Generate simple excel file

<?php
 function xBOF() {echo pack("ssssss", 0x809, 0x8, 0x0, 0x10, 0x0, 0x0);}
 
 function xEOF() {echo pack("ss", 0x0A, 0x00);}
 
 function Number($Row, $Col, $Value) {
  echo pack("sssss", 0x203, 14, $Row, $Col, 0x0);
  echo pack("d", $Value);
 }

 function Label($Row, $Col, $Value ) {
  $L = strlen($Value);
  echo pack("ssssss", 0x204, 8 + $L, $Row, $Col, 0x0, $L);
  echo $Value;
  return;
 }
 
 header("Pragma: public");
 header("Expires: 0");
 header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
 header("Content-Type: application/force-download");
 header("Content-Type: application/octet-stream");
 header("Content-Type: application/download");;
 header("Content-Disposition: attachment;filename=result.xls");
 header("Content-Transfer-Encoding: binary");
 
 xBOF();
 Label(0, 0, "Cell A1");
 Label(0, 1, "Cell B1");
 Number(1, 0, 10); // Cell A2
 xEOF();
?>