cmd/*: refactor get flag value (#24761)

cmd/ethkey/generate.go

@@ -35,6 +35,17 @@ type outputGenerate struct {
 	AddressEIP55 string
 }
 
+var (
+	privateKeyFlag = cli.StringFlag{
+		Name:  "privatekey",
+		Usage: "file containing a raw private key to encrypt",
+	}
+	lightKDFFlag = cli.BoolFlag{
+		Name:  "lightkdf",
+		Usage: "use less secure scrypt parameters",
+	}
+)
+
 var commandGenerate = cli.Command{
 	Name:      "generate",
 	Usage:     "generate new keyfile",
@@ -48,14 +59,8 @@ If you want to encrypt an existing private key, it can be specified by setting
 	Flags: []cli.Flag{
 		passphraseFlag,
 		jsonFlag,
-		cli.StringFlag{
-			Name:  "privatekey",
-			Usage: "file containing a raw private key to encrypt",
-		},
-		cli.BoolFlag{
-			Name:  "lightkdf",
-			Usage: "use less secure scrypt parameters",
-		},
+		privateKeyFlag,
+		lightKDFFlag,
 	},
 	Action: func(ctx *cli.Context) error {
 		// Check if keyfile path given and make sure it doesn't already exist.
@@ -71,7 +76,7 @@ If you want to encrypt an existing private key, it can be specified by setting
 
 		var privateKey *ecdsa.PrivateKey
 		var err error
-		if file := ctx.String("privatekey"); file != "" {
+		if file := ctx.String(privateKeyFlag.Name); file != "" {
 			// Load private key from file.
 			privateKey, err = crypto.LoadECDSA(file)
 			if err != nil {
@@ -99,7 +104,7 @@ If you want to encrypt an existing private key, it can be specified by setting
 		// Encrypt key with passphrase.
 		passphrase := getPassphrase(ctx, true)
 		scryptN, scryptP := keystore.StandardScryptN, keystore.StandardScryptP
-		if ctx.Bool("lightkdf") {
+		if ctx.Bool(lightKDFFlag.Name) {
 			scryptN, scryptP = keystore.LightScryptN, keystore.LightScryptP
 		}
 		keyjson, err := keystore.EncryptKey(key, passphrase, scryptN, scryptP)

cmd/ethkey/inspect.go

@@ -33,6 +33,13 @@ type outputInspect struct {
 	PrivateKey string
 }
 
+var (
+	privateFlag = cli.BoolFlag{
+		Name:  "private",
+		Usage: "include the private key in the output",
+	}
+)
+
 var commandInspect = cli.Command{
 	Name:      "inspect",
 	Usage:     "inspect a keyfile",
@@ -45,10 +52,7 @@ make sure to use this feature with great caution!`,
 	Flags: []cli.Flag{
 		passphraseFlag,
 		jsonFlag,
-		cli.BoolFlag{
-			Name:  "private",
-			Usage: "include the private key in the output",
-		},
+		privateFlag,
 	},
 	Action: func(ctx *cli.Context) error {
 		keyfilepath := ctx.Args().First()
@@ -67,7 +71,7 @@ make sure to use this feature with great caution!`,
 		}
 
 		// Output all relevant information we can retrieve.
-		showPrivate := ctx.Bool("private")
+		showPrivate := ctx.Bool(privateFlag.Name)
 		out := outputInspect{
 			Address: key.Address.Hex(),
 			PublicKey: hex.EncodeToString(

cmd/ethkey/message.go

@@ -142,7 +142,7 @@ It is possible to refer to a file containing the message.`,
 }
 
 func getMessage(ctx *cli.Context, msgarg int) []byte {
-	if file := ctx.String("msgfile"); file != "" {
+	if file := ctx.String(msgfileFlag.Name); file != "" {
 		if len(ctx.Args()) > msgarg {
 			utils.Fatalf("Can't use --msgfile and message argument at the same time.")
 		}