ethereumjs-codesim

ethereumjs-codesim

A simple CLI app for running EVM simulations. It supports loading raw EVM bytecode or Solidity source files.

Usage

There are plenty of options for codesim.

First of the source must be specified:

• -c for specifying the actual code in the commandline
• -f for supplying a filename

By default it assumes the source is an EVM bytecode. To compile with solc pass -C. Optionally, -optimize will turn on optimizations in solc. Also a Solidity source code might contain multiple contracts, choose the desired one with --use-contract.

It is assumed, the bytecode is a contract deployment code which deploys the actual code. This means codesim will execute two simulations: deployment, followed by the actual contract execution. To disabled this, use -R for setting runtime mode.

Raw data can be passed to the contract with -D <data>.

Alternatively use the ABI encoder with ---callmethod.

For the following Solidity example.sol:

contract Test {
  function method1() returns (bool) {
    return true;
  }
  function method2(bool test) returns (bool) {
    return test;
  }
  function method3(string test) returns (string) {
    return test;
  }
}

Example invocations and outputs:

• codesim -C -f example.sol --callmethod 'method1()': 0000000000000000000000000000000000000000000000000000000000000001 (true)
• codesim -C -f example.sol --callmethod 'method2(bool)' true: 0000000000000000000000000000000000000000000000000000000000000001 (true)
• codesim -C -f example.sol --callmethod 'method3(string)' 'Hello world': 0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000b48656c6c6f20776f726c64000000000000000000000000000000000000000000 (ABI encoded 'Hello world')

For more commandline options see codesim -h.