linux overview / quiz 1

Question 1

ls

Answer 1

list the directory contents

Question 2

cd

Answer 2

change the working directory

Question 3

pwd

Answer 3

print the name of the working directory

Question 4

mkdir

Answer 4

create a new directory

Question 5

cp

Answer 5

copy a file or directory

Question 6

mv

Answer 6

move or rename a file or directory

Question 7

rm

Answer 7

remove a file or directory

Question 8

rmdir

Answer 8

remove an empty directory

Question 9

file

Answer 9

determine the file type

Question 10

touch

Answer 10

change file timestamp or create an empty file if it doesn’t exist

Question 11

wc

Answer 11

print the number of lines, words, and characters in a file

Question 12

sort

Answer 12

sort lines of a file numerically or alphabetically

Question 13

ps

Answer 13

print a snapshot of current processes

Question 14

top

Answer 14

display dynamic view of running processes

Question 15

netstat

Answer 15

print network statistics

Question 16

pstree

Answer 16

print a tree of processes

Question 17

kill

Answer 17

sends a signal to terminate a process

Question 18

who

Answer 18

display current users logged on to the system

Question 19

whoami

Answer 19

print effective userid (actually, identify current user)

Question 20

groups

Answer 20

print the groups that the user is in

Question 21

which

Answer 21

used to locate the executable file associated with the given command by searching it in the path environment variable

Question 22

whereis

Answer 22

locate the binary, source, and man page files for a command

Question 23

find

Answer 23

search for files in a directory hierarchy

Question 24

locate

Answer 24

find files by name

Question 25

grep

Answer 25

print lines matching to a pattern using regular expressions

Question 26

cat

Answer 26

concatenate files and print to standard output (terminal)

Question 27

echo

Answer 27

print a line of text

Question 28

type

Answer 28

print a brief description of a command

Question 29

more

Answer 29

file viewer for paging through text on screen at a time
more command is used to view the text files in the command prompt, displaying one screen at a time in case the file is large (For example log files). The more command also allows the user do scroll up and down through the page.

Question 30

less

Answer 30

file viewer similar to more, but with more features
Less command is a Linux utility that can be used to read the contents of a text file one page (one screen) at a time.

Question 31

head

Answer 31

print the first n lines of a file

Question 32

tail

Answer 32

print the last n lines of a file

Question 33

diff

Answer 33

compare files line-by-line
shell command

Question 34

date

Answer 34

print date and time in various formats

Question 35

cal

Answer 35

print calendar for month and year

Question 36

df

Answer 36

print file system disk space usage

Question 37

du

Answer 37

estimate file space usage for directory and all subdirectories

Question 38

clear

Answer 38

clear the terminal screen

Question 39

sleep

Answer 39

does nothing for a specified amount of time

Question 40

history

Answer 40

print history of recently used commands

Question 41

chmod

Answer 41

set file permissions
can add or take away read, write, and execute permissions
set by owner, group, and others

Question 42

input redirection

Answer 42

accomplished using the less than symbol for the input file
command < input_file

Question 43

output redirection

Answer 43

redirects the output to a file using the greater than symbol
command > output_file
can append instead of overwriting file using > >

Question 44

combined input and output redirection

Answer 44

command < input_file > output_file

Question 45

piping |

Answer 45

|, allows the output of a command to be connected to the input of another command

Question 46

the directory is a type of file (True/False)

Answer 46

True

Question 47

which linux command is used to go back from a directory to the directory before that?

Answer 47

cd..

Question 48

how many types of basic permissions are available in linux to grant a user?

Answer 48

3 (read, write, execute)

Question 49

in a multiuser multitasking linux operating system, what does “multitasking” refer to?

Answer 49

The capability of the operating system to run multiple programs concurrently on a single processor.

Question 50

You need to list all files and directories in the current directory, including hidden ones. Which linux command would you use?

Answer 50

ls -a

Question 51

You need to copy a file named “report.txt” to a directory named “backup”. How would you do that? Choose the right command.

Answer 51

cp report.txt backup

Question 52

What is the output shown for a “type echo” command?

Answer 52

echo is a shell built-in

Question 53

After issuing the command chmod go+rx apple.c, which of the following file permissions is possible for the ordinary file apple.c?

Hint: g stands for group and o stands for others

Answer 53

-rwxr-xr-x

Question 54

In a system call, the user has super-privileges whereas the kernel has no privilege. (true/false)

Answer 54

false

Question 55

When a process running in user mode makes a system call to open() to access a file, what accurately represents the role of kernel and user mode,

Answer 55

The open() system call switches the process to kernel mode, which accesses the file on behalf of the process

Question 56

_____________ primarily provides a text-based interface through which users can execute commands, manage files, and perform various system tasks in the Linux OS. It allows users to control and manage the system using text-based commands and scripting.

Answer 56

shell

Question 57

Device drivers in an operating system are responsible only for providing hardware-specific functionalities and have no role in managing the communication between software applications and hardware devices. (true/false)

Answer 57

false

Question 58

What is a fundamental difference between the C standard library functions and system calls in a Unix-like operating system?

Answer 58

C standard library functions execute in user mode, while system calls transition to kernel mode to access privileged operations.

Question 59

What does cd .. command do ?

Answer 59

Directory switched to the previous level