This legendary underground classic, reproduced without modification, is really two works in one:
▪︎ the complete source code to an early version of the UNIX operating system; and
▪︎ a brilliant commentary on that code by John Lions
Dennis Ritchie, Ken Thompson, and other UNIX luminaries have contributed new essays on the enduring value of this Computer Science masterpiece.
Lions’ marriage of source code with commentary was originally used as an operating systems textbook, a purpose for which it remains well-suited. As a self-study UNIX conceptual tutorial, it has informed and inspired computer professionals and advanced operating system students for over twenty years.