// prepare a signed transaction
func sign_tx(tx *btc.Tx) {
for in := range tx.TxIn {
uo := UO(unspentOuts[in])
var found bool
for j := range publ_addrs {
if publ_addrs[j].Owns(uo.Pk_script) {
found = true
er := tx.Sign(in, uo.Pk_script, btc.SIGHASH_ALL, publ_addrs[j].Pubkey, priv_keys[j][:])
if er != nil {
fmt.Println("Error signing input", in, "of", len(tx.TxIn))
fmt.Println("...", er.Error())
}
break
}
}
if !found {
fmt.Println("WARNING: You do not have key for", hex.EncodeToString(uo.Pk_script))
}
}
}