#include <iostream>

#define LIBSSH_STATIC 1
#include <libssh/libssh.h>
#include <stdlib.h>

void sftpSession()
{
    ssh_session test_session = ssh_new();
    if (!test_session) {
        throw std::runtime_error("Could not create a session?!");
        return;
    }
    ssh_free(test_session);
    std::cout << "Session created & freed successfully." << std::endl;
}

int main(int argc, char **argv)
{
    std::cout << "SFTP test program" << std::endl;
    try {
        sftpSession();
    }
    catch (const std::runtime_error &e) {
        std::cout << "thrown: " << e.what() << std::endl;
    }
    return EXIT_SUCCESS;
}

x86_64-w64-mingw32-g++.exe
  -Wall -fexceptions -O2 -std=c++0x -g -m64 -Dmine_dev=1
  -I"C:Program Fileszlibzlib-1.2.8-dllinclude"
  -I"C:Program Files (x86)libsshlibssh-0.6.5include"
  -c C:Users ... SFTP_testingmain.cpp
  -o objReleasemain.o

x86_64-w64-mingw32-g++.exe
  -L"C:Program Files (x86)IngresIngresIIingreslib"
  -o binReleaseSFTP_testing.exe
  objReleasemain.o
  -s
  "C:Program Files (x86)libsshlibssh-0.6.5liblibssh.dll.a"

objReleasemain.o: In function `sftpSession()':
C:/Users/ ... /SFTP_testing/main.cpp:9: undefined reference to `ssh_new'
C:/Users/ ... /SFTP_testing/main.cpp:14: undefined reference to `ssh_free'
collect2.exe: error: ld returned 1 exit status
Process terminated with status 1 (0 minute(s), 2 second(s))
3 error(s), 0 warning(s) (0 minute(s), 2 second(s))

#ifdef __cplusplus
extern "C" {
#endif
...
LIBSSH_API ssh_session ssh_new(void);
...
LIBSSH_API void ssh_free(ssh_session session);
...
#ifdef __cplusplus
}
#endif