how to delete zip file after download complete php

Question

am trying to create a zip file by php (ZipArrchive),then after user download complete i want to remove the temp created zip file , i tried to use unlink() but logically it will not work because i did not know when the users`s downloading complete , so , any help ?

i`ve tried this code :

if(file_exists('test.zip')){
    //Set Headers:
    header('Pragma: public');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Last-Modified: ' . gmdate('D, d M Y H:i:s', filemtime('test.zip')) . ' GMT');
    header('Content-Type: application/force-download');
    header('Content-Disposition: inline; filename="test.zip"');
    header('Content-Transfer-Encoding: binary');
    header('Content-Length: ' . filesize('test.zip'));
    header('Connection: close');
    readfile('test.zip');
    exit();
}

if(file_exists('test.zip')){
    unlink('test.zip');

}