All Questions

7
votes
1answer
187 views

How to get started after participating in the presale?

I participated in the Ethereum presale and have my wallet stored safely in my password manager. Then I stepped away from all things ethereum for a couple years. Now I'm ready to get back into it. I ...
8
votes
1answer
4k views

Basic example of interaction between 2 contracts?

What is a basic example of one contract invoking a method in another (non-calling) contract? Would the address of the contract having that method always need to be hardcoded?
3
votes
2answers
240 views

How to invoke a contract function in the future (under 10 blocks)

This is not a duplicate question, as the alarm contract only allows function calls to be made in the future, over a period of at least 10+ blocks... The current thinking is to just use the alarm ...
2
votes
1answer
1k views

How can configure EthereumJ to connect to the public testnet.?

I need to connect to the public testnet via ethereumj can anybody help me please.
9
votes
3answers
6k views

How can I get the data of the latest 10 blocks via web3.js?

How can I get latest 10 block data by using web3.js like most block explorer does?
8
votes
2answers
44k views

How do I check my mining hashrate?

I've wrangled an old altcoin mining machine into an ethereum mining rig, it has two Radeon 280X cards in it. I'm running geth, with two instances of ethminer, one per card. However the output of ...
6
votes
2answers
746 views

Why does an empty message still invoke the code of the contract?

An empty message still invokes the code of the contract and is the mechanism that allows Solidity to implement a feature of a fallback function per contract. But when msg.data is empty, why does ...
3
votes
1answer
1k views

Member “call” not found or not visible after argument-dependent lookup

Here's the contract: contract Martyr{ function Martyr(){ var address0 = 0x093ff7d4edbd201f1762297e31afcde50bdf4c81; address0.call(bytes4(0x2808241a),...
8
votes
3answers
4k views

Mist: “No data is deployed on the contract address!”

I'm testing a contract on testnet using Mist. When I deploy it, it says "No data is deployed on the contract address!". And then it doesn't appear on the contracts section. What does it mean?
2
votes
1answer
1k views

Can't open the wallet (Windows 10, 64 bit)

Only thing I have is an image saying Starting Ethereum node... If I quit and start it again it says: Couldn't start an Ethereum node! Are you already running a node Windows 10 64bit
10
votes
1answer
542 views

Bad jump array solidity and data location

I'm having a strange issues with an array inside a struct. I will copy you the example code, so that you can understand: Foo[] public foos; struct Foo { uint fooX; uint[] fooArray; } ...
19
votes
3answers
23k views

Mist: What does “intrinsic gas too low” mean?

I'm running the Mist wallet, and I've deployed this contract to testnet (from https://ethereum.stackexchange.com/a/179/520) : contract Notary{ struct Document { uint timestamp; ...
2
votes
3answers
471 views

Is it safe to keep Ether on an exchanges during the Homestead switchover?

There are several exchanges like Kraken, Gatecoin, etc. Is it safe to keep Ether on one of these exchanges when the switchover from Pioneer to Homestead takes place?
2
votes
3answers
191 views

Is it possible to chain mulitiple individual transactions into a single “all or nothing” transaction?

Lets say I have a contract with a bunch of individual properties. For example, a person with a firstName and lastName field. A user of a dapp wants to change both fields, which would take two ...
4
votes
2answers
48 views

What's the Purpose of the Vertical Rule Dividing the Work-Space in Browser-Solidity?

And can it be eliminated? I find it distracting.
3
votes
1answer
451 views

Node.js, Geth & Events

I've been tracking a case where my Node.Js server just stop receiving events, basically for each contract, when I do a contact.allEvents({ fromBlock: startblock }, (error, data) => { ... }); It ...
16
votes
5answers
12k views

geth import vs copying chaindata

I'm trying to sync my RPi 2 with the blockchain. geth import runs quite slowly, as well as syncing from scratch. What would be the problem in just copying the .ethereum/chaindata folder from ...
3
votes
1answer
373 views

Can STRATO be utilized as an Ethereum client?

