All Questions
6,660 questions
9
votes
2
answers
2k
views
Float not allowed in solidity vs decimal places asked for token contract
We know that solidity doesn't support the float values. But here (https://www.ethereum.org/token#understanding-the-code) they accept one input parameter 'decimal places' for calculation purpose. How ...
- 3,545
9
votes
5
answers
13k
views
How to get private through UTC files in keystore [duplicate]
I create accounts by geth account new with a password, then I get a UTC file which is a json file saved in folder keystore under data directory. Now I am attempt to get private key from this json file....
- 700
9
votes
2
answers
7k
views
Getting Go-Ethereum current network id
How can I know the network id, with web3 or command line, so I know to which network my geth has attached?
- 23k
9
votes
3
answers
5k
views
geth account creation Failed to enumerate USB devices
I'm trying to create a private Ethereum network on a Kubernetes cluster using ethereum/client-go docker image but getting bellow error while trying to create an account:
~/.ethereum # geth account ...
- 263
9
votes
1
answer
5k
views
What does block reached canonical chain mean?
In my geth node I see sometimes on the output the message
block reached canonical chain
I tried googling for the answer but could not find one. Does anyone know what this means.
- 1,313
9
votes
3
answers
22k
views
Send ether to contract address in web3.js
I want to send ether to this contract's contribute function using web3.js
I'm trying below code for the same but this doesn't work for me.
var AbiOfContract = 'abi_code';
var contractAddress = "...
- 137
9
votes
1
answer
4k
views
Is it possible to call debug_traceTransaction from nodejs?
Following answer (https://ethereum.stackexchange.com/a/9437/4575) [ 1 ] guide us to call debug_trace through using geth:
As documented in debug.traceTransaction(...), you can only access this API ...
- 8,404
9
votes
4
answers
11k
views
How to run two nodes on the same device?
I want to run two separate nodes on my computer but it seems that the two nodes will collide with other. I know some considerations should be taken such as the ports, but anything else should I take ...
- 2,426
9
votes
2
answers
6k
views
Search all smart contracts
I would like to search the code (binary grep) of all deployed contracts. The goal is to search for vulnerabilities and other research.
How can I do this with geth, Parity or the like? And is this ...
- 4,730
9
votes
2
answers
6k
views
How To SSL Ethereum Geth Node?
I have a geth node up and running but I want to be able to connect to it via https. For example https://eth-node-domain.com:8545 or https://121.213.231.24:8545 How can I go about doing this? I have ...
- 91
9
votes
2
answers
3k
views
Best way of accepting ERC20 tokens in my service
I need to allow users to deposit and extract ERC20 tokens in my service, and I'm wondering what's the best way of implementing that. My idea is to generate an account for each user, and when a user ...
- 427
9
votes
1
answer
8k
views
Could somebody please explain in detail what this Ethereum contract is doing?
I am new to ethereum & blockchain technology and trying to understand somethings(Etheruem, Truffle, DApps etc.) here and there from the internet.
From Ethereum official website,
Create a ...
- 391
9
votes
4
answers
6k
views
Optimal way of waiting for transactions to be mined in geth
I'm currently checking if a transaction has been mined using the following function (using web3.js):
function waitForTx(tx_hash) {
var result = null;
// This is not really efficient ...
- 5,284
9
votes
1
answer
3k
views
How to send ether to a cold storage account?
Is it possible to do the following:
Back up the keystore on a usb drive.
Format the computer used to generate the keystore.
Send ether to a public address in the keystore.
Reinstall geth (or other ...
- 555
9
votes
1
answer
5k
views
geth rewinds chain on every startup
I'm using geth to connect to the rinkeby network with fast sync. However, every time I restart geth I receive the following output:
Maximum peer count ETH=25 LES=0 total=25
...
- 193
9
votes
2
answers
2k
views
Accessing off-chain data from a smart contract to make a decision
I just started studying about smart contracts and from what I understand, smart contracts only deal with the data present on the blockchain. While working on a private blockchain, I want to know ...
- 3,930
9
votes
1
answer
1k
views
How can I stop the block gas limit on a private chain dropping to the public chain default?
I've got a little private chain running which occasionally runs some rather labour-intensive transactions.
I was able to set the initial block gas limit using the "gasLimit" parameter in genesis.json ...
- 16.9k
9
votes
1
answer
2k
views
Losing connection between nodes on private network
I have 3 nodes running on a private network.
