<?php
http_response_code(403);
/* setcookie() will add a response header on its own */
setcookie('foo', 'bar');
/* Define a custom response header
This will be ignored by most clients */
header("X-Sample-Test: foo");
/* Specify plain text content in our response */
header('Content-type: text/plain');
/* What headers are going to be sent? */
var_dump(headers_list());