Distinguishing between ISO9660 and UDF

Hello,

Is there a way to figure out if a CD has ISO9660 or UDF filesystem on it without mounting? I am looking for something like say "string starting at 65432 should say udf" or something similar.

I am writing a program which is potentially operated by nontechnical people, and all they need to do is to pop in the CD, provide a name, and hit enter. Then the program does everything from here including mounting the CD, reading, unmounting, and ejecting.

The problem is that we get CDs from all over the world, written with a myriad of software, and a lot of them are written incorrectly. I need to handle all of them.

One way to ignore the ISO9660-UDF difference is to have udf,iso9660 inetc-fstab, but it doesn't always work. We just came across some CDs which hang if I try to mount as udf (shut down after 10 minutes) instead of timing out relatively quickly. Going the other way, having iso9660,udf in fstab doesn't work either since I can mount udf as iso9660, but later I will get a read error. I can work my way around it, say "mount iso, read, if error remount udf ...", but I would like a cleaner solution.

So is there an easy way to distinguish between UDF and ISO9660? If yes how?

Thanks, Vilmos