Question 1

A user needs the following permissions to be able to use a script as a command
A) Read and write
B) Write
C) Read
D) Execute

Accepted Answer

In order to use a script as a command, the user only needs to have execute permission. This allows the user to run the script as a program. They do not need to be able to read or write the script file itself.

Question 2

The pipe operator, which directs the output from one command to another, is
A) /
B) #
C) |
D) >

Accepted Answer

The pipe operator is represented by the vertical bar symbol "|". It is used to pass the output of one command as input to another command. Therefore, option C is the correct answer.

Option A (/) is the forward slash used in file paths. 
Option B (#) is the hash or pound symbol used for comments in scripts and programming languages. 
Option D (>) is the output redirection operator used to redirect output from a command to a file instead of the terminal screen.

Question 3

Consider the following script. The output will be newlines replaced by spaces for brevity): #! /bin/bash
for number in $\{ 5 \ldots 1 \}$
do 
echo snumber
done
A) 5 .. 1
B) 5 4 3 2 1
C) 1 2 3 4 5
D) 5 3 1

Accepted Answer

The for loop iterates over the range of numbers from 5 to 1, inclusive, in descending order. The echo command prints the value of the number variable, which is the current number in the range.

Question 4

The command to view the contents of a variable at the shell prompt is
A) variablename
B) echo variablename
C) echo $variablename
D) $variablename

Accepted Answer

To view the contents of a variable at the shell prompt, we need to use the "echo" command followed by the variable name preceded by a dollar sign. So the correct command to view the contents of a variable is "echo $variablename".

Question 5

Consider the following script. The output will be newlines replaced by spaces):#! /bin/bash
for number in $\{ 7 \ldots 1 \ldots 3 \}$
do 
echo snumber
done
A) 1 3 5 7
B) 1 4
C) 1 4 7
D) 7 4 1

Accepted Answer

The script uses a for loop with a brace expansion syntax to iterate over a sequence. However, the syntax is incorrect. The correct syntax should be {7..1..-3} to count down from 7 to 1 with a step of -3. Assuming the intention was to count down, the correct output would be 7 4 1.

Question 6

The cat command in Linux is used to
A) Edit a shell script
B) Execute a shell script
C) Display the contents of a file
D) Find files

Accepted Answer

The 'cat' command in Linux is used to display the contents of a file. It stands for "concatenate", and is used to display the contents of a file or concatenate files together and display the result. It is not used for editing, executing or finding files.

Question 7

Consider the following script. The output will be: 
#! /bin/bash
guess = 2
start = 3
check = $     $start $\div 2 ) + 1 )$ )
if [ $guess -eq $check]
then
echo "Correct Guess: The number is $start"
else
echo "Sorry, wrong guess"
A) Correct Guess: The number is 3
B) Correct Guess: The number is 2
C) Sorry, wrong guess
D) Indeterminate

Accepted Answer

The script checks if the guess is equal to the result of dividing the start value by 2 and adding 1. If the guess is correct, it prints "Correct Guess: The number is $start". Otherwise, it prints "Sorry, wrong guess". In this case, the guess is 2 and the start value is 3. Dividing 3 by 2 and adding 1 gives 2, which is equal to the guess. Therefore, the output will be "Correct Guess: The number is 3".

Question 8

File users.csv contains lines as: Christine:Riggs:christine.riggs@sunshine.edu. The command to extract emails from the file is
A) cut -d: -f3 users.csv
B) cut -d, -f3 users.csv
C) cut -d: -f1,2,3 users.csv
D) cut -d, -f1,2,3 users.csv

Accepted Answer

Since the email is the third field in each line of the file and the delimiter is ":" in this case, we have to use -d flag to specify the delimiter and -f flag to indicate the field number to retrieve. Therefore, the correct command is 
"cut -d: -f3 users.csv"

Question 9

Consider the following script. The output will be newlines replaced by spaces): #! / bin/bash
for number in $\{ 1 \ldots 7 \ldots 3 \}$
do 
echo $number
done
A) 1 3 5 7
B) 1 4
C) 1 4 7
D) 7 4 1

Accepted Answer

The correct syntax for a range in bash is {START..END..INCREMENT}, so $\{1\ldots7\ldots3\}$ is interpreted as {1..7..3}, which generates a sequence starting from 1 to 7 with an increment of 3, resulting in 1, 4, 7.

Question 10

In programming languages, loops are used to
A) Loop through the execution logic and understand the program
B) Collect all comments
C) Mark the beginning and end of the program
D) Repeat a set of commands

Accepted Answer

Loops in programming languages are used to repeat a set of commands multiple times, based on certain conditions or criteria. This helps to automate repetitive tasks and improve the efficiency of the program.

Question 11

Comment lines in script begin with the character
A) /
B) #
C) |
D) >

Accepted Answer

In most programming languages, comment lines begin with the # character.

