如何在php的exeoutput中获取系统mac地址

Question

Recently I have Purchase exeoutphp software in that I want to get user's system mac address, Note: below code working fine in wampserver

<?php 

 // Turn on output buffering
 ob_start();
 //Get the ipconfig details using system commond
 system('ipconfig /all');
 // Capture the output into a variable
 $mycom=ob_get_contents();
 // Clean (erase) the output buffer
 ob_clean();
 $findme = "Physical";
 //Search the "Physical" | Find the position of Physical text 
 $pmac = strpos($mycom, $findme);
// Get Physical Address
 echo $mac=substr($mycom,($pmac+36),17);
 //Display Mac Address

 ?>

Error Message: PHP Error: PHP Warning: system(): Unable to fork [ipconfig /all].

Please help me.

Thanks !!