path: root/src/bitcoin-cli.cpp

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif

#include <chainparamsbase.h>
#include <clientversion.h>
#include <optional.h>
#include <rpc/client.h>
#include <rpc/mining.h>
#include <rpc/protocol.h>
#include <rpc/request.h>
#include <util/strencodings.h>
#include <util/system.h>
#include <util/translation.h>
#include <util/url.h>

#include <functional>
#include <memory>
#include <stdio.h>
#include <string>
#include <tuple>

#include <event2/buffer.h>
#include <event2/keyvalq_struct.h>
#include <support/events.h>

#include <univalue.h>
#include <compat/stdin.h>

const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
UrlDecodeFn* const URL_DECODE = urlDecode;

static const char DEFAULT_RPCCONNECT[] = "127.0.0.1";
static const int DEFAULT_HTTP_CLIENT_TIMEOUT=900;
static const bool DEFAULT_NAMED=false;
static const int CONTINUE_EXECUTION=-1;

/** Default number of blocks to generate for RPC generatetoaddress. */
static const std::string DEFAULT_NBLOCKS = "1";

static void SetupCliArgs(ArgsManager& argsman)
{
    SetupHelpOptions(argsman);

    const auto defaultBaseParams = CreateBaseChainParams(CBaseChainParams::MAIN);
    const auto testnetBaseParams = CreateBaseChainParams(CBaseChainParams::TESTNET);
    const auto regtestBaseParams = CreateBaseChainParams(CBaseChainParams::REGTEST);

    argsman.AddArg("-version", "Print version and exit", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-conf=<file>", strprintf("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)", BITCOIN_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-datadir=<dir>", "Specify data directory", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-generate", strprintf("Generate blocks immediately, equivalent to RPC generatenewaddress followed by RPC generatetoaddress. Optional positional integer arguments are number of blocks to generate (default: %s) and maximum iterations to try (default: %s), equivalent to RPC generatetoaddress nblocks and maxtries arguments. Example: bitcoin-cli -generate 4 1000", DEFAULT_NBLOCKS, DEFAULT_MAX_TRIES), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-getinfo", "Get general information from the remote server. Note that unlike server-side RPC calls, the results of -getinfo is the result of multiple non-atomic requests. Some entries in the result may represent results from different states (e.g. wallet balance may be as of a different block from the chain state reported)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-netinfo", "Get network peer connection information from the remote server. An optional boolean argument can be passed for a detailed peers listing (default: false).", ArgsManager::ALLOW_BOOL, OptionsCategory::OPTIONS);

    SetupChainParamsBaseOptions(argsman);
    argsman.AddArg("-named", strprintf("Pass named instead of positional arguments (default: %s)", DEFAULT_NAMED), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcclienttimeout=<n>", strprintf("Timeout in seconds during HTTP requests, or 0 for no timeout. (default: %d)", DEFAULT_HTTP_CLIENT_TIMEOUT), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcconnect=<ip>", strprintf("Send commands to node running on <ip> (default: %s)", DEFAULT_RPCCONNECT), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpccookiefile=<loc>", "Location of the auth cookie. Relative paths will be prefixed by a net-specific datadir location. (default: data dir)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcpassword=<pw>", "Password for JSON-RPC connections", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcport=<port>", strprintf("Connect to JSON-RPC on <port> (default: %u, testnet: %u, regtest: %u)", defaultBaseParams->RPCPort(), testnetBaseParams->RPCPort(), regtestBaseParams->RPCPort()), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcuser=<user>", "Username for JSON-RPC connections", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcwait", "Wait for RPC server to start", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-rpcwallet=<walletname>", "Send RPC for non-default wallet on RPC server (needs to exactly match corresponding -wallet option passed to bitcoind). This changes the RPC endpoint used, e.g. http://127.0.0.1:8332/wallet/<walletname>", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-stdin", "Read extra arguments from standard input, one per line until EOF/Ctrl-D (recommended for sensitive information such as passphrases). When combined with -stdinrpcpass, the first line from standard input is used for the RPC password.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-stdinrpcpass", "Read RPC password from standard input as a single line. When combined with -stdin, the first line from standard input is used for the RPC password. When combined with -stdinwalletpassphrase, -stdinrpcpass consumes the first line, and -stdinwalletpassphrase consumes the second.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-stdinwalletpassphrase", "Read wallet passphrase from standard input as a single line. When combined with -stdin, the first line from standard input is used for the wallet passphrase.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
}

