在不知道PHP扩展名的情况下查找文件

I have a bunch of uniquely named images with different extensions, if I have one of the unique names, but I don't know the extension (it's an image extension), how can I find the image extension as fast as possible? I've seen other people doing this by searching all possible file extensions on that file name, but it seems too slow to try and load 6 different possible combinations before bringing up the original image.

Does anyone know an easier way?

You could use glob for this. Might not be the best solution but it is simple;

The glob() function searches for all the pathnames matching pattern according to the rules used by the libc glob() function, which is similar to the rules used by common shells.

$files = glob('filenamewithoutextension.*');
if (sizeof($files) > 0) {
    $file = $files[0]; // Might be more than one hit however we are only interested in the first one?
}

After getting the filename you can use pathinfo to get the specific extension.

$extension = pathinfo($file, PATHINFO_EXTENSION);