php获取mac用于网站绑定服务器

<?php
class GetMacAddr{ 

            var $return_array = array(); // 返回带有MAC地址的字串数组
            var $mac_addr; 

            function GetMacAddr($os_type){
                 switch ( strtolower($os_type) ){
                          case "linux":
                                    $this->forLinux();
                                    break;
                          case "solaris":
                                    break;
                          case "unix":
                                     break;
                           case "aix":
                                     break;
                           default:
                                     $this->forWindows();
                                     break; 

                  } 

                  $temp_array = array();
                  foreach ( $this->return_array as $value ){ 

                            if (
    preg_match("/[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f]/i",$value,
    $temp_array ) ){
                                     $this->mac_addr = $temp_array[0];
                                     break;
                           } 

                  }
                  unset($temp_array);
                  return $this->mac_addr;
             } 

             function forWindows(){
                  @exec("ipconfig /all", $this->return_array);
                  if ( $this->return_array )
                           return $this->return_array;
                  else{
                           $ipconfig = $_SERVER["WINDIR"]."\system32\ipconfig.exe";
                           if ( is_file($ipconfig) )
                              @exec($ipconfig." /all", $this->return_array);
                           else
                              @exec($_SERVER["WINDIR"]."\system\ipconfig.exe /all", $this->return_array);
                           return $this->return_array;
                  }
             } 

             function forLinux(){
                  @exec("ifconfig -a", $this->return_array);
                  return $this->return_array;
             } 

    }
//方法使用
$mac = new GetMacAddr(PHP_OS);
echo $mac->mac_addr;
?>