/** libevent event log callback */
static void libevent_log_cb(int severity, const char *msg)
{
#ifndef EVENT_LOG_ERR // EVENT_LOG_ERR was added in 2.0.19; but before then _EVENT_LOG_ERR existed.
# define EVENT_LOG_ERR _EVENT_LOG_ERR
#endif
    // Ignore everything other than errors
    if (severity >= EVENT_LOG_ERR) {
        throw std::runtime_error(strprintf("libevent error: %s", msg));
    }
}

//////////////////////////////////////////////////////////////////////////////
//
// Start
//

//
// Exception thrown on connection error.  This error is used to determine
// when to wait if -rpcwait is given.
//
class CConnectionFailed : public std::runtime_error
{
public:

    explicit inline CConnectionFailed(const std::string& msg) :
        std::runtime_error(msg)
    {}

};

//
// This function returns either one of EXIT_ codes when it's expected to stop the process or
// CONTINUE_EXECUTION when it's expected to continue further.
//
static int AppInitRPC(int argc, char* argv[])
{
    //
    // Parameters
    //
    SetupCliArgs(gArgs);
    std::string error;
    if (!gArgs.ParseParameters(argc, argv, error)) {
        tfm::format(std::cerr, "Error parsing command line arguments: %s\n", error);
        return EXIT_FAILURE;
    }
    if (argc < 2 || HelpRequested(gArgs) || gArgs.IsArgSet("-version")) {
        std::string strUsage = PACKAGE_NAME " RPC client version " + FormatFullVersion() + "\n";
        if (!gArgs.IsArgSet("-version")) {
            strUsage += "\n"
                "Usage:  bitcoin-cli [options] <command> [params]  Send command to " PACKAGE_NAME "\n"
                "or:     bitcoin-cli [options] -named <command> [name=value]...  Send command to " PACKAGE_NAME " (with named arguments)\n"
                "or:     bitcoin-cli [options] help                List commands\n"
                "or:     bitcoin-cli [options] help <command>      Get help for a command\n";
            strUsage += "\n" + gArgs.GetHelpMessage();
        }

        tfm::format(std::cout, "%s", strUsage);
        if (argc < 2) {
            tfm::format(std::cerr, "Error: too few parameters\n");
            return EXIT_FAILURE;
        }
        return EXIT_SUCCESS;
    }
    if (!CheckDataDirOption()) {
        tfm::format(std::cerr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", ""));
        return EXIT_FAILURE;
    }
    if (!gArgs.ReadConfigFiles(error, true)) {
        tfm::format(std::cerr, "Error reading configuration file: %s\n", error);
        return EXIT_FAILURE;
    }
    // Check for -chain, -testnet or -regtest parameter (BaseParams() calls are only valid after this clause)
    try {
        SelectBaseParams(gArgs.GetChainName());
    } catch (const std::exception& e) {
        tfm::format(std::cerr, "Error: %s\n", e.what());
        return EXIT_FAILURE;
    }
    return CONTINUE_EXECUTION;
}


