dlopen-Example

do.cpp

/**
 * @module do.cpp
 * @author eray arslan
 * @date 06.2015
 *
 * dylib : g++ -dynamiclib -o do.dylib do.cpp 
 * so    : g++ -bundle -o do.so do.cpp
 *
 */

#include <iostream>
#include <unistd.h>

using std::cout;

extern "C" void doIt() {
	cout << getpid();
}

main.cpp

/**
 * @module main.cpp
 * @author eray arslan
 * @date 06.2015
 *
 * g++ main.cpp
 * ./a.out
 *
 */

#include <iostream>
#include <dlfcn.h>

const char * f = "doIt";
const char * l = "do.dylib"; // or do.so

using namespace std;

int main() {
    void* handle = dlopen(l, RTLD_LAZY);
    if (!handle) { return 1; }
    typedef void (*doIt_f)();
    dlerror();
    doIt_f doIt = (doIt_f) dlsym(handle, f);
    const char *dlsym_error = dlerror();
    if (dlsym_error) {
        dlclose(handle);
        return 1;
    }
    doIt();
    dlclose(handle);
    return 0;
}