sequence to kill the X server

Terminating Xorg with Ctrl+Alt+Backspace

cat > /usr/local/etc/X11/xorg.conf.d/keyboard-zap.conf <<EOF
Section "InputClass"
 Identifier "KeyboardDefaults"
 Driver  "keyboard"
 MatchIsKeyboard "on"
 Option  "XkbOptions" "terminate:ctrl_alt_bksp"
EndSection
EOF