SHELL

Disable MacBook from Booting Automatically

# Reenable the Mac startup chime
sudo nvram BootAudio=%01
# And to disable it:
sudo nvram BootAudio=%00
# To reset your Mac to its default behavior
sudo nvram AutoBoot=%03

Disable MacBook from Booting Automatically

# for disable autoboot
sudo nvram AutoBoot=%00
#/Applications/Utilities/, and then enter the following command syntax exactly:
# for Return to Default Setting of Booting
sudo nvram AutoBoot=%03