From 7a2eb86dd5724a7fd8835824415529442faba854 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Fri, 10 Mar 2023 10:46:30 -0800
Subject: [PATCH] feat: cli: Add an EVM command to fetch a contract's bytecode

---
 cli/evm.go                    | 49 +++++++++++++++++++++++++++++++++++
 documentation/en/cli-lotus.md | 14 ++++++++++
 2 files changed, 63 insertions(+)

diff --git a/cli/evm.go b/cli/evm.go
index d153e7212..84cbf8c61 100644
--- a/cli/evm.go
+++ b/cli/evm.go
@@ -35,6 +35,7 @@ var EvmCmd = &cli.Command{
 		EvmGetInfoCmd,
 		EvmCallSimulateCmd,
 		EvmGetContractAddress,
+		EvmGetBytecode,
 	},
 }
 
@@ -486,3 +487,51 @@ func ethAddrFromFilecoinAddress(ctx context.Context, addr address.Address, fnapi
 
 	return ethAddr, faddr, nil
 }
+
+var EvmGetBytecode = &cli.Command{
+	Name:      "bytecode",
+	Usage:     "Write the bytecode of a smart contract to a file",
+	ArgsUsage: "[contract-address] [file-name]",
+	Flags: []cli.Flag{
+		&cli.BoolFlag{
+			Name:  "bin",
+			Usage: "write the bytecode as raw binary and don't hex-encode",
+		},
+	},
+	Action: func(cctx *cli.Context) error {
+
+		if cctx.NArg() != 2 {
+			return IncorrectNumArgs(cctx)
+		}
+
+		contractAddr, err := ethtypes.ParseEthAddress(cctx.Args().Get(0))
+		if err != nil {
+			return err
+		}
+
+		fileName := cctx.Args().Get(1)
+
+		api, closer, err := GetFullNodeAPIV1(cctx)
+		if err != nil {
+			return err
+		}
+		defer closer()
+		ctx := ReqContext(cctx)
+
+		code, err := api.EthGetCode(ctx, contractAddr, "latest")
+		if err != nil {
+			return err
+		}
+		if !cctx.Bool("bin") {
+			newCode := make([]byte, hex.EncodedLen(len(code)))
+			hex.Encode(newCode, code)
+			code = newCode
+		}
+		if err := os.WriteFile(fileName, code, 0o666); err != nil {
+			return xerrors.Errorf("failed to write bytecode to file %s: %w", fileName, err)
+		}
+
+		fmt.Printf("Code for %s written to %s\n", contractAddr, fileName)
+		return nil
+	},
+}
diff --git a/documentation/en/cli-lotus.md b/documentation/en/cli-lotus.md
index 4458599ab..325b2738d 100644
--- a/documentation/en/cli-lotus.md
+++ b/documentation/en/cli-lotus.md
@@ -2647,6 +2647,7 @@ COMMANDS:
      stat              Print eth/filecoin addrs and code cid
      call              Simulate an eth contract call
      contract-address  Generate contract address from smart contract code
+     bytecode          Write the bytecode of a smart contract to a file
      help, h           Shows a list of commands or help for one command
 
 OPTIONS:
@@ -2721,6 +2722,19 @@ OPTIONS:
    
 ```
 
+### lotus evm bytecode
+```
+NAME:
+   lotus evm bytecode - Write the bytecode of a smart contract to a file
+
+USAGE:
+   lotus evm bytecode [command options] [contract-address] [file-name]
+
+OPTIONS:
+   --bin  write the bytecode as raw binary and don't hex-encode (default: false)
+   
+```
+
 ## lotus net
 ```
 NAME: