1 echo filesize('test.png');

 1 function transf_byte($byte) { //传入字节单位
 2     //换算
 3     $KB = 1024;
 4     $MB = $KB * 1024;
 5     $GB = $MB * 1024;
 6     $TB = $GB * 1024;
 7     if ($byte < $KB) {
 8         return $byte . 'B';
 9     } else if ($byte < $MB) {
10         //取两位小数四舍五入
11         return round($byte / $KB, 2) . 'KB';
12     } else if ($byte < $GB) {
13         return round($byte / $MB, 2) . 'MB';
14     } else if ($byte < $TB) {
15         return round($byte / $GB, 2) . 'GB';
16     } else {
17         return round($byte / $TB, 2) . 'TB';
18     }
19 }
20 //测试
21 $size = filesize('test.png');
22 echo transf_byte($size);