// getArgs parses command line args and asserts that a private key and an
// address are present and correctly formatted.
func getArgs() requiredArgs {
flag.Parse()
if *a == "" || *k == "" || *t == "" || *v == -1 {
fmt.Println("\nThis tool generates a bitcoin transaction that moves coins from an input to an output.\n" +
"You must provide a key, an address, a transaction id (the hash\n" +
"of a tx) and the index into the outputs of that tx that fund your\n" +
"address! Use http://blockchain.info/pushtx to send the raw transaction.\n")
flag.PrintDefaults()
fmt.Println("")
os.Exit(0)
}
pkBytes, err := hex.DecodeString(*k)
if err != nil {
log.Fatal(err)
}
privKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), pkBytes)
addr, err := btcutil.DecodeAddress(*a, &btcnet.MainNetParams)
if err != nil {
log.Fatal(err)
}
txid, err := btcwire.NewShaHashFromStr(*t)
args := requiredArgs{
txid: txid,
vout: uint32(*v),
toAddress: addr,
privKey: privKey,
}
return args
}
// getFundingParams pulls the relevant transaction information from the json returned by blockchain.info
// To generate a new valid transaction all of the parameters of the TxOut we are
// spending from must be used.
func getFundingParams(rawtx *blockChainInfoTx, vout uint32) (*btcwire.TxOut, *btcwire.OutPoint) {
blkChnTxOut := rawtx.Outputs[vout]
hash, err := btcwire.NewShaHashFromStr(rawtx.Hash)
if err != nil {
log.Fatal(err)
}
// Then convert it to a btcutil amount
amnt := btcutil.Amount(int64(blkChnTxOut.Value))
if err != nil {
log.Fatal(err)
}
outpoint := btcwire.NewOutPoint(hash, vout)
subscript, err := hex.DecodeString(blkChnTxOut.ScriptHex)
if err != nil {
log.Fatal(err)
}
oldTxOut := btcwire.NewTxOut(int64(amnt), subscript)
return oldTxOut, outpoint
}