After asking this question, I've manually added node1 as peer to node2 and node3, so my network looks like this:
_______ ...
- 2,491
9
votes
2
answers
57k
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 ...
- 223
9
votes
1
answer
4k
views
How do I access member variables of a contract from web3.eth?
For example:
enum Stages {
AcceptingBookings,
StopAcceptingBookings,
Finished
}
Stages public stage = Stages.AcceptingBookings;
function rand ( uint256 param) atStage(Stages....
- 307
9
votes
1
answer
15k
views
Post-merge network, but no beacon client seen. Please launch one to follow the chain!
Ethereum GOerli Network Sync stopped block number 7382822.
And one warning come (Post-merge network, but no beacon client seen. Please launch one to follow the chain! )
how to start sync in goerli ...
- 91
9
votes
1
answer
1k
views
DAPPS - Scope of what to put in your smart contract
As I'm learning more and more about developing Dapps, I'm having trouble understanding what needs to be stored in the smart contract (over our database etc..).
Let's take the case of a simple betting ...
- 203
9
votes
3
answers
4k
views
Can't verify contract on etherscan.io
guys. I have created simple contract, migrated to testnet via truffle. It can be founded here. But I can't verify it. I double check:
1. name of contract
2. version of compiler (ver. 0.4.11 in ...
- 293
9
votes
3
answers
7k
views
How could "ethereum block explorer" connect into geth that is already running on the main server securely?
I am working on private Ethereum Network. I run Ethereum boot-node and Ethereum Block Explorer app ( https://github.com/etherparty/explorer (A lightweight ethereum block explorer.) ) on the main ...
- 8,404
9
votes
2
answers
1k
views
geth: shh_newIdentity does not exists/is not available
I'm trying out whispers with web3 and geth on a private testnet. I'm just running the following code taken from Ethereum Whisper wiki.
function sendWhisper() {
var shh = web3.shh;
var appName ...
- 193
9
votes
2
answers
2k
views
Light clients for android
I am trying to develop an android wallet using Ethereum go and I ran the DroidGeth from this link. I tried to ran ethereum on the testnet, but its taking for ever to download the blockchain.
How can ...
- 515
9
votes
1
answer
3k
views
Solidity is installed but is not working within geth, on Ubuntu 16.04
Geth console outputs after admin.setSolc("/usr/bin/solc"):
eth.compile.solidity("")
I0601 15:31:56.663260 common/compiler/solidity.go:114] solc, the solidity compiler commandline interface
Version: 0....
- 3,930
9
votes
2
answers
6k
views
Is JSON-RPC error behavior documented?
Running geth, it's easy to see what its implementation of JSON-RPC does on errors:
$ curl -X POST --data '{"jsonrpc":"2.0","method":"eth_compileSolidity","params":["contract test { function multiply(...
- 465
9
votes
1
answer
2k
views
How can I generate a V3 of the Ethereum wallet file format in js, from strings: 'Passphrase' and 'Email or username' required by Quorumwallet?
Quorum Wallet prompts for a Passphrase and a Email or username to generate the account.
On the FAQs there is a description of the algorithm to generate the account:
What is the algorithm used to ...
- 161
9
votes
2
answers
3k
views
What filesystem should I use for geth and leveldb?
I used old LGA775 machine for running geth node. Its mobo has older sata 3gb/s (benchmark showed that ssd bottlenecked there) and only 4gb of DDR2, with windows installed. So syncing is a real pain ...
- 248
9
votes
1
answer
4k
views
supports SSL (https) JSON-RPC connections
Does ethereum node supports SSL (https) JSON-RPC connections like in Bitcoin? is there any work on control access over ethereum rpc nodes?
Thank you
- 719
9
votes
1
answer
3k
views
RPC error "invalid or missing value for params" when calling contract constant void functions
My contract has a function defined like this:
{"constant":true,"inputs":[],"name":"queryNumEscrows","outputs":
[{"name":"","type":"uint256"}],"payable":false,"type":"function"}
Having no inputs. Its ...
9
votes
2
answers
2k
views
Are there actual peers with IPv6 addresses?
geth has IPv6 support and listens on IPv6 as well. But I find, on my geth node, no IPv6 traffic. I tested both with lsof -n -i | grep geth (shows no IPv6 address) and tcpdump -n ip6. IPv6 works fine ...
- 693
9
votes
1
answer
2k
views
Link solc with geth problem
After upgrading to geth 1.4.4 I am no longer able to from to reference the compiler from geth.
