Disable Keyboard & Mouse input on unix (under X)

Assuming your GUI is X-based (as almost all UNIX GUIs are), use xinput.

First, list your devices:

$ xinput --list
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Windows mouse                             id=6    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
↳ Windows keyboard                          id=7    [slave  keyboard (3)]

List the details for your mouse (id=6 in our example):

$ xinput --list-props 6
Device 'Windows mouse':
    Device Enabled (112):   1
    Coordinate Transformation Matrix (114): 1.000000, 0.000000, 0.000000, 0.000000,   1.000000, 0.000000, 0.000000, 0.000000, 1.000000
    Device Accel Profile (222):     0
    Device Accel Constant Deceleration (223):       1.000000
    Device Accel Adaptive Deceleration (224):       1.000000
    Device Accel Velocity Scaling (225):    10.000000

Now disable it:

$ export DISPLAY=:0
$ xinput set-int-prop 6 "Device Enabled" 8 0

To enable it do:

$ xinput set-int-prop 6 "Device Enabled" 8 1

The same goes for the keyboard, just replace the int-prop number with the proper id.
Tested and worked on cygwin.

Of course, you have to plan beforehand how will you enable your devices again. such as schedule it on cron, re-enable it remotely, or disable just one of them in first place.

Your answer is probably best for your second use case (doing something remotely), but probably not for your first (being away from keyboard). How would you run xinput again to restore access when you return?

The standard solution to locking the system while away from it is XScreenSaver, which is installed by default in most distros. If configured to lock the keyboard, it will prompt for your password before unlocking it.

If you are using a Desktop Enviromnet and or login manager, (GNOME,KDE,XFCE,LXDE) almost all of them have a lock screen function where you have to type in your password to get back to your programs.

However since that is really simple i sense your problem is more complex / different.

Depending on your hardware, you can remove the modules, controlling your hardware. I have such a script, touchpadtoggle, to enable and disable my touchpad.

lsmod | grep -q psmouse && rmmod psmouse || modprobe psmouse

But the keyboard doesn't seem to have a module associated, and the psmouse-module will only work occasionally.