Help()
{
    echo ""
    echo "No arguments supplied - take this:"
    echo ""
    echo "expandcidr - A file with a scope list in CIDR notation is expanded "
    echo "             to all possible IPs. It can also output instead a"
    echo "▅▅▅▅▅▅▅▅▅    a specified number of unique random IPs from the output"
    echo "▅▅▅▅▅▅▅▅▅    file (useful for sample testing, for ex.)."
    echo "▅▅▅▅▅▅▅▅▅    Script leverages on nmap - same scope list format"
    echo "▅▅▅▅ ▅▅▅▅ "               
    echo "▅▅▅▅▅▅▅▅▅    Example: expandcidr scope.txt output.txt 4000" 
    echo ""
    echo "Usage: expandcidr [input file] [output file] [optional-rnd-#-ips]"
    echo ""
    echo ""
}

while getopts ":h" option; do
   case $option in
      h) # display Help
         Help
         exit;;
   esac
done

if [ $# -eq 0 ]
  then Help
    exit 1
fi

# command chain

if [ -z $3 ]
    then
        nmap -sL -n -iL $1 | grep 'Nmap scan report for' | cut -f 5 -d ' ' > $2
    else
        nmap -sL -n -iL $1 | grep 'Nmap scan report for' | cut -f 5 -d ' ' | shuf -n $3 > $2
fi