Do xrandr stuff

screens.sh

#!/bin/bash

laptop_screen="LVDS1"
external_screen="HDMI1"
position="left"

if [[ ! -z "$1" ]]; then
    external_screen="$1"
fi

xr_conn=$(xrandr -q | grep -w "connected")
xr_disconn=$(xrandr -q | grep -w "disconnected")

# Configure screens to be their default resolution
while read -r line; do
    monitor=$(echo "$line" | cut -f1 -d" ")	
    xrandr --output "$monitor" --auto
done <<< "$xr_conn"

# Turn off disconnected screens
while read -r line; do
    monitor=$(echo "$line" | cut -f1 -d" ")	
    xrandr --output "$monitor" --off
done <<< "$xr_disconn"

# Configure external screen to be left of laptop, if both present
if [[ "$xr_conn" =~ "$laptop_screen connected" ]] && [[ "$xr_conn" =~ "$external_screen connected" ]]; then
    xrandr --output "$laptop_screen" --"$position"-of "$external_screen"
    xrandr --output "$external_screen" --primary
fi