root/404-notifier/trunk/404-notifier.php

<?php

/*
Plugin Name: 404 Notifier
Plugin URI: http://alexking.org/projects/wordpress
Description: This plugin will log 404 hits on your site and can notify you via e-mail or you can subscribe to the generated RSS feed of 404 events. Adjust your settings <a href="options-general.php?page=404-notifier.php">here</a>.
Version: 1.2a
Author: Alex King
Author URI: http://alexking.org
*/ 

// Copyright (c) 2006-2008 Alex King. All rights reserved.
// http://alexking.org/projects/wordpress
//
// Released under the GPL license
// http://www.opensource.org/licenses/gpl-license.php
//
// This is an add-on for WordPress
// http://wordpress.org/
//
// **********************************************************************
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
// **********************************************************************

load_plugin_textdomain('404-notifier');

$_SERVER['REQUEST_URI'] = ( isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : $_SERVER['SCRIPT_NAME'] . (( isset($_SERVER['QUERY_STRING']) ? '?' . $_SERVER['QUERY_STRING'] : '')));

class ak_404 {
    var $url_404;
    var $url_refer;
    var $user_agent;
    var $mailto;
    var $mail_enabled;
    var $rss_limit;
    var $options;
    
    function ak_404() {
        if (isset($_SERVER['REQUEST_URI'])) {
            $this->url_404 = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
        }
        else {
            $this->url_404 = '';
        }
        if (isset($_SERVER['HTTP_REFERER'])) {
            $this->url_refer = $_SERVER['HTTP_REFERER'];
        }
        else {
            $this->url_refer = '';
        }
        if (isset($_SERVER['HTTP_USER_AGENT'])) {
            $this->user_agent = $_SERVER['HTTP_USER_AGENT'];
        }
        else {
            $this->user_agent = '';
        }
        $this->mailto = '';
        $this->mail_enabled = 0;
        $this->rss_limit = 100;
        $this->options = array(
            'mailto' => 'email'
            , 'mail_enabled' => 'int'
            , 'rss_limit' => 'int'
        );
    }
    
    function install() {
        global $wpdb;
        $result = $wpdb->query("
            CREATE TABLE `$wpdb->ak_404_log` (
            `id` INT( 11 ) NOT NULL AUTO_INCREMENT PRIMARY KEY ,
            `url_404` TEXT NOT NULL ,
            `url_refer` TEXT NULL ,
            `user_agent` TEXT NULL ,
            `date_gmt` DATETIME NOT NULL
            )
        ");
        add_option('ak404_mailto', $this->mailto, 'Address to send mail to.');
        add_option('ak404_mail_enabled', $this->mail_enabled, 'Send mail notifications?');
        add_option('ak404_rss_limit', $this->rss_limit, '# of items to show at once in RSS Feed');
    }
    
    function update_settings() {
        foreach ($this->options as $option => $type) {
            if (isset($_POST[$option])) {
                switch ($type) {
                    case 'email':
                        $value = stripslashes($_POST[$option]);
                        if (!ak_check_email_address($value)) {
                            $value = '';
                        }
                        break;
                    case 'int':
                        $value = intval($_POST[$option]);
                        break;
                    default:
                        $value = stripslashes($_POST[$option]);
                }
                update_option('ak404_'.$option, $value);
            }
            else {
                update_option('ak404_'.$option, $this->$option);
            }
        }

        header('Location: '.get_bloginfo('wpurl').'/wp-admin/options-general.php?page=404-notifier.php&updated=true');
        die();
    }
    
    function get_settings() {
        foreach ($this->options as $option => $type) {
            $this->$option = get_option('ak404_'.$option);
            switch ($type) {
                case 'email':
                    $this->$option = $this->$option;
                    break;
                case 'int':
                    $this->$option = intval($this->$option);
                    break;
            }
        }
    }
    
    function log_404() {
        global $wpdb;
        if (empty($this->url_404)) {
            return;
        }
        $wpdb->query("
            INSERT INTO $wpdb->ak_404_log
            ( url_404
            , url_refer
            , user_agent
            , date_gmt
            )
            VALUES
            ( '".mysql_real_escape_string($this->url_404)."'
            , '".mysql_real_escape_string($this->url_refer)."'
            , '".mysql_real_escape_string($this->user_agent)."'
            , '".current_time('mysql',1)."'
            )
        ");
        $this->mail_404();
    }
    
