C Traps and PitfallsC Traps and Pitfalls* Andrew Koenig AT&T Bell Laboratories Murray Hill, New Jersey 07974 ABSTRACT The C language is like a carving knife: simple, sharp, and extremely useful in skilled hands. Like any sharp tool, C can injure people who don’t know how to handle it. This paper shows some of the ways C can injure the unwary, and how to avoid injury. 0. Introduction The C language and its typical implementations are designed to be used easily by experts. The language is terse and expressive. There are few restrictions to keep the user from blundering. A user who has blundered is often rewarded by an effect that is not obviously related to the cause. In this paper, we will look at some of these unexpected rewards. Because they are unexpected, it may well be impossible to classify them complet……