Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: 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
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
/**
BUY, HOLD, EARN, BURN!
Telegram: https://t.me/buyholdearn
Website: http://buyholdearn.com
X: https://twitter.com/buyholdearn
*/
// SPDX-License-Identifier: MIT
/**
This contract is derived from the ERC20.sol by openzeppelin and the
reflection token contract by CoinTools. The contract removes liquidity and
burn fee and only redistributes tokens to holders.
*/
pragma solidity 0.8.18;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/utils/Context.sol";
contract HoldEarn is Context, IERC20, IERC20Metadata, Ownable {
uint256 private constant MAX = ~uint256(0);
uint256 private _rTotalSupply; // total supply in r-space
uint256 private immutable _tTotalSupply; // total supply in t-space
string private _name;
string private _symbol;
address[] private _excludedFromReward;
uint256 public taxFee = 200; // 200 => 2%
uint256 public totalFees;
mapping(address => uint256) private _rBalances; // balances in r-space
mapping(address => uint256) private _tBalances; // balances in t-space
mapping(address => mapping(address => uint256)) private _allowances;
mapping(address => bool) public isExcludedFromFee;
mapping(address => bool) public isExcludedFromReward;
event SetFee(uint256 value);
constructor(address owner_) {
_name = 'HOLD';
_symbol = 'EARN';
_tTotalSupply = 1000000000 * 10 ** decimals();
excludeFromFee(owner_);
excludeFromFee(address(this));
_mint(owner_, _tTotalSupply);
_transferOwnership(owner_);
}
function name() public view virtual override returns (string memory) {
return _name;
}
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
function decimals() public view virtual override returns (uint8) {
return 18;
}
function totalSupply() public view virtual override returns (uint256) {
return _tTotalSupply;
}
function balanceOf(
address account
) public view virtual override returns (uint256) {
uint256 rate = _getRate();
return _rBalances[account] / rate;
}
function transfer(
address to,
uint256 amount
) public virtual override returns (bool) {
_transfer(msg.sender, to, amount);
return true;
}
function allowance(
address account,
address spender
) public view virtual override returns (uint256) {
return _allowances[account][spender];
}
function approve(
address spender,
uint256 amount
) public virtual override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
function increaseAllowance(
address spender,
uint256 addedValue
) public virtual returns (bool) {
_approve(
msg.sender,
spender,
allowance(msg.sender, spender) + addedValue
);
return true;
}
function decreaseAllowance(
address spender,
uint256 subtractedValue
) public virtual returns (bool) {
uint256 currentAllowance = allowance(msg.sender, spender);
require(
currentAllowance >= subtractedValue,
"ERC20: decreased allowance below zero"
);
unchecked {
_approve(msg.sender, spender, currentAllowance - subtractedValue);
}
return true;
}
function setFee(uint256 newTxFee) public onlyOwner {
taxFee = newTxFee;
emit SetFee(taxFee);
}
function excludeFromReward(address account) public onlyOwner {
require(!isExcludedFromReward[account], "Address already excluded");
require(_excludedFromReward.length < 100, "Excluded list is too long");
if (_rBalances[account] > 0) {
uint256 rate = _getRate();
_tBalances[account] = _rBalances[account] / rate;
}
isExcludedFromReward[account] = true;
_excludedFromReward.push(account);
}
function includeInReward(address account) public onlyOwner {
require(isExcludedFromReward[account], "Account is already included");
uint256 nExcluded = _excludedFromReward.length;
for (uint256 i = 0; i < nExcluded; i++) {
if (_excludedFromReward[i] == account) {
_excludedFromReward[i] = _excludedFromReward[
_excludedFromReward.length - 1
