这就是我正在做的事情：
$ php
<?php
$finfo=finfo_open(FILEINFO_MIME, '/usr/share/file/magic');
这就是我得到的：
PHP Notice: finfo_open(): Warning: description `8-bit ISDN mu-law compressed (CCITT G.721 ADPCM voice data enco' truncated in - on line 2
PHP Notice: finfo_open(): Warning: description `8-bit ISDN mu-law compressed (CCITT G.721 ADPCM voice data enco' truncated in - on line 2
PHP Notice: finfo_open(): Warning: <= not supported in - on line 2
PHP Notice: finfo_open(): Warning: <= not supported in - on line 2
PHP Notice: finfo_open(): Warning: <= not supported in - on line 2
PHP Notice: finfo_open(): Warning: >= not supported in - on line 2
PHP Warning: finfo_open(): Failed to load magic database at '/usr/share/file/magic'. in - on line 2
这是干净的 CentOS 5.5 安装，PHP 5.3。该文件/usr/share/file/magic存在并且可以访问。