cmd/evm: Allow loading input from file (ethereum#20273)

Make it possible to load input from a file. Simlar to `--code` / `--codefile`, have `--input`/`--inputfile`.

Author: michaelforney

cmd/evm/main.go

@@ -79,6 +79,10 @@ var (
 		Name:  "input",
 		Usage: "input for the EVM",
 	}
+	InputFileFlag = cli.StringFlag{
+		Name:  "inputfile",
+		Usage: "file containing input for the EVM",
+	}
 	VerbosityFlag = cli.IntFlag{
 		Name:  "verbosity",
 		Usage: "sets the verbosity level",
@@ -130,6 +134,7 @@ func init() {
 		ValueFlag,
 		DumpFlag,
 		InputFlag,
+		InputFileFlag,
 		MemProfileFlag,
 		CPUProfileFlag,
 		StatDumpFlag,

cmd/evm/runner.go

@@ -205,14 +205,24 @@ func runCmd(ctx *cli.Context) error {
 	}
 	tstart := time.Now()
 	var leftOverGas uint64
+	var hexInput []byte
+	if inputFileFlag := ctx.GlobalString(InputFileFlag.Name); inputFileFlag != "" {
+		if hexInput, err = ioutil.ReadFile(inputFileFlag); err != nil {
+			fmt.Printf("could not load input from file: %v\n", err)
+			os.Exit(1)
+		}
+	} else {
+		hexInput = []byte(ctx.GlobalString(InputFlag.Name))
+	}
+	input := common.FromHex(string(bytes.TrimSpace(hexInput)))
 	if ctx.GlobalBool(CreateFlag.Name) {
-		input := append(code, common.Hex2Bytes(ctx.GlobalString(InputFlag.Name))...)
+		input = append(code, input...)
 		ret, _, leftOverGas, err = runtime.Create(input, &runtimeConfig)
 	} else {
 		if len(code) > 0 {
 			statedb.SetCode(receiver, code)
 		}
-		ret, leftOverGas, err = runtime.Call(receiver, common.Hex2Bytes(ctx.GlobalString(InputFlag.Name)), &runtimeConfig)
+		ret, leftOverGas, err = runtime.Call(receiver, input, &runtimeConfig)
 	}
 	execTime := time.Since(tstart)