How to make Shared Library in linux OS with C++

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#ifndef __PLUGIN_H__
#define __PLUGIN_H__
 ?
#include <sstream>
#include <string.h>
  
typedef char* Bytes;
typedef unsigned int size_t;
typedef const char* cBytes;
  
#define DELOBJ(obj)         {if(obj!=NULL){delete obj;obj=NULL;}}
  
enum encryptAloglType {
    BASE64, HASH , MD4 ,MD5 ,OPENSSL
};
  
enum ioType {?
    CPP_STREAM , C_LOWLEVEL
};
 ?
class Encryptor_Interface
{
public:
    virtual ~Encryptor_Interface() {}
  
    virtual void getEncBuffer(Bytes & buffer, cBytes fileName) const = 0;
    virtual void getDecBuffer(std::istringstream** sstream, cBytes fileName) const = 0;
    virtual void setIoType(ioType =C_LOWLEVEL) = 0;
    virtual void setAlgolType(encryptAloglType) = 0;
    virtual void dispose(int) =0;
    virtual size_t getReadedSize() =0;
  
};
  
typedef Plugin_Interface* PluginEnctyptorPtr;
  
#endif // __PLUGIN_H__

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gcc -ggdb3 -shared -fPIC libdep.c -o libEncryptor.so

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?? ??? ???? ?? ??????? ?? ????? ???????? ??? ?? ?????? ???? ???? ??? ???????? ?? ?? ?? ????? ??????? ?????? ??? ???? ??? ?? ?? ???? Wrapper ??????? ?? ???? ???? Solver ?? ?? ??? ???? ???? ? ?? ??? solve ??? ???? ???? ????? ???? ???????? ??? ?? ???????.

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/*
 * Library_Loader.h
 *
 *  Created on: Jan 1, 2019
 *      Author: f.shiri
 */?
  
#ifndef PLUGINLOADER_H_
#define PLU?GINLOADER_H_
  
#include "Encryptor_interface.h"
#include <stdexcept>
#include <memory>
#include <dlfcn.h>
  
#define LibEncryptorName "./libEncryptor.so"
#define LibFactoryMethod "create_plugin"
#define LibDestyoryMethod "destroy_plugin"
 ?
#define LogicFileName    "logic.ini"
#define __CleanupLibClose __attribute__((cleanup(closedl)))
  
#ifdef SCL_EQUIPPED
#include "SCLVoter_Inter?face.h"
#include "initsclvoter.h"
extern ISCLVoterManager* pSCLVoterManager;
#endif
  
typedef Encryptor_Interface* encAbstractPtr;
//typedef ISCLVoterManager*    pISCLVoter;
/* load shared library or static library and dynamic
 * declare library virtual function.
 * template arg1 : interface class library pointer.
 * */
template<class InterfacePtr>
class PluginLoader {
private:
  
    /*clean up macro function calling by compiler, delete the pointer
     when the pointer's life cycle is end */
    static inline int closedl(void* handle) {
        int tmp = -1;
        if (handle)
            tmp = dlclose(handle);
        handle = NULL;
        return tmp;
    }
   struct {
        /* union data type contained
         * dynamic link library objects.
         * */
        union {
            void* dlsym;
            InterfacePtr (*factoryMethod)();
        } factoryObject;
  
        union {
            void* dlsym;
            bool (*destoryMethod)(InterfacePtr);
        } destroyObject;
  
        /* shared library handler */
   } libraryObject;
  
    void* m_handle;
  
public:
    explicit PluginLoader() {
    }
    ;
    ~PluginLoader() {
    }
    ;
  
    // Dynamic load, encryption function from shared library.
    /*
     * arg1 : shared library name.
     * arg2 : reference factory method name in shared library.
     * arg3 : reference declarative interface class pointer.
     * arg4 : own request for the symbol in library or main executable.
    // arg5 : reference destroy method name in shared library.
     * return type : reference interface pointer.
     */
    template<class CInterfacePtr>
    inline void operator()(cBytes libName, cBytes factoryFuncName,
             CInterfacePtr** pClassInterface,cBytes destroyFuncName =NULL) {
  
        dlerror();
        /*
         * The RTLD_DEEPBIND attribute specifies that when resolving a symbol in a shared library,
         * the symbols in the shared library are put ahead of the global symbol scope.
         * example-> When you load the ???.so, it has it's own request for the symbol.
         * Because you use RTLD_DEEPBIND this definition is looked up in the dependencies of this library first,
         * before looking in the main executable.
         */
        __CleanupLibClose void* m_handle = dlopen(libName, RTLD_DEEPBIND | RTLD_NOW | RTLD_LOCAL);
  
  
        if (!m_handle) {
            throw std::runtime_error(dlerror());
        }
  
        if(factoryFuncName!=NULL){
            if (!(libraryObject.factoryObject.dlsym = dlsym(m_handle, factoryFuncName))) {
                throw std::runtime_error(dlerror());
            }
        }
  
        if(destroyFuncName!=NULL){
            if (!(libraryObject.destroyObject.dlsym = dlsym(m_handle, destroyFuncName))) {
                throw std::runtime_error(dlerror());
            }
        }
  
