<?php

$codes = array();
$headers = explode("\n","HTTP/1.1 100 Continue
HTTP/1.1 302 Found
HTTP/1.1 200 OK
HTTP/1.1 400 Not Found");

foreach ($headers AS $header) {
    list($http, $code, $status) = explode(" ", $header, 3);
    $codes[$code] = $status;
}

print_r($codes);

?>