/** Reply structure for request_done to fill in */
struct HTTPReply
{
    HTTPReply(): status(0), error(-1) {}

    int status;
    int error;
    std::string body;
};

static std::string http_errorstring(int code)
{
    switch(code) {
#if LIBEVENT_VERSION_NUMBER >= 0x02010300
    case EVREQ_HTTP_TIMEOUT:
        return "timeout reached";
    case EVREQ_HTTP_EOF:
        return "EOF reached";
    case EVREQ_HTTP_INVALID_HEADER:
        return "error while reading header, or invalid header";
    case EVREQ_HTTP_BUFFER_ERROR:
        return "error encountered while reading or writing";
    case EVREQ_HTTP_REQUEST_CANCEL:
        return "request was canceled";
    case EVREQ_HTTP_DATA_TOO_LONG:
        return "response body is larger than allowed";
#endif
    default:
        return "unknown";
    }
}

static void http_request_done(struct evhttp_request *req, void *ctx)
{
    HTTPReply *reply = static_cast<HTTPReply*>(ctx);

    if (req == nullptr) {
        /* If req is nullptr, it means an error occurred while connecting: the
         * error code will have been passed to http_error_cb.
         */
        reply->status = 0;
        return;
    }

    reply->status = evhttp_request_get_response_code(req);

    struct evbuffer *buf = evhttp_request_get_input_buffer(req);
    if (buf)
    {
        size_t size = evbuffer_get_length(buf);
        const char *data = (const char*)evbuffer_pullup(buf, size);
        if (data)
            reply->body = std::string(data, size);
        evbuffer_drain(buf, size);
    }
}

#if LIBEVENT_VERSION_NUMBER >= 0x02010300
static void http_error_cb(enum evhttp_request_error err, void *ctx)
{
    HTTPReply *reply = static_cast<HTTPReply*>(ctx);
    reply->error = err;
}
#endif

/** Class that handles the conversion from a command-line to a JSON-RPC request,
 * as well as converting back to a JSON object that can be shown as result.
 */
class BaseRequestHandler
{
public:
    virtual ~BaseRequestHandler() {}
    virtual UniValue PrepareRequest(const std::string& method, const std::vector<std::string>& args) = 0;
    virtual UniValue ProcessReply(const UniValue &batch_in) = 0;
};

/** Process getinfo requests */
class GetinfoRequestHandler: public BaseRequestHandler
{
public:
    const int ID_NETWORKINFO = 0;
    const int ID_BLOCKCHAININFO = 1;
    const int ID_WALLETINFO = 2;
    const int ID_BALANCES = 3;

    /** Create a simulated `getinfo` request. */
    UniValue PrepareRequest(const std::string& method, const std::vector<std::string>& args) override
    {
        if (!args.empty()) {
            throw std::runtime_error("-getinfo takes no arguments");
        }
        UniValue result(UniValue::VARR);
        result.push_back(JSONRPCRequestObj("getnetworkinfo", NullUniValue, ID_NETWORKINFO));
        result.push_back(JSONRPCRequestObj("getblockchaininfo", NullUniValue, ID_BLOCKCHAININFO));
        result.push_back(JSONRPCRequestObj("getwalletinfo", NullUniValue, ID_WALLETINFO));
        result.push_back(JSONRPCRequestObj("getbalances", NullUniValue, ID_BALANCES));
        return result;
    }

