#!/bin/bash
#  rolldice -- parse requested dice to roll and simulate those rolls
#      examples: d6 = one 6-sided die
#                2d12 = two 12-sided dice
#                d4 3d8 2d20 = a 4-side die, 3 8-sided and 2 20-sided dice

proc rolldie {
   setvar dice = "$1"
   setvar dicecount = '1'
   setvar sum = '0'

   # first step, break down arg into MdN

   if test -z $(echo $dice | grep 'd')  {
     setvar quantity = '1'
     setvar sides = "$dice"
   } else {
     setvar quantity = $(echo $dice | cut -dd -f1)
     if test -z $quantity  {       # user specifyed dN not just N
       setvar quantity = '1'
     }
     setvar sides = $(echo $dice | cut -dd -f2)
   }

   echo "" ; echo "rolling $quantity $sides-sided die"

   # now roll the dice...

   while test $dicecount -le $quantity {
     setvar roll = $(( ( $RANDOM % $sides ) + 1 ))
     setvar sum = $(( $sum + $roll ))
     echo "  roll #$dicecount = $roll"
     setvar dicecount = $(( $dicecount + 1 ))
   }

   echo I rolled $dice and it added up to $sum
}

while test $Argc -gt 0 {
  rolldie $1
  setvar sumtotal = $(( $sumtotal + $sum ))
  shift
}

echo ""
echo "In total, all of those dice add up to $sumtotal"
echo ""
exit 0