LPI Part 2

Question 1

/etc/group

Answer 1

A text file which defines the groups to which users belong

Question 2

GID

Answer 2

Group ID
Each user must be assigned a group ID. You can see this number in your /etc/passwd file

Question 3

id

Answer 3

Used to find out user and group names and numeric ID’s (UID or group ID) of the current user or any other user in the server

Question 4

id information

Answer 4

-User name and real user id.
-Find out the specific Users UID.
-Show the UID and all groups associated with a user.
-List out all the groups a user belongs to.
-Display security context of the current user.

Question 5

last

Answer 5

Displays information about the last logged-in users.
Takes the system log file /var/log/wtmp as the data source to generate reports.

Question 6

who

Answer 6

Displays information about currently logged-in users.
-Time of last system boot
-Current run level of the system
-List of logged-in users and more.

Question 7

w

Answer 7

Displays important information about who is currently using the computer, how much the computer is being used, and what programs are running.
Syntax: w [options] user […]

Question 8

/etc/skel

Answer 8

A directory that contains files and directories that are automatically copied over to a new user’s when it is created from useradd command.

Question 9

useradd

Answer 9

Used to add user accounts to your system.
Syntax: useradd [options] [user_name]

Question 10

useradd -u

Answer 10

Creates a new user with a custom UID

Question 11

useradd -g

Answer 11

Creates a new user and assigns a specific group ID

Question 12

useradd -M

Answer 12

Creates a new user without a home directory

Question 13

groupadd

Answer 13

Used to create groups.
Syntax: groupadd [options] group_name

Question 14

groupadd -f

Answer 14

Forces the command to abort silently if the group with the given name already assists

Question 15

groupadd -g

Answer 15

This option assigns a specific numeric group id to the newly created group

Question 16

groupadd -r

Answer 16

Creates a system group

Question 17

passwd

Answer 17

Modifies user passwords
Syntax: passwd [options] [username]

Question 18

passwd -d

Answer 18

Deletes the user password, making the account password-less.

Question 19

passwd -e

Answer 19

Immediately expires the account password, prompting the user to change it on the next login.

Question 20

passwd -i

Answer 20

Sets the number of days after password expiration before the account is deactivated.

Question 21

chmod

Answer 21

Used to change the access mode of a file.
Syntax: chmod [options] [mode] [File_name]

Question 22

chmod -R

Answer 22

Apply the permission change recursively to all the files and directories within the specified directory.

Question 23

chmod -v

Answer 23

It will display a message for each file that is processed. while indicating the permission change that was made.

Question 24

chmod Operators

Answer 24

+ Add permissions
- Remove Permissions
= Set the permissions to the specified values

Question 25

chmod Reference List

Answer 25

u = Owner
g = Group
o = Others
a = All

Question 26

chmod Example

Answer 26

chmod u+rw,go+r [file_name]

Question 27

chmod Octal Mode

Answer 27

First digit specify the permission for Owner.
Second digit specify the permission for Group.
Third digit specify the permission for Others.

Question 28

Octal Mode Digit Values

Answer 28

4 Read Permission
2 Write
1 Execute

Question 29

ln

Answer 29

Used to create hard links between files

Question 30

ln -s

Answer 30

Used to create soft links between files

Question 31

/tmp/

Answer 31

Used to store the data used by the system and user applications to store the data that are needed for a short period of time. Most Linux distributions are preconfigured to empty the tmp directory after each reboot.

Question 32

/var/tmp/

Answer 32

Used to store data by the system on physical storage, use this for longer term tmp files.