Consensys announced yesterday that BlockApps STRATO is available for Microsoft Azure. Joseph Lubin says, It is also a better Ethereum public mainnet node for various kinds of decentralized apps ...
5
votes
1answer
1k views

How can I connect geth by IPC on rails?

I'd like to connect geth by IPC on rails. I start geth as follows. $build/bin/geth --datadir "/home/vagrant/.ethereum" --networkid "1" --ipcapi "admin,db,eth,debug,miner,net,shh,txpool,personal,web3" ...
10
votes
1answer
2k views

Can I run Geth without syncing?

I want to test some api calls using web3.js and so I am using geth as HttpProvider. Can I start geth without the syncing? Is something like geth --nosync --rpc available?
5
votes
1answer
921 views

How to replicate Bitcoin's OP_RETURN functionality on Ethereum?

I know Ethereum is more advanced, and allows for more interesting things than associating data to a transaction. But let's say I have a legacy system that uses Bitcoin's OP_RETURN. What options do I ...
3
votes
0answers
80 views

Which is the safest way to generate a random number? [duplicate]

I need a function that generates a random number from 0 to n for the lottery. I found 2 ways to do that: 1. https://gist.github.com/alexvandesande/259b4ffb581493ec0a1c But miners can influence the ...
1
vote
1answer
173 views

Is there a loadscript equivalent in eth?

I got this error in eth client : Error: Uncaught ReferenceError: loadscript is not defined is there a loadscript equivalent command in the cpp client eth?
2
votes
1answer
378 views

ETH vs Tokens price issue [duplicate]

Is there any possibility for one token (e.g. Augur's REP) to become more valuable than the total Ether market cap? If so, how would that be possible? In Security of PoS if/when Assets (Tracked or ...
6
votes
3answers
15k views

How can I install go-ethereum on CentOS?

I'd like to setup go-ethereum on centos6.5. However,this reference doesn't show how to install go-ethereum on centos. I tried [vagrant@vagrant-centos65 ~]$ bash <(curl -L https://install-geth....
8
votes
2answers
18k views

What are some good mining pools? [closed]

I'd like to try a bit of mining, but my GPU is way too weak to mine on my own. I've tried finding reviews on existing mining pools for ether but they're very sparse. Could you recommend a pool?
4
votes
1answer
522 views

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

In a previous question, I asked how Geth's --fast flag worked. I'm now moving over to using Eth, so my question is: is there an equivalent option to allow Eth to quickly sync the block data? If so, ...
2
votes
0answers
19 views

Block data duplication when moving from Geth to Eth (or vice versa) [duplicate]

I've so far been using Geth (the Go client) as my client of choice. I'm now interested in using the Mix IDE, a requirement of which is that I use Eth (the C++ client) instead. I've already synced the ...
35
votes
5answers
23k views

How to delete an element at a certain index in an array?

Anyone know how to delete an element in a array? Is there any built in method to do that? If not, does anyone know of how to implement such a method?
10
votes
1answer
985 views

Why do some blocks contain no transactions?

While poking through my Geth logs I noticed that block 1,000,006 doesn't actually contain any transactions. Why is that?
4
votes
2answers
511 views

Windows Wallet, Beta 7, stuck at 460,000 out of 663,000?

My friend downloaded the Windows Beta 7 wallet and as you can see in the picture he is stuck at block 460.000. Also the "out of" blocks statistic keeps jumping between 663,000 to 1,000,000+. Even ...
10
votes
4answers
4k views

Sorting an Array of integer with Ethereum

I'm trying to have a simple array of integer sorted in Solidity but i couldn't find any real ressources so instead i'm trying to do it "the hard way" but so far with very little success. Is anyone ...
12
votes
3answers
3k views

How can I completely automate a Docker image and Dockerfile for a geth test network

I would like to create a Docker image for a test network that has everything ready to go - pre-created accounts with ether already allocated. The problem is there doesn't seem to be a way to do this ...
5
votes
1answer
472 views

Is anyone working on a mobile wallet that can facilitate custom coin transactions?

