ERC20Contract
Switch branches/tags
Nothing to show
Clone or download
Latest commit 28750a1 Nov 13, 2017
Permalink
Failed to load latest commit information.
README.md Create README.md Nov 13, 2017

README.md

cryptoISBN

ERC20Contract pragma solidity ^0.4.16;

/**

  • @title SafeMath
  • @dev Math operations with safety checks that throw on error
  • Created for providing ISB Crypto ISBN Token @ www.cryptoisbn.com support@cryptousbn.com
  • website www.cryptoisbn.com initiative of CryptoISBN TEAM cryptoisbn@gmail.com */ 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; } }

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); }

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); }

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]; }

}

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; }

}

contract CISBN is StandardToken {

string public constant name = "ISB"; string public constant symbol = "ISB"; uint8 public constant decimals = 9;

uint256 public constant INITIAL_SUPPLY = 10000000000000000;

/**

  • @dev Contructor that gives msg.sender all of existing tokens. */ function CISBN() { totalSupply = INITIAL_SUPPLY; balances[msg.sender] = INITIAL_SUPPLY; }

}