Chapter 2 Study Cards

Question 1

Account

Answer 1

Stored information and reserved directory that allows an individual (or sometimes a utility or server program) to use a computer. the term is often used and thought of as if it were a distinct virtual component of a computer that a person can use, as in “Sam logged into his account” or “Miranda’s account isn’t working.”

Question 2

American Standard Code for Information Interchange (ASCII)

Answer 2

An encoding method for alphanumeric data, commonly used for text files. ASCII is common code, but because it lacks character used by many non-English languages, other encoding methods, such as UTP-8, are slowly supplanting it.

Question 3

ASCII

Answer 3

An encoding method for alphanumeric data, commonly used for text files. ASCII is common code, but because it lacks character used by many non-English languages, other encoding methods, such as UTP-8, are slowly supplanting it.

Question 4

bash

Answer 4

The GNU Bourne Again Shell (bash) is based on the earlier Bourne shell for Unix but extends it in several ways. In Linux, bash is the most common default shell for user accounts.

Question 5

bsh

Answer 5

The Bourne shell upon which bash is based also goes by the name bsh It’s not often used in Linux, although the bsh command is sometimes a symbolic link to bash.

Question 6

Command completion

Answer 6

A feature of many Linus shells that simplifies typing long commands. Pressing the Tab key causes the shell to search for possible commands or filenames that would complete the command. If only one command or filename matches the characters typed so far, the shell completes the entry. If not, the shell enters the characters up to the point where the user must specify another.

Question 7

csh

Answer 7

The original C shell isn’t much used on Linux, but if a user is familiar with csh, tcsh makes a good substitute.

Question 8

Environment Variables

Answer 8

Environment variables are like variables in programming languages- they hold data to be referred to by the variable name. Environment variables differ from programs’ internal variables in that they’re part of the environment of a program, and other programs, such as the shell can modify this environment.

Question 9

Graphical user interface (GUI)

Answer 9

A method of human-computer interaction characterized by a graphical display, a mouse to move a pointer around the screen, and the ability to perform actions by pointing at objects on the screen and clicking a mouse button.

Question 10

grep

Answer 10

The grep command searches for files that contain a specified string and returns the name of the file and (if it’s a text file) a line of context for that string.

Question 11

GUI

Answer 11

A method of human-computer interaction characterized by a graphical display, a mouse to move a pointer around the screen, and the ability to perform actions by pointing at objects on the screen and clicking a mouse button.

Question 12

Here document

Answer 12

A form of redirection, denoted by <

Question 13

ksh

Answer 13

The Korn Shell (ksh) was designed to take the best features of the Bourne shell and the C shell and extend them. It has a small but dedicated following among Linux users.

Question 14

Pipe

Answer 14

A method of executing two programs so that one program’s output serves as the second program’s input. Piped programs are separated in a Linux shell by a vertical bar (|).

Question 15

Pipeline

Answer 15

A method of executing two programs so that one program’s output serves as the second program’s input. Piped programs are separated in a Linux shell by a vertical bar (|).

Question 16

Redirection

Answer 16

A procedure in which a program’s standard output is sent to a file rather than to the screen or in which the program’s standard input is obtained from a file rather than form the keboard.
Standard Input:
The default method of delivering input to a program. It normally corresponds to the keyboard at which you type.
Standard Output:
The default method of delivering purely text-based information from a program to the user. It normally corresponds to a text-mode screen, xterm window, or the like.

Question 17

Regular Expression

Answer 17

A method of matching textual information that may vary in important ways but that contains commonalities. The regular expression captures the commonalities and uses various types of wildcards to match variable information.

Question 18

sed

Answer 18

The sed command directly modifies the contents of files sending the changed file to standard output.

Question 19

Shell history

Answer 19

A log of commands typed at a shell. The shell history enables easy repetition of previously typed command.

Question 20

Split

Answer 20

The split command can split a file into two or more files. Unlike most of the text-manipulation commands described in this Lesson, this command requires you to enter an output filename-or more precisely, an output filename prefix, to which is added an alphabetic code.

Question 21

Standard error

Answer 21

An output stream that’s reserved for high-priority messages, such as errors
See also Standard ouput:
The default method of delivering purely text-based information from a program to the user. It normally corresponds to a text-mode screen, xterm window, or the like.

Question 22

Standard input

Answer 22

The default method of delivering input to a program. It normally corresponds to the keyboard at which you type.

Question 23

Standard Output

Answer 23

The default method of delivering purely text-based information from a program to the user. It normally corresponds to a text-mode screen, xterm window, or the like.

Question 24

Stream

Answer 24

Text or other input or output as processed by a program. Examples include files, keyboard input, and output to a screen.

Question 25

tcsh

Answer 25

This shell is based on the earlier C shell (csh). It’s a fairly popular shell in some circles, but no major Linux distributions make it the default shell. Although it’s similar to bash in many respects, some operational details differ. For instance, you don’t assign environment variables in the same way in tcsh as in bash.

Question 26

zsh

Answer 26

The Z shell (zsh) takes shell evolution further than the Korn Shell, incorporating features from earlier shells and adding still more.