gistfile1.txt

$url = parse_url($_SERVER["SCRIPT_URI"]);
$apath = explode("/", $url['path']);

if ( (
    $_SERVER['HTTP_HOST'] == "mktg-dev.apigee.com" || 
    $_SERVER['HTTP_HOST'] == "mktg-stg.apigee.com" || 
    $_SERVER['HTTP_HOST'] == "apigee.com" 
  ) && (
    $apath[1] != "about"
  )){
    header("location: /about");
  }