All Questions

7,021 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
0
votes
1answer
146 views

can't create token

I copy and pasted the coin code into the ethereum wallet contracts section - gave it a name and: initial supply: 10000 decimal places: 2 symbol: Kk When the contract gets picked up it has no name (a ...
0
votes
2answers
626 views

How to use a private network in geth?

I am following this answer: How do I set up a private ethereum network? but my result of miner.start() will return null Is it because my geth version is 1.6.6-stable? Also welcome any beginner's ...
0
votes
1answer
125 views

is it possible to have a password bug in mist wallet 0.8.10

I was playing with account creation with in MIST and i find one account always saying "password wrong" when i try to transfer ether to other accounts. It can still receive ether though. I use same ...
0
votes
2answers
186 views

Is there any tool for Ethereum which can convert smart contract into REST API similar to hyperledger fabric?

In Hyperledger Fabric, REST API can be created for chain code/smart contract using composer-rest-server. Is there any tool which can do the same for Ethereum Smart Contract? So that any front ...
0
votes
1answer
38 views

When a Callcalled contract calls an other contract normally, who is msg.sender?

If I understand correctly CALLCODE substitute/replace (and not add) the ledger of the target contract with the one the calling contract, isn’t it ? So that when contract Victor CALLCODE Alice, Alice ...
0
votes
1answer
74 views

Parent-Child Contract Synergy Broken

When I call a function from a child contract which has been generated through a parent contract, then the mapping within the parent contract which consist of information related to the child contract (...
0
votes
1answer
242 views

Manually Set enode in Parity?

I deleted my network/key file and want to use my old enode because it is in the chain spec, etc. Is there a way to do this or is it cryptographically impossible?
0
votes
1answer
570 views

ERC20 token recovery

I am sorry if this is a stupid question but if someone can help I would appreciate it. first I have the keystore to where the tokens were linked to, I already sync completely to the network. I show ...
-1
votes
1answer
44 views

How and when should I use a Ethereum smart contract in document verification process?

First, a student applies for a certificate in his/her University . The University creates his degree certificate . Now , how do I write a smart contract in Solidity so that anyone in blockchain can ...
-1
votes
2answers
42 views

Help a noob testing: it ' should deposit 1 Ether'

I wanted to revive or refactor this old smart contract as an exercise to learn solidity and js coding. Truffle compiled it and migrated it and it passed the first test (Although I'm not sure if it ...
-1
votes
1answer
49 views

Unable to test a smart contract on ropsten test network

I launch and verify an ERC20 based smart contract on a ropsten test network which allows user to interact with the contract (send eth to it and the contract automatically send token in returns as in ...
-1
votes
1answer
22 views

How can we use private chain token in public chain?

I'm software engineer in japan. now, I'm trying to create a dapp by using private chain like kaleid, then will create token in private chain. In the future, I'd like our token to be listed to ...
-1
votes
1answer
20 views

I want to create a account on blockchain using web3swift in IOS app, but I am new on blockchain don't know how to do. Please can anyone help me out?

I want to create an account on the blockchain using web3swift in the IOS app, but I am new on blockchain don't know how to do it. Please, can anyone help me out?
-1
votes
1answer
67 views

How many projects are there which implement ERC1155 standard?

New ERC1155 standard which is thought to be an improved version of ERC721 and ERC20. But I see many projects still prefer ERC20 or ERC721 standards. If so, do you know any projects implementing ...
-1
votes
2answers
46 views

contractAddress: null

I use sendSignedTransaction to send the contract and return contractAddress: null let rpcUrl = "https://ropsten.infura.io/v3/6756e6f8f0e34482a262a7cf1d15f2c2"; var web3 = new Web3(new Web3....
-1
votes
1answer
164 views

Error while deploying smart contract (quorum-examples tutorial by truffle)

:~workspace/myproject$truffle migrate --reset Compiling your contracts... Everything is up to date, there is nothing to compile. Running migration: 1_initial_migration.js Replacing Migrations... ...
-1
votes
1answer
124 views

How to create and manage a referral link on solidity Smart Contract (unique referral link)

