Linux Command Lines

Question 1

Prompt to enter new command

Answer 1

$

Question 2

Output specific string of text

Answer 2

Echo

Question 3

Prints working directory onto the screen

Answer 3

Pwd

Question 4

Displays names of files and directories in the current working directory

Answer 4

ls

Question 5

Navigates between directories

Answer 5

cd

Question 6

Displays the content of a file

Answer 6

cat

Question 7

Displays just the beginning of a file by default 10 lines

Answer 7

head

Question 8

/home

Answer 8

Each user in the system gets their own home directory.

Question 9

/bin

Answer 9

This directory stands for “binary” and contains binary files and other executables. Executables are files that contain a series of commands a computer needs to follow to run programs and perform other functions.

Question 10

/etc

Answer 10

This directory stores the system’s configuration files.

Question 11

/tmp

Answer 11

This directory stores many temporary files. The /tmp directory is commonly used by attackers because anyone in the system can modify data in these files.

Question 12

/mnt

Answer 12

This directory stands for “mount” and stores media, such as USB drives and hard drives.

Question 13

Displays end of the file by default 10 lines

Answer 13

tail

Question 14

Returns the content of a file one page at a time

Answer 14

Less

Question 15

Searches a specific file and returns all lines in the file containing a specified string

Answer 15

grep

Question 16

Searches for directories and files that meet specific criteria

Answer 16

Find

Question 17

Sends the standard output of one command as standard input to another command for further processing

Answer 17

(vertical line piping)

Question 17

Find files in a directory that contain specific name

Answer 17

-name (case sensitive)
-iname (not case sensitive)

Question 18

Finding files or directories modified within a certain time

Answer 18

-mtime
-based on days +1 indicates a day ago -1 indicates files less than a day ago

Question 19

Creates new directory

Answer 19

mkdir

Question 20

Remove or delete directory

Answer 20

rmdir

Question 21

Create a new file

Answer 21

touch

Question 22

Removes or deletes files

Answer 22

rm

Question 23

Moves a file or directory to a new location

Answer 23

mv

Question 24

Copies a file or directory into a new location

Answer 24

cp

Question 25

Displays permissions to files and directories

Answer 25

ls-l

Question 26

Display hidden files

Answer 26

ls -a

Question 27

Display permissions to file and directories including hidden files

Answer 27

ls -la

Question 28

Changes permission on files and directories

Answer 28

chmod

Question 29

Adds a user to the system

Answer 29

useradd

Question 30

Deletes a user from the system

Answer 30

userdel

Question 31

Command to temporarily grants elevated permissions to specific users

Answer 31

sudo

Question 32

Sets the user’s default group also called their primary group

Answer 32

-g

Question 33

Adds the user to additional groups, also called supplementary or secondary groups

Answer 33

-G

Question 34

Command that modifies existing user accounts

Answer 34

usermod

Question 35

Command to append a user to an existing group without replacing existing supplemental group

Answer 35

-a

Question 36

Other options used with usermod

Answer 36

-a appends user to an existing group -d changes users home directory -l changes users login name -L locks the account so user cannot login

Question 37

Command line to delete all files under specific user in their home directory

Answer 37

Userdel -r (username)

Question 38

Command to lock user account without deleting

Answer 38

usermod -L

Question 39

Command to change ownership of file or directory

Answer 39

chown

Question 40

Displays information on other commands and how they work

Answer 40

man

Question 41

Displays a description of a command on a single line

Answer 41

whatis

Question 42

Searches the manual page descriptions for a specified string

Answer 42

apropos

Question 43

Company 2 files byte by byte

Answer 43

cmp file name file name

Question 44

Generate Hash for a file

Answer 44

sha256sum

Question 45

Security controls that manage access authorization, and accountability of information

Answer 45

Access controls

Question 46

AAA framework

Answer 46

Authentication (Who are you?) Authorization (access to Information only last as long as needed) Accounting (practice of monitoring the access logs of a system)

Question 47

Factors of authentication

Answer 47

1) knowledge: something the users knows 2) ownership something the user possesses (random number via text) 3) characteristic something the user is (bio Id)

Question 48

A technology that combines several different logins into one

Answer 48

Single sign on (SSO)

Question 49

Insecurity measure, which require requires a user to verify their identity and two or more ways to access a system or network

Answer 49

Multifactor authentication (MFA)

Question 50

The principal that users should not be given levels of authorization that would allow them to misuse a system

Answer 50

Separation of duties

Question 51

The technology used to establish a user request to access a server

Answer 51

Basic auth 

Question 52

O auth

Answer 52

An open standard authorization protocol that shares designated access between applications

Question 53

A small block of encrypted code that contains information about a user

Answer 53

API token

Question 54

Sequence of network HTTPbasic authorization request and responses associated with the same user

Answer 54

Session

Question 55

Unique, talking that identify a user and their device will access in the system

Answer 55

Session ID

Question 56

He took that website used to validate a session and determine how long that session should last

Answer 56

Session cookie

Question 57

An event when attackers obtaining legitimate users session ID

Answer 57

Session hijacking