Is there a terminal command in Mac OS X to disable/enable the trackpad/mouse? I know that I can disable the trackpad of my MacBook Pro when an external mouse is connected. But is this also possible without a peripherial connected?
You would have to unload the kexts, which would remove support for the hardware until reloaded. I don't really recommend this.
sudo kextunload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTrackpad.kext
sudo kextload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTrackpad.kext
I tried this in OS X 10.9.5
sudo kextunload /System/Library/Extensions/AppleUSBMultitouch.kext
it gives error "(kernel) Can't unload kext com.apple.driver.AppleUSBMultitouch; classes have instances" but it disables the Trackpad successfully.
sudo kextload /System/Library/Extensions/AppleUSBMultitouch.kext
it enables the Trackpad again.
In OS X 10.9 I tried
sudo kextunload /System/Library/Extensions/AppleUSBMultitouch.kext/
to disable a temperamental trackpad, but that gave an error and didn't do anything. But moving the extension elsewhere, i.e.
sudo mv /System/Library/Extensions/AppleUSBMultitouch.kext ~
and restarting did the trick—though for some reason it also disabled the internal keyboard (except for the power button).
FYI, Apple menu > About This Mac > More Info... > System Report... > Extensions (under Software) shows which kernel extensions are currently active.