All Questions

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1answer
2k views

getting error nonce too low , but nonce is proper stuck since one day

I am working with web3.js since sometime now , but now i am stuck with nonce too low error , the nonce is proper also i have checked private key and other addresses , they also seem to proper , ...
0
votes
1answer
764 views

how to check if my testnet geth node has mined some ether?

As per the instructions detailed in this post, I've created an account: and started running my geth node: how can I check if it's mined any ether yet? the answer of @lungj resulted in this:
0
votes
1answer
103 views

Problem with meteor server side call to Ethereum node

I try to interact with Ethereum node via web3 lib. (meteor add ethereum:web3) Meteor 1.5.4.1 lib.js if (typeof web3 === ‘undefined’){ web3 = new Web3(new Web3.providers.HttpProvider(‘http://127.0.0....
0
votes
1answer
103 views

Truffle: how to setup some smart contract's attributes before writing test

For example I have a smart contract with 2 attributes: contract SimpleSmartContract { uint256 currentPrices; mapping(uint8 => uint256) public priceIncrements; } When I write test, I want ...
0
votes
2answers
696 views

truffle/web3 event listeners returns nothing

We have an event being triggered in a contract and our listeners on the client cant receive the return value. https://gist.github.com/stupeters187/9529b54fe0d48ee606ad06ced6b16031 Update: metamask ...
0
votes
2answers
242 views

pragma solidity ^0.4.11; vulnarability

As stated on this website http://fluidai.co/examples/ one of Solidity's vulnerabilities is using an open version in pragma: pragma solidity ^0.4.11; You're telling the Solidity compiler to use ...
0
votes
2answers
483 views

Why is string getter returning an empty response?

This is a sequence of another question I asked. I have the following contract contract User { string publicKey; function setPublicKey(string _publicKey) onlyOwner { ...
0
votes
1answer
262 views

How to add peers to a private blockchain network without using IP address?

I have created a private blockchain network and added peers to that network using the admin.addPeers() command. But the problem is, in that method I have to give the local IP address of the system ...
0
votes
1answer
220 views

How to transfer tokens to bounty participants?

What is best practice to send ERC20-compliant tokens to bounty participants? There could be from 1 to N participants. Also there will be some table with list of users/addresses/tokens/etc. Should I ...
0
votes
1answer
153 views

Getting TypeError: Operator == not compatible with types int_const 1000000000000000000 and address payable

I am trying to use external modifier however I getting error as below code. { require(block.timestamp < start + buyPeriod); require(1 ether == msg.sender);<--- error got here ...
0
votes
1answer
225 views

Problem of deploying contract with “testRPC” and “remix” : “creation of contract pending …”

When I try to deploy a contract using testRPC and remix, I receive: creation of contract pending ... I tried even the default contract of http://remix.ethereum.org. Steps: First I open cmd. Then ...
0
votes
2answers
122 views

Gas issue on sendRawTransaction on the rinkeby network

I'm facing a gas issue on rinkeby network on sendRawTransaction. Tested with various gas value to experiment and getting either insufficient funds for gas * price + value or exceeds block gas limit. ...
0
votes
2answers
1k views

How do I know if my private net is using Byzantium?

Is there a flag that is showing that Byzantium is actually enabled in my private network? This is the only thing I have found in my log at geth startup: INFO [10-26|01:10:40] Initialised chain ...
0
votes
1answer
17 views

Define “difficultyHardforkTransition” parameter?

I have looked through all of the glossaries I know of for genesis/chain spec files but I don't see this one. Can anyone tell me what "difficultyHardforkTransition" means?
0
votes
1answer
815 views

GETH ~ why do i get ERROR: no space left on device

While downloading blockchain im getting this error Fatal: Error starting protocol stack: write /root/.ethereum/geth/chaindata/230944.ldb: no space left on device how this can be resolved? Im ...
0
votes
1answer
674 views

Unlock remote account

I have smart contract deployed that accepts funds (via fallback function function() payable { ... }). Also I have frontend using web3 to send funds. When I tested it with local node (and JSON wallets ...
0
votes
2answers
299 views

