Essentials of Linux

Question 1

What command is used to redirect standard output to a file?

Answer 1

sort file1 > sort.out

Question 2

How can you redirect both standard output and error to the same file?

Answer 2

ls /etc/ |& ls.out

Question 3

What command formats and displays the contents of a text file?

Answer 3

pr

Question 4

What does the command ‘tr’ do?

Answer 4

translates input provided

Question 5

Fill in the blank: The default behavior of a shell is to take input from the _______.

Answer 5

keyboard

Question 6

What command is used to append output to an existing file?

Answer 6

date | tee -a /tmp/ll.out

Question 7

What character is used to represent a pipe in Bash?

Answer 7

|

Question 8

What is the default number of commands stored in the Bash history?

Answer 8

1000

Question 9

True or False: The command ‘whoami’ displays the username of the user who executes the command.

Answer 9

True

Question 10

What do you use to disable the special meaning of certain characters?

Answer 10

Masking

Question 11

What is the primary command prompt for root users?

Answer 11

#

Question 12

What command would you use to change directories?

Answer 12

cd

Question 13

What does the command ‘pwd’ stand for?

Answer 13

print working directory

Question 14

What is the purpose of the ‘export’ command?

Answer 14

to set environment variables

Question 15

Fill in the blank: The command ‘cut’ extracts selected _______ of data from a row.

Answer 15

columns

Question 16

What is the difference between local and environment variables?

Answer 16

Local variables are private to the shell; environment variables are available to child processes.

Question 17

What shell is known as the most widely used and is the default for all users including root?

Answer 17

Bourne Again Shell (BASH)

Question 18

What does the command ‘uname’ display?

Answer 18

basic information about the OS

Question 19

What is the purpose of the command ‘cal’?

Answer 19

displays calendar for the current month

Question 20

Fill in the blank: The command ‘which’ displays the _______ path of the command that will be executed.

Answer 20

absolute

Question 21

What is tilde substitution in Bash?

Answer 21

Expands to the user’s home directory or other related directories.

Question 22

How do you create a shortcut for a lengthy command in Bash?

Answer 22

Using command aliasing

Question 23

What command is used to send a broadcast message to all logged-in users?

Answer 23

wall

Question 24

What does the command ‘hwclock’ do?

Answer 24

shows date/time based on system’s hardware clock

Question 25

What is the command to see a short description of commands?

Answer 25

whatis

Question 26

What command is used to view the manual pages for a command?

Answer 26

man

Question 27

What is the purpose of the 'tee' command?

Answer 27

sends output to two destinations at the same time

Question 28

What are the three special characters used for masking in Bash?

Answer 28

* ' "

Question 29

True or False: The command 'clear' wipes the terminal screen.

Answer 29

True

Question 30

What is the command history file in Bash?

Answer 30

$HOME/.bash_history

Question 31

What command can be used to log out from the session?

Answer 31

exit or Ctrl+d

Question 32

Fill in the blank: The command 'date' displays the system _______.

Answer 32

date/time

Question 33

What character matches exactly one character in Bash?

Answer 33

?

Question 34

What are meta characters in Bash?

Answer 34

Special characters that have a specific meaning.

Question 35

What does the command 'id' display?

Answer 35

user identification information