I'm new to write a smart contract with Ethereum.
According to an official document, compiling a smart contract needs to remove all the line-breaks in the contract's source-code :
var greeterSource = 'contract mortal { address owner; function mortal() { owner = msg.sender; } function kill() { if (msg.sender == owner) suicide(owner); } } contract greeter is mortal { string greeting; function greeter(string _greeting) public { greeting = _greeting; } function greet() constant returns (string) { return greeting; } }'
var greeterCompiled = web3.eth.compile.solidity(greeterSource)
https://ethereum.gitbooks.io/frontier-guide/content/contract_greeter.html
As I think the removing process is not smart, I want to compile the code itself like:
var greeterCompiled = web3.eth.compile.solidity_infile( "greeter.txt" )
# The function "solidity_infile" does not exists actually,
# but represents what I want to do.
greeter.txt
contract
mortal {
/* Define variable owner of the type address*/
address owner;
/* this function is executed at initialization and sets the owner of the contract */
function mortal() { owner = msg.sender; }
/* Function to recover the funds on the contract */
function kill() { if (msg.sender == owner) suicide(owner); }
}
contract greeter is mortal {
/* define variable greeting of the type string */
string greeting;
/* this runs when the contract is executed */
function greeter(string _greeting) public {
greeting = _greeting;
}
/* main function */
function greet() constant returns (string) {
return greeting;
}
}
Does anyone how to do that?
The compiler I'm using is Solidity.
How about loading the contract from a file into var someContractText and then do the following
someContractText = someContractText.replace(/(\r\n|\n|\r)/gm,"");
Related
I'm new to Solidity but I can't find much information about my problem.
For example, I want to make different contracts for different functionalities (I see them as classes)
For example
Main contract
// SPDX-License-Identifier: None
pragma solidity >=0.8.6;
import "./AuthContract.sol";
contract Contract {
string public message;
constructor() {
message = "test";
}
function getMessage() public view returns(string memory) {
return message;
}
}
and second contract
contract Auth {
struct UserDetail {
address addr;
string name;
string password;
string CNIC;
bool isUserLoggedIn;
}
mapping(address => UserDetail) user;
// user registration function
function register(
address _address,
string memory _name,
string memory _password,
string memory _cnic
) public returns (bool) {
require(user[_address].addr != msg.sender);
user[_address].addr = _address;
user[_address].name = _name;
user[_address].password = _password;
user[_address].CNIC = _cnic;
user[_address].isUserLoggedIn = false;
return true;
}
// user login function
function login(address _address, string memory _password)
public
returns (bool)
{
if (
keccak256(abi.encodePacked(user[_address].password)) ==
keccak256(abi.encodePacked(_password))
) {
user[_address].isUserLoggedIn = true;
return user[_address].isUserLoggedIn;
} else {
return false;
}
}
// check the user logged In or not
function checkIsUserLogged(address _address) public view returns (bool) {
return (user[_address].isUserLoggedIn);
}
// logout the user
function logout(address _address) public {
user[_address].isUserLoggedIn = false;
}
}
How could I use the functionalities from that contract in the main contract?
Is such a thing possible in the blockchain?
I am quite new here also but i can solve your problem, if not solve i can lead you to a good path .
so firstly you said you want to create multiple contract for different functionalities, this is good but keep in my you are going to exhaust a lot of gas.
so the answer to your problem is easy you can just read it and implement it.
if you want to use a contract in the Another contract (main in your case) you can do it in two ways(according to my knowledge there might be other).
using new keyword
using address of your previously deployed contract
we will be using the First case as i suppose you havenot deployed the second contract yet
In Order to do it you can use
Auth myObj=new Auth();
This will create a new instance of the contract Auth in your main contract and now you can use the Auth contract's function in your Main contract.you can create a function copy the above line and you can use the Functions using dot operator.
myObj.register(_address,_name,moreandmore);
I believe this will solve your problem if not you can ask it.
Thank You!
