Linux+ Guide Glossary: A-C

Front 1

ab (Apache benchmark) command

Back 1

A command that can be used to obtain performance benchmarks for a Web server such as Apache.

Front 2

absolute pathname

Back 2

The full pathname to a certain file or directory, starting from the root directory.

Front 3

accepting printer

Back 3

A printer that accepts print jobs into the print queue.

Front 4

active partition

Back 4

The partition searched for by an OS after the MBR.

Front 5

AIX

Back 5

A version of Unix developed by IBM

Front 6

alias command

Back 6

A command used to create special variables that are shortcuts to longer command strings.

Front 7

ANDing

Back 7

The process by which binary bits are compared to calculate the network and host IDs from an IP address and subnet mask.

Front 8

apachectl command

Back 8

A command that can be used to start, stop, and restart the Apache Web server as well as check for syntax errors within the Apache configuration file.

Front 9

application

Back 9

The software that runs on an operating system and provides the user with specific functionality (such as word processing or financial calculation).

Front 10

archive

Back 10

the location (file or device) that contains a copy of files; it is typically created by a backup utility.

Front 11

arguments

Back 11

The text that appears after a command name, does not start with a dash "-" character, and specifies information the command requires to work properly.

Front 12

artistic license

Back 12

An open source license that allows source code to be distributed freely but changed only at the discretion of the original author.

Front 13

assistive technologies

Back 13

Software programs that cater to specific user needs

Front 14

asymmetric encryption

Back 14

A type of encryption that uses a key pair to encrypt and decrypt data.

Front 15

at command

Back 15

The command used to schedule commands and task to run at a preset time in the future.

Front 16

at daemon (atd)

Back 16

The system daemon that executes tasks at a future time; it is configured with the at command.

Front 17

authentication

Back 17

The act of verifying a user's identity by comparing a user name and password with a system database.

Front 18

Automatic Private IP addressing (APIPA)

Back 18

A feature that automatically configures a network interface using an IPv4 address on the 169.254.0.0 network.

Front 19

awk command

Back 19

A filter command used to search for and display text.

Front 20

background (bg) command

Back 20

The command used to run a foreground process in the background.

Front 21

background process

Back 21

A process that does not require the BASH shell to wait for its termination. Upon execution, the user receives the BASH shell prompt immediately.

Front 22

bad blocks

Back 22

The areas of a storage medium unable to store data properly.

Front 23

Baseline

Back 23

A measure of normal system activity.

Front 24

BASH shell

Back 24

The Bourne Again Shell; it is the default command-line interface in Linux

Front 25

BBC Linux

Back 25

A small CD/DVD based Linux distribution

Front 26

Beowulf clustering

Back 26

A popular and widespread method of clustering computers together to perform useful tasks using Linux.

Front 27

Berkeley Internet Name Domain (BIND)

Back 27

The standard that all DNS servers and DNS configuration files adhere to.

Front 28

binary data file

Back 28

A file that contains machine language (binary 1s and 0s) and stores information (such as common functions and graphics) used by binary compiled programs.

Front 29

BIND configuration utility

Back 29

A graphical utility that can be used to generate and modify the files that are used by the DNS name daemon.

Front 30

BIOS (Basic input/Output System)

Back 30

The part of a computer system that contains the programs used to initialize hardware components at boot time.

Front 31

block

Back 31

The unit of data commonly used by filesystem commands; a block can contain several sectors.

Front 32

block devices

Back 32

The storage devices that transfer data to and from the system in chunks of many data bits by caching the information in RAM; they are represented by block device files.

Front 33

Boot loader

Back 33

A program used to load an OS

Front 34

Broadcast

Back 34

The TCP/IP communication destined for all computers on a network.

Front 35

BSD (Berkeley Software Distributions)

Back 35

A version of UNIX developed out of the original UNIX source code and given free to the University of California at Berkeley by AT&T.

Front 36

buffer overrun

Back 36

An attack in which a network service is altered in memory

Front 37

bunzip2 command

Back 37

The command used to decompress files compressed by the bzip2 command

Front 38

bus mastering

Back 38

The process by which peripheral components perform tasks normally executed by the CPU.

Front 39

bzcat command

Back 39

The command used to view the contents of an archive created with bzip2 to SO.

Front 40

bzip2 command

Back 40

The command used to compress files using a Burrows-Wheeler Block Sorting Huffman Coding compression algorithm.