    /** Collect values from the batch and form a simulated `getinfo` reply. */
    UniValue ProcessReply(const UniValue &batch_in) override
    {
        UniValue result(UniValue::VOBJ);
        const std::vector<UniValue> batch = JSONRPCProcessBatchReply(batch_in);
        // Errors in getnetworkinfo() and getblockchaininfo() are fatal, pass them on;
        // getwalletinfo() and getbalances() are allowed to fail if there is no wallet.
        if (!batch[ID_NETWORKINFO]["error"].isNull()) {
            return batch[ID_NETWORKINFO];
        }
        if (!batch[ID_BLOCKCHAININFO]["error"].isNull()) {
            return batch[ID_BLOCKCHAININFO];
        }
        result.pushKV("version", batch[ID_NETWORKINFO]["result"]["version"]);
        result.pushKV("blocks", batch[ID_BLOCKCHAININFO]["result"]["blocks"]);
        result.pushKV("headers", batch[ID_BLOCKCHAININFO]["result"]["headers"]);
        result.pushKV("verificationprogress", batch[ID_BLOCKCHAININFO]["result"]["verificationprogress"]);
        result.pushKV("timeoffset", batch[ID_NETWORKINFO]["result"]["timeoffset"]);
        result.pushKV("connections", batch[ID_NETWORKINFO]["result"]["connections"]);
        result.pushKV("proxy", batch[ID_NETWORKINFO]["result"]["networks"][0]["proxy"]);
        result.pushKV("difficulty", batch[ID_BLOCKCHAININFO]["result"]["difficulty"]);
        result.pushKV("chain", UniValue(batch[ID_BLOCKCHAININFO]["result"]["chain"]));
        if (!batch[ID_WALLETINFO]["result"].isNull()) {
            result.pushKV("keypoolsize", batch[ID_WALLETINFO]["result"]["keypoolsize"]);
            if (!batch[ID_WALLETINFO]["result"]["unlocked_until"].isNull()) {
                result.pushKV("unlocked_until", batch[ID_WALLETINFO]["result"]["unlocked_until"]);
            }
            result.pushKV("paytxfee", batch[ID_WALLETINFO]["result"]["paytxfee"]);
        }
        if (!batch[ID_BALANCES]["result"].isNull()) {
            result.pushKV("balance", batch[ID_BALANCES]["result"]["mine"]["trusted"]);
        }
        result.pushKV("relayfee", batch[ID_NETWORKINFO]["result"]["relayfee"]);
        result.pushKV("warnings", batch[ID_NETWORKINFO]["result"]["warnings"]);
        return JSONRPCReplyObj(result, NullUniValue, 1);
    }
};

/** Process netinfo requests */
class NetinfoRequestHandler : public BaseRequestHandler
{
private:
    bool m_verbose{false}; //!< Whether user requested verbose -netinfo report
public:
    const int ID_PEERINFO = 0;
    const int ID_NETWORKINFO = 1;

    UniValue PrepareRequest(const std::string& method, const std::vector<std::string>& args) override
    {
        if (!args.empty()) {
            const std::string arg{ToLower(args.at(0))};
            m_verbose = (arg == "true" || arg == "t");
        }
        UniValue result(UniValue::VARR);
        result.push_back(JSONRPCRequestObj("getpeerinfo", NullUniValue, ID_PEERINFO));
        result.push_back(JSONRPCRequestObj("getnetworkinfo", NullUniValue, ID_NETWORKINFO));
        return result;
    }

    UniValue ProcessReply(const UniValue& batch_in) override
    {
        const std::vector<UniValue> batch{JSONRPCProcessBatchReply(batch_in)};
        if (!batch[ID_PEERINFO]["error"].isNull()) return batch[ID_PEERINFO];
        if (!batch[ID_NETWORKINFO]["error"].isNull()) return batch[ID_NETWORKINFO];
        std::string result;
        return JSONRPCReplyObj(UniValue{result}, NullUniValue, 1);
    }
};

/** Process RPC generatetoaddress request. */
class GenerateToAddressRequestHandler : public BaseRequestHandler
{
public:
    UniValue PrepareRequest(const std::string& method, const std::vector<std::string>& args) override
    {
        address_str = args.at(1);
        UniValue params{RPCConvertValues("generatetoaddress", args)};
        return JSONRPCRequestObj("generatetoaddress", params, 1);
    }

    UniValue ProcessReply(const UniValue &reply) override
    {
        UniValue result(UniValue::VOBJ);
        result.pushKV("address", address_str);
        result.pushKV("blocks", reply.get_obj()["result"]);
        return JSONRPCReplyObj(result, NullUniValue, 1);
    }
protected:
    std::string address_str;
};

/** Process default single requests */
class DefaultRequestHandler: public BaseRequestHandler {
public:
    UniValue PrepareRequest(const std::string& method, const std::vector<std::string>& args) override
    {
        UniValue params;
        if(gArgs.GetBoolArg("-named", DEFAULT_NAMED)) {
            params = RPCConvertNamedValues(method, args);
        } else {
            params = RPCConvertValues(method, args);
        }
        return JSONRPCRequestObj(method, params, 1);
    }

