All Questions

Filter by
Sorted by
Tagged with
1
vote
1answer
27 views

What mean “Deep froze chain segment”?

I have question My geth show me like that "Deep froze chain segment" repeatedly What mean??
0
votes
1answer
17 views

How to check if BIP39 seed phrase is valid?

I am producing a game for a hackaton community to expose more people to Ethereum and blockchain. After hacking something my hackers will get many different seed phrases (similar to one generated by ...
0
votes
1answer
14 views

npm ERR! code ENOENT npm ERR! syscall spawn git

I use the command npx truffle unbox react to develop a dapp but I get these errors below in my console. Can anybody help me? I really don't know how can I solve them.
0
votes
1answer
6 views

should I stop geth for copying /chaindata to another machine?

Since I've made stats from geth full node by calling rpc api, it is burdensome for me to stop geth a few hours. Nowadays my local machine uses about 95% disk, so I want to migrate my /chaindata to ...
3
votes
2answers
49 views

Which mnemonic generators exist or existed?

I am unable to open a wallet I created roughly 2 years ago. In that time I have been using MEW, MetaMask and something that I installed locally on Window, which I forgot the name of. Not sure which ...
0
votes
1answer
13 views

Error sending erc20 tokens

I try to send erc20 tokens in this way var Tx = require('ethereumjs-tx'); var Web3 = require('web3') var web3 = new Web3(new Web3.providers.HttpProvider('https://mainnet.infura.io/v3/...
0
votes
1answer
52 views

Unable to call methods on my deployed contract

Problem: All method calls to my deployed contract return null Versions: Geth: 1.9.9-unstable Git Commit: c2d65d34d5c6f27b8d1a52280964023a3eefd66e solc: Version: 0.5.13+commit.5b0b510c....
0
votes
0answers
10 views

mobile web3 v1.0 not listening to events

I'm able to listen to contract events on desktop but it's not listening on mobile (coinbase wallet). const contractInstance = new web3.eth.Contract(abi, contractAddress); contractInstance.events....
1
vote
1answer
17 views

truffle unbox pet-shop gives DownloadingError: read ECONNRESET at TLSWrap.onStreamRead (internal/stream_base_commons.js:201:27)

Ubuntu 18.04. Truffle v5.1.2 (core: 5.1.2) Solidity v0.5.12 (solc-js) Node v13.2.0 Web3.js v1.2.2 When I execute truffle unbox pet-shop on terminal, I get error ✔ Preparing to download ⠼ ...
1
vote
2answers
30 views

Different address make same signature for one message

Is it possible two different wallets (address) make the same signature for one message? I have one message: '...
0
votes
2answers
25 views

Position of emit

I'm new to solidity and wondering where the emit should stay inside a function. For example: function getPlayers(address players, bool enabled) external { require( msg.sender == _admin, ...
1
vote
1answer
21 views

How to fork current eth mainnet chain in new private blockchain from block #####

I want to run my own eth fork from mainnet (keeping history of transactions, balances & etc). How can I start my new geth instance that will start working after ###### block of mainnet chain? I ...
-1
votes
1answer
16 views

How ETH is generated?

I still do not get the concept of Ethereum. How does the ETH money/coin/value is generated? Who generate that? Are the miners who process a transaction get ETH from the other user (fee) or the system ...
0
votes
0answers
12 views

Please advise new shard shuffling policy

I have a question in my think about shuffling policy. I would appreciate it if you tell me about any contradictions (can’t be justified) or supplement. Suffling shard is high cost in node because ...
0
votes
0answers
11 views

Sending tokens from multiple addresses to the main address

There is an exchanger, during registration, unique eth addresses are created for each user, I store private keys on the server, how to make sure that if users deposit erc20 tokens to their addresses, ...
1
vote
1answer
25 views

Build go-ethereum source code

I wanted to build go-ethereum source code in my local side and test it in geth. I have followed up the instructions in the github go-ethereum as it is. However, I have got fail with some errors when I ...
0
votes
1answer
19 views

