这就是我正在做的事情：
$ php <?php $finfo=finfo_open(FILEINFO_MIME, '/usr/share/file/magic'); 这是我得到的：
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
这是一个干净的CentOS 5.5安装，PHP 5.3。 文件/usr/share/file/magic存在并且可以访问。