File descriptor -> name?

[Alan Corey]

Is there a way to get the name of a file that's open when all you've 
got is a file descriptor?

I'm working on porting something, that I didn't write. with directories 
full of source.  I'm seeing a problem with an ioctl being the wrong type, 
but I'm looking at the code where it happens, I can't see what the file 
descriptor passed in is pointing to.  Seems like there should be a way.

  Alan