> Take Unix for example. If you call close on a file descriptor you never opened, you get an error code back. If you call open and hand it a null pointer instea

> Take Unix for example. If you call close on a file descriptor you never opened, you get an error code back. If you call open and hand it a null pointer instead of a pathname? You get an error code back. Both of these are violations of a system call’s preconditions, and both are handled through the same error mechanism that handles “file not found” and other cases that can happen in a correct program. > On Hubris, if you break a system call’s preconditions, your task is immediately destroyed with no opportunity to do anything else. Oh, yeah. I've long thought EBADF and EINVALs (and EFAULT, I guess) should basically always be fatal.