pHP语句该怎么处理
<?php$book="book.txt";
$f = fopen($book,"r+");
$msg = fread($f,filesize($book));
fclose($f);
?>
该语句就是要是BOOK。TXT为空的时候出现一个错误，就是，
Warning: fread() [function.fread]: Length parameter must be greater than 0 in E:\zhang\php\wenbenshujuku\add.php on line 17
请问，该怎么处理，谢谢各位大侠！