        *pClassInterface =(*libraryObject.factoryObject.factoryMethod)();
  
    }
  
    template<class CInterfacePtr>
    bool destroy(CInterfacePtr** pClassInterface) {
        return libraryObject.destroyObject.destoryMethod(*pClassI  nterface);
    }
  
private:
    PluginLoader(const PluginLoader&);
    PluginLoader& operator=(const PluginLoader&);
  
};
  
/* this class is invoke strategy shared library wrapper
 * template arg1: reference interface class
 */
template<class InterfacePtr>
class Solver {
public:
    Solver(){};
    Solver(cBytes cLibName, cBytes cFactoryFuncName
            ,cBytes cDestroyFuncName=NULL) :m_interfacePtr(NULL){
        m_pluginLoader(cLibName, cFactoryFuncName,
                &m_interfacePtr ,cDestroyFuncName);
    }
    virtual ~Solver(){
        m_pluginLoader.destroy(&m_interfacePtr);
        DELOBJ(m_interfacePtr);
    }
    // important: this pure virtual method must be implemented in derived class.
    virtual void solve() =0;
  
protected:
    template<class CInterfacePtr>
    inline void getInterface(CInterfacePtr& inputInterFace){
        if(m_interfacePtr!=NULL){
            inputInterFace = m_interfacePtr;
        }
    }
private:
    //shared library interface class member.
    InterfacePtr m_interfacePtr;
    //instance of plugin loader class.
    PluginLoader<InterfacePtr> m_pluginLoader;
};
  
  
  
/*proxy class shared library. this class is immutable type
 * class type: pointer type of shared library interface class.
 * template arg1 : encrypt interface class pointer
 * template arg2 : string stream reference pointer
 * */
template<class InterfacePtr ,typename InputType>
class EncryptLibraryLoader : public Solver<InterfacePtr>{
  
protected:
  
public:
    // arg1 : shared library name.
    // arg2 : reference factory method name in shared library.
    // arg3 : reference destroy method name in shared library.
    // arg4 : output string stream
    EncryptLibraryLoader(InputType outStream ,cBytes cLibName, cBytes cFactoryFuncName
            ,cBytes cDestroyFuncName=NULL) : Solver<InterfacePtr>(cLibName,cFactoryFuncName,cDe  stroyFuncName)
             , m_outStream(outStream) {
        /* important: must be call getInterface in super class and get
         *            interface class reference and copy in member pointer in this class.
         */
        getInterface(m_interfacePtr);
    }
    virtual ~EncryptLibraryLoader() {
        //clean up member pointer
        DELOBJ(m_interfacePtr);
        DELOBJ(m_outStream);
    }
    /* get the byte stream from encrypt logic.ini file.
     * arg1 : reference bytes stream.
     * return type : reference stream pointer
     *
     * important: must be call getInterface in super class and get
     *            interface class reference and copy in member pointer in this class.
     * */
    inline void solve(){
        if(m_outStream!=NULL){
            try {
                if (m_interfacePtr!=NULL) {
                    m_interfacePtr->setIoType(C_LOWLEVEL);
                    m_interfacePtr->getDecBuffer(m_outStream,const_cast<char*> (LogicFileName));
                }
                //important : if interfacePtr is loaded.
                //            this method dispossess member static pointer in memory section of library.
                m_interfacePtr->dispose(0);
            } catch (std::runtime_error& e) {
                printf("%s \n", e.what());
            }
        }
    }
  
private:
    //EncryptLibraryLoader();
    EncryptLibraryLoader(const EncryptLibraryLoader&);
    EncryptLibraryLoader& operator=(const EncryptLibraryLoader&);
  
    //shared library interface class member.
    InterfacePtr m_interfacePtr;
    InputType m_outStream;
};
  
#endif /* PLUGINLOADER_H_ */

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std::istringstream* file=NULL ;
{
    Solver<encAbstractPtr> *loader = new    EncryptLibraryLoader<encAbstractPtr,std::istringst  ream**> (
            &file ,LibEncryptorName, LibFactoryMethod , LibDestyoryMethod);
    // initial encryption library.
    loader->solve();
    loader=NULL;
    
}

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