Preface to the first edition
C is a general-purpose programming language with features economy of
expression, modern
flow control and data structures, and a rich set of operators. C is not a
``very high level''
language, nor a ``big'' one, and is not specialized to any particular area of
application. But its
absence of restrictions and its generality make it more convenient and effective for many
tasks than supposedly more powerful languages.
C was originally designed for and implemented on the UNIX operating system on the DEC
PDP-11, by Dennis Ritchie. The operating system, the C compiler, and essentially all UNIX
applications programs (including all
of the software used to prepare this book) are written in
C. Production compilers also exist for several other machines, including
the IBM System/370,
the Honeywell 6000, and the Interdata 8/32. C is not tied to any particular hardware or
system, however, and it is easy to write programs that will run without change on any
machine that supports C.
This book is meant to help the reader learn how to program in C. It contains a tutorial
introduction to get new users started as soon as possible, separate chapters on each major
feature, and a reference manual. Most of the treatment is based on reading, writing and
revising examples, rather than on mere statements of rules. For the most part,
the examples
are complete, real programs rather than isolated fragments. All examples have been tested
directly from the text, which is in machine-readable form. Besides showing how to make
effective use of the language, we have also tried where possible to illustrate useful
algorithms
and principles of good style and sound design.
The book is not an introductory programming manual; it assumes some familiarity with basic
programming concepts like variables, assignment statements, loops, and functions.
Nonetheless, a novice programmer should be able to read along and pick up the language,
although access to more knowledgeable colleague will help.
In our experience, C has proven to be a pleasant, expressive and versatile
language for a wide
variety of programs. It is easy to learn, and it wears well as on's experience
with it grows. We
hope that this book will help you to use it well.
The thoughtful criticisms and suggestions of many friends and
colleagues have added greatly
to this book and to our pleasure in writing it. In particular, Mike Bianchi, Jim Blue, Stu
Feldman, Doug McIlroy Bill Roome, Bob Rosin and Larry Rosler all read multiple volumes
with care. We are also indebted to Al Aho, Steve Bourne, Dan Dvorak, Chuck Haley, Debbie
Haley, Marion Harris, Rick Holt, Steve Johnson, John Mashey, Bob Mitze, Ralph Muha,
Peter Nelson, Elliot Pinson, Bill Plauger, Jerry Spivack, Ken Thompson, and Peter
Weinberger for helpful comments at various stages, and to Mile Lesk and Joe Ossanna for
invaluable assistance with typesetting.
Brian W. Kernighan
Dennis M. Ritchie