Boost(3) Use of MemmoryMap.

#include <iostream>
#include <string>
#include <boost/interprocess/managed_shared_memory.hpp>
#include <cstdlib> //std::system
#include <sstream>
 
using namespace std;
using namespace boost;
using namespace boost::interprocess;
 
//	const data
const char * MMMAP_NAME = "MySharedMemory";
int max_share_size = 65536;
int real_share_size = 1024;
 
int main (int argc, char *argv[])
{
	if(argc == 1){ 
		shared_memory_object::remove(MMMAP_NAME);
		// Create a managed shared memory segment
		managed_shared_memory segment(create_only, MMMAP_NAME, max_share_size);
 
		// Allocate a portion of the segment (raw memory)
		std::size_t free_memory = segment.get_free_memory();
		void * shptr = segment.allocate(real_share_size);
 
		// Check invariant
		if(free_memory > segment.get_free_memory()){
 
			char *pbuff=(char *)shptr;
			pbuff[0]='A';
			pbuff[1]='B';
			pbuff[2]='C';
			pbuff[3]=NULL;
 
			// convert memory to handle
			managed_shared_memory::handle_t handle = segment.get_handle_from_address(shptr);
			// set of child process param .
			std::stringstream s;
			s << argv[0] << " " << handle;
			s << std::ends;
			cout << "handle:"  << handle << endl;
			// Launch child process
			int nchild = std::system(s.str().c_str());
 
			cout << "child return:"  << nchild << endl;
			cout << "changed?:"<< pbuff << endl;
 
			//	delete share memory
			segment.deallocate(pbuff);
 
			string sdata;
			cin >> sdata ;	//	any key input!! --> exit.
 
			//	delete share memory
			shared_memory_object::remove(MMMAP_NAME);
 
		} else {
			//	delete share memory
			shared_memory_object::remove(MMMAP_NAME);
 
			return 1;
		}
	} else {
		//Open managed segment
		managed_shared_memory segment(open_only, MMMAP_NAME);
 
		//An handle from the base address can identify any byte of the shared 
		//memory segment even if it is mapped in different base addresses
		managed_shared_memory::handle_t handle = 0;
 
		//Obtain handle value
		std::stringstream s; s << argv[1]; s >> handle;
 
		// Get buffer local address from handle
		void *msg = segment.get_address_from_handle(handle);
 
		char *pbuff=(char *)msg;
 
		cout << "origin:" << pbuff << endl;
 
		//	change data!!
		pbuff[0]='D';
		pbuff[1]='E';
		pbuff[2]='F';
		pbuff[3]=NULL;
 
	}
	return 0;
}