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1500 questions
11
votes
5 answers
Truffle Error- VM Exception while processing transaction: revert
I create a smart contract to sell my token.I am following the Dapp University(youtube channel) course.
I have done unit testing of smart contract.All test cases pass.
And I am trying to buy token on my client side application.So there is…
Anupam Jain
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11
votes
1 answer
truffle migrate specific file
Is it possible to truffle migrate only one specific file?
I found this on the internet: https://github.com/trufflesuite/truffle-migrate/issues/23
but truffle migrate -from 2 starts to migrate from file 2_... and goes then to the next.
My goal is to…
fabem
- 113
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11
votes
1 answer
Geth: what does "commit new work on block" exactly mean?
First intuition was that it signals that there are transactions to be mined, but even without a tx on a private net sometimes I see it three times per block
I0604 10:00:49.877830 miner/worker.go:337] Mined stale block (#233 / 52f98d53).
I0604…
Roland Kofler
- 11,638
- 3
- 44
- 83
11
votes
4 answers
I've got an error while compiling.Use "constructor(...) { ... }" instead
I've followed the lecture on Udemy. But I've got an error
here's my 'Inbox/contracts/Inbox.sol'
pragma solidity ^0.4.17;
contract Inbox {
string public message;
function Inbox(string initialMessage) public {
message =…
Sang-hoon Shin
- 425
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11
votes
3 answers
How to calculate the assigned txHash of a transaction?
Solidity does not support txHash variable yet, but it has been requested at EIP 901 https://github.com/ethereum/EIPs/issues/901 . Meanwhile how could I calculate the txHash of a transaction using Solidity code in the Smart Contract? I guess txHash…
Juan Ignacio Pérez Sacristán
- 3,550
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11
votes
2 answers
Invoking events without "emit" prefix is deprecated in Transfer(msg.sender, _to, _value);
I'm following this page instructions to create my own crypto-currency with Ethereum. Here is my code:
pragma solidity ^0.4.18;
contract MyToken {
string public name;
string public symbol;
uint8 public decimals;
event Transfer(address…
learnercys
- 215
- 1
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11
votes
1 answer
How to edit a contract that has already been deployed?
I have been writing my first few contracts. So, as I understand it, once you write, compile, and deploy your contract, the only way to then interact with that contract is via something like web3.js and the ABI Definitions within the contract…
Taylor Pechacek
- 161
- 1
- 5
11
votes
1 answer
How could msg.sender != tx.origin AND extcodesize(caller) == 0 be true?
I'm working on a puzzle where msg.sender != tx.origin, so the implication is that the caller needs to be a contract or at least something in between the calling account.
But extcodesize(caller) == 0 also needs to be true. So the caller needs to be…
Joe Blow
- 111
- 3
11
votes
3 answers
How to connect to infura and deploy contract use web3.py？
the orgin question is below:
How to connect to Ropston and deploy contract use web3.py？
I have deploy a contract to Ropston use remix and MetaMask.
I want know how to deploy a contract to Ropston via infura using web3.py without geth or parity.
I…
Abirdcfly
- 213
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11
votes
7 answers
How to check whether MetaMask is installed?
How to check from client-side JavaScript whether MetaMask is installed?
porton
- 1,774
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11
votes
1 answer
IPFS hash algorithm
How actually is an IPFS hash (ipfs add) is generated?
I'm looking for step by step operations done on input(bytes/string) to get output(in this case IPFSHash)
Nikola M.
- 196
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- 8
11
votes
4 answers
"potential rewrite attack" message on Geth
When I was sending Ether using Mist I got the following message on Geth.
I0528 18:34:57.312997 core/blockchain.go:959] imported 1 block(s) (0 queued 0 ignored) including 3 txs in 19.344963ms. #1602638 [e4523f86 / e4523f86]
I0528 18:35:24.519128…
wacax
- 1,388
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11
votes
5 answers
Are there any drawbacks of being Turing complete?
I understand that Turing Complete means that Ethereum is robust and able to implement any idea that can be codified including best features from other networks.
Aside from blockchain bloat based on the amount of data that may need to eventually…
cindy smith
- 393
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- 9
11
votes
2 answers
Ed25519 in smart contracts
Is there a practical way (preferrably OSS library or implementation) to verify Ed25519 signatures in Solidity (compiled for and run on the EVM), in smart contracts?
Update: I've created EIP665
oberstet
- 175
- 10
11
votes
3 answers
Are communications encrypted?
I'd like to know whether the messages delivered to the ethereum network by my wallet are encrypted such that any identifying information about the wallet is inaccessible to the ISP?
in other words, can ownership of the wallet be traced to me via…
ekkis
- 207
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- 6