I've met some people who are in need of a coin for their collective hackerspace. If I can get my custom coin into a decent mobile wallet (doesn't really need to be super robust) they can start using ...
5
votes
1answer
442 views

Problems accessing my funds with Ethereum Wallet 0.3.9

Unfortunately, I have a problem before me. I have on my computer the wallet "Ethereum-Wallet-win64-0-3-9" I have updated recently. On this wallet there is a "contract address" linked to an "account ...
6
votes
1answer
610 views

Is there a mobile wallet for iOS?

I looks like JAXX is only for Android. Is there really no option for iPhone yet?
29
votes
1answer
23k views

How to Initialize a Struct?

I have a struct like so : struct fooStruct { uint foo; uint figther; } I would like to initialize that struct but it won't be stored in a mapping but inside an array. Is there a way to ...
3
votes
1answer
968 views

What is the purpose of multiple addresses in a wallet?

In eth-lightwallet from consensys there is a function generateNewAddress. What is the purpose of having multiple addresses for the same account? I can think of a few usages: accounting solution: 1 ...
4
votes
1answer
723 views

How does a Solidity fallback function work with the raw CALL opcode of the EVM?

Since a fallback function is a Solidity feature, how does it work if the EVM opcode CALL is used? If msg.data is empty, how can Solidity run the fallback function? Shouldn't the EVM just transfer ...
2
votes
2answers
427 views

I sent a transaction and got a hash, but blockchain explorers don't see it. What happened?

I used in the eth client web3.eth.sendTransaction({from:sender,to:receiver,value:amount) to try send some ether, typed yes to the question, then got a hash number ...
11
votes
2answers
17k views

When is the geth.ipc file produced?

I'd like to access geth.ipc file in order to connect geth via IPC. I've got an advice and it suggested me to access geth.ipc, but I've not found it on my mac. Could you tell me when that file is ...
2
votes
2answers
653 views

Transaction using geth is stuck

I have created a wallet using geth on my mac. I have sent a small amount from Kraken to that account but its stuck on "sending". Do I need to download the blockchain first on my node so it can be ...
3
votes
1answer
227 views

How problematic is transitioning Augur's full-Serpent smart contract suite?

I read here that Augur's smart contract suite is actually written in Serpent. I'm aware that it is a relatively well supported language at the moment (at least compared to Mutan and LLL), but given ...
6
votes
3answers
3k views

Is there any API for sending and receiving Ethers?

Is there any API for send and receive Ethers? If not, i am trying to use web3.js in my own server; What are the technical implications? Major security concerns? Can I use the same API for creating ...
4
votes
1answer
249 views

How can I check the current state of a token I made?

How can I check what coins have gone where using the standard coin contract? I know how to check the balance of an address, but I'd like to see something like a ledger of all the current coin balances....
6
votes
1answer
1k views

How does a fallback function rejecting ether work?

A contract in Solidity can have a fallback function like: // This contract rejects any Ether sent to it. It is good // practise to include such a function for every contract // in order not to loose ...
7
votes
3answers
4k views

How can you parse blockchain files stored in a local node to get blocks and transactions details?

I want to get all details of blocks and transactions without using event logs. For example, I want to get a list of of transaction data which are sent to a specific contract. How can I parse local ...
5
votes
2answers
5k views

What is the difference between ICAP and HEX addresses?

I've read what Kraken have mentioned in the difference guide but I haven't understood it well. I plan to mine ethereum. What fits better for me?
4
votes
1answer
4k views

How can I import geth accounts into eth?

I had two accounts under ~/.ethereum/keystore when I used geth a while ago. I got a new PC, recompiled only the C++ version and I can't see my two accounts in eth. web3.admin.eth.allAccounts() ...
6
votes
1answer
963 views

How can you implement two way pegged Ethereum <-> Ethereum sidechain?

If you want to create an Ethereum sidechain which is two-way pegged to main (public or private) Ethereum, how can you implement sidechain? For example, How can you lock ether? How can you verify ...

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