The solc compiler is installed in /usr/local/bin but this is what I get when I check for available ...
- 91
9
votes
2
answers
3k
views
How to preallocate multiple accounts with ether for geth --dev chain?
I'm trying to set up a private chain with geth using --dev that has several accounts with lots of ether. It seems unclear if this is possible anymore according to this.
Here's what I tried on geth 1....
- 261
9
votes
2
answers
8k
views
Get smartcontract token balance via JSON RPC
Via Geth commandline I can get my smartcontract token balance with:
var mytest = eth.contract([{interface}]).at(contract address);
mytest.balanceOf(eth.accounts[0])
>998
I want to present the ...
- 191
9
votes
1
answer
848
views
Check if a contract implements specific ABI using JSON-RPC
In my Python web service, I'd like to confirm if a contract supports specific ABI (certain call methods). I am running get and communicating over JSON RPC.
What are steps to for this? I am guessing ...
- 23k
9
votes
2
answers
2k
views
Geth will not start mining in private network!
Will somebody please help me out? I am stuck at this since hours; did the process +3 times, each time deleting the datadir content. Geth still will not start mining!!
Specs:
Geth 1.8.11, on macOS X
...
- 91
9
votes
2
answers
2k
views
Persistent "deep transaction reorg" whilst syncing full geth node
Whilst syncing a new full node using the geth comand "geth --syncmode full", every other line after a few hundred blocks I see the following:
WARN [12-02|02:30:46] Skipping deep transaction reorg ...
9
votes
2
answers
3k
views
What does mean "Failed to retrieve current release"?
When I start with geth with light syncmode, I get the following error message:
ERROR[date] Failed to retrieve current release err="can't fetch trie key ...
- 870
9
votes
1
answer
3k
views
Why is Geth's "fast" sync now the default, whereas before it wasn't?
As of version 1.6.0, the default method used by Geth for syncing the chaindata is "fast":
The default sync mode is --syncmode=fast, for full sync please use
--syncmode=full.
Previously, the ...
- 38k
9
votes
1
answer
1k
views
No signer to authorize the transaction with
When trying to make a transaction on a boundContract with geth-api through the library of @karalabe. I am missing a way to get the signer. I only see the interface for signer in the aar but no way to ...
- 1,193
9
votes
1
answer
927
views
Geth 1.4.10 -- faild enc handshake: EOF
Geth suddenly stopped working for me - when I run it on verbosity level 5 I get repeating error messages like the following:
dyn dial conn 120.27.122.174:30303 faild enc handshake: EOF
Any thoughts ...
- 91
9
votes
2
answers
1k
views
What is the safest way to use WS-RPC server in geth?
In this answer, it is suggested that it is not safe to use --wsorigins="*" for security reasons. What are the security reasons?
=> How could I make WS-RPC server connection secure in geth?...
- 8,404
9
votes
1
answer
1k
views
Geth 6.2: miner.start() returns null and miner's hash-rate drop for all miners down due to the update
On Geth Version: 1.6.2-unstable miner.start() returns null, it used to return number of processes assigned. Is it normal? miner.start(num) num identifies the thread number?
> miner.stop()
true
>...
- 8,404
9
votes
1
answer
657
views
Filtering on events of the entire blockchain not possible in testrpc via truffle
A contract I wrote has an event in its constructor.
Since I want to find it back in the logs it doesn't seem possible to start listening to the latest block.
Because the event is already 'fired' ...
- 91
9
votes
1
answer
2k
views
getting started with geth and ENS commands: Error: invalid address
I'm starting from square zero, sorry. I'm just trying to get a javascript console up and running so that I can learn more about ENS:
http://docs.ens.domains/en/latest/userguide.html#resolving
I've ...
9
votes
1
answer
605
views
Installing go-ethereum nodes using docker swarm?
Has anybody installed and configured go-ethereum nodes using dockerswarm ?
Appreciate if anybody could share any docs or relevant information.
- 149
8
votes
3
answers
6k
views
CPU mining JSON_PARSE_ERROR
I just wanted to mine ETH with my CPU. I use Windows 7 64 Bit with ethminer.
I started the cpu miner with a batch
ethminer -t 6 -C -F http://ethereumpool.co/?miner=5@0x17C0Bea7c44*******...
- 161
8
votes
4
answers
10k
views
How to decode Log.Data in Go
I'm fetching the logs using client.SubscribeFilterLogs. The event parameters are encoded in types.Log.Data. How can I decode it in go?
- 448