];
_tBalances[account] = 0;
isExcludedFromReward[account] = false;
_excludedFromReward.pop();
break;
}
}
}
function excludeFromFee(address account) public onlyOwner {
isExcludedFromFee[account] = true;
}
function includeInFee(address account) public onlyOwner {
isExcludedFromFee[account] = false;
}
function withdrawTokens(
address tokenAddress,
address receiverAddress
) external onlyOwner returns (bool success) {
IERC20 tokenContract = IERC20(tokenAddress);
uint256 amount = tokenContract.balanceOf(address(this));
return tokenContract.transfer(receiverAddress, amount);
}
function _getRate() private view returns (uint256) {
uint256 rSupply = _rTotalSupply;
uint256 tSupply = _tTotalSupply;
uint256 nExcluded = _excludedFromReward.length;
for (uint256 i = 0; i < nExcluded; i++) {
rSupply = rSupply - _rBalances[_excludedFromReward[i]];
tSupply = tSupply - _tBalances[_excludedFromReward[i]];
}
if (rSupply < _rTotalSupply / _tTotalSupply) {
rSupply = _rTotalSupply;
tSupply = _tTotalSupply;
}
// rSupply always > tSupply (no precision loss)
uint256 rate = rSupply / tSupply;
return rate;
}
function _transfer(
address from,
address to,
uint256 amount
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
uint256 _taxFee;
if (isExcludedFromFee[from] || isExcludedFromFee[to]) {
_taxFee = 0;
} else {
_taxFee = taxFee;
}
// calc t-values
uint256 tAmount = amount;
uint256 tTxFee = (tAmount * _taxFee) / 10000;
uint256 tTransferAmount = tAmount - tTxFee;
// calc r-values
uint256 rate = _getRate();
uint256 rTxFee = tTxFee * rate;
uint256 rAmount = tAmount * rate;
uint256 rTransferAmount = rAmount - rTxFee;
// check balances
uint256 rFromBalance = _rBalances[from];
uint256 tFromBalance = _tBalances[from];
if (isExcludedFromReward[from]) {
require(
tFromBalance >= tAmount,
"ERC20: transfer amount exceeds balance"
);
} else {
require(
rFromBalance >= rAmount,
"ERC20: transfer amount exceeds balance"
);
}
// Overflow not possible: the sum of all balances is capped by
// rTotalSupply and tTotalSupply, and the sum is preserved by
// decrementing then incrementing.
unchecked {
// udpate balances in r-space
_rBalances[from] = rFromBalance - rAmount;
_rBalances[to] += rTransferAmount;
// update balances in t-space
if (isExcludedFromReward[from] && isExcludedFromReward[to]) {
_tBalances[from] = tFromBalance - tAmount;
_tBalances[to] += tTransferAmount;
} else if (
isExcludedFromReward[from] && !isExcludedFromReward[to]
) {
// could technically underflow but because tAmount is a
// function of rAmount and _rTotalSupply == _tTotalSupply
// it won't
_tBalances[from] = tFromBalance - tAmount;
} else if (
!isExcludedFromReward[from] && isExcludedFromReward[to]
) {
// could technically overflow but because tAmount is a
// function of rAmount and _rTotalSupply == _tTotalSupply
// it won't
_tBalances[to] += tTransferAmount;
}
// reflect fee
// can never go below zero because rTxFee percentage of
// current _rTotalSupply
_rTotalSupply = _rTotalSupply - rTxFee;
totalFees += tTxFee;
}
emit Transfer(from, to, tTransferAmount);
}
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_rTotalSupply += (MAX - (MAX % amount));
unchecked {
_rBalances[account] += _rTotalSupply;
}
emit Transfer(address(0), account, amount);
}
function _approve(
address account,
address spender,
uint256 amount
) internal virtual {
require(account != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[account][spender] = amount;
emit Approval(account, spender, amount);
}
function _spendAllowance(
address account,
address spender,
uint256 amount
) internal virtual {
uint256 currentAllowance = allowance(account, spender);
if (currentAllowance != type(uint256).max) {
require(
currentAllowance >= amount,
"ERC20: insufficient allowance"
);
unchecked {
_approve(account, spender, currentAllowance - amount);
}
}
}
}