Iterate over specific files in a directory

I need to get all images that begin with "t_" using glob. What pattern should I use to do this?

        //get any image files that begin with "t_" -- (t_image.jpg) not (image.jpg)
        $images = glob("" . $dir . "*.jpg");

        foreach($开发者_运维知识库images as $image)
        {
            echo $image;
        }

foreach (glob("t_*.jpg") as $filename) {
    echo "$filename size " . filesize($filename) . "\n";
}

This implies:

foreach (glob("$dir/t_*.jpg") as $filename) {
    echo "$filename size " . filesize($filename) . "\n";
}

See also:

http://ca2.php.net/manual/en/function.glob.php