I'm building a DApp in solidity where I want give a bonus to the users that wants promote it. My problem is that, to use my Referral system, now I need to insert manually the wallet address of the ...
-1
votes
1answer
42 views

Smart contract to strore and retrieve address and ID in blockchian using mapping

I want to store some address and their ids in blockchain using mapping and i want to know how to get the stored addresses when searching with their respective IDs.
-1
votes
1answer
47 views

Problem retrieving array of struct with web3js

I'm trying to return the struct values contained in array everytime i push a button thet call inserimento and ritornavalore functions. here is my code in solidity: pragma solidity ^0.5.1; pragma ...
-1
votes
1answer
71 views

Embark Demo Issues

I've been able to open the embark console but I found that there were a few missing messages on the console. It appears that there is "no blockchain" and the status does not show anything. I tried ...
-1
votes
1answer
382 views

How to concatenate string array into a single string

I am trying to concatenate a whole array of string into a single array for printing purpose. function getArray() public view returns (string) { arr.push("Max"); arr.push("good"); arr....
-1
votes
1answer
35 views

Do I need to start mining in order to process my own transaction in GETH?

I am running my own GETH node, so that I can check status, and make transaction when possible. I can sync with the main net and check status of contracts without start mining. But when I send a ...
-1
votes
1answer
87 views

How to generate Dapp Url? which can be used in status app browser to run our dapp in mobile?

I want to develop an mobile app using ethereum, for that I'm using status app as a wallet in mobile. But i'm stuck at the point that actually what is the Dapp URL which we have to add in Status ...
-1
votes
1answer
297 views

How to diagnose “invalid opcode” when compiling?

I have a huge contract so isolating the cause will be very arduous manually. Is there any way to get an indication automatically of what might be causing an "invalid opcode" error?
-1
votes
1answer
6 views

What is the cons and pros of using decentralized crypto exchange instead of centralized?

I found this wallet and want to test it. I previously used CEX only.
-1
votes
1answer
48 views

how can I pair my ERC20 token with Ethereum

I am building an exchange and i just want to know how this pairing thing works. How can I pair my ERC20 token with other crypto assets like Ether and BTC?
-1
votes
1answer
265 views

Found a Telegram ETH scammer/theif's main wallet address on Etherscan with $150,000 worth of stolen coin. What can be done?

Someone in my Telegram Telcoin group that I've talked to for months say they were a victim of ETH theft by a known ETH scammer in Telegram. This person sent me proof of pictures they took of ...
-1
votes
1answer
14 views

Next software release

Afternoon Community, I was wondering if anyone knows the date, or approx date, of the next software update. Also if anyone has some good sources for pooling this kind of information that they could ...
-1
votes
1answer
108 views

Enabling HTTPS / 2 Way SSL Communication between Ethereum / Quorum Nodes

To further enhance security and comply to regulatory requirements, there is a need to enable HTTPS / 2 Way SSL Communication between Ethereum / Quorum Nodes. Understand that Quorum uses existing ...
-1
votes
1answer
56 views

What is the status of this transaction?

https://etherscan.io/tx/0xfed520a57c874af9dbddc8fd0e7a470f738c45ad4432266fee8f0e18df50e0de It says the status is false. I sent money from my jaxx wallet to poloniex. Poloniex do not credit the fund. ...
-1
votes
1answer
62 views

Capture Solidity Emit Events without Web3 — E.g., Calling via Postman

Is there some way to capture Solidity Emit Events without the use of Web3? For example, I am calling via Postman JSON RPC eth_sendTransaction. How to capture the returned results?
-1
votes
1answer
46 views

Which node server for creating Ethereum keypairs and sending transaction programatically?

