  |
| |
* (Asterisk)
Unix metacharacter that represents any string of zero or more characters.
\ (Backslash)
Unix metacharacter that keeps the shell from interpreting other metacharacters,
allowing them to represent themselves. Also used at the end of line to
indicate
command continues on next line.
^ (Circumflex)
Unix metacharacter used to correct errors in the previous command line.
# (Number Sign)
Unix character, sometimes called a pound sign, often used as the first
character in the name of a temporary file.
? (Question Mark)
Unix metacharacter that represents any single character.
/ (Slash)
Symbol for the root directory. Also used to separate parts of a pathname.
~ (Tilde)
Unix metacharacter representing your home directory or, when preceding
a user's login name, that user's home directory. Also, in vi, a symbol
for empty lines in
a file, and a command to change the case of the current character.
| (Vertical Bar)
Unix metacharacter, referred to as a pipe, that tells the shell to
use the output of one command as the input of another.
< (Left Angle Bracket)
Unix metacharacter that tells the shell to use a file as the input
for a command.
> (Right Angle Bracket)
Unix metacharacter that tells the shell to send the output of a command
to a file.
10-Base 2
A type of ethernet that uses coaxial cable as the medium.
10-Base T
A type of ethernet that uses twisted pair wiring as the transport media.
10-base T is unreliable over long distances. Point-to-Point media.
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Absolute Pathname
A directory path expressed in relation to the Unix root directory.
Active Window
The window in an X Window environment in which what you type appears.
If there is no active window, what you type is lost. Only one terminal
window can
be active at a time.
alias
An alternate name for a command or entire command line. Also, in mail,
a distribution list that contains names of one or more users.
AppleTalk
Local Area Network based on phone wire and small transformers to interconnect
Macintosh computers.
ASCII
American Standard Code for Information Exchange: a standard for data
transmission that is used in the Unix system. ASCII assigns sets of 0s
and 1s to
represent 128 characters, including alphabetical characters, numerals,
and standard special characters, such as #, $,%, and &.
Baud Rate
A measure of the speed of data transfer from a computer to a peripheral
device (such as a terminal) or from one device to another. Common baud
rates are
300, 1200, 4800, 9600. As a general guide, divide a baud rate by 10
to get the approximate number of English characters transmitted each second.
Bernoulli
Type of removable storage. A "Bernoulli box" can write cartridges for
either PCs or Macintoshes.
\bin
A descendant of the Unix root directory that contains many of the programs
that make up the ULTRIX system.
Bourne Shell
One of the shells available in the Unix operating system. The Bourne
shell was developed by AT&T.
Broadcast
A message sent to all computers on a network.
BSD
Berkeley Software Distribution, the version of Unix originating at
the University of California at Berkeley.
C++
An object-oriented programming language.
C Shell
One of the shells available in the Unix operating system. The C shell
was developed by the University of California at Berkeley.
Click
To press and release a mouse button. The term comes from the fact that
pressing and releasing the buttons of most mice makes a clicking sound.
Command
An instruction that makes the computer perform some operation.
.cshrc
In Unix, a file containing commands that set up your shell environment.
CTRL Command
A command you give by holding down the CTRL key while pressing another
key.
CTRL-d
The command that kills the foreground process. Also, when your terminal
is being used as standard input, the command that signals the end of your
input.
CTRL-h
The command that backspaces.
CTRL-l
The command that refreshes the screen in the vi editor.
CTRL-q
The command that resumes scrolling (if flow control is enabled).
CTRL-r
The command that redisplays partially typed commands.
CTRL-s
The command that stops scrolling (if flow control is enabled).
CTRL-z
The command that stops the foreground process.
DAT
Digital Audio Tape, 4mm tape technology.
DEC
Digital Equipment Corporation. Manufactures computers and workstations
that run either the VMS or Ultrix (Unix) operating systems.
DECnet
A Local Area Network (LAN) of DEC computers running the VMS operating
system.
DECwindows
An environment that uses menus and multiple windows instead of single
terminal screen.
DEL Key
The key that erases other keystrokes.
Dicomed
SCD's film output device that supports fiche, microfilm, and movies
in color or black and white.
Directory
A file that contains other files.
Diskette
Removable storage for PCs, Macintoshes, and workstations, either 3.5"
or 5.25" in size.
Double Click
To press and release a mouse button twice in rapid succession.
Drag
To press and hold down a mouse button while moving the mouse on the
desktop (and the pointer on the screen). Typically, dragging is used with
menu selecting,
window moving, and resizing.
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emacs
A powerful screen editor for use in the Unix environment.
Environment
The conditions under which you work while using the Unix system. Your
environment includes those things that personalize your login and allow
you to interact in
specific ways with the Unix or other operating system. For example,
your shell environment includes such things as your shell prompt string,
specifics for
backspace and erase characters, and commands for sending output from
your terminal to the computer.
ESC Key
In vi, the key you press to signal the end of the text insertion. If
your terminal does not have an ESC key, use CTRL-[ instead.
Ethernet
Physical hardware medium for transmission of various networking protocols.
Ethernet Terminal Server
A machine that allows users to log in via the PACX to connect to other
machines via ethernet.
