unresolved externals errors while compiling a code using jsoncpp, libcurl and libwebsockets

Question

Using functions from this project, I am trying to compile an run this code:

#define _CRT_SECURE_NO_WARNINGS

#include <iostream>

#include <curl/curl.h>
#include <json/json.h>


#define BINANCE_HOST "https://api.binance.com"

const __int64 DELTA_EPOCH_IN_MICROSECS = 11644473600000000;


using namespace std;

class BinaCPP {

    static string api_key;
    static string secret_key;
    static CURL* curl;

public:
    static void curl_api(string& url, string& result_json);
    static void curl_api_with_header(string& url, string& result_json, vector <string>& extra_http_header, string& post_data, string& action);
    static size_t curl_cb(void* content, size_t size, size_t nmemb, string* buffer);

    static void init(string& api_key, string& secret_key);
    static void cleanup();
};

class BinaCPP_logger {

    static int debug_level;
    static string debug_log_file;
    static int debug_log_file_enable;
    static FILE* log_fp;


    static void open_logfp_if_not_opened();

public:
    static void write_log(const char* fmt, ...);
    static void write_log_clean(const char* fmt, ...);
    static void set_debug_level(int level);
    static void set_debug_logfile(string& pDebug_log_file);
    static void enable_logfile(int pDebug_log_file_enable);

};


struct timezone2
{
    __int32  tz_minuteswest; /* minutes W of Greenwich */
    bool  tz_dsttime;     /* type of dst correction */
};

struct timeval2 {
    __int32    tv_sec;         /* seconds */
    __int32    tv_usec;        /* microseconds */
};

int gettimeofday(struct timeval2* tv/*in*/, struct timezone2* tz/*in*/)
{
    FILETIME ft;
    __int64 tmpres = 0;
    TIME_ZONE_INFORMATION tz_winapi;
    int rez = 0;

    ZeroMemory(&ft, sizeof(ft));
    ZeroMemory(&tz_winapi, sizeof(tz_winapi));

    GetSystemTimeAsFileTime(&ft);

    tmpres = ft.dwHighDateTime;
    tmpres <<= 32;
    tmpres |= ft.dwLowDateTime;

    /*converting file time to unix epoch*/
    tmpres /= 10;  /*convert into microseconds*/
    tmpres -= DELTA_EPOCH_IN_MICROSECS;
    tv->tv_sec = (__int32)(tmpres * 0.000001);
    tv->tv_usec = (tmpres % 1000000);


    //_tzset(),don't work properly, so we use GetTimeZoneInformation
    rez = GetTimeZoneInformation(&tz_winapi);
    tz->tz_dsttime = (rez == 2) ? true : false;
    tz->tz_minuteswest = tz_winapi.Bias + ((rez == 2) ? tz_winapi.DaylightBias : 0);

    return 0;
}

////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////

void BinaCPP::init(string& api_key, string& secret_key)
{
    curl_global_init(CURL_GLOBAL_DEFAULT);
    BinaCPP::curl = curl_easy_init();
    BinaCPP::api_key = api_key;
    BinaCPP::secret_key = secret_key;
}

void
BinaCPP::cleanup()
{
    curl_easy_cleanup(BinaCPP::curl);
    curl_global_cleanup();
}

void
BinaCPP::curl_api(string& url, string& result_json) {
    vector <string> v;
    string action = "GET";
    string post_data = "";
    curl_api_with_header(url, result_json, v, post_data, action);
}

size_t
BinaCPP::curl_cb(void* content, size_t size, size_t nmemb, std::string* buffer)
{
    BinaCPP_logger::write_log("<BinaCPP::curl_cb> ");

    buffer->append((char*)content, size * nmemb);

    BinaCPP_logger::write_log("<BinaCPP::curl_cb> done");
    return size * nmemb;
}


void
BinaCPP::curl_api_with_header(string& url, string& str_result, vector <string>& extra_http_header, string& post_data, string& action)
{

    BinaCPP_logger::write_log("<BinaCPP::curl_api>");

    CURLcode res;

    if (BinaCPP::curl) {

        curl_easy_setopt(BinaCPP::curl, CURLOPT_URL, url.c_str());
        curl_easy_setopt(BinaCPP::curl, CURLOPT_WRITEFUNCTION, BinaCPP::curl_cb);
        curl_easy_setopt(BinaCPP::curl, CURLOPT_WRITEDATA, &str_result);
        curl_easy_setopt(BinaCPP::curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_easy_setopt(BinaCPP::curl, CURLOPT_ENCODING, "gzip");

        if (extra_http_header.size() > 0) {

            struct curl_slist* chunk = NULL;
            for (int i = 0; i < extra_http_header.size(); i++) {
                chunk = curl_slist_append(chunk, extra_http_header[i].c_str());
            }
            curl_easy_setopt(BinaCPP::curl, CURLOPT_HTTPHEADER, chunk);
        }

        if (post_data.size() > 0 || action == "POST" || action == "PUT" || action == "DELETE") {

            if (action == "PUT" || action == "DELETE") {
                curl_easy_setopt(BinaCPP::curl, CURLOPT_CUSTOMREQUEST, action.c_str());
            }
            curl_easy_setopt(BinaCPP::curl, CURLOPT_POSTFIELDS, post_data.c_str());
        }

        res = curl_easy_perform(BinaCPP::curl);

        /* Check for errors */
        if (res != CURLE_OK) {
            BinaCPP_logger::write_log("<BinaCPP::curl_api> curl_easy_perform() failed: %s", curl_easy_strerror(res));
        }

    }

    BinaCPP_logger::write_log("<BinaCPP::curl_api> done");

}



//////////////////////////////////////////////
/////////////////////////////////////////////////


//-----------------------------------------------
void
BinaCPP_logger::write_log(const char* fmt, ...)
{
    if (debug_level == 0) {
        return;
    }
    if (debug_log_file_enable == 1) {
        open_logfp_if_not_opened();
    }

    va_list arg;

    char new_fmt[1024];

    timeval2 tv;
    gettimeofday(&tv, NULL);
    time_t t = tv.tv_sec;
    struct tm* now = localtime(&t);


    sprintf(new_fmt, "%04d-%02d-%02d %02d:%02d:%02d %06ld :%s\n", now->tm_year + 1900, now->tm_mon + 1, now->tm_mday, now->tm_hour, now->tm_min, now->tm_sec, tv.tv_usec, fmt);

    va_start(arg, fmt);

    if (debug_log_file_enable && log_fp) {
        vfprintf(log_fp, new_fmt, arg);
        fflush(log_fp);
    }
    else {
        vfprintf(stdout, new_fmt, arg);
        fflush(stdout);
    }

    va_end(arg);


}



//-----------------------------------------------
// Write log to channel without any timestamp nor new line
void
BinaCPP_logger::write_log_clean(const char* fmt, ...)
{
    if (debug_level == 0) {
        return;
    }
    if (debug_log_file_enable == 1) {
        open_logfp_if_not_opened();
    }

    va_list arg;
    va_start(arg, fmt);

    if (debug_log_file_enable && log_fp) {
        vfprintf(log_fp, fmt, arg);
        fflush(log_fp);
    }
    else {
        vfprintf(stdout, fmt, arg);
        fflush(stdout);
    }
    va_end(arg);

}


//---------------------
void
BinaCPP_logger::open_logfp_if_not_opened() {

    if (debug_log_file_enable && log_fp == NULL) {

        log_fp = fopen(debug_log_file.c_str(), "a");

        if (log_fp) {
            printf("log file in %s\n", debug_log_file.c_str());
        }
        else {
            printf("Failed to open log file.\n");
        }
    }

}


//---------------------
void
BinaCPP_logger::set_debug_level(int level)
{
    debug_level = level;
}

//--------------------
void
BinaCPP_logger::set_debug_logfile(string& pDebug_log_file)
{
    debug_log_file = pDebug_log_file;
}

//--------------------
void
BinaCPP_logger::enable_logfile(int pDebug_log_file_enable)
{
    debug_log_file_enable = pDebug_log_file_enable;
}


int main()
{
    BinaCPP Session;

    string api_key = "";
    string secret_key = "";
    Session.init(api_key, secret_key);

    cout << endl;

    system("pause");

    return 0;
}

I installed co[libcurl], libwebsockets and jsoncpp via vcpkg and then integrated the installs (x86 version) for visual studio. When I try to compile the code (x86 version also) I have those unresolved externals symbols:

LNK2001 unresolved external symbol "private: static int BinaCPP_logger::debug_level" (?debug_level@BinaCPP_logger@@0HA)

LNK2001 unresolved external symbol "private: static int BinaCPP_logger::debug_log_file_enable" (?debug_log_file_enable@BinaCPP_logger@@0HA)

LNK2001 unresolved external symbol "private: static class std::basic_string<char,struct std::char_traits,class std::allocator > BinaCPP::api_key" (?api_key@BinaCPP@@0V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A)

LNK2001 unresolved external symbol "private: static void * BinaCPP::curl" (?curl@BinaCPP@@0PAXA)

I have no clue how to solve this. Are the librairies installed not the correct ones ?

Thank you for the help

Does this answer your question? [Undefined reference to a static member](https://stackoverflow.com/questions/9110487/undefined-reference-to-a-static-member) — user17732522, Jan 10 '22 at 05:10
That is way too much code for a [mre]. If you had put in the effort to reduce your code to something resembling "minimal", you should have discovered that the list of things you've installed is not relevant to your question. That is one of the reasons for producing a *minimal* reproducible example -- it removes noise and lets people focus on what is relevant. — JaMiT, Jan 10 '22 at 05:24

unresolved externals errors while compiling a code using jsoncpp, libcurl and libwebsockets

0 Answers0