為什麼我的 /usr/share/file/magic 在 CentOS 的 PHP 中沒有載入？

Question

這就是我正在做的：

$ php
<?php
$finfo=finfo_open(FILEINFO_MIME, '/usr/share/file/magic');

這就是我得到的：

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

這是一個乾淨的 CentOS 5.5 安裝，PHP 5.3。該文件/usr/share/file/magic存在並且可以存取。