"</li>
<li>Set the content type of our output to <code>text/html</code></li>
<li>Write "Hello, world!" back to the client browser</li>
<li>Let the server know that we took care of this request and everything went fine</li>
</ol>
-In C code, our example handler will now look like this:<br/>
-
+<p>
+In C code, our example handler will now look like this:
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <code style='color:#c34e00; '>/* First off, we need to check if this is a call for the "example-handler" handler.</code>
-<code style='color:#c34e00; '>     * If it is, we accept it and do our things, if not, we simply return DECLINED,</code>
-<code style='color:#c34e00; '>     * and the server will try somewhere else.</code>
-<code style='color:#c34e00; '>     */</code>
- <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>
-
- <code style='color:#c34e00; '>/* Now that we are handling this request, we'll write out "Hello, world!" to the client.</code>
-<code style='color:#c34e00; '>     * To do so, we must first set the appropriate content type, followed by our output.</code>
-<code style='color:#c34e00; '>     */</code>
- <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>
- <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>
-
- <code style='color:#c34e00; '>/* Lastly, we must tell the server that we took care of this request and everything went fine.</code>
-<code style='color:#c34e00; '>     * We do so by simply returning the value OK to the server.</code>
-<code style='color:#c34e00; '>     */</code>
- <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
-<code style='color:#806030; '>}</code>
-</pre>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">int</code> example_handler<code class="sh_misc">(</code>request_rec <code class="sh_misc">*</code>r<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_comment">/* First off, we need to check if this is a call for the "example-handler" handler.</code>
+<code class="sh_comment">     * If it is, we accept it and do our things, if not, we simply return DECLINED,</code>
+<code class="sh_comment">     * and the server will try somewhere else.</code>
+<code class="sh_comment">     */</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code><code class="sh_misc">!</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">handler</code> <code class="sh_misc">|</code><code class="sh_misc">|</code> <code class="sh_function">strcmp</code><code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">handler</code><code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">example-handler</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">)</code> <code class="sh_declare">return</code> <code class="sh_misc">(</code>DECLINED<code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Now that we are handling this request, we'll write out "Hello, world!" to the client.</code>
+<code class="sh_comment">     * To do so, we must first set the appropriate content type, followed by our output.</code>
+<code class="sh_comment">     */</code>
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">text/html</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">Hello, world!</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Lastly, we must tell the server that we took care of this request and everything went fine.</code>
+<code class="sh_comment">     * We do so by simply returning the value OK to the server.</code>
+<code class="sh_comment">     */</code>
+ <code class="sh_declare">return</code> OK<code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
Now, we put all we have learned together and end up with a program that
looks like
<a href="http://people.apache.org/~humbedooh/mods/examples/mod_example_1.c">mod_example_1.c</a>
. The functions used in this example will be explained later in the section
-<a href= "#functions">"Some useful functions you should know"</a>
-. </section> <section id="request_rec"><title>The request_rec structure
-</title> <p>The most essential part of any request is the <em>request record
+<a href= "#functions">"Some useful functions you should know"</a>.
+</p>
+</section>
+<section id="request_rec"><title>The request_rec structure</title>
+<p>The most essential part of any request is the <em>request record
</em>. In a call to a handler function, this is represented by the <code>
request_req* </code> structure passed along with every call that is made.
This struct, typically just refered to as <code>r</code> in modules,
contains all the information you need for your module to fully process any
HTTP request and respond accordingly.</p> <p>Some key elements of the <code>
request_req </code> structure are:
+</p>
<ul>
-<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>
-<li><code><code style='color:#008833'>r->method</code> (char*)</code>: Contains the HTTP method being used, f.x. GET or POST</li>
-<li><code><code style='color:#008833'>r->filename</code> (char*)</code>: Contains the translated filename the client is requesting</li>
-<li><code><code style='color:#008833'>r->args</code> (char*)</code>: Contains the query string of the request, if any</li>
-<li><code><code style='color:#008833'>r->headers_in</code> (apr_table_t*)</code>: Contains all the headers sent by the client</li>
-<li><code><code style='color:#008833'>r->connection</code> (conn_rec*)</code>: A record containing information about the current connection</li>
-<li><code><code style='color:#008833'>r->useragent_ip</code> (char*)</code>: The IP address of the client connecting to us</li>
-<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 "
+<li><code><code class="sh_subobject">r->handler</code> (char*)</code>: Contains the name of the handler the server is currently asking to do the handling of this request</li>
+<li><code><code class="sh_subobject">r->method</code> (char*)</code>: Contains the HTTP method being used, f.x. GET or POST</li>
+<li><code><code class="sh_subobject">r->filename</code> (char*)</code>: Contains the translated filename the client is requesting</li>
+<li><code><code class="sh_subobject">r->args</code> (char*)</code>: Contains the query string of the request, if any</li>
+<li><code><code class="sh_subobject">r->headers_in</code> (apr_table_t*)</code>: Contains all the headers sent by the client</li>
+<li><code><code class="sh_subobject">r->connection</code> (conn_rec*)</code>: A record containing information about the current connection</li>
+<li><code><code class="sh_subobject">r->useragent_ip</code> (char*)</code>: The IP address of the client connecting to us</li>
+<li><code><code class="sh_subobject">r->pool</code> (apr_pool_t*)</code>: The memory pool of this request. We'll discuss this in the "
<a href="#memory">Memory management</a>" chapter.</li>
</ul>
+<p>
A complete list of all the values contained with in the <code>request_req</code> structure can be found in
the <a href="http://svn.apache.org/repos/asf/httpd/httpd/trunk/include/httpd.h"><code>httpd.h</code></a> header
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>.