Truffle js test. Test not really testing

I have this tests that supposedly pass (in the terminal, I can see the checks). But they never actually run the code: it("should add an exam to the exams list", () => { let hash_test = "...
0
votes
1answer
9 views

web3py error while interacting with smart contract 'message': 'execution error: revert', 'code': -32000

When I try to interact with the contract with web3.py, I am using ganache, I get the completely useless error message: ValueError: {'message': 'execution error: revert', 'code': -32000, ... , '...
-1
votes
0answers
8 views

Warning! Error encountered during contract execution [Reverted] in Vesting Contract [closed]

I created a vesting contract it is same with maticvestingcontract https://etherscan.io/address/0xcbfe11b78c2e6cb25c6eda2c6ff46cd4755c8fca#code when what should ı do for withdraw from vesting contract. ...
0
votes
0answers
29 views

Could not find declaration module for file 'solc'

I was trying with a simple contract,when I do "node compile.js" in my windows cmd it throws an error.I was using vscode it showing error in const solc = require('solc'),I installed everything ...
0
votes
0answers
10 views

Best Discovery Protocol implementation

Do you guys know an easy Discovery Protocol implementation that is not deprecated and is powerful enough. I've checked some, but all of them are not suitable for my task (reasons below). Checked ...
0
votes
0answers
14 views

Help me fix Error: No “from” address specified in neither the given options, nor the default options. I'm use MetaMask

file web3.js import Web3 from 'web3'; const web3 = new Web3(window.web3.currentProvider); export default web3; file image.js import web3 from './web3'; const address = '...
0
votes
0answers
17 views

Recover public key from message and signature [duplicate]

I try to recover a public key (not an address) from a message and a signature. I have the following message: def offer_hash(msg, nonce): types = ['bytes', 'bytes', '...
0
votes
1answer
26 views

Error Installing Truffle [closed]

OS: Ubuntu 18.04 I am following this guide (https://www.codeooze.com/blockchain/ethereum-dev-environment-2019/) to install Ganache, npm, and then Truffle. Everything is fine till I execute sudo ...
0
votes
0answers
6 views

Is there a standard for modelling smart contracts such as ERM for databases?

I want to document my Dapp including the "data structure" (i.e. the relationship between different contracts). Is there a good way of modelling smart contracts that anyone has used successfully?
0
votes
0answers
21 views

Error: Cross origin null forbidden : ---Problem in downloading Open source contracts from Etherscan.io

UPDATED: I am trying to download source code of open source verified contract from Etherscan.io. Here is my procedure as directed by Ann. 1. Download CSV file of captioned contracts. 2. Write ...
0
votes
0answers
18 views

Saving huge volumes of data in Ethereum

I would like to save daily prices of about 3000 items (about 2mb in size) on a public blockchain, and I would like to create a DAPP to retrieve the data. I am considering saving the data on Ethereum. ...
0
votes
0answers
13 views

Is it possible to create false positives, aka “throwing exception” on purpose in solidity?

I've been playing with this over the past weekend and it seems impossible, I guess since it's considered a big security issue if it was possible. Example to illustrate what I am trying to achieve: ...
0
votes
0answers
13 views

About genesisfile

ethereum-wallet-xxx.jsonfile exists when purchasing genesis. I do not know if I set a password. Is this possible to restore? There are encseed, bkp, ethaddr, btcaddr, and email file formats.
1
vote
1answer
27 views

Why does Ropsten faucet show “Your account is grey listed for 0 hours and 0 minutes”?

I am requesting test ether from a Ropsten faucet, but it is showing an error. Please help me to resolve this error.
0
votes
0answers
9 views

How does specifying job parameters on Chainlink work?

I am trying to understand Chainlink, and I am running into a wall. I found this tutorial, which explains how I can create a job spec using JSON. The tutorial explains that you can specify the url, ...
0
votes
0answers
25 views

Why does this code outputs error:“unknown account”?

Python code: from web3 import Web3 import json web = "http://10.0.141.114:8545" web3 = Web3(Web3.HTTPProvider(web)) abi=json.loads('[ { "constant": false, "inputs": [ { "name": "_cad_number", "type":...
-3
votes
0answers
14 views

how to solve the syntax error and debug it [closed]

Expected identifier but got 'function' function test() public{ ^------^
1
vote
0answers
22 views

How to check current status of state variables

I have deployed my contract locally into Ganache (GUI) and then send/call lot of transactions. After these transactions, now I want to check the current status of all state variables. Is there any way/...
0
votes
0answers
18 views

When to stop importing new chain segments from Rinkeby testnet?

