// This example demonstrates creating a script which pays to a bitcoin address.
// It also prints the created script hex and uses the DisasmString function to
// display the disassembled script.
func ExamplePayToAddrScript() {
// Parse the address to send the coins to into a btcutil.Address
// which is useful to ensure the accuracy of the address and determine
// the address type. It is also required for the upcoming call to
// PayToAddrScript.
addressStr := "12gpXQVcCL2qhTNQgyLVdCFG2Qs2px98nV"
address, err := btcutil.DecodeAddress(addressStr, &chaincfg.MainNetParams)
if err != nil {
fmt.Println(err)
return
}
// Create a public key script that pays to the address.
script, err := txscript.PayToAddrScript(address)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("Script Hex: %x\n", script)
disasm, err := txscript.DisasmString(script)
if err != nil {
fmt.Println(err)
return
}
fmt.Println("Script Disassembly:", disasm)
// Output:
// Script Hex: 76a914128004ff2fcaf13b2b91eb654b1dc2b674f7ec6188ac
// Script Disassembly: OP_DUP OP_HASH160 128004ff2fcaf13b2b91eb654b1dc2b674f7ec61 OP_EQUALVERIFY OP_CHECKSIG
}
func TestLimitAndSkipFetchTxsForAddr(t *testing.T) {
testDb, err := setUpTestDb(t, "tstdbtxaddr")
if err != nil {
t.Errorf("Failed to open test database %v", err)
return
}
defer testDb.cleanUpFunc()
// Insert a block with some fake test transactions. The block will have
// 10 copies of a fake transaction involving same address.
addrString := "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa"
targetAddr, err := btcutil.DecodeAddress(addrString, &chaincfg.MainNetParams)
if err != nil {
t.Fatalf("Unable to decode test address: %v", err)
}
outputScript, err := txscript.PayToAddrScript(targetAddr)
if err != nil {
t.Fatalf("Unable make test pkScript %v", err)
}
fakeTxOut := wire.NewTxOut(10, outputScript)
var emptyHash wire.ShaHash
fakeHeader := wire.NewBlockHeader(&emptyHash, &emptyHash, 1, 1)
msgBlock := wire.NewMsgBlock(fakeHeader)
for i := 0; i < 10; i++ {
mtx := wire.NewMsgTx()
mtx.AddTxOut(fakeTxOut)
msgBlock.AddTransaction(mtx)
}
// Insert the test block into the DB.
testBlock := btcutil.NewBlock(msgBlock)
newheight, err := testDb.db.InsertBlock(testBlock)
if err != nil {
t.Fatalf("Unable to insert block into db: %v", err)
}
// Create and insert an address index for out test addr.
txLoc, _ := testBlock.TxLoc()
index := make(database.BlockAddrIndex)
for i := range testBlock.Transactions() {
var hash160 [ripemd160.Size]byte
scriptAddr := targetAddr.ScriptAddress()
copy(hash160[:], scriptAddr[:])
index[hash160] = append(index[hash160], &txLoc[i])
}
blkSha := testBlock.Sha()
err = testDb.db.UpdateAddrIndexForBlock(blkSha, newheight, index)
if err != nil {
t.Fatalf("UpdateAddrIndexForBlock: failed to index"+
" addrs for block #%d (%s) "+
"err %v", newheight, blkSha, err)
return
}
// Try skipping the first 4 results, should get 6 in return.
txReply, txSkipped, err := testDb.db.FetchTxsForAddr(targetAddr, 4, 100000, false)
if err != nil {
t.Fatalf("Unable to fetch transactions for address: %v", err)
}
if txSkipped != 4 {
t.Fatalf("Did not correctly return skipped amount"+
" got %v txs, expected %v", txSkipped, 4)
}
if len(txReply) != 6 {
t.Fatalf("Did not correctly skip forward in txs for address reply"+
" got %v txs, expected %v", len(txReply), 6)
}
// Limit the number of results to 3.
txReply, txSkipped, err = testDb.db.FetchTxsForAddr(targetAddr, 0, 3, false)
if err != nil {
t.Fatalf("Unable to fetch transactions for address: %v", err)
}
if txSkipped != 0 {
t.Fatalf("Did not correctly return skipped amount"+
" got %v txs, expected %v", txSkipped, 0)
}
if len(txReply) != 3 {
t.Fatalf("Did not correctly limit in txs for address reply"+
" got %v txs, expected %v", len(txReply), 3)
}
// Skip 1, limit 5.
txReply, txSkipped, err = testDb.db.FetchTxsForAddr(targetAddr, 1, 5, false)
if err != nil {
t.Fatalf("Unable to fetch transactions for address: %v", err)
}
if txSkipped != 1 {
t.Fatalf("Did not correctly return skipped amount"+
" got %v txs, expected %v", txSkipped, 1)
}
if len(txReply) != 5 {
t.Fatalf("Did not correctly limit in txs for address reply"+
" got %v txs, expected %v", len(txReply), 5)
}
}
// loadConfig initializes and parses the config using a config file and command
// line options.
