hex to string bash function

hex2string.sh

#!/usr/bin/env bash

# echo 68656c6c6f20776f726c64|hex2string -> hello world

function hex2string(){
    i=${1:-$(</dev/stdin)};
    spaced=$(echo "$i"|fold -w2);
    for i in ${spaced[@]};   do
	echo -n -e "\x$i";
    done
}