creates a random checkers pattern and export it to png

pattern.sh

WIDTH=300
HEIGHT=300
BGCOLOR="#0f232c"


echo "" > pattern.svg

echo -n "<svg id=\"subtle\" width=\"${WIDTH}\" height=\"${HEIGHT}\" version=\"1.1\" xmlns=\"http://www.w3.org/2000/svg\">" >> pattern.svg
echo -n "<rect x=\"0\" y=\"0\" width=\"100%\" height=\"100%\" fill=\"${BGCOLOR}\"></rect>" >> pattern.svg

for i in `seq 1 10 $WIDTH`; do
	for j in `seq 1 10 $WIDTH`; do
		OPACITY=`shuf -i 1-10 -n 1`
		FILLER=`shuf -i 0-1 -n 1`
		OPACITY=`echo "scale=2; ${OPACITY}/100.0" | bc`
		if [[ "$FILLER" == "1" ]]; then
		   FILLE="#222"
		else
		   FILLE="#ddd"
		fi
		echo -n "<rect x=\"$i\" stroke=\"#000\" stroke-opacity=\"0.1\" y=\"$j\" width=\"10\" height=\"10\" style=\"fill: ${FILLE}; fill-opacity: ${OPACITY};\"></rect>" >> pattern.svg
	done
done
echo -n "</svg>" >> pattern.svg
inkscape -z -e pattern.png pattern.svg