The C Programming Language

The C Programming Language (sometimes referred to as K&R, after its authors' initials) is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the language, as well as co-designed the Unix operating system with which development of the language was closely intertwined. The book was central to the development and popularization of the C programming language and is still widely read and used today. Because the book was co-authored by the original language designer, and because the first edition of the book served for many years as the de facto standard for the language, the book was regarded by many to be the authoritative reference on C.

The first edition of the book, published in 1978, was the first widely available book on the C programming language. C was created by Dennis Ritchie. Brian Kernighan wrote the first C tutorial. The authors came together to write the book in conjunction with the language's early development at AT&T Bell Labs. The version of C described in this book is sometimes referred to as K&R C (after the book's authors), often to distinguish this early version from the later version of C standardized as ANSI C.

In 1988, the second edition of the book was published, updated to cover the changes to the C programming language resulting from the then-new ANSI C standard, particularly with the inclusion of reference material on standard libraries. The second edition (and as of 2016, the most recent edition) of the book has since been translated into over 20 languages. In 2012 an eBook version of the second edition was published in ePub, Mobi, and PDF formats.

ANSI C, first standardized in 1989 (as ANSI X3.159-1989), has since undergone several revisions, the most recent of which is ISO/IEC 9899:2011 (also known as "C11"), adopted as an ANSI standard in October 2011. However, no new edition of The C Programming Language has been issued to cover the more recent standards.

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