url_encode()
{
	local text="$1"
	local pos char

	while [ ${pos:-0} -lt ${#text} ]; do {
		pos=$(( $pos + 1 ))
		char="$( echo "$text" | cut -b $pos )"

		case "$char" in
			"_"|"."|"~"|"-")
				echo -n "$char"
			;;
			[A-Za-z0-9])
				echo -n "$char"
			;;
			" ")
				echo -n "+"
			;;
			*)
				echo -n "%$( echo "$char" | hexdump -C | cut -d' ' -f3 | head -n1 )"
			;;
		esac
	} done
}