</p>
+
+
<p>
Let's try out some of these variables in another example handler:<br/>
-
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <code style='color:#c34e00; '>/* Set the appropriate content type */</code>
- <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>
-
- <code style='color:#c34e00; '>/* Print out the IP address of the client connecting to us: */</code>
- <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>
-
- <code style='color:#c34e00; '>/* If we were reached through a GET or a POST request, be happy, else sad. */</code>
- <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:#80000
0; '>"</code><code style='color:#806030; '>)</code> <code style='color:#806030; '>)</code> <code style='color:#806030; '>{</code>
- 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>
- <code style='color:#806030; '>}</code>
- <code style='color:#400000; font-weight:bold; '>else</code> <code style='color:#806030; '>{</code>
- 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>
- <code style='color:#806030; '>}</code>
-
- <code style='color:#c34e00; '>/* Lastly, if there was a query string, let's print that too! */</code>
- <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>
- <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>
- <code style='color:#806030; '>}</code>
- <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
-<code style='color:#806030; '>}</code>
-</pre>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">int</code> example_handler<code class="sh_misc">(</code>request_rec <code class="sh_misc">*</code>r<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_comment">/* Set the appropriate content type */</code>
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">text/html</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Print out the IP address of the client connecting to us: */</code>
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value"><h2>Hello, </code><code class="sh_reference">%s</code><code class="sh_value">!</h2></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">useragent_ip</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* If we were reached through a GET or a POST request, be happy, else sad. */</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code> <code class="sh_misc">!</code><code class="sh_function">strcmp</code><code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">method</code><code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">POST</code><code class="sh_character">"</code><code class="sh_misc">)</code> <code class="sh_misc">|</code><code class="sh_misc">|</code> <code class="sh_misc">!</code><code class="sh_function">strcmp</code><code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">method</code><code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">GET</code><code class="sh_character">"</code><code class="sh_misc">)</code> <code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value">You used a GET or a POST method, that makes us happy!<br></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ <code class="sh_declare">else</code> <code class="sh_misc">{</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value">You did not use POST or GET, that makes us sad :(<br></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+
+ <code class="sh_comment">/* Lastly, if there was a query string, let's print that too! */</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">args</code><code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">Your query string was: </code><code class="sh_reference">%s</code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">args</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ <code class="sh_declare">return</code> OK<code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
-
-</p>
</section>
<section id="return_value"><title>Return values</title>
@@ -344,19 +364,19 @@ module is not interested in handling a s
return the value <code>DECLINED</code>. If it is handling a request, it
should either return the generic value <code>OK</code>, or a specific HTTP
status code, for example:
-
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <code style='color:#c34e00; '>/* Return 404: Not found */</code>
- <code style='color:#400000; font-weight:bold; '>return</code> HTTP_NOT_FOUND<code style='color:#806030; '>;</code>
-<code style='color:#806030; '>}</code>
-</pre>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">int</code> example_handler<code class="sh_misc">(</code>request_rec <code class="sh_misc">*</code>r<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_comment">/* Return 404: Not found */</code>
+ <code class="sh_declare">return</code> HTTP_NOT_FOUND<code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
Returning <code>OK</code> or a HTTP status code does not necessarily mean
that the request will end. The server may still have other handlers that are
interested in this request, for instance the logging modules which, upon a
@@ -367,12 +387,15 @@ know that it should cease all activity o
the next, without informing other handlers.
