topleft -- move mouse pointer to top left of current screen

gistfile1.sh

#!/bin/bash

# check for binaries
type -P xmousepos &>/dev/null || {
	echo "can't find xmousepos -- install xautomation" >&2
	exit 1
}
type -P xte &>/dev/null || {
	echo "can't find xte -- install xautomation" >&2
	exit 1
}

# get current horizontal mouse position
mousex=$(xmousepos | awk '{print $1}')

# walk through widths of screens (assuming they're in order left to right) until 
# the mouse is on the current screen, building offset from left
offset=0
for width in $(xrandr | grep '*' | awk '{print $1}' | sed -r 's/x.*//'); do
	[ $mousex -lt $(expr $offset + $width) ] && break
	offset=$(expr $offset + $width)
done

# move the pointer to the top left of the screen
xte "mousemove $offset 0"