Ethertalk
Software for sending AppleTalk packets on an ethernet network.
Exabyte
Type of 8-mm tape drive used for archiving data.
Execute
The computer's action of running a program or command and performing
the indicated operations.
File Server
Type of computer designed to be a primary location for user accounts,
home directories, and other files.
File System
A collection of files and the structure that links them together. The
Unix file system is a hierarchical structure.
Folder
In the Unix mail system, a file that contains messages you have read
and sorted into groups.
Fonts
A text character style.
Foreground Process
A process that is actively using your terminal or a window.
FORTRAN
A programming language. (FORmula TRANslation.)
FTP
File Transfer Protocol. A Unix utility to interactively copy files
between computers without having to log on. Uses TCP/IP network transferring
protocols.
Full Duplex
A type of data communication in which a computer system can transmit
and receive data simultaneously. Terminals and modems usually have settings
for half
duplex (one-way) and full duplex communication; the Unix system uses
the full-duplex setting.
Group
Users who need access to the same data on the computer.
HDF
Hierarchical Data Format. A way of representing floating point data
that is machine-independent and can be used by the NCSA ximage utility.
Hidden File
A file that does not appear in directory listings unless you use the
-a option with the ls command. Names of hidden files start with a period.
HOLD Screen
A key on some terminals that controls scrolling.
Home Directory
The directory that you enter when you log in. You can use a tilde (~)
to represent the home directory in Unix commands.
Host
Computer on which applications may be executed or logins allowed.
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IEEE
Institute of Electrical and Electronics Engineers. This organization
defines many computer standards.
Internet
Network of Unix computers that support e-mail, remote utilities, and
TCP/IP protocols.
IP Address
Internet Protocol Address. Mnemonic name corresponding to a unique
machine such as oak.mmm.ucar.edu.
IP Number
Internet Protocol Number. Number that corresponds to a unique machine.
The IP number of oak is 128.117.88.9.
IRIX
Silicon Graphics Incorporated version of the Unix operating system.
Kernel
The central program that manages the computer system.
Kilobyte
1,024 bytes (characters) of information.
Korn Shell
One of the shells available in the Unix operating system. The Korn
shell is an extended version of the Bourne shell that includes many of
the features of the C
shell.
Logging In
Signing on to the computer to begin a session.
Logging Out
Signing off your computer with the logout or exit command when you
finish work.
.login
The primary file that contains commands that set up your shell environment.
Login Name
The name by which the computer knows you.
Lowercase
The Unix operating system differentiates between uppercase and lowercase
letters.
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MacX
X-Windows Server software for a Macintosh.
Magnetic Tape
Type of 9-track tape used to archive data.
mail
A program that lets you exchange written messages with other users.
.mailrc
The Unix file that contains commands that set up your mail environment.
make
Unix program for creating and configuring applications from program
modules. Allows you to make changes to a program module and recompile only
that
module, not the entire program.
Manpage
A shortened form of the term "manual page," meaning a Unix reference
page.
mbox
The file in your Unix home directory that contains messages you have
read but not deleted or moved to folders.
Megabyte
1024 Kilobytes, or 1,048,576 bytes (characters) of information.
Metacharacter
A character that represents something besides itself. The right angle
bracket (>) and the vertical bar (|) are examples of Unix metacharacters.
Wildcards are also
metacharacters.
MIGS
MASnet Internet Gateway System. Software for submitting jobs to shavano.
Modem
A device that connects a terminal and a computer by way of a telephone
line. A modem converts digital signals to tones and converts tones back
to digital
signals, allowing a terminal and a computer to exchange data over standard
telephone lines.
MS DOS
PC Operating system developed by Microsoft for PC computers.
MSS
Mass Storage Subsystem. A tape/disk storage system at NCAR accessed
via MIGS.
Multitasking
The ability of an operating system to execute more than one program
at a time.
Multiuser
The ability of an operating system to support several users on the
system at the same time.
NCSA Telnet
Public domain Telnet software for PCs and Macintoshes. Supports file
tranfers with ftp.
New Mail File
A portion of the system's mail directory that holds your new and unread
mail messages.
NFS
Network File System. Unix software to allow file sharing via ethernet.
NQS
Network Queueing System. The type of JCL used by UNICOS on the Cray
Y-MP.
OSF
Open Software Foundation. A Unix standards organization.
Owner
The person who created a file.
Password
A combination of characters that verifies your identity to the computer.
Pathname
The path from root to a directory or file.
Peripheral Device
Auxiliary devices under the control of the main computer, used mostly
for input, output, and storage functions. Some examples include terminals,
printers, and
disk drives.
Permissions
Access modes, associated with directories and files, that permit or
deny system users the ability to read, write, and/or execute the directories
and files. In Unix,
you determine the permissions for your directories and files by changing
the mode for each one with the chmod command.
Pipe
In Unix, a method of redirecting the output of one command to be the
input of another command. It is named for the character | that redirects
the output. For
example, the shell command who | wc -1 pipes output from the who command
to the wc command, telling you the total number of people logged into your
Unix
system.