Front 41

bzless command

Back 41

A command used to view the contents of an archive created with bzip2 to SO in a page-by-page fashion.

Front 42

bzmore command

Back 42

A command used to view the contents of an archive created with bzip2 to SO in a page-by-page fashion.

Front 43

cancel command

Back 43

The command used to remove print jobs from the print queue in the CUPS print system.

Front 44

cat command

Back 44

A Linux command used to display (or concatenate) the entire contents of a text file to the screen.

Front 45

cd (change directory) command

Back 45

A Linux command used to change the current directory in the directory tree.

Front 46

cfdisk command

Back 46

A command used to partition hard disks; it displays a graphical interface in which the user can select partitioning options.

Front 47

chage command

Back 47

The command used to modify password expiry information for user accounts.

Front 48

chains

Back 48

The components of a firewall that specify the general type of network traffic to which rules apply.

Front 49

character devices

Back 49

The storage devices that transfer data to and from the system one data bit at a time, they are represented by character device files.

Front 50

checksum

Back 50

A calculated value that is unique to a file's size and contents.

Front 51

chfn command

Back 51

The command used to change the GECOS for a user.

Front 52

chgrp (change group) command

Back 52

The command used to change the group owner of a file or directory.

Front 53

child process

Back 53

A process that was started by another process (parent process)

Front 54

chkconfig command

Back 54

A command that can be used to configure daemon startup by runlevel.

Front 55

chmod (change mode) command

Back 55

The command used to change the mode (permissions) of a file or directory.

Front 56

chown (change owner) command

Back 56

The command used to change the owner and group owner of a file or directory.

Front 57

chsh command

Back 57

The command used to change a valid shell to an invalid shell.

Front 58

Classless interdomain routing (CIDR) notation

Back 58

A notation that is often used to represent an IP address and its subnet mask.

Front 59

closed source software

Back 59

The software whose source code is not freely available from the original author; windows 7, for example.

Front 60

cluster

Back 60

A grouping of several smaller computers that function as one large supercomputer.

Front 61

clustering

Back 61

The act of making a cluster.

Front 62

command

Back 62

a program that exists on the hard disk and is executed when typed on the command line.

Front 63

command mode

Back 63

one of the two modes in vi; it allows a user to perform any available text editing task that is not related to inserting text into the document.

Front 64

Common Unix Printing System (CUPS)

Back 64

The printing system commonly used on Linux computers.

Front 65

compiz

Back 65

A window manager that is commonly used within the KDE and GNOME desktops to provide 3D effects

Front 66

compress command

Back 66

The command used to compress files using a Lempel-Ziv compression algorithm.

Front 67

compression

Back 67

The process in which files are reduced in size by a compression algorithm.

Front 68

compression algorithm

Back 68

The set of instructions used to reduce the contents of a file systematically.

Front 69

compression ratio

Back 69

The amount of compression that occurred during compression.

Front 70

Concatenation

Back 70

The joining of text to make one larger whole. In Linux, words and strings of text are joined together to form a displayed file.

Front 71

counter variable

Back 71

A variable that is altered by loop constructs to ensure that commands are not executed indefinitely.

Front 72

cp (copy) command

Back 72

The command used to create copies of files and directories.

Front 73

cpio (copy in/out) command

Back 73

A command used to run a common backup utility.

Front 74

cracker

Back 74

a person who uses computer software maliciously for personal profit.

Front 75

cron daemon (crond)

Back 75

The system daemon that executes tasks repetitively in the future and that is configured using cron tables.

Front 76

cron table

Back 76

a file specifying tasks to be run by the cron daemon; there are user cron tables and system cron tables.

Front 77

crontab command

Back 77

The command used to view and edit user cron tables.

Front 78

cups daemon (cupsd)

Back 78

The daemon responsible for printing in the CUPS printing system.

Front 79

cupsaccept command

Back 79

The command used to allow a printer to accept jobs into the print queue.

Front 80

cupsdisable command

Back 80

The command used to prevent print jobs from leaving the print queue.

Front 81

cupsenable command

Back 81

The command used to allow print jobs to leave the print queue.

Front 82

cupsreject command

Back 82

The command used to force a printer to reject jobs from entering the print queue.

Front 83

curl command

Back 83

A command that can be used to obtain a Web page from a Web server.

Front 84

cylinder

Back 84

A series of tracks on a hard disk that are written to simultaneously by the magnetic heads in a hard disk drive.