<br/>
<strong>General response codes:</strong>
+</p>
<ul>
<li><code>DECLINED</code>: We are not handling this request</li>
<li><code>OK</code>: We handled this request and it went well</li>
<li><code>DONE</code>: We handled this request and the server should just close this thread without further processing</li>
-</ul><br/>
+</ul>
+<p>
<strong>HTTP specific return codes (excerpt):</strong>
+</p>
<ul>
<li><code>HTTP_OK (200)</code>: Request was okay</li>
<li><code>HTTP_MOVED_PERMANENTLY (301)</code>: The resource has moved to a new URL</li>
@@ -381,7 +404,6 @@ the next, without informing other handle
<li><code>HTTP_NOT_FOUND (404)</code>: File not found</li>
<li><code>HTTP_INTERNAL_SERVER_ERROR (500)</code>: Internal server error (self explanatory)</li>
</ul>
-</p>
</section>
<section id="functions"><title>Some useful functions you should know</title>
@@ -395,7 +417,7 @@ the next, without informing other handle
<!-- BEGIN EXAMPLE CODE -->
-<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>
+<p class="source">ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value">Hello, world!</code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code></p>
<!-- END EXAMPLE CODE -->
@@ -407,7 +429,7 @@ the next, without informing other handle
<!-- BEGIN EXAMPLE CODE -->
-<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>
+<p class="source"><code class="sh_declare"><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#ga5e91eb6ca777c9a427b2e82bf1eeb81d">ap_rprintf</a></code><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">Hello, </code><code class="sh_reference">%s</code><code class="sh_value">!</code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">useragent_ip</code><code class="sh_misc">)</code><code class="sh_misc">;</code></p>
<!-- END EXAMPLE CODE -->
</li>
@@ -418,7 +440,7 @@ the next, without informing other handle
<!-- BEGIN EXAMPLE CODE -->
-<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>
+<p class="source"><code class="sh_declare"><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__PROTO.html#gaa2f8412c400197338ec509f4a45e4579">ap_set_content_type</a></code><code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">text/plain</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code> <code class="sh_comment">/* force a raw text output */</code></p>
<!-- END EXAMPLE CODE -->
</li>
@@ -439,9 +461,10 @@ clean up after yourself - pretty neat, h
<p>
In our module, we will primarily be allocating memory for each request, so
-it's appropriate to use the <code style='color:#008833'>r->pool</code>
+it's appropriate to use the <code class="sh_subobject">r->pool</code>
reference when creating new objects. A few of the functions for allocating
memory within a pool are:
+</p>
<ul>
<li><code>void* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__pools.html#ga85f1e193c31d109affda72f9a92c6915">apr_palloc</a>(
apr_pool_t *p, apr_size_t size)</code>: Allocates <code>size</code> number of bytes in the pool for you</li>
@@ -451,52 +474,54 @@ apr_pool_t *p, apr_size_t size)</code>:
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>
<li><code>char* <a href="http://apr.apache.org/docs/apr/1.4/group__apr__strings.html#ga3eca76b8d293c5c3f8021e45eda813d8">apr_psprintf</a>(
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>
-
</ul>
-Let's put these functions into an example handler:<br/>
+
+<p>Let's put these functions into an example handler:</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <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>
- <code style='color:#400000; font-weight:bold; '>char</code><code style='color:#806030; '>*</code> copy<code style='color:#806030; '>;</code>
- <code style='color:#400000; font-weight:bold; '>int</code><code style='color:#806030; '>*</code> integers<code style='color:#806030; '>;</code>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">int</code> example_handler<code class="sh_misc">(</code>request_rec <code class="sh_misc">*</code>r<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_declare">const</code> <code class="sh_declare">char</code><code class="sh_misc">*</code> original <code class="sh_misc">=</code> <code class="sh_character">"</code><code class="sh_value">You can't edit this!</code><code class="sh_character">"</code><code class="sh_misc">;</code>
+ <code class="sh_declare">char</code><code class="sh_misc">*</code> copy<code class="sh_misc">;</code>
+ <code class="sh_declare">int</code><code class="sh_misc">*</code> integers<code class="sh_misc">;</code>
- <code style='color:#c34e00; '>/* Allocate space for 10 integer values and set them all to zero. */</code>
- 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>
+ <code class="sh_comment">/* Allocate space for 10 integer values and set them all to zero. */</code>
+ integers <code class="sh_misc">=</code> apr_pcalloc<code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code>pool<code class="sh_misc">,</code> <code class="sh_declare">sizeof</code><code class="sh_misc">(</code><code class="sh_declare">int</code><code class="sh_misc">)</code><code class="sh_misc">*</code><code class="sh_reference">10</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
- <code style='color:#c34e00; '>/* Create a copy of the 'original' variable that we can edit. */</code>
- 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>
- <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
-<code style='color:#806030; '>}</code>
-</pre>