//
// The configuration proceeds as follows:
// 1) Start with a default config with sane settings
// 2) Pre-parse the command line to check for an alternative config file
// 3) Load configuration file overwriting defaults with any specified options
// 4) Parse CLI options and overwrite/add any specified options
//
// The above results in btcd functioning properly without any config settings
// while still allowing the user to override settings with config files and
// command line options. Command line options always take precedence.
func loadConfig() (*config, []string, error) {
// Default config.
cfg := config{
ConfigFile: defaultConfigFile,
DebugLevel: defaultLogLevel,
MaxPeers: defaultMaxPeers,
BanDuration: defaultBanDuration,
RPCMaxClients: defaultMaxRPCClients,
RPCMaxWebsockets: defaultMaxRPCWebsockets,
DataDir: defaultDataDir,
LogDir: defaultLogDir,
DbType: defaultDbType,
RPCKey: defaultRPCKeyFile,
RPCCert: defaultRPCCertFile,
MinRelayTxFee: defaultMinRelayTxFee.ToBTC(),
FreeTxRelayLimit: defaultFreeTxRelayLimit,
BlockMinSize: defaultBlockMinSize,
BlockMaxSize: defaultBlockMaxSize,
BlockPrioritySize: defaultBlockPrioritySize,
SigCacheMaxSize: defaultSigCacheMaxSize,
MaxOrphanTxs: maxOrphanTransactions,
Generate: defaultGenerate,
AddrIndex: defaultAddrIndex,
}
// Service options which are only added on Windows.
serviceOpts := serviceOptions{}
// Pre-parse the command line options to see if an alternative config
// file or the version flag was specified. Any errors aside from the
// help message error can be ignored here since they will be caught by
// the final parse below.
preCfg := cfg
preParser := newConfigParser(&preCfg, &serviceOpts, flags.HelpFlag)
_, err := preParser.Parse()
if err != nil {
if e, ok := err.(*flags.Error); ok && e.Type == flags.ErrHelp {
fmt.Fprintln(os.Stderr, err)
return nil, nil, err
}
}
// Show the version and exit if the version flag was specified.
appName := filepath.Base(os.Args[0])
appName = strings.TrimSuffix(appName, filepath.Ext(appName))
usageMessage := fmt.Sprintf("Use %s -h to show usage", appName)
if preCfg.ShowVersion {
fmt.Println(appName, "version", version())
os.Exit(0)
}
// Perform service command and exit if specified. Invalid service
// commands show an appropriate error. Only runs on Windows since
// the runServiceCommand function will be nil when not on Windows.
if serviceOpts.ServiceCommand != "" && runServiceCommand != nil {
err := runServiceCommand(serviceOpts.ServiceCommand)
if err != nil {
fmt.Fprintln(os.Stderr, err)
}
os.Exit(0)
}
// Load additional config from file.
var configFileError error
parser := newConfigParser(&cfg, &serviceOpts, flags.Default)
if !(preCfg.RegressionTest || preCfg.SimNet) || preCfg.ConfigFile !=
defaultConfigFile {
err := flags.NewIniParser(parser).ParseFile(preCfg.ConfigFile)
if err != nil {
if _, ok := err.(*os.PathError); !ok {
fmt.Fprintf(os.Stderr, "Error parsing config "+
"file: %v\n", err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
configFileError = err
}
}
// Don't add peers from the config file when in regression test mode.
if preCfg.RegressionTest && len(cfg.AddPeers) > 0 {
cfg.AddPeers = nil
}
// Parse command line options again to ensure they take precedence.
remainingArgs, err := parser.Parse()
if err != nil {
if e, ok := err.(*flags.Error); !ok || e.Type != flags.ErrHelp {
fmt.Fprintln(os.Stderr, usageMessage)
}
return nil, nil, err
}
// Create the home directory if it doesn't already exist.