I am using geth to sync up with the Rinkeby testnet using the command: geth --rinkeby --syncmode "fast". First it downloaded the blocks, then account states, and now new chain segments are being ...
0
votes
2answers
26 views

It seems impossible to perform some action and then throw returning an error?

How can I accomplish something like this: accept ether, set owner or anything and then return 1, throw...just return This doesn't seem to work despite crossing through functions and using if ...
0
votes
0answers
19 views

Error when interacting with smart contract on MEW (MyEtherWallet) [closed]

I'm getting the error below when trying to call a function in my smart contract to transfer a token from the current wallet in MEW to an address. Here's the screenshot, https://nimb.ws/NZCD8u I used ...
0
votes
0answers
13 views

Synchronization mode

What kind of node synchronization should I choose to work with a centralized exchange? Is there enough quick synchronization, or is full synchronization necessary?
1
vote
1answer
21 views

If msg.value is specified in a call such as “msg.sender.call.value(msg.value)” then where is msg.value taken from, when this is from contract?

Given the following example: function x(address receiver) public { receiver.call.value(msg.value)(); } Am I correct that receiver can be any address but msg.value cannot be controlled via ...
0
votes
1answer
13 views

Truffle Error: ContractName has no network configuration for its current network id (1575203139857)

Im doing the tutorial at https://github.com/ConsenSys-Academy/proof-of-existence-exercise and running into the following error: $ truffle console truffle(development)> var poe = await ...
0
votes
0answers
18 views

How to query ERC20Token kinds [closed]

I want to query kinds of ERC20Token which some address holding,I used etherscan's api but only find ERC20Token's balance. Is there one api can finding?
0
votes
1answer
25 views

Smart Contract deployment failed

I am making my project of BlockChain subject. I am having a problem with deploying smart contracts. Can anyone help me with this error I have tried everything I could but still failed to resolve this ...
0
votes
1answer
12 views

If you need a server to store HTML and java script code, then what is the use of the block chain?

I have been studying block chain for a while, and I came to know that decentralisation of data is its greatest pros. From my understanding, if block chain is massively adopted in the future, we will ...
0
votes
1answer
9 views

Nethereum contract.getPastEvents equivalent

I want to query all transfers regarding a contract with Nethereum. This means, in the end I want to have all transactions, so that I can print a statement of account. I suppose with the web3.js ...
0
votes
1answer
24 views

RPC error when interacting with contract using Ganache GUI, but it works fine when using Ganache CLI

I have a truffle project, if I migrate it onto ganache-cli and then interact with my contract (via Metamask) it works great. But if I try and do the exact same thing using ganahe-gui the contract ...
0
votes
1answer
10 views

Deploy smart contract on Ropsten, Kovan

When I deploy my truffle smart contract on test networks like Ropsten and Kovan, can I interact with it using multiple PCs at once simultaneously? And will the data updated from one PC be visible on ...
0
votes
1answer
16 views

Node synchronization

The question is about the node, is the node functionality enough in fast synchronization for the functioning of a centralized exchange? Or is it necessary to download a node in full synchronization?
0
votes
0answers
18 views

Did I get this right that with delegatecall the msg.sender is the last entity that calls delegatecall (example below)?

In other words: If contract B is called by contract A: B: function externalcall() public { //msg.sender is contract A... msg.sender.call.value(0); } Then assuming msg.sender.call above calls back ...
0
votes
0answers
5 views

Server configuration selection

What server configuration is needed to raise a node? And will there be enough nodes in fast synchronization mode for the exchange, or is full synchronization necessary?
0
votes
1answer
23 views

How does smart contracts exactly work?

I have read about smart contracts and I am left with some doubts. Every invocation of a function in smart contract is a transaction which costs some ether.A miner chooses a smart contract on ...

15 30 50 per page