Simple multi-desktop wallpaper changer

changeDesktop.sh

#!/bin/bash

# Simple multi-desktop wallpaper changer
# Place desired wallpapers in same directory, name by desktop number
# 0.png for first desktop, 1.png on second, etc
# Requires xprop, wmctrl, feh

# Usage: changeDesktop.sh [deskop] [action] 
#       desktop     desktop number, or p/n for previous/next
#       action      m- Move active window to new desktop
#                   w- Wrap between first and last desktop


# Exit if no arguments
if [ $# -eq 0 ]
then
echo "Usage: changeDesktop.sh [deskop] [-m]"
exit 1
fi

# Simplified argument parsing
if [ $# = "2" ] && [[ $2 == "-"* ]];then
    # Move window if necessary
    if [[ $2 == *"m"* ]];then
        echo Move active
        MOVE=1
    fi
    if [[ $2 == *"w"* ]];then
        echo Wrap around
        WRAP=1
    fi
fi

# To be honest
# https://stackoverflow.com/questions/59895/getting-the-source-directory-of-a-bash-script-from-within
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

# Gives the last two characters from xprop query
# Using to get numbers, hopefully no more than 2 digits
function getProp {
    local prop=$(xprop -root $1)
    echo ${prop:(-2)}
}
CURRDESK=$(getProp _NET_CURRENT_DESKTOP)
NUMDESKS=$(getProp _NET_NUMBER_OF_DESKTOPS)
echo On desktop $CURRDESK, $NUMDESKS total

# Next desktop
if [[ $1 = "n"  && ( ! -z $WRAP || $CURRDESK -lt $(($NUMDESKS-1)) ) ]]; then
    let "CURRDESK = ($CURRDESK + 1) % $NUMDESKS"
# Previous desktop
elif [[ $1 = "p" && ( ! -z $WRAP ||  $CURRDESK -gt "0" ) ]]; then
    let "CURRDESK = ($CURRDESK - 1 + $NUMDESKS) % $NUMDESKS"
# Numbered desktop
elif [[ $1 != "p" && $1 != "n" ]]; then
    echo To $1
    let "CURRDESK = $1"
fi
echo Will switch to desktop $CURRDESK

# Set new background
feh --bg-fill $(echo $DIR"/"$CURRDESK".png")

# Move active window if necessary
if [ ! -z $MOVE ]; then
    echo Moving active
    wmctrl -r :ACTIVE: -t $CURRDESK
fi

# Switch desktop
wmctrl -s $CURRDESK

wallpapers.sh

#!/bin/bash
#
# Script to enable different wallpapers on each workspace and monitor.
# Written by damo <damo@bunsenlabs.org> November 2015
#
# To run while logged in, add "wallpapersd &" to your autostart
#
# REQUIRES: 'feh'
###############################################################################

# To be honest$
# https://stackoverflow.com/questions/59895/getting-the-source-directory-of-a-bash-script-from-within$
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

FEH_CMD="feh --bg-fill" # edit this, or wallpapers.cfg, to use a different feh command

NUM_DESKTOPS=$(xprop -root _NET_NUMBER_OF_DESKTOPS | tail -c -2)

xprop -root -spy _NET_CURRENT_DESKTOP | (   # <-- this is the watching process
while read -r;do
CURR_DESKTOP=${REPLY:${#REPLY}-1:1}
echo $CURR_DESKTOP
feh --bg-fill $(echo $DIR"/"$CURR_DESKTOP".png")
done
)