15 votes

CPU mining JSON_PARSE_ERROR

In reference to this: http://ethpool.org/ "If you receive frequent "JSON-RPC Problem" errors try to increase your --farm-recheck value. You should find a valid share every 1-2 minutes. If it ...
jdsika's user avatar
  • 341
14 votes

ETH sent to ETC address

At the core, there are no ETC and ETH account addresses. Private keys are equally valid on both chains. But, a contract can be deployed on one chain or the other uniquely and so contract addresses can ...
ETHeREAL's user avatar
  • 206
12 votes
Accepted

How do you create a new contract instance with an address *and* arguments?

You can't. In the first example, you are not merely instantiating a contract that is there. You are deploying a new instance and passing arguments into the constructor function. Constructors run one ...
Rob Hitchens's user avatar
  • 55.2k
10 votes
Accepted

Sign raw transaction offline with C++ on arduino

You can use our Firefly Hardware Wallet (https://firefly.city) for the ATmega328 to do: secp256k1 signing RLP decoding transactions keccak256 generating checksum addresses (or raw addresses) Signing ...
RicMoo's user avatar
  • 477
9 votes
Accepted

Is it possible to tell whether an address is mist, mew or parity?

TL;DR: Sort of. As Ismael notes above, keys are random and all clients are following the same basic standards, meaning that being able to tell which client an address was generated by is not an ...
Jeff Coleman's user avatar
  • 22.1k
9 votes

Hi, is Ethereum MIt licensed?

A note adding to both predecessors: For "business use" you would need to rely on the piece of software for a long time (mostly). The copyright owner of the various sources (client, core, etc) can ...
jdsika's user avatar
  • 341
8 votes
Accepted

How store ETH in a smart contract

Your transfer is transferring from the contract to the contract. It's not needed, and you can just delete it: function storeETH() payable public { // nothing to do here } https://...
user19510's user avatar
  • 28k
7 votes
Accepted

Convert an eth key to a geth key

It's possible but not recommended and therefore a not documented feature. Get the UUID of the account: ~ $ ethkey listbare 8766c082-432f-5548-608c-6eec600757f9 Display the private key: ~ $ ...
q9f's user avatar
  • 32.9k
7 votes
Accepted

How to build C++ Ethereum without GUI/Qt?

in your build folder you cmake .. -DGUI=0
euri10's user avatar
  • 4,640
6 votes

Convert an eth key to a geth key

The way to do this is risky but it is doable. It involves showing your private key on screen which is generally a REALLY bad thing to do. ethkey listbare 462352b14-0121-0454-5a4f-15f791233f1a So ...
Lefteris's user avatar
  • 250
6 votes
Accepted

How to listen to events generated by an existing contract in web3 1.x.x?

In version 1.x.x using HttpProvider is deprecated you have to use webSocketProvider for listening events web3js.readthedocs.io/en/1.0/web3-eth.html?highlight=deprecated. web3socket = new Web3(new ...
rahul_eth's user avatar
  • 556
5 votes

CPU mining JSON_PARSE_ERROR

Ethminer.exe is not allowed to get through the windows firewall. You must add ethminer.exe to the exceptions in Control-Center -> Windows-Firewall
alwe's user avatar
  • 151
5 votes
Accepted

is the code for the ETH contract available?

The way presale ether was distributed was through inclusion in the genesis block. At the genesis block, all nodes fetched the list of initial balances from data stored on the Bitcoin blockchain. ...
Tjaden Hess's user avatar
  • 37.1k
5 votes
Accepted

What's the difference between eth and cpp-ethereum?

In this context eth is the more updated version of cpp-ethereum. cpp-ethereum was renamed to TurboEthereum in September 2015 by the core dev team. TurboEthereum is now a full software suite that ...
Joël's user avatar
  • 1,720
5 votes
Accepted

How to bootstrap AlethZero on Morden testnet?

