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316 views

plateforms to develop private blockchain [duplicate]

plateforms to develop private blockchain Hello ! I want to develop a private blockchain , and i wanna know what's the best plateforms / logiciel to work with thank you
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1answer
270 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 ...
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0answers
47 views

Why incorrect number of tokens are sent according to the current rate to the contributor.?

Token Contract https://ropsten.etherscan.io/address/0x6f5c43f62b4b18aa8ed37b42f2804f7049cbe0e9#code CrowdSale Contract https://ropsten.etherscan.io/address/0x9b94e1894abe2051e6e96bf1b57fe5d3adbbc5aa#...
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1answer
66 views

How can I decode transaction input to know what method was called and what arguments were passed in (and arguments types)?

following to the approach explained here to use etherscan api from Python to get transactions info such as input How to retrieve transactions' info such as gaslimit and gasprice from Etherscan? ...
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1answer
114 views

How to deploy Smart Contracts With Web3 Using Async/Await?

This is my Javascript code. I keep getting an error that states Error: No privateKey given to the TransactionSigner. at TransactionSigner._callee$ (/Users/payton/WebstormProjects/Esgro_DAPP/...
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1answer
621 views

Deployment of Smart Contracts with Azure Ethereum Consortium does not work

I created an Azure Ethereum Consortium. The Ethereum Network deployed has 2 Transaction Nodes behind a load balancer. Via Putty I connect to one of the transaction nodes. Then I enter geth attach ...
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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
1answer
482 views

Proper way of using allEvents()

I'm trying to get all events for a contract: let events = token.allEvents({fromBlock: creationBlock, toBlock: 'latest'}, (err, res) => { try { let result = events.get(); ...
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1answer
182 views

How to get all the contracts deployed by a specific ethereum address?

It is anyhow possible to get all the contracts deployed by a specific ethereum address in lifetime? If yes, is it possible to get ABI details of the contract by their address?
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2answers
663 views

Increase all values of mapping or array without loop

Would it be possible to increase all the values of a mapping or array (without a loop)? Example: mapping(address => uint) score; uint[] values; function increase_scores() public { // ...
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1answer
131 views

Am I paying gas in ETH for sending tokens to a specific miner?

Am I paying gas in ETH for sending tokens to a specific miner? If so is it possible to find out how that miner is and to make a deal with that miner to pay less gas for many transactions or maybe pay ...
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0answers
25 views

web3.utils.toHex but combined, hex concat?

I'm currently working with bytes in Remix. The goal I wanted to achieve was to put variables into bytes in one function, copy bytes, paste bytes to another function as a parameter and unpack these ...
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2answers
2k views

Returning dynamic array not works

I'm trying to build a function that, when called, returns a mapping as two different array. The problem that I have a mapping (address => uint) content2view and I have to get this value outside ...
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1answer
178 views

Smart contract with authorized actions based on addresses

I want to build a service where users can sign up (off-chain) to get credentials which give them the right to perform certain on-chain actions. For example, lets pretend I'm building a service where ...
0
votes
1answer
550 views

Cannot connect to testrpc

I have a testrpc running on a virtual machine (Ubuntu 16.04) and it works properly when I interact with it using the truffle console. My only goal is to call a smart contract that simply sends ether ...
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0answers
20 views

Which are the operations providing gas refund available immediatly for the current running transaction?

Most of gas refund operation aren’t available immediately, but instead increase the refund counter (which if I understand correctly is refunded not after the end of contract creation or call by ...
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1answer
86 views

dApp index.html fails to load for dAppUniversity election application

Hit a brick wall with this. git clone https://github.com/dappuniversity/election The following is the Shell output I get when I npm run dev. I’m using the cloned project from GitHub but I’ve ...
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1answer
47 views

Latest block of multiple mining nodes

Lets say I have a private chain with 3 nodes (all mining) A, B and C. I want to get the latest block of my chain. I connect to node A and get this information with getBlock("latest"). Lets imagine ...
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2answers
962 views

Cancel a transaction that has not been pushed via Mist

I submitted a transaction via Mist with the fee slider at the leftmost position. Nothing happened for a day now, so I suspect that the displayed gas price has been to small, although Mist told me that ...
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1answer
84 views

How can I send array of structs as arguments?