    UniValue ProcessReply(const UniValue &reply) override
    {
        return reply.get_obj();
    }
};

static UniValue CallRPC(BaseRequestHandler* rh, const std::string& strMethod, const std::vector<std::string>& args, const Optional<std::string>& rpcwallet = {})
{
    std::string host;
    // In preference order, we choose the following for the port:
    //     1. -rpcport
    //     2. port in -rpcconnect (ie following : in ipv4 or ]: in ipv6)
    //     3. default port for chain
    int port = BaseParams().RPCPort();
    SplitHostPort(gArgs.GetArg("-rpcconnect", DEFAULT_RPCCONNECT), port, host);
    port = gArgs.GetArg("-rpcport", port);

    // Obtain event base
    raii_event_base base = obtain_event_base();

    // Synchronously look up hostname
    raii_evhttp_connection evcon = obtain_evhttp_connection_base(base.get(), host, port);

    // Set connection timeout
    {
        const int timeout = gArgs.GetArg("-rpcclienttimeout", DEFAULT_HTTP_CLIENT_TIMEOUT);
        if (timeout > 0) {
            evhttp_connection_set_timeout(evcon.get(), timeout);
        } else {
            // Indefinite request timeouts are not possible in libevent-http, so we
            // set the timeout to a very long time period instead.

            constexpr int YEAR_IN_SECONDS = 31556952; // Average length of year in Gregorian calendar
            evhttp_connection_set_timeout(evcon.get(), 5 * YEAR_IN_SECONDS);
        }
    }

    HTTPReply response;
    raii_evhttp_request req = obtain_evhttp_request(http_request_done, (void*)&response);
    if (req == nullptr)
        throw std::runtime_error("create http request failed");
#if LIBEVENT_VERSION_NUMBER >= 0x02010300
    evhttp_request_set_error_cb(req.get(), http_error_cb);
#endif

    // Get credentials
    std::string strRPCUserColonPass;
    bool failedToGetAuthCookie = false;
    if (gArgs.GetArg("-rpcpassword", "") == "") {
        // Try fall back to cookie-based authentication if no password is provided
        if (!GetAuthCookie(&strRPCUserColonPass)) {
            failedToGetAuthCookie = true;
        }
    } else {
        strRPCUserColonPass = gArgs.GetArg("-rpcuser", "") + ":" + gArgs.GetArg("-rpcpassword", "");
    }

    struct evkeyvalq* output_headers = evhttp_request_get_output_headers(req.get());
    assert(output_headers);
    evhttp_add_header(output_headers, "Host", host.c_str());
    evhttp_add_header(output_headers, "Connection", "close");
    evhttp_add_header(output_headers, "Authorization", (std::string("Basic ") + EncodeBase64(strRPCUserColonPass)).c_str());

    // Attach request data
    std::string strRequest = rh->PrepareRequest(strMethod, args).write() + "\n";
    struct evbuffer* output_buffer = evhttp_request_get_output_buffer(req.get());
    assert(output_buffer);
    evbuffer_add(output_buffer, strRequest.data(), strRequest.size());

    // check if we should use a special wallet endpoint
    std::string endpoint = "/";
    if (rpcwallet) {
        char* encodedURI = evhttp_uriencode(rpcwallet->data(), rpcwallet->size(), false);
        if (encodedURI) {
            endpoint = "/wallet/" + std::string(encodedURI);
            free(encodedURI);
        } else {
            throw CConnectionFailed("uri-encode failed");
        }
    }
    int r = evhttp_make_request(evcon.get(), req.get(), EVHTTP_REQ_POST, endpoint.c_str());
    req.release(); // ownership moved to evcon in above call
    if (r != 0) {
        throw CConnectionFailed("send http request failed");
    }

    event_base_dispatch(base.get());

