исходный код взят из TCPDF библиотеки
// download PDF as file
if (ob_get_contents()) {
$this->Error('Some data has already been output, can\'t send PDF file');
}
header('Content-Description: File Transfer');
if (headers_sent()) {
$this->Error('Some data has already been output to browser, can\'t send PDF file');
}
header('Cache-Control: public, must-revalidate, max-age=0'); // HTTP/1.1
header('Pragma: public');
header('Expires: Sat, 26 Jul 1997 05:00:00 GMT'); // Date in the past
header('Last-Modified: '.gmdate('D, d M Y H:i:s').' GMT');
// force download dialog
if (strpos(php_sapi_name(), 'cgi') === false) {
header('Content-Type: application/force-download');
header('Content-Type: application/octet-stream', false);
header('Content-Type: application/download', false);
header('Content-Type: application/pdf', false);
} else {
header('Content-Type: application/pdf');
}
// use the Content-Disposition header to supply a recommended filename
header('Content-Disposition: attachment; filename="'.basename($name).'";');
header('Content-Transfer-Encoding: binary');
$this->sendOutputData($this->getBuffer(), $this->bufferlen);
break;
в любом случае самая важная часть
header('Content-Disposition: attachment; filename="'.basename($name).'";');
и обратите внимание, что final ;
внутри строки, без него не будет работать