I need help how to fix the "else if" = only owner is allowed to call the _action from the main contract. this is just the logger. below is the contract logger.
contract logger {
function log(address _caller, uint _amount, string memory _action) public {
if (equal(_action, "withdraw")) {
revert("It's a frank!");
else if (equal(_caller, "owner"));
assert();
}
}
function equal(string memory _a, string memory _b) public pure returns (bool) {
return keccak256(abi.encode(_a)) == keccak256(abi.encode(_b));
So I am guessing you want to call the function from the main contract in the logger contract. So we need to know the address of the main contract and the function signature of the action function in the main contract. Suppose the function signature of action function in the main contract is action(unit256). And let's initialize the main contract in the constructor.
So the contract logger would look like this:
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import "./MainContract.sol";
contract Logger {
address private owner;
MainContract mainContract;
constructor(address _mainContract){
owner = msg.sender;
mainContract = new MainContract(_mainContract);
}
function log(address _caller, uint _amount, string memory _action, uint256 value) public {
if (equal(_action, "withdraw")) {
// Do whatever you want
}
else if (_caller == owner){
mainContract.action(value);
// Do whatever you want
}
}
function equal(string memory _a, string memory _b) public pure returns (bool) {
return keccak256(abi.encode(_a)) == keccak256(abi.encode(_b));
}
}
I am trying the below code, elementary reentrancy example.
The current code works but transfer or send doesn't work. It reverts. What are the reasons?
Note: I chose setCaller to reenter to test the fact that updating the dirty state variable (already modified var in the same tx) takes less gas.
// SPDX-License-Identifier: Unlicensed
pragma solidity 0.8.7;
contract TestFund {
// success, if caller is itself.
address public caller;
constructor() payable {}
function getBalance() public view returns (uint) {
return address(this).balance;
}
function emptyFn(address dummy) public {}
function setCaller(address _caller) public {
caller = _caller;
}
function withdraw() external {
caller = msg.sender;
// require(payable(msg.sender).send(1 wei));
// payable(msg.sender).transfer(1 wei);
(bool success, bytes memory data) = payable(msg.sender).call{gas: 2300, value:1 wei}("");
require(success);
}
}
contract Attack {
function getBalance() public view returns (uint) {
return address(this).balance;
}
function attack(address target) external {
TestFund(target).withdraw();
}
receive() external payable {
if (getBalance() == 1 wei) {
TestFund(msg.sender).setCaller(msg.sender);
}
}
}
How to call run-local (without sending a message) function of another contract from debot? For example, for getting a public variable.
This was useful for me.
In debot:
Create interface for function of another contract with function (if public variable too).
interface IOther {
function funcName()
external returns(uint);
}
Build the message and send it.
function runLocal() public{
optional(uint256) pubkey = 0;
address remoteContract = address.makeAddrStd(0, 0xceaa3bc6b00cf2b1e750dae2dd94d246a126a989009a3fb3bb73bea1a48b3b);
TvmCell message = tvm.buildExtMsg({
abiVer: 2,
callbackId: tvm.functionId(onSuccessFuncName),
onErrorId: tvm.functionId(onErrorFuncName),
time: uint64(now),
dest: remoteContract,
call: {
IOther.funcName
}
});
tvm.sendrawmsg(message, 1);
}
function onSuccessFuncName(uint response) public{
/* working with response from remote contract */
}
function onErrorFuncName() public{
/* catch error */
}
I have two contracts as shown below. I am saving document details to document contract through the DocInfo contract. But when I tried to get the details through the docINfo contract I am getting empty result. Is there anything I missed here?
pragma solidity 0.5.0;
contract DocumentContract {
struct Document{
string DocumentNo;
address DigitalID;
}
mapping(string=>Document) doc;
function CreateDocument(string calldata DocumentNo,address DigitalID) external {
doc[DocumentNo] = Document({
DocumentNo: DocumentNo,
DigitalID: DigitalID
});
}
function GetDocument(string calldata documentNumber) external view returns(address) {
Document memory document = doc[documentNumber];
return (document.DigitalID);
}
}
contract DocInfo {
function CreateDocument(address digitalID,string memory documentId) public returns (bool success) {
address contractAddress =<<Document contract address>>;
DocumentContract doc = DocumentContract(contractAddress);
doc.CreateDocument(documentId,digitalID);
return true;
}
function GetDocument(string memory documentId)
public view returns (address) {
address contractAddress = <<Document contract address>>;
DocumentContract doc = DocumentContract(contractAddress);
address digitalId = doc.GetDocument(documentId);
return digitalId;
}
}