test-sixel-delete.sh

#!/bin/bash

tput sc

# first print a red square
printf '\eP;1q'
printf '"1;1;60;60'
for N in {1..10}
do
    printf "#2!60~-"
done
printf '\e\\'

tput rc

# then cover it up with cyan lines, flagged to first delete all previous images
printf '\eP100;1q'
printf '"1;1;60;60'
for N in {1..10}
do
    printf "#5!60w-"
done
printf '\e\\'           # End Sixel

# If you see either the red square, or the red square behind the cyan
# lines, then the test has failed.