Deck 7: Working With the Bash Shell

Question 1

You can use the sed command to remove unwanted lines of text.

Answer 1

True

Question 2

What permissions are required to execute a shell script in a manner similar to any other executable program on the system?

A) read
B) write and read
C) execute
D) read and execute

Answer 2

D

Question 3

The ability to extract, manipulate, and format text using pattern action statements belongs to which command below?

A) sed
B) grep
C) awk
D) nl

Answer 3

C

Question 4

What number represents the stdin file descriptor?

A) 0
B) 1
C) 2
D) 3

Question 5

What character is used to delimit most Linux configuration files?

A) tab
B) colon
C) space
D) semicolon

Question 6

Given the syntax command && command, the command on the left of the && construct is executed only if the command on the right of the && construct completed successfully.

Question 7

You are limited to using one pipe | metacharacter on the command line to pipe information from one command to another command.

Question 8

Select the escape sequence that is used for a form feed:

A) \n
B) \f
C) /f
D) /n

Question 9

A list of all exported environment and user-defined variables in a shell can be viewed with what command below?

A) env
B) set
C) setenv
D) getenv

Question 10

The standard output and standard error from a terminal screen within the BASH shell can be redirected to a file on the filesystem using what shell metacharacter, followed by the absolute or relative pathname of the file?

A) #
B) <
C) >
D) |

Question 11

Select the metacharacter that can be used to send the standard output of one command to another command as standard input:

A) <
B) |
C) >
D) #

Question 12

What number represents the stderr file descriptor?

A) 0
B) 1
C) 2
D) 3

Question 13

The default BASH shell prompt is set by an environment variable. What command can be used to view this variable?

A) ls $PWD
B) echo #PWD
C) echo $PS1
D) ls #PS1

Question 14

The environment variables that are set by default and their current values can be viewed with what command?

A) env
B) get
C) set
D) setenv

Question 15

Which command can be used to count the number lines, words, and characters in a file?

A) pr
B) nl
C) tr
D) wc

Question 16

In order to redirect a file to the standard input of a command, what metacharacter should be used?

A) >
B) #
C) |
D) <

Question 17

What environment file is always executed immediately after login for all users on the system, and sets most environment variables, such as HOME and PATH?

A) ˜/.bash_profile
B) ˜/.bash_login
C) /etc/profile
D) ˜/.profile

Question 18

To prevent a file from being cleared by the BASH shell and append output to the existing output, you can specify three > metacharacters alongside the file descriptor.

Question 19

What command can be used to replace characters in a file sent via Standard Input?

A) tr
B) rt
C) ts
D) st

Question 20

Any command that can be executed on the command line can also be placed inside any environment file.

Question 21

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​The first line in a shell script, which defines the shell that will be used to interpret the commands in the script file.

Question 22

The ____________________ environment variable contains a list of directories to search for executable programs.

Question 23

Explain the while construct, and demonstrate how it can be used.

Question 24

Select the escape sequence that starts a new line when used with echo:

A) ​\\
B) ​\a
C) ​\n
D) ​\r

Question 25

Detail shell scripts and explain how they are used and executed.

Question 26

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​A special construct used in a shell script to alter the flow of the program based on the outcome of a command or contents of a variable. Common decision constructs include if, case, &&, and ||.

Question 27

Select the test statement that can be used to determine if A is numerically greater than B:

A) [ A -g B ]
B) [ A -ge B ]
C) [ A -gt B ]
D) [ A +eq B ]

Question 28

Provide information on decision constructs, and explain how to use the most common type of decision construct.

Question 29

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​A special construct used in a shell script to execute commands repetitively. Common decision constructs include for and while.

Question 30

The ____________________ command takes user input from stdin and places it in a variable specified by an argument.

Question 31

Describe what file descriptors are, and then list three that can be used within the BASH shell, and discuss how they can be used.

Question 32

Describe shell variables, and explain environment and user-defined variables.

Question 33

Most commands that are run by the shell are run in a separate ____________________, which is created by the current shell.

Question 34

A case construct must be ended by ____________________.

Question 35

What character combination at the start of a shell script are referred to as a hashpling, and allow for the specification of the shell that interprets the contents of the script?

A) ​@!
B) ​#!
C) ​//
D) ​->

Question 36

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​A file descriptor that represents information input to a command during execution.

Question 37

​What construct is intended for use in processing a list of objects, such as files, directories, users, printers, and so on?

A) ​for
B) ​while
C) ​case
D) ​switch

Question 38

​What operator below is known as the NOT operator?

A) ​-o
B) ​-a
C) ​!
D) ​%

Question 39

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​A variable that is altered by loop constructs to ensure that commands are not executed indefinitely.

Question 40

Any command that can take standard input and transform it into standard output is called a(n) ____________________ command.

Question 41

In an if construct, what statements are optional?​

A) ​fi
B) ​elif
C) ​else
D) ​then

Question 42

Select the two escape sequences that represent a horizontal tab and a vertical tab, respectively:​

A) ​\V
B) ​\t
C) ​\v
D) ​\b

Question 43

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​The numeric labels used to define command input and command output.

Question 44

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​The process of changing the default locations of Standard Input, Standard Output, and Standard Error.

Question 45

​What two BASH environment variables represent the current working directory, and the absolute pathname of the current shell, respectively?

A) ​PWD
B) ​CWD
C) ​PATH
D) ​SHELL

Question 46

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​The variables that store information commonly accessed by the system or programs executing on the system; together, these variables form the user environment.

Question 47

Select the two commands below that will provide the number of lines in a file, and the number of characters in a file, respectively:​

A) ​count -c
B) ​pr -d
C) ​wc -l
D) ​wc -c

Question 48

What two files below are the first two BASH environment files to be executed?​

A) ​/etc/profile
B) ​/etc/bashrc
C) ​˜/.bashrc
D) ​˜/.bash_profile

Question 49

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​A file descriptor that represents any error messages generated by a command.

Question 50

​Match each correct item with the statement below.​
a.​counter variable
b.decision construct​
c.​environment variables
d.​file descriptors
e.​hashpling
f.loop construct​
g.​redirection
h.Standard Error (stderr)​
i.​Standard Input (stdin)
j.Standard Output (stdout)
​A file descriptor that represents the desired output from a command.