php判断是否有权限下载

<?php
if($_GET['id']==2)
{
//$file_name = "info_check.exe";
//$file_dir = "/public/www/download/";
$dir='maze.png';
if (!file_exists($dir)) { //检查文件是否存在
echo "文件找不到";
exit;
} else {
$file = fopen($dir,"r"); // 打开文件
//$file=file_get_contents($dir);
// 输入文件标签
Header("Content-type: application/octet-stream");
Header("Accept-Ranges: bytes");
Header("Accept-Length: ".filesize($dir));
Header("Content-Disposition: attachment; filename=" . $dir);
// 输出文件内容
//echo $file;
echo fread($file,filesize($dir));
fclose($file);
exit;
}
}
else
{
echo "<mce:script type="text/javascript"><!--
history.go(-1);
// --></mce:script>";
}
?>

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