    function mail_404() {
        if (!empty($this->mailto) && $this->mail_enabled) {
            $to      = $this->mailto;
            $subject = '404: '.$this->url_404;
            $message = '404 Report - a file not found error was registered on your site.'."\n\n"
                .'404 URL:     '.$this->url_404."\n\n"
                .'Referred by: '.$this->url_refer."\n\n"
                .'User Agent: '.$this->user_agent."\n\n";
            $headers = 'From: '.$this->mailto . "\r\n"
                .'Reply-To: '.$this->mailto . "\r\n"
                .'X-Mailer: PHP/' . phpversion();
            
            mail($to, $subject, $message, $headers);
        }
    }

    function options_form() {
        switch ($this->mail_enabled) {
            case '1':
                $enabled = ' checked="checked"';
                break;
            case '0':
                $enabled = '';
                break;
        }
        print('
            <div class="wrap">
                <h2>'.__('404 Notifier Options', '404-notifier').'</h2>
                <form name="ak_404" action="'.get_bloginfo('wpurl').'/wp-admin/options-general.php" method="post">
                    <fieldset class="options">
                        <p>
                            <input type="checkbox" name="mail_enabled" id="ak404_mail_enabled" value="1" '.$enabled.'/>
                            <label for="ak404_mail_enabled">'.__('Enable mail notifications on 404 hits.', '404-notifier').'</label>
                        </p>
                        <p>
                            <label for="mailto">'.__('E-mail address to notify:', '404-notifier').'</label>
                            <input type="text" size="35" name="mailto" id="mailto" value="'.htmlspecialchars($this->mailto).'" />
                        </p>
                        <p>
                            <label for="rss_limit">'.__('Limit the RSS Feed to how many items?', '404-notifier').'</label>
                            <input type="text" size="5" name="rss_limit" id="rss_limit" value="'.intval($this->rss_limit).'" />
                        </p>
                        <p><a href="'.get_bloginfo('wpurl').'/wp-admin/options-general.php?ak_action=404_feed">'.__('RSS Feed of 404 Events', '404-notifier').'</a></p>
                        <input type="hidden" name="ak_action" value="update_404_settings" />
                    </fieldset>
                    <p class="submit">
                        <input type="submit" name="submit" value="'.__('Update 404 Notifier Settings', '404-notifier').'" />
                    </p>
                </form>
            </div>
        ');
    }
    
    function rss_feed() {
        global $wpdb;
        $events = $wpdb->get_results("
            SELECT *
            FROM $wpdb->ak_404_log
            ORDER BY date_gmt DESC
            LIMIT $this->rss_limit
        ");
        header('Content-type: text/xml; charset=' . get_option('blog_charset'), true);
        echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>';
?>
<rss version="2.0" 
    xmlns:content="http://purl.org/rss/1.0/modules/content/"
    xmlns:wfw="http://wellformedweb.org/CommentAPI/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
>

<channel>
    <title><?php print(__('404 Report for: ', '404-notifier')); bloginfo_rss('name'); ?></title>
    <link><?php bloginfo_rss('url') ?></link>
    <description><?php bloginfo_rss("description") ?></description>
    <pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></pubDate>
    <generator>http://wordpress.org/?v=<?php bloginfo_rss('version'); ?></generator>
    <language><?php echo get_option('rss_language'); ?></language>
<?php
        if (count($events) > 0) {
            foreach ($events as $event) {
                $content = '
                    <p>'.__('404 URL: ', '404-notifier').'<a href="'.$event->url_404.'">'.$event->url_404.'</a></p>
                    <p>'.__('Referring URL: ', '404-notifier').'<a href="'.$event->url_refer.'">'.$event->url_refer.'</a></p>
                    <p>'.__('User Agent: ', '404-notifier').$event->user_agent.'</p>
                ';
?>
    <item>
        <title><![CDATA[<?php print('404: '.htmlspecialchars($event->url_404)); ?>]]></title>
        <link><![CDATA[<?php print($event->url_404); ?>]]></link>
        <pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', $event->date_gmt, false); ?></pubDate>
        <guid isPermaLink="false"><?php print($event->id); ?></guid>
        <description><![CDATA[<?php print($content); ?>]]></description>
        <content:encoded><![CDATA[<?php print($content); ?>]]></content:encoded>
    </item>
<?php $items_count++; if (($items_count == get_option('posts_per_rss')) && !is_date()) { break; } } } ?>
</channel>
</rss>
<?php
        die();
    }
}

