Contract Source Code:
File 1 of 1 : EVXToken
pragma solidity ^0.4.13;
/**
* Everex Token Contract
* Copyright © 2017 by Everex https://everex.io
*/
/**
* @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) constant returns (uint256);
function transfer(address to, uint256 value) 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) constant returns (uint256);
function transferFrom(address from, address to, uint256 value) returns (bool);
function approve(address spender, uint256 value) returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @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) returns (bool) {
require(_to != address(0));
// SafeMath.sub will throw if there is not enough balance.
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) 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 amount of tokens to be transferred
*/
function transferFrom(address _from, address _to, uint256 _value) returns (bool) {
require(_to != address(0));
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[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = _allowance.sub(_value);
Transfer(_from, _to, _value);
return true;
}
/**
* @dev Approve 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) 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 specifying the amount of tokens still available for the spender.
*/
function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
return allowed[_owner][_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
*/
function increaseApproval (address _spender, uint _addedValue)
returns (bool success) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval (address _spender, uint _subtractedValue)
returns (bool success) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
}
/**
* @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;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/
function Ownable() {
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) onlyOwner {
require(newOwner != address(0));
OwnershipTransferred(owner, newOwner);
owner = newOwner;
}
}
/**
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
function mul(uint256 a, uint256 b) internal constant returns (uint256) {
uint256 c = a * b;
assert(a == 0 || c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal constant 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) internal constant returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal constant returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
/**
* @title Pausable
* @dev Base contract which allows children to implement an emergency stop mechanism.
*/
contract Pausable is Ownable {
event Pause();
event Unpause();
bool public paused = false;
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() {
require(!paused);
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() {
require(paused);
_;
}
/**
* @dev called by the owner to pause, triggers stopped state
*/
function pause() onlyOwner whenNotPaused {
paused = true;
Pause();
}
/**
* @dev called by the owner to unpause, returns to normal state
*/
function unpause() onlyOwner whenPaused {
paused = false;
Unpause();
}
}
/**
* @title evxOwnable
* @dev The evxOwnable contract has an owner address, and provides basic authorization control
* functions, this simplifies the implementation of "user permissions".
*/
contract evxOwnable is Ownable {
address public newOwner;
/**
* @dev Allows the current owner to transfer control of the contract to an otherOwner.
* @param otherOwner The address to transfer ownership to.
*/
function transferOwnership(address otherOwner) onlyOwner {
require(otherOwner != address(0));
newOwner = otherOwner;
}
/**
* @dev Finish ownership transfer.
*/
function approveOwnership() {
require(msg.sender == newOwner);
OwnershipTransferred(owner, newOwner);
owner = newOwner;
newOwner = address(0);
}
}
/**
* @title Moderated
* @dev Moderator can make transfers from and to any account (including frozen).
*/
contract evxModerated is evxOwnable {
address public moderator;
address public newModerator;
/**
* @dev Throws if called by any account other than the moderator.
*/
modifier onlyModerator() {
require(msg.sender == moderator);
_;
}
/**
* @dev Throws if called by any account other than the owner or moderator.
*/
modifier onlyOwnerOrModerator() {
require((msg.sender == moderator) || (msg.sender == owner));
_;
}
/**
* @dev Moderator same as owner
*/
function evxModerated(){
moderator = msg.sender;
}
/**
* @dev Allows the current moderator to transfer control of the contract to an otherModerator.
* @param otherModerator The address to transfer moderatorship to.
*/
function transferModeratorship(address otherModerator) onlyModerator {
newModerator = otherModerator;
}
/**
* @dev Complete moderatorship transfer.
*/
function approveModeratorship() {
require(msg.sender == newModerator);
moderator = newModerator;
newModerator = address(0);
}
/**
* @dev Removes moderator from the contract.
* After this point, moderator role will be eliminated completly.
*/
function removeModeratorship() onlyOwner {
moderator = address(0);
}
function hasModerator() constant returns(bool) {
return (moderator != address(0));
}
}
/**
* @title evxPausable
* @dev Slightly modified implementation of an emergency stop mechanism.
*/
contract evxPausable is Pausable, evxModerated {
/**
* @dev called by the owner or moderator to pause, triggers stopped state
*/
function pause() onlyOwnerOrModerator whenNotPaused {
paused = true;
Pause();
}
/**
* @dev called by the owner or moderator to unpause, returns to normal state
*/
function unpause() onlyOwnerOrModerator whenPaused {
paused = false;
Unpause();
}
}
/**
* Pausable token with moderator role and freeze address implementation
*
**/
contract evxModeratedToken is StandardToken, evxPausable {
mapping(address => bool) frozen;
/**
* @dev Check if given address is frozen. Freeze works only if moderator role is active
* @param _addr address Address to check
*/
function isFrozen(address _addr) constant returns (bool){
return frozen[_addr] && hasModerator();
}
/**
* @dev Freezes address (no transfer can be made from or to this address).
* @param _addr address Address to be frozen
*/
function freeze(address _addr) onlyModerator {
frozen[_addr] = true;
}
/**
* @dev Unfreezes frozen address.
* @param _addr address Address to be unfrozen
*/
function unfreeze(address _addr) onlyModerator {
frozen[_addr] = false;
}
/**
* @dev Declines transfers from/to frozen addresses.
* @param _to address The address which you want to transfer to
* @param _value uint256 the amout of tokens to be transfered
*/
function transfer(address _to, uint256 _value) whenNotPaused returns (bool) {
require(!isFrozen(msg.sender));
require(!isFrozen(_to));
return super.transfer(_to, _value);
}
/**
* @dev Declines transfers from/to/by frozen addresses.
* @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) whenNotPaused returns (bool) {
require(!isFrozen(msg.sender));
require(!isFrozen(_from));
require(!isFrozen(_to));
return super.transferFrom(_from, _to, _value);
}
/**
* @dev Allows moderator to 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 moderatorTransferFrom(address _from, address _to, uint256 _value) onlyModerator returns (bool) {
balances[_to] = balances[_to].add(_value);
balances[_from] = balances[_from].sub(_value);
Transfer(_from, _to, _value);
return true;
}
}
/**
* EVXToken
**/
contract EVXToken is evxModeratedToken {
string public constant version = "1.1";
string public constant name = "Everex";
string public constant symbol = "EVX";
uint256 public constant decimals = 4;
/**
* @dev Constructor that gives msg.sender all of existing tokens.
*/
function EVXToken(uint256 _initialSupply) {
totalSupply = _initialSupply;
balances[msg.sender] = _initialSupply;
}
}