#!/bin/bash
# Israel Torres
# 20160920
#
STRING='Here I am, and there you are.'

function chr () { # in 65, out A
[ "$1" -lt 256 ] || return 1
printf "\\$(printf '%03o' "$1")"
}

function ord () { # in A, out 65
LC_CTYPE=C printf '%d' "'$1"
}

for (( c=0; c<=${#STRING}; c++ )); do
#echo -en "${STRING:$c:1}"
ORDVAR=$(ord "${STRING:$c:1}")
XORVAR=$(( ORDVAR ^ 20 ))
#echo -en "$XORVAR"
CHRVAR=$(chr $XORVAR)
echo -en "$CHRVAR"
done

#EOF