Contract Source Code (Solidity)

IDE

• Blockscan IDE
• 🤖 Code ReaderBeta
• Remix IDE

Outline

•  contract ERC20
•    - function balanceOf(address who)
•    - function transfer(address to, uint256 ...
•    - function allowance(address owner, add ...
•    - function approve(address spender, uin ...
•    - function transferFrom(address from, a ...
• interface TokenRecipient
•    - function receiveApproval(address _fro ...
•  contract TokenERC20 is ERC20
•    - function TokenERC20(uint256 _initialS ...
•    - function balanceOf(address _owner)
•    - function allowance(address _owner, ad ...
•    - function _transfer(address _from, add ...
•    - function transfer(address _to, uint25 ...
•    - function transferFrom(address _from, ...
•    - function approve(address _spender, ui ...
•    - function approveAndCall(address _spen ...
•    - function burn(uint256 _value)
•    - function burnFrom(address _from, uint ...
•    - function increaseApproval(address _sp ...
•    - function decreaseApproval(address _sp ...
•  contract FairToken is TokenERC20 *
•    - function FairToken()

More Options

• Similar
• Sol2Uml
• Submit Audit
• Compare

/**
 *Submitted for verification at Etherscan.io on 2017-12-27
*/

pragma solidity ^0.4.16;

pragma solidity ^0.4.16;

pragma solidity ^0.4.16;


contract ERC20 {

    uint256 public totalSupply;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    function balanceOf(address who) public view returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);

    function allowance(address owner, address spender) public view returns (uint256);
    function approve(address spender, uint256 value) public returns (bool);
    function transferFrom(address from, address to, uint256 value) public returns (bool);

}


interface TokenRecipient {
    function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) public;
}



contract TokenERC20 is ERC20 {
    // Public variables of the token
    string public name;
    string public symbol;
    uint8  public decimals = 18;
    // 18 decimals is the strongly suggested default, avoid changing it

    // Balances
    mapping (address => uint256) balances;
    // Allowances
    mapping (address => mapping (address => uint256)) allowances;


    // ----- Events -----
    event Burn(address indexed from, uint256 value);


    /**
     * Constructor function
     */
    function TokenERC20(uint256 _initialSupply, string _tokenName, string _tokenSymbol, uint8 _decimals) public {
        name = _tokenName;                                   // Set the name for display purposes
        symbol = _tokenSymbol;                               // Set the symbol for display purposes
        decimals = _decimals;

        totalSupply = _initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balances[msg.sender] = totalSupply;                // Give the creator all initial tokens
    }

    function balanceOf(address _owner) public view returns(uint256) {
        return balances[_owner];
    }

    function allowance(address _owner, address _spender) public view returns (uint256) {
        return allowances[_owner][_spender];
    }

    /**
     * Internal transfer, only can be called by this contract
     */
    function _transfer(address _from, address _to, uint _value) internal returns(bool) {
        // Prevent transfer to 0x0 address. Use burn() instead
        require(_to != 0x0);
        // Check if the sender has enough
        require(balances[_from] >= _value);
        // Check for overflows
        require(balances[_to] + _value > balances[_to]);
        // Save this for an assertion in the future
        uint previousBalances = balances[_from] + balances[_to];
        // Subtract from the sender
        balances[_from] -= _value;
        // Add the same to the recipient
        balances[_to] += _value;
        Transfer(_from, _to, _value);
        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balances[_from] + balances[_to] == previousBalances);

        return true;
    }

    /**
     * Transfer tokens
     *
     * Send `_value` tokens to `_to` from your account
     *
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transfer(address _to, uint256 _value) public returns(bool) {
        return _transfer(msg.sender, _to, _value);
    }

    /**
     * Transfer tokens from other address
     *
     * Send `_value` tokens to `_to` in behalf of `_from`
     *
     * @param _from The address of the sender
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns(bool) {
        require(_value <= allowances[_from][msg.sender]);     // Check allowance
        allowances[_from][msg.sender] -= _value;
        return _transfer(_from, _to, _value);
    }

    /**
     * Set allowance for other address
     *
     * Allows `_spender` to spend no more than `_value` tokens in your behalf
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     */
    function approve(address _spender, uint256 _value) public returns(bool) {
        allowances[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    /**
     * Set allowance for other address and notify
     *
     * Allows `_spender` to spend no more than `_value` tokens in your behalf, and then ping the contract about it
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     * @param _extraData some extra information to send to the approved contract
     */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns(bool) {
        if (approve(_spender, _value)) {
            TokenRecipient spender = TokenRecipient(_spender);
            spender.receiveApproval(msg.sender, _value, this, _extraData);
            return true;
        }
        return false;
    }

