Index Preface to the First Edition

The computing world has undergone a revolution since the publication of The C Programming Language in 1978. Big computers are much bigger, and personal computers have capabilities that rival mainframes of a decade ago.

Preface The Computing World Has Changed

During this time, C has changed too, although only modestly, and it has spread far beyond its origins as the language of the UNIX operating system. The growing popularity of C, the changes in the language over the years, and the creation of compilers by groups not involved in its design, combined to demonstrate a need for a more precise and more contemporary definition of the language than the first edition of this book provided.

ANSI Standard for C

The result is the ANSI standard for C. This standard formalizes constructions that were hinted but not described in the first edition, particularly structure assignment and enumerations. It provides a new form of function declaration that permits cross-checking of definition with use. It specifies a standard library, with an extensive set of functions for performing input and output, memory management, string manipulation, and similar tasks.

The Impact on Modern Computing

This Second Edition of The C Programming Language describes C as defined by the ANSI standard. Although we have noted the places where the language has evolved, we have chosen to write exclusively in the new form. For the most part, this makes no significant difference; the most visible change is the new form of function declaration and definition.

Modern Computing and C

Modern compilers already support most features of the standard. We have tried to retain the brevity of the first edition. C is not a big language, and it is not well served by a big book. We have improved the exposition of critical features, such as pointers, that are central to C programming.

Refining the Language

We have refined the original examples, and have added new examples in several chapters. For instance, the treatment of complicated declarations is augmented by programs that convert declarations into words and vice versa. As before, all examples have been tested directly from the text, which is in machine-readable form.

Appendix A: The Reference Manual

The reference manual is not the standard, but our attempt to convey the essentials of the standard in a smaller space. It is meant for easy comprehension by programmers, but not as a definition for compiler writers – that role properly belongs to the standard itself.

Appendix B: Facilities of the Standard Library

This appendix provides a concise summary of the facilities of the standard library. It too is meant for reference by programmers, not implementers.

Appendix C: Changes from the Original Version

As we said in the preface to the first edition, C "wears well as one's experience with it grows". With a decade more experience, we still feel that way. We hope that this book will help you learn C and use it well.