Dynamic loading DLL in C++ for Linux Platform

Question

I am trying a Create a Linux C++ project using the same header and .cpp files from a Windows C++ project using Visual Studio. I am using below function to load a DLL dynamically in Windows

HINSTANCE hGetProcIDDLL = LoadLibraryA(sDllPath.c_str());
GetPluginInfoList GetInfoList = (GetPluginInfoList)GetProcAddress(hGetProcIDDLL, "GetPluginInfoList");

I think these functions hail from <windows.h>

When it comes to Linux C++ project I am not getting those functionalities. For Linux C++, what is the replacement for HINSTANCE and LoadLibraryA?

Note that C++ has name mangling so the routines need an extern "C" interface see https://www.tldp.org/HOWTO/html_single/C++-dlopen/ — cup, Jan 28 '20 at 09:30
You also could look at Boost.DLL: https://www.boost.org/doc/libs/1_64_0/doc/html/boost_dll.html — JulianW, Jan 28 '20 at 09:45
@HariSankarvm in the spirit of this Q&A site, it would be great if you answered your own question with your findings. — 0xC0000022L, Jan 28 '20 at 10:18
@Quentin, When I build the project, it is showing error linke ***Undefined reference to dlopen*** can you help me to solve this. — Hari Sankar v m, Jan 30 '20 at 06:14
@HariSankarvm you need to [link with the `dl` library](https://stackoverflow.com/questions/19146525/meaning-of-library-dl-in-gcc). — Quentin, Jan 30 '20 at 09:21

score 2 · Answer 1 · answered Jan 28 '20 at 10:25

I am posting my answer here. Thanks everyone for the support

typedef CPluginInfoList(*GetPluginInfoList)(void);



#if _WINDLL
    HINSTANCE hGetProcIDDLL = LoadLibraryA(sDllPath.c_str());

#else
    void* hGetProcIDDLL = dlopen(sDllPath.c_str(), RTLD_LAZY);

#endif


#if _WINDLL
    GetPluginInfoList GetInfoList = (GetPluginInfoList)GetProcAddress(hGetProcIDDLL, "GetPluginInfoList");
#else
    GetPluginInfoList GetInfoList = (GetPluginInfoList)dlsym(hGetProcIDDLL, "GetPluginInfoList");
#endif


GetInfoList(); //Function Call

Remember that there is a dlclose if you wish to fix memory leaks on program closure. — cup, Jan 28 '20 at 11:08

Dynamic loading DLL in C++ for Linux Platform

1 Answers1