How to send everything in a bitcoind account?
I would highly recommend that you not use the accounts system as it is deprecated and has been removed for Bitcoin Core 0.17 and beyond. Furthermore, the way that you want to use the accounts system is not how it actually works. Accounts are only associated with addresses for receiving; for spending, when you "send from" an account, all that happens is the numbers for the account are deducted, not that addresses that were associated with the account for receiving are the ones actually used in the inputs.

To send everything from an account, just use the sendfrom command with the balance of the account. This will change the accounting entries so that that account is deducted however much you sent. Note that this will not necessarily choose the inputs that you think are associated with the account; it can choose any input in the wallet to create the transaction. However if you call getbalance &lt;account&gt;, you will see the account's balance be 0.