The C Programming Language (book)
Encyclopedia
The C Programming Language (sometimes referred to as K&R) is a well-known 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 is regarded by many to be the authoritative reference on C.
. 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 new ANSI C standard, particularly with the inclusion of reference material on standard libraries
. The second edition (and as of 2011, the most recent edition) of the book has since been translated into over 20 languages.
ANSI C, first standardized in 1988, has since undergone several revisions, the most recent of which is ISO/IEC 9899:1999 (also known as "C99
"), adopted as an ANSI
standard in March 2000. However, no new edition of The C Programming Language has yet been issued to cover the more recent standards.
, due to the book's clear presentation and concise treatment. In just 228 pages (272 pages in the second edition), the book covers C comprehensively. Examples generally consist of complete programs of the type one is likely to encounter in daily usage of the language, with an emphasis on system programming
. The technical details of C are balanced by the authors' observations on good programming practice, which are immediately illustrated with concrete, realistic examples. As the authors write in the preface to the second edition:
Perhaps the most famous example program from the book is its "hello world
" program, which just prints out the text "hello, world" to the terminal, as an illustration of a minimal working C program. Numerous texts since then have followed that convention for introducing a programming language.
Before the advent of ANSI C
, the first edition of the text served as the de facto standard of the language for writers of C compilers. With the standardization of ANSI C, the authors more consciously geared the second edition toward programmers rather than compiler writers; in the authors' own words (again in the preface to the second edition):
The influence of The C Programming Language on programmers, a generation of whom first worked with C in universities and industry, has led many to accept the authors' programming style and conventions as recommended practice, if not normative practice. For example, the coding and formatting style of the programs presented in both editions of the book is often referred to as "K&R style" or the "One True Brace Style" and, significantly, became the coding style used by convention in the source code for the Unix
and Linux
kernels.
Book
A book is a set or collection of written, printed, illustrated, or blank sheets, made of hot lava, paper, parchment, or other materials, usually fastened together to hinge at one side. A single sheet within a book is called a leaf or leaflet, and each side of a leaf is called a page...
written by Brian Kernighan
Brian Kernighan
Brian Wilson Kernighan is a Canadian computer scientist who worked at Bell Labs alongside Unix creators Ken Thompson and Dennis Ritchie and contributed to the development of Unix. He is also coauthor of the AWK and AMPL programming languages. The 'K' of K&R C and the 'K' in AWK both stand for...
and Dennis Ritchie
Dennis Ritchie
Dennis MacAlistair Ritchie , was an American computer scientist who "helped shape the digital era." He created the C programming language and, with long-time colleague Ken Thompson, the UNIX operating system...
, the latter of whom originally designed and implemented the language, as well as co-designed the Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
with which development of the language was closely intertwined. The book was central to the development and popularization of the C programming language
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
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
De facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...
standard for the language, the book is regarded by many to be the authoritative reference on C.
History
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 RitchieDennis Ritchie
Dennis MacAlistair Ritchie , was an American computer scientist who "helped shape the digital era." He created the C programming language and, with long-time colleague Ken Thompson, the UNIX operating system...
. Brian Kernighan
Brian Kernighan
Brian Wilson Kernighan is a Canadian computer scientist who worked at Bell Labs alongside Unix creators Ken Thompson and Dennis Ritchie and contributed to the development of Unix. He is also coauthor of the AWK and AMPL programming languages. The 'K' of K&R C and the 'K' in AWK both stand for...
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
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
. 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
ANSI C
ANSI C refers to the family of successive standards published by the American National Standards Institute for the C programming language. Software developers writing in C are encouraged to conform to the standards, as doing so aids portability between compilers.-History and outlook:The first...
.
In 1988 the second edition
Edition (book)
The bibliographical definition of an edition includes all copies of a book printed “from substantially the same setting of type,” including all minor typographical variants.- First edition :...
of the book was published, updated to cover the changes to the C programming language resulting from the new ANSI C standard, particularly with the inclusion of reference material on standard libraries
C standard library
The C Standard Library is the standard library for the programming language C, as specified in the ANSI C standard.. It was developed at the same time as the C POSIX library, which is basically a superset of it...
. The second edition (and as of 2011, the most recent edition) of the book has since been translated into over 20 languages.
ANSI C, first standardized in 1988, has since undergone several revisions, the most recent of which is ISO/IEC 9899:1999 (also known as "C99
C99
C99 is a modern dialect of the C programming language. It extends the previous version with new linguistic and library features, and helps implementations make better use of available computer hardware and compiler technology.-History:...
"), adopted as an ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
standard in March 2000. However, no new edition of The C Programming Language has yet been issued to cover the more recent standards.
Influence
The C Programming Language has often been cited as a model for technical writingTechnical writing
Technical writing, a form of technical communication, is a style of writing used in fields as diverse as computer hardware and software, engineering, chemistry, the aerospace industry, robotics, finance, consumer electronics, and biotechnology....
, due to the book's clear presentation and concise treatment. In just 228 pages (272 pages in the second edition), the book covers C comprehensively. Examples generally consist of complete programs of the type one is likely to encounter in daily usage of the language, with an emphasis on system programming
System programming
System programming is the activity of programming system software. The primary distinguishing characteristic of systems programming when compared to application programming is that application programming aims to produce software which provides services to the user System programming (or systems...
. The technical details of C are balanced by the authors' observations on good programming practice, which are immediately illustrated with concrete, realistic examples. As the authors write in the preface to the second edition:
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. 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.
Perhaps the most famous example program from the book is its "hello world
Hello world program
A "Hello world" program is a computer program that outputs "Hello world" on a display device. Because it is typically one of the simplest programs possible in most programming languages, it is by tradition often used to illustrate to beginners the most basic syntax of a programming language, or to...
" program, which just prints out the text "hello, world" to the terminal, as an illustration of a minimal working C program. Numerous texts since then have followed that convention for introducing a programming language.
Before the advent of ANSI C
ANSI C
ANSI C refers to the family of successive standards published by the American National Standards Institute for the C programming language. Software developers writing in C are encouraged to conform to the standards, as doing so aids portability between compilers.-History and outlook:The first...
, the first edition of the text served as the de facto standard of the language for writers of C compilers. With the standardization of ANSI C, the authors more consciously geared the second edition toward programmers rather than compiler writers; in the authors' own words (again in the preface to the second edition):
Appendix A, 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 is a summary of the facilities of the standard library. It too is meant for reference by programmers, not implementers. Appendix C is a concise summary of the changes from the original version.
The influence of The C Programming Language on programmers, a generation of whom first worked with C in universities and industry, has led many to accept the authors' programming style and conventions as recommended practice, if not normative practice. For example, the coding and formatting style of the programs presented in both editions of the book is often referred to as "K&R style" or the "One True Brace Style" and, significantly, became the coding style used by convention in the source code for the Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
and Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
kernels.