#! /bin/sh

lb=0
ub=32768

if [ $# -eq 1 ]; then
        ub="$1"
elif [ $# -eq 2 ]; then
        lb="$1"
        ub="$2"
elif [ $# -ne 0 ]; then
        echo "Usage: $0 [[lower_bound] upper_bound]"
        echo "  to generate a random number in the range [lower_bound, upper_bound)"
        exit 1
fi

{
        echo 'ibase = 16'
        printf 'r = '
        dd bs=16 count=1 </dev/urandom 2>/dev/null | hexdump -ve '/1 "%02X"'
        echo
        echo 'ibase = A'
        echo "r % ($ub - $lb) + $lb"
} | bc 2>/dev/null