Hijack Comment Links: A Wordpress Plugin

 
<?php
/*
 
Plugin Name: Hijack Comment Links
Plugin URI: http://dfhu.org/scripts/
Description: Replace Comment Links With Links of Your Choice
Author: Victory
Version: 1.0 (really see source for right Version number)
Author URI: http://dfhu.org/
 
@author: Victory
@site: http://dfhu.org
@copyright: dfhu.org
@report_bugs: bugs(at)dfhu.org
@feature_request: features(at)dfhu.org
@file: zzz-hijack-comment-links/zzz-hijack-comment-links.php
@license: BSD
@version: 5
 
@description:
 
  This Wordpress Plugin, replaces the 'http://.*' style strings in
  comments with random urls of your choice.
 
$Date:: 2009-08-01 15:36:46 #$:
$Rev ::                      $:
 
*/
 
 
function hijack_comment_links_warning() {
  // Post a Little message to the wordpress admin to let people know
  // they have yet to update the list of links they wish to inject.
 
  echo "
<div id='dfhu-warning' class='updated fade'>
<p><strong>"
.__('Hijack Comment Links is Almost Ready.')
."</strong> "
.sprintf(__('You must 
<a href="%1$s">enter the links you want to inject</a> for it to work.'), 
	 "options-general.php?page=hijack-comment-links-group")
."</p></div>
";
}
 
function hijack_comment_links_menu() {
  // Just creat the submenu for the options.
  add_submenu_page('options-general.php',
		   'Hijack Comment Links Options', 
		   'Hijack Comment Links Options', 
		   8, 
		   'hijack-comment-links-group', 
		   'hijack_comment_links_options');   
}
 
// If the admin hasn't put any links in the yet ...
if(get_option('hjcl_links_to_inject') == ""){
  // ... then we suggest that she does so.
  add_action('admin_notices', 
	     'hijack_comment_links_warning');
}
 
// if we are admin ...
if ( is_admin() ){
  // then let us mess around with hjcl's settings
  add_action('admin_menu', 'hijack_comment_links_menu');
  add_action('admin_init', 'hijack_comment_links_settings' );
}
 
function hijack_comment_links_settings(){
  // register the links, nofollow and retro settings
  register_setting('hijack-comment-links-group', 
		   'hjcl_links_to_inject');
  register_setting('hijack-comment-links-group', 
		   'hjcl_remove_nofollow');
  register_setting('hijack-comment-links-group', 
		   'hjcl_retro');
}
 
 
function hijack_comment_links_options() { 
  // The Options Page for HJCL
  ?>
  <h2>Hijack Comment Links Options</h2>
  <form method="post" action="options.php">
    <input type="hidden" name="action" value="update" />
 
    <input 
  type="hidden"
  name="page_options" 
  value="hjcl_links_to_inject,hjcl_remove_nofollow,hjcl_retro"/>
 
    <?php wp_nonce_field('update-options');  
         settings_fields('hijack-comment-links-group' );
    ?>
 
    <table class="form-table">
 
      <tr>
	<th scope="row">
Enter <b>1</b> To Remove nofollow,
<b>0</b> To Keep nofollow.
	</th>
	<td>
	  <input 
	     type="text" 
	     name="hjcl_remove_nofollow" 
	     value="<?php 
echo intval(get_option('hjcl_remove_nofollow')); 
           ?>">
	</td>
      </tr>
 
      <tr>
	<th scope="row">
Enter <b>1</b> To Effect Links Retroactively (not recommended), 
<b>0</b> To just inject on new posts.
	</th>
	<td>
	  <input 
	     type="text" 
	     name="hjcl_retro" 
	     value="<?php 
echo intval(get_option('hjcl_retro')); 
           ?>">
	</td>
      </tr>
 
 
 
      <tr valign="top">
	<th scope="row">
	  <b>List of URLs to Inject. One Per Line.</b> 
	</th>
	<td>
	  <textarea 
	     cols="80"
	     rows="30"
             name="hjcl_links_to_inject"><?php
$hjcl_links=explode("\n",get_option('hjcl_links_to_inject'));
if(count($hjcl_links) < 3){
 echo "http://dfhu.org/
http://dfhu.org/blog/\n";
}
foreach($hjcl_links as $hjcl){  
  echo trim($hjcl) . "\n";
 
}
          ?></textarea>
	</td>
      </tr>
 
    </table>
 
    <p class="submit">
      <input type="submit" 
	     class="button-primary" 
	     value="<?php _e('Save Changes') ?>" />
    </p>
 
  </form>
</div>
 
<?php
}
 
 
function hijack_comment_links($comment){
  /* 
     Searches through the comment text for and replaces them with one
     of your preset http(s) urls
  */
 
  // really small comments dont, have links, so ...
  if(strlen($comment) < 15){
    // we can just return the comment as is
    return $comment;
  }
 
 
  // We want to seed the random generator. We use the sum of the
  // Ordinal of the 2nd 12th,14th and 10th letters of the comment, why
  // those numbers?
 
  // we want to store the old seed, so that we can re-randomize the
  // PRG again.
  $o_seed=rand();
  srand(
   array_sum(
    array_map(
     'ord',
     array($comment[1],
	   $comment[11],
	   $comment[13],
	   $comment[10]))));
 
  // The links are stored, one per line, so we explode over the
  // newline char.
  $links=explode("\n",get_option('hjcl_links_to_inject'));
 
  // Lets make sure we have links, but if we dont ...
  if(!is_array($links)){
    // ... then just return the comment as is.
    return $comment;
  }
 
  // hey! we have links, long comments, lets get a random url
  $link=$links[array_rand($links)];
 
  // hey random number generator, here is your seed back.
  srand($o_seed); 
 
 
  // We can check to see if we are going get all crazy and remove no
  // follows, so our link juice sales.
  if(get_option('hjcl_remove_nofollow') == 1){
    // link juice be sailing, so nofollow is a no gone.
    $comment=preg_replace("/nofollow/","",$comment);
  }
 
  // the most flawless regex ever created by mankind to catch a
  // http(s) url, /sarcasm. If you don't like this regex you can
  // spruce it up to your likings. Or maybe you could do something
  // with var_filter(), or whatever makes you happy, for me, here is
  // the the regex.
  $r=';https?://[^" ]+;';
 
  // Now just replace all the urls in the comment with our url of
  // random choice.
  return preg_replace($r,$link.'"',$comment);
}
 
 
// Before the links get iserted we hijack the links if any. We call as
// the very last step, before the comment gets packed into the db.
add_filter('preprocess_comment', 'hijack_comment_links', 100);
 
 
// If you want the injection to work retroactively on old posts, This
// will results in links being randomized everytime you edit your
// injected link list, its not recommened.
 
/**/
if(get_option('hjcl_retro') == 1){
  add_filter('comment_text', 'hijack_comment_links', 100);
  add_filter('comment_text_rss', 'hijack_comment_links', 100);
  add_filter('comment_excerpt', 'hijack_comment_links', 100);
}
/**/
 
?>