+ <code class="sh_comment">/* Create a copy of the 'original' variable that we can edit. */</code>
+ copy <code class="sh_misc">=</code> apr_pstrdup<code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code>pool<code class="sh_misc">,</code> original<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">return</code> OK<code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
+<p>
This is all well and good for our module, which won't need any
pre-initialized variables or structures. However, if we wanted to
initialize something early on, before the requests come rolling in, we
could simply add a call to a function in our <code>register_hooks</code>
function to sort it out:
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <code style='color:#c34e00; '>/* Call a function that initializes some stuff */</code>
- <code style='color:#800040; '>example_init_function</code><code style='color:#806030; '>(</code>pool<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
- <code style='color:#c34e00; '>/* Create a hook in the request handler, so we get called when a request arrives */</code>
- <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>
-<code style='color:#806030; '>}</code>
-</pre>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">void</code> register_hooks<code class="sh_misc">(</code>apr_pool_t <code class="sh_misc">*</code>pool<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_comment">/* Call a function that initializes some stuff */</code>
+ <code class="sh_function">example_init_function</code><code class="sh_misc">(</code>pool<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_comment">/* Create a hook in the request handler, so we get called when a request arrives */</code>
+ <code class="sh_function">ap_hook_handler</code><code class="sh_misc">(</code>example_handler<code class="sh_misc">,</code> <code class="sh_constant">NULL</code><code class="sh_misc">,</code> <code class="sh_constant">NULL</code><code class="sh_misc">,</code> APR_HOOK_LAST<code class="sh_misc">)</code><code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
+<p>
In this pre-request initialization function we would not be using the
same pool as we did when allocating resources for request-based functions.
Instead, we would use the pool given to us by the server for allocating memory
on a per-process based level.
-
</p>
</section>
@@ -515,38 +540,39 @@ digest.
<p>
Since the introduction of Apache HTTP Server 2.4, parsing request data from GET and
POST requests have never been easier. All we require to parse both GET and
-POST data is four simple lines:
+POST data is four simple lines:
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
+<p class="source">
<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__apr__tables.html#gad7ea82d6608a4a633fc3775694ab71e4">apr_table_t</a> *GET;
<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/structapr__array__header__t.html">apr_array_header_t</a> *POST;
<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__SCRIPT.html#gaed25877b529623a4d8f99f819ba1b7bd">ap_args_to_table</a>(r, &GET);
-<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);
-</pre>
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__DAEMON.html#ga9d426b6382b49754d4f87c55f65af202">ap_parse_form_data</a>(r, <code class="sh_constant">NULL</code>, &POST, -1, 8192);
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
In our specific example module, we're looking for the <code>digest</code>
value from the query string, which now resides inside a table called <code>
GET</code>. To extract this value, we need only perform a simple operation:
-<br/>
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<code style='color:#c34e00; '>/* Get the "digest" key from the query string, if any. */</code>
-<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>
+<p class="source">
+<code class="sh_comment">/* Get the "digest" key from the query string, if any. */</code>
+<code class="sh_declare">const</code> <code class="sh_declare">char</code><code class="sh_misc"> *</code>digestType <code class="sh_misc">=</code> <a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__apr__tables.html#ga4db13e3915c6b9a3142b175d4c15d915">apr_table_get</a><code class="sh_misc">(</code>GET<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">digest</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
-<code style='color:#c34e00; '>/* If no key was returned, we will set a default value instead. */</code>
-<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>
+<code class="sh_comment">/* If no key was returned, we will set a default value instead. */</code>
+<code class="sh_declare">if</code> <code class="sh_misc">(</code><code class="sh_misc">!</code>digestType<code class="sh_misc">)</code> digestType <code class="sh_misc">=</code> <code class="sh_character">"</code><code class="sh_value">sha1</code><code class="sh_character">"</code><code class="sh_misc">;</code>
-</pre>
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
The structures used for the POST and GET data are not exactly the same, so
if we were to fetch a value from POST data instead of the query string, we
would have to resort to a few more lines, as outlined in <a href="#get_post"
@@ -555,130 +581,133 @@ would have to resort to a few more lines
</section>
<section id="advanced_handler"><title>Making an advanced handler</title>
+<p>
Now that we have learned how to parse form data and manage our resources,
