Linux Operations

Question 1

What command allows you to write a messagem to a specific user or to all users that are logged in to a server?

Answer 1

To a specific user: write (user) \n (message)

To all users: wall \n (message)

Question 2

What commands are there that shutdown ( in different ways ) the server, explain their differences

Answer 2

reboot - restart server
halt - stop all cpu functions
poweroff - system power down

Question 3

How can you check which run level you are on?

Answer 3

who -r

runlevel

Question 4

Which command allows you to check the current runlevel in human format (unit) and to set the default runlevel?

Answer 4

systemctl get-default

systemctl set-default graphical.target