Most Popular
1500 questions
16
votes
4 answers
unable to connect Ethereum node even RPC port: 8545 is open
I have created my private Ethereum blockchain network. From different servers I am able to connected and added into the network as peer without any problem.
The way I run my server:
geth --targetgaslimit "994712388" --port 3000 --networkid 23422…
alper
- 8,395
- 11
- 63
- 152
16
votes
5 answers
Solidity: Is there a way to get the timestamp of a transaction that executed?
Is there a way for a contract to be able to get the exact time someone called a function in it?
For example, if someone sends funds to the contract address, is there a timestamp recorded by the blockchain that would give the received time of this…
Pabi
- 1,129
- 4
- 11
- 18
16
votes
3 answers
invalid arrayify value while using bytes32 array
Since we cannot pass string arrays as parameters in solidity I used a byte32 array in a function. The code gives no error at compile time. But when I give input to the drawCard function as below in Remix IDE
"this is token uri",…
mzaidi
- 992
- 2
- 13
- 36
16
votes
2 answers
Explain "griefing" attack on Aave flash loan
Aave doc about flash loan warns to never store funds inside a receiver contract as it can be exposed to "griefing" attack.
So my questions are
Can you give an example of this attack?
How can funds be stored, when they need to be returned in the…
tsknakamura
- 611
- 4
- 9
16
votes
1 answer
How can I retrieve my account's Augur (REP) token balance via JSON-RPC?
How can I check the contract balance, like Augur (REP), on an address with JSON-RPC? There doesn't seem to be alot of documentation about this.
Julian
- 263
- 2
- 6
16
votes
4 answers
How to automatically get user's wallet info if they are connected but NOT show the metamask pop up if they are not?
I don't want metamask to pop up on page load forcing a user to connect, so we only connect via a button - but after a user is connected if they refresh the page - they need to press the button again to connect (although nothing happens in metamask,…
Zach
- 571
- 3
- 7
- 25
16
votes
2 answers
ERC721 Token Transfers and Approvals
ORIGINAL POST (EDITED POST BELOW):
I keep getting the following error in my ERC721 Contract:
“ERC721: transfer caller is not owner nor approved”
This happens when I’m trying to buy a Token that has already been minted and transferred by this same…
Mark55
- 1,011
- 2
- 13
- 27
16
votes
2 answers
How do I convert my The DAO tokens into ethers on the Ethereum Classic chain?
According to Whitehat Withdrawal contract - Update and Next Steps and Whitehat Withdrawal contract - Last update before deployment, the Goodies will be deploying the withdrawal contracts whetcwithdraw.sol, authorized_addresses.sol and…
BokkyPooBah
- 40,274
- 14
- 123
- 193
16
votes
1 answer
How much does it cost to use a contract?
Still new to ethereum and would like to know the price for a contract.
Patoshi パトシ
- 4,800
- 7
- 45
- 93
16
votes
1 answer
Bytecode on block chain different from the one used when deploying
When I deploy a contract from node.js using the web3 JavaScript API (connected to a locally running geth), and then check the deployed bytecode using eth.getCode(address) (either from the JS console or in node, both connected to a locally running…
mazi
- 443
- 4
- 10
16
votes
7 answers
Can I write and deploy smart contracts in Java language?
I am a Java developer. I want to write a smart contract using Java and deploy it to a private blockchain network.
Does Ethereum provide the facility to write smart contracts using Java language? If yes, how can I do this?
jambu gunvant
- 311
- 1
- 2
- 5
16
votes
2 answers
How do I get a refund for the amount I paid in excess of 1 ether to 100 The DAO tokens
Anyone who bought DAOs in the last two weeks of The DAO crowdfunding phase paid more than 1 ether (ETH) per 100 The DAO tokens (DAO). The ETH amount in excess of 1 ETH per 100 DAOs was stored in The DAO's extraBalance account. The balance of the…
BokkyPooBah
- 40,274
- 14
- 123
- 193
16
votes
1 answer
Difference between transactions and raw transactions in web3.js
Reading the documentation of web3.js I have come across sending transactions and raw transactions.In the documentation it's specified that send raw transaction sends an already signed transaction.
Does this imply that web3.js does not sign…
Sebi
- 5,294
- 6
- 27
- 52
16
votes
2 answers
Difference between window.ethereum and window.web3?
If I log the two functions, I get two objects, that both contain for example selectedAddress, but the structure of the objects seem different. I couldn't find a comparison in the documentation.
I did find out that window.web3.currentProviderand…
Marcellvs
- 423
- 1
- 4
- 13
16
votes
5 answers
How to get the actual Gas price?
Is there a way to get the lowest and average price miners are asking for gas? Some statistics sites seem to have prices but they are outdated.
Roland Kofler
- 11,638
- 3
- 44
- 83