Response to clarified first part
You're pretty close, I suspect you want something simpler like this (and then typing in the xprv you extracted from an Electrum 2.x (unencrypted) wallet file):
bx hd-private --index 2 --hard | qrencode -o - | feh -
In particular, don't include the bx hd-to-wif step, that's probably what's tripping you up.
When you do the ...
Start Bitcoin Core with the wallet.dat you want to export
Dump all wallet keys via Bitcoin Core's Console using dumpwallet wallet.dump, where wallet.dump is the name of the dump file to be created.
If you get an error, try specifying an absolute file path with a dir to which Bitcoin Core has the permission to write to, e.g. you can specify the same dir as ...
According to this FAQ:
In Electrum 2.0, you cannot import private keys in a wallet that has a seed. You should sweep them instead.
If you want to import private keys and not sweep them you need to create a special wallet that does not have a seed. For this, create a new wallet, select “restore”, and instead of typing your seed, type a list of private keys, ...
Backup your original wallet.dat file (~/Library/Application Support/Bitcoin/wallet.dat by default). This contains the private keys for your bitcoins. If you lose it, you lose your coins.
Install Bitcoin Core on a machine with 100s of gigabytes of free space. Allow it to download the blockchain. This could take days.
Replace the wallet.dat file on ...
OK found a way! Only cost me $8 to switch wallets! WTF?
Go here and save the web page to disk: https://iancoleman.github.io/bip39/
Since I don't know what wallet app on Android you're using, I'll give an answer that should work for any:
If you create an account at Coinbase, you can import your private keys and then send them to an address on your Android wallet. This requires the private keys being in plain text. If your private key export is encrypted (with a password you gave it) or ...
the other answers suggest closing your node copying directories etc, NOT necessary. Here is how i did it starting with an old wallet2.dat file:
create a folder foo (any name, any directory)
copy the file wallet2.dat into folder foo and rename the wallet to wallet.dat
on the GUI click Window->Console and type into the > field: help loadwallet which will tell ...
If you export the private keys for the addresses you want to keep then you are literally your own bank, most wallets allow you to import private keys in some way. I don't know the specifics of doing it on Electrum though.
To export from bitcoin-qt go into the debug console from the menus, and enter
Keep that key safe - it ...
Do I have such a recovery seed?
No. Bitcoin Core does not use mnemonics nor is the seed exportable.
Is there any other way I can migrate my wallet to the trezor? (Other than creating a new wallet and transferring funds from the existing one to this new one)
No. The only way to migrate is to send a transaction that transfers your Bitcoin to your Trezor.
MultiBit developer here.
You'll need to use MultiBit Classic version 0.5.19 available as a download from the site https://multibit.org. This will allow you to open the .key file and synchronise with the block chain to recover all the funds associated with the private keys held in the file.
Once you have imported the keys, we strongly recommend that you ...
Is this even possible?
You can move wallet contents from almost any Bitcoin wallet software to any other Bitcoin wallet software that supports the same standards. For example, if the first wallet supports Bech32, you will need the second wallet to also support Bech32.
There are only a couple of small pieces of data that need to be copied ...
There is (yet) no multi wallet support in bitcoin-core.
You can try to stop Bitcoin-Qt, replace your wallet.dat (rename the old one, place the new one) and start Bitcoin-Qt. If your wallet is really old, it will perform a rescan for new transactions and this can take some minutes.
To merge your wallets:
Open Console and enter dumpwallet <filename>
All your addresses and private keys in MultiBit HD are produced from the wallet words that you are given when you create a wallet. (This is why it is so important to write your wallet words down).
Because everything is generated from one thing the randomly generated private keys in MultiBit Classic cannot be imported into MultiBit HD.
The safest way to ...
Unfortunately the electrum seed is not compatible with BIP32/BIP44, which is essentially what Coinomi implements, so the answer to your question is no, you cannot import your electrum seed into coinomi at the moment, although this might be possible in the future.
Unless you plan on doing ECC math and hashing algorithms by hand (it would take you about a day just to do a single round of SHA256) and publishing the raw binary transaction via raw network protocol, you're going to need some software.
I would recommend getting Mycelium, which has a paper wallet import feature. You can then spend it where you like using ...
If you are using release binaries, yes. You must make sure to shut down Bitcoin Core cleanly before moving the file over, though.
If you're using self-compiled versions, this is only possible if both versions are compiled against the same BDB library.
Incoming payments will show up in both wallets.
If you spend any of the balance, the other wallet may show a 0 balance because the "change" will only go to the wallet you sent from. The other wallet won't know about the new "change" address.
The safest thing to do is to transfer all the funds to a new address.
After lots of suffering I managed to do it. Very unfortunately mycelium does not even support importing their old keys.
Fortunately they provide a backuputil which converts the private key in their format into WIF (Wallet Import Format): https://github.com/mycelium-com/wallet/tree/master/backuputil
I takes some effort to built this tool but afterwards you ...
is there a way to allow the user to import his existing wallet into my app
That looks a bit like this API function:
Create Wallet API
Create blockchain wallets programmatically
The create_wallet method can be used to create a new blockchain.info bitcoin wallet.
The structure of the Bitcoin Core wallet makes it difficult to implement importing extended public keys. This structure makes several assumptions about keys available in the keypool which xpubs do not meet. One such assumption is availability of private keys. While it isn't impossible to implement support for it, doing so is difficult to do, difficult to ...
This guide is intended for users of Bitcoin-Qt who do not want to wait for their wallet to be synchronized with the network, which may take many hours or days depending on the hardware spec. The guide teaches users how to transfer their coins to Electrum bitcoin wallet, which has lower security but a faster startup time.
To answer your ...
Though not really bitcoin related...
How are the two systems connected? I mean, can you already login via ssh? Or do you only have a terminal running on both, and no ssh daemon?
If no ssh daemon, then netcat is the tool of choice.
If ssh daemon is running, use secure copy tool:
scp -port source target
scp -P 22022 ~/.bitcoin/wallet.dat 192.168....
Your verge wallet will have made itself a wallet.dat file in its default data directory if you did not specificy a different directory yourself. You can overwrite that wallet.dat file with your one from dogecoindark if you haven't used the new one at all (obviously if you have, you should back it up). I have never used verge wallet before, but if it uses the ...
You can import a Multibit-HD (v0.4.1) wallet into Breadwallet (v38) just by using the 12 seed words and it works fine - Breadwallet shows the right balance and generates the same receive addresses.
This has been my preferred method of accessing Multibit-HD wallet from a smartphone.
Find the 'Import/Export' tab and you can find what you're looking for there.
Once you find your addresses, click "More options" and then click the private key button. I believe there was also a script somewhere but that's... gone?
Once done, go to your bitcoin-cli and use the import function like mentioned above
It's possible to export your private keys from Blockchain.info (a bit of googling showed me this: https://github.com/OmniLayer/omniwallet/wiki/Exporting-Private-Key-from-Blockchain.info-and-Importing-to-Omniwallet.org) and then import it in bitcoind using the import function (as described in https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list)