'KB','D'=>'MB','E'=>'GB','F'=>'B')    *假如出错，返回false    */    function Space($arr){        //检查参数        if(is_array($arr)){            //初始化存储值            $memory = array();            foreach($arr as $disk=>$size){                $D = strtoupper($disk).':';//转化为大写的键盘路径                $S = strtoupper($size);//转变为大写的单位                if(in_array($D,array('C:','D:','E:','F:')) && in_array($S,array('B','KB','MB','GB','TB'))){                    switch($S){                        case 'B':                            $memory[$disk]= disk_free_space($D).'B';                        break;                        case 'KB':                            $d = round(disk_free_space($D) / 1024);                            $memory[$disk] = $d .'KB';                        break;                        case 'MB':                            $d = round(disk_free_space($D) / pow(1024,2));                            $memory[$disk]= $d.'MB';                        break;                        case 'GB':                            $d = round(disk_free_space($D) / pow(1024,3));                            $memory[$disk]= $d.'GB';                        break;                        case 'TB':                            $d =  sprintf("%.4f", disk_free_space($D) / pow(1024,4));                            $memory[$disk] = $d .'TB';                        break;                        default:                            return 0;                        break;                    }                }else{                    return null;                }            }            return $memory;        }else{            return null;        }    }    $arr = array('c'=>'kb','d'=>'Mb','e'=>'Gb','f'=>'Tb');    var_dump(Space($arr));

 　　根据上面获取磁盘可用空间，我们可以利用电脑的定时器进行磁盘监控，并报警磁盘的剩余空间应急

　　//要报警的磁盘和设置的单位    $di = array('c'=>'gb','d'=>'gb','e'=>'gb','f'=>'gb');    $_space = Space($di);    //应急配置    $alarm = '50GB';    $data = array();    //报警处理    foreach ($_space as $k=>$v){        //当磁盘空间小于50GB的情况        if(intval(substr($v,0,-2)) <= intval(substr($alarm,0,-2))){            $data[] = array('data'=>$k.'磁盘空间不足'.$v.'，请尽快处理');        }    }    echo json_encode($data,JSON_UNESCAPED_UNICODE);