<h2><a name="introduction" id="introduction">Introduction</a></h2>
<h3><a name="what" id="what">What we will be discussing in this document</a></h3>
<p>
-This document will discuss how you can easily create modules for the Apache
+This document will discuss how you can create modules for the Apache
HTTP Server 2.4, by exploring an example module called
<code>mod_example</code>. In the first part of this document, the purpose
of this module will be to calculate and print out various digest values for
<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>
+<li><code>ap_hook_quick_handler</code>: Similar to <code>ap_hook_handler</code>, except it is run before any other request hooks (translation, auth, fixups etc)</li>
+<li><code>ap_hook_log_transaction</code>: Place a hook that executes when the server is about to add a log entry of the current request</li>
</ul>
<li><code>r->args (char*):</code> Contains the query string of the request, if any</li>
<li><code>r->headers_in (apr_table_t*):</code> Contains all the headers sent by the client</li>
<li><code>r->connection (conn_rec*):</code> A record containing information about the current connection</li>
+<li><code>r->user (char*):</code> If the URI requires authentication, this is set to the username provided</li>
<li><code>r->useragent_ip (char*):</code> The IP address of the client connecting to us</li>
-<li><code>r->pool (apr_pool_t*)</code>: The memory pool of this request. We'll discuss this in the "
-<a href="#memory">Memory management</a>" chapter.</li>
+<li><code>r->pool (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
<pre class="prettyprint lang-c">
-<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, NULL, &POST, -1, 8192);
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__apr__tables.html#gad7ea82d6608a4a633fc3775694ab71e4">apr_table_t</a> *GET; <em>
+</em><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/structapr__array__header__t.html">apr_array_header_t</a>*POST;
+<em>
+</em>
+<a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__SCRIPT.html#gaed25877b529623a4d8f99f819ba1b7bd">
+ap_args_to_table</a>(r, &GET); <em>
+</em><a href="http://ci.apache.org/projects/httpd/trunk/doxygen/group__APACHE__CORE__DAEMON.html#ga9d426b6382b49754d4f87c55f65af202">
+ap_parse_form_data</a>(r, NULL, &POST, -1, 8192);
</pre>
<pre class="prettyprint lang-c">
void* merge_dir_conf(apr_pool_t* pool, void* BASE, void* ADD) {
- example_config* base = (example_config *) BASE ;
- example_config* add = (example_config *) ADD ;
- example_config* conf = (example_config *) create_dir_conf(pool, "Merged configuration");
+ example_config* base = (example_config *) BASE ; /* This is what was set in the parent context */
+ example_config* add = (example_config *) ADD ; /* This is what is set in the new context */
+ example_config* conf = (example_config *) create_dir_conf(pool, "Merged configuration"); /* This will be the merged configuration */
+ /* Merge configurations */
conf->enabled = ( add->enabled == 0 ) ? base->enabled : add->enabled ;
conf->typeOfAction = add->typeOfAction ? add->typeOfAction : base->typeOfAction;
strcpy(conf->path, strlen(add->path) ? add->path : base->path);
<div class="section">
<h2><a name="snippets" id="snippets">Some useful snippets of code</a></h2>
-<h3><a name="get_post" id="get_post">Retrieve a variable from POST form data</a></h3>
+<h3><a name="get_post" id="get_post">Retrieve variables from POST form data</a></h3>
<pre class="prettyprint lang-c">
-const char *read_post_value(const apr_array_header_t *fields, const char *key)
-{
- /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
- int i;
- apr_table_entry_t *e = 0;
- /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
- e = (apr_table_entry_t *) fields->elts;
- for(i = 0; i < fields->nelts; i++) {
- if(!strcmp(e[i].key, key)) return e[i].val;
+typedef struct {
+ const char* key;
+ const char* value;
+} keyValuePair;
+
+keyValuePair* readPost(request_req* r) {
+ apr_array_header_t *pairs = NULL;
+ apr_off_t len;
+ apr_size_t size;
+ int res;
+ int i = 0;
+ char *buffer;
+ keyValuePair* kvp;
+
+ res = ap_parse_form_data(r, NULL, &pairs, -1, HUGE_STRING_LEN);
+ if (res != OK || !pairs) return NULL; /* Return NULL if we failed or if there are is no POST data */
+ kvp = apr_pcalloc(r->pool, sizeof(keyValuePair) * (pairs->nelts + 1));
+ while (pairs && !apr_is_empty_array(pairs)) {
+ i++;
+ ap_form_pair_t *pair = (ap_form_pair_t *) apr_array_pop(pairs);
+ apr_brigade_length(pair->value, 1, &len);
+ size = (apr_size_t) len;
+ buffer = apr_palloc(r->pool, size + 1);
+ apr_brigade_flatten(pair->value, buffer, &size);
+ buffer[len] = 0;
+ kvp[i]->key = apr_pstrdup(r->pool, pair->name);
+ kvp[i]->value = buffer;
}
- return 0;
+ return kvp;
}
+
static int example_handler(request_req *r)
{
/*~~~~~~~~~~~~~~~~~~~~~~*/
- apr_array_header_t *POST;
- const char *value;
- /*~~~~~~~~~~~~~~~~~~~~~~*/
- ap_parse_form_data(r, NULL, &POST, -1, 8192);
- value = read_post_value(POST, "valueA");
- if (!value) value = "(undefined)";
- ap_rprintf(r, "The value of valueA is: %s", value);
+ keyValuePair* formData;
+ /*~~~~~~~~~~~~~~~~~~~~~~*/
+
+ formData = readPost();
+ if (formData) {
+ int i;
+ for (i = 0; formData[i]; i++) {
+ ap_rprintf(r, "%s = %s\n", formData[i]->key, formData[i]->value);
+ }
+ }
return OK;
}
</pre>
</div></div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="../en/developer/modguide.html" title="English"> en </a></p>
-</div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>This section is experimental!</strong><br />Comments placed here should not be expected
-to last beyond the testing phase of this system, nor do we in any way guarantee that we'll read them.</div>
+</div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. Comments placed here should be pointed towards suggestions on improving the documentation or server, and may be removed again by our moderators if they are either implemented or considered invalid/off-topic. Questions on how to manage the Apache HTTP Server should be directed at either our IRC channel, #httpd, on Freenode, or sent to our <a href="http://httpd.apache.org/lists.html">mailing lists</a>.</div>
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