funcName := "loadConfig"
err = os.MkdirAll(btcdHomeDir, 0700)
if err != nil {
// Show a nicer error message if it's because a symlink is
// linked to a directory that does not exist (probably because
// it's not mounted).
if e, ok := err.(*os.PathError); ok && os.IsExist(err) {
if link, lerr := os.Readlink(e.Path); lerr == nil {
str := "is symlink %s -> %s mounted?"
err = fmt.Errorf(str, e.Path, link)
}
}
str := "%s: Failed to create home directory: %v"
err := fmt.Errorf(str, funcName, err)
fmt.Fprintln(os.Stderr, err)
return nil, nil, err
}
// Multiple networks can't be selected simultaneously.
numNets := 0
// Count number of network flags passed; assign active network params
// while we're at it
if cfg.TestNet3 {
numNets++
activeNetParams = &testNet3Params
}
if cfg.RegressionTest {
numNets++
activeNetParams = ®ressionNetParams
}
if cfg.SimNet {
numNets++
// Also disable dns seeding on the simulation test network.
activeNetParams = &simNetParams
cfg.DisableDNSSeed = true
}
if numNets > 1 {
str := "%s: The testnet, regtest, and simnet params can't be " +
"used together -- choose one of the three"
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Append the network type to the data directory so it is "namespaced"
// per network. In addition to the block database, there are other
// pieces of data that are saved to disk such as address manager state.
// All data is specific to a network, so namespacing the data directory
// means each individual piece of serialized data does not have to
// worry about changing names per network and such.
cfg.DataDir = cleanAndExpandPath(cfg.DataDir)
cfg.DataDir = filepath.Join(cfg.DataDir, netName(activeNetParams))
// Append the network type to the log directory so it is "namespaced"
// per network in the same fashion as the data directory.
cfg.LogDir = cleanAndExpandPath(cfg.LogDir)
cfg.LogDir = filepath.Join(cfg.LogDir, netName(activeNetParams))
// Special show command to list supported subsystems and exit.
if cfg.DebugLevel == "show" {
fmt.Println("Supported subsystems", supportedSubsystems())
os.Exit(0)
}
// Initialize logging at the default logging level.
initSeelogLogger(filepath.Join(cfg.LogDir, defaultLogFilename))
setLogLevels(defaultLogLevel)
// Parse, validate, and set debug log level(s).
if err := parseAndSetDebugLevels(cfg.DebugLevel); err != nil {
err := fmt.Errorf("%s: %v", funcName, err.Error())
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Validate database type.
if !validDbType(cfg.DbType) {
str := "%s: The specified database type [%v] is invalid -- " +
"supported types %v"
err := fmt.Errorf(str, funcName, cfg.DbType, knownDbTypes)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
if cfg.AddrIndex && cfg.DropAddrIndex {
err := fmt.Errorf("addrindex and dropaddrindex cannot be " +
"activated at the same")
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Memdb does not currently support the addrindex.
if cfg.DbType == "memdb" && cfg.AddrIndex {
err := fmt.Errorf("memdb does not currently support the addrindex")
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Validate profile port number
if cfg.Profile != "" {
profilePort, err := strconv.Atoi(cfg.Profile)
if err != nil || profilePort < 1024 || profilePort > 65535 {
str := "%s: The profile port must be between 1024 and 65535"
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
}
// Don't allow ban durations that are too short.
if cfg.BanDuration < time.Duration(time.Second) {
str := "%s: The banduration option may not be less than 1s -- parsed [%v]"
err := fmt.Errorf(str, funcName, cfg.BanDuration)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// --addPeer and --connect do not mix.
if len(cfg.AddPeers) > 0 && len(cfg.ConnectPeers) > 0 {
str := "%s: the --addpeer and --connect options can not be " +
"mixed"
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// --proxy or --connect without --listen disables listening.
if (cfg.Proxy != "" || len(cfg.ConnectPeers) > 0) &&
len(cfg.Listeners) == 0 {
cfg.DisableListen = true
}
// Connect means no DNS seeding.
if len(cfg.ConnectPeers) > 0 {
cfg.DisableDNSSeed = true
}
// Add the default listener if none were specified. The default
// listener is all addresses on the listen port for the network
// we are to connect to.