if (!function_exists('ak_check_email_address')) {
    function ak_check_email_address($email) {
// From: http://www.ilovejackdaniels.com/php/email-address-validation/
// First, we check that there's one @ symbol, and that the lengths are right
        if (!ereg("^[^@]{1,64}@[^@]{1,255}$", $email)) {
            // Email invalid because wrong number of characters in one section, or wrong number of @ symbols.
            return false;
        }
// Split it into sections to make life easier
        $email_array = explode("@", $email);
        $local_array = explode(".", $email_array[0]);
        for ($i = 0; $i < sizeof($local_array); $i++) {
             if (!ereg("^(([A-Za-z0-9!#$%&'*+/=?^_`{|}~-][A-Za-z0-9!#$%&'*+/=?^_`{|}~\.-]{0,63})|(\"[^(\\|\")]{0,62}\"))$", $local_array[$i])) {
                return false;
            }
        }    
        if (!ereg("^\[?[0-9\.]+\]?$", $email_array[1])) { // Check if domain is IP. If not, it should be valid domain name
            $domain_array = explode(".", $email_array[1]);
            if (sizeof($domain_array) < 2) {
                    return false; // Not enough parts to domain
            }
            for ($i = 0; $i < sizeof($domain_array); $i++) {
                if (!ereg("^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]+))$", $domain_array[$i])) {
                    return false;
                }
            }
        }
        return true;
    }
}

function ak404_log() {
    if (is_404()) {
        global $ak404;
        $ak404->log_404();
    }
}
add_action('shutdown', 'ak404_log');

function ak404_options() {
    if (function_exists('add_options_page')) {
        add_options_page(
            __('404 Notifier Options', '404-notifier')
            , __('404 Notifier', '404-notifier')
            , 10
            , basename(__FILE__)
            , 'ak404_options_form'
        );
    }
}
add_action('admin_menu', 'ak404_options');

function ak404_options_form() {
    global $ak404;
    $ak404->options_form();
}

function ak404_request_handler() {
    $ak404 = new ak_404;
    if (!empty($_POST['ak_action'])) {
        switch($_POST['ak_action']) {
            case 'update_404_settings': 
                $ak404->update_settings();
                break;
        }
    }
    if (!empty($_GET['ak_action'])) {
        switch($_GET['ak_action']) {
            case '404_feed':
                $ak404->rss_feed();
                break;
        }
    }
}
add_action('init', 'ak404_request_handler', 99);

function ak404_init() {
    global $ak404, $wpdb;
    $ak404 = new ak_404;
    $wpdb->ak_404_log = $wpdb->prefix.'ak_404_log';
    // CHECK FOR 404 NOTIFIER TABLES
    if (isset($_GET['activate']) && $_GET['activate'] == 'true') {
        $result = mysql_list_tables(DB_NAME);
        $tables = array();
        while ($row = mysql_fetch_row($result)) {
            $tables[] = $row[0];
        }
        if (!in_array($wpdb->ak_404_log, $tables)) {
            $ak404->install();
        }
    }
    $ak404->get_settings();
}
add_action('init', 'ak404_init');

function ak404_admin_head() {
    global $wp_version;
    if (isset($wp_version) && version_compare($wp_version, '2.5', '>=')) {
        print('
<style type="text/css">
fieldset.options {
    border: 0;
    padding: 10px;
}
fieldset.options p {
    margin-bottom: 10px;
}
</style>
        ');
    }
}
add_action('admin_head', 'ak404_admin_head');

?>