php glob不匹配目录中的任何文件

I am trying to display random images from a directory, but glob keeps giving me this error:

Undefined offset: 0

Which leads me to believe that it is not matching the .png files. However shouldn't it match all files in the directory? Thanks

Code:

$banners = glob("/lib/theme/ivao/images/banners/*");
$img1 = $banners[rand(0,count($banners)-1)];

$banners is empty. So when you try to access an item, PHP returns an error.

To avoid this kinds of mistakes, do not hesitate to show your array with var_dump or print_r for example:

$banners = glob("/lib/theme/ivao/images/banners/*");
var_dump($banners);

Several reasons may explain why glob returns an empty array: PHP can perhaps not access to the directory or it may be empty or does not exist.