Transferring bitcoin from old bitcoin core wallet to electrum I have a 7 year old wallet.dat file that was created by the bitcoin-qt program (https://bitcoin.org/en/bitcoin-core/).
Downloading the blockchain takes too long and I experienced that the downloaded chain risks getting corrupted. I decided to use Electrum so I can access the wallet's contents sooner.
I tried following the steps from https://en.bitcoin.it/wiki/Transferring_coins_from_Bitcoin-Qt_to_Electrum, but I'm stuck at the step dumpprivkey, because I don't know what &lt;your bitcoin address&gt; means. I have installed a new bitcoin-qt version so naturally the list of receiving addresses is empty.
I have also tried another approach with dumpwallet. This yields a 250 kb file with thousands of lines and I don't know what to do with that. Surely sweeping every single private key from that file isn't feasible?
Edit: with the command listreceivedbyaddress 0 true bitcoin-qt shows all addresses that once received bitcoin. I supplied them to the dumpprivkey function in order to get the corresponding private keys. This allowed me to finish the steps as described in the wiki article.
I have a 7 year old wallet.dat file

I guess that predates HD wallets. Which I think means you'll need to sweep all private keys which have money (UTXOs) currently associated with them.
For an HD wallet I believe you can probably sweep the Extended Private Masterkey shown at  the top of the dumpwallet output.

I'm stuck at the step dumpprivkey, because I don't know what &lt;your bitcoin address&gt; means.

listunspent should help by giving you a list of addresses which actually have money associated with them.