Pipeline
In Unix, a series of filters separated by | (the pipe character). The
output of each filter becomes the input of the next filter in the line.
The last filter in the pipeline
writes to its standard output, or may be redirected to a file.
Piping
In Unix, the process of sending the output from one command directly
to another for use as the latter command's input. You use the vertical
bar character (|) as a
pipe between commands.
Pointer
Sometimes called the mouse cursor, the pointer indicates the location
of the mouse. The pointer's shape depends on its location. In the root
window, the pointer
is an X. On a window frame, the pointer is an arrowhead.
POSIX
Portable Operating System Interface on Unix. An attempt to define a
Unix standard.
PostScript
A page description language used by many modern laser printers.
Printer
An output device that prints hardcopy (paper) of the data it receives
from the computer.
Process
A job running on the computer. Each process is associated with a unique
process identification number (PID).
Program
A file that contains a series of commands. Also known to Unix users
as a binary.
Project Number
Specific account number to which computer resources (e.g., Cray time,
GAUs) are charged by SCD.
Pull-Down Menu
A menu accessed by pointing to the menu bar and pulling down with the
mouse. Pull-down menus are generally organized by the types of functions
they contain.
Push Button
A control that causes an immediate action. To press a push button on
the screen, point to it and click the select button.
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Quota System
Software used for regulating the use of disk storage on Unix systems.
Redirection
In Unix, the process of writing output from a command to a file using
the right angle ( > ), or of reading input for a command from a file using
the left angle
bracket ( < ).
Reference Page
A page from a Unix reference manual that you can call up on your screen
with the man command. Also known as a "manpage."
Relative Pathname
A directory path expressed in relation to present location.
Remote System
A system other than the one on which you are working.
Restore
To change an icon back into its original window.
RETURN Key
The key that you press to signal the end of a command line or a line
of input.
RISC
Reduced Instruction Set Computer. High-speed computer technology.
Root
The top-level directory in the Unix file system. The root directory
is represented by a slash ( / ).
SCSI
Small Computer System Interface. Used to attach peripherals to workstations
and desktop computers.
Scrolling
Lines of output roll off one end of the screen as new lines appear
at the other. You can pause and resume scrolling with HOLD SCREEN, or pause
with
CTRL-S and resume with CTRL-Q, when scrolling is enabled.
Select Button
The mouse button used for most operations. By default, the select button
is the left mouse button.
SGI
Silicon Graphics Incorporated. Manufacturer of workstations running
the IRIX (Unix) operating system.
Shell
A Unix program that controls user interactions with the system and
executes commands. Also called a command interpreter.
Software
Instructions and programs that tell the computer what to do. Contrast
with hardware.
Solaris
Solaris is the name of Sun Microsystems new-generation Unix operating
system.
Source Code
The uncompiled version of a program written in a language such as C
or FORTRAN. The source code must be translated to machine language by a
program
known as a compiler before the computer can execute the program.
SPARC
High speed computer processor similar to RISC processors and currently
used on SUN computers.
Standard Error
A file that represents where commands will place their error messages,
usually assigned to your terminal screen. When the system writes to the
standard error file
(stderr), the output appears on your screen unless you have redirected
the standard error.
Standard Input
A file that represents where commands will get their input, usually
assigned to your terminal keyboard. Typed commands are treated as standard
input unless you
have redirected the standard input to come from elsewhere.
Standard Output
A file that represents where commands will place their output, usually
assigned to your terminal screen. When the system writes to the standard
output file
(stdout), the output appears on your screen unless you have redirected
the standard output.
Subdirectory
A directory that descends from another directory.
Subnet
A portion of a physical network in which packets are isolated from
the outside world.
Sun
Sun Microsystems. Manufacturer of workstations that run either the
SunOS or Solaris operating systems.
SunOS
Sun Microsystems version of the Unix operating system.
Syntax
The exact way you must enter a command. Specifies the order and contents
of options and arguments.
TCP/IP
Transmission Control Protocol / Internet Protocol. A communications
protocol used by ethernet-based networks.
Telnet
A terminal emulation program that allows you to log on to and do work
on a computer anywhere on the Internet.
Terminal Type
The type of terminal attached to your computer. The operating system
uses the terminal type to set the TERM environment variable so that it
can communicate
with the terminal correctly. The terminal type is usually set at login,
but can be set afterward.
TeX
A typesetting/page-layout programming language.
Thin Net
A type of ethernet that uses coaxial cable as the medium
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Unix
A popular operating system that works on many different types of computers.
Uppercase
The Unix operating system differentiates between uppercase and lowercase
letters.
User
Anyone who uses a computer or an operating system.
Utility
Software used to carry out routine functions or to assist a programmer
or system user in establishing routine tasks.
Window Manager
The window manager controls the size, placement, and operation of windows
on the root window.
Window Menu
The menu that appears when you press the window menu button on a window
frame. Every window has a system menu that enables you to control the size,
shape, and position of the window.
Working Directory
The directory you are currently in. When you log in, you enter your
home directory. You can change your working directory with the cd command,
and find the
name of your current working directory with the pwd command.
World
All the users who have accounts on the system
xload
An X client program that displays the work load of the system as a
histogram.
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