    if (response.status == 0) {
        std::string responseErrorMessage;
        if (response.error != -1) {
            responseErrorMessage = strprintf(" (error code %d - \"%s\")", response.error, http_errorstring(response.error));
        }
        throw CConnectionFailed(strprintf("Could not connect to the server %s:%d%s\n\nMake sure the bitcoind server is running and that you are connecting to the correct RPC port.", host, port, responseErrorMessage));
    } else if (response.status == HTTP_UNAUTHORIZED) {
        if (failedToGetAuthCookie) {
            throw std::runtime_error(strprintf(
                "Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set.  See -rpcpassword and -stdinrpcpass.  Configuration file: (%s)",
                GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME)).string()));
        } else {
            throw std::runtime_error("Authorization failed: Incorrect rpcuser or rpcpassword");
        }
    } else if (response.status >= 400 && response.status != HTTP_BAD_REQUEST && response.status != HTTP_NOT_FOUND && response.status != HTTP_INTERNAL_SERVER_ERROR)
        throw std::runtime_error(strprintf("server returned HTTP error %d", response.status));
    else if (response.body.empty())
        throw std::runtime_error("no response from server");

    // Parse reply
    UniValue valReply(UniValue::VSTR);
    if (!valReply.read(response.body))
        throw std::runtime_error("couldn't parse reply from server");
    const UniValue reply = rh->ProcessReply(valReply);
    if (reply.empty())
        throw std::runtime_error("expected reply to have result, error and id properties");

    return reply;
}

/**
 * ConnectAndCallRPC wraps CallRPC with -rpcwait and an exception handler.
 *
 * @param[in] rh         Pointer to RequestHandler.
 * @param[in] strMethod  Reference to const string method to forward to CallRPC.
 * @param[in] rpcwallet  Reference to const optional string wallet name to forward to CallRPC.
 * @returns the RPC response as a UniValue object.
 * @throws a CConnectionFailed std::runtime_error if connection failed or RPC server still in warmup.
 */
static UniValue ConnectAndCallRPC(BaseRequestHandler* rh, const std::string& strMethod, const std::vector<std::string>& args, const Optional<std::string>& rpcwallet = {})
{
    UniValue response(UniValue::VOBJ);
    // Execute and handle connection failures with -rpcwait.
    const bool fWait = gArgs.GetBoolArg("-rpcwait", false);
    do {
        try {
            response = CallRPC(rh, strMethod, args, rpcwallet);
            if (fWait) {
                const UniValue& error = find_value(response, "error");
                if (!error.isNull() && error["code"].get_int() == RPC_IN_WARMUP) {
                    throw CConnectionFailed("server in warmup");
                }
            }
            break; // Connection succeeded, no need to retry.
        } catch (const CConnectionFailed&) {
            if (fWait) {
                UninterruptibleSleep(std::chrono::milliseconds{1000});
            } else {
                throw;
            }
        }
    } while (fWait);
    return response;
}

/** Parse UniValue result to update the message to print to std::cout. */
static void ParseResult(const UniValue& result, std::string& strPrint)
{
    if (result.isNull()) return;
    strPrint = result.isStr() ? result.get_str() : result.write(2);
}

/** Parse UniValue error to update the message to print to std::cerr and the code to return. */
static void ParseError(const UniValue& error, std::string& strPrint, int& nRet)
{
    if (error.isObject()) {
        const UniValue& err_code = find_value(error, "code");
        const UniValue& err_msg = find_value(error, "message");
        if (!err_code.isNull()) {
            strPrint = "error code: " + err_code.getValStr() + "\n";
        }
        if (err_msg.isStr()) {
            strPrint += ("error message:\n" + err_msg.get_str());
        }
        if (err_code.isNum() && err_code.get_int() == RPC_WALLET_NOT_SPECIFIED) {
            strPrint += "\nTry adding \"-rpcwallet=<filename>\" option to bitcoin-cli command line.";
        }
    } else {
        strPrint = "error: " + error.write();
    }
    nRet = abs(error["code"].get_int());
}

