transfer_eth.go

package main

import (
	"context"
	"crypto/ecdsa"
	"fmt"
	"log"

	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
)

var transactionHash string

func transferEth(privateKeystr string, value *big.Int) {
    
	privateKey, err := crypto.HexToECDSA(privateKeystr)
	if err != nil {
		log.Fatal(err)
	}

    publicKey := privateKey.Public()
    
    fmt.Println("trasnfer from %s", publicKey)
    fmt.Println("trasnfer to %s", address)

	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
	if !ok {
		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
	}

	fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
	nonce, err := client.PendingNonceAt(context.Background(), fromAddress)
	if err != nil {
		log.Fatal(err)
	}

	gasLimit := uint64(21000) // in units
	gasPrice, err := client.SuggestGasPrice(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	toAddress := common.HexToAddress(address)
	var data []byte
	tx := types.NewTransaction(nonce, toAddress, value, gasLimit, gasPrice, data)

	chainID, err := client.NetworkID(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	signedTx, err := types.SignTx(tx, types.NewEIP155Signer(chainID), privateKey)
	if err != nil {
		log.Fatal(err)
	}

	err = client.SendTransaction(context.Background(), signedTx)
	if err != nil {
		log.Fatal(err)
	}
	transactionHash = signedTx.Hash().Hex()
	fmt.Printf("tx sent: %s", transactionHash)
}