Product of a digit with a shell script

Question

How do I get the product of a 1 number in bash? (12345 > 1x2x3x4x5)

I am trying to get a script to do multiplication, I have tried escaping the * char but no luck, I have also tried fiddling with expr.

echo -n "Enter number "
read n

len=$(echo $n | wc -c)

len=$(( $len - 1 ))

for (( i=1; i <= $len; i++ ))
do
   prod=$(($prod \* $(echo $n | cut -c $i) ))
done
echo "Product of $n is $prod"

Answer 1

You can get the length of a string from parameter expansion, no need to call external tools.

#!/bin/bash
read -p 'Enter number: ' n

product=1
for (( i=0; i < ${#n}; ++i )) ; do
    d=${n:i:1}
    (( product *= d ))
done
printf '%d\n' $product

And, for fun, using Perl:

perl -MList::Util=product -le 'print product(split //, shift)' -- "$n"