if len(cfg.Listeners) == 0 {
cfg.Listeners = []string{
net.JoinHostPort("", activeNetParams.DefaultPort),
}
}
// Check to make sure limited and admin users don't have the same username
if cfg.RPCUser == cfg.RPCLimitUser && cfg.RPCUser != "" {
str := "%s: --rpcuser and --rpclimituser must not specify the " +
"same username"
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Check to make sure limited and admin users don't have the same password
if cfg.RPCPass == cfg.RPCLimitPass && cfg.RPCPass != "" {
str := "%s: --rpcpass and --rpclimitpass must not specify the " +
"same password"
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// The RPC server is disabled if no username or password is provided.
if (cfg.RPCUser == "" || cfg.RPCPass == "") &&
(cfg.RPCLimitUser == "" || cfg.RPCLimitPass == "") {
cfg.DisableRPC = true
}
// Default RPC to listen on localhost only.
if !cfg.DisableRPC && len(cfg.RPCListeners) == 0 {
addrs, err := net.LookupHost("localhost")
if err != nil {
return nil, nil, err
}
cfg.RPCListeners = make([]string, 0, len(addrs))
for _, addr := range addrs {
addr = net.JoinHostPort(addr, activeNetParams.rpcPort)
cfg.RPCListeners = append(cfg.RPCListeners, addr)
}
}
// Validate the the minrelaytxfee.
cfg.minRelayTxFee, err = btcutil.NewAmount(cfg.MinRelayTxFee)
if err != nil {
str := "%s: invalid minrelaytxfee: %v"
err := fmt.Errorf(str, funcName, err)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Limit the max block size to a sane value.
if cfg.BlockMaxSize < blockMaxSizeMin || cfg.BlockMaxSize >
blockMaxSizeMax {
str := "%s: The blockmaxsize option must be in between %d " +
"and %d -- parsed [%d]"
err := fmt.Errorf(str, funcName, blockMaxSizeMin,
blockMaxSizeMax, cfg.BlockMaxSize)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Limit the max orphan count to a sane vlue.
if cfg.MaxOrphanTxs < 0 {
str := "%s: The maxorphantx option may not be less than 0 " +
"-- parsed [%d]"
err := fmt.Errorf(str, funcName, cfg.MaxOrphanTxs)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Limit the block priority and minimum block sizes to max block size.
cfg.BlockPrioritySize = minUint32(cfg.BlockPrioritySize, cfg.BlockMaxSize)
cfg.BlockMinSize = minUint32(cfg.BlockMinSize, cfg.BlockMaxSize)
// Check getwork keys are valid and saved parsed versions.
cfg.miningAddrs = make([]btcutil.Address, 0, len(cfg.GetWorkKeys)+
len(cfg.MiningAddrs))
for _, strAddr := range cfg.GetWorkKeys {
addr, err := btcutil.DecodeAddress(strAddr,
activeNetParams.Params)
if err != nil {
str := "%s: getworkkey '%s' failed to decode: %v"
err := fmt.Errorf(str, funcName, strAddr, err)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
if !addr.IsForNet(activeNetParams.Params) {
str := "%s: getworkkey '%s' is on the wrong network"
err := fmt.Errorf(str, funcName, strAddr)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
cfg.miningAddrs = append(cfg.miningAddrs, addr)
}
// Check mining addresses are valid and saved parsed versions.
for _, strAddr := range cfg.MiningAddrs {
addr, err := btcutil.DecodeAddress(strAddr, activeNetParams.Params)
if err != nil {
str := "%s: mining address '%s' failed to decode: %v"
err := fmt.Errorf(str, funcName, strAddr, err)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
if !addr.IsForNet(activeNetParams.Params) {
str := "%s: mining address '%s' is on the wrong network"
err := fmt.Errorf(str, funcName, strAddr)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
cfg.miningAddrs = append(cfg.miningAddrs, addr)
}
// Ensure there is at least one mining address when the generate flag is
// set.
if cfg.Generate && len(cfg.MiningAddrs) == 0 {
str := "%s: the generate flag is set, but there are no mining " +
"addresses specified "
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Add default port to all listener addresses if needed and remove
// duplicate addresses.
cfg.Listeners = normalizeAddresses(cfg.Listeners,
activeNetParams.DefaultPort)
// Add default port to all rpc listener addresses if needed and remove
// duplicate addresses.
cfg.RPCListeners = normalizeAddresses(cfg.RPCListeners,
activeNetParams.rpcPort)
// Only allow TLS to be disabled if the RPC is bound to localhost
// addresses.
