fold (hard wrap) in pure bash

fold.sh

fold() {
	data="$1"
	width="$2"
	length=$(echo -n "$data" | wc -c)
	while [ $length -gt $width ]
	do
		echo ${data:0:$width}
		data=${data:$width}
		length=$(echo -n "$data" | wc -c)
	done
	echo $data
}