display.sh

#!/bin/bash

HDMI=HDMI1
EDP=eDP1

if xrandr | grep -q "${HDMI} disconnected"; then
    dmode=disconnected
else
    dmode=connected
fi

BG=$HOME/pics/wallpaper.png

MODE='--right-of'
ROTATE=''

function print_usage {
    cat <<EOF
Usage: display.sh [OPTIONS]

This program checks if there is a second monitor conected and
configures X to use multiple displays using xrandr.

Options:
  -m,--mirror         Acivates mirror mode. Default is extended mode.
  -d,--disconected    Turn off the second display.
  -b,--background     Sets background image. Default is ${BG}
  -r,--rotate     Sets background image. Default is ${BG}
  -h,--help           Diplays this text
EOF
}

while [[ $# -gt 0 ]]
do
    case $1 in
        -m|--mirror)
            MODE='--same-as'
            ;;
        -d|--disconnected)
            dmode=disconnected
            ;;
        -b|--background)
            if [[ ! -f $2 ]]; then
                echo "File not found: $2"
                exit 1
            fi
            BG=$2
            shift
            ;;
        -r|--rotate)
            ROTATE='--rotate left'
            ;;
        -h|--help)
            print_usage
            exit 0
            ;;
        *)
            echo "Unknown option: $1"
            exit 1
            ;;
    esac
    shift
done

# I have doubts about this next config
# This script is called as root and without X knowledge
#export DISPLAY=:0.0

if [ "${dmode}" = disconnected ]; then
    echo "Setting single monitor"
    xrandr --output $EDP --auto --output $HDMI --off
elif [ "${dmode}" = connected ]; then
    echo "Setting dual monitor"
    xrandr --output $EDP --primary --auto \
      --output $HDMI \
      --auto \
      ${ROTATE} \
      ${MODE} $EDP
else
    echo "Ops... I don't undestand ${dmode}"
    exit 1
fi

# Set wallpaper
feh --no-fehbg --bg-scale ${BG}
# set random wallpaper from directory
#feh --no-fehbg --bg-scale $(find ~/pics/stellaris -type f | shuf -n 1)