if !cfg.DisableRPC && cfg.DisableTLS {
allowedTLSListeners := map[string]struct{}{
"localhost": struct{}{},
"127.0.0.1": struct{}{},
"::1": struct{}{},
}
for _, addr := range cfg.RPCListeners {
host, _, err := net.SplitHostPort(addr)
if err != nil {
str := "%s: RPC listen interface '%s' is " +
"invalid: %v"
err := fmt.Errorf(str, funcName, addr, err)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
if _, ok := allowedTLSListeners[host]; !ok {
str := "%s: the --notls option may not be used " +
"when binding RPC to non localhost " +
"addresses: %s"
err := fmt.Errorf(str, funcName, addr)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
}
}
// Add default port to all added peer addresses if needed and remove
// duplicate addresses.
cfg.AddPeers = normalizeAddresses(cfg.AddPeers,
activeNetParams.DefaultPort)
cfg.ConnectPeers = normalizeAddresses(cfg.ConnectPeers,
activeNetParams.DefaultPort)
// Tor stream isolation requires either proxy or onion proxy to be set.
if cfg.TorIsolation && cfg.Proxy == "" && cfg.OnionProxy == "" {
str := "%s: Tor stream isolation requires either proxy or " +
"onionproxy to be set"
err := fmt.Errorf(str, funcName)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
// Setup dial and DNS resolution (lookup) functions depending on the
// specified options. The default is to use the standard net.Dial
// function as well as the system DNS resolver. When a proxy is
// specified, the dial function is set to the proxy specific dial
// function and the lookup is set to use tor (unless --noonion is
// specified in which case the system DNS resolver is used).
cfg.dial = net.Dial
cfg.lookup = net.LookupIP
if cfg.Proxy != "" {
_, _, err := net.SplitHostPort(cfg.Proxy)
if err != nil {
str := "%s: Proxy address '%s' is invalid: %v"
err := fmt.Errorf(str, funcName, cfg.Proxy, err)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
if cfg.TorIsolation &&
(cfg.ProxyUser != "" || cfg.ProxyPass != "") {
btcdLog.Warn("Tor isolation set -- overriding " +
"specified proxy user credentials")
}
proxy := &socks.Proxy{
Addr: cfg.Proxy,
Username: cfg.ProxyUser,
Password: cfg.ProxyPass,
TorIsolation: cfg.TorIsolation,
}
cfg.dial = proxy.Dial
if !cfg.NoOnion {
cfg.lookup = func(host string) ([]net.IP, error) {
return torLookupIP(host, cfg.Proxy)
}
}
}
// Setup onion address dial and DNS resolution (lookup) functions
// depending on the specified options. The default is to use the
// same dial and lookup functions selected above. However, when an
// onion-specific proxy is specified, the onion address dial and
// lookup functions are set to use the onion-specific proxy while
// leaving the normal dial and lookup functions as selected above.
// This allows .onion address traffic to be routed through a different
// proxy than normal traffic.
if cfg.OnionProxy != "" {
_, _, err := net.SplitHostPort(cfg.OnionProxy)
if err != nil {
str := "%s: Onion proxy address '%s' is invalid: %v"
err := fmt.Errorf(str, funcName, cfg.OnionProxy, err)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, usageMessage)
return nil, nil, err
}
if cfg.TorIsolation &&
(cfg.OnionProxyUser != "" || cfg.OnionProxyPass != "") {
btcdLog.Warn("Tor isolation set -- overriding " +
"specified onionproxy user credentials ")
}
cfg.oniondial = func(a, b string) (net.Conn, error) {
proxy := &socks.Proxy{
Addr: cfg.OnionProxy,
Username: cfg.OnionProxyUser,
Password: cfg.OnionProxyPass,
TorIsolation: cfg.TorIsolation,
}
return proxy.Dial(a, b)
}
cfg.onionlookup = func(host string) ([]net.IP, error) {
return torLookupIP(host, cfg.OnionProxy)
}
} else {
cfg.oniondial = cfg.dial
cfg.onionlookup = cfg.lookup
}
// Specifying --noonion means the onion address dial and DNS resolution
// (lookup) functions result in an error.
if cfg.NoOnion {
cfg.oniondial = func(a, b string) (net.Conn, error) {
return nil, errors.New("tor has been disabled")
}
cfg.onionlookup = func(a string) ([]net.IP, error) {
return nil, errors.New("tor has been disabled")
}
}
// Warn about missing config file only after all other configuration is
// done. This prevents the warning on help messages and invalid
// options. Note this should go directly before the return.
if configFileError != nil {
btcdLog.Warnf("%v", configFileError)
}
return &cfg, remainingArgs, nil
}