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hackervalley · Guest

Voila , j'essaye de faire un wrapper de dlopen.
Je bloque sur dlsym, car je n'arrive pas à avoir l'adresse du symbol.
Mon code donne ceci :

Filename :libModule1.so
Flag :2
Handle :0x804ab90
libModule1.so open
vInitModules1 0
../PluginDemo: undefined symbol: vInitModules1

Une indication serrait la bien venue.
Voici le code :

[Makefile]
all: demonstration module

# Create object file
# -fPIC flag. PIC stands for "Position Independent Code"
#Creating a Shared Library
# g++ -shared -Wl,-soname,your_soname -o library_name file_list library_list
module:
g++ -fPIC -Wall -g -c Module1.cc
g++ -shared -Wl,-soname,libModule1.so -o libModule1.so Module1.o

demonstration:
g++ -Wall -o PluginDemo Plugin.cc main.cc -ldl
# -ldl link libdl dlopen library

clean :
rm -f *.o *.so* PluginDemo

..PHONY : clean

[Module1.cc]
#include <iostream>

using namespace std;

void vInitModules1(void)
{
cout << "Module 1" << endl;
}

[Plugin.hh]
#ifndef PLUGIN_HH
#define PLUGIN_HH

extern "C"
{
// Header for dynamically load libraries
#include }

#include <string>

using namespace std;

class CPlugin
{
public :

CPlugin();

// See <dlfcn.h> for definition of flag
void vOpen(const string filename, int flag=RTLD_NOW);
void vClose();
void vSymbol(const char *symbol);

private:
const string filename;
int flag;
void *handle;
char *error;
const char *symbol;
void *sym;
};

[Plugin.cc]
#include "Plugin.hh"

#include <iostream>

using namespace std;

CPlugin::CPlugin ()
{
}

void
CPlugin::vOpen (const string filename, int flag)
{

handle = dlopen (filename.c_str (), flag);

cout << "Filename :" << filename << endl;
cout << "Flag :" << flag << endl;
cout << "Handle :" << handle << endl;

if (!handle)
{
error = dlerror ();
cout << error << endl;
exit(1);
}
else
cout << filename << " open " << endl;
}

void
CPlugin::vClose ()
{
if (dlclose (handle) != 0)
{
error = dlerror ();
cout << string(error) << endl;
cout << filename << " NOT CLOSED " << endl;
}
else
cout << "Shared Object closed " << endl;
}

void
CPlugin::vSymbol(const char * symbol)
{
dlerror(); /* Clear any existing error */
sym = dlsym(handle, symbol);
cout << symbol << " " << sym << endl;
if (!sym)
{error = dlerror();
if (error != 0)
cout << error << endl;
exit(1);
}
else
cout << symbol << " " << sym << endl;
}

[main.cc]
#include #include "Plugin.hh"

using namespace std;

int
main (int argc, char **argv)
{
CPlugin plugin;

plugin.vOpen("libModule1.so");

/*
If only filename define LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH
*/

plugin.vSymbol("vInitModules1");

plugin.vClose();

return 0;
}

A++
hackervalley
http://hackervalley.free.fr

Frédéric Lachasse · Guest

"hackervalley" <hackervalley (AT) free (DOT) fr> wrote

Jean-Marc Bourguet · Guest

"Frédéric Lachasse" <frederic.lachasse (AT) verizon (DOT) net> writes:

hackervalley · Guest

Merci pour ces indications, le code "marche".

A++