• 目录层级
  

• lib/Deal.cpp

#include "Deal.hpp"
#include <iostream>

int DataInc(int num)
{
  std::cout << __FUNCTION__ << " Dealing " << num << "..." << std::endl;
  return ++num;
}

int DataDec(int num)
{
  std::cout << __FUNCTION__ << " Dealing " << num << "..." << std::endl;
  return --num;
}

• lib/Deal.hpp

#pragma once

extern "C" int DataInc(int num);
extern "C" int DataDec(int num);

• lib/CMakeLists.txt

file(GLOB source_dir   "${CMAKE_CURRENT_SOURCE_DIR}/*cpp")
list(APPEND source_dir "${CMAKE_CURRENT_SOURCE_DIR}/Deal.cpp")

add_library(Deal SHARED ${source_dir}) # SHARED STATIC MODULE EXCLUDE_FROM_ALL

• CmakeLists.txt

cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
project(LibTest LANGUAGES CXX)

#add_library(libDeal SHARED Deal.cpp) # SHARED STATIC MODULE EXCLUDE_FROM_ALL
add_subdirectory(lib)

add_executable(LibTest main.cpp)
target_link_libraries(LibTest Deal dl)

• main.cpp

#include <iostream>
#include <dlfcn.h>
#include "lib/Deal.hpp"

#define LIBPATH "./lib/libDeal.so"
typedef int (*DataDecFun)(int);

int main() 
{
	int data = 7;
	int dataDone = DataInc(data);
	std::cout << "DataInc result: " << dataDone << std::endl;

	void* handle = dlopen(LIBPATH, RTLD_LAZY);
	DataDecFun _DataDec = (DataDecFun) dlsym(handle, "DataDec");
	if (NULL == _DataDec)
	{
		std::cerr << "failed to load fun DataDec from  " << LIBPATH << std::endl;
		return -1;
	}

	dataDone = _DataDec(data);
	std::cout << "DataInc result: " << dataDone << std::endl;
	
	dlclose(handle);
  	return 0;
}

• result