Geth account management through console

A few years ago I used to access my ethereum account in ~/.ethereum/keystore though geth console as follows:

eth.accounts[0] 

(returned ethereum account)

personal.unlockAccount(eth.accounts[0]) 

(unlock account in order to send ether)

web3.fromWei(eth.getBalance(eth.accounts[0]), "ether") 

(get balance)

etc.

But now when I log into the geth console:

geth attach http://127.0.0.1:8545 

then eth.accounts or web3.eth.accounts return an empty array, and eth.account returns "undefined".

How can I now access my ethereum account in keystore?