feof() does not test for the actual end of a file, it tests for an exceptional condition known as end-of-file. (It's based on the C function of the same name which "tests the end-of-file indicator for the stream")
That is to say, feof() only tells you whether fread() (and friends) have run into EOF, to allow you to differentiate it from other errors. You should be testing the return value of fread() (or whatever function you're using to read), not feof().
In particular, if your filehandle is invalid (file doesn't exist / permissions issue / etc.) or fread() encounters some other error, feof will return false, and your code will be running an infinite loop processing the FALSE returned from fread().
From the (C) manpage for fread():
fread() does not distinguish between end-of-file and error, and callers
must use feof(3) and ferror(3) to determine which occurred.
That is the SOLE purpose for feof().
