以下是关于php fread()函数报错的代码！有无高手指点一下哦！

Question

Warning: fread() [function.fread]: Length parameter must be greater than 0 in E:\xampp\xampp\htdocs\temp\index.php on line 4
fread()函数报错·<?php
$dir = "../huion/cache/array_cache/index/template_data.cache.php";
$fp = fopen($dir,"w");
$data = fread($fp,filesize($dir));
fclose($fp);
?> 这是源代码

Answer 1

$dir = "../huion/cache/array_cache/index/template_data.cache.php";这个文件是空的 或者不存在吧

Answer 2

$data = ($filesize = filesize($dir)) ? fread($fp, $filesize) : "";