文件 1 的 1:TokenBase.sol
pragma solidity ^0.4.25;
interface IERC20 {
function balanceOf(address _owner) external view returns (uint256);
function allowance(address _owner, address _spender) external view returns (uint256);
function transfer(address _to, uint256 _value) external returns (bool);
function transferFrom(address _from, address _to, uint256 _value) external returns (bool);
function approve(address _spender, uint256 _value) external returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
assert(c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a / b;
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
contract TokenBase is IERC20 {
using SafeMath for uint256;
address private owner;
string public name = "Fowin Global Token";
string public symbol = "FOT";
uint8 public constant decimals = 18;
uint256 public constant decimalFactor = 10 ** uint256(decimals);
uint256 public totalSupply = 1000000000 * decimalFactor;
mapping (address => uint256) balances;
mapping (address => mapping (address => uint256)) internal allowed;
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
event Burn(address indexed target,uint256 value);
constructor() public {
balances[msg.sender] = totalSupply;
emit Transfer(address(0), msg.sender, totalSupply);
}
modifier onlyOwner {
if (msg.sender != owner) revert();
_;
}
function burn(uint256 _value) public returns(bool){
require(_value <= balances[msg.sender]);
totalSupply=totalSupply.sub(_value);
balances[msg.sender]=balances[msg.sender].sub(_value);
emit Burn(msg.sender,_value);
return true;
}
function balanceOf(address _owner) public view returns (uint256 balance) {
return balances[_owner];
}
function allowance(address _owner, address _spender) public view returns (uint256) {
return allowed[_owner][_spender];
}
function transfer(address _to, uint256 _value) public returns (bool) {
require(_value <= balances[msg.sender]);
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
emit Transfer(_from, _to, _value);
return true;
}
function approve(address _spender, uint256 _value) public returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
}
{
"compilationTarget": {
"TokenBase.sol": "TokenBase"
},
"evmVersion": "byzantium",
"libraries": {},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}