redirect 404 ke search wordpress

<?php
function ganti_setiap_karakter($minta) {
        $minta = htmlspecialchars($minta);
                $minta = str_replace('/search/', '', $minta);
        $minta = str_replace('/', '', $minta);
        $minta_a = explode(' ',$minta);
        $minta_baru = array();
        foreach ($minta_a as $baru) {
            $minta_baru[] = ucwords(trim($baru));
        }
        $minta = implode(' ', $minta_baru);
        return $minta;
    }
?>
<?php
if($_SERVER['REQUEST_URI']){
$gantikode = array (' ','++','+++','-');
$urlredirect = get_settings('home') . '/article/' . strtolower(str_replace($gantikode, '-' ,ganti_setiap_karakter($_SERVER['REQUEST_URI']))) . '/';
header("HTTP/1.1 301 Moved Permanently");
header( "Location: $urlredirect" ) ;
die();
}
?>