    /**
     * Destroy tokens
     *
     * Remove `_value` tokens from the system irreversibly
     *
     * @param _value the amount of money to burn
     */
    function burn(uint256 _value) public returns(bool) {
        require(balances[msg.sender] >= _value);   // Check if the sender has enough
        balances[msg.sender] -= _value;            // Subtract from the sender
        totalSupply -= _value;                      // Updates totalSupply
        Burn(msg.sender, _value);
        return true;
    }

    /**
     * Destroy tokens from other account
     *
     * Remove `_value` tokens from the system irreversibly on behalf of `_from`.
     *
     * @param _from the address of the sender
     * @param _value the amount of money to burn
     */
    function burnFrom(address _from, uint256 _value) public returns(bool) {
        require(balances[_from] >= _value);                // Check if the targeted balance is enough
        require(_value <= allowances[_from][msg.sender]);    // Check allowance
        balances[_from] -= _value;                         // Subtract from the targeted balance
        allowances[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
        totalSupply -= _value;                              // Update totalSupply
        Burn(_from, _value);
        return true;
    }

    /**
     * approve should be called when allowances[_spender] == 0. To increment
     * allowances 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) public returns (bool) {
        // Check for overflows
        require(allowances[msg.sender][_spender] + _addedValue > allowances[msg.sender][_spender]);

        allowances[msg.sender][_spender] += _addedValue;
        Approval(msg.sender, _spender, allowances[msg.sender][_spender]);
        return true;
    }

    function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
        uint oldValue = allowances[msg.sender][_spender];
        if (_subtractedValue > oldValue) {
            allowances[msg.sender][_spender] = 0;
        } else {
            allowances[msg.sender][_spender] = oldValue - _subtractedValue;
        }
        Approval(msg.sender, _spender, allowances[msg.sender][_spender]);
        return true;
    }


}


contract FairToken is TokenERC20 {

    function FairToken() TokenERC20(1200000000, "Fair Token", "FAIR", 18) public {

    }
}

• No Contract Security Audit Submitted- Submit Audit Here

[{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_value","type":"uint256"}],"name":"burn","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_subtractedValue","type":"uint256"}],"name":"decreaseApproval","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_value","type":"uint256"}],"name":"burnFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"},{"name":"_extraData","type":"bytes"}],"name":"approveAndCall","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_addedValue","type":"uint256"}],"name":"increaseApproval","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Burn","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"}]

