#include <sys/mman.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
typedef struct{
	char name[4];
	int  age;
}people;

main(int argc, char** argv)	// map a normal file as shared mem:
{
	int fd,i;
	people *p_map;
	fd=open( argv[1],O_CREAT|O_RDWR,00777 );
	p_map = (people*)mmap(NULL,sizeof(people)*10,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
	for(i = 0;i<10;i++)
	{
	printf( "name: %s age %d;\n",(*(p_map+i)).name, (*(p_map+i)).age );

	}
	munmap( p_map,sizeof(people)*10 );
}