There are much fewer nodes on Morden than on the main network. 6377 on the main network right now (http://ethernodes.org/network/1) 344 on Morden (http://ethernodes.org/network/2) We have also had ...
Bob Summerwill's user avatar
5 votes

Convert an eth key to a geth key

The json files that eth uses are not the same as the keystore (json) files that geth uses. In order to successfully switch between clients, you must re-import the accounts via the unencrypted private ...
tayvano's user avatar
  • 16k
5 votes

Unable to send raw transaction

I believe you need to use canonical hex representation: eth.sendRawTransaction('**0x**...
tayvano's user avatar
  • 16k
5 votes
Accepted

How to implement role-based access control to user's private data?

Agree with Sanchit about using modifiers to control access to functions. However, the example implementation is misleading. I would flag that for a redesign. A couple of things to consider. As ...
Rob Hitchens's user avatar
  • 55.2k
5 votes
Accepted

Ethereum Merkle Patricia Trie (Extension node)

Whenever a new item is added to the trie the algorithm can decide whether to insert a branch, a leaf or an extension. Let's say you need to insert 3 key-value pairs: "0x01": 1 "0x01234": 2 "0x01235": ...
medvedev1088's user avatar
5 votes

Ethereum Merkle Patricia Trie and Hashes

Each node in the trie is identified by it's hash. Suppose there is a leaf with encodedPath 0x01 and a value 0x78 (I omit some things like even/odd coding for simplicity): leaf [0x01, 0x78] The hash ...
medvedev1088's user avatar
4 votes

How can I check which network I'm working on?

By default, all Ethereum clients use the main "Frontier" network. If you haven't manually changed the genesis block or network ID, you're good to go. If you want to be really sure you're on the ...
Tjaden Hess's user avatar
  • 37.1k
4 votes
Accepted

How to install eth on debian? (symbol lookup error)

The Ubuntu PPAs are not compatible with Debian. The main issue is the wrong version for libcrypto++-dev package. You have to follow the generic build process for linux and compile it from source. ...
q9f's user avatar
  • 32.9k
4 votes
Accepted

Does Eth have an equivalent to Geth's --fast flag?

The c++ implementation does not yet have the fast-sync feature. It can be used to fast sync from, but it will not fast sync itself. You can track the progress on implementing this feature on github.
chriseth's user avatar
  • 3,392
4 votes

Mining ETH on HD 6950 DAG allocation problem

It seems the HD6950 is limited to a 512MB allocation even with much more RAM onboard. C:\Program Files\Ethereum 0.9.41\Release>ethminer --list-devices Listing OpenCL devices. FORMAT: [deviceID] ...
mozreactor's user avatar
4 votes

Can't enter any commands after starting eth on Windows

You need to open a console, like that: eth --frontier console The -b -i flags don't exist anymore. The docs really need to be updated. Edit: And please update your client to version 1.2.0 or later ...
q9f's user avatar
  • 32.9k
4 votes
Accepted

ethminer Failed to submit hashrate

Your client is trying to submit something to the server that's operated by the pool. Instead of returning valid json like it should; the server returns a string: Database Error It seems obvious to ...
Sjon's user avatar
  • 164
4 votes

C++ library for Ethereum client documentation

From the main Ethereum GitHub page, you want the cpp-ethereum repository (right in the middle of the main page). The README for the repository contains lots of useful links, including to the main cpp-...
Richard Horrocks's user avatar
4 votes

How to implement role-based access control to user's private data?

You can implement access control on your smart contract functions with the help of modifiers. Let's say you don't want some function to be called by everyone using your contract, in that case, you can ...
Sanchit's user avatar
  • 3,492
4 votes
Accepted

Customize minimum payout on ethermine

Find your address on etherminer by searching it in the top bar -> go to settings -> change minimum to 0.05 or whatever you want it to be, and provide your public IP as proof it is you (just google my ...
Durf Fungus's user avatar
4 votes
Accepted

Any export keyword in Solidity?

No, this is not possible. The EVM has no access to a filesystem. The import keyword is used at contract compile time, in your local build environment. It imports Solidity code ahead of creating the ...
benjaminion's user avatar
  • 9,267

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