Transaction Hash:
Block:
22546610 at May-23-2025 03:59:11 PM +UTC
Transaction Fee:
0.00008544086938225 ETH
$0.22
Gas Used:
24,163 Gas / 3.53602075 Gwei
Emitted Events:
796 |
FOX.Approval( owner=[Sender] 0x2c27da465d47ee55d5807e6e59e624308a5f6786, spender=0x00000000...43aC78BA3, value=0 )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x2c27DA46...08a5f6786 |
0.000229359872721 Eth
Nonce: 13
|
0.00014391900333875 Eth
Nonce: 14
| 0.00008544086938225 | ||
0x4838B106...B0BAD5f97
Miner
| (Titan Builder) | 10.680793520046582017 Eth | 10.680817683046582017 Eth | 0.000024163 | |
0xc770EEfA...d808ee52d |
Execution Trace
FOX.approve( spender=0x000000000022D473030F116dDEE9F6B43aC78BA3, value=0 ) => ( True )
approve[ERC20 (ln:171)]
Approval[ERC20 (ln:175)]
pragma solidity 0.5.4; interface IERC20 { function transfer(address to, uint256 value) external returns (bool); function approve(address spender, uint256 value) external returns (bool); function transferFrom(address from, address to, uint256 value) external returns (bool); function totalSupply() external view returns (uint256); function balanceOf(address who) external view returns (uint256); function allowance(address owner, address spender) external view returns (uint256); event Transfer(address indexed from, address indexed to, uint256 value); event Approval(address indexed owner, address indexed spender, uint256 value); } library SafeMath { /** * @dev Multiplies two unsigned integers, reverts on overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b); return c; } /** * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { // Solidity only automatically asserts when dividing by 0 require(b > 0); uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; } /** * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend). */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { require(b <= a); uint256 c = a - b; return c; } /** * @dev Adds two unsigned integers, reverts on overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a); return c; } /** * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo), * reverts when dividing by zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { require(b != 0); return a % b; } } library Roles { struct Role { mapping (address => bool) bearer; } /** * @dev give an account access to this role */ function add(Role storage role, address account) internal { require(account != address(0)); require(!has(role, account)); role.bearer[account] = true; } /** * @dev remove an account's access to this role */ function remove(Role storage role, address account) internal { require(account != address(0)); require(has(role, account)); role.bearer[account] = false; } /** * @dev check if an account has this role * @return bool */ function has(Role storage role, address account) internal view returns (bool) { require(account != address(0)); return role.bearer[account]; } } contract ERC20 is IERC20 { using SafeMath for uint256; mapping (address => uint256) private _balances; mapping (address => mapping (address => uint256)) private _allowed; uint256 private _totalSupply; /** * @dev Total number of tokens in existence */ function totalSupply() public view returns (uint256) { return _totalSupply; } /** * @dev Gets the balance of the specified address. * @param owner The address to query the balance of. * @return An uint256 representing the amount owned by the passed address. */ function balanceOf(address owner) public view returns (uint256) { return _balances[owner]; } /** * @dev Function to check the amount of tokens that an owner allowed to a spender. * @param owner address The address which owns the funds. * @param spender address The address which will spend the funds. * @return A uint256 specifying the amount of tokens still available for the spender. */ function allowance(address owner, address spender) public view returns (uint256) { return _allowed[owner][spender]; } /** * @dev Transfer token for a specified address * @param to The address to transfer to. * @param value The amount to be transferred. */ function transfer(address to, uint256 value) public returns (bool) { _transfer(msg.sender, to, value); return true; } /** * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender. * Beware that changing an allowance with this method brings the risk that someone may use both the old * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * @param spender The address which will spend the funds. * @param value The amount of tokens to be spent. */ function approve(address spender, uint256 value) public returns (bool) { require(spender != address(0)); _allowed[msg.sender][spender] = value; emit Approval(msg.sender, spender, value); return true; } /** * @dev Transfer tokens from one address to another. * Note that while this function emits an Approval event, this is not required as per the specification, * and other compliant implementations may not emit the event. * @param from address The address which you want to send tokens from * @param to address The address which you want to transfer to * @param value uint256 the amount of tokens to be transferred */ function transferFrom(address from, address to, uint256 value) public returns (bool) { _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value); _transfer(from, to, value); emit Approval(from, msg.sender, _allowed[from][msg.sender]); return true; } /** * @dev Increase the amount of tokens that an owner allowed to a spender. * approve should be called when allowed_[_spender] == 0. To increment * allowed value is better to use this function to avoid 2 calls (and wait until * the first transaction is mined) * From MonolithDAO Token.sol * Emits an Approval event. * @param spender The address which will spend the funds. * @param addedValue The amount of tokens to increase the allowance by. */ function increaseAllowance(address spender, uint256 addedValue) public returns (bool) { require(spender != address(0)); _allowed[msg.sender][spender] = _allowed[msg.sender][spender].add(addedValue); emit Approval(msg.sender, spender, _allowed[msg.sender][spender]); return true; } /** * @dev Decrease the amount of tokens that an owner allowed to a spender. * approve should be called when allowed_[_spender] == 0. To decrement * allowed value is better to use this function to avoid 2 calls (and wait until * the first transaction is mined) * From MonolithDAO Token.sol * Emits an Approval event. * @param spender The address which will spend the funds. * @param subtractedValue The amount of tokens to decrease the allowance by. */ function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) { require(spender != address(0)); _allowed[msg.sender][spender] = _allowed[msg.sender][spender].sub(subtractedValue); emit Approval(msg.sender, spender, _allowed[msg.sender][spender]); return true; } /** * @dev Transfer token for a specified addresses * @param from The address to transfer from. * @param to The address to transfer to. * @param value The amount to be transferred. */ function _transfer(address from, address to, uint256 value) internal { require(to != address(0)); _balances[from] = _balances[from].sub(value); _balances[to] = _balances[to].add(value); emit Transfer(from, to, value); } /** * @dev Internal function that mints an amount of the token and assigns it to * an account. This encapsulates the modification of balances such that the * proper events are emitted. * @param account The account that will receive the created tokens. * @param value The amount that will be created. */ function _mint(address account, uint256 value) internal { require(account != address(0)); _totalSupply = _totalSupply.add(value); _balances[account] = _balances[account].add(value); emit Transfer(address(0), account, value); } /** * @dev Internal function that burns an amount of the token of a given * account. * @param account The account whose tokens will be burnt. * @param value The amount that will be burnt. */ function _burn(address account, uint256 value) internal { require(account != address(0)); _totalSupply = _totalSupply.sub(value); _balances[account] = _balances[account].sub(value); emit Transfer(account, address(0), value); } /** * @dev Internal function that burns an amount of the token of a given * account, deducting from the sender's allowance for said account. Uses the * internal burn function. * Emits an Approval event (reflecting the reduced allowance). * @param account The account whose tokens will be burnt. * @param value The amount that will be burnt. */ function _burnFrom(address account, uint256 value) internal { _allowed[account][msg.sender] = _allowed[account][msg.sender].sub(value); _burn(account, value); emit Approval(account, msg.sender, _allowed[account][msg.sender]); } } contract MinterRole { using Roles for Roles.Role; event MinterAdded(address indexed account); event MinterRemoved(address indexed account); Roles.Role private _minters; constructor () internal { _addMinter(msg.sender); } modifier onlyMinter() { require(isMinter(msg.sender)); _; } function isMinter(address account) public view returns (bool) { return _minters.has(account); } function addMinter(address account) public onlyMinter { _addMinter(account); } function renounceMinter() public { _removeMinter(msg.sender); } function _addMinter(address account) internal { _minters.add(account); emit MinterAdded(account); } function _removeMinter(address account) internal { _minters.remove(account); emit MinterRemoved(account); } } contract ERC20Mintable is ERC20, MinterRole { /** * @dev Function to mint tokens * @param to The address that will receive the minted tokens. * @param value The amount of tokens to mint. * @return A boolean that indicates if the operation was successful. */ function mint(address to, uint256 value) public onlyMinter returns (bool) { _mint(to, value); return true; } } contract ERC20Capped is ERC20Mintable { uint256 private _cap; constructor (uint256 cap) public { require(cap > 0); _cap = cap; } /** * @return the cap for the token minting. */ function cap() public view returns (uint256) { return _cap; } function _mint(address account, uint256 value) internal { require(totalSupply().add(value) <= _cap); super._mint(account, value); } } contract FOX is ERC20, ERC20Capped { string public constant name = "FOX"; string public constant symbol = "FOX"; uint8 public constant decimals = 18; constructor() ERC20Capped(1000001337 * (uint(10) ** decimals)) public { mint(msg.sender, 1000001337 * (uint(10) ** decimals)); } }