I want to send to my contract an array of currency and its price so it will store it: pragma solidity ^0.4.24; contract ExchangeContract { enum CurrencyType { USD, TWOKEY, BTC, ETH, DAI, USDT, ...
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0answers
62 views

Web3 Websocket Connection To Infura Rinkeby Ropsten

This is my Javascript code. I keep getting an error that states (node:30062) UnhandledPromiseRejectionWarning: TypeError: privateKey.startsWith is not a function I am using node 12.1.0 & ...
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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 ...
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0answers
523 views

“callback contain no result Error: Error: base fee exceeds gas limit” when call selfdestruct function (using Remix IDE)

I'm testing this simple contract. All the functions works well, but when I call the kill() function I'm getting this error: callback contain no result Error: Error: base fee exceeds gas limit I'm ...
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1answer
317 views

Truffle will not compile contract written in VS code. Pragma error

I'm trying to run example from https://truffleframework.com/tutorials/pet-shop, but when I run truffle compile I get error saying Error parsing C:/WINDOWS/system32/TruffleTest/pet-shop-tutorial/...
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1answer
755 views

Disable block mining reward in private testnet

Is there a way I can disable the generation of block reward in a private network during creation? Any parameter in genesis.json can do so?
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votes
1answer
132 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), ...
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votes
1answer
1k views

Detect token transaction to a contract

Is there a way to detect when my contract receive tokens? I don’t own the token contract, I only want to know the address and amount of token sent to my contract.
0
votes
1answer
185 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
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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] ...
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votes
2answers
402 views

web3 detect/listen to events if someone send ether to addresses

I need to constantly keep running some code to detect if someone has in the past minute sent some ether/token to a lot of addresses, is there better way to do than https://ethereum.stackexchange.com/a/...
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2answers
716 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
1answer
382 views

Truffle Exec Gets Stuck [closed]

I want to exec a script in the truffle console. script const artifacts = require('./build/contracts/Message.json') const contract = require('truffle-contract') const Message = contract(artifacts); ...
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votes
1answer
2k views

How to quickly check Ethereum Hashing Speed?

I have 4-5 different GPUs with me. What would be the easiest way to quickly run a Hashing Speed Test on those cards assuming I already have the Drivers for them installed?
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3answers
199 views

Error trying to create a crowdfunding contract?

I am using the template code found on the Ethereum website for crowdfunding and when I insert it in the solidity contract source code in the Ethereum wallet, it returns: Unused local variable ...
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votes
2answers
2k views

Web3.js browser version only

I want to create a simple page to interact with my deployed contract. I don't want to use Node.js. I want to use html + web3.js browser version. I got a link: https://github.com/ethereum/web3.js/tree/...
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1answer
822 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:
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2answers
592 views

How to send transaction/call function from server-side?

After an event emits from my smart contract and I hear it server-side, I want to call a certain function in the smart contract and pass it some information to use. I'm wondering how you place a ...
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2answers
50 views

Where the Smart Contract deployment charges goes?

I'm newbie to Ethereum, and finding answers of some questions that I have. I have learned about SC deployment that deploying the contract cost 0.01072934 ether, or about $3.21 USD So, where that cost ...
0
votes
1answer
29 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....
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1answer
102 views

Can manage node in my ethereum private network

I have created ethereum private network. there are two node got connected with in this network. both are mining. I have created small contract for transaction. All transaction is happening through my ...
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0answers
30 views

how I can add a new account to the web3 object to run contract functions? (from specific sender)

** this is my previous post : web3.eth.accounts.wallet.add(account) not working what I have tried? -1: web3 = new Web3(new Web3.providers.HttpProvider(connectionString)); const account = await ...
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votes
1answer
140 views

web3.eth.accounts.wallet.add(account) not working

I need help with adding a new wallet to a web3 instance. e.g.: web3 = new Web3(new Web3.providers.HttpProvider(connectionString)); const account = await web3.eth.accounts.privateKeyToAccount('0x'+...
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votes
1answer
257 views

Export a JS package from Truffle?

Truffle has this whole build process for deploying fronted code that is kinda mediocre. Does anyone know if I can just have Truffle output a single javascript file that will work in a web3 enabled ...
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0answers
953 views

passing address as a function parameter in web3

I've this contract that gets 'address' type variable as input parameter to function and sets it to a variable. This works fine in Remix. I'm trying to call this using web3js and am getting an Uncaught ...
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votes
2answers
18 views

ParserError: Expected identifier but got 'address'

I am trying to execute the following code: pragma solidity ^0.5.1; contract contractA { function blah(int x, int y) public payable {} } contract contractB { function invokeContractA() { ...
0
votes
1answer
253 views

Can't set gas limit for oraclize callback function higher than the default 200000

Could you please help me with the following. I am using OraclizeIt (https://github.com/oraclize/ethereum-api) to retrieve a JSON from some other service via REST. Basically the smart contract method ...
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2answers
66 views

My question is about forks in general. If I have a portion of a coin do I get the exact portion of that new coin?

my question is about forks in general. If I have a portion of coins and it gets forked do I get the exact amount of the new forked coin?
0
votes
1answer
114 views

Mist hash Identicon

Upon finding this thread How are the account "pictures" used in Mist generated? I tried to use this version of blockies to generate the identicon based on a wallet/contract hash Although i ...
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votes
1answer
698 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
1answer
156 views

How to avoid using tx.origin when we really need it?

It's been recommended that we should avoid using tx.origin. However, there're some cases it's really needed, like the following case. Assume we have two smart contracts: Sc1 and Sc2, both of which ...

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