How to import a DLL function in C?

Question

I was given a DLL that I'm trying to use. The DLL contains the function "send". this is what I did:

#include <stdio.h>
#include <Windows.h>

int main(int argc, char * argv[])
{
    HMODULE libHandle;

    if ((libHandle = LoadLibrary(TEXT("SendSMS.dll"))) == NULL)
    {
        printf("load failed\n");
        return 1;
    }
    if (GetProcAddress(libHandle, "send") == NULL)
    {
        printf("GetProcAddress failed\n");
        printf("%d\n", GetLastError());
        return 1;
    }
    return 0;
}

GetProcAddress returns NULL, and the last error value is 127. (procedure was not found)

What am I doing wrong?

Answer 1

Code look more or less good, so probably something is wrong with *.dll. Please download Dependency Walker application and check what kind of functions are exported by this library.

Answer 2

If you running 64bit environment and "sendsms.dll" is compiled as 32bit loadlibrary does not work. You need to compile your project as 32bit to load dlls.