My Password Generator

#!/bin/sh

read key start len

L=$key
K=""
end=`expr $start + $len`
for i in `seq 1 129`; do
    L=`echo -n $L | sha512sum -b | cut -f1 -d' '`
    K="$K$L"
done
echo $K | xz -c -f | base64 -w0 | cut -c${start}-${end}