Query images in $wallpapers and select a random image for each connected display.

rbg

#!/bin/bash
# sets a random background image with a resolution
# that matches each connected display

# Query connected displays
echo "Attempting to randomize wallpapers ..."
wallpapers="/usr/share/wallpapers"

# get a list of connected displays and their respective resolutions
displays=$(xrandr --prop | egrep '\sconnected' | awk '{print $1" " $3}' | cut -d '+' -f-1 )

# set the app which will be used to set background images
base="feh "

shopt -s globstar

while IFS='\n' read -ra line; do
                display_name=$(echo $line | cut -d ' ' -f1)
                resolution=$(echo $line | cut -d ' ' -f2)
                echo -e "\nDisplay: $line\n"
                echo "Resolution: $resolution"
                # find pictures in $wallpapers that match the resolution $resolution
                #echo $wallpapers
                pictures=$(identify -quiet -ping -format '%d/%f %wx%h\n' $wallpapers/**/*.jpg | rg $resolution$ | cut -d ' ' -f1)
                echo -e "Pictures: $pictures"

                # select a single picture at random
                random_picture=$(echo $pictures | tr ' ' '\n' |shuf | head -n1)

                # set picture as background
                #echo "Random picture: $random_picture"
                base+="--bg-fill $random_picture "
                echo "Set $display_name to $random_picture"
done <<<"$displays"

#echo "Command: $base"
exec $base