PHP Fileinfo获取文件MIME类型

<?php

//Create a new fileinfo resource
$finfo = finfo_open(FILEINFO_MIME); 

$filename = "test.txt";

//Return information about a file
echo finfo_file($finfo, $filename);

//Close fileinfo resource
finfo_close($finfo);

/** 面向对象风格 */
$finfo = new finfo(FILEINFO_MIME); 

$filename = "test.txt";
echo $finfo->file($filename);