PhpSpreadsheet return file instead of saving it

Question

I have generated xmlx file and I am able to save it and provide it for the user via:

$writer->save('hello world.xlsx');
header('Location: hello world.xlsx');

However, then the file remains on the hard drive. I need to get rid of it as it is a security threat.

I tried unlinking the file

unlink('hello world.xlsx');

but that deletes the file too early so the user doesn't have access to it. If it can work with unlink then I need to be sure the file will be deleted (so proper using of die(); and such)

EDIT: It is not only for security reasons anymore. The provider doesn't allow saving files so it is the only way to go.

Answer 1

Use php://output

header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment; filename="file.xls"');
$writer->save("php://output");

Answer 2

You could send the file directly after its creation, instead of the redirect to the file.

$filename = 'hello world.xlsx';
$writer->save($filename);

// Set the content-type:
header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
header('Content-Length: ' . filesize($filename));
readfile($filename); // send file
unlink($filename); // delete file
exit;