Introduction to Unix

The Unix operating system (OS) was developed about 30 years ago. The inspiration for Unix came from the programmers at MIT's Bell Labs, who created MULTICS. They envisioned an operating system with remarkable data sharing skills, but alas, due to its physical (hardware) limitations, this did not pan out. With similar hopes and dreams, the great computer programmers Ken Thompson and Dennis Ritchie created their brainchild UNIX (in assembly, no less) which had the ability to share files between individual users. Thus the first version of Unix was born. In their generosity, Thompson and Ritchie shared Unix with several companies, where it inspired many subsequent versions. Among them is XENIX from Microsoft, which was known for its memory sharing, improved security, text manipulation utilities, and utilities for writing code. Another one came from Santa Cruz Operation, called SCO-UNIX, which featured new improvements including random password generation and sysadmsh, which allowed an administrator to supervise the OS. Another noteworthy version is Berkeley Software Distribution, known by most computer geeks as BSD. BSD was created at UC Berkeley and made significant contributions to Unix's legacy, such as the text editor vi, a C shell, file names up to 256 characters long, and the ability to store files on remote computers.

Alas, the differences between these talented programmers inevitably generated incompatibilities between their Unix creations. Attempting to bridge the gaps, AT&T developed their own version, UNIX System V Release 4. SVR4, its more popular name, had the best qualities of its forefathers (UNIX System V Release 3, BSD, and XENIX). Furthermore, it had improved its security system to government standards and defined where the OS code ended and application code began. Further down the line came Advanced Interactive Executive, AIX. It is known as an Unix platform designed for Unix-ready hardware. AIX also has a menu-styled maintenance system called System Management Interface Tool (SMIT) and the InfoExplorer which provides all necessary Unix information online. The most recent addition to this long line of Unix systems is Linux, a smaller version of Unix meant for PCs and laptops.

To get the full joy of Unix, you need to be at a command line. The default shell for the UW's Uniform Access (UA) computers is "PSH" (for more on shells, skip ahead to shells and text editors). If you log into Dante or Homer and your screen looks something like the below, you're in PSH.

Type S to get to a command-line shell, and we'll start talking about what you can do with Unix.