60606040526003805460ff19166012179055341561001c57600080fd5b6347868c00604080519081016040908152600a82527f4661697220546f6b656e0000000000000000000000000000000000000000000060208301528051908101604052600481527f464149520000000000000000000000000000000000000000000000000000000060208201526012600183805161009e9291602001906100f0565b5060028280516100b29291602001906100f0565b506003805460ff191660ff928316179081905516600a0a92909202600081815533600160a060020a03168152600460205260409020555061018b9050565b828054600181600116156101000203166002900490600052602060002090601f016020900481019282601f1061013157805160ff191683800117855561015e565b8280016001018555821561015e579182015b8281111561015e578251825591602001919060010190610143565b5061016a92915061016e565b5090565b61018891905b8082111561016a5760008155600101610174565b90565b610b1e8061019a6000396000f3006060604052600436106100cf5763ffffffff7c010000000000000000000000000000000000000000000000000000000060003504166306fdde0381146100d4578063095ea7b31461015e57806318160ddd1461019457806323b872dd146101b9578063313ce567146101e157806342966c681461020a578063661884631461022057806370a082311461024257806379cc67901461026157806395d89b4114610283578063a9059cbb14610296578063cae9ca51146102b8578063d73dd6231461031d578063dd62ed3e1461033f575b600080fd5b34156100df57600080fd5b6100e7610364565b60405160208082528190810183818151815260200191508051906020019080838360005b8381101561012357808201518382015260200161010b565b50505050905090810190601f1680156101505780820380516001836020036101000a031916815260200191505b509250505060405180910390f35b341561016957600080fd5b610180600160a060020a0360043516602435610402565b604051901515815260200160405180910390f35b341561019f57600080fd5b6101a761046e565b60405190815260200160405180910390f35b34156101c457600080fd5b610180600160a060020a0360043581169060243516604435610474565b34156101ec57600080fd5b6101f46104e9565b60405160ff909116815260200160405180910390f35b341561021557600080fd5b6101806004356104f2565b341561022b57600080fd5b610180600160a060020a036004351660243561057b565b341561024d57600080fd5b6101a7600160a060020a0360043516610669565b341561026c57600080fd5b610180600160a060020a0360043516602435610684565b341561028e57600080fd5b6100e761075e565b34156102a157600080fd5b610180600160a060020a03600435166024356107c9565b34156102c357600080fd5b61018060048035600160a060020a03169060248035919060649060443590810190830135806020601f820181900481020160405190810160405281815292919060208401838380828437509496506107dd95505050505050565b341561032857600080fd5b610180600160a060020a036004351660243561091a565b341561034a57600080fd5b6101a7600160a060020a03600435811690602435166109bb565b60018054600181600116156101000203166002900480601f0160208091040260200160405190810160405280929190818152602001828054600181600116156101000203166002900480156103fa5780601f106103cf576101008083540402835291602001916103fa565b820191906000526020600020905b8154815290600101906020018083116103dd57829003601f168201915b505050505081565b600160a060020a03338116600081815260056020908152604080832094871680845294909152808220859055909291907f8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b9259085905190815260200160405180910390a350600192915050565b60005481565b600160a060020a038084166000908152600560209081526040808320339094168352929052908120548211156104a957600080fd5b600160a060020a03808516600090815260056020908152604080832033909416835292905220805483900390556104e18484846109e6565b949350505050565b60035460ff1681565b600160a060020a0333166000908152600460205260408120548290101561051857600080fd5b600160a060020a0333166000818152600460205260408082208054869003905581548590039091557fcc16f5dbb4873280815c1ee09dbd06736cffcc184412cf7a71a0fdb75d397ca59084905190815260200160405180910390a2506001919050565b600160a060020a033381166000908152600560209081526040808320938616835292905290812054808311156105d857600160a060020a033381166000908152600560209081526040808320938816835292905290812055610603565b600160a060020a03338116600090815260056020908152604080832093881683529290522083820390555b600160a060020a0333811660008181526005602090815260408083209489168084529490915290819020547f8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925915190815260200160405180910390a35060019392505050565b600160a060020a031660009081526004602052604090205490565b600160a060020a038216600090815260046020526040812054829010156106aa57600080fd5b600160a060020a03808416600090815260056020908152604080832033909416835292905220548211156106dd57600080fd5b600160a060020a03808416600081815260046020908152604080832080548890039055600582528083203390951683529390528281208054869003905580548590039055907fcc16f5dbb4873280815c1ee09dbd06736cffcc184412cf7a71a0fdb75d397ca59084905190815260200160405180910390a250600192915050565b60028054600181600116156101000203166002900480601f0160208091040260200160405190810160405280929190818152602001828054600181600116156101000203166002900480156103fa5780601f106103cf576101008083540402835291602001916103fa565b60006107d63384846109e6565b9392505050565b6000806107ea8585610402565b1561090d575083600160a060020a038116638f4ffcb1338630876040518563ffffffff167c01000000000000000000000000000000000000000000000000000000000281526004018085600160a060020a0316600160a060020a0316815260200184815260200183600160a060020a0316600160a060020a0316815260200180602001828103825283818151815260200191508051906020019080838360005b838110156108a257808201518382015260200161088a565b50505050905090810190601f1680156108cf5780820380516001836020036101000a031916815260200191505b5095505050505050600060405180830381600087803b15156108f057600080fd5b6102c65a03f1151561090157600080fd5b50505060019150610912565b600091505b509392505050565b600160a060020a0333811660009081526005602090815260408083209386168352929052908120548281011161094f57600080fd5b600160a060020a033381166000818152600560209081526040808320948816808452949091529081902080548601908190557f8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925915190815260200160405180910390a350600192915050565b600160a060020a03918216600090815260056020908152604080832093909416825291909152205490565b600080600160a060020a03841615156109fe57600080fd5b600160a060020a03851660009081526004602052604090205483901015610a2457600080fd5b600160a060020a03841660009081526004602052604090205483810111610a4a57600080fd5b50600160a060020a0380841660008181526004602052604080822080549489168084528284208054898103909155938590528154880190915591909301927fddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef9086905190815260200160405180910390a3600160a060020a03808516600090815260046020526040808220549288168252902054018114610ae757fe5b5060019493505050505600a165627a7a723058206777faf8892e7a2d6dc1203d203f812dabb5734028863d99cb50a11dcce532410029

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

bzzr://6777faf8892e7a2d6dc1203d203f812dabb5734028863d99cb50a11dcce53241