Term syntax to killall and cut power completely?

[cognus]

Can someone cure my ignorance please? I'm looking for the command line to killall processes and shutdown all power. On the Intel-based early 2015 MBA, holding the power button after shutdown does not accomplish that. Many other Intel-based ultrabook spec laptops do.

Thanks in advance!
c

 

[fivenotrump]

sudo shutdown -h now

 

[cognus]

sudo shutdown -h now

thanks! didn't realize same as on many other os
For the sake of others searching:
first: sudo su
enter password
then sudo shutdown -h now

works!