Ethereum transaction RangeError: private key length is invalid

I'm running a tutorial on how to sign an ethereum transaction programmatically, and I'm getting the following error: RangeError: private key length is invalid This is the code: var Web3 = require(...
0
votes
1answer
32 views

how to get the real balance of ETH by eth_getbalance

as I know, the transaction should be confirmed by 11 times then it will be done. but when i use eth_getbalance to get the balance ,it will return some fake balance without confirmed. so How can I get ...
0
votes
1answer
2k views

Contract Not sending ether to other account

I have created a contract which store the address of the users and i want to send 1 ether all the users stored in array. Here is my code contract project{ address public user; bytes32[10] ...
0
votes
1answer
243 views

eth.getBalance(eth.coinbase) = 0, node/client not fully synced yet

I just started to get my fingertips wet with Ethereum and Dapps. After receiving some ether on Ropsten to test with: https://ropsten.etherscan.io/address/0x05c86fc0ec0b80715f1cbc2fa96e86ba18e2eb90 I ...
0
votes
3answers
1k views

HOW TO AIRDROP TOKENS SUCCESSFULLY

Hi guys quick and simple question.... i have the script for airdropping tokens, all i need is to know what and how to input these value on the drop section of remix script:token,recipient,values. ...
0
votes
1answer
145 views

Best way to do USD math in Solidity?

Pardon the n00b question! I am trying to do some simple math in solidity using USD values. For example, say the start price of a token offering is $0.50 USD and the contribution is $10.00 USD, then ...
0
votes
1answer
477 views

R,S,V ECDSA packet signatures

I am using BouncyCastle to generate .NET core packet signatures. I want to be able to get the v value for the Ethereum signature. To these ends, and with my understanding of the meaning of the v ...
0
votes
1answer
158 views

how to deal with bytes32 to string in javascript?

I am going to set a email address from users and going to save it to ethereum network. I kept email as bytes32 in smart contract and when I am sending the value to javascript i am getting always a ...
0
votes
1answer
421 views

Invoke contract B from A and preserve msg.sender [duplicate]

is it possible to call a function in deployed contract B from contract A while preserving msg.sender to be original sender that invoked contract A. I know there is delegatecall method but also passes ...
0
votes
1answer
26 views

Truffle test error: deducts the amount from the allowance

What i did first was watching at Dapp university tutorials, I manage to watch all 14 videos and run it with Ganache. But since everything is doing good at local, I created my own private network. Then....
0
votes
1answer
182 views

Monax :-Issue in executing job configuration file

I am using Monax version 0.18.0.I am following the tutorial for deploying contracts in Monax https://monax.io/docs/getting-started/. I have used the sample contract defined in their starting tutorial....
0
votes
1answer
313 views

Transferring tokens to hardcoded addresses

If i have a list of addresses and the exact amount of tokens that I want sent to each address, how can I hardcode a transfer function to transfer the exact amount of tokens to all specific addresses ...
0
votes
1answer
720 views

Loading LevelDB in Java

I am trying to iterate through the ethereum ldb files. When I run this code my iterator believes there is nothing stored on the ropsten's testnet blockchain. There are no errors, and the iter gets to ...
0
votes
1answer
68 views

Unable to input address[] parameter in remix

I need help for deploy below smart contract on remix IDE. I have facing a problem as I need to input to 'setgrantaddress' as address[], How to input data in it? There is two file name owned.sol and ...
0
votes
1answer
182 views

syncing finished but stuck returning zeros

in the process of deploying a smart contract I've run into problems on both Ropsten and Mainnet. I've run geth --rpc --rpcapi eth,net,web3,personal --rpcport 8545 --testnet in one terminal window ...
0
votes
2answers
1k views

Can I use ICO (Initial Coin Offering) to fund for a non-blockchain project?

