Xinput

Distribution	Package
Archlinux	`xorg-xinput`
Ubuntu	`xinput`

List devices:

xinput list

Usually laptop's keyboard is:

AT Translated Set 2 keyboard    id=15   [slave  keyboard (3)]

Disable laptop's keyboard:

xinput float "AT Translated Set 2 keyboard"

Re-enable laptop's keyboard, 3 is from slave keyboard (3):

xinput reattach "AT Translated Set 2 keyboard" 3