we can move on to creating an advanced version of our module, that spits
-out the MD5 or SHA1 digest of files:<br/>
+out the MD5 or SHA1 digest of files:
+</p>
<!-- BEGIN EXAMPLE CODE -->
-<pre style='color:#000000;background:#ffffef;border: 1px dashed #333; padding: 0.5em; margin: 1em 2em 1em 1em;'>
-<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>
- <code style='color:#400000; font-weight:bold; '>int</code> rc<code style='color:#806030; '>,</code> exists<code style='color:#806030; '>;</code>
- apr_finfo_t finfo<code style='color:#806030; '>;</code>
- apr_file_t<code style='color:#806030; '> *</code>file<code style='color:#806030; '>;</code>
- <code style='color:#400000; font-weight:bold; '>char</code> <code style='color:#806030; '>*</code>filename<code style='color:#806030; '>;</code>
- <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>
- apr_size_t readBytes<code style='color:#806030; '>;</code>
- <code style='color:#400000; font-weight:bold; '>int</code> n<code style='color:#806030; '>;</code>
- apr_table_t<code style='color:#806030; '> *</code>GET<code style='color:#806030; '>;</code>
- apr_array_header_t<code style='color:#806030; '> *</code>POST<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>digestType<code style='color:#806030; '>;</code>
-
-
- <code style='color:#c34e00; '>/* Check that the "example-handler" handler is being called. */</code>
- <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>
-
- <code style='color:#c34e00; '>/* Figure out which file is being requested by removing the .sum from it */</code>
- 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>
- 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>
-
- <code style='color:#c34e00; '>/* Figure out if the file we request a sum on exists and isn't a directory */</code>
- 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>
- <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>
- exists <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><code style='color:#806030; '>=</code> APR_NOFILE<code style='color:#806030; '>)</code>
- <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>
- <code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
- <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>
- <code style='color:#806030; '>}</code>
- <code style='color:#c34e00; '>/* If apr_stat failed, we're probably not allowed to check this file. */</code>
- <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>
-
- <code style='color:#c34e00; '>/* Parse the GET and, optionally, the POST data sent to us */</code>
-
- 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>
- 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>
-
- <code style='color:#c34e00; '>/* Set the appropriate content type */</code>
- 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>
-
- <code style='color:#c34e00; '>/* Print a title and some general information */</code>
- 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>
- 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>
-
- <code style='color:#c34e00; '>/* Get the digest type the client wants to see */</code>
- 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>
- <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>
+<p class="source">
+<code class="sh_declare">static</code> <code class="sh_declare">int</code> example_handler<code class="sh_misc">(</code>request_rec <code class="sh_misc">*</code>r<code class="sh_misc">)</code>
+<code class="sh_misc">{</code>
+ <code class="sh_declare">int</code> rc<code class="sh_misc">,</code> exists<code class="sh_misc">;</code>
+ apr_finfo_t finfo<code class="sh_misc">;</code>
+ apr_file_t<code class="sh_misc"> *</code>file<code class="sh_misc">;</code>
+ <code class="sh_declare">char</code> <code class="sh_misc">*</code>filename<code class="sh_misc">;</code>
+ <code class="sh_declare">char</code> buffer<code class="sh_misc">[</code><code class="sh_reference">256</code><code class="sh_misc">]</code><code class="sh_misc">;</code>
+ apr_size_t readBytes<code class="sh_misc">;</code>
+ <code class="sh_declare">int</code> n<code class="sh_misc">;</code>
+ apr_table_t<code class="sh_misc"> *</code>GET<code class="sh_misc">;</code>
+ apr_array_header_t<code class="sh_misc"> *</code>POST<code class="sh_misc">;</code>
+ <code class="sh_declare">const</code> <code class="sh_declare">char</code><code class="sh_misc"> *</code>digestType<code class="sh_misc">;</code>
+
+
+ <code class="sh_comment">/* Check that the "example-handler" handler is being called. */</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code><code class="sh_misc">!</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">handler</code> <code class="sh_misc">|</code><code class="sh_misc">|</code> <code class="sh_function">strcmp</code><code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">handler</code><code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">example-handler</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">)</code> <code class="sh_declare">return</code> <code class="sh_misc">(</code>DECLINED<code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Figure out which file is being requested by removing the .sum from it */</code>
