WordPress search keyword blocker

block-keywords.php

<?php

/* Add this function to theme functions.php */

add_filter( 'pre_get_posts', 'rlv_block_search' );
function rlv_block_search( $query ) {
  if (!empty($query->query_vars['s'])) {
    $blacklist = array( '大奖', 'q82' ); // add blacklist entries here; no need for whole words, use the smallest part you can
    foreach( $blacklist as $term ) {
      if( mb_stripos( $query->query_vars['s'], $term ) !== false ) exit();
    }
  }
}

/* Stop here */

?>