pragma solidity ^0.4.18; | |
/** | |
* @title ERC20Basic | |
* @dev Simpler version of ERC20 interface | |
* @dev see https://github.com/ethereum/EIPs/issues/179 | |
*/ | |
contract ERC20Basic { | |
uint256 public totalSupply; | |
function balanceOf(address who) public constant returns (uint256); | |
function transfer(address to, uint256 value) public returns (bool); | |
event Transfer(address indexed from, address indexed to, uint256 value); | |
} | |
/** | |
* @title ERC20 interface | |
* @dev see https://github.com/ethereum/EIPs/issues/20 | |
*/ | |
contract ERC20 is ERC20Basic { | |
function allowance(address owner, address spender) public constant returns (uint256); | |
function transferFrom(address from, address to, uint256 value) public returns (bool); | |
function approve(address spender, uint256 value) public returns (bool); | |
event Approval(address indexed owner, address indexed spender, uint256 value); | |
} | |
/** | |
* @title SafeMath | |
* @dev Math operations with safety checks that throw on error | |
*/ | |
library SafeMath { | |
function mul(uint256 a, uint256 b) pure internal returns (uint256) { | |
uint256 c = a * b; | |
assert(a == 0 || c / a == b); | |
return c; | |
} | |
function div(uint256 a, uint256 b) pure internal returns (uint256) { | |
// assert(b > 0); // Solidity automatically throws when dividing by 0 | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
function sub(uint256 a, uint256 b) pure internal returns (uint256) { | |
assert(b <= a); | |
return a - b; | |
} | |
function add(uint256 a, uint256 b) pure internal returns (uint256) { | |
uint256 c = a + b; | |
assert(c >= a); | |
return c; | |
} | |
} | |
/** | |
* @title Basic token | |
* @dev Basic version of StandardToken, with no allowances. | |
*/ | |
contract BasicToken is ERC20Basic { | |
using SafeMath for uint256; | |
mapping(address => uint256) balances; | |
/** | |
* @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) { | |
balances[msg.sender] = balances[msg.sender].sub(_value); | |
balances[_to] = balances[_to].add(_value); | |
Transfer(msg.sender, _to, _value); | |
return true; | |
} | |
/** | |
* @dev Gets the balance of the specified address. | |
* @param _owner The address to query the the balance of. | |
* @return An uint256 representing the amount owned by the passed address. | |
*/ | |
function balanceOf(address _owner) public constant returns (uint256 balance) { | |
return balances[_owner]; | |
} | |
} | |
/** | |
* @title Standard ERC20 token | |
* | |
* @dev Implementation of the basic standard token. | |
* @dev https://github.com/ethereum/EIPs/issues/20 | |
* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol | |
*/ | |
contract StandardToken is ERC20, BasicToken { | |
mapping (address => mapping (address => uint256)) allowed; | |
/** | |
* @dev Transfer tokens from one address to another | |
* @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 amout of tokens to be transfered | |
*/ | |
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) { | |
var _allowance = allowed[_from][msg.sender]; | |
// Check is not needed because sub(_allowance, _value) will already throw if this condition is not met | |
// require (_value <= _allowance); | |
balances[_to] = balances[_to].add(_value); | |
balances[_from] = balances[_from].sub(_value); | |
allowed[_from][msg.sender] = _allowance.sub(_value); | |
Transfer(_from, _to, _value); | |
return true; | |
} | |
/** | |
* @dev Aprove the passed address to spend the specified amount of tokens on behalf of msg.sender. | |
* @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) { | |
// To change the approve amount you first have to reduce the addresses` | |
// allowance to zero by calling `approve(_spender, 0)` if it is not | |
// already 0 to mitigate the race condition described here: | |
// https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 | |
require((_value == 0) || (allowed[msg.sender][_spender] == 0)); | |
allowed[msg.sender][_spender] = _value; | |
Approval(msg.sender, _spender, _value); | |
