System and Utility Commands

Question 1

What is the command to have most of the information about the system?

Answer 1

uname -a

Question 2

What is the command to have the user ID and group ID?

Answer 2

id

Question 3

What is the command to display the date, time and time zone?

Answer 3

date

Question 4

What is the command to display the calendar of the current month?

Answer 4

cal

Question 5

What is the command to display the calendar of a particular year?

Answer 5

cal [year]

Question 6

What is the command to see how long a command take to execute?

Answer 6

time [command to execute]

Question 7

What is the command to display the content of a compressed files?

Answer 7

zcat

Question 8

What is the command to connect an external device file system?

Answer 8

mount

Question 9

What is the command to exit the current shell?

Answer 9

exit

Question 10

What is the command to clear the terminal in Linux?

Answer 10

clear

Question 11

What is the command to see how long the machine has been up?

Answer 11

uptime

Question 12

What is the command to create a command shortcut?

Answer 12

alias [shorcut command]=’[command]’

Question 13

How to remove a shorcut made with alias?

Answer 13

unalias [shortcut]

Question 14

What is the command to add a new group?

Answer 14

groupadd [group name]

Question 15

What is the command to add a user to a group?

Answer 15

usermod -a -G [group name] [username]

Question 16

What is the command to change the owner of a file?

Answer 16

chown [username] [file name]

Question 17

What is the command to change the group of a file?

Answer 17

chown :[group name] [file name]

Question 18

What is the command to change the owner and group of a file?

Answer 18

chown [username]:[group name] [file name]

Question 19

What is the command to change the permission of a file?

Answer 19

chmod [permissions] [file name]