filter karater \|#

<?php
$user = $_POST["user"];
$pass = $_POST["pass"];
if(in_array($user,[hex2bin("5c"),"|","#"]) or in_array($pass,[hex2bin("5c"),"|","#"])){
echo "Maaf karakter tidak diijinkan";
}else{
//echo "welcome";
/* proses login */
}
?>