pragma solidity ^0.4.14; //Fixed Base EAee supply token contract // (c) 7/7/2017. The MIT Licence.; // define standard fields for ERC20 contract contract ERC20 { // uint public totalSupply; // NOTE(en): this should not be exposed, use a getter function instead // NOTE from Jacks: almost every token contract uses public uint variable. Total supply of your tokens is not a big secret I think. string public standard = 'ERC20'; function balanceOf(address who) constant returns (uint); function allowance(address owner, address spender) constant returns (uint); function transfer(address to, uint value) returns (bool ok); function transferFrom(address from, address to, uint value) returns (bool ok); function approve(address spender, uint value) returns (bool ok); event Transfer(address indexed from, address indexed to, uint value); event Approval(address indexed owner, address indexed spender, uint value); } // needed to add restrictions who could execute commands (in this case owner - person who deployed the contract) contract Ownable { address public owner; function Ownable() { owner = msg.sender; }
modifier onlyOwner {
assert(msg.sender == owner);
_;
}
function transferOwnership(address newOwner) onlyOwner {
if (newOwner != address(0)) owner = newOwner;
}
} // best practice to use safe mathematic operations to avoid major problems library SafeMath { // NOTE (hen): use "library" contract is better function safeMul(uint a, uint b) internal returns (uint) { uint c = a * b; assert(a == 0 || c / a == b); return c; }
function safeDiv(uint a, uint b) internal returns (uint) {
// assert(b > 0); // NOTE (ihen): solidity will automatically throws when divided by 0
uint c = a / b;
// assert(a == b * c + a % b); NOTE (izgzhen): unnecessary
return c;
}
function safeSub(uint a, uint b) internal returns (uint) {
assert(b <= a);
return a - b;
}
function safeAdd(uint a, uint b) internal returns (uint) {
uint c = a + b;
assert(c >= a); // a + b can't be larger than or equal to a when overflowed
return c;
}
function max64(uint64 a, uint64 b) internal constant returns (uint64) {
return a >= b ? a : b;
}
function min64(uint64 a, uint64 b) internal constant returns (uint64) {
return a < b ? a : b;
}
function max256(uint256 a, uint256 b) internal constant returns (uint256) {
return a >= b ? a : b;
}
function min256(uint256 a, uint256 b) internal constant returns (uint256) {
return a < b ? a : b;
}
} contract TokenSpender { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData); } contract EEKER4 is ERC20, Ownable { using SafeMath for uint256; /* Public variables of the token */ string public name; string public symbol; uint8 public decimals; string public version = 'v1.0'; // uint public initialSupply; // useless if it is hardcoded in constructor uint public totalSupply; mapping (address => uint) public balances; // NOTE(hen): those should be public mapping (address => mapping (address => uint)) public allowed;
pragma solidity ^0.4.14;
//Fixed Base EAee supply token contract
// (c) 7/7/2017. The MIT Licence.;
// define standard fields for ERC20 contract
contract ERC20 {
// uint public totalSupply; // NOTE(en): this should not be exposed, use a getter function instead
// NOTE from Jacks: almost every token contract uses public uint variable. Total supply of your tokens is not a big secret I think.
string public standard = 'ERC20';
function balanceOf(address who) constant returns (uint);
function allowance(address owner, address spender) constant returns (uint);
function transfer(address to, uint value) returns (bool ok);
function transferFrom(address from, address to, uint value) returns (bool ok);
function approve(address spender, uint value) returns (bool ok);
event Transfer(address indexed from, address indexed to, uint value);
event Approval(address indexed owner, address indexed spender, uint value);
}
// needed to add restrictions who could execute commands (in this case owner - person who deployed the contract)
contract Ownable {
address public owner;
function Ownable() {
owner = msg.sender;
}
modifier onlyOwner {
assert(msg.sender == owner);
_;
}
function transferOwnership(address newOwner) onlyOwner {
if (newOwner != address(0)) owner = newOwner;
}
}
// best practice to use safe mathematic operations to avoid major problems
library SafeMath { // NOTE (hen): use "library" contract is better
function safeMul(uint a, uint b) internal returns (uint) {
uint c = a * b;
assert(a == 0 || c / a == b);
return c;
}
function safeDiv(uint a, uint b) internal returns (uint) {
// assert(b > 0); // NOTE (ihen): solidity will automatically throws when divided by 0
uint c = a / b;
// assert(a == b * c + a % b); NOTE (izgzhen): unnecessary
return c;
}
function safeSub(uint a, uint b) internal returns (uint) {
assert(b <= a);
return a - b;
}
function safeAdd(uint a, uint b) internal returns (uint) {
uint c = a + b;
assert(c >= a); // a + b can't be larger than or equal to a when overflowed
return c;
}
function max64(uint64 a, uint64 b) internal constant returns (uint64) {
return a >= b ? a : b;
}
function min64(uint64 a, uint64 b) internal constant returns (uint64) {
return a < b ? a : b;
}
function max256(uint256 a, uint256 b) internal constant returns (uint256) {
return a >= b ? a : b;
}
function min256(uint256 a, uint256 b) internal constant returns (uint256) {
return a < b ? a : b;
}
}
contract TokenSpender {
function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData);
}
contract EEKER4 is ERC20, Ownable {
using SafeMath for uint256;
/* Public variables of the token */
string public name;
string public symbol;
uint8 public decimals;
string public version = 'v1.0';
// uint public initialSupply; // useless if it is hardcoded in constructor
uint public totalSupply;
mapping (address => uint) public balances; // NOTE(hen): those should be public
mapping (address => mapping (address => uint)) public allowed;
function EEKER4() {
totalSupply = 1000000;
balances[msg.sender] = 1000000;
name = 'EEKER4';
symbol = 'EK4';
decimals = 18;
}
function transfer(address _to, uint _value) returns (bool) {
if (balances[msg.sender] >= _value &&
_value > 0 /* zero transfer is not allowed */ &&
balances[_to] + _value > balances[_to] /* check overflow */) {
balances[msg.sender] = balances[msg.sender] - _value;
balances[_to] = balances[_to] + _value;
Transfer(msg.sender, _to, _value);
return true;
} else {
return false;
}
}
function transferFrom(address _from, address _to, uint _value) returns (bool) {
if (balances[_from] >= _value &&
allowed[_from][msg.sender] >= _value &&
_value > 0 &&
balances[_to] + _value > balances[_to]) {
balances[_from] -= _value;
allowed[_from][msg.sender] -= _value;
balances[_to] += _value;
return true;
} else {
return false;
}
}
/* Approve and then comunicate the approved contract in a single tx */
function approveAndCall(address _spender, uint256 _value, bytes _extraData) {
TokenSpender spender = TokenSpender(_spender);
if (approve(_spender, _value)) {
spender.receiveApproval(msg.sender, _value, this, _extraData);
}
}
function allowance(address _owner, address _spender) constant returns (uint remaining) {
return allowed[_owner][_spender];
}
}
} }