return true; | |
} | |
/** | |
* @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 specifing the amount of tokens still available for the spender. | |
*/ | |
function allowance(address _owner, address _spender) public constant returns (uint256 remaining) { | |
return allowed[_owner][_spender]; | |
} | |
} | |
/** | |
* @title Burnable Token | |
* @dev Token that can be irreversibly burned (destroyed). | |
*/ | |
contract BurnableToken is StandardToken { | |
event Burn(address indexed burner, uint256 value); | |
/** | |
* @dev Burns a specific amount of tokens. | |
* @param _value The amount of token to be burned. | |
*/ | |
function burn(uint256 _value) public { | |
require(_value > 0); | |
require(_value <= balances[msg.sender]); | |
// no need to require value <= totalSupply, since that would imply the | |
// sender's balance is greater than the totalSupply, which *should* be an assertion failure | |
address burner = msg.sender; | |
balances[burner] = balances[burner].sub(_value); | |
totalSupply = totalSupply.sub(_value); | |
Burn(burner, _value); | |
} | |
} | |
/** | |
* @title Ownable | |
* @dev The Ownable contract has an owner address, and provides basic authorization control | |
* functions, this simplifies the implementation of "user permissions". | |
*/ | |
contract Ownable { | |
address public owner; | |
/** | |
* @dev The Ownable constructor sets the original `owner` of the contract to the sender | |
* account. | |
*/ | |
function Ownable() public { | |
owner = msg.sender; | |
} | |
/** | |
* @dev Throws if called by any account other than the owner. | |
*/ | |
modifier onlyOwner() { | |
require(msg.sender == owner); | |
_; | |
} | |
/** | |
* @dev Allows the current owner to transfer control of the contract to a newOwner. | |
* @param newOwner The address to transfer ownership to. | |
*/ | |
function transferOwnership(address newOwner) public onlyOwner { | |
require(newOwner != address(0)); | |
owner = newOwner; | |
} | |
} | |
/** | |
* @title Mintable token | |
* @dev Simple ERC20 Token example, with mintable token creation | |
* @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120 | |
* Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol | |
*/ | |
contract MintableToken is BurnableToken, Ownable { | |
event Mint(address indexed to, uint256 amount); | |
event MintFinished(); | |
bool public mintingFinished = false; | |
modifier canMint() { | |
require(!mintingFinished); | |
_; | |
} | |
/** | |
* @dev Function to mint tokens | |
* @param _to The address that will recieve the minted tokens. | |
* @param _amount The amount of tokens to mint. | |
* @return A boolean that indicates if the operation was successful. | |
*/ | |
function mint(address _to, uint256 _amount) public onlyOwner canMint returns (bool) { | |
totalSupply = totalSupply.add(_amount); | |
balances[_to] = balances[_to].add(_amount); | |
Mint(_to, _amount); | |
Transfer(0x0, _to, _amount); | |
return true; | |
} | |
/** | |
* @dev Function to stop minting new tokens. | |
* @return True if the operation was successful. | |
*/ | |
function finishMinting() public onlyOwner returns (bool) { | |
mintingFinished = true; | |
MintFinished(); | |
return true; | |
} | |
} | |
contract DVFooToken2 is MintableToken { | |
string public standard = 'DVFooToken 2'; | |
string public name; | |
string public symbol; | |
uint8 public decimals; | |
/* Initializes contract with initial supply tokens to the creator of the contract */ | |
function DVFooToken2( | |
uint256 initialSupply, | |
string tokenName, | |
uint8 decimalUnits, | |
string tokenSymbol | |
) public { | |
balances[msg.sender] = initialSupply; // Give the creator all initial tokens | |
totalSupply = initialSupply; // Update total supply | |
name = tokenName; // Set the name for display purposes | |
symbol = tokenSymbol; // Set the symbol for display purposes | |
decimals = decimalUnits; // Amount of decimals for display purposes | |
} | |
} |
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