The fun starts when you hit one of the situations where the whole php stacktrace is `in file "" at 0` (or something similar). I've got 4 php programmers around me and I hear about the "white page" almost once a week, so it's not that uncommon :(
Shutdown functions still run after a fatal error (something I just learned), so you can display the error or redirect to another page:
function shutdown() {
if (($error = error_get_last())) {
ob_clean();
// report the event, send email etc.
// Redirect
header("Location: http://hostname/error");
}
register_shutdown_function('shutdown');
There are some situations which cause PHP to just die and not log anything, but those are pretty rare.
It's pretty common practice to have display_errors to on for development, and off for production. Are you not doing that already? Or is everyone developing on production systems?
Use SplFileObject (part of SPL that is part of PHP core) for object-oriented way to manipulate files. On a failure (like your permission issue) it throws Exceptions and if not handled this will result in a "hard" error with a backtrace log.