This is an excerpt from a book "Obfuscated C and Other Mysteries", one of the stranger programming books I've ever owned. About half the chapters are discussion

This is an excerpt from a book "Obfuscated C and Other Mysteries", one of the stranger programming books I've ever owned. About half the chapters are discussions like this one -- taking a (relatively) small, practical programming task and going into detail how to address it. There's a grab-bag of subjects, and it doesn't even adhere strictly to C, as a couple of chapters discuss the use of Tcl in C programs. The majority of the book, however, discusses the winners of the first few years of the International Obfuscated C Code Contents. He not only presents the source code and explains what they do, but he also goes into some detail (sometimes great detail) as to how they work. There's nothing else like it that I know of, and it is one of my favorite programming books of all time.