Restrict mouse to screen

pointer_barrier.sh

#!/bin/bash 
# Original from: https://gist.github.com/Akselmo/d4f35798a222b9af5d0c0f1b4021d11d
# I tightened up the while loop. I find putting a little buffer (like 20 pixels) help reliability
# Usage: ./pointer_barrier.sh [Xleft [Ytop [Xright [Ybottom]]]]
# Example: ./pointer_barrier.sh 0 0 1919 1080
# Requires: sudo apt install xdotool

borderxl=${1:-20}
borderyu=${2:-40}

borderxr=${3:-1900}
borderyd=${4:-1060}

if [ $borderxl -gt $borderxr ] || [ $borderyu -gt $borderyd ]; then
    echo "Invalid border"
    exit 1
elif [ "$XDG_SESSION_TYPE" == "wayland" ]; then
    echo "This script is mean for X11"
    exit 1
else
    echo "Restricting mouse $borderxl $borderyu $borderxr $borderyd"
fi

while [ true ]; do
    check=0
    read xpos ypos << COMMAND
        $(xdotool getmouselocation | cut -d" " -f1-2 | sed -e s/.://g)
COMMAND

    if [ $xpos -gt $borderxr ]; then
        check=1
        xpos=$borderxr
    elif [ $xpos -lt $borderxl ]; then
        check=1
        xpos=$borderxl
    fi

    if [ $ypos -gt $borderyd ]; then
        check=1
        ypos=$borderyd
    elif [ $ypos -lt $borderyu ]; then
        check=1
        ypos=$borderyu
    fi

    if [ $check -ge "1" ]; then
        xdotool mousemove $xpos $ypos
    fi
done