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pragma solidity ^0.4.21; | |
contract EIP20 { | |
uint256 constant private MAX_UINT256 = 2**256 - 1; | |
uint256 public totalSupply; | |
mapping (address => uint256) public balances; | |
mapping (address => mapping (address => uint256)) public allowed; | |
string public name; //fancy name: eg Simon Bucks | |
uint8 public decimals; //How many decimals to show. | |
string public symbol; //An identifier: eg SBX | |
event Transfer(address indexed _from, address indexed _to, uint256 _value); | |
event Approval(address indexed _owner, address indexed _spender, uint256 _value); | |
function EIP20( | |
uint256 _initialAmount, | |
string _tokenName, | |
uint8 _decimalUnits, | |
string _tokenSymbol | |
) public { | |
balances[msg.sender] = _initialAmount; // Give the creator all initial tokens | |
totalSupply = _initialAmount; // Update total supply | |
name = _tokenName; // Set the name for display purposes | |
decimals = _decimalUnits; // Amount of decimals for display purposes | |
symbol = _tokenSymbol; // Set the symbol for display purposes | |
} | |
function transfer(address _to, uint256 _value) public returns (bool success) { | |
require(balances[msg.sender] >= _value); | |
balances[msg.sender] -= _value; | |
balances[_to] += _value; | |
emit Transfer(msg.sender, _to, _value); //solhint-disable-line indent, no-unused-vars | |
return true; | |
} | |
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { | |
uint256 allowance = allowed[_from][msg.sender]; | |
require(balances[_from] >= _value && allowance >= _value); | |
balances[_to] += _value; | |
balances[_from] -= _value; | |
if (allowance < MAX_UINT256) { | |
allowed[_from][msg.sender] -= _value; | |
} | |
emit Transfer(_from, _to, _value); //solhint-disable-line indent, no-unused-vars | |
return true; | |
} | |
function balanceOf(address _owner) public view returns (uint256 balance) { | |
return balances[_owner]; | |
} | |
function approve(address _spender, uint256 _value) public returns (bool success) { | |
allowed[msg.sender][_spender] = _value; | |
emit Approval(msg.sender, _spender, _value); //solhint-disable-line indent, no-unused-vars | |
return true; | |
} | |
function allowance(address _owner, address _spender) public view returns (uint256 remaining) { | |
return allowed[_owner][_spender]; | |
} | |
} |
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const abi = fs.readFileSync('erc20_abi.json', 'utf-8'); | |
const contract = new web3.eth.Contract(JSON.parse(abi), contract_address) | |
contract.methods.balanceOf(address).call().then(console.log).catch(console.error); | |
contract.methods.transfer(to_address, amount).send().then(console.log).catch(console.error); |
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