/**
 * GetWalletBalances calls listwallets; if more than one wallet is loaded, it then
 * fetches mine.trusted balances for each loaded wallet and pushes them to `result`.
 *
 * @param result  Reference to UniValue object the wallet names and balances are pushed to.
 */
static void GetWalletBalances(UniValue& result)
{
    DefaultRequestHandler rh;
    const UniValue listwallets = ConnectAndCallRPC(&rh, "listwallets", /* args=*/{});
    if (!find_value(listwallets, "error").isNull()) return;
    const UniValue& wallets = find_value(listwallets, "result");
    if (wallets.size() <= 1) return;

    UniValue balances(UniValue::VOBJ);
    for (const UniValue& wallet : wallets.getValues()) {
        const std::string wallet_name = wallet.get_str();
        const UniValue getbalances = ConnectAndCallRPC(&rh, "getbalances", /* args=*/{}, wallet_name);
        const UniValue& balance = find_value(getbalances, "result")["mine"]["trusted"];
        balances.pushKV(wallet_name, balance);
    }
    result.pushKV("balances", balances);
}

/**
 * Call RPC getnewaddress.
 * @returns getnewaddress response as a UniValue object.
 */
static UniValue GetNewAddress()
{
    Optional<std::string> wallet_name{};
    if (gArgs.IsArgSet("-rpcwallet")) wallet_name = gArgs.GetArg("-rpcwallet", "");
    DefaultRequestHandler rh;
    return ConnectAndCallRPC(&rh, "getnewaddress", /* args=*/{}, wallet_name);
}

/**
 * Check bounds and set up args for RPC generatetoaddress params: nblocks, address, maxtries.
 * @param[in] address  Reference to const string address to insert into the args.
 * @param     args     Reference to vector of string args to modify.
 */
static void SetGenerateToAddressArgs(const std::string& address, std::vector<std::string>& args)
{
    if (args.size() > 2) throw std::runtime_error("too many arguments (maximum 2 for nblocks and maxtries)");
    if (args.size() == 0) {
        args.emplace_back(DEFAULT_NBLOCKS);
    } else if (args.at(0) == "0") {
        throw std::runtime_error("the first argument (number of blocks to generate, default: " + DEFAULT_NBLOCKS + ") must be an integer value greater than zero");
    }
    args.emplace(args.begin() + 1, address);
}

static int CommandLineRPC(int argc, char *argv[])
{
    std::string strPrint;
    int nRet = 0;
    try {
        // Skip switches
        while (argc > 1 && IsSwitchChar(argv[1][0])) {
            argc--;
            argv++;
        }
        std::string rpcPass;
        if (gArgs.GetBoolArg("-stdinrpcpass", false)) {
            NO_STDIN_ECHO();
            if (!StdinReady()) {
                fputs("RPC password> ", stderr);
                fflush(stderr);
            }
            if (!std::getline(std::cin, rpcPass)) {
                throw std::runtime_error("-stdinrpcpass specified but failed to read from standard input");
            }
            if (StdinTerminal()) {
                fputc('\n', stdout);
            }
            gArgs.ForceSetArg("-rpcpassword", rpcPass);
        }
        std::vector<std::string> args = std::vector<std::string>(&argv[1], &argv[argc]);
        if (gArgs.GetBoolArg("-stdinwalletpassphrase", false)) {
            NO_STDIN_ECHO();
            std::string walletPass;
            if (args.size() < 1 || args[0].substr(0, 16) != "walletpassphrase") {
                throw std::runtime_error("-stdinwalletpassphrase is only applicable for walletpassphrase(change)");
            }
            if (!StdinReady()) {
                fputs("Wallet passphrase> ", stderr);
                fflush(stderr);
            }
            if (!std::getline(std::cin, walletPass)) {
                throw std::runtime_error("-stdinwalletpassphrase specified but failed to read from standard input");
            }
            if (StdinTerminal()) {
                fputc('\n', stdout);
            }
            args.insert(args.begin() + 1, walletPass);
        }
        if (gArgs.GetBoolArg("-stdin", false)) {
            // Read one arg per line from stdin and append
            std::string line;
            while (std::getline(std::cin, line)) {
                args.push_back(line);
            }
            if (StdinTerminal()) {
                fputc('\n', stdout);
            }
        }
        std::unique_ptr<BaseRequestHandler> rh;
        std::string method;
        if (gArgs.IsArgSet("-getinfo")) {
            rh.reset(new GetinfoRequestHandler());
        } else if (gArgs.GetBoolArg("-netinfo", false)) {
            rh.reset(new NetinfoRequestHandler());
        } else if (gArgs.GetBoolArg("-generate", false)) {
            const UniValue getnewaddress{GetNewAddress()};
            const UniValue& error{find_value(getnewaddress, "error")};
            if (error.isNull()) {
                SetGenerateToAddressArgs(find_value(getnewaddress, "result").get_str(), args);
                rh.reset(new GenerateToAddressRequestHandler());
            } else {
                ParseError(error, strPrint, nRet);
            }
        } else {
            rh.reset(new DefaultRequestHandler());
            if (args.size() < 1) {
                throw std::runtime_error("too few parameters (need at least command)");
            }
            method = args[0];
            args.erase(args.begin()); // Remove trailing method name from arguments vector
        }
        if (nRet == 0) {
            // Perform RPC call
            Optional<std::string> wallet_name{};
            if (gArgs.IsArgSet("-rpcwallet")) wallet_name = gArgs.GetArg("-rpcwallet", "");
            const UniValue reply = ConnectAndCallRPC(rh.get(), method, args, wallet_name);

