Unix Overview (main)

Unix Applications

Shortcuts and Operators

Command Summary (in Guide, PDF)

Working on UNIX (in Guide, PDF)

Unix was the original operating system for Eos/Unity and has been supported for more than a decade as our principal platform. A mainstay of high-end computational computing, Unix is powerful, secure, and robust.

Unix and its applications are not widely known in the world of personal computing, which mainly belongs to Microsoft. However, educating students in computing technology means exposing them to operating environments they do not already know. Also, much high-end engineering computing runs on Unix.

Linux, a Unix variant for the Intel PC, is a recent addition to Eos/Unity and shares the strengths of Unix, but is cheaper, open source, and an alternative environment for academic computing on campus.

Unix on Eos: Sun Solaris

Unix on Eos/Unity is Sun Solaris, running on one-third of the workstations in the Eos labs (200+) and nearly 120 workstations in public Unity labs. In the past, Eos/Unity supported several Unix OSes but has lately standardized on one. Any Sun workstation you see in the labs runs Solaris/Unix. The campus computing infrastructure is also built on Sun Solaris, with AFS, Linux, and Windows interoperating with its services.

TCP/IP, the central Internet protocol, has been at the core of Solaris networking since its inception. Solaris scales to handle heavy network traffic, compute-intensive problems, and large numbers of devices and users. For more on Solaris, see the datasheet at the Sun Solaris web site.

X Window System and fvwm2 Window Manager

The fvwm2 Window Manager is the Graphical User Interface (GUI) on Unix, giving it its "look and feel" and standardizing the way applications are presented on-screen. It runs under the X Window System, developed in the MIT Athena Project. X's windowing system is the Unix equivalent of Microsoft Windows, providing the display and managing the graphical information that users see.

When a user successfully logs in to the Sun Unix workstation, the login screen disappears and a default screen takes its place. While not very colorful or inviting, the default interface is a clean "desktop" where the user works. The interface does not have to remain unexciting if the user wants to customize it . The settings are saved out to the user's AFS space, so no matter where the user logs in, the customized environment is downloaded to the workstation.

The gray background defines an area called the root window. The small window that first appears in the upper left corner of the screen is called the console window. It monitors the user's session and what goes on in the system. Users do not work in the console window; rather, they should watch it closely for messages and other information. Warning: Closing the console window will log you off!

Command Line Interpreter

The users' interaction with the operating system can take place via a command interpreter (or shell), which runs in a terminal window on the screen. The shell surrounds the kernel, which is the core programming that is responsible for machine-level operation and connection to hardware devices.

The Xterm window is the terminal window that appears in the center of the screen. It contains a shell prompt, which is the location of the command line where Unix commands may be typed into the system. These commands are interpreted, executed, and passed on to the Unix operating system by a shell program, which controls the user's interactions with the operating system. The shell prompt tells which shell the system is running. The percent sign ( % ) means that Eos/ Unity runs a C shell (csh).

Documentation: Unix Man(ual) Pages

Information is available online in documentation called "man pages" to explain how to use Unix commands. Man pages are reference pages that experienced users of Unix find useful, but which the beginner may find difficult to use.

A separate man page exists for every command. The man command followed by the name of a Unix command will bring up that command's man page. Most man pages provide the following information:

• Name: a simple definition of the command.
• Syntax: the correct way to type the command and its options and arguments.
• Description: a longer explanation of how to use the command and in what situations.
• Options: the options (characters or terms preceded by a hyphen) that may be combined with the command and what effect they have.
• Restrictions: known limitations on the use of the command.
• See Also: a list of cross-references to other commands that are related to or can shed light on the use of the command.
  

Commands are numbered by the type of command they are:

1 User Commands
2 System Commands
3 Library Calls
4 Devices
5 File Systems
6 Games
7 Miscellaneous
8 System Administration
l Local Commands
n New Commands

Most commands that the general user encounters will be of the (1) User Command variety, so this is the default. Some commands, such as chmod, have multiple usages, chmod (1), chmod (2) and chmod (3f).

To look up a set of commands of a particular type, use man with the option -k for keyword, which lets you to specify a keyword to search for. For more information on the man command, a logical place to look is man man, which displays the Unix manual page on man itself.

man -k keyword
man man

See also Files and Commands and Managing Directories.

Definitions

AFS
Athena Project
console window
C shell
default
distributed file system
graphical user interface
icon
kernel
man pages
multitasking
operating system
prompt
TCP/IP
terminal
server
shell
Unix
window manager
X Window System

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College of Engineering, North Carolina State University, Raleigh, NC 27695
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