How can a program measure device size in AIX?

Question

My C program mounts a raw device, then lseeks to its end to find the length. This works well in Linux and Windows, but fails in AIX - apparently you can seek to any location, even past the end. Any idea on how to do it correctly in C?

Answer 1

I've never used AIX, but have you tried using read. It may fail either at or past the end, so you could do binary search for the end using seek and read, maybe.

Answer 2

Nategoose, There must be a better way. Running "df" shows the size immediately. I don't understand why stat or fstat don't work. I even tried taking the _cnt field from the opaque FILE structure (a big no no, I know, but I'm getting desperate). It's 0.