Motivation

Reference/Research

• Function selectors

Commands

1. Help : hextool --help << or -h>> will list available commands. hextool help <COMMAND> will print out the flags each command accepts or expects.

2. Hex to Int: hextool toint --hex 0x0000000000000000000000000000000000000000000000000000000000690208 // 6881800

3. Hex to String hextool tostring --hex 0x486578746f6f6c204d616b657320457468657265756d204465762045617369657221 // Hextool Makes Ethereum Dev Easier!

4. Retrieve function signature if given a function selector (Note: you must pass a path or url to a valid json object that has an abi property on it with an ABI array value). See below for examples. hextool funcsig --selector 0xa9059cbb --url https://gist.githubusercontent.com/zeuslawyer/ecec03ff3f50311e510c201de4c076d5/raw/f096531942e922cb3f1d5daa2132f0e476356ced/good-data-erc20.json // transfer(address,uint256)

   or, using a path on your file system hextool funcsig --path "/PATH/TO/FILE/erc20.abi.json" --selector 0x095ea7b3 // approve(address,uint256)

   
   Please examine [the shape of the object](https://gist.githubusercontent.com/zeuslawyer/ecec03ff3f50311e510c201de4c076d5/raw/f096531942e922cb3f1d5daa2132f0e476356ced/good-data-erc20.json) for this to work correctly. The ABI json files produced by Hardhat will work too.
   

5. Calculate the function selector from the ABI-specified function signature (excludes the word 'function'): hextool selector --sig 'transfer(address,uint256)' // 0xa9059cbb
   Note: The signature must be enclosed in single or double quotes.
   

6 Decode a method's selector (4 bytes) into the function signature, given a valid ABI file. hextool decodeMethodSelector --selector 0xa9059cbb --url "https://gist.githubusercontent.com/zeuslawyer/ecec03ff3f50311e510c201de4c076d5/raw/f096531942e922cb3f1d5daa2132f0e476356ced/good-data-erc20.json">

should return transfer(address,uint256)

7 Decode an error's selector (4 bytes) into the error's signature, given a valid ABI file. hextool decodeErrorSelector --selector 0x07da6ee6 --url https://raw.githubusercontent.com/Cyfrin/ccip-contracts/main/contracts-ccip/abi/v0.8/Router.json

should return InsufficientFeeTokenAmount()

8. Decode the topic hash (on block explorers this shows up as topic0). The full 32-byte hexstring is needed, as is a valid ABI. hextool decodeEvent --topic 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef --url "https://gist.githubusercontent.com/zeuslawyer/ecec03ff3f50311e510c201de4c076d5/raw/f096531942e922cb3f1d5daa2132f0e476356ced/good-data-erc20.json"

9. Decode abi-encoded hex input with hextool abi.decode --hex <<abi encoded hex>> --types "<<comma separated types in a string>>".
   Example:

hextool abi.decode --hex "00000000000000000000000000000000000000000000000000000000000003e90000000000000000000000000000000000000000000000000000000000000060000000000000000000000000208aa722aca42399eac5192ee778e4d42f4e5de300000000000000000000000000000000000000000000000000000000000000057a7562696e000000000000000000000000000000000000000000000000000000" --types 'uint16,string,address'

Produces [1001 zubin 0x208AA722Aca42399eaC5192EE778e4D42f4E5De3].

10. Abi-encode data (with their corresponding values). hextool abi.encode --types '<<comma separated types in a string>>' --values '<<comma separated data string>>'

eg: hextool abi.encode --types 'uint64,string,address' --values '1981,bananas dude!,0x208AA722Aca42399eaC5192EE778e4D42f4E5De3' will produce: 0x00000000000000000000000000000000000000000000000000000000000007bd0000000000000000000000000000000000000000000000000000000000000060000000000000000000000000208aa722aca42399eac5192ee778e4d42f4e5de3000000000000000000000000000000000000000000000000000000000000000d62616e616e617320647564652100000000000000000000000000000000000000

Try and reverse that with hextool abi.decode!

Other projects for research

https://github.com/umbracle/ethgo/tree/main //wrapper pkg https://github.com/defiweb/go-eth // wrapper pkg

https://gist.github.com/crazygit/9279a3b26461d7cb03e807a6362ec855 // decoding tx logs, and reading contract ABI from etherscan