I need to create Key Pairs, and send transactions from my server program (probably node.js.) The code part is clear -- at least in terms of available examples -- and I know where to go with it. My ...
-1
votes
1answer
111 views

Generate ETH address with button on my website

I'd like to open a website that I can easily generate an ETH address like this website: http://taschh.com/microworkers/cv/generate/ Of course, I will have all of ETH address and its private key. I don'...
-1
votes
1answer
64 views

Interacting with Ethereum smart contract that has been deployed via address

I'am total beginner in Ethereum so how to interact with smart contract via address ? here is the address : 0x259a065256212183490b3ee3f4702c900c37d712 ABI: [{"constant":true,"inputs":[],"name":"...
-1
votes
1answer
355 views

how to withdraw ether from a ERC20 token contract Address

how to add withdraw function to get smart contract ether to my wallet https://github.com/rohitsahu21/Token-Sale
-1
votes
1answer
518 views

How to store blockchain data in database

I am new in blockchain. I want to know that which database should I use to store blockchain data? How can i store blockchain data in codeigniter?
-1
votes
1answer
232 views

why appears this warnings

browser/ballot.sol:3:28: Warning: Functions in interfaces should be declared external. interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes ...
-1
votes
1answer
376 views

What is the data option of eth_sendTransaction?

I am trying to send ERC20 token using JSON RPC. I am very new in this step and learning. I am using eth_sendTransaction function. What is "value" and "data" option in this case ? Please help
-1
votes
1answer
90 views

Problem with web3?

When I try to get the list of accounts by using command line in web3 console, it doesn't work. Let me show you the result in my machine. Please help me!
-1
votes
1answer
171 views

Problem in Veifying Smart Contract On Testnet

I'm not able to verify my smart contract on Rinkeby and Ropsten Testnet Network. Rinkeby Link - https://rinkeby.etherscan.io/address/0x029798a8c21050cbaaa2d5ecbd5e06622b602b82 Ropsten Link - https:/...
-1
votes
2answers
94 views

Help on crowd sale contract

For a crowd sale contract can we use the etherscan API to identify the contributors and distribute the tokens, Also it will be great if someone can provide a sample contract to do the automatic ...
-1
votes
2answers
2k views

I got this problem in my private ethereum blockchain(Node is not syncing, Node data write error ,Synchronisation failed, retrying)

I am new to ethereum and right now getting the ethereum blockchain using geth with geth --port 3000 --networkid 58342 --rpc --rpcport 8545 --rpcaddr 10.0.0.2 --rpccorsdomain "*" console INFO [03-...
-1
votes
1answer
37 views

How do we know what time/what website is a MEW wallet created?

I lost Private Key + JSON file to open my myEtherwallet. But is there anybody knowing somehow to find: What time is a MEW wallet created? what website that has created an Ethereum wallet? (This is ...
-1
votes
1answer
277 views

minimum investment required during ICO?

how and where to set minimum investment in ETH & BTC in ERC20 contract ? done lots of google search but cant able to find the suitable article or tutorial how to place it in !
-1
votes
1answer
77 views

Trying to create a simple coin, but getting warnings for the last two functions. Can you find and solve the error?

pragma solidity ^0.4.0; contract Bubblecoin{ mapping(address => uint) balances; uint supply; function totalSupply() public constant returns (uint){ return supply; } ...
-1
votes
1answer
179 views

Value of msg.sender is not changing after specifying {from} in truffle

Given two contracts : contract First { function cSender() public view returns(address){ return msg.sender; } } contract Second { First f; function Second() public { f = new First(); ...
-1
votes
2answers
1k views

Error: listen EADDRINUSE :::8545

C:\Users\Kane>testrpc EthereumJS TestRPC v6.0.3 (ganache-core: 2.0.2) C:\Users\Kane\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:74143 ... ... ******Error: listen ...
-1
votes
2answers
489 views

Windows - Can mist be used from the command line?

I see that mist can be used from the command line in Linux, but the mist and/or ethereumwallet commands don't work in PowerShell or even Git bash in Windows. Is there any way to use Mist from the ...
-1
votes
1answer
782 views

WTFx1000 The ERC-20 Token Transfer might have Failed (ErrCode: unable to locate corresponding Transfer event log), check with sender

im sending from one mew to another mew my gas is doubled why do i keep getting this TxHash: 0xac2bdee062f62ede0a478ea6a60e4c4465d76f099e3764895b849c491baa5f75 TxReceipt Status:FailBlock Height:...
-1
votes
1answer
310 views

myether wallet not flashing my token after the confirmation

I have just Transfered My Premine token to my Myetherwallet. The transcation show on etherscam confirmed but myether is not flashing or showing my token. Does myetherwallet usually takes time to show ...

15 30 50 per page