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Sending ethereum smart contract transactions to miners

We are building a decentralized document issuance application using the ethereum blockchain. For every transaction, some gas costs deduced in the form of ether. Is it possible to host ethereum miner ...
1
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2answers
13 views

Error: gas required exceeds allowance or always failing transaction in Remix using Ropsten network

I am facing this error , My Contract is quite simple pragma solidity ^0.5.0; contract sendEther { address payable sender; function showReceiver() public view returns (address payable) { ...
0
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0answers
10 views

Can my eth adress be found through ens domain?

I have squaded several .eth domains and have since released them, now, I dont want them to be associated with my address. 1. They still pop up when I enter my ens manager, can I somehow make them ...
0
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0answers
17 views

Nested usage of interfaces?

Using solidity ^4.x, it seems I can use an interface as a parameter type in a function from a different interface. Example: interface IERC20 { function transfer() external; } import "./IERC20....
1
vote
1answer
13 views

How to add custom precompiled contract?

I want to implement some features as precompiled contracts in Ethereum. I read some articles and the contract code, but I still don't know how to do this. Is there's a tutorial from scratch?
0
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0answers
14 views

Web extension doesn't see Metamask

I am working on a web extension which have to link with Metamask. But the problem is: In console, ethereum.enable() works well, in the console of my web extension, does not work.. How to fix that? ...
0
votes
2answers
27 views

How do I send part of a transaction to all token holders?

Here is the code for someone performing a transfer of my token function transfer(address to, uint256 value) public returns (bool) { require(value <= _balances[msg.sender]); require(to != ...
0
votes
2answers
31 views

How to set and get marketprice of token in contract?

I am building a simple erc-20 token. I don't have an idea as how token price is setup. However, I need to get my token's market price inside another contract. If you see this example of token BOMB, it ...
3
votes
1answer
16 views

Why does the `DoCall` function use the first account by default?

In this line, // Set sender address or use a default if none specified var addr common.Address if args.From == nil { if wallets := b.AccountManager().Wallets(); len(wallets) > ...
1
vote
1answer
14 views

Why does function GetEVM set the balance of from address to MaxBig256?

As you can see in this line, func (b *LesApiBackend) GetEVM(ctx context.Context, msg core.Message, state *state.StateDB, header *types.Header) (*vm.EVM, func() error, error) { state.SetBalance(...
0
votes
1answer
19 views

How to get ethereum gasPrice from a transaction hash?

I need to get the gasUsed and gasPrice so that I can calculate the correct amount of gas required for a transaction. I can get the gasUsed using: var accountOneReceipt = await contractInstance....
0
votes
1answer
13 views

ECC scalar multiplication

I'm now trying to use scalar multiplication to recover v, but I have questions with ECC scalar multiplication. I'm wondering if the following equations are correct. If scalar * P = Q, then scalar * (...
1
vote
1answer
32 views

Remix - another transaction execution failed

I am trying to reproduce the results on Remix with the smart-contract as written here: https://etherscan.io/address/0xb6ed7644c69416d67b522e20bc294a9a9b405b31#code (for remix, go to http://remix....
0
votes
0answers
4 views

Mapping an ethers.js pattern to web3 library

I'm working off an example that looks something like this: this.web3js = new Web3(window.web3.currentProvider) const ethersProvider = new ethers.providers.Web3Provider(this.web3js.currentProvider) ...
0
votes
1answer
8 views

Map error status 403 for https://cdn.ethers.io/scripts/ethers-v4.min.js

My webpage is not rendering the a table with sample code below. I can see on the Browser Console the promised block objects but this message shows: Source map error: request failed with status 403 ...
1
vote
1answer
13 views

Does truffle test mimic the exact network state of an actual migration?

I've defined a truffle migration step as follows: Deploy my 'main' smart contract, nothing out of the ordinary: var UniversityVoting = artifacts.require('./UniversityVoting.sol'); module....
1
vote
1answer
13 views

Update on the projected coin inflation for ethereum?