            // Parse reply
            UniValue result = find_value(reply, "result");
            const UniValue& error = find_value(reply, "error");
            if (error.isNull()) {
                if (gArgs.IsArgSet("-getinfo") && !gArgs.IsArgSet("-rpcwallet")) {
                    GetWalletBalances(result); // fetch multiwallet balances and append to result
                }
                ParseResult(result, strPrint);
            } else {
                ParseError(error, strPrint, nRet);
            }
        }
    } catch (const std::exception& e) {
        strPrint = std::string("error: ") + e.what();
        nRet = EXIT_FAILURE;
    } catch (...) {
        PrintExceptionContinue(nullptr, "CommandLineRPC()");
        throw;
    }

    if (strPrint != "") {
        tfm::format(nRet == 0 ? std::cout : std::cerr, "%s\n", strPrint);
    }
    return nRet;
}

#ifdef WIN32
// Export main() and ensure working ASLR on Windows.
// Exporting a symbol will prevent the linker from stripping
// the .reloc section from the binary, which is a requirement
// for ASLR. This is a temporary workaround until a fixed
// version of binutils is used for releases.
__declspec(dllexport) int main(int argc, char* argv[])
{
    util::WinCmdLineArgs winArgs;
    std::tie(argc, argv) = winArgs.get();
#else
int main(int argc, char* argv[])
{
#endif
    SetupEnvironment();
    if (!SetupNetworking()) {
        tfm::format(std::cerr, "Error: Initializing networking failed\n");
        return EXIT_FAILURE;
    }
    event_set_log_callback(&libevent_log_cb);

    try {
        int ret = AppInitRPC(argc, argv);
        if (ret != CONTINUE_EXECUTION)
            return ret;
    }
    catch (const std::exception& e) {
        PrintExceptionContinue(&e, "AppInitRPC()");
        return EXIT_FAILURE;
    } catch (...) {
        PrintExceptionContinue(nullptr, "AppInitRPC()");
        return EXIT_FAILURE;
    }

    int ret = EXIT_FAILURE;
    try {
        ret = CommandLineRPC(argc, argv);
    }
    catch (const std::exception& e) {
        PrintExceptionContinue(&e, "CommandLineRPC()");
    } catch (...) {
        PrintExceptionContinue(nullptr, "CommandLineRPC()");
    }
    return ret;
}