Deck 10: Shell Scripting

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

Answer 1

Execute

Question 2

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

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

Answer 2

C

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

Answer 3

5 4 3 2 1

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

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

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

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

Question 8

File users.csv contains lines as: Christine:Riggs:[e-mail]. 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

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

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

Question 11

Comment lines in script begin with the character

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

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

Question 13

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

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

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

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

Question 16

Shell scripts can obtain user input using the command

A) input
B) var
C) read
D) cat

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"

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

Question 19

Shell scripts are used for

A) Serving as firewalls
B) Automating processes in operating systems
C) End-point protection
D) 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

Question 21

Consider the following script. The output will be newlines replaced by spaces for brevity): #! /bin/bash
counter=1
while [ \$counter -le 5]
do
$\quad$ echo $counter
$\quad$ counter=$counter $+ 1 )$ )
done

A) 5 .. 1
B) 5 4 3 2 1
C) 1 2 3 4 5
D) 5 3 1

Question 22

The difference between break and continue while processing loop input is that

A) break exits the loop, but continue only exits the current iteration of the loop
B) break only exits the current iteration of the loop, but continue exits the loop
C) break and continue exit the loop
D) break and continue both exit only the current iteration of the loop

Question 23

A specific set of commands is to be executed until a pre-specified condition is reached. The most appropriate loop construct to accomplish this is

A) for
B) while
C) do
D) if

Question 24

An infinite loop a loop that runs forever can sometimes be useful

Question 25

Consider the following script. The output will be newlines replaced by spaces for brevity): #! /bin/bash
counter=1
while [ $counter -le 2]
do
echo $counter
done

A) 5 .. 1
B) 5 4 3 2 1
C) 1 2 3 4 5
D) 1 1 1 1 1 1 ……. indefinitely)