check wallet before sending

We could only send money from our own wallet.

If the parameter is not an address in our wallet, exit the program gracefully
and show an error message.

cli_send.go

@@ -22,8 +22,12 @@ func (cli *CLI) send(from, to string, amount int, nodeID string, mineNow bool) {
 		log.Panic(err)
 	}
 	wallet := wallets.GetWallet(from)
+	if wallet == nil {
+		fmt.Println("The Address doesn't belongs to you!")
+		return
+	}
 
-	tx := NewUTXOTransaction(&wallet, to, amount, &UTXOSet)
+	tx := NewUTXOTransaction(wallet, to, amount, &UTXOSet)
 
 	if mineNow {
 		cbTx := NewCoinbaseTX(from, "")

wallets.go

@@ -49,8 +49,8 @@ func (ws *Wallets) GetAddresses() []string {
 }
 
 // GetWallet returns a Wallet by its address
-func (ws Wallets) GetWallet(address string) Wallet {
-	return *ws.Wallets[address]
+func (ws Wallets) GetWallet(address string) *Wallet {
+	return ws.Wallets[address]
 }
 
 // LoadFromFile loads wallets from the file