+ filename <code class="sh_misc">=</code> apr_pstrdup<code class="sh_misc">(</code>r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">pool</code><code class="sh_misc">,</code> r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">filename</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ filename<code class="sh_misc">[</code><code class="sh_function">strlen</code><code class="sh_misc">(</code>filename<code class="sh_misc">)</code><code class="sh_misc">-</code><code class="sh_reference">4</code><code class="sh_misc">]</code> <code class="sh_misc">=</code> <code class="sh_reference">0</code><code class="sh_misc">;</code> <code class="sh_comment">/* Cut off the last 4 characters. */</code>
+
+ <code class="sh_comment">/* Figure out if the file we request a sum on exists and isn't a directory */</code>
+ rc <code class="sh_misc">=</code> apr_stat<code class="sh_misc">(</code><code class="sh_misc">&</code>finfo<code class="sh_misc">,</code> filename<code class="sh_misc">,</code> APR_FINFO_MIN<code class="sh_misc">,</code> r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">pool</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code>rc <code class="sh_misc">=</code><code class="sh_misc">=</code> APR_SUCCESS<code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ exists <code class="sh_misc">=</code>
+ <code class="sh_misc">(</code>
+ <code class="sh_misc">(</code>finfo<code class="sh_misc">.</code>filetype <code class="sh_misc">!</code><code class="sh_misc">=</code> APR_NOFILE<code class="sh_misc">)</code>
+ <code class="sh_misc">&</code><code class="sh_misc">&</code> <code class="sh_misc">!</code><code class="sh_misc">(</code>finfo<code class="sh_misc">.</code>filetype <code class="sh_misc">&</code> APR_DIR<code class="sh_misc">)</code>
+ <code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code><code class="sh_misc">!</code>exists<code class="sh_misc">)</code> <code class="sh_declare">return</code> HTTP_NOT_FOUND<code class="sh_misc">;</code> <code class="sh_comment">/* Return a 404 if not found. */</code>
+ <code class="sh_misc">}</code>
+ <code class="sh_comment">/* If apr_stat failed, we're probably not allowed to check this file. */</code>
+ <code class="sh_declare">else</code> <code class="sh_declare">return</code> HTTP_FORBIDDEN<code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Parse the GET and, optionally, the POST data sent to us */</code>
+
+ ap_args_to_table<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_misc">&</code>GET<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ ap_parse_form_data<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_constant">NULL</code><code class="sh_misc">,</code> <code class="sh_misc">&</code>POST<code class="sh_misc">,</code> <code class="sh_misc">-</code><code class="sh_reference">1</code><code class="sh_misc">,</code> <code class="sh_reference">8192</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Set the appropriate content type */</code>
+ ap_set_content_type<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">text/html</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+
+ <code class="sh_comment">/* Print a title and some general information */</code>
+ ap_rprintf<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value"><h2>Information on </code><code class="sh_reference">%s</code><code class="sh_value">:</h2></code><code class="sh_character">"</code><code class="sh_misc">,</code> filename<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ ap_rprintf<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value"><b>Size:</b> </code><code class="sh_reference">%u</code><code class="sh_value"> bytes<br/></code><code class="sh_character">"</code><code class="sh_misc">,</code> finfo<code class="sh_misc">.</code>size<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_comment">/* Get the digest type the client wants to see */</code>
+ digestType <code class="sh_misc">=</code> apr_table_get<code class="sh_misc">(</code>GET<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">digest</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code><code class="sh_misc">!</code>digestType<code class="sh_misc">)</code> digestType <code class="sh_misc">=</code> <code class="sh_character">"</code><code class="sh_value">MD5</code><code class="sh_character">"</code><code class="sh_misc">;</code>
- 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>
- <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>
+
+ rc <code class="sh_misc">=</code> apr_file_open<code class="sh_misc">(</code><code class="sh_misc">&</code>file<code class="sh_misc">,</code> filename<code class="sh_misc">,</code> APR_READ<code class="sh_misc">,</code> APR_OS_DEFAULT<code class="sh_misc">,</code> r<code class="sh_misc">-</code><code class="sh_misc">></code><code class="sh_subobject">pool</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code>rc <code class="sh_misc">=</code><code class="sh_misc">=</code> APR_SUCCESS<code class="sh_misc">)</code> <code class="sh_misc">{</code>
- <code style='color:#c34e00; '>/* Are we trying to calculate the MD5 or the SHA1 digest? */</code>
- <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>
- <code style='color:#c34e00; '>/* Calculate the MD5 sum of the file */</code>
- <code style='color:#400000; font-weight:bold; '>union</code> <code style='color:#806030; '>{</code>
- <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>
- uint32_t num<code style='color:#806030; '>[</code><code style='color:#c00000; '>4</code><code style='color:#806030; '>]</code><code style='color:#806030; '>;</code>
- <code style='color:#806030; '>}</code> digest<code style='color:#806030; '>;</code>
- apr_md5_ctx_t md5<code style='color:#806030; '>;</code>
