This text contains comprehensive coverage of UNIX, including basic concepts, popular utilities, shells, networking, systems programming, internals and system administration. Features include the Bourne, C and Korn shells which are described using a logical and layered approach, over 100 utilities and their common options are documented, including awk, grep, sed, vi, and emacs. There is also a fully-documented Internet Shell program, which is a shell that supports redirection and piping to other shells on remote hosts.