Well suited to medium-scale general purpose computing, the Unix time-
sharing operating system is deservedly popular with academic
institutions, research laboratories, and commercial establishments
alike. Its user com- munity, until recently a brotherhood of experienced
computer profes- sionals, it now attracting many people concerned with
computer appli- cations rather than the computer systems themselves.
This book is intended for that new audience, people who have never
encountered the Unix system before but who do have some acquaintance
with computing. While helping beginning users get started is the primary
aim of this book, it is also intended to serve as a handy reference
subsequently. However, it is not designed to replace the definitive Unix
system docu- mentation. Unix operating systems now installed in
computing centers, offices, and personal computers come in three related
but distinct breeds: Seventh Edition Unix, Berkeley 4.2 BSD, and System
V. These differ from each other in details, even though their family
resemblance is strong. This book emphasizes System V, while paying heed
to its two popular cousins. It also includes a few facilities in wide
use, but not included in the normal system releases. Individual details,
of course, must be found in the manuals supplied with each system.