getallheaders Fetch all HTTP request headers arraygetallheaders getallheaders is an alias for apache_request_headers. It will return an associative array of all the HTTP headers in the current request. Please read the apache_request_headers documentation for more information on how this function works. In PHP 4.3.0, getallheaders became an alias for apache_request_headers. Essentially, it was renamed. This is because this function only works when PHP is compiled as an Apache Module. ¬e.apache.nsapi-module; See also apache_request_headers.