runlevel - Print previous and current SysV runlevel
0 - Halt
1 - Single-user mode
2 - Not used (user-definable)
3 - Full multi-user mode
4 - Not used (user-definable)
5 - Full multi-user mode (with an X-based login screen)
6 - Reboot
To see the current runlevel of the system
$ runlevel
N 3
Full multi-user mode in CLI mode
To temporarily change the runlevel to 5 (Full multi-user mode with an
X-based login screen) from 3
$ init 5
To permanently change the runlevel to 5 from 3
$ sudo vim /etc/default/grub
GRUB_CMDLINE_LINUX="5"
:x
$ sudo update-grub
$ sudo reboot
regards,
T.Dhanasekar