めも。
var_dump(apache_response_headers());
↓
array(4) {
["X-Powered-By"]=>
string(9) "PHP/5.3.3"
["Expires"]=>
string(29) "Thu, 19 Nov 1981 08:52:00 GMT"
["Cache-Control"]=>
string(62) "no-store, no-cache, must-revalidate, post-check=0, pre-check=0"
["Pragma"]=>
string(8) "no-cache"
}