It's to stop lint(1) complaining that you're not checking the return value from printf(). I see you're an old-timer here but maybe you missed out on lint: http

It's to stop lint(1) complaining that you're not checking the return value from printf(). I see you're an old-timer here but maybe you missed out on lint: http://en.wikipedia.org/wiki/Lint_(software) http://en.wikipedia.org/wiki/Lint_(software) That page says it dates from the late seventies; I was still using it mid-nineties. I don't remember the last time that I linted but today Ubuntu is lint-unaware. These days the compiler will pick up most of the things that lint used to.