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jcmartinezdev/erc20-token-sample.sol

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  1. jcmartinezdev revised this gist Oct 19, 2020. 1 changed file with 187 additions and 0 deletions.
    187 changes: 187 additions & 0 deletions erc20-token-sample.sol
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,187 @@
    pragma solidity ^0.4.24;

    // ----------------------------------------------------------------------------
    // Sample token contract
    //
    // Symbol : LCST
    // Name : LCS Token
    // Total supply : 100000
    // Decimals : 2
    // Owner Account : 0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe
    //
    // Enjoy.
    //
    // (c) by Juan Cruz Martinez 2020. MIT Licence.
    // ----------------------------------------------------------------------------


    // ----------------------------------------------------------------------------
    // Lib: Safe Math
    // ----------------------------------------------------------------------------
    contract SafeMath {

    function safeAdd(uint a, uint b) public pure returns (uint c) {
    c = a + b;
    require(c >= a);
    }

    function safeSub(uint a, uint b) public pure returns (uint c) {
    require(b <= a);
    c = a - b;
    }

    function safeMul(uint a, uint b) public pure returns (uint c) {
    c = a * b;
    require(a == 0 || c / a == b);
    }

    function safeDiv(uint a, uint b) public pure returns (uint c) {
    require(b > 0);
    c = a / b;
    }
    }


    /**
    ERC Token Standard #20 Interface
    https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
    */
    contract ERC20Interface {
    function totalSupply() public constant returns (uint);
    function balanceOf(address tokenOwner) public constant returns (uint balance);
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);

    event Transfer(address indexed from, address indexed to, uint tokens);
    event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
    }


    /**
    Contract function to receive approval and execute function in one call
    Borrowed from MiniMeToken
    */
    contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 tokens, address token, bytes data) public;
    }

    /**
    ERC20 Token, with the addition of symbol, name and decimals and assisted token transfers
    */
    contract LCSTToken is ERC20Interface, SafeMath {
    string public symbol;
    string public name;
    uint8 public decimals;
    uint public _totalSupply;

    mapping(address => uint) balances;
    mapping(address => mapping(address => uint)) allowed;


    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------
    constructor() public {
    symbol = "LCST";
    name = "LCS Token";
    decimals = 2;
    _totalSupply = 100000;
    balances[0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe] = _totalSupply;
    emit Transfer(address(0), 0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe, _totalSupply);
    }


    // ------------------------------------------------------------------------
    // Total supply
    // ------------------------------------------------------------------------
    function totalSupply() public constant returns (uint) {
    return _totalSupply - balances[address(0)];
    }


    // ------------------------------------------------------------------------
    // Get the token balance for account tokenOwner
    // ------------------------------------------------------------------------
    function balanceOf(address tokenOwner) public constant returns (uint balance) {
    return balances[tokenOwner];
    }


    // ------------------------------------------------------------------------
    // Transfer the balance from token owner's account to to account
    // - Owner's account must have sufficient balance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transfer(address to, uint tokens) public returns (bool success) {
    balances[msg.sender] = safeSub(balances[msg.sender], tokens);
    balances[to] = safeAdd(balances[to], tokens);
    emit Transfer(msg.sender, to, tokens);
    return true;
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for spender to transferFrom(...) tokens
    // from the token owner's account
    //
    // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
    // recommends that there are no checks for the approval double-spend attack
    // as this should be implemented in user interfaces
    // ------------------------------------------------------------------------
    function approve(address spender, uint tokens) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    return true;
    }


    // ------------------------------------------------------------------------
    // Transfer tokens from the from account to the to account
    //
    // The calling account must already have sufficient tokens approve(...)-d
    // for spending from the from account and
    // - From account must have sufficient balance to transfer
    // - Spender must have sufficient allowance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transferFrom(address from, address to, uint tokens) public returns (bool success) {
    balances[from] = safeSub(balances[from], tokens);
    allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
    balances[to] = safeAdd(balances[to], tokens);
    emit Transfer(from, to, tokens);
    return true;
    }


    // ------------------------------------------------------------------------
    // Returns the amount of tokens approved by the owner that can be
    // transferred to the spender's account
    // ------------------------------------------------------------------------
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
    return allowed[tokenOwner][spender];
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for spender to transferFrom(...) tokens
    // from the token owner's account. The spender contract function
    // receiveApproval(...) is then executed
    // ------------------------------------------------------------------------
    function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
    return true;
    }


    // ------------------------------------------------------------------------
    // Don't accept ETH
    // ------------------------------------------------------------------------
    function () public payable {
    revert();
    }
    }
  2. jcmartinezdev revised this gist Aug 31, 2020. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion erc20-token.sol
    View file
    Original file line number Diff line number Diff line change
    @@ -71,7 +71,7 @@ contract ApproveAndCallFallBack {
    /**
    ERC20 Token, with the addition of symbol, name and decimals and assisted token transfers
    */
    contract {{TokenSymbol}}Token is ERC20Interface, SafeMath {
    contract {{Token Symbol}}Token is ERC20Interface, SafeMath {
    string public symbol;
    string public name;
    uint8 public decimals;
  3. jcmartinezdev created this gist Aug 18, 2020.
    187 changes: 187 additions & 0 deletions erc20-token.sol
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,187 @@
    pragma solidity ^0.4.24;

