How do you determine the size of a file in C?

Question

How can I figure out the size of a file, in bytes?

#include 

unsigned int fsize(char* file){
  //what goes here?
}

Answer 1

A quick search in Google found a method using fseek and ftell and a thread with this question with answers that it can't be done in just C in another way.

You could use a portability library like NSPR (the library that powers Firefox) or check its implementation (rather hairy).