In solc 0.4.x assembly, how can I check if a non-constant function returns ‘bool’ or nothing?

I know how to do it for a constant function, for example: pragma solidity 0.4.25; contract Callee0 {function func() external pure returns (bool) {return false;}} contract Callee1 {function func() external pure returns (bool) {return true;}} contract Callee2 {function func() external pure {}} contract Caller { bytes4 private constant FUNC_SELECTOR = bytes4(uint256(keccak256(“func()”) >> (256 – 4…

raw transactions to send ERC20 token fails on private network(POA)

I am trying to transfer ERC20 tokens on private ethereum network(POA) Transaction flow: raw tx object creation on backend. { “gasLimit”: 37000, “gasPrice”: 4000000000, “to”: <contract address>, “value”: 0, “chainId”: 15, “data”: “0xa9059cbb000000000000000000000000ff70ccdc55a319428fd88809ce848a61087ab2ac0000000000000000000000000000000000000000000000003782dace9d900000” } sign tx on front end. { messageHash: ‘0x4bbc38ad53cf154ca1445365c9007dfeca0c0cce251945feb2a8ff3bd6de8795’, v: ‘0x42’, r: ‘0xa664add8c614f05d52104a29b16312744cb8849bc5af5cb78a9ba7daf19e8a12’, s: ‘0x38c055e9a7c1e5b0321f5d82d832d91da3a2207025756b84c44b8ca31cbbb4f2’, rawTransaction: ‘0xf8a80884ee6b280082908894324e19e928239d0c7f8b93247d559b54a4e0d03080b844a9059cbb0000000000000000000000008d75f6db12c444e290db995f2650a68159364e2500000000000000000000000000000000000000000000000270801d946c94000042a0a664add8c614f05d52104a29b16312744cb8849bc5af5cb78a9ba7daf19e8a12a038c055e9a7c1e5b0321f5d82d832d91da3a2207025756b84c44b8ca31cbbb4f2’ } submit tx from backend…

eth_sendTransaction does not exist / is not available

I try to send eth from one address to another, but I get an error: Returned error: The method eth_sendTransaction does not exist / is not available const Web3 = require(‘web3’) const web3 = new Web3(new Web3.providers.HttpProvider(‘’)) sender = “addr1” receiver = “addr2” amount = web3.utils.toWei(“0.002″,”ether”) web3.eth.sendTransaction({from:sender, to:receiver, value:amount})

No response from live networks except ganache when interacting with truffle-contract

I am developing a Web3 app for a private Ethereum network. Throughout the development I used ganache-cli and now I wanted to test in the private live network. I can successfully interact with the network at the ganache network. I deployed the contract successfully to the live network. I see the transaction being mined successfully…

Web3py. Error getting events using Infura: “The method eth_newFilter does not exist/is not available”

I’m trying to get all events from contract, but get error: “ValueError: {‘code’: -32601, ‘message’: ‘The method eth_newFilter does not exist/is not available’}” I’m using Web3py and Infura. My code: myfilter = <myContract>.events.<MyEvent>.createFilter(fromBlock=0) or myFilter = web3.eth.filter({“address”: <myContractAddress>}) Why is this error? How do I get events? Help me please.