Probleme mit dynmodulloader

Tuxist

Habe Modul Ladeprogramm für Linux geschrieben um Module dynamisch im c++ zu laden leider klappt dies nur mit void Funktionen aber nicht mit einer string Funktion.

module.cpp

/*
Writen by Jan Koster release under lgpl

*/
#include <iostream>
#include <dlfcn.h>
#include <string>
#include <easyc.h>
#include "module.h"

using namespace std;
using namespace easyc;

string modul(string modulpath, string env){

    void* handle = dlopen(stringtochar(modulpath), RTLD_NOW);
    string     *iptr, (*fptr)(int);

    if (!handle) {
        cerr << "Cannot open library: " << dlerror() << '\n';
        return "Cannot open library: ";
    }

    typedef string (*loadmodul_t)();

    // reset errors
    dlerror();
    loadmodul_t loadmodul = (loadmodul_t) dlsym(handle, "loadmodul");
    const char *dlsym_error = dlerror();
    if (dlsym_error) {
        cerr << "Cannot load symbol 'loadmodul': " << dlsym_error <<
            '\n';
        dlclose(handle);

    }

    string temp = loadmodul();
    return temp;
}

module.h

/*
Writen by Jan Koster release under lgpl

*/

#ifndef module_H
#define module_H

std::string modul(std::string modulpath, std::string env);

#endif

modul xml.h

#ifndef XML_H_
#define XML_H_

class xml
{
private: 
std::string readfile();
std::string createfile();
public:
std::string createxml();
};

#endif

module xml.cpp

#include <iostream>
#include <string>
#include <map>
#include "xml.h"
#include "main.h"

using namespace std; 

extern "C" string loadmodul()
{
    xml modulxml;
    return modulxml.createxml();
}

string xml::readfile()
{

}

string  xml::createfile()
{
string filedata;
filedata +="<?xml version=\"1.0\" encoding=\"UTF-8\"?> <?xml-stylesheet href=\"testdata.xsl\" type=\"test/xsl\" ?>";
filedata +="<!DOCTYPE testdata [";
for( multimap<string,string>::iterator ii=testdata.begin(); ii!=testdata.end(); ++ii)
   {
      filedata =(*ii).first;
      filedata.insert(1,"!ELEMENT "); 
      filedata.insert(filedata.size() &-1,"(#PCDATA)");

   }
filedata +="]><xml>";
for( multimap<string,string>::iterator ii=testdata.begin(); ii!=testdata.end(); ++ii)
   {
      filedata +=(*ii).first;
      filedata += (*ii).second;
   }
filedata +="</xml>";
return filedata;
}

string xml::createxml()
{

}

gdb output: