Source code in the unix programming language

sum=0
prod=1
list="1 2 3"
for n in $list
do sum="$(($sum + $n))"; prod="$(($prod * $n))"
done
echo $sum $prod

sum=0
prod=1
for n
do sum="$(($sum + $n))"; prod="$(($prod * $n))"
done
echo $sum $prod

sum=0
prod=1
while read n
do sum="$(($sum + $n))"; prod="$(($prod * $n))"
done
echo $sum $prod

list=(20 20 2);
(( sum=0, prod=1 ))
for n in "${list[@]}"; do
   (( sum += n, prod *= n ))
done
printf '%d\t%d\n' "$sum" "$prod"