The author should've been wary of strncpy, because his solution is wrong. "If there is no null byte among the first n bytes of src, the string placed in dest w

The author should've been wary of strncpy, because his solution is wrong. "If there is no null byte among the first n bytes of src, the string placed in dest will not be null-terminated." So copying sizeof(dest)-1 will not append a NULL byte as the author implies. You'll have to do that manually.