Check if file is a key file

[Kiefer, Sascha]

Hi you,

As i'm writing a program that automates the gnupg stuff and i want to achive
the following:
I have a file. Maybe it is a valid key file or it is not. But i want that
gnupg finds
it out for me. My idea was to use dry-run and import: if gnupg is possible
to import
something then I'm sure the file is a key file (or at least, it has an key
in it).
This works fine if the file contains just one key but if the file contains
about 1000-5000
Key,s things are getting slow. So is there a command that tests a file?

Thanks.
Sascha