add example with keys

example/keys.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/miguelmota/go-ethereum-hdwallet"
+)
+
+func main() {
+	mnemonic := "tag volcano eight thank tide danger coast health above argue embrace heavy"
+	fmt.Println("deriving from mnenonic")
+	fmt.Println(mnemonic)
+	wallet, err := hdwallet.NewFromMnemonic(mnemonic)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	path := hdwallet.MustParseDerivationPath("m/44'/60'/0'/0/0")
+	account, err := wallet.Derive(path, false)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println("account address", account.Address.Hex())
+
+	pk, _ := wallet.PrivateKeyHex(account)
+	fmt.Println("private key hex: ", pk)
+
+	pub, _ := wallet.PublicKeyHex(account)
+	fmt.Println("public key hex: ", pub)
+
+}