How to use the Curl library for c++ correctly?

Question

I’m having trouble copying a simple test using the Curl library to C++ because it always returns this error:

C:\Users\Raphael\Desktop\HTTP Request\collect2.exe  [Error] ld returned 1 exit status

Makefile.win # Project: SQL Request # Makefile created by Dev-C++ 5.6.3

CPP      = g++.exe
CC       = gcc.exe
WINDRES  = windres.exe
OBJ      = "SQL\ Request.o"
LINKOBJ  = "SQL Request.o"
LIBS     = -L"C:/Program Files (x86)/Dev-Cpp/MinGW32/lib" -L"C:/Program Files (x86)/Dev-Cpp/MinGW32/mingw32/lib" -static-libstdc++ -static-libgcc
INCS     = -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/include" -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/mingw32/include" -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/lib/gcc/mingw32/4.8.1/include"
CXXINCS  = -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/include" -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/mingw32/include" -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/lib/gcc/mingw32/4.8.1/include" -I"C:/Program Files (x86)/Dev-Cpp/MinGW32/lib/gcc/mingw32/4.8.1/include/c++"
BIN      = "SQL Request.exe"
CXXFLAGS = $(CXXINCS) 
CFLAGS   = $(INCS) 
RM       = rm.exe -f

.PHONY: all all-before all-after clean clean-custom

all: all-before $(BIN) all-after

clean: clean-custom
    ${RM} $(OBJ) $(BIN)

$(BIN): $(OBJ)
    $(CPP) $(LINKOBJ) -o $(BIN) $(LIBS) // AQUI OCORRE O ERRO

"SQL\ Request.o": SQL\ Request.cpp
    $(CPP) -c "SQL Request.cpp" -o "SQL Request.o" $(CXXFLAGS)

My Code:

#include <stdio.h>
#include "libs/curl/curl.h"

int main(void)
{
  CURL *curl;
  CURLcode res;

  curl_global_init(CURL_GLOBAL_DEFAULT);

  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");

#ifdef SKIP_PEER_VERIFICATION
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
#endif

#ifdef SKIP_HOSTNAME_VERIFICATION
    /*
     * If the site you're connecting to uses a different host name that what
     * they have mentioned in their server certificate's commonName (or
     * subjectAltName) fields, libcurl will refuse to connect. You can skip
     * this check, but this will make the connection less secure.
     */
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
#endif

    /* Perform the request, res will get the return code */
    res = curl_easy_perform(curl);
    /* Check for errors */
    if(res != CURLE_OK)
      fprintf(stderr, "curl_easy_perform() failed: %s\n",
              curl_easy_strerror(res));

    /* always cleanup */
    curl_easy_cleanup(curl);
  }

  curl_global_cleanup();

  return 0;
}

Answer 1

Apparently Voce needs to link the library. In the Dev Voce build options you need to put -lcurl.

According to that answer, You also need to add the directory:

Project > Project Options > Directories > Library Directories and add the directory that has the files .a.