A fixed-supply token with transfers and allowance spending, deployed March 2016.
Context
Frontier and Homestead era deployment.
Token Information
Key Facts
Description
A fixed-supply token supporting transfers and allowance spending, plus approvals that call back into the spending contract. Deployed March 2016 by 0xc0d4b32728acc42b8a610b2a87c867b3ba3810db.
Source Verified
Heuristic Analysis
The following characteristics were detected through bytecode analysis and may not be accurate.
Homestead Era
The first planned hard fork. Removed the canary contract, adjusted gas costs.
Bytecode Overview
Verified Source Available
Source verified through compiler archaeology and exact bytecode matching.
View Verification ProofShow source code (Solidity)
// Submitted by EthereumHistory (ethereumhistory.com)
contract tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData); }
contract MyToken {
/* Public variables of the token */
string public name;
string public symbol;
string public version;
uint8 public decimals;
uint256 public totalSupply;
/* This creates an array with all balances */
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;
mapping (address => mapping (address => uint256)) public spentAllowance;
/* This generates a public event on the blockchain that will notify clients */
event Transfer(address indexed from, address indexed to, uint256 value);
/* Initializes contract with initial supply tokens to the creator of the contract */
function MyToken(uint256 initialSupply, string tokenName, uint8 decimalUnits, string tokenSymbol, string versionOfTheCode) {
balanceOf[msg.sender] = 21000000; // Give the creator all initial tokens
totalSupply = initialSupply; // Update total supply
name = tokenName; // Set the name for display purposes
symbol = tokenSymbol; // Set the symbol for display purposes
decimals = decimalUnits; // Amount of decimals for display purposes
version = versionOfTheCode;
}
/* Send coins */
function transfer(address _to, uint256 _value) {
if (balanceOf[msg.sender] < _value) throw; // Check if the sender has enough
if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
balanceOf[msg.sender] -= _value; // Subtract from the sender
balanceOf[_to] += _value; // Add the same to the recipient
Transfer(msg.sender, _to, _value); // Notify anyone listening that this transfer took place
}
/* Allow another contract to spend some tokens in your behalf */
function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
allowance[msg.sender][_spender] = _value;
tokenRecipient spender = tokenRecipient(_spender);
spender.receiveApproval(msg.sender, _value, this, _extraData);
return true;
}
/* A contract attempts to get the coins */
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
if (balanceOf[_from] < _value) throw; // Check if the sender has enough
if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
if (spentAllowance[_from][msg.sender] + _value > allowance[_from][msg.sender]) throw; // Check allowance
balanceOf[_from] -= _value; // Subtract from the sender
balanceOf[_to] += _value; // Add the same to the recipient
spentAllowance[_from][msg.sender] += _value;
Transfer(_from, _to, _value);
return true;
}
/* This unnamed function is called whenever someone tries to send ether to it */
function () {
throw; // Prevents accidental sending of ether
}
}External Links
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