`./geth --preload "/Users/you/here/reentrancy_attack/scripts/scenario.js" attach ipc:newdata/geth.ipc`

reentrancy_attack.js

var VictimContract = eth.contract([
  {
    "constant": false,
    "inputs": [],
    "name": "withdraw",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [],
    "name": "deposit",
    "outputs": [],
    "payable": true,
    "stateMutability": "payable",
    "type": "function"
  }
]);

var Victim = VictimContract.at('0xed1f0ae556562f41e4f689fae1abeefd9426fc34');

var AttackerContract = eth.contract([
    {
      "constant": true,
      "inputs": [],
      "name": "count",
      "outputs": [
        {
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    },
    {
      "inputs": [
        {
          "name": "victim",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "constructor"
    },
    {
      "payable": true,
      "stateMutability": "payable",
      "type": "fallback"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "name": "c",
          "type": "uint256"
        },
        {
          "indexed": false,
          "name": "balance",
          "type": "uint256"
        }
      ],
      "name": "LogFallback",
      "type": "event"
    },
    {
      "constant": false,
      "inputs": [],
      "name": "attack",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    }
]);

var Attacker = AttackerContract.at('0xbf3615b919cc305f2a69fb874148d0804dfdc087');

getBalance = eth.getBalance;

function balanceInEth(address) { 
  return web3.fromWei(getBalance(address).toString());
}