File format and extension doesn't match error occurs in excel .xls using readfile(). But, output excel file in app/tmp/excel/ is not a problem. Also using chrome browser.
my code is below.
$filename = date('YmdHis').'.xls';
$upload = realpath( TMP );
$upload .= DS . 'excel' . DS;
$objWrite = new PHPExcel_Writer_Excel5($PHPExcel);
$objWrite->save($downloadPath);
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 ($fileName)).' GMT');
header('Cache-Control: private',false);
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment; filename="'.basename($fileName).'"');
header('Content-Transfer-Encoding: binary');
header('Content-Length: '.filesize($fileName)); // provide file size
header('Connection: close');
readfile($fileName);