overlay_desktop.sh

#!/bin/bash

# Overlay bill due dates on desktop
# Use hints from this page
#   https://www.reddit.com/r/linux4noobs/comments/2upg57/custom_cheat_sheet_wallpaper_anyone/
#

DTPIC=/usr/share/backgrounds/System76-Fractal_Mountains-by_Kate_Hazen_of_System76.png
CURR_WALLPAPER=$HOME/Pictures/mywallpaper.png

if [ ! -f $DTPIC ]
then
    echo "no desktop picture was specified"
    exit 1
fi

which due >/dev/null 2>&1
if [ $? -ne 0 ]
then
    echo "the program, due, is not in your path"
    exit 1
fi

TEMP_IMG=$(mktemp).png
OVERLAY_DATA=$(due | sed -E -e ':a;N;$!ba;s/\r{0,1}\n/\\n/g' -e 's/^ /\\ /')

convert \
    -font Courier-Bold \
    -fill white \
    -background none \
    -undercolor none -trim +repage \
    -pointsize 18 \
    -size 900x \
    "caption:$OVERLAY_DATA" \
    PNG32:$TEMP_IMG
convert \
    $DTPIC $TEMP_IMG \
    -gravity NorthEast \
    -geometry +50+50 \
    -composite $CURR_WALLPAPER

rm -f $TEMP_IMG

exit 0