headers_list() returns a list of headers as strings

[johnbillion]

Example return value from headers_list():

array(6) {
  [0]=>
  string(24) "X-Powered-By: PHP/8.0.19"
  [1]=>
  string(38) "Expires: Wed, 11 Jan 1984 05:00:00 GMT"
  [2]=>
  string(51) "Cache-Control: no-cache, must-revalidate, max-age=0"
  [3]=>
  string(48) "Referrer-Policy: strict-origin-when-cross-origin"
  [4]=>
  string(27) "X-Frame-Options: SAMEORIGIN"
  [5]=>
  string(38) "Content-Type: text/html; charset=UTF-8"
}

Ref: https://www.php.net/manual/en/function.headers-list.php