DAK Utility Token Smart Contract (Specimen)
Summary
This document is a specimen of the DAK Utility Token Smart Contract, which outlines the code and rules for the DAK Token, an ERC20-compliant cryptocurrency token. The contract specifies how tokens are created, transferred, and managed, with all tokens initially assigned to the creator. It includes functions for transferring tokens, approving spending by others, and checking balances. The contract is intended for use on the Ethereum blockchain and is written in Solidity. No specific parties are named, as this is a template for token issuance and management.
EX-4.4 7 dako_ex44.htm CONTRACT dako_ex44.htm
EXHIBIT 4.4
Specimen DAK Utility Token Smart Contract
pragma solidity ^0.4.18;
contract SafeMath {
function safeAdd(uint256 x, uint256 y) internal returns(uint256) {
uint256 z = x + y;
assert((z >= x) && (z >= y));
return z;
}
function safeSubtract(uint256 x, uint256 y) internal returns(uint256) {
assert(x >= y);
uint256 z = x - y;
return z;
}
function safeMult(uint256 x, uint256 y) internal returns(uint256) {
uint256 z = x * y;
assert((x == 0)||(z/x == y));
return z;
}
}
contract Token {
uint256 public totalSupply;
function balanceOf(address _owner) constant returns (uint256 balance);
function transfer(address _to, uint256 _value) returns (bool success);
function transferFrom(address _from, address _to, uint256 _value) returns (bool success);
function approve(address _spender, uint256 _value) returns (bool success);
function allowance(address _owner, address _spender) constant returns (uint256 remaining);
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
/* ERC 20 token */
contract StandardToken is Token, SafeMath {
mapping (address => uint256) balances;
mapping (address => mapping (address => uint256)) allowed;
modifier onlyPayloadSize(uint numwords) {
assert(msg.data.length == numwords * 32 + 4);
_;
}
function transfer(address _to, uint256 _value)
returns (bool success)
{
if (balances[msg.sender] >= _value && _value > 0 && balances[_to] + _value > balances[_to]) {
balances[msg.sender] = safeSubtract(balances[msg.sender], _value);
balances[_to] = safeAdd(balances[_to], _value);
Transfer(msg.sender, _to, _value);
return true;
} else {
return false;
}
}
function transferFrom(address _from, address _to, uint256 _value)
returns (bool success)
{
if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0 && balances[_to] + _value > balances[_to]) {
balances[_to] = safeAdd(balances[_to], _value);
balances[_from] = safeSubtract(balances[_from], _value);
allowed[_from][msg.sender] = safeSubtract(allowed[_from][msg.sender], _value);
Transfer(_from, _to, _value);
return true;
} else {
return false;
}
}
function balanceOf(address _owner) constant returns (uint256 balance) {
return balances[_owner];
}
function approve(address _spender, uint256 _value)
onlyPayloadSize(2)
returns (bool success)
{
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
return true;
}
function allowance(address _owner, address _spender)
constant
onlyPayloadSize(2)
returns (uint256 remaining)
{
return allowed[_owner][_spender];
}
}
/**
* @title DAKToken
* @dev ERC20 Token, where all tokens are pre-assigned to the creator.
* Note they can later distribute these tokens as they wish using `transfer` and other
* `StandardToken` functions.
*/
contract DAKToken is StandardToken {
string public name = "DAK Token";
string public symbol = "DAK";
uint256 public decimals = 18;
uint256 public INITIAL_SUPPLY = 5250000000 * 1 ether;
/**
* @dev Contructor that gives msg.sender all of existing tokens.
*/
function DakToken() {
totalSupply = INITIAL_SUPPLY;
balances[msg.sender] = INITIAL_SUPPLY;
}
}