Question 12

Shell scripts are
A) A list of shell commands in a text file
B) Scripts used as a shell, with no content until used
C) A type of compiled programs
D) Lists of drugs prescribed by a physician

Accepted Answer

Shell scripts are a collection of shell commands that are saved in a file and can be executed by a shell. These scripts can automate tasks, perform system administration functions, and simplify command-line operations.

Question 13

The redirect operator used to send the output of a command to a file is written as
A) /
B) #
C) |
D) >

Accepted Answer

The redirect operator ">" is used to redirect (or send) the output of a command to a file.

Question 14

Consider the following script. The output will be: #! /bin/bash
guess=2
check=$ $RANDOM $\left. \left. \div 2 \right) + 1 \right)$ )
if [ $guess -eq $check]
then 
echo "Correct Guess: The number is $check"
else echo "Sorry, wrong guess"
A) Correct Guess: The number is 3
B) Indeterminate
C) Correct Guess: The number is 2
D) Sorry, wrong guess

Accepted Answer

The script contains syntax errors and incorrect command usage, making its output indeterminate. The use of $ $RANDOM and the parentheses are not valid syntax in bash for arithmetic operations or generating random numbers.

Question 15

A specific set of commands is to be executed 10 times. The most appropriate loop construct to accomplish this is
A) for
B) while
C) do
D) if

Accepted Answer

The for loop is specifically designed for executing a specific set of commands a certain number of times. It allows for easy control of the number of iterations and the iteration variable. The other options do not provide this level of control or are not designed for looping through a set of commands.

Question 16

Shell scripts can obtain user input using the command
A) input
B) var
C) read
D) cat

Accepted Answer

The command "read" is used to obtain user input in a shell script. It allows the script to wait for input from the user and store it in a variable for later use.

Question 17

The command that will create a new variable in a bash script is
A) let firstname = "John"
B) firstname="John"
C) string firstname = "John"
D) str firstname = "John"

Accepted Answer

In Bash scripts, variables can be created by assigning a value to a name. The most common way of doing this is by using the format "variable_name=value". Therefore, the correct syntax for creating a variable named firstname with a value of "John" in a Bash script is "firstname="John"". Option A is incorrect because the "let" keyword is not necessary in Bash for assigning variables. Options C and D are incorrect because Bash doesn't have a data type declaration keyword such as "string" or "str".

Question 18

The first line of an executable script needs to be #!/bin/bash, in order to
A) Inform the shell which shell interpreter to use to execute the script
B) Remind the user of the shell interpreter to use when executing the script
C) Remind the user of the shell interpreter used to create the script
D) Serve as a comment for the shell interpreter when executing the script

Accepted Answer

The first line of an executable script needs to be #!/bin/bash to inform the shell which shell interpreter to use to execute the script. This is called a shebang line and specifies the interpreter that should be used to execute the script.

Question 19

Shell scripts are used for
A) Serving as firewalls
B) Automating processes in operating systems
C) End-point protection
D) Detecting intrusions

Accepted Answer

Shell scripts are used to automate tasks or processes in operating systems, such as running a backup or installing software updates. They are not typically used for serving as firewalls, end-point protection, or detecting intrusions.

Question 20

Environment variables are
A) Variables describing the user's access to the computer environment
B) Variables describing the local climate
C) Variables describing the state of the host system
D) Variables created automatically when a user starts a new terminal window

Accepted Answer

The answer of Environment variables are
A) Variables describing the user's...

Quiz 10: Shell Scripting

A user needs the following permissions to be able to use a script as a command

The pipe operator, which directs the output from one command to another, is

Consider the following script. The output will be newlines replaced by spaces for brevity) : #! /bin/bash for number in $\{ 5 \ldots 1 \}$ do echo snumber done

The command to view the contents of a variable at the shell prompt is

Consider the following script. The output will be newlines replaced by spaces) :#! /bin/bash for number in $\{ 7 \ldots 1 \ldots 3 \}$ do echo snumber done

The cat command in Linux is used to

Consider the following script. The output will be: #! /bin/bash guess = 2 start = 3 check = $ $start $\div 2 ) + 1 )$ ) if [ $guess -eq $check] then echo "Correct Guess: The number is $start" else echo "Sorry, wrong guess"

File users.csv contains lines as: Christine:Riggs:christine.riggs@sunshine.edu. The command to extract emails from the file is

Consider the following script. The output will be newlines replaced by spaces) : #! / bin/bash for number in $\{ 1 \ldots 7 \ldots 3 \}$ do echo $number done

In programming languages, loops are used to

Comment lines in script begin with the character

Shell scripts are

The redirect operator used to send the output of a command to a file is written as

Consider the following script. The output will be: #! /bin/bash guess=2 check=$ $RANDOM $\left. \left. \div 2 \right) + 1 \right)$ ) if [ $guess -eq $check] then echo "Correct Guess: The number is $check" else echo "Sorry, wrong guess"

A specific set of commands is to be executed 10 times. The most appropriate loop construct to accomplish this is

Shell scripts can obtain user input using the command

The command that will create a new variable in a bash script is

The first line of an executable script needs to be #!/bin/bash, in order to

Shell scripts are used for

Environment variables are