- apr_md5_init<code style='color:#806030; '>(</code><code style='color:#806030; '>&</code>md5<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
- readBytes <code style='color:#806030; '>=</code> <code style='color:#c00000; '>256</code><code style='color:#806030; '>;</code>
- <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>
- 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>
- <code style='color:#806030; '>}</code>
- 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>
+ <code class="sh_comment">/* Are we trying to calculate the MD5 or the SHA1 digest? */</code>
+ <code class="sh_declare">if</code> <code class="sh_misc">(</code><code class="sh_misc">!</code>strcasecmp<code class="sh_misc">(</code>digestType<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_value">md5</code><code class="sh_character">"</code><code class="sh_misc">)</code><code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ <code class="sh_comment">/* Calculate the MD5 sum of the file */</code>
+ <code class="sh_declare">union</code> <code class="sh_misc">{</code>
+ <code class="sh_declare">char</code> chr<code class="sh_misc">[</code><code class="sh_reference">16</code><code class="sh_misc">]</code><code class="sh_misc">;</code>
+ uint32_t num<code class="sh_misc">[</code><code class="sh_reference">4</code><code class="sh_misc">]</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code> digest<code class="sh_misc">;</code>
+ apr_md5_ctx_t md5<code class="sh_misc">;</code>
+ apr_md5_init<code class="sh_misc">(</code><code class="sh_misc">&</code>md5<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ readBytes <code class="sh_misc">=</code> <code class="sh_reference">256</code><code class="sh_misc">;</code>
+ <code class="sh_declare">while</code> <code class="sh_misc">(</code> apr_file_read<code class="sh_misc">(</code>file<code class="sh_misc">,</code> buffer<code class="sh_misc">,</code> <code class="sh_misc">&</code>readBytes<code class="sh_misc">)</code> <code class="sh_misc">=</code><code class="sh_misc">=</code> APR_SUCCESS <code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ apr_md5_update<code class="sh_misc">(</code><code class="sh_misc">&</code>md5<code class="sh_misc">,</code> buffer<code class="sh_misc">,</code> readBytes<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ apr_md5_final<code class="sh_misc">(</code>digest<code class="sh_misc">.</code>chr<code class="sh_misc">,</code> <code class="sh_misc">&</code>md5<code class="sh_misc">)</code><code class="sh_misc">;</code>
- <code style='color:#c34e00; '>/* Print out the MD5 digest */</code>
- 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>
- <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>
- 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>
- <code style='color:#806030; '>}</code>
- 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>
- <code style='color:#c34e00; '>/* Print a link to the SHA1 version */</code>
- 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>
- <code style='color:#806030; '>}</code>
- <code style='color:#400000; font-weight:bold; '>else</code> <code style='color:#806030; '>{</code>
- <code style='color:#c34e00; '>/* Calculate the SHA1 sum of the file */</code>
- <code style='color:#400000; font-weight:bold; '>union</code> <code style='color:#806030; '>{</code>
- <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>
- uint32_t num<code style='color:#806030; '>[</code><code style='color:#c00000; '>5</code><code style='color:#806030; '>]</code><code style='color:#806030; '>;</code>
- <code style='color:#806030; '>}</code> digest<code style='color:#806030; '>;</code>
- apr_sha1_ctx_t sha1<code style='color:#806030; '>;</code>
- apr_sha1_init<code style='color:#806030; '>(</code><code style='color:#806030; '>&</code>sha1<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
- readBytes <code style='color:#806030; '>=</code> <code style='color:#c00000; '>256</code><code style='color:#806030; '>;</code>
- <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>
- 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>
- <code style='color:#806030; '>}</code>
- 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>
+ <code class="sh_comment">/* Print out the MD5 digest */</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value"><b>MD5: </b><code></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">for</code> <code class="sh_misc">(</code>n <code class="sh_misc">=</code> <code class="sh_reference">0</code><code class="sh_misc">;</code> n <code class="sh_misc"><</code> APR_MD5_DIGESTSIZE<code class="sh_misc">/</code><code class="sh_reference">4</code><code class="sh_misc">;</code> n<code class="sh_misc">+</code><code class="sh_misc">+</code><code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ ap_rprintf<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_reference">%08x</code><code class="sh_character">"</code><code class="sh_misc">,</code> digest<code class="sh_misc">.</code>num<code class="sh_misc">[</code>n<code class="sh_misc">]</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value"></code></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_comment">/* Print a link to the SHA1 version */</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value"><br/><a href='?digest=sha1'>View the SHA1 hash instead</a></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ <code class="sh_declare">else</code> <code class="sh_misc">{</code>
