1) if I set "subtractfeefromamount" to false, fee deducted from where? and How is fee calculated?
2) for example , if i have 2 bitcoin in my wallet, and the user withdraws one bitcoin, the rest coin (one bitcoin - fee) how calculated (utxo) ?
It's always "false" by default and the fee should be covered by the input, 2) for example , if i have 2 bitcoin in my wallet, and the user withdraws one bitcoin, the rest coin (one bitcoin - fee) how calculated (utxo) ?
if its value isn't enough, Bitcoin core will have to include your other inputs or select the one with the right value,
otherwise, it will return with an error: "Insufficient funds"
Quote from: ayza_aa
3) consider the above example, I want the rest coin return to the new address (different from the source address (HD wallet)), Is there a way?
Use sendmany (0.21.0/rpc/wallet/sendmany) instead of sendtoaddress and enable "subtractfeefromamount" for the "new address" to make sure that it wont generate a change address.The tricky part is to set the correct amount up to the last satoshi, if it was set with lower amount, a change output will be added.
For example (RegTest):
Code:
sendmany "" "{\"bcrt1qk3hqnujdex64v045qdh7df28vywg5rwtdzj008\":1,\"2Mu9fzGjgnuvCrAJ1cuAu1vZGfDVzHZNHKU\":18.10239312}" 1 "comment" "[\"2Mu9fzGjgnuvCrAJ1cuAu1vZGfDVzHZNHKU\"]"- bcrt1qk3hqnujdex64v045qdh7df28vywg5rwtdzj008 - user's address that you'll pay.
- 2Mu9fzGjgnuvCrAJ1cuAu1vZGfDVzHZNHKU - your "new address" from other wallet that will receive the rest of the balance.
The example wallet's balance is 19.10239312 RegTestBTC, so the values of the outputs are 1 and 18.10239312 respectively.
But the final sent amount to 2Mu9fzGjgnuvCrAJ1cuAu1vZGfDVzHZNHKU is only 18.10238080 RegTestBTC because it's set with subtractfeefromamount flag "true".
