The Unix Programming Environment, first published in 1984 by Prentice Hall

Prentice Hall

Prentice Hall is a major educational publisher. It is an imprint of Pearson Education, Inc., based in Upper Saddle River, New Jersey, USA. Prentice Hall publishes print and digital content for the 6-12 and higher-education market. Prentice Hall distributes its technical titles through the Safari...

, is a book written by Brian W. Kernighan and Rob Pike, both of 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...

 and considered an important and early document of 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...

.

The book starts off with an introduction to Unix for beginners. Next, it goes into the basics of the file system

Unix File System

The Unix file system is a file system used by many Unix and Unix-like operating systems. It is also called the Berkeley Fast File System, the BSD Fast File System or FFS...

 and shell

Unix shell

A Unix shell is a command-line interpreter or shell that provides a traditional user interface for the Unix operating system and for Unix-like systems...

. The reader is led through topics ranging from the use of filters

Filter (Unix)

In Unix and Unix-like operating systems, a filter is a program that gets most of its data from its standard input and writes its main results to its standard output . Unix filters are often used as elements of pipelines...

, to how to use C

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....

 for programming robust Unix applications, and the basics of grep

Grep

grep is a command-line text-search utility originally written for Unix. The name comes from the ed command g/re/p...

, sed

Sed

sed is a Unix utility that parses text and implements a programming language which can apply transformations to such text. It reads input line by line , applying the operation which has been specified via the command line , and then outputs the line. It was developed from 1973 to 1974 as a Unix...

, make, and awk

AWK (programming language)

The AWK utility is a data extraction and reporting tool that uses a data-driven scripting language consisting of a set of actions to be taken against textual data for the purpose of producing formatted reports...

. The book closes with a tutorial on making a programming language parser with yacc

Yacc

The computer program yacc is a parser generator developed by Stephen C. Johnson at AT&T for the Unix operating system. The name is an acronym for "Yet Another Compiler Compiler." It generates a parser based on an analytic grammar written in a notation similar to BNF.Yacc used to be available as...

 and how to use troff

Troff

troff is a document processing system developed by AT&T for the Unix operating system.-History:troff can trace its origins back to a text formatting program called RUNOFF, written by Jerome H. Saltzer for MIT's CTSS operating system in the mid-1960s...

 with ms and mm

Troff macro

The troff typesetting system includes sets of commands called macros that are run before starting to process the document. These macros include setting up page headers and footers, defining new commands, and generally influencing how the output will be formatted.The command-line argument for...

 to format documents, the preprocessors tbl

Tbl

Part of the troff suite of Unix document layout tools, tbl is a preprocessor that formats tables.Like the main troff program, tbl uses command lines interspersed with data to be printed...

, eqn

Eqn

Part of the troff suite of Unix document layout tools, eqn is a preprocessor that formats equations for printing. A similar program, neqn, accepted the same input as eqn, but produced output tuned to look better in nroff...

, and pic

Pic language

In computing, Pic is a domain-specific programming language by Brian Kernighan for specifying diagrams in terms of objects such as boxes with arrows between them. The pic compiler translates this description into concrete drawing commands. Pic is a procedural programming language, with variable...

, and making man pages with the man macro set. The appendices cover the ed editor

Ed (text editor)

ed is a line editor for the Unix operating system. It was one of the first end-user programs hosted on the system and has been standard in Unix-based systems ever since. ed was originally written in PDP-11/20 assembler by Ken Thompson in 1971...

 and the abovementioned programming language, named hoc

Hoc (programming language)

hoc, an acronym for High Order Calculator, is an interpreted programming language that was used in the 1984 book The Unix Programming Environment to demonstrate how to build interpreters using Yacc....

, which stands for "high-order calculator".

The book is perhaps most valuable for its exposition of the Unix philosophy

Unix philosophy

The Unix philosophy is a set of cultural norms and philosophical approaches to developing software based on the experience of leading developers of the Unix operating system.-McIlroy: A Quarter Century of Unix:...

 of small cooperating tools with standardized inputs and outputs, a philosophy that also shaped the end-to-end philosophy of the Internet. It is this philosophy, and the architecture based on it

Unix architecture

A Unix architecture is a computer operating system system architecture that embodies the Unix philosophy. It may adhere to standards such as the Single UNIX Specification or similar POSIX IEEE standard...

, that has allowed open source projects to be assembled into larger systems such as 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...

, without explicit coordination between developers.

The book was written before 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...

 was first drafted, therefore the programs in the book are nonstandard and follow K&R style. However, the source code available on the book's website has been updated for ANSI C conformance (but uses the implicit int rule, which is disallowed in 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:...

).

ISBN 0-13-937681-X (paperback), 0-13-937699-2 (hardback).