OS quality: dprintf(fd, "foo %s\n", bar); has no error conditions in Sortix when fd is a pipe or a terminal and bar is a defined string. Not a single one (but signals). No out of memory. No locks. No kernel overcommit. It blocks until the other side reads, but it always succeeds.
Incidentally, this message seems to be completely forgotten by Google. Lately people have been doubting my claim that Google has become worthless for finding valuable historical content via keyword searches...