I've seen this question: What is Ethereum's inflation rate? (how quickly will new ether be created) but the answers are vague and out-of date I know that Bitcoin is halving and all coins will be ...
0
votes
1answer
16 views

The constructor should be payable if you send value. The transaction has been reverted to the initial state

I'm following a LinkedIn course on Solidity and creating a simple contract. Code below: I'm new to solidity so I'm not sure exactly where I'm going wrong but I get the following error: Transact to ...
0
votes
0answers
12 views

LocalEthereum Won't Let Me Create or Log In With Ledger

I have a Ledger Nano S and created a LocalEthereum account awhile ago by connecting my ledger to the account. It worked fine and I purchased some Ethereum. A few weeks later, I attempted to sign back ...
2
votes
0answers
17 views

Ethereum pruning: What if no archival node existed?

I was reading about pruning in Ethereum which is basically a way to run a full node without needing to keep over 1TB of blockchain data. To my understanding, the whole blockchain exists but only keeps ...
2
votes
1answer
37 views

How to modify the algorithm of transaction selection in Ethereum private net?

By default, miners select transactions with high fees from the mempool. So, transactions which are dependent and have a specific order can be selected randomly without respecting this order. Will I be ...
0
votes
3answers
22 views

Why are contacts from Remix editor and explorer different after deploying?

I try to deploy my ERC20 token. My steps are: 1) I created a contact with Remix (by some manual) https://gist.github.com/pistol88/a934da7fcaa93a92f4c4de60df56a0cf contract TestToken is ERC20Standard ...
1
vote
2answers
28 views

ecrecover() always returns 0x0000000000000000000000000000000000000000

I'm aware of these posts How do you sign an verify a message in javascript proving you own an Ethereum address? How does one properly use ecrecover to verify Ethereum signatures? I'd like to sign a ...
0
votes
2answers
45 views

Solidity - How do I generate a random address

I would like to generate a random 0X address using solidity. It would be the best if it could be an existing address, however, I understand that it might be too complicated to do (it might need an ...
0
votes
1answer
21 views

Is it possible to create a trigger when a state variable contract is i.e. 10?

Let's supose this is my contract: Contract MyContract{ uint a = 0; function myFunction(){ a = 0; } } I want "myFunction" to fire up when "a" value is 10. Thanks.
0
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0answers
17 views

I can see my ethereum but its not going to my wallet

My ethereum has been confirmed delivered but not in my wallet,fairly new but I have made successful transactions before,I can see my ethereum in etherscan.io 0x2ecc74c6e9c42eea14863fbc1e1d9656b339a6ec ...
0
votes
1answer
23 views

Custom token showing balance of 0 in MyEtherWallet

I made a new token on the Ropsten test network. Here's the contract address: 0x801fd9c17087ec868dc8540055b7ea3cb6dbbe34. When I followed the instructions to add this custom token to MyEtherWallet (by ...
0
votes
0answers
22 views

How to enable and use the accounting module?

I found the accounting module in this line and want to use them. i attached the accounting module to parameter --rpcapi accounting when run console node but could not found this module. run node: ....
0
votes
1answer
28 views

error: VM Exception while processing transaction: revert SafeMath: subtraction overflow on migrating crowdsale conract

I am developing the token sale Dapp using openzepplin-solidity version 2.3. While migrating, I got the following error. Returned error: VM Exception while processing transaction: revert SafeMath:...
0
votes
1answer
23 views

Create self-airdrop to 20,000 wallet addresses with specific conditions

I want to create an aidrop to my ERC20 token with automatic distribution: -The user must therefore send 0 ETH to the smart contract or to a specific address, and he will automatically receive his ...
0
votes
1answer
17 views

Tallying Majority Consensus From Nested Struct

How do I tally the votes of a nested struct to find out majority consensus? as an example, if we have following scenario below; I want to create a function which allows me to calculate whether ...
0
votes
1answer
16 views

What is the best combination of transactions to send to an Address for a given target amount?

Let's suppose I have 100 unlocked accounts with different balances and I want to have in a target account an amount X. Knowing that I have to make an individual transaction for every account, what ...
0
votes
0answers
19 views

What is meant by Ethereum instrumentation?

Some body please tell me what is meant by Ethereum instrumentation? I found this term in following two articles at: [EVM* From Offline Detection to Online Reinforcement for Ethereum Virtual Machine1 ...
0
votes
1answer
19 views

How can i make payment application using the blockchain?

i want to make payment based application by scratch using blockchain, so where can i learn from scratch and what are the different component that i should learn to make an application or a website ...
0
votes
0answers
7 views

HyperLedger Mobile Application Development

For market reasons I am studying the HyperLedger platform. In the last year I studied the Ethereum platform where I developed web/mobile applications. My question regarding HyperLedger Fabric is: On ...
1
vote
1answer
17 views

Upgradability Proxy ADMIN_SLOT assembly sstore does not update

I'm currently playing around with Proxy Upgradability, and noticed the use of assembly in terms of the new upgraded contract and the slot assigned. Real implementation can be seen here. I have ...
0
votes
0answers
25 views

Interaction smart contract and third-party app : How to make sure the request comes from the original contract?

I'm working on a blockchain project where I need to access data stored outside the smart contract. The smart contract own a RSA keypair (one public and one private key). We want the private key to ...
-2
votes
0answers
31 views

My vote Count is not updating (https://github.com/llSourcell/Your_First_Decentralized_Application) i'm trying this project

Total vote is not increamenting, code link web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545")); abi = JSON.parse('[{"constant":false,"inputs":[{"name":"candidate","type":"...
0
votes
1answer
21 views

Private transaction validation in quorum

I was going through the quorum documentation and stumbled upon how private transactions are validated in quorum. Take the following example where there are four nodes - Node A, Node B, Node C and Node ...
4
votes
2answers
117 views

Inline assembly, good or bad practice

I often see inline assembly in Solidity contracts. I consider this a bad practice because of the poor readability, however this is my opinion only and there must be valid reasons to use it. There are ...
0
votes
1answer
37 views

I am getting error while installing truffle in Ubuntu 16.04 LTS. How to resolve this issue?

When i enter this command: sudo npm install -g truffle I get the following error: > truffle@5.0.27 postinstall /usr/lib/node_modules/truffle > node ./scripts/postinstall.js Error: EACCES: ...
1
vote
0answers
14 views

I can not get to my MEW using Ledger Nano S [on hold]

When I want to open my wallet using ledger, it says that "No Compatible devices were found"( it is just in Slovak language), however my ledger works as I am using it with another wallets. It only ...
2
votes
2answers
28 views

Transaction disappeared from the pending transactions in node

My ether wallet has been working for more than 1 year. Today There was a memory issue in my node and the node shutdown. When I restarted the node via geth client the node resound ~5000 blocks behind ...
0
votes
2answers
45 views

How to create a RawTransaction for contract interaction Web3j

I want to sign a transaction that calls a smart contract function and send it to the Rinkeby network. I found on Web3j documentation the RawTransaction class that supports the methods for the ...
0
votes
1answer
21 views

Initialising Empty Arrays & Structs In Struct-based Storage Graph Structures?

How do I initialise empty arrays and structs in nested structs data structures? contract NewBook { struct ReviewerData { string name, uint industryXP // ...
2
votes
1answer
27 views

How make Ethereum QR-code with Input Data?

how i can make QR code with address, amount, gas price and Input Data? Is it possible?
0
votes
1answer
30 views

How to use window function in controller (node.js)?

So this is my users controller to upload a file : exports.postUploadFile = (req, res, next) => { var ethereumURI = req.body.ethereumURI; var abi = JSON.parse(req.body.abi); var ...
0
votes
2answers
15 views

it'll give me a parser error

pragma solidity ^0.5.0; contract fisrtCoin { address deployer; mapping(address=>uint) balances; public function fisrtcoin() { deployer = msg.sender; } public ...
0
votes
0answers
14 views

Why can’t light nodes broadcast transactions directly?

Everything I’ve read about Ethereum thus far seems to state that light nodes are incapable of broadcasting/relaying/etc. transactions themselves. It is also my understanding that light nodes have ...
2
votes
1answer
31 views

How to detect coin transfer from transaction

This is my transaction data. How to detect transfer coin from it (eth, bee, binance coin,...). Thanks. { "status": 200, "title": "OK", "description": "Successful request", "payload": { "...

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