I did a fair amount of googling before posting. Let's just say, I am planning to create a yet-another-blog-engine which is noway related to blockchain. Can I use ICO (Initial Coin Offering) to fund ...
0
votes
1answer
117 views

Synchronous call of external contract function in Solidity

I have two Solidity contracts, where contract Caller depends on a second contract Callee. Contract Callee provides a public view function which checks the validity of a string (e.g. an password), ...
0
votes
1answer
42 views

Integrate more then one user with one ethereum account

I have many users inside the organization and I want to use same ethereum account for all the users , but with different usernames, so it there anyway to do that ?
0
votes
2answers
1k views

Solidity: How could I apply delete to complete storage ref[] with one call?

Definition: mapping(address => data) clusterContract; struct data { //defined inside a Library. mapping(address => Library.Struct[]) my_status; } data list; ...
0
votes
2answers
474 views

using abi generated by truffle in DApp

I use truffle to deploy contract to ganache network. I like to use the json file generated by the truffle in the DApp rather writing messy ABI into it. I tried the below piece of code and it gives ...
0
votes
1answer
616 views

Out of gas on truffle test

I am following the tutorial on http://truffleframework.com/tutorials/pet-shop I am using Ganache for testing, where i am also deploying the tutorial contract. 1) TestAdoption "before all" hook: ...
0
votes
1answer
2k views

why am I getting this error : Fatal: Error starting protocol stack: datadir already used by another process

I was trying out on creating a private ethereum network by following this link . However the first connection took too long so I uninstalled it and reinstalled it again. However when I try to run ...
0
votes
2answers
651 views

create ethereum wallet in Api

I want to create an Ethereum wallet, and I need an address and a private key, but I am unable to generate both. Please suggest a way to generate key pairs.
0
votes
1answer
43 views

Apparent mismatch between Oraclize CBOR and python3 CBOR encodings

I encoded a value using the Oraclize CBOR library like so: Buffer.buffer memory cborArgs; Buffer.init(cborArgs, 64); cborArgs.startArray(); cborArgs.encodeUInt(10); cborArgs....
0
votes
0answers
57 views

command line brings up code instead of running commands [duplicate]

I am trying to run truffle commands on commandline but it brings up the code file instead like this
0
votes
1answer
328 views

Create a faucet for Ethereum Private network to get Ethers

I have came up with a private ethereum network. I was able to do the transactions and contract deployments. The funds for all the nodes were specified in genesis. But I need to get a way to send any ...
0
votes
1answer
281 views

TestRPC and persistence of data

I am using a smart contract on the TestRPC net. In order to deploy my contract for the first time I write this in the node cmd: >Web3 = require('web3') > web3 = new Web3(new Web3.providers....
0
votes
1answer
232 views

Deploy Contract for every user [duplicate]

I have an application in which I have to put each user information on a different block to get the block unique address, do I have to deploy contract every time I will add new user information?
0
votes
1answer
178 views

Solidity smart contract inherited function output failed

I'm trying to inherit a function from the parent contract into child contract and its working fine in remix JavaScript VM. I did the following steps: Deployed the parent contract in remix JavaScript ...
0
votes
1answer
98 views

identifier problem with “require”

function transfer(address to, uint tokens) public returns (bool success) ; uint256 public max_contribution = 50 ether; uint256 public min_contribution = 0.1 ether; require (msg.value &...
0
votes
1answer
371 views

Can a contract function both change the state and return a value when it's called externally [duplicate]

Assume we have a test() function in our contract: contract { uint state; function test() returns (bool ){ state= 5; return true; } } I'm aware that if the test() function didn't have to ...
0
votes
0answers
15 views

What are the specifications of Ethereum wallet smart contract?

I just want to know the must-have specs of an Ethereum ERC20 wallet contract. How can I make a wallet for normal users(Can just perform txns of their tokens.) and for high level(Can perform every ...
-1
votes
2answers
645 views

Forward contract

I am a complete noob with solidity and smart contracts. I was looking for a script that solves the following problem. User sends ether to a smart contract then the smart contract forwards the eth ...
-1
votes
1answer
2k views

Tutorial for ethereum wallet creation in android [duplicate]

I am very new to ethereum and would like to learn it. Is there some tutorial available which lets me create an ethereum wallet for android ?

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