Node script to sweep accounts

Question

I have a rather large list of accounts (HD wallets) I want to sweep into one.

They've all been imported into geth, and all have the same password.

I wrote a script to do this in node but get this error:

Error: Insufficient funds for gas * price + value

Here is the node script:

//web3
var Web3 = require('web3');
var web3 = new Web3();

//starting index... main account is 0... don't sweep that one ^.^
var startSweep = 1;

//account shell
var accounts = [];

//transaction cost... i think?
var gas = 21000;

//geth stuff
var sys = require('util');
var exec = require('child_process').execSync;
function puts(error, stdout, stderr) { sys.puts(stdout) };

//connect to node
web3.setProvider(new web3.providers.HttpProvider('http://localhost:8545'));

//get accounts
var accounts = web3.eth.accounts;

//set default account for gas
web3.eth.defaultAccount = accounts[0];

//loop through accounts and sweep balances
for(var x = startSweep; x<accounts.length; x++){
    //get current account balance
    var balance = web3.eth.getBalance(accounts[x]);

    //if balance is greater than 0 lets transfer... 
    if(balance > gas){
        //command to unlock account 
        var execCommand = 'geth --exec "personal.unlockAccount(eth.accounts['+x+'], \'password\', 1000)" attach';
        console.log(execCommand);

        //execute command
        exec(execCommand, puts);
        console.log(' Unlocked account ' + accounts[x] + ' with a balance of ' + balance + '! ' + 'TRANSFERING!');
        var transaction = {
            "to" : accounts[0],
            "from" : accounts[x],
            "value" : balance - gas,
            "gas": gas
        };

        //send transaction
        web3.eth.sendTransaction(transaction);
        console.log('Sent transaction from : '+ accounts[x]);
    }
}

I read that the cost of a transaction was 21000, but I get that error.... So I just kept bumping the gas up until I received the error:

Error: Exceeds block gas limit

So I guess I'm doing something wrong. Any suggestions?

Answer 1

I was not calculating the gas correctly. Here is the updated code in case anyone wants to do something similar.

//web3
var Web3 = require('web3');
var web3 = new Web3();

//starting index... main account is 0... don't sweep that one ^.^
var startSweep = 1;

//account shell
var accounts = [];

//transaction cost.
var gas = 21000;

//geth stuff
var sys = require('util');
var exec = require('child_process').execSync;
function puts(error, stdout, stderr) { sys.puts(stdout) };

//connect to node
web3.setProvider(new web3.providers.HttpProvider('http://localhost:8545'));

//current gas price
var gasPrice = web3.eth.gasPrice.toNumber();

//get accounts
var accounts = web3.eth.accounts;

//set default account
web3.eth.defaultAccount = accounts[0];

//loop through accounts and sweep balances
for(var x = startSweep; x<accounts.length; x++){
    //get current account balance
    var balance = web3.eth.getBalance(accounts[x]);
    //see if this is worth sending ^.^
    var balanceMinusFee = balance - (gas * gasPrice);
    if(balanceMinusFee > 0){
        //command to unlock account 
        var execCommand = 'geth --exec "personal.unlockAccount(eth.accounts['+x+'], \'password\', 1000)" attach';
        console.log(execCommand);

        //execute command
        exec(execCommand, puts);
        console.log(' Unlocked account ' + accounts[x] + ' with a balance of ' + balanceMinusFee + '! ' + 'TRANSFERING!');
        var transaction = {
            "to" : accounts[0],
            "from" : accounts[x],
            "value" : balanceMinusFee,
            "gas": gas
        };

        //send transaction
        web3.eth.sendTransaction(transaction);
        console.log('Sent transaction from : '+ accounts[x]);
    }
}