    // ----------------------------------------------------------------------------
    // Sample token contract
    //
    // Symbol : {{Token Symbol}}
    // Name : {{Token Name}}
    // Total supply : {{Total Supply}}
    // Decimals : {{Decimals}}
    // Owner Account : {{Owner Account}}
    //
    // Enjoy.
    //
    // (c) by Juan Cruz Martinez 2020. MIT Licence.
    // ----------------------------------------------------------------------------


    // ----------------------------------------------------------------------------
    // Lib: Safe Math
    // ----------------------------------------------------------------------------
    contract SafeMath {

    function safeAdd(uint a, uint b) public pure returns (uint c) {
    c = a + b;
    require(c >= a);
    }

    function safeSub(uint a, uint b) public pure returns (uint c) {
    require(b <= a);
    c = a - b;
    }

    function safeMul(uint a, uint b) public pure returns (uint c) {
    c = a * b;
    require(a == 0 || c / a == b);
    }

    function safeDiv(uint a, uint b) public pure returns (uint c) {
    require(b > 0);
    c = a / b;
    }
    }


    /**
    ERC Token Standard #20 Interface
    https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
    */
    contract ERC20Interface {
    function totalSupply() public constant returns (uint);
    function balanceOf(address tokenOwner) public constant returns (uint balance);
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);

    event Transfer(address indexed from, address indexed to, uint tokens);
    event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
    }


    /**
    Contract function to receive approval and execute function in one call
    Borrowed from MiniMeToken
    */
    contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 tokens, address token, bytes data) public;
    }

    /**
    ERC20 Token, with the addition of symbol, name and decimals and assisted token transfers
    */
    contract {{TokenSymbol}}Token is ERC20Interface, SafeMath {
    string public symbol;
    string public name;
    uint8 public decimals;
    uint public _totalSupply;

    mapping(address => uint) balances;
    mapping(address => mapping(address => uint)) allowed;


    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------
    constructor() public {
    symbol = "{{Token Symbol}}";
    name = "{{Token Name}}";
    decimals = {{Decimals}};
    _totalSupply = {{Total Supply}};
    balances[{{Owner Account}}] = _totalSupply;
    emit Transfer(address(0), {{Owner Account}}, _totalSupply);
    }


    // ------------------------------------------------------------------------
    // Total supply
    // ------------------------------------------------------------------------
    function totalSupply() public constant returns (uint) {
    return _totalSupply - balances[address(0)];
    }


    // ------------------------------------------------------------------------
    // Get the token balance for account tokenOwner
    // ------------------------------------------------------------------------
    function balanceOf(address tokenOwner) public constant returns (uint balance) {
    return balances[tokenOwner];
    }


    // ------------------------------------------------------------------------
    // Transfer the balance from token owner's account to to account
    // - Owner's account must have sufficient balance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transfer(address to, uint tokens) public returns (bool success) {
    balances[msg.sender] = safeSub(balances[msg.sender], tokens);
    balances[to] = safeAdd(balances[to], tokens);
    emit Transfer(msg.sender, to, tokens);
    return true;
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for spender to transferFrom(...) tokens
    // from the token owner's account
    //
    // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
    // recommends that there are no checks for the approval double-spend attack
    // as this should be implemented in user interfaces
    // ------------------------------------------------------------------------
    function approve(address spender, uint tokens) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    return true;
    }


    // ------------------------------------------------------------------------
    // Transfer tokens from the from account to the to account
    //
    // The calling account must already have sufficient tokens approve(...)-d
    // for spending from the from account and
    // - From account must have sufficient balance to transfer
    // - Spender must have sufficient allowance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transferFrom(address from, address to, uint tokens) public returns (bool success) {
    balances[from] = safeSub(balances[from], tokens);
    allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
    balances[to] = safeAdd(balances[to], tokens);
    emit Transfer(from, to, tokens);
    return true;
    }


    // ------------------------------------------------------------------------
    // Returns the amount of tokens approved by the owner that can be
    // transferred to the spender's account
    // ------------------------------------------------------------------------
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
    return allowed[tokenOwner][spender];
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for spender to transferFrom(...) tokens
    // from the token owner's account. The spender contract function
    // receiveApproval(...) is then executed
    // ------------------------------------------------------------------------
    function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
    return true;
    }


    // ------------------------------------------------------------------------
    // Don't accept ETH
    // ------------------------------------------------------------------------
    function () public payable {
    revert();
    }
    }