+ <code class="sh_comment">/* Calculate the SHA1 sum of the file */</code>
+ <code class="sh_declare">union</code> <code class="sh_misc">{</code>
+ <code class="sh_declare">char</code> chr<code class="sh_misc">[</code><code class="sh_reference">20</code><code class="sh_misc">]</code><code class="sh_misc">;</code>
+ uint32_t num<code class="sh_misc">[</code><code class="sh_reference">5</code><code class="sh_misc">]</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code> digest<code class="sh_misc">;</code>
+ apr_sha1_ctx_t sha1<code class="sh_misc">;</code>
+ apr_sha1_init<code class="sh_misc">(</code><code class="sh_misc">&</code>sha1<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ readBytes <code class="sh_misc">=</code> <code class="sh_reference">256</code><code class="sh_misc">;</code>
+ <code class="sh_declare">while</code> <code class="sh_misc">(</code> apr_file_read<code class="sh_misc">(</code>file<code class="sh_misc">,</code> buffer<code class="sh_misc">,</code> <code class="sh_misc">&</code>readBytes<code class="sh_misc">)</code> <code class="sh_misc">=</code><code class="sh_misc">=</code> APR_SUCCESS <code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ apr_sha1_update<code class="sh_misc">(</code><code class="sh_misc">&</code>sha1<code class="sh_misc">,</code> buffer<code class="sh_misc">,</code> readBytes<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ apr_sha1_final<code class="sh_misc">(</code>digest<code class="sh_misc">.</code>chr<code class="sh_misc">,</code> <code class="sh_misc">&</code>sha1<code class="sh_misc">)</code><code class="sh_misc">;</code>
- <code style='color:#c34e00; '>/* Print out the SHA1 digest */</code>
- 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>
- <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>
- 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>
- <code style='color:#806030; '>}</code>
- 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>
+ <code class="sh_comment">/* Print out the SHA1 digest */</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value"><b>SHA1: </b><code></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_declare">for</code> <code class="sh_misc">(</code>n <code class="sh_misc">=</code> <code class="sh_reference">0</code><code class="sh_misc">;</code> n <code class="sh_misc"><</code> APR_SHA1_DIGESTSIZE<code class="sh_misc">/</code><code class="sh_reference">4</code><code class="sh_misc">;</code> n<code class="sh_misc">+</code><code class="sh_misc">+</code><code class="sh_misc">)</code> <code class="sh_misc">{</code>
+ ap_rprintf<code class="sh_misc">(</code>r<code class="sh_misc">,</code> <code class="sh_character">"</code><code class="sh_reference">%08x</code><code class="sh_character">"</code><code class="sh_misc">,</code> digest<code class="sh_misc">.</code>num<code class="sh_misc">[</code>n<code class="sh_misc">]</code><code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value"></code></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
- <code style='color:#c34e00; '>/* Print a link to the MD5 version */</code>
- 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>
- <code style='color:#806030; '>}</code>
- apr_file_close<code style='color:#806030; '>(</code>file<code style='color:#806030; '>)</code><code style='color:#806030; '>;</code>
+ <code class="sh_comment">/* Print a link to the MD5 version */</code>
+ ap_rputs<code class="sh_misc">(</code><code class="sh_character">"</code><code class="sh_value"><br/><a href='?digest=md5'>View the MD5 hash instead</a></code><code class="sh_character">"</code><code class="sh_misc">,</code> r<code class="sh_misc">)</code><code class="sh_misc">;</code>
+ <code class="sh_misc">}</code>
+ apr_file_close<code class="sh_misc">(</code>file<code class="sh_misc">)</code><code class="sh_misc">;</code>
- <code style='color:#806030; '>}</code>
+ <code class="sh_misc">}</code>
- <code style='color:#c34e00; '>/* Let the server know that we responded to this request. */</code>
- <code style='color:#400000; font-weight:bold; '>return</code> OK<code style='color:#806030; '>;</code>
-<code style='color:#806030; '>}</code>
-</pre>
+ <code class="sh_comment">/* Let the server know that we responded to this request. */</code>
+ <code class="sh_declare">return</code> OK<code class="sh_misc">;</code>
+<code class="sh_misc">}</code>
+</p>
<!-- END EXAMPLE CODE -->
-
+<p>
This version in its entirity can be found here:
<a href="http://people.apache.org/~humbedooh/mods/examples/mod_example_2.c">mod_example_2.c</a>.
+</p>
</section>
</section>
@@ -693,141 +722,150 @@ advanced configurations
for your modules.
</p>
<section id="config_intro"><title>An introduction to configuration
-directives</title> If you are reading this, then you probably already know
+directives</title>
+<p>
+If you are reading this, then you probably already know
what a configuration directive is. Simply put, a directive is a way of
telling an individual module (or a set of modules) how to behave, such as
these directives control how <code>mod_rewrite</code> works:
+</p>
<example><pre>
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/foo/bar
RewriteRule ^/foo/bar/(.*)$ /foobar?page=$1
</pre></example>
+<p>
Each of these configuration directives are handled by a separate function,
that parses the parameters given and sets up a configuration accordingly.
+</p>
</section>
<section id="config_simple"><title>Making an example configuration</title>
[... 1500 lines stripped ...]