PHP glob（）正则表达式模式

I have a folder that contains logos for sponsors. In my website, a user can belong to a sponsor and the sponsor_id is set in session when the user logs in.

Here is my code:

function sponsor_logos($sponsor_id) {
    $logos = glob("resources/content/sites/{$sponsor_id}*");

    foreach($logos as $logo) {
        if(file_exists("{$logo}"))
            echo "<img src='/{$logo}' />";
    }
}

The above works, but a sponsor can have multiple logos. So the multiple logos are saved like so: sponsor_id.jpg, sponsor_id_2.jpg, sponsor_id_3.jpg

I am not the strongest at regex, so any help is greatly appreciated! thanks!

You better open directory and check all files in it (if there are not so much files). You could do it like that:

function sponsor_logos($sponsor_id) {
    if ($dh = opendir('resources/content/sites/')) {
        while (($file = readdir($dh)) !== false) {
            if(strpos($file, $sponsor_id . '.') === 0) {
                $sponsor_files[] = $file;
            }
            else if(strpos($file, $sponsor_id . '_') === 0) {
                $sponsor_files[] = $file;
            }
        }
        closedir($dh);
    }
    foreach($sponsor_files as $logo) {
        echo "<img src='resources/content/sites/" . $logo . "' />";
    }
}

But best solution is to have normal naming scheme.

use this regex sponsor_id(_\d+)?\.jpg