This book is meant to help the reader learn how to program in C. It is the definitive reference guide, now in a second edition. Although the first edition was written in 1978, it continues to be a worldwide best-seller. This second edition brings the classic original up to date to include the ANSI standard. For evolution of the planet earth and our modern understanding of biology, there was Darwin's Origin of the Species. For mathematics, there was Newton's Philosophiæ Naturalis Principia Mathematica. Well, for the internet, for Facebook, for LinkedIn, Twitter, Instgram, Snapchat, WhatsApp, Pornhub and even the odious website for Justin Bieber would never have existed without Kernigan and Ritchie (more affectionately known as K&R)'s classic, The C Programming Language. What language was TCP/IP written in? C. What language inspired both C++ and Java (and the abominable C#)? C. What language are most libraries on most operating systems written in if not assembler? C.