Stephen Rago's update is a long overdue benefit to the community of professionals using the versatile family of UNIX and UNIX-like operating environments. It removes obsolescence and includes newer developments. It also thoroughly updates the context of all topics, examples, and applications to recent releases of popular implementations of UNIX and UNIX-like environments. And yet, it does all this while retaining the style and taste of the original classic. Stephen Rago's update is a long overdue benefit to the community of professionals using the versatile family of UNIX and UNIX-like operating environments. It removes obsolescence and includes newer developments. It also thoroughly updates the context of all topics, examples, and applications to recent releases of popular implementations of UNIX and UNIX-like environments. And yet, it does all this while retaining the style and taste of the original classic.