Random File Rename for random wallpaper in Linux

RandomFileRename.sh

#!/bin/bash
# Seed random generator
RANDOM=$$$(date +%s)

# read all jpg files in folder
# replace the $( ) with '' for older versions

# creates an array of all the files in ~/bin/images/wp
FILES=(~/bin/images/wp/*)                     

NFILES="${#FILES[@]}"         #determines the length of the FILES array
randomid=$((RANDOM % NFILES)) #$RANDOM selects a random number between 0 and $NFILES
F="${FILES[$randomid]}" #the random file 
echo "Processing $F ..."
cp "$F"  ~/bin/images/wp/tmp.jpg          #does the actual moving


exit 0

Thanks, Dason. The script was more about teaching myself more about BASH scripting than anything else. This generic code works on all platforms, in a personal script I set my wp specific to the machine I'm on. In this case it's a machine running i3, and I use something like the above. However setting tmp.jpg as your back ground in works on all systems right?