PHP获取MAC地址的类库代码：

<?php  
    /**  
    获取网卡的MAC地址原码；目前支持WIN/LINUX系统  
    获取机器网卡的物理（MAC）地址  
    **/ 
         
    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;  
?>