Hello Gil, I'm going to ask the obvious just in case :-)
In this line:
open(FILE, "/path/to/file.ext") or die("Couldn't open the file.");
You have replaced /path/to/file.ext with the actual path & filename, right?
In this line:
open(FILE, "/path/to/file.ext") or die("Couldn't open the file.");
You have replaced /path/to/file.ext with the actual path & filename, right?