All Questions

Filter by
Sorted by
Tagged with
0
votes
2answers
171 views

Installation of pyethapp fails on Raspberry Pi

I'm trying to install pyethapp on Raspberry PI B+ sudo pip install pyethapp getting error Complete output from command python setup.py egg_info: Couldn't find index page for 'pytest-runner' (maybe ...
0
votes
2answers
20 views

How can I get the current user account selected in MetaMask with Web3 js?

I'm using the next function to get the first account from user's MetaMask: var account = web3.eth.getAccounts((error,result) => { if (error) { console.log(error); } ...
0
votes
0answers
6 views

Problem with understanding contract containing array of structure

I got the following code for a contract from a Solidity tutorial website: pragma solidity 0.5.1; contract MyContractPersonStruct { Person[] public people; uint256 public peopleCount; ...
1
vote
1answer
228 views

Truffle test case to unit test withdrawal pattern

How can I test the withdraw() function in a truffle javascript test case for the below contract? The problem is, If I use the msg.sender from the same contract, the before and after balance will be ...
0
votes
2answers
203 views

How can i read transation data from ethereum to file or database?

I want read transations data "input" field from ethereum to file.How can i do it?thanks.
1
vote
0answers
14 views

Contract does not exist at address

I have setup a private Quorum network and successfully deployed contracts and executed contract functions using Visual Studio Code and remix. When i try to deploy the exact same contract manually ...
0
votes
2answers
20 views

Cannot transfer ether from smart contract to another address

I am using truffle and when we type truffle develop it provides us with 10 address ** So, the problem I am facing is I have created 2 functions one to deposit ether and the other one to transfer the ...
0
votes
1answer
558 views

Geth: Genesis block mismatch & subprotocol error

I'm using Geth 1.7.3 in MacOS 10.13.2 High Sierra. When I'm running Geth to sync the main network, the verbose log (verbosity=4) tells there are quite a few errors: subprotocol error Genesis block ...
0
votes
1answer
12 views

getBalance of shows the wrong balance

I have this code to show the erc20 token balance of an account var tokenAddress = '0xb97E9bBB6fd49865709d3F1576e8506ad640a13B'; var walletAddress = '0x62f28320f688A7A4e0021c55d7ffD1acd770A133'; ...
0
votes
0answers
8 views

custom ERC20 token balance does not show up on my own 0x exchange

I created my own 0x exchange according to the 0x Launch kit and the FAQ. I could add my newly created, custom ERC20 token to my 0x exchange, the token appears and I could even buy/sell them. The ...
0
votes
1answer
70 views

Gas is 0 when executing CALL opcode?

I wrote a very simple smart contract like this: contract Test{ function test1(address payable addr, uint256 value) payable public { addr.transfer(value); } } And I compiled it using ...
0
votes
2answers
88 views

how to add my custom token to 0x protocol in testnet/mainnet

I am new to the 0x protocol. Is it possible to add custom token using 0x Portal DApp?. Share any example or document. I have deployed my own exchange medium. it is running in http://localhost:3001 I ...
1
vote
2answers
582 views

How to connect peers which are on different computers in geth on private network?

I am trying to setup a private network and trying to connect peers. Currently I'm trying it on my laptop and virtual machine(VM) runing on the same laptop (both of them are connected to internet). I ...
0
votes
1answer
374 views

How ERC20 Token balance are recovered during Ethereum chain rolling-back

My Answer: Ok, the problem is really with Ganache ... If I use geth, everything is alright. ... ... sorry for your time ... ---------------- The Original Question -------------------- My ...
1
vote
0answers
423 views

Is there an API or library available to integrate an ERC20 compatible wallet into my android app?

If the android app being developed is going to display balances and allow sending and receiving of ERC20 tokens, is there an API or library that people would recommend for this functionality?
9
votes
4answers
17k views

Is there API to create Ether wallet?

I know how to create wallet manually, however I would not like to take my clients out of website (I doubt anyone would) and would rather do their wallet creation behind the scenes when they register ...
0
votes
0answers
8 views

How to call contract function in deployed conctract with Infura and nethereum

i'am trying to call smart contract function in test network "Ropsten" https://ropsten.etherscan.io/address/0xa89d48b51801b61b27f9dee744b888ae152c2115 (few failed transaction is just testing with empty ...
0
votes
1answer
202 views

Python3, Populus installed but not working, deprecation

Populus was functioning well until I began getting deprecation warnings. So I did pip uninstall populus and then pip3 install populus. Also installed all required python3 libraries. The install worked ...
0
votes
1answer
15 views

What is the differenc between Person and Account variables

What is the difference between Person and Account? struct Account { address addr ; uint balance ; } Account[ ] public accounts; function applyInterest () public returns ( uint ) { for ( ...
0
votes
1answer
420 views

Ethereum's State sharding vs Zilliqa's Network Sharding

From Zilliqa what I get is they have temporary transactions done in parallel in different shards then merged into a main chain. What's the difference between the latest sharding specification for ...
0
votes
0answers
11 views

How is this possible using web3 and truffle accounts

all i want is this Alice sends contract 1 Ether. Now contract has 1 Ether. Contract forwards 1 Ether to Bob. Now contract has 0 Ether. I know this is possible but to accomplish it with front end AND ...
0
votes
0answers
9 views

“truffle migrate --network ropsten” stuck after compiling

I am trying to redeploy a contract on Ropsten Testnet using the command: truffle migrate --reset -f 1567182283 --network ropsten Here, "1567182283" is the prefix of my migration file. Upon executing,...
0
votes
1answer
61 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 ...
0
votes
2answers
387 views

I cannot send ETH from my blockchain wallet

Yesterday i have Transaction {Dropped & Replaced) https://etherscan.io/tx/0xfdca0e5c597f0a3f298afd5d56e939a8cefc10117df6b22d5342e1b6d5803caf I saw it Replaced by TxHash:...
0
votes
1answer
7 views

Integrity of old blocks in the blockchain

I am learning Ethereum using Geth, and I am testing PoA-Clique networks. Now I have a conceptual doubt about old blocks integrity. Suppose I have a private blockchain network of only one miner node ...
2
votes
1answer
189 views

call graphs for solidity smart contracts

Do we have some open source tools where we can get call graphs for solidity smart contracts execution ? For ex: Suppose Function A in contract C calls some other function B so the graph should contain ...
0
votes
1answer
238 views

How to access storage areas when libraries are used?

I am testing storage areas to see exactly the efficiency aspects of this and I have trouble finding the storage on the disk for the contract/library combination. Here is the code - pragma solidity ^...
2
votes
3answers
655 views

How to make a token private

How can I create a smart contract that has a function that receives an input ( either eth or another erc20 token ) and sends it to a specified address without revealing who sent it? Basically making ...
0
votes
1answer
42 views

Ethereum Contract Scalability (Single vs Multiple Contracts)

I am writing a token swap contract on Ethereum Blockchain to manage ERC 20 token swap in an exchange. The Questions is that in terms of scalability, which of the following two options would be better ...
2
votes
1answer
358 views

How to connect my private ethereum network to ethereum android app?

I want to access my smart contract through a mobile app, which is on my private network. There is ethereum android app, can I connect that app to my ethereum network or if there any other app through ...
1
vote
2answers
486 views

function () public payable modifier can trigger actions when sending tokens or only works when sending ether?

Modifier payable triggers an action when an address sends ether to a contract. For example: function () public payable { require(msg.data.length == 0); DoSomething(); } Is this ...
0
votes
4answers
722 views

how much does using ethereum services cost

Lets say im creating my own cryptocurrency and my own blockchain on ethereum, what would be the basic costs for setting all this up if i am developing on Ethereum
1
vote
1answer
229 views

Convert future date to UTC

Is there an easy way to convert a set time to UTC and stored in a smart contract? I know we can set dates relative to the current timestamp such as "now + 5 days". Though if we wanted to set a ...
0
votes
1answer
24 views

cant call contract instances on my UI

I want to be able to display the read functions of my contract on a UI. These are the calls I make to my UI Those functions work perfectly in the console using node but when i try to call them from ...
0
votes
2answers
468 views

Message Signing using MyCrypto and MyEtherWallet

I am trying to update my Token information and it is asking me to sign the message using either MyCrypto and MyEther Wallet and proceed. Unfortunately tried both and both of them are not creating ...
1
vote
1answer
295 views

How to get the returned value of a smart contract function when it called by using cacheSend() in drizzle

I just tried to build a simple DApp using truffle, react and drizzle. My question is how to get the returned value of a smart contract function when it called by using cacheSend() in drizzle? As ...
0
votes
1answer
56 views

Supply amount exceed total supply! Why the quantity supply shown 1.00 E+59

the quantity amount over the total supply, shown 1E +59 Airdrop solidity code maybe got something problem, does someone had idea?? Can't check for token Holder, "Sorry, We Are Unable To Generate The ...
0
votes
2answers
195 views

How to communicate with a deployed token?

Using Truffle, I am trying to deploy the following contract: pragma solidity ^0.4.13; contract ERC20Events { event Approval(address indexed src, address indexed guy, uint wad); event ...
0
votes
3answers
508 views

Access to a child contract method

my question is simple and I want to know if there is a possibility to achieve something like this. I have two contracts, one inherit from the other; I want to access to a method of the child contract ...
0
votes
1answer
15 views

Redeploy contract on Ropsten Network

I have already deployed my smart contract on Ropsten network for testing using truffle suite. The command line I used was: truffle deploy --network ropsten Now, I have made some changes to my ...
0
votes
1answer
19 views

How to store a erc token instead of eth into solidity function

How to store a token instead of eth into solidity function below are the code for storing ether. how to change into erc 20 token instead function deposit() public payable{ require(msg.value >= 1 ...
7
votes
1answer
606 views

Parity Error: Account not found for the current chain (Kovan)

I am having problem starting Parity with a account that I created using Metamask. This account 0x76Eb17471A5fb78EF6768254D1dAEc528ec6b5a8 has received multiple ETH from Kovan faucets. Running the ...
2
votes
1answer
288 views

Pending transactions Geth private Blockchain

I have an ethereum consortium blockchain based on Azure (Geth 1.7.3). I've been experimenting with an application which has a very simple smart contract. The contracts itself, stores data that comes ...
0
votes
1answer
458 views

Ethereum transaction taking forever? From MEW to IDEX wallet

new to IDEX and mew, but I hooked up my MEW wallet to IDEX and than deposited ethereum to my IDEX wallet with the default gwei, just wondering why its taking so long? its been 4 hours and no ...
0
votes
1answer
25 views

Making contract compatible with newer solidity version

I have a simple ERC20 contract however it doesn't work with modern solidity compilers, Could anyone make my contract compatible with solidity newer than 0.5.16? Thanks. Here is the code, it only ...
0
votes
0answers
35 views

Whas this Error Code and how can i get rid of it?

Im using this code to query the balance of the logged-in address // get sellPrice function sellPrice() { web3.eth.getAccounts(function (error, accounts) { contract.sellPrice(address, ...
1
vote
1answer
61 views

Where does parity look when trying to import geth keystore files

I'm in the directory for parity keystore files, namely, ~/.local/share/io.parity.ethereum/keys/ and I've run: parity --import-geth-keys But I get an error saying: Failed to find geth keys ...
2
votes
2answers
693 views

modify truffle console command to execute function on ropsten deployed contract thru geth

There are a couple of commands, reproduced below, which I've used successfully in the truffle console, executing on testrpc, which work and elicit the responses that I expect. How can I change them ...
2
votes
1answer
260 views

Error on transaction submission: insufficient funds for gas * price + value - web3 v1+

I am trying to submit a transaction via web3 and getting the following error: Error: Returned error: insufficient funds for gas * price + value. Here is my code: console.dir(txParams); const tx = ...
1
vote
1answer
528 views

Where is the compiler in Remix?

I installed remix-ide. It is able to compile contracts. So it somehow calls Solidity compiler. Where